Faq

How should hydraulic punching machines and mechanical punching presses be maintained, and how can their service life be extended?

1. The working hydraulic oil should be changed once a year, and the time interval between changes should not exceed three months;

2. The slider should be lubricated frequently, the exposed surface of the column should be kept clean, and engine oil should be sprayed before each operation;

3. The oil must be strictly filtered before being added to the tank;

4. Calibrate and check the pressure gauge every six months;

5. Under a nominal pressure of 500T, the maximum allowable eccentricity of the concentrated load is 40mm. Excessive eccentricity can easily cause damage to the column or other adverse phenomena;

6. If the machine is left unused for a long period, all surfaces should be cleaned and coated with rust preventive oil;

7. Operators of stainless steel pipe punching machines must undergo training to understand the structure and performance of the equipment, be familiar with the operating procedures, and obtain operating permission before independent operation;

8. The mold should be firmly fastened, the upper and lower molds should be aligned, the correct position should be ensured, and the machine should be tested by hand (empty run) to ensure that the mold is in good condition before operation;

9. Check whether the transmission, connection, lubrication, and other parts and protective safety devices of the CNC hydraulic pipe punching machine are normal. The mold screws must be tightened and must not be moved;

10. Correctly use the protection and control devices on the stainless steel pipe punching machine and do not disassemble them arbitrarily;

11. When the stainless steel pipe punching machine is started or in operation, the operator should stand properly, keep their hands and head at a certain distance from the punching machine, and always pay attention to the punch movement. Talking to others is strictly prohibited;

12. When punching long parts, a material support rack or other safety measures should be set up to prevent injury;

13. Stop the machine and cut off the power supply of the stainless steel pipe punching machine in time after work, wipe the machine, and clean up the environment.

Can hydraulic sealing equipment use mechanical seals?

　　Can hydraulic sealing equipment use mechanical seals? First, we need to understand the requirements for using hydraulic seals and the requirements for equipment using mechanical seals. At the same time, we also need to consider whether the mechanical seal model meets the requirements of hydraulic sealing equipment, etc., so that appropriate measures can be taken to install it. Current mechanical seals are one of the more complex mechanical basic components, and are key components of various pumps, reaction synthesis kettles, turbo compressors, submersible motors, etc. Their sealing performance and service life depend on many factors, such as selection, machine precision, and correct installation and use. Hydraulic sealing equipment requires seals with certain pressure requirements, requiring a certain degree of smoothness on the contact surface. Sealing elements mostly use rubber, and the sealing effect is achieved through local deformation of the sealing element.

　　Hydraulic seal design structures often include the following types: Y-type seals, lip seals, U-type seals, oil seals, V-type seals, and commonly used combined seal types for hydraulic cylinders include gland seals and O-rings. The design series of mechanical seals are all configured in a container style, such as container-type seal series, light-duty mechanical seal series, heavy-duty mechanical seal series, etc. When the design of the mechanical seal model meets the sealing performance requirements required by hydraulic sealing, it can be completely adopted.

　　When selecting seals, Dongsheng Seal Manufacturer suggests selecting according to the required material, color, performance, and parameters, and providing samples is ideal. If there are no suitable mechanical seals, we can also use custom methods and refer to the improved material design of the sample to improve performance requirements. Necessary analysis can be carried out from the following aspects:

　　• Size Angle: Using new sample customized hydraulic mechanical seals, high accuracy;

　　• Pressure Angle: Inferring the working pressure by observing the hardness and structure of the original mechanical seal to select the material;

　　• Direction of Movement Angle: First determine the direction of movement of the mechanical seal, such as reciprocating, rotating, spiral, or fixed;

　　• Sealing Application Angle: The sealing active point is the inner diameter pull rod seal or the active point is the outer diameter piston seal, etc.;

　　• Working Temperature Angle: Evaluate the working temperature of the actual working environment and determine the required materials.

Hazards of hydraulic impact in four-column hydraulic presses

　　In the hydraulic system of a four-column hydraulic press, the sudden opening and closing or reversal of valves causes rapid alternating flow of liquid in the pipes, resulting in pressure fluctuations. This process is known as hydraulic shock, and it should not be underestimated as it can significantly damage the hydraulic press.

　　Hydraulic shock in a four-column hydraulic press is mainly divided into two types: direct hydraulic shock and indirect hydraulic shock. The shock caused by the sudden opening and closing of valves is direct shock. For indirect shock, let T be the opening and closing time of the hydraulic system valve, L be the pipe length from the valve to the larger cavity, and c be the propagation speed of the pressure wave in the hydraulic press pipe. Then Tc = 2L/c. When T is greater than Tc, the peak pressure is relatively small, indicating that indirect shock is less harmful.

　　When hydraulic shock occurs during the operation of the hydraulic press, the instantaneous peak pressure of the liquid is three to four times the normal pressure. The rapid pressure increase causes varying degrees of damage to the pipes, sealing devices, and hydraulic components of the four-column hydraulic press. It can also cause mechanical vibrations, rapid oil temperature rise, increased noise, and even cause misoperation of valves or pressure relays, damaging the hydraulic equipment and affecting normal operation.

　　Now you know how serious hydraulic shock can be. During normal operation, we should try to extend the switching time of the actuator of the four-column hydraulic press. For example, manual switching actions should not be too fast or forceful. For hydraulic or electro-hydraulic directional valves, the speed of the directional valve movement should be reduced to effectively extend the switching time of the hydraulic press and reduce hydraulic shock.

What additives are commonly used in the hydraulic oil of a four-column hydraulic press?

　　The external forces acting on a four-column hydraulic press are mainly driving force and working resistance. Generally, the external force is much smaller than the driving force and resistance to ensure stable operation. The stable operating power is negligible, and the size and change of the driving force and working resistance determine the characteristics of the hydraulic press.

　　A four-column hydraulic press relies on hydraulic oil to transmit energy, and additives mainly improve the properties and performance of the base oil to meet various requirements for the working medium. Commonly used additives for hydraulic oil generally include: Viscosity improvers increase the viscosity and viscosity index of the base oil, also known as thickeners; Pour point depressants reduce the pour point of the hydraulic oil; Anti-wear agents reduce wear on the press, further improving efficiency and extending lifespan; Anti-foaming agents prevent foam formation and promote foam breakdown; Emulsifiers allow the hydraulic oil to form a relatively stable emulsion; Antioxidants prevent hydraulic oil oxidation; Rust inhibitors prevent metal corrosion.

　　What if a four-column hydraulic press malfunctions? It needs to be repaired, of course. But before that, the cause of the malfunction must be determined. A hydraulic press is a machine integrating mechanical, hydraulic, and electrical components; malfunctions are a combined reflection of these three aspects. Check from the outside in; mechanical faults are relatively easy to identify, and following the order of mechanical then electrical can save a lot of time; Repair personnel should not act blindly. First, inquire about the process and status of the malfunction from the hydraulic press operator, review manuals and other materials before starting any work, and proceed methodically to troubleshoot; When multiple faults are present in a four-column hydraulic press and it is difficult to start, address the solvable and easier faults first. Solving simple faults may resolve complex ones. Clarifying the thinking process and simplifying complex issues is also a good approach.

How to deal with the rapid temperature rise of the hydraulic press?

　　Hydraulic presses, utilizing Pascal's Law for liquid pressure transmission, can experience rapid or excessive temperature increases during prolonged operation. Understanding the cause of this malfunction is crucial for effective troubleshooting.

　　Current discussions emphasize the impact of the overall environment. High ambient temperature and humidity can cause temperature increases in hydraulic presses. A small oil tank with insufficient surface area, lack of a cooling system, or an undersized cooling system can contribute to this. A fixed-displacement pump system, where pump capacity is selected based on fast-forward speed, results in a significant excess flow being returned through the relief valve under high pressure, generating heat. Excessive length, narrowness, or bends in the hydraulic system piping lead to significant pressure losses, causing temperature increases. Insufficient component precision or poor assembly quality results in excessive friction during relative motion, leading to increased losses. Malfunctions in the unloading circuit or the absence of such a circuit prevent proper pump unloading when the machine stops, causing the entire pump flow to overflow under high pressure, generating heat and raising the temperature. In four-column hydraulic presses, excessively tight or loose clearances in mating parts due to wear lead to increased internal and external leakage, resulting in reduced efficiency and rapid temperature increases. Similarly, excessively tight seals or damaged seals can increase leakage, requiring higher pressure for operation. The hydraulic system may be operating at a much higher pressure than actually needed.

　　Regularly monitor oil level and temperature in the tank, maintaining the correct level and replenishing as needed. Ensure that replenished oil is filtered to a precision no lower than the system's requirements. Maintain an appropriate oil temperature; typically, hydraulic systems operate within a range of 35℃-60℃. In cold weather, preheat the hydraulic press. When starting the hydraulic pump, cycle it on and off several times to raise the oil temperature before normal operation. While heaters can raise oil temperature, the entire hydraulic system remains cold, and heating only the oil can easily lead to malfunctions. Monitor local temperature changes; excessive local temperatures may indicate excessive friction or internal leakage. Excessive temperature at the solenoid valve coil is usually caused by voltage fluctuations. A pressure difference across the filter exceeding the specified value indicates severe clogging and requires filter replacement.