Three common faults and troubleshooting methods of four column hydraulic press

Four column hydraulic presses are widely used in the pressing process of plastic materials. Such as extrusion metal forming, sheet stretching, horizontal pressing, bending pressing, correction and other processes. The common faults in hydraulic systems are relatively precise components, and the fault point is not only difficult to determine but also the cause is complex and difficult to determine. Four column hydraulic presses are widely used in automotive manufacturing enterprises due to their many advantages. However, frequent system failures in hydraulic equipment often affect the normal use of machines and directly affect the production efficiency of enterprises. In order to ensure that the production and operation of enterprises are not affected, it is necessary to ensure that the hydraulic system of the four column hydraulic press has good technical performance and normal operation, especially to quickly handle system faults, identify the causes and solve them. Understanding the analysis and maintenance technology of hydraulic system faults is a very important topic.

Three common fault phenomena in the hydraulic system of a four column hydraulic press
There are three basic "pathogenic" factors in hydraulic systems: oil temperature overheating, air entering the system, and oil contamination. Practice has proven that 75% of hydraulic system diseases are caused by these three reasons.

1. The oil temperature is too hot.
Hydraulic oil is the working medium of hydraulic transmission systems, generally suitable between 35 ℃ and 60 ℃. If the oil temperature is too hot, not only will it damage the viscosity of the oil, but it will also make the lubricating oil film thinner, leading to a decrease in the efficiency of the hydraulic system and serious leakage; Moreover, it will increase mechanical wear, damage the normal fitting clearance of various components, cause severe wear on the matching surface between the pump and valve, increase friction resistance, and lock the valve core, resulting in the equipment not working properly. At the same time, excessive oil temperature can cause oil vaporization, water evaporation, and hydraulic component cavitation, leading to the inability of the hydraulic system to function properly. In addition, excessive oil temperature can accelerate the aging of rubber seals, greatly shorten their lifespan, and even lose their sealing performance, causing serious leakage in the hydraulic system.

2. The hydraulic system is mixed with air.
Mixing air into the hydraulic system can cause unstable movement of the hydraulic actuator, causing air corrosion and dry friction on hydraulic components, shortening the service life of hydraulic components, and causing symptoms such as pipeline and equipment vibration, noise, and sliding block crawling.

3. The work oil is contaminated and spoiled.
In long-term harsh working environment, impurities and dirt are easily mixed into the oil; When contaminated hydraulic oil enters the pump and valve, it can scratch and damage the accuracy and roughness of the mating surface, thereby increasing the amount of leakage. At the same time, it will also cause an increase in oil temperature, resulting in insufficient pressure, unstable pressure retention, insensitive actuator action, and the appearance of sliders after parking.

Hydraulic system faults and troubleshooting methods of four column hydraulic press

1. The electromagnetic safety valve releases pressure. The manual adjustment function cannot adjust to the rated pressure, and the electromagnetic valve core frequently moves, causing wear and tear on the valve hole, resulting in oil leakage at the control port of the overflow valve and inability to increase the pressure. The damping hole of the main valve core is blocked, allowing the main valve core to start overflowing at a lower pressure. The main valve core and valve seat holes are poorly sealed and there is oil leakage. The main cylinder pressure cannot rise because the solenoid valve is burnt out, the slide valve block cannot be switched to the closed position, or the valve core is stuck in the open position.

Method: Check and analyze the faults in various parts of the safety valve, adjust the safety valve handwheel, adjust the pressure to 26MPa, and tighten the handwheel nut. Control the gap between the valve core and the valve hole to be ≤ 0.008mm. Clean the damping hole and all parts of the safety valve and keep them unobstructed. Replace the sealing ring between the main valve core and the valve seat hole, without oil leakage. If the solenoid valve coil is burnt out, it should be replaced to ensure that the valve core is flexible during reversing and switching.

2. The spring of the main cylinder filling valve is broken, causing poor sealing of the filling valve.
Method: Replace the spring, grind the sealing surface of the filling valve, and ensure there is no leakage.

3. The sealing ring of the main oil cylinder is worn, causing the pressure oil in the upper and lower chambers to communicate with each other.
Method: Replace the sealing ring. If the inner wall of the main oil cylinder is pulled, the ground should be repaired to prevent damage to the sealing ring.

4. Insufficient oil in the fuel tank causes air to enter the suction port.

Exclusion: Hydraulic oil of the same grade should be added to remove air from the hydraulic system.