News Details

Jonz upgraded the processing equipment to further improve the processing accuracy and delivery capacity of precision sheet metal, parts and fixture molds, better meet the customized processing requirements of customers in various industries, and consolidate the hardware foundation of Seiko manufacturing.

There are various types of hydraulic system failures. Some failures are caused by the failure of a single hydraulic component, and some are the result of the combination of multiple components. Some faults are caused by improper selection or contamination of hydraulic oil, while others may be related to mechanical, electrical or external factors.

Some of these failures are gradual, but many are sudden. Many users of hydraulic equipment ignore routine maintenance and often proceed to deal with it after the equipment fails. In order to catch up with the construction period or the pursuit of economic benefits, sometimes even with the disease operation equipment, greatly shorten its service life.

The process of troubleshooting hydraulic equipment may be as short as half a day or as long as several days. Users are often anxious during the maintenance process, and some people even consider replacing new equipment. Hydraulic technology is relatively new and difficult to master.

So, for the maintenance personnel who do not have a deep grasp of hydraulic technology and lack of special testing instruments, how can they quickly analyze and find out the cause of the failure?

This paper takes "multi-function bending machine hydraulic system" as an example to explore the troubleshooting method of hydraulic system failure.

 The equipment is used for bending metal products with a diameter of 4.5~12mm, and is composed of three parts: the host, the hydraulic station and the electrical control cabinet.

During the operation of the equipment, common faults include:

Sudden increase of 1. noise and decrease of working pressure

Observe the compressor oil in the oil tank for air bubbles. If there are bubbles, it means that there is air entering the system. If there are no bubbles, proceed to the second step.

By observing whether there are two types of bubbles in the lubricating oil: one is a layer of large bubbles floating on the oil surface (almost no lubricating oil inside), and the other is small bubbles dispersed in the lubricating oil.

The first reason for air intake: the hydraulic oil pump inlet hose leaks, the joint hydraulic seal is damaged, or the hydraulic oil pump shaft seal is damaged (usually the shaft seal is more likely to be damaged).

Solution: replace the oil inlet hose, replace the joint hydraulic seal or replace the hydraulic oil pump shaft seal.

The second reason for air intake: No. 1 oil filter blockage or tubing aging.

Solution: Clean or replace the No. 1 oil filter and replace the oil pipe (be sure to use acid and alkali resistant oil pipe). If the lubricating oil is seriously polluted, it must be replaced with new oil of the same type and specification.

Adjust the No. 5 and No. 6 speed control valves. When the system is loaded to the rated state, touch the No. 2 and No. 3 hydraulic pumps with hands. If the temperature rises too fast and the vibration is abnormal, the internal damage of the pump is indicated.

Solution: Replace or repair the hydraulic pump.

No sound and no working pressure on the 2. system

First, observe whether there is normal oil return at the oil return port of the system. If the oil return is normal, listen to whether there is a sound of lubricating oil flow near the speed control valves No. 5 and No. 6. If so, determine which valve is causing the problem and deal with it. If the oil return is abnormal, the pump is damaged. Solution: repair or replace the hydraulic pump.

The 3. system has no sound, the working pressure is normal at low temperature, and the pressure drops at high temperature

Such common faults are difficult to judge by basic methods and can be handled by segmented enumeration. 

First analyze the hydraulic schematic: the system can be divided into three subsystems (each subsystem is controlled by a hydraulic cylinder):

1. The sub-system controlled by No. 7 electro-hydraulic reversing valve is supplied by No. 2 hydraulic pump;

2. The two subsystems controlled by No. 12 and No. 14 electro-hydraulic reversing valves are supplied by No. 3 hydraulic pump.