The failure of intermediate frequency spot welding machine is not accidental. There will always be omens before it happens. When accumulated to a certain extent, it will cause fault problems. At present, the method of checking spot welding system fault is logical analysis gradually approaching to break. The basic idea of this method is comprehensive analysis, condition judgment, that is, maintenance personnel provide observation, listening, touching and simple testing, as well as the welding system Understand, rely on experience to judge the location and cause of the failure. When the welding system fails, there are many possible causes of the failure, and conventional analysis methods such as naked eye observation, touch, listening, etc. can also be used. However, this method is suitable for technicians who have mechanical operation for many years and have strong analysis ability. Then, the possible failure causes are listed, and then gradually according to the principle of easy to difficult Finally, find out the fault point and the specific cause of the fault.

　　Conventional methods can be divided into:

　　First of all, understand the mechanical parts. When a certain equipment has problems, first of all, you should understand its working system and be familiar with the relevant technical reports, understand the working principle of the weld, understand the specific functions of the basic structure of the components in the system, record the relevant data such as: working pressure, speed, water flow, thermal cycle time, and be able to find out the cause of the fault in the working state.

　　Ask the operator about the specific situation of the equipment, such as whether the fuselage is overheated, the noise is too loud, whether the AC is not closed tightly, whether the working speed is slow, whether there is abnormal squeaking sound when starting, whether the programming system is abnormal, etc.

　　Touch the oil pipe and high pressure oil pipe for softening and damage. For leakage, check whether the internal wiring lug and screws of each part are loose.

　　In the maintenance practice of medium frequency spot welding machine, it is concluded that attention should be paid to the control of welding quality. The welding current of general medium frequency spot welding machine can reach about 7000A, which can be used for low strength plate welding. However, for some ultra-high strength steel, the welding current may be more than 10000 a, otherwise the solder joint can not guarantee enough strength. Because we can't see whether the plate is welded well from the appearance, we should find the same material for test welding before spot welding. During the test welding, the pressure, current and time of welding should be adjusted continuously, and then destructive test should be carried out to verify whether the welding strength is achieved.