How to troubleshoot some common faults of spot welding machines will cause buyers and sellers to contact many problems. In the process of using the spot welder, the common faults can be divided into the following categories. Write these problems one by one, and the problems will be solved.
1. The phenomenon of insufficient pressure or pressing force is that the welding part slips when the welding spot is seriously spattered. The reasons may be:
1) The seal in the cylinder is broken. At this time, the cylinder exhausts continuously. If the pipe of the welding machine does not leak, you can hear the continuous exhaust sound.
2) The stroke of the cylinder has reached the limit. At this time, the weldment can be removed and the pressure can be checked to check the stroke.
3) When the spot welding machine adopts double gas valve, if the pressure valve fails, the welding head can be lowered by its own weight after exhausting the rising gas valve. If you don't pay attention, it can be mistaken for pressure.
2. The power-on time is inaccurate. Although the normal welding parameters are used during spot welding, it is still found that the solder joints are smaller than normal and there is no penetration. Sometimes it is mistaken for insufficient current. The reasons may be:
1) When the welding machine uses the LCD display to set the time, a certain contact of the spot welding machine is in poor contact, which causes one circuit to fail, resulting in a significant reduction in welding time.
2) In the welding machine using NAND circuit, some welding machines use 100Hz frequency division and count at 50Hz. When the frequency division integrated block is damaged, the welding time is reduced by half.
3. When the current is out of control, the current suddenly appears too large, and even the welding wheel is burned out. The reason is that the thyristor is short-circuit damaged and has entered a continuous solder joint.
4. Cracks appear on the clamping edge of the butt welded alloy steel weldment. The temperature of the weldment is greatly different from the contact edge of the conductive block of the jaw during the butt welding. The part of the weldment is cooled too quickly and cracks occur, especially on the welding machine. During post heat treatment. Generally, the smooth transition of the jaw end can be avoided.
5. The electrode grip is sliding or the jaws are loose. This phenomenon often occurs in the case of fixed parts with non-through holes and screw holes. When the length of the screw is equal to the depth of the screw hole, although the screw has been tightened, it is actually the screw that has reached the limit The fixed surface is not tight. Although it cannot be pushed by hand, it will loosen under working force. Especially when the screws with a slightly different length are wrongly installed after disassembly, the phenomenon that the original can be tightly tightened may occur.
For specific welding machine operation failure, you must refer to the manual and its schematic diagram to eliminate. At present, microcomputer-controlled spot welding machines generally do not provide internal schematic diagrams. At this time, they can only ask the manufacturer for repair.