Analysis and solution of cold welding and falling welding in precision resistance welding
For a period of time after the technicians of the spot welding machine manufacturer complete the debugging, cold welding and falling welding usually do not occur. However, when the welding workpiece is replaced but the parameters are not debugged well, the electrode is used for too long and is not repaired, the water, electricity and gas of the welding machine are improperly reconnected, the employee makes an error in operation, or there is a fault inside the welding machine, these problems may occur. Since cold welding and falling welding seriously affect the safety of the product and will greatly increase the production cost, they must be handled in time. The following is an analysis and solution to the cold welding and falling welding problems of precision resistance welding.
1. Problem analysis
The cold welding and falling welding problems mainly come from three aspects: water, electricity and gas sources, machinery and equipment, and operating staff.
Water, electricity and gas sources:
After the equipment is installed and debugged, it should be avoided to move and reconnect without reason.
If it is necessary to move and reconnect, it should be operated by a professional electrician, and the normal value should be measured before and after wiring.
Machinery and equipment:
The normal parameters of the spot welding number adjustment need to be set according to the thickness of the upper and lower materials.
The conductive performance of the fixture is poor due to wear, different specifications, poor matching or rust.
Precision resistance welding has been used for too long, and the mismatch of accessories during maintenance leads to unstable discharge.
Insufficient pre-pressing time can easily generate sparks and affect the quality of the workpiece.
Operator:
The self-inspection frequency is not enough.
Adjust the precision resistance welding parameters at will.
The principle that the resistance of the spot welding machine affects the quality of spot welding due to heat is not understood.
2. Solution
Equipment debugging and training:
Organize assembly workshop technicians to debug equipment to ensure that the equipment is in good condition before employees go to the machine.
Inform employees of the principle that the resistance of the spot welding machine affects the quality of spot welding due to heat.
Standardize pre-pressing time:
The pre-pressing time of precision resistance welding should be specified in detail, and it is strictly forbidden to adjust it privately.
The team leader should check the pre-pressing time setting frequently.
Strengthen self-inspection and supervision:
Employees should conduct self-inspection in units of 20 spot welding.
The workshop team leader should check the spot welding effect every hour, and promptly discover and adjust the welding phenomenon.
Skill training and inheritance:
Old employees should teach new employees the relevant skills and precautions for spot welding to ensure the quality of spot welding.
Standardization of fixtures:
Clean and repair the fixtures in the assembly workshop to achieve standardization as much as possible.
Testing and cleaning:
The mold adjustment technician in the workshop should test the coordination of the fixtures to ensure good conductivity.
Clean the rusty copper rod before assembling the mold.
Welding parameter adjustment and maintenance:
Each spot welder shall prepare a welding parameter adjustment table according to the hardness of the welded workpiece and post it together with the welder maintenance card.
Each employee shall do daily maintenance of the welder before leaving get off work every day, and perform a major cleaning and maintenance once a month.
Through the implementation of the above analysis and solutions, the problem of false welding and falling welding in precision resistance welding can be effectively solved, and product quality and production efficiency can be improved.
