Resistance spot welding machine pressurizing control method based on servo motor driving

Abstract

The invention discloses a resistance spot welding machine pressurizing control method based on servo motor driving. The resistance spot welding machine pressurizing control method is characterized in that a servo motor is adopted for driving a welding movable arm of a spot welding machine to move towards a welding static arm so as to clamp and weld a to-be-welded workpiece between the welding movable arm and the welding static arm; and the displacement of the welding movable arm is driven through the servo motor, so that the corresponding deformation quantity of the welding static arm can be generated, and then the workpiece welding pressure can be precisely controlled. In the welding process, the welding static arm has the characteristics of being equipped with an elastic body of a perfect structure as well as achieving the high-precision calibration and correction of the electrode position, and the pressure is precisely controlled due to a corresponding relation between the deformation quantity of the welding static arm and the designed welding pressure, so that the pressure control can be more precise, and then the welding process quality can be perfectly guaranteed; and through the control of the deformation quantity of the welding static arm, the problem about poor control precision caused by various resistances of a transmission mechanism to the precise control of the welding pressure can be completely solved, and particularly, the remarkable low-pressure welding effect can be achieved.

Description

Technical field: [0001] The invention relates to the technical field of resistance welding, in particular to a pressure control method for a resistance spot welding machine driven by a servo motor. Background technique: [0002] Resistance welding refers to the welding method that uses the resistance heat generated by the current passing through the workpiece and the contact surface as heat input to locally heat the workpiece, and at the same time needs to pressurize the workpiece through the welding tongs. [0003] In the resistance spot welding process, it is necessary to pressurize the welding workpiece through the welding tongs; in the existing resistance welding, the piston cylinder is generally used to control the welding pressure by the air pressure in the cylinder, or the servo press is used to use the motor torque. The output of the control pressure is indirectly transmitted to the electrode of the welding gun through the transmission mechanism for pressurization. ...

AI Technical Summary

Problems solved by technology

In actual use, the pressure transmitted to the welding electrode is unstable due to the resistance change during the movement and the wear between the transmission parts, resulting in poor pressure control accuracy, especially in the case of low pressure. The driving force ratio is very large, making its control accuracy worse

At the same time, in the prior art, pressure sensors are also used to detect welding pressure and control the welding pressure according to the detection results, but this method is complicated to install, complicated to control, and poor in stability

[0004] In the field of resistance welding technology, the accuracy of welding pressure control is an important factor affecting the quality of joints. During the welding process, due to poor pressure control accuracy, it is easy to cause During the process, spatter, indentation diameter is too large or too small, nugget formation is not beautiful, etc., which directly affect the welding process is not perfect, and can not guarantee stable welding quality

Moreover, after a long time of use, the clamp arm will be deformed, and the deformation is not easy to recover, which makes the welding accuracy lower and lower, resulting in unstable product quality and low welding repeatability

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