No-indentation welding monitoring device and method for monitoring the same

1. A no-indentation welding monitoring apparatus, comprising:

a pressing force measuring device measuring a pressing force for pressing a welding target by a welding tip of a welding gun;

a voltage measuring device measuring a voltage applied to the welding tip of the welding gun; and

a monitor device including a controller and digitizing a welding quality of the welding target by use of the measured pressing force and the measured voltage transmitted from the pressing force measuring device and the voltage measuring device, respectively,

wherein the monitoring device determines the welding quality using an average value of the pressing force formed between a pressure stabilization time point and a power application time point, a minimum value of the pressing force in a welding section to which a power is applied, and a maximum value of the voltage in the welding section.

2. The no-indentation welding monitoring apparatus of claim 1 , further including:

a communication device transmitting values of the measured pressing force of the pressing force measuring device and the measured voltage of the voltage measuring device to the monitoring device.

3. The no-indentation welding monitoring apparatus of claim 1 , wherein the welding tip includes an upper tip and a lower tip which are in contact with upper and lower surfaces of plates of the welding target to be coupled to each other to apply the power to the plates.

4. The no-indentation welding monitoring apparatus of claim 3 , wherein the voltage measuring device measures the voltage applied to the plates of the welding target through the upper tip and the lower tip.

5. The no-indentation welding monitoring apparatus of claim 3 , wherein the pressing force measuring device includes a load cell for measuring the pressing force applied to the upper tip and the lower tip when the upper tip and the lower tip press the upper and lower surfaces of the plates of the welding target.

6. A method for monitoring no-indentation welding, the method including:

contacting an upper welding tip and a lower welding tip of a welding gun to a first side and a second side of a welding target and pressing;

detecting a pressing force applied to the welding target, wherein the pressing is performed by the upper welding tip or the lower welding tip to press the welding target by the pressing force;

applying a voltage to the welding target through the upper welding tip or the lower welding tip, and detecting the applied voltage; and

determining, by a controller, a score using the detected pressing force and the applied voltage,

wherein the score is determined by an average value of the pressing force formed between a pressure stabilization time point and a power application time point, a minimum value of the pressing force in a welding section to which a power is applied, and a maximum value of the voltage in the welding section.

7. The method for monitoring the no-indentation welding of claim 6 , wherein a welding quality of the welding target is determined by the score.

8. The method for monitoring the no-indentation welding of claim 6 , wherein after the power is applied to the welding target, a predetermined pressure holding time is maintained and the pressing force is removed.

9. A no-indentation welding monitoring system for performing the method for monitoring the no-indentation welding of claim 6 .