| 摘要 |
<p>An apparatus for circulating cooling water of a spot welding gun of the present invention, which includes an intake tube line and a discharging tube line installed so that cooling water from a water supply source with a blocking valve is in contact with a welding tip detachably attached to the front end of a welding arm of a spot welding gun and returns back, comprises: at least one discharging check valve and at least one drain check valve arranged between the discharging tube line and a drain hole in series so that cooling water flows only toward the drain hole; a cylinder which reciprocates so that a negative pressure and a positive pressure are alternatively applied to the connection tube line between the discharging check valve and the drain check valve; and a pressure switch detecting a pressure at any position from a blocking valve to the cylinder. The cylinder starts reciprocating by a blocking signal of the blocking valve, and stops reciprocating by a pressure signal generated when the detected pressure is less than or equal to a predetermined pressure. If the negative pressure is generated in the connection pipe line by reciprocating of the cylinder, cooling water is sucked from the discharging pipe line to the connection pipe line by opening only the discharging check valve. If the positive pressure is generated in the connection pipe line, the cooling water is discharged from the connection pipe line to the drain hole by opening only the drain check valve.</p> |
