A welding station includes a welding gun that includes first and second caps. The welding gun is movable between a working position and a maintenance position. The working position corresponds to a welding operation on at least one workpiece. A maintenance tool assembly is configured to cooperate with the first and second caps in the maintenance position. The maintenance tool assembly includes a cap extractor, a cap dispenser and a cap dresser. The cap extractor is configured to remove the first and second caps from the welding gun. The cap dispenser is configured to provide a new cap to the welding gun for installation. The cap dresser is configured to shape the cap face. The maintenance tool assembly includes a lift actuator. A translate actuator is respectively configured to move the maintenance tool assembly in the lift and translate directions with respect to the welding gun.

A robot is provided which has: a first arm portion to which an end effector is attached, a second arm portion configured to support, at a tip portion thereof, the first arm portion swingably about a first axis, a third arm portion configured to support a base end portion of the second arm portion rotatably about a second axis orthogonal to the first axis, a tube arranged from the base end portion side toward the tip portion side of the second arm portion and connected to the end effector; and a first recess portion and a second recess portion, which are formed along an arrangement direction of the tube between the base end portion and the tip portion on one side and the other side in a direction orthogonal to both of the first and second axes, respectively.

The invention relates to a spot welding cap changer (1) with a cap puller (2) and two cap magazines (3, 3A), the cap puller (2) having a gripper (20) with spring-loaded, pivotable jaws (21, 22), which in response to a turning and axial pulling-off movement detaches a spot welding cap (K) of a pincer spot welding head introduced into it from a shaft of the pincer welding head in such a way that it is clamped to prevent it twisting, and the cap magazines (3, 3A) holding spot welding caps respectively in a round cap carrier (31) such that they are circularly arranged in a directed and oriented manner and are respectively transported individually one after the other into an access position against a stop (32) by an advancing force (P).

In the present disclosure, a pair of removing members (5) are provided to be able to move toward and away from each other. Each of the removing members (5) includes a nail (5A, 5B) capable of being inserted into a gap (S1) between a large diameter portion (11a) and an electrode tip (12), and a protrusion (54) extending in a direction intersecting with a direction of insertion of the nail (5A, 5B) into the gap. The protrusions (54) of one and the other one of the removing members (5) are axially supported respectively by first and second support portions (81a, 81b) provided on one end of an arm member (8). The first support portion (81a) is in the shape of a groove that is shaped to be gradually closer to the other one of the removing members as progressing toward the other end of the arm member (8).

A moving mechanism brings the rotational axis of each driven rotator into alignment with the rotational axis of a drive rotator, which has an engaging face extending along its rotational axis. Each driven rotator has an engageable face extending along the rotational axis of the drive rotator. Rotating the drive rotator while moving the driven rotator, of which the rotational axis is aligned with the rotational axis, toward the drive rotator will bring the engaging face into engagement with the engageable face.

A pressing unit presses a plurality of electrodes housed in a housing path in a housing case toward an electrode outlet port. When a lever member swings to one side, a distal end of the lever member comes to be in a first position in which the lever member covers a part of the electrode outlet port. When the lever member swings to the other side, the lever member comes to be in a second position in which the distal end exposes the electrode outlet port. A first coil spring is disposed between a proximal end of the lever member and a first side surface portion of the housing case, and biases the proximal end of the lever member to a direction away from the housing case.

A first electrode coolant path is configured to cool a first welding electrode by liquid coolant flowing from a supply path through the first electrode coolant path to a return path. A second electrode coolant path is configured to cool a second welding electrode by liquid coolant flowing from the supply path through the second electrode coolant path to the return path. Three or more valves are configured to stop or reduce liquid coolant flow through the first or second electrode coolant path and configured to stop or reduce liquid coolant backflow from the return path when the first or second welding electrode is at least partially detached. At least one valve is coupled in the first or second electrode coolant path. A drawback apparatus generates a suction force to draw liquid coolant away from a gap formed when the first or second welding electrode is at least partially detached.

A pressing unit presses a plurality of electrodes housed in a housing path in a housing case toward an electrode outlet port. When a lever member swings to one side, a distal end of the lever member comes to be in a first position in which the lever member covers a part of the electrode outlet port. When the lever member swings to the other side, the lever member comes to be in a second position in which the distal end exposes the electrode outlet port. A first coil spring is disposed between a proximal end of the lever member and a first side surface portion of the housing case, and biases the proximal end of the lever member to a direction away from the housing case.

A first electrode coolant path is configured to cool a first welding electrode by liquid coolant flowing from a supply path through the first electrode coolant path to a return path. A second electrode coolant path is configured to cool a second welding electrode by liquid coolant flowing from the supply path through the second electrode coolant path to the return path. Three or more valves are configured to stop or reduce liquid coolant flow through the first or second electrode coolant path and configured to stop or reduce liquid coolant backflow from the return path when the first or second welding electrode is at least partially detached. At least one valve is coupled in the first or second electrode coolant path. A drawback apparatus generates a suction force to draw liquid coolant away from a gap formed when the first or second welding electrode is at least partially detached.

A device is configured for changing electrode caps of a welding unit. The device includes at least one reserve unit configured to hold in reserve electrode caps which are required for welding with the welding unit. The device also includes a cap changing unit configured to change an electrode cap mounted on a welding tool for another electrode cap held in reserve in the reserve unit. The cap changing unit is configured to arrange the electrode cap demounted from the welding tool in the at least one reserve unit.