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.

In an electrode chip attachment device, a guide member which is formed such that the guide member can be divided into a first half member and a second half member with a division surface that is passed though the communication hole and that is parallel to the axial direction and a coupling shaft serving as a separate mechanism which separates the first half member and the second half member from each other when the chip holder is pushed into the first tapered portion and the second tapered portion from the opposite side of the electrode chip and which passes the chip holder to the side of the electrode chip.

A welding electrode is disclosed that includes an electrode welding shell and a blind adapter that are joined together to cooperatively define an internal cavity. The electrode welding shell and the blind adapter may be integrally formed or they may be distinct components that are attached together. The presence of the internal cavity defined by the electrode welding shell and the blind adapter reduces the thermal mass of the welding electrode and slows the rate of conductive heat transfer from the weld face to a cooling fluid, which allows in the center of the weld face to retain heat for a longer duration once current flow through the welding electrode is terminated, thereby positively affecting the spot welding process for particular types of workpiece stack-ups including those that include an aluminum workpiece and an overlapping adjacent steel workpiece.

A welding electrode and a method of using the welding electrode for resistance spot welding are disclosed. The welding electrode includes a body and a weld face. The weld face includes a central dome portion and a shoulder portion that surrounds the central dome portion and extends from an outer circumference of the weld face upwardly and radially inwardly to the central dome portion. The central dome portion has a series of radially-spaced ringed ridges that project outwardly from a base dome face surface. The series of radially-spaced ringed ridges on the central dome portion includes an innermost ringed ridge and an outermost ringed ridge. The outermost ringed ridge on the central dome portion has a radial inner side surface and a radial outer side surface. The radial outer side surface extends below the base dome face surface down to the shoulder portion of the weld face.

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.

Embodiments described herein are generally directed to a venturi valve. The venture valve includes an inlet; an outlet opposite of the inlet; a passage, a primary orifice, and an insert. The passage is positioned between the inlet and the outlet and fluidly coupling the inlet to the outlet. The primary orifice is positioned between the inlet and the outlet and in fluid communication with the passage such that the primary orifice permits fluid to enter the passage. The insert is positioned between the inlet and the outlet, the insert configured to enclose at least a portion of the passage.

A guide hole is constituted of a large-diameter hole, a medium-diameter hole, and a small-diameter hole. A sliding part fitted in the guide hole is formed of a synthetic resin material. A large-diameter portion of the sliding part is fitted in the large-diameter hole in a slidable state, and a medium-diameter portion is fitted in the medium-diameter hole in a slidable state. A movable end surface of the sliding part is in close contact with a stationary inner end surface of the guide hole. By configuring a width dimension of the movable end surface to be less than half of a thickness dimension of the large-diameter portion, a pressurizing force of the movable end surface is increased and a minute metal piece is pushed from the movable end surface into a base material of the sliding part, and a thickness dimension of the medium-diameter portion is set large.

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.

Disclosed are weld electrode plugs with polymeric inserts for loss-of-cooling detection, methods for making or for using such weld electrode plugs, and electric welding systems equipped with loss-of-cooling detection plugs. A disclosed loss-of-cooling detection assembly includes a plug that attaches to the weld shank of a welding system such that the plug fluidly couples to a coolant bore within the shank. The plug includes a plug body with a clearance hole extending therethrough. An insert detachably mounts to the plug such that the insert fluidly seals the clearance hole. This insert is fabricated from a polymeric material, such as a shape memory polymer, that alters a physical property, such as shape/size, of the insert responsive to changes in temperature and/or pressure of coolant fluid in the shank's bore. When this physical property is altered, the insert unseals the clearance hole causing a detectable leak of fluid from the shank.

An electrode tip for resistance spot welding includes a main body with tip and base portions. The tip portion has a bottomed and substantially cylindrical shape. The base portion has a substantially cylindrical shape and merges into the tip portion. The main body is made of a copper alloy such as chromium copper. The tip portion has a bottom part and a barrel part. The bottom part has a pressure-contact surface that is not recessed with respect to a workpiece to be pressed. The barrel part has a substantially cylindrical shape and merges into the bottom part. The electrode tip may have an inner diameter ratio (inner diameter of the barrel part to an outer diameter of the base portion) of 0.4 to 0.6, and may also have a bottom thickness ratio (thickness of the bottom part to the outer diameter of the base portion) of 0.15 to 0.5.