Provided are a projection welding device and an electrode cleaning method for the same with which it is possible to keep a stud holding hole formed in a welding electrode clean. A projection welding device welds a stud to a workpiece by holding the stud using a second electrode, bringing the stud into contact with the workpiece, and causing a welding current to flow through the second electrode, wherein the second electrode includes a stud holding hole which extends from a cap opening formed in the distal end, to a bottom portion formed on the base end side, and at least one lateral hole which extends from a side wall opening formed in a side wall to the bottom portion, and the projection welding device is provided with a stud supply device which ejects air into the stud holding hole from the cap opening of the second electrode.

A main body and an end cover are made of metal. A major diameter hole and a minor diameter hole that communicates with a through hole of the end cover are provided in a heat insulating guide sleeve inserted into the main body. A cooling water passage is formed in the heat insulating guide sleeve. A portion of the heat insulating guide sleeve located at an inner side of the cooling water passage serves as a heat insulating portion. A container of a permanent magnet is slidably inserted into the heat insulating portion. A magnetic force transmission member is slidably inserted into the minor diameter hole. The permanent magnet, the heat insulating portion, and the cooling water passage are arranged in a diameter direction of the main body. A depth dimension of the cooling water passage is smaller than a thickness dimension of the heat insulating portion.

A main body and an end cover are made of metal. A major diameter hole and a minor diameter hole that communicates with a through hole of the end cover are provided in a heat insulating guide sleeve inserted into the main body. A cooling water passage is formed in the heat insulating guide sleeve. A portion of the heat insulating guide sleeve located at an inner side of the cooling water passage serves as a heat insulating portion. A container of a permanent magnet is slidably inserted into the heat insulating portion. A magnetic force transmission member is slidably inserted into the minor diameter hole. The permanent magnet, the heat insulating portion, and the cooling water passage are arranged in a diameter direction of the main body. A depth dimension of the cooling water passage is smaller than a thickness dimension of the heat insulating portion.

The dissimilar material joint structure 1 includes a plate member 20, a weld nut 10 on a front surface of the plate member, and a washer 30 on a back surface of the plate member. The weld nut and the plate member are made of dissimilar materials different from each other. The weld nut includes a projection 12 on a bearing surface thereof. The plate member has a bolt through-hole 23 located on a center axis of the weld nut, for passing therethrough a bolt 40 corresponding to the weld nut and a projection through-hole 24 on the periphery of the bolt through-hole. The projection through-hole is penetrable by the projection. The weld nut is not directly welded to the plate member but joined to the plate member by being welded to the washer via the projection penetrating the projection through-hole.

A component loading-welding system for welding a component panel to a vehicle body panel includes a rotation portion body having first and second opposing sides. The first opposing side is coupled to a robot arm. A picking device is installed in the rotation portion body and is configured to hold and release the component panel. A vehicle body pressurizing tip is installed in the rotation portion body. A pressurizing portion body is rotatably installed at the second opposing side of the rotation portion body. A pin clamp is installed in the pressurizing portion body and is configured to clamp the component panel. A component pressurizing tip is installed in the pressurizing portion body and is configured to apply pressure to the component panel. A multi point projection welding method is also disclosed.

A component loading-welding system for welding a component panel to a vehicle body panel includes a rotation portion body having first and second opposing sides. The first opposing side is coupled to a robot arm. A picking device is installed in the rotation portion body and is configured to hold and release the component panel. A vehicle body pressurizing tip is installed in the rotation portion body. A pressurizing portion body is rotatably installed at the second opposing side of the rotation portion body. A pin clamp is installed in the pressurizing portion body and is configured to clamp the component panel. A component pressurizing tip is installed in the pressurizing portion body and is configured to apply pressure to the component panel. A multi point projection welding method is also disclosed.

An electrical apparatus includes first and second welded members that are welded together. The first welded member has a first metal part and a first resin part covering part of the first metal part. The second welded member has a second metal part and a second resin part covering part of the second metal part. The first metal part has a first standing terminal portion exposed from the first resin part and standing in a standing direction. The second metal part has a second standing terminal portion exposed from the second resin part and standing in the standing direction. The first and second standing terminal portions are welded to each other so that a weld is formed therebetween. The first and second resin parts partially overlap each other in the standing direction. The weld is within a projection region of the first and second resin parts in the standing direction.

A manufacturing method for a cylinder device which includes a cylinder, a piston, a piston rod, a seal member, and an installing member, the method includes: a welding step for fixing the installing member to the cylinder through electrical resistance welding; a demagnetizing step for demagnetizing at least an opening portion of the cylinder; and an assembling step for assembling the piston, the piston rod, and the seal member in the cylinder through the opening portion.

A projection welding electrode holder has a holder body, a holder barrel, and a coned-disc spring. The holder body is configured for attachment to a welding machine and defines a holder body bore. The holder barrel is carried within the holder body bore and has a holder head that extends therefrom for attachment to a welding electrode. The holder barrel is movable relative to the holder body between a first position, in which the holder head extends from the holder body bore a first distance, and a second position, in which the holder head extends from the holder body bore a second distance, the first distance being greater than the second distance. The coned-disc spring resides within the holder body bore, biases the holder barrel toward the first position, and is compressed by movement of the holder barrel from the first position to the second position.

A projection welding electrode holder has a holder body, a holder barrel, and a coned-disc spring. The holder body is configured for attachment to a welding machine and defines a holder body bore. The holder barrel is carried within the holder body bore and has a holder head that extends therefrom for attachment to a welding electrode. The holder barrel is movable relative to the holder body between a first position, in which the holder head extends from the holder body bore a first distance, and a second position, in which the holder head extends from the holder body bore a second distance, the first distance being greater than the second distance. The coned-disc spring resides within the holder body bore, biases the holder barrel toward the first position, and is compressed by movement of the holder barrel from the first position to the second position.