A welding gun includes a proximity restricting mechanism that is provided between a shaft and a cover member in a manner to surround the shaft and to be displaceable relative to the shaft in an axial direction in accordance with expansion and contraction of the cover member, and that restricts the cover member from approaching too closely the shaft.

A method for adaptive control of the traveling electrode of a spot welding gun includes causing the traveling electrode of the welding gun to move at a first speed when performing a welding (working) cycle and to switch to a second speed at a point, the coordinate of which is calculated based on the point of contact of the coordinate of the electrode obtained at the configuration cycle performed before the working cycle. The method allows for a reduction in welding cycle time.

A spot welding apparatus (10) according to the present invention includes: a circular cylindrical cam (12) having an outer circumferential surface, in which a spiral-shaped large lead cam groove (12a) inclined at a steep angle and a spiral-shaped small lead cam groove (12b) inclined at a gentle angle are formed; and a pressurizing shaft (13) including a plurality of rollers (R1, R2) insertable into the respective cam grooves (12a, 12b) and configured to move along an axis of rotation of the circular cylindrical cam (12) when the circular cylindrical cam (12) rotates. When the rollers (R1, R2) are inserted into the large lead cam groove (12a), a roller (R1, R2) located at one end side of a row comes into contact with one of two sides surfaces of the cam groove (12a) and a roller (R1, R2) located at another end side of the row comes into contact with the other one of the two side surfaces of the cam groove (12a), and when the rollers (R1, R2) are inserted into the small lead cam groove (12b), each of the rollers (R1, R2) comes into contact with at least one of one side surface and the other side surface of two side surfaces of the cam groove (12b).

A welding gun for resistance spot welding includes a first electrode; a second electrode having a fixed part and a movable part movable toward the first electrode, an electromechanical linear actuator of the first electrode fixedly attached to the fixed part of the second electrode and having a first force sensor and a rod connected to the first electrode; an electromechanical linear actuator of the movable part of the second electrode having a housing, an electric motor, an inverted roller-screw gear transforming rotary motor movement into rod translation, a position sensor determining a position of the movable part of the second electrode, and a bevel gear transferring electric motor rotation to the inverted roller-screw gear. The rod of the electromechanical linear actuator is connected to the movable part of the second electrode. The welding gun further includes a second force sensor configured to measure force on the second electrode.

A collet assembly including an actuator and a collet connected to the actuator. The collet assembly is adapted to be installed on a welding electrode holder having an electrode. The collet is moveable by the actuator from an advanced position, in which the collet is adapted to grip a fastener such as a welding rivet, and a retracted position, in which at least a portion of the collet is retracted into the actuator to enable the electrode to engage the fastener for welding to a work piece, and the collet is adapted to release the fastener.

A welding device of a robot arm includes a welding machine having a first pressing member which includes a cylindrical first pressing part and a second pressing member which includes a second pressing part inserted into a hollow of the first pressing part. A transformer supplies a positive (+) current to the first pressing member and a negative (−) current to the second pressing member. The first and second pressing parts have the same co-axis.

A joining apparatus for panel sheets and a joining method for panel sheets using the same are provided. The joining apparatus includes an element punching device which stores and supplies elements according to a specification of a panel sheet and inserts the element into a first panel sheet among different types of panel sheets. Additionally, a welding device resistively welds a part of the first panel sheet into which the element is inserted by the element punching device.

A spot welding apparatus includes a spot welding gun and a welding gun control apparatus. The welding gun control apparatus includes a pressurizing force control part controlling the pressurizing force, a position control part controlling the position of at least one electrode, and a determination part determining whether or not the welding is performed in a normal state. The position control part controls an electrode drive motor so as to hold the electrodes, after the supply of the electric current is started, at positions when the initial pressurizing force is applied before the electric current is supplied. The determination part acquires the pressurizing force and determines whether or not the welding is performed in a normal state based on change tendency in the pressurizing force.

A cooling device includes a refrigerant circulation channel, and a pump configured to pump refrigerant in the refrigerant circulation channel A heat generating part of an articulated robot includes a heat generating part of an end effector, and a part of the refrigerant circulation channel is formed as a first heat exchanging part configured to exchange heat between the heat generating part of the end effector and the refrigerant, and another part of the refrigerant circulation channel is formed as a radiator. The radiator is a passive radiator, and is attached in an exposed state to a part of the surface of an arm, configured to move in a space when a joint of the arm is driven.

A welding gun includes: a moving mechanism portion (ball screw mechanism) for moving a movable electrode back and forth; a motor that includes a rotor and drives the moving mechanism portion to move the movable electrode back and forth; and a brake mechanism that prevents rotation of the rotor during a braking operation, wherein the brake mechanism includes an annular brake disc that is attached to an outer peripheral surface of the rotor and rotates integrally with the rotor, and a clamping portion that prevents rotation of the brake disc by clamping the brake disc during the braking operation.