A spot welding system includes a position detection part which detects the position of a movable arm, a first calculation part which calculates the combined spring constant of the movable arm and a fixed arm based on a position when the movable arm is driven by a predetermined drive force and the drive force, a second calculation part which calculates the spring constant of the movable arm based on a position when the movable arm is driven by a predetermined drive force and the drive force, a third calculation part which calculates the spring constant of the fixed arm based on the combined spring constant and the spring constant of the movable arm, and an elastic displacement calculation part which calculates an amount of elastic displacement of the fixed arm based on the spring constant of the fixed arm and a drive force when welding is performed.

An apparatus for manufacturing wire wrapped screens utilizing a wire and support ribs is provided. The apparatus employs welding pressure control, utilizing a welding device mounted on a support assembly, wherein the support assembly is moveable in relation to a mounting structure and the wire and support rib weld pieces. Welding pressure is determined by a force measurement device, and a control and feedback system adjusts pressure. Mechanical actuator cylinders mounted on the support assembly and the mounting structure provide load balance. A method for making wire wrapped screens is also provided.

A welding portion inspection system includes a sensing head, and first and second electrodes that are disposed a predetermined distance from each other at one side of the sensing head, where front end portions of the first and second electrodes contact both sides of a welding portion to apply current such that a temperature of the welding portion is heated, and an infrared camera is disposed on the sensing head and detects a temperature distribution of the welding portion.

A plate thickness test mechanism includes a detection section that detects an abnormality when a plate thickness is thinner than a desired plate thickness by a predetermined amount or more or thicker than the desired plate thickness by the predetermined amount or more, a determination section that determines whether or not the detection section functions normally, and a plate-shaped test jig that has a first plate portion having a plate thickness thinner than a predetermined specific plate thickness, and a second plate portion having a plate thickness thicker than the specific plate thickness. The determination section determines whether or not a plate thickness test is normally performed on the basis of a detection result of the detection section obtained when the detection section tests the plate thicknesses of the first and second plate portions by taking the desired plate thickness as the specific plate thickness.

According to one embodiment, a control device controls a welding device performing resistance welding. When an inspection value satisfies a first condition, the control device modifies a setting value for the resistance welding and causes the welding device to perform the resistance welding. The inspection value is obtained by an inspection of a weld zone formed by the resistance welding. The control device does not cause the welding device to perform the resistance welding when the inspection value satisfies a second condition.

According to one embodiment, a control device controls a welding device performing resistance welding. When an inspection value satisfies a first condition, the control device modifies a setting value for the resistance welding and causes the welding device to perform the resistance welding. The inspection value is obtained by an inspection of a weld zone formed by the resistance welding. The control device does not cause the welding device to perform the resistance welding when the inspection value satisfies a second condition.

A spot-welding system including a spot-welding gun including a movable part including a movable electrode, and a drive part that drives the movable part, a controller that controls the drive part, an applied pressure sensor that measures an applied pressure from the movable electrode of the spot-welding gun, and an own-weight calculator that calculates an own weight of the movable part based on the applied pressure detected by the applied pressure sensor in two different postures of the spot-welding gun that places the movable electrode in different movement directions. The controller superimposes a dither signal onto a control signal so as to control the drive part in measuring the applied pressure for use in calculating the own weight of the movable part by the own-weight calculator, and after the own weight is calculated, the controller corrects the control signal based on the calculated own weight.

A welding apparatus includes a movement assembly for at least one electrode configured to which can be passed through by current for the execution of welding treatments. The assembly includes at least one cylinder and at least one stem which rigidly supports the electrode; the stem is at least partially accommodated in the cylinder and is coaxially movable with an alternating straight motion along the longitudinal axis of the cylinder, in order to press the electrode against the parts to be welded with a corresponding welding force.

A device for measuring the welding force is also provided, which has a plate, which is stably interposed between the stem and the electrode with the respective faces arranged at right angles to the longitudinal axis, and a plurality of deformation sensors accommodated in through slots provided in the plate and distributed along an imaginary circumference which is centered along the longitudinal axis.

In electric resistance welding for energizing a workpiece formed by superimposing plural metal plates, an energization resistance reduction amount between a pair of electrodes pressurizing the workpiece is detected at a specified time interval during each welding process under a specified welding condition, frequency distribution of the energization resistance reduction amount under the welding condition is calculated on the basis of data relating to the energization resistance reduction amount, the frequency distribution is fitted with a Gaussian function, and occurrence of an expulsion under the welding condition is determined on the basis of whether the fitting is statistically significant.

The present technology relates to a method for evaluating resistance welding quality of a battery by using eddy current signal characteristics, wherein high reliability can be provided by preventing an error caused by a variation according to differences in physical properties of individual batteries, and an evaluation process is simple and clear by applying a non-destructive method.