A floating constant pressure control friction stir welding device and method

Abstract

The invention discloses a floating type constant-pressure control friction stir welding device. The floating type constant-pressure control friction stir welding device is mainly composed of a ball spline, a spline shaft, a coil, a permanent magnet, a force sensor, a cutter handle and a stirring tool. The coil and the permanent magnet are installed on an end cover of the ball spline and the splineshaft correspondingly, and electromagnetic force generated between the coil and the permanent magnet is used for applying axial pressure on the stirring tool. The force sensor is connected with the coil so that the axial pressure can be measured in real time and fed back to the control system. The stirring tool is connected with the spline shaft through the cutter handle. The spline shaft is matched with the ball spline so that axial moving of the stirring tool can be achieved. The ball spline is connected with a spindle motor so that rotation motion of the stirring tool can be achieved. By means of the floating type constant-pressure control friction stir welding device, the rotating motion of the motor is transmitted to the stirring tool through spline fit, the electromagnetic force isaccurately controlled by adjusting the currents in the coil in the welding process, and therefore constant axial pressure can be applied to the stirring tool. Constant-pressure force friction stir welding of workpieces with uneven surfaces can be achieved, the responding speed is high, and the structure is simple.

Description

technical field [0001] The invention belongs to the field of friction stir welding, in particular to a floating constant pressure control friction stir welding device. Background technique [0002] Friction stir welding is a solid-phase joining method. Its main joining mechanism is to generate heat through the rotating friction of the stirring tool, so that the material enters a plastic state, and then through the stirring and local forging of the stirring tool and the dynamic recrystallization of the joined materials. Dense welds. Among them, the axial pressure of the stirring tool on the material to be welded is an important factor to ensure good weld quality. In the prior art, the method of pressing the stirring tool into the surface of the workpiece for a certain amount of displacement is usually used to apply axial pressure to the material to be welded, that is, the constant pressure input amount control method. However, due to the heat softening of the workpiece duri...

AI Technical Summary

Problems solved by technology

However, due to the long feedback link of this control method, there are many mechanical transmission links, the response speed is slow, and the pressure control accuracy is low, so it is not suitable for constant pressure friction stir welding of workpieces with uneven surfaces.

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