Welding method for cathode of electrical vacuum device

Abstract

The invention discloses a welding method for the cathode of an electrical vacuum device. The welding method comprises the following steps that the output voltage of a laser welding machine is regulated to 55-65 V, and the pulse width of the laser welding machine is regulated to 6.9-7.4 ms; the size of light spots of the laser welding machine is adjusted; welding shielding gas is led into the laser welding machine; the cathode and a conductive connecting rod are assembled on a mold according to drawing requirements; the assembled cathode is placed below an optical bench focus lens of a microscope, the cathode and a supporting rod are made to be located on the focal point of the microscope and in the center of a cross by adjusting the positions of the cathode and the supporting rod, and then the positions of a lamp and a nozzle of the laser welding machine are adjusted, so that the lamp and the nozzle of the laser welding machine are made to aim at a point to be welded; a welding wire is added, laser light of the laser welding machine is made to aim at the welding wire, and then welding is conducted; after welding is completed, the welding wire is wound slowly, so that the residual portion of the welding wire is separated; and the welded cathode is flatly placed below the microscope for checking of a welding spot. By the adoption of the welding method for the cathode of the electrical vacuum device, the welding stress is small, deformation of the cathode is small, the conductivity is good, and pseudo welding is avoided.

Description

technical field [0001] The invention relates to a welding technology of an electric vacuum device, in particular to a welding method of a cathode of an electric vacuum device. Background technique [0002] The filament is the core component of an electric vacuum device, and must have long life, high voltage resistance, strong stability, and high reliability. The electron emission efficiency of pure tungsten filament is low, but its high melting point, low vapor pressure, high mechanical strength and stable electron emission make pure tungsten filament still widely used. [0003] The cathode of the electric vacuum device is welded on the conductive connecting rod, and the cathode is energized on the conductive connecting rod to light up the cathode. The cathode is a very small and precise part. [0004] The existing mature technology is connected by mechanical clamping or spot welding. The problem with mechanical clamping is that because the cathode is too small, it is diff...

AI Technical Summary

Problems solved by technology

The problem with mechanical clamping is that because the cathode is too small, it is difficult to clamp, not to pinch off, not to pinch crookedly

If it is not clamped, it will lead to no electricity. If the clamp is crooked, it will affect the subsequent assembly and performance of the cathode.

Spot welding can tightly weld the filament and the conductive connecting rod, and the power can be guaranteed, but the welding head must be pressed tightly during spot welding, and the filament is easily deformed or broken by force. It is difficult to align when welding the disc-shaped cathode, and the deformation is particularly obvious. Either due to incorrect parameter settings, resulting in false welding, or making the cathode brittle

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