Magnetron tube core for microwave heating

Abstract

The invention belongs to a magnetron tube core for microwave heating in the field of magnetron design and production. Including the hot cathode emitter and its upper and lower shielding caps, the bimetallic central support and the upper electrode power supply connecting rod welded by metal molybdenum and iron-nickel-cobalt fixed-expansion ceramic seal alloy, and the iron-nickel-cobalt fixed-expansion ceramic seal Alloy side supports and lower electrode power connection rods, lower magnetic poles, tube core shells, and high-voltage ceramics with sealed connection holes. In this invention, the iron-nickel-cobalt fixed-expansion ceramic seal alloy with a linear expansion coefficient very similar to that of high-voltage ceramics and a resistivity much lower than that of metal molybdenum is used as the side support, the lower electrode power connection rod and the center support and the upper electrode power connection rod. Half section, so the sealing structure and welding process of the magnetron tube core are simple, excellent sealing performance, high reliability at work, long service life, high yield in production, low cost, and certain electrical performance of the cathode. degree of improvement and so on.

Description

Technical field [0001] The invention belongs to the field of magnetron design and production technology, and more specifically relates to the design and production of a magnetron tube core structure for microwave heating. The use of the magnetron tube core can prolong its service life and at the same time. The production process is simplified and the production cost is reduced; the magnetron adopting the tube core is particularly suitable as a microwave heating magnetron for microwave high-temperature industrial furnaces. Background technique [0002] The hot cathode is used as the electron emission source in the conventional magnetron tube core for microwave heating, and current needs to be supplied to the hot cathode during operation to increase the temperature of the cathode to 1200°C to 2500°C. Since the magnetron is an electric vacuum device, it must work in a good vacuum environment, so the good sealing performance of the magnetron core is a key factor to ensure the perform...

AI Technical Summary

Problems solved by technology

When the magnetron is in good working condition, the temperature of the high-voltage ceramics 1-8 is generally about 120°C. Due to the large difference in expansion coefficient between the high-voltage ceramics 1-8 and metal molybdenum, the high-voltage ceramics 1-8 will A certain amount of stress is generated, especially in the intermittent operation due to the repeated stress of uneven expansion and contraction. This stress will affect the sealing performance of the brazing part of the high-voltage ceramics and metal molybdenum, as well as the metallized end leads of the high-voltage ceramics. To adverse effects, affecting its sealing and service life

This situation is particularly prominent in microwave high-temperature furnaces heated by magnetrons (in this environment, the temperature of high-voltage ceramics 1-8 in the magnetron can sometimes be as high as about 300 ° C), and the magnetron is more likely to be damaged; in addition , fully use metal molybdenum rods as the central support and the upper electrode power supply connecting rod and side support and the lower electrode power connecting rod, there are also resistivity (the resistivity of industrial pure polycrystalline molybdenum is 570μΩ·m) and high cost, and high voltage The sealing structure and welding process between ceramics are complicated, the yield rate in production is low, and the electrical performance of the cathode is also poor.

Images