JPH0590788U - Electrode tube cathode structure - Google Patents

Abstract

(57) [Summary] [Construction] In the cathode structure for an electron tube of the present invention, the heat of the heater is conducted to the side of the cathode holder through the cathode sleeve to increase the temperature around the cathode and reduce the heat conduction to the cathode substrate. In order to prevent the phenomenon that deteriorates the electron emission characteristics of the cathode, a large number of through holes are formed in the lower side of the heater starting part below the cathode sleeve to reduce the heat conduction area to the cathode holder. The heat conduction of the heater to the cathode holder is suppressed, and the heat conduction to the cathode substrate is relatively increased to improve the heat efficiency of the heater, thereby improving the electron emission characteristics of the electron tube.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cathode structure for an electron tube. Specifically, a plurality of through holes are formed on the peripheral surface of the cathode sleeve to suppress heat conduction to the cathode holder and to relatively heat the cathode substrate. The present invention relates to a cathode structure for an electron tube, which has improved conductivity.

[0002]

[Prior Art]

 Conventionally, in a cathode structure used for an electron tube, as shown in FIG. 2 (A), a cathode sleeve 2 is welded to a cathode holder 3 and a cathode substrate 1 is welded to the cathode sleeve 2 so that the inside As shown in FIG. 2 (B), the cathode sleeve 21 is formed integrally with the cathode holder 22 and the cathode sleeve 21 is integrally formed with the heater 4 having the heat generating portion 4a and the starting portion 4b on the side. It has been known that the cathode substrate 1 is welded to the inner side of which the heater 4 having the heat generating portion 4a and the starting portion 4b is housed inside thereof.

In the conventional cathode structure thus configured, when power is supplied to the heater, heat is generated from the opening 4b of the heater 4 and maximum heat is generated in the heat generating portion 4a within a few seconds. Then, the heat is conducted directly to the cathode base 1, while the heat is conducted to the cathode base 1 via the cathode sleeve 2 and to the cathode holder 3 via the cathode sleeve. It is classified as one. Among them, the heat conducted to the cathode substrate 1 is required to emit electrons from the electron emitting material (not shown) coated on the upper side surface of the cathode substrate 1, but is conducted to the cathode holder 3. The generated heat unnecessarily raised only the temperature around the cathode and relatively lowered the heat conduction to the cathode substrate 1.

[0004]

[Problems to be solved by the device]

 However, when the temperature around the cathode unnecessarily rises and the amount of heat conduction to the cathode substrate 1 relatively decreases, the electron emission characteristic of the electron tube deteriorates due to the thermal change. there were. That is, when the cathode operating temperature (1 T portion) on the upper side surface of the conventional cathode substrate 1 is about 800 ° C., the unnecessary negative electrode temperature on the lower side portion (3 T portion) of the cathode holder 3 becomes about 490 ° C., which is caused by the heater heat. The cathode temperature ratio (cathode operating temperature / unnecessary cathode temperature) decreases to 1.63, the heat of the heater 4 is not efficiently conducted to the cathode substrate 1, and the power consumption of the heater for maintaining the cathode operating temperature appropriately is reduced. There was a disadvantage that the temperature of unnecessary cathodes increased and electron emission characteristics deteriorated.

The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, intend to provide the following cathode structure for an electron tube. An object of the present invention is to form a large number of through holes on the lower peripheral surface of the cathode sleeve to suppress heat conduction to the cathode holder so that the heat of the heater can be efficiently conducted to the cathode substrate. It is intended to provide a structure.

[0006]

[Means for Solving the Problems]

 In such a cathode structure for an electron tube, when the cathode sleeve and the cathode holder are separately formed, a large number of through holes are formed in the peripheral surface of the cathode sleeve near the cathode holder. When the sleeve and the cathode holder are integrally formed, a large number of through holes are formed in the lower peripheral surface of the cathode sleeve to suppress conduction of heat generated by the heater to the cathode holder side. The unnecessary heating of the peripheral portion is prevented and the heat conduction efficiency to the cathode substrate is improved.

[0007]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings according to the present invention, the same reference numerals are used for the same parts as the conventional ones. FIG. 1A is a view showing a cathode structure in which a cathode sleeve and a cathode holder according to the present invention are separated. As shown, a cathode sleeve 2 is formed in which a cathode base 1 is welded to the upper side and a heater 4 having a heat generating portion 4a and a starting portion 4b is accommodated on the inner side, and a lower end of the cathode sleeve 2 is formed. Is welded to the cathode holder 3, and a large number of through holes 2a having a predetermined size are formed in the lateral direction at a predetermined portion on the lower peripheral surface of the cathode sleeve 2 on the upper side of the cathode holder 3.

Further, as shown in FIG. 1B, in the cathode structure in which the cathode sleeve 21 and the cathode holder 22 are integrally formed, the lower end of the cathode sleeve 21 is expanded and the cathode holder 22 is expanded. Therefore, a large number of through holes 21a having a predetermined size are laterally formed at a predetermined portion on the peripheral surface immediately above the cathode holder 22 portion. The operation of the cathode structure for an electron tube according to the present invention constructed as above will be described as follows. When the heater 4 having the heat generating portion 4a, the starting portion 4b and the leg portion 4c is housed inside the cathode sleeve 2 and the cathode holder 3 and power is applied to the heater, the heat generating portion 4a of the heater 4 Maximum heat is generated and conducted to the cathode substrate 1 and the cathode holder 3 through the cathode sleeve 21. At this time, since a large number of through holes 2a are formed on the lower peripheral surface of the cathode sleeve 2, heat conduction to the cathode holder 3 side is reduced by the through holes 2a. The heat conduction is suppressed and the heat conduction to the cathode substrate 1 side is relatively increased, and the heat of the heater is efficiently conducted to the cathode substrate 1. In addition, in order to improve the heat conduction efficiency to the cathode substrate 1, it is preferable that the through hole 2a is located below the starting portion 4b of the heater 4. That is, when the through hole 2a on the peripheral surface of the cathode sleeve 2 is located on the heat generating portion 4a side of the heater 4, the heater heat is radiated to the outside of the cathode through the through hole 2a, and the heat conductivity of the heater is lowered. To be done.

In addition, the heat of the heater 4 is maximally suppressed from being conducted to the cathode holder 3, and the heat of the heater 4 is minimized from being emitted to the outside of the cathode through the through hole 2a. It is preferable to make the size of the through holes 2a as small as possible and relatively increase the number of the through holes 2a. Furthermore, laser processing is preferable in order to reduce the size of the through hole 2a and form it accurately. It may be machined with a pin or a drill, or may be chemically etched with nitric acid or the like. At this time, the through hole 2a can be formed after assembling the cathode substrate 1, the cathode sleeve and the cathode holder 3, or can be formed and assembled before assembling them.

Further, in this embodiment, after the cathode substrate 1, the cathode sleeve 2 and the cathode holder 3 are assembled by welding, four through holes 2a having a diameter of 8.5 mm are formed on the lower peripheral surface of the cathode sleeve 2 by pins. After forming and housing the heater 4 inside the cathode, power was applied to the heater 4 to measure the cathode operating temperature 1T on the upper side surface of the cathode substrate 1 and the unnecessary cathode temperature 3T on the lower side of the cathode holder 3, respectively. As a result, the cathode operating temperature 1T is about 830 ° C, the unnecessary cathode temperature 3T is about 460 ° C, and the cathode temperature ratio due to the heater heat is 1.80, which means that the heater heat is applied to the cathode substrate 1 more efficiently than before. It was confirmed to be transmitted. Moreover, in this case, if the cathode operating temperature 1T is lowered to about 800 ° C., the power consumption of the heater is reduced, and the unnecessary cathode temperature 3T in the cathode holder 3 portion is also lowered to reduce the thermal change of the cathode and the surroundings. The electron emission characteristics of the electron tube can be maintained stable.

Also, in the embodiment shown in FIG. 1B, the same effect as that of the above embodiment can be obtained.

[0012]

[Effect of the device]

 As described above, in the cathode structure for an electron tube according to the present invention, by forming a through hole in the cathode sleeve to suppress conduction of heater heat to the cathode holder, heat to the cathode substrate is reduced. This has the effect of increasing the conductivity and improving the heat conductivity of the heater to improve the electron emission characteristics of the electron tube.

[Brief description of drawings]

FIG. 1 is a view showing a cathode structure for an electron tube according to the present invention, FIG.
[Fig. 4] is a vertical sectional view of another embodiment.

FIG. 2 is a view showing a conventional cathode structure for an electron tube,
(A) is a vertical cross-sectional view of an example thereof, and (B) is a vertical cross-sectional view of the example.

[Explanation of symbols]

 1 Cathode Base 2, 21 Cathode Sleeve 2a, 21a Through Hole 3, 22 Cathode Holder 4 Heater 4b Start Part

Claims (2)

[Scope of utility model registration request] 1. Cathode substrate (1) and cathode sleeve (2)
(21), cathode heater (4), cathode holder (3)
(22) A cathode structure for an electron tube, comprising: a plurality of through holes (2a) (21a) having a predetermined size formed in a peripheral surface portion of the cathode sleeve (2) (21). Negative electron tube cathode structure. 2. The through holes (2a, 21a) formed in the peripheral surface of the cathode sleeve (2) (21) are formed below the starting portion (4b) of the cathode heater (4). The cathode structure for an electron tube according to item (1).