Gas discharge tube

Abstract

The utility model relates to the technical field of discharge tubes, in particular to a gas discharge tube, which comprises a discharge tube electrode, a metal sputtering layer is arranged on the side surface of an emitting surface of the discharge tube electrode facing a discharge space, and the metal melting point of the metal sputtering layer is higher than that of the discharge tube electrode. Due to the arrangement of the metal sputtering layer, the direct influence of high temperature in the discharge space on the discharge tube electrode can be isolated, and meanwhile, the metal melting point of the metal sputtering layer is higher than the metal melting point of the discharge tube electrode, so that the surge resistance of the product or the high-temperature resistance caused by follow current can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of discharge tubes, in particular to a gas discharge tube. Background Art

[0002] In the wide application environment of power supply systems (including AC power supply and DC power supply systems), not only are they vulnerable to large surge currents, especially the 10 / 350us surge impact, but it is also possible that the normal operation of the power supply system will be affected or damaged due to the abnormal damage of protection components. The main reason for this phenomenon is that the large current causes the electrodes of the gas discharge tube to reach the level where they can emit thermoelectrons. At the same time, the gas between the electrodes is ionized under the strong electric field and high temperature, making the conductive channel of the entire gas discharge tube in a low-impedance state. As the current continues to increase, the temperature of the electrodes will further rise, which may cause the temperature on the surface of the electrodes to rise sharply to the temperature of metal evaporation, resulting in a decrease in the anode region voltage. Therefore, in a certain discharge section, the arc voltage decreases with the increase of current. The arc voltage is related to factors such as electrode material, gas, current, and spacing.

[0003] A gas discharge tube is a switch-type overvoltage protection device composed of metal electrodes and high-insulation ceramics, which are hermetically sealed at high temperature after filling with a corresponding proportion of mixed gas. Most electrodes are composed of iron-nickel or oxygen-free copper electrodes. Due to the melting points of these two metals (the melting point of iron-nickel is 1453°C, and the melting point of oxygen-free copper material is 1083°C), generally, copper materials with better thermal conductivity are selected for the electrodes of high-current products. These materials are subjected to large surge impact currents, resulting in metal evaporation and sputtering onto the inner side wall of the porcelain tube; or due to the large continuous current existing in the protection circuit in the power supply working loop, the metal electrode materials of the gas discharge tube used as a protection component are melted by high temperature, affecting important parameters such as the resistance, DC breakdown voltage, and protection voltage of the product. Seriously, it may lead to the risk of fire caused by the long-term discharge and heating of the gas discharge tube. Due to the increasing requirements for system safety, the safety and reliability of the discharge tube are also getting higher and higher. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide a gas discharge tube that can improve the surge resistance or high-temperature resistance due to continuous current of the product.

[0005] To solve the above technical problem, the technical solution adopted by the utility model is:

[0006] A gas discharge tube includes discharge tube electrodes, and a metal sputtering layer is provided on the side of the emission surface of the discharge tube electrodes facing the discharge space, and the melting point of the metal in the metal sputtering layer is higher than the melting point of the metal of the discharge tube electrodes.

[0007] Further, the thickness range of the metal sputtering layer is 3μm - 18μm.

[0008] Further, the thickness of the metal sputtering layer is 4 μm.

[0009] Further, the thickness of the metal sputtering layer is 10 μm.

[0010] Further, the material of the metal sputtering layer is tungsten, nickel, chromium or copper-tungsten alloy.

[0011] Further, a diffusion layer is provided between the emission surface and the metal sputtering layer.

[0012] Further, the diffusion layer is formed by partial penetration of the metal sputtering layer toward the emission surface during heat treatment.

[0013] Further, it further includes a metallized porcelain tube, and the metallized porcelain tube is connected to the discharge tube electrode to form a discharge tube unit.

[0014] Further, the metallized porcelain tube and the discharge tube electrode are sealed by high-temperature brazing.

[0015] Further, one or more discharge tube units form a gas discharge tube.

[0016] The beneficial effects of the present utility model are as follows:

[0017] For a gas discharge tube provided by the present utility model, a metal sputtering layer is provided on the side surface of the emission surface of the discharge tube electrode facing the discharge space, and the melting point of the metal of the metal sputtering layer is higher than the melting point of the metal of the discharge tube electrode. Due to the setting of the metal sputtering layer, it can isolate the direct influence of the high temperature in the discharge space on the discharge tube electrode. At the same time, the melting point of the metal of the metal sputtering layer is higher than the melting point of the metal of the discharge tube electrode, thereby improving the surge resistance of the product or the high-temperature resistance due to continuous current. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is the front view of a gas discharge tube of the present utility model;

[0019] Figure 2 is the schematic structural diagram of a gas discharge tube of the present utility model with 1 section;

[0020] Figure 3 is the schematic structural diagram of a gas discharge tube of the present utility model with 3 sections;

[0021] Figure 4 is the schematic structural diagram of a gas discharge tube of the present utility model with 5 sections;

[0022] Label Description:

[0023] 1. Discharge tube electrode; 2. Solder; 3. Metallized porcelain tube; 4. Conductive strip; 5. Emission surface; 6. Sealing surface; 7. Metal sputtering layer; 8. Intermediate electrode. Detailed implementation mode

[0024] To describe in detail the technical content, achieved purpose and effects of the present utility model, the following is described in conjunction with the implementation modes and with reference to the drawings.

[0025] Please refer to Figures 1 to 4 , a gas discharge tube provided by the present utility model includes a discharge tube electrode, and a metal sputtering layer is provided on the side surface of the emission surface of the discharge tube electrode facing the discharge space, and the melting point of the metal of the metal sputtering layer is higher than the melting point of the metal of the discharge tube electrode.

[0026] From the above description, it can be seen that the beneficial effect of the present utility model is that:

[0027] For a gas discharge tube provided by the present utility model, a metal sputtering layer is provided on the side surface of the emission surface of the discharge tube electrode facing the discharge space, and the melting point of the metal of the metal sputtering layer is higher than the melting point of the metal of the discharge tube electrode. Due to the setting of the metal sputtering layer, it can isolate the direct influence of the high temperature in the discharge space on the discharge tube electrode, and at the same time, the melting point of the metal of the metal sputtering layer is higher than the melting point of the metal of the discharge tube electrode, so as to improve the surge resistance of the product or the high temperature resistance due to continuous current.

[0028] Further, the thickness range of the metal sputtering layer is 3μm to 18μm.

[0029] From the above description, it can be seen that the thickness range of the metal sputtering layer is 3μm to 18μm, which can meet the effect of improving the surge resistance of the product or the high temperature resistance due to continuous current.

[0030] Further, the thickness of the metal sputtering layer is 4μm.

[0031] From the above description, it can be seen that when the thickness of the metal sputtering layer is 4μm, the effect is the best.

[0032] Further, the thickness of the metal sputtering layer is 10μm.

[0033] From the above description, it can be seen that when the thickness of the metal sputtering layer is 10μm, the effect is the best.

[0034] Further, the material of the metal sputtering layer is tungsten, nickel, chromium or copper-tungsten alloy.

[0035] As can be seen from the above description, the electrode design of the large current discharge tube in a general power supply system consists of copper electrodes with good heat dissipation and weldability. However, the melting point of copper is relatively low (the melting point of copper is 1083 and the work function is 4.65 eV), while the melting point of nickel is 1453 and the work function is 5.15 eV, the melting point of chromium is 1907 and the work function is 4.50 eV; the melting point of tungsten is 3410 and the work function is 4.55 eV. The work functions of these high-temperature metals or alloys for generating electrons are similar and do not prevent electron emission.

[0036] Furthermore, a diffusion layer is provided between the emission surface and the metal sputtering layer.

[0037] As can be seen from the above description, the setting of the diffusion layer improves the adhesion between the metal sputtering layer and the electrode.

[0038] Furthermore, the diffusion layer is formed by partial penetration of the metal sputtering layer towards the emission surface during heat treatment.

[0039] As can be seen from the above description, through heat treatment, mutual diffusion and penetration occur between the sputtering layer and the discharge tube electrode substrate to form a diffusion layer at the interface, improving the adhesion between the metal sputtering layer and the electrode and reducing the impact on the discharge tube electrode substrate and parameters.

[0040] Furthermore, it also includes a metallized ceramic tube, and the metallized ceramic tube is connected to the discharge tube electrode to form a discharge tube unit.

[0041] Furthermore, the metallized ceramic tube and the discharge tube electrode are sealed by high-temperature brazing.

[0042] As can be seen from the above description, through the above structure, a discharge tube unit is formed.

[0043] Furthermore, more than one discharge tube unit forms a gas discharge tube.

[0044] As can be seen from the above description, a gas discharge tube is composed of one or more discharge tube units.

[0045] Please refer to Figures 1 to 4 , Example 1 of the present invention is:

[0046] A gas discharge tube provided by the utility model includes a discharge tube electrode 1, and a metal sputtering layer 7 is provided on the emission surface 5 of the discharge tube electrode. The thickness range of the metal sputtering layer 7 is 3μm to 18μm, preferably 4μm or 10μm. In this embodiment, the material of the metal sputtering layer 7 is tungsten, nickel, chromium or copper-tungsten alloy. Generally, the electrode design of the large current discharge tube in the power supply system is composed of copper electrodes with better heat dissipation and weldability. However, the melting point of copper is relatively low (the melting point of copper is 1083 and the work function is 4.65eV), while the melting point of nickel is 1453 and the work function is 5.15eV, the melting point of chromium is 1907 and the work function is 4.50eV; the melting point of tungsten is 3410 and the work function is 4.55eV. The work functions of these high-temperature resistant metals or alloys for generating electrons are similar and will not prevent the emission of electrons. The above-mentioned metal sputtering layer 7 adopts the existing sputtering process, which has the advantages of environmental protection, good reliability, consistency of the sputtering layer and no pollution.

[0047] A diffusion layer is provided between the emission surface 5 and the metal sputtering layer 7. The diffusion layer is formed by partial penetration of the metal sputtering layer towards the emission surface during the heat treatment. Through the heat treatment, mutual diffusion and penetration occur between the sputtering layer and the discharge tube electrode substrate to form a diffusion layer at the interface, improving the adhesion between the metal sputtering layer and the electrode and reducing the influence on the discharge tube electrode substrate and parameters.

[0048] The metallized ceramic tube 3 and the discharge tube electrode 1 are hermetically sealed by high-temperature brazing to form a discharge tube unit, that is, the sealing surface 6 of the discharge tube electrode is hermetically sealed with the metallized ceramic tube 3 through the solder 2. The emission surfaces 5 of two oppositely arranged discharge tube electrodes are connected through a conductive band 4. One or more discharge tube units form a gas discharge tube.

[0049] The above-mentioned gas discharge tube is formed by hermetically sealing the discharge tube electrode and the metallized ceramic tube. According to the product performance requirements and mold settings, through the surface sputtering process, a certain thickness of high-temperature resistant and difficult-to-evaporate metal materials such as tungsten, nickel, chromium or copper-tungsten alloy is sputtered on the inner surface of the discharge tube electrode or a certain area of the emission surface, and then through the production process of the discharge tube, the discharge tube electrode and the metallized ceramic tube are hermetically sealed with solder by high-temperature brazing to form a discharge tube unit; it can be a single discharge tube unit or a gas discharge tube formed by multiple discharge tube units.

[0050] As Figure 2 shown, it is a gas discharge tube composed of one discharge tube unit; when there are more than one section, an intermediate electrode 8 is required, that is, both of its two opposite sides are emission surfaces. Multiple discharge tube units are arranged side by side in a row, as Figure 3 shown, it is a gas discharge tube composed of three discharge tube units; as Figure 4As shown, it is a gas discharge tube composed of five discharge tube units. Of course, the number of discharge tube units can also be two, four, six, etc., which can be adjusted according to requirements.

[0051] In summary, for a gas discharge tube provided by the present utility model, a metal sputtering layer is provided on the side of the emission surface of the discharge tube electrode facing the discharge space, and the melting point of the metal in the metal sputtering layer is higher than the melting point of the metal of the discharge tube electrode. Due to the setting of the metal sputtering layer, it can isolate the direct influence of the high temperature in the discharge space on the discharge tube electrode. At the same time, the melting point of the metal in the metal sputtering layer is higher than the melting point of the metal of the discharge tube electrode, thereby improving the surge resistance of the product or the high temperature resistance generated by the follow current.

[0052] The above are only the embodiments of the present utility model, and do not limit the patent scope of the present utility model accordingly. Any equivalent transformation made by using the content of the specification and drawings of the present utility model, or directly or indirectly applied in the relevant technical fields, shall be equally included in the patent protection scope of the present utility model.

Claims

1. A gas discharge tube, comprising a discharge tube electrode, characterized in that: A metal sputtering layer is provided on the side of the emission surface of the discharge tube electrode facing the discharge space, and the metal melting point of the metal sputtering layer is higher than the metal melting point of the discharge tube electrode; A diffusion layer is arranged between the emitting surface and the metal sputtering layer.

2. A gas discharge tube according to claim 1, characterized in that: The thickness of the metal sputtering layer ranges from 3 μm to 18 μm.

3. A gas discharge tube according to claim 2, characterized in that: The thickness of the metal sputtering layer is 4 μm.

4. A gas discharge tube according to claim 2, characterized in that: The thickness of the metal sputtering layer is 10 μm.

5. A gas discharge tube according to claim 1, characterized in that: The material of the metal sputtering layer is metal tungsten, nickel, chromium or copper-tungsten alloy.

6. A gas discharge tube according to claim 1, characterized in that: The diffusion layer is formed by the metal sputtering layer partially penetrating toward the emission surface during the heating process.

7. A gas discharge tube according to claim 1, characterized in that: It also includes a metallized porcelain tube, which is connected with the discharge tube electrode to form a discharge tube unit.

8. A gas discharge tube according to claim 7, characterized in that: The metallized porcelain tube and the discharge tube electrode are sealed by high-temperature brazing.

9. A gas discharge tube according to claim 7, characterized in that: One or more discharge tube units constitute a gas discharge tube.

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