DE212021000252U1 - gas discharge tube - Google Patents

Abstract

A gas discharge tube characterized by comprising two electrodes and an insulating tube body for forming an accommodating cavity by enclosing with the two electrodes, the accommodating cavity being used for accommodating insulating gas, and an electron emitter fixed to a surface of the electrodes located in the accommodating cavity and wherein the electron emitter contains graphite in a mass fraction of 70%-100% and titanium dioxide in a mass fraction of 0%-30%.

Description

TECHNICAL AREA

The present application relates to the technical field of discharge tubes, in particular a gas discharge tube.

STATE OF THE ART

A gas discharge tube is a circuit protection device commonly used as a surge protector. The gas discharge tubes currently used generally comprise an insulating tube body and electrodes sealed at both ends thereof. An appropriate amount of inert gas medium is filled between the insulating tubular body and the electrodes encapsulated at both ends thereof, and the opposite surfaces of the two electrodes are coated with electron emission materials (such as electron powder). When the voltage of the two ends of the gas discharge tube exceeds the breakdown voltage of the gas, gap discharge is caused, and the gas discharge tube quickly changes from a high-resistance state to a low-resistance state, forming conduction, thereby causing other devices connected in parallel with the gas discharge tube protects.

With the popularization of mobile terminals and the requirement for miniaturization of electronic products, products with a lower breakdown voltage and better protection ability are urgently needed to prevent the surge voltage in electronic circuits, and the voltage protection class of current gas discharge tubes with a lower breakdown voltage is not stable enough.

CONTENT OF THE PRESENT INVENTION

The purpose of the embodiment of the present application is to provide a gas discharge tube to solve the technical problem in the prior art that the voltage protection class of the existing gas discharge tubes with a lower breakdown voltage has poor stability.

In order to achieve the above objective, the present application uses the following technical solution: a gas discharge tube is provided comprising two electrodes and an insulating tube body for forming an accommodating cavity by enclosing with the two electrodes, the accommodating cavity for accommodating insulating gas is used and wherein an electron emitter is fixed to a surface of the electrodes located in the accommodating cavity, and wherein the electron emitter contains graphite at a mass fraction of 70%-100% and titanium dioxide at a mass fraction of 0%-30%.

In one embodiment, a surface of the electrodes located in the receiving cavity is provided with a depressed portion, with the corresponding electron emitter firmly embedded in the depressed portion.

In one embodiment, a surface of the electrodes located in the accommodating cavity is provided with a protruding portion, and the corresponding electron emitter is fixed in the protruding portion and covers the protruding portion.

In one embodiment, the insulating gas in the receiving cavity is an electronegative gas.

In one embodiment, the containment cavity is used to contain one or more of carbon tetrafluoride gas, sulfur hexafluoride gas, a mixed gas of heptafluorobutyronitrile gas and nitrogen, a mixed gas of heptafluoroisobutyronitrile gas, and carbon dioxide.

In one embodiment, the insulating tube body is a polytetrafluoroethylene tube body or an epoxy resin tube body.

• Vorbereiten von zwei Elektroden, und Herstellen von zwei Elektronenemittern aus Graphitpulvern mit einem Massenanteil von 70%-100% und Titandioxidpulvern mit einem Massenanteil von 0%-30%;
• Befestigen der jeweiligen Elektronenemitter an den entsprechenden Elektroden;

The gas discharge tube may have been manufactured through the following steps:

• preparing two electrodes, and fabricating two electron emitters from graphite powders with a mass fraction of 70%-100% and titanium dioxide powders with a mass fraction of 0%-30%;
• attaching the respective electron emitters to the corresponding electrodes;

Fixing the two electrodes using a mold in an electronegative gas environment, pouring liquid epoxy resin or liquid polytetrafluoroethylene on the outer periphery of the two electrodes to form an insulating tubular body.

In one embodiment, attaching the respective electron emitters to the corresponding electrodes includes: stamping the electrode emitter into the corresponding electrode using an external machining device; or casting the ent speaking electrode on the outer circumference of the electron emitter.

• Mischen von Graphitpulvem mit einem Massenanteil von 70%-100% und Titandioxidpulvern mit einem Massenanteil von 0%-30%bis zu einem gleichmäßigen Zustand, um ein erstes gemischtes Pulver zu erhalten, und Formen des ersten gemischten Pulvers;

In one embodiment, the step of fabricating the two electron emitters includes:

• mixing graphite powders of 70%-100% by weight and titanium dioxide powders of 0%-30% by weight to a uniform state to obtain a first mixed powder, and shaping the first mixed powder;

introducing the first mixed powder after molding into a sintering apparatus for sintering, wherein the sintering temperature is 1500°C-2000°C.

• Mischen von Graphitpulvem mit einem Massenanteil von 70%-100% und Titandioxidpulvern mit einem Massenanteil von 0%-30% bis zu einem gleichmäßigen Zustand, um ein zweites gemischtes Pulver zu erhalten, und Zugeben von einem Bindemittel ins zweite gemischte Pulver;
• Einbringen des zweiten gemischten Pulver mit dem Bindemittel in eine Form und Herstellen eines Presslings;

In one embodiment, the step of fabricating the two electron emitters includes:

• mixing graphite powders of 70%-100% by weight and titanium dioxide powders of 0%-30% by weight to a uniform state to obtain a second mixed powder, and adding a binder to the second mixed powder;
• placing the second mixed powder with the binder in a mold and making a compact;

Put the compact in a baking apparatus for baking, the baking temperature being 150°C-200°C.

The gas discharge tube according to the present application has the following advantageous effects: compared to the prior art, the electron emitter in the gas discharge tube according to the present application has a small work function, a high electron emission rate and a short time for forming the electron avalanche between the two electrodes, so that the response time of the gas discharge tube is short and the breakdown voltage is low, which allows the gas discharge tube to quickly discharge the surge voltage and adapt to the requirements of the electrical components of low breakdown voltage; because the electron emitter has a stable work function, the electron density emitted by the electron emitter is stable, in addition, the electron emitter has good resistance to the high-temperature arc, and can be firmly bonded to the corresponding electrode surface, not easy to fall off, thus preventing electrode melting and sputtering and others Phenomena are avoided, so that the gas discharge tube has a small breakdown voltage fluctuation and good stability of the voltage protection class during long-term use.

character list

• 1 zeigt eine schematische Strukturansicht einer Gasentladungsröhre in einem Ausführungsbeispiel der vorliegenden Anmeldung.
• 2 zeigt ein schematisches Diagramm der Explosionsstruktur einer Gasentladungsröhre gemäß 1.
• 3 zeigt ein schematisches Diagramm der Teilstruktur einer Gasentladungsröhre gemäß 1.
• 4 zeigt eine erste schematische Strukturansicht einer Elektrode und eines Elektronenemitters in einem Ausführungsbeispiel der vorliegenden Anmeldung, wobei der Elektronenemitter in der Elektrode eingebettet ist.
• 5 zeigt eine zweite schematische Strukturansicht einer Elektrode und eines Elektronenemitters in einem Ausführungsbeispiel der vorliegenden Anmeldung, wobei der Elektronenemitter in der Elektrode eingebettet ist.
• 6 zeigt eine erste schematische Strukturansicht einer Elektrode und eines Elektronenemitters in einem Ausführungsbeispiel der vorliegenden Anmeldung, wobei der Elektronenemitter an der Elektrode eingeschnappt ist.

In order to explain the technical solution in the exemplary embodiments of the present application more clearly, the figures to be used in the explanation of the exemplary embodiments or the prior art are briefly presented below. Obviously, the figures outlined below only show a few exemplary embodiments of the present application. Those of ordinary skill in the art can obtain other figures based on the figures without having any creative work.

• 1 12 is a schematic structural view of a gas discharge tube in an embodiment of the present application.
• 2 FIG. 12 shows a schematic diagram of the exploded structure of a gas discharge tube according to FIG 1 .
• 3 FIG. 12 shows a schematic diagram of the partial structure of a gas discharge tube according to FIG 1 .
• 4 12 shows a first schematic structural view of an electrode and an electron emitter in an embodiment of the present application, wherein the electron emitter is embedded in the electrode.
• 5 12 is a second schematic structural view of an electrode and an electron emitter in an embodiment of the present application, wherein the electron emitter is embedded in the electrode.
• 6 12 shows a first schematic structural view of an electrode and an electron emitter in an embodiment of the present application, wherein the electron emitter is snapped to the electrode.

Reference List

100

electrode

110

Recessed section

120

Protruding section

200

Insulating tubular body

300

receiving cavity

400

electron emitter

410

recess

DETAILED DESCRIPTION

The exemplary embodiment of the present application is explained in more detail below. All examples of the exemplary embodiment are shown in figures, with the same or similar reference symbols from start to finish standing for the same or similar elements or elements with the same or similar function. The embodiments explained in connection with the figures are exemplary, serve to explain the present application and cannot be understood as a limitation for the present application.

It should be noted that in the discussion of the present application, directional or positional relationships are identified with terms such as "length", "width", "top", "bottom", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directional or positional relationships depicted in figures. They only serve to explain the present application and to facilitate the explanation. They do not indicate or imply that the devices or elements depicted have any particular orientation or are intended to be constructed and operated in any particular direction. Because of this, they cannot be understood as a limitation for the present application.

Furthermore, "the first", "the second" are only used to explain the objective and they cannot be taken to direct or imply the relative importance or to implicitly indicate the number of technical features directed. Because of this, the features defined with "the first", "the second" may include one or more of the features explicitly or implicitly. In the discussion of the present application, "plural" refers to two or more than 2 unless otherwise specified.

Please refer 1 until 3 , a gas discharge tube provided by an embodiment of the present application will be explained. The gas discharge tube comprises two electrodes 100 and an insulating tube body 200 for forming an accommodating cavity 300 by enclosing the two electrodes 100, the accommodating cavity 300 being used for accommodating the insulating gas, and an electron emitter on a surface of the electrodes 100 located in the accommodating cavity 300 400 is fixed, and wherein the electron emitter 400 contains graphite with a mass fraction of 70%-100% and titanium dioxide with a mass fraction of 0%-30%.

It should be noted that the electrode 100 can be made of a variety of materials, such as copper, iron-nickel alloys, etc., the materials can be selected as needed, which is not specifically limited here. The graphite has the property of small and stable work function, and the titanium dioxide has the properties of good electron transport performance, high temperature resistance and good stability. The mass fraction of the graphite powder and the mass fraction of the titanium dioxide powder in the electron emitter 400 add up to 100%, e.g. the electron emitter 400 can consist of 80% graphite powder and 20% titanium dioxide powder. As another example, the electron emitter 400 may be composed of 99% graphite powder and 1% titanium dioxide powder. As another example, the electron emitter 400 may be composed of 70% graphite powder and 30% titanium dioxide powder.

In comparison with the prior art, the electron emitter 400 in the gas discharge tube according to the present application as a whole has the characteristics of a low work function, a high electron emission rate and a short time for forming the electron avalanche between the two electrodes 100, so that the response time of the gas discharge tube is short and the Breakdown voltage is low, which allows the gas discharge tube to quickly discharge the lightning burst and adapt to the requirements of the electrical components to low breakdown voltage; because the electron emitter 400 has a stable work function, the electron density emitted by the electron emitter 400 is stable, in addition, the electron emitter 400 has good resistance to the high-temperature arc, and can be firmly bonded to the corresponding electrode surface without falling off easily, thus avoiding melting and sputtering of the Electrode 100 and other phenomena are avoided, so that the gas discharge tube has a small breakdown voltage fluctuation and good stability of the voltage protection class during long-term use.

As in 4 and 5 1, in another embodiment, a surface of the electrodes 100 located in the receiving cavity 300 is provided with a depressed portion 110, and the electron emitter 400 is fixedly embedded in the depressed portion 110, respectively.

It should be noted that the cross section of the electron emitter 400 is matched to the cross section of the depressed portion 110, polygonal, circular, etc., and can be adjusted as needed, which is not clear here is limited. The electron emitter 400 can be embedded in the recessed portion 110 in various ways, for example using a machining device to stamp the electron emitter 400 into the surface of the electrode 100 to form the recessed portion 110 while the electron emitter 400 is fixed to the surface of the electrode 100 is bonded; for example, the electrode 100 is formed by pouring liquid metal or a liquid metal alloy directly onto the outer periphery of the electron emitter 400, and the electrode 100 is firmly bonded to the electron emitter 400 after cooling.

Compared with the conventional gas discharge tube using the electron emitting material coating, in the gas discharge tube provided by the present embodiment, the thickness of the electron emitter 400 is greater than the thickness of the electron emitting material coating, thereby achieving a better covering effect for the electrode 100 to avoid that caused by the high-temperature arc To avoid melting or sputtering of the electrode 100, and the connection between the electron emitter 400 and the electrode 100 is safer than the connection between the electron emission material coating and the electrode 100, when the gas discharge tube is turned on, the electron emitter 400 is not prone to detach from the surface of the electrode 100 to peel off, which has a more stable protective effect on the electrode 100 and is further advantageous for improving the stability of the withstand voltage class of the gas discharge tube.

In another embodiment of the present application, a surface of the electrodes 100 located in the receiving cavity 300 is provided with a protruding portion 120, and the corresponding electron emitter 400 is fixed in the protruding portion 120 and covers the protruding portion 120, as in FIG 6 shown.

It should be noted that the electron emitter 400 can be fixed to the projecting portion 120 in various ways, such as first using a mold to fix the electron emitter 400 and then attaching the electrode 100 to the electron emitter 400 by casting formed of liquid metal or a liquid metal alloy, as another example, the electron emitter 400 is provided with a recess 410 whose inner diameter is slightly smaller than the outer diameter of the protruding portion 120, then using a machining device, the protruding portion 120 is machined into the recess 410 of the Electron emitter 400 pressed, which can be adjusted as needed and is not clearly limited here.

In the gas discharge tube provided by the present embodiment, not only can the electron emitter 400 be firmly bonded to the surface of the electrode 100 located in the accommodating cavity 300, but the electron emitter 400 can also completely cover the surface of the protruding portion 120, which gives the electrode 100 a provides better protection.

In another embodiment of the present application, the insulating gas in the receiving cavity 300 is an electronegative gas, as in FIG 3 shown. In the gas discharge tube with the above structure, the electronegative gas has a strong ability to collect electrons, which can quickly extinguish the freewheeling current with the working frequency, and at the same time increase the voltage drop of the arc, which can avoid the arc re-ignition.

In another embodiment of the present application, the accommodating cavity 300 is used for accommodating one or more of carbon tetrafluoride gas, sulfur hexafluoride gas, a mixed gas of heptafluorobutyronitrile gas and nitrogen, a mixed gas of heptafluoroisobutyronitrile gas and carbon dioxide, as in 3 shown.

In particular, when the distance between the two electrodes 100 of the gas discharge tube, the material of the electron emitter 400 and the type of electronegative gas in the accommodating cavity 300 are fixed, the breakdown pressure of the gas discharge tube increases with the pressure of the electronegative gas, first decreases and then increases. The pressure of the electronegative gas in the containment cavity 300 can be adjusted according to the required breakthrough pressure and other factors, for example, the pressure of the electronegative gas in the containment cavity 300 can be between -70 kPa and 80 kPa, but is not specifically limited here.

It should be noted that in the mixed gas of heptafluorobutyronitrile gas and nitrogen, the content of heptafluorobutyronitrile gas and nitrogen can be adjusted as needed, and in the mixed gas of heptafluoroisobutyronitrile gas and carbon dioxide, the content of heptafluoroisobutyronitrile gas and carbon dioxide can be adjusted as needed. Compared with the carbon tetrafluoride gas and sulfur hexafluoride gas, the heptafluorobutyronitrile gas and heptaf are luorisobutyronitrile gas more environmentally friendly, do not produce greenhouse effect, and have better dielectric strength and higher liquefaction temperature, when mixed with carbon dioxide or nitrogen with a lower liquefaction temperature to form a mixed gas, it can have a more suitable liquefaction temperature, which is suitable for gas discharge tube application .

The electronegative gas of the gas discharge tube provided by the present embodiment has not only good arc-extinguishing performance, but also low liquefaction temperature, good chemical stability, easy manufacture and low cost, which are suitable for the manufacture and application of the gas discharge tube.

In another embodiment of the present application, the insulating tube body 200 is a tube body made of epoxy resin.

It should be noted that the epoxy resin refers to the macromolecular compound containing an epoxy group in the molecular structure, has good physical and chemical properties after curing, and has excellent adhesion strength to the surfaces of the metal and nonmetal materials. The epoxy resin has good dielectric properties, low deformation shrinkage, good product dimensional stability, high hardness, good flexibility, and is stable to alkali and most solvents.

In the gas discharge tube provided by the present embodiment, the epoxy resin tube body has good mechanical properties and can ensure good connection with the electrode 100, so that the gas discharge tube has good structural stability, and the epoxy resin tube body has good arc resistance and high temperature resistance, which can ensure the stability of the voltage protection class of the gas discharge tube.

In another embodiment of the present application, the insulating tube body 200 is a tube body made of polytetrafluoroethylene.

It should be noted that the polytetrafluoroethylene is a polymer compound formed by the polymerization of tetrafluoroethylene and has excellent chemical stability, corrosion resistance, tightness, electrical insulation and good resistance to aging.

In the gas discharge tube provided by the present embodiment, the tube body made of polytetrafluoroethylene has stable mechanical and chemical properties, which can ensure the structural stability of the gas discharge tube, and the tube body made of polytetrafluoroethylene has excellent arc resistance and high temperature resistance in the low-voltage system, which has good stability of the voltage protection class of the gas discharge tube can ensure.

• Vorbereiten von zwei Elektroden, und Herstellen von zwei Elektronenemittern 400 aus Graphitpulvern von 70%-100% und Titandioxidpulvern von 0%-30%;
• Befestigen der jeweiligen Elektronenemitter 400 an den entsprechenden Elektroden 100;

The present embodiment further provides a gas discharge tube manufacturing method, the gas discharge tube manufacturing method being used to manufacture the above gas discharge tube, and the gas discharge tube manufacturing method comprising:

• preparing two electrodes, and fabricating two electron emitters 400 from graphite powders of 70%-100% and titanium dioxide powders of 0%-30%;
• attaching the respective electron emitters 400 to the corresponding electrodes 100;

Fixing the two electrodes 100 using a mold in an electronegative gas environment, pouring liquid epoxy resin or liquid polytetrafluoroethylene on the outer periphery of the two electrodes 100 to form an insulating tubular body 200.

The manufacturing method for a gas discharge tube provided by the present embodiment can integrate the complicated operations in the conventional process such as cleaning the surface of the electrode 100, preparing the electronic powder, applying the electronic powder coating, drying the electronic powder coating and placing the gas discharge tube Avoid drying vessel for storage after drying the gas discharge tube, this greatly simplifies the manufacturing process, the labor cost is low, and the gas discharge tube produced by the above method has a stable and low breakdown voltage, which excellently meets the electrical requirements of the electrical components for low breakdown voltage can.

• Mischen von Graphitpulvem mit einem Massenanteil von 70%-100% und Titandioxidpulvern mit einem Massenanteil von 0%-30% bis zu einem gleichmäßigen Zustand, um ein erstes gemischtes Pulver zu erhalten, und Formen des ersten gemischten Pulvers;

In another embodiment of the present application, the step of manufacturing the two electron emitters 400 includes the following:

• Mixing of graphite powders with a mass fraction of 70%-100% and titanium dioxide powders with a mass fraction of 0%-30% up to one uniform state to obtain a first mixed powder, and shaping the first mixed powder;

introducing the first mixed powder after molding into a sintering apparatus for sintering, wherein the sintering temperature is 1500°C-2000°C.

In particular, the first mixed powder can be shaped in various ways such as compression molding or extrusion, which can be selected according to need and is not particularly limited here.

The electron emitter 400 manufactured by the above gas discharge tube manufacturing method is sintered at an appropriate sintering temperature, the structure has good uniformity and relatively good electromechanical properties, which is conducive to the gas discharge tube maintaining a stable breakdown voltage.

• Mischen von Graphitpulvem mit einem Massenanteil von 70%-100% und Titandioxidpulvern mit einem Massenanteil von 0%-30% bis zu einem gleichmäßigen Zustand, um ein zweites gemischtes Pulver zu erhalten, und Zugeben von einem Bindemittel ins zweite gemischte Pulver;
• Einbringen des zweiten gemischten Pulver mit dem Bindemittel in eine Form und Herstellen eines Presslings;

In another embodiment of the present application, the step of manufacturing the two electron emitters 400 includes the following:

• mixing graphite powders of 70%-100% by weight and titanium dioxide powders of 0%-30% by weight to a uniform state to obtain a second mixed powder, and adding a binder to the second mixed powder;
• placing the second mixed powder with the binder in a mold and making a compact;

Put the compact in a baking apparatus for baking, the baking temperature being 150°C-200°C.

Specifically, the binder may be polyethylene oxide or polyvinyl alcohol, and may be selected according to need, which is not specifically limited here.

With the above manufacturing method for a gas discharge tube, the electron emitter 400 is manufactured, which consumes less fuel and has a low cost, and after baking at a suitable temperature, the binder in the electron emitter 400 is completely vaporized, which is conducive to the insulating gas in the gas discharge tube to maintain a high level of purity.

In another embodiment of the present application, fixing the respective electron emitters to the corresponding electrodes 100 includes: punching the emitter of the electrode 100 into the corresponding electrode 100 using an external machining device; or casting the corresponding electrode 100 on the outer periphery of the electron emitter 400.

The gas discharge tube manufacturing method provided by the present embodiment can fix the electron emitter 400 with the corresponding electrode 100 easily and quickly, which has good production efficiency and low production cost.

The above content only represents preferred exemplary embodiments of the present application, the present application is not limited thereto. All changes, equivalent substitutions, and improvements made under the spirit and principles of the present application should be construed as being within the scope of the present application.

Claims (6)

A gas discharge tube, characterized in that it comprises two electrodes and an insulating tube body for forming an accommodating cavity by enclosing with the two electrodes, the accommodating cavity being used for accommodating insulating gas, and an electron emitter fixed to a surface of the electrodes located in the accommodating cavity and wherein the electron emitter contains graphite in a mass fraction of 70%-100% and titanium dioxide in a mass fraction of 0%-30%. gas discharge tube claim 1 , characterized in that a surface of the electrodes located in the accommodating cavity is provided with a depressed portion, the corresponding electron emitter being firmly embedded in the depressed portion. gas discharge tube claim 1 , characterized in that a surface of the electrodes located in the accommodating cavity is provided with a protruding portion, the corresponding electron emitter being fixed in the protruding portion and covering the protruding portion. gas discharge tube claim 1 , characterized in that the insulating gas in the receiving cavity is an electronegative gas. gas discharge tube claim 1 characterized in that the accommodating cavity is used for accommodating one or more of carbon tetrafluoride gas, sulfur hexafluoride gas, a mixed gas of heptafluorobutyronitrile gas and nitrogen, a mixed gas of heptafluoroisobutyronitrile gas and carbon dioxide. Gas discharge tube according to one of Claims 1 until 5 characterized in that the insulating tube body is a polytetrafluoroethylene tube body or an epoxy resin tube body.

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