JP3150958U - Discharge tube - Google Patents

Abstract

Disclosed is a discharge delay caused by an increase in a discharge start voltage when used in the dark or in a high temperature environment, and stable continuous over a long time when operated repeatedly in a short cycle. Discharge tubes having discharge characteristics are provided. Both ends of a cylindrical case member 12 are hermetically sealed with a pair of lid members that also serve as discharge electrodes to form an airtight envelope, and a discharge gas is contained in the airtight envelope. In addition, a discharge gap is formed between the discharge electrode portions 18 and 18 of the lid member, and both ends thereof are disposed on the inner wall surface 24 of the case member 12 with a small discharge gap therebetween. A plurality of trigger discharge films 28 are formed, and a plurality of holes 29 arranged on the circles X and Y concentric with the inner wall surface 24 of the cylindrical case member 12 are formed on the surface of the discharge electrode portion 18. At the same time, a film containing titanium, cesium molybdate, potassium molybdate and zirconium silicate was formed on the inner surface of the hole 29. [Selection] Figure 13

Description

  The present invention relates to a discharge tube, in particular, as a switching spark gap for supplying a constant voltage for lighting or ignition to a high-pressure discharge lamp such as a projector or a metal halide lamp of an automobile, or an ignition plug of a gas cooker, or The present invention relates to a discharge tube that can be suitably used as a gas arrester for absorbing surge voltage.

As this type of discharge tube, the present applicant has previously proposed Utility Model Registration No. 3141985.
As shown in FIG. 18, the discharge tube 60 is hermetically sealed with a pair of lid members 64, 64 that also serve as discharge electrodes, at both ends of a cylindrical case member 62 made of an insulating material that opens at both ends. Thus, an airtight envelope 66 is formed, and a predetermined discharge gas is sealed in the airtight envelope 66.

The lid member 64 includes a flat discharge electrode portion 68 that protrudes greatly toward the center of the hermetic envelope 66, and a joint portion 70 that contacts the end surface of the case member 62. A predetermined discharge gap 72 is formed between the discharge electrode portions 68 and 68.
Further, a plurality of linear trigger discharge films 78 are formed on the inner wall surface 74 of the case member 62 so that both ends thereof are opposed to the lid members 64 and 64 that also serve as discharge electrodes with a minute discharge gap 76 therebetween. Has been.

On the surface of the discharge electrode portion 68, titanium (Ti), cesium molybdate (Cs ₂ MoO ₄ ), magnesium oxide (MgO), potassium molybdate (K ₂ MoO ₄ ), and rubidium molybdate (Rb ₂ MoO ₄ ). A film 80 containing is formed.

In the discharge tube 60 having the above-described configuration, when a voltage equal to or higher than the discharge start voltage of the discharge tube 60 is applied between the pair of lid members 64 and 64 that also serve as discharge electrodes, the trigger discharge film 78 is provided. The electric field is concentrated in the minute discharge gap 76 between the both ends of the cover member 64 and the lid members 64, 64, whereby electrons are emitted into the minute discharge gap 76 to generate creeping corona discharge as a trigger discharge. Next, this creeping corona discharge shifts to glow discharge due to an electron priming effect. Then, this glow discharge is transferred to the discharge gap 72 between the discharge electrode portions 68 and 68, and is transferred to arc discharge as the main discharge.
Utility model registration No. 3141985

  The discharge tube 60 is used in the dark and in a high temperature environment by forming a coating 80 containing titanium, cesium molybdate, magnesium oxide, potassium molybdate and rubidium molybdate on the surface of the discharge electrode portion 68. In this case, it has excellent characteristics capable of suppressing a discharge delay caused by an increase in the discharge start voltage.

  However, depending on the use conditions of the discharge tube, such as when the discharge tube is used as a switching spark gap, for example, not only the above characteristics, but also a stable continuous over a long time when operated repeatedly in a short cycle. Discharge characteristics may be required.

  The present invention has been made in view of the above-described conventional problems, and its object is to suppress a discharge delay caused by an increase in discharge start voltage when used in the dark and in a high temperature environment. It is also possible to realize a discharge tube having a continuous discharge characteristic that is stable over a long period of time when it is repeatedly operated at a short cycle.

As a result of various investigations on materials to be included in the coating, the present inventors have found that titanium (Ti), cesium molybdate (Cs ₂ MoO ₄ ), potassium molybdate (K ₂ MoO ₄ ), and zirconium silicate (ZrSiO _4). ) In the case where the coating is formed, it is possible to suppress a discharge delay due to an increase in the discharge start voltage when used in the dark and in a high temperature environment, and when it is repeatedly operated in a short cycle. It has been found that stable continuous discharge characteristics can be obtained over a long period of time, and the present invention has been completed.
That is, a first discharge tube according to the present invention is a discharge tube in which a plurality of discharge electrodes are arranged with a discharge gap and sealed together with a discharge gas in an airtight envelope. A film containing titanium, cesium molybdate, potassium molybdate, and zirconium silicate is formed on the surface.

  The second discharge tube according to the present invention is a discharge tube in which a plurality of discharge electrodes are arranged with a discharge gap and sealed together with a discharge gas in an airtight envelope. A large number of holes are formed on the surface, and a film containing titanium, cesium molybdate, potassium molybdate and zirconium silicate is formed on the inner surface of the hole.

  Furthermore, the third discharge tube according to the present invention forms an airtight envelope by hermetically sealing the both end openings of the cylindrical case member with a pair of lid members that also serve as discharge electrodes, A discharge gas is enclosed in the hermetic envelope, and a discharge gap is formed between the discharge electrode portions of the lid member arranged in the hermetic envelope, and both ends of the case member are formed on the inner wall surface of the case member. In the discharge tube formed by forming a plurality of trigger discharge films arranged with a gap between the lid member and the micro discharge gap, the surface of the discharge electrode portion is formed on a circle concentric with the inner wall surface of the cylindrical case member. And a coating film containing titanium, cesium molybdate, potassium molybdate, and zirconium silicate is formed on the inner surface of the hole.

  The titanium, cesium molybdate, potassium molybdate and zirconium silicate are contained in an amount of 0.01 to 50% by weight of titanium, 0.01 to 50% by weight of cesium molybdate, and 0.01 to 50 of potassium molybdate. It is preferable that the weight percentage of zirconium silicate is 0.01 to 50 weight%.

  In the first to third discharge tubes according to the present invention, the surface of the discharge electrode (discharge electrode portion) contains titanium, cesium molybdate, potassium molybdate, and zirconium silicate. As a result, it is possible to suppress a delay in discharge caused by an increase in the discharge start voltage when used in the dark and in a high temperature environment, and it is stable for a long time when operated repeatedly in a short cycle. Continuous discharge characteristics can be realized.

  Further, in the second discharge tube, by forming a large number of holes on the surface of the discharge electrode part and forming a film on the inner surface of the hole part, the adhesion between the discharge electrode part and the film is improved, There is an effect of suppressing spattering of the coating film due to an impact during discharge.

The coating is easily sputtered by the impact at the time of discharge, and the constituent material of the coating (hereinafter referred to as spatter scattered) deposited by sputtering adheres to and accumulates on the inner wall surface of the case member and the trigger discharge film. This is a cause of voltage instability, and in particular, the amount of spatter scattered is different for each part of the inner wall surface of the case member and the trigger discharge film, which promotes instability of the discharge start voltage. It is a big factor.
In the third discharge tube according to the present invention, a large number of holes where the coating is formed are arranged on a circle concentric with the inner wall surface of the cylindrical case member, so that they are arranged on the same circle. The distances between the holes and the inner wall surface of the case member are all the same.
For this reason, it is possible to suppress the occurrence of a slight difference in the amount of spatter scattered on a specific portion of the inner wall surface of the case member and a specific trigger discharge film, and the spatter scattering on the inner wall surface of the case member and the trigger discharge film. Since the accumulation amount of the material is leveled, the discharge start voltage can be stabilized.

  A first discharge tube 10 according to the present invention shown in FIGS. 1 and 2 has a pair of lids that serve as discharge electrodes at both ends of a cylindrical case member 12 made of ceramic as an insulating material having both ends open. The hermetic envelope 16 is formed by hermetically sealing with the members 14 and 14.

The lid member 14 includes a substantially cylindrical discharge electrode portion 18 projecting greatly toward the center of the hermetic envelope 16, and a joint portion 20 in contact with the end surface of the case member 12, and both lid members 14, 14 A predetermined discharge gap 22 is formed between the discharge electrode portions 18 and 18.
The lid member 14 provided with the discharge electrode portion 18 and the joint portion 20 is made of oxygen-free copper or zirconium copper containing oxygen-free copper containing zirconium (Zr). Note that the end face of the case member 12 and the joint portion 20 of the lid member 14 are hermetically sealed through a sealing material (not shown) such as silver solder.

In addition, a plurality of linear trigger discharge films 28 are formed on the inner wall surface 24 of the case member 12 so that both ends of the case member 12 are spaced apart from the lid members 14 and 14 that also serve as discharge electrodes and a minute discharge gap 26. ing. 1 and 2 exemplify a case where eight trigger discharge films 28 are formed at equal intervals of 45 degrees in the circumferential direction of the inner wall surface 24 of the case member 12.
The trigger discharge film 28 is made of a conductive material such as a carbon-based material. The trigger discharge film 28 can be formed, for example, by rubbing a core material made of a carbon-based material.

A film 30 containing titanium (Ti), cesium molybdate (Cs ₂ MoO ₄ ), potassium molybdate (K ₂ MoO ₄ ), and zirconium silicate (ZrSiO ₄ ) is formed on the surface of the discharge electrode portion 18. Has been.

The coating 30 is formed by the following method.
First, a binder obtained by dissolving sodium silicate in pure water, titanium hydride (TiH ₂ ) powder, cesium molybdate powder, potassium molybdate powder, and zirconium silicate powder are prepared.
Next, titanium hydride (TiH ₂ ) powder, cesium molybdate powder, potassium molybdate powder, and zirconium silicate powder are added to the binder, followed by stirring.
Next, the binder to which titanium hydride (TiH ₂ ) powder, cesium molybdate powder, potassium molybdate powder, and zirconium silicate powder are added is applied to the surface of the discharge electrode portion 18.
Then, in the hermetic sealing step between the case member 12 and the lid member 14, when the case member 12 is evacuated while heating the case member 12, the moisture in the binder evaporates in the heating process, In addition, high purity titanium can be formed by removing hydrogen (H) in titanium hydride (TiH ₂ ).
As a result, the coating film 30 containing titanium, cesium molybdate, potassium molybdate, and zirconium silicate is formed on the surface of the discharge electrode portion 18.

The content of titanium, cesium molybdate, potassium molybdate and zirconium silicate is 0.01 to 50% by weight of titanium, 0.01 to 50% by weight of cesium molybdate, and 0.01 to 50 of potassium molybdate. % By weight and zirconium silicate of 0.01 to 50% by weight suppress the rise of the discharge start voltage when used in the dark and in a high temperature environment, and a long time when repeatedly operated in a short cycle From the viewpoint of stable continuous discharge characteristics.
Moreover, the compounding ratio of titanium, cesium molybdate, potassium molybdate and zirconium silicate and the binder is 10 to 90% by weight for titanium, cesium molybdate, potassium molybdate and zirconium silicate, and 10 to 90% by weight for the binder. %.
The blending ratio of sodium silicate and pure water in the binder is such that sodium silicate is 0.01 to 70% by weight and pure water is 99.99 to 30% by weight.

A predetermined discharge gas is sealed in the hermetic envelope 16. As this discharge gas, for example, a discharge gas configured by mixing hydrogen (H ₂ ) in a mixed gas of neon (Ne) and argon (Ar) is applicable.

  In the first discharge tube 10 of the present invention, when a voltage equal to or higher than the discharge start voltage of the discharge tube 10 is applied between the pair of lid members 14 and 14 also serving as discharge electrodes, a trigger discharge is generated. The electric field concentrates in the minute discharge gap 26 between the both ends of the film 28 and the lid members 14 and 14, whereby electrons are emitted into the minute discharge gap 26 to generate creeping corona discharge as a trigger discharge. Next, this creeping corona discharge shifts to glow discharge due to an electron priming effect. Then, the glow discharge is transferred to the discharge gap 22 between the discharge electrode portions 18 and 18, and the arc discharge as the main discharge is transferred.

In the first discharge tube 10 of the present invention, a coating 30 containing titanium, cesium molybdate, potassium molybdate, and zirconium silicate is formed on the surface of the discharge electrode portion 18, so that it is dark and high temperature. Achieving stable continuous discharge characteristics over a long period of time when it is possible to suppress a discharge delay due to an increase in the discharge start voltage when used in an environment and when it is repeatedly operated in a short cycle. Can do.
In addition, it is possible to suppress the discharge delay due to the increase of the discharge starting voltage when used in the dark and in a high temperature environment by containing titanium, cesium molybdate, potassium molybdate and zirconium silicate. When 30 is configured, it is considered that, even when placed in the dark and in a high temperature environment, emission of impure gas in the coating 30 is suppressed, and a stable discharge with good electron emission characteristics can be obtained.

  FIGS. 3 to 6 show a second discharge tube 40 according to the present invention. The second discharge tube 40 has a number of substantially rectangular parallelepiped holes 29 on the surface of the discharge electrode portion 18. It is arranged and formed in a substantially matrix shape, and is characterized in that a coating 30 containing titanium, cesium molybdate, potassium molybdate and zirconium silicate is formed on the inner surface of each hole 29. This is substantially the same as the first discharge tube 10.

Even in the second discharge tube 40 of the present invention, the surface of the discharge electrode portion 18 contains titanium, cesium molybdate, potassium molybdate, and zirconium silicate, as in the first discharge tube 10. By forming the coated film 30, it is possible to suppress a discharge delay due to an increase in the discharge start voltage when used in the dark and in a high temperature environment, and for a long time when repeatedly operating in a short cycle. A stable continuous discharge characteristic can be realized.
The second discharge tube 40 has a large number of hole portions 29 formed on the surface of the discharge electrode portion 18 and the coating 30 is formed on the inner surface of the hole portion 29 so that the discharge electrode portion 18 and the coating 30 are in close contact with each other. The force is improved, and the effect of suppressing the spattering of the coating film 30 due to the impact during discharge is achieved.

FIG. 7 shows a pulse voltage applied to the HID lamp when the second discharge tube 40 according to the present invention is incorporated in an igniter circuit for use as a switching spark gap for HID lamp lighting and is repeatedly operated at a cycle of 20 ms. FIG. 8 shows a comparison using a film containing titanium, cesium molybdate, magnesium oxide, potassium molybdate, and rubidium molybdate instead of the film 30 of the second discharge tube 40. It is a chart which shows transition of the pulse voltage applied to an HID lamp when an example discharge tube is incorporated in an igniter circuit for use as a switching spark gap for HID lamp lighting and is repeatedly operated at a cycle of 20 ms.
That is, as shown in FIG. 9, the igniter circuit 41 includes a power source E, a resistor R, a capacitor C, a second discharge tube 40, a pulse transformer 43, and an HID lamp 45, and the capacitor C stores the accumulated power. When electric charge is applied as a voltage pulse to the primary side of the pulse transformer 43 through the second discharge tube 40, a high voltage pulse is generated from the secondary side of the pulse transformer 43, and this high voltage pulse is generated by the HID lamp. By being supplied to 45, the HID lamp 45 is turned on.
In this test, a second discharge tube 40 having a discharge start voltage of 200 V, a discharge tube of a comparative example, and a pulse transformer 43 having a step-up ratio of 10 were used. The titanium content in the coating 30 of the second discharge tube 40 is 2.21% by weight, the cesium molybdate content is 6.64% by weight, the potassium molybdate content is 2.21% by weight, The content ratio of zirconium silicate is 0.44% by weight.
Thus, as shown in the chart of FIG. 7, the second discharge tube 40 according to the present invention has a stable pulse voltage of about ± 2000 V, and the stable waveform shown in FIG. In addition, stable continuous discharge characteristics were obtained over a long period of time.
On the other hand, as shown in the chart of FIG. 8, the discharge tube of the comparative example was unstable due to variations in the pulse voltage, and the variation occurred in the pulse voltage only 3 to 5 minutes after the start of operation.

FIG. 10 is a graph showing a relationship between the number of discharges in the dark of the second discharge tube 40 according to the present invention and the initial discharge start voltage, and FIG. 11 is a graph of the second discharge tube 40 according to the present invention in the dark. It is a graph which shows the relationship between the frequency | count of discharge and follow-up discharge start voltage.
The initial discharge start voltage refers to the first discharge start voltage when the discharge tube is repeatedly operated, and the second and subsequent discharge start voltages subsequent to the initial discharge start voltage are referred to as follow-up discharge start voltages.
As test conditions, AC200V was applied, and ON and OFF were repeated every 30 s.
As shown in the graphs of FIGS. 10 and 11, the second discharge tube 40 of the present invention has little increase in initial discharge start voltage and follow-up discharge start voltage even in the case where the number of discharges reaches 30 million times, and in the dark. It can be seen that the discharge delay when used is suppressed.

12 to 15 show a third discharge tube 50 according to the present invention. This third discharge tube 50 has a number of substantially hemispherical hole portions 29 formed on the surface of the discharge electrode portion 18. The inner surface of each hole 29 is characterized in that the coating 30 containing titanium, cesium molybdate, potassium molybdate and zirconium silicate is formed. It is substantially the same as the discharge tube 10.
As shown in FIGS. 13 and 15, the holes 29 are formed at equal intervals on circles (hereinafter referred to as concentric circles) X and Y that are concentric with the inner wall surface 24 of the cylindrical case member 12. . That is, twelve hole portions 29 are formed on the concentric circle X at equal intervals of 30 degrees, and four hole portions 29 are formed on the concentric circle Y at equal intervals of 90 degrees. A single hole 29 is also arranged and formed at the center of the cylindrical case member 12.
The concentric circles X and Y in FIGS. 13 and 15 are virtual circles shown for convenience of explanation.

Note that the shape of the hole 29 formed on the surface of the discharge electrode portion 18 is not limited to the “substantially hemispherical shape” described above, and is shown in a modification of the third discharge tube 50 in FIGS. 16 and 17. Thus, it may be “substantially rectangular parallelepiped”.
However, the case where the hole 29 is formed to be “substantially hemispherical” is preferable because the state of the coating 30 can be stabilized and variations in discharge characteristics can be reduced. That is, when the hole portion 29 is formed to be “substantially hemispherical”, the surface tension is uniformly applied from all directions of the hole portion 29, and as a result, the coating film 30 is formed uniformly in all directions. This stabilizes the state and can reduce variations in discharge characteristics.

  Even in the third discharge tube 50 of the present invention, similarly to the first discharge tube 10, the surface of the discharge electrode portion 18 contains titanium, cesium molybdate, potassium molybdate, and zirconium silicate. By forming the coated film 30, it is possible to suppress a discharge delay due to an increase in the discharge start voltage when used in the dark and in a high temperature environment, and for a long time when repeatedly operating in a short cycle. A stable continuous discharge characteristic can be realized.

Note that the coating 30 is easily sputtered by an impact at the time of discharge, and the spatter scattered on the inner wall surface 24 and the trigger discharge film 28 of the case member 12 causes the discharge start voltage to become unstable. In particular, the fact that the amount of spatter scattered is different for each part of the inner wall surface 24 and the trigger discharge film 28 of the case member 12 is a major factor that promotes instability of the discharge start voltage. .
That is, when the holes 29 in which the coating 30 is formed are arranged in a matrix on the surface of the discharge electrode portion 18 as in the above-described discharge tube 40, the inner wall surface 24 of the cylindrical case member 12 Since the distance to each hole 29 varies, the amount of spatter scattered on the inner wall surface 24 and the trigger discharge film 28 of the case member 12 at a location where the distance from the hole 29 is small increases. Since the amount of spatter scattered on the inner wall surface 24 and the trigger discharge film 28 of the case member 12 at a location where the distance from the portion 29 is large is small, the discharge start voltage may become unstable.
On the other hand, in the third discharge tube 50 according to the present invention, the numerous holes 29 in which the coating 30 is formed are arranged on the circles X and Y concentric with the inner wall surface 24 of the cylindrical case member 12. Therefore, the distances between the holes 29 arranged on the same circle X or Y and the inner wall surface 24 of the case member 12 are all the same.
For this reason, it is possible to suppress the occurrence of a slight difference in the amount of spatter scattered in a specific portion of the inner wall surface 24 of the case member 12 and a specific trigger discharge film 28, and the inner wall surface 24 and trigger discharge of the case member 12 can be suppressed. Since the amount of spatter scattered on the film 28 is leveled, the discharge start voltage can be stabilized.

It is a schematic sectional drawing which shows the 1st discharge tube which concerns on this invention. It is an AA schematic sectional drawing of FIG. It is a schematic sectional drawing which shows the 2nd discharge tube which concerns on this invention. It is a BB schematic sectional drawing of FIG. It is a principal part expanded sectional view of the 2nd discharge tube which concerns on this invention. It is an enlarged view which shows the discharge electrode part surface of the 2nd discharge tube which concerns on this invention. It is a chart which shows transition of the pulse voltage applied to an HID lamp when the 2nd discharge tube concerning the present invention is built in an igniter circuit, and it is made to operate repeatedly at a cycle of 20 ms. It is a chart which shows transition of the pulse voltage applied to a HID lamp when a discharge tube of a comparative example is incorporated in an igniter circuit and is repeatedly operated at a cycle of 20 ms. It is a circuit diagram which shows the igniter circuit incorporating the 2nd discharge tube which concerns on this invention. It is a graph which shows the relationship between the frequency | count of discharge in the dark of the 2nd discharge tube which concerns on this invention, and an initial stage discharge start voltage. It is a graph which shows the relationship between the frequency | count of discharge in the dark of the 2nd discharge tube which concerns on this invention, and a follow-up discharge start voltage. It is a schematic sectional drawing which shows the 3rd discharge tube which concerns on this invention. It is CC schematic sectional drawing of FIG. It is a principal part expanded sectional view of the 3rd discharge tube which concerns on this invention. It is an enlarged view which shows the discharge electrode part surface of the 3rd discharge tube which concerns on this invention. It is an enlarged view which shows the discharge electrode part surface of the modification of the 3rd discharge tube which concerns on this invention. It is a principal part expanded sectional view of the modification of the 3rd discharge tube which concerns on this invention. It is a schematic sectional drawing which shows the conventional discharge tube.

10 First discharge tube
12 Case material
14 Lid member
16 Airtight envelope
18 Discharge electrode
20 joints
22 Discharge gap
24 Inner wall surface of case member
26 Micro discharge gap
28 Trigger discharge membrane
29 holes
30 coating
40 Second discharge tube
50 Third discharge tube X A circle Y concentric with the inner wall surface of the cylindrical case member Y A circle concentric with the inner wall surface of the cylindrical case member

Claims (4)

  In a discharge tube in which a plurality of discharge electrodes are arranged with a discharge gap and sealed together with a discharge gas in an airtight envelope, titanium, cesium molybdate, potassium molybdate and A discharge tube characterized in that a film containing zirconium silicate is formed.   In the discharge tube in which a plurality of discharge electrodes are arranged with a discharge gap and sealed in a hermetic envelope together with a discharge gas, a plurality of holes are formed on the surface of the discharge electrode, and A discharge tube characterized in that a film containing titanium, cesium molybdate, potassium molybdate and zirconium silicate is formed on the inner surface of the hole.   A hermetic envelope is formed by hermetically sealing both ends of the cylindrical case member with a pair of lid members that also serve as discharge electrodes, and a discharge gas is sealed in the hermetic envelope, In addition, a discharge gap is formed between the discharge electrode portions of the lid member arranged in the hermetic envelope, and both ends of the case member are arranged on the inner wall surface of the case member with a minute discharge gap therebetween. In the discharge tube formed by forming a plurality of trigger discharge films, on the surface of the discharge electrode portion, a number of holes are arranged on a circle concentric with the inner wall surface of the cylindrical case member, A discharge tube characterized in that a coating containing titanium, cesium molybdate, potassium molybdate and zirconium silicate is formed on the inner surface of the hole.   The titanium, cesium molybdate, potassium molybdate and zirconium silicate are contained in an amount of 0.01 to 50% by weight of titanium, 0.01 to 50% by weight of cesium molybdate, and 0.01 to 50 of potassium molybdate. The discharge tube according to any one of claims 1 to 3, wherein the weight percent and zirconium silicate are 0.01 to 50 weight percent.

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