JP2005071974A - Surge absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surge absorber without the possibility of damaging a glass tube by discharge, capable of reducing the size and the cost, and easy to manufacture. <P>SOLUTION: On the surge absorber 10-1, electrodes 30, 30 are mounted on the opposing faces of a pair of sealing electrodes 20, 20 respectively, and the pair of electrodes 30, 30 are inserted into an insulation tube 40 from both sides thereof with a prescribed distance between them. The insulation tube 40 in which the electrodes 30, 30 are inserted, and the sealing electrodes 20, 20 are housed in the glass tube 50, and the boundary between the end parts of the glass tube 50 and the sealing electrodes 20, 20 are sealed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a surge absorber that releases a surge current by discharging.

  There is a risk that a surge current from lightning or the like may enter the electronic device and destroy it. Therefore, conventionally, a surge absorber is attached in order to release this surge current by discharging, thereby protecting the electronic equipment.

  Here, as shown in FIG. 5, the conventional surge absorber houses the surge absorbing element 100 in a glass tube 110 filled with a predetermined gas, and seals both ends of the glass tube 110 with sealing electrodes 120 and 120. In addition, the sealing electrodes 120 and 120 are configured to be in contact with terminal electrodes 108 and 108 attached to both ends of the surge absorbing element 100. In the surge absorbing element 100, a conductive film 103 is formed on the surface of a rod-shaped insulator 101, a discharge trigger gap 105 for dividing the conductive film 103 is provided at the center thereof, and cap-shaped terminal electrodes 108, 108 are provided at both ends. It is configured with an attached. When a surge current is applied between the lead terminals 121 and 121 attached to the sealing electrodes 120 and 120, first, a discharge is generated in the discharge trigger gap 105, and the insulation in the glass tube 110 is broken, whereby both terminal electrodes 108, Discharge starts between 108.

  However, in the above conventional surge absorber, the conductive film 103 is formed on the surface of the insulator 101 and the discharge trigger gap 105 is provided by laser cutting, or the terminal electrodes 108 and 108 are attached to both ends of the surge absorbing element 100. Thus, the production is complicated, and the cost cannot be reduced.

  In the conventional surge absorber, the discharge light is discharged along the inner wall of the glass tube 110 when absorbing the surge, thereby damaging the glass tube 110, and thus a surge current is repeatedly applied. The glass tube 110 may be damaged.

Further, in the conventional surge absorber described above, it is necessary to secure a space necessary for discharge between the surge absorbing element 100 installed in the center and the glass tube 110 covering the periphery thereof, so that downsizing of the inner diameter of the glass tube 110 is limited. For this reason, the surge absorber cannot be downsized.
JP 2001-135455 A

  The present invention has been made in view of the above points, and an object of the present invention is to provide a surge absorber that can be easily manufactured and reduced in cost.

  Another object of the present invention is to provide a surge absorber that can be reduced in size without fear of damaging the glass tube.

  The invention according to claim 1 of the present application includes a pair of sealing electrodes each having an electrode attached to an opposing surface, an insulating tube that accommodates the pair of electrodes on both sides thereof, an insulating tube that accommodates the electrode, and a sealing tube. A surge absorber characterized by comprising a stop electrode and a glass tube sealed between the sealing electrode and a predetermined gas introduced into the glass tube.

  The invention according to claim 2 of the present application is the surge absorber according to claim 1, wherein conductive powder for inducing discharge is scattered and adhered to the inner wall of the insulating tube.

  The invention according to claim 3 of the present application includes a pair of sealing electrodes each having an electrode attached to the opposing surface, an insulating plate on which the pair of electrodes are installed on both sides, and an insulating plate on which the electrodes are installed. And a sealing electrode, and a glass tube sealed between the sealing electrode and a predetermined gas introduced into the glass tube.

  According to a fourth aspect of the present invention, the surge according to the third aspect is characterized in that a conductive portion for inducing a discharge is provided in an intermediate portion of the surface on which the pair of electrodes of the insulating plate is installed. It is an absorber.

  According to the surge absorber of the first aspect, the manufacture of the surge absorber is facilitated, and the cost can be reduced. In addition, since the discharge is performed in the insulating tube, the discharge light is not discharged along the inner wall of the glass tube, and thus the glass tube is not damaged. Therefore, even if a surge current is repeatedly applied, the glass tube is not damaged. The tube will not break. Moreover, since it does not break even if a large current flows, the pressure resistance is improved. Further, in this surge absorber, a space (discharge space) necessary for discharge can be secured in the central portion (inside the insulating tube), so that the outer diameter of the glass tube can be reduced and the surge absorber can be reduced in size.

  According to the surge absorber according to claim 2, since the conductive powder adheres to the inner wall of the insulating tube, the discharge start voltage is stabilized substantially constant even if the application speed of the surge voltage to the surge absorber changes. Can do.

  According to the surge absorber of claim 3, the manufacture of the surge absorber is facilitated, and the cost can be reduced. In addition, although a portion of the electrode is covered with an insulating plate, a portion of the discharge light along the inner wall of the glass tube is reduced and damage to the glass tube can be reduced. The tube will not break.

  According to the surge absorber according to claim 4, since the discharge inducing conductive portion is provided in the middle portion of the surface on which the pair of electrodes of the insulating plate is installed, the application speed of the surge voltage to the surge absorber changes. However, the discharge start voltage can be stabilized substantially constant.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic cross-sectional view of a surge absorber 10-1 according to an embodiment of the present invention. As shown in the figure, the surge absorber 10-1 has electrodes 30 and 30 attached to opposing surfaces of a pair of sealing electrodes 20 and 20, respectively, and these pair of electrodes 30 and 30 are inserted from both sides of the insulating tube 40. The insulating tube 40 and the sealing electrodes 20 and 20 that house the electrodes 30 and 30 are housed in a tube 50 (hereinafter referred to as “glass tube”) filled with a predetermined gas. Both ends of the tube 50 are sealed with the sealing electrodes 20 and 20. Lead terminals 60, 60 are attached to the outer surfaces of the sealing electrodes 20, 20. Each component will be described below.

  The sealing electrodes 20 and 20 are formed in a columnar shape, and the material thereof is constituted by a jumet wire that is a special metal (copper-coated iron-nickel alloy wire) having high adhesion to glass.

  The electrodes 30 and 30 are formed in a cylindrical shape having a smaller diameter than the sealing electrodes 20 and 20, and the material thereof is made of metal, for example, nickel, nickel chrome, or tungsten.

  The insulating tube 40 is formed in a cylindrical shape whose inner diameter is slightly larger than the outer diameter of the electrode 30 and whose outer diameter is smaller than the outer diameter of the sealing electrode 20, and the material thereof is made of ceramic, for example, alumina. Has been.

  The glass tube 50 is formed in a cylindrical shape whose inner diameter is slightly larger than the outer diameter of the sealing electrode 20.

  Next, the manufacturing method of this surge absorber 10-1 is demonstrated. First, as shown to Fig.2 (a), the electrodes 30 and 30 are each previously attached to the opposing surface of a pair of sealing electrodes 20 and 20 by welding (spot welding). Lead terminals 60 and 60 are attached to the opposite surfaces of the sealing electrodes 20 and 20 by welding (spot welding), respectively.

  2A, the pair of electrodes 30 are inserted into the insulating tube 40 from both ends of the insulating tube 40, and as shown in FIG. A glass tube 50 is installed so as to surround the outer periphery of the stop electrodes 20 and 20.

  Then, the atmosphere around the glass tube 50 is evacuated in the state shown in FIG. 2 (b), and then an inert gas such as carbon dioxide, argon gas, nitrogen gas, xenon gas is introduced and the atmosphere of these gases is introduced. After that, the glass tube 50 is heated from the surroundings (for example, 700 ° C.), whereby the glass tube 50 is softened and contracted, and welded to the outer periphery of the sealing electrodes 20 and 20. As a result, both ends of the glass tube 50 are sealed, and the inside thereof is completely cut off from the outside and sealed to complete the surge absorber 10-1 shown in FIG.

  That is, the surge absorber 10-1 includes cylindrical sealing electrodes 20 and 20 having a diameter larger than the outer diameter of a pair of electrodes 30 each having cylindrical electrodes 30 and 30 attached to opposite surfaces, and the pair. The cylindrical insulating tube 40 that inserts and positions the electrodes 30 and 30 from both sides into the hollow interior and separates them by a predetermined distance, the insulating tube 40 that stores the electrodes 30 and 30, and the sealing electrodes 20 and 20 are stored. In addition, the cylindrical glass tube 50 is configured to be sealed between the outer peripheral surface of the sealing electrodes 20 and 20 and the inner wall surface thereof. Here, the end surface of the sealing electrode 20 on which the electrode 30 is attached is in contact with the end surface of the insulating tube 40. The inner wall of the glass tube 50 and the outer wall of the insulating tube 40 are configured to be separated from each other by a predetermined dimension. This is because the thermal expansion coefficients of the two are different, so that if they are in contact, the glass tube 50 is broken by high heat when sealing both ends of the glass tube 50, so that this is avoided.

  When a surge current is applied between the lead terminals 60, 60 of the surge absorber 10-1 configured as described above, a discharge is started in the insulating tube 40, and a spark discharge → a glow discharge → an arc discharge. The insulation of the space in the insulating tube 40 is destroyed while changing instantaneously, and eventually, the discharge is performed between the electrodes 30 and 30 by arc discharge.

  In this surge absorber 10-1, since discharge is performed in the strong insulating tube 40, the discharge light is not discharged along the inner wall of the glass tube 50, which is weaker than the insulating tube 40. Therefore, the glass tube 50 is not damaged, and therefore the glass tube 50 is not broken even when a surge current is repeatedly applied. Moreover, since it does not break even if a large current flows, the pressure resistance is improved.

  Further, in this surge absorber 10-1, both ends of the insulating tube 40 are not sealed (the insulating tube 40 is not fixed to the electrodes 30, 30 and the glass tube 50), and sealed with the glass tube 50 having excellent adhesion. Since the inside of the surge absorber 10-1 is sealed by the stop electrodes 20, 20, the inside of the surge absorber 10-1 can be reliably sealed. That is, in the present invention, considering that it is difficult to completely seal the ceramic insulating tube 40 to the electrode 30, the insulating tube 40 and the electrode 30 are not sealed and sealed separately from the glass tube 50 surrounding them. The space between the stop electrodes 20 is sealed.

  Further, in the surge absorber 10-1, since discharge is performed in the central portion thereof, a space (discharge space) necessary for discharge can be ensured in the central portion (inside the insulating tube 40). The diameter can be reduced, and the surge absorber 10-1 can be reduced.

  The surge absorber 10-1 is manufactured by inserting the electrodes 30, 30 attached to the pair of sealing electrodes 20, 20 from both sides of the insulating tube 40, and then connecting the insulating tube 40 and the sealing electrodes 20, 20 together. The glass tube 50 is housed in the glass tube 50, and both ends of the glass tube 50 can be easily sealed by the sealing electrodes 20 and 20. Formation of the conductive film 103 as in the conventional example shown in FIG. 5, laser cutting, etc. Is unnecessary, so the cost can be reduced.

  FIG. 3 is a schematic cross-sectional view of a surge absorber 10-2 according to another embodiment of the present invention. In the figure, the same or corresponding parts as those of the surge absorber 10-1 shown in FIG. In the surge absorber 10-2 shown in the figure, the only difference from the surge absorber 10-1 shown in FIG. That is, the electrode 30 used for the surge absorber 10-2 is formed in a spherical shape. If the electrode 30 is formed in this way, the surge current enters the spherical surface constituting the electrode 30 perpendicularly, so that the incident position of the surge current does not concentrate in one place but is dispersed and incident on the spherical surface. Therefore, the electrode 30 is not easily damaged, and the life of the surge absorber 10-2 can be further increased. The part formed in a spherical shape may be a part of the electrode 30. For example, the opposing surfaces of the pair of electrodes 30, 30 may be spherical. At this time, the electrode 30 is formed in a hemispherical shape, for example. Further, the above-mentioned effect is produced to some extent even if it is constituted by a gulf pole surface other than a spherical surface. The point is that at least the opposing surfaces of the pair of electrodes 30, 30 may be configured in the shape of a bay pole surface.

  FIG. 4 is a schematic cross-sectional view of a surge absorber 10-3 according to still another embodiment of the present invention. In the figure, the same or corresponding parts as those of the surge absorber 10-1 shown in FIG. In the surge absorber 10-3 shown in the figure, the difference from the surge absorber 10-1 shown in FIG. 1 is that the conductive powder 70 for inducing discharge is scattered on the inner wall of the insulating tube 40. Only.

  Here, the conductive powder 70 is, for example, a carbon graphite or carbon black powder having an average particle size of about 15 μm. After the powder is dispersed in the solution, for example, over the entire inner wall of the insulating tube 40, the solution is added to the conductive powder 70. Deposit by evaporation. It is preferable that there is a predetermined separation distance between the conductive powders 70, and it is particularly preferable that the conductive powders are scattered over the entire inner wall surface. The reason why the conductive powder 70 is attached in this way is to prevent the discharge start voltage from changing according to the application speed of the surge voltage to the surge absorber 10-3 and to stabilize the discharge start voltage substantially constant.

  That is, generally, the voltage applied to the surge absorber increases as the voltage is applied more rapidly, and the discharge start voltage in the surge absorber becomes higher. According to the experiment, in the case of the surge absorber 10-1 shown in FIG. 1, when the applied voltage was slowly increased at a rate of 100 (V / sec), the discharge was started at 2 (kV), but 10 k (V / In the case where the applied voltage was suddenly increased in μsec), the discharge was started at 4 (kV).

  Therefore, in this embodiment, the conductive powder 70 is scattered on the inner wall of the insulating tube 40 forming the discharge space. When a surge voltage is applied, first, a discharge (spark discharge or glow) is performed between the conductive powders 70 at a relatively low voltage. Discharge) was started, and thereby, the arc discharge between the electrodes 30 and 30 was smoothly and rapidly transferred. According to the experiment, in the case of the surge absorber 10-3, when the applied voltage is slowly increased at a rate of 100 (V / sec), the discharge starts at 2 (kV), while suddenly at 10 k (V / μsec). When the applied voltage was increased, discharge started at 2.9 (kV). That is, even when a high voltage is applied in a short time compared to the surge absorber 10-1 shown in FIG. 1, the response does not slow down.

  FIG. 6 is a schematic cross-sectional view of a surge absorber 10-4 according to still another embodiment of the present invention (only the glass tube 50 is shown in cross section), and FIG. 6 (a) is a schematic plan cross-sectional view, FIG. 6 (b) is a schematic sectional side view. In this embodiment, the same reference numerals are given to the same or corresponding parts as those of the respective embodiments. In the surge absorber 10-4 shown in the figure, electrodes 30, 30 are respectively attached to the opposing surfaces of the pair of sealing electrodes 20, 20, and the pair of electrodes 30, 30 are arranged on both sides of the surface of the insulating plate 40-4. The insulating plate 40-4 on which the electrodes 30 and 30 are installed and the sealing electrodes 20 and 20 are placed in a tube (hereinafter referred to as “glass tube”) 50 filled with a predetermined gas. The both ends of the glass tube 50 are sealed with the sealing electrodes 20 and 20. Lead terminals 60, 60 are attached to the outer surfaces of the sealing electrodes 20, 20. Each component will be described below.

  The sealing electrodes 20 and 20 are formed in a columnar shape as in the above-described embodiments, and the material thereof is constituted by a special metal (copper-coated iron-nickel alloy wire) having a high degree of adhesion to glass. Has been.

  The electrodes 30 and 30 are formed in a columnar shape having a smaller diameter than the sealing electrodes 20 and 20 as in the above embodiments, and the material thereof is made of metal, for example, nickel, nickel chromium, or tungsten.

  FIG. 7 is a perspective view of the insulating plate 40-4. As shown in the figure, the insulating plate 40-4 has a rectangular and flat base portion 41-4, and faces the longitudinal direction of the upper surface of the base portion 41-4 (the surface on which the pair of electrodes 30 and 30 are installed). By providing four protrusions 43-4 upward from both ends on both the left and right sides, a concave electrode housing 45-4 is formed between each pair of protrusions 43-4 on both ends. The material is made of ceramic, for example, alumina. The width L1 of the electrode housing 45-4 is formed to be substantially the same as or slightly larger than the outer diameter of the electrode 30, and the height L2 of the electrode housing 45-4 is larger than the outer diameter of the electrode 30. The dimensions are slightly smaller. The length L3 of the insulating plate 40-4 in the direction (longitudinal direction) connecting both the electrode storage portions 45-4 and 45-4 is obtained by adding the length of the pair of sealing electrodes 20 and 20 to the length L3. The length of the glass tube 50 is substantially the same as the length of the glass tube 50.

  On the other hand, a conductive portion 47-4 having a conductive pattern for inducing discharge is provided in an intermediate portion of the upper surface of the base portion 41-4 of the insulating plate 40-4. The conductive portion 47-4 is formed of a carbon film in this embodiment, but may be formed of other various conductive materials. In this embodiment, the conductive portion 47-4 is formed by a linear pattern extending in the longitudinal direction of the insulating plate 40-4. However, the conductive portion 47-4 may be formed by a plurality of dot patterns. As in the case of the surge absorber 10-3 shown in Fig. 5, the conductive powder may be attached so as to be scattered. In short, any shape, structure or material can be used as long as the discharge starting voltage can be stabilized substantially constant. It may be.

  The glass tube 50 is formed in a cylindrical shape whose inner diameter is slightly larger than the outer diameter of the sealing electrode 20.

  Next, the manufacturing method of this surge absorber 10-4 is demonstrated. First, as shown in FIG. 8, the electrodes 30 and 30 are previously attached to the opposing surfaces of a pair of sealing electrodes 20 and 20 by welding (spot welding), respectively. Lead terminals 60 and 60 are attached to the opposite surfaces of the sealing electrodes 20 and 20 by welding (spot welding), respectively. Then, one sealing electrode 20 is housed to the bottom in a housing hole 81 having a dimensional shape (circular shape) for housing the glass tube 50 provided in the jig 80 indicated by a dotted line in FIG. The glass tube 50 is inserted so as to surround the outer periphery of the stop electrode 20, then the insulating plate 40-4 is inserted into the glass tube 50, and the other sealing electrode 20 is inserted into the glass tube 50. At this time, both the electrodes 30 and 30 are placed on the upper surface of the insulating plate 40-4 while being housed in the electrode housing portion 45-4 of the insulating plate 40-4. The electrodes 30 and 30 are housed in the electrode housing portions 45-4 and 45-4 in a state of being press-fitted into the electrode housing portion 45-4 according to the dimension of the width L1 (see FIG. 7) of the electrode housing portion 45-4. You can also just insert it. In addition, since both end surfaces of the insulating plate 40-4 are in contact with the opposite end surfaces of the sealing electrodes 20 and 20, the distance between the electrodes 30 and 30 can be accurately made constant.

  Then, the atmosphere around the glass tube 50 is evacuated in the state shown in FIG. 8 (or in the state taken out from the jig 80 shown in FIG. 8), and then carbon dioxide, argon gas, nitrogen gas, xenon gas, etc. After introducing an active gas into an atmosphere of these gases, the glass tube 50 is heated from the surroundings (for example, 700 ° C.), thereby softening and shrinking the glass tube 50, and the outer periphery of the sealing electrodes 20, 20. To weld. As a result, both ends of the glass tube 50 are sealed, and the inside thereof is completely cut off from the outside and sealed to complete the surge absorber 10-4 shown in FIG.

  That is, the surge absorber 10-4 includes a pair of cylindrical sealing electrodes 20 and 20 having a diameter larger than the outer diameter of the electrode 30 formed by attaching the cylindrical electrodes 30 and 30 to the opposing surfaces, respectively. And the insulating plate 40-4 on which the electrodes 30 and 30 are installed (placed) on both sides thereof, the insulating plate 40-4 on which the electrodes 30 and 30 are installed, and the sealing electrodes 20 and 20 are housed. A cylindrical glass tube 50 sealed between the outer peripheral surface of the sealing electrodes 20 and 20 and the inner wall surface thereof is provided. Here, the end surface of the sealing electrode 20 on which the electrode 30 is attached is in contact with the end surface of the insulating plate 40-4.

  When a surge current is applied between the lead terminals 60 and 60 of the surge absorber 10-4 configured as described above, discharge is started near the surface of the insulating plate 40-4, and spark discharge → glow discharge → While instantaneously changing to arc discharge, the insulation in the space near the surface of the insulating plate 40-4 is destroyed, and eventually, discharge is performed between the electrodes 30 and 30 by arc discharge.

  The surge absorber 10-4 is manufactured by placing the electrodes 30 and 30 attached to the pair of sealing electrodes 20 and 20 on both sides of the insulating plate 40-4, and then sealing the insulating plate 40-4. The electrodes 20 and 20 are accommodated in the glass tube 50, and the both ends of the glass tube 50 are easily sealed with the sealing electrodes 20 and 20, and the conductive film 103 as in the conventional example shown in FIG. The cost reduction can be achieved because there is no need for the formation of laser and laser cutting.

  Moreover, since the periphery of the pair of electrodes 30 and 30 is partially covered with the insulating plate 40-4, the discharge light along the inner wall of the glass tube 50 is reduced, and the damage to the glass tube 50 can be reduced. Even if a surge current is applied, the glass tube 50 is not damaged.

  Further, according to the surge absorber 10-4, since the conductive portion 47-4 for inducing discharge is provided in the middle portion of the surface on which the pair of electrodes 30 and 30 of the insulating plate 40-4 are installed, the surge absorber 10-4 Even if the surge voltage application speed changes, the discharge start voltage can be stabilized substantially constant.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. Note that any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are exhibited. For example, it goes without saying that various changes can be made to the material, shape, and structure of various components such as the sealing electrode 20, the electrode 30, the insulating tube 40, the insulating plate 40-4, and the glass tube 50 constituting the surge absorber. .

1 is a schematic cross-sectional view of a surge absorber 10-1 according to an embodiment of the present invention. It is manufacturing method explanatory drawing of the surge absorber 10-1. It is a schematic sectional drawing of the surge absorber 10-2 concerning other embodiment of this invention. It is a schematic sectional drawing of the surge absorber 10-3 concerning further another embodiment of this invention. It is a schematic sectional drawing of the conventional surge absorber. It is a schematic sectional drawing (only the glass tube 50 is shown by the cross section) of the surge absorber 10-4 concerning further another embodiment of this invention, Fig.6 (a) is a schematic plane sectional drawing, FIG.6 (b) ) Is a schematic sectional side view. It is a perspective view of insulating board 40-4. It is manufacturing method explanatory drawing of the surge absorber 10-4.

Explanation of symbols

10-1 Surge absorber 20 Sealing electrode 30 Electrode 40 Insulating tube 50 Glass tube 10-2 Surge absorber 10-3 Surge absorber 70 Conductive powder 10-4 Surge absorber 40-4 Insulating plate 41-4 Base 43-4 Projection 45 -4 Electrode storage part 47-4 Conductive part

Claims (4)

  A pair of sealing electrodes each having an electrode attached to each of the opposing surfaces; an insulating tube for storing the pair of electrodes on both sides thereof; an insulating tube for storing the electrodes; and a sealing electrode; A surge absorber characterized by comprising a glass tube sealed between and a predetermined gas introduced into the glass tube.   The surge absorber according to claim 1, wherein conductive powder for inducing discharge is scattered and adhered to the inner wall of the insulating tube.   Accommodates and seals a pair of sealing electrodes each having an electrode attached to the opposing surface, an insulating plate on which the pair of electrodes are installed on both sides, and the insulating plate and the sealing electrode on which the electrodes are installed. A surge absorber comprising a glass tube sealed between a stop electrode and a predetermined gas introduced into the glass tube.   The surge absorber according to claim 3, wherein a conductive portion for inducing discharge is provided in an intermediate portion of the surface on which the pair of electrodes of the insulating plate is installed.

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