TW202001964A - Surge protection element capable of being manufactured at low cost to obtain a high parallelism of opposite surfaces of sealing electrodes - Google Patents

Abstract

Provided is a surge protection element capable of being manufactured at low cost to obtain a high parallelism of opposite surfaces of sealing electrodes. The surge protection element of the present invention includes: an insulating tube (2); a pair of sealing electrodes (3) for blocking opening portions at both ends of the insulating tube and sealing a discharge control gas in the insulating tube; and a distance adjusting member (4) sandwiched between opposite surfaces of the pair of sealing electrodes for defining a distance between the pair of sealing electrodes, wherein the distance adjusting member is provided with three or more insulating spheres (4a) having the same diameter. As a result, it is easy for the opposite surfaces of the pair of sealing electrodes to be parallel with each other. That is, with a simple configuration in which three or more insulating spheres having the same diameter are sandwiched between a pair of sealing electrodes, the surge protection element can be manufactured at low cost, and the high parallelism of the opposite surfaces of the sealing electrodes can be obtained.

Description

Surge protection element

The present invention relates to a surge protection element that protects various devices from surges that occur from lightning strikes and the like, and prevents accidents.

In the part where the electronic equipment used for communication equipment such as telephones, fax machines, modems, etc. is connected to the communication line, the driving circuit on the screen of the power cord, antenna or CRT, LCD TV and plasma TV, etc. is susceptible to lightning surges. In order to prevent the electrical voltage or the abnormal voltage (surge voltage) caused by the static electricity, the surge protection element is connected to the electronic device or the printed circuit board equipped with the device to prevent the thermal damage or fire caused by the abnormal voltage.

Conventionally, for example, Patent Document 1 describes a micro-gap surge protection element in which a member covered with a conductive layer is sandwiched between opposed metal members in a glass tube. In this micro-gap surge protection element, a slit (gap) of several μm to several tens of μm is provided in the center of the member covered with the conductive layer, so that it does not flow between the opposing metal members if it is below a predetermined voltage The structure of the current. Furthermore, if the set voltage is exceeded, an arc discharge occurs between the slits, and a current flows between the opposing metal members.

The surge protection element is a device that utilizes the energy of the shape change of the glass softening of the glass tube and the bonding characteristics with the metal, and is also excellent in mass productivity, so it is used in a wide range of fields. Furthermore, Patent Document 2 describes a surge protection element called an arrester that sandwiches an insulating plate in a gap between electrodes. In addition, Patent Documents 3 and 4 describe a surge protection element in which an insulating sphere is sandwiched between electrodes. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 63-57918 [Patent Literature 2] Japanese Shikai Hei No. 2-1891 [Patent Document 3] Japanese Patent Publication No. 7-75190 [Patent Document 4] Japanese Patent Laid-Open No. 11-317276

[Problems to be solved by the invention]

In the above-mentioned conventional technology, the following problems remain. That is, the glass-covered micro-gap surge protection element has good adhesion between the glass and the metal member, and has excellent reliability such as gas tightness, air or moisture blocking properties, etc., but constitutes a slit of the micro-gap The width is narrow, and the thickness of the conductive coating layer forming the periphery of the micro gap is tens of μm thin, so the limit of the surge resistance is about 1500A. Furthermore, a film-forming process for the conductive cover layer or a laser processing process for forming micro-gap is necessary, the process becomes complicated and it takes time to manufacture, and it has the disadvantage of high cost.

On the other hand, the surge arrester-type surge protection element is that the product with a diameter of 5mm has a capacity of 2000A and the product with a diameter of 8mm has a capacity of 5000A. It has a higher surge resistance than the glass-covered micro-gap type surge protection element Quantity characteristics. This surge arrester-type surge protection element is used in basic equipment such as large household appliances that require high reliability, solar power generation, water supply and sewerage, etc. In addition, the surge arrester-type surge protection element is a cylindrical member made of aluminum oxide which requires an expensive bonding agent (silver-based welding material) or is more expensive than a cylindrical member made of glass in the joining of metal and ceramics. In addition, the bonding of ceramics and metal parts requires very high technology, and it is necessary to provide an electrode auxiliary material (graphite, etc.) inside the electrode, in order to protect the electrode and help discharge the dielectric material on the counter electrode surface, so that Manufacturing engineering becomes complicated. Therefore, the production cost of surge arrester-type surge protection elements tends to increase significantly compared to glass-covered micro-gap surge protection elements. In particular, in the case of countermeasures against static electricity, it is necessary to separate the opposing electrodes from each other at very narrow intervals like the above-mentioned micro gap, and it is difficult to set the gap with high accuracy.

In addition, in Patent Document 3, a pair of sealed electrodes sandwiches an insulating sphere to set the gap between the electrodes. However, as shown in FIG. If the sandwiched insulating sphere 4 is arranged at a position offset from the center of the opposing surface to the side, since there is a clearance C for inserting the sealing electrode 3 into the insulating tube 2, the axis of the sealing electrode 3 will be opposite The inclination of the axis of the insulating tube 2 makes the opposing surfaces of the sealed electrode 3 non-parallel to each other, and there is a problem that the operation stability of the discharge is reduced due to the discharge start voltage that cannot be obtained. Therefore, the surge protection element described in Patent Document 4 uses other members of the cylindrical body to arrange the insulating sphere on the axis of the sealed electrode. In this case, the structure becomes complicated and the cost or engineering of the member increases. problem.

The present invention has been accomplished in view of the aforementioned problems, and its object is to provide a surge protection element that can be manufactured at low cost and that can obtain a high parallelism of the opposing surface of the sealed electrode. [Means to solve the problem]

In order to solve the aforementioned problems, the present invention adopts the following structure. That is, the surge protection element of the first invention is characterized by comprising: an insulating tube, a pair of sealed electrodes that closes the openings at both ends of the insulating tube and seals the discharge control gas inside, and The opposing surface of the pair of sealed electrodes sandwiches and defines an interval adjusting member between the pair of sealed electrodes. The interval adjusting member is three or more insulating spheres of the same diameter.

In this surge protection element, the interval adjustment member is three or more insulating spheres of the same diameter, so the contact points between the three or more insulating spheres of the same diameter and the opposing surface of the sealed electrode constitute a triangle or more The polygonal shape makes it easy to make the opposing surfaces of the pair of sealed electrodes parallel to each other. Therefore, a simple structure in which three or more insulating spheres of the same diameter are sandwiched by a pair of sealed electrodes can be manufactured at low cost, and high parallelism of the opposing surfaces of the sealed electrodes can be obtained.

The surge protection element of the second invention is characterized in that, in the first invention, at least one of the pair of sealed electrodes has a convex portion in the center of the opposing surface. That is, in the surge protection element, at least one of the pair of sealed electrodes has a convex portion in the center of the opposing surface, so that each insulating sphere is arranged around the convex portion, and it is easy to disperse each other to form a wide Polygonal shape can obtain higher parallelism of the opposite surface of the sealed electrode.

The surge protection element of the third invention is characterized in that, in the first or second invention, at least one of the pair of the sealed electrodes has a number of concave portions corresponding to the number of the insulating spheres on the facing surface thereof The insulating sphere is embedded in the recess. That is, in the surge protection element, the insulating sphere is embedded in the concave portion, and the insulating sphere can be positioned without using other members, and a higher parallelism of the opposing surface of the sealed electrode can be obtained.

The surge protection element of the fourth invention is characterized in that, in the first or second invention, at least one of the pair of the sealed electrodes has an opposing surface having the same central axis as the opposing surface and is formed as a ring In the shape of the groove, the insulating sphere is fitted into the groove. That is, in the surge protection element, the insulating sphere is embedded in the annular groove, so the annular groove can be used to position each insulating sphere.

The surge protection element of the fifth invention is characterized in that in any of the first to third inventions, the insulating tube is a glass tube. That is, in this surge protection element, the insulating tube is a glass tube, so it can be manufactured cheaper than ceramics such as alumina, and excellent reliability is obtained by high gas tightness and moisture blocking properties . [Effect of invention]

According to the present invention, the following effects can be exerted. That is, according to the surge protection element of the present invention, the interval adjusting member is three or more insulating spheres with the same diameter, so it can be manufactured at low cost, and high parallelism of the opposing surface of the sealed electrode can be obtained. Therefore, the surge protection element of the present invention is suitable for use in power supply circuit parts or communication circuit parts of electrical appliances that require small, inexpensive, and highly reliable products. In particular, the surge protection device of the present invention is suitable for a wide range of applications including countermeasures against static electricity when mounted on a substrate.

Hereinafter, the first embodiment of the surge protection element of the present invention will be described with reference to FIGS. 1 to 3. In addition, in the drawings used in the following description, the scale may be appropriately changed in order to be able to recognize each member or to make it easy to recognize the size.

As shown in FIGS. 1 to 3, the surge protection element 1 of this embodiment includes an insulating tube 2, a pair of openings at both ends of the insulating tube 2 that are blocked, and a discharge control gas sealed inside The sealed electrode 3 and the interval adjusting member 4 sandwiched between the opposing surfaces of the pair of sealed electrodes 3 and defining the interval between the pair of sealed electrodes 3. The above-mentioned interval adjusting member 4 is composed of three or more insulating spheres 4a having the same diameter. In this embodiment, three insulating spheres 4a are used as the interval adjusting member 4.

The insulating tube 2 is cylindrical, and is formed of a glass tube such as lead glass. The insulating tube 2 is preferably formed of a glass tube that is inexpensive and excellent in sealing performance, but may be formed of a crystalline ceramic material such as alumina. The discharge control gas enclosed in the insulating tube 2 is an inert gas, such as He, Ar, Ne, Xe, Kr, SF ₆ , CO ₂ , C ₃ F ₈ , C ₂ F ₆ , CF ₄ , H _2. Atmosphere, etc. and their mixed gases.

The above-mentioned sealed electrode 3 is formed in a cylindrical shape with, for example, a bimetal (Dual metal) wire, 42 alloy (Fe: 58 wt%, Ni: 42 wt%), Cu, or the like. In each sealed electrode 3, a base end portion of a lead 5 protruding outward is embedded.

The insulating sphere 4a is, for example, a sphere of glass, ceramics, resin, etc., for example, a diameter of 200 to 800 μm is used. That is, the insulating sphere 4a becomes a spacer, and in this embodiment, the gap between the pair of sealed electrodes 3 is defined by the diameter of the insulating sphere 4a.

When the three insulating spheres 4a are sandwiched by the opposing surfaces of the pair of sealed electrodes 3, the vertices of the insulating spheres 4a are connected as shown by the two-dot chain line shown in FIG. 3. In a triangle, when the opposing surface of the sealed electrode 3 is in contact with each vertex, the same triangle is formed by a line connecting each contact point. By forming the plane of the triangle, the opposing surfaces of the pair of sealed electrodes 3 are arranged parallel to each other. In addition, the larger the number of insulating spheres 4a, the more the contact points with the opposing surface of the sealed electrode 3 form a polygon, and the sealed electrode 3 will be more difficult to incline, so that the opposing surfaces can be highly parallel degree.

As described above, in the surge protection element 1 of the present embodiment, the interval adjusting member 4 is three or more insulating spheres 4a having the same diameter, so the pair of the three or more insulating spheres 4a having the same diameter and the sealing electrode 3 The contact points between the facing surfaces constitute a polygon of more than a triangle, whereby it is easy to make the facing surfaces of the pair of sealed electrodes 3 parallel to each other. That is, a simple structure in which three or more insulating balls 4a of the same diameter are sandwiched by a pair of sealed electrodes 3 can be manufactured at low cost, and high parallelism of the opposing surface of the sealed electrode 3 can be obtained. In particular, the insulating tube 2 is a glass tube, which can be manufactured at a lower cost than ceramics such as alumina, and has excellent reliability due to high gas tightness and moisture blocking properties.

Next, the second and third embodiments of the surge protection element of the present invention will be described with reference to FIGS. 4 to 7. In addition, in the description of the following embodiments, the same constituent elements as those described in the above embodiments are denoted by the same symbols, and the descriptions thereof are omitted.

The difference between the second embodiment and the first embodiment is that, in the first embodiment, the opposite surface of the sealed electrode 3 is a flat surface. In contrast, the surge protection element 21 in the second embodiment is as shown in FIG. As shown in FIGS. 4 and 5, at least one of the pair of sealed electrodes 23 has a convex portion 23a at the center of its opposing surface. That is, in the second embodiment, a mountain-shaped convex portion 23a is formed in the center of the opposing surface of the sealed electrode 23.

In the second embodiment, the convex portions 23a are formed on the opposing surfaces of both the pair of sealed electrodes 23, respectively. In addition, the height of the convex portion 23a is set to be lower than the insulating sphere 4a. As described above, in the surge protection element 21 of the second embodiment, at least one of the pair of sealed electrodes 23 has the convex portion 23a at the center of the opposing surface, so that the insulating spheres 4a are arranged on the convex portion 23a. Around, it is easy to disperse each other to form a wide polygon, and a high parallelism of the opposing surface of the sealed electrode 23 can be obtained.

Next, the difference between the third embodiment and the second embodiment is that, in the second embodiment, a convex portion 23a is formed in the center of the opposing surface of the sealed electrode 23, whereas the surge in the third embodiment As shown in FIGS. 6 and 7, at least one of the pair of sealed electrodes 33 has a number of concave portions 33a corresponding to the number of insulating spheres 4a on the opposing surface, and each insulating The ball 4a is fitted into the recess 33a.

That is, in the third embodiment, in accordance with the shapes of the three insulating spheres 4a, three concave portions 33a having an arc-shaped cross section and a circular shape in plan view are formed on the opposing surface of the sealed electrode 33. Furthermore, in the third embodiment, both sides of the pair of sealed electrodes 33 are respectively formed with recesses 33a at corresponding positions on the opposing surfaces. The depth of these concave portions 33a is uniformly set to be lower than the radius of the insulating sphere 4a. That is, the gap between the pair of sealed electrodes 33 is a value obtained by subtracting the depth at which the two concave portions 33a are fitted up and down from the diameter of the insulating sphere 4a.

The three recesses 33a are formed to avoid the center of the opposing surface of the sealed electrode 33, and are respectively arranged at the vertices of a regular triangle surrounding the center of the opposing surface. As described above, the plurality of concave portions 33a are preferably arranged at equal intervals so as to surround the center of the opposing surface of the sealed electrode 33. In the third embodiment, in a state where the lower portion of the insulating sphere 4a is fitted into each recess 33a of one sealed electrode 33 inserted below the insulating tube 2, the other sealed electrode 33 is inserted to form the insulating sphere 4a In the state where the upper part of the is fitted into each recess 33a of the other sealed electrode 33, the insulating tube 2 of the glass tube and the pair of sealed electrodes 33 are tightly fixed by heat sealing treatment.

As described above, in the surge protection element 31 of the third embodiment, the insulating sphere 4a is embedded in the concave portion 33a, and the insulating sphere 4a can be positioned without using other members, so that the opposite side of the sealed electrode 33 can be obtained. High parallelism.

Next, the difference between the fourth embodiment and the third embodiment is that in the third embodiment, the insulating spheres 4a are embedded in the three recesses 33a formed separately from each other. In contrast, in the fourth embodiment As shown in FIGS. 8 and 9, at least one of the pair of sealed electrodes 43 is formed in a ring shape with the same central axis as the opposite surface on the opposite surface thereof as shown in FIGS. 8 and 9. The groove 43a and the insulating sphere 4a are fitted into the groove 43a.

That is, in the fourth embodiment, the opposing surface of the sealed electrode 43 is provided with an annular groove 43a having an arc-shaped cross section corresponding to the shape of the insulating sphere 4a. The three or more insulating spheres 4a are embedded in the annular groove portion 43a and sealed to produce the surge protection element 41 of the fourth embodiment. As described above, in the surge protection element 41 of the fourth embodiment, the insulating sphere 4a is fitted into the annular groove 43a. Therefore, the insulating sphere 4a can be positioned by the annular groove 43a.

Moreover, the technical scope of the present invention is not limited to the above-mentioned embodiments, and various modifications can be added within a range that does not deviate from the gist of the present invention.

In the above embodiments, although three insulating spheres are used, four or more may be used. In addition, the relationship between the number of balls and the diameter of the disposable insulating sphere and the diameter of the sealed electrode will be described using FIG. 11. For example, FIG. 11 shows the arrangement of insulating spheres with a total number of insulating spheres of 1-10. In this case, the total number of insulating spheres is defined as n, and the number of spheres of insulating spheres that are continuously arranged in a ring in the sealed electrode (in the opposite plane) is defined as n _r . It can be seen from FIG. 11 that up to five insulating spheres can be arranged in a ring in the sealed electrode. In addition, when there are six insulating spheres, six rings are formed, or one is placed in the center of the five rings. In addition, when there are 7 to 9 insulating spheres, n _r (n-1) and one in the center may be arranged in a continuous ring shape. In addition, when there are 10 or more insulating spheres, it may not be possible to form a continuous annular arrangement.

Table 1 shows the relationship between the number n _r of the insulating spheres, the diameter X, and the diameter D of the sealed electrode in the case where n _r consecutive insulating spheres are arranged side by side in the sealed electrode.

In addition, when n insulating spheres are continuously arranged in a ring shape in a sealed electrode, the maximum diameter X of the insulating spheres n _r converging in the sealed electrode can be expressed by the following formula.

1, 21, 31, 41 ‧‧‧ Surge protection element 2‧‧‧Insulation tube 3. 23, 33, 43 ‧‧‧ sealed electrode 4‧‧‧Interval adjustment member 4a‧‧‧Insulating sphere 23a‧‧‧Convex 33a‧‧‧recess 43a‧‧‧Ditch

FIG. 1 is a perspective view when sealed with a sealed electrode showing a first embodiment of the surge protection element of the present invention. 2 is a front view of the surge protection element in a state where the insulating tube is broken in the first embodiment. Fig. 3 is a cross-sectional view taken along the line A-A of Fig. 2. 4 is a front view of the surge protection element in a state where the insulating tube is broken in the second embodiment of the surge protection element of the present invention. 5 is a perspective view showing a sealed electrode in the second embodiment. Fig. 6 is a front view of the surge protection element in a third embodiment of the surge protection element of the present invention, showing a state where the insulating tube is broken. 7 is a perspective view showing a sealed electrode in a third embodiment. 8 is a perspective view showing a sealed electrode in a fourth embodiment of the surge protection element of the present invention. 9 is a front view of the surge protection element in a state where the insulating tube is broken in the fourth embodiment. 10 is a front view of the surge protection element in a state where the insulating tube is broken in the previous example of the present invention. 11 is an explanatory diagram showing the relationship between the number of balls and the diameter of the insulating sphere and the diameter of the sealed electrode.

1‧‧‧Surge protection element

2‧‧‧Insulation tube

3‧‧‧sealed electrode

4‧‧‧Interval adjustment member

4a‧‧‧Insulating sphere

5‧‧‧Lead

Claims (5)

A surge protection element characterized by: Insulation tube, A pair of sealed electrodes sealing the openings at both ends of the insulating tube and sealing the discharge control gas inside, and An interval adjusting member sandwiched between the opposing surfaces of the pair of sealed electrodes and defining the interval between the pair of sealed electrodes, The above-mentioned interval adjusting members are three or more insulating spheres with the same diameter. The surge protection element according to claim 1, wherein, At least one of the pair of sealed electrodes has a convex portion in the center of the opposing surface. The surge protection element according to claim 1 or 2, wherein, At least one of the pair of the sealed electrodes has a number of concave portions corresponding to the number of the insulating spheres on the opposite surface, The insulating sphere is fitted into the recess. The surge protection element according to claim 1 or 2, wherein, At least one of the pair of the sealed electrodes has a groove formed in an annular shape on the opposite surface of the same center axis as the opposite surface, The insulating sphere is embedded in the groove. The surge protection element according to claim 1 or 2, wherein, The aforementioned insulating tube is a glass tube.

Images