JP2000182808A - Nonlinear resistance member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve discharge energy withstand amount so as to prevent breakdown, when discharge energy is applied. SOLUTION: Metal material, constituted of a wire whose diameter is at most 3.2 mm, is fused in a combustion gas and sprayed on the upper and the lower surfaces of a sintered member, and electrodes are formed. Thereby particles of the metal material to be fused can be restricted to only fine particles, the surfaces of the electrodes are smoothed, and the number of pores in the electrode is reduced. Hence the number of gaps in the electrode is reduced, and discharge energy withstanding amount of a nonlinear resistance member is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-linear resistor having zinc oxide as a main component and having non-linear resistance characteristics, and more particularly to a non-linear resistor whose electrode forming conditions are limited. .

[0002]

2. Description of the Related Art Generally, an overvoltage protection device such as a lightning arrester or a surge absorber is installed in a power system. An overvoltage protection device is a device that removes an overvoltage superimposed on a normal voltage in order to protect a power system or an electric device. Conventionally, a non-linear resistor has been frequently used in this overvoltage protection device. The non-linear resistor has a so-called non-linear resistance characteristic which shows almost insulation characteristics at a normal voltage and has a low resistance value when an overvoltage is applied, and is most suitable for removing the overvoltage.

A non-linear resistor is provided with a disk-shaped or annular sintered body. The sintered body contains zinc oxide as a main component, and at least one or more metal oxides are added to obtain non-linear characteristics, mixed with zinc oxide, granulated, molded, and finally formed. It is formed by sintering. Further, an insulating layer is formed on a side surface of the sintered body, and a pair of electrodes are formed on upper and lower surfaces of the sintered body. Of these, the insulating layer is formed by applying an inorganic insulator to the side surface of the sintered body and baking it. On the other hand, the electrodes are formed by melting a metal material such as aluminum in a combustion gas or an arc and spraying the molten material on the upper and lower surfaces of the sintered body.

[0004] In recent years, the power transmission system voltage has increased along with the power demand, and accordingly, the discharge energy applied to the nonlinear resistor has also tended to increase. Discharge energy tolerance is set to the non-linear resistor according to the applied discharge energy, but when a large discharge energy is applied to the non-linear resistor and exceeds the discharge energy withstand, the non-linear resistor is mechanically damaged. Or electrical breakdown may occur. Possible causes of the destruction of the non-linear resistor include non-uniform current distribution in the non-linear resistor due to separation of the electrode and the like, and occurrence of discharge in a gap in the electrode. Note that the gaps in the electrodes include not only those existing inside the electrodes but also gaps due to unevenness between the electrodes when the non-linear resistors are stacked.

[0005] In order to prevent such destruction of the non-linear resistor, it is important to improve the discharge energy resistance of the non-linear resistor. Therefore, the following conventional examples have been proposed as non-linear resistors having improved discharge energy resistance. First, in the technique described in Japanese Patent Publication No. 7-44087 by the present applicant, a non-linear resistor using aluminum containing any of Mg, Ca, and Ti as a metal material for forming a sprayed electrode is disclosed. Have been. Japanese Patent Application Laid-Open No. 3-125401 discloses a difference between a maximum value and a minimum value of a distance between an end of an electrode and an outer peripheral edge of a non-linear resistor, that is, a disc-shaped sintered body including an electrode insulating layer. Eccentricity,
A non-linear resistor of 1 mm or less is described.

[0006]

However, at the present time when the demand for electric power is increasing remarkably, the voltage of the transmission system is also increasing steadily. Therefore, the non-linear resistor is required to have a higher withstand level of discharge energy so as not to be damaged even when a large discharge energy is applied.

The present invention has been proposed in view of such circumstances, and an object of the present invention is to provide a non-linear resistor having improved discharge energy withstand capability in order to prevent destruction when applying discharge energy. That is.

[0008]

In order to achieve the above object, a non-linear resistor according to claim 1 is provided with a disc-shaped or annular sintered body containing zinc oxide as a main component. 2. A non-linear resistor having a pair of electrodes formed on the upper and lower surfaces of the sintered body while forming an insulating layer on the side surface of the sintered body.
An electrode is formed by melting a metal material made of a wire of 2 mm or less in a combustion gas and spraying the molten metal on the upper and lower surfaces of a sintered body.

The non-linear resistor according to claim 2 has a particle diameter of 12
An electrode is formed by melting a metal material made of powder of 0 μm or less in a combustion gas and spraying the molten metal on the upper and lower surfaces of a sintered body.

According to a third aspect of the present invention, there is provided a non-linear resistor comprising a metal material made of two wires having a diameter of 1.6 mm or less and having a diameter of 20 k.
An electrode is formed by energizing at an output of W or less, short-circuiting and melting, and spraying the melt on the upper and lower surfaces of the sintered body.

In the nonlinear resistor according to the first, second or third aspect of the present invention, the metal material to be melted is limited to fine particles by defining the diameter or particle size of the metal material. Can be. Therefore, the surfaces of the electrodes sprayed on the upper and lower surfaces of the sintered body are extremely smooth, and when the non-linear resistors are stacked, voids due to unevenness between the electrodes can be reduced. In addition, since the metal material particles are fine, the number of pores in the electrode is reduced, and voids inside the electrode can be reduced. In such a non-linear resistor having a small gap in the electrode, the discharge in the gap can be suppressed even when a large discharge energy is applied.
Therefore, it is possible to increase the discharge energy resistance of the nonlinear resistor.

According to a fourth aspect of the present invention, there is provided the nonlinear resistor according to the first, second or third aspect, wherein the metal material for forming the electrode is mainly composed of aluminum, copper, zinc, nickel, silver or tin. It is characterized by doing. Claim 4
In the described invention, aluminum, copper, zinc, nickel, silver, or tin is used as a main component of the electrode, so that not only the conductivity of the electrode is increased, but also the adhesion between the electrode and the sintered body can be increased. Therefore, the electrode does not peel off from the upper and lower surfaces of the sintered body, it is possible to prevent uneven current distribution in the non-linear resistor, and to obtain an excellent discharge energy resistance.

[0013] The invention according to claim 5 is the invention according to claims 1, 2, and 3.
Alternatively, in the nonlinear resistor according to 4, the average surface roughness of the upper and lower surfaces of the sintered body is in a range of 3 μm to 8 μm. According to the fifth aspect of the present invention, since the average surface roughness of the upper and lower surfaces of the sintered body is set to 3 μm or more, the surface area of the sintered body can be widened, and the adhesion between the sintered body and the electrode can be reduced. It can be sufficiently secured. At the same time, since the average surface roughness of the upper and lower surfaces of the sintered body is suppressed to 8 μm or less, non-uniform current distribution does not appear at the tips of the concave portions on the upper and lower surfaces of the sintered body. Thereby, the discharge energy resistance of the non-linear resistor can be increased.

[0014] The invention according to claim 6 is the first or second invention.
3. The nonlinear resistor according to 3, 4, or 5, wherein the porosity contained in the electrode is 15% or less.
In the invention described in claim 6 above, the fact that the porosity in the electrode is 15% or less means that the void in the electrode is extremely small, and the occurrence of discharge in the void can be suppressed. In addition, it is possible to prevent the current distribution from becoming non-uniform due to the void at the interface between the sintered body and the electrode. Therefore, excellent discharge energy resistance can be secured.

[0015] The invention according to claim 7 is based on claims 1 and 2,
3. The nonlinear resistor according to 3, 4, 5, or 6, wherein the weight ratio of the metal oxide contained in the electrode to the metal is 25% or less. In the seventh aspect of the present invention, since the weight ratio of the metal oxide is small, the voids in the electrode can be reduced, and the generation of discharge in the voids can be prevented, and the discharge energy resistance can be increased.

[0016] The invention described in claim 8 is based on claims 1, 2 and
3. The nonlinear resistor according to 3, 4, 5, 6, or 7,
The average thickness of the electrode is in the range of 5 μm to 500 μm. Claim 8 having the above configuration.
In the non-linear resistor described above, by defining the average thickness of the electrode, it is possible to prevent insufficient film thickness and poor adhesion in the electrode and prevent separation of the sintered body and the electrode due to an increase in residual stress in the electrode. . Therefore, non-uniformity of the current distribution in the non-linear resistor due to insufficient film thickness, poor adhesion, peeling, and the like in the electrode can be prevented, and the discharge energy resistance can be improved.

The ninth aspect of the present invention relates to the first, second and third aspects.
3. The nonlinear resistor according to 3, 4, 5, 6, 7 or 8, wherein the average surface roughness of the electrode is 8 μm or less. In the ninth aspect of the present invention, since the electrode surface is flat, the gap between the electrodes when the non-linear resistors are stacked can be reduced. Therefore, it is possible to prevent the occurrence of discharge between the electrodes when the discharge energy is applied, and to increase the discharge energy resistance of the non-linear resistor.

The invention according to claim 10 is the invention according to claims 1, 2,
3. The nonlinear resistor according to 3, 4, 5, 6, 7, 8 or 9, wherein the resistivity of the electrode is 15 μΩ · cm or less. According to the tenth aspect, a high-resistance portion is not formed at the interface between the sintered body and the electrode.
As a result, the current distribution in the non-linear resistor can be prevented from becoming uneven, and a high discharge energy resistance can be obtained.

The invention according to claim 11 is the invention according to claims 1, 2,
In the nonlinear resistor according to 3, 4, 5, 6, 7, 8, 9 or 10, the distance between the end of the electrode and the end of the sintered body is set to 0.
It is characterized in that it is within a range from 01 mm to 1.0 mm. According to the eleventh aspect of the present invention having the above-described configuration, by limiting the formation range of the electrodes, the generation of discharge between the electrodes when the discharge energy is applied and the unevenness of the current distribution in the non-linear resistor. Can be prevented, and the discharge energy resistance of the non-linear resistor can be increased.

According to the twelfth aspect of the present invention,
3. The nonlinear resistor according to 3, 4, 5, 6, 7, 8, 9, 10 or 11, wherein unevenness in a main surface direction at an end of the electrode is ± 0.5 mm or less. According to the twelfth aspect of the invention, it is possible to prevent local nonuniformity of the current distribution in the nonlinear resistor when the discharge energy is applied, and to obtain a high discharge energy resistance.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) First Embodiment: Corresponding to Claim 1, see FIGS. 1 and 2 Hereinafter, a first embodiment including the invention of claim 1 will be described with reference to the drawings. This will be specifically described. Before describing the features of the first embodiment, first, the manufacturing process of the non-linear resistor will be described.

[Manufacturing Process of Non-Linear Resistor] First, a raw material of a sintered body is prepared mainly with zinc oxide (ZnO). That is, manganese dioxide (MnO) is added to zinc oxide (ZnO).
2) and cobalt oxide (Co2 O3)
mol%, bismuth oxide (Bi2 O3), antimony oxide (Sb2 O3), and nickel oxide (NiO) are added at 1 mol% each. Next, this raw material is put into a mixing device together with water, an organic dispersant, and a binder and mixed, and the mixture is spray-granulated by a spray drier. These granulated powders are put into a mold and pressurized. In this case, a compact having a diameter of 100 mm and a thickness of 30 mm is formed into a disc. Then, this molded body is fired at 1200 ° C. to produce a sintered body 1 as shown in FIG. Next, after applying an alumina-based inorganic insulator to the side surface of the sintered body 1,
The insulating layer 2 is formed by baking at the above temperature. The upper and lower surfaces of the sintered body 1 provided with the insulating layer 2 are polished. Thereafter, the sintered body 1 is covered with a guard mask, and a metal material such as aluminum is sprayed on the polished surface to form the electrode 3. To form a non-linear resistor.

[Configuration] The first embodiment is characterized in that the following electrode 3 is formed in the step of forming the electrode 3 when the electrode 3 is formed on the basis of the above manufacturing steps. That is, a metal material made of a wire having a diameter of 3.2 mm or less is melted in a combustion gas, and the molten metal material is sprayed on the upper and lower surfaces of the sintered body 1 to form the electrode 3.

[Discharge Energy Withstand Test] A discharge energy withstand test is performed on the first embodiment as described above. For comparison with the test results of the first embodiment, a plurality of types of non-linear resistors were manufactured by changing only the diameter of the wire, which is a metal material, and the same test was performed on these. In addition, the test is 10
Set went.

The discharge energy tolerance test is specifically performed as follows. First, three non-linear resistors manufactured under the same conditions are laminated to form one sample. Then, a rectangular wave discharge energy of 2 ms is applied to the samples at intervals of 5 minutes while gradually increasing the discharge energy amount from 200 J / cc to 20 J / cc for each sample. The application is continued until at least one of the bodies is electrically broken. At this time, the maximum amount of discharge energy absorbed before breaking is defined as discharge energy resistance (J / cc).

FIG. 1 shows the results of a discharge energy resistance test of a non-linear resistor when the electrode 3 of the non-linear resistor is formed and the diameter of the wire is changed. The nonlinear resistor in which the electrode 3 is formed by a wire having a diameter of 3.2 mm or less corresponds to the first embodiment.

[Effects] As is clear from the results shown in FIG. 1, the first embodiment shows a remarkably excellent discharge energy resistance of 500 J / cc or more. That is,
In a non-linear resistor other than the first embodiment, the diameter is 3.
Since the electrode 3 is formed using a wire larger than 2 mm, the particles of the metal material to be melted are large, the surface of the electrode 3 is not smooth, and the inside of the electrode 3 contains many pores. Therefore, when a large amount of discharge energy is applied, a gap is generated in which discharge occurs, and the discharge energy resistance is limited to about 400 J / cc.

On the other hand, in the first embodiment, a wire having a diameter of 3.2 mm or less is
Is formed, the particles of the molten metal material become finer. Therefore, the surface of the electrode 3 is smoothed, and the gap due to unevenness between the electrodes 3 when the non-linear resistors are stacked is small. In addition, since the particles of the metal material are fine, the number of pores inside the electrode 3 is extremely small, and the space inside the electrode 3 can be greatly reduced. As described above, if the gap in the electrode 3 is small, even if a large discharge energy is applied to the non-linear resistor, there is no possibility that a discharge is generated in the gap. Thereby, the first embodiment can obtain excellent discharge energy resistance.

(2) Second embodiment: Corresponding to claim 2,
Referring to FIG. 3, an embodiment corresponding to the second aspect of the present invention will be described as a second embodiment of the present invention with reference to FIG. The second embodiment is characterized in that an electrode 3 is formed by melting a metal material made of powder having a particle size of 120 μm or less in a combustion gas and spraying the molten metal material on the upper and lower surfaces of a sintered body 1. And

The above-described second embodiment is subjected to the above-described discharge energy withstand test. For comparison with the test results of the second embodiment, a plurality of types of non-linear resistors were produced by changing only the powder diameter of the metal material powder, and the same test was performed on these. FIG. 3 is a graph showing a result of a discharge energy resistance test of a non-linear resistor in which a powder particle size is changed in gas spraying when forming an electrode of the non-linear resistor. At this time, a non-linear resistor having an average particle size of 120 μm or less in FIG. 3 corresponds to the second embodiment.

[Effects] That is, the powder particle size is set to 120
According to the second embodiment in which the electrode 3 is formed to have a thickness of μm or less, the surface of the electrode can be smoothed, and the number of pores in the electrode can be reduced. Therefore, it is possible to secure an excellent discharge energy resistance of 500 J / cc or more.

(3) Third Embodiment: Corresponding to claim 3,
4 and 5 [Configuration] A third embodiment according to the third aspect of the present invention will be described with reference to FIGS. A feature of the third embodiment is that a metal material composed of two wires having a diameter of 1.6 mm or less is short-circuited and melted by supplying electricity at a power of 20 kW or less, and the melted metal material is formed on the upper and lower surfaces of the sintered body 1. To form an electrode by spraying.

The above-described third embodiment is subjected to the above discharge energy withstand test. In addition, in order to compare with the test result of the third embodiment, a plurality of types of non-linear resistors were produced by changing the diameters of the two wires and the energizing output, and the same test was carried out for this. . FIG.
Is a result of a discharge energy withstand test of a non-linear resistor in which the diameter of two wires is changed when an electrode of the non-linear resistor is formed. FIG. 5 shows the results of a discharge energy withstand test of the nonlinear resistor in which the output is changed when the two wires are energized when forming the electrode of the nonlinear resistor. At this time, the non-linear resistor having an arc sprayed wire diameter of 1.6 mm or less in FIG. 4 and the non-linear resistor having a spray output of 20 kW or less in FIG. 5 correspond to the third embodiment.

[Effects] As is clear from the test results shown in FIGS. 4 and 5, the wire diameter is set to 1.6 mm or less.
In the third embodiment in which the electrodes are formed with a current output of 20 kW or less, the surface of the electrode 3 can be smoothed and the number of pores inside the electrode 3 can be reduced.
It is possible to exhibit an extremely excellent discharge energy resistance of at least 00 J / cc.

(4) Fourth embodiment: Corresponding to claim 4,
[Configuration] Next, a fourth embodiment will be described.
The fourth to twelfth embodiments described below correspond to the inventions of claims 4 to 12, respectively, and each embodiment corresponds to the first embodiment. The electrode in: "An electrode formed by melting and spraying a wire having a diameter of 3.2 mm or less in a combustion gas", or the electrode in the second embodiment: "Powder having a particle size of 120 μm or less is contained in the combustion gas. An electrode formed by being melted and sprayed at the electrode, or an electrode in the third embodiment: "two wire metal materials having a diameter of 1.6 mm or less are subjected to an output current of 20 kW or less, and are short-circuited and melted; And an electrode formed by spraying. Further, the discharge energy withstand capability in each of the embodiments was determined by performing the same discharge energy withstand test as described above.

The nonlinear resistor according to the fourth embodiment is characterized in that the metal material is mainly composed of aluminum, copper, zinc, nickel, tin or silver. FIG. 6 is a graph showing the relationship between the main component of the metal material forming the non-linear resistor electrode 3 and the discharge energy resistance (J / cc). In the graph, aluminum, copper,
Represents a non-linear resistor having zinc, nickel, tin, silver, and iron as main components of a metal material, respectively. In other words, the non-linear resistors (1) to (4) correspond to the fourth embodiment.

[Function and Effect] As is apparent from FIG. 6, the fourth embodiment in which the main component of the metal material for forming the electrodes is aluminum, copper, zinc, nickel, tin and silver has an average of 500 J. / Cc, but the non-linear resistor whose main component of the metal material is iron has a low discharge energy withstand of about 400 J / cc. That is, according to the fourth embodiment, the electrode 3
Aluminum, as a main component of the metal material forming
Since copper, zinc, nickel, tin or silver is used, the conductivity of the electrode is extended, and the sintered body 1 and the electrode 3 are strongly adhered. Therefore, the electrode 3 does not peel off from the upper and lower surfaces of the sintered body 1, it is possible to prevent uneven current distribution in the non-linear resistor, and it is possible to obtain excellent discharge energy resistance.

(5) Fifth Embodiment: Corresponding to claim 5,
See FIG. 7 [Configuration] A feature of the fifth embodiment is that the average surface roughness of the upper and lower surfaces of the sintered body 1 forming the electrode 3 is in the range of 3 μm to 8 μm. FIG. 7 is a graph showing the relationship between the average surface roughness (μm) of the sintered body 1 and the discharge energy resistance (J / cc) at the time of forming the electrode of the nonlinear resistor. More specifically, when polishing the upper and lower surfaces of the sintered body 1 in producing a non-linear resistor, the grain size of a polishing grindstone is changed, or the grain size of abrasive grains is changed after polishing and blasting is performed. Then, the surface roughness of the upper and lower surfaces of the sintered body 1 was changed to produce a plurality of types of non-linear resistors having different average surface roughnesses of the sintered body 1, and these were subjected to a discharge energy resistance test. The result. In FIG. 7, a non-linear resistor in which the surface roughness of the sintered body 1 is 3 μm to 8 μm corresponds to the fifth embodiment.

[Operation and Effect] The operation and effect of the fifth embodiment are as follows. That is, when the average surface roughness of the sintered body 1 is less than 3 μm or more than 8 μm, the non-linear resistor has a low discharge energy resistance. On the other hand, the average surface roughness of the sintered body 1 is 3 to 8 μm.
m in the fifth embodiment, the average is 500 J / c
It can exhibit a high discharge energy resistance of c or more.
This is because the surface area of the sintered body 1 is increased by increasing the average surface roughness of the sintered body 1 to more than 3 μm.
This is because the adhesive strength between the electrode 3 and the electrode 3 is increased, and the electrode 3 is hardly peeled off from the sintered body 1. Also, by suppressing the average surface roughness of the sintered body 1 to 8 μm, it is possible to prevent uneven current distribution at the tip of the concave portion on the surface of the sintered body 1 when absorbing the discharge energy. Contribute to the improvement of

(6) Sixth Embodiment: Corresponding to claim 6,
FIG. 8 [Configuration] The nonlinear resistor according to the sixth embodiment is characterized in that the porosity contained in the electrode 3 is 15% or less. FIG. 8 is a graph showing the relationship between the porosity (%) of the electrode 3 and the discharge energy resistance (J / cc). More specifically, the condition for forming the electrode 3 is changed to change the electrode 3. The results of performing discharge energy withstand tests on a plurality of types of non-linear resistors having different porosity while varying the porosity therein are shown. Here, the porosity was determined by taking out a test piece of only the electrode 3 from the non-linear resistor and performing a mercury intrusion test on the test piece. In FIG. 8, a nonlinear resistor having a porosity of 15% or less corresponds to the sixth embodiment.

[Effects] As is clear from the test results shown in FIG. 8, in the sixth embodiment in which the porosity of the electrode 3 is 15% or less, the pores at the interface between the sintered body 1 and the electrode 3 are reduced. The resulting nonuniform current distribution in the non-linear resistor can be prevented, and a high discharge energy resistance of 500 J / cc or more can be obtained on average.

(7) Seventh embodiment: Corresponding to claim 7,
See FIG. 9 [Structure] The seventh embodiment is characterized in that the weight ratio of the metal oxide contained in the electrode 3 to the metal is 25% or less. FIG. 9 shows the weight ratio (%) of the metal oxide in the electrode 3 and the discharge energy resistance (J).
/ Cc) is a graph showing the relationship. Specifically, the weight ratio of the metal oxide in the electrode 3 is changed by changing the electrode formation conditions, and a plurality of types of non-linear resistors having different weight ratios of the metal oxide are produced. Was carried out. Here, the weight ratio of the metal oxide is obtained by taking out a test piece of only the electrode 3 from the non-linear resistor, obtaining the amount of oxygen in the test piece by a combustion method, and calculating the weight ratio as the metal oxide. In FIG. 9, the non-linear resistor having a metal oxide ratio of 25% or less is the seventh non-linear resistor.
This is an embodiment of the present invention.

[Function and Effect] If the weight ratio of the metal oxide in the electrode 3 is as low as 25% or less, the current distribution in the non-linear resistor due to the metal oxide at the interface between the sintered body 1 and the electrode 3 is not sufficient. Uniformity can be prevented. Therefore, as shown in FIG. 9, in the seventh embodiment, a high discharge energy resistance of 500 J / cc or more can be obtained on average.

(8) Eighth Embodiment Corresponding to claim 8,
FIG. 10 [Configuration] The nonlinear resistor according to the eighth embodiment is characterized in that the average thickness of the electrode 3 is in the range of 5 μm to 500 μm. FIG. 10 shows the average thickness of the electrode 3 (μ
6 is a graph showing the relationship between m) and discharge energy resistance (J / cc). Specifically, the electrode 3 is changed by changing the electrode forming conditions.
Produce multiple types of non-linear resistors with different average thickness of
The results of performing a discharge energy withstand test on these are shown. Here, the average thickness of the electrode 3 is the average thickness obtained from the film thickness in the microscopic observation photograph of the electrode cross section. In FIG. 10, a non-linear resistor having an electrode film thickness in the range of 5 μm to 500 μm corresponds to the eighth embodiment.

[Effects] As shown in the test results shown in FIG. 10, in the eighth embodiment in which the average thickness of the electrode 3 is in the range of 5 μm to 500 μm, the average thickness is 500 μm.
A high discharge energy resistance of J / cc or more can be obtained. This is for the following reasons. That is, the electrode 3
By defining the average thickness of the electrode 3, it is possible to reduce a region in the electrode 3 where insufficient film thickness or poor adhesion occurs. At the same time, separation between the sintered body 1 and the electrode 3 due to an increase in the residual stress in the electrode 3 can be prevented. Therefore, the current distribution in the non-linear resistor can be made uniform. As a result, it is possible to increase the discharge energy resistance.

(9) Ninth Embodiment: Corresponding to claim 9,
See FIG. 11 [Configuration] A feature of the ninth embodiment is that the average surface roughness of the electrode 3 is 8 μm or less. FIG. 11 shows the average surface roughness (μm) of the electrode 3 and the discharge energy resistance (J / c).
7 is a graph showing the relationship with c), and specifically shows the results of a discharge energy withstand test of a plurality of types of non-linear resistors having different average surface roughnesses of the electrodes 3 by changing the electrode forming conditions. I have. In FIG. 11, a non-linear resistor in which the surface roughness of the electrode 3 is 8 μm or less corresponds to the ninth embodiment.

[Effects] As is clear from the test results shown in FIG. 11, in the ninth embodiment, the average surface roughness of the electrode 3 was limited to 8 μm or less, so that the distance between the stacked nonlinear resistors was reduced. The occurrence of voids is reduced, and the resulting discharge can be prevented. Therefore, on average 5
An excellent discharge energy resistance of 00 J / cc or more can be obtained.

(10) Tenth embodiment: Claim 10
Correspondence, see FIG. 12 [Configuration] The non-linear resistor according to the tenth embodiment is characterized in that the resistivity of the electrode 3 is set to 15 μΩ · cm or less. FIG. 12 is a graph showing the relationship between the electrode resistivity (μΩ · cm) and the discharge energy resistance (J / cc).
More specifically, the resistivity of the electrode 3 is changed by changing the conditions when the electrode 3 is formed, a plurality of non-linear resistors having different resistivity are produced, and the results of these discharge energy withstand tests are performed. Is shown. Here, the electrode resistivity is obtained by taking out a test piece of only the electrode 3 from the non-linear resistor, obtaining the resistance value of the test piece by a DC four-terminal method, and calculating the resistance value and the shape of the test piece. In FIG. 12, a non-linear resistor having an electrode resistivity of 15 μΩ · cm or less corresponds to the tenth embodiment.

[Operation and Effect] In general, when the resistivity in the electrode 3 exceeds 15 μΩ · cm, a high resistance portion exists at the interface between the sintered body 1 and the electrode 3. Therefore, when the non-linear resistor absorbs the discharge energy, the electrode distribution of the non-linear resistor becomes non-uniform due to the high resistance portion, and the discharge energy resistance is reduced. On the other hand, if the electrode resistivity is 15 μΩ · cm or less, there is no high-resistance portion at the interface between the sintered body 1 and the electrode 3, which can prevent the current distribution in the non-linear resistor from becoming uneven. . Therefore, as shown in FIG. 12, in the tenth embodiment in which the electrode resistivity is 15 μΩ · cm or less, the average is 500 J / cc.
The above-described excellent discharge energy resistance can be obtained.

(11) Eleventh embodiment. Claim 11
Correspondence, see FIGS. 13 and 14 [Configuration] The non-linear resistor according to the eleventh embodiment has a distance between the end 11 of the sintered body 1 and the end 13 of the electrode 3 as shown in FIG. 15 is in the range of 0.01 mm to 1.0 mm. FIG. 14 is a graph showing the relationship between the distance (mm) between the end of the sintered body of the non-linear resistor and the end of the electrode and the discharge energy resistance (J / cc) of the non-linear resistor. More specifically, it is a result of producing a plurality of non-linear resistors having different electrode shapes by changing electrode forming conditions, and performing a discharge energy withstand test thereof. In FIG. 14, the eleventh embodiment is a non-linear resistor in which the distance between the end of the sintered body and the end of the electrode is 0.01 to 1.0 mm.

[Effects] As apparent from the test shown in FIG. 14, the distance 15 between the sintered body end 11 and the electrode end 13
Is less than 0.01 mm, the discharge energy resistance of the non-linear resistor becomes low. This is because dielectric breakdown easily occurs at the interface between the sintered body 1 and the insulating layer 2 or inside the insulating layer 2 or the side surface of the insulating layer 2 when the nonlinear resistor absorbs discharge energy. Also, when the distance 15 between the end 11 of the sintered body and the end 13 of the electrode is longer than 1.0 mm, the discharge energy resistance of the non-linear resistor decreases. This is because when the non-linear resistor absorbs discharge energy, the current distribution inside the non-linear resistor becomes non-uniform.

On the other hand, in the eleventh embodiment in which the distance 15 between the end 11 of the sintered body and the end 13 of the electrode is within the range of 0.01 mm to 1.0 mm, the sintering at the time of discharge energy absorption is performed. Interface between body 1 and insulating layer 2, inside insulating layer 2 and insulating layer 2
Can be prevented from being caused on the side surface of the non-linear resistor and the current distribution in the nonlinear resistor can be made non-uniform. Therefore, on average 50
A high discharge energy resistance of 0 J / cc or more can be exhibited.

(12) Twelfth Embodiment: Claim 1
13 and FIG. 15 [Configuration] In the twelfth embodiment, the maximum value (± mm) 16 of the unevenness of the electrode end 13 shown in FIG.
It is characterized by being 0.5 mm or less. FIG.
Are the maximum value (± mm) of the unevenness of the electrode end 13 in the non-linear resistor and the discharge energy resistance (J /
9 is a graph showing the relationship of (cc). Specifically, a plurality of types of non-linear resistors having different electrode shapes were produced by changing the electrode forming conditions, and the results of the discharge energy withstand test are shown.

[Operation and Effect] In the twelfth embodiment, the maximum value 16 of the unevenness of the electrode end 13 is set to ± 0.5 m of the average value 14.
m or less, it is possible to prevent the current distribution in the non-linear resistor from becoming uneven. Therefore, as is clear from the test results shown in FIG. 15, a high discharge energy resistance of 500 J / cc or more is shown on average.

[0055]

As described above, according to the nonlinear resistor of the present invention, a wire having a diameter of 3.2 mm or less, a powder having a particle size of 120 μm or less, or a diameter of 1.6 mm or less which is energized with an output of 20 kW or less. By dissolving a metal material such as the two wires described above and spraying it on the upper and lower surfaces of the sintered body to form an electrode, it is possible to suppress a discharge in a gap in the electrode and improve a discharge energy resistance. Thus, destruction at the time of applying discharge energy could be prevented.

[Brief description of the drawings]

FIG. 1 is a graph showing a relationship between a diameter of a wire and a discharge energy resistance when an electrode of a non-linear resistor is formed.

FIG. 2 is a sectional view of a non-linear resistor according to the present invention.

FIG. 3 is a graph showing a relationship between a particle diameter of a powder and a discharge energy resistance when an electrode of a non-linear resistor is formed.

FIG. 4 is a graph showing the relationship between the diameter of an arc sprayed wire and the discharge energy resistance when forming a non-linear resistor electrode.

FIG. 5 is a graph showing the relationship between arc spraying power and discharge energy resistance when forming a non-linear resistor electrode.

FIG. 6 is a graph showing a relationship between a main component of a metal material for an electrode of a non-linear resistor and a discharge energy resistance.

FIG. 7 is a graph showing the relationship between the average surface roughness of a sintered body and the discharge energy resistance when forming a non-linear resistor electrode.

FIG. 8 is a graph showing the relationship between the porosity of the electrode of the nonlinear resistor and the discharge energy resistance.

FIG. 9 is a graph showing the relationship between the ratio of the metal oxide in the electrode of the non-linear resistor and the discharge energy resistance.

FIG. 10 is a graph showing the relationship between the electrode film thickness of a non-linear resistor and the discharge energy resistance.

FIG. 11 is a graph showing the relationship between the average surface roughness of a non-linear resistor electrode and the discharge energy resistance.

FIG. 12 is a graph showing the relationship between the electrode resistivity of the nonlinear resistor and the discharge energy resistance.

FIG. 13 is an enlarged plan view of a sintered body end and an electrode end of the nonlinear resistor according to the present invention.

FIG. 14 is a graph showing the relationship between the distance between the end of the sintered body and the end of the electrode of the nonlinear resistor and the discharge energy resistance.

FIG. 15 is a graph showing the relationship between the unevenness of the electrode end of the nonlinear resistor and the discharge energy resistance.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Sintered body 2 ... Insulating layer 3 ... Electrode 11 ... Sintered body end 13 ... Electrode end 15 ... Distance between sintered body end 11 and electrode end 13 14 ... Average of unevenness of electrode end 13 Value 16: Maximum value of unevenness of the electrode end 13

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hironori Suzuki 2-1 Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Toshiba Hamakawasaki Plant (72) Inventor Takahiko Shindo 2, Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture No. 1 Inside Toshiba Hamakawasaki Plant (72) Inventor Susumu Susumu Nishiwaki No. 2-1 Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside F-term (Reference) 5E034 EA07 EA08 EB05

Claims (12)

[Claims] 1. A disk-shaped or annular sintered body containing zinc oxide as a main component is provided, an insulating layer is formed on a side surface of the sintered body, and a pair of electrodes are formed on upper and lower surfaces of the sintered body. In the nonlinear resistor described above, a metal material made of a wire having a diameter of 3.2 mm or less is melted in a combustion gas, and the molten metal material is sprayed on upper and lower surfaces of the sintered body to form the electrode. And a non-linear resistor. 2. A disk-shaped or annular sintered body containing zinc oxide as a main component is provided, an insulating layer is formed on side surfaces of the sintered body, and a pair of electrodes are formed on upper and lower surfaces of the sintered body. In the nonlinear resistor, a metal material made of powder having a particle size of 120 μm or less is melted in a combustion gas, and the molten metal material is sprayed on upper and lower surfaces of the sintered body to form the electrode. Non-linear resistor. 3. A disk-shaped or annular sintered body containing zinc oxide as a main component is provided, an insulating layer is formed on a side surface of the sintered body, and a pair of electrodes are formed on upper and lower surfaces of the sintered body. In the above-mentioned nonlinear resistor, two metal materials each having a diameter of 1.6 mm or less are short-circuited and melted by applying a current of 20 kW or less at an output of 20 kW or less, and the molten metal material is sprayed on the upper and lower surfaces of the sintered body. A non-linear resistor, wherein the electrode is formed by: 4. The nonlinear resistor according to claim 1, wherein the metal material is mainly composed of aluminum, copper, zinc, nickel, tin or silver. 5. An average surface roughness of the upper and lower surfaces of the sintered body is 3
5. The non-linear resistor according to claim 1, wherein the thickness is in the range of from 8 [mu] m to 8 [mu] m. 6. The nonlinear resistor according to claim 1, wherein a porosity contained in the electrode is 15% or less. 7. The non-linear structure according to claim 1, wherein a weight ratio of the metal oxide contained in the electrode to the metal is 25% or less. Resistor. 8. An electrode having an average thickness of 5 μm to 500 μm.
3. The method according to claim 1, wherein the distance is in the range of μm.
The nonlinear resistor according to 3, 4, 5, 6 or 7. 9. The method according to claim 1, wherein an average surface roughness of said electrode is 8 μm or less.
9. The nonlinear resistor according to 7 or 8. 10. The method according to claim 1, wherein the resistivity of the electrode is 15 μΩ · cm or less.
10. The nonlinear resistor according to 6, 7, 8 or 9. 11. The apparatus according to claim 1, wherein a distance between an end of said electrode and an end of said sintered body is within a range of 0.01 mm to 1.0 mm. , 6, 7,
11. The nonlinear resistor according to 8, 9 or 10. 12. The method according to claim 1, wherein irregularities in a main surface direction at an end portion of the electrode are set to ± 0.5 mm or less. Or 11
The non-linear resistor as described.