KR0171607B1 - Vacuum circuit breaker and contact - Google Patents

Abstract

An electrode for a vacuum circuit breaker, the main component of which is copper and / or chromium, and the balance thereof is substantially 40% by weight or less of vanadium; In a vacuum circuit breaker comprising a fixed electrode, a movable electrode installed to access or detach from the fixed electrode, and an insulating case capable of accommodating two electrodes in a vacuum state, each of the movable and fixed electrodes is composed of copper and / or chromium as main components. A vacuum circuit breaker having a residual amount of substantially 40% by weight or less of vanadium; And chromium, copper, niobium, vanadium and incidental impurities, wherein the amount of chromium is greater than the respective amounts of niobium and vanadium.

Description

Electrode for vacuum circuit breaker and vacuum circuit breaker

1 is a cross-sectional view showing a vacuum circuit breaker to perform a circuit breaking performance test.

FIG. 2 is a metal structure photograph (100 times) of a material manufactured by vacuum melting of an alloy of 20 wt% Cr, 10 wt% V, and 70 wt% Cu,

3 and 4 are photographs of metal structures of Cu-Cr-V alloys prepared by sintering and copper infiltration,

5 is a photograph of the metal structure of the Cr-Cu-V alloy prepared by the plasma spray method,

6 is a metal structure photograph of Cu—60 wt% Cr electrode material according to a comparative example,

7 is a graph showing the relationship between the amount of vanadium added and the circuit breaking performance,

8 is a graph showing the relationship between the amount of vanadium added and the breakdown voltage,

9 is a graph showing the relationship between the amount of vanadium added and the chopping capacity,

10 is a graph showing the relationship between the amount of chromium added to Cu-5 wt% V alloy and the breakdown voltage,

11 is a photograph of metal structures of 87.5 wt.% Cr and Cu (50Cr-50Cu)-10Nb-2.5V alloys prepared by the infiltration method according to Example 4 of the present invention for producing an electrode for use in a vacuum circuit breaker. ,

12 is a metal structure photograph of 77.5 wt% Cr and Cu (70Cr-30Cu) -20Nb-2.5V alloy prepared by the hot isostasis pressing method according to Example 4 of the present invention.

13a and 13b are photographs of the metal structure of the alloy cross section shown in FIG. 12 after the circuit breaking test. FIG. 13a is a metal structure enlarged 200 times, and FIG. 13b is a metal structure enlarged 500 times.

14 is a graph showing the relationship between the added niobium and withstand voltage,

15 is a graph showing the breakdown voltage of a material prepared by adding niobium and vanadium according to Example 4,

16 is a graph showing the relationship between the amount of niobium added and the circuit breaking performance,

FIG. 17 is a graph showing circuit breaking performance of a material prepared by adding niobium and vanadium according to Example 4. FIG.

* Explanation of symbols for main parts of the drawings

1: Insulation Case 2, 3: Terminal Board

4, 5: base 6: seal

7, 8: electrode

The present invention relates to an electrode for use in a vacuum circuit breaker and a vacuum circuit breaker exhibiting excellent high current breaking characteristics and satisfactory withstand voltage performance.

Electrodes used in vacuum circuit breakers shall have the following characteristics: In other words

(1) The blocking ability is large.

(2) High withstand voltage.

(3) Low contact resistance (excellent conductivity).

(4) It should have welding resistance.

(5) Low contact wear.

(6) The current chopping should be small.

However, since it is difficult to satisfy all of the superficial characteristics at the same time, electrodes have been used which have only the necessary characteristics while giving up other characteristics.

Various materials such as Cu-Bi, Cu-Pb, Cu-Co-Bi, Cu-Co-Pb, Cu-Cr-Bi, Cu-Cr-Pb, etc. It is known to be used to make. Since the above electrode materials all contain a small low melting point metal, the lead or bismuth element scatters and evaporates due to the repetition of the large current interruption, so that the improvement of the current chopping characteristics and the weldability can be significantly realized. However, since the breakdown voltage and / or the circuit breaking performance may be degraded, none of the above materials can be used to cut off the high voltage high current.

As a material for producing a high voltage high current interruption, a material containing Cu-Cr has been used in spite of inferior in solderability or current chopping characteristics compared to an electrode containing no low melting point metal. However, a problem arises that this type of material cannot easily make a uniform form of the properties obtained due to the discharge of gas or the like from the electrode material depending on the method of manufacturing the electrode material or during the circuit breaking operation. Even worse, there is a limit to the nature of the circuit breaking. Thus, the shape of the electrode is designed so that the current flows preferably along the electrode surface. Therefore, the circuit breaking characteristic is improved by generating a magnetic field and forcibly interrupting the high current arc. Moreover, other electrodes which contain Cu and Cr as main components and which are manufactured by the same method as adding a metal such as Co, Ta, Ti, W, FeV and the like as third components have been disclosed and put into practice.

Patent inventions related to the above materials include Japanese Patent Laid-Open Nos. 59-91617, 61-140011, 62-264526, and Japanese Patent Laid-Open Nos. 63-36090 and 1-57457.

However, vacuum circuit breakers have recently been desired to block high currents of high voltage, and are desired to be reduced to the size of vacuum circuit breakers. However, conventional electrode materials cannot fully satisfy the above requirements. Thus, there is a need for the emergence of improved materials.

Accordingly, an object of the present invention is to solve the above-mentioned problems faced by the prior art and to provide a vacuum circuit capable of breaking a large current, which exhibits excellent circuit breakdown characteristics with materials of electrodes and excellent withstand voltage characteristics for use in a vacuum circuit breaker. To provide a circuit breaker.

In order to achieve the above object, one of the objects of the present invention is a vacuum circuit breaker whose main component is at least one of copper or chromium, and the remaining amount is substantially 0.1 to 40% by weight of vanadium, which is less than the amount of Cr. The present invention provides an electrode for use. Another object of the present invention is that the main component is at least one of 10 to 80% by weight of copper (preferably 40 to 80% by weight) or Cr I0 to 80% by weight (preferably 10 to 50% by weight), the remaining amount is substantially Vanadium 0.1 to 40% by weight, which is to provide an electrode for a vacuum circuit breaker that is less than the amount of chromium.

Preferably, the electrode is prepared such that chromium is 10 to 45% by weight, vanadium is 0.5 to 30% by weight and the balance is copper. In particular the composition is made such that 20 to 40% by weight of chromium, 2 to 20% by weight of vanadium and most preferably 3 to 10% by weight and the balance is substantially copper. In the electrode, copper, chromium and vanadium are preferably present in the form of Cr-rich phase V-rich phase and / or alloy phase.

It is still another object of the present invention to provide a vacuum circuit breaker electrode in which the main component is at least one of copper or chromium and the remaining amount is substantially 40% by weight or less (preferably 2 to 40% by weight) of vanadium. Is applied in an amount exceeding the limit that can be contained in a solid solution, and they are precipitated in the form of a V-rich phase or a Cr-V alloy phase or a Cu-Cr-V alloy phase in the copper matrix. In providing. It is preferable to add chromium to the copper matrix in an amount exceeding the limit contained in the solid solution and to prepare the electrode material so that it can precipitate in the form of Cr-rich phases in the copper matrix.

A further object of the present invention is a copper circuit breaker electrode wherein copper is the main component, and the chromium matrix is Cr-, with 10 to 60% by weight of chromium, up to 40% by weight of vanadium and preferably 2 to 4% by weight. It is to provide an electrode in which the rich phase and / or V-rich phase has a crystallized structure. It is preferable to prepare an electrode containing at least 15 wt% or less of a low melting point metal selected from the group consisting of Bi, Pb, Te, Sb, Tl, Se, Ce, Ca and Ag.

The above-mentioned purpose is to provide a vacuum circuit breaker containing chromium and copper as main components, both of which are preferably 50% by weight or more, and other components containing 0.1 to 20% by weight of Nb, 0.1 to 20% by weight of V, and incidental impurities. This is accomplished by providing the electrode structure used.

Still another object of the present invention is to provide a fixed and movable circuit breaker comprising a fixed electrode, a movable electrode having a movable electrode disposed thereon so as to be accessible or detached from the fixed electrode, and an insulating case for accommodating two electrodes in a vacuum state. The electrode is chromium and copper as the first electrode or main component, each of which is copper and chromium each of which is substantially 40% by weight or less of vanadium, and 0.1 to 20% by weight of niobium, 0.1 to 20% by weight of vanadium and incidental impurities Provided is a vacuum circuit breaker formed of any of the second electrodes. The second electrode contains substantially chromium in chromium, 16 to 48 weight percent copper, 0.1 to 20 weight percent niobium and 0.1 to 20 weight percent vanadium. The matrix except for both niobium and vanadium has chromium as the main component, the weight ratio of chromium to copper has a ratio of chromium to copper of 1: 1 to 4: 1 and vanadium is less than 20% by weight. In addition, chromium, copper, niobium and vanadium are each dispersed in the form of a single material metal or alloy. In addition, niobium and vanadium are added to the chromium and copper in amounts exceeding those contained in the solid solution to form Nb-rich phases, V-rich phases, Cr-Nb alloy phases, Cr-V alloy phases or Nb-V alloy phases. To be deposited.

Each of the above electrode materials can be produced by vacuum arc melting, metal powder sintering, or penetration. Also, after the metal powder sintering method or the penetration method is completed, when the forced compression or high temperature heating such as HP (hot pressing), CIP (cold isostatic pressing) or HIP (hot isostatic pressing) is performed, a remarkably improved effect is obtained. Can be. In addition, the electrode material according to the present invention can also be produced by the plasma spray method.

If the content of chromium is 20% or more, it is preferable to prepare the electrode material by sintering the mixed powder including vanadium to form a skeleton and then infiltrating the porous skeleton with copper. When chromium is 20% or less, it is preferable to melt and manufacture an electrode material.

It is well known that high withstand voltage, high current interruption performance and low surge characteristics interact with each other. There is no electrode that simultaneously meets the above characteristics. However, according to the present invention, a very wide range of characteristics can be obtained by appropriately selecting the ratios of copper, chromium, vanadium and niobium.

In the prior art, the surface of the conventional Cu—Cr electrode may become excessively rough due to the repeated application of the blocking arc heat due to the low melting point of copper, which is the main component of the conventional Cu—Cr electrode surface. Thus, undesired and indeterminate protrusions occur, which causes focusing of the electric field. As a result, the withstand voltage becomes inferior in the prior art.

The electrode material of vanadium forming a solid solution in copper has a melting point 1.5 times higher than that of copper. Thus, the conductivity of vanadium and / or niobium does not significantly decrease even if vanadium and / or niobium forms a solid solution in copper. Therefore, contact welding by arc heat can be prevented, and the roughened surface of the contact surface (the surface where the two electrodes contact each other) can be prevented. Thus, a smooth surface can always be maintained. As a result, generation of protrusions causing focusing of the electric field is reduced. This also improves the circuit breaking characteristics. According to the present invention, it is possible to provide a vacuum circuit breaker which exhibits a current interruption characteristic that is 1.8 times larger than that of the conventional Cr-Cu electrode material.

In addition, since the added vanadium has excellent electrical conductivity, satisfactory insulation recovery characteristics and excellent large current blocking performance can be obtained.

Vanadium elements in excess of the amount that can be contained in the solid solution precipitate in the copper matrix similarly to chromium elements added simultaneously. The precipitated vanadium element is dispersed in the form of V-rich phase due to precipitation or in the form of Cr-V alloy phase and Cu-Cr-V alloy phase. The V-rich phase, Cr-V alloy phase and Cu-Cr-V alloy phase precipitated in the matrix described above may coexist with the independently precipitated Cr-rich phase.

The withstand voltage can be increased by the interaction of these phases.

Since the electrode material according to the present invention is manufactured by adding vanadium or both vanadium and niobium, it is possible to obtain significantly uniform high current interruption characteristics and withstand voltage. Therefore, the electrode material according to the present invention exhibits more stable characteristics than the conventional Cu-Cr electrode material. When only vanadium is added, excellent properties can be obtained when giving a composition consisting of 20 to 80% by weight of copper, 20 to 70% by weight of chromium and 40% by weight or less of vanadium, preferably 2 to 40% by weight.

When both vanadium and niobium are added, these metals are added up to 20% by weight to improve the breakdown voltage and high current interruption characteristics. If more than 20% by weight is added, the conductivity is degraded, causing deterioration of the electrode properties. If vanadium and niobium are more than 20% by weight, the property is deteriorated because the surface is non-conductive when the two electrodes contact each other. In addition, when the content is less than 0.1%, a satisfactory effect cannot be obtained. It is preferred to add 0.5 to 10% of vanadium and niobium, most preferably 3 to 7%. The electrode material in which niobium and vanadium form a solid solution in copper has a melting point 1.5 times higher than that of copper. In addition, the conductivity of each of niobium and vanadium is not so degraded even when niobium and vanadium form a solid solution in copper. Therefore, contact welding by arc heat can be prevented, and the roughened surface of the contact surface (the surface where two electrodes contact each other) can be prevented from occurring. As a result, it is possible to reduce the occurrence of protrusions that can cause focusing of the electric field. Therefore, the circuit breaking characteristic can be improved.

Chromium is added in a larger amount than other elements for the purpose of increasing the vacuum withstand voltage. When vanadium and niobium are added, chromium is preferably added at 55 to 70%, most preferably at 55 to 65%. Copper is added for the purpose of improving conductivity, circuit breaking performance and high withstand voltage.

When niobium and vanadium are added, copper is 16 to 48%, more preferably 20 to 40%, most preferably 28 to 32%.

When niobium and vanadium are added, niobium and vanadium added in an amount exceeding the limit that can be contained in the solid solution state precipitate in the copper matrix similarly to the chromium component added simultaneously. Precipitated niobium and vanadium elements are dispersed in Nb-rich and V-rich phase forms or exist in Cr-Nb alloy phase, Cr-V alloy phase and Nb-V alloy phase. The Nb-rich phase and V-rich phase, Cr-Nb alloy phase, Cr-V alloy phase and Nb-V alloy phase precipitated in the matrix may coexist with each other. The withstand voltage can be improved by the interaction of these phases.

Since the electrode material according to the present invention is manufactured by adding vanadium or both vanadium and niobium, significantly uniform withstand voltage and high current interruption characteristics can be obtained. Therefore, the electrode material according to the present invention exhibits more stable characteristics than the conventional Cu-Cr electrode material.

When both niobium and vanadium are added, these metals are added in an amount of 20% by weight in order to improve the breakdown voltage and high current interruption characteristics. If more than 20% by weight is added, the conductivity is degraded, leading to deterioration of the electrode properties. If the total amount of vanadium and niobium is more than 20% by weight, the property is deteriorated because the surface is non-conductive when the two electrodes contact each other. Also, when added at less than 0.1%, a satisfactory effect cannot be obtained. Vanadium and niobium are preferably added at 0.5 to 10%, more preferably at 3 to 7%.

Other objects, features and advantages of the present invention will become more apparent from the following description.

1 shows the structure of a vacuum valve for use in a circuit breaking patent test performed according to various electrode materials. In Fig. 1, the vacuum valve is provided with a container composed of a cylindrical ceramic insulated case 1 and stainless terminal boards 2 and 3. The pressure of the vacuum valve is maintained at a relatively high vacuum level of 10 ^-5 to 10 ^-8 Torr. The container has a pair of electrodes, which are made of the electrode material according to the present invention. The pair of electrodes consists of a fixed electrode 7 fixed to a pedestal 4 of a copper product, and a movable electrode 8 fixed to another pedestal 5 of a copper product, the electrode 8 through bellows. It is possible to move. The cylindrical shield 6 arranged as shown in the figure prevents the scattered electrode material from adhering to the inner surface of the insulating case 1 when the electrode material is evaporated or dispersed by the circuit breaking arc. Two electrodes (7) and (8), each 20 mm in diameter, are installed in the vacuum valve and the evaluation test described below is carried out. Each electrode is shaped like a disk and brazed to a copper base.

The withstand voltage test in various electrical performances is as follows. After 10 times of AC of 300A, a voltage of 5 kV increases in steps until dielectric breakdown occurs between electrodes, and the discharge voltage value at the time of dielectric breakdown is measured.

In the circuit breakdown performance test, AC is interrupted to a 20mm diameter electrode, and it is stepped up by 500A to obtain a threshold current when the circuit breakage becomes impossible. In addition, the chopping current test measures the chopping current generated when the small current of 2 to 8A is interrupted 100 times to obtain the maximum and minimum values.

Example 1

2 is a metal structure photograph (100 magnification) of the material according to Example 1 of the present invention, and is prepared by vacuum melting that the weight percent of Cr-V-Cu alloy is 20%, 10% and 70%, respectively. The alloy is melted at a temperature of 1600-1800 ° C. where vanadium can form a solid solution in copper. As a result of the metallographic analysis, it was confirmed that a solid solution of 3 to 4% vanadium and a small amount of a solid solution of chromium were formed in the Cu matrix. In addition, chromium and vanadium in amounts exceeding the dissolution limit were precipitated in the Cu matrix.

Example 2

3 and 4 are metal structure photographs (100 magnifications) of the Cu—Cr—V alloy according to Example 2 of the present invention, and were manufactured by injecting copper into a porous sintered body of chromium and vanadium. 3 shows 48%, 48% and 4% Cr-Cu-V alloys respectively, and FIG. 4 shows 30%, 50% and 20% Cr-Cu-V alloys, respectively. . Each of the above alloys is made by molding and sintering a mixed powder of Cr-Cu-V before they penetrate into copper. The sintering temperature is about 1100 ° C and the temperature at which they penetrate into copper is about 1200 ° C.

The amount of vanadium and chromium in excess of the limit that can be contained in the solid solution state is precipitated in the V-rich phase, Cr-rich phase, Cr-V alloy phase and Cu-Cr-V alloy phase.

Example 3

5 is a metal structure photograph (100 magnification) of a Cu—Cr—V alloy according to Example 3 of the present invention and is made by a plasma spray method. 5 shows a metal structure photograph of a coating obtained by plasma spraying of mixed powder of Cr-5Cu-10V.

Example 4

According to example 4, the electrodes 7 and 8 of the vacuum circuit breaker are made using a material whose main component is Cr and additionally contains Cu, Nb, V and incidental impurities.

The materials for the electrodes 7 and 8 are manufactured using the powder metallurgy method and the penetration method. In other words, when producing 90 Cr and Cu (60Cr-40Cu) -5Nb-5V (wt%) alloys, Nb powder having a particle size of 200 to 325 mesh, V powder of the same size, Cu powder having a particle size of 100 mesh or less, and particle size Cr powder having 100 to 325 mesh is weighed to a ratio of 3.0: 3.0: 3.0: 91. These are mixed for 1 hour using a V-type mixer, and the mixed powder thus obtained is placed in a mold having a predetermined shape and compression molded at a pressure of 3 ton / cm 2.

Subsequently, the produced compact is sintered under a hydrogen atmosphere at 1100 ° C. for 2 hours to form a temporary sintered body.

Subsequently, agglomerates of oxygen-free copper are placed on the temporary sintered body, and they are heated and maintained at 1220 ° C. under vacuum for 1 hour. As a result, the temporary sintered body is infiltrated with oxygen-free copper to form a material for the electrodes 7 and 8.

FIG. 11 is a metal structure photograph (100 magnification) of 87.5 Cr and Cu (55Cr-45Cu) -10Nb-2.5V alloys according to Example 4, which was manufactured by combining powder sintering and Cu infiltration. As can be seen from the structural photograph, the Nb-rich and V-rich phases are uniformly dispersed in the matrix 55Cr-45Cu.

Example 5

According to Example 5, the electrodes 8 and 7 of the vacuum circuit breaker are made using a material whose main component is Cr and additionally contains Cu, Nb, V and incidental impurities.

The materials for the electrodes 7 and 8 are made by using both a powder metallurgy method and a high temperature isothermal compression method. That is, when making 90 Cr and Cu (80Cr-20Cu) -5Nb-5V (wt%) alloys, Nb powder having a particle size of 200 to 325 mesh, V powder having the same particle size, Cu powder having a particle size of 100 mesh or less, and particle size of 100 Cr powder with 325 mesh is weighed to 5: 5: 18: 72. The mixed powder is put into a mold having a shape beforehand and compression molded under a pressure of 4 tons / cm 2.

Subsequently, the produced compact is sintered in a hydrogen atmosphere at 1100 ° C. for 2 hours to form a temporary sintered body.

Subsequently, the temporary sintered compact is vacuum milled in a stainless steel pipe and stored at 100 ° C. for 2 hours, and the Insurger is pressed at a pressure of 2000 kg / cm 2 by a high temperature isothermal crimping process to form an electrode material.

FIG. 12 is a metal structure photograph (100 magnification) of 77.5Cr and Cu (70Cr-30Cu) -20Nb-2.5V alloy manufactured by combining powder sintering method and high temperature isothermal compression method.

As can be seen from the metal structure photograph, it can be seen that the Nb-rich and V-rich phases are uniformly dispersed in the matrix 70Cr-30Cu.

13A and 13B are cross-sectional photographs of metal structures of 77.5Cr and Cu (70Cr-30Cu) -20Nb-2.5V alloy samples shown in FIG. 12 in which circuit interruption was repeated 50 times of current flow and stop. 13A shows the same thing at 200 magnification, and FIG. 13B shows the layer which rapidly solidified at 500 magnification. In the photograph, the molten and rapidly solidified layer generated by the arc heat can be observed just below the surface of the electrical contact. In addition, fine crystal grains can be observed in the structure.

The analysis shows that 1-3% of vanadium and niobium and a small amount of chromium are in solid solution in the Cu matrix, and chromium, vanadium and niobium in amounts exceeding the solid solubility limit of the solid solution are Cr-rich, Cr- Precipitates in the V alloy phase, Cr-Nb alloy phase, or Nb-V alloy phase.

6 is a photograph of a metal structure of a conventional Cu—Cr alloy for making an electrode according to a comparative example. Conventional Cu-Cr according to the comparative example is 60 wt% Cr-40 wt% Cu alloy, which mixes 5 wt% copper powder and 95 wt% Cr powder, and temporarily sinters the mixed powder to 65% bulk density. It is made by infiltrating with copper.

[Experiment result]

FIG. 7 is a graph showing the test results using the vacuum valve shown in FIG. 1 for the purpose of investigating the relationship between the amount of added vanadium and the circuit breaking performance. Prior to this test, the surface of each electrode was subjected to 50 repetitions of flowing and interrupting current at a voltage lower than the breakdown voltage of the electrode with a high vacuum of 10 ^-9 Torr to allow arcing between the electrodes (7) and (8). To stabilize. In tests other than this test, the above preparatory treatment is carried out before the following test.

Due to the preparation process, a quenched and solidified layer having fine crystal grains is formed on the surface of each electrode. It was confirmed that the electrode made of Cr—Cr-Cr bicomponent alloy having a Cr amount in the range of 40 to 60% by weight has excellent characteristics, and 60% by weight Cr-40% by weight Cu alloy was used in the comparative example. In addition, the weight ratio of Cr to Cu of the electrode material according to the present invention is always adjusted to have a constant value (= 60: 40). In the above-mentioned state, the change of the characteristic of the alloy with the change of the quantity of the added vanadium was investigated. The axis of the graph shown in FIG. 7 is the numerical value which made the specific value of the normal Cu-60 weight% Cr alloy one. As can be seen in FIG. 7, the circuit breaking performance of Cr-Cu-V alloys according to Examples 1, 2 and 3 of the present invention is increased in proportion to the amount of vanadium added. Thus, 7 to 10 weight% of vanadium is contained, and circuit breaking performance improves 1.9 times that of the normal material. However, the circuit breaker performance deteriorates gradually when V is added by 10% by weight or more, and when vanadium is added by 15% by weight or more, a definite decrease occurs.

FIG. 8 also shows the results of tests conducted for the purpose of investigating the relationship between the amount of vanadium added and the breakdown pressure performance. FIG. 8 also shows the breakdown voltage and the amount of FeV (55 wt.% V alloy) added in place of V. FIG. Show the relationship. The test piece described above was produced in the same manner as in Example 2. As can be seen in FIG. 8, in the case of an electrode prepared by adding pure vanadium, there is no significant difference from the conventional material (Cu-60 wt% Cr alloy) when the amount of vanadium is 0.5 weight or less. However, when 30% by weight of vanadium is contained, the withstand voltage is improved in proportion to the amount of vanadium added, which has about 1.8 times higher than that of the conventional electrode. If more vanadium is added, the performance is not significantly improved and the breakdown voltage characteristic is not affected.

The withstand voltage of the electrode made by adding FeV (Fe-55 wt% V alloy) instead of pure vanadium is improved by about 1.4 times that of the conventional material when FeV is added in an amount of 10 wt%. However, the withstand voltage is not improved even if the FeV is increased by 10% by weight or more. It can be understood that the electrode made by adding FeV is worse than the breakdown voltage of the electrodes according to Examples 1, 2 and 3 in which pure vanadium is added. In addition, materials containing 10-30% by weight of FeV have a roughened surface that is unsatisfactory compared to that of conventional materials after the above test is completed.

Moreover, in the FeV-added material, the electrical conductivity (IACS%) is lowered after the test. This is considered to be due to the fact that the FeV melted and the Fe component solidified in Cu due to the arc heat generated in the test week.

9 shows the relationship between the amount of vanadium added and the performance of the engraving current. As is clear from FIG. 9, the most improved performance is obtained when 5-10 wt% of vanadium is contained.

FIG. 10 shows the relationship between the amount of Cr added and the breakdown voltage when the amount of vanadium and copper added to the electrode material is maintained at a constant value of 5% by weight and 95% by weight, respectively. As shown in FIG. 10, when the amount of added Cr is 10% by weight or less, there is no significant difference from the conventional material. However, as the amount is increased, the breakdown voltage is improved, and for a material containing 40 wt% Cr, it is about 1.5 times better than the conventional material.

Although omitted from the graph, similarly improved or better circuit breaker performance and withstand voltage further contain at least one selected from several low melting metals such as Bi, Te, Sb, Tl, Se, Ce, Ca and Ag. It was confirmed that it can be obtained from another electrode material. However, in the case where at least one selected from various low melting metals is added in an amount of 15% by weight or more, the circuit breaking performance decreases because the contact surface becomes excessively rough. It was confirmed that it is preferable to add 2-7 weight% of said additive.

FIG. 14 shows the results of a breakdown voltage test using the vacuum valve shown in FIG. 1 for an electrode material prepared by adding niobium to various Cu-Cr alloys.

FIG. 15 shows the results of a breakdown voltage test using the vacuum valve shown in FIG. 1 for an electrode material prepared by adding niobium and vanadium to various Cu-Cr alloys. As can be seen from FIGS. 14 and 15, the most improved breakdown voltage was achieved when the amount of niobium added to the various Cr-Cu materials was 5 to 10% by weight and the amount of vanadium was 10% by weight, so the comparative material 1.9 to 2.0q was improved over the breakdown voltage of 50% by weight Cu-50% by weight Cr. However, if niobium and vanadium are each added by more than 10% by weight, the breakdown voltage decreases as shown in FIG. In addition, if niobium and vanadium are each added in an amount of 30% by weight, the breakdown voltage is extremely low.

Figure 16 illustrates the relationship between added niobium and breaking current performance. 17 illustrates the relationship between the amount of niobium and vanadium and the breaking current performance according to Examples 4 and 5. FIG. As can be seen from FIG. 16 and FIG. 17, in the case of the alloy of 5 to 10% by weight Nb and 10% by weight V, the breaking current performance is extremely improved, and the breaking current performance of the alloy is 50% by weight Cu-50% by weight 1.6q of Cr alloy. However, if more than 10% by weight of niobium and more than 10% by weight of vanadium are added to various Cr-Cr materials, the breaking current performance decreases as shown in FIG. Also, if niobium and vanadium are each added in an amount of 30% by weight, the circuit breaking performance is extremely degraded.

Although omitted from the graph, the test of the chopping current shows that the chopping current performance is 1.2 times better than that of the comparative example when the electrode is made of an alloy of less than 10% by weight Nb and less than 10% by weight. However, alloys containing at least 10% by weight of Nb and at least 10% by weight of V have no significant difference compared to alloys containing less than 10% by weight of Nb and less than 10% by weight of V.

14 to 17 show the mean values of the tests, respectively. The electrode materials according to Examples 4 and 5 are remarkably stable electrode materials and have relatively little variation. This is because the deviation range of the test results of the electrode material is 40% or less of that of the test results of the 50 wt% Cu-50 wt% Cr alloy of the comparative example.

As described above, according to Examples 4 and 5, the electrode material contains Cr as a main component and additionally contains only Cu, Nb, V and incidental impurities. Therefore, an electrode material for a vacuum circuit breaker exhibiting excellent circuit breaking performance and satisfactory withstand voltage can be obtained. Improvements in both circuit breakdown performance and withstand voltage are realized by combining Cu, Cr, Nb and V in one material form and alloying them, so the most desirable performance is achieved by the proper selection of each component. Can be.

The vacuum circuit breaker made of the electrode materials according to the embodiments 4 and 5 can meet the requirements of the small size, can improve the large current breaking performance as compared with that obtained from the conventional structure, and the remarkable stable characteristics of the characteristics Can make the deviation less.

According to the present invention, a two-electrode material containing Cu and additionally containing only Cr and V or only Cr, V and Nb and incidental impurities is provided. Thus, an electrode material for vacuum circuit breaker exhibiting excellent chopping performance, circuit breaking performance and satisfactory withstand voltage can be obtained. The improvement thus achieved is obtained by the presence of Cu, Cr and V or Cu, Cr, V and Nb, respectively, as a single substance, as an alloy and in a combination thereof, so the most desirable performance is to properly select the proportion of each component. Can be achieved.

In addition, according to the present invention, a remarkably large current breaking performance and satisfactory withstand voltage can be achieved with a small deviation range with respect to the circuit breaking performance. Therefore, an electrode material and a circuit breaker for a vacuum circuit breaker exhibiting a very large current breaking performance, satisfactory withstand voltage, and a small deviation range in the circuit breaking performance can be obtained.

The vacuum circuit breaker using the electrode material according to the present invention can reduce the overall size, and has the advantage of having a high withstand voltage and a large current breaking performance compared to the conventional structure.

In addition, while the present invention has been described in a preferred form, including some specific matters, what is disclosed in the preferred form of the present invention may be changed within the scope and spirit of the present invention.

Claims (15)

Cu 40 to 80% by weight, Cr 10 to 50% by weight, V 0.1 to 20% by weight and the electrode for the vacuum circuit breaker, characterized in that consisting of inevitable impurities. The vacuum circuit breaker electrode according to claim 2, wherein said Cu, Cr, and V exist as a single metal. Cu 40 to 80% by weight, Cr 10 to 50% by weight, V: less than 0.1 to 20% by weight and unavoidable impurities, V is added to the Cu matrix in an amount greater than or equal to the amount contained in the solid solution, An electrode for vacuum circuit breakers, characterized in that it is crystallized as V-unit, Cr-V alloy or Cu-Cr-V alloy. The electrode for a vacuum circuit breaker according to claim 4, wherein Cr is added to the Cu matrix in an amount greater than or equal to the amount contained in the solid solution, and crystallized as Cr-unit in the Cu matrix. The vacuum circuit breaker electrode according to claim 4, wherein the matrix has a structure in which Cr and V are crystallized out. The low-melting metal of at least one of Bi, Pb, Te, Sb, Tl, Se, Ce, Ca and Ag is contained in an amount of 15 wt% or less. Electrode for vacuum circuit breaker. In the vacuum circuit breaker having a fixed electrode, a moving electrode freely accessible or detached from the fixed electrode, and an insulating case for accommodating the positive electrode in a vacuum state, the fixed electrode and the moving electrode are Cu 40 to 80% by weight, An electrode for a vacuum circuit breaker, characterized in that it is formed of an electrode consisting of Cr 10 to 50% by weight, V 0.1 to 20% by weight and unavoidable impurities. A vacuum comprising from 44 to 79.92% by weight of Cr, from 16 to 48% by weight of Cu, from 0.1 to 20% by weight of Nb and from 0.1 to 19.5% by weight of V, wherein the total amount of Nb and V is 20% by weight or less; Electrode material for circuit breakers. In a vacuum circuit breaker having a fixed electrode, a movable electrode which is arranged to be freely accessible to or separated from the fixed electrode, and an insulating case for accommodating the two electrodes in a vacuum state, the fixed electrode and the moving electrode are made of Cr 44 to C. A vacuum circuit breaker comprising 79.92% by weight, 16 to 48% by weight of Cu, less than 0.1 to 20% by weight of Nb and 0.1 to 19.5% by weight of V, wherein the total amount of Nb and V is 20% by weight or less. An electrode material for a vacuum circuit breaker, comprising an alloy containing 44 wt% to 79.92 wt% Cr, 16 wt% to 48 wt% Cu, and 0.1 wt% to 20 wt% Nb. A vacuum circuit breaker having a fixed electrode, a movable electrode which is freely arranged to approach or leave the fixed electrode, and an insulating case for accommodating these two electrodes in a vacuum state, wherein the fixed electrode and the moving electrode are made of Cr 44 to 79.92. A vacuum circuit breaker, comprising: an alloy containing% by weight, 16 to 48% by weight of Cu, and 0.1 to 20% by weight of Nb. An electrode material for a vacuum circuit breaker, comprising an alloy containing 40 to 50 wt% Cr, 40 to 80 wt% Cu, and 0.1 to 5 wt% Nb. A vacuum circuit characterized by consisting of an alloy containing 40 to 50% by weight of Cr, 40 to 80% by weight of Cu and 0.1 to 5% by weight of Nb and 0.1 to 19.9% by weight of V, wherein the total amount of Nb and V is 20% by weight or less. Electrode material for circuit breakers. In a vacuum circuit breaker having a fixed electrode, a movable electrode which is freely arranged to be approached or detached from the fixed electrode, and an insulating case for accommodating these two electrodes in a vacuum state, the fixed electrode and the movable electrode are made of Cr 40 to 50. A vacuum circuit breaker comprising an alloy containing% by weight, 40 to 80% by weight of Cu, and 0.1 to 5% by weight of Nb. In a vacuum circuit breaker having a fixed electrode, a movable electrode which is freely arranged to be approached or detached from the fixed electrode, and an insulating case for accommodating these two electrodes in a vacuum state, the fixed electrode and the movable electrode are made of Cr 40 to 50. A vacuum circuit breaker comprising an alloy containing 40% by weight to 40% by weight of Cu, 0.1% to 5% by weight of Nb, and 0.1% to 19.9% by weight, and the total amount of Nb and V is 20% by weight or less.

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