JP2002279867A - Vacuum valve, its manufacturing method and vacuum circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve both energization characteristics and breaking characteristics of a vacuum circuit breaker. SOLUTION: An Ag-Cu-In alloy layer with 60 to 75 wt.% of Ag, 0.1 to 15 wt.% of In, and the rest of Cu is formed on the surface of an end part of each conductive axis of vacuum valve on the side connected to an outside conductor to lead to the vacuum circuit breaker. With this structure, contact resistance characteristics at coupling part of the energization axes of the vacuum valve and the outside conductor are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum valve having excellent current-carrying and shut-off characteristics, a method for manufacturing the same, and a vacuum circuit breaker.

[0002]

2. Description of the Related Art <Representative structure of vacuum valve> FIG.
It is sectional drawing which shows the typical structure of a vacuum valve. A pair of contact materials 104 and 105 are provided facing each other in a vacuum container 103 in which openings at both ends of the insulating container 101 are hermetically sealed by metal covers 102a and 102b.
02a, 102b, and contact material 104,
105 are attached. The energizing shaft 107 can be moved in the axial direction (M) by an operation mechanism (not shown), so that the contact material 104 (hereinafter, “fixed contact 1
04 ") with a contact material 105 (hereinafter referred to as" movable contact 105 "as appropriate).

[0003] A bellows 1 is provided between the metal lid 102b and the energizing shaft 107 to keep the inside of the vacuum vessel 103 airtight and to allow the energizing shaft 107 to move in the axial direction.
08 is provided. In the figure, reference numeral 109 denotes a shield provided for enclosing the contact materials 104 and 105 and the energizing shafts 106 and 107.

FIG. 4 is a sectional view showing another configuration of a typical vacuum valve. Instead of the contact materials 104 and 105 in FIG. 3, a pair of contact materials 41 and 51 are provided so as to face each other, and on the back surface of the contact material 41 (the surface on the side to which the conducting shaft 106 is connected), the surface of the contact material 41 is provided. A small coil electrode (not shown) for generating a magnetic field is provided, and is supported by the flat electrode 40. Also, a coil electrode (not shown) is provided on the back surface of the contact material 51, and is supported by the flat electrode 50.

[0005] FIG. 5 shows a current-carrying shaft 106, 1 of a vacuum valve.
FIG. 7 is a diagram showing a state in which 07 is connected to external conductors for connecting to a vacuum circuit breaker. Fixed-side energized shaft 106
End 123 opposite to the contact material 104
Is fixed to the outer conductor 121 (power supply terminal, not shown in FIG. 1) on the left lower surface with a bolt outside the insulating container 101. The end 124 of the movable energizing shaft 107 on the opposite side to the contact material 105 is inserted into the annular conductor 125 and brazed. On the right side of the conductor 125, a thin metal plate is laminated. The upper end of the formed flexible conductor 126 is fixed by a bolt, and the lower end of the flexible conductor 126 is fixed to the movable outer conductor 122 by a bolt.

<Representative method of assembling vacuum valve>
(1) One method of manufacturing a vacuum valve is, for example, Ag
Using a 58.5% Ag-Cu-10% Pd alloy consisting of 58.5% by weight (wt%, hereinafter, simply referred to as "%"), 10% of Pd, and the remaining 31.5% of Cu. Each member such as a connection portion between the contact material and the current-carrying shaft, a connection portion between the contact material and the electrode, and a connection portion between the metal lid and the bellows portion is previously "partially brazed"("partialbrazing").
Process). This 58.5% Ag-Cu-10% Pd
The alloy layer has a solidus temperature of 825 ° C, a liquidus temperature of 850 ° C,
Appropriate joining work temperature 850-950 ° C, JIS standard BP
d-2.

Next, the members that have been "partially brazed" are stored in an insulating container 101, and both ends of the insulating container 101 are closed with metal lids 102a and 102b.
An alloy with a melting temperature low enough that the Cu-10% Pd alloy does not melt, typically the most reliable 72% Ag-
28% Cu alloy (solidus temperature 780 ° C, liquidus temperature 78
Each member is joined at an appropriate joining operation temperature (820 to 830 ° C) of 0 ° C and JIS standard BAg-8). Then, while keeping the inside of the insulating container 101 airtight (evacuating the inside to a vacuum), the insulating container 101 is closed with the metal lids 102a and 102a.
The final assembly of the vacuum valve is performed by hermetic sealing in 2b ("whole assembly" step). The method of performing the assembly by the “partial brazing” step and the “whole assembly” step is called a separation and assembly method.

(2) As another method of manufacturing a vacuum valve, the "partial brazing" step and the "whole assembly" step are performed separately without separately connecting the members and evacuating. collective assembly method has also been implemented.

<Electrification Characteristics and Interruption Characteristics of Vacuum Circuit Breaker> In general, the main part of the vacuum circuit breaker is composed of a pair of contact materials 104 arranged at respective ends of two fixed-side and movable-side energization shafts 106 and 107. And a vacuum valve for opening and closing a current by utilizing the excellent arc diffusivity in a vacuum while opening and closing, and an end opposite to a side on which a connecting material for each of the conducting shafts 106 and 107 is mounted. And external conductors 121 and 122 connected so as to sandwich a vacuum valve therebetween.

The vacuum circuit breaker is normally energized when the quantity contact material is connected. When the energizing shaft 107 moves in the direction of arrow M in FIG. 1 from this state, the movable contact 105 is separated from the fixed contact 104, and an arc is generated between both contact materials. This arc is maintained by the generation of the metal vapor from the cathode (for example, the movable contact 105) side. When the current reaches the zero point (zero point), the generation of the metal vapor stops, the arc cannot be maintained, and the interruption is completed.

If the breaking current is large, the arc generated between the two contact materials becomes extremely unstable due to the interaction between the magnetic field generated by the arc itself and the magnetic field generated by the external circuit. As a result, the arc contact material 104,
05 (if the contact material is attached to and integrated with the electrode, the arc may also move on the electrode surface) and offset to the edge or periphery of the contact material next, the portions locally overheated to release a large amount of metal vapor, lowering the degree of vacuum in the vacuum chamber 103. This often depends mainly on the state of the contact material, which is one of the factors that lower the current interrupting performance of the vacuum circuit breaker.

Immediately after the high current is cut off and immediately after the rated current is cut off, the surfaces of the contact materials 104 and 105 become extremely hot mainly due to arc heat, and the heat passes through the conduction shafts 106 and 107 and becomes high. It is transmitted to the end surface of the energized shaft. Joule heat is also generated, and the heat is also transmitted to the end surface through each current-carrying shaft. The magnitude of the former arc heat depends on the interrupted power energy, and mainly depends on the contact characteristics of the contact material.
The magnitude of the Joule heat is determined by the bulk resistance of the contact material,
It depends on the contact resistance between the fixed contact and the movable contact, and also on the contact resistance between the end of the conducting shaft and the external conductor.

In a vacuum circuit breaker, such current interruption performance,
In addition to the three basic conditions of withstand voltage performance and welding resistance performance,
Suppression of the occurrence of restriking is an important condition. However, because some of these elements are contradictory, it is impossible to satisfy all the conditions if the contact material is made of a single metal type.

For this reason, in many vacuum valves in practical use, contact materials combining two or more kinds of elements that mutually complement the insufficient performance are specified, such as those for large current and high withstand voltage. The selection and adoption of contact materials suitable for the above-mentioned applications have been carried out, and vacuum valves have been developed that are compatible with some functions. At present, a vacuum valve that sufficiently satisfies both of the energizing characteristics and the breaking characteristics, which has been further enhanced, has not yet been obtained.

For example, Cu—Cr containing about 50% by weight of Cr is used as a contact material for the purpose of breaking large current.
Alloys (JP-A-45-35101) are known. This alloy is excellent in that Cr itself retains almost the same vapor pressure characteristics as Cu, and realizes high-voltage large-current disconnection by strong gas gettering, and achieves both high voltage resistance and large-capacity cutoff. Contact material. In addition, the material is manufactured (sintering process, etc.) while giving due consideration to the selection of the raw material powder, the contamination of impurities, the management of the atmosphere, and the like, and the product is made with consideration given to the processing technology from the material to the contact material. However, despite the use of such excellent contact materials,
In some cases, the current-carrying characteristics and the breaking performance are reduced, and improvements are desired.

Factors that degrade the current-carrying characteristics and breaking performance of the vacuum circuit breaker include contact resistance characteristics between the fixed contact and the movable contact, the conductivity (specific resistance) of each conducting shaft and the external conductor,
It is considered that the contact resistance characteristics generated between the current-carrying shaft and the outer conductor, the contact thermal resistance characteristics between the current-carrying shaft and the outer conductor, and the like have a significant effect. In addition, the contact resistance between the end of the current-carrying shaft and the external conductor often fluctuates during the manufacturing process of the vacuum valve.

Further, in recent years, since the adaptation to a severe circuit in which a higher current interruption and a higher voltage may be applied has been performed on a daily basis, the above-mentioned contact material is used. By simply improving the characteristics described above, there is a possibility that an abnormal increase in contact resistance or an abnormal increase in temperature will occur when the next current is opened or closed, and the current-carrying characteristics and cutoff characteristics of the vacuum circuit breaker cannot be sufficiently obtained.

Therefore, in recent manufacturing of a vacuum valve, in order to avoid such a situation, an external conductor (fixed side) 121 is connected to the upper end 123 of the fixed side conducting shaft 106 as shown in FIG. In order to reduce the contact resistance and the contact thermal resistance at the time of connection, Ag plating (which forms an AgCu alloy because the current-carrying shaft is mainly made of Cu) or Sn (tin) plating (when Sn diffuses, AgCu
(Forming a Sn alloy). Similarly, the lower end 124 of the movable shaft 107 is also plated with Ag or Sn.

[0019]

However, plating with such an AgCu alloy or AgCuSn alloy has the following problems.

(1) 60% as a reference example at the end of the conducting shaft
In the case of forming an Ag-30% Cu-10% Sn alloy layer (appropriate joining operation temperature of 720 to 840 ° C; JIS standard BAg-18), the solidus temperature is greatly reduced to 600 ° C.
And the liquidus temperature also drops significantly to 720 ° C. For this reason, when bonding is performed at an appropriate bonding temperature of 820 to 830 ° C. for a 72% Ag-28% Cu alloy, the 60% Ag-30% Cu-10% Sn alloy layer on the surface of the end portion of the conducting shaft becomes:
Excessive fluidity due to the low melting temperature is shown, it flows excessively not only on the surface of the end of the energized shaft but also around the energized shaft and the side of the energized shaft and is unevenly distributed. Become. As a result, there is a problem that the contact resistance varies due to a shortage of the alloy layer on the surface of the end of the current-carrying shaft and the stability of the contact resistance between the end of the current-carrying shaft and the external conductor is impaired. Was. For example, 55 in which the ratio of Ag and Sn is changed
In the case of the% Ag-30% Cu-15% Sn alloy layer, the solidus temperature and the liquidus temperature were further lowered, and had the same problem.

(2) On the other hand, 72% Ag-
When forming a 28% Cu alloy layer (JIS standard BAg-8), both the solidus temperature and the liquidus temperature are 779 ° C., so that the suitable joining of the 72% Ag-28% Cu alloy layer is performed. When joined at an operating temperature of 820 to 830 ° C., a sufficiently melted 72% Ag-28% Cu
An alloy layer is formed.

However, when the diameter of the end of the current-carrying shaft is relatively large, the joining operation temperature (820-830 ° C.)
Despite being higher than the melting temperature of the 2% Ag-28% Cu alloy, 72% Ag-28% C on the end surface of the conducting shaft
There is an unexpected phenomenon that a region where the u alloy does not partially melt exists. Further, even when the heat capacity of the energized shaft is excessively large, 7
The thickness of the 2% Ag-28% Cu alloy layer phenomenon also seen that non-uniform region will be present. These phenomena, the stability of the contact resistance between the current-carrying rod and the outer conductor is disadvantageously impaired.

[0023] Thus, improved contact material, despite being promoted and improvement of contact resistance characteristic between the current-carrying rod and the outer conductor, under recent circumstances as described above, yet the vacuum circuit breaker Are not sufficient in current-carrying characteristics and cut-off characteristics.

The present invention has been made in view of the above, and an object of the present invention is to provide a vacuum valve capable of improving both the current-carrying characteristics and the breaking characteristics of a vacuum circuit breaker.

Another object of the present invention is to provide a method for manufacturing the above-mentioned vacuum valve and a vacuum circuit breaker using the above-mentioned vacuum valve.

[0026]

In order to achieve the above object, a vacuum valve according to claim 1 is provided with a pair of contact materials inside an airtightly sealed insulating container, and inserted from both ends of the insulating container. A vacuum valve in which one end of each energized shaft is connected to each contact material, and the other end of each energized shaft is connected to an external conductor for connecting to a vacuum circuit breaker outside the insulating container. Ag is 60 to 75% by weight on the surface of the end of each energized shaft on the side connected to the conductor,
A containing 0.1 to 15% by weight of In and the balance of Cu
A g-Cu-In alloy layer is formed.

In the present invention, the surface of the end of each energized shaft on the side connected to the external conductor has 60 to 75% by weight of Ag and 0.1 to 15% by weight of In (indium) (wt.
%, Hereinafter appropriately referred to as “%”), and the remainder is formed by forming an Ag—Cu—In alloy layer made of Cu.
The contact resistance characteristics of the connection portion between the current-carrying shaft of the vacuum valve and the external conductor for connection to the vacuum circuit breaker are improved, so that good current-carrying characteristics and good breaking characteristics can be obtained.

That is, I in the Ag—Cu—In alloy layer
When the amount of n exceeds 15% by weight, the solidus temperature becomes 63%.
0 ℃ less, the liquidus temperature decreases to 680 ° C. or less, 72% Ag-28% Cu alloy suitable junction working temperature (eight hundred twenty to eight hundred and thirty ° C.) with Ag-Cu-In alloy layer of the energization shaft When joined to the end, the Ag-Cu-In alloy layer shows excessive fluidity on the surface of the end of the energized shaft, and is not only on the end surface of the energized shaft but also around the energized shaft. The Ag-Cu-In alloy layer is distributed to an uneven thickness, because the Ag-Cu-In alloy layer excessively flows to the side surface of the current-carrying shaft. For this reason, the contact resistance between the current-carrying shaft and the external conductor varies, and the contact resistance characteristics become unstable. Such unstable contact resistance characteristics have an unfavorable effect on the temperature rise characteristics of the connection portion between the current-carrying shaft and the external conductor, and also lead to a decrease in the current-carrying characteristics.

On the other hand, when the amount of In in the Ag—Cu—In alloy layer is less than 0.1% by weight, the solidus temperature of the alloy layer,
Low effect of lowering the liquidus temperature, 72% Ag-28
% Cu alloy layer when joined at an appropriate joining operation temperature,
Local unmelted portions, thickness non-uniformity, and the like are seen, and the contact resistance characteristics are still unstable.

For example, when a 60% Ag-30% Cu-10% In alloy layer according to the present invention is formed on the end surface of each energized shaft, the solidus temperature is 60% Ag of the reference example. −
The temperature is 685 ° C., which is much higher than that of the 30% Cu-10% Sn alloy layer (the liquidus temperature is almost equal to 710 ° C.). As a result, when the joining operation is performed at a general joining operation temperature of 820 to 830 ° C. of a 72% Ag-28% Cu alloy,
The 60% Ag-30% Cu-10% In alloy layer flows in a good state (a state in which the alloy layer has a uniform thickness and no unmelted region) only on the end surface of the conducting shaft, and is uniformly distributed. Shows stable contact resistance characteristics.

As described above, the alloy layer formed on the end surface of the current-carrying shaft, when the same amount (% by weight) of In or Sn is contained in the AgCu alloy, the AgCuI of the present invention is used.
In the n alloy layer and the AgCuSn alloy layer of the reference example, when In is used, a higher solidus temperature is exhibited and appropriate fluidity is exhibited, whereas in the case of Sn, excessive fluidity is exhibited. It flows out to an unnecessary part to be shown, which causes instability of the contact resistance characteristic.

The vacuum valve according to the present invention described in claim 2 is the vacuum valve according to claim 1, wherein the Ag-C
The u-In alloy layer has a solidus temperature of 630 ° C. or more and 78
0 ° C or lower and liquidus temperature 680 ° C or higher and 780 ° C
Less than.

In the present invention, by setting the solidus temperature of the Ag—Cu—In alloy layer to 630 ° C. or more and less than 780 ° C. and the liquidus temperature to 680 ° C. or more and less than 780 ° C.
When an Ag-Cu-In alloy layer is formed on the end surface of the current-carrying shaft at an appropriate joining operation temperature (820 to 830 ° C) when using a 2% Ag-28% Cu alloy, Since the solidus temperature and liquidus temperature are appropriate, it prevents the unmelted region of the alloy layer from being formed on the end surface, so that a uniform thickness can be obtained and stable contact resistance characteristics can be obtained. I have.

That is, the solidus temperature of the metal layer is 630 ° C.
When the joining is performed at an appropriate joining temperature (820 to 830 ° C.) of a 72% Ag-28% Cu alloy, the alloy layer on the surface of the end of the conducting shaft shows excessive fluidity, The alloy layer flows out to the periphery of the shaft and to the side surface of the current-carrying shaft, leading to a shortage of the alloy layer at a necessary portion, causing variation in the contact resistance distribution and instability of the contact resistance characteristics.

On the other hand, when the solidus temperature exceeds 780 ° C., A containing In in the alloy layer on the end surface of the current-carrying axis
The production amount of the gCu compound increases, and an unmelted region is produced, which causes instability of the contact resistance characteristics.

When the liquidus temperature of the metal layer is lower than 680 ° C., if the joining operation is performed at an appropriate joining operation temperature (820 to 830 ° C.) of a 72% Ag-28% Cu alloy, the excessive fluidity will still occur. And the alloy layer flows out to unnecessary portions. When the liquidus temperature exceeds 780 ° C., an unmelted region is also formed in the alloy layer on the end surface of the current-carrying shaft, and the contact resistance characteristics become unstable.

A vacuum valve according to a third aspect of the present invention is the vacuum valve according to the first or second aspect, wherein
The g-Cu-In alloy layer is characterized in that its thickness is in the range of 1 to 200 μm.

In the present invention, by setting the thickness of the Ag—Cu—In alloy layer to be in the range of 1 to 200 μm, the contact resistance characteristics between each current-carrying shaft and the external conductor are improved. Energizing characteristics and cutoff characteristics are obtained.

According to a fourth aspect of the present invention, there is provided the vacuum valve according to any one of the first to third aspects, wherein the Ag—Cu—In alloy layer has a ratio of Ag to Cu [(Ag ) / (Ag + Cu)] from 0.65 to 0.8
The range is characterized by.

In the present invention, the ratio of Ag to Cu in the Ag—Cu—In alloy layer [(Ag) / (Ag + C
u)] is in the range of 0.65 to 0.8, so that the contact resistance characteristics between each energized shaft and the external conductor are improved, and good energization characteristics and cutoff characteristics are obtained.

That is, [(Ag) / (Ag) in the alloy layer
+ Cu)] values less than 0.65 and 0.8 or more are based on the fact that it is difficult and unsuitable to control the solidus temperature and liquidus temperature within the predetermined ranges.

According to a fifth aspect of the present invention, there is provided the vacuum valve according to any one of the first to fourth aspects, wherein the Ag-Cu-In alloy layer comprises a matrix containing an AgCu alloy as a main component. And an In compound containing Ag or / and Cu, wherein the In compound is dispersed in a matrix.

In the present invention, since the In compound in the alloy layer on the end surface of the current-carrying shaft is more brittle than the matrix mainly composed of the AgCu alloy, the In compound is dispersed in the matrix. In this In
Crack growth originating from the compound can be absorbed by the matrix.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a vacuum valve, wherein a pair of contact materials are provided inside an airtightly sealed insulating container, and the end of each energized shaft inserted from both ends of the insulating container. parts are connected to each contact material, in the manufacturing method of the other end of each current-carrying rod to produce a vacuum valve which is connected to the outer conductor for connecting the vacuum circuit breaker outside of the insulating container, wherein the outer conductor On the surface of the end of each energized shaft on the side connected to
Ag in which n is 0.1 to 15% by weight and the balance is Cu
-It is characterized in that the Cu-In alloy layer is joined at a joining operation temperature of 780 ° C or more and less than 840 ° C.

In the present invention, an Ag—Cu—In alloy layer is joined to the end surface of each energized shaft at a joining operation temperature of 780 ° C. or more and less than 840 ° C., so that 72% Ag-2
Against 8% Cu alloy bonding working temperature (eight hundred twenty to eight hundred and thirty ° C.), to allow bonding at a suitable temperature, so that stable contact resistance characteristic can be obtained.

For example, if the joining temperature is lower than 780 ° C., the Ag—Cu—In alloy layer on the end surface of the current-carrying shaft does not have sufficient fluidity, which leads to instability of the contact resistance characteristics. Becomes

According to a seventh aspect of the present invention, there is provided the method of manufacturing a vacuum valve according to the sixth aspect, wherein Ag is 60 to 75% by weight, In is 0.1 to 15% by weight, A having a thickness of 1 to 200 μm with the remainder being Cu
placing the g-Cu-In alloy foil in contact with the surface of the end of each of the energized shafts, and applying the alloy foil to the surface of the end of each of the energized shafts at a joining operation temperature of 780 ° C or more and less than 840 ° C. And a joining step.

[0048] In the present invention, Ag is 60 to 75 wt%, an In 0.1 to 15 wt%, the Ag-Cu-In alloy foil with a thickness of 1~200μm that the balance of Cu, 780
The contact resistance between each energized shaft and the external conductor is improved by joining the end surfaces of the energized shafts at a working temperature of 840 ° C. or more and less than 840 ° C., and good energizing and blocking characteristics Is to be obtained.

That is, at the time of joining, diffusion of Ag, Cu, and In alloy particles into the current-carrying axis (Cu) occurs.
If the thickness of the Cu—In alloy layer is less than 1 μm, the amount is too small, so that the alloy layer after diffusion cannot maintain the initial composition, and as a result of the composition fluctuation, the appropriate solidus temperature and liquidus temperature are obtained. Is difficult to secure.

On the other hand, when the thickness of the Ag—Cu—In alloy layer is 2
If the thickness exceeds 00 μm, the surface of the alloy layer after melting loses smoothness, the contact resistance characteristics and the temperature rise characteristics vary, and the amount of the alloy layer on the end surface of the current-carrying shaft becomes excessive.
The remaining alloy layer flows out to unnecessary portions such as the periphery and side surfaces of the current-carrying shaft, which causes instability of the contact resistance characteristics.

The method for manufacturing a vacuum valve according to the present invention according to claim 8 is the method for manufacturing a vacuum valve according to claim 6, wherein Ag is 60 to 75% by weight, In is 0.1 to 15% by weight, A step of laminating a single foil of Ag, In, and Cu, each having a thickness adjusted so that the remainder is Cu, on the surface of the end portion of each of the energized shafts; Bonding the single foil to the surface of the end of each energized shaft.

According to the present invention, A is finally composed of 60 to 75% by weight of Ag, 0.1 to 15% by weight of In and the balance of Cu.
In order to obtain a g-Cu-In alloy layer, even if the form before the start of the joining operation is a single foil of Ag, In, and Cu, an alloy layer similar to that obtained when ternary alloying is obtained from the beginning is obtained. It is based on

According to a ninth aspect of the present invention, there is provided a method for manufacturing a vacuum valve according to the sixth aspect, wherein the alloy foil comprising any two of Ag, In, and Cu and the remaining one is used. A single foil composed of a single foil of which the thickness is adjusted on the surface of the end of each of the energized shafts so that Ag is 60 to 75% by weight, In is 0.1 to 15% by weight, and the remainder is Cu. And bonding the alloy foil and the single foil to the surface of the end of each of the energized shafts at a bonding operation temperature of 780 ° C. or more and less than 840 ° C.

According to the present invention, the final composition of A is 60 to 75% by weight of Ag, 0.1 to 15% by weight of In, and the balance of Cu.
To obtain a g-Cu-In alloy layer, Ag, In, Cu
This is based on the fact that the same alloy layer as in the case of ternary alloying from the beginning can be obtained even if the alloy foil composed of any two of the above and the single foil composed of the remaining one is compounded.

According to a tenth aspect of the present invention, there is provided a method of manufacturing a vacuum valve according to any one of the sixth to ninth aspects, wherein the ratio of Ag to Cu [(A
g) / (Ag + Cu)] is referred to as comprising a step of in the range of 0.65 to 0.8.

In the present invention, the ratio of Ag to Cu in the Ag—Cu—In alloy layer [(Ag) / (Ag + C)
u)] is in the range of 0.65 to 0.8, so that the contact resistance characteristics between each energized shaft and the external conductor are improved, and good energization characteristics and cutoff characteristics are obtained.

An eleventh aspect of the present invention provides a vacuum circuit breaker using the vacuum valve according to any one of the first to fifth aspects.

According to a twelfth aspect of the present invention, there is provided a vacuum circuit breaker using a vacuum valve manufactured by the manufacturing method according to any one of the sixth to tenth aspects.

According to the eleventh and twelfth aspects of the present invention, by using the above-mentioned vacuum valve or the vacuum valve manufactured by the above-described manufacturing method, the distance between each energized shaft of the vacuum valve and the external conductor is reduced. The contact resistance characteristics are improved, and the current-carrying characteristics and the breaking characteristics of the vacuum circuit breaker can be improved.

[0060]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to improve the current-carrying characteristics and the breaking characteristics of a vacuum valve, stabilization of the contact resistance characteristics between the end of a current-carrying shaft (power introduction terminal) and an external conductor is deeply involved. In the present embodiment, in order to stabilize the contact resistance characteristics, the surface of the end of the current-carrying shaft is coated with Ag-Cu-
An In alloy layer is formed.
75% by weight, 0.1 to 15% by weight of In (indium), the balance being Cu, thickness of 1 to 200 μm, solidus temperature of 680 ° C. or more and less than 780 ° C., liquidus temperature of 68
It is characterized in that the temperature is not lower than 0 ° C. and lower than 780 ° C.

[0061] Hereinafter, will be explained with reference to drawings, embodiments of the present invention.

FIG. 1 is a table showing a summary of the evaluation conditions of the Ag—Cu—In alloy layer for examining the current-carrying characteristics, the breaking characteristics, and the like. In the same figure, Examples 1 to 8 show an Ag—Cu—In alloy layer to which the present invention was applied, and Comparative Example 1
To 8 are Ag- prepared for comparison of characteristics with each of the examples.
3 shows a Cu-In alloy layer.

The evaluation conditions include the composition of the alloy layer formed on the end surface of the energized shaft, the melting temperature of the alloy layer, the joining work temperature for forming the alloy layer on the end of the energized shaft, and the end of the energized shaft. The thickness of the alloy layer formed on the part surface was set. The composition of this alloy layer is based on the ratio of Ag and Cu [(Ag) / (Ag + C
u)], and the In content (% by weight).

FIG. 2 is a table showing a summary of evaluation results of the Ag—Cu—In alloy layer. The items of the evaluation result are
(1) conduction characteristics, (2) contact resistance characteristics, (3) breaking characteristics, and (4) remarks.

<1. Current-carrying characteristics> Dismountable vacuum using a 25 mm-diameter Cu-made current-carrying shaft and 30 mm-diameter, 5 mm-thick disk-shaped fixed / movable contacts (75% Cu-25% Cr is used for the contact material) Attach to the breaker, the end of the conducting shaft and thickness 5mm, width 25mm, length 200m
The simple type vacuum circuit breaker was assembled by making face-to-face contact with the m external conductor. The basic configuration of this vacuum valve and the connection configuration between the current-carrying shaft and the external conductor are almost the same as those shown in FIGS.

When the circuit of 200V × 500A is opened and closed 2000 times, the temperature characteristics (the average value of the rising values excluding the measured ambient temperature,
The maximum rise) was measured. The evaluation of the measured values at this time was determined as follows, and the evaluations A to C were “passed”, and the evaluations X to
The evaluation Z was used as a measure of “poor”.

The rise value is 10 ° C. or less (Evaluation A) The rise value is less than 10 to 20 ° C. (Evaluation B) The rise value is less than 20 to 40 ° C. (Evaluation C) The rise Value is less than 40 to 60 ° C. (Evaluation X) Rise value is less than 60 to 80 ° C. (Evaluation Y) Rise value is 80 ° C. or more (Evaluation Z) <2. Contact Resistance Characteristics> After measuring the above temperature characteristics, the connecting portion between the end of the conducting shaft and the external conductor is disassembled and separated, and then reconnected, a 100 kg load is applied to this connecting portion, and the contact resistance is measured at a measuring current of 20 A. Was measured. In FIG. 2,
The relative value when the contact resistance value of Example 2 is set to 100 is shown.

<3. Breaking characteristics> Attach a vacuum valve for a breaking test equipped with a contact material with a diameter of 70 mm to the vacuum circuit breaker, apply baking, voltage aging, etc., connect to a 24 kv, 50 Hz circuit, and increase the current by approximately 1 kA. The current value at which the cutoff limit was reached was evaluated for three vacuum valves. Note that in FIG.
The relative value when the current value of the sample was set to 1.0 was shown by the variation width of three lines.

As an outline of the assembly of the vacuum valve for the shut-off test, first, a ceramic insulating container mainly made of AL ₂ O ₃ polished to an average surface roughness of about 1.5 μm was prepared. This For ceramic insulating vessel was subjected to a heat treatment prior to 1600 ° C. prior to assembly. A 42% Ni-Fe alloy having a plate thickness of 2 mm was prepared as a sealing metal. As a brazing material, 0.1% thick 72% Ag-
A 28% Cu alloy plate was prepared. For the contact material, 7
5% Cu-25% Cr was prepared. By placing the respective members have been prepared so as to allow hermetic sealing, 5 × 10 ^-4 Pa
In the vacuum atmosphere, the sealing fitting and the ceramic insulating container were hermetically sealed.

[0070] <4. Remarks> Bonding condition when Ag-Cu-In alloy layer is formed on the end surface of current-carrying shaft at a suitable joining temperature (820-830 ° C) of 72% Ag-28% Cu alloy, and comprehensive evaluation showed that. The overall evaluation was evaluated as “O” if good, and “X” otherwise.

Next, a description will be given of the results of a study on each example and each comparative example.

<Examples 1-4 and Comparative Examples 1-2> As shown in the evaluation conditions of FIG. 1, A formed on the end surface of the current-carrying shaft
Ratio of Ag and Cu in g-Cu-In alloy [(Ag)
/ (Ag + Cu)] is 0.72, and the joining operation temperature when forming an alloy layer on the end surface of the conducting shaft is 820 to 830.
℃, the thickness of the alloy layer formed on the end surface of the conducting shaft is 95
The In amount in the alloy was zero in Comparative Example 1, 0.1 to 0.2% in Example 1, 3 to 3.5% in Example 2, and 7.4 in Example 3. ~ 7.6
%, 14.5 to 15.0% in Example 4, and 20.1 to 20.5% in Comparative Example 2, and the current-carrying characteristics, contact resistance characteristics, and cutoff characteristics were examined.

As shown in the evaluation results of FIG. 2, the amount of In formed on the end surface of the current-carrying shaft was 0.1 to 15.0 (Example 1).
In the cases of (4) to (4), the average values of the temperature rise characteristics indicating the current-carrying characteristics during the 2,000 times opening / closing were (Evaluation A to B), and the maximum values were also (Evaluation A to C), which were in good ranges. The contact resistance characteristics were in a good range, with the relative value when Example 2 was set to 100 being 90 to 110 before and after the energization test. The relative value when the blocking characteristic was 1.0 in Example 2 was 0.95.
~ 1.05, which was a good range.

On the other hand, the In amount was zero (Comparative Example 1).
In the case of (1), the average value of the temperature rise characteristics indicating the current-carrying characteristics was good in (Evaluation C), but the maximum value was (Evaluation Y), indicating a large variation. The relative value of the contact resistance characteristic when the value of Example 2 was set to 100 was 90 to 3 after the energization test.
10 showed a large variation. As for the cutoff characteristic, the relative value when Example 2 was set to 1.0 was 0.95 to 1.05.
And within a good range.

When the amount of In was 20.1 to 20.5% (Comparative Example 2), the average value and the maximum value of the temperature rise characteristics were (Evaluation X to Y), indicating a large variation. . As for the contact resistance characteristics, the relative value when Example 2 is set to 100 is 120 to 240 before the energization test, and 130 to 240 after the energization test.
Degradation 340 (degree numbers contact resistance is larger, the characteristics decrease)
did. As for the cutoff characteristics, the relative value when Example 2 was set to 1.0 was 0.9 to 1.0, which was in a good range.

As described above, the I formed on the end surface of the conducting shaft
The amount of n is related to various properties, and it has been confirmed that the amount is appropriately in the range of 0.1 to 15%.

<Example 5, Comparative Examples 3-4> Example 1
-4, Comparative Examples 1-2, the joining operation temperature was 820-8
Although the temperature was kept constant at 30 ° C., here, the joining operation temperature was changed and the current-carrying characteristics, the contact resistance characteristics, and the breaking characteristics were investigated.

As shown in the evaluation conditions of FIG. 1, in Example 5, the joining temperature was set at 780 to 840 ° C., and in Comparative Example 3, 87
0 to 890 ° C., and 750 to 780 ° C. in Comparative Example 4, respectively. In each case, the ratio of Ag to Cu was constant at 0.72, the In amount was constant at 7.4 to 7.6%, the melting temperature of the alloy layer was 646 to 748 ° C, and the thickness of the alloy layer was 95%.
１０５105 μm.

As shown in the evaluation results of FIG. 2, when the joining temperature is 780 to 840 ° C. (Example 5), 200
The temperature rise characteristics during the zero-time opening and closing were both in the average value and the maximum value (evaluation A), and were in a favorable range. The contact resistance characteristics were in a good range, with the relative value when Example 2 was set to 100 being 90 to 110 before and after the energization test. The relative value when the barrier properties were also Example 2 and 1.0, 0.95
~ 1.05, which was a good range.

On the other hand, the joining operation temperature was 870-89.
In the case of 0 ° C. (Comparative Example 3), the average value of the temperature rise characteristics of the current-carrying shaft was good in (Evaluation B), but the maximum value was (Evaluation X), showing a large variation. As a result of surface observation, it was found that the alloy layer on the end surface of the current-carrying shaft flowed out from the end to an unnecessary portion. This leads to non-uniformity in the thickness of the alloy layer, which is not preferable. The contact resistance characteristic of Comparative Example 3 is 90
１１０110, which is in a good range, but deteriorated to 90〜230 after the energization test. The cutoff characteristic was 1.0 in Example 2.
And the relative value was 0.95 to 1.05, which was a good range.

[0081] On the other hand, the junction working temperature is 750~780 ℃
In the case of (Comparative Example 4), the average value of the temperature rise characteristics of the current-carrying shaft was good in (Evaluation C), but the maximum value was (Evaluation X), indicating a large variation. The contact resistance characteristic is 100 to 180 before the energization test and is in a good range,
It deteriorated to 100 to 275 after the energization test. The relative value when the blocking characteristic is 1.0 in Example 2 is 0.8 to
Degraded to 0.9. This is due to poor formation of the alloy layer due to too low a working temperature.

As described above, the Ag-Cu
The bonding operation temperature when forming the -In alloy layer is 780 to
It was confirmed that the range of 840 ° C. was appropriate.

<Examples 6 to 7, Comparative Examples 5 to 6> In Examples 1 to 5 and Comparative Examples 1 to 4, the thickness of the alloy layer formed on the end surface of the conducting shaft was fixed at 95 to 105 μm. Although the case was shown, here, the thickness of the alloy layer was changed, and the current-carrying characteristics, the contact resistance characteristics, and the breaking characteristics were investigated.

As shown in the evaluation conditions of FIG. 1, the thickness was 1.0 to 3.0 μm in the sixth embodiment, and 195 to 2 μm in the seventh embodiment.
00 μm, less than 0.1 μm in Comparative Example 5, and 400 to 500 μm in Comparative Example 6, respectively. In each case, the ratio of Ag to Cu was 0.72, and the In content was 7.4 to 7.4.
7.6%, the melting temperature of the alloy layer was 646-748 ° C, and the joining temperature was 820-830 ° C.

As shown in the evaluation results of FIG. 2, the thickness of the alloy layer formed on the end surface of the current-carrying shaft is 1.0 to 3.0 μm.
In the case of (Example 6), the average value of the temperature rise characteristics during opening and closing 2000 times was (Evaluation B), and the maximum value was (Evaluation C), which was in a good range. The contact resistance characteristics were also 10 in Example 2.
The relative value when set to 0 is 90 to 1 before and after the energization test.
10 was a good range. The relative value when the blocking characteristic was set to 1.0 in Example 2 was 0.95 to 1.05, which was in a favorable range.

When the thickness of the alloy layer was 195 to 200 μm (Example 7), the average and maximum values of the temperature rise characteristics during opening and closing 2,000 times (Evaluation A) were in a good range. Further, the contact resistance characteristics and the cutoff characteristics were in good ranges as in Example 6.

On the other hand, when the thickness of the alloy layer is 0.1 μm
In the case of less than (Comparative Example 5), the average value of the temperature rise characteristics of the current-carrying shaft was good in (Evaluation C), but the maximum value was (Evaluation Z), indicating a large variation. Contact resistance characteristics
Before the energization test, it was 90 to 120, which is in a good range, but after the energization test, it deteriorated to 90 to 350. At the end surface of the current-carrying shaft after the current-carrying test, Cu was exposed on the current-carrying shaft due to the insufficient thickness of the metal layer, and local oxidation of the Cu portion caused variations in the temperature rise characteristics and the contact resistance characteristics. As for the cutoff characteristic, the relative value when Example 2 was set to 1.0 was 0.95 to 1.05, which was in a good range.

The thickness of the alloy layer is 400 to 500 μm.
In the case of (Comparative Example 6), the average value of the temperature rise characteristics of the current-carrying shaft was good in (Evaluation B), but the maximum value was (Evaluation X), indicating a large variation. The contact resistance characteristics were similarly 9
0 to 110, which is a good range, and 90 to 110 after the energization test, which is in a good range. The relative value when the blocking characteristic is 1.0 in Example 2 is 0.95 to 1.0.
5 is in a good range. After all, since the maximum value of the temperature rise characteristic of the energized shaft indicates (evaluation X), it is determined to be “x” overall.

[0089] From the above, the thickness of the alloy layer of Ag-Cu-In to form the end surfaces of the current-carrying rod, it was confirmed range 1~200μm is appropriate.

<Embodiment 8, Comparative Examples 7 to 8>
In Comparative Examples 1 to 6, [(Ag) / (Ag + C) in the Ag—Cu—In alloy layer formed on the end surface of the current-carrying shaft.
u)] The ratio is fixed at 0.72, but here, when the ratio is changed, the energization characteristics, the contact resistance characteristics,
The blocking characteristics were investigated.

As shown in the evaluation conditions in FIG. 1, in Example 8, this ratio was 0.65 to 0.8, and in Comparative Example 7, it was 0.4 to 0.8.
0.5 and Comparative Example 8 were constant at 0.9 to 0.95.

As shown in the evaluation results in FIG. 2, [(Ag)
/ (Ag + Cu)] ratio is 0.65 to 0.8 (Example 8), the average value of the temperature rise characteristics indicating the current-carrying characteristics is (Evaluation A to B), and the maximum value is also (Evaluation B to C). And was in a good range. The contact resistance characteristics also showed a relative value when the value of Example 2 was set to 100, which was 90 to 180 before the energization test and 100 to 200 after the energization test, all in good ranges. The relative value when the blocking characteristic was set to 1.0 in Example 2 was 0.9 to 1.1, which was a good range.

[0093] On the other hand, [(Ag) / (Ag + C
u)] When the ratio is 0.4 to 0.5 (Comparative Example 7),
The average value of the temperature rise characteristics of the current-carrying shaft was good in (Evaluation A to B), but the maximum value was (Evaluation D to Y), indicating a large variation. The contact resistance characteristic was 380 before the energization test.
It is shown, in after the energization test showed significant deterioration and variation indicates 3500. The interrupting test was stopped because a part of the joint was defective, such as the presence of an unmelted alloy layer on the end surface of the conducting shaft.

[0094] Further, favorable in the case [(Ag) / (Ag + Cu)] ratio of 0.9 to 0.95 (Comparative Example 8), the average value of the temperature rise characteristic of the current axis (Evaluation A-B) However, the maximum value showed (Evaluation D to Z), and further showed a significant variation. Contact resistance characteristics were 450 before the energization test.
After the energization test, the value was 5,000 or more, indicating significant deterioration and variation. The breaking test was stopped due to poor bonding such as the presence of an unmelted alloy layer on the end surface of the conducting shaft.

From the above, [(Ag) / (Ag + C) in the Ag—Cu—In alloy layer formed on the end surface of the conducting shaft
u)] It was confirmed that the ratio was appropriately in the range of 0.65 to 0.8.

[0096]

As described above, according to the present invention,
The surface of the end of each energized shaft on the side connected to the external conductor
g is 60 to 75% by weight, In is 0.1 to 15% by weight, and the rest is formed of an Ag-Cu-In alloy layer made of Cu, so that the current can be applied to the current-carrying shaft of the vacuum valve and the vacuum circuit breaker Since the contact resistance characteristics of the connection portion with the external conductor for connection are improved, both the current-carrying characteristics and the breaking characteristics of the vacuum circuit breaker can be improved.

[0097] Further, according to the present invention, Ag-Cu-In
By setting the solidus temperature of the alloy layer to 630 ° C or more and less than 780 ° C and the liquidus temperature to 680 ° C or more and less than 780 ° C, appropriate joining work when using a normal 72% Ag-28% Cu alloy When the Ag—Cu—In alloy layer is formed on the end surface of the current-carrying shaft at a temperature (820-830 ° C.), an unmelted region of the alloy layer is prevented from being formed on the end surface, and the thickness is uniform. As a result, stable contact resistance characteristics can be obtained, so that both the current-carrying characteristics and the breaking characteristics of the vacuum circuit breaker can be improved.

Further, according to the present invention, Ag—Cu—In
By setting the thickness of the alloy layer in the range of 1 to 200 μm, the contact resistance characteristics between each current-carrying shaft and the external conductor are improved, so that both the current-carrying characteristics and the breaking characteristics of the vacuum circuit breaker are improved. Can be.

Further, according to the present invention, Ag-Cu-In
Ratio of Ag and Cu in alloy layer [(Ag) / (Ag + C
u)] is set in the range of 0.65 to 0.8, so that the contact resistance characteristics between each energized shaft and the external conductor are improved.
Both the current-carrying characteristics and the breaking characteristics of the vacuum circuit breaker can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a typical vacuum valve.

FIG. 2 is a cross-sectional view showing another configuration of a typical vacuum valve.

FIG. 3 is a diagram showing a state in which an energizing shaft of a vacuum valve is connected to an external conductor for connecting to a vacuum circuit breaker.

FIG. 4 is an Ag-C for examining a current-carrying characteristic, a breaking characteristic, and the like
It is a figure which shows the table | surface which put together the evaluation conditions of the u-In alloy layer.

FIG. 5 is a diagram showing a table summarizing evaluation results of an Ag—Cu—In alloy layer.

[Explanation of symbols]

 Reference numeral 40: electrode (back of contact 41) 41: fixed contact 50: electrode (back of contact 51) 51: movable contact M: moving direction of conducting shaft 107 101: insulating container 102a: metal cover (fixed side) 102b: metal the lid (movable side) 103 ... vacuum chamber 104 ... fixed contact 105 ... movable contact 106 ... energizing shaft (fixed side) 107 ... energizing shaft (movable side) 108 ... bellows 109 ... arc shield 121 ... external conductor (fixed side) 122 ... outer conductor (movable side) 123 ... connection part on the upper end surface of fixed side conduction shaft 106 124 ... connection part on the outer periphery of the lower end of movable side conduction shaft 107 125 ... annular conductor 126 ... flexible conductor

 ────────────────────────────────────────────────── ─── front page of the continuation (72) inventor Takashi Kusano Fuchu, Tokyo Toshiba-cho, address, Ltd. Toshiba Fuchu business premises (72) inventor Katsumi Oshiumi Fuchu, Tokyo Toshiba-cho, address, Ltd. Toshiba Fuchu business premises ( 72) Inventor Atsushi Yamamoto 1 Toshiba-cho, Fuchu-shi, Tokyo F-term in the Fuchu office of Toshiba Corporation 5G023 AA03 BA01 CA11 5G026 BA07 BB02 BB04 BB30 BC02 BC03 BC06 5G050 AA01 AA13 AA19 BA04 CA01 CA04 DA06 DA10 EA13 FA01

Claims (12)

[Claims] 1. A pair of contact materials are provided inside an airtightly sealed insulating container, and the ends of respective energized shafts inserted from both ends of the insulating container are connected to the respective contact materials, respectively. In the vacuum valve, the other end of which is connected to an external conductor for connecting to a vacuum circuit breaker outside the insulating container, the surface of the end of each energized shaft on the side connected to the external conductor has Ag of 60%. 75% by weight, 0.1 to 15% by weight of In, and the rest of the vacuum valve is formed of an Ag-Cu-In alloy layer made of Cu. 2. The Ag—Cu—In alloy layer has a solidus temperature of 630 ° C. or more and less than 780 ° C., and a liquidus temperature of 680 ° C. or more and less than 780 ° C. The vacuum valve according to 1. 3. The vacuum valve according to claim 1, wherein the thickness of the Ag—Cu—In alloy layer is in a range of 1 to 200 μm. 4. The Ag—Cu—In alloy layer has a ratio of Ag to Cu [(Ag) / (Ag + Cu)] of 0.65.
4. The method according to claim 1, wherein the range is from 0.8 to 0.8.
The vacuum valve according to any one of the above. 5. The Ag—Cu—In alloy layer is made of AgC
5. A matrix comprising a matrix mainly composed of a u alloy and an In compound containing Ag and / or Cu, wherein the In compound is dispersed in the matrix. A vacuum valve as described in Crab. 6. A pair of contact materials is provided inside an airtightly sealed insulating container, and ends of each energized shaft inserted from both ends of the insulating container are connected to each contact material, respectively. in the manufacturing method of the other end to produce a vacuum valve which is connected to the outer conductor for connecting the vacuum circuit breaker outside of the insulating container, the surface of the end of each current-carrying rod of the side connected to the outer conductor An Ag-Cu-In alloy layer comprising 60 to 75% by weight of Ag, 0.1 to 15% by weight of In and the balance of Cu is formed at a joining temperature of 780 ° C or more and less than 840 ° C. Manufacturing method of a vacuum valve. 7. Ag is 60 to 75% by weight and In is 0.1% by weight.
１５15% by weight, the balance being made of Cu
The Ag-Cu-In alloy foil [mu] m, the the step of contacting disposed on the surface of the end of each current-carrying rod, the alloy wherein the surface of the end of each current-carrying rod at the junction working temperature of less than 780 ° C. or higher 840 ° C. The method for manufacturing a vacuum valve according to claim 6, comprising: bonding a foil. 8. Ag is 60 to 75% by weight and In is 0.1% by weight.
A step of laminating Ag, In, and Cu single foils each having a thickness adjusted so that the remaining portion becomes Cu on the surface of the end portion of each of the energized shafts, from 780 ° C to less than 840 ° C. 7. The method for manufacturing a vacuum valve according to claim 6, further comprising: bonding the single foil to a surface of an end portion of each of the energized shafts at a bonding operation temperature of (c). 9. An alloy foil made of any two of Ag, In, and Cu and a single foil made of the remaining one are mixed with Ag of 60%.
Adjusting the thickness on the surface of the end portion of each of the current-carrying shafts so that the thickness becomes 75% by weight, the content of In becomes 0.1 to 15% by weight, and the remainder becomes Cu; 7. The method for manufacturing a vacuum valve according to claim 6, further comprising: bonding the alloy foil and the single foil to the surface of the end of each of the energized shafts at the bonding operation temperature. 10. The ratio of Ag to Cu [(Ag) / (A
g + Cu)] in the range of 0.65 to 0.8. 10. The method of manufacturing a vacuum valve according to claim 6, further comprising: 11. A vacuum circuit breaker using the vacuum valve according to claim 1. 12. A vacuum circuit breaker using a vacuum valve manufactured by the manufacturing method according to claim 6. Description: