JP2000129373A - Production of vacuum valve contact material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of cracks in a molded body even if being molded by using a pattern by arc resistant componental powder with specified grain size to be mixed to a contact material having a specified compsn. of Cu and TiC or VC with a specified ratio of powdery Cu and paraffine in succession. SOLUTION: A contact material for a vacuum valve composed of 40 to 55 vol.% electrically conductive components essentially consisting of Cu and 45 to 60 vol.% arc resistant components essentially consisting of TiC or VC is mixed with powder of 0.3 to 3 μm grain size essentially consisting of arc resistant componental powder to form into a skeleton molded formed body, which is heat-treated to infiltrate the electrically conductive components into the formed body. The arc resistant components to be mixed to the contact material is blended with 16 to 43 vol.% powdery Cu of <=100 μm grain size, and the mixed powder is preferably added with 5 to 30 vol.% paraffin as well. The contact material for a vacuum valve combining low cutting characteristics, large current breaking characteristics and large current conducting characteristics can inexpensively be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inexpensive device for manufacturing a vacuum valve contact which has both low cutting characteristics, large current breaking characteristics and large current carrying characteristics.

[0002]

2. Description of the Related Art A large current interrupting characteristic of a vacuum valve for interrupting a current in a high vacuum utilizing arc diffusivity in a vacuum is generally determined by a contact material and an electrode structure. There are a variety of contact materials depending on the application, but a Cu-Cr contact is most widely used as a contact material having excellent large current interruption characteristics. On the other hand, in the case of a vacuum valve that has both low surge characteristics and a certain
A g-WC contact material is generally used. Recently, Cu-T
A contact material having both excellent breaking characteristics such as iC and low surge characteristics has been invented (Japanese Patent Application No. 9-169039).

[0003] These sintering contact materials are generally produced by either the solid phase sintering method or the pre-sintering infiltration method. In the case of the solid phase sintering method, the conductive component and the arc-resistant component are used. Through the respective steps of powder mixing, powder compaction, and sintering of the compact. In the case of the temporary sintering infiltration method, the contact shape is formed through steps of forming a powder mainly composed of the arc-resistant component powder, temporarily sintering the formed body, and infiltrating the sintered body with the conductive component. Processed into

[0004]

DISCLOSURE OF THE INVENTION Cu-TiC and Cu similar thereto having both low surge characteristics and large current interruption characteristics
-VC is formed by mixing TiC or VC powder arc-resistant component powder with Cu powder, and when a punching die usually used for forming a disk-shaped molded body such as a contact is molded as a die, the mixed powder to be molded is formed. If the ratio of the TiC powder in the inside is high, cracks tend to occur in the molded body when the molded body is extracted from the mold. In order to prevent such cracks, Japanese Patent Application No. 9-169039, which is incorporated herein by reference.
In No., molding is performed using a split mold that can be divided after molding, but mass production is very difficult with this method.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a method for manufacturing a low-cost vacuum valve contact material having excellent large current cutoff characteristics, cutting characteristics, and large current conduction characteristics. The purpose is to:

[0006]

In order to solve the above-mentioned problems, a method of manufacturing a contact material for a vacuum valve according to the present invention is characterized in that a conductive component of 40 to 55 vol%, whose main component is Cu, and a main component of which are Cu. 45-60v made of TiC or VC
ol% of the arc-resistant component is mixed with a powder mainly composed of an arc-resistant component powder having a particle size of 0.3 to 3 μm, and the mixed powder is skeletonized. A molding step of molding into a molded body, and a step of infiltrating a conductive component into a skeleton-shaped molded body are performed in this order, and in the manufacturing method, in the mixing step, powdery Cu is added to the arc-resistant component powder by 16 to 43 vol%, and 5 to 30 vol% of paraffin is added to the mixed powder.

[0007] The addition of this paraffin improves the moldability of the TiC powder or VC powder, prevents cracks in the compact, and enables stable production. The method of manufacturing a contact material for a vacuum valve according to claim 2 is characterized in that, in the mixing step, the particle size of the powdered Cu to be blended is 100 μm or less.

[0008] The finer the powder of Cu in the compact, the smaller the voids in the compact, the smaller the amount of Cu infiltrated, and the smaller the amount of Cu in the contacts, but by reducing this to 100 µm or less, The amount of Cu can be set to be equal to or less than an upper limit value for securing predetermined cutting characteristics.

The paraffin added in the mixing step needs to be removed in a subsequent step, but the deparaffinization is usually performed at 1 atm from the viewpoint of furnace maintenance. When this treatment is performed in a hydrogen atmosphere, a part of the Ti carbide is replaced by Ti hydride, so that hydrogen is contained in the contact, which has a serious adverse effect on the breaking performance.

Therefore, the method for producing a contact material for a vacuum valve according to claim 3 is characterized in that, prior to the infiltration step of infiltrating the conductive component into the molded article formed in the molding step, 10 to 300 ° C. in nitrogen at 300 to 500 ° C. Min., And adding a deparaffinization step of evaporating paraffin and removing it from the molded body. In the infiltration step, 1100 to 12
It is characterized by infiltrating a conductive component mainly composed of Cu at 00 ° C.

Further, even if deparaffinization is performed in hydrogen to increase the hydrogen content of the contact, it is possible to remove the hydrogen in a subsequent step. The method for producing a contact material for a vacuum valve according to claim 4, wherein the melting point of the conductive component to be infiltrated at 300 ° C. or higher before the infiltration step of infiltrating the conductive component into the molded article formed in the molding step. A deparaffinization step in which the paraffin is evaporated and removed from the compact at a temperature of not more than 10 minutes by holding in hydrogen, and 9 minutes in a vacuum atmosphere
In addition to adding a step of dehydrating by holding at a temperature of not less than 00 ° C. and a melting point of the infiltrant for 30 minutes or more, in the infiltration step,
It is characterized by infiltrating a conductive component containing Cu as a main component at 1100 to 1200 ° C.

As a method for removing paraffin, there is a chemical method in addition to the above-mentioned thermal method. In the method for producing a contact material for a vacuum valve according to claim 5, before the infiltration step of infiltrating the conductive component into the molded product formed in the molding process, the contact material is immersed in a carbohydrate-based cleaning liquid having a boiling point of 50 to 200 ° C. , 40
C. and at the temperature not higher than the boiling point of the washing liquid, and a paraffin removal step of dissolving and extracting paraffin in the washing liquid to remove from the molded body is added. It is characterized by infiltrating a conductive component as a main component.

Since the paraffin extraction rate of a hydrocarbon-based cleaning liquid having a boiling point of 50 to 200 ° C., for example, n-hexane, depends on the paraffin concentration in hexane, it is necessary to lower the paraffin concentration in order to increase the extraction rate. It is important to do it.

Therefore, a method of manufacturing a contact material for a vacuum valve according to claim 6 is characterized in that, in the deparaffinization step, the washing liquid to be immersed is replaced at least once with a liquid having a low paraffin concentration or the molded body is transferred. I do.

As described above, it is possible to reduce the amount of voids into which Cu is infiltrated by reducing the particle size of Cu, but it is also possible to suppress the amount of voids by sintering.
In order to shrink the compact by sintering, it is necessary to add a sintering aid. However, sintering aids such as Co, Fe, Ni, and Cr form a solid solution in Cu and reduce the conductivity of Cu. Therefore, the addition must be kept to the minimum necessary.

According to a seventh aspect of the present invention, in the method of manufacturing a contact material for a vacuum valve, the mixing step includes the step of:
It is characterized by adding Ni of not more than wt% or Cr of not more than 3 wt%.

In the infiltration step, voids in the compact are filled with an infiltrant. If the amount of the infiltrant is larger than necessary, excess infiltrant solidifies around the compact and shrinks during solidification. This may cause cracks in the molded body.

Therefore, in the method of manufacturing a contact material for a vacuum valve according to the present invention, in the infiltration step, the amount of the infiltrating material infiltrating the molded body is 100, which is an amount necessary to fill the void of the molded body. １１０110%.

It is considered that the cracks generated in the molded body are generated by being pushed back from the side of the mold at the time of unloading the molding pressure. In order to alleviate such a force, it is preferable to provide a difference in the inner diameter at both ends of the mold, widen one side, and continuously change the inner diameter in the axial direction.

According to a ninth aspect of the present invention, in the method of manufacturing a contact material for a vacuum valve, in the molding step, a mold for molding the powder is formed by extracting a disk-shaped molded body after molding, and removing the molded body from the mold. It is characterized in that the inner diameter of the mold from which the molded body is extracted is larger than the other inner diameter.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the following drawings, the same reference numerals indicate the same or corresponding parts. First,
A configuration example of a vacuum valve to which a method for manufacturing a contact material for a vacuum valve according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

In FIG. 1, reference numeral 1 denotes a shut-off chamber. The shut-off chamber 1 is made of an insulating container 2 formed of an insulating material in a substantially cylindrical shape, and a metal member provided at both ends thereof with sealing metals 3a and 3b. And the lids 4a and 4b are airtight.
Electrodes 7 and 8 attached to opposing ends of the electrode rods 5 and 6 are disposed in the shut-off chamber 1, and the upper electrode 7 in the drawing is a fixed electrode and the lower electrode 8 is a movable electrode. . A bellows 9 is attached between the movable electrode 8 and the electrode rod 6,
The electrode rod 6 can be moved in the axial direction while keeping the inside of the cutoff chamber 1 airtight.

An upper part of the bellows 9 is provided with a metal arc shield 10 for preventing a deposited film of an arc product from adhering to the bellows 9. Further, an arc shield 11 is provided in the cut-off chamber 1 so as to cover the fixed electrode 7 and the movable electrode 8, thereby preventing a deposition film of an arc product from adhering to the insulating container 2. Contact materials manufactured according to the present invention are disposed at the contact portions of the electrodes 7 and 8 as the contacts 13a and 13b.

As shown in FIG. 2, the movable electrode 8 is
Are connected by brazing at the brazing section 12. (Or may be connected by caulking). The contact 13b is brazed to the movable electrode 8 at a brazing portion 14.

Next, a method of manufacturing a contact material for a vacuum valve according to an embodiment of the present invention will be described in order. Examples of the present invention will be described with reference to Tables 1 to 6.

Tables 1 to 3 show the production methods of the examples and comparative examples and the presence or absence of cracks during production. TiC having an average particle size of 1.5 μm and Cu having an average particle size of 40 μm are mixed at a mixing ratio of 84 to 16 by volume, and 15 vol% of paraffin is added to the mixed powder (mixing step), and the extraction side and the other side are added. Using a punching die with an inner diameter ratio of 1.1
After performing a deparaffinization treatment once in nitrogen at 300 ° C. for 2 hours (deparaffinization step), a heat treatment at 1150 ° C. for 30 minutes in a vacuum atmosphere is performed to remove one of the voids of the molded body. A manufacturing process in which 0.05 volume of Cu is melted and infiltrated (infiltration step) is defined as a basic process of this embodiment.

As shown in FIG. 3, a cross section of the mold used for molding has a ratio of the inner diameter of the mold, that is, the ratio (Da / D / D) of the inner diameter Da on the extraction side to the inner diameter Db on the other side. D
b) is set to 1.1, and the inner diameter of the mold is continuously changed in the axial direction of the mold at a portion Hb of 80 to 100% of the height Ha of the portion where the molded body contacts the inside of the mold. Good. In the basic process, the heat treatment temperature in the infiltration step is set to 11
Although it was set to 50 ° C., it may be in the range of 1100 to 1200 ° C.
The amount of the infiltrant is defined as the volume Va of the infiltrant and the void volume V of the compact.
b (Va / Vb).

The production parameters of the basic process were changed to check for the presence or absence of cracks. If no cracks were formed, the material composition, conductivity,
The gas content was examined, and the cutoff characteristics and the cutting characteristics were evaluated according to the above-described method. With respect to the case where paraffin was added, the paraffin removal rate after the deparaffinization step was also examined.

The method and evaluation conditions for obtaining data on the material properties and electrical properties of the contact materials manufactured in the examples shown in Tables 4 to 6 will be described. Since the contact material manufactured by the manufacturing method of the present invention is intended to have both a large current interrupting property, a cutting property and a large current carrying property, the electrical properties of the large current interrupting property and the cutting property are shown below. The evaluation was performed. In addition, the current-carrying characteristics were evaluated by measuring the conductivity of the contact material by using an eddy current measurement type conductivity meter.

1) Large current breaking characteristics: The breaking test was performed by JEC standard No. 5 test, and the breaking characteristics were evaluated. Passes and rejects are shown in Tables 4 to 6. 2) Current cutting characteristics: An assembled valve evacuated to 10-5 Pa or less with each contact attached was prepared.
The cutting current value when the electrode was opened at an opening speed of 8 m / sec and a small current was interrupted was measured. The breaking current value was 20 A (effective value) and 50 Hz. The opening phase is random, and 5
The cutting current value at the time of interruption of 00 times was measured for three sets of electrodes, and the maximum value was shown in Tables 1 to 3. The numerical values are shown as relative values when the maximum value of the cutting current in Example 1 is set to 1.0.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

[Table 4]

[0035]

[Table 5]

[0036]

[Table 6]

[Examples 1 to 6 and Comparative Examples 1 to 9] The amount of Cu in the basic process was set in the range of 16 to 43% by volume.
In addition, the amount of paraffin added was changed in the range of 0 to 50 vol% and examined (see Tables 1 and 4).

In Comparative Examples 1, 4, and 7 in which paraffin was not added and Comparative Examples 2, 5, and 8 in which the addition amount was 3 vol%, cracks occurred in the molded product, but Example 1 in which the addition amount was 5 to 30 vol%. In Nos. 6 to 6, no cracks were generated, the conductivity after the production was good, and the breaking performance and the conduction performance were also good.

However, when the amount of paraffin added was 50 vol%
In Comparative Examples 3, 6, and 9, the Cu content exceeded 55 vol%, and the cutting characteristics were insufficient. This is because Cu is infiltrated into a region of the molded body that was occupied by paraffin before deparaffinization, and therefore, if the amount of paraffin becomes excessive, the amount of Cu increases.

Examples 7 to 8 and Comparative Examples 10 to 11
The investigation was performed by changing the TiC particle size in the basic process in the range of 0.2 to 5 μm (see Tables 1 and 4).

In Comparative Example 10 in which the TiC particle size was 0.2 μm, cracks occurred in the compact, but the TiC particle size was 0.3 μm.
In Examples 7 to 8 having a thickness of ３3 μm, no crack was generated,
The conductivity after production is also good, and the breaking performance and energizing performance are also good. However, in Comparative Example 11 in which the TiC particle size was 5 μm, the blocking characteristics were insufficient.

Examples 9 to 10 and Comparative Example 12 Investigations were performed by changing the Cu particle size in the basic process in the range of 5 to 150 μm (see Tables 1 and 4).

In Comparative Example 12 having a Cu particle size of 150 μm,
Although cracks occurred in the molded product, cracks did not occur at all in Examples 9 to 10 in which the Cu particle size was 100 μm or less, the electrical conductivity after production was good, and the breaking performance and electric conduction performance were also good.

[Examples 11 to 12 and Comparative Examples 13 to 1]
8] The deparaffinization atmosphere of the basic process was tried for nitrogen and hydrogen, and the deparaffinization treatment temperature was set to 200 to 600.
The temperature was changed in the range of ° C. (see Tables 2 and 5).

Comparative Example 13 in which the deparaffinization temperature was 200 ° C.
In the cases of Nos. 15 and 15, the paraffin removal was insufficient, so that the subsequent steps could not be performed. Example 11 where the atmosphere for deparaffinization was nitrogen and the temperature was 300 to 500 ° C
In Comparative Examples 14 and 12, a good material can be produced, and the cutoff characteristics, cutting characteristics, and current-carrying characteristics are also good. However, in Comparative Example 14 similarly treated at 600 ° C. in a nitrogen atmosphere, the oxygen content in the material increases. , The cutoff characteristics are rejected.
This is because oxidation by oxygen contained in nitrogen occurred.

The materials of Comparative Examples 16 to 18 which were treated in a hydrogen atmosphere all had a high hydrogen content, and the cutoff characteristics were rejected. [Examples 13 to 16 and Comparative Examples 19 to 20] The deparaffinization atmosphere in the basic process was hydrogen, and after the deparaffinization treatment temperature, the temperature was changed to 0.2 to 1.
A 0-hour dehydrogenation treatment was performed in vacuum (see Tables 2 and 5).

Comparative Example 1 in which the dehydrogenation temperature was 800 ° C. for 1 hour
In Comparative Examples 20 at 9 and 1000 ° C. for 0.2 hours, the removal of hydrogen was insufficient and the cutoff characteristics were unacceptable, but Example 13 in which the treatment was performed at a temperature of 900 ° C. or more for 0.5 hour or more. In the case of No. to No. 16, a good material having a sufficiently low hydrogen content can be produced, and the cutoff characteristics, the cutting characteristics, and the current-carrying characteristics are also good.

[Examples 17 and 18 and Comparative Examples 21 and 2]
2] The deparaffinization atmosphere of the basic process was hydrogen, the deparaffinization treatment temperature was in the range of 200 to 1100 ° C., and the dehydrogenation treatment was performed in vacuum at 1000 ° C. for 1.0 hour (Table 2 and Table 2). See Table 5).

Comparative Example 21 having a deparaffinization temperature of 200 ° C.
Then, the subsequent steps became impossible due to insufficient paraffin removal. However, Example 17 was performed in a temperature range of 300 ° C. or more and 1083 ° C. or less, which is the melting point of the conductive component.
In the case of No. 18 to 18, a good material having a sufficiently low hydrogen content can be produced, and the cutoff characteristics, the cutting characteristics, and the current-carrying characteristics are also good.
On the other hand, Comparative Example 21, in which the deparaffinization temperature was 1100 ° C., was insufficient in the removal of hydrogen, and thus had insufficient barrier properties.
Because this was processed at a temperature above the melting point of the conductive component,
This is because the hydrogen in the paraffin has been dissolved in the molten conductive component.

[Examples 19 to 22 and Comparative Examples 23 to 2]
4] Deparaffinization of the basic process is performed at 30-68 ° C.
-Performed in hexane. Also, the number of times n-hexane was replaced with a solution having a low paraffin concentration was tried up to two times (see Tables 2 and 5).

In Comparative Example 23 in which the liquid was changed once at a deparaffinization temperature of 30 ° C. and in Comparative Example 24 in which the liquid was not changed at a deparaffinization temperature of 68 ° C., the removal of the paraffin was insufficient. Became inoperable. n-
In Examples 19 to 22 in which the liquid was exchanged at least once at a hexane temperature of 40 to 68 ° C, a good material could be manufactured, and the cut-off characteristics, cutting characteristics, and current-carrying characteristics were also good.

[Examples 23 to 30 and Comparative Examples 25 to 2]
8] In the mixing step of the basic process, Co, Fe, Ni and Cr as sintering aids are added to a mixed powder of TiC and Cu.
After deparaffinization by adding a small amount of each, sintering was performed at 1150 ° C. in a vacuum atmosphere for 2 hours (see Tables 3 and 6).

Co, Fe, Ni and Cr are 0.1 wt%, 0.1 wt%, 0.3 wt% and 3 w
In Comparative Examples 25 to 28 in which the content is larger than t%, the conductivity of the material is 20 IACS% or less, which is poor. On the other hand, in Examples 23 to 30 lower than these limit values, a good material can be manufactured, and the cutoff characteristics, the cutting characteristics, and the conduction characteristics are also within the allowable range.

Examples 31 to 32 and Comparative Examples 29 to 3
0] In the mixing step of the basic process, the amount of the infiltrating material infiltrating into the voids of the molded body is set to 90 to 120 vol.
% (See Tables 3 and 6).

In Comparative Example 29 in which the amount of the infiltrating material was 90 vol% of the volume of the voids, the oxygen content in the material was extremely large due to the large number of pores inside the material, and the cutoff characteristics were unacceptable due to the low conductivity. Has become.

The infiltration material is 100 to 110% by volume of the void.
In Examples 31 to 32, a good material having few voids inside and no cracks can be manufactured, and the cut-off characteristics, cutting characteristics, and current-carrying characteristics are also good.

On the other hand, the amount of the infiltration material is 120 vol.
In Comparative Example 30 of%, cracks were observed inside the material, which was poor. This is considered to be due to the formation of cracks due to shrinkage of the excess infiltrant during solidification.

[Examples 33 to 35 and Comparative Example 31] In a basic process step, a punching die having an inner diameter ratio (Da / Db) of 1.0 to 2.0 on the extraction side and the other side was used, and no paraffin was used. It was molded by addition and examined (see Tables 3 and 6).

In Comparative Example 31 in which the inner diameter ratio was 1.0, cracks occurred in molding and molding was impossible, but the inner diameter ratio was 1.0.
In one or more of Examples 33 to 35, a good material without cracks can be manufactured, and the cutoff characteristics, the cutting characteristics, and the current-carrying characteristics are also good.

[Other Embodiments] In the above embodiments, Cu-
Although the method of manufacturing the TiC contact has been described, the Cu-V
Similarly, the manufacturing method of the present invention is effective for the C contact.

In the above embodiment, n-hexane was used as the hydrocarbon-based cleaning liquid used for deparaffinization. However, other hydrocarbon-based cleaning agents of the first petroleum or second petroleum having a boiling point of 50 ° C. or more were used. For example, it is obvious that similar effects can be obtained by using petroleum naphtha, naphthenic hydrocarbons, or a mixture thereof.

[0062]

As described above, according to the method for producing a contact material for a vacuum valve according to the first aspect, 5 to 30 vol% of paraffin is added to the molding powder mainly composed of the arc-resistant component powder. Therefore, even if the punching die is formed, it is possible to produce a contact material which is inexpensive and suitable for mass production without causing cracks in the formed body, and has a large current interrupting property, a cutting property, and a large current carrying property.

According to the method for manufacturing a contact material for a vacuum valve according to the second aspect, the particle size of the Cu powder mixed with the molding powder mainly composed of the arc-resistant component powder is set to 100 μm or less. The content can be reduced to 50 vol% or less, and it is possible to exhibit excellent cutting characteristics.

According to the method for producing a contact material for a vacuum valve according to the third aspect, before the infiltration step, the compact of the powder mainly composed of the arc-resistant component powder is heated at 300 to 500 ° C. in nitrogen for 10 minutes or more. Since it is retained and the paraffin is evaporated and removed from the molded body, a gas such as hydrogen, which adversely affects the shut-off characteristics, is not absorbed into the contacts, and excellent shut-off characteristics can be exhibited.

According to the method for manufacturing a contact material for a vacuum valve according to the fourth aspect, before the infiltration step, the temperature of the molded body of the powder mainly composed of the arc-resistant component powder is set to a temperature not lower than 300 ° C. and not higher than the melting point of the infiltrant. After holding in hydrogen for 10 minutes or more and evaporating paraffin to remove it from the compact,
After dehydration by holding at 0 ° C. for 30 minutes or more, 1100-1
Since the conductive component containing Cu as a main component is infiltrated at 200 ° C., the content of hydrogen gas is small, and excellent blocking characteristics can be exhibited.

According to the method for manufacturing a contact material for a vacuum valve according to the fifth aspect, before the infiltration step, the formed body of the powder mainly composed of the arc-resistant component powder is converted into a carbohydrate cleaning liquid having a boiling point of 50 to 200 ° C. It is immersed and maintained at a temperature of 40 ° C or higher and lower than the boiling point of the cleaning liquid, and paraffin is dissolved and extracted in the cleaning liquid and removed from the molded body. And excellent blocking characteristics can be exhibited.

According to the method of manufacturing a contact material for a vacuum valve according to the sixth aspect, before the infiltration step, the compact of the powder mainly composed of the arc-resistant component powder is converted into a carbohydrate cleaning liquid having a boiling point of 50 to 200 ° C. When immersing, holding at a temperature of 40 ° C. or higher and lower than the boiling point of the washing liquid and dissolving and extracting paraffin in the washing liquid and removing it from the molded body, the washing liquid to be immersed is replaced with a liquid having a low paraffin concentration at least once or Since the molded body is transferred, the paraffin can be removed in a shorter time, and an inexpensive contact material can be manufactured.

According to the method for manufacturing a contact material for a vacuum valve according to the present invention, when the powder mainly composed of the arc-resistant component powder is mixed, 0.1 wt% or less of Co or 0.1 wt% or less of F is mixed.
e or 0.3 wt% or less of Ni or 3 wt% or less of Cr, so that the Cu content of the contact is reduced to 50 vol.
1% or less, and it is possible to exhibit excellent cutting characteristics.

According to the method for manufacturing a contact material for a vacuum valve according to the eighth aspect, the amount of the infiltrating material infiltrating into the compact of the powder mainly composed of the arc-resistant component powder can fill the voids of the compact. Since the required amount is 100 to 110%, cracks do not occur in the compact during solidification of the infiltration material, and stable production of the contact material can be achieved.

According to the method for manufacturing a contact material for a vacuum valve according to the ninth aspect, the mold for molding the powder mainly composed of the arc-resistant component powder is formed by extracting a disk-shaped molded body, and extracting the molded body from the mold. Since the inner diameter of the mold on the side from which the molded body is extracted is larger than the other, the force applied to the molded body by the mold during unloading of the molding pressure is reduced, and cracks in the molded body are suppressed. As a result, stable production of contact materials becomes possible.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a vacuum valve to which a method for manufacturing a contact material for a vacuum valve according to an embodiment of the present invention is applied.

FIG. 2 is an enlarged sectional view of a contact portion of the vacuum valve shown in FIG.

FIG. 3 is a sectional view of a mold used in a molding step according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Interruption chamber 2 ... Insulating container 3a, 3b ... Sealing fitting 4a, 4b ... Lid 5, 6 ... Conductive rod 7, 8 ... Electrode 9 ... Bellows 10, 11 ... Arc shield 13a, 13b ... Contact

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01H 11/04 B22F 3/02 M 33/66 3/10 C (72) Inventor Atsushi Yamamoto Fuchu-shi, Tokyo 1 in Toshiba-cho, Fuchu Plant, Toshiba Corporation (72) Inventor Takashi Kusano 1 in Toshiba-cho, Fuchu-shi, Tokyo, Tokyo Inside the factory (72) Inventor Makoto Kataoka 1 Toshiba-cho, Fuchu-shi, Tokyo Toshiba Corporation Fuchu factory

Claims (9)

[Claims] 1. A composition comprising 40 to 55% by volume of Cu as a main component.
And the main component is TiC or VC 45
A mixing step of mixing a contact material for a vacuum valve composed of up to 60% by volume of an arc resistant component with a powder mainly composed of an arc resistant component powder having a particle size of 0.3 to 3 μm; The molding step of molding into a molded body of, and the step of infiltrating the conductive component into the skeleton-shaped molded body, in this order, in the method of manufacturing, in the mixing step, powdered Cu to the arc resistant component powder 16 to 43 vol%, and 5 to 30 v of paraffin with respect to the mixed powder.
A method for producing a contact material for a vacuum valve, characterized by adding ol%. 2. The method for producing a contact material for a vacuum valve according to claim 1, wherein in the mixing step, the particle size of the powdered Cu to be blended is 100 μm or less. 3. A molded product obtained by holding at 300 to 500 ° C. in nitrogen for 10 minutes or more at 300 to 500 ° C. to evaporate paraffin before the infiltration step of infiltrating a conductive component into the molded product molded in the molding process. And a deparaffinization step for removing from the infiltration step.
The method for producing a contact material for a vacuum valve according to claim 1 or 2, wherein a conductive component containing Cu as a main component is infiltrated at 0 to 1200 ° C. 4. Prior to the infiltration step of infiltrating the conductive component into the molded article formed in the forming step, hydrogen is applied at a temperature not lower than 300 ° C. and not higher than the melting point of the conductive component to be infiltrated. Holding for 10 minutes or more, removing paraffin from the molded body by evaporating paraffin, and 9 minutes in a vacuum atmosphere
A dehydrogenation step is added by holding at a temperature of not less than 00 ° C. and not more than the melting point of the infiltration material for not less than 30 minutes, and in the infiltration step, a conductive component mainly composed of Cu is infiltrated at 1100 to 1200 ° C. The method for producing a contact material for a vacuum valve according to claim 1 or 2, wherein: 5. The method according to claim 1, wherein a boiling point is 50 to 200 before the infiltration step of infiltrating the conductive component into the molded article formed in the molding step.
Immersion in a carbohydrate-based cleaning solution at a temperature of 40 ° C. or higher, and holding at a temperature of 40 ° C. or higher and lower than the boiling point of the cleaning solution, dissolving and extracting paraffin in the cleaning solution, and adding a deparaffinization step of removing from the molded body. The method for producing a contact material for a vacuum valve according to claim 1, wherein a conductive component containing Cu as a main component is infiltrated at 1100 to 1200 ° C. in a vacuum atmosphere. 6. The vacuum valve according to claim 1, wherein, in the deparaffinization step, the cleaning liquid to be immersed is replaced at least once or more with a liquid having a low paraffin concentration or the molded body is transferred. Method of manufacturing contact materials for use. 7. In the mixing step, 0.1 wt% or less Co, 0.1 wt% or less Fe, or 0.3 wt% or less.
The method for producing a contact material for a vacuum valve according to any one of claims 1 to 6, wherein Ni is added in an amount of not more than wt% or Cr is added in an amount of not more than 3 wt%. 8. The method according to claim 1, wherein in the infiltration step, the amount of the infiltrating material infiltrating the molded body is 100 to 110% of the amount required to fill the voids in the molded body. A method for producing a contact material for a vacuum valve according to claim 7. 9. In the molding step, the mold for molding the powder has a structure in which a disk-shaped molded body is extracted after molding, and is taken out from the mold. 2. The method according to claim 1, wherein the inner diameter is larger than the inner diameter of
A method for manufacturing a contact material for a vacuum valve according to claim 8.