EP0178796B1 - Fabrication de contacts d'interrupteurs à vide - Google Patents

Fabrication de contacts d'interrupteurs à vide Download PDF

Info

Publication number
EP0178796B1
EP0178796B1 EP19850306634 EP85306634A EP0178796B1 EP 0178796 B1 EP0178796 B1 EP 0178796B1 EP 19850306634 EP19850306634 EP 19850306634 EP 85306634 A EP85306634 A EP 85306634A EP 0178796 B1 EP0178796 B1 EP 0178796B1
Authority
EP
European Patent Office
Prior art keywords
vacuum interrupter
interrupter contacts
mixture
chromium
approximately
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP19850306634
Other languages
German (de)
English (en)
Other versions
EP0178796A3 (en
EP0178796A2 (fr
Inventor
Denzil Malcolm Atkinson
Peter Melkin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
VACUUM INTERRUPTERS Ltd
Original Assignee
VACUUM INTERRUPTERS Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by VACUUM INTERRUPTERS Ltd filed Critical VACUUM INTERRUPTERS Ltd
Publication of EP0178796A2 publication Critical patent/EP0178796A2/fr
Publication of EP0178796A3 publication Critical patent/EP0178796A3/en
Application granted granted Critical
Publication of EP0178796B1 publication Critical patent/EP0178796B1/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00—Contacts
    • H01H1/02—Contacts characterised by the material thereof
    • H01H1/0203—Contacts characterised by the material thereof specially adapted for vacuum switches
    • H01H1/0206—Contacts characterised by the material thereof specially adapted for vacuum switches containing as major components Cu and Cr

Definitions

  • the present invention relates to vacuum type circuit interrupters and more particularly to a method for forming the contact structure which is a part of such vacuum interrupters.
  • Vacuum type circuit interrupters generally comprise an evacuated insulating envelope having separable contacts disposed within the insulating envelope.
  • the contacts are movable between a closed position in which the contacts are engaged and an open position in which the contacts are separated and an arcing gap is established therebetween.
  • An arc is initiated between the contact surfaces when the contacts move into or out of engagement while the circuit in which the interrupter is used is energized.
  • an arc may be formed that results in the melting and vaporising of some contact material. Then after the contacts are brought together under high pressure engagement welds may be formed between the contact surfaces due to the melted contact material formed during arcing. Current surges also occur in the first few milliseconds of contact closing and these can also cause contact welding. The magnitude of the force required to break the weld so that the contacts can be opened depends upon many factors including the previous fault current, for example, the contact area, and the contact material.
  • One proposed solution to this problem is to adjust the welding characteristics of the contacts so that the welding which may take place is of sufficiently low strength that the weld may be readily broken without unduly distorting or changing the surface of the contact material at which the weld occurs.
  • the fundamental characteristics of the contact materials namely, good current interruption ability, high voltage withstand capability and low electrical resistance including low chopping and low erosion characteristics must not be altered during operation.
  • One approach has been to utilize a major proportion of a very strong element and form a sintered network of powdered particles of this material and thereafter infiltrate the same with a lesser amount of another component which will produce a compromise in the various characteristics of the individual components.
  • Typical of such materials has been the employment of a major constituent comprising a refractory metal such as chromium which is characterised by an high melting point and thereby minimise the welding tendency of the electrode.
  • a pure sintered refractory metal contact formed for example, of chromium will not provide the required electrical conductivity nor the chopping characteristics and high voltage withstand capability.
  • Chromium-copper contacts are well known from for example U.K. Patent No. 1,194,674 and U.S. Patent Nos. 3,960,554 and 4,048,117.
  • the chromium is first pressed into a matrix and then infiltrated with copper.
  • a further component of the contact material is an "anti-welding" element which displays "anti-welding" characteristics in a vacuum environment.
  • bismuth was dissolved in the copper before being infiltrated into the chromium matrix, which had been cold pressed and sintered beforehand.
  • Bismuth is one example of elements such as lead, tellurium, antimony, tungsten and similar metals which form a brittle intermetallic phase thereby decreasing the ductility of the welds and so enabling the weld to be broken more easily.
  • the invention provides a method of manufacturing vacuum interrupter contacts comprising the steps of mixing a metal of high electrical conductivity in powder form with an embrittling agent in powder form and a refractory metal in powder form, the mass of the embrittling agent being less than 0.25% of the total mass of the mixture, cold pressing the mixture to a density of greater than 90% relative to theoretical maximum, sintering under vacuum, and then cold coining the sintered contact up to a density of greater than 97% relative to the theoretical maximum.
  • the metal with high electrical conductivity is copper and the refractory metal is chromium.
  • the embrittling agent is preferably bismuth but may be any one of lead, tellurium, thallium, antimony or tungsten or, in some cases, a mixture thereof.
  • the copper powder which preferably has a particle size range of up to approximately 100 11m is conveniently first mixed with the bismuth which preferably has a particle size range of up to approximately 40 pm. This base mixture is then mixed with the chromium powder which preferably has a particle size range of up to 22 ⁇ m.
  • the proportion of base mixture to chromium is preferably in the range 40-90% by mass of base mixture to 60-10% of chromium and is most preferably approximately 75% base mixture to 25% of chromium.
  • the mixture is first cold pressed to a density of approximately 93% relative to theoretical maximum, vacuum sintered at a temperature of between about 950 ⁇ 1050°C and then cold coined to a density of approximately 98% relative to theoretical maximum.
  • copper powder 1 with a particle size of less than 100 ⁇ m is first thoroughly mixed with bismuth powder 3 with a particle size range of less than 40 um.
  • This base mixture 4 is then thoroughly mixed with chromium powder 2 with a particle size range of up to 200 um in the proportions of 75% by mass of base mixture 4 to the remainder chromium 2.
  • the amount of bismuth 3 in this mixture being 0.15% by mass.
  • the mixture 5 is then cold pressed 6 at approximately 45 ton/sq. inch (70 X 10 6 kg/m 2 ) to a density of approximately 93% relative to theoretical maximum. It is then sintered 7 under vacuum at a temperature of about 1025°C for four hours to achieve partial bonding of the copper/copper and copper/chromium and annealing of the compact material.
  • the sintered compact is then cold coined 8 at approximately 72 ton/sq. inch (113 X 10 6 kg/m 2 ) to a density of approximately 98% relative to theoretical maximum. It is then finally machined to prepare for inclusion as a contact in a vacuum interrupter.

Landscapes

  • High-Tension Arc-Extinguishing Switches Without Spraying Means (AREA)
  • Pressure Welding/Diffusion-Bonding (AREA)
  • Manufacture Of Switches (AREA)

Claims (9)

1. Méthode de fabrication des contacts d'interrupteurs à vide couvrant les étapes de mélange d'un métal d'une haute conductivité électrique sous forme de poudre, avec un agent de fragilisation sous forme de poudre et un métal réfractaire sous forme de poudre, caractérisée par le fait que l'agent de fragilisation représente moins de 0,25% de la masse totale du mélange, le mélange est comprimé à froid à une densité non supérieure à 90% par rapport au maximum théorique, puis fritté sous vide, et la masse frittée est ensuite estampée à froid jusqu'à une densité de plus de 97% par rapport au maximum théorique.
2. Méthode de fabrication des contacts d'interrupteurs à vide selon la Revendication No. 1, caractérisée par le fait que le métal de haute conductivité électrique est le cuivre.
3. Méthode de fabrication des contacts d'interrupteurs à vide selon la Revendication No. 2, caractérisée par le fait que le métal réfractaire est le chrome, et l'agent de fragilisation est le bismuth.
4. Méthode de fabrication des contacts d'interrupteurs à vide selon la Revendication No. 2, caractérisée par le fait que l'agent de fragilisation est le plomb ou le tellurium ou le thallium ou l'antimoine ou le tungstène.
5. Méthode de fabrication des contacts d'interrupteurs à vide selon la Revendication No. 2, caractérisée par le fait que l'agent de fragilisation est un mélange d'une combinaison quelconque de plomb, de tellurium, de thallium, d'antimoine, de tungstène ou de bismuth.
6. Méthode de fabrication des contacts d'interrupteurs à vide selon la Revendication No. 3, caractérisée par le fait que la poudre de cuivre est d'une granulométrie allant jusqu'à 100 Ilm environ, que le bismuth (3) est d'une granulométrie allant jusqu'à 40 pm environ, et que la poudre de cuivre (1) est d'abord mélangée avec le bismuth (3) pour former un mélange de base (4) qui est ensuite mélangé avec le chrome (2).
7. Méthode de fabrication des contacts d'interrupteurs à vide selon la Revendication No. 6, caractérisée par le fait que le mélange de base (4), composé de poudre de cuivre et de bismuth, est mélangé avec de la poudre de chrome (2) d'une granulométrie allant jusqu'à 200 pm environ.
8. Méthode de fabrication des contacts d'interrupteurs à vide selon la Revendication No. 7, caractérisée par le fait que le mélange de base (4) et le chrome (2) sont proportionnés à raison de 40-90% en masse pour le mélange de base et 60-10% en masse pour le chrome, ce mélange comportant environ 0,15% en masse de bismuth (3).
9. Méthode de fabrication des contacts d'interrupteurs à vide selon la Revendication No. 8, caractérisée par le fait que le mélange (5) est d'abord comprimé à froid (6) jusqu'à une densité de 93% environ par rapport au maximum théorique, fritté sous vide (7) à une température de 950-1050°C environ, puis estampé à froid (8) jusqu'à une densité de 98% environ par rapport au maximum théorique.
EP19850306634 1984-10-15 1985-09-18 Fabrication de contacts d'interrupteurs à vide Expired EP0178796B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8426009 1984-10-15
GB848426009A GB8426009D0 (en) 1984-10-15 1984-10-15 Vacuum interrupter contacts

Publications (3)

Publication Number Publication Date
EP0178796A2 EP0178796A2 (fr) 1986-04-23
EP0178796A3 EP0178796A3 (en) 1987-05-27
EP0178796B1 true EP0178796B1 (fr) 1989-11-02

Family

ID=10568206

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19850306634 Expired EP0178796B1 (fr) 1984-10-15 1985-09-18 Fabrication de contacts d'interrupteurs à vide

Country Status (5)

Country Link
EP (1) EP0178796B1 (fr)
JP (1) JPS6196621A (fr)
DE (1) DE3574074D1 (fr)
GB (2) GB8426009D0 (fr)
IN (1) IN164807B (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4743718A (en) * 1987-07-13 1988-05-10 Westinghouse Electric Corp. Electrical contacts for vacuum interrupter devices
DE58905069D1 (de) * 1989-05-31 1993-09-02 Siemens Ag Verfahren zur herstellung eines cucr-kontaktwerkstoffes fuer vakuumschuetze sowie zugehoeriger kontaktwerkstoff.
TW237551B (fr) * 1990-06-07 1995-01-01 Toshiba Co Ltd
JP2908071B2 (ja) * 1991-06-21 1999-06-21 株式会社東芝 真空バルブ用接点材料

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1194674A (en) * 1966-05-27 1970-06-10 English Electric Co Ltd Vacuum Type Electric Circuit Interrupting Devices
DE2346179A1 (de) * 1973-09-13 1975-06-26 Siemens Ag Verbundmetall als kontaktwerkstoff fuer vakuumschalter
US3960554A (en) * 1974-06-03 1976-06-01 Westinghouse Electric Corporation Powdered metallurgical process for forming vacuum interrupter contacts
US4048117A (en) * 1974-10-29 1977-09-13 Westinghouse Electric Corporation Vacuum switch contact materials
US4190753A (en) * 1978-04-13 1980-02-26 Westinghouse Electric Corp. High-density high-conductivity electrical contact material for vacuum interrupters and method of manufacture
JPS54147481A (en) * 1978-05-11 1979-11-17 Mitsubishi Electric Corp Contact for vacuum breaker
US4304600A (en) * 1979-11-01 1981-12-08 Bell Telephone Laboratories, Incorporated Manufacture of high-strength metallic articles
JPS59163726A (ja) * 1983-03-04 1984-09-14 株式会社日立製作所 真空しや断器

Also Published As

Publication number Publication date
DE3574074D1 (en) 1989-12-07
EP0178796A3 (en) 1987-05-27
GB2166161A (en) 1986-04-30
IN164807B (fr) 1989-06-03
EP0178796A2 (fr) 1986-04-23
GB2166161B (en) 1988-08-24
JPS6196621A (ja) 1986-05-15
GB8521984D0 (en) 1985-10-09
GB8426009D0 (en) 1984-11-21

Similar Documents

Publication Publication Date Title
EP0153635B1 (fr) Matière d'une électrode de contact pour interrupteur à vide et méthode pour sa fabrication
JP2874522B2 (ja) 真空遮断器及びそれに用いる真空バルブと真空バルブ用電極並びにその製造法
CA1327131C (fr) Contacts pour interrupteurs d'aspirateur
CA1118823A (fr) Materiaux a grande densite et a grande conductivite pour contacts d'interrupteur a vide et methode de fabrication
EP2081200B1 (fr) Contact électrique pour interrupteur sous vide
EP0083200B1 (fr) Composition d'électrode pour interrupteur à vide
EP0101024B1 (fr) Matériau de contact pour interrupteur à vide et son procédé de fabrication
Schroder Silver-metal oxides as contact materials
JP2941682B2 (ja) 真空バルブ及びその製造方法
EP0155322B1 (fr) Electrode de vis d'admission d'air
US4547639A (en) Vacuum circuit breaker
JPH0534406B2 (fr)
EP0178796B1 (fr) Fabrication de contacts d'interrupteurs à vide
CA1230909A (fr) Electrode d'interrupteur a vide ayant une partie a faible conductivite pour la rotation magnetique de l'arc
CA1219024A (fr) Materiau de contact pour interrupteurs sous vide
Stevens Powder-metallurgy solutions to electrical-contact problems
EP0126347B1 (fr) Matériau de contact pour interrupteur sous vide, membre de contact de ce matériau, interrupteur sous vide et utilisation de ce matériau
JPH0510782B2 (fr)
JP2000188045A (ja) 真空遮断器及びそれに用いる真空バルブとその電極
JPH04132127A (ja) 真空バルブ用接点
KR0171607B1 (ko) 진공회로 차단기용 전극 및 진공회로 차단기
EP0440340A2 (fr) Matériaux pour contacts électriques et leur procédé de fabrication
JPH0711357A (ja) 真空インタラプタ用電極材料
JPS585928A (ja) 真空しや断器
JP2002161327A (ja) 遮断器用接点材料，その製造方法および遮断器

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE NL

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE NL

17P Request for examination filed

Effective date: 19870513

17Q First examination report despatched

Effective date: 19890404

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE NL

REF Corresponds to:

Ref document number: 3574074

Country of ref document: DE

Date of ref document: 19891207

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20030814

Year of fee payment: 19

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20030821

Year of fee payment: 19

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050401

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050401

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20050401