EP4258064A1 - Non-magnetic swivelling axis - Google Patents
Non-magnetic swivelling axis Download PDFInfo
- Publication number
- EP4258064A1 EP4258064A1 EP22167305.6A EP22167305A EP4258064A1 EP 4258064 A1 EP4258064 A1 EP 4258064A1 EP 22167305 A EP22167305 A EP 22167305A EP 4258064 A1 EP4258064 A1 EP 4258064A1
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- EP
- European Patent Office
- Prior art keywords
- tungsten
- weight
- pivot axis
- content
- magnetic
- 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.)
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Links
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims abstract description 19
- 239000010937 tungsten Substances 0.000 claims abstract description 19
- 229910001080 W alloy Inorganic materials 0.000 claims abstract description 18
- 229910052721 tungsten Inorganic materials 0.000 claims abstract description 18
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 30
- 229910052802 copper Inorganic materials 0.000 claims description 13
- 239000010949 copper Substances 0.000 claims description 13
- 239000012535 impurity Substances 0.000 claims description 10
- 229910052759 nickel Inorganic materials 0.000 claims description 9
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 8
- 229910052742 iron Inorganic materials 0.000 claims description 6
- 229910052750 molybdenum Inorganic materials 0.000 claims description 6
- 230000005291 magnetic effect Effects 0.000 description 16
- 235000019589 hardness Nutrition 0.000 description 15
- 229910000831 Steel Inorganic materials 0.000 description 9
- 239000010959 steel Substances 0.000 description 9
- 229910045601 alloy Inorganic materials 0.000 description 8
- 239000000956 alloy Substances 0.000 description 8
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 4
- 229910052698 phosphorus Inorganic materials 0.000 description 4
- 239000011574 phosphorus Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000005298 paramagnetic effect Effects 0.000 description 3
- 238000005096 rolling process Methods 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- 230000035939 shock Effects 0.000 description 3
- 238000007514 turning Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000005292 diamagnetic effect Effects 0.000 description 2
- 229910052746 lanthanum Inorganic materials 0.000 description 2
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 2
- 239000000696 magnetic material Substances 0.000 description 2
- 229910000734 martensite Inorganic materials 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910000915 Free machining steel Inorganic materials 0.000 description 1
- 229910021193 La 2 O 3 Inorganic materials 0.000 description 1
- -1 La 2 O 3 Chemical compound 0.000 description 1
- 230000005290 antiferromagnetic effect Effects 0.000 description 1
- 239000002885 antiferromagnetic material Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000002889 diamagnetic material Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003302 ferromagnetic material Substances 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 238000007542 hardness measurement Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 238000005404 magnetometry Methods 0.000 description 1
- VCTOKJRTAUILIH-UHFFFAOYSA-N manganese(2+);sulfide Chemical class [S-2].[Mn+2] VCTOKJRTAUILIH-UHFFFAOYSA-N 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 239000010979 ruby Substances 0.000 description 1
- 229910001750 ruby Inorganic materials 0.000 description 1
- 230000009528 severe injury Effects 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
- 238000011282 treatment Methods 0.000 description 1
Images
Classifications
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- G—PHYSICS
- G04—HOROLOGY
- G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
- G04B13/00—Gearwork
- G04B13/02—Wheels; Pinions; Spindles; Pivots
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C27/00—Alloys based on rhenium or a refractory metal not mentioned in groups C22C14/00 or C22C16/00
- C22C27/04—Alloys based on tungsten or molybdenum
-
- G—PHYSICS
- G04—HOROLOGY
- G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
- G04B17/00—Mechanisms for stabilising frequency
- G04B17/32—Component parts or constructional details, e.g. collet, stud, virole or piton
-
- G—PHYSICS
- G04—HOROLOGY
- G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
- G04B43/00—Protecting clockworks by shields or other means against external influences, e.g. magnetic fields
- G04B43/007—Antimagnetic alloys
-
- G—PHYSICS
- G04—HOROLOGY
- G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
- G04B15/00—Escapements
- G04B15/14—Component parts or constructional details, e.g. construction of the lever or the escape wheel
Definitions
- the present invention relates to a part for a clock movement and in particular to a non-magnetic pivot axis for a mechanical clock movement and more particularly to a balance axis, an anchor rod and a non-magnetic escapement pinion.
- the manufacture of a watch pivot axis consists, from a hardenable steel bar, of carrying out turning operations to define different active surfaces (span, shoulder, pivots, etc.) then subjecting the turned axis to heat treatment operations comprising at least one quench to improve the hardness of the axis and one or more tempers to improve its toughness.
- the heat treatment operations are followed by a rolling operation of the axis pivots, an operation consisting of polishing the pivots to bring them to the required dimensions. During the rolling operation, the hardness and roughness of the pivots are further improved.
- the pivot axes for example the balance axes, conventionally used in mechanical watch movements are made in grades of free-cutting steels which are generally carbon martensitic steels including lead and manganese sulphides to improve their machinability.
- a steel of this type designated 20AP is typically used for these applications.
- This type of material has the advantage of being easily machinable, in particular of being suitable for bar turning and presents, after quenching and tempering treatments, high mechanical properties which are very interesting for the production of watch pivot axes.
- These steels have in particular high hardness after heat treatment, making it possible to obtain very good resistance to shocks.
- the hardness of the pivots of an axle made of 20 AP steel can reach a value exceeding 700 HV after heat treatment and rolling.
- this type of material has the disadvantage of being magnetic and of being able to disrupt the running of a watch after being subjected to a magnetic field, in particular when this material is used to produce a balance axis cooperating with a spiral balance made of ferromagnetic material. This phenomenon is well known to those skilled in the art. It should also be noted that these martensitic steels are also sensitive to corrosion.
- austenitic stainless steels which have the particularity of being non-magnetic, that is to say of the paramagnetic or diamagnetic or antiferromagnetic type.
- these austenitic steels have a crystallographic structure that does not allow them to be quenched and to achieve hardness and therefore impact resistance compatible with the requirements required for the production of watch pivot axes.
- the axes obtained then present marks or severe damage in the event of shocks which will then have a negative influence on the timing of the movement.
- One way to increase the hardness of these steels is work hardening, however this hardening operation does not make it possible to obtain hardnesses greater than 500 HV. Consequently, in the context of parts requiring pivots with high impact resistance, the use of this type of steel remains limited.
- the object of the invention is to overcome the aforementioned drawbacks by proposing a pivot axis making it possible to limit the sensitivity to magnetic fields and to obtain mechanical properties enabling it to meet shock resistance requirements in the watchmaking field.
- the invention relates to a pivot axis for a watch movement made at least partly in tungsten or in a tungsten alloy.
- the tungsten alloys are alloys comprising either lanthanum oxide, copper, or nickel with the addition of one or more elements chosen from Fe, Cu, Co and Mo.
- the oxide Lanthanum acts as a chipbreaker, which improves the machinability of the tungsten alloy.
- Tungsten and its alloys combine high hardness with values greater than or equal to 500 HV0.5, very good corrosion resistance and very low magnetic susceptibility.
- This material is known to be very difficult to machine, which has hampered its use in the watchmaking field to this day.
- the term “amagnetic” material means a paramagnetic or diamagnetic or antiferromagnetic material, the magnetic permeability of which is between 0.99 and 1.01.
- An alloy of an element is an alloy containing at least 50% by weight of said element.
- the invention relates to a part for a watch movement and in particular to a non-magnetic pivot axis for a mechanical watch movement.
- the invention will be described below in the context of an application to a non-magnetic balance axis 1.
- other types of watch pivot axes are possible, such as for example watch mobile axes, typically pinions. exhaust, or even anchor rods.
- Parts of this type have diameters at the body level preferably less than 2 mm, and pivots with a diameter less than 0.2 mm, with a precision of a few microns.
- a balance axis 1 which comprises a plurality of sections 2 of different diameters, preferably formed by bar turning or any other machining technique by removal of chips, and conventionally defining surfaces 2a and shoulders 2b arranged between two end portions defining two pivots 3. These pivots are each intended to pivot in a bearing, typically in an orifice of a stone or a ruby.
- At least part of the balance axis 1, namely the pivot 3, is made of a non-magnetic metallic material in order to limit advantageously its sensitivity to magnetic fields.
- said material is pure tungsten or a tungsten alloy.
- Pure tungsten means a material comprising tungsten in a weight percentage greater than or equal to 99.5%, preferably greater than or equal to 99.7%. It may contain possible impurities such as Mo, C, Fe and O, cited as an example.
- Tungsten alloys are alloys comprising either lanthanum oxide, copper or nickel with the addition of one or more elements chosen from Fe, Cu, Co and Mo.
- the alloy of tungsten with lanthanum oxide comprises the latter in a percentage by weight of between 0.2 and 5%, preferably between 0.3 and 3%, more preferably between 0.5 and 2%.
- the alloy consists of tungsten, lanthanum oxide in a percentage by weight of between 0.2 and 5%, preferably between 0.3 and 3%, more preferably between 0.5 and 2%, and possible impurities with a total content for the latter less than or equal to 1.5% by weight.
- the alloy of tungsten with copper comprises the latter in a percentage by weight of between 2 and 49%, preferably between 3 and 45%, more preferably between 5 and 40%.
- the alloy consists of tungsten, copper in a percentage by weight of 2 and 49%, preferably between 3 and 45%, more preferably between 5 and 40% and possible impurities with a total content for the latter. less than or equal to 1.5% by weight.
- the alloy of tungsten with nickel comprises the latter with a weight content of between 0.5 and 20%, preferably between 1 and 15%, more preferably between 1.5 and 10%, and comprises one or more of the chosen elements among Fe, Cu, Co and Mo with a total content for said element(s) of between 0.2 and 10%, preferably between 0.5 and 5%.
- the alloy consists of tungsten, nickel in a percentage by weight of between 0.5 and 20%, preferably between 1 and 15%, more preferably between 1.5 and 10% and possible impurities with a total content for the latter less than or equal to 1.5% by weight.
- Tungsten and tungsten alloys according to the invention have a hardness greater than or equal to 500 HV0.5. They have a low magnetic susceptibility with typically values lower than 8 ⁇ 10 -5 , preferably 7 ⁇ 10 -5 .
- the balance axis 1, namely the pivot 3 is made of the aforementioned non-magnetic material 4 which is covered at least on part of its external surface with a layer 5 ensuring resistance to wear of the pivot.
- the layer is made of Ni or NiP.
- the phosphorus level can preferably be between 0% (we then have pure Ni) and 15% by weight.
- the phosphorus level in the NiP can be an average level of between 6% and 9%, or a high level of between 9% and 12%. It is obvious, however, that NiP can contain a low level of phosphorus.
- the layer when it is medium or high phosphorus NiP, it can be hardened by heat treatment.
- the heat treatment is carried out between 200°C and 400°C for a time of between 20 minutes and 24 hours.
- the Ni or NiP layer has a hardness preferably greater than 400 HV0.5, more preferably greater than 500 HV0.5.
- the unhardened Ni or NiP layer has a hardness preferably greater than 500 HV0.5, but less than 600 HV0.5, that is to say preferably between 500 HV0.5 and 550 HV0.5.
- the NiP layer can have a hardness between 900 HV0.5 and 1000 HV0.5.
- the Ni or NiP layer can have a thickness of between 0.5 ⁇ m and 10 ⁇ m, preferably between 1 ⁇ m and 5 ⁇ m, and more preferably between 1 ⁇ m and 2 ⁇ m.
- the layer is a layer of NiP, and more particularly a layer of chemical NiP, that is to say deposited by chemical means.
- the pivot may comprise at least one adhesion sub-layer deposited between the non-magnetic material and the Ni or NiP layer.
- a gold underlayer and/or a galvanic nickel underlayer may be provided under the Ni or NiP layer.
- the Ni or NiP layer is deposited according to a process chosen from the group comprising PVD, CVD, ALD, galvanic and chemical, and preferably chemical, deposits.
- the M(H) hysteresis curve was characterized at room temperature by varying the field applied to the samples with a vibrating sample magnetometer (VSM) of the MicroSense EZ9 type.
- VSM vibrating sample magnetometer
- Figure 3 represents the curve for pure tungsten.
- the magnetic susceptibility ( ⁇ m ) is equal to 6.8 ⁇ 10 -5 . Similar values were obtained for the tungsten alloys according to the invention.
- HV0.5 hardnesses The hardnesses measured are HV0.5 hardnesses. A value of 540 HV0.5 is obtained for the tungsten alloy with 1% by weight of carbon dioxide. lanthanum. Values in the range 500-600 HV0.5 were obtained for other tungsten alloys and pure tungsten.
Abstract
L'invention concerne un axe de pivotement (1) pour mouvement horloger, réalisé au moins en partie dans du tungstène ou dans un alliage de tungstène.The invention relates to a pivot axis (1) for a watch movement, made at least partly from tungsten or a tungsten alloy.
Description
La présente invention se rapporte à une pièce pour mouvement d'horlogerie et notamment à un axe de pivotement amagnétique pour un mouvement d'horlogerie mécanique et plus particulièrement à un axe de balancier, une tige d'ancre et un pignon d'échappement amagnétiques.The present invention relates to a part for a clock movement and in particular to a non-magnetic pivot axis for a mechanical clock movement and more particularly to a balance axis, an anchor rod and a non-magnetic escapement pinion.
La fabrication d'un axe de pivotement horloger consiste, à partir d'une barre en acier trempable, à réaliser des opérations de décolletage pour définir différentes surfaces actives (portée, épaulement, pivots etc.) puis à soumettre l'axe décolleté à des opérations de traitement thermique comprenant au moins une trempe pour améliorer la dureté de l'axe et un ou plusieurs revenus pour en améliorer la ténacité. Les opérations de traitements thermiques sont suivies d'une opération de roulage des pivots des axes, opération consistant à polir les pivots pour les amener aux dimensions requises. Au cours de l'opération de roulage la dureté ainsi que la rugosité des pivots sont encore améliorées.The manufacture of a watch pivot axis consists, from a hardenable steel bar, of carrying out turning operations to define different active surfaces (span, shoulder, pivots, etc.) then subjecting the turned axis to heat treatment operations comprising at least one quench to improve the hardness of the axis and one or more tempers to improve its toughness. The heat treatment operations are followed by a rolling operation of the axis pivots, an operation consisting of polishing the pivots to bring them to the required dimensions. During the rolling operation, the hardness and roughness of the pivots are further improved.
Les axes de pivotement, par exemple les axes de balancier, utilisés classiquement dans les mouvements d'horlogerie mécaniques sont réalisés dans des nuances d'aciers de décolletage qui sont généralement des aciers martensitiques au carbone incluant du plomb et des sulfures de manganèse pour améliorer leur usinabilité. Un acier de ce type désigné 20AP est typiquement utilisé pour ces applications.The pivot axes, for example the balance axes, conventionally used in mechanical watch movements are made in grades of free-cutting steels which are generally carbon martensitic steels including lead and manganese sulphides to improve their machinability. A steel of this type designated 20AP is typically used for these applications.
Ce type de matériau a l'avantage d'être facilement usinable, en particulier d'être apte au décolletage et présente, après des traitements de trempe et de revenu, des propriétés mécaniques élevées très intéressantes pour la réalisation d'axes de pivotement horlogers. Ces aciers présentent en particulier après traitement thermique une dureté élevée, permettant d'obtenir une très bonne tenue aux chocs. Typiquement la dureté des pivots d'un axe réalisé en acier 20 AP peut atteindre une valeur dépassant les 700 HV après traitement thermique et roulage.This type of material has the advantage of being easily machinable, in particular of being suitable for bar turning and presents, after quenching and tempering treatments, high mechanical properties which are very interesting for the production of watch pivot axes. These steels have in particular high hardness after heat treatment, making it possible to obtain very good resistance to shocks. Typically the hardness of the pivots of an axle made of 20 AP steel can reach a value exceeding 700 HV after heat treatment and rolling.
Bien que fournissant des propriétés mécaniques satisfaisantes pour les applications horlogères décrites ci-dessus, ce type de matériau présente l'inconvénient d'être magnétique et de pouvoir perturber la marche d'une montre après avoir été soumis à un champ magnétique, et ce notamment lorsque ce matériau est utilisé pour la réalisation d'un axe de balancier coopérant avec un balancier spiral en matériau ferromagnétique. Ce phénomène est bien connu de l'homme du métier. On notera également que ces aciers martensitiques sont également sensibles à la corrosion.Although providing satisfactory mechanical properties for the watchmaking applications described above, this type of material has the disadvantage of being magnetic and of being able to disrupt the running of a watch after being subjected to a magnetic field, in particular when this material is used to produce a balance axis cooperating with a spiral balance made of ferromagnetic material. This phenomenon is well known to those skilled in the art. It should also be noted that these martensitic steels are also sensitive to corrosion.
Des essais pour tenter de remédier à ces inconvénients ont été menés avec des aciers inoxydables austénitiques qui présentent la particularité d'être amagnétiques, c'est-à-dire du type paramagnétique ou diamagnétique ou antiferromagnétique. Toutefois, ces aciers austénitiques présentent une structure cristallographique ne permettant pas de les tremper et d'atteindre des duretés et donc des résistances aux chocs compatibles avec les exigences requises pour la réalisation d'axes de pivotement horlogers. Les axes obtenus présentent alors des marques ou des endommagements sévères en cas de chocs qui vont avoir ensuite une influence négative sur la chronométrie du mouvement. Un moyen d'augmenter la dureté de ces aciers est l'écrouissage, toutefois cette opération de durcissement ne permet pas d'obtenir des duretés supérieures à 500 HV. Par conséquent, dans le cadre de pièces nécessitant des pivots présentant une grande résistance aux chocs, l'utilisation de ce type d'aciers reste limitée.Tests to try to remedy these drawbacks have been carried out with austenitic stainless steels which have the particularity of being non-magnetic, that is to say of the paramagnetic or diamagnetic or antiferromagnetic type. However, these austenitic steels have a crystallographic structure that does not allow them to be quenched and to achieve hardness and therefore impact resistance compatible with the requirements required for the production of watch pivot axes. The axes obtained then present marks or severe damage in the event of shocks which will then have a negative influence on the timing of the movement. One way to increase the hardness of these steels is work hardening, however this hardening operation does not make it possible to obtain hardnesses greater than 500 HV. Consequently, in the context of parts requiring pivots with high impact resistance, the use of this type of steel remains limited.
L'invention a pour objet de pallier aux inconvénients précités en proposant un axe de pivotement permettant à la fois de limiter la sensibilité aux champs magnétiques et d'obtenir des propriétés mécaniques permettant de répondre aux exigences de résistance aux chocs dans le domaine horloger.The object of the invention is to overcome the aforementioned drawbacks by proposing a pivot axis making it possible to limit the sensitivity to magnetic fields and to obtain mechanical properties enabling it to meet shock resistance requirements in the watchmaking field.
A cet effet, l'invention se rapporte à un axe de pivotement pour mouvement horloger réalisé au moins en partie dans du tungstène ou dans un alliage de tungstène. De préférence, les alliages de tungstène sont des alliages comprenant soit de l'oxyde de lanthane, soit du cuivre, soit du nickel additionné d'un ou plusieurs éléments choisis parmi le Fe, Cu, Co et Mo. En particulier, l'oxyde de lanthane joue le rôle de brise-copeaux, ce qui améliore l'usinabilité de l'alliage de tungstène.To this end, the invention relates to a pivot axis for a watch movement made at least partly in tungsten or in a tungsten alloy. Preferably, the tungsten alloys are alloys comprising either lanthanum oxide, copper, or nickel with the addition of one or more elements chosen from Fe, Cu, Co and Mo. In particular, the oxide Lanthanum acts as a chipbreaker, which improves the machinability of the tungsten alloy.
Le tungstène et ses alliages combinent une dureté élevée avec des valeurs supérieures ou égales à 500 HV0.5, une très bonne résistance à la corrosion et une susceptibilité magnétique très faible.Tungsten and its alloys combine high hardness with values greater than or equal to 500 HV0.5, very good corrosion resistance and very low magnetic susceptibility.
Ce matériau est réputé très difficile à usiner, ce qui a freiné son utilisation dans le domaine horloger jusqu'à ce jour.This material is known to be very difficult to machine, which has hampered its use in the watchmaking field to this day.
D'autres caractéristiques et avantages de l'invention apparaîtront à la lecture de la description détaillée qui va suivre, en référence aux dessins annexés.Other characteristics and advantages of the invention will appear on reading the detailed description which follows, with reference to the appended drawings.
-
La
figure 1 représente un axe de pivotement selon l'invention.Therefigure 1 represents a pivot axis according to the invention. -
La
figure 2 représente en coupe partielle un pivot d'un axe de pivotement selon l'invention comportant un revêtement sur sa surface externe.Therefigure 2 represents in partial section a pivot of a pivot axis according to the invention comprising a coating on its external surface. -
La
figure 3 représente le comportement paramagnétique du tungstène présentant une susceptibilité magnétique χm de 6.8×10-5.ThereFigure 3 represents the paramagnetic behavior of tungsten having a magnetic susceptibility χ m of 6.8×10 -5 .
Dans la présente description, le terme matériau « amagnétique » signifie un matériau paramagnétique ou diamagnétique ou antiferromagnétique, dont la perméabilité magnétique est comprise entre 0.99 et 1.01.In the present description, the term “amagnetic” material means a paramagnetic or diamagnetic or antiferromagnetic material, the magnetic permeability of which is between 0.99 and 1.01.
Un alliage d'un élément est un alliage contenant au moins 50% en poids dudit élément.An alloy of an element is an alloy containing at least 50% by weight of said element.
L'invention se rapporte à une pièce pour mouvement d'horlogerie et notamment à un axe de pivotement amagnétique pour un mouvement d'horlogerie mécanique. L'invention sera décrite ci-après dans le cadre d'une application à un axe de balancier amagnétique 1. Bien évidemment, d'autres types d'axes de pivotement horlogers sont envisageables comme par exemple des axes de mobiles horlogers, typiquement des pignons d'échappement, ou encore des tiges d'ancre. Les pièces de ce type présentent au niveau du corps des diamètres inférieurs de préférence à 2 mm, et des pivots de diamètre inférieur de préférence à 0.2 mm, avec une précision de quelques microns.The invention relates to a part for a watch movement and in particular to a non-magnetic pivot axis for a mechanical watch movement. The invention will be described below in the context of an application to a
En se référant à la
Avec le magnétisme induit par les objets rencontrés au quotidien, il est important de limiter la sensibilité de l'axe de balancier 1 sous peine d'influencer la marche de la pièce d'horlogerie dans laquelle il est incorporé.With the magnetism induced by objects encountered on a daily basis, it is important to limit the sensitivity of the
Ainsi, au moins une partie de l'axe de balancier 1, à savoir le pivot 3, est réalisé dans un matériau métallique amagnétique afin de limiter de manière avantageuse sa sensibilité aux champs magnétiques. Selon l'invention, ledit matériau est du tungstène pur ou un alliage de tungstène.Thus, at least part of the
On entend par tungstène pur un matériau comprenant du tungstène dans un pourcentage en poids supérieur ou égal à 99.5%, de préférence supérieur ou égal à 99.7%. Il peut comporter des impuretés éventuelles telles que du Mo, C, Fe et O, citées à titre d'exemple.Pure tungsten means a material comprising tungsten in a weight percentage greater than or equal to 99.5%, preferably greater than or equal to 99.7%. It may contain possible impurities such as Mo, C, Fe and O, cited as an example.
Les alliages de tungstène sont des alliages comprenant soit de l'oxyde de lanthane, soit du cuivre, soit du nickel additionné d'un ou plusieurs éléments choisis parmi le Fe, Cu, Co et Mo.Tungsten alloys are alloys comprising either lanthanum oxide, copper or nickel with the addition of one or more elements chosen from Fe, Cu, Co and Mo.
Plus précisément, l'alliage de tungstène avec de l'oxyde de lanthane, à savoir du La2O3, comporte ce dernier dans un pourcentage en poids compris entre 0.2 et 5%, de préférence entre 0.3 et 3%, plus préférentiellement entre 0.5 et 2%. Avantageusement, l'alliage est constitué de tungstène, d'oxyde de lanthane dans un pourcentage en poids compris entre 0.2 et 5%, de préférence entre 0.3 et 3%, plus préférentiellement entre 0.5 et 2%, et d'impuretés éventuelles avec une teneur totale pour ces dernières inférieure ou égale à 1.5% en poids.More precisely, the alloy of tungsten with lanthanum oxide, namely La 2 O 3 , comprises the latter in a percentage by weight of between 0.2 and 5%, preferably between 0.3 and 3%, more preferably between 0.5 and 2%. Advantageously, the alloy consists of tungsten, lanthanum oxide in a percentage by weight of between 0.2 and 5%, preferably between 0.3 and 3%, more preferably between 0.5 and 2%, and possible impurities with a total content for the latter less than or equal to 1.5% by weight.
Plus précisément, l'alliage de tungstène avec du cuivre comporte ce dernier dans un pourcentage en poids compris 2 et 49%, de préférence entre 3 et 45%, plus préférentiellement entre 5 et 40%. Avantageusement, l'alliage est constitué de tungstène, de cuivre dans un pourcentage en poids compris 2 et 49%, de préférence entre 3 et 45%, plus préférentiellement entre 5 et 40% et d'impuretés éventuelles avec une teneur totale pour ces dernières inférieure ou égale à 1.5% en poids.More precisely, the alloy of tungsten with copper comprises the latter in a percentage by weight of between 2 and 49%, preferably between 3 and 45%, more preferably between 5 and 40%. Advantageously, the alloy consists of tungsten, copper in a percentage by weight of 2 and 49%, preferably between 3 and 45%, more preferably between 5 and 40% and possible impurities with a total content for the latter. less than or equal to 1.5% by weight.
Plus précisément, l'alliage de tungstène avec du nickel comporte ce dernier avec une teneur en poids comprise entre 0.5 et 20%, de préférence entre 1 et 15%, plus préférentiellement entre 1.5 et 10%, et comporte un ou plusieurs des éléments choisis parmi le Fe, Cu, Co et Mo avec une teneur totale pour le ou lesdits éléments comprise entre 0.2 et 10%, de préférence entre 0.5 et 5%. Avantageusement, l'alliage est constitué de tungstène, de nickel dans un pourcentage en poids compris entre 0.5 et 20%, de préférence entre 1 et 15%, plus préférentiellement entre 1.5 et 10% et d'impuretés éventuelles avec une teneur totale pour ces dernières inférieure ou égale à 1.5% en poids.More precisely, the alloy of tungsten with nickel comprises the latter with a weight content of between 0.5 and 20%, preferably between 1 and 15%, more preferably between 1.5 and 10%, and comprises one or more of the chosen elements among Fe, Cu, Co and Mo with a total content for said element(s) of between 0.2 and 10%, preferably between 0.5 and 5%. Advantageously, the alloy consists of tungsten, nickel in a percentage by weight of between 0.5 and 20%, preferably between 1 and 15%, more preferably between 1.5 and 10% and possible impurities with a total content for the latter less than or equal to 1.5% by weight.
Le tungstène et les alliages de tungstène selon l'invention ont une dureté supérieure ou égale à 500 HV0.5. Ils ont une susceptibilité magnétique faible avec typiquement des valeurs inférieures à 8×10-5, de préférence à 7×10-5.Tungsten and tungsten alloys according to the invention have a hardness greater than or equal to 500 HV0.5. They have a low magnetic susceptibility with typically values lower than 8×10 -5 , preferably 7×10 -5 .
Selon une variante, au moins une partie de l'axe de balancier 1, à savoir le pivot 3, est réalisé dans le matériau amagnétique 4 précité qui est recouvert au moins sur une partie de sa surface externe d'une couche 5 assurant la résistance à l'usure du pivot. Cette variante est représentée à la
En outre, lorsque la couche est du NiP à taux moyen ou élevé de phosphore, elle peut être durcie par traitement thermique. Typiquement, le traitement thermique est réalisé entre 200°C et 400°C pendant un temps compris entre 20 minutes et 24 heures.In addition, when the layer is medium or high phosphorus NiP, it can be hardened by heat treatment. Typically, the heat treatment is carried out between 200°C and 400°C for a time of between 20 minutes and 24 hours.
La couche de Ni ou NiP présente une dureté de préférence supérieure à 400 HV0.5, plus préférentiellement supérieure à 500 HV0.5. D'une manière particulièrement avantageuse, la couche en Ni ou NiP non durcie présente une dureté de préférence supérieure à 500 HV0.5, mais inférieure à 600 HV0.5, c'est-à-dire de préférence comprise entre 500 HV0.5 et 550 HV0.5. Lorsqu'elle est durcie par traitement thermique, la couche en NiP peut présenter une dureté comprise entre 900 HV0.5 et 1000 HV0.5.The Ni or NiP layer has a hardness preferably greater than 400 HV0.5, more preferably greater than 500 HV0.5. In a particularly advantageous manner, the unhardened Ni or NiP layer has a hardness preferably greater than 500 HV0.5, but less than 600 HV0.5, that is to say preferably between 500 HV0.5 and 550 HV0.5. When hardened by heat treatment, the NiP layer can have a hardness between 900 HV0.5 and 1000 HV0.5.
D'une manière avantageuse, la couche de Ni ou NiP peut présenter une épaisseur comprise entre 0,5 µm et 10 µm, de préférence entre 1 µm et 5 µm, et plus préférentiellement entre 1 µm et 2 µm.Advantageously, the Ni or NiP layer can have a thickness of between 0.5 µm and 10 µm, preferably between 1 µm and 5 µm, and more preferably between 1 µm and 2 µm.
De préférence, la couche est une couche de NiP, et plus particulièrement une couche de NiP chimique, c'est-à-dire déposée par voie chimique.Preferably, the layer is a layer of NiP, and more particularly a layer of chemical NiP, that is to say deposited by chemical means.
Afin d'améliorer la tenue de la couche de Ni ou NiP, le pivot peut comprendre au moins une sous-couche d'adhésion déposée entre le matériau amagnétique et la couche de Ni ou NiP. Par exemple, une sous-couche d'or et/ou une sous-couche de nickel galvanique peu(ven)t être prévue(s) sous la couche de Ni ou NiP.In order to improve the strength of the Ni or NiP layer, the pivot may comprise at least one adhesion sub-layer deposited between the non-magnetic material and the Ni or NiP layer. For example, a gold underlayer and/or a galvanic nickel underlayer may be provided under the Ni or NiP layer.
Selon l'invention, la couche de Ni ou NiP est déposée selon un procédé choisi parmi le groupe comprenant les dépôts PVD, CVD, ALD, galvanique et chimique, et de préférence chimique.According to the invention, the Ni or NiP layer is deposited according to a process chosen from the group comprising PVD, CVD, ALD, galvanic and chemical, and preferably chemical, deposits.
On précisera que seule la surface externe des pivots ou même seule une partie de la surface externe des pivots peut être recouverte de la couche de Ni ou NiP. En variante, toute la surface externe de l'axe de balancier comprenant les pivots peut être recouverte de la couche de Ni ou NiP.It will be noted that only the external surface of the pivots or even only part of the external surface of the pivots can be covered with the layer of Ni or NiP. Alternatively, the entire external surface of the balance shaft including the pivots can be covered with the layer of Ni or NiP.
Des mesures de dureté et de susceptibilité magnétique ont été réalisées sur plusieurs échantillons non revêtus.Hardness and magnetic susceptibility measurements were carried out on several uncoated samples.
Pour les propriétés magnétiques, la courbe d'hystérèse M(H) a été caractérisée à température ambiante en faisant varier le champ appliqué sur les échantillons avec un magnétomètre à échantillon vibrant (VSM) de type MicroSense EZ9. La
Les duretés mesurées sont des duretés HV0.5. Une valeur de 540 HV0.5 est obtenue pour l'alliage de tungstène avec 1% en poids d'oxyde de lanthane. Des valeurs dans la fourchette 500-600 HV0.5 ont été obtenues pour les autres alliages de tungstène et le tungstène pur.The hardnesses measured are HV0.5 hardnesses. A value of 540 HV0.5 is obtained for the tungsten alloy with 1% by weight of carbon dioxide. lanthanum. Values in the range 500-600 HV0.5 were obtained for other tungsten alloys and pure tungsten.
Claims (11)
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP22167305.6A EP4258064A1 (en) | 2022-04-08 | 2022-04-08 | Non-magnetic swivelling axis |
| PCT/EP2023/059119 WO2023194522A1 (en) | 2022-04-08 | 2023-04-06 | Non-magnetic pivot pin |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP22167305.6A EP4258064A1 (en) | 2022-04-08 | 2022-04-08 | Non-magnetic swivelling axis |
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| EP4258064A1 true EP4258064A1 (en) | 2023-10-11 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP22167305.6A Pending EP4258064A1 (en) | 2022-04-08 | 2022-04-08 | Non-magnetic swivelling axis |
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| EP (1) | EP4258064A1 (en) |
| WO (1) | WO2023194522A1 (en) |
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| CH702774A4 (en) * | 1974-05-22 | 1975-10-31 | ||
| US20140198624A1 (en) * | 2013-01-17 | 2014-07-17 | Omega S.A. | Part for a timepiece movement |
| US20200133200A1 (en) * | 2018-10-24 | 2020-04-30 | Seiko Epson Corporation | Timepiece part and timepiece |
| CN111996430B (en) * | 2020-07-28 | 2021-09-28 | 深圳市飞亚达精密科技有限公司 | Tungsten-copper alloy free from influence of magnetic field and manufacturing method and application thereof |
| EP3940112A1 (en) * | 2020-07-16 | 2022-01-19 | Richemont International Sa | Method for improving a material for timepiece |
-
2022
- 2022-04-08 EP EP22167305.6A patent/EP4258064A1/en active Pending
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2023
- 2023-04-06 WO PCT/EP2023/059119 patent/WO2023194522A1/en active Search and Examination
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| CH702774A4 (en) * | 1974-05-22 | 1975-10-31 | ||
| US20140198624A1 (en) * | 2013-01-17 | 2014-07-17 | Omega S.A. | Part for a timepiece movement |
| US20200133200A1 (en) * | 2018-10-24 | 2020-04-30 | Seiko Epson Corporation | Timepiece part and timepiece |
| EP3940112A1 (en) * | 2020-07-16 | 2022-01-19 | Richemont International Sa | Method for improving a material for timepiece |
| CN111996430B (en) * | 2020-07-28 | 2021-09-28 | 深圳市飞亚达精密科技有限公司 | Tungsten-copper alloy free from influence of magnetic field and manufacturing method and application thereof |
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| WO2023194522A1 (en) | 2023-10-12 |
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