EP3273312A1 - Method for adjusting the running of a timepiece - Google Patents

Abstract

The invention relates to a method of adjusting the running of a timepiece after casing to ensure a better operation of the timepiece.

Description

Field of the invention

The invention relates to a method for adjusting the running of a timepiece and, more particularly, to a setting of a clockwork movement equipped with a resonator of the balance-spring type to guarantee a better running at the same time. timepiece.

Background of the invention

It is known to adjust the movement of a watch movement, before its casing, in different positions, in order to tighten to the maximum the curves of anisochronism of the future timepiece.

However, it was found that walking a well-regulated movement outside of its box tended to drift to wear.

Summary of the invention

• monter un mouvement muni d'un résonateur balancier - spiral dans une boîte de la pièce d'horlogerie ;
• mesurer la marche de la pièce d'horlogerie ;
• déterminer la valeur de correction à appliquer à l'inertie du balancier pour obtenir une marche souhaitée ;
• modifier, par ajout d'une matière sur le balancier, l'inertie du balancier selon ladite valeur de correction.

The object of the present invention is to overcome all or part of the disadvantages mentioned above by proposing a new method of adjusting the running of a timepiece.
For this purpose, the invention relates to a method of adjusting a timepiece comprising the following steps:

• to mount a movement equipped with a balance-spring resonator in a box of the timepiece;
• measure the progress of the timepiece;
• determine the correction value to be applied to the inertia of the balance to obtain a desired step;
• modify, by adding a material on the balance, the inertia of the balance according to said correction value.

It is therefore clear that the adjustment is not made only on the bare movement, that is to say when it is not yet fitted, but that an additional adjustment advantageously according to the invention is carried out at the end of manufacture of the timepiece allowing a fine adjustment of the timepiece which takes into account the changes in walking induced at the time of the casing as, for example, the constraints generated on the movement by the casing and / or aerodynamic changes induced by the closed environment of the box.

• la mesure de la marche est réalisée sans contact avec le résonateur balancier - spiral ;
• la mesure de la marche est réalisée sous forme optique ou acoustique ;
• la valeur de correction est déterminée en comparant la marche mesurée et la fréquence souhaitée pour le résonateur ;
• la valeur de correction correspond à la distribution symétrique d'au moins deux masses de la matière sur le balancier afin de modifier l'inertie du balancier sans modifier son centre de masse ;
• la valeur de correction est déterminée en comparant, d'une part, la marche mesurée et, d'autre part, le balourd et la fréquence souhaités pour le résonateur ;
• la valeur de correction correspond à la distribution asymétrique d'au moins une masse de la matière sur le balancier afin de modifier l'inertie du balancier et son centre de masse ;
• l'ajout de matière est effectuée par une phase de projection de la matière sur le balancier ;
• la matière comporte une colle, une peinture ou une suspension de métal ;
• la phase de projection de matière est suivie d'une phase de solidification de la matière projetée.

According to other advantageous variants of the invention:

• the measurement of the step is performed without contact with the balance-spring resonator;
• the measurement of the step is performed in optical or acoustic form;
• the correction value is determined by comparing the measured step and the desired frequency for the resonator;
• the correction value corresponds to the symmetrical distribution of at least two masses of the material on the balance so as to modify the inertia of the balance without modifying its center of mass;
• the correction value is determined by comparing, on the one hand, the measured step and, on the other hand, the desired unbalance and frequency for the resonator;
• the correction value corresponds to the asymmetrical distribution of at least one mass of the material on the balance to modify the inertia of the balance and its center of mass;
• the addition of material is performed by a projection phase of the material on the balance;
• the material comprises a glue, a paint or a suspension of metal;
• the material projection phase is followed by a phase of solidification of the projected material.

Brief description of the drawings

• la figure 1 est un schéma fonctionnel du procédé de réglage selon l'invention ;
• la figure 2 est une vue de dessus d'un balancier après réglage ;
• la figure 3 est une vue de la figure 2 selon la coupe A-A ;
• la figure 4 est une vue en coupe d'une alternative de la figure 3.

Other particularities and advantages will emerge clearly from the description which is given hereinafter, by way of indication and in no way limiting, with reference to the appended drawings, in which:

• the figure 1 is a block diagram of the control method according to the invention;
• the figure 2 is a top view of a balance after adjustment;
• the figure 3 is a view of the figure 2 according to section AA;
• the figure 4 is a sectional view of an alternative of the figure 3 .

Detailed Description of the Preferred Embodiments

The invention relates to a method for adjusting the running of a timepiece. The invention relates more particularly to the setting of a clockwork movement equipped with a resonator of the balance-spring type.

dans laquelle m représente sa masse et r son rayon de giration qui dépend également de la température par l'intermédiaire du coefficient de dilatation α_b du balancier.Such a balance spring-type resonator generally comprises a balance forming an inertia and a spring forming a resilient, which are mounted on the same axis. In such a resonator, the moment of inertia I of the balance responds, in known manner, to the formula: $$I={\mathit{mr}}^2$$

in which m represents its mass and r its radius of gyration, which also depends on the temperature via the coefficient of expansion α _b of the balance.

dans laquelle E est le module d'Young du matériau utilisé, h sa hauteur, e son épaisseur et L sa longueur développée.In addition, the elastic torque C of the spiral with a constant section responds, in a known manner, to the formula: $$\mathrm{VS}=\frac{{\mathit{<figure-callout\; id="3"\; label="ehe"\; filenames="imgf0001.png"\; state="\{\{state\}\}">ehe</figure-callout>}}^3}{12\mathrm{The}}$$

in which E is the Young's modulus of the material used, h its height, e its thickness and L its developed length.

Finally, the frequency f of the balance-spring resonator corresponds to the formula: $$f=\frac{1}{2\pi }\sqrt{\frac{\mathrm{VS}}{I}}$$

From these three general formulas and the construction of the movement, it is known to adjust the movement of a watch movement, before its casing, in different positions, in order to tighten up the anisochronism curves of the future piece to the maximum watchmaking. Such an adjustment can consist in particular to adapt the unbalance of the balance, the eccentric development of the hairspring or the delay created by the exhaust.

However, it was found that walking a well-regulated movement tended to drift to wear. After analysis, it was found that the step changes significantly at the time of nesting because of the constraints generated on the movement by the casing and aerodynamic changes induced by the closed environment of the box.

It has therefore appeared essential that the method 1 according to the invention comprises a first step 3 intended to mount the movement to adjust in its future timepiece box. In other words, the process begins with the casing of the movement provided with a balance-spring resonator.

A second step 5 is intended to measure the running of the timepiece, that is to say the nested movement. Preferably, the measurement of the step is performed without contact with the balance-spring resonator. Indeed, the movement being already nested access to the resonator is particularly narrow. In known manner, the measurement of the walking of the timepiece can thus be performed, for example, in optical or acoustic form.

This second step 5 is important for two reasons. Thus, on the one hand, it makes it possible to compare the measured step with a desired step. On the other hand, it also allows to know the beat of the balance in order to synchronize it with the projection of material to precisely deposit the material on the balance.

The method 1 continues with a third step 7 for determining the correction value to be applied to the inertia of the balance to obtain a desired step.

According to a first embodiment, during step 7, the correction value is determined by comparing the measured step and the desired frequency for the resonator in particular from equations (1) to (3) above.

As explained above, since the last step 9 is intended to add material to the balance, the adjustment according to the invention only allows the increase of the moment of inertia I of the balance. It is therefore understood that the nested movement is preferably provided so that it has a march advance which will be corrected during the last step 9.

According to the first embodiment, the correction value therefore corresponds to a symmetrical distribution of at least two masses of the material on the balance in order to modify the inertia of the balance without modifying its center of mass. It is understood that the correction value will be distributed, in a balanced manner, according to the number of desired deposits. By way of non-limiting example, if the deposit is made on the balance rod, the correction value will be divided by the number of desired deposits and each deposit will be distributed on the serge at an angle δ equal to 360 ° divided by the number of desired deposits.

According to a second embodiment, during step 7, the correction value is determined by comparing, on the one hand, the measured step and, on the other hand, the desired unbalance and frequency for the resonator, in particular from equations (1) to (3) above. So we understand that the second embodiment takes into account more parameters than the first embodiment. It is also immediate that the second step 5 can then take into account, in addition, the amplitude of the balance in at least the 4 usual vertical control positions in order to be able to balance the balance. Indeed, the unbalance, via gravity, causes a torque that is added to the return torque of the hairspring and therefore causes a walking error.

As explained above, since the last step 9 is intended to add material to the balance, the adjustment according to the invention only allows the increase of the moment of inertia I of the balance. It is therefore understood that the nested movement is preferably provided so that it has a march advance which will be corrected during the last step 9.

According to the second embodiment, the correction value corresponds to the asymmetrical distribution of at least one mass of the material on the balance to modify the inertia of the balance and its center of mass. It is understood that the correction value will be distributed so as to balance the balance or form an imbalance on the balance according to the number of desired deposits. By way of non-limiting example, if the deposit is made on the balance rod, the correction value will be divided by the number of desired deposits. Then weighting is performed according to the desired unbalance correction. It is therefore clear that the weighting may consist of asymmetrically depositing the material, that is to say a distribution of the larger deposit number in a given sector of the balance and / or at least one deposit with a larger mass in a specific sector of the pendulum.

Whatever the embodiment, the method 1 ends with the fourth step 9 intended to modify, by adding a material on the balance, the inertia of the balance according to said correction value.

Such a step 9 is preferably carried out by the addition of material by means of a projection phase of the material on the beam. This step 9 may be, for example, performed by placing the movement nested without the bottom box or without the entire bottom box.

This projection phase can be advantageously carried out using an Aerosol Jet printer from the company Optomec which allows a very precise projection with a very small volume of material. However, any other projection or maskless printing technology is also possible. In a nonlimiting manner, the material deposited on the balance may include an adhesive, a paint or a metal suspension.

Preferably, the material projection phase is followed by a solidification phase of the projected material. This second phase may according to the material used consist of evaporating the solvent, thermo-harden the material or crosslink my material. Preferably, according to the invention, a polymer is deposited on the balance during the first phase and is then crosslinked during the second phase by means of ultraviolet radiation, which makes it possible to avoid as much as possible that pollution is accidentally introduced into the second phase. movement.

Step 9 can be performed statically (pendulum motionless) or dynamic (movement in operation). In the case of the latter, as explained above according to the embodiment, the second step 5 is important in order to know the beat of the balance and, optionally, according to the control positions, in order to be able to synchronize the projection of material for drop the material precisely on the balance.

The Figures 2 to 3 show an example of a rocker 11 modified after an adjustment according to the method 1. As visible in the example of Figures 2 and 3 , step 9 according to the first embodiment consisted of dividing the correction value into four masses of material 15 ₁ , 15 ₂ , 15 ₃ , ₄ identical and distributed every 90 ° on the shank 13 of the balance 11 in order to finely adjust the timepiece.

According to an alternative intended to better limit pollution accidentally introduced into the movement, the rocker 21 could include recesses for receiving the material projected in step 9 and thus block any splashing. As seen in the example of the figure 4 Step 9 consisted in dividing the correction value according to at least two masses of material 25 ₂ , 25 ₄ identical and received in the recesses 24 ₂ , 24 ₄ of the serge 23 of the balance 21 in order to finely adjust the workpiece. watchmaking.

Of course, the present invention is not limited to the illustrated example but is susceptible of various variations and modifications that will occur to those skilled in the art. In particular, the movement fitted if it comprises an automatic winding mechanism could be inclined so that the oscillating mass does not hide the balance.

In addition, it is also conceivable to deposit material at other places than the serge 13, 23 such as, for example, the arms 17, 27 or the hub 19, 29.

Claims (10)

Method (1) for adjusting a timepiece comprising the following steps: - Mount (3) a movement provided with a pendulum resonator - spiral in a box of the timepiece; - measure (5) the running of the timepiece; determining (7) the correction value to be applied to the inertia of the balance (11, 21) to obtain a desired step; modifying (9), by adding a material (15 ₁ , 15 ₂ , 15 ₃ , 15 ₄ , 25 ₂ , 25 ₄ ) on the balance (11, 21), the inertia of the balance (11, 21) according to said correction value. Method (1) according to the preceding claim, characterized in that the measurement of the step is performed without contact with the balance-spring resonator. Method (1) according to the preceding claim, characterized in that the measurement of the step is performed in optical or acoustic form. Method (1) according to one of the preceding claims, characterized in that the correction value is determined by comparing the measured step and the desired frequency for the resonator. Method (1) according to the preceding claim, characterized in that the correction value corresponds to the symmetrical distribution of at least two masses of the material (15 ₁ , 15 ₂ , 15 ₃ , 15 ₄ , 25 ₂ , 25 ₄ ). on the balance to change the inertia of the balance (11, 21) without changing its center of mass. Method (1) according to one of Claims 1 to 3, characterized in that the correction value is determined by comparing, on the one hand, the measured step and, secondly, the unbalance and frequency desired for the resonator. Method (1) according to the preceding claim, characterized in that the correction value corresponds to the asymmetrical distribution of at least one mass of the material (15 ₁ , 15 ₂ , 15 ₃ , 15 ₄ , 25 ₂ , 25 ₄ ). on the balance (11, 21) in order to modify the inertia of the balance (11, 21) and its center of mass. Method (1) according to the preceding claim, characterized in that the addition of material (15 ₁ , 15 ₂ , 15 ₃ , 15 ₄ , 25 ₂ , 25 ₄ ) is carried out by a material projection phase (15 ₁ , ₂ , 15 ₃ , ₄ , 25 ₂ , ₄ ) on the balance (11, 21). Method (1) according to the preceding claim, characterized in that the material (15 ₁ , 15 ₂ , 15 ₃ , 15 ₄ , 25 ₂ , 25 ₄ ) comprises an adhesive, a paint or a metal suspension. Method (1) according to claim 8 or 9, characterized in that the material projection phase (15 ₁ , 15 ₂ , 15 ₃ , 15 ₄ , 25 ₂ , 25 ₄ ) is followed by a solidification phase of the material (15 ₁ , 15 ₂ , 15 ₃ , 15 ₄ , 25 ₂ , 25 ₄ ) projected.

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