HK1181472B - Method for regulating the relative position of a first part and a second part of a mechanical assembly - Google Patents

Description

Method for adjusting the relative position of a first part and a second part of a mechanical assembly

Technical Field

The invention relates to a method of adjusting a device. The device comprises a first part and at least one second part, wherein the at least one second part is fixed to the first part by means of a joint arranged between the first and second parts.

The technical field of the invention is the field of machinery.

Background

Many devices require an adjustment step after production in order to fit well. This need for high precision exists in the field of micro-technology such as watchmaking. In fact, in the field of watchmaking, dimensions ranging from millimetres to hundredths of millimetres are concerned. Examples of devices where accuracy is important include wheel trains or escapements. In practice, the escapement is formed by an anchor and an escape wheel cooperating with each other. The rotation of the escape wheel is controlled by the anchor of the escapement system, which is supplied with impulses by the sprung balance. Thus, the escapement system comprises an anchor mounted to pivot on an axis. The anchor pallet comprises a lever, at a first end of which a fork is mounted for cooperation with a pin mounted on the pallet, and at a second end of which an arm is mounted for receiving a pallet stone (pallet) for cooperation with the escape wheel. During operation of the anchor, the anchor pivots on its axis in the following manner: the pallet stones of the arm come into contact with the teeth of the escape wheel to control the rotation of the train. Now, if the pallet stones of the anchor cannot be positioned accurately, the pulsation between the pallet stones and the escape wheel of the anchor will be imperfect and a miss will occur, thus affecting the efficiency of the escapement and therefore the precision of the watch. Currently, the pallet stones are assembled on anchor pallets using gum lacquers (gum lacquer), which are natural products having similar properties to thermoplastic materials. These characteristics enable the pallet-stones to be repositioned with respect to the anchor by locally heating the anchor. However, the quality of the gum lacquer fluctuates greatly from one batch to another, which makes repositioning a very delicate operation. Furthermore, because the viscosity of the gum lacquer is difficult to control and the amount of gum deposited is difficult to control, gum overflow often occurs, which can lead to potentially unacceptable aesthetic defects. Furthermore, since the gum lacquer is an organic material, it will age and as a result the fixing effect of the pallet-stone will be reduced.

Another possible method is to use brazing or soldering. However, both solutions are also problematic, since in order to have any opportunity to solder ceramic or silicon or mineral materials, reactive brazing/soldering must be used, which must be performed at higher temperatures (typically above 700 ℃) and in a neutral atmosphere or in a high vacuum. This would make the assembly cycle too long and there could be a risk of material damage/breakage.

Disclosure of Invention

The object of the present invention is to overcome the drawbacks of the prior art by proposing a simple, reliable and precise adjustment method.

To this end, the invention relates to the conditioning method described above, characterized in that said first material is an at least partially amorphous metal alloy and in that said method further comprises the following steps:

-heating at least the joint to a heating temperature in a range between the glass transition temperature and the crystallization temperature of the first material;

-modifying the position of the at least one second component until a desired determined position is obtained;

-cooling at least the joint so that the joint remains at least partially amorphous.

A first advantage of the invention is that a controlled adjustment of the position of the second part relative to the first part can be achieved. In fact, at least partially amorphous materials such as amorphous metals have the following capabilities: when the material is heated to a temperature in the range between the glass transition temperature and the crystallization temperature of the material, the material will soften significantly. In this temperature range, the viscosity of the amorphous metal is significantly reduced, wherein the reduction in viscosity is dependent on the temperature: the higher the temperature, the more the viscosity decreases. The reduced tack thus allows the fixation to be loosened so that the second component can be displaced to modify its position and give it the desired precise position. The viscosity can be adjusted to simplify the adjustment process.

Another advantage of the method is that the method is reproducible, i.e. once the amorphous metal has solidified by cooling, the metal can be reheated to a temperature in the range between the glass transition temperature and the crystallization temperature in order to modify the less than perfect position of the second component relative to the first component.

Advantageous embodiments of the method are subject matter of the dependent claims.

In a first advantageous embodiment, said first material is completely amorphous.

In a second advantageous embodiment, the metal alloy comprises at least one noble metal element selected from the group consisting of: gold, platinum, palladium, rhenium, ruthenium, rhodium, silver, iridium or osmium.

In a third advantageous embodiment, in said heating step, said heating temperature is selected to obtain a determined viscosity of said first material.

In another advantageous embodiment, the method further comprises a step of crystallization of the first material, said step comprising heating the first material to a temperature in the range between its glass transition temperature and its melting temperature, holding the material at this temperature for a period of time, and cooling the material.

In another advantageous embodiment, the temperature and the holding time of the first material are selected so as to achieve a defined crystallization rate.

In another advantageous embodiment, the joint and the first component form only a single component made of the first material.

In another advantageous embodiment, said first component is an anchor and said at least one second component is a pallet-stone.

One of the advantages of these embodiments is that the adjustment can be maintained by crystallizing the amorphous metal junction. In fact, the crystallization of the amorphous material is such that the material cannot be brought into a viscous state by heating to a temperature in the range between the glass transition temperature and the crystallization temperature. Thus, returning the joint to an amorphous form requires the joint to be brought into a liquid form and cooled rapidly, which can damage the equipment.

The invention also proposes a device comprising a first component and at least one second component, wherein the at least one second component is fixed to the first component by means of a joint arranged between the first component and the second component. The device is characterized in that the joint is made of an at least partially amorphous metal alloy.

Drawings

The objects, advantages and features of the method according to the invention will become more apparent from the following detailed description of at least one embodiment of the invention, given by way of non-limiting example only and illustrated in the accompanying drawings, wherein:

fig. 1 schematically shows an anchor pallet prior to the production process;

fig. 2 schematically shows an anchor pallet at the end of the production process;

fig. 3 schematically shows an anchor pallet during the adjustment method according to the invention;

fig. 4 schematically shows an anchor pallet after having received the adjustment method according to the invention;

fig. 5 schematically shows a variant of an anchor pallet which is receiving the adjustment method according to the invention.

Detailed Description

Fig. 1 and 2 show a device 1 comprising a first part 2 and at least one second part 3. For example, the device 1 may be part of an escapement mechanism of a timepiece. The escapement 1 is formed by an anchor and an escape wheel cooperating with each other. The rotation of the escape wheel is regulated by the anchor of the escapement system, which is supplied with impulses by the sprung balance. Thus, the escapement system comprises an anchor mounted to pivot on an axis. The anchor 2 represents the first component and is provided in the form of a lever 20, at a first end of which lever 20 a fork 21 is mounted for cooperation with a pin mounted on a pallet, and at a second end of which lever 20 at least two arms 22 are mounted. This anchor 2 is intended to receive at least one second member 3, i.e. pallet-stone, in order to cooperate with the escape wheel. During operation of the anchor 2, the anchor 2 pivots on its axis in the following manner: pallet-stone 3 is in contact with the teeth of the escape wheel, thus controlling the rotation of the train.

The pallet-stones 3 are fixed to the lever 20 of the anchor 2 at a recess 23 provided on each of the two arms 22. These pockets 23 have dimensions calculated as follows: when inserting said pallet-stone 3 into recess 23, a gap or space 24 can be created between arm 22 and pallet-stone 3. This gap 24 is exploited in order to be able to arrange the coupling element 4 made of the first material between said arm 22 of the anchor 2 and said pallet-stone 3.

In a first embodiment of the invention, the joint 4 is made of a first material which is an at least partially amorphous material comprising at least one metal element. The first material may be an at least partially amorphous metal alloy. The metal element may be a noble metal element such as gold, platinum, palladium, rhenium, ruthenium, rhodium, silver, iridium, osmium, or the like. An at least partially amorphous material is understood to be a material which is capable of at least partially solidifying in an amorphous phase. The first material is preferably entirely amorphous.

The assembly of the pallet-stones 3 onto the anchor 2 by means of the coupling element 4 precedes the adjustment step and can be done in different ways.

The position of the pallet stones 3 of the anchor 2 is modified by the characteristics of the amorphous materials which are such that these materials have a viscosity which decreases significantly within a given temperature range for each material, while still remaining amorphous.

The first step of the adjustment method comprises providing said anchor 2 to which pallet-stones 3 are fixed.

The second step consists in raising the temperature of at least one part of the anchor 2. Advantageously, the joint 4 is subjected to said elevated temperature. In fact, the engagement element 4 remains fixed to the pallet-stone 3 of the anchor 2, and the adjustment can be achieved by acting on the engagement element 4. The joining member 4 is heated to a temperature in the range between the glass transition temperature Tg and the crystallization temperature Tx of the first material. This increase in temperature will result in a decrease in the viscosity of the first material forming the joint 4.

A third step comprises displacing at least one of the pallet-stones 3 to place it at a desired position, as shown in fig. 3. This displacement is possible because the first material is an amorphous metal alloy having a very low viscosity when heated to a temperature in the range between its glass transition temperature Tg and its crystallization temperature Tx. Such low viscosity enables shifting of one or more pallet-stones 3 without causing deterioration or damage of one or more engagement members 4. To optimize the process, the temperature to which the joint 4 is heated can be adjusted to obtain a determined viscosity. In fact, viscosity is temperature dependent, i.e. the higher the temperature, the lower the viscosity and vice versa. At this point, if the viscosity is too low, the displacement of pallet-stone 3 will become difficult, since pallet-stone 3 will be displaced too easily and therefore the precision of adjustment will be reduced. Conversely, if the viscosity is too high, a greater force must be applied to displace pallet-stone 3, which may create a risk of breakage.

Once pallet-stone 3 is placed at the desired position, a fourth step is performed: cooling coupling member 4 of amorphous metal, so that coupling member 4 remains at least partially amorphous and maintains the position of pallet-stone 3, as shown in fig. 4. The advantage of said method is therefore that any degassing of the material is prevented, while ensuring the fixing of the pallet stones with high intensity on the anchor 2. The advantage is that engagement member 4 is always in the amorphous state, which enables the position of pallet-stone 3 to be modified again as required.

In a first variant, an additional or fifth step is provided in which the amorphous metal joint 4 is crystallized. The crystallization is performed by heating these joining members 4 to a temperature in the range between the glass transition temperature Tg and the crystallization temperature Tx of the material forming the joining members. The first material is then slowly cooled to allow the atoms to align themselves into a crystalline structure. This crystallization enables the position of the pallet-stone to be maintained, since after this crystallization step it is no longer possible to modify the position of pallet-stone 3 by heating joining member 4 between the glass transition temperature Tg and the crystallization temperature Tx of the material.

Furthermore, in some cases, such crystallization may result in an increase in the volume of the material changing from an amorphous state to a crystalline state. As a result of this increase in volume, the stresses exerted by the engagement member 4 on the anchor 2 and pallet-stone 3 increase. These pallet-stones 3 are thus held under the action of force, so that there is no risk of pallet-stones 3 being displaced in the event of an impulse by a tooth of the escape wheel.

In a second embodiment of the invention, shown in fig. 5, the engagement member 4 and the anchor 2 form a single component. It can therefore be understood that the anchor 2 is made of said first material, i.e. of amorphous metal. The anchor 2 thus acts like a coupling element 4.

The anchor 2 may be manufactured by hot forming or cold forming. Thus forming said anchor 2 while fixing the pallet-stone 3 to said anchor 2.

Once anchor 2 has been formed, the position of pallet-stone 3 can be adjusted if pallet-stone 3 is not correctly placed.

The first step of the adjustment method therefore comprises providing said anchor 2 to which the pallet-stones 3 are fixed.

The second step consists in raising the temperature of at least one zone of the anchor 2. The warming must be performed locally at the fixing area between the first component 2 and the second component 3. In the case of anchor 2, these regions are regions of the recess of arm 22 in which pallet-stone 3 is inserted. These regions are heated to a temperature in the range between the glass transition temperature Tg and the crystallization temperature Tx of the amorphous metal. Such an increase in temperature leads to a decrease in the viscosity of the amorphous metal without losing its amorphous state.

The third step is similar to that of the first embodiment, and therefore includes displacements along three axes: the length, width and height directions of at least one of the pallet-stones 3, to place pallet-stone 3 in a desired position. To optimize the process, the temperature to which the joint 4 is heated can be adjusted to obtain the desired viscosity.

Once pallet-stone 3 is placed at the desired position, a fourth step is performed: this amorphous metal region is cooled so that said region remains at least partially amorphous and maintains the position of said pallet-stone 3. The advantage of said method is therefore that any degassing of the material is prevented while ensuring the fixing of the pallet-stone to the anchor with great strength.

It should be understood that this adjustment process can be performed again if the adjustment performed is not perfect or in the case of a later modification of the position of pallet-stone 3.

A fifth optional step may be performed. This step consists in at least partially crystallizing the region at the position where pallet-stone 3 is fixed. This step is performed by raising the temperature of the zone at the position where pallet-stone 3 is fixed. The temperature is raised to a temperature in the range between the glass transition temperature Tg and the crystallization temperature Tx or melting temperature of the amorphous metal. The amorphous metal has a reduced viscosity while remaining amorphous. These heated regions are then held at this temperature and then slowly cooled so that the regions form a crystalline structure. The cooling temperature and duration and the time for holding the metal at this temperature are parameters that allow the crystallization rate to be fixed. This crystallization is used to maintain the adjustments previously made. In fact, when the material is in crystalline form, it is not possible to withstand the conditioning process according to the invention. The only way is to change it to an amorphous form, i.e. to heat it above the melting temperature so that the material becomes liquid and then cool it rapidly below the glass transition temperature so that the material is amorphous. At this point, with respect to the joint 4 between the pallet-stone 3 and the anchor 2, the melting of the joint at least causes a deterioration of the joint 4, or may even damage the device 1, making adjustment impossible.

In a variant of the second embodiment, it can be provided that pallet-stones 3 are also made of amorphous metal. The amorphous metal used for pallet 3 is preferably different from the metal used for anchor 2, so that when the amorphous metal of anchor 2 is heated to a temperature in the range between its glass transition temperature Tg and crystallization temperature Tx, the amorphous metal of the pallet does not become as viscous as the amorphous metal of anchor 2.

It will be appreciated that various modifications and/or improvements and/or combinations obvious to a person skilled in the art may be applied to the different embodiments of the invention discussed above without departing from the framework of the invention as defined by the appended claims.

It is of course understood that said adjustment method is not limited to the adjustment of the position of the pallet-stones 3 and the anchor 2. The method can be used in other devices. The device using this adjustment method is for example a device comprising a wheel pressed onto an axle, wherein the device comprises a joint between the axle and the wheel. By applying this adjustment method to the joint, the position of the wheel can be adjusted. The adjustment may be performed along the axis or at an angle.

Claims (10)

1. A method for adjusting an apparatus (1), the apparatus (1) comprising a first part (2) and at least one second part (3), wherein the at least one second part is fixed to the first part prior to the adjustment by means of a joint (4) made of a first material and arranged between the first part and the second part, characterized in that the first material is an at least partially amorphous metal alloy; the method further comprises the steps of:

-heating at least the joint to a heating temperature in the range between the glass transition temperature and the crystallization temperature of the first material;

-modifying the position of the at least one second component until a desired determined position is obtained;

-cooling at least the joint so that the joint remains at least partially amorphous.

2. The method of claim 1, wherein the first material is completely amorphous.

3. The method of claim 1, wherein the metal alloy comprises at least one noble metal element selected from the group consisting of: gold, platinum, palladium, rhenium, ruthenium, rhodium, silver, iridium or osmium.

4. The method of claim 2, wherein the metal alloy comprises at least one noble metal element selected from the group consisting of: gold, platinum, palladium, rhenium, ruthenium, rhodium, silver, iridium or osmium.

5. The method of claim 1, wherein in the heating step, the heating temperature is selected to obtain a determined viscosity of the first material.

6. The method of claim 1, further comprising a step of crystallizing the first material, the step of crystallizing comprising heating the first material to a temperature in a range between the glass transition temperature and the melting temperature, holding the material at this temperature for a period of time, and cooling the material.

7. The method of claim 5, wherein the temperature and holding time of the first material are selected to achieve a defined crystallization rate.

8. The method according to claim 1, characterized in that the joint (4) and the first component (2) form only a single part made of the first material.

9. Method according to claim 1, wherein said first element (2) is an anchor pallet and said at least one second element (3) is a pallet stone.

10. An apparatus comprising a first component (2) and at least one second component (3), wherein the at least one second component is fixed to the first component by means of a joint (4) arranged between the first component and the second component, characterized in that the joint is made of an at least partially amorphous metal alloy; the position of the at least one second component relative to the first component is adjusted by using the method according to claim 1.