CN203643750U - Hairspring for mechanical timepiece - Google Patents

Abstract

The utility model provides a hairspring for mechanical timepieces, which comprises an inner end part and an outer end part, wherein a single extension part extends from the inner end part to the outer end part; and a reinforcement consisting of two or more spaced apart arms located at the outer periphery of the balance spring, such that the bending strength of the reinforcement is greater than that of a single extension; when the balance spring oscillates around the rotating shaft in the compression and stretching processes, the rigidity of the balance spring reinforcing part can improve the coaxiality of the balance spring ring around the rotating shaft.

Description

The hairspring of mechanical clock

Technical field

The utility model relates to a kind of hairspring of mechanical clock.More specifically, the utility model relates to a kind of hairspring that better right alignment is in use provided.

Background technology

Hairspring is the critical component of mechanical clock.Clock and watch oscillator has two critical pieces, and one of them is hairspring, and another is escapement.Simple harmonic quantity by oscillator swings, and it provides the mode of Timing.

Escapement is as a kind of inertance element, and engages with the inner of helical hair spring.The helical geometry of hairspring is generally the shape of spiral of Archimedes, and it has constant pitch.The outer end of hairspring is fixedly attached on fixed leg (stud) conventionally.

Ideally, hairspring provides restoring torque for escapement, and this restoring torque and escapement are proportional apart from the displacement of equilibrium position, and can utilize the equation of motion to describe second-order linear system.Oscillator equilibrium position is defined as the escapement angle position of escapement when static, the position, escapement angle when the net torque that is namely applied to escapement when hairspring is zero.When the oscillator producing is like this grade, the natural frequency of oscillator and its amplitude are irrelevant in other words.

Because oscillator need to be inputted with friction compensation dissipation effect from the regular torque of escapement, therefore tautochronism is the important performance of clock and watch oscillator.Owing to there are multiple direct factors that affect oscillator amplitude, therefore the torque of escapement may not be constant.Just because of this, isochronous oscillation device (isochronous oscillator) provides more reliable and stable Timing.

Typically, in the time that escapement rotates around its equilibrium position, the spiral coil of clock watch balance spring will keep concentric as far as possible, and reason comprises:

(i) if hairspring disalignment, the mass centre of hairspring just can be near rotating shaft.In the time that escapement rotates, mass centre may drift about, and has so just produced the radial force that will be compensated by bearing, causes excessive friction;

(ii) if hairspring disalignment, in operational process, hairspring also can have the geometric configuration that departs from spiral of Archimedes, thereby produces anisochrouous nonlinear second-order system.

(ii) in some cases, if hairspring disalignment, the helical geometry of hairspring may significantly be out of shape, and collision and damage mutually between adjacent turn like this, while also having caused the not grade of system.

In the prior art, according to Phillips (Karen Phillips) and Lossier mathematical model for hairspring design, by changing the geometric configuration of hairspring the inner and overcoil, can improve the right alignment of hairspring.

Breguet (Breguet) has been applied in this theory the double-deck hairspring of Breguet (over-coil) and for its outer end.Double-deck hairspring has used improved outmost turns, and this outmost turns is for upwards and aduncate.But what the method only can retaining part is coaxial, and produces desired outmost turns shape and can increase manufacture difficulty and cost.

In order to keep the tautochronism of hairspring, need to hairspring be designed to temperature variation insensitive.The Young modulus that determines the material of the strength of materials, varies with temperature very little.

In hairspring, the natural frequency of oscillator that Young modulus has determined spring constant and final decision.Hairspring Young modulus, with any variation of temperature, all produces negative influence by the ability to the oscillator reliable adjustment time.

By use nivarox (Nivarox) in the process of manufacturing hairspring, extensively solve the temperature susceplibility problem of modern hairspring Young modulus.Nivarox (Nivarox) is a kind of metal alloy, and its Young modulus is very little but be not equal to 0 with regard to the susceptibility of temperature variation.

In the past ten years, in wrist-watch industry, there is micro-processing technology and used silicon, thereby having introduced Design and manufacture and have the new method of the hairspring that improves tautochronism.This technique can be manufactured hairspring according to hairspring bar wide variety, thereby changes selectively the bending strength of hairspring along its whole arc length.

And this technique can make the Young modulus of hairspring be hopeful to reach completely insensitive to temperature variation.Making hairspring Young modulus is temperature compensation about the insensitive procedure definition of temperature variation.

Because micro-processing technology can produce any high-precision plane component, therefore, only actually utilizes micro-processing technology just can produce to have the hairspring that changes hairspring bar width.

Based on theory, numerical simulation or experiment, utilize micro-processing technology can improve the right alignment of hairspring.An example of silicon hairspring is Patek (Patek Philippe, wrist-watch brand) Spiromax hairspring, it has the hairspring bar width segments of the increase near hairspring outmost turns outer end, and such hairspring setting and size can improve hairspring right alignment.

Such micro-processing technology can also be by applying silicon dioxide thin coating to reach temperature compensation object on silicon hairspring.The Young modulus of silicon increases and reduces with temperature, and the Young modulus of silicon dioxide is tending towards increasing with temperature increase.

Therefore, by accurately apply the silicon dioxide coating of appropriate thickness to silicon wafer, can form compound hairspring, wherein the temperature susceplibility of bi-material Young modulus is cancelled out each other substantially.This can make the total Young modulus of hairspring insensitive to temperature variation in theory.

The shortcoming of the silicon hairspring building by micro-processing technology in prior art is can not realize in the design that improves right alignment having larger freedom simultaneously, and wishes to carry out total temperature compensation.

Micro-processing technology is only defined in manufacture plane component conventionally.Although it can produce the double-deck hairspring of Breguet pattern in theory, there are multiple overlapping layers, such manufacturing capacity is insecure at present, and at least manufacture process has significant additional complexity.

Utility model content

Therefore, the purpose of this utility model is to provide a kind of hairspring, and it overcomes or at least substantially improves at least a portion shortcoming presenting in prior art.

First aspect, the invention provides a kind of helical hair spring for stem-winder, and described hairspring comprises: inner end and outer end, and wall scroll extension extends to described outer end from described inner end; And the rib being formed by two or more the isolated arms of outer ring that are positioned at described hairspring, make the bending strength of described rib be greater than the bending strength of described wall scroll extension; Wherein, in the compression of described hairspring and drawing process, vibrate while swinging around rotating shaft, the rigidity of described hairspring rib can improve around the right alignment of the hairspring circle of described rotating shaft.

Hairspring as above, wherein, the xsect of described two or more isolated arms of described wall scroll extension and described rib is all rectangle, and there is each other equal width and equal height, wherein said wall scroll extension and described rib are formed by the first material, and further comprise the outer covering layer being formed by the second material.

Hairspring as above, wherein, described the first material has the first Young modulus, and described the second material has the second Young modulus, described the first Young modulus and described the second Young modulus have contrary temperature dependency, and the thickness of the size of described wall scroll extension, the size of described rib and described outer covering layer is set to, make the elasticity of described hairspring insensitive to temperature variation.

In a preferred embodiment, described the first material is silicon, and described the second material is silicon dioxide.

Hairspring as above, wherein, described wall scroll extension can be constant pitch substantially, and an arm of described rib has above-mentioned pitch, and wherein radially the arm of inner side also there is above-mentioned pitch.

Hairspring as above, wherein, described wall scroll extension can be constant pitch substantially, and two adjacent arms of described rib equidistantly distribute substantially along the track of described pitch, and distance between two adjacent arms of wherein said rib is substantially constant.

Hairspring as above, wherein, described hairspring has and is arranged on two ribs between wall scroll extension, and wherein said wall scroll extension and described rib the arm of inner side there is the pitch equating.

Hairspring as above, wherein, the outermost arm of described rib has with adjacent wall scroll extension the pitch equating, and the arm of the inner side of described rib has with the arm of adjacent rib the pitch equating.

Hairspring as above, wherein, rib is arranged on the outer end of described hairspring, and the each described arm of described rib has end.

Hairspring as above, wherein, described adjacent wall scroll extension has substantially equal pitch, and an arm of described rib also has described pitch, and the inner side arm of wherein said rib also has described pitch.

Hairspring as above, wherein, the outer arm of described rib is shorter than the adjacent inner arm of described rib substantially.Alternatively, an adjacent inner arm of being substantially longer than described rib in described rib outer arm.

Hairspring as above, wherein, described rib comprises the spiral turns that is less than half-turn.

Hairspring as above, wherein, the adjacent arm of described rib interconnects in the centre of the end of described rib.

Hairspring as above, wherein, the described wall scroll extension of described rib and two or more isolated arms are substantially coplanar.

In the utility model, if rib has suitable size and is arranged on appropriate location, just can improve the right alignment of hairspring.

The utility model can complete the temperature compensation of the silicon hairspring to having silicon dioxide coating substantially, because each parallel branch of many spires keeps with other branch of other spiral section the width equating.

In the utility model, in order to reach effect temperature compensation, consider convenient manufacture, the needed silicon dioxide thickness of total temperature compensation is determined according to the width of silicon hairspring bar, and current manufacturing technology only can make silicon dioxide have consistent thickness.

Accompanying drawing explanation

In accompanying drawing, describe preferred embodiment of the present utility model, and carried out following explanation with reference to the following drawings, wherein:

Fig. 1 shows the cantilever beam structure with two beams, and two beams are with parallel structural join;

Fig. 2 a shows the cantilever beam structure with single beam, and single beam has consistent xsect;

Fig. 2 b shows the viewgraph of cross-section of the cantilever beam structure of describing in Fig. 2 a;

Fig. 3 a shows the cantilever beam structure with two beams, and the xsect of two beams is different and connect with serial arrangement.

Fig. 3 b shows the cantilever beam structure described in Fig. 2 a by first the viewgraph of cross-section in two beams;

Fig. 3 c shows the cantilever beam structure of describing in Fig. 2 a by the viewgraph of cross-section of second in two beams;

Fig. 4 a shows the cantilever beam structure with Liang Geliang connected in series district, and two beams that one of them Liang Qu is connected by the arrangement that walks abreast form and another Liang Qu is made up of single beam;

Fig. 4 b shows the cantilever beam structure of describing in Fig. 4 a by the viewgraph of cross-section of any beam;

Fig. 5 shows the first embodiment according to hairspring of the present utility model;

Fig. 6 shows many spire arrangements according to the another embodiment of hairspring of the present utility model;

Fig. 7 shows many spire arrangements according to another embodiment of hairspring of the present utility model;

Fig. 8 shows many spire arrangements according to another embodiment of hairspring of the present utility model;

Fig. 9 shows many spire arrangements according to another embodiment of hairspring of the present utility model; And

Figure 10 shows the alternative embodiment according to hairspring of the present utility model; And

Figure 11 shows the exemplary embodiment according to hairspring of the present utility model.

Embodiment

With reference to accompanying drawing, the utility model is described.

For the manifestation mode of the utility model feature is described, utilize solid mechanics theory, particularly utilize semi-girder Principles of Statics, with reference to Fig. 1-4b, use the Euler-Bernoulli Jacob beam formula (Euler-Bernoulli beam formula) providing to describe.Although this formula and subsidiary theory thereof are based on straight semi-girder model strictly speaking, this formula also can be the helical hair spring with elongate strip result is accurately provided rationally, because the overwhelming majority of typical hairspring restoring torque is from the bending of hairspring bar.

For this reason, Euler-Bernoulli Jacob beam formula is widely used in wrist-watch industry, to assess the bending strength of hairspring.

With reference to Fig. 1, show cantilever beam structure 10 here, formed by two of parallel join parallel beam 11A, 11B.It must be emphasized that, run through instructions and utilized in full term " parallel ", will extend to the understanding of this term the textural element of arrangement connection that walks abreast, and need to be not parallel in strict geometric definition.These cantilever beam structure 10 analytical tables are understood to effect to this structural bending intensity, and bending strength is defined as the ratio of opplied moment and the synthetic deflection of beam.

Cantilever beam structure 10 right-hand members have fixed boundary condition 15, opposing displacement and rotation.Cantilever beam structure 10 left ends are freely, but have the plate 14 that is fixed to two beam 11A, 11B, to guarantee that two beams are can be together bending and each other can not translation or rotation.Two beam 11A, 11B are each has length L, width b, and height h.Two constant distance d intervals that beam 11A, 11B are also measured by center line 12A, 12B from them.Cantilever beam structure 10 also has neutral axis 13, and in above situation, neutral axis and beam center line 12A, 12B are equidistant.

In the time comparing with equal length and the xsect single semi-girder the same with each beam 11A, 11B, cantilever beam structure 10 has larger bending strength, due to following two reasons:

(i) cantilever beam structure 10 has larger cross-sectional area than single beam; And

(ii) two of cantilever beam structure 10 beam 11A, 11B arrange away from neutral axis 13 more, thereby have increased the cross sectional moment of inertia in this region and therefore larger bending strength is provided.

Utilize following Euler-Bernoulli Jacob beam formula, and represent Young modulus by E, can calculate the bending strength k of single beam 11A, 11B ₁.

$k_1=\frac{\mathrm{Eh}{b}^3}{12L}---\left(1\right)$

For reduced equation, be nb apart from d redefinable, n is the value of d:b here.By contrast, utilize following parallel axis theorem can further calculate the bending strength k of cantilever beam structure 10 ₂:

$k_2=\frac{\mathrm{Eh}{b}_3}{2L}(\frac{1}{3}+n^2)---\left(2\right)$

Suppose that cantilever beam structure 10 is planes, n value must be greater than 1 otherwise two beam 11A, 11B will be overlapping.

Those skilled in the art will recognize that, for the cantilever beam structure 10 of plane, k ₂minimum feasible value be always greater than k ₁.In fact, k ₂minimum feasible value is defined as k _{2, min}, be k ₁value 8 times.

According to the utility model, it will be appreciated by persons skilled in the art that the hairspring bar length L that can implement by the existing micro-processing technology of Adjust and use, k can be set ₁<k ₂<k _{2, min}.

Equation (1) and (2) show by the effect that the bending strength that improves cantilever beam structure 10 is set of two beam 11A, 11B of parallel arrangement.

Parallel axis theorem can also be applied to the cantilever beam structure 10 more than two beam 11A, 11B with parallel arrangement, and can produce identical conclusion.

Even if the distance d of beam is not constant, from having and the cantilever beam structure 10 of cross girders 11A, 11B also can lead to the same conclusion, can be more complicated and need the method for for example infinitesimal analysis for calculating although derive the bending strength of cantilever beam structure 10.

In order to illustrate that parallel hairspring bar designs the advantage in temperature compensation, describes and illustrated the effect on silicon beam with the Young modulus of silicon dioxide coating with reference to accompanying drawing 2a and 2b.The susceptibility of Young modulus to temperature variation only considered in this graphical analysis, and do not comprise thermal expansion effects.Because the temperature effect of Young modulus is than large several orders of magnitude of thermal expansion effects, the thermal effect of considering only to utilize Young modulus is to produce rationally approximate and identical result substantially.

With reference to Fig. 2, show the cantilever beam structure 20 of the single beam 21 with unified xsect, wherein all reference coordinates are all the right-hands rule based on solid mechanics.Beam 21 has width b, height h, and length L.Left end 22 is freely, and right-hand member 23 is fixed.The xsect 24 of beam 21 shows silicon core 25, and it has the silicon dioxide coating 26 that thickness is ζ.

Can obtain by the approximate linear function about temperature variation providing as follows the Young modulus of silicon and silicon dioxide:

E _Si(ΔT)=E _Si，0(1+e _SiΔT) (3)

E _SiO2(ΔT)=E _SiO2，0(1+e _SiO2ΔT) (4)

In equation (3) and (4), E _{si, 0}, E _siO2, e _si, e _siO2be all constant, and Δ T is temperature variation.Constant E _{si, 0}, E _siO2, e _si, e _siO2at room temperature there is respectively the numerical value of approximate 148GPa, 72.4GPa ,-60ppm/K, 215ppm/K.

Constant e _si, e _siO2there is contrary sign, and this Young modulus that shows silicon is along with temperature increases and reduces, and the Young modulus of silicon dioxide increases with temperature.

Suppose that the cantilever beam structure 20 in Fig. 2 is subject to the moment on y direction of principal axis, the Young modulus of equal value of composite beam 21 can be calculated as follows:

$E_{\mathrm{eq}}\left(\mathrm{\&Delta;T}\right)=[E_{\mathrm{Si}}\left(\mathrm{\&Delta;T}\right)-E_{\mathrm{SiO}2}\left(\mathrm{\&Delta;T}\right)]{(1-\frac{2\mathrm{\&zeta;}}{b})}^3(1-\frac{2\mathrm{\&zeta;}}{h})+E_{\mathrm{SiO}2}\left(\mathrm{\&Delta;T}\right)---\left(5\right)$

Δ T is differentiated and by equation (3) and (4) substitution, equation (5) becomes as follows:

$\frac{{\mathrm{dE}}_{\mathrm{eq}}\left(\mathrm{\&Delta;T}\right)}{\mathrm{d\&Delta;T}}=(E_{\mathrm{Si},0}{e}_{\mathrm{Si}}-E_{\mathrm{SiO}\mathrm{2,0}}{e}_{\mathrm{SiO}2}){(1-\frac{2\mathrm{\&zeta;}}{b})}^3(1-\frac{2\mathrm{\&zeta;}}{h})+E_{\mathrm{SiO}\mathrm{2,0}}{e}_{\mathrm{SiO}2}---\left(6\right)$

Equation (6) has been described E _eqto the susceptibility of Δ T, and in order to reach total temperature compensation, must be set to 0 by changing ζ.

To large-scale aspect ratio, be defined as b:h, for the xsect with silicon core and silicon dioxide coating, optimum ζ: b value is quite stable in the time approaching 6%.These results show, by silicon dioxide coating, are feasible in theory for total temperature compensation of the silicon hairspring of permanent xsect.

For the hairspring of variable cross-section, can not draw identical conclusion.This just can prove by the simple cantilever beam example with two varying cross-sections.

With reference to Fig. 3, show 30, two beams of cantilever beam structure with two beam 31A, 31B and there is different xsect 34A, 34B and connected in series.All reference coordinates are all the right-hands rule of the solid mechanics based on having set up.

Beam 31A has free end 32 and beam 31A is connected with beam 31B at its right-hand member 33 at its left end.Beam 31B is connected to beam 31A at its left end 33, and beam 31B has fixed boundary condition 34 at its right-hand member.Beam 31A has width bA, height hA, and length L A, and beam 31B has width bB, height hB, and length L B.

The xsect 35A of beam 31A shows has the silicon core 36A that thickness is the silicon dioxide coating 37A of ζ, and the xsect 35B of beam 31B shows and has the silicon core 36B that thickness is the silicon dioxide coating 37B of ζ.Because current micro-processing technology can not be realized variable coating thickness on same parts, therefore, xsect 35A, 35B have equal silicon dioxide coating thickness.

Suppose that cantilever beam structure 30 is subject to the moment on y direction of principal axis, the Young modulus of equal value of each beam 31A, 31B can be calculated as follows:

E _eq，A(ΔT)=E _A，0(ζ)(1+e _A(ζ)ΔT) (7)

E _eq，B(ΔT)=E _B，0(ζ)(1+e _B(ζ)ΔT) (8)

This is pointed out that, E _{eq, A}(Δ T), E _{eq, B}(Δ T) corresponds respectively to the Young modulus of equal value of beam 31A and 31B.Term E _{a, 0}(ζ), E _{b, 0}(ζ), e _a(ζ), e _b(ζ) can be unfolded as follows according to equation (3), (4) and (5):

$E_{A,0}\left(\mathrm{\&zeta;}\right)={(1-\frac{2\mathrm{\&zeta;}}{b_A})}^3(1-\frac{2\mathrm{\&zeta;}}{h_A})(E_{\mathrm{Si},0}-E_{\mathrm{SiO}\mathrm{2,0}})+E_{\mathrm{SiO}\mathrm{2,0}}---\left(9\right)$

$E_{B,0}\left(\mathrm{\&zeta;}\right)={(1-\frac{2\mathrm{\&zeta;}}{b_B})}^3(1-\frac{2\mathrm{\&zeta;}}{h_B})(E_{\mathrm{Si},0}-E_{\mathrm{SiO}\mathrm{2,0}})+E_{\mathrm{SiO}\mathrm{2,0}}---\left(10\right)$

$e_A\left(\mathrm{\&zeta;}\right)=\frac{{(1-\frac{2\mathrm{\&zeta;}}{b_A})}^3(1-\frac{2\mathrm{\&zeta;}}{h_A})(E_{\mathrm{Si},0}{e}_{\mathrm{Si}}-E_{\mathrm{SiO}\mathrm{2,0}}{e}_{\mathrm{SiO}2})+E_{\mathrm{SiO}\mathrm{2,0}}{e}_{\mathrm{SiO}2}}{{(1-\frac{2\mathrm{\&zeta;}}{b_A})}^3(1-\frac{2\mathrm{\&zeta;}}{h_A})(E_{\mathrm{Si},0}-E_{\mathrm{SiO}\mathrm{2,0}})+E_{\mathrm{SiO}\mathrm{2,0}}}---\left(11\right)$

$e_B\left(\mathrm{\&zeta;}\right)=\frac{{(1-\frac{2\mathrm{\&zeta;}}{b_B})}^3(1-\frac{2\mathrm{\&zeta;}}{h_B})(E_{\mathrm{Si},0}{e}_{\mathrm{Si}}-E_{\mathrm{SiO}\mathrm{2,0}}{e}_{\mathrm{SiO}2})+E_{\mathrm{SiO}\mathrm{2,0}}{e}_{\mathrm{SiO}2}}{{(1-\frac{2\mathrm{\&zeta;}}{b_B})}^3(1-\frac{2\mathrm{\&zeta;}}{h_B})(E_{\mathrm{Si},0}-E_{\mathrm{SiO}\mathrm{2,0}})+E_{\mathrm{SiO}\mathrm{2,0}}}---\left(12\right)$

The bending strength of each beam 31A, 31B utilizes Euler-Bernoulli Jacob beam formula to calculate as follows:

K _A(ΔT)=K _A，0(ζ)[1+e _A(ζ)(ΔT)] (13)

K _B(ΔT)=K _B，0(ζ)[1+e _B(ζ)(ΔT)] (14)

It is to be noted K _a(Δ T), K _b(Δ T) is respectively the bending strength of beam 31A, 31B.Term K _{a, 0}(ζ), K _{b, 0}(ζ), k _a(ζ), k _b(ζ) can launch as follows:

$K_{A,0}\left(\mathrm{\&zeta;}\right)=\frac{E_{A,0}\left(\mathrm{\&zeta;}\right){b_A}^3{h}_A}{12L_A}---\left(16\right)$

$K_{B,0}\left(\mathrm{\&zeta;}\right)=\frac{E_{B,0}\left(\mathrm{\&zeta;}\right){b_B}^3{h}_B}{12L_B}---\left(16\right)$

In the time that two beam 31A, 31B are connected in series, their bending strength of equal value can be calculated as follows:

$K_{\mathrm{eq}}\left(\mathrm{\&Delta;T}\right)=\frac{K_A\left(\mathrm{\&Delta;T}\right)K_B\left(\mathrm{\&Delta;T}\right)}{K_A\left(\mathrm{\&Delta;T}\right)+K_B\left(\mathrm{\&Delta;T}\right)}=\frac{K_{A,0}\left(\mathrm{\&zeta;}\right)K_{B,0}\left(\mathrm{\&zeta;}\right)[1+e_A\left(\mathrm{\&zeta;}\right)\mathrm{\&Delta;T}][1+e_B\left(\mathrm{\&zeta;}\right)\mathrm{\&Delta;T}]}{K_{A,0}\left(\mathrm{\&zeta;}\right)[1+e_A\left(\mathrm{\&zeta;}\right)\mathrm{\&Delta;T}]+K_{B,0}\left(\mathrm{\&zeta;}\right)[1+e_B\left(\mathrm{\&zeta;}\right)\mathrm{\&Delta;T}]}---\left(17\right)$

Δ T is differentiated and by equation (13) and (14) substitution, equation (17) becomes as follows:

$\frac{{\mathrm{dK}}_{\mathrm{eq}}\left(\mathrm{\&Delta;T}\right)}{\mathrm{d\&Delta;T}}=\frac{N_2\left(\mathrm{\&zeta;}\right){\mathrm{\&Delta;T}}^2+N_1\left(\mathrm{\&zeta;}\right)\mathrm{\&Delta;T}+N_0\left(\mathrm{\&zeta;}\right)}{D_2\left(\mathrm{\&zeta;}\right){\mathrm{\&Delta;T}}^2{+D}_1\left(\mathrm{\&zeta;}\right)\mathrm{\&Delta;T}+D_0\left(\mathrm{\&zeta;}\right)}---\left(18\right)$

Equation (18) has been described K _eqto the susceptibility of Δ T, and coefficient N2, N1, N0, D2, D1, D0 are defined as follows:

N ₂(ζ)=K _A，0K _B，0e _A(ζ)e _B(ζ)[K _A，0e _A(ζ)+K _B，0e _B(ζ)] (19)

N ₁(ζ)=2K _A，0K _B，0e _A(ζ)e _B(ζ)(K _A，0+K _B，0) (20)

N ₀(ζ)=K _A，0K _B，0[K _A，0e _B(ζ)+K _B，0e _A(ζ)] (21)

D ₂(ζ)=[K _A，0e _A(ζ)+K _B，0e _B(ζ)] ² (22)

D ₁(ζ)=2{K ² _A，0e _A(ζ)+K _A，0K _B，0[e _A(ζ)+e _B(ζ)]+K ² _B，0e _B(ζ)]} (23)

D ₀(ζ)=(K _A，0+K _B，0) ² (24)

In order to reach total temperature compensation, silicon dioxide coating thickness must be provided so that equation (18) all becomes 0 to all Δ T values.The denominator of supposing equation (18) is non-zero, and molecule that only need to equation (18) to all Δ T values is set to 0.

But the molecule of equation (18) is the quadratic function of Δ T, means and only have two Δ T values can make molecule equal 0.Equation (18) has proved that it is infeasible that two beam 31A, 31B to having varying cross-section carry out total temperature compensation by the cantilever beam structure obtaining 30 connected in series.

Cantilever beam structure to the xsect with discrete or continuous variable is similarly analyzed, and will lead to the same conclusion, and has proved that the silicon hairspring of variable cross-section is carried out to total temperature compensation infeasible in theory.

In contrast, to having the hairspring of parallel hairspring bar, to carry out total temperature compensation be feasible in theory.

With reference to Fig. 4, show the cantilever beam structure 40 with Liang Geliang connected in series district 41,42.Beam district 42 has two the beam 42A, the 42B that connect with the arrangement that walks abreast.All reference coordinates are all based on the right-hand rule.

Beam 41 has free end 43 and is connected to beam district 42 at its right-hand member 44 places at its left end.Beam district 42 has two the beam 42A, the 42B that connect with the arrangement that walks abreast, and whole beam district 42 is connected to beam 41 and right-hand member has fixed boundary condition 45 at its left end.All beam 41,42A, 42B have identical cross-section 46, and this xsect has wide b, high h, and the thickness silicon dioxide coating that is ζ.The length of beam 41 is that the length of LA and beam 42A, 42B is LB.

Owing to being parallel arrangement, therefore beam district 42 is larger than the bending strength of beam 41.By adjusting length L A and LB and the middle distance d of beam 42A, 42B in beam district 41,42, can design the cantilever beam structure 40 with the cantilever beam structure 30 of Fig. 3 with phase homology equivalence bending strength.

But, because each beam 41,42A, 42B have identical cross-sectional geometry, the ratio ζ of silicon dioxide coating thickness and the width of beam: b is identical to all beams 41,42A, 42B.The total moisture content compensation in any one beam district 41,42 is meaned to other Liang district is also identical total moisture content compensation.This has proved according to being feasible in the total moisture content compensatory theory of the silicon hairspring of the hairspring bar with parallel join of the present utility model.

With reference to Fig. 5, show according to the hairspring 50 of the utility model the first embodiment, there are many spires 55 of the parallel branch 55A, the 55B that comprise rectangular section, the single outer end 57 of hairspring is connected on post 58.

Hairspring 50 center comprises becket (collet) 51.Internal main hairspring bar 53 is from the inner 52 that is connected to becket 51 to inverted position turn, until hairspring part 55 is divided into two parallel branch 55A, 55B at a 54A.

Two 55A of branch, 55B meet at a bit again at a 54B, enter into the main hairspring bar 56 in single outside until the outer end 57 that its arrival is fixed and clamps.The hairspring part 55 with parallel branch 55A, 55B is larger than the bending strength of internal main hairspring bar 53 and outside main hairspring bar 56.By such as gradient method of Automated Design optimized algorithm, using the distance between the length of hairspring part 55 and the position of placement and the 55A of branch and 55B as region of search, the right alignment of maximizing hairspring 50.For the design parameter of variation is further provided, the distance between the 55A of branch and 55B can be along the length variations of hairspring part 55.The 55A of branch, 55B can for example separate and assemble, and are understandable that free space is confined to allow helical hair spring compression and stretch, and adjacent circle are not in contact with one another and hairspring does not contact other element of escapement.

Therefore, be understandable that, according to initial hairspring geometric configuration, the hairspring part 55 of the present embodiment can be size and shape arbitrarily, and can be placed on and have sufficient space Anywhere.

But parallel branch 55A, 55B preferably have substantially constant spacing distance conventionally, for simplifying calculating and the optimization of hairspring characteristic.

With reference to Fig. 6,7 and 8, show according to 3 of the utility model hairspring further embodiment, comprise many spires with two parallel branchs.Those skilled in the art will recognize that, these embodiment can extend to easily and comprise many spires that have more than two parallel branchs.

With reference to Fig. 6, show many spire arrangements 60 according to the further embodiment of the utility model hairspring, wherein two parallel branch 63A, 63B separate suddenly and then converge to suddenly in the single branch of two adjacent single hairspring bar part 61A, 61B of hairspring.

With reference to Fig. 7, show many spires 70 according to another embodiment of the utility model hairspring.The main hairspring bar 71A in left side is connected to a parallel branch 73A glossily, and this parallel branch 73A is then connected to right side main hairspring bar 71B glossily.

Parallel branch 73A separates suddenly and converges to suddenly right side main hairspring bar 71B at intersection point 72B from the main hairspring bar 71A of left side at intersection point 72A place.

With reference to Fig. 8, show many spires 80 according to another further embodiment of the utility model hairspring.The main hairspring bar 81A in left side is connected to a parallel branch 83B glossily.

From left side, main hairspring bar 81A is suddenly separately and be smoothly connected right side main hairspring bar 81B at intersection point 82A place for parallel branch 83A.Parallel branch 83B converges to suddenly right side main hairspring bar 81B at intersection point 82B place.

With reference to Fig. 9, show according to the arrangement of many spires 90 of still another embodiment of hairspring of the present utility model, comprise pillar 94.

Parallel branch 93A, 93B are connected to left side and right side by intersection point 92A, 92B by main hairspring bar 91A, 91B respectively.

In the time that whole many spires 90 are bending, parallel branch 93A, 93B may have the bending of slightly different radius-of-curvature.According to the geometric configuration of hairspring and bending amplitude, parallel branch 93A, 93B may be pushed to each other, and may contact.Pillar 94 has stoped the generation of this situation, and if the width of pillar 94 is little more a lot of than the length of spiral section 90, and also can be very little on the statics impact of many spires 90.

Cognoscible, according to the geometric configuration of hairspring, profile, size and application scenario, can utilize more than one pillar 94.

With reference to Figure 10, show here according to the alternative embodiment of hairspring 100 of the present utility model.

Hairspring designs the heart therein and has becket 101.Main hairspring bar 103 has the inner 102 that is connected to becket 101, and main hairspring bar 103 is to external spiral until it arrives many spires 105 at intersection point 104 places.So, main hairspring bar 103 is divided into two parallel branch 105A and 105B, wherein each finishes at the outer end 106A, the 106B that are fixed and clamp respectively independently, and the embodiment that again meets at any with the parallel branch 55A, the 55B that describe in Fig. 5 in outer end forms contrast.

With reference to Figure 11, show here according to the photo of the embodiment of hairspring 200 of the present utility model and represent.

Hairspring 200 comprises the inner end 210 being connected with becket 220 and the outer end 230 being connected with starting point (start) 240, the first extension 250 extending from the outside end 230 of inner end 210, and be positioned at the rib 260 of hairspring 200 outer rings.In this embodiment, rib comprises the inner arm 262 and outer arm 264 two parts of bifurcated, and the pillar 266 extending therein.

Jointly increase the cross sectional moment of inertia of rib 260 with two parts arm 262,264 of certain intervals, and jointly strengthened the cross sectional moment of inertia of this part hairspring.

Those skilled in the art can be familiar with and understand, and utilize two arms 262,264 with certain intervals, and the cross sectional moment of inertia of forked section has correspondingly also increased bending strength.

To be pointed out that, the first extension is identical with the cross sectional dimensions of rib, and similarly, each of two arms of the first extension and rib 262,264, all has identical cross-sectional area.Similarly, the first extension is formed by identical material with rib and has an identical cross-sectional area, and the Young modulus of considering the hairspring being formed by single piece of material is also constant, therefore change along with regard to temperature variation with regard to Young modulus, the temperature effect of hairspring different piece is identical.

Hairspring 200 in the present embodiment forms by micro-processing technology, can in the time producing these class article or articles for use, have high dimensional accuracy.

Micro-processing technology in the present embodiment can be to temperature-insensitive, form first material with the first Young modulus of hairspring and there is the second material of the second Young modulus as clad material by utilization, the first and second Young moduluss have contrary temperature dependency, and similarly, outside coating can have suitable size and have certain thickness, makes the elastic performance of hairspring insensitive to temperature variation.

Forming is silicon according to the suitable material of the hairspring of the present embodiment, and it has silicon dioxide coating.

In hairspring stretching and compression process, in order to increase right alignment, and reduce mass effect variation, rib can be included in hairspring.

And, can optimize the size of rib according to method of the present utility model, to provide suitable rigidity to make to minimize the distortion of hairspring in rotary course, reduce the quality of drifting about.Utilize and above-mentionedly relevant to the utility model minimize cost function and can reach this object.

Can find out, under some specified criteria, the inertia cross section square of forked section can be designed to be equivalent to the inertia cross section square with the reinforcing section that increases width.

For example, the nominal width of hairspring and be highly respectively b0 and h.Relatively two hairspring parts.A part has single hairspring bar, and hairspring bar has the width of increase, and this width is n times of b0.Another part has the hairspring bar of two bifurcateds, and each have the width equating with nominal value b0 and the distance d interval being recorded from the center line of each hairspring bar.Suppose that d keeps constant at whole separate section, can utilize parallel axis theorem that d is set, making the part of widening and separate is identical with respect to the inertia cross section square of z axle.Synthetic d is calculated as follows:

$d=b_0\sqrt{\frac{n^3-2}{6}}---\left(25\right)$

Notice if n equals 2 the hairspring bar that separates contact and become the hairspring bar of widening.

Can adopt easily optimized algorithm with part bifurcated to that widen.In the former situation, the width of this part is as a transformable design parameter in optimized algorithm.In the latter's situation, the distance of the hairspring bar of this bifurcated is as a transformable design parameter.Be noted that and utilize equation (12) these two kinds of methods can be exchanged.

Those skilled in the art will recognize that, although two parallel branch 105A and 105B do not meet at a bit again, also can near outer end, reach the intensity of enhancing according to the utility model the present embodiment.

The utility model provides a kind of micro-processing technology that utilizes to produce the clock watch balance spring with high dimensional accuracy and mechanical precision.

There is the right alignment of increase according to hairspring of the present utility model, the method that increases right alignment is to add strong position to reduce the mass centre of hairspring in use around the drift of rotating shaft by providing, due to acceleration and swing, this minimizing of drift has also reduced the radial inertial effect of hairspring, has therefore also just reduced the radial force of centre bearing.

And insensitive due to temperature, provides according to hairspring of the present utility model the tautochronism increasing.

The effect that this has the tautochronism that increases hairspring and oscillator mechanism, therefore provides the more importantly hairspring of position that has for timing object.

And, the friction force that reduces to reduce the bearing that is positioned at oscillator assembly center of radial force, when friction force swings while exerting an influence oscillator, it can also increase tautochronism, and also can reduce wearing and tearing and damage to bearing.

Such result is the life-span that has increased hairspring oscillator mechanism, and need to carry out less maintenance and maintenance to the wearing and tearing of element.Due to the yojan of nonlinear second-order system, the increase of right alignment between shaking peroid, can make tautochronism increase, also can reduce hairspring in the chance of compressing and drawing process middle reaches wire ring is tending towards being in contact with one another, the mesosphere of hairspring and adjacent turn contact and collide the mechanical property that can change hairspring, this has very adverse influence to tautochronism.And the collision of adjacent mesosphere and impact may cause damage and the potential failure of hairspring, again reduce the reliability of hairspring and increase maintenance cost.

Although with reference to above-mentioned example and preferred embodiment, the utility model is illustrated, those skilled in the art will recognize that, these examples just help the utility model to understand, and do not mean that restricted.Modification that it will be apparent to those skilled in the art or details or modification, and the improvement that it is carried out, all should be considered to equivalent of the present utility model.

Claims (15)

1. for a helical hair spring for stem-winder, it is characterized in that, described hairspring comprises:

Inner end and outer end, wall scroll extension extends to described outer end from described inner end; And

The rib being made up of two or more the isolated arms of outer ring that are positioned at described hairspring, makes the bending strength of described rib be greater than the bending strength of described wall scroll extension;

Wherein, in the compression of described hairspring and drawing process, vibrate while swinging around rotating shaft, the rigidity of described hairspring rib can improve around the right alignment of the hairspring circle of described rotating shaft.

2. according to the hairspring of claim 1, it is characterized in that, the xsect of described two or more isolated arms of described wall scroll extension and described rib is all rectangle, and there is each other equal width and equal height, wherein said wall scroll extension and described rib are formed by the first material, and further comprise the outer covering layer being formed by the second material.

3. according to the hairspring of claim 2, it is characterized in that, described the first material has the first Young modulus, and described the second material has the second Young modulus, described the first Young modulus and described the second Young modulus have contrary temperature dependency, and the thickness of the size of described wall scroll extension, the size of described rib and described outer covering layer is set to, make the elasticity of described hairspring insensitive to temperature variation.

4. according to the hairspring of claim 2 or 3, it is characterized in that, described the first material is silicon, and described the second material is silicon dioxide.

5. according to the hairspring of aforementioned any one claim, it is characterized in that, described wall scroll extension is constant pitch substantially, and an arm of described rib has above-mentioned pitch, and wherein radially the arm of inner side also there is above-mentioned pitch.

6. according to the hairspring of aforementioned any one claim, it is characterized in that, described wall scroll extension is constant pitch substantially, and two adjacent arms of described rib equidistantly distribute substantially along the track of described pitch, and distance between two adjacent arms of wherein said rib is substantially constant.

7. according to the hairspring of aforementioned any one claim, it is characterized in that, described hairspring has and is arranged on two ribs between wall scroll extension, and wherein said wall scroll extension and described rib the arm of inner side there is the pitch equating.

8. according to the hairspring of claim 7, it is characterized in that, the outermost arm of described rib has with adjacent wall scroll extension the pitch equating, and the arm of the inner side of described rib has with the arm of adjacent rib the pitch equating.

9. according to the hairspring of aforementioned any one claim, it is characterized in that, rib is arranged on the outer end of described hairspring, and the each described arm of described rib has end.

10. according to the hairspring of claim 9, it is characterized in that, described adjacent wall scroll extension has substantially equal pitch, and an arm of described rib also has described pitch, and the inner side arm of wherein said rib also has described pitch.

11. according to the hairspring of claim 10, it is characterized in that, the outer arm of described rib is shorter than the adjacent inner arm of described rib substantially.

12. according to the hairspring of claim 10, it is characterized in that, an adjacent inner arm of being substantially longer than described rib in described rib outer arm.

13. according to the hairspring of aforementioned any one claim, it is characterized in that, described rib comprises the spiral turns that is less than half-turn.

14. according to the hairspring of aforementioned any one claim, it is characterized in that, the adjacent arm of described rib interconnects in the centre of the end of described rib.

15. according to the hairspring of aforementioned any one claim, it is characterized in that, the described wall scroll extension of described rib and two or more isolated arms are substantially coplanar.

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