CN111650826A - Pallet and its manufacturing method, and pallet assembly and its manufacturing method - Google Patents

Abstract

The invention discloses a pallet and a manufacturing method thereof, and a pallet assembly and a manufacturing method thereof. The whole escapement fork is made of ceramic materials and comprises a middle connecting rod, a fork head part integrally formed on the middle connecting rod and an escapement pallet part integrally connected to the middle connecting rod; the pallet-stone part comprises a first arm and a second arm which are respectively connected with the middle connecting rod, and a positioning hole which is positioned between the first arm and the second arm; the first arm is integrally formed with a tile inlet, and the second arm is integrally formed with a tile outlet. The whole pallet is made of ceramic materials, and has the advantages of high hardness, low friction coefficient, capability of reducing the loss of parts and improving the travel precision and the transmission efficiency, and no influence of a magnetic field; the pallet has the advantages that the pallet inlet and outlet are integrally formed on the pallet part, so that jewels do not need to be embedded in the manufacturing process, and the problems of high assembly difficulty and easy deformation of parts in the existing pallet manufacturing process are fundamentally solved; meanwhile, the manufacturing cost is also reduced.

Description

Pallet and its manufacturing method, and pallet assembly and its manufacturing method

Technical Field

The invention relates to the technical field of mechanical clock movements, in particular to a pallet and a manufacturing method thereof, and an escapement assembly and a manufacturing method thereof.

Background

The escapement is the heart of a mechanical timepiece, usually consisting of an escape wheel, a pallet fork and a sprung balance. The escapement wheel drives the escapement fork to catch one vertical, completes the actions of locking, impulse transmission and release, transmits power to the balance wheel, and achieves the effect of speed regulation by the time distribution of the balance wheel.

As is known, pallets comprise a fork body, a fork pin, a fork body, a fork shaft, and a pallet stone inlet and a pallet stone outlet provided at both ends of the fork body (see fig. 1). In the existing escapement fork, the escapement fork is small in size and high in precision requirement, mainly adopts metal materials, and is produced by machining modes such as turning, milling and grinding. However, since the hardness of metal materials is low and the wear resistance is poor, the inlet and outlet shoes in pallets are often made of precious stones with high hardness and low friction coefficients and are fixed at the two ends of the pallet body in an inlaid manner, so that the loss of parts is reduced, and the travel precision and the transmission efficiency are improved.

However, this general technique suffers from several significant drawbacks: firstly, the assembly difficulty is increased by inlaying gems on tiny components, and parts are deformed, so that the travel time deviation of a machine center is large; secondly, for the opposite grinding parts which can not be embedded with the jewels, the friction loss is large, so that the running time is inaccurate, and the movement often needs to be maintained to remove abrasive dust, so that the maintenance cost is increased; and thirdly, part of metal parts contain ferromagnetic elements and are easily influenced by a magnetic field, so that the watch is inaccurate in time running.

The ceramic material has high hardness and low friction coefficient, can reduce the loss of parts and components when used as a transmission component, improves the travel precision and the transmission efficiency, is not influenced by a magnetic field, and is an ideal transmission component material.

However, since the ceramic material has high hardness, the traditional machining modes such as turning, milling and grinding cannot realize complex forming of parts, and although injection forming can form ceramic parts with complex shapes, the size range and precision are only suitable for large-size parts under the current technical level, and the size and precision of the prior art are far from the requirements of movement parts. Under the structure of the existing escapement system, no technical scheme is disclosed for high-precision (tolerance range is micron level) and small-size components (dimension range is less than 5 mm in length and width and micron level in thickness) represented by watch movement components at present.

Disclosure of Invention

The invention aims to solve the technical problem of providing a pallet fork which has high hardness and low friction coefficient, can reduce the loss of parts and components, improves the travel precision and the transmission efficiency and is not influenced by a magnetic field.

Another object of the present invention is to provide an escapement assembly having the above pallet.

Another object of the present invention is to provide a method for manufacturing the pallet fork.

A further object of the present invention is to provide a method for manufacturing an escapement assembly as described above.

In order to solve the above technical problems, the present invention adopts a technical solution of providing an escapement fork applied to a timepiece movement, the escapement fork being entirely made of a ceramic material, including a middle link, a fork head portion integrally formed at one end of the middle link, and a pallet stone portion integrally connected to the other end of the middle link; the pallet-stone part comprises a first arm and a second arm which are respectively connected with the other end of the middle connecting rod, and a fork shaft hole which is positioned between the first arm and the second arm; the free end of the first arm is integrally formed with a tile inlet, and the free end of the second arm is integrally formed with a tile outlet.

In the pallet fork provided by the present invention, the fork head portion includes a fork connected to one end of the intermediate link, the fork including a first prong and a second prong spaced apart from each other, the first prong and the second prong each being integrally formed with the intermediate link.

In the pallet fork according to the present invention, the fork head portion includes a fork pin connected to one end of the intermediate link, the fork pin being integrally formed with the intermediate link, the fork pin being located at a notch formed between the first branch and the second branch.

In the pallet fork provided by the invention, one side of the fork pin facing the first branch is directly connected with the first branch, one side of the fork pin facing the second branch is directly connected with the second branch, one side of the fork pin facing away from the middle connecting rod forms a tip, the first branch and the second branch are formed between the first branch and the second branch, and the tip extends out of a gap between the first branch and the second branch along the extension direction of the middle connecting rod.

In the pallet fork provided by the present invention, the thickness of the prong pin is smaller than the thicknesses of the first branch and the second branch.

In the pallet fork according to the present invention, the first fork, the second fork, the intermediate link, the first arm, the second arm, the inlet shoe, and the outlet shoe form a body piece having a uniform thickness.

In order to solve another technical problem mentioned above, the invention proposes an escape assembly for a timepiece movement, comprising an escape wheel and a pallet as described above, the advance and exit shoes of said pallet cooperating with the teeth of said escape wheel.

In the escapement assembly provided by the invention, the whole escape wheel is made of ceramic material.

In order to solve still another problem described above, an aspect of the present invention is to provide a manufacturing method of a pallet fork as described above, including:

step S1, selecting a flaky ceramic blank with the thickness of 0.3mm-2mm, and carrying out double-sided grinding on the ceramic blank to form a blank;

step S2, cutting positioning holes on the blank by adopting laser;

step S3, using the positioning hole as a reference, and adopting femtosecond laser to carry out laser cutting on a blank to form a prototype with uniform thickness and provided with the intermediate connecting rod and the pallet stone part;

step S4, laser ablating the hatchling to form the pallet fork head at one end of the hatchling, resulting in the pallet fork.

In order to solve still another technical problem, the invention provides a method for manufacturing an escapement assembly as described above, comprising the steps of:

step S1, manufacturing the pallet fork using a ceramic blank;

step S2, manufacturing the escape wheel using a ceramic blank;

step S3, assembling the escape wheel and the pallet;

the step S1 includes:

step S11, selecting a flaky ceramic blank with the thickness of 0.3mm-2mm, and carrying out double-sided grinding on the ceramic blank to form a blank;

step S12, cutting positioning holes on the blank by adopting laser;

step S13, using the positioning hole as a reference, and adopting femtosecond laser to carry out laser cutting on a blank to form a prototype with uniform thickness and provided with the intermediate connecting rod and the pallet stone part;

step S14, laser ablating the hatchling to form the pallet fork head at one end of the hatchling, thereby obtaining the pallet fork;

the step S2 includes:

step S21, selecting a second flaky ceramic blank with the thickness of 0.1mm-2mm, and carrying out double-sided grinding on the second ceramic blank to form a second blank;

step S22, cutting a second positioning hole in the second blank by adopting laser;

and step S23, performing laser cutting on the second blank by taking the second positioning hole as a reference to obtain the escape wheel.

The implementation of the invention can achieve the following beneficial effects:

1. the whole escapement fork is made of ceramic materials, so that the escapement fork has the advantages of high hardness, low friction coefficient, capability of reducing the loss of parts and improving the travel precision and the transmission efficiency, and is not influenced by a magnetic field;

2. the pallet stone part is integrally formed with the inlet and outlet pallets, so that jewels do not need to be embedded in the manufacturing process, and the problems of high assembly difficulty and easy deformation of parts in the existing pallet manufacturing process are fundamentally solved; meanwhile, the manufacturing cost is also reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts:

FIG. 1 is a photograph of a prior art pallet;

fig. 2 is a schematic top view of a pallet fork according to the present invention;

FIG. 3 is a schematic cross-sectional view taken at A-A in FIG. 2;

fig. 4 is a schematic view of an escape wheel in the escapement assembly provided by the present invention.

The reference numerals in the detailed description illustrate:

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Exemplary embodiments of the invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The terms including ordinal numbers such as "first", "second", and the like used in the present specification may be used to describe various components, but the components are not limited by the terms. These terms are used only for the purpose of distinguishing one constituent element from other constituent elements. For example, a first component may be named a second component, and similarly, a second component may also be named a first component, without departing from the scope of the present invention.

Example one

The present embodiment provides a pallet 1 for a timepiece movement. Said pallet 1 is made entirely of ceramic material and comprises an intermediate link 12, a fork head 11 integrally formed at one end of said intermediate link 12, and a pallet stone 13 integrally connected to the other end of said intermediate link 12; said pallet-stone portion 13 comprises a first arm 131 and a second arm 132 connected to the other end of said intermediate link 12, respectively, and a fork shaft hole 133 between said first arm 131 and said second arm 132; the free end of the first arm 131 is integrally formed with the inlet shoe 14, and the free end of the second arm 132 is integrally formed with the outlet shoe 15.

In this embodiment, the ceramic material has the following characteristics: 1) the density is lower, namely not higher than 6g/cm3, the low density can reduce the energy loss in the transmission process of the movement and can improve the delay time; 2) the friction coefficient is low, namely not higher than 0.2, the travel precision can be improved, the loss is reduced, and the movement cleaning time is prolonged; 3) high hardness, i.e., 1200HV1 or more. Specifically, the ceramic material is silicon nitride ceramic. Since the pallet 1 is entirely made of the ceramic material, the pallet 1 has advantages of high hardness, low friction coefficient, reduced loss of parts, improved travel accuracy and transmission efficiency, and no influence of magnetic field. Moreover, the inlet and outlet shoes 14 and 15 of the pallet 1 are integrally formed on the pallet part 13, so that in the manufacturing process, no jewel needs to be embedded, and the problems of high assembly difficulty and easy deformation of parts in the manufacturing process of the conventional pallet 1 are fundamentally solved; meanwhile, the manufacturing cost is also reduced.

In some other embodiments, the ceramic material may be a carbide ceramic, a nitride ceramic, a carbonitride ceramic, an oxide ceramic, and the like, and more particularly, includes one or more of a carbon-containing ceramic, a nitrogen-containing ceramic, and a carbon and nitrogen-containing ceramic. For example: silicon carbide, silicon nitride, silicon oxycarbide, titanium carbide, titanium nitride, titanium carbonitride, alumina, zirconia, and the like.

In this embodiment, the yoke head 11 includes a yoke 111 connected to one end of the intermediate link 12, the yoke 111 includes a first branch 1111 and a second branch 1112 spaced apart, and the first branch 1111 and the second branch 1112 are integrally formed with the intermediate link 12. Since the fork 111 is integrally formed with the intermediate link 12, no additional process is required to mount the fork 111 to the intermediate link 12 during the manufacturing process, further simplifying the difficulty of manufacturing the pallet fork 1.

In this embodiment, the prong head 11 includes a prong nail 112 connected to one end of the intermediate link 12, the prong nail 112 is integrally formed with the intermediate link 12, and the prong nail 112 is located at a gap formed between the first prong 1111 and the second prong 1112. The side of the clevis 112 facing the first branch 1111 is directly connected to the first branch 1111, the side of the clevis 112 facing the second branch 1112 is directly connected to the second branch 1112, the side of the clevis 112 facing away from the intermediate link 12 forms a tip 1121, the first branch 1111 is formed between the second branch 1112, and the tip 1121 protrudes out of a gap between the first branch 1111 and the second branch 1112 along the extending direction of the intermediate link 12.

In this embodiment, the thickness of the prong nail 112 is less than the thickness of the first prong 1111 and the second prong 1112. Preferably, the first branch 1111, the second branch 1112, the intermediate link 12, the first arm 131, the second arm 132, the inlet shoe 14 and the outlet shoe 15 form a body piece having a uniform thickness. Specifically, the thickness of the main body piece is 0.3mm, and the thickness of the jaw nail 112 is 0.08 mm.

In some other embodiments, the thickness of the body piece and the prongs 112 may be adjusted according to actual requirements.

Example two

The present embodiment provides an escapement assembly for a timepiece movement. The escapement assembly comprises an escape wheel 2 and the pallet 1 as provided in the first embodiment. The inlet and outlet shoes 14, 15 of the pallet 1 cooperate with the teeth of the escape wheel 2.

In this embodiment, the escape wheel 2 is made entirely of ceramic material. Preferably, the ceramic material used for escape wheel 2 is the same as that used for pallet 1. Thus, the two counter-grinding parts of the escape wheel 2 and the escape fork 1 have similar friction coefficients and are not easy to wear.

After assembly, through a practical walking test, after the escapement assembly provided by the embodiment is adopted to replace the escapement assembly in the organic core, the continuous walking time can be increased from the original 42 hours to 66 hours, the average day difference is reduced from-5 to +20s to-4 to +6s, the cleaning and maintenance time of the escapement mechanism is increased from the original average 25 months to more than 48 months, and lubricating oil is not needed. Furthermore, the escapement assembly is made entirely of non-metallic material, so that it is completely unaffected by magnetic fields.

EXAMPLE III

The present embodiment provides a manufacturing method of pallet 1 in the first embodiment. The manufacturing method comprises the following steps:

step S1, selecting a flaky ceramic blank with the thickness of 0.3mm-2mm, and carrying out double-sided grinding on the ceramic blank to form a blank; specifically, the ceramic blank is a silicon nitride ceramic blank, the density of the selected silicon nitride ceramic is 3.10-3.26g/cm3, the hardness is over 1800HV1, the thickness of the selected silicon nitride blank is 0.3-2mm, and the ceramic blank is subjected to double-sided grinding until the requirements on the thickness and the precision of parts in a design drawing are met to form a blank;

step S2, cutting positioning holes on the blank by adopting laser;

step S3, performing laser cutting on the blank by taking the positioning hole as a reference to form a prototype with uniform thickness and provided with the intermediate connecting rod 12 and the pallet-stone part 13; here, the coefficient of friction of the surface obtained by cutting was 0.12;

step S4, performing laser ablation on the hatchling to form the pallet fork head 11 at one end of the hatchling, thereby obtaining the pallet fork 1; it will be apparent that, with reference to fig. 1, the fork head 11 may be obtained by laser ablation of only one groove in one end of the preform. It should be explained that the laser used is a nanosecond laser, the side of the groove facing away from pallet-stone portion 13 is open, and after laser ablation of a predetermined size of the groove according to design, the bottom wall of the groove is the dart 112, and the two side walls of the groove are the first prong 1111 and the second prong 1112.

In this embodiment, the femtosecond laser is used to perform laser cutting on the blank in step S3, because only with this laser, the machined surface of the component can meet the surface finish requirement of the core component, and a smooth surface is formed, so as to meet the requirement of the friction coefficient. The laser used in the steps S2 and S4 is one or more of femtosecond laser, nanosecond laser, and picosecond laser, and for the non-working contact surface, the cost can be reduced by selecting the nano laser and the picosecond laser.

Example four

This embodiment provides a method of manufacturing the escapement assembly of the second embodiment. The manufacturing method comprises the following steps:

step S1, manufacturing pallet fork 1 from a ceramic blank;

step S2, manufacturing escape wheel 2 from a ceramic blank;

step S3, assembling the escape wheel 2 and the pallet fork 1;

please refer to embodiment three for the implementation process of step S1, which is not described herein again.

The step S2 includes:

step S21, selecting a second flaky ceramic blank with the thickness of 0.1mm-2mm, and carrying out double-sided grinding on the second ceramic blank to form a second blank; the second ceramic blank is selected to be a silicon nitride ceramic blank, the selected silicon nitride ceramic has the density of 3.10-3.26g/cm3, the hardness is 1800HV1 or more, the selected silicon nitride blank has the thickness of 0.1mm-2mm, and the second ceramic blank is subjected to double-sided grinding until the thickness and the precision of parts in the drawing are achieved to form a second blank.

Step S22, cutting a second positioning hole in the second blank by adopting laser;

step S23, laser cutting the second blank with the second positioning hole as a reference to obtain the escape wheel 2; here, the coefficient of friction of the surface obtained by cutting was 0.12.

Finally, the escapement wheel 2 and the escapement fork 1 which are processed are connected with other matching parts of the movement in a viscose mode, and the escapement mechanism which can be used on the clock can be obtained.

While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (10)

1. A pallet (1) applied to a timepiece movement, characterized in that the whole of said pallet (1) is made of ceramic material and comprises an intermediate link (12), a pallet head (11) integrally formed at one end of said intermediate link (12), and a pallet stone portion (13) integrally connected to the other end of said intermediate link (12); said pallet-stone portion (13) comprising a first arm (131) and a second arm (132) respectively connected to the other end of said intermediate link (12), and a pallet-stone hole (133) located between said first arm (131) and said second arm (132); the free end of the first arm (131) is integrally formed with a tile inlet (14), and the free end of the second arm (132) is integrally formed with a tile outlet (15).

2. The pallet fork (1) according to claim 1, characterized in that the fork head (11) comprises a fork (111) connected to one end of the intermediate link (12), the fork (111) comprising a first branch (1111) and a second branch (1112) spaced apart, both the first branch (1111) and the second branch (1112) being integral with the intermediate link (12).

3. Pallet fork (1) according to claim 2, characterized in that the fork head (11) comprises a fork pin (112) connected to one end of the intermediate link (12), the fork pin (112) being integral with the intermediate link (12), the fork pin (112) being located in a gap formed between the first branch (1111) and the second branch (1112).

4. The pallet fork (1) according to claim 3, characterized in that the side of the prong (112) facing the first prong (1111) is directly connected to the first prong (1111), the side of the prong (112) facing the second prong (1112) is directly connected to the second prong (1112), the side of the prong (112) facing away from the intermediate link (12) forms a tip (1121), the first prong (1111) and the second prong (1112) being formed between them, the tip (1121) projecting out of the gap between the first prong (1111) and the second prong (1112) in the direction of extension of the intermediate link (12).

5. Pallet fork (1) according to claim 3, characterized in that the thickness of the prong (112) is less than the thickness of the first prong (1111) and the second prong (1112).

6. The pallet fork (1) according to claim 5, characterized in that said first prong (1111), said second prong (1112), said intermediate link (12), said first arm (131), said second arm (132), said inlet shoe (14) and said outlet shoe (15) form a body piece of uniform thickness.

7. Escapement assembly, applied to a timepiece movement, characterized in that it comprises an escapement wheel (2) and an escapement pallet (1) according to any one of claims 1 to 6, the inlet (14) and outlet (15) of the escapement pallet (1) cooperating with the teeth of the escapement wheel (2).

8. Escapement assembly according to claim 7, characterized in that the escape wheel (2) is made entirely of ceramic material.

9. A method for manufacturing a pallet fork (1) according to any one of claims 1 to 6, characterized in that it comprises the following steps:

step S1, selecting a flaky ceramic blank with the thickness of 0.3mm-2mm, and carrying out double-sided grinding on the ceramic blank to form a blank;

step S2, cutting positioning holes on the blank by adopting laser;

step S3, using the positioning hole as a reference, and adopting femtosecond laser to perform laser cutting on the blank to form a prototype with uniform thickness and provided with the intermediate connecting rod (12) and the pallet stone part (13);

step S4, laser ablation of the hatchling is performed to form the pallet fork head (11) at one end of the hatchling, thus obtaining the pallet fork (1).

10. A method of manufacturing an escapement assembly according to claim 8, characterized in that it comprises the following steps:

step S1, manufacturing the pallet fork (1) by using a ceramic blank;

step S2, manufacturing the escape wheel (2) by using a ceramic blank;

step S3, assembling the escape wheel (2) and the pallet (1);

the step S1 includes:

step S11, selecting a flaky ceramic blank with the thickness of 0.3mm-2mm, and carrying out double-sided grinding on the ceramic blank to form a blank;

step S12, cutting positioning holes on the blank by adopting laser;

step S13, using the positioning hole as a reference, and adopting femtosecond laser to perform laser cutting on the blank to form a prototype with uniform thickness and provided with the intermediate connecting rod (12) and the pallet stone part (13);

step S14, performing laser ablation on the hatchling to form the pallet fork head (11) at one end of the hatchling, thereby obtaining the pallet fork (1);

the step S2 includes:

step S21, selecting a second flaky ceramic blank with the thickness of 0.1mm-2mm, and carrying out double-sided grinding on the second ceramic blank to form a second blank;

step S22, cutting a second positioning hole in the second blank by adopting laser;

and step S23, carrying out laser cutting on the second blank by taking the second positioning hole as a reference to obtain the escape wheel (2).

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