Mechanical watch escapement heat treatment process

Abstract

The application discloses a mechanical watch escapement wheel heat treatment processing technology, comprising the following steps: step one, cleaning; step two, preheating; step three, heating; step four, processing; step five, quenching; step six, tempering; step seven, air cooling; step eight, deep cooling; step nine, detection; wherein in the above step one, the semi-finished escapement wheel made of 42CrMo material is placed in an ultrasonic cleaning device, the surface residual impurities of the semi-finished escapement wheel are removed by using the ultrasonic principle, and after the removal is completed, the semi-finished escapement wheel is taken out, then the semi-finished escapement wheel is evenly placed in a draining tray, and the draining tray with the semi-finished escapement wheel is placed in a dry drying room for draining and drying treatment; the application eliminates the stress generated by the escapement wheel by deep cooling treatment before finishing, thereby improving the quality of the escapement wheel and prolonging the service life of the escapement wheel.

Description

Technical Field

[0001] This invention relates to the field of watch manufacturing technology, specifically to the heat treatment process for the escapement wheel of a mechanical watch. Background Technology

[0002] Mechanical watches can generally be divided into two types: manual winding and automatic winding. Both types are powered by a mainspring within the movement, which drives gears and subsequently the hands; the only difference lies in the method of power generation. A watch consists of basic components such as the crystal, case, strap, bezel, dial, hands, clasp, crown, case back, movement, and escapement wheel. During the production of the escapement wheel, it undergoes heat treatment. Due to the special nature of the escapement wheel, this heat treatment process can easily concentrate stress, reducing its strength and shortening its lifespan. Summary of the Invention

[0003] The purpose of this invention is to provide a heat treatment process for the escapement wheel of a mechanical watch, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a heat treatment process for the escapement wheel of a mechanical watch, comprising the following steps: Step 1, cleaning; Step 2, preheating; Step 3, heating; Step 4, processing; Step 5, quenching; Step 6, tempering; Step 7, air cooling; Step 8, deep cooling; Step 9, inspection.

[0005] In step one above, the semi-finished escape wheel, which is roughly machined from 42CrMo material, is placed in an ultrasonic cleaning device. The ultrasonic principle is used to remove the impurities remaining on the surface of the semi-finished escape wheel. After cleaning, the semi-finished escape wheel is taken out and then placed evenly in a draining tray. The draining tray containing the semi-finished escape wheel is then placed in a dry room for draining and drying.

[0006] In step two above, the semi-finished escapement wheel processed in step one is placed in a heating furnace for preheating treatment. The preheating temperature is 230-250℃, and carbon dioxide is introduced as a protective gas and kept at this temperature for 5-6 hours.

[0007] In step three above, the temperature in the heating furnace is raised to 870-900℃ and held for 1 hour, followed by air cooling to room temperature.

[0008] In step four above, the semi-finished escapement wheel cooled to room temperature in step three is subjected to semi-finishing processing, and at the same time, tooth making processing is performed.

[0009] In step five above, the escape wheel after tooth making in step four is placed in a heating furnace for the first heating treatment, and the first heating temperature is 840℃, and it is kept at that temperature for 1 hour.

[0010] In step six above, the escape wheel is placed in a heating furnace for tempering.

[0011] In step seven above, the escape wheel is placed in a heating furnace for a second heating treatment, and the heating temperature in the second heating furnace is 900℃ and held for 35 seconds. Then it is immediately placed in quenching oil for quenching and cooling treatment.

[0012] In step eight above, the escape wheel, which has been cooled to room temperature by air, is immersed in liquid nitrogen for cryogenic treatment. After the internal and external temperatures are uniform, it is then rapidly treated with hot steam. The opposite thermal stresses generated by rapid cooling and rapid heating offset some of the stresses generated.

[0013] In step nine above, the escape wheel processed in step eight is precision machined to obtain an escape wheel of the required size. Then, the obtained escape wheel is inspected and packaged.

[0014] Preferably, in step one, the draining tray has drain holes, and the diameter of the drain holes is half the outer diameter of the semi-finished escape wheel. The drying temperature in the drying room is 35-40℃. The next process can be carried out after there is no moisture residue on the surface of the semi-finished escape wheel.

[0015] Preferably, in step two, the semi-finished escapement wheel needs to be acid-washed before preheating.

[0016] Preferably, in step five, the escape wheel after heat preservation is taken out of the heating furnace and immediately placed in quenching oil for quenching and cooling treatment, and the quenching and cooling treatment time is 50-60 minutes.

[0017] Preferably, in step six, the temperature in the heating furnace is adjusted to 450-500℃, and then kept warm and cooled at a rate of 80-90℃ per hour for 6-7 hours. Finally, the furnace is removed and air-cooled to room temperature.

[0018] Preferably, in step seven, after cooling to room temperature, the escape wheel is placed in a heating furnace for heating and tempering treatment, and the escape wheel is kept at a temperature of 150-180°C for 3 hours. Then, the escape wheel is air-cooled to room temperature.

[0019] Compared with the prior art, the beneficial effects of the present invention are: the escapement wheel heat treatment process of the mechanical watch involves deep cryogenic treatment of the escapement wheel before fine machining, thereby eliminating the stress generated by the escapement wheel and improving the strength of the escapement wheel. At the same time, the processing stability is improved during the fine machining process, which not only improves the quality of the escapement wheel, but also extends the service life of the escapement wheel. Attached Figure Description

[0020] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figure 1 The present invention provides an embodiment of a heat treatment process for the escapement wheel of a mechanical watch, comprising the following steps: Step 1, cleaning; Step 2, preheating; Step 3, heating; Step 4, processing; Step 5, quenching; Step 6, tempering; Step 7, air cooling; Step 8, deep cooling; Step 9, inspection.

[0023] In step one above, the semi-finished escapement wheel, roughly machined from 42CrMo material, is placed in an ultrasonic cleaning device. The ultrasonic principle is used to remove the impurities remaining on the surface of the semi-finished escapement wheel. After cleaning, the semi-finished escapement wheel is removed and then evenly placed in a draining tray. The draining tray containing the semi-finished escapement wheel is placed in a dry drying room for draining and drying. The draining tray has drain holes with a diameter that is half the outer diameter of the semi-finished escapement wheel. The drying temperature in the drying room is 35-40℃. When there is no moisture remaining on the surface of the semi-finished escapement wheel, the next step can be carried out.

[0024] In step two above, the semi-finished escape wheel processed in step one is placed in a heating furnace for preheating treatment. The preheating temperature is 230-250℃, and carbon dioxide is introduced as a protective gas and kept at this temperature for 5-6 hours. Before the preheating treatment, the semi-finished escape wheel needs to be acid-washed.

[0025] In step three above, the temperature in the heating furnace is raised to 870-900℃ and held for 1 hour, followed by air cooling to room temperature.

[0026] In step four above, the semi-finished escapement wheel cooled to room temperature in step three is subjected to semi-finishing processing, and at the same time, tooth making processing is performed.

[0027] In step five above, the escape wheel with teeth made in step four is placed in a heating furnace for the first heating treatment. The first heating temperature is 840℃ and it is held for 1 hour. Then, the escape wheel after holding for 1 hour is taken out of the heating furnace and immediately placed in quenching oil for quenching and cooling treatment. The quenching and cooling treatment time is 50-60 minutes.

[0028] In step six above, the escape wheel is placed in a heating furnace for tempering treatment, and the temperature in the heating furnace is adjusted to 450-500℃. Then, it is kept at a cooling rate of 80-90℃ per hour for 6-7 hours. Finally, it is taken out of the furnace and air-cooled to room temperature.

[0029] In step seven above, the escape wheel is placed in a heating furnace for a second heating treatment at a temperature of 900°C for 35 seconds. Then, it is immediately placed in quenching oil for quenching and cooling. After cooling to room temperature, the escape wheel is placed in a heating furnace for heating and tempering treatment and held at 150-180°C for 3 hours. After holding, the escape wheel is air-cooled to room temperature.

[0030] In step eight above, the escape wheel, which has been cooled to room temperature by air, is immersed in liquid nitrogen for cryogenic treatment. After the internal and external temperatures are uniform, it is then rapidly treated with hot steam. The opposite thermal stresses generated by rapid cooling and rapid heating offset some of the stresses generated.

[0031] In step nine above, the escape wheel processed in step eight is precision machined to obtain an escape wheel of the required size. Then, the obtained escape wheel is inspected and packaged.

[0032] Based on the above, the advantages of this invention are that, when used, the escapement wheel undergoes heat treatment and cryogenic treatment during the manufacturing process, effectively removing the internal stress of the escapement wheel. This significantly reduces production errors during subsequent precision manufacturing. When the escapement wheel is used in a mechanical watch, it avoids the phenomenon of tooth misalignment caused by uneven teeth, thereby reducing timekeeping errors. At the same time, it reduces wear on the escapement wheel during operation and extends its service life.

[0033] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. The heat treatment process for the escapement wheel of a mechanical watch includes the following steps: Step 1, cleaning; Step 2, preheating; Step 3, heating; Step 4, machining; Step 5, first heating and quenching; Step 6, tempering; Step 7, second heating and air cooling; Step 8, deep cooling; Step 9, finishing and inspection; Its features are: In step one above, the semi-finished escape wheel, which is roughly machined from 42CrMo material, is placed in an ultrasonic cleaning device. The ultrasonic principle is used to remove the impurities remaining on the surface of the semi-finished escape wheel. After cleaning, the semi-finished escape wheel is taken out and then placed evenly in a draining tray. The draining tray containing the semi-finished escape wheel is then placed in a dry room for draining and drying. In step two above, the semi-finished escapement wheel processed in step one is placed in a heating furnace for preheating treatment. The preheating temperature is 230-250℃, and carbon dioxide is introduced as a protective gas and kept at this temperature for 5-6 hours. In step three above, the temperature in the heating furnace is raised to 870-900℃ and held for 1 hour, followed by air cooling to room temperature. In step four above, the semi-finished escapement wheel cooled to room temperature in step three is subjected to semi-finishing processing, and at the same time, tooth making processing is performed. In step five above, the escapement wheel with teeth made in step four is placed in a heating furnace for its first heating treatment at a temperature of 840℃ and held for 1 hour. After holding, the escapement wheel is removed from the heating furnace and immediately placed in quenching oil for quenching and cooling treatment for 50-60 minutes. In step six above, the escape wheel is placed in a heating furnace for tempering. In step seven above, the escape wheel is placed in a heating furnace for a second heating treatment at a temperature of 900°C for 35 seconds. Then, it is immediately placed in quenching oil for quenching and cooling. After cooling to room temperature, the escape wheel is placed in a heating furnace for tempering treatment and held at 150-180°C for 3 hours. After that, the escape wheel is air-cooled to room temperature. In step eight above, the escape wheel, which has been cooled to room temperature by air, is immersed in liquid nitrogen for cryogenic treatment. After the internal and external temperatures are uniform, it is then rapidly treated with hot steam. The opposite thermal stresses generated by rapid cooling and rapid heating offset some of the stresses generated. In step nine above, the escape wheel processed in step eight is precision machined to obtain an escape wheel of the required size. Then, the obtained escape wheel is inspected and packaged.

2. The heat treatment process for the escapement wheel of a mechanical watch according to claim 1, characterized in that: In step one, the draining tray has drain holes, and the diameter of the drain holes is half the outer diameter of the semi-finished escape wheel. The drying temperature in the drying room is 35-40℃. When there is no moisture residue on the surface of the semi-finished escape wheel, the next process can be carried out.

3. The heat treatment process for the escapement wheel of a mechanical watch according to claim 1, characterized in that: In step two, the semi-finished escapement wheel needs to be acid-washed before preheating.

4. The heat treatment process for the escapement wheel of a mechanical watch according to claim 1, characterized in that: In step six, the temperature in the heating furnace is adjusted to 450-500℃, and then kept at a cooling rate of 80-90℃ per hour for 6-7 hours. Finally, the furnace is removed and air-cooled to room temperature.

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