Thermal treatment equipment for string instruments

Abstract

The invention discloses thermal treatment equipment for string instruments, and aims to solve the problems of insufficient improvement of tensile strength of strings, serious oxidation loss, high surface roughness, poor intonation stability and the like in a traditional thermal treatment technology. The tensile strength of the steel string with the diameter of 0.26 mm can be improved to 2050 MPa, the thickness of an oxide layer is controlled to be 0.1 m, the surface roughness Ra value reaches high precision, and the intonation stability is improved to 0.5 tones. The device comprises a composite substrate electromagnetic induction heating belt, a vertical tension guide column mechanism, an intelligent temperature controller and the like. According to the method, the performance of the strings is improved, the production cost is reduced, the method is suitable for heat treatment of the strings of different specifications, and the method has remarkable technical progress and wide application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of heat treatment, and in particular to a heat treatment device for stringed musical instruments. Background Art

[0002] The following problems generally exist in traditional string heat treatment technologies:

[0003] When traditional heat treatment processes are used to process violin steel strings, especially the E string (with a diameter of about 0.26 mm), the increase in tensile strength usually does not exceed 10%. For professional players, this may not meet their requirements for the durability and stability of the strings; during the heat treatment process, the steel strings are prone to oxidation, resulting in an increase in the thickness of the oxide layer. In traditional heat treatment methods, the thickness of the oxide layer often reaches more than 2.5 μm, which not only affects the appearance of the strings but also reduces their service life; due to oxidation loss, the surface roughness Ra value of the strings processed by traditional processes is usually about 2.5 μm, which requires polishing after heat treatment, increasing production time and cost; due to temperature fluctuations during the heat treatment process, the pitch stability of the strings processed by traditional processes is poor, and the pitch error is usually more than 2.5 cents, which is unacceptable for professional orchestras.

[0004] The solution of the present invention to the above-mentioned disadvantages of the prior art is as follows: during the heat treatment process, the tensile strength of steel strings with a diameter of 0.26 mm can be increased to 2050 MPa, compared with 1650 MPa of the traditional process, an increase of 24.2%; through an optimized heat treatment process, the thickness of the oxide layer is controlled at 0.1 μm, which is significantly reduced compared with 2.5 μm of the traditional process, almost eliminating oxidation loss; the surface roughness Ra value of the strings after heat treatment reaches 0.1 μm, far lower than 2.5 μm of the traditional process, and no additional polishing process is required; the pitch stability is improved to 0.5 cents, which is significantly improved compared with 2.5 cents of the traditional process, meeting the requirements of professional orchestras; through precise displacement resolution (0.001 mm) and temperature control (temperature difference compensation accuracy ±3°C), precise control of the string length and tension is ensured. Summary of the Invention

[0005] In order to solve the above-mentioned existing technical problems, the present invention provides a heat treatment device for stringed musical instruments to overcome the disadvantages of poor heating uniformity, low tension control accuracy, serious oxidation loss, high energy consumption and poor adaptability in the prior art.

[0006] To achieve the above object, the present invention provides a heat treatment device for stringed musical instruments, including a machine tool, a high-temperature resistant base, a vertical tension guide post mechanism, a heat treatment disk mechanism, an adaptive clamping mechanism, a quenching-tempering linkage mechanism, and an intelligent temperature controller. Among them,

[0007] The high-temperature resistant base is arranged on the left side of the machine tool and includes a composite substrate, a composite substrate placement groove, a composite substrate electromagnetic induction heating belt, and a countercurrent heat exchanger;

[0008] The composite substrate is composed of a composite of silicon carbide ceramics and a molybdenum alloy layer, with a thickness ratio of 3:1. A placement groove is opened on the outside of the left side of the high-temperature resistant base. The composite substrate electromagnetic induction heating belt is arranged in the middle of the high-temperature resistant base. The power density of the composite substrate electromagnetic induction heating belt is set to 15 W / mm 2 , and the frequency is adjustable from 20 to 100 kHz. The countercurrent heat exchanger is arranged on the outside right side of the high-temperature resistant base. The internal cooling water flow rate of the countercurrent heat exchanger is set to 10 L / min, which is used to adjust the rapid and uniform heating of the string through the eddy current effect so that the temperature difference of the composite substrate is ≤ 10 °C, avoiding local overheating.

[0009] The vertical tension guide post mechanism is arranged in the middle of the machine tool and includes a coolant storage tank, a tension control system, a guide post lifting plate, a guide post lifting slide bar, a guide post lifting stable block, and a cooling pipeline nozzle;

[0010] The tension control system drives and controls the guide post lifting plate to move along the guide post lifting slide bar within the guide post lifting stable block. The displacement accuracy of the guide post lifting stable block is controlled by the tension control system to be ±0.01 mm. The coolant storage tank controls the cooling pipe nozzle to spray a 50% ethylene glycol solution onto the string placed on the composite substrate through the tension control system, which is used to inhibit high-temperature creep. The vertical tension guide post mechanism is used to dynamically adjust the string tension control accuracy to ±0.5 N. Combined with the coolant spraying, the string length deviation is ≤ 0.5 mm at 800 °C.

[0011] The heat treatment disk mechanism is arranged inside the middle of the machine tool and includes a moving groove, a moving part, a lifting plate, a cooling plate, a clamping block, and a heat treatment disk;

[0012] The moving part moves outside the moving groove through a first motor. When the moving groove moves, it drives the lifting plate to move. A cooling plate is arranged on the outside right side of the lifting plate. A clamping block is arranged outside the cooling plate. A heat treatment disk is arranged at the bottom end outside the clamping block. The heat treatment disk adopts a graphite material layer with a diameter of 600 mm. The cooling plate is embedded with a Peltier semiconductor, which is used to control the local temperature difference compensation accuracy to ±3 °C.

[0013] The adaptive clamping mechanism is arranged at the bottom of the middle of the machine tool and includes a clamping fixed frame, a clamping through body, a clamping body, a first motor, a radiator, and a boron nitride coating device;

[0014] The surface of the clamping body is coated with a boron nitride coating through the boron nitride coater and the friction coefficient is set to 0.05. The clamping body is driven by a first motor to drive the clamping through-body to move open and close. The radiator is connected to the clamping through-body and the clamping fixing frame, and is used to reduce the temperature of the clamping area through air cooling. The boron nitride coater is connected to the first motor and is used to spray a high-temperature resistant coating to prevent scratching of the string surface.

[0015] The quenching-tempering linkage mechanism is arranged outside the right side of the machine tool. It includes a quenching liquid nitrogen atomizing cooling medium connector, a quenching warning light, a quenching cavity, a quenching temperature controller, a tempering argon protection gas connector, a tempering cavity, a tempering warning light, a tempering temperature controller, and a heat treatment conveyor belt.

[0016] The quenching cavity is connected to the quenching liquid nitrogen atomizing cooling medium connector, with a jet pressure of 20 MPa and an atomization particle size ≤ 10 μm. The tempering cavity is connected to the tempering argon protection gas connector, with the oxygen content in the introduced argon < 10 ppm. At the same time, the quenching temperature controller and the tempering temperature controller are set to maintain 300 ± 5 °C. The heat treatment conveyor belt has a station switching time ≤ 2 seconds and an overall oxygen exposure < 5 ppm, and is used for seamless connection of quenching and tempering operations to achieve a string oxidation layer thickness < 0.5 μm and a surface roughness Ra ≤ 0.4 μm.

[0017] The intelligent temperature controller is arranged outside the right side of the machine tool and is used to monitor the heating power, cooling rate, and tension data in real time and dynamically optimize the process curve.

[0018] As the core of the heat treatment equipment for stringed instruments, the intelligent temperature controller receives the power output data of the composite substrate electromagnetic induction heating belt, and dynamically adjusts the heating frequency and power density according to the string material and target performance to achieve precise temperature control.

[0019] At the same time, the intelligent temperature controller uses the Peltier semiconductors embedded in the cooling plate to perform local temperature difference compensation according to the temperature data collected by the infrared temperature measurement probe to ensure uniform heating of the strings.

[0020] Regarding the tension change generated by the strings at high temperatures, the intelligent temperature controller receives the strain data of the fiber Bragg grating sensors in the vertical tension guide post mechanism, calculates and automatically compensates the tension in real time to ensure that the tension control accuracy is within ±0.5 N.

[0021] In addition, the intelligent temperature controller also closely cooperates with the quenching-tempering linkage mechanism, monitors the temperatures of the quenching cavity and the tempering cavity, and dynamically adjusts the heating power to ensure the stability of the quenching and tempering temperatures.

[0022] Meanwhile, it controls the clamping force of the clamping block, the coating thickness of the boron nitride coater, the cooling mode of the radiator, and the station switching time of the heat treatment conveyor belt, ensuring the smooth progress of the string heat treatment process from all aspects;

[0023] Finally, the intelligent temperature controller interacts with the user through the human-machine interface (HMI). The user can select different heat treatment modes, preset the target tensile strength and pitch error tolerance, and view real-time data and process curves to achieve full-process monitoring and control.

[0024] The present invention provides a heat treatment device for stringed musical instruments, which has the advantages of significantly improving the tensile strength of the strings: through the heat treatment device provided by the present invention, the tensile strength of a steel string with a diameter of 0.26 mm can be increased to 2050 MPa, which is 24.2% higher than 1650 MPa of the traditional process, greatly enhancing the durability and stability of the strings and meeting the high requirements of professional players for string performance; through the optimized heat treatment process of the present invention, the thickness of the oxide layer is controlled within 0.1 μm, which is significantly reduced compared with 2.5 μm of the traditional process, almost eliminating the oxidation loss, thereby extending the service life of the strings and maintaining the beauty of the strings; the surface roughness Ra value of the strings after heat treatment of the present invention reaches 0.1 μm, which is much lower than 2.5 μm of the traditional process, eliminating the need for additional polishing processes and reducing production time and costs; improving pitch stability: the heat treatment device of the present invention can improve the pitch stability to 0.5 cents, which is significantly improved compared with 2.5 cents of the traditional process, meeting the high-precision requirements of professional orchestras for pitch; through the precise displacement resolution (0.001 mm) and temperature control (temperature difference compensation accuracy of ±3°C), the present invention ensures the precise control of the string length and tension, improving the overall performance and consistency of the strings; the device design of the present invention, including the composite substrate electromagnetic induction heating belt and the vertical tension guide post mechanism, can achieve rapid and uniform heating of the strings and dynamic tension control, avoiding local overheating and high-temperature creep, and improving production efficiency and product quality;

[0025] In summary, the heat treatment device provided by the present invention has significant advantages in improving string performance, reducing production costs, and increasing production efficiency, bringing important technological progress to the field of stringed musical instrument manufacturing. Brief Description of the Drawings

[0026] Figure 1 It is a front view schematic diagram of a heat treatment device for stringed musical instruments in an embodiment of the present invention;

[0027] Figure 2 It is a left view schematic diagram of a heat treatment device for stringed musical instruments in an embodiment of the present invention;

[0028] Figure 3Schematic perspective view of a heat treatment device for stringed instruments in an embodiment of the present invention Figure 1 ;

[0029] Figure 4 Schematic perspective view of a heat treatment device for stringed instruments in an embodiment of the present invention Figure 2 ;

[0030] Figure 5 Schematic enlarged view A of a heat treatment device for stringed instruments in an embodiment of the present invention;

[0031] Figure 6 Schematic enlarged view B of a heat treatment device for stringed instruments in an embodiment of the present invention;

[0032] Figure 7 Schematic enlarged view C of a heat treatment device for stringed instruments in an embodiment of the present invention.

[0033] Explanation of reference numerals:

[0034] 1 - Machine tool;

[0035] 2 - High-temperature resistant base, 21 - Composite substrate, 22 - Composite substrate placement groove, 23 - Composite substrate electromagnetic induction heating belt, 24 - Countercurrent heat exchanger;

[0036] 3 - Vertical tension guide column mechanism;

[0037] 31 - Coolant storage tank, 32 - Tension control system, 33 - Guide column lifting plate, 34 - Guide column lifting slide rod, 35 - Guide column lifting stabilizer block, 36 - Cooling pipeline nozzle;

[0038] 4 - Heat treatment disc mechanism;

[0039] 41 - Moving groove, 42 - Moving part, 43 - Lifting plate, 44 - Cooling plate, 45 - Clamping block, 46 - Heat treatment disc;

[0040] 5 - Adaptive clamping mechanism;

[0041] 51 - Clamping fixed frame, 52 - Clamping through body, 53 - Clamping body, 54 - First motor, 55 - Radiator, 56 - Boron nitride coating device;

[0042] 6 - Quenching-tempering linkage mechanism;

[0043] 61 - Quenching liquid nitrogen atomization cooling medium connector, 62 - Quenching indicator light, 63 - Quenching cavity, 64 - Quenching temperature controller, 65 - Tempering argon protection gas connector, 66 - Tempering cavity, 67 - Tempering indicator light, 68 - Tempering temperature controller, 69 - Heat treatment conveyor belt;

[0044] 7 - Intelligent temperature controller;

[0045] Enlarged view A-A, enlarged view B-B, enlarged view C-C. Detailed implementation manners

[0046] In order to make the objectives and advantages of the present invention clearer and more understandable, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0047] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0048] In addition, it should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] As Figure 1 - Figure 7 shown, the present invention provides a heat treatment device for stringed musical instruments, including:

[0050] Machine tool 1;

[0051] High-temperature resistant base 2, arranged on the left side of the machine tool 1, including composite substrate 21, composite substrate placement groove 22, composite substrate electromagnetic induction heating belt 23, and countercurrent heat exchanger 24;

[0052] Vertical tension guide column mechanism 3, arranged in the middle of the machine tool 1, including coolant storage tank 31, tension control system 32, guide column lifting plate 33, guide column lifting slide bar 34, guide column lifting stabilizing block 35, and cooling pipeline nozzle 36;

[0053] Heat treatment disc mechanism 4, arranged inside the middle of the machine tool 1, including moving groove 41, moving part 42, lifting plate 43, cooling plate 44, clamping block 45, and heat treatment disc 46;

[0054] Adaptive clamping mechanism 5, arranged at the bottom of the machine tool 1, including clamping fixed frame 51, clamping through body 52, clamping body 53, first motor 54, radiator 55, and boron nitride coating device 56;

[0055] The quenching-tempering linkage mechanism 6 is arranged outside the right side of the machine tool 1 and includes a quenching liquid nitrogen atomization cooling medium connector 61, a quenching indicator light 62, a quenching cavity 63, a quenching temperature controller 64, a tempering argon protection gas connector 65, a tempering cavity 66, a tempering indicator light 67, a tempering temperature controller 68, and a heat treatment conveyor belt 69;

[0056] The intelligent temperature controller 7 is arranged outside the right side of the machine tool 1 and is used to monitor the heating power, cooling rate, and tension data in real time and dynamically optimize the process curve;

[0057] Among them, the high-temperature resistant base 2, the vertical tension guide column mechanism 3, the heat treatment disk mechanism 4, the adaptive clamping mechanism 5, the quenching-tempering linkage mechanism 6, and the intelligent temperature controller 7 form a closed-loop collaborative control through mechanical transmission and data feedback.

[0058] Specifically, a heat treatment device for stringed musical instruments further includes:

[0059] The high-temperature resistant base 2 is arranged on the left side of the machine tool 1 and includes a composite substrate 21, a composite substrate placement groove 22, a composite substrate electromagnetic induction heating belt 23, and a countercurrent heat exchanger 24;

[0060] The composite substrate 21 is composed of a composite of silicon carbide ceramics and a molybdenum alloy layer with a thickness ratio of 3:1. A placement groove 22 is opened outside the left side of the high-temperature resistant base 2. The composite substrate electromagnetic induction heating belt 23 is arranged in the middle of the high-temperature resistant base 2. The power density of the composite substrate electromagnetic induction heating belt 23 is set to 15 W / mm 2 , and the frequency is adjustable from 20 to 100 kHz. The countercurrent heat exchanger 24 is arranged on the outside right side of the high-temperature resistant base 2. The internal cooling water flow rate of the countercurrent heat exchanger 24 is 10 L / min, which is used to adjust the rapid and uniform heating of the strings through the eddy current effect so that the temperature difference of the composite substrate 21 is ≤ 10 °C to avoid local overheating.

[0061] The vertical tension guide column mechanism 3 is arranged in the middle of the machine tool 1 and includes a coolant storage tank 31, a tension control system 32, a guide column lifting plate 33, a guide column lifting slide rod 34, a guide column lifting stabilizing block 35, and a cooling pipeline nozzle 36;

[0062] The tension control system 32 drives and controls the guide post lifting plate 33 to move along the guide post lifting slide rod 34 within the guide post lifting stabilizing block 35. The displacement accuracy of the guide post lifting stabilizing block 35 is controlled by the tension control system 32 with an accuracy of ±0.01 mm. The coolant storage tank 31 controls the coolant pipe nozzle 36 through the tension control system 32 to spray a 50% ethylene glycol solution onto the strings placed on the composite substrate 21 for suppressing high-temperature creep. The vertical tension guide post mechanism 3 is used to dynamically adjust the string tension control accuracy to ±0.5 N. Combined with coolant spraying, the string length deviation is ≤0.5 mm at 800 °C.

[0063] The heat treatment disk mechanism 4 is arranged inside the middle of the machine tool 1 and includes a moving groove 41, a moving part 42, a lifting plate 43, a cooling plate 44, a clamping block 45, and a heat treatment disk 46.

[0064] The moving part 42 moves outside the moving groove 41 through the first motor 54. When the moving groove 41 moves, it drives the lifting plate 43 to move. A cooling plate 44 is arranged on the right side outside the lifting plate 43. A clamping block 45 is arranged outside the cooling plate 44. A heat treatment disk 46 is arranged at the bottom end outside the clamping block 45. The heat treatment disk 46 adopts a graphite material layer with a diameter of 600 mm. The cooling plate 44 is embedded with a Peltier semiconductor for controlling the local temperature difference compensation accuracy to ±3 °C.

[0065] The adaptive clamping mechanism 5 is arranged at the bottom middle of the machine tool 1 and includes a clamping fixed frame 51, a clamping through body 52, a clamping body 53, a first motor 54, a radiator 55, and a boron nitride coating device 56.

[0066] The surface of the clamping body 53 is coated with a boron nitride coating through the boron nitride coating device 56 and the friction coefficient is set to 0.05. The clamping body 53 is driven by the first motor 54 to drive the clamping through body 52 to open and close. The radiator 55 is connected to the clamping through body and the clamping fixed frame 51 for reducing the temperature of the clamping area through air cooling. The boron nitride coating device 56 is connected to the first motor 54 for spraying a high-temperature resistant coating to prevent scratching of the string surface.

[0067] The quenching-tempering linkage mechanism 6 is arranged outside the right side of the machine tool 1 and includes a quenching liquid nitrogen atomization cooling medium connector 61, a quenching warning light 62, a quenching cavity 63, a quenching temperature controller 64, a tempering argon protection gas connector 65, a tempering cavity 66, a tempering warning light 67, a tempering temperature controller 68, and a heat treatment conveyor belt 69.

[0068] The quenching cavity 63 is connected to the quenching liquid nitrogen atomizing cooling medium connector 61, with a spraying pressure of 20 MPa and an atomizing particle size of ≤10 μm. The tempering cavity 66 is connected to the tempering argon protective gas connector 65, with the oxygen content in the introduced argon being <10 ppm. At the same time, a quenching temperature controller 64 and a tempering temperature controller 68 are set to maintain 300 ± 5 °C. The heat treatment conveyor belt 69 has a station switching time of ≤2 seconds and an overall oxygen exposure of <5 ppm, enabling seamless connection between quenching and tempering operations, achieving a string oxidation layer thickness of <0.5 μm and a surface roughness Ra of ≤0.4 μm.

[0069] The intelligent temperature controller 7 is set outside the right side of the machine tool 1 and is used to monitor the heating power, cooling rate, and tension data in real time and dynamically optimize the process curve.

[0070] As the core of the heat treatment equipment for stringed musical instruments, the intelligent temperature controller 7 receives the power output data of the composite substrate electromagnetic induction heating belt 23 and dynamically adjusts the heating frequency and power density according to the string material and target performance to achieve precise temperature control.

[0071] At the same time, the intelligent temperature controller uses the Peltier semiconductors embedded in the cooling plate 44 to perform local temperature difference compensation based on the temperature data collected by the infrared temperature measurement probe to ensure uniform heating of the strings.

[0072] Regarding the tension change of the strings at high temperatures, the intelligent temperature controller receives the strain data of the fiber Bragg grating sensors in the vertical tension guide post mechanism 3, calculates and automatically compensates the tension in real time to ensure that the tension control accuracy is within ±0.5 N.

[0073] In addition, the intelligent temperature controller also closely cooperates with the quenching-tempering linkage mechanism 6 to monitor the temperatures of the quenching cavity 63 and the tempering cavity 66 and dynamically adjust the heating power to ensure the stability of the quenching and tempering temperatures.

[0074] At the same time, it controls the clamping force of the clamping block 45, the coating thickness of the boron nitride coater 56, the cooling mode of the radiator 55, and the station switching time of the heat treatment conveyor belt 69 to ensure the smooth progress of the string heat treatment process in all aspects.

[0075] Finally, the intelligent temperature controller interacts with the user through the user interface (HMI). The user can select different heat treatment modes, preset the target tensile strength and pitch error tolerance, and view the real-time data and process curve to achieve full-process monitoring and control.

[0076] Such as Figure 1 - Figure 7As shown in the figure, in the first embodiment, the present invention provides a heat treatment device for stringed instruments. In the heat treatment of the E string of a violin steel string with a diameter of 0.26 mm, the tensile strength of the steel string is increased by 17.8%, the oxidation loss is close to zero, and the polishing process is completely eliminated. The present invention is achieved through the following steps:

[0077] Fix the 0.26-mm steel string on the composite substrate 21, energize the electromagnetic induction heating belt 23 of the composite substrate, set the frequency to 80 kHz (matching the skin depth of steel of 0.2 mm), and the power density is 15 W / mm 2 , so that the string rises from room temperature to 800 °C within 5 seconds, with a heating rate of 160 °C / s. At the same time, the counterflow heat exchanger 24 is started synchronously, and the cooling water circulates at a flow rate of 10 L / min to ensure that the surface temperature gradient of the substrate is ≤ 10 °C. Move the composite substrate 21 to the clamping block 45 through the electromagnetic induction heating belt 23 of the composite substrate;

[0078] The gear set of the moving member 42 is meshed with the first motor 54 through worm drive, with a transmission ratio of 1:30 and a displacement resolution of 0.001 mm. At the same time, the moving member 42 horizontally displaces in the moving groove 41, driving the lifting plate 43 to rise to a set height (matching the string diameter, H = 10 × d = 2.6 mm). The clamping block 45 places the composite substrate 21 on the heat treatment plate 46. The heat treatment plate 46 uses a graphite material layer with a diameter of 600 mm to assist the string in being evenly heated. The temperature difference compensation accuracy is controlled within ±3 °C. It is started through the Peltier semiconductor in the cooling plate 44 to apply a +3 °C compensation to the local low-temperature area of the string (detecting a temperature difference > 5 °C) and a -3 °C compensation to the high-temperature area. An infrared temperature measurement probe (integrated on the edge of the heat treatment plate 46) inside the heat treatment plate 46 collects temperature data every 10 ms and uploads it to the intelligent temperature controller 7;

[0079] The first motor 54 drives the clamping through-body 52 to close, and the clamping force is automatically adjusted to 15 N according to the string diameter (formula: F = K × d 2 , where K is the material coefficient, K = 2.2 N / mm for steel strings 2 , d refers to the diameter of the string, with the unit of millimeter (mm). Select the "steel string - high strength" mode on the HMI interface of the intelligent temperature controller 7, preset the target tensile strength to 1600 MPa, and the pitch error tolerance is ±1 cent. The boron nitride coating device 56 sprays a boron nitride coating with a thickness of 0.1 μm on the surface of the clamping body 53 in real time, reducing the friction coefficient to 0.05 to prevent scratches on the string surface. The radiator 55 starts the air-cooling mode (wind speed 3 m / s) to control the temperature of the clamping area below 50 °C to avoid local temperature rise before preheating;

[0080] The tension control system 32 of the vertical tension guide post mechanism 3 starts to drive the guide post lifting plate 33 to move downward along the slide bar 34. The initial tension is set at 180 N. The fiber Bragg grating sensor (integrated in the guide post lifting and stabilizing block 35) monitors the string strain in real time and feeds it back to the intelligent temperature controller 7. When it is detected that the string tension drops to 175 N due to thermal expansion, the system automatically compensates the tension to 187 N (compensation formula: ΔF = E×A×α×ΔT, E = 200 GPa, A = 0.049 mm 2 ,α = 12×10 -6 / ℃ ,ΔT = 780 °C), and the cooling pipeline nozzle 36 sprays 50% ethylene glycol solution (flow rate 0.5 L / min) onto the string to form a micron-level liquid film, suppressing the high-temperature creep rate to 0.01% / min;

[0081] The clamping block 45 transfers the composite substrate 21 on the heat treatment plate 46 to the heat treatment conveyor belt 69 and moves it to the quenching cavity 63 for liquid nitrogen quenching. The magnetic gate valve switching time is 1.8 seconds, the oxygen content monitoring value is 3 ppm, the quenching liquid nitrogen atomization cooling medium connector 61 starts, the spraying pressure is 20 MPa, the liquid nitrogen atomization particle size is 8 μm, covering the entire surface of the string, and the cooling rate reaches 300 °C / s. The string drops from 800 °C to 200 °C within 0.5 seconds;

[0082] The heat treatment conveyor belt 69 is switched to the tempering cavity 66, and argon gas (purity 99.999%, oxygen content 5 ppm) is introduced. The tempering temperature controller 68 maintains 300 ± 2 °C. The strings of the composite substrate 21 are kept in the tempering furnace for 90 seconds to complete the transformation from martensite to tempered sorbite. The quenching temperature controller 64 synchronously monitors the temperature fluctuation in the tempering furnace and dynamically adjusts the heating power (PID parameters: Kp = 2.5, Ki = 0.1, Kd = 0.05). The quenching indicator light 62 and the tempering indicator light 67 are electrically linked to ensure no delay in the process switching;

[0083] Index Measured value Comparison with traditional process Tensile strength 1650 MPa 1400 MPa (±15%) Surface roughness Ra 0.35 μm 1.8 μm Pitch error +0.7 cents ±3 cents Length deviation (800 °C) 0.2 mm 2 mm

[0084] Conclusion: The equipment of the present invention increases the tensile strength of the steel string by 17.8%, and the oxidation loss is close to zero, completely eliminating the polishing process. The conclusion is based on the tensile strength of the traditional process: 1400 MPa (measured fluctuation ±15%, that is, 1190 - 1610 MPa), and the tensile strength of the process of the present invention: 1650 MPa (measured fluctuation ±3%, that is, 1600 - 1700 MPa),

[0085] The dynamic compensation calculation of the tension involved in the above content, formula: ΔF = E·A·α·ΔT

[0086] E = 200 GPa (elastic modulus of steel, referring to ASTM A228 standard);

[0087] A = π·(d / 2) 2 = 0.049 mm² (cross-sectional area of the string, d = 0.26 mm);

[0088] α = 12×10 -6 / ℃ (linear expansion coefficient of steel);

[0089] ΔT = 780 °C (from room temperature 20 °C to 800 °C);

[0090] ΔF = 200×10 3 MPa·0.049 mm 2 ·12×10 -6 / ℃ ·780 °C = 7.3 N

[0091] The initial tension is set to 180 N. When the detected tension drops to 175 N, the compensation amount:

[0092] F_compensation = 180 N + 7.3 N = 187.3 N (rounded to 187 N).

[0093] As Figure 1 - Figure 7 shown, in Example 2, the present invention provides a heat treatment device for stringed musical instruments. In the heat treatment of the A string of the titanium alloy string of a cello with a diameter of 0.5 mm, the tensile strength of the titanium alloy string is increased by 24.2%, the oxidation loss approaches zero, and the surface roughness Ra = 0.1 μm, meeting the ultra-high precision requirements of a symphony orchestra. The present invention is achieved through the following steps:

[0094] Fix the 0.5 mm titanium alloy string in the composite substrate 21. The electromagnetic induction heating belt 23 of the composite substrate is energized, and the frequency is set to 120 kHz (matching the skin depth of steel, 0.15 mm), and the power density is 18 W / mm 2 , rising from room temperature to 950 °C within 3 seconds, with a heating rate of 316 °C / s. The counterflow heat exchanger 24 is started synchronously, and the cooling water circulates at a flow rate of 12 L / min. The surface temperature gradient of the substrate is ≤ 8 °C. Move the composite substrate 21 to the clamping block 45 through the electromagnetic induction heating belt 23 of the composite substrate;

[0095] The gear set of the moving part 42 is meshed with the first motor 54 through a worm drive. At the same time, the moving part 42 horizontally displaces in the moving groove 41, driving the lifting plate 43 to rise to the set height H = 10×d = 5 mm. The clamping block 45 places the composite substrate 21 on the heat treatment plate 46. The heat treatment plate 46 uses a graphite material layer with a diameter of 600 mm to assist the string in being evenly heated. The cooling plate 44 is embedded with a Peltier semiconductor to apply a ±2.5 °C compensation to the area where the local temperature difference > 4 °C. The infrared temperature probe at the edge of the heat treatment plate 46 collects temperature data every 5 ms and uploads it to the intelligent temperature controller 7 to dynamically adjust the heating power (fluctuation ±0.3 kW);

[0096] The first motor (54) drives the clamping through-body 52 to close, and the clamping force is automatically adjusted to 25 N according to the string diameter (formula: F = K × d 2 , K 钛合金 = 1.8 N / mm 2 , select the "titanium alloy - high toughness" mode on the HMI interface of the intelligent thermostat 7, preset the target tensile strength to 2000 MPa, the pitch error tolerance to ±0.8 cents, the boron nitride coating device 56 sprays a boron nitride coating with a thickness of 0.15 μm on the surface of the clamping body 53 in real time, the friction coefficient is reduced to 0.03, the radiator 55 starts the liquid cooling mode (flow rate 1.5 L / min), and controls the temperature of the clamping area below 60°C;

[0097] The tension control system 32 of the vertical tension guide post mechanism 3 starts to drive the guide post lifting plate 33 to move down along the slide bar 34, the initial tension is set to 250 N, the fiber Bragg grating sensor (integrated in the guide post lifting and stabilizing block 35) monitors the string strain in real time and feeds it back to the intelligent thermostat 7. When it is detected that the tension drops to 242 N due to thermal expansion, the system automatically compensates to 257 N (compensation formula: ΔF = E·A·α·ΔT, E = 110 GPa, A = 0.196 mm 2 , α = 8.6×10 -6 / °C, ΔT = 930°C), and the compensation amount is calculated as;

[0098] ΔF = 110×10 3 MPa·0.196 mm 2 ·8.6×10 -6 / °C·930°C = 16.8 N

[0099] The actual compensated tension is rounded to 257 N (based on the accuracy of ±1 N);

[0100] The clamping block 45 transfers the composite substrate 21 on the heat treatment disk 46 to the heat treatment conveyor belt 69 and moves it to the quenching cavity 63 for liquid nitrogen quenching. The quenching cavity 63 switches to the helium jet mode (purity 99.999%), the pressure is 25 MPa, the atomization particle size is ≤5 μm, and the cooling rate reaches 500°C / s. The string is cooled from 950°C to 150°C within 0.3 seconds;

[0101] The heat treatment conveyor belt 69 switches to the tempering cavity 66. The tempering cavity 66 is evacuated to 1 Pa, and an argon-hydrogen mixture (hydrogen content 2%) is introduced. The thermostat 68 maintains 400 ± 3°C, and the holding time is 120 seconds to eliminate the β-phase brittleness and improve the toughness. The quenching indicator light 62 and the tempering indicator light 67 are electrically linked, and the switching time is ≤1.5 seconds;

[0102] Index Measured value Comparison with traditional process Tensile strength 2050 MPa 1650 MPa (±12%) Elastic modulus 115 GPa 105 GPa Oxide layer thickness 0.1 μm 2.5 μm Pitch stability ±0.5 cents ±2.5 cents

[0103] Conclusion: The device of the present invention increases the tensile strength of the titanium alloy string by 24.2%, the oxidation loss approaches zero, and the surface roughness Ra = 0.1 μm, meeting the ultra-high precision requirements of the symphony orchestra. Measured by a white light interferometer (resolution 0.1 nm) according to ISO 4287 standard, Ra = 0.1 μm. Due to oxidation and mechanical damage in the traditional process, Ra = 2.5 μm, and additional polishing is required (3 minutes per piece). Oxide layer thickness formula:

[0104] k = 0.02 μm / s 0.5 (Titanium alloy oxidation rate constant), t = 0.3 s (high temperature exposure time), Q = 150 kJ / mol, T = 1223 K (950 °C), calculation result:

[0105]

[0106] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0107] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; for those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent substitution, improvement, etc. made within the spirit and scope of the present invention shall be included in the protection scope of the present invention.

Claims

1. A string instrument heat treatment device, characterized in that: include: Machine tools (1); A high temperature resistant base (2) is arranged on the left side of the machine tool (1), comprising a composite substrate (21), a composite substrate placement groove (22), a composite substrate electromagnetic induction heating belt (23) and a counter-flow heat exchanger (24); A vertical tension guide column mechanism (3) is arranged in the middle of the machine tool (1), comprising a coolant storage tank (31), a tension control system (32), a guide column lifting plate (33), a guide column lifting slide bar (34), a guide column lifting stabilizing block (35) and a cooling pipeline nozzle (36); A heat treatment disk mechanism (4) is arranged inside the middle part of the machine tool (1), and comprises a moving groove (41), a moving part (42), a lifting plate (43), a cooling plate (44), a clamping block (45) and a heat treatment disk (46); An adaptive clamping mechanism (5) is arranged at the bottom of the machine tool (1), comprising a clamping fixing frame (51), a clamping through-body (52), a clamping body (53), a first motor (54), a heat sink (55) and a boron nitride coater (56); a quenching-tempering linkage mechanism (6), arranged on the right side of the machine tool (1), comprising a quenching liquid nitrogen atomization cooling medium connector (61), a quenching warning light (62), a quenching chamber (63), a quenching temperature controller (64), a tempering argon protective gas connector (65), a tempering chamber (66), a tempering warning light (67), a tempering temperature controller (68) and a heat treatment conveyor belt (69); An intelligent temperature controller (7) is arranged outside the right side of the machine tool (1) and is used to monitor heating power, cooling rate and tension data in real time and dynamically optimize the process curve; The high temperature resistant base (2), the vertical tension guide column mechanism (3), the heat treatment disk mechanism (4), the adaptive clamping mechanism (5), the quenching-tempering linkage mechanism (6) and the intelligent temperature controller (7) form a closed-loop collaborative control through mechanical transmission and data feedback.

2. The stringed instrument heat treatment equipment according to claim 1, characterized in that: The composite substrate (21) is composed of a silicon carbide ceramic and a molybdenum alloy layer, with a thickness ratio of 3:

1. The left outer portion of the high temperature resistant base (2) is concave to form a placement groove (22). The composite substrate electromagnetic induction heating belt (23) is arranged in the middle of the high temperature resistant base (2) and is connected to the counter-flow heat exchanger (24). The composite substrate electromagnetic induction heating belt (23) is set with a power density of 15 W / mm 2 , frequency 20-100kHz, the counter-flow heat exchanger (24) is arranged on the right side of the outside of the high temperature resistant base (2) and fixed by an inner hexagon, and the cooling water flow rate of 10L / min is set inside the counter-flow heat exchanger (24).

3. The string instrument heat treatment equipment according to claim 1, characterized in that: The tension control system (32) drives and controls the guide post lifting plate (33) to move along the guide post lifting slide bar (34) in the guide post lifting stabilizing block (35); the guide post lifting stabilizing block (35) controls the displacement accuracy of ±0.01 mm through the tension control system (32); the coolant storage tank (31) controls the cooling pipe nozzle (36) through the tension control system (32) to spray 50% ethylene glycol solution onto the strings placed on the composite substrate (21) to inhibit high temperature creep; the vertical tension guide post mechanism (3) is used to dynamically adjust the string tension control accuracy of ±0.5N.

4. The string instrument heat treatment equipment according to claim 1, characterized in that: The movable member (42) is moved outside the movable groove (41) by the first motor (54), and the movable groove (41) drives the lifting plate (43) to move when moving. A cooling plate (44) is arranged on the right side outside the lifting plate (43), and a clamping block (45) is arranged outside the cooling plate (44). A heat treatment disk (46) is arranged at the bottom end of the outside of the clamping block (45). The heat treatment disk (46) adopts a graphite material layer with a diameter of 600 mm. The cooling plate (44) is embedded with a Peltier semiconductor for controlling the local temperature difference compensation accuracy of ±3°C.

5. The string instrument heat treatment equipment according to claim 1, characterized in that: The surface of the clamping body (53) is plated with a boron nitride coating by a boron nitride coating device (56) and the friction coefficient is set to 0.

05. The clamping body (53) is driven by a first motor (54) to open and close the clamping through-body (53). The heat sink (55) is connected to the clamping through-body (53) and the clamping fixing frame (51) and is used to reduce the temperature of the clamping area by air cooling. The boron nitride coating device (56) is connected to the first motor (54) and is used to spray a high-temperature resistant coating to prevent the surface of the strings from being scratched.

6. The string instrument heat treatment equipment according to claim 1, characterized in that: The quenching chamber (63) is connected to the quenching liquid nitrogen atomization cooling medium connector (61), and the injection pressure is set to 20MPa, and the atomization particle size is ≤10μm. The tempering chamber (66) is connected to the tempering argon protective gas connector (65), and the oxygen content in the introduced argon is set to be less than 10ppm. At the same time, the quenching temperature controller (64) and the tempering temperature controller (68) are set to maintain 300±5°C. The heat treatment conveyor belt (69) is set to have a station switching time of ≤2 seconds and a whole process oxygen exposure of <5ppm, so as to seamlessly connect the quenching and tempering operations, so as to achieve a string oxide layer thickness of <0.5μm and a surface roughness Ra of ≤0.4μm.

7. The stringed instrument heat treatment equipment according to claim 5, characterized in that: The surface of the clamping body (53) is plated with a boron nitride coating, with a friction coefficient of 0.

05. The clamping force is automatically adjusted according to the diameter of the string, and the calculation formula is F=K×d 2 , where K is the material coefficient, steel string K = 2.2N / mm 2 , titanium alloy string K = 1.8N / mm 2 , d refers to the diameter of the string, measured in millimeters.

8. A stringed instrument heat treatment device according to claims 1-7, characterized in that: It is suitable for processing guitar strings with a diameter of 0.2-3mm and a length of 0.5-2m. The tensile strength is increased by ≥17.8%, the surface roughness Ra≤0.4μm, and the pitch stability error is ±1 cent.

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