Electric annealing device for tungsten wire diamond wire

Abstract

The utility model provides an electric annealing device for a tungsten wire diamond wire, which comprises a pay-off wheel and a wire drawing machine, a front-end conductive chuck and a rear-end conductive chuck are arranged between the pay-off wheel and the wire drawing machine at a certain interval, and a tungsten wire enters a take-up reel through the pay-off wheel, the front-end conductive chuck, the rear-end conductive chuck and the wire drawing machine in sequence. The front-end conductive chuck and the rear-end conductive chuck are connected with the positive electrode and the negative electrode of an electric control system through power lines, a temperature measuring instrument used for monitoring the temperature of the tungsten filament is arranged between the front-end conductive chuck and the rear-end conductive chuck, and the temperature measuring instrument is connected with the electric control system through electric signals. The device can ensure the annealing quality of the tungsten wire diamond wire.

Description

Technical Field

[0001] The utility model mainly relates to the technical field related to tungsten wire annealing, and specifically is an electric annealing device for tungsten wire diamond wire. Background Technique

[0002] The production of tungsten wire diamond wire requires annealing treatment. The prior art uses a mixture of natural gas and air to enter a heating furnace to heat the tungsten wire. The process requirements mainly heat and anneal the φ0.39 tungsten wire. The temperature of the tungsten wire needs to be stable at 1600 °C, and the fluctuation range is ±10 °C, and it is necessary to ensure sufficient time during the heating process. This annealing process must ensure a constant temperature and a stable speed to ensure a stable change in the internal molecular structure of the tungsten wire.

[0003] Tungsten wire has high thermal stability in air, is not easily oxidized and evaporated in a high-temperature environment, and its melting point is very high, up to 3410 degrees Celsius. The temperature coefficient of tungsten wire has an important impact on thermal stability and service life. The smaller the temperature coefficient, the better the thermal stability and the longer the service life.

[0004] In a high-temperature environment, tungsten wire can operate stably, but it will also face problems such as stress relaxation, fracture, and electron migration. These factors may reduce its thermal stability and service life. In the existing annealing process of gas heating furnaces, the surface thermal radiation heating method is mainly used. The heat penetrates from the surface of the tungsten wire to the inside. The surface temperature rises rapidly first and then conducts to the core. It takes a certain time process for the heat to conduct to the core. This stage may cause uneven heating and annealing, resulting in uneven local changes in the internal structure of the tungsten wire, and it is easy to break during subsequent processing.

[0005] Considering comprehensively the annealing process of gas heating furnaces, due to factors such as the existing heating method, air pressure, natural gas pressure fluctuation, and speed change, it is easy to have deviation in the processing performance of tungsten wire during the annealing process. Each factor change in this process will directly affect its processing quality. Therefore, it is necessary to adopt a more reasonable annealing device to realize the annealing treatment of tungsten wire diamond wire. Content of the Utility Model

[0006] To solve the deficiencies of the current technology, the utility model combines the existing technology and starts from practical applications to provide an electric annealing device for tungsten wire diamond wire, which can ensure the annealing quality of tungsten wire diamond wire.

[0007] The technical solution of the utility model is as follows:

[0008] A tungsten wire electro-annealing device includes a wire pay-off reel and a wire drawing machine. A front conductive chuck and a rear conductive chuck with a certain distance are arranged between the wire pay-off reel and the wire drawing machine. The tungsten wire passes through the wire pay-off reel, the front conductive chuck, the rear conductive chuck, and the wire drawing machine in sequence and enters the take-up reel. The front conductive chuck and the rear conductive chuck are connected to the positive and negative electrodes of the electric control system through power lines. A temperature measuring instrument for monitoring the temperature of the tungsten wire is arranged between the front conductive chuck and the rear conductive chuck, and the temperature measuring instrument is electrically connected to the electric control system through an electric signal.

[0009] Furthermore, both the front conductive chuck and the rear conductive chuck include an upper chuck and a lower chuck, and the tungsten wire is wound around both the upper chuck and the lower chuck.

[0010] Furthermore, the upper chuck is connected with a horizontal handle-type clamp.

[0011] Furthermore, a connecting shaft is arranged on the horizontal handle-type clamp. The upper chuck is installed on an upper insulating board, and the upper insulating board is installed on the connecting shaft. A spring is sleeved on the connecting shaft to adjust the downward pressure of the upper chuck.

[0012] Furthermore, the lower chuck is installed on a bracket, and a lower insulating board is arranged between the lower chuck and the bracket.

[0013] Furthermore, the bracket includes a bottom plate, a lower connecting column of the bracket, and an upper connecting column of the bracket. The lower connecting column of the bracket is installed on the bottom plate, the upper connecting column of the bracket is installed on the lower connecting column of the bracket and can be adjusted up and down in position, and the lower chuck is installed on the upper connecting column of the bracket.

[0014] Furthermore, the distance between the lower connecting columns of the brackets corresponding to the front conductive chuck and the rear conductive chuck is adjustable.

[0015] Furthermore, the bottom plate is an insulating board.

[0016] The beneficial effects of the present utility model are as follows:

[0017] 1. The original gas heating annealing uses the surface heat radiation heating method of the tungsten wire. Its heat penetrates from the surface of the tungsten wire to the inside. The surface temperature first rises sharply and then conducts to the core. It takes a certain time process for the heat to conduct to the core, which may lead to uneven heating annealing, resulting in uneven local changes in the internal structure of the tungsten wire and being prone to breakage during subsequent processing. The electro-annealing device of this application uses the heat generated by the movement of electrons inside the conductor. When ensuring the same current density, its heat is evenly generated from the inside to the outside, ensuring uniform changes in the internal structure, thereby improving the annealing quality of the tungsten wire.

[0018] 2. During traditional manual operation, due to fluctuations in natural gas pressure or air pressure, the temperature of the tungsten wire varies greatly, being sometimes high and sometimes low. When the temperature changes rapidly, manual adjustment of the valve is required to regulate the temperature. If the rapid temperature change goes unnoticed, it will cause deviations in the properties of the wire. The existing device can first ensure temperature stability under the condition of stable speed and wire diameter. When there are changes, the temperature can also be automatically adjusted according to the feedback of the temperature measuring instrument.

[0019] 3. The annealing device of this application has a reasonable structural design. By winding the tungsten wire around the chuck, its heat resistance is increased, preventing the chuck from being damaged during the high-temperature process. Moreover, heat-insulating insulating boards are added at the upper and lower ends of the conductive chuck, achieving the effects of insulation and heat insulation. The horizontal handle-type clamp facilitates wire threading operation, and the clamping force on the tungsten wire can be adjusted. For tungsten wires of the same wire diameter, parameters do not need to be adjusted, improving work efficiency. When a single person is operating, several devices can be operated simultaneously during the processing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Attached Figure 1 is a schematic diagram of the overall structure of the present utility model.

[0021] Attached Figure 2 is a three-dimensional structural schematic diagram of the conductive chuck support.

[0022] Attached Figure 3 is a front view structural schematic diagram of the conductive chuck support.

[0023] Attached Figure 4 is a structural schematic diagram of the conductive chuck.

[0024] Attached Figure 5 is a structural schematic diagram of the chuck.

[0025] The reference numerals shown in the figures: 1. wire pay-off reel; 2. tungsten wire; 3. front-end conductive chuck; 4. rear-end conductive chuck; 5. wire drawing machine; 6. power cord; 7. electric control system; 8. bottom plate; 9. lower connecting column of the bracket; 10. upper connecting column of the bracket; 11. lower insulating board; 12. lower chuck; 13. upper chuck; 14. upper insulating board; 15. spring; 16. connecting shaft; 17. horizontal handle-type clamp. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] In combination with the accompanying drawings and specific embodiments, the present utility model will be further described. It should be understood that these embodiments are only used to illustrate the present utility model and not to limit the scope of the present utility model. In addition, it should be understood that after reading the content taught by the present utility model, those skilled in the art can make various changes or modifications to the present utility model, and these equivalent forms also fall within the scope defined by this application.

[0027] This embodiment provides a tungsten wire electro-annealing device.

[0028] In this application, the tungsten wire electro-annealing device utilizes the low resistivity and thermal stability of tungsten wire, enabling it to withstand a greater current density during the energization of thin wires. According to the principle that a conductor generates heat when current passes through it, which is caused by the frictional force generated by the movement of electrons in the conductor. When the current density increases, the movement of electrons in the conductor also speeds up, resulting in more heat generation. According to Ohm's law, the relationship between current and resistance can be expressed as I = V / R, where I is the current, V is the voltage, and R is the resistance. Therefore, it can be concluded that when the voltage is constant, the current is inversely proportional to the resistance. The greater the current, the smaller the resistance, and the greater the heat generated by the conductor.

[0029] When current passes through a conductor, the length of time also affects the heat generated. The amount of heat can be expressed by Joule's law of heat: Q = I^2RT, where Q is the heat, I is the current, R is the resistance, and T is the time. This formula shows that when the current and resistance are constant, the heat is proportional to the time. That is, the longer the time the current passes through the conductor, the greater the heat.

[0030] The wire current density refers to the magnitude of the current passing through a unit cross-sectional area, usually expressed in A / mm². The calculation formula for current density is: J = I / A, where I is the current, J is the current density, and A is the cross-sectional area vector. In an electrical circuit, the current density of a wire is a very important parameter because the maximum current that a wire can withstand is jointly determined by its cross-sectional area and the maximum current density that the material can withstand.

[0031] In summary, it can be seen that when the voltage applied across the conductor is constant and the cross-sectional area is constant, the current density of the conductor is constant. Theoretically, when the resistance, voltage, and time are constant, the current is constant, and thus the heat generated is also constant.

[0032] According to the special properties of tungsten wire, referring to Figure 1 As shown, this annealing device mainly includes a wire pay-off reel 1, a front conductive chuck 3, a rear conductive chuck 4, and a wire drawing machine 5 arranged in sequence. The tungsten wire 2 passes through the wire pay-off reel 1, the front conductive chuck 3, the rear conductive chuck 4, and the wire drawing machine 5 and finally enters the take-up reel. The tungsten wire 2 is heated and annealed by the front conductive chuck 3 and the rear conductive chuck 4.

[0033] In this embodiment, the front conductive chuck 3 and the rear conductive chuck 4 are respectively connected to the positive and negative poles of the electronic control system 7 through a power cord 6. The electronic control system 7 is energized to heat the tungsten wire 2. Among them, a thermometer for monitoring the temperature of the tungsten wire 2 is provided between the front conductive chuck 3 and the rear conductive chuck 4. The temperature information of the tungsten wire 2 after heating is fed back through the thermometer, so that the electronic control system 7 can be adjusted to ensure the annealing quality of the tungsten wire 2.

[0034] In this application, both the front-end conductive chuck 3 and the rear-end conductive chuck 4 include an upper chuck 13 and a lower chuck 12. Among them, fine tungsten wires are wound around both the upper chuck 13 and the lower chuck 12. The contact surface is evenly wound with 30-μm fine tungsten wires to increase the heat resistance performance so that the chuck will not be damaged during the high-temperature process.

[0035] In this application, the upper chuck 13 is connected to a horizontal handle-type clamp 17 to facilitate rapid wire threading. Among them, a connecting shaft 16 is provided on the horizontal handle-type clamp 17, a spring 15 is provided on the connecting shaft 16, the connecting shaft 16 is a threaded shaft, and its position on the horizontal handle-type clamp 17 is adjusted by bolts. A slidable upper bakelite board 14 is installed at the bottom, and the upper chuck 13 is installed below the upper bakelite board 14. The spring 15 applies a downward force to the upper bakelite board 14, thereby adjusting the clamping force on the tungsten wire between the upper chuck 13 and the lower chuck 12.

[0036] In this application, the lower chuck 12 is installed on a bracket. The bracket includes a bottom plate 8, a lower connecting column 9 of the bracket, and an upper connecting column 10 of the bracket. The bottom plate 8 has long slots, and the distance between the two lower connecting columns 9 of the bracket can be adjusted to adjust the distance between the front-end conductive chuck 3 and the rear-end conductive chuck 4. Long slots are provided between the upper connecting column 10 of the bracket and the lower connecting column 9 of the bracket to adjust the height of the upper connecting column 10 of the bracket, thereby adjusting the height of the front-end conductive chuck 3 and the rear-end conductive chuck 4. The bottom plate 8 is made of an electrically insulating wooden board, and a lower bakelite board 11 is provided between the upper connecting column 10 of the bracket and the lower chuck 12 to ensure the insulation performance.

[0037] In this application, after the tungsten wire is manually threaded in sequence according to the structure, the clamping force of the conductive chuck can be adjusted to adjust the contact force between the tungsten wire and the chuck surface. The contact surface of the conductive chuck is evenly wound with 30-μm fine tungsten wires to increase the heat resistance performance so that the chuck will not be damaged during the high-temperature process. Moreover, heat-insulating bakelite boards are added to the upper and lower ends of the conductive chuck to achieve the effects of insulation and heat insulation. Due to the excellent electrical conductivity and low resistivity of the tungsten wire, a load voltage of 0-36V is usually used, and the safety voltage ensures that the operator will not be at risk of electric shock.

[0038] After adjusting the clamping force of the chuck, the wire drawing machine 5 can be started to operate normally. At the same time, the electric annealing device is started, and the process temperature is set. The voltage is adjusted to the process temperature by using the temperature feedback of the thermometer. When the temperature tends to be stable, the electric control system 7 is adjusted to the automatic mode. After that, the voltage value will be automatically calibrated and finely adjusted according to the temperature signal feedback by the thermometer. This process is to eliminate the possible influence of two problem points on the annealing temperature: According to Q = I^2RT, where Q is heat, I is current, R is resistance, and T is time. 1) The unstable speed change of the rear-end wire drawing machine leads to unstable speed, that is, the heat change caused by the change of the over-current time of the tungsten wire clamped in the chuck. 2) Due to the possible uneven wire diameter deviation during the wire drawing process of the front-end equipment, the surface area changes, resulting in a change in resistance and a temperature change. Considering that R resistance and T time will change, according to Q = I^2RT, the current value can be adjusted. And according to I = V / R, where I is current, V is voltage, and R is resistance. When the voltage is constant, the current is inversely proportional to the resistance. The larger the current, the smaller the resistance, and the greater the heat of the conductor. Thus, it can be known that when the resistance becomes smaller (larger), the current will become larger (smaller). In this process, the electric control system 7 performs PID automatic adjustment according to the feedback temperature parameter and the set temperature parameter to make the temperature value tend to be stable, so as to ensure the annealing quality of the tungsten wire.

Claims

1. An electric annealing device for tungsten diamond wire, comprising a pay-off wheel and a wire drawing machine, characterized in that: A front end conductive chuck and a rear end conductive chuck are arranged at a certain distance between the pay-off wheel and the wire drawing machine. The tungsten wire enters the take-up reel through the pay-off wheel, the front end conductive chuck, the rear end conductive chuck and the wire drawing machine in sequence. The front end conductive chuck and the rear end conductive chuck are connected to the positive and negative poles of the electric control system through a power line. A thermometer for monitoring the temperature of the tungsten wire is arranged between the front end conductive chuck and the rear end conductive chuck. The thermometer is connected to the electric control system through an electrical signal.

2. The electrical annealing device for tungsten diamond wire according to claim 1, characterized in that: The front end conductive chuck and the rear end conductive chuck both include an upper chuck and a lower chuck, and tungsten wires are wound around the upper chuck and the lower chuck.

3. The electrical annealing device for tungsten diamond wire according to claim 2, characterized in that: The upper clamp is connected with a horizontal handle type clamp.

4. The electrical annealing device for tungsten diamond wire according to claim 3, characterized in that: A connecting shaft is arranged on the horizontal handle type clamp, the upper clamp is mounted on the upper bakelite board, the upper bakelite board is mounted on the connecting shaft, and a spring is sleeved on the connecting shaft for adjusting the downward pressure of the upper clamp.

5. The electrical annealing device for tungsten diamond wire according to claim 2, characterized in that: The lower clamp is installed on the bracket, and a lower bakelite board is arranged between the lower clamp and the bracket.

6. The electrical annealing device for tungsten diamond wire according to claim 5, characterized in that: The bracket includes a base plate, a lower bracket connecting column and an upper bracket connecting column. The lower bracket connecting column is installed on the base plate, the upper bracket connecting column is installed on the lower bracket connecting column and can be adjusted up and down, and the lower clamp is installed on the upper bracket connecting column.

7. The electrical annealing device for tungsten diamond wire according to claim 6, characterized in that: The spacing between the connecting columns under the bracket corresponding to the front conductive clamp and the rear conductive clamp is adjustable.

8. The electrical annealing device for tungsten diamond wire according to claim 6, characterized in that: The bottom plate is a bakelite plate.

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