A cooling device and a cooling method for a rotating mirror of a laser cleaning machine

Abstract

The present application relates to a kind of cooling device for laser cleaning machine rotating mirror, including cooling working medium supply and stabilizing system, rotating mirror control system, temperature pressure control system, rotating mirror control system provides power for rotating mirror rotation, cooling working medium supply and stabilizing system is cooled to rotating mirror, temperature pressure control system adjusts the output of cooling working medium.It also relates to a kind of cooling method for laser cleaning machine rotating mirror, including data processor to the temperature signal, pressure signal received by data collector carries out data processing, is transmitted to electric valve controller by feedback controller, electric valve controller adjusts the opening of pressure reducing valve, to control cooling working medium flow, reach the goal of controlling rotating mirror temperature.The present application carries out individual cooling to rotating mirror, guarantees the stability of laser cleaning machine light path.Slit type impact nozzle is used, higher rotating mirror outer surface heat exchange coefficient is obtained, applicable to laser cleaning machine under higher heating power condition work.

Description

Technical Field

[0001] This invention belongs to the field of laser cleaning technology, and specifically relates to a cooling device for a rotating mirror in a laser cleaning machine. Background Technology

[0002] Laser cleaning machines utilize ultra-high-power lasers to irradiate the surface to be cleaned. The focused laser rapidly heats the impurities on the surface, causing them to burn or vaporize instantly, thus cleaning the surface. To reduce the movement range of the laser head and increase cleaning efficiency, a reciprocating optical path system is added to achieve a wide-range, high-speed reciprocating motion of the laser spot. In this system, a rotating mirror is a commonly used key component. Since the light reflectivity of the rotating mirror surface cannot reach 100%, some heat remains on the mirror surface and inside after the ultra-high-power laser irradiates it. To prevent damage to the mirror from high temperatures, excessive thermal stress due to large internal and external temperature differences, and optical path distortion caused by thermal deformation due to temperature rise, active cooling is required for key areas of the mirror.

[0003] When the heat inside the rotating mirror cavity cannot be effectively dissipated, the temperature inside the cavity continues to rise. The thermal expansion of the fixed components of the rotating mirror structure causes thermal deformation, affecting the optical path structure and reducing the output light quality of the laser cleaning machine. Furthermore, the long-term reliable operation of the rotating mirror depends on controlling the working environment of the mirror body and the surface light-reflecting film within an appropriate range. However, existing laser cleaning equipment with rotating mirrors does not employ a dedicated device for cooling and temperature control of the rotating mirror components, highlighting the importance of this invention.

[0004] The shortcomings of existing laser cleaning machine rotating mirror cooling are: existing laser cleaning machines lack separate cooling for the rotating mirror system. If the rotating mirror is not effectively cooled during long-term operation, it will cause damage to the coating on the outer surface of the rotating part. If heat accumulates for a long time and is not effectively dissipated, the temperature difference between the inside and outside of the rotating mirror will be too large, which may also lead to the mirror body cracking due to excessive thermal stress. If the rotating mirror is cooled at the same time, the temperature of the rotating mirror cavity can be effectively reduced, thereby reducing the thermal deformation of the entire rotating mirror cavity wall and thus effectively ensuring the stability of the optical path. Summary of the Invention

[0005] To address the shortcomings of insufficient cooling for rotating mirrors in laser cleaning equipment, which leads to thermal deformation of the rotating mirror cavity due to inadequate cooling and consequently affects the light output quality, this invention proposes a cooling device for rotating mirrors in laser cleaning machines.

[0006] The technical solution adopted by this invention to solve its technical problem is as follows:

[0007] A cooling device for a rotating mirror in a laser cleaning machine includes a cooling medium supply and stabilization system, a rotating mirror control system, and a temperature and pressure control system.

[0008] The cooling device uses the rotating mirror of the laser cleaning machine as the object of cooling. The rotating mirror control system provides power for the rotation of the mirror, and the cooling medium supply and stabilization system cools the mirror. The temperature and pressure control system collects the mirror temperature and the pressure entering the nozzle in the cooling medium supply and stabilization system, processes the data, and feeds it back to the cooling medium supply and stabilization system, which then adjusts the output of the cooling medium.

[0009] The temperature and pressure control system includes a pressure sensor, a temperature sensor, a data acquisition unit, a data processor, and a feedback controller.

[0010] The pressure sensor is connected to the cooling fluid supply and stabilization system, receives the pressure entering the nozzle, and outputs a pressure signal to the data acquisition unit.

[0011] The temperature sensor is located on the surface of the rotating mirror, converting the mirror's temperature into an electrical signal and transmitting it to the data acquisition unit. The data acquisition unit sends the received temperature signal from the rotating mirror and the pressure signal from the pressure sensor to the data processor. The data processor processes the temperature and pressure signals received by the data acquisition unit and transmits them to the cooling fluid supply and stabilization system through the feedback controller, thereby controlling the ambient temperature around the rotating mirror.

[0012] The aforementioned cooling device for the rotating mirror of a laser cleaning machine, the temperature and pressure control system further includes a coupling and a conductive slip ring.

[0013] The coupling connects the rotating mirror and the conductive slip ring, which transmits the electrical signal collected by the temperature sensor to the data acquisition unit.

[0014] The cooling device for the rotating mirror of the laser cleaning machine described above includes a nitrogen cylinder, an electric valve controller, a pressure reducing valve, a liquid nitrogen tank, and a nozzle.

[0015] The nitrogen cylinder, the pressure reducing valve, the liquid nitrogen tank, and the nozzle are connected in sequence. Nitrogen gas from the nitrogen cylinder enters the liquid nitrogen tank through the pressure reducing valve, and the liquid nitrogen tank outputs a cooling medium to the nozzle. The nozzle is a slit-type impact nozzle that sprays the cooling medium to cool the rotating mirror.

[0016] The pressure sensor is located on the pipeline from the liquid nitrogen tank to the nozzle, and receives the pressure entering the nozzle pipeline and outputs a pressure signal.

[0017] The electric valve controller is connected to the pressure reducing valve and the feedback controller, and receives instructions from the feedback controller to control the opening degree of the pressure reducing valve.

[0018] The cooling device for the rotating mirror of the laser cleaning machine described above, the cooling working fluid supply and stabilization system also includes a gas cylinder valve, an inlet valve, a self-pressurizing valve, an exhaust valve, a drain valve, and a pressure gauge.

[0019] The gas cylinder valve is located between the nitrogen cylinder and the pressure reducing valve, and the inlet valve is located between the pressure reducing valve and the liquid nitrogen tank. The self-pressurizing valve is connected to the liquid nitrogen tank and is used to adjust the liquid nitrogen pressure in the liquid nitrogen tank. The vent valve and the drain valve are both located between the liquid nitrogen tank and the nozzle. The vent valve is used to regulate the nitrogen flow rate from the liquid nitrogen tank to the nozzle, and the drain valve is used to regulate the liquid nitrogen flow rate from the liquid nitrogen tank to the nozzle.

[0020] There are a total of 3 pressure gauges to display the pressure. Two are located on the pipeline between the nitrogen cylinder and the pressure reducing valve, and between the pressure reducing valve and the inlet valve, respectively. One is used to display the pressure inside the liquid nitrogen tank and is connected to the liquid nitrogen tank.

[0021] The cooling device for the rotating mirror of the laser cleaning machine described above, wherein the rotating mirror control system includes a rotating mirror, a rotating mirror motor, a rotating mirror motor controller, and a motor controller power supply.

[0022] The rotating mirror motor controller controls the rotation of the rotating mirror motor, and the rotating mirror rotates under the drive of the rotating mirror motor. The power supply of the motor controller provides power to the rotating mirror motor and the rotating mirror motor controller.

[0023] A cooling method for a rotating mirror in a laser cleaning machine includes the following steps:

[0024] The temperature of the rotating mirror surface is collected and fed back to the cooling medium supply and stabilization system through data processing. The cooling medium supply and stabilization system adjusts the form and output of the cooling medium. The form of the cooling medium is low-temperature cold nitrogen gas or liquid nitrogen.

[0025] In the above-mentioned cooling method for the rotating mirror of a laser cleaning machine, the low-temperature cold nitrogen is obtained by filling room-temperature nitrogen into a liquid nitrogen tank, and then evaporating the liquid nitrogen in the tank while simultaneously cooling the room-temperature nitrogen with the heat absorbed by the evaporating liquid nitrogen; the liquid nitrogen is obtained by filling room-temperature nitrogen into a liquid nitrogen tank and then discharging the liquid nitrogen.

[0026] The beneficial effects of this invention are:

[0027] A cooling device for a rotating mirror in a laser cleaning machine combines the characteristics of existing liquid nitrogen tanks, which can release both cryogenic cold nitrogen gas and liquid nitrogen, in an open environment. By using cryogenic cold nitrogen gas or liquid nitrogen as the cooling medium for the rotating mirror, the outer surface temperature of the rotating mirror is controlled to be below 70°C, effectively suppressing the thermal deformation of the rotating mirror cavity.

[0028] A cooling device for a rotating mirror in a laser cleaning machine uses liquid nitrogen / cryo-cold nitrogen as the cooling medium, a liquid nitrogen tank as the cooling medium container, and a high-pressure nitrogen cylinder and a pressure reducing valve as the main components of the pressure stabilization system. It can stably regulate the pressure inside the liquid nitrogen tank within the target range, thereby achieving the purpose of controlling the flow rate of cryogenic cold nitrogen or liquid nitrogen by controlling the pressure inside the liquid nitrogen tank.

[0029] A cooling device for a rotating mirror in a laser cleaning machine is provided. The rotating mirror is controlled by a motor control system and is equipped with a conductive slip ring, which enables the measurement of the temperature distribution on the outer surface of the rotating mirror under different rotation speeds.

[0030] A cooling device for a rotating mirror in a laser cleaning machine. Since the outer surface of the rotating mirror has a certain width, when using low-temperature cold nitrogen as the cooling medium, a slit-type impact nozzle can be used to obtain a higher heat transfer coefficient on the outer surface of the rotating mirror, thereby achieving effective cooling of the reflective surface of the rotating mirror when the laser cleaning machine is operating under higher heating power conditions. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the device system of the present invention;

[0032] Figure 2 This is a schematic diagram of the device connection relationship of the present invention.

[0033] In the diagram: 1. Cooling medium supply and stabilization system; 2. Rotating mirror control system; 3. Temperature and pressure control system; 4. Nitrogen cylinder; 5-1. Cylinder valve; 5-2. Inlet valve; 5-3. Self-pressurizing valve; 5-4. Exhaust valve; 5-5. Drain valve; 6. Electric valve controller; 7. Pressure reducing valve; 8. Liquid nitrogen tank; 9. Pressure gauge; 10. Nozzle; 11. Pressure sensor; 12. Rotating mirror; 13. Temperature sensor; 14. Coupling; 15. Data acquisition unit; 16. Conductive slip ring; 17. Rotating mirror motor; 18. Rotating mirror motor controller; 19. Power supply; 20. Data processor; 21. Feedback controller. Detailed Implementation

[0034] Example 1

[0035] A rotating mirror cooling device for a laser cleaning machine mainly includes a cooling medium supply and stabilization system 1, a rotating mirror control system 2, and a temperature and pressure control system 3, such as... Figure 1 As shown.

[0036] like Figure 1As shown, the rotating mirror 12 is driven by the rotating mirror control system 2, and the temperature and pressure control system 3 is connected to the rotating mirror 12 via a shaft system. The cooling medium supply and stabilization system 1 is not directly connected to the rotating mirror control system 2 and the temperature and pressure control system 3. Temperature sensors 13 are attached to the outer surface and key positions of the rotating mirror 12, and pressure sensors 11 are arranged in the pipeline at the front end of the cooling medium nozzle 10, thereby connecting the temperature and pressure control system 3 with the other subsystems. In the cooling medium supply and stabilization system 1, the cooling medium with relatively stable temperature and pressure cools the high-temperature area on the outer surface of the rotating mirror 12, while creating a low-temperature environment around the rotating mirror 12 during the flow process, thereby controlling the temperature of the surrounding environment.

[0037] The cooling medium supply and stabilization system 1 mainly consists of a liquid nitrogen tank 8, a pressure gauge 9, a high-pressure nitrogen cylinder 4, a pressure reducing valve 7, an electric valve controller 6, and piping, such as... Figure 2 As shown.

[0038] like Figure 2 As shown, liquid nitrogen tank 8 is filled with liquid nitrogen. The top of the tank has an inlet valve 5-2, a drain valve 5-5, an exhaust valve 5-4, a pressure gauge 9, and a self-pressurizing valve 5-3. The drain valve is used to regulate the liquid nitrogen flow rate, the exhaust valve is used to regulate the nitrogen flow rate, the pressure gauge is used to display the pressure inside the liquid nitrogen tank, and the self-pressurizing valve is used to increase the liquid nitrogen pressure inside the tank. A high-pressure nitrogen cylinder 4 is used to provide sufficient pressure differential to liquid nitrogen tank 8 to maintain pressure stability when the pressure inside the liquid nitrogen tank cannot be maintained. A pressure reducing valve 7 is used to reduce the high-pressure gas in the high-pressure nitrogen cylinder to the required pressure value. An electric valve controller 6 is used to receive temperature feedback and regulate the opening of the pressure reducing valve. A liquid nitrogen nozzle 10 is used to control the cooling medium leaving the cooling medium supply and stabilization system to produce a specific spraying effect, such as a mist or a layered appearance.

[0039] The rotating mirror control system 2 mainly consists of a rotating mirror 12, a rotating mirror motor 17, a rotating mirror motor controller 18, and a motor controller power supply 19, etc. Figure 2 As shown.

[0040] The rotating mirror 12 is a rotating component in the laser cleaning equipment that reflects high-energy laser light; the rotating mirror motor 17 drives the rotating mirror 12 to rotate; the rotating mirror motor controller 18 regulates key driving parameters such as the rotation speed and drive current of the rotating mirror motor 17; the power supply 19 of the motor controller supplies power to the rotating mirror motor 17 and the rotating mirror motor driver 18, such as... Figure 2 As shown.

[0041] The temperature and pressure control system 3 mainly consists of a temperature sensor 13, a coupling 14, a conductive slip ring 16, a pressure sensor 11, a data acquisition unit 15, and a feedback controller 21, etc. Figure 2 As shown.

[0042] Temperature sensor 13 is used to convert the temperature signal of the part to be measured in the system into an electrical signal for data acquisition device 15 to collect and record; coupling 14 is used to connect rotating mirror 12 and conductive slip ring 16, and weaken the system vibration caused by the different axiality between rotating mirror 12 and conductive slip ring 16; conductive slip ring 16 is used to transmit the electrical signal collected by temperature sensor 13 in the rotating state to the stationary data acquisition device 15; pressure sensor 13 is used to collect the pressure of the cooling medium in the pipeline before it leaves the nozzle; temperature and pressure control system 3 will perform feedback regulation on electric valve controller 6 in cooling medium supply and stabilization system 1 according to the temperature and pressure signals collected by temperature and pressure sensor 11. When the surface temperature of rotating mirror 12 is too high, the opening of pressure reducing valve 7 is increased to increase the pressure in liquid nitrogen tank 8 and thus increase the flow rate of cooling medium. When the surface temperature of rotating mirror 12 is too low, the opening of pressure reducing valve 7 is decreased to reduce the pressure in liquid nitrogen tank 8 and thus decrease the flow rate of cooling medium.

[0043] The cooling medium is either cryogenic cold nitrogen or liquid nitrogen. Cryogenic cold nitrogen is obtained by filling a liquid nitrogen tank with room temperature nitrogen, causing the liquid nitrogen to evaporate and simultaneously cooling the room temperature nitrogen with the heat absorbed by the evaporating liquid nitrogen. Liquid nitrogen is obtained by filling a liquid nitrogen tank with room temperature nitrogen and then draining the liquid nitrogen.

Claims

1. A cooling device for a rotating mirror in a laser cleaning machine, characterized in that, Includes a cooling working fluid supply and stabilization system (1), a rotating mirror control system (2), and a temperature and pressure control system (3). The cooling device uses the rotating mirror (12) of the laser cleaning machine as the object of cooling. The rotating mirror control system (2) provides power for the rotation of the rotating mirror (12), and the cooling medium supply and stabilization system (1) cools the rotating mirror (12). The temperature and pressure control system (3) collects the temperature of the rotating mirror (12) and the pressure of the nozzle (10) entering the cooling medium supply and stabilization system (1), and feeds the data back to the cooling medium supply and stabilization system (1) through data processing. The cooling medium supply and stabilization system (1) adjusts the output of the cooling medium. The temperature and pressure control system (3) includes a pressure sensor (11), a temperature sensor (13), a data acquisition unit (15), a data processor (20), and a feedback controller (21). The pressure sensor (11) is connected to the cooling working fluid supply and stabilization system (1), receives the pressure entering the nozzle (10) and outputs the pressure signal to the data acquisition unit (15). The temperature sensor (13) is located on the surface of the rotating mirror (12), converts the temperature of the rotating mirror (12) into an electrical signal, and transmits it to the data acquisition unit (15); the data acquisition unit (15) sends the received temperature signal of the rotating mirror (12) and the pressure signal of the pressure sensor (11) to the data processor (20); the data processor (20) processes the temperature signal and pressure signal received by the data acquisition unit (15), and transmits them to the cooling working fluid supply and stabilization system (1) through the feedback controller (21) to realize the control of the ambient temperature around the rotating mirror (12); The temperature and pressure control system (3) also includes a coupling (14) and a conductive slip ring (16). The coupling (14) connects the rotating mirror (12) and the conductive slip ring (16), and the conductive slip ring (16) transmits the electrical signal collected by the temperature sensor (13) to the data acquisition unit (15). The cooling working fluid supply and stabilization system (1) includes a nitrogen cylinder (4), an electric valve controller (6), a pressure reducing valve (7), a liquid nitrogen tank (8), and a nozzle (10). The nitrogen cylinder (4), the pressure reducing valve (7), the liquid nitrogen tank (8), and the nozzle (10) are connected in sequence. The nitrogen gas in the nitrogen cylinder (4) enters the liquid nitrogen tank (8) through the pressure reducing valve (7), and the liquid nitrogen tank (8) outputs the cooling medium to the nozzle (10). The nozzle (10) is a slit-type impact nozzle that sprays out the cooling medium to cool the rotating mirror (12). The pressure sensor (11) is located on the pipeline from the liquid nitrogen tank (8) to the nozzle (10), receives the pressure entering the pipeline of the nozzle (10) and outputs a pressure signal; The electric valve controller (6) is connected to the pressure reducing valve (7) and the feedback controller (21), and receives instructions from the feedback controller (21) to control the opening degree of the pressure reducing valve (7).

2. The cooling device for the rotating mirror of a laser cleaning machine according to claim 1, characterized in that, The cooling working fluid supply and stabilization system (1) also includes an exhaust pipe, a drain pipe, an exhaust valve, and a drain valve; One end of the exhaust pipe is located above the liquid nitrogen tank, and the other end is connected to the nozzle (10) through the exhaust valve; The exhaust valve is used to regulate the flow rate of cryogenic nitrogen from the liquid nitrogen tank (8) to the nozzle (10); One end of the drain pipe is located inside the liquid nitrogen tank at the bottom, and the other end is connected to the nozzle (10) through the drain valve; The drain valve is used to regulate the flow rate of liquid nitrogen from the liquid nitrogen tank (8) to the nozzle (10).

3. The cooling device for the rotating mirror of a laser cleaning machine according to claim 2, characterized in that, The cooling working fluid supply and stabilization system (1) also includes a gas cylinder valve, an inlet valve, a self-pressurizing valve, and a pressure gauge (9). The gas cylinder valve is located between the nitrogen cylinder (4) and the pressure reducing valve (7), and the inlet valve is located between the pressure reducing valve (7) and the liquid nitrogen tank (8); the self-pressurizing valve is connected to the liquid nitrogen tank (8) and is used to adjust the liquid nitrogen pressure of the liquid nitrogen tank (8); There are 3 pressure gauges (9) in total, which are used to display pressure. Two are located on the pipeline between the nitrogen cylinder (4) and the pressure reducing valve (7) and between the pressure reducing valve (7) and the inlet valve, respectively. One is used to display the pressure inside the liquid nitrogen tank (8) and is connected to the liquid nitrogen tank (8).

4. The cooling device for the rotating mirror of a laser cleaning machine according to claim 1, characterized in that, The rotating mirror control system (2) includes a rotating mirror (12), a rotating mirror motor (17), a rotating mirror motor controller (18), and a motor controller power supply (19). The rotating mirror motor controller (18) controls the rotating mirror motor (17) to rotate, and the rotating mirror (12) rotates under the drive of the rotating mirror motor (17). The motor controller power supply (19) supplies power to the rotating mirror motor (17) and the rotating mirror motor controller (18).

5. A cooling method for a rotating mirror in a laser cleaning machine, employing the cooling device for a rotating mirror in a laser cleaning machine as described in any one of claims 1-4, characterized in that, Includes the following steps: The temperature of the surface of the rotating mirror (12) is collected and fed back to the cooling medium supply and stabilization system (1) through data processing. The cooling medium supply and stabilization system (1) adjusts the form and output of the cooling medium. The form of the cooling medium is low-temperature cold nitrogen or liquid nitrogen.

6. The cooling method for the rotating mirror of a laser cleaning machine according to claim 5, characterized in that, The low-temperature cold nitrogen is obtained by filling room-temperature nitrogen into a liquid nitrogen tank, then evaporating the liquid nitrogen in the tank and simultaneously cooling the room-temperature nitrogen with the heat absorbed by the evaporating liquid nitrogen; the liquid nitrogen is obtained by filling room-temperature nitrogen into a liquid nitrogen tank and then discharging the liquid nitrogen.

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