Dry cleaning and low temperature microlubrication combined system and working method

Abstract

The application discloses a dry cleaning and low-temperature micro-lubrication combined system and a working method, solves the problem that workpiece lubrication and chip processing are separately processed in the prior art, has the beneficial effect of convenient operation, and specifically has the following technical scheme: a dry cleaning and low-temperature micro-lubrication combined system, which comprises a liquid carbon dioxide bottle, a primary valve, a first valve and a cooling bin which are sequentially connected, part of liquid carbon dioxide is decompressed by the primary valve to form gaseous carbon dioxide from the liquid carbon dioxide bottle, the liquid carbon dioxide and the gaseous carbon dioxide can flow to the cooling bin through a pressure reducing valve after passing through the first valve, or can be divided into two paths, one path directly flows to a heat exchange pipeline in the cooling bin, and the other path is converted into gaseous carbon dioxide after passing through the pressure reducing valve and flows to the cooling bin, and the gaseous carbon dioxide discharged from the cooling bin can enter an adjustable nozzle or a gas-liquid mixed nozzle after passing through a second valve.

Description

Technical Field

[0001] This invention relates to the field of milling fluid supply and chip removal in machining, and in particular to a dry cleaning and low-temperature micro-lubrication combined system and working method. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Cryogenic Minimum Quantity Lubrication (CMQL) is an advanced machining technology that combines cryogenic cooling and micro-lubrication. It achieves highly efficient cooling and lubrication by using a cryogenic medium combined with a small amount of lubricating oil. This technology demonstrates significant advantages when machining difficult-to-machine materials, not only meeting the requirements of green manufacturing but also significantly improving machining efficiency and workpiece surface quality.

[0004] Carbon dioxide dry cleaning technology is an environmentally friendly and efficient cleaning method that primarily utilizes the different physical states of carbon dioxide to remove surface contaminants. This technology is not only environmentally friendly but also effectively removes various types of contaminants, and is widely used in industries such as manufacturing, electronics, and food processing.

[0005] Difficult-to-machine materials such as titanium alloys present several challenges during milling due to their unique physical properties. First, titanium alloys have low thermal conductivity, making it difficult to dissipate heat generated during cutting. This heat tends to accumulate in the cutting area, leading to excessive tool wear and cracking, and shortening tool life. Second, titanium alloys have a low modulus of elasticity, meaning they are prone to elastic deformation during machining, resulting in burrs, especially noticeable when machining thin-walled or ring-shaped parts. This affects machining accuracy and surface finish. Furthermore, titanium alloys have a strong affinity for the cutting tool material, easily causing chips to accumulate and become entangled on the tool. This not only hinders the cutting process but can also damage the tool. Titanium alloys are also prone to vibration during machining, which further affects cutting stability and machining quality.

[0006] To address the aforementioned problems, existing technologies employ carbon dioxide for workpiece cleaning. For example, Chinese patent application CN201920035075.1 discloses a carbon dioxide snowflake cleaning system. This system maintains the pressure of carbon dioxide entering the cleaning nozzle at 55-70 bar by connecting multiple carbon dioxide cylinders in parallel. Compressed gas, generated by a compressed gas source, accelerates the ejection of carbon dioxide snowflakes formed when liquid carbon dioxide is sprayed out. However, the disclosed technical solution requires an additional gas compression device to generate compressed gas to carry the carbon dioxide snowflakes out. The formation mechanism of the carbon dioxide snowflakes varies depending on the medium used to carry them out.

[0007] In addition, existing technologies also include a solution of lubricating the workpiece by mixing carbon dioxide and lubricating oil. Oil lubrication is used during the tool machining process, and the supply of lubricating oil is cut off after machining is completed. However, there are chips on the surface of the workpiece at this time, which need to be dealt with in time. If they are not dealt with in time, it will affect the subsequent machining. Existing technologies also use other air sources to deal with chips, but they require manual control, which results in insufficient response time. Moreover, multiple air sources need to be set up, which is not easy to operate. Summary of the Invention

[0008] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a dry cleaning and low-temperature micro-lubrication combined system to solve existing problems such as liquid supply and chip removal.

[0009] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0010] A dry cleaning and low-temperature micro-lubrication combined system includes a liquid carbon dioxide cylinder, a primary valve, a first valve, and a cooling chamber connected in sequence. Part of the liquid carbon dioxide from the liquid carbon dioxide cylinder is depressurized through the primary valve to form gaseous carbon dioxide. The liquid carbon dioxide and gaseous carbon dioxide pass through the first valve and can flow towards the cooling chamber through the pressure reducing valve, or they can be divided into two paths: one path flows directly to the heat exchange pipes inside the cooling chamber, and the other path, after passing through the pressure reducing valve, converts the liquid carbon dioxide into gaseous carbon dioxide and flows into the cooling chamber. During the conversion to gaseous carbon dioxide, the temperature rises. The liquid carbon dioxide discharged from the heat exchange pipes of the cooling chamber enters an adjustable nozzle. The gaseous carbon dioxide discharged from the cooling chamber can enter the adjustable nozzle or the gas-liquid mixing nozzle after passing through the second valve. The gaseous carbon dioxide entering the adjustable nozzle mixes with the liquid carbon dioxide to perform dry cleaning on the workpiece, and the gaseous carbon dioxide entering the gas-liquid mixing nozzle mixes with lubricating oil to perform low-temperature lubrication on the workpiece.

[0011] As described above, in a dry cleaning and low-temperature micro-lubrication combined system, the first valve and the second valve are respectively connected to a control unit. The control unit is connected to a milling machine control system to transmit the milling cutter entry and exit signals to the control unit. When the milling cutter enters, the gas-liquid mixing nozzle operates and the adjustable nozzle closes. When the milling cutter exits, the adjustable nozzle operates and the gas-liquid mixing nozzle closes.

[0012] In the dry cleaning and low-temperature micro-lubrication combined system described above, when the milling cutter cuts in, the passage between the first valve and the heat exchange pipeline is closed, the passage between the first valve and the pressure reducing valve is open, the passage between the second valve and the adjustable nozzle is closed, and the passage between the second valve and the gas-liquid mixing nozzle is open.

[0013] In the dry cleaning and low-temperature micro-lubrication combined system described above, when the milling cutter cuts out, the passage between the first valve and the heat exchange pipeline and the pressure reducing valve are all open, the passage between the second valve and the gas-liquid mixing nozzle is closed, and the passage between the second valve and the adjustable nozzle is open.

[0014] As described above, in a dry cleaning and low-temperature micro-lubrication combined system, the gas-liquid mixing nozzle is connected to a micro-lubricating oil pump, which is connected to the control unit. The micro-lubricating oil pump can directly adjust the lubricant flow rate, reducing the need for additional valves.

[0015] The gas-liquid mixing nozzle and the adjustable nozzle are respectively placed on both sides of the milling cutter, and both the gas-liquid mixing nozzle and the adjustable nozzle are inclined relative to the central axis of the milling cutter.

[0016] In the dry cleaning and low-temperature micro-lubrication combined system described above, the heat exchange pipelines in the cooling chamber are arranged in a spiral shape.

[0017] In the dry cleaning and low-temperature micro-lubrication combined system described above, a flow meter is installed between the cooling chamber and the second valve. The flow meter is connected to the control unit and can adjust the flow rate and pressure of the cold air.

[0018] As described above, in a dry cleaning and low-temperature micro-lubrication combined system, the first valve includes a housing, a carbon dioxide inlet on one side of the housing, a partition inside the housing, and a distance between the partition and the carbon dioxide inlet. The housing supports a rotary power source, which is connected to the partition to drive the partition to rotate relative to the housing. The partition has a fan-shaped area, and an arc-shaped hole is provided on the periphery of the fan-shaped area. The housing has a first outlet and a second outlet. During the rotation of the partition, the arc-shaped hole is connected to at least one of the first outlet and the second outlet.

[0019] In the dry cleaning and low-temperature micro-lubrication combined system described above, the structure of the first valve is the same as that of the second valve, and the angle of the arc-shaped orifice is greater than 180°.

[0020] Secondly, the present invention also provides a method for operating a dry cleaning and low-temperature micro-lubrication combined system, comprising the following:

[0021] Liquid carbon dioxide is discharged from the liquid carbon dioxide bottle, and some of the liquid carbon dioxide is depressurized through the first-stage valve to form gaseous carbon dioxide;

[0022] Liquid carbon dioxide and gaseous carbon dioxide pass through the first valve and then through the pressure reducing valve. The liquid carbon dioxide is converted into gaseous carbon dioxide and flows into the cooling chamber. During the conversion into gaseous carbon dioxide, the temperature rises and the gaseous carbon dioxide enters the cooling chamber. The gaseous carbon dioxide discharged from the cooling chamber enters the second valve and flows through the second valve to the gas-liquid mixing nozzle. The gaseous carbon dioxide entering the gas-liquid mixing nozzle mixes with the lubricating oil to lubricate the workpiece at low temperature.

[0023] Alternatively, liquid carbon dioxide and gaseous carbon dioxide are split into two streams after passing through the first valve. One stream flows directly into the heat exchange pipes inside the cooling chamber, while the other stream, after passing through the pressure reducing valve, converts the liquid carbon dioxide into gaseous carbon dioxide and flows into the cooling chamber. During the conversion into gaseous carbon dioxide, the temperature rises. The liquid carbon dioxide discharged from the heat exchange pipes of the cooling chamber enters the adjustable nozzle, and the gaseous carbon dioxide discharged from the cooling chamber enters the adjustable nozzle through the second valve. The gaseous carbon dioxide and liquid carbon dioxide entering the adjustable nozzle mix and then perform dry cleaning on the workpiece.

[0024] The beneficial effects of the present invention are as follows:

[0025] 1) The overall structure of this invention is reasonably designed. By using the cooling chamber, the first valve, and the second valve, it can be connected to the adjustable nozzle and the gas-liquid mixing nozzle. Different functions are achieved by utilizing different states of carbon dioxide. The mixture of gaseous carbon dioxide and lubricating oil is used to lubricate the workpiece surface. The low-temperature micro-lubrication part provides cooling and lubrication for the cutting zone, removing a large amount of cutting heat. The whole invention has the advantages of easy operation, reduced pollution, safe use, and easy cleaning. The high-pressure, low-temperature liquid carbon dioxide expands rapidly at the outlet to form dry ice particles. Under the impact of high-speed, low-temperature gaseous carbon dioxide, the dry ice particles are ejected at high speed. The low temperature characteristics of the dry ice particles cause the dirt to cool and shrink rapidly, thereby destroying the adhesion between it and the processing surface. The high-speed ejected dry ice particles provide sufficient kinetic energy to break or loosen the dirt. After the solid dry ice particles touch the dirt, they immediately sublimate into gaseous carbon dioxide, expanding in volume by about 800 times, peeling the dirt off the processing surface and carrying it away.

[0026] 2) In this invention, dry cleaning and low-temperature lubrication use the same gas source, but use different states of the same medium. Low-temperature gaseous carbon dioxide formed after the liquid carbon dioxide is depressurized is used to cool the carbon dioxide in the dry cleaning pipe and maintain its liquid state. The pressure at the nozzle drops rapidly to form dry ice particles, which are carried out by the high-speed low-temperature carbon dioxide gas. By using liquid carbon dioxide as the supply source, the use of an additional air compressor is avoided, which greatly reduces the cost and complexity of the equipment, facilitates transportation, and reduces the risk of operators being burned by cold due to transportation at ambient temperature during use.

[0027] 3) In this invention, the first valve and the second valve are connected to the control unit, and the control unit communicates with the milling machine control system. The milling cutter entry and exit signals are fed back to the control unit. The control unit controls the opening of the corresponding pipelines of the first valve and the second valve according to the milling cutter entry and exit signals to achieve different functions. The structure is reasonably designed.

[0028] 4) The first valve and the second valve in this invention are reasonably structured. The first valve and the second valve are respectively equipped with partitions. The partitions are rotatable relative to the shell. The partitions are provided with fan-shaped areas. Arc-shaped holes are provided on the periphery of the fan-shaped areas. The shell is provided with a first outlet and a second outlet. During the rotation of the partitions, the arc-shaped holes can connect with the first outlet and / or the second outlet, thereby enabling the opening of one or both outlets of the first valve and the opening of one outlet of the second valve.

[0029] 5) The present invention provides a system that can provide low-temperature carbon dioxide, which is suitable for high-speed machining of difficult-to-machine materials such as titanium alloys; when the milling cutter enters, the system has a cooling and lubrication function; when the milling cutter exits, the system has a dry cleaning function, removing chips and impurities; the system has strong overall applicability and can be easily replaced with other air sources. Attached Figure Description

[0030] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0031] Figure 1 This is a front view of a dry cleaning and low-temperature micro-lubrication combined system according to one or more embodiments of the present invention.

[0032] Figure 2 This is the present invention. Figure 1 A magnified view of a portion of point A in the middle.

[0033] Figure 3 This is a schematic diagram of the first valve and the second valve in a dry cleaning and low-temperature micro-lubrication combined system according to one or more embodiments of the present invention.

[0034] Figure 4This is a cross-sectional view of the first valve in a dry cleaning and low-temperature micro-lubrication combined system according to one or more embodiments of the present invention.

[0035] Figure 5 This is a side sectional view of the first valve in a dry cleaning and low-temperature micro-lubrication combined system according to one or more embodiments of the present invention.

[0036] Figure 6 This is a cross-sectional view of the second valve in a dry cleaning and low-temperature micro-lubrication combined system according to one or more embodiments of the present invention.

[0037] Figure 7 This is a side sectional view of the second valve in a dry cleaning and low-temperature micro-lubrication combined system according to one or more embodiments of the present invention.

[0038] Figure 8 This is a perspective view of the cooling chamber in a dry cleaning and low-temperature micro-lubrication combined system according to one or more embodiments of the present invention.

[0039] Figure 9 This is a cross-sectional view of the cooling chamber in a dry cleaning and low-temperature micro-lubrication combined system according to one or more embodiments of the present invention.

[0040] Figure 10 This is a control flowchart of a dry cleaning and low-temperature micro-lubrication combined system according to one or more embodiments of the present invention.

[0041] Figure 11 This is a three-phase diagram of carbon dioxide.

[0042] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0043] The components include: 1. Liquid carbon dioxide cylinder; 2. Cryogenic insulation pipe; 3. Primary valve; 4. First valve; 5. Pressure reducing valve; 6. Cooling chamber; 7. Mass flow meter; 8. Second valve; 9. Adjustable nozzle; 10. Gas-liquid mixing nozzle; 11. Micro-lubricating oil pump; 12. Control unit; 13. Milling machine communication interface; 14. Cryogenic carbon dioxide inlet I; 15. Cryogenic carbon dioxide outlet II; 16. Cryogenic carbon dioxide outlet III; 17. Cryogenic carbon dioxide inlet IV; 18. Cryogenic carbon dioxide outlet V; 19. Cryogenic carbon dioxide outlet VI; 20. Cryogenic carbon dioxide inlet VI I; 21. Cryogenic carbon dioxide inlet VIII; 22. Liquid carbon dioxide outlet IX; 23. Cryogenic carbon dioxide outlet X; 24. Drive motor; 25. Arc-shaped hole; 26. Partition plate; 27. Shell; 28. Fan-shaped area. Detailed Implementation

[0044] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0045] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0046] As described in the background section, the prior art has the problem of handling workpiece lubrication and chip removal separately. In order to solve the above technical problems, the present invention proposes a combined dry cleaning and low-temperature micro-lubrication system.

[0047] Example 1

[0048] In a typical embodiment of the present invention, reference is made to Figure 1 As shown, a dry cleaning and low-temperature micro-lubrication combined system includes a liquid carbon dioxide cylinder 1, a first valve 4, and a cooling chamber 6 connected in sequence. A second valve 8 and the cooling chamber 6 are respectively connected to an adjustable nozzle 9. The second valve 8 and the micro-lubricating oil pump 11 are respectively connected to a gas-liquid mixing nozzle 10. The liquid carbon dioxide cylinder 1 and the first valve are connected through a low-temperature insulation pipe 2. A primary valve 3 is installed at the low-temperature insulation pipe 2. A pressure reducing valve 5 is installed between the first valve 4 and the cooling chamber 6. A mass flow meter 7 is installed between the cooling chamber 6 and the second valve 8.

[0049] The first valve 4 is connected to an external air source at one end, and splits into two paths at the other end, which are respectively connected to the low-temperature carbon dioxide inlet VI I 20 of the cooling chamber 6 and the pressure reducing valve 5; the second valve 8 is connected to a flow meter such as a mass flow meter 7 at one end, and splits into two paths at the other end, which are respectively connected to the adjustable nozzle 9 and the gas-liquid mixing nozzle 10.

[0050] Among them, the first-stage valve 3 is a safety valve, and the first valve 4, mass flow meter 7, second valve 8, and micro-lubricating oil pump 11 are each individually connected to the control unit 12.

[0051] refer to Figure 3As shown, the first valve 4 and the second valve 8 are both electrically controlled two-way valves. The first valve and the second valve 8 have the same structure. Both of them have a built-in rotary power source, which is a drive motor 24. The drive motor 24 drives the partition 26 to rotate to realize the opening and closing control of the passage. The drive motor 24 is connected to the control unit 12. The control unit sends a signal to the control unit 12 through the milling machine control system. The control unit controls the rotation of the corresponding drive motor 24. The partition 26 is provided with a fan-shaped area 28. The partition 26 is provided with an arc-shaped hole 25 on the periphery of the fan-shaped area 28. A carbon dioxide inlet is provided on one side of the shell. A cavity is formed between the partition 26 and the carbon dioxide inlet. The shell 27 is provided with a first outlet and a second outlet. During the rotation of the partition 26, the arc-shaped hole 25 is connected to at least one of the first outlet and the second outlet. The fan-shaped area 28 can block the first outlet. The angle corresponding to the fan-shaped area 28 is between 40° and 60°.

[0052] In this embodiment, the initial position of the sector area in the first valve 4 and the second valve 8 is the position of the upper first outlet. At this time, the sector area covers the first outlet, so that the first outlet is closed. The included angle of the sector area on the partition is 40°. This sector area 28 is only used to control the opening and closing of the upper first outlet. When the drive motor drives the partition to rotate by a set angle, the arc hole 25 is connected to both the first outlet and the second outlet, so that both the first outlet and the second outlet are opened.

[0053] refer to Figure 4 and Figure 5 As shown, the first valve has a cryogenic carbon dioxide inlet (Ⅰ14), and a first outlet (Ⅱ15) and a second outlet (Ⅲ16), respectively. (Reference) Figure 6 and Figure 7 As shown, the carbon dioxide inlet of the second valve is cryogenic carbon dioxide inlet Ⅳ17, and the first outlet and the second outlet are cryogenic carbon dioxide outlet Ⅴ18 and cryogenic carbon dioxide outlet Ⅵ19, respectively.

[0054] It should be noted that the drive motors 24 of the first valve 4 and the second valve 8 are both connected to the control unit 12. The control unit 12 is connected to the milling machine control system (the milling machine control system is programmed to communicate with the control unit 12 and send the milling cutter entry and exit signals to the control unit 12) through the reserved milling machine communication interface 13. When the milling cutter enters, the low-temperature carbon dioxide outlet II 15 of the first valve 4 and the low-temperature carbon dioxide outlet V 18 of the second valve 8 are both closed. At this time, the low-temperature micro-lubrication system is turned on to provide cooling and lubrication for the cutting area. When the milling cutter exits, both low-temperature carbon dioxide outlets of the first valve 4 are turned on, the low-temperature carbon dioxide outlet V 18 of the second valve 8 is turned on, and the low-temperature carbon dioxide outlet VI 19 is closed. At this time, dry cleaning is turned on. Dry cleaning and low-temperature micro-lubrication use two nozzles respectively. No additional oil mist is introduced during dry cleaning.

[0055] It should be explained that when both outlets of the first valve 4 are open, the rotation angle of the baffle is greater than 30°. When the second valve closes the lower opening and opens the upper opening, the rotation angle of the baffle is 180°, so that the fan-shaped area closes the lower opening. In this way, the control unit controls the rotation angle of the baffle in the first valve and the second valve to open or close the corresponding passages of the first valve 4 and the second valve 8.

[0056] refer to Figure 8 and Figure 9 As shown, cooling chamber 6 has two cryogenic carbon dioxide inlets, namely cryogenic carbon dioxide inlet VII 20 and cryogenic carbon dioxide inlet VIII 21, and two outlets, one for liquid carbon dioxide IX 22 and the other for cryogenic carbon dioxide X 23. Cryogenic carbon dioxide inlet VII 20 is connected to cryogenic carbon dioxide outlet II 15 of the first valve 4. The heat exchange pipeline coils through the cooling chamber 6 to increase the heat exchange area. Cryogenic carbon dioxide inlet VIII 21 is connected to pressure reducing valve 5, and the depressurized cryogenic carbon dioxide fills the entire cooling chamber 6 as the heat exchange medium. The pressure of the pipeline connected to cryogenic carbon dioxide inlet VIII 21 of cooling chamber 6 is greatly reduced after passing through the pressure reducing valve, thus causing the gas temperature to drop significantly, down to -50℃. The heat exchange pipeline connected to cryogenic carbon dioxide inlet VI 20 of cooling chamber 6 is not depressurized, and the pressure inside the heat exchange pipeline is the same as that after passing through the first-stage valve. Figure 11 As can be seen from the three-phase diagram of carbon dioxide, the gaseous and liquid carbon dioxide entering the heat exchange pipeline through the low-temperature carbon dioxide inlet VI I 20 of the cooling chamber 6 is gaseous and liquid carbon dioxide. After heat exchange with the gas in the cooling chamber 6, it is converted into liquid carbon dioxide and discharged through the liquid carbon dioxide outlet IX22. Since both pipelines contain low-temperature media, this heat exchange process will not cause the temperature of the carbon dioxide used in the micro-lubrication system to rise significantly.

[0057] It is easy to understand that the pressure reducing valve 5 regulates the gas pressure in the low-temperature micro-lubrication system pipeline. Since the gas pressure inside the bottle is as high as 6.5 MPa, the pressure required for micro-lubrication is only below 0.5 MPa, which is sufficient to regulate with the first-stage valve 3 and the pressure reducing valve 5. The mass flow meter 7 regulates the gas flow rate. The lubricating oil is supplied by the micro-lubricating oil pump 11. The lubricating oil is sprayed out after being fully mixed by high-speed gas in the gas-liquid mixing nozzle 10.

[0058] Example 2

[0059] This embodiment provides a working method for a combined dry cleaning and low-temperature micro-lubrication system, referencing... Figure 10 As shown, it includes the following:

[0060] Liquid carbon dioxide is discharged from the liquid carbon dioxide bottle, and some of the liquid carbon dioxide is depressurized through the first-stage valve to form gaseous carbon dioxide;

[0061] Liquid carbon dioxide and gaseous carbon dioxide pass through the first valve 4 and then through the pressure reducing valve 5. The liquid carbon dioxide is converted into gaseous carbon dioxide and flows into the cooling chamber 6. During the conversion into gaseous carbon dioxide, the temperature rises and the gaseous carbon dioxide enters the cooling chamber. The gaseous carbon dioxide discharged from the cooling chamber enters the second valve and flows through the second valve to the gas-liquid mixing nozzle 10. The gaseous carbon dioxide entering the gas-liquid mixing nozzle 10 mixes with the lubricating oil to lubricate the workpiece at low temperature.

[0062] Alternatively, liquid carbon dioxide and gaseous carbon dioxide are split into two streams after passing through the first valve 4. One stream flows directly into the heat exchange pipe inside the cooling chamber 6, while the other stream, after passing through the pressure reducing valve, converts the liquid carbon dioxide into gaseous carbon dioxide and flows into the cooling chamber. During the conversion into gaseous carbon dioxide, the temperature rises. The liquid carbon dioxide discharged from the heat exchange pipe of the cooling chamber enters the adjustable nozzle 9, and the gaseous carbon dioxide discharged from the cooling chamber enters the adjustable nozzle 9 through the second valve 8. The gaseous carbon dioxide and liquid carbon dioxide entering the adjustable nozzle mix and then perform dry cleaning on the workpiece.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A dry cleaning and low-temperature micro-lubrication combined system, characterized in that, The system includes a liquid carbon dioxide cylinder, a primary valve, a first valve, and a cooling chamber connected in sequence. Some liquid carbon dioxide is depressurized from the liquid carbon dioxide cylinder through the primary valve to form gaseous carbon dioxide. After passing through the first valve, the liquid and gaseous carbon dioxide can flow towards the cooling chamber through the pressure reducing valve, or they can be divided into two paths. One path flows directly into the heat exchange pipes inside the cooling chamber, while the other path, after passing through the pressure reducing valve, converts the liquid carbon dioxide into gaseous carbon dioxide and flows into the cooling chamber. During the conversion into gaseous carbon dioxide, the temperature rises. The liquid carbon dioxide discharged from the heat exchange pipes of the cooling chamber enters the adjustable nozzle. The gaseous carbon dioxide discharged from the cooling chamber can enter the adjustable nozzle or the gas-liquid mixing nozzle after passing through the second valve. The gaseous carbon dioxide and liquid carbon dioxide entering the adjustable nozzle mix to perform dry cleaning on the workpiece, while the gaseous carbon dioxide entering the gas-liquid mixing nozzle mixes with lubricating oil to perform low-temperature lubrication on the workpiece. The first valve and the second valve are respectively connected to the control unit. The control unit is connected to the milling machine control system to transmit the signals of the milling cutter entering and exiting to the control unit. When the milling cutter enters, the gas-liquid mixing nozzle is working and the adjustable nozzle is closed. When the milling cutter exits, the adjustable nozzle is working and the gas-liquid mixing nozzle is closed.

2. The dry cleaning and low-temperature micro-lubrication combined system according to claim 1, characterized in that, When the milling cutter cuts in, the passage between the first valve and the heat exchange pipeline is closed, the passage between the first valve and the pressure reducing valve is opened, the passage between the second valve and the adjustable nozzle is closed, and the passage between the second valve and the gas-liquid mixing nozzle is opened.

3. The dry cleaning and low-temperature micro-lubrication combined system according to claim 1, characterized in that, When the milling cutter cuts out, the passage between the first valve and the heat exchange pipeline and the pressure reducing valve is opened, the passage between the second valve and the gas-liquid mixing nozzle is closed, and the passage between the second valve and the adjustable nozzle is opened.

4. The dry cleaning and low-temperature micro-lubrication combined system according to claim 1, characterized in that, The gas-liquid mixing nozzle is connected to a micro-lubricating oil pump, and the micro-lubricating oil pump is connected to the control unit. The gas-liquid mixing nozzle and the adjustable nozzle are respectively placed on both sides of the milling cutter, and both the gas-liquid mixing nozzle and the adjustable nozzle are inclined relative to the central axis of the milling cutter.

5. The dry cleaning and low-temperature micro-lubrication combined system according to claim 1, characterized in that, The heat exchange pipes in the cooling chamber are arranged in a spiral shape.

6. The dry cleaning and low-temperature micro-lubrication combined system according to claim 1, characterized in that, A flow meter is installed between the cooling chamber and the second valve, and the flow meter is connected to the control unit.

7. The dry cleaning and low-temperature micro-lubrication combined system according to claim 1, characterized in that, The first valve includes a housing, a carbon dioxide inlet on one side of the housing, a baffle inside the housing, a distance between the baffle and the carbon dioxide inlet, a rotating power source supported by the housing, the rotating power source connected to the baffle to drive the baffle to rotate relative to the housing, the baffle having a fan-shaped area, an arc-shaped hole on the periphery of the fan-shaped area, and the housing having a first outlet and a second outlet. During the rotation of the baffle, the arc-shaped hole is connected to at least one of the first outlet and the second outlet.

8. The dry cleaning and low-temperature micro-lubrication combined system according to claim 7, characterized in that, The structure of the first valve is the same as that of the second valve, and the angle of the arc-shaped hole is greater than 180°.

9. The working method of the dry cleaning and low-temperature micro-lubrication combined system according to any one of claims 1-8, characterized in that, Includes the following: Liquid carbon dioxide is discharged from the liquid carbon dioxide bottle, and some of the liquid carbon dioxide is depressurized through the first-stage valve to form gaseous carbon dioxide; Liquid carbon dioxide and gaseous carbon dioxide pass through the first valve and then through the pressure reducing valve. The liquid carbon dioxide is converted into gaseous carbon dioxide and flows into the cooling chamber. During the conversion into gaseous carbon dioxide, the temperature rises and the gaseous carbon dioxide enters the cooling chamber. The gaseous carbon dioxide discharged from the cooling chamber enters the second valve and flows through the second valve to the gas-liquid mixing nozzle. The gaseous carbon dioxide entering the gas-liquid mixing nozzle mixes with the lubricating oil to lubricate the workpiece at low temperature. Alternatively, liquid carbon dioxide and gaseous carbon dioxide are split into two streams after passing through the first valve. One stream flows directly into the heat exchange pipes inside the cooling chamber, while the other stream, after passing through the pressure reducing valve, converts the liquid carbon dioxide into gaseous carbon dioxide and flows into the cooling chamber. During the conversion into gaseous carbon dioxide, the temperature rises. The liquid carbon dioxide discharged from the heat exchange pipes of the cooling chamber enters the adjustable nozzle, and the gaseous carbon dioxide discharged from the cooling chamber enters the adjustable nozzle through the second valve. The gaseous carbon dioxide and liquid carbon dioxide entering the adjustable nozzle mix and then perform dry cleaning on the workpiece.

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