A device for oil and gas lubrication of a roll
By designing an oil-air lubrication device that combines lubricating oil and compressed gas in a mixed spraying method, the failure problem of traditional roll lubrication under high temperature and high speed conditions was solved, achieving efficient lubrication and cooling of the rolls and extending their service life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUIZHOU NANGANG METAL SQUASH & EXTEND CO LTD
- Filing Date
- 2025-07-16
- Publication Date
- 2026-05-29
AI Technical Summary
In traditional roll lubrication methods, oil lubrication is prone to failure under high temperature and high speed conditions, while air lubrication has poor lubrication effect and cannot meet the roll's requirements for high-performance lubrication and cooling.
An oil-gas lubrication device is designed to achieve precise control and efficient delivery of the oil-gas lubrication process by optimizing the oil supply component, oil quantity control component, compressed gas delivery component, and oil-gas mixing and spraying component. The device combines lubricating oil and compressed gas for mixed spraying to ensure uniform and stable spraying onto the roll surface.
It improves the lubrication effect and service life of the rolls, achieving simultaneous lubrication and cooling functions, thereby enhancing the working efficiency and service life of the rolls.
Smart Images
Figure CN224294282U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of rolling mill surface lubrication technology, and in particular to an oil-air lubrication device for rolling mills. Background Technology
[0002] In modern industrial production, rolling mill rolls are key components of rolling mills. Their performance and service life have a crucial impact on production efficiency and product quality. During operation, rolling mill rolls are subjected to severe conditions such as enormous pressure, friction, and high temperatures. Therefore, effective lubrication and cooling measures are required to ensure their normal operation, reduce wear, and extend their service life.
[0003] Traditional roll lubrication methods mainly include oil lubrication and air lubrication. Although oil lubrication can provide good lubrication, under high temperature and high speed operation conditions, the lubricating oil is prone to deterioration and failure due to excessive temperature, and it is difficult to achieve uniform distribution, resulting in insufficient lubrication in some areas and affecting the service life of the roll. Air lubrication has the advantages of good cooling effect and cleanliness without pollution, but when using air lubrication alone, the lubrication effect is relatively poor and cannot meet the high requirements of roll lubrication performance. Utility Model Content
[0004] This invention addresses the shortcomings of existing technologies by proposing an oil-air lubrication device for rolling mill rolls. This device optimizes the structural design of the oil supply component, oil quantity control component, compressed gas delivery component, and oil-air mixture spraying component to achieve precise control and efficient delivery of the oil-air lubrication process. This improves the quality and stability of the oil-air mixture, thereby significantly enhancing the lubrication effect and service life of the rolling mill rolls, and meeting the demands of modern industrial production for high-performance lubrication and cooling of rolling mill rolls.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] An oil-air lubrication device for a rolling mill roll includes a support, a drive component on one side of the support, a rolling mill roll on one side of the drive component, an oil reservoir on one side of the support, a cover plate on the upper side of the oil reservoir, a controller on the upper side of the cover plate, an oil supply assembly on the shaft end of the rolling mill roll, an oil quantity control assembly on one side of the oil supply assembly, a compressed gas delivery assembly on the upper side of the cover plate, and an oil-air mixing spraying assembly on one side of the oil quantity control assembly and the compressed gas delivery assembly.
[0007] Through the above technical solution, the oil storage tank stores lubricating oil, the drive component drives the roll to rotate, and the oil supply component plays a role at the end of the roll shaft. It transmits power to the impeller through a series of gears and connecting rods. The impeller rotates in the oil guide pipe, causing the lubricating oil to flow from the oil storage tank to the oil discharge pipe through the oil guide pipe. At the same time, the compressor in the compressed gas conveying component delivers compressed gas through the compressed gas pipe. After the gas is purified by the filter, it mixes with the lubricating oil in the oil-gas mixing pipeline of the oil-gas mixing spraying component. Finally, it is sprayed onto the roll surface in an atomized state through the atomizing nozzle on the guide pipe to achieve oil-gas lubrication of the roll.
[0008] This device combines lubricating oil and compressed gas to lubricate the rolls through an oil-gas mixture spray, achieving both lubrication and cooling functions simultaneously, thereby improving the rolls' service life and working efficiency.
[0009] By setting up an oil supply component, an oil quantity control component, a compressed gas delivery component, and an oil-gas mixture spraying component, precise control and efficient delivery of the oil-gas lubrication process are achieved, ensuring that the oil-gas mixture can be sprayed evenly and stably onto the roll surface, thereby improving the lubrication effect.
[0010] Preferably, the oil supply assembly includes a first bevel gear, which is disposed at one end of the roll. A second bevel gear is meshed with one side of the first bevel gear. A first connecting rod is disposed on one side of the second bevel gear. A first gear is disposed at one end of the first connecting rod. A second gear is meshed with one side of the first gear. A second connecting rod is disposed on one side of the second gear. An impeller is disposed at one end of the second connecting rod.
[0011] Through the above technical solution, the operation of the roll drives the first bevel gear to rotate, the first bevel gear meshes with the second bevel gear, causing the second bevel gear to rotate, which in turn drives the first connecting rod to move. The first connecting rod drives the first gear to rotate, the first gear meshes with the second gear, causing the second gear to rotate, and the second gear drives the impeller to rotate in the oil guide pipe through the second connecting rod. The rotation of the impeller causes the lubricating oil to flow in the oil guide pipe, providing a lubricating oil source for subsequent oil-air mixing.
[0012] The oil supply assembly utilizes the rotational power of the rollers. Bevel gear one drives bevel gear two, bevel gear two drives connecting rod one to drive gear one, gear one drives gear two, gear two drives connecting rod two to drive the impeller, thus rotating the impeller and realizing the delivery of lubricating oil. No additional power source is required, saving energy. The transmission structure is simple and reliable, and maintenance is convenient. The impeller is placed inside the oil guide pipe, which can directly generate power in the lubricating oil flow channel, making the lubricating oil flow smoother, improving the delivery efficiency of lubricating oil, and ensuring that lubricating oil can be supplied to the oil-gas mixing pipeline in a timely and stable manner.
[0013] Preferably, the oil quantity control component includes an oil guide pipe disposed on one side of the cover plate, a flow limiting control valve disposed at one end of the oil guide pipe, an oil discharge pipe disposed on one side of the flow limiting control valve, and the impeller disposed inside the oil guide pipe.
[0014] Through the above technical solution, lubricating oil flows from the oil reservoir through the oil guide pipe to the flow limiting control valve. The flow limiting control valve precisely controls the flow rate of the lubricating oil according to the set flow parameters, adjusts the flow rate and flow of the lubricating oil, so that the lubricating oil flows into the drain pipe in an appropriate amount, and then enters the oil-gas mixing pipeline. This ensures that the supply of lubricating oil meets the requirements when the oil and gas are mixed, and achieves precise control of the oil quantity to meet the lubricating oil requirements of the rolls under different working conditions.
[0015] The flow-limiting control valve in the oil quantity control component can precisely control the flow rate of lubricating oil. It can flexibly adjust the supply of lubricating oil according to the working conditions and needs of different rolls, achieve precise control of oil quantity, avoid waste of lubricating oil, and ensure that the rolls are fully lubricated. The design of the oil guide pipe and oil discharge pipe provides a stable channel for the delivery of lubricating oil, so that the lubricating oil can flow smoothly from the oil tank to the oil-gas mixing pipeline, ensuring a stable and reliable supply of lubricating oil during the oil-gas mixing process.
[0016] Preferably, the compressed gas delivery assembly includes a compressor fan, which is disposed on the upper side of the cover plate. A compressed air pipe is disposed on one side of the compressor fan, and a filter is disposed on the outer side of the compressed air pipe.
[0017] Through the above technical solution, the compressor blower starts and generates compressed gas. The compressed gas is transported through the compressed gas pipe. During the transportation process, the gas is filtered by a filter to remove impurities and particulate matter, ensuring the purity of the compressed gas entering the oil-gas mixing pipeline. This prevents impurities from adversely affecting the oil-gas mixing effect, providing a clean and stable source of compressed gas for oil-gas mixing, so that the compressed gas can be fully mixed with the lubricating oil to form a uniform oil-gas mixture.
[0018] The compressed gas conveying assembly's compressor can stably generate compressed gas, providing a sufficient gas source for oil-gas mixing, ensuring the formation and conveying of the oil-gas mixture. The filter filters the compressed gas, removing impurities and particulate matter, ensuring that the compressed gas entering the oil-gas mixing pipeline is pure and free of impurities, preventing impurities from adversely affecting the oil-gas mixing effect, improving the quality of the oil-gas mixture, and thus improving the lubrication effect on the rolls.
[0019] Preferably, the oil-gas mixing spraying assembly includes an oil-gas mixing pipeline, which is disposed on the upper side of the support and connected to one end of the oil drain pipe and the compressed air pipe, respectively. One end of the oil-gas mixing pipeline is provided with a guide pipe, and a plurality of atomizing nozzles are provided on the outside of the guide pipe.
[0020] Through the above technical solution, lubricating oil flows from the oil drain pipe into the oil-gas mixing pipeline, while compressed gas also enters the oil-gas mixing pipeline from the compressed gas pipe. Inside the oil-gas mixing pipeline, the lubricating oil and compressed gas mix together to form an oil-gas mixture. The oil-gas mixture flows through the guide pipe to the atomizing nozzle, which further atomizes the oil-gas mixture, spraying it onto the roll surface in the form of fine droplets. This achieves uniform lubrication of the roll, improves the lubrication effect, and ensures that the roll surface is adequately lubricated and cooled.
[0021] The oil-gas mixing spray assembly thoroughly mixes lubricating oil and compressed gas through an oil-gas mixing pipeline to form a uniform oil-gas mixture. This mixture is then atomized and sprayed onto the roll surface through an atomizing nozzle. This ensures uniform and fine lubrication of the roll surface, improving lubrication efficiency and reducing wear and scratches. The atomizing nozzle design sprays the oil-gas mixture into fine droplets, increasing the contact area between the mixture and the roll surface, thus improving lubrication efficiency. Furthermore, the atomized oil-gas mixture adheres better to the roll surface, extending the lubrication time and further enhancing the lubrication effect.
[0022] Preferably, an insulated box is provided on the upper side of the bracket, the oil-gas mixing pipeline is provided inside the insulated box, a box cover is provided on the upper side of the insulated box, and a semiconductor refrigeration unit is embedded in the inner wall of the insulated box.
[0023] With the above technical solution, the insulation box is set on the upper side of the support, the oil-gas mixing pipeline is located inside the insulation box, and the box cover seals the insulation box. When the semiconductor cooling unit on the inner wall of the insulation box is working, it can cool down the oil-gas mixture in the oil-gas mixing pipeline, preventing the oil-gas mixture from deteriorating or affecting its lubrication performance due to excessive temperature during transportation, ensuring that the oil-gas mixture is sprayed onto the roll surface at a suitable temperature, improving the lubrication effect and the service life of the roll.
[0024] The insulated box and semiconductor refrigeration unit can cool down the oil-gas mixture in the oil-gas mixing pipeline, preventing the oil-gas mixture from deteriorating or affecting its lubrication performance due to excessive temperature during transportation. This ensures that the oil-gas mixture is sprayed onto the roll surface at a suitable temperature, improving lubrication and extending the roll's service life. The insulated box also protects the oil-gas mixing pipeline from adverse effects of the external environment. At the same time, the sealed design of the box cover ensures the cooling effect inside the insulated box, improving the stability and reliability of the device.
[0025] In summary, this invention combines lubricating oil and compressed gas to lubricate the rolls via oil-gas mixture spraying, achieving both lubrication and cooling functions simultaneously. This improves the rolls' service life and working efficiency. By incorporating an oil supply component, an oil quantity control component, a compressed gas delivery component, and an oil-gas mixture spraying component, precise control and efficient delivery of the oil-gas lubrication process are achieved, ensuring that the oil-gas mixture is sprayed evenly and stably onto the roll surface, thus enhancing the lubrication effect.
[0026] This utility model utilizes the rotational power of the rollers to supply oil. Bevel gear one drives bevel gear two, bevel gear two drives connecting rod one to drive gear one, gear one drives gear two, gear two drives connecting rod two to drive the impeller, thus rotating the impeller and realizing the delivery of lubricating oil. No additional power source is required, saving energy. Moreover, the transmission structure is simple and reliable, and maintenance is convenient. The impeller is placed inside the oil guide pipe, which can directly generate power in the lubricating oil flow channel, making the lubricating oil flow smoother, improving the delivery efficiency of lubricating oil, and ensuring that lubricating oil can be supplied to the oil-gas mixing pipeline in a timely and stable manner.
[0027] In this invention, the compressed gas conveying assembly uses a compressed blower that can stably generate compressed gas, providing a sufficient gas source for oil-gas mixing, ensuring the formation and conveying of the oil-gas mixture. The filter filters the compressed gas, removing impurities and particulate matter, ensuring that the compressed gas entering the oil-gas mixing pipeline is pure and free of impurities, preventing impurities from adversely affecting the oil-gas mixing effect, improving the quality of the oil-gas mixture, and thus improving the lubrication effect on the rolls. Attached Figure Description
[0028] Figure 1 This is a schematic diagram of the exploded structure of this utility model;
[0029] Figure 2 This is a schematic diagram of the front axial side of this utility model;
[0030] Figure 3 This is a schematic diagram of the structure of the present invention with a frontal cross-section of the axial side.
[0031] In the diagram: 1. Support; 2. Drive unit; 3. Roller; 4. Oil tank; 5. Cover plate; 6. Controller; 7. Bevel gear one; 8. Bevel gear two; 9. Connecting rod one; 10. Gear one; 11. Gear two; 12. Connecting rod two; 13. Impeller; 14. Oil guide pipe; 15. Flow control valve; 16. Oil drain pipe; 17. Compressor; 18. Compressed air pipe; 19. Filter; 20. Oil-air mixing pipeline; 21. Guide pipe; 22. Atomizing nozzle; 23. Insulation box; 24. Box cover; 25. Semiconductor refrigeration unit. Detailed Implementation
[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.
[0033] like Figures 1-3 As shown, an oil-air lubrication device for a rolling mill roll includes a bracket 1, which is fixed in a suitable working position to ensure its structural stability. A drive component 2 is installed on one side of the bracket 1. The drive component 2 can be a power device such as a motor to provide power to the rolling mill roll 3. The drive component 2 is connected to an external power source and debugged to ensure normal operation. The rolling mill roll 3 is installed on one side of the drive component 2 and connected to the drive component 2 to ensure that the rolling mill roll 3 can rotate normally under the drive of the drive component 2. During the installation process, the axial position of the rolling mill roll 3 must be accurate and the connection with the drive component 2 must be firm and reliable.
[0034] An oil storage tank 4 is installed on the other side of the bracket 1. The oil storage tank 4 is used to store lubricating oil. A cover plate 5 is installed on the upper side of the oil storage tank 4. The cover plate 5 serves to seal and protect the oil storage tank 4, preventing dust and other impurities from entering the interior of the oil storage tank 4. A controller 6 is installed on the upper side of the cover plate 5. The controller 6 is used to control the operation of the entire oil-air lubrication device, including the working status of the oil supply component, oil quantity control component, compressed gas delivery component, and oil-air mixing spray component. The controller 6 is connected to the control circuits of each component and debugged to ensure that the controller 6 can control the operation of each component normally.
[0035] An oil supply assembly is installed on the shaft end of roll 3. Bevel gear 7 is installed on one end of roll 3, ensuring that bevel gear 7 fits tightly with the shaft end of roll 3. Bevel gear 8 is installed on one side of bevel gear 7 and the two are meshed. Then, one end of connecting rod 9 is connected to bevel gear 8, and gear 10 is installed on the other end. Gear 11 is installed on one side of gear 10 and the two are meshed. One end of connecting rod 12 is connected to gear 11, and impeller 13 is installed on the other end, ensuring that the connection between each gear and connecting rod is firm and the transmission is flexible.
[0036] An oil guide pipe 14 is installed on one side of the cover plate 5. One end of the oil guide pipe 14 is connected to the oil storage tank 4 and is used to transport lubricating oil from the oil storage tank 4 to the oil supply component. A flow limiting control valve 15 is installed at the other end of the oil guide pipe 14. The flow rate of lubricating oil can be controlled by adjusting the flow limiting control valve 15. An oil drain pipe 16 is installed on one side of the flow limiting control valve 15. The oil drain pipe 16 is used to transport the lubricating oil after being regulated by the flow limiting control valve 15 to the oil-gas mixing spray component. An impeller 13 is placed inside the oil guide pipe 14 to ensure that the impeller 13 can rotate normally inside the oil guide pipe 14 and drive the lubricating oil to flow.
[0037] A compressor fan 17 is installed on the upper side of the cover plate 5. The compressor fan 17 is used to generate compressed gas. A compressed air pipe 18 is installed on one side of the compressor fan 17 for conveying compressed gas. A filter 19 is installed on the outside of the compressed air pipe 18 for filtering impurities in the compressed gas to ensure that the compressed gas delivered to the oil-gas mixing spraying assembly is pure.
[0038] An oil-gas mixing pipe 20 is installed on the upper side of the support 1. One end of the oil-gas mixing pipe 20 is connected to the oil drain pipe 16 and the compressed air pipe 18 respectively, and is used to mix lubricating oil and compressed gas. A guide pipe 21 is installed at the other end of the oil-gas mixing pipe 20. The guide pipe 21 is used to guide the flow direction of the oil-gas mixture. Several atomizing nozzles 22 are evenly installed on the outside of the guide pipe 21. The atomizing nozzles 22 are used to atomize the oil-gas mixture and spray it onto the surface of the roll 3 to achieve oil-gas lubrication of the roll 3.
[0039] An insulation box 23 is installed on the upper side of the bracket 1, and the oil-gas mixing pipeline 20 is placed inside the insulation box 23. The insulation box 23 serves to insulate and protect the oil-gas mixing pipeline 20. A box cover 24 is installed on the upper side of the insulation box 23 to seal the insulation box 23. A semiconductor cooling unit 25 is fitted into the inner wall of the insulation box 23. The semiconductor cooling unit 25 is used to cool and lower the oil-gas mixture in the oil-gas mixing pipeline 20 to ensure that the oil-gas mixture is sprayed onto the surface of the roll 3 at a suitable temperature, thereby improving the lubrication effect.
[0040] In this embodiment, the starting device is as follows: First, the compressor 17 is started. The compressor 17 starts working and generates compressed gas. The compressed gas is transported through the compressed air pipe 18. During the transport process, it is filtered by the filter 19 to remove impurities and particulate matter from the gas, resulting in pure compressed gas.
[0041] Oil supply assembly operation: When the roller 3 starts to run under the drive of the drive component 2, the bevel gear 7 rotates accordingly. Since the bevel gear 7 meshes with the bevel gear 8, the bevel gear 8 is driven to rotate. The rotation of the bevel gear 8 is transmitted to the gear 10 through the connecting rod 9. The gear 10 meshes with the gear 11, causing the gear 11 to rotate. The rotation of the gear 11 is then transmitted to the impeller 13 through the connecting rod 12. The impeller 13 rotates in the oil guide pipe 14. The rotation of the impeller 13 causes the lubricating oil to flow from the oil reservoir 4 through the oil guide pipe 14 to the oil drain pipe 16.
[0042] Oil quantity control component operation: When the lubricating oil flows in the oil guide pipe 14, it passes through the flow limiting control valve 15. By adjusting the flow limiting control valve 15, the flow rate of the lubricating oil can be precisely controlled, so that the lubricating oil flows into the oil drain pipe 16 in an appropriate amount. The oil drain pipe 16 delivers the lubricating oil after being regulated by the flow limiting control valve 15 to the oil-gas mixing pipeline 20.
[0043] The oil-gas mixing spraying assembly operates as follows: pure compressed gas enters the oil-gas mixing pipeline 20 from the compressed gas pipe 18, while lubricating oil also flows into the oil-gas mixing pipeline 20 from the oil drain pipe 16. Inside the oil-gas mixing pipeline 20, the lubricating oil and compressed gas mix to form an oil-gas mixture. The oil-gas mixture flows to the atomizing nozzle 22 through the guide pipe 21. The atomizing nozzle 22 further atomizes the oil-gas mixture, spraying it onto the surface of the roll 3 in the form of fine droplets, thereby achieving oil-gas lubrication of the roll 3.
[0044] The insulation box 23 and the semiconductor refrigeration unit 25 operate as follows: During the transportation of the oil-gas mixture in the oil-gas mixing pipeline 20, the insulation box 23 provides insulation to prevent adverse effects of the external ambient temperature on the oil-gas mixture. Simultaneously, the semiconductor refrigeration unit 25 operates to cool the oil-gas mixture within the oil-gas mixing pipeline 20. Through the cooling effect of the semiconductor refrigeration unit 25, the oil-gas mixture is ensured to be sprayed onto the surface of the roll 3 at a suitable temperature, improving lubrication and extending the service life of the roll 3.
[0045] Regularly check the lubricating oil level in oil reservoir 4 to ensure sufficient lubricating oil. At the same time, check the quality of the lubricating oil. If the lubricating oil is found to be deteriorated or contains too many impurities, it should be replaced in time to ensure the cleanliness and performance of the lubricating oil.
[0046] Check filter 19: Regularly check filter 19, clean impurities and particles inside filter 19 to prevent filter 19 from becoming clogged, and ensure that compressed gas can pass through filter 19 smoothly and remain pure.
[0047] Check the connections of each component: Regularly check whether the connections between the oil supply component, oil quantity control component, compressed gas delivery component, and oil-gas mixing spray component are secure and reliable. If any loose or damaged connections are found, tighten them in time.
[0048] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.
Claims
1. An oil-air lubrication device for a rolling mill roll, comprising a support (1), a drive member (2) disposed on one side of the support (1), a rolling mill roll (3) disposed on one side of the drive member (2), an oil reservoir (4) disposed on one side of the support (1), a cover plate (5) disposed on the upper side of the oil reservoir (4), and a controller (6) disposed on the upper side of the cover plate (5), characterized in that, The roller (3) is provided with an oil supply component at its shaft end. An oil quantity control component is provided on one side of the oil supply component. A compressed gas conveying component is provided on the upper side of the cover plate (5). An oil-gas mixing spraying component is provided on one side of the oil quantity control component and the compressed gas conveying component.
2. The device for oil-air lubrication of rolling mill rolls according to claim 1, characterized in that, The oil supply assembly includes a bevel gear one (7), which is disposed at one end of the roller (3). A bevel gear two (8) is meshed with one side of the bevel gear one (7). A connecting rod one (9) is disposed on one side of the bevel gear two (8). A gear one (10) is disposed at one end of the connecting rod one (9). A gear two (11) is meshed with one side of the gear one (10). A connecting rod two (12) is disposed on one side of the gear two (11). An impeller (13) is disposed at one end of the connecting rod two (12).
3. The device for oil-air lubrication of rolling mill rolls according to claim 2, characterized in that, The oil quantity control component includes an oil guide pipe (14), which is located on one side of the cover plate (5). A flow control valve (15) is provided at one end of the oil guide pipe (14), and an oil drain pipe (16) is provided on one side of the flow control valve (15). The impeller (13) is placed inside the oil guide pipe (14).
4. The device for oil-air lubrication of rolling mill rolls according to claim 3, characterized in that, The compressed gas delivery assembly includes a compressor (17), which is located on the upper side of the cover plate (5). A compressed air pipe (18) is provided on one side of the compressor (17), and a filter (19) is provided on the outer side of the compressed air pipe (18).
5. The device for oil-air lubrication of rolling mill rolls according to claim 4, characterized in that, The oil-gas mixing spraying assembly includes an oil-gas mixing pipeline (20), which is located on the upper side of the support (1) and is connected to one end of the oil drain pipe (16) and the compressed air pipe (18). One end of the oil-gas mixing pipeline (20) is provided with a guide pipe (21), and a plurality of atomizing nozzles (22) are provided on the outside of the guide pipe (21).
6. The apparatus for oil-air lubrication of rolling mill rolls according to claim 5, characterized in that, An insulation box (23) is provided on the upper side of the bracket (1), the oil-gas mixing pipeline (20) is provided inside the insulation box (23), a box cover (24) is provided on the upper side of the insulation box (23), and a semiconductor refrigeration unit (25) is embedded in the inner wall of the insulation box (23).