Oiling machine

By adding temporary storage tanks between the liquid storage tank and the filling gun, a closed-loop liquid supply system is formed, which solves the problem of long flow time caused by long-distance pipelines, and the continuity and stability of the filling equipment are achieved, and the filling efficiency is improved.

CN223163215UActive Publication Date: 2025-07-29GUANGZHOU GUIDIAN IND CONTROL TECH CO LTD
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Patent Information

Application Number
CN202422231402.4
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-09-12
Publication Date
2025-07-29
Estimated Expiration
2034-09-12

AI Technical Summary

Technical Problem

In traditional liquid filling systems, long-distance pipelines lead to a long flow time of liquid flow, affecting the continuity and stability of the filling equipment and reducing production efficiency.

Method used

A temporary storage tank is added between the liquid storage tank and the filling gun, and a closed-loop system is formed through the liquid filling pump and the filling pump to ensure that the filling gun is continuously supplied with liquid and shorten the liquid flow distance. The liquid filling pump and the liquid return pump are used to achieve continuous supply of liquid.

Benefits of technology

It improves the filling efficiency of the filling gun, ensures the continuity and stability of the filling, shortens the liquid flow time, and improves production efficiency.

✦ Generated by Eureka AI based on patent content.

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    Figure CN223163215U_ABST
Patent Text Reader

Abstract

The utility model relates to the technical field of oiling machines, and discloses an oiling machine which is characterized in that a liquid storage tank is provided with a liquid storage inlet, a liquid storage return port, a liquid storage outlet and a liquid storage cavity which are communicated with one another, a temporary storage tank is provided with a temporary storage liquid inlet, a temporary storage liquid outlet and a temporary storage liquid return port, the liquid storage outlet is communicated with the temporary storage liquid inlet through a liquid adding pipe, and the liquid storage cavity is communicated with the temporary storage liquid inlet through a liquid return pipe. The liquid adding pipe is communicated with the liquid adding pump, the temporary storage liquid outlet is communicated with the filling gun through a liquid outlet pipe, the liquid outlet pipe is communicated with the filling pump, the temporary storage liquid return opening is communicated with the liquid storage liquid return opening through a liquid return pipe, the liquid return pipe is communicated with the liquid return pump, the temporary storage tank is provided with a temporary storage upper limit, the temporary storage upper limit is provided with a temporary storage liquid level sensor, and the liquid return pump is electrically connected with the temporary storage liquid level sensor. The liquid adding pump, the liquid return pump, the filling pump, the filling gun and the temporary storage liquid level sensor are electrically connected with the controller. According to the oiling machine, the liquid inlet end of the filling gun ensures that liquid continuously exists, the flowing distance from the liquid to the filling gun is shortened, and the filling efficiency of the filling gun is improved.
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Description

Technical Field

[0001] The utility model relates to the technical field of garden landscapes, in particular to an oil filling machine. Background Art

[0002] Traditional liquid filling systems often directly connect a liquid storage tank to a filling device (such as a filling gun) through a long pipeline. Although this design is simple and direct, it exposes several problems in practical applications. First, the long-distance pipeline for liquid transportation increases the time for liquid flow. Especially in occasions where frequent filling is required, this delay will significantly reduce production efficiency. Directly supplying liquid from the liquid storage tank to the filling gun makes it difficult to ensure that the filling gun can immediately obtain sufficient liquid supply when needed. Factors such as the liquid level fluctuation of the liquid storage tank and the instability of the pumping efficiency may affect the continuity and stability of filling, thereby affecting product quality and production progress. Summary of the Utility Model

[0003] It aims to solve at least one of the technical problems existing in the prior art. The utility model provides an oil filling machine, which ensures that there is continuous liquid at the liquid inlet end of the filling gun. At the same time, it shortens the flow distance of the liquid to the filling gun, shortens the time for the liquid to flow to the filling gun, and improves the filling efficiency of the filling gun.

[0004] To achieve the above object, the utility model provides an oil filling machine, which includes a liquid storage tank, a temporary storage tank, a liquid adding pump, a liquid returning pump, a filling pump, a controller and a filling gun. The liquid storage tank is provided with a liquid storage inlet, a liquid storage return port, a liquid storage outlet and a liquid storage cavity that are interconnected. The temporary storage tank is provided with a temporary storage inlet, a temporary storage outlet and a temporary storage return port. The liquid storage outlet is connected to the temporary storage inlet through a liquid adding pipe, and the liquid adding pipe is connected to the liquid adding pump. The temporary storage outlet is connected to the filling gun through an outlet pipe, and the outlet pipe is connected to the filling pump. The temporary storage return port is connected to the liquid storage return port through a return pipe, and the return pipe is connected to the liquid returning pump. The temporary storage tank is provided with a temporary storage upper limit, and the temporary storage upper limit is provided with a temporary storage liquid level sensor. The liquid returning pump is electrically connected to the temporary storage liquid level sensor. The liquid adding pump, the liquid returning pump, the filling pump, the filling gun and the temporary storage liquid level sensor are respectively electrically connected to the controller.

[0005] As a preferred solution, it further includes a weighing device and a flow meter. The controller further includes a review module. The flow meter is connected to the outlet pipe, and the weighing device, the flow meter and the filling pump are respectively electrically connected to the review module.

[0006] As a preferred solution, the liquid outlet pipe includes a quick filling pipe and a slow filling pipe, the filling pump includes a quick filling pump and a slow filling pump, the quick filling pipe, the quick filling pump, the temporary storage liquid outlet and the filling gun are connected to form a quick filling channel, and the slow filling pipe, the slow filling pump, the temporary storage liquid outlet and the filling gun are connected to form a slow filling channel.

[0007] As a preferred solution, the liquid storage tank, the temporary storage tank, the liquid adding pump, the liquid returning pump, the filling pump and the filling gun are connected to form a filling assembly, and multiple groups of the filling assemblies are provided.

[0008] As a preferred solution, it further includes a box frame and an oil return frame. The box frame is provided with an assembly cavity, a box body oil inlet and a box body oil outlet. A plurality of the liquid storage tanks are connected in the assembly cavity. The numbers of the box body oil inlet and the box body oil outlet are respectively set corresponding to the number of the liquid storage tanks. The box body oil inlet is communicated with the liquid storage inlet, and the box body oil outlet is communicated with the liquid storage outlet. A plurality of the temporary storage tanks are placed on the oil return frame.

[0009] As a preferred solution, the liquid storage tank is provided with a heating port, and an explosion-proof heater is hermetically connected to the heating port, and at least a part of the explosion-proof heater extends into the liquid storage cavity.

[0010] As a preferred solution, a temperature sensor is connected to the outer side wall of the liquid storage tank, and the temperature sensor and the explosion-proof heater are respectively electrically connected to the controller.

[0011] As a preferred solution, an oil drain port is provided at the bottom of the liquid storage tank, and the oil drain port is communicated with the liquid storage cavity.

[0012] As a preferred solution, an upper limit liquid level port is provided at the upper end of the liquid storage tank, and a first liquid level sensor is connected to the upper limit liquid level port. A lower limit liquid level port is provided at the lower end of the liquid storage tank, and a second liquid level sensor is connected to the lower limit liquid level port. A liquid inlet pump is connected to the liquid storage inlet, and the first liquid level sensor, the second liquid level sensor and the liquid inlet pump are respectively electrically connected to the controller.

[0013] As a preferred solution, a nitrogen connection port, a pressure gauge connection port and a pressure relief valve are provided at the top of the liquid storage tank. The nitrogen connection port, the pressure gauge connection port and the pressure relief valve are respectively communicated with the liquid storage cavity, and a pressure gauge is connected to the pressure gauge connection port.

[0014] Compared with the prior art, an oil filling machine according to an embodiment of the present utility model has the following beneficial effects: The liquid storage tank is used to store the liquid to be filled. The temporary storage tank is used to temporarily store the liquid to be filled. The liquid storage tank is connected to the temporary storage tank through a liquid adding pipe, and a liquid adding pump is connected to the liquid adding pipe. The liquid storage tank continuously fills the temporary storage tank with liquid through the liquid adding pump. The temporary storage tank is communicated with the filling gun through an outlet pipe, and a filling pump is connected to the outlet pipe. Thus, when the filling gun is opened, the filling gun can be filled with liquid. The liquid adding pump continuously fills the temporary storage tank with liquid, so that the temporary storage tank always maintains a liquid state and is always ready to fill the filling gun with liquid, improving the filling efficiency of the filling gun. Adding a temporary storage tank between the liquid storage pipe and the filling gun shortens the flow distance of the liquid to the filling gun and shortens the time for the liquid to flow to the filling gun, further improving the filling efficiency of the filling gun. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 FIG. is a schematic assembly structure diagram of the liquid storage tank and the box frame according to an embodiment of the present utility model.

[0016] Figure 2 FIG. is a schematic assembly structure diagram of the liquid storage tank in the box frame according to an embodiment of the present utility model.

[0017] Figure 3 FIG. is a schematic structure diagram of the temporary storage tank on the oil return frame according to an embodiment of the present utility model.

[0018] Figure 4 FIG. is a schematic structure diagram of the liquid storage tank according to an embodiment of the present utility model.

[0019] Figure 5 FIG. is a schematic structure diagram of the liquid storage tank from another angle according to an embodiment of the present utility model.

[0020] Figure 6 FIG. is a schematic structure diagram of the oil circuit according to an embodiment of the present utility model.

[0021] In the figure:

[0022] 10. Liquid storage tank; 11. Liquid storage inlet; 12. Liquid storage return port; 13. Liquid storage outlet; 14. Liquid adding pipe; 16. Liquid storage cavity; 17. Explosion-proof heater; 18. Heating port; 19. Temperature sensor; 20. Oil discharge port; 21. Upper limit liquid level port; 22. First liquid level sensor; 23. Lower limit liquid level port; 24. Second liquid level sensor; 25. Nitrogen connection port; 26. Pressure gauge connection port; 27. Pressure relief valve;

[0023] 30. Temporary storage tank; 31. Temporary storage inlet; 32. Temporary storage outlet; 33. Outlet pipe; 34. Filling pump; 35. Temporary storage return port; 36. Return pipe;

[0024] 40, filling gun; 42, quick filling pipe; 43, quick filling pump; 45, slow filling pipe; 46, slow filling pump;

[0025] 50, box rack; 51, assembly cavity; 52, box body oil inlet; 53, box body oil outlet; 54, oil return rack. Detailed implementation manners

[0026] The following combines the accompanying drawings and embodiments to further describe in detail the detailed implementation manners of the present utility model. The following embodiments are used to illustrate the present utility model, but are not used to limit the scope of the present utility model.

[0027] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. in the present utility model is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0028] In the description of the present utility model, it should be understood that the terms "connected", "connected", "fixed", etc. in the present utility model should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, a welded connection; it can be directly connected, or indirectly connected through an intermediate medium. It can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0029] As Figures 1 to 6As shown in the figure, an oil filling machine according to a preferred embodiment of the present utility model includes a liquid storage tank 10, a temporary storage tank 30, a liquid adding pump, a liquid returning pump, a filling pump 34, and a filling gun 40. The liquid storage tank 10 is provided with a liquid storage inlet 11, a liquid storage return port 12, a liquid storage outlet 13, and a liquid storage chamber 16 that communicate with each other. The temporary storage tank 30 is provided with a temporary storage inlet 31, a temporary storage outlet 32, and a temporary storage return port 35. The liquid storage outlet 13 is connected to the temporary storage inlet 31 through a liquid adding pipe 14, and the liquid adding pipe 14 is connected to the liquid adding pump. The temporary storage outlet 32 is connected to the filling gun 40 through a liquid outlet pipe 33, and the liquid outlet pipe 33 is connected to the filling pump 34. The temporary storage return port 35 is connected to the liquid storage return port 12 through a liquid return pipe 36, and the liquid return pipe 36 is connected to the liquid returning pump. The temporary storage tank 30 is provided with a temporary storage upper limit, and the temporary storage upper limit is provided with a temporary storage liquid level sensor. The liquid returning pump is electrically connected to the temporary storage liquid level sensor. The liquid adding pump, the liquid returning pump, the filling pump 34, the filling gun 40, and the temporary storage liquid level sensor are respectively electrically connected to the controller.

[0030] For the oil filling machine of the present utility model, the liquid storage tank 10 is used to store the liquid to be filled. The temporary storage tank is used to temporarily store the liquid to be filled. The liquid storage tank 10 is connected to the temporary storage tank 30 through the liquid adding pipe 14, and the liquid adding pipe 14 is connected with a liquid adding pump. The liquid storage tank 10 continuously fills the temporary storage tank 30 with liquid through the liquid adding pump. The temporary storage tank 30 is communicated with the filling gun 40 through the liquid outlet pipe 33, and the liquid outlet pipe 33 is connected with a filling pump 34. Then, when the filling gun 40 is opened, liquid can be filled into the filling gun 40. The liquid adding pump continuously fills the temporary storage tank 30 with liquid, so that the temporary storage tank 30 always maintains a liquid state and is always ready to fill the filling gun 40 with liquid, improving the filling efficiency of the filling gun 40. Adding the temporary storage tank 30 between the liquid storage pipe and the filling gun 40 shortens the flow distance of the liquid to the filling gun 40 and shortens the time for the liquid to flow to the filling gun 40, further improving the filling efficiency of the filling gun 40.

[0031] Further, it further includes a weighing device and a flowmeter. The controller further includes a review module. The flowmeter is connected to the liquid outlet pipe 33. The weighing device, the flowmeter, and the filling pump 34 are respectively electrically connected to the review module. When the filling gun 40 is filling, the flow is controlled through the flowmeter. The object to be filled is placed on the weighing device, and the object to be filled is weighed through the weighing device, and the flow is reviewed again to improve the filling accuracy.

[0032] As one of the embodiments, when the filling amount measured by the flowmeter is inconsistent with the filling amount weighed by the weighing device, the filling amount of the weighing device shall prevail, and the object to be filled shall be compensated and filled.

[0033] Further, as Figure 6As shown, the liquid outlet pipe 33 includes a rapid filling pipe 42 and a slow filling pipe 45. The filling pump 34 includes a rapid filling pump 43 and a slow filling pump 46. The rapid filling pipe 42, the rapid filling pump 43, the temporary storage liquid outlet 32 and the filling gun 40 are connected to form a rapid filling channel. The slow filling pipe 45, the slow filling pump 46, the temporary storage liquid outlet 32 and the filling gun 40 are connected to form a slow filling channel. The power set for the rapid filling pump 43 is greater than the power set for the slow filling pump 46, thus being able to meet different filling requirements. Of course, the rapid filling channel and the slow filling channel are respectively connected with valve bodies to control the opening and closing of the rapid filling channel and the slow filling channel.

[0034] Further, as Figure 6 shown, the liquid storage tank 10, the temporary storage tank 30, the liquid adding pump, the liquid returning pump, the filling pump 34 and the filling gun 40 are connected to form a filling assembly, and multiple groups of the filling assemblies are provided. By providing multiple groups of filling assemblies, different oil types can be filled simultaneously, improving the filling efficiency and filling convenience.

[0035] Further, as Figures 1 to 3 shown, it further includes a box frame 50 and a return oil frame 54. The box frame 50 is provided with an assembly cavity 51, a box body oil inlet 52 and a box body oil outlet 53. A plurality of the liquid storage tanks 10 are connected in the assembly cavity 51. The numbers of the box body oil inlet 52 and the box body oil outlet 53 are respectively set corresponding to the number of the liquid storage tanks 10. The box body oil inlet 52 is communicated with the liquid storage inlet 11, and the box body oil outlet 53 is communicated with the liquid storage outlet 13. A plurality of the temporary storage tanks 30 are placed on the return oil frame 54. By integrating multiple groups of filling assemblies through the box frame 50 and the return oil frame 54 to form a whole, it is convenient for transportation and daily maintenance management.

[0036] Further, as Figures 4 to 5 shown, the liquid storage tank 10 is provided with a heating port 18, and an explosion-proof heater 17 is hermetically connected to the heating port 18. At least a part of the explosion-proof heater 17 extends into the liquid storage cavity 16. The liquid in the liquid storage cavity 16 is heated at a constant temperature by the explosion-proof heater 17.

[0037] Further, as Figures 4 to 5 shown, a temperature sensor 19 is connected to the outer side wall of the liquid storage tank 10. The temperature sensor 19 and the explosion-proof heater 17 are respectively electrically connected to the controller. The temperature of the liquid in the liquid storage tank 10 is obtained through the temperature sensor 19, and then the heating power of the explosion-proof heater 17 is controlled through the controller.

[0038] Further, as Figures 4 to 5As shown, an oil drain port 20 is provided at the bottom of the liquid storage tank 10, and the oil drain port 20 communicates with the liquid storage chamber 16. The oil drain port 20 is used to drain the waste oil in the liquid storage chamber 16, for cleaning the liquid storage tank 10, facilitating the daily maintenance of the liquid storage tank 10.

[0039] Further, as Figures 4 to 5 shown, an upper limit liquid level port 21 is provided at the upper end of the liquid storage tank 10, the upper limit liquid level port 21 is connected with a first liquid level sensor 22, a lower limit liquid level port 23 is provided at the lower end of the liquid storage tank 10, the lower limit liquid level port 23 is connected with a second liquid level sensor 24, and the liquid inlet 11 of the liquid storage is connected with a liquid inlet pump. The first liquid level sensor 22, the second liquid level sensor 24 and the liquid inlet pump are respectively electrically connected with the controller. The upper limit liquid level port 21 and the lower limit liquid level port 23 communicate with the liquid storage chamber 16 respectively. The first liquid level sensor 22 is used to obtain the upper limit information of the liquid in the liquid storage chamber 16, and the second liquid level sensor 24 is used to obtain the lower limit information of the liquid in the liquid storage chamber 16. The liquid inlet pump is used to input liquid into the liquid storage chamber 16. The first liquid level sensor 22, the second liquid level sensor 24 and the liquid inlet pump are respectively electrically connected with the controller to control the liquid volume in the liquid storage chamber 16 within a preset range.

[0040] Further, as Figures 4 to 5 shown, a nitrogen connection port 25, a pressure gauge connection port 26 and a pressure relief valve 27 are provided at the top of the liquid storage tank 10. The nitrogen connection port 25, the pressure gauge connection port 26 and the pressure relief valve 27 communicate with the liquid storage chamber 16 respectively. The pressure gauge connection port 26 is connected with a pressure gauge for obtaining the pressure value in the liquid storage chamber 16. The pressure relief valve 27 is used to adjust the pressure value in the liquid storage chamber 16, improving the use safety. The nitrogen connection port 25 is used to connect with a nitrogen source. Connecting nitrogen during the oil injection process can effectively prevent the oil from contacting with oxygen in the air, avoiding the oxidation of the oil, thereby prolonging the service life of the oil. At the same time, it promotes the discharge of the liquid in the liquid storage chamber 16.

[0041] In summary, the embodiment of the present utility model provides an oil filling machine. The liquid storage tank 10 is used to store the liquid to be filled. The temporary storage tank is used to temporarily store the liquid to be filled. The liquid storage tank 10 is connected to the temporary storage tank 30 through a liquid adding pipe 14. A liquid adding pump is connected to the liquid adding pipe 14. The liquid storage tank 10 continuously fills the temporary storage tank 30 with liquid through the liquid adding pump. The temporary storage tank 30 is communicated with a filling gun 40 through a liquid outlet pipe 33. A filling pump 34 is connected to the liquid outlet pipe 33. Thus, when the filling gun 40 is opened, the filling gun 40 can be filled with liquid. The liquid adding pump continuously fills the temporary storage tank 30 with liquid, so that the temporary storage tank 30 always maintains a liquid state and is always ready to fill the filling gun 40 with liquid, improving the filling efficiency of the filling gun 40. Adding a temporary storage tank 30 between the liquid storage pipe and the filling gun 40 shortens the flow distance of the liquid to the filling gun 40 and shortens the time for the liquid to flow to the filling gun 40, further improving the filling efficiency of the filling gun 40.

[0042] The above is only the preferred embodiment of the present utility model. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the technical principle of the present utility model, several improvements and replacements can still be made, and these improvements and replacements should also be regarded as the protection scope of the present utility model.

Claims

1. An oil filling machine, characterized in that: It includes a liquid storage tank, a temporary storage tank, a liquid filling pump, a liquid return pump, a filling pump, a controller and a filling gun. The liquid storage tank is provided with a liquid storage inlet, a liquid storage return port, a liquid storage outlet and a liquid storage cavity that are interconnected. The temporary storage tank is provided with a temporary storage inlet, a temporary storage outlet and a temporary storage return port. The liquid storage outlet is communicated with the temporary storage inlet through a liquid filling pipe, and the liquid filling pipe is communicated with the liquid filling pump. The temporary storage outlet is communicated with the filling gun through a liquid outlet pipe, and the liquid outlet pipe is communicated with the filling pump. The temporary storage return port is communicated with the liquid storage return port through a liquid return pipe, and the liquid return pipe is communicated with the liquid return pump. The temporary storage tank is provided with a temporary storage upper limit, and the temporary storage upper limit is provided with a temporary storage liquid level sensor. The liquid return pump is electrically connected to the temporary storage liquid level sensor. The liquid filling pump, the liquid return pump, the filling pump, the filling gun and the temporary storage liquid level sensor are respectively electrically connected to the controller.

2. The oil filling machine according to claim 1, wherein: It further includes a weighing device and a flow meter. The controller further includes a verification module. The flow meter is connected to the liquid outlet pipe. The weighing device, the flow meter and the filling pump are respectively electrically connected to the verification module.

3. The oil filling machine according to claim 1, wherein: The liquid outlet pipe includes a fast filling pipe and a slow filling pipe. The filling pump includes a fast filling pump and a slow filling pump. The fast filling pipe, the fast filling pump, the temporary storage outlet and the filling gun are communicated to form a fast filling channel. The slow filling pipe, the slow filling pump, the temporary storage outlet and the filling gun are communicated to form a slow filling channel.

4. The oil filling machine according to claim 1, wherein: The liquid storage tank, the temporary storage tank, the liquid filling pump, the liquid return pump, the filling pump and the filling gun are connected to form a filling assembly, and multiple groups of the filling assemblies are provided.

5. The oil filling machine according to claim 4, characterized in that: It further includes a box frame and a return oil frame. The box frame is provided with an assembly cavity, a box body inlet and a box body outlet. A plurality of the liquid storage tanks are connected in the assembly cavity. The numbers of the box body inlet and the box body outlet are respectively set corresponding to the number of the liquid storage tanks. The box body inlet is communicated with the liquid storage inlet, and the box body outlet is communicated with the liquid storage outlet. A plurality of the temporary storage tanks are placed on the return oil frame.

6. The oil filling machine according to claim 1, wherein: The liquid storage tank is provided with a heating port, and an explosion-proof heater is hermetically connected to the heating port. At least a part of the explosion-proof heater extends into the liquid storage cavity.

7. The oil filling machine according to claim 6, characterized in that: A temperature sensor is connected to the outer side wall of the liquid storage tank. The temperature sensor and the explosion-proof heater are respectively electrically connected to the controller.

8. The oil filling machine according to claim 1, wherein: An oil drain port is provided at the bottom of the liquid storage tank, and the oil drain port is communicated with the liquid storage cavity.

9. The oil filling machine according to claim 1, characterized in that: An upper limit liquid level port is provided at the upper end of the liquid storage tank, and a first liquid level sensor is connected to the upper limit liquid level port. A lower limit liquid level port is provided at the lower end of the liquid storage tank, and a second liquid level sensor is connected to the lower limit liquid level port. A liquid inlet pump is connected to the liquid storage inlet. The first liquid level sensor, the second liquid level sensor and the liquid inlet pump are respectively electrically connected to the controller.

10. The oil filling machine according to claim 1, wherein: A nitrogen connection port, a pressure gauge connection port and a pressure relief valve are provided at the top of the liquid storage tank. The nitrogen connection port, the pressure gauge connection port and the pressure relief valve are respectively communicated with the liquid storage cavity. A pressure gauge is connected to the pressure gauge connection port.