Capillary anti-blocking self-cleaning high-viscosity lubricating oil kinematic viscosity testing device

Abstract

The application relates to the technical field of new material detection, and discloses a capillary anti-blocking self-cleaning high-viscosity lubricating oil kinematic viscosity testing device. The application comprises a device main body, a water bath cylinder and a viscometer arranged in the water bath cylinder. The viscometer is provided with a measuring tube, a capillary, a liquid storage ball and a buffer ball connected with the capillary. The bottom of the device main body is provided with a pumping assembly, the top of the device main body is provided with a plunger pump, and the pipeline is controlled to be connected or disconnected through a valve assembly. The piston plate of the pumping assembly is driven by a compression spring and a second telescopic cylinder to slowly ascend for sampling and quickly descend for energy storage and release, so that high-speed turbulent flow is automatically formed in the capillary after the measurement is completed, and complete self-cleaning of high-viscosity residual oil samples is realized. The application effectively solves the technical problem that the capillary is prone to be blocked, integrates spiral heat conduction pipe preheating and liquid level sensing automatic timing, realizes full-process automatic measurement, and significantly improves the detection precision and efficiency.

Description

Technical Field

[0001] This invention relates to the field of new material testing technology, and in particular to a capillary anti-clogging self-cleaning device for testing the kinematic viscosity of high-viscosity lubricating oil. Background Technology

[0002] Kinematic viscosity is a core indicator for measuring the rheological properties of lubricating oils and is crucial for new material research and development and industrial applications. Currently, both domestically and internationally, kinematic viscosity meters based on glass capillaries are commonly used for measurement. While this method is standard, it has significant limitations when handling high-viscosity, easily residue-prone lubricating oil samples. After testing, traditional equipment easily leaves high-viscosity oil samples adhering to the inner wall of the capillary. If not thoroughly cleaned, this can lead to changes in the capillary diameter or even blockage, severely affecting the accuracy of subsequent measurements. Existing cleaning methods often rely on manual rinsing with organic solvents, which is not only cumbersome and inefficient but also poses risks such as incomplete cleaning, solvent contamination, and personnel health hazards.

[0003] Existing automation improvements primarily focus on automating the measurement process, such as automatic sample introduction and timing, but they fail to effectively address the fundamental problem of capillary blockage caused by high-viscosity lubricating oil. While some devices possess simple backflushing functions, their cleaning power is insufficient to generate turbulence strong enough to remove stubborn oil residues. Furthermore, inadequate sample preheating leading to a temperature difference between the oil sample entering the measurement unit and the constant-temperature bath is also a significant factor introducing measurement errors. Therefore, developing a device capable of automatically and thoroughly cleaning the capillary and ensuring sample temperature uniformity for testing the kinematic viscosity of high-viscosity lubricating oil has become a pressing technical bottleneck in this field. Summary of the Invention

[0004] The technical problem to be solved by this invention is the shortcomings of the prior art. To address this, we propose a capillary anti-clogging self-cleaning high-viscosity lubricating oil kinematic viscosity testing device.

[0005] To achieve the above objectives, this application adopts the following technical solution: a capillary anti-clogging self-cleaning high-viscosity lubricating oil kinematic viscosity testing device, comprising a main body of the device and a water bath cylinder arranged in front of the main body of the device. A viscometer is installed inside the water bath cylinder. The viscometer includes a measuring tube and venting pipes and air inlet pipes arranged on both sides of the measuring tube. The top end of the venting pipe is bent and connected to the upper part of the measuring tube. A one-way valve is provided at the bend of the top end of the venting pipe. An upper liquid storage ball and a measuring ball are arranged sequentially below the measuring tube. A capillary tube is connected to the bottom of the measuring tube. A buffer ball is provided at the bottom of the capillary tube. The bottom of the venting pipe is connected to the buffer ball. A main liquid storage ball is provided at the bottom of the air inlet pipe. The bottom of the main liquid storage ball and the bottom of the buffer ball are connected by a bend pipe. An inlet and outlet pipe are connected to the bottom of the bend pipe. Spiral heat-conducting pipes are evenly distributed below the inlet and outlet pipes. A plunger pump is movably arranged at the top front of the main body of the device. The plunger pump is used to generate negative pressure in the measuring tube.

[0006] A pumping assembly is located at the front bottom of the main body of the device. The pumping assembly includes a housing, inside which a piston plate is movably mounted. A second telescopic cylinder is connected to the bottom of the housing. The second telescopic cylinder is used to control the movement of the piston plate within the housing. The piston plate divides the interior of the housing into upper and lower spaces. The upper space inside the housing is a liquid storage chamber, which is connected to a spiral heat-conducting pipe via a connecting pipe. A valve assembly is also installed on the vent pipe and the air inlet pipe. A connecting pipe is provided between the valve assembly and the housing. One end of the connecting pipe is connected to the lower space inside the housing. This is used to generate positive pressure when the piston plate descends, causing the valve assembly to close the vent pipe and the air inlet pipe, thereby creating negative pressure inside the measuring tube to draw in the capillary.

[0007] Preferably, the water bath is equipped with a first liquid level sensor timer and a second liquid level sensor timer. The first liquid level sensor timer corresponds to the middle position between the upper liquid storage ball and the measuring ball, and the second liquid level sensor timer corresponds to the position below the measuring ball.

[0008] Preferably, a first telescopic cylinder is installed at the top front of the main body of the device. The output end of the first telescopic cylinder is fixedly connected to the plunger pump. The first telescopic cylinder is used to control the docking of the plunger pump with the top of the measuring tube. The one-way closing valve is configured such that when the plunger pump draws suction from the measuring tube, a negative pressure is generated inside the measuring tube, and the one-way closing valve is in a closed state. When the measuring tube is under normal pressure, the one-way closing valve is in a connected state.

[0009] Preferably, the valve assembly includes a housing mounted on the vent pipe and the intake pipe. The housing has a vertically penetrating channel inside and a slide groove inside. A slider is slidably connected in the slide groove. A valve plate is installed on the side of the slider near the channel, extending into the channel to change the internal communication state of the vent pipe and the intake pipe. A return spring is fixedly installed between the other side of the slider and the inner wall of the slide groove. An air inlet is provided on the side of the housing away from the channel, communicating with the inside of the slide groove. The return spring is configured such that it is in a compressed state under normal pressure inside the air inlet.

[0010] Preferably, the pumping assembly further includes a compression spring fixedly installed between the bottom of the piston plate and the inner wall of the housing, and a connecting block is provided at the bottom of the piston plate, with a transverse movable groove and a longitudinal movable groove inside the connecting block.

[0011] Preferably, both sides of the transverse movable groove are slidably connected to an extrusion block, and a small spring is installed between the extrusion block and the inner wall of the transverse movable groove. The interior of the longitudinal movable groove is slidably connected to a limit block, and a movable rod is installed at the bottom of the limit block. The other end of the movable rod passes through the bottom of the housing and is fixedly connected to the second telescopic cylinder.

[0012] Preferably, the cross-sectional shape of the extrusion block is a right trapezoid with opposite inclined surfaces and a smaller top and larger bottom, and the cross-section of the limiting block is an isosceles trapezoid with a larger top and smaller bottom.

[0013] Preferably, a connecting rod is fixedly installed on the bottom inner wall of the housing, and a guide post is fixedly connected to the end of the connecting rod. Extrusion grooves are provided at the top and bottom of the extrusion block.

[0014] Preferably, the lower sides of the interior of the housing are provided with exhaust holes that communicate with the outside, so as to prevent the piston plate inside the housing from being unable to move.

[0015] Preferably, the outer side of the housing is connected to a drain pipe and a liquid inlet pipe, and a switch valve is provided on the drain pipe and the liquid inlet pipe respectively.

[0016] The technical effects and advantages of this invention are as follows:

[0017] In this invention, the pumping and valve components work simultaneously. After measurement, an anti-clogging and self-cleaning process is automatically triggered. The compressed spring releases its stored energy to drive the piston plate, generating a transient strong suction force. Combined with the automatic closure of the valve, this creates high-speed turbulence within the capillary, thoroughly removing high-viscosity oil sample residue and fundamentally solving the capillary clogging problem. Simultaneously, it achieves full automation from sample introduction, temperature control, measurement to cleaning. Combined with the preheating function of the spiral heat pipe, it effectively eliminates measurement errors caused by temperature differences, significantly improving detection efficiency and equipment maintenance convenience while ensuring the accuracy of high-viscosity sample testing. Attached Figure Description

[0018] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals are used to refer to the same parts:

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 This is a partial structural schematic diagram of the present invention;

[0021] Figure 3 This is a front view of the viscometer and pumping assembly structure of the present invention;

[0022] Figure 4 This is a cross-sectional view of the viscometer of the present invention;

[0023] Figure 5 This is a partial structural diagram of the viscometer, valve assembly, and pumping assembly of the present invention.

[0024] Figure 6 This is a cross-sectional view of the valve assembly structure of the present invention;

[0025] Figure 7 This is a cross-sectional view of the pumping assembly structure of the present invention;

[0026] Figure 8 This is a schematic diagram of the extrusion block, limiting block, and guide post structure of the present invention.

[0027] Legend: 1. Main body of the equipment; 2. Water bath; 3. Measuring tube; 4. Vent pipe; 5. Air inlet pipe; 6. Upper liquid storage bulb; 7. Measuring bulb; 8. Capillary tube; 9. Buffer bulb; 10. Main liquid storage bulb; 11. Bend; 12. Inlet and outlet pipes; 13. Spiral heat conduction pipe; 14. One-way closing valve; 15. Outer shell; 16. Channel; 17. Valve plate; 18. Slide groove; 19. Sliding block; 20. Return spring; 21. Air inlet; 22. First liquid level sensor timer; 23. Second liquid level sensor 24. Timer; 25. Plunger pump; 26. First telescopic cylinder; 27. Connecting pipe; 28. Housing; 29. ​​Piston plate; 30. Liquid storage chamber; 31. Compression spring; 32. Exhaust port; 33. Connecting block; 34. Lateral movable groove; 35. Longitudinal movable groove; 36. Small spring; 37. Extrusion block; 38. Extrusion groove; 39. Limiting block; 40. Movable rod; 41. Connecting rod; 42. Guide column; 43. Second telescopic cylinder; 44. Connecting pipe; 45. Drain pipe; 46. Inlet pipe. Detailed Implementation

[0028] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.

[0029] Please see Figures 1 to 8 The present invention provides a capillary anti-clogging self-cleaning high viscosity lubricating oil kinematic viscosity testing device; the device includes a main body 1 and a water bath 2 disposed in front of the main body 1; a viscometer is disposed inside the water bath 2, and the water bath 2 is used to provide a constant temperature environment to ensure the accuracy of viscosity measurement.

[0030] The viscometer includes a measuring tube 3 and venting pipes 4 and inlet pipes 5 located on both sides of the measuring tube 3. The measuring tube 3 is used to carry the liquid to be measured and to measure its viscosity. The top end of the venting pipe 4 is bent and communicates with the upper part of the measuring tube 3. A one-way valve 14 is provided at the bend in the top end of the venting pipe 4. The one-way valve 14 is configured such that when the plunger pump 24 draws suction from the measuring tube 3, a negative pressure is generated inside the measuring tube 3, and the one-way valve 14 is in a closed state, ensuring that the negative pressure inside the measuring tube 3 can effectively act on the liquid. When the measuring tube 3 is under normal pressure, the one-way valve 14 is in a connected state, allowing air to flow and facilitating the descent of the oil inside the buffer ball 9.

[0031] Below the measuring tube 3, an upper liquid reservoir 6 and a measuring ball 7 are arranged sequentially; the upper liquid reservoir 6 and the measuring ball 7 are components in the viscometer used to store and measure the volume of liquid; a capillary tube 8 is connected to the bottom of the measuring tube 3, which is used to generate fluid resistance and perform viscosity measurement; a buffer ball 9 is located at the bottom of the capillary tube 8, which is used to buffer the flow of the liquid and is connected to the bottom of the venting tube 4; a main liquid reservoir 10 is located at the bottom of the inlet tube 5, which is used to store the liquid to be measured; the bottom of the main liquid reservoir 10 is connected to the buffer ball 9. The bottoms of the punch balls 9 are connected by a bend 11, and the bottom of the bend 11 is connected to the inlet and outlet pipes 12. The inlet and outlet pipes 12 are the channels for the liquid to enter and exit the viscometer. Spiral heat conduction pipes 13 are evenly distributed below the inlet and outlet pipes 12. The spiral heat conduction pipes 13 are used to preheat the liquid before it enters the viscometer to reduce the viscosity of the high-viscosity lubricating oil and facilitate measurement. The spiral heat conduction pipes 13, with their large surface area, can efficiently transfer the heat in the water bath 2 to the flowing liquid, achieving uniform and rapid preheating.

[0032] A plunger pump 24 is movably installed at the top front of the main body 1. The plunger pump 24 is used to generate negative pressure in the measuring tube 3, thereby drawing the liquid to be measured into the measuring tube 3 for measurement. In order to achieve precise docking between the plunger pump 24 and the measuring tube 3, a first telescopic cylinder 25 is installed at the top front of the main body 1. The output end of the first telescopic cylinder 25 is fixedly connected to the plunger pump 24. The first telescopic cylinder 25 is used to control the docking between the plunger pump 24 and the top of the measuring tube 3.

[0033] A pumping assembly is installed at the bottom front of the main body 1. The pumping assembly is used to pump the liquid to be tested to the viscometer and achieve the cleaning function. The pumping assembly includes a housing 27, and a piston plate 28 is movably installed inside the housing 27. A second telescopic cylinder 42 is connected to the bottom of the housing 27. The second telescopic cylinder 42 is used to control the movement of the piston plate 28 inside the housing 27. The piston plate 28 divides the interior of the housing 27 into upper and lower spaces. The upper space inside the housing 27 is a liquid storage chamber 29, which is used to store the liquid to be tested. The liquid storage chamber 29 is connected to the spiral heat conduction pipe 13 through the connecting pipe 26 to form a liquid delivery path.

[0034] Valve assemblies are also provided on the vent pipe 4 and the intake pipe 5; a connecting pipe 43 is provided between the valve assembly and the housing 27, and one end of the connecting pipe 43 is connected to the lower space inside the housing 27; the connecting pipe 43 is used to transfer the positive pressure generated in the lower space inside the housing 27 to the valve assembly when the piston plate 28 descends, so as to cause the valve assembly to close the vent pipe 4 and the intake pipe 5, thereby generating a negative pressure inside the measuring tube 3 to draw the capillary tube 8, and realizing the self-cleaning function.

[0035] In a preferred embodiment, a first liquid level sensor timer 22 and a second liquid level sensor timer 23 are installed inside the water bath 2; the first liquid level sensor timer 22 corresponds to the middle position between the upper liquid storage ball 6 and the measuring ball 7, and the second liquid level sensor timer 23 corresponds to the position below the measuring ball 7; these two liquid level sensor timers are used to accurately detect the time it takes for the liquid to flow through a specific position, thereby automatically calculating the kinematic viscosity value, improving the automation and accuracy of the measurement.

[0036] In a preferred embodiment, see [reference] Figure 6 The valve assembly includes a housing 15 mounted on the vent pipe 4 and the intake pipe 5, with a vertically penetrating channel 16 inside the housing 15; a slide groove 18 is also provided inside the housing 15, with a slider 19 slidably connected within the slide groove 18; a valve plate 17 is mounted on the side of the slider 19 near the channel 16, extending into the channel 16 to change the communication state between the vent pipe 4 and the intake pipe 5; a return spring 20 is fixedly installed between the other side of the slider 19 and the inner wall of the slide groove 18; the housing 15... An air inlet 21 is provided on the side away from the channel 16, and the air inlet 21 is connected to the inside of the slide groove 18. The return spring 20 is configured such that: under normal pressure inside the air inlet 21, the return spring 20 is in a compressed state, so that the valve plate 17 does not obstruct the connection of the channel 16; when the air inlet 21 receives positive pressure from the connecting pipe 43, the positive pressure overcomes the elastic force of the return spring 20, pushes the slider 19 and the valve plate 17 to move, thereby closing the channel 16 and realizing the closure of the vent pipe 4 and the air inlet pipe 5.

[0037] Example 2

[0038] Please see Figure 7 and Figure 8 This embodiment, based on Embodiment 1, further describes in detail the structure and working principle of the pumping component.

[0039] The pumping assembly also includes a compression spring 30 fixedly installed between the bottom of the piston plate 28 and the inner wall of the housing 27; the compression spring 30 is compressed when the piston plate 28 descends and releases energy under specific conditions to drive the piston plate 28 to rebound quickly and generate a strong suction force; a connecting block 32 is also provided at the bottom of the piston plate 28, and the interior of the connecting block 32 is provided with a transverse movable groove 33 and a longitudinal movable groove 34.

[0040] Both sides of the transverse movable groove 33 are slidably connected to the extrusion block 36, and small springs 35 are installed between the extrusion block 36 and the inner wall of the transverse movable groove 33. The small springs 35 are used to push the extrusion block 36 inward. The interior of the longitudinal movable groove 34 is slidably connected to the limit block 38, and the bottom of the limit block 38 is equipped with a movable rod 39. The other end of the movable rod 39 passes through the bottom of the housing 27 and is fixedly connected to the second telescopic cylinder 42.

[0041] The cross-sectional shape of the extrusion block 36 is a right trapezoid with opposite inclined surfaces and a smaller upper surface and a larger lower surface. The cross-section of the limiting block 38 is an isosceles trapezoid with a larger upper surface and a smaller lower surface. This allows the limiting block 38 to push the extrusion block 36 outward through its inclined surface and return to the area below the extrusion block 36 when it moves downward to reset.

[0042] A connecting rod 40 is fixedly installed on the bottom inner wall of the housing 27, and a guide post 41 is fixedly connected to the end of the connecting rod 40; the top and bottom of the extrusion block 36 are provided with extrusion grooves 37; under normal conditions, the upper part of the limiting block 38 contacts the lower part of the two sets of extrusion blocks 36, at which time the extrusion block 36 is pushed upward by the limiting block 38, thereby pushing the piston plate 28.

[0043] Working principle:

[0044] Phase 1: Slow Sample Injection and Synchronous Heating: In the initial state, the second telescopic cylinder 42 starts, and its output end pushes the limiting block 38 upward through the movable rod 39. The upper part of the limiting block 38 contacts the lower part of the extrusion block 36. Due to the special trapezoidal structure of the limiting block 38 and the extrusion block 36, the limiting block 38 pushes the extrusion block 36 during its ascent, causing the connecting block 32 and the piston plate 28 to move slowly upward. The slow rise of the piston plate 28 smoothly pushes the lubricating oil to be tested inside the liquid storage chamber 29 into the spiral heat conduction tube 13 through the connecting pipe 26. When the lubricating oil flows through the spiral heat conduction tube 13, due to the huge surface area of ​​the spiral heat conduction tube 13, it can efficiently absorb heat from the water bath 2, achieving uniform and rapid preheating, reducing its viscosity, and facilitating subsequent measurement. The preheated lubricating oil enters the bottom of the viscometer through the inlet and outlet pipes 12 and slowly fills the main liquid storage ball 10 and other parts.

[0045] Phase Two: Constant Temperature Measurement and Automatic Timing: After the sample is filled, the first telescopic cylinder 25 is activated, pressing down the plunger pump 24 and sealing it with the top of the measuring tube 3. Subsequently, the plunger pump 24 operates, generating negative pressure inside the measuring tube 3. At this time, the one-way valve 14 at the top of the venting tube 4 automatically closes due to the negative pressure, ensuring a negative pressure environment inside the measuring tube 3. Under the negative pressure, the oil sample at the bottom of the viscometer is drawn up and flows upward through the capillary tube 8, sequentially entering the measuring ball 7 and the upper reservoir ball 6. Then, the first telescopic cylinder 25 drives the plunger pump 24 to reset, the one-way valve opens, the oil sample below the capillary tube 8 is vented, and the oil sample in the measuring tube 3 flows under gravity, officially starting the test. When the oil sample level passes the first liquid level sensor timer 22 and the second liquid level sensor timer 23, the system automatically records its flow time and calculates the kinematic viscosity value according to the preset formula.

[0046] Phase 3: After measurement, the system automatically enters cleaning mode; the second telescopic cylinder 42 continues to extend, further pushing the movable rod 39 and the limiting block 38 upward; when the limiting block 38 pushes the extrusion block 36 to the bottom, the guide column 41, through the guiding action of the extrusion groove 37, causes the two sets of extrusion blocks 36 to overcome the elastic force of the small spring 35 and move away from each other, thereby disengaging from the limiting block 38 and releasing the lock on the piston plate 28; the compressed compression spring 30 quickly releases energy, pulling the piston plate 28 downward rapidly. At the same time, the air below the piston plate 28 is compressed, and the generated positive pressure gas is forced into the air inlet 21 of the valve assembly. This positive pressure overcomes the elastic force of the return spring 20, pushing the slider 19 and the valve plate 17. The valve plate 17 is moved to the middle of the channel 16, thereby simultaneously closing the vent pipe 4 and the air inlet pipe 5. At this time, a closed system is formed inside the viscometer. The rapid descent of the piston plate 28 generates a strong suction force in the liquid storage chamber 29. This strong negative pressure is transmitted to the bottom of the viscometer through the connecting pipe 26, the spiral heat conduction pipe 13 and the inlet and outlet pipes 12, which quickly draws out the waste liquid in the viscometer and forms a high-speed turbulent flow in the capillary tube 8. This effectively washes away the residual oil sample on the tube wall, achieving rapid and thorough cleaning of the capillary tube 8 and effectively preventing blockage. During this process, cleaning fluid can be injected from the top of the measuring tube 3 to cooperate with this strong negative pressure suction process, achieving thorough cleaning of the entire pipeline and capillary tube.

[0047] In a preferred embodiment, the lower sides of the housing 27 are provided with exhaust holes 31 that communicate with the outside, so as to prevent the piston plate 28 inside the housing 27 from being unable to move, and to ensure that the air pressure in the space below the piston plate 28 can be discharged in time when the piston plate 28 moves, while also ensuring that the inside is still in a positive pressure state, so as to ensure the smooth movement of the piston plate 28 and the closing of the valve assembly.

[0048] In a preferred embodiment, a drain pipe 44 and an inlet pipe 45 are connected to the outside of the housing 27. The drain pipe 44 and the inlet pipe 45 are respectively equipped with a switch valve. The drain pipe 44 is used to discharge waste liquid or cleaning liquid in the liquid storage chamber 29, and the inlet pipe 45 is used to replenish new test samples or cleaning liquid. The inlet and outlet of the liquid can be easily controlled by the switch valve.

[0049] The technical scope of this invention is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the protection scope of this invention.

Claims

1. A capillary anti-blocking self-cleaning high viscosity lubricating oil kinematic viscosity testing device, characterized in that, The device includes a main body and a water bath located in front of the main body. A viscometer is installed inside the water bath. The viscometer includes a measuring tube and venting and inlet pipes on both sides of the measuring tube. The top of the venting pipe is bent and communicates with the upper part of the measuring tube. A one-way valve is installed at the bend in the top of the venting pipe. An upper liquid storage ball and a measuring ball are sequentially arranged below the measuring tube. A capillary tube is connected to the bottom of the measuring tube, and a buffer ball is located at the bottom of the capillary tube. The bottom of the venting pipe communicates with the buffer ball. A main liquid storage ball is located at the bottom of the inlet pipe. The bottom of the main liquid storage ball and the bottom of the buffer ball are connected by a bend pipe. An inlet and outlet pipe are connected to the bottom of the bend pipe. Spiral heat-conducting pipes are evenly distributed below the inlet and outlet pipes. A plunger pump is movably installed at the top front of the main body of the device. The plunger pump is used to generate negative pressure inside the measuring tube. A pumping assembly is located at the front bottom of the main body of the equipment. The pumping assembly includes a housing, inside which a piston plate is movably mounted. A second telescopic cylinder is connected to the bottom of the housing. The second telescopic cylinder is used to control the movement of the piston plate inside the housing. The piston plate divides the interior of the housing into upper and lower spaces. The upper space inside the housing is a liquid storage chamber, which is connected to a spiral heat-conducting pipe through a connecting pipe. A valve assembly is also installed on the vent pipe and the air inlet pipe. A connecting pipe is provided between the valve assembly and the housing. One end of the connecting pipe is connected to the lower space inside the housing. This is used to generate positive pressure when the piston plate descends, causing the valve assembly to close the vent pipe and the air inlet pipe, thereby generating negative pressure inside the measuring tube to draw the capillary. The valve assembly includes a housing mounted on the vent pipe and the intake pipe. The housing has a vertically penetrating channel inside and a slide groove inside. A slider is slidably connected in the slide groove. A valve plate is mounted on the side of the slider near the channel and extends into the channel to change the internal communication state of the vent pipe and the intake pipe. A return spring is fixedly installed between the other side of the slider and the inner wall of the slide groove. An air inlet is provided on the side of the housing away from the channel and communicates with the inside of the slide groove. The return spring is configured such that it is in a compressed state under normal pressure inside the air inlet. The pumping assembly also includes a compression spring fixedly installed between the bottom of the piston plate and the inner wall of the housing. The bottom of the piston plate is also provided with a connecting block, and the interior of the connecting block is provided with a transverse movable groove and a longitudinal movable groove. Both sides of the transverse movable groove are slidably connected to the extrusion blocks, and small springs are installed between the extrusion blocks and the inner wall of the transverse movable groove. The interior of the longitudinal movable groove is slidably connected to the limit block, and a movable rod is installed at the bottom of the limit block. The other end of the movable rod passes through the bottom of the housing and is fixedly connected to the second telescopic cylinder. The cross-sectional shape of the extrusion block is a right trapezoid with opposite inclined surfaces and a smaller top and larger bottom, while the cross-section of the limiting block is an isosceles trapezoid with a larger top and smaller bottom. A connecting rod is fixedly installed on the bottom inner wall of the housing, and a guide post is fixedly connected to the end of the connecting rod. Extrusion grooves are provided at the top and bottom of the extrusion block.

2. The capillary anti-clogging self-cleaning high-viscosity lubricating oil kinematic viscosity testing device according to claim 1, characterized in that: The water bath is equipped with a first liquid level sensor timer and a second liquid level sensor timer. The first liquid level sensor timer corresponds to the middle position between the upper liquid storage ball and the measuring ball, and the second liquid level sensor timer corresponds to the position below the measuring ball.

3. The capillary anti-clogging self-cleaning high-viscosity lubricating oil kinematic viscosity testing device according to claim 1, characterized in that: A first telescopic cylinder is installed at the top front of the main body of the device. The output end of the first telescopic cylinder is fixedly connected to the plunger pump. The first telescopic cylinder is used to control the plunger pump to dock with the top of the measuring tube. The one-way closing valve is configured such that when the plunger pump draws suction from the measuring tube, a negative pressure is generated inside the measuring tube, and the one-way closing valve is in a closed state. When the measuring tube is under normal pressure, the one-way closing valve is in a connected state.

4. The capillary anti-clogging self-cleaning high-viscosity lubricating oil kinematic viscosity testing device according to claim 1, characterized in that: The lower sides of the interior of the housing are provided with exhaust vents that communicate with the outside, so as to prevent the piston plate inside the housing from being unable to move.

5. The capillary anti-clogging self-cleaning high-viscosity lubricating oil kinematic viscosity testing device according to claim 4, characterized in that: The outer side of the housing is connected to a drain pipe and a liquid inlet pipe, and each of the drain pipe and the liquid inlet pipe is equipped with a switch valve.

Images