Porous material aperture testing device and use method thereof

Abstract

The invention belongs to the technical field of material aperture testing, and particularly relates to a porous material aperture testing device and a using method thereof.The porous material aperture testing device comprises a water supply assembly, a pressure supply testing mechanism, a workpiece self-locking mechanism, a circulating assembly and a main bottom plate, the water supply assembly comprises a water supply disc and a pressure sensor, and the water supply disc is arranged on the main bottom plate; and the pressure sensor is arranged in the water supply disc. According to a flow calculation formula of fluid in a pipeline, in combination with the relation between the specific resistance of the pipeline and the pipe diameter, it can be obtained that in a relation curve of the pressure difference and the square of the flow speed, the inclination degree is mainly influenced by the pipe diameter, and on the basis, the pipe diameter and the total flow intercepting area jointly influence the height of the curve; according to the phenomenon, in combination with the characteristic of continuous measurement of the scheme, a continuous pressure-speed relation curve can be obtained, so that two conditions of small and dense holes and large and sparse holes are distinguished.

Description

Technical Field

[0001] The present invention belongs to the technical field of material pore size testing, and in particular relates to a porous material pore size testing device and a method for using the same. Background Art

[0002] Porous materials are widely used in filtration, catalysis, biomedicine and other fields, and their pore size distribution is a key performance indicator. The pore size test of porous materials is microscopic, and the traditional mercury intrusion method and bubble point method have problems such as complex equipment steps, long test cycles, and possible damage to samples. This solution determines the pore size and density of porous materials by the relationship between pressure and flow rate when the liquid passes through the porous material. This solution has the advantages of simplicity and speed.

[0003] The basic principle of this solution is similar to the above two methods. Both methods use pressure to force the fluid through micropores. However, there is a problem with this test: small and dense pores and large and sparse pores may pass through the sample at the same speed under the same pressure. Therefore, how to distinguish between these two situations is a key step in improving this solution. Summary of the Invention

[0004] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a porous material aperture testing device and a method for using the same. According to the flow calculation formula of the fluid in the pipeline, combined with the relationship between the pipeline specific resistance and the pipe diameter, it can be concluded that in the relationship curve between the pressure difference and the square of the flow rate, the degree of inclination is mainly affected by the pipe diameter. On this basis, the pipe diameter and the total cross-sectional area jointly affect the height of the curve; based on this phenomenon, combined with the characteristic of continuous measurement possessed by this scheme, a continuous pressure difference and flow rate square curve can be obtained, thereby distinguishing between small and dense pores and large and sparse pores.

[0005] The technical solution adopted by the present invention is as follows: The present invention proposes a porous material pore size testing device, including a water supply component, a pressure supply testing mechanism, a workpiece self-locking mechanism, a circulation component and a main base plate, the water supply component including a water supply tray and a pressure sensor, the water supply tray is arranged on the main base plate, and the pressure sensor is arranged in the water supply tray; The pressure supply test mechanism includes a test box and a flow rate sensing component, wherein the test box is arranged on the main bottom plate, and the flow rate sensing component includes a box cover, a drain pipe and a flow rate sensor, wherein the box cover is arranged on the test box, the drain pipe is arranged on the box cover, and the flow rate sensor is arranged in the drain pipe; According to the flow calculation formula of the fluid in the pipeline, combined with the relationship between the pipeline specific resistance and the pipe diameter, it can be concluded that in the relationship curve between the pressure difference and the square of the flow velocity, the degree of inclination is mainly affected by the pipe diameter. On this basis, the pipe diameter and the total cross-sectional area jointly affect the height of the curve. Based on this feature, it is possible to distinguish between small and dense holes and large and sparse holes through continuous measurement.

[0006] The water supply tray is provided with a water distribution pipe connected to the bottom of the test box; The workpiece self-locking mechanism is arranged in the test box.

[0007] Through the pressure sensor and flow rate sensor, the pressure difference at both ends of the workpiece being measured and the speed of the liquid flowing through the workpiece being measured can be collected, and the relative relationship can be obtained. According to the height and inclination of the curve, the aperture of the workpiece being measured can be detected, so as to determine the deviation amplitude between it and the standard sample, which is conducive to judging the qualification of the product.

[0008] Furthermore, the workpiece self-locking mechanism includes a pressure plate locking assembly and an automatic telescopic assembly, the pressure plate locking assembly is arranged in the test box, and the automatic telescopic assembly is slidably arranged in the pressure plate locking assembly.

[0009] Preferably, the pressure plate locking assembly includes a workpiece mounting frame, a sliding locking pin and a supporting pressure plate. The workpiece mounting frame is fixed to the inner wall of the test box. The workpiece mounting frame is evenly distributed with horizontal sliding grooves in a ring shape. The sliding locking pin is engaged and slidably arranged in the horizontal sliding groove. The supporting pressure plate is engaged in the workpiece mounting frame. The supporting pressure plate is located above the workpiece to be measured.

[0010] By extending the sliding lock pin, the workpiece to be measured and the supporting pressure plate can be locked and limited, thereby preventing the workpiece to be measured and the supporting pressure plate from shifting upward when impacted by liquid.

[0011] The support platen can support the workpiece to be tested, avoiding the problem that the sliding locking pin cannot lock it when testing the workpiece made of flexible material. Although the support platen will interfere with the flow of liquid, since the interference it causes to all samples is the same, this interference can be eliminated through software compensation.

[0012] As a further preferred embodiment of the present invention, the automatic telescopic assembly includes a hollow floating ring, a ridged chain and a reset spring. The bottom of the workpiece mounting frame is also provided with an annular slide groove. The hollow floating ring is engaged and slidably arranged in the annular slide groove. The two ends of the ridged chain are respectively connected to the sliding lock pin and the hollow floating ring. The ridged chain can transmit tension and thrust while deforming.

[0013] Through the lifting drive of the hollow floating ring and the push-pull transmission of the ridge chain, the workpiece to be tested and the supporting platen can be automatically locked when the liquid level in the test chamber reaches a certain value. When the liquid level in the test chamber is lower than this value, the workpiece to be tested and the supporting platen are automatically unlocked, which simplifies the operation steps and speeds up the loading and unloading of the workpiece to be tested.

[0014] As a further preferred embodiment of the present invention, the return spring is provided between the hollow floating ring and the workpiece mounting bracket.

[0015] Furthermore, the pressure supply testing mechanism also includes an exhaust assembly, which includes an exhaust valve body and a floating valve core. The exhaust valve body is arranged on the box cover, and the floating valve core is provided with a T-shaped limit rod. The T-shaped limit rod is located in the exhaust valve body, and the floating valve core can seal the exhaust valve body when it rises.

[0016] Preferably, the box cover is further provided with a water inlet, the exhaust assembly further comprises a soft plug, the soft plug is detachably provided in the water inlet, and the box cover is further provided with a handle.

[0017] By lifting and opening and closing the floating valve core, the air in the test box can be automatically discharged when the liquid level rises, and it will automatically close after the liquid fills the test box, which can prevent the liquid from overflowing from the exhaust valve body.

[0018] Preferably, the circulation component includes a water tank and a water pump, a filtering device is provided in the water tank, the water pump is arranged below the water supply tray, the main base plate and the water tank are connected by a water pump and a hose, and the drain pipe and the filtering device are connected by a hose. The water in the filtering device will flow back into the water tank after filtration.

[0019] The present invention also provides a method for using a porous material pore size testing device, which specifically includes the following steps: Step 1: First open the box cover, put the workpiece to be tested and the support plate into the test box in sequence, make them enter the workpiece mounting frame, and then close the box cover; Step 2: Start the water pump to pump the liquid in the water tank into the water supply tray, and then into the test box through the water distribution pipe, so that the liquid level in the test box rises. Before measurement, the test box needs to be filled with liquid. This step can also be done by removing the soft plug and adding liquid manually. Step 3: As the liquid level in the test chamber rises, the air in the test chamber is discharged through the gap between the exhaust valve body and the floating valve core. When the test chamber is filled with liquid, the floating valve core will rise to block the exhaust valve body. Therefore, even after the test chamber is filled with liquid, there will be no leakage from the exhaust valve body. Step 4: As the liquid level rises, the buoyancy of the hollow float will continue to increase until it is sufficient to overcome the elastic force of the return spring and rise. When the hollow float rises, it can push the sliding lock pin to slide out horizontally through the ridge chain, locking the support plate. The ridge chain is composed of several blocks hinged in sequence, and the rotation angle of adjacent blocks is limited; Step 5: After the preparation is completed, you can start the water pump for testing. During the test, the pressure sensor in the water supply tray can sense the water pressure under the workpiece being tested. The water in the test box will overflow through the drain pipe, and the flow rate sensor will sense the flow rate, and the flow rate can also be obtained; Step 6: The monitoring results of the pressure sensor can form a closed-loop regulation for the water pump, so that the water supply pressure in the water supply tray shows a stable and slowly rising trend. According to the readings of the pressure sensor and the flow rate sensor, the relationship between the square of the flow rate and the water supply pressure can be obtained; when the liquid flows from the hole in the middle of the measured workpiece, the square of the flow rate is proportional to the pressure difference between the two ends. Since the overflow end is connected to the atmosphere, the changing trend of the pressure sensor reading is the changing trend of the pressure difference between the two ends. The relationship between the square of the flow rate and the water supply pressure is an overall oblique line; the aperture affects the degree of inclination of the oblique line, and on this basis, the total intercepting area affects the height of the oblique line; Step 7: Compare the measured curve with the curve of the standard sample to determine the deviation of the workpiece and then determine its eligibility; Step 8: The liquid overflowing from the drain pipe enters the filter device and flows back into the water tank after being filtered by the filter device.

[0020] The beneficial effects achieved by the present invention using the above structure are as follows: (1) According to the flow calculation formula of the fluid in the pipeline, combined with the relationship between the pipeline specific resistance and the pipe diameter, it can be concluded that in the relationship curve between the pressure difference and the square of the flow velocity, the degree of inclination is mainly affected by the pipe diameter. On this basis, the pipe diameter and the total cross-sectional area jointly affect the height of the curve; based on this feature, it is possible to distinguish between small and dense holes and large and sparse holes through continuous measurement.

[0021] (2) Through the pressure sensor and flow rate sensor, the pressure difference at both ends of the workpiece and the speed of the liquid flowing through the workpiece can be collected, and the relative relationship can be obtained. According to the height and inclination of the curve, the aperture of the workpiece can be detected, so as to judge the deviation between it and the standard sample, which is conducive to judging the qualification of the product.

[0022] (3) By extending the sliding lock pin, the workpiece to be measured and the supporting pressure plate can be locked and limited to avoid the upward position displacement of the workpiece to be measured and the supporting pressure plate when the liquid impacts.

[0023] (4) By lifting and opening and closing the floating valve core, the air in the test chamber can be automatically discharged during the rising of the liquid level, and it will automatically close after the liquid fills the test chamber, thus preventing the liquid from overflowing from the exhaust valve body.

[0024] (5) The support plate can support the workpiece to be tested, avoiding the problem that the sliding lock pin cannot lock the workpiece when testing the workpiece made of flexible material. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A three-dimensional diagram of a porous material pore size testing device proposed by the present invention; Figure 2 This is a front view of a porous material pore size testing device proposed by the present invention; Figure 3 This is a left view of a porous material pore size testing device proposed by the present invention; Figure 4 A top view of a porous material pore size testing device proposed by the present invention; Figure 5 for Figure 3 A cross-sectional view along the cutting line AA; Figure 6 A schematic diagram of a half-section structure of a porous material pore size testing device proposed in the present invention; Figure 7 for Figure 5 A partial enlarged view of point Ⅰ in the middle; Figure 8 for Figure 5 A partial enlarged view of the middle II; Figure 9 for Figure 6 A partial enlarged view of point III in the middle; Figure 10 Schematic diagram of the relationship between the pressure sensor reading and the square of the flow sensor reading.

[0026] Among them, 1. Water supply component, 2. Pressure supply test mechanism, 3. Workpiece self-locking mechanism, 4. Circulation component, 5. Main base plate, 6. Water supply plate, 7. Pressure sensor, 8. Water distribution pipe, 9. Test box, 10. Flow rate sensing component, 11. Exhaust component, 12. Support legs, 13. Box cover, 14. Drain pipe, 15. Flow rate sensor, 16. Exhaust valve body, 17. Floating valve core, 18. Soft plug, 19. Handle, 20. Water inlet, 21. T-shaped limit rod, 22. Pressure plate locking assembly, 23. Automatic telescopic assembly, 24. Workpiece mounting frame, 25. Sliding lock pin, 26. Support pressure plate, 27. Hollow floating ring, 28. Ridge chain, 29. Return spring, 30. Annular slide, 31. Horizontal slide, 32. Water tank, 33. Water pump, 34. Filter device, 35. Workpiece to be measured.

[0027] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be understood that terms such as "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0030] like Figures 1 to 9 As shown, the present invention proposes a porous material pore size testing device, including a water supply component 1, a pressure supply testing mechanism 2, a workpiece self-locking mechanism 3, a circulation component 4 and a main base plate 5. The water supply component 1 includes a water supply tray 6 and a pressure sensor 7. The water supply tray 6 is arranged on the main base plate 5, and the pressure sensor 7 is arranged in the water supply tray 6; The pressure supply test mechanism 2 includes a test box 9 and a flow rate sensing assembly 10. The test box 9 is provided with a support leg 12, and the test box 9 is mounted on the main base plate 5 via the support leg 12. The flow rate sensing assembly 10 includes a box cover 13, a drain pipe 14, and a flow rate sensor 15. The box cover 13 is mounted on the test box 9, the drain pipe 14 is mounted on the box cover 13, and the flow rate sensor 15 is mounted in the drain pipe 14. According to the flow calculation formula of the fluid in the pipeline, combined with the relationship between the pipeline specific resistance and the pipe diameter, it can be concluded that in the relationship curve between the pressure difference and the square of the flow velocity, the degree of inclination is mainly affected by the pipe diameter. On this basis, the pipe diameter and the total cross-sectional area jointly affect the height of the curve. Based on this feature, it is possible to distinguish between small and dense holes and large and sparse holes through continuous measurement.

[0031] The water supply tray 6 is provided with a water distribution pipe 8 connected to the bottom of the test box 9; The workpiece self-locking mechanism 3 is arranged in the test box 9 .

[0032] Through the pressure sensor 7 and the flow rate sensor 15, the pressure difference at both ends of the workpiece 35 to be measured and the speed of the liquid flowing through the workpiece 35 to be measured can be collected, and the relative relationship can be obtained. According to the height and inclination of the curve, the aperture of the workpiece 35 to be measured can be detected, so as to judge the deviation amplitude between it and the standard sample, which is conducive to judging the qualification of the product.

[0033] The workpiece self-locking mechanism 3 includes a pressure plate locking assembly 22 and an automatic telescopic assembly 23 . The pressure plate locking assembly 22 is disposed in the test box 9 , and the automatic telescopic assembly 23 is slidably disposed in the pressure plate locking assembly 22 .

[0034] The pressure plate locking assembly 22 includes a workpiece mounting frame 24, a sliding locking pin 25 and a supporting pressure plate 26. The workpiece mounting frame 24 is fixed to the inner wall of the test box 9. The workpiece mounting frame 24 is evenly distributed with horizontal sliding grooves 31 in a ring shape. The sliding locking pin 25 is engaged and slidably arranged in the horizontal sliding grooves 31. The supporting pressure plate 26 is engaged in the workpiece mounting frame 24. The supporting pressure plate 26 is located above the workpiece 35 to be measured.

[0035] By extending the sliding lock pin 25, the workpiece 35 to be measured and the supporting platen 26 can be locked and limited, thereby preventing the workpiece 35 to be measured and the supporting platen 26 from shifting upward when liquid impacts.

[0036] The supporting platen 26 can support the workpiece 35 to be tested, thereby avoiding the problem that the sliding locking pin 25 cannot lock the workpiece 35 made of flexible material when testing it.

[0037] The automatic telescopic assembly 23 includes a hollow floating ring 27, a ridged chain 28 and a return spring 29. An annular slide groove 30 is also provided at the bottom of the workpiece mounting frame 24. The hollow floating ring 27 is engaged and slidably arranged in the annular slide groove 30. The two ends of the ridged chain 28 are respectively connected to the sliding lock pin 25 and the hollow floating ring 27. The ridged chain 28 can transmit tension and thrust while deforming.

[0038] Through the lifting drive of the hollow float 27 and the push-pull transmission of the ridge chain 28, the workpiece 35 to be tested and the supporting platen 26 can be automatically locked when the liquid level in the test box 9 reaches a certain value. When the liquid level in the test box 9 is lower than this value, the workpiece 35 to be tested and the supporting platen 26 are automatically unlocked, which simplifies the operation steps and also speeds up the loading and unloading speed of the workpiece 35 to be tested.

[0039] The return spring 29 is provided between the hollow floating ring 27 and the workpiece mounting frame 24 .

[0040] The pressure supply test mechanism 2 also includes an exhaust assembly 11, which includes an exhaust valve body 16 and a floating valve core 17. The exhaust valve body 16 is arranged on the box cover 13, and the floating valve core 17 is provided with a T-shaped limit rod 21. The T-shaped limit rod 21 is located in the exhaust valve body 16, and the floating valve core 17 can seal the exhaust valve body 16 when it rises.

[0041] The box cover 13 is further provided with a water inlet 20 . The exhaust assembly 11 further includes a soft plug 18 . The soft plug 18 is detachably disposed in the water inlet 20 . The box cover 13 is further provided with a handle 19 .

[0042] By lifting and opening and closing the floating valve core 17, the air in the test box 9 can be automatically discharged during the process of rising liquid level, and it will automatically close after the liquid fills the test box 9, thereby preventing liquid from overflowing from the exhaust valve body 16.

[0043] The circulation component 4 includes a water tank 32 and a water pump 33. A filter device 34 is provided in the water tank 32. The water pump 33 is arranged below the water supply tray 6. The main base plate 5 and the water tank 32 are connected by the water pump 33 and a hose. The drain pipe 14 and the filter device 34 are connected by a hose. The water in the filter device 34 will flow back into the water tank 32 after being filtered.

[0044] like Figure 10 As shown, the horizontal axis represents the reading P of the pressure sensor 7. Since the drain pipe 14 is connected to the external atmosphere, the changing trend of the reading of the pressure sensor 7 is the changing trend of the pressure difference across the test box 9. The vertical axis represents the square of the reading of the flow rate sensor 15, which can reflect the flow rate or flow rate of the liquid when it flows through the workpiece 35 being tested. The area between a and b represents the measurement range of the statistical indications. The workpiece self-locking mechanism 3 has completed automatic locking before a. D, B, and C are curve examples of three samples. Taking into account factors such as accuracy and error, the actual curve may fluctuate, but the overall trend is linear as shown in the figure. According to the calculation formula of the flow rate in the pipeline: ; ; Where Q is the flow rate, A is the cross-sectional area, v is the flow velocity; P is the pressure difference between the two ends, ρ is the fluid density, g is the acceleration of gravity, S is the pipe resistance, L is the pipe length; n is the roughness coefficient of the pipe (related to the material), and d is the inner diameter of the pipe. According to the above formula, P and v² are proportional, d affects the proportional coefficient of the two (the smaller d is, the smaller the proportional coefficient of the two is, and the smaller the slope of the curve is), and the other parameters are fixed values; D represents the measurement result curve of the standard sample. B and D have an intersection, which means that when the test pressure is c, the flow rates of the two are equal. However, combined with the slope analysis of the curve, it can be seen that the pore size of sample B is smaller than that of sample D. At the same time, the total cross-sectional area of ​​sample B is larger than that of sample D. The total cross-sectional area represents the sum of all pore sizes of the sample. The slopes of curves C and B are equal, indicating that their pore sizes are close, but the different pore densities result in different total cross-sectional areas, so the heights of the two curves are different.

[0045] When in use, first open the box cover 13, put the workpiece 35 and the support plate 26 into the test box 9 in sequence, make them enter the workpiece mounting frame 24, and then close the box cover 13; Start the water pump 33 to pump the liquid in the water tank 32 into the water supply tray 6, and then into the test box 9 through the water distribution pipe 8, so that the liquid level in the test box 9 rises. Before measurement, the test box 9 needs to be filled with liquid. This step can also be done manually by removing the soft plug 18.

[0046] As the liquid level in the test box 9 rises, the air in the test box 9 is discharged through the gap between the exhaust valve body 16 and the floating valve core 17. When the test box 9 is filled with liquid, the floating valve core 17 will block the exhaust valve body 16 by its own rise. Therefore, even after the test box 9 is filled with liquid, there will be no leakage from the exhaust valve body 16. As the liquid level rises, the buoyancy of the hollow float 27 will continue to increase until it is sufficient to overcome the elastic force of the return spring 29 and rise. When the hollow float 27 rises, it can push the sliding lock pin 25 to slide out laterally through the ridge chain 28, locking the support pressure plate 26. The ridge chain 28 is composed of several blocks hinged in sequence, and the rotation angle of adjacent blocks is limited.

[0047] After the preparation work is completed, the water pump 33 can be started for testing. During the test, the pressure sensor 7 in the water supply tray 6 can sense the water pressure under the workpiece 35 to be tested. The water in the test box 9 will overflow through the drain pipe 14 and sense the flow rate through the flow rate sensor 15, and the flow rate can also be known.

[0048] The monitoring results of the pressure sensor 7 can form a closed-loop regulation for the water pump 33, so that the water supply pressure in the water supply tray 6 shows a stable and slowly rising trend. According to the readings of the pressure sensor 7 and the flow rate sensor 15, the relationship between the square of the flow rate and the water supply pressure can be obtained; when the liquid flows from the hole in the middle of the workpiece 35 to be measured, the square of the flow rate is proportional to the pressure difference at both ends. Since the overflow end is connected to the atmosphere, the changing trend of the reading of the pressure sensor 7 is the changing trend of the pressure difference at both ends. The relationship between the square of the flow rate and the water supply pressure is an overall oblique line; the aperture affects the inclination of the oblique line, and on this basis the total intercepting area affects the height of the oblique line.

[0049] The measured curve is compared with the curve of the standard sample to determine the deviation amplitude of the measured workpiece 35 and thus determine its conformity; The liquid overflowing from the drain pipe 14 enters the filter device 34 and flows back into the water tank 32 after being filtered by the filter device 34 .

[0050] Example 1: When conducting a research and development test, the pore size and pore density of the material can be reflected based on the test result curve.

[0051] Example 2: When conducting production quality inspection tests, the deviation of the test result curve from the standard sample curve can reflect the deviation of the material's pore size and pore density from the standard value, thereby providing a basis for judging the product's eligibility.

[0052] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0053] The present invention and its embodiments are described above. This description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs structures and embodiments similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A porous material pore size testing device, characterized by: It comprises a water supply assembly (1), a pressure supply test mechanism (2), a workpiece self-locking mechanism (3), a circulation assembly (4) and a main base plate (5); the water supply assembly (1) comprises a water supply tray (6) and a pressure sensor (7); the water supply tray (6) is arranged on the main base plate (5); and the pressure sensor (7) is arranged in the water supply tray (6); The pressure supply test mechanism (2) comprises a test box (9) and a flow rate sensing assembly (10), wherein the test box (9) is arranged on the main bottom plate (5), and the flow rate sensing assembly (10) comprises a box cover (13), a drainage pipe (14) and a flow rate sensor (15), wherein the box cover (13) is arranged on the test box (9), the drainage pipe (14) is arranged on the box cover (13), and the flow rate sensor (15) is arranged in the drainage pipe (14); The water supply tray (6) is provided with a water distribution pipe (8) connected to the bottom of the test box (9); The workpiece self-locking mechanism (3) is arranged in the test box (9).

2. The porous material pore size testing device according to claim 1, characterized in that: The workpiece self-locking mechanism (3) comprises a pressure plate locking assembly (22) and an automatic telescopic assembly (23); the pressure plate locking assembly (22) is arranged in the test box (9); and the automatic telescopic assembly (23) is slidably arranged in the pressure plate locking assembly (22).

3. The porous material pore size testing device according to claim 2, characterized in that: The pressure plate locking assembly (22) includes a workpiece mounting frame (24), a sliding locking pin (25) and a supporting pressure plate (26), wherein the workpiece mounting frame (24) is fixed to the inner wall of the test box (9), and the workpiece mounting frame (24) is evenly distributed with horizontal sliding grooves (31) in an annular shape, and the sliding locking pin (25) is engaged and slidably arranged in the horizontal sliding grooves (31), and the supporting pressure plate (26) is engaged in the workpiece mounting frame (24), and the supporting pressure plate (26) is located above the workpiece (35) to be measured.

4. The porous material pore size testing device according to claim 3, characterized in that: The automatic telescopic assembly (23) includes a hollow floating ring (27), a ridge chain (28) and a return spring (29). The bottom of the workpiece mounting frame (24) is also provided with an annular slide groove (30). The hollow floating ring (27) is engaged and slidably arranged in the annular slide groove (30). The two ends of the ridge chain (28) are respectively connected to the sliding lock pin (25) and the hollow floating ring (27). The ridge chain (28) can transmit tension and thrust while deforming.

5. The porous material pore size testing device according to claim 4, characterized in that: The return spring (29) is arranged between the hollow floating ring (27) and the workpiece mounting frame (24).

6. The porous material pore size testing device according to claim 5, characterized in that: The pressure supply test mechanism (2) further comprises an exhaust assembly (11), wherein the exhaust assembly (11) comprises an exhaust valve body (16) and a floating valve core (17), wherein the exhaust valve body (16) is arranged on the box cover (13), and the floating valve core (17) is provided with a T-shaped limiting rod (21), wherein the T-shaped limiting rod (21) is located in the exhaust valve body (16), and the floating valve core (17) can block the exhaust valve body (16) when rising.

7. The porous material pore size testing device according to claim 6, characterized in that: The box cover (13) is further provided with a water inlet (20), the exhaust assembly (11) further comprises a soft plug (18), the soft plug (18) is detachably arranged in the water inlet (20), and the box cover (13) is further provided with a handle (19).

8. The porous material pore size testing device according to claim 7, characterized in that: The circulation assembly (4) includes a water tank (32) and a water pump (33). A filter device (34) is provided in the water tank (32). The water pump (33) is located below the water supply tray (6). The main base plate (5) and the water tank (32) are connected via the water pump (33) and a hose. The drain pipe (14) and the filter device (34) are connected via a hose. Water in the filter device (34) is filtered and then flows back into the water tank (32).

9. A method for using the porous material pore size testing device according to claim 8, characterized in that: The steps include: Step 1: First, open the box cover (13), place the workpiece (35) and the support plate (26) into the test box (9) in sequence, place them into the workpiece mounting frame (24), and then close the box cover (13); Step 2: Start the water pump (33) to pump the liquid in the water tank (32) into the water supply tray (6), and then into the test box (9) through the water distribution pipe (8), so that the liquid level in the test box (9) rises. Before measurement, the test box (9) needs to be filled with liquid. This step can also be done manually after removing the soft plug (18); Step 3: During the process of the liquid level in the test box (9) rising, the air in the test box (9) will be discharged through the gap between the exhaust valve body (16) and the floating valve core (17). When the test box (9) is filled with liquid, the floating valve core (17) will block the exhaust valve body (16) by its own rise. Therefore, even after the test box (9) is filled with liquid, there will be no leakage from the exhaust valve body (16); Step 4: As the liquid level rises, the buoyancy of the hollow float (27) will continue to increase until it is sufficient to overcome the elastic force of the return spring (29) and rise. When the hollow float (27) rises, it can push the sliding lock pin (25) to slide out horizontally through the ridge chain (28) to lock the support plate (26). The ridge chain (28) is composed of a number of blocks hinged in sequence, and the rotation angle of adjacent blocks is limited; Step 5: After the preparation work is completed, the water pump (33) can be started to conduct the test. During the test, the pressure sensor (7) in the water supply tray (6) can sense the water pressure under the workpiece (35) to be tested. The water in the test box (9) will overflow through the drain pipe (14) and sense the flow rate through the flow rate sensor (15), and the flow rate can also be obtained; Step 6: The monitoring result of the pressure sensor (7) can form a closed-loop regulation for the water pump (33), so that the water supply pressure in the water supply tray (6) shows a stable and slowly rising trend. According to the readings of the pressure sensor (7) and the flow rate sensor (15), the relationship between the square of the flow rate and the water supply pressure can be obtained; when the liquid flows from the hole in the middle of the workpiece (35) to be measured, the square of the flow rate is proportional to the pressure difference at both ends. Since the overflow end is connected to the atmosphere, the change trend of the reading of the pressure sensor (7) is the change trend of the pressure difference at both ends. The relationship between the square of the flow rate and the water supply pressure is a slanted line as a whole; The aperture affects the degree of inclination of the slope, and on this basis the total intercepting area affects the height of the slope; Step 7: Compare the measured curve with the curve of the standard sample to determine the deviation of the workpiece (35) to determine its eligibility; Step 8: The liquid overflowing from the drain pipe (14) enters the filter device (34), is filtered by the filter device (34), and then flows back into the water tank (32).

Images