Micro-pressure tap density tester and testing method

Abstract

The invention discloses a micro-pressure tap density tester which comprises a micro-pressure tap density testing measuring cylinder and a vibration device, the micro-pressure tap density testing measuring cylinder comprises a measuring cylinder main body and a piston type flattening block which is arranged in the measuring cylinder main body and is used for flattening powder in the measuring cylinder main body; the piston type flattening block comprises a flattening body, a sealing ring, a filtering assembly and a balancing weight, and the sealing ring is arranged on the outer side of the flattening body; the flattening body is provided with an air hole penetrating through the surface and the bottom face of the flattening body, and the filtering assembly is arranged at an inlet or an outlet of the air hole. The balancing weight is borne on the surface of the flattening body; and the vibrating device is used for compacting the powder in the micro-pressure tap density testing measuring cylinder. The problem that the surface of the compacted powder is uneven can be solved, and test data are more accurate. In addition, the invention further discloses a micro-pressure tap density testing method.

Description

Technical Field

[0001] The invention relates to a micro-pressure tap density testing device, in particular to a micro-pressure tap density testing measuring cylinder, a testing instrument and a testing method. Background Art

[0002] In the field of battery material technology, mainly silicon carbon, hard carbon, artificial graphite and other materials, tap density test is required during production. The tap density test is to put a certain amount of powder in a measuring cylinder and vibrate it through a vibration device until the volume of the powder no longer decreases. The mass of the powder is divided by the volume after tapping to obtain the tap density. However, in the actual testing process, the powder surface is required to be flattened to form a horizontal plane before the tap test, but after the tap test, the upper surface of the powder cannot form a horizontal plane, and there are protrusions, peaks, occasional spherical agglomerations and other problems, which affect the accuracy of the tap density test. In addition, due to the processing accuracy of existing instruments and equipment and the wear problems during use, the tap density test shows an increase in fluctuation or an unstable difference. Therefore, there is a need for a micro-pressure tap density test device that can overcome the problem of uneven surface after powder tapping, and can reduce the test differences between different devices, and the test data of different devices tend to be stable. Summary of the invention

[0003] The purpose of the present invention is to provide a micro-pressure tap density tester which can overcome the problem of uneven surface of powder after tapping and has accurate test data.

[0004] Another object of the present invention is to provide a micro-pressure tap density test method which can overcome the problem of uneven surface of powder after tapping and can reduce test differences and provide accurate data.

[0005] In order to achieve the above-mentioned purpose, the micro-pressure tap density tester provided by the present invention includes a micro-pressure tap density test cylinder and a vibration device, the micro-pressure tap density test cylinder includes a cylinder body and a piston-type flattening block arranged in the cylinder body for flattening the powder in the cylinder body, the piston-type flattening block includes a flattening body, a sealing ring, a filter assembly and a counterweight block, the sealing ring is arranged on the outside of the flattening body to seal the gap between the flattening body and the inner wall of the cylinder; the flattening body is provided with an air vent running through its surface and bottom surface, the filter assembly is arranged at the inlet or outlet of the air vent; the counterweight block is carried on the surface of the flattening body so that the flattening body flattens the powder; the vibration device vibrates the powder in the micro-pressure tap density test cylinder.

[0006] Compared with the prior art, the present invention provides a piston-type flattening block in the measuring cylinder body, and uses the piston-type flattening block to apply pressure to the powder, so that the powder can be vibrated under a certain pressure, and the upper surface of the powder can be completely flattened; furthermore, the inside of the measuring cylinder body is sealed by using the sealing ring of the piston-type flattening block, and the air vents and filter components are provided on the piston-type flattening block, so that the gas inside the measuring cylinder can be completely discharged, which is conducive to compacting the powder, so that the reading of the powder in the measuring cylinder body is accurate, and at the same time, the powder is prevented from leaking outward, and the powder test amount is guaranteed to be unchanged, so that the volume of the powder can be accurately measured, and then the accurate tap density can be calculated. Therefore, the entire micro-pressure tap density test measuring cylinder can be used on different vibration devices, so that the test differences between different vibration devices are reduced, and the test data also tends to be stable or consistent, which greatly improves the accuracy of the tap density test of the entire micro-pressure tap density tester.

[0007] Preferably, the number of the sealing rings is two, and the two sealing rings are respectively arranged on the upper side and the lower side of the outer circumference of the flattening body, so that the sealing performance between the piston flattening block and the measuring cylinder body can be higher, which is conducive to ensuring the accuracy of the tap density test.

[0008] Preferably, an arc-shaped protrusion is provided in the middle of the bottom surface of the flattening body, so that the piston-type flattening block can be pressed more stably in the middle, so that the gap between the side wall of the flattening body and the inner side wall of the measuring cylinder body is consistent in the circumferential direction, thereby ensuring the sealing performance.

[0009] Preferably, the flattening body is provided with a receiving hole, the receiving hole is communicated with the air vent, and the filter assembly is arranged in the receiving hole. This is convenient for installing the filter assembly, reducing the volume of the piston flattening block, and making it easier to place it in the measuring cylinder body.

[0010] Specifically, the accommodating hole extends toward the surface of the flattened body and penetrates the upper surface of the flattened body, which is beneficial to the installation and disassembly of the filter assembly and makes replacement more convenient.

[0011] Specifically, the piston-type flattening block further includes a limit plate, which is arranged on the upper surface of the flattening body and covers the accommodating hole. The limit plate can limit the filter assembly to prevent the filter assembly from accidentally detaching from the flattening body, thereby ensuring the sealing performance during the filtering process.

[0012] Specifically, the piston-type flattening block further comprises a magnet, which is arranged on the flattening body and attracts the limit plate by magnetic attraction, so that the limit plate is positioned on the flattening body. By using the magnetic force of the magnet to attract the limit plate, the filter assembly and the limit plate can be positioned, and the filter assembly and the limit member can be assembled and disassembled more conveniently and quickly, thereby improving the convenience of use.

[0013] Preferably, the piston-type flattening block further comprises a magnet, which is arranged on the flattening body and attracts the counterweight block through magnetic attraction, so that the counterweight block is positioned on the flattening body. By using a magnet to position the counterweight block, it is possible to prevent the counterweight block from deviating from the flattening body to ensure that the upper surface of the powder can be flattened, thereby improving the accuracy of the reading, and to prevent the counterweight block from hitting the measuring cylinder body during vibration, or falling out of the measuring cylinder body during operation, thereby improving the safety of use.

[0014] A micro-compression tap density test method is provided. The micro-compression tap density tester is used to perform a tap test on powder, and the method comprises the following steps: selecting a micro-compression tap density test cylinder with suitable capacity; selecting a certain amount of test powder, loading all the test powder into a measuring cylinder body, weighing to obtain a weight m, placing a piston-type flattening block in the measuring cylinder body and pressing on the top of the test powder; fixing the test measuring cylinder on a vibration device; starting the vibration device after setting the test parameters of the vibration device; waiting for the vibration of the vibration device to be completed, reading the scale number on the measuring cylinder body corresponding to the lower edge of the piston-type flattening block, and obtaining the volume of the test powder as V; and calculating the compaction density ρ of the test powder according to the compaction density relationship: ρ=m / V. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of the micro-pressure tap density tester of the present invention.

[0016] Figure 2 It is a structural diagram of a micro-pressure tap density testing cylinder of the present invention.

[0017] Figure 3 It is a side structural diagram of the piston-type flattening block of the micro-pressure tap density testing cylinder of the present invention.

[0018] Figure 4 It is a top view of the internal structure of the flattened body of the micro-pressure tap density testing cylinder of the present invention.

[0019] Figure 5 It is a bottom view of the flattened body of the micro-pressure tap density testing cylinder of the present invention.

[0020] Figure 6 It is a flow chart of the micro-pressure tap density testing method of the present invention. DETAILED DESCRIPTION

[0021] In order to explain the technical content, structural features and effects achieved by the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0022] like Figures 1 to 5 As shown, the micro-pressure tap density tester 100 of the present invention is suitable for vibrating and compacting powder, and includes a micro-pressure tap density test cylinder 1 and a vibration device 2. The micro-pressure tap density test cylinder 1 includes a cylinder body 11 and a piston-type flattening block 12 arranged in the cylinder for flattening the powder in the cylinder body 11. The piston-type flattening block 12 includes a flattening body 121, a sealing ring 122, a filter assembly 123 and a counterweight 124. The cross section of the cylinder body 11 is circular, and the cross section of the flattening body 121 is also circular. The outer diameter of the flattening body 121 is smaller than the inner diameter of the cylinder body 11, so that a certain gap is formed between the side walls of the two. The sealing ring 122 is arranged on the outside of the flattening body 121 to seal the gap between the flattening body 121 and the inner wall of the cylinder body 11. The flattening body 121 is provided with an air vent 121a that passes through its surface and bottom surface, and the filter assembly 123 is arranged at the inlet or outlet of the air vent 121a; the filter assembly 123 is a filter cotton, which is used to filter powder with a particle diameter greater than 0.1um. The counterweight block 124 is carried on the surface of the flattening body 121, and the counterweight block 124 is a weight; the micro-pressure tap density test cylinder 1 is filled with powder, and the piston-type flattening block 12 is pressed on the top of the powder. The vibration device 2 is used to vibrate the powder in the micro-pressure tap density test cylinder 1. When the counterweight block 124 presses the powder in the cylinder body 11 with a certain pressure, the piston-type flattening block 12 moves into the cylinder body 11 in a piston-like manner relative to the cylinder body 11, and the gas in the cylinder body 11 is discharged from the air vent 121a through the filter assembly 123, so that the piston-type flattening block 12 further flattens the powder.

[0023] See also Figure 3 As shown, the number of the sealing rings 122 is two, and the two sealing rings 122 are respectively arranged on the upper side and the lower side of the outer circumference of the flattening body 121. In this way, the sealing performance between the piston-type flattening block 12 and the measuring cylinder body 11 can be higher, which is conducive to ensuring the accuracy of the tap density test. An arc-shaped protrusion 121b is provided in the middle of the bottom surface of the flattening body 121. In this way, the piston-type flattening block 12 can be pressed more smoothly in the middle, so that the gap between the side wall of the flattening body 121 and the inner side wall of the measuring cylinder body 11 is consistent in the circumferential direction, thereby ensuring the sealing performance.

[0024] See also Figure 3, Figure 4 and Figure 5 The flattened body 121 is provided with a receiving hole 121c, the number of the air holes 121a is multiple and arranged circumferentially around the central axis of the flattened body 121, the number of the receiving holes 121c is multiple and arranged circumferentially around the central axis of the flattened body 121, and the receiving holes 121c are coaxially arranged and connected with the air holes 121a in a one-to-one correspondence. In this embodiment, the number of the air holes 121a is 4, the number of the receiving holes 121c is 4, and the number of the filter components 123 is also 4. The air holes 121a are close to the bottom surface of the flattened body 121, and the receiving holes 121c are close to the surface of the flattened body 121. The receiving holes 121c extend toward the surface of the flattened body 121 and penetrate the upper surface of the flattened body 121. The diameter of the receiving holes 121c is larger than the diameter of the air holes 121a. The filter components 123 are respectively disposed in the receiving holes 121 c, which is conducive to installing and disassembling the filter components 123, making replacement more convenient, and reducing the volume of the piston-type flattening block 12, making its structure more compact and easier to place in the measuring cylinder body 11.

[0025] For example Figure 3 , Figure 4 and Figure 5As shown, the piston-type flattening block 12 also includes a limit plate 125, which is arranged on the upper surface of the flattening body 121 and covers the accommodating hole 121c. The limit plate 125 is provided to limit the filter assembly 123, prevent the filter assembly 123 from accidentally detaching from the flattening body 121, and ensure the sealing performance during the filtering process. The piston-type flattening block 12 also includes a magnet 126, which is embedded in the flattening body 121 and attracts the limit plate 125 through magnetic attraction, so that the limit plate 125 is positioned on the flattening body 121. The number of the magnets is 5, one of which is coaxial with the central axis of the flattening body 121, and the other 4 are evenly distributed on the periphery around the central axis of the flattening body 121. By using the magnetic force of the magnet 126 to attract the limit plate 125, the filter assembly 123 and the limit member can be positioned, and the filter assembly 123 and the limit plate 125 can be assembled and disassembled more conveniently and quickly, thereby improving the convenience of use. The magnet 126 can also attract the counterweight 124 through magnetic attraction, so that the counterweight 124 is positioned on the limit plate 125 on the surface of the flattening body 121. By using the magnet 126 to position the counterweight 124, the counterweight 124 can be prevented from deviating from the flattening body 121 to ensure that the upper surface of the powder can be flattened, thereby improving the accuracy of the reading, and the counterweight 124 can be prevented from hitting the measuring cylinder body 11 during vibration, or falling out of the measuring cylinder body 11 during operation, thereby improving the safety of use.

[0026] Compared with the prior art, the present invention provides a piston-type flattening block 12 in the measuring cylinder body 11, and uses the piston-type flattening block 12 to apply pressure to the powder, so that the powder can be vibrated under a certain pressure, and the upper surface of the powder can be completely flattened; furthermore, the inner part of the measuring cylinder body 11 is sealed by using the sealing ring 122 of the piston-type flattening block 12, and the air vent 121a and the filter assembly 123 are provided on the piston-type flattening block 12, so that the gas inside the measuring cylinder can be completely discharged, which is conducive to compacting the powder, so that the reading of the powder in the measuring cylinder body 11 is accurate, and at the same time, the powder is prevented from leaking outward, and the powder test amount is guaranteed to be unchanged, so that the volume of the powder can be accurately measured, and then the accurate tap density can be calculated. Therefore, the entire micro-pressure tap density test measuring cylinder 1 can be used on different vibration devices 2, so that the test differences between different vibration devices 2 are reduced, and the test data also tends to be stable or consistent, which greatly improves the accuracy of the tap density test of the entire micro-pressure tap density tester 100.

[0027] See also Figure 6 The present invention also provides a micro-pressure tap density test method, which uses the micro-pressure tap density tester 100 to perform a tap density test on powder, comprising the following steps:

[0028] Step S1, select a micro-pressure tap density test cylinder 1 with appropriate capacity. In this step, the size of the cylinder body 11 can be selected according to the amount of test powder, such as 10ml, 25ml, 50ml, 100ml, 200ml, 250ml, 500ml and other common specifications, and the corresponding piston flattening block 12 is selected to match the size of the cylinder body 11.

[0029] Step S2, select a certain amount of test powder, load all the test powder into the measuring cylinder body 11, and weigh to obtain the weight m; the weight is accurately read to 0.0001g, so that the piston flattening block 12 is placed in the measuring cylinder body 11 and pressed on the top of the test powder; after the test powder is completely loaded into the measuring cylinder body 11, the flattening body 121 is placed on the upper surface of the test powder. During this process, the air in the measuring cylinder body 11 will be discharged outward through the air vent 121a and the filter assembly 123; thereafter, the counterweight block 124 is placed on the flattening body 121 and is attracted by the magnet 126.

[0030] Step S3, fixing the micro-pressure tap density test cylinder 1 vertically on the vibration device 2;

[0031] Step S4, after setting the test parameters of the vibration device 2, start the vibration device 2; specifically, the vibration device 2 is electrically connected to the control system, and the test parameters specifically refer to the vibration frequency and vibration times of the vibration device 2. The vibration frequency and vibration times of the vibration device 2 can be input through the control system input module.

[0032] Step S5, waiting for the vibration of the vibration device 2 to be completed, reading the scale number on the measuring cylinder body 11 corresponding to the lower edge of the piston flattening block 12, and obtaining the volume of the test powder as V;

[0033] Step S6, calculating the compaction density ρ of the test powder according to the compaction density relationship: ρ=m / V.

[0034] The following is an example of a specific test process based on the above-mentioned micro-pressure tap density test method, as follows:

[0035] Example 1:

[0036] Select a 50ml micro-pressure tap density test cylinder 1, place it on a balance, and then clear the balance reading. Use a funnel to add 50g of hard carbon powder sample into the measuring cylinder body 11, and read the balance to an accuracy of 0.0001g. The weighed mass this time is 50.0003g. Place the piston flattening block 12 into the measuring cylinder body 11, and place a 5g weight on the piston flattening block 12 at the same time. The weight is attracted and fixed by the magnet 126. Fix the micro-pressure tap density test cylinder 1 consisting of the piston flattening block 12 and the measuring cylinder body 11 on the vibration device. Set the test parameters of the vibration device, the vibration frequency is 250 times / minute, the number of vibrations is 5000 times, and start the vibration device. Wait for the vibration device 2 to complete vibration, read the corresponding scale numbers on the lower edge of the piston flattening block 12 and the measuring cylinder body 11, and record the volume / capacity. The measuring cylinder reading is 38.2ml. Using the compaction density calculation formula ρ=m / V, the measurement result is ρ=50.0003 / 38.2=1.309g / cm 3 .

[0037] In the above example 1, the sample weight range can be expanded to 5g-5000g, and the weight is different for different types of powders. The vibration frequency can be adjusted from 1-1000 times / minute. The number of vibrations ranges from 100-100000 times. The weight of the weight can be adjusted from 1g-1000g.

[0038] In order to verify the repeatability and accuracy of the micro-pressure tap density, the following example 2 is listed. The same sample is taken and divided into two groups for testing. Each group is tested 6 times. The repeatability and accuracy of the micro-pressure tap density are tested based on the test results. The test steps are as follows:

[0039] The first group: The micro-pressure tap density tester 100 of the present scheme is used, specifically, a 50ml micro-pressure tap density test cylinder 1 is selected, placed on a balance, and then the balance reading is cleared to zero. Use a funnel to add 50g of hard carbon powder sample into the measuring cylinder body 11, and read the balance to an accuracy of 0.0001g. The weighed mass this time is 50.0003g. Place the piston-type flattening block 12 into the measuring cylinder body 11, and place a 5g weight on the piston-type flattening block 12 at the same time. The weight is attracted and fixed by the magnet 126. The integral body composed of the piston-type flattening block 12 and the measuring cylinder body 11, that is, the micro-pressure tap density test cylinder 1, is fixed on the tapping device. Set the test parameters of the tapping device, the vibration frequency is 250 times / minute, the number of vibrations is 5000 times, and start the tapping device. Wait for the vibration device 2 to complete vibration, read the corresponding scale numbers on the lower edge of the piston flattening block 12 and the measuring cylinder body 11, and record the volume / capacity. Use the compaction density calculation formula ρ=m / V to calculate the measurement result of ρ=50.0003 / 38.2=1.31g / cm 3 . Follow the above steps to continue the test for 5 times, and calculate the remaining 5 measurement results, and record the above numbers in a table. The specific test results are as follows:

[0040] Test results of micro-pressure tap density tester 100

[0041]

[0042] The second group: Use an ordinary tap density tester, the measuring cylinder has no flattening device, take a 50ml ordinary tap density tester special measuring cylinder, place it on the balance, then clear the balance reading, use a funnel, add 50g of hard carbon powder sample to the measuring cylinder, and read accurately to 0.0001g. The weighed mass this time is 50.0025g. Fix the measuring cylinder on the ordinary tap density tester. Set the test parameters of the ordinary tap density tester, the vibration frequency is 250 times / minute, the number of vibrations is 5000 times, start the ordinary tap density tester, and wait for the ordinary tap density tester to complete vibration. After the vibration is completed, the surface of the sample cannot form a horizontal plane. It is necessary to read the corresponding measuring cylinder scale from three directions / angles and record them. Finally, use the compaction density calculation formula ρ=m / V to calculate the average value of this measurement result. According to the above steps, continue to perform 5 tests, and calculate the remaining 5 measurement results. Record the above numbers in the table. The specific test results are as follows:

[0043] Test results of ordinary tap density tester

[0044]

[0045]

[0046] From the data in the above two tables, we can see that

[0047] Comparison of the ranges between the two: The difference between the test results of the micro-pressure vibration density tester 100 is smaller, with a range of only 0.006g / cm 3 The test result of ordinary tap density tester is 0.056g / cm 3 , the difference between the two is 9.3 times, therefore, the test result of the micro-pressure tap density tester 100 is better.

[0048] Comparison of the standard deviations of the two: reflects the degree of discreteness of a data set. The smaller the degree of discreteness, the better the data. The standard deviation of the test results of the Micro-Compression Tap Density Tester 100 is 0.002; the standard deviation of the test results of the ordinary tap density tester is 0.019, which is 9.5 times different. Therefore, the test results of the Micro-Compression Tap Density Tester 100 are better.

[0049] The structure of the compaction device 2 involved in the micro-pressure compaction density tester 100 of the present invention is well known to ordinary technicians in the field and will not be described in detail here.

[0050] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention still fall within the scope covered by the present invention.

Claims

1. A micro-pressure tap density tester, characterized in that: It comprises a micro-pressure tap density test cylinder and a vibration device, wherein the micro-pressure tap density test cylinder comprises a cylinder body and a piston-type flattening block arranged in the cylinder body for flattening the powder in the cylinder body, the piston-type flattening block comprises a flattening body, a sealing ring, a filter assembly and a counterweight block, the sealing ring is arranged on the outside of the flattening body to seal the gap between the flattening body and the inner wall of the cylinder; the flattening body is provided with air holes penetrating its surface and bottom surface, the filter assembly is arranged at the inlet or outlet of the air hole; the counterweight block is carried on the surface of the flattening body so that the flattening body flattens the powder; the vibration device compacts the powder in the micro-pressure tap density test cylinder.

2. The micro-pressure tap density tester according to claim 1, characterized in that: The number of the sealing rings is two, and the two sealing rings are respectively arranged on the upper side and the lower side of the outer circumference of the flattened body.

3. The micro-pressure tap density tester according to claim 1, characterized in that: An arc-shaped protrusion is provided in the middle of the bottom surface of the flattened body.

4. The micro-pressure tap density tester according to claim 1, characterized in that: The flattened body is provided with a receiving hole, the receiving hole is communicated with the air vent, and the filter assembly is arranged in the receiving hole.

5. The micro-pressure tap density tester according to claim 4, characterized in that: The accommodating hole extends toward the surface of the flattened body and passes through the upper surface of the flattened body.

6. The micro-pressure tap density tester according to claim 5, characterized in that: The piston-type flattening block further comprises a limiting plate, which is arranged on the upper surface of the flattening body and covers the accommodating hole.

7. The micro-pressure tap density tester according to claim 6, characterized in that: The piston-type flattening block further comprises a magnet, which is disposed on the flattening body and attracts the limit plate through magnetic attraction, so that the limit plate is positioned on the flattening body.

8. The micro-pressure tap density tester according to claim 1, characterized in that: The piston-type flattening block further comprises a magnet, which is disposed on the flattening body and attracts the counterweight block through magnetic attraction, so that the counterweight block is positioned on the flattening body.

9. A micro-pressure tap density test method, characterized in that: The powder is subjected to a tap density test using the micro-pressure tap density tester according to claims 1 to 8, comprising the following steps: Select a micro-pressure tap density test cylinder with appropriate capacity; A certain amount of test powder is selected and weighed to obtain a weight m, and the test powder is completely loaded into the measuring cylinder body, and a piston-type flattening block is placed in the measuring cylinder body and pressed on the top of the test powder; Fixing the test cylinder on a vibration device; After setting the test parameters of the vibration device, starting the vibration device; Waiting for the vibration device to complete vibration, reading the scale number on the measuring cylinder body corresponding to the lower edge of the piston flattening block, and obtaining the volume of the test powder as V; According to the compaction density relationship: ρ=m / V, the compaction density ρ of the test powder is calculated.

Images