Sealing element performance monitoring device and method

Abstract

The invention relates to the technical field of sealing element service life prediction, and discloses a sealing element performance monitoring device comprising a stress monitoring module, the stress monitoring module comprises a stress monitoring sensor, a connecting wire and a data acquisition system, and the stress monitoring sensor is used for obtaining contact stress borne by a sealing element to be detected; the air tightness monitoring module comprises an upper clamping plate, a lower clamping plate, a limiting part and a fixing piece, the fixing piece acts on the upper clamping plate and the lower clamping plate to enable the upper clamping plate and the lower clamping plate to be fixed or loosened, the limiting part is located between the upper clamping plate and the lower clamping plate, and the limiting part is located between the upper clamping plate and the lower clamping plate. The upper clamping plate is provided with an air inlet hole and an air outlet hole, the air inlet hole and the air outlet hole are respectively provided with a corresponding air inlet valve and an air outlet valve, the top of the lower clamping plate is provided with a groove, and the relative position of the groove is located between the air inlet hole and the air outlet hole.

Description

Technical Field

[0001] The present invention relates to the technical field of seal life prediction, and in particular to a seal performance monitoring device and method. Background Art

[0002] Seals, as key components in industrial equipment, play an important role in preventing fluid or gas leakage from adjacent joints and preventing external impurities such as dust and moisture from invading the interior of machinery and equipment. They are known as the "guardians" of industrial equipment and are essential to ensure the normal operation of equipment, extend its service life, and improve the stability and reliability of the overall system.

[0003] Rubber is often used as a material for seals because of its moderate price, good processing performance, good elasticity, wear resistance and air tightness. It is widely used in the fields of automobiles, engineering machinery, electronic equipment, furniture, etc., playing an important role in sealing, blocking, preventing leakage and foreign matter from entering the system. In actual use, rubber seals will gradually age and their performance will continue to deteriorate due to long-term exposure to air, heat, oxygen, water, salt spray and other environments, and eventually the rubber seals will fail, causing safety accidents and irreparable losses. Therefore, a more accurate estimate of the service life of rubber seals can avoid the occurrence of safety accidents caused by aging failure. The existing compression static load loading devices and airtightness monitoring devices cannot monitor the stress changes during the aging process of the seals, and are usually complex in structure. Therefore, how to provide a more accurate monitoring method for the aging of rubber seals in service is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0004] The technical problem to be solved by the present invention is to solve the problem of inaccurate prediction of the service life of existing seals.

[0005] In order to solve the above technical problems, the present invention provides a seal performance monitoring device, the seal performance monitoring device comprising:

[0006] A stress monitoring module, the stress monitoring module comprising a stress monitoring sensor, connecting wires and a data acquisition system, the stress monitoring sensor being used to obtain the contact stress of the seal to be tested;

[0007] An air tightness monitoring module, the air tightness monitoring module includes an upper clamping plate, a lower clamping plate, a limiting portion and a fixing member, the fixing member acts on the upper clamping plate and the lower clamping plate to fix or loosen the upper clamping plate and the lower clamping plate, the limiting portion is located between the upper clamping plate and the lower clamping plate, the upper clamping plate is provided with an air inlet hole and an air outlet hole, the air inlet hole and the air outlet hole are respectively provided with corresponding air inlet valves and air outlet valves, the top of the lower clamping plate is provided with a groove, and the relative position of the groove is located between the air inlet hole and the air outlet hole.

[0008] Furthermore, the stress monitoring sensor is a flexible sensor.

[0009] Furthermore, the fixing members are bolts and nuts, and the bolts and nuts are located outside the grooves.

[0010] Furthermore, the groove is an annular groove.

[0011] Furthermore, a circular groove is provided at the center of the lower clamping plate, one end of the limiting portion is connected to the circular groove, and the other end of the limiting portion is in contact with the bottom of the upper clamping plate.

[0012] Furthermore, the length of the limiting portion is adjustable.

[0013] Furthermore, the upper clamping plate and the lower clamping plate are made of high-strength, corrosion-resistant materials.

[0014] According to another aspect of the present invention, a seal performance monitoring method is provided, the seal performance monitoring method comprising:

[0015] S1, placing the seal performance monitoring device with the seal to be tested installed in the environmental test chamber for aging test;

[0016] S2, obtaining the contact stress of the seal to be tested by a stress monitoring sensor;

[0017] S3, after the aging test is completed, the sealing performance monitoring device is taken out to perform an airtightness test, the airtightness failure condition of the tested sealing component is obtained, and the failure time of the tested sealing component is determined according to the airtightness failure condition;

[0018] S4, obtaining a change rule of the contact stress of the seal to be tested and the failure time of the seal to be tested according to the relationship between the contact stress of the seal to be tested and the failure time of the seal to be tested;

[0019] S5, estimating the failure time and service life of other similar seals based on the variation rule.

[0020] Furthermore, in step S5, the method of inferring the failure time and service life of other similar seals through the variation law is to establish a mathematical model of contact stress and failure time.

[0021] Furthermore, the environmental test box is provided with a comprehensive environmental test condition parameter adjustment function, and the comprehensive environmental test condition parameter adjustment function includes temperature adjustment, humidity adjustment, light intensity adjustment and salt spray adjustment.

[0022] Compared with the prior art, the seal performance monitoring device and method according to the embodiment of the present invention have the following beneficial effects:

[0023] The embodiment of the present invention integrates an airtightness monitoring module and a stress monitoring module into a seal performance monitoring device. The stress monitoring module of the device is used to monitor the pressure applied by the upper and lower plates in the airtightness monitoring device to the seal to be tested. The stress monitoring module does not need to apply additional pressure to the seal to be tested. After the stress monitoring is completed, the operator can directly seal the upper and lower plates, and then perform airtightness monitoring. The failure time of the seal to be tested can be determined through airtightness monitoring. Then, by analyzing the relationship between the failure time of the seal to be tested and the contact stress, the aging failure time of other similar seals can be analyzed, and the aging of other similar seals can be determined. The failure time of the seal can be predicted; the embodiment of the present invention can obtain the aging failure time of the seal by drawing the stress-aging time variation relationship curve and the airtightness monitoring result, and analyze the aging failure time of other seals by analyzing the stress variation law before and after the failure; the embodiment of the present invention comprehensively considers the contact stress and the aging failure time of the seal, thereby improving the accuracy of the seal life prediction; the integrated design of the seal performance monitoring device of the embodiment of the present invention enables the seals to be tested to be continuously operated in the same device, shortening the monitoring time, improving the monitoring efficiency, reducing unnecessary operations, reducing the monitoring error rate, and improving the accuracy of the seal life prediction. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a structural schematic diagram of a stress monitoring module of a seal performance monitoring device provided in an embodiment of the present invention;

[0025] Figure 2 is a structural schematic diagram of an airtightness monitoring module of a sealing performance monitoring device provided in an embodiment of the present invention;

[0026] Figure 3 It is a schematic structural diagram of an upper clamping plate and a lower clamping plate of a seal performance monitoring device provided by an embodiment of the present invention;

[0027] Figure 4 is a flow chart of a seal performance monitoring method provided by an embodiment of the present invention;

[0028] Figure 5 is a graph showing changes in stress of a nitrile rubber seal provided by an embodiment of the present invention as a function of aging time;

[0029] Figure 6 This is a diagram of the inflation pressure change of the nitrile rubber seal provided in an embodiment of the present invention.

[0030] In the figure, 100, stress monitoring module; 110, stress monitoring sensor; 120, connecting wire; 130, data acquisition system; 200, air tightness monitoring module; 210, upper clamping plate; 220, lower clamping plate; 221, groove; 230, limit part; 240, fixing part; 250, air inlet hole; 260, air outlet hole; 251, air inlet valve; 252, air outlet valve; 300, sealing part to be tested; 400, sealing tape. DETAILED DESCRIPTION

[0031] The following is a description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope of the present invention. Similarly, for clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0032] like Figure 1-6 As shown, in an optional embodiment of the present invention, the present invention provides a seal performance monitoring device comprising:

[0033] A stress monitoring module 100, wherein the stress monitoring module 100 comprises a stress monitoring sensor 110, a connecting wire 120 and a data acquisition system 130, wherein the stress monitoring sensor 110 is used to obtain the contact stress of the seal 300 to be tested;

[0034] The air tightness monitoring module 200 includes an upper clamping plate 210, a lower clamping plate 220, a limiting portion 230 and a fixing member 240. The fixing member 240 acts on the upper clamping plate 210 and the lower clamping plate 220 to fix or loosen the upper clamping plate 210 and the lower clamping plate 220. The limiting portion 230 is located between the upper clamping plate 210 and the lower clamping plate 220. The upper clamping plate 210 is provided with an air inlet 250 and an air outlet 260. The air inlet 250 and the air outlet 260 are respectively provided with corresponding air inlet valves 251 and air outlet valves 252. The top of the lower clamping plate 220 is provided with a groove 221. The relative position of the groove 221 is located between the air inlet 250 and the air outlet 260.

[0035] Among them, the data acquisition system 130 is used to collect and analyze the contact stress collected by the stress monitoring module 100, and this contact stress is provided by the upper clamping plate 210 and the lower clamping plate 220 of the airtightness monitoring module 200; the limiting part 230 can be used to adjust the distance between the upper clamping plate 210 and the lower clamping plate 220, and the pressure of the upper clamping plate 210 and the lower clamping plate 220 on the seal 300 to be tested is adjusted by adjusting the distance between the upper clamping plate 210 and the lower clamping plate 220. The groove 221 set in the lower clamping plate 220 is used to place the seal 300 to be tested and the stress monitoring sensor 110; the air inlet 250 is connected to the groove 221. When performing airtightness monitoring, the staff can seal the clamping plate that clamps the seal 300 to be tested, inject air through the air inlet 250, put the device into water, observe the bubbles in the water, and judge the failure time of the seal through the airtightness monitoring device.

[0036] Specifically, the specific working process of the seal performance monitoring device is as follows: (1) Install the stress sensor under the seal 300 to be tested, and then place the seal in the groove 221, and select the limit part 230 of appropriate height according to the required compression rate; (2) Fix the upper clamping plate 210 and the lower clamping plate 220, and use the fixing part 240 to fix the upper and lower clamping plates 220; (3) Put the test device loaded with the seal 300 sample to be tested into the environmental test box for aging test, and place the data acquisition system 130 in the room at normal temperature. Monitor the resistance change of the stress monitoring sensor 110 through the connecting wire 120, analyze the obtained resistance information, and obtain the pressure value of the seal 300 to be tested; (4) After the aging test is completed, remove the stress monitoring sensor 110 from the test device. Take it out, use sealing tape to seal the chamber formed by the upper and lower clamps 220 of the device, and re-secure it; (5) Use an inflation device to inflate the device from the air inlet 250 through the ventilation hose, and then put the ventilation hose connected to the air outlet 260 or the entire device into a water tank to observe whether there are bubbles. If not, it means that the air tightness of the seal is maintained well. If so, it means that the gas escapes through the air outlet 260 and the seal has aged and failed; (6) Regularly read the contact stress indication of the seal, and carry out air tightness monitoring, draw a stress-aging time change relationship curve, judge the seal failure time based on the air tightness monitoring results, analyze the stress change law before and after failure, and based on this law, analyze the aging failure time of other types of seals through the stress-aging time change relationship curve.

[0037] Specifically, the compression rate refers to the ratio of the compression deformation of the seal to its original length when it is subjected to a certain pressure. In the test, the corresponding compression rate is usually selected according to the hardness of the seal, so as to further determine the required height of the limit part. For example, if the original thickness of the seal is T, the required compression rate is C, and the depth of the groove for placing the limit part is D, then the height h of the limit part should be T×(1-C)+D. A specific embodiment of analyzing the aging failure time of other types of seals through a stress-aging time change relationship curve chart. In this embodiment, nitrile rubber seals are selected to carry out aging tests. The environmental test conditions are 8h 90℃ / 30%RH, 8h 85℃ / 85%RH / salt spray and 8h 90℃ / 40%RH / solar radiation cycle tests. The compression deformation is 25%, and the pressure values ​​and air tightness of the seals aged for 0, 3 months, 6 months, 9 months and 1 year are recorded respectively. The test results of this embodiment are as follows Figure 5 As shown in the figure, as the aging time increases, the stress load on the nitrile rubber seal gradually increases, and a large increase occurs in 6-9 months, and then tends to be flat. Figure 6 The airtightness monitoring results show that the rubber seal leaked in the 9th month, indicating that the seal had aged and failed in the 9th month. It can be inferred that the greater the difference between the stress on the seal and the initial state, the greater the performance change and the higher the possibility of failure. In the 9th month, the seal completely failed. When monitoring other similar seals, we can infer the life of other similar seals based on the comparison between the current stress of the seal and the initial state stress.

[0038] The embodiment of the present invention integrates the airtightness monitoring module 200 and the stress monitoring module 100 into a sealing performance monitoring device. The stress monitoring module 100 of the device is used to monitor the pressure applied by the upper clamping plate 210 and the lower clamping plate 220 in the airtightness monitoring device to the sealing member 300 to be tested. The stress monitoring module 100 does not need to apply additional pressure to the sealing member 300 to be tested. After the stress monitoring is completed, the operator can directly seal the upper clamping plate 210 and the lower clamping plate 220, and then perform airtightness monitoring. The failure time of the sealing member 300 to be tested can be determined through the airtightness monitoring. Then, by analyzing the relationship between the failure time of the sealing member 300 to be tested and the contact stress, the aging failure of other similar sealing members can be analyzed. The aging failure time of other similar seals can be predicted by calculating the effective time. The embodiment of the present invention can obtain the aging failure time of the seal by drawing the stress-aging time variation relationship curve and the airtightness monitoring result, and analyze the aging failure time of other types of seals by analyzing the stress variation law before and after failure. The embodiment of the present invention comprehensively considers the contact stress and the aging failure time of the seal, thereby improving the accuracy of the seal life prediction. The integrated design of the seal performance monitoring device of the embodiment of the present invention enables the seal 300 to be tested continuously in the same device, shortens the monitoring time, improves the monitoring efficiency, reduces the monitoring error rate while reducing unnecessary operations, and improves the accuracy of the seal life prediction.

[0039] In an optional embodiment of the present invention, the stress monitoring sensor 110 is a flexible sensor.

[0040] Among them, when in use, the stress monitoring sensor 110 is sensed by the mutual force between the seal 300 to be tested and the stress monitoring sensor 110. When the stress monitoring sensor 110 is under pressure, its resistance will change, and the wire transmits the resistance change signal of the stress monitoring sensor 110 to the data acquisition system 130, and the stress value is obtained by analyzing the signal. During the contact process between the stress monitoring sensor 110 and the seal 300 to be tested, due to the mutual pressure generated, if a harder stress monitoring sensor 110 is used to contact the seal 300 to be tested, the seal 300 to be tested will be damaged. Using a flexible sensor does not affect the integrity of the seal 300 to be tested during testing and can protect the seal 300 to be tested.

[0041] In the embodiment of the present invention, since the flexible sensor has good flexibility and ductility, it can avoid damaging the seal 300 when in contact with the seal 300. The flexible sensor can also better fit the shape and surface features of the seal 300 to be tested, thereby providing more accurate stress measurement and improving data reliability.

[0042] like Figure 1-3As shown, in an optional embodiment of the present invention, the fixing member 240 is a bolt, and the bolt is located outside the groove 221 .

[0043] Among them, bolts are used as the fixing parts 240, and the upper clamping plate 210 and the lower clamping plate 220 can be connected by eight bolts. The eight bolts are all located on the outside of the annular groove, and the fixed connection effect is guaranteed. The eight bolts are evenly distributed in a ring shape, so that the force of the fixing part 240 to fix the seal 300 to be tested is more uniform.

[0044] like Figure 1-3 As shown, in an optional embodiment of the present invention, the groove 221 is an annular groove.

[0045] The annular groove is designed to fit the shape of the annular seal. Since most seals are circular in shape, the annular seal can be installed in the annular groove more easily and accurately. This not only simplifies the installation process of the seal into the groove 221, but also reduces the risk of monitoring failure caused by improper installation.

[0046] like Figure 3 As shown, in an optional embodiment of the present invention, a circular groove is provided at the center of the lower clamping plate 220 , one end of the limiting portion 230 is connected to the circular groove, and the other end of the limiting portion 230 is connected to the bottom of the upper clamping plate 210 .

[0047] In an optional embodiment of the present invention, the length of the limiting portion 230 is adjustable.

[0048] Among them, since the limiting part 230 is located between the upper clamping plate 210 and the lower clamping plate 220, the adjustable length of the limiting part 230 makes the distance between the upper clamping plate 210 and the lower clamping plate 220 adjustable. The adjustable distance between the upper clamping plate 210 and the lower clamping plate 220 makes the pressure on the seal 300 to be tested adjustable, so it can adapt to the testing requirements of different seals.

[0049] like Figure 1-6 According to another aspect of the present invention, a method for monitoring seal performance is provided, comprising:

[0050] S1, placing the seal performance monitoring device with the seal to be tested installed in the environmental test chamber for aging test;

[0051] S2, obtaining the contact stress of the seal to be tested by a stress monitoring sensor;

[0052] S3, after the aging test is completed, the sealing performance monitoring device is taken out to perform an airtightness test, the airtightness failure condition of the tested sealing component is obtained, and the failure time of the tested sealing component is determined according to the airtightness failure condition;

[0053] S4, obtaining a change rule of the contact stress of the seal to be tested and the failure time of the seal to be tested according to the relationship between the contact stress of the seal to be tested and the failure time of the seal to be tested;

[0054] S5, estimating the failure time and service life of other similar seals based on the variation rule.

[0055] Among them, multi-factor comprehensive aging tests can be carried out in the environmental simulation test chamber, which can simulate the four-factor comprehensive test environment of temperature / humidity / solar radiation / salt spray.

[0056] Specifically, in this embodiment, a nitrile rubber seal is selected to carry out an aging test. The environmental test conditions are 8h 90℃ / 30%RH, 8h 85℃ / 85%RH / salt spray and 8h 90℃ / 40%RH / solar radiation cycle tests, the compression set is 25%, and the pressure values ​​and air tightness of the seal after aging for 0, 3 months, 6 months, 9 months and 1 year are recorded respectively. The test results of this embodiment are shown in FIG. Figure 5 As shown in the figure, as the aging time increases, the stress load on the nitrile rubber seal gradually increases, and a large increase occurs in 6-9 months, and then tends to be flat. Figure 6 The airtightness monitoring results show that the rubber seal leaked in the 9th month, indicating that the seal had aged and failed in the 9th month. It can be inferred that the greater the difference between the stress on the seal and the initial state, the greater the performance change and the higher the possibility of failure. In the 9th month, the seal completely failed. When monitoring other similar seals, we can infer the life of other similar seals based on the comparison between the current stress of the seal and the initial state stress.

[0057] In an optional embodiment of the present invention, in step S5, the method of inferring the failure time and service life of the seal according to the variation law is to establish a mathematical model of contact stress and failure time and draw a curve chart of the variation relationship between stress and aging time.

[0058] Specifically, during the aging test, the contact stress values ​​of the seal are recorded regularly. These values ​​can be obtained by stress monitoring sensors and recorded in the data acquisition system. At the same time, the airtightness monitoring results of the seal at different aging time points are recorded, including whether there is leakage, the degree of leakage, etc. Based on the collected contact stress data and airtightness monitoring results, a mathematical model of contact stress and failure time is established. This model can be linear, nonlinear, or a prediction model based on machine learning. The purpose of the model is to find the mathematical relationship between the change in contact stress and the failure time of the seal, so as to be able to predict the state of the seal at a certain time point in the future. Using the collected data, a stress-aging time change relationship curve is drawn. This chart can intuitively show the change trend of the contact stress of the seal during the aging process. On the chart, the time point when the seal starts to leak or fail can be marked for comparative analysis with the stress change. Observe the stress-aging time change relationship curve and analyze the change law of contact stress with aging time. Pay attention to the characteristic points such as inflection points and slope changes in the curve, which reflect the key changes in the performance of the seal. According to the established mathematical model and the drawn curve, the failure time and service life of the seal are inferred. A threshold can be set. When the contact stress exceeds this threshold, the seal is considered to be about to fail. The contact stress value at a certain point in the future is predicted by the model and compared with the threshold to determine the expected failure time and remaining service life of the seal. The model is verified using actual test data to ensure its accuracy and reliability. If it is found that there is a large deviation between the model prediction results and the actual test results, the model can be adjusted and optimized.

[0059] In the embodiments of the present invention, the failure time and service life of the seal can be predicted more accurately, providing a scientific basis for the maintenance and replacement of the seal.

[0060] In an optional embodiment of the present invention, the environmental test box is provided with a comprehensive environmental test condition parameter adjustment function, and the comprehensive environmental test condition parameter adjustment function includes temperature adjustment, humidity adjustment, light intensity adjustment and salt spray adjustment.

[0061] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0062] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A seal performance monitoring device, characterized in that: The seal performance monitoring device comprises: A stress monitoring module, the stress monitoring module comprising a stress monitoring sensor, connecting wires and a data acquisition system, the stress monitoring sensor being used to obtain the contact stress of the seal to be tested; An air tightness monitoring module, the air tightness monitoring module includes an upper clamping plate, a lower clamping plate, a limiting portion and a fixing member, the fixing member acts on the upper clamping plate and the lower clamping plate to fix or loosen the upper clamping plate and the lower clamping plate, the limiting portion is located between the upper clamping plate and the lower clamping plate, the upper clamping plate is provided with an air inlet hole and an air outlet hole, the air inlet hole and the air outlet hole are respectively provided with corresponding air inlet valves and air outlet valves, the top of the lower clamping plate is provided with a groove, and the relative position of the groove is located between the air inlet hole and the air outlet hole.

2. The seal performance monitoring device according to claim 1, characterized in that: The stress monitoring sensor is a flexible sensor.

3. The seal performance monitoring device according to claim 1, characterized in that: The fixing members are bolts and nuts, and the bolts and nuts are located outside the grooves.

4. The seal performance monitoring device according to claim 1, characterized in that: The groove is an annular groove.

5. The seal performance monitoring device according to claim 1, characterized in that: A circular groove is arranged at the center of the lower clamping plate, one end of the limiting portion is connected to the circular groove, and the other end of the limiting portion is in contact with the bottom of the upper clamping plate.

6. The seal performance monitoring device according to claim 5, characterized in that: The length of the limiting portion is adjustable.

7. The seal performance monitoring device according to claim 1, characterized in that: The upper clamping plate and the lower clamping plate are made of high-strength, corrosion-resistant materials.

8. A method for monitoring seal performance, characterized in that: The seal performance monitoring method comprises: S1, placing the seal performance monitoring device with the seal to be tested installed in the environmental test chamber for aging test; S2, obtaining the contact stress of the seal to be tested by a stress monitoring sensor; S3, after the aging test is completed, the sealing performance monitoring device is taken out to perform an airtightness test, the airtightness failure condition of the tested sealing component is obtained, and the failure time of the tested sealing component is determined according to the airtightness failure condition; S4, obtaining a change rule of the contact stress of the seal to be tested and the failure time of the seal to be tested according to the relationship between the contact stress of the seal to be tested and the failure time of the seal to be tested; S5, estimating the failure time and service life of other similar seals based on the variation rule.

9. The seal performance monitoring method according to claim 8, characterized in that: In step S5, a method for estimating the failure time and service life of other similar seals according to the variation rule is to establish a mathematical model of contact stress and failure time.

10. The seal performance monitoring method according to claim 8, characterized in that: The environmental test box is provided with a comprehensive environmental test condition parameter adjustment function, and the comprehensive environmental test condition parameter adjustment function includes temperature adjustment, humidity adjustment, light intensity adjustment and salt spray adjustment.

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