An optical-based real-time measurement device for actual contact in static seals

Abstract

The present invention provides a real-time measurement device for actual contact in an optical-based static seal, including a seal fixture assembly. The seal fixture assembly includes a fixture end plate, a transparent fixture plate, and a fastener. The seal to be measured is disposed between the fixture end plate and the transparent fixture plate, and the fastener applies a pressure load to the seal to be measured. A ring of light sources is provided on the side of the transparent fixture plate. A seal medium inlet is opened on the fixture end plate, and the seal medium inlet is opened in the sealed cavity formed by the seal to be measured. The seal medium inlet is connected to a medium filling module. The present invention can perform real-time observation on the actual contact situation of an actual static seal with a pressurized seal medium inside and a pressure load applied by a fastener, and improve the detection accuracy of the contact situation of the actual seal.

Description

Technical Field

[0001] The present invention belongs to the technical field of static sealing, and particularly relates to a real-time measurement device for actual contact in static sealing based on optics. Background Art

[0002] In the actual contact between two surfaces, the two visually close surfaces actually have macroscopic waviness and microscopic surface roughness. The actual contact does not occur on the entire visually close surface, but is the sum of the actual contact areas formed by individual independent point contacts on the surface. If the non-contact points form a continuous path, gaseous or liquid media will flow out through these continuous paths.

[0003] Static sealing is an important type of sealing state with wide applications. The main working principle of static sealing is: applying a compressive force to make the seal and the component to be sealed in close contact, using the resilience of rubber and plastic materials to block the gaps between the contact surfaces, and avoiding the formation of continuous paths by non-contact points to achieve a good sealing effect. Therefore, in static sealing, measuring the actual contact situation between the two contact surfaces is very important for evaluating the sealing performance. The actual contact situations concerned in static sealing include the actual contact area, whether the width of the actual contact surface is continuous and evenly distributed in the sealing length direction.

[0004] In many static sealing problems, there is a pressurized sealing medium inside the sealing cavity. And in order to achieve detachable sealing, in petrochemical equipment, fire-fighting equipment, energy and power equipment, transportation pipelines, the valve cover and valve body of valves, single cells and battery plates, etc., bolt flanges and bolt end covers are widely used for connection.

[0005] For static sealing with a pressurized sealing medium inside, during the process of filling the sealing medium, the internal pressure of the medium will cause an axial force, resulting in the separation of the upper and lower compression surfaces, the change of the actual contact situation, the reduction of the compression amount of the sealing gasket, and the rebound of the sealing gasket. The sealing performance during the equipment's pressurized operation is closely related to the actual contact situation after the rebound of the sealing gasket.

[0006] Currently, for the designs of bolt flange connections and bolt end cover connections with a pressurized sealing medium inside, a large number of studies have been carried out, but there are deficiencies in the research on sealing performance detection methods. Various leak detection methods, such as pressure drop leak detection method, helium mass spectrometer leak detection method, differential pressure leak detection method, etc., can only give the results of leakage rates, and it is difficult to determine whether the seal is structurally stable before filling the sealing medium, difficult to determine the change of the actual contact situation before and after filling the sealing medium, and also difficult to accurately locate the position of the leakage point.

[0007] In a detachable static seal with a pressurized sealing medium inside, compared with the ordinary two-surface contact problem, the actual contact situation between the seal and the component to be sealed has the following characteristics: 1) In actual use, many seals are not uniformly loaded with pressure through a loading device, but are fastened by common fixtures such as bolt-nut-washer fasteners. This fastening method has stress concentration near the fasteners, and the pressure received by the seal is not uniform. 2) Seals are generally narrow rings, and the cross-sectional size is much smaller than the length size. Therefore, it is necessary to improve the observation accuracy to identify local small contact areas within a large range. 3) In a static seal, there is mostly a pressurized gas / liquid medium in the seal cavity. The charging process of the sealing medium will affect the actual contact situation and the pressure on the contact surface, and even cause the seal to tilt, twist, and move, resulting in greater leakage. 4) When the sealing medium exists stably in the seal cavity at a certain pressure, the actual contact situation is different from that before the medium is charged.

[0008] The Chinese patent "An actual contact area measuring instrument based on the total reflection method" (application number: 201910214039.6, publication number: CN109931891A, publication date: 2019-06-25) measures the actual contact area of experimental materials based on the total reflection of light, and uniformly applies pressure to the experimental materials through a pressure loading device to observe the actual contact area of the experimental materials. However, this method cannot reflect the contact situation when the seal in the actual static seal is subjected to non-uniform pre-tightening force applied by the fastener, nor can it reflect the difference in the contact situation before and after the sealing medium is charged. Moreover, the image clarification process for the actual contact area is insufficient, the clarity of the contact boundary is low, and external environments such as background light and stains will affect the judgment of the actual contact area. For the problem of local small contact areas within a large range of the seal, it is easy to lead to misjudgment of the actual contact area.

[0009] Considering the existing measurement methods for the actual contact area comprehensively, they all lack the ability to observe the real-time change of the contact situation of the sealing surface under actual static seal conditions. Obtaining the actual contact situation through in-situ and real-time observation methods is very important for studying the sealing performance of static seals. Further, it is of great significance for studying the influence of fastener distribution, seal structure stability, seal material aging, temperature and humidity, etc. on the static seal effect. Summary of the Invention

[0010] The purpose of the present invention is to provide an optical-based real-time measurement device for actual contact in static seals, which solves the limitations of existing actual contact measurement methods applied to actual static seals. It can measure actual static seals with pressure loads applied by fasteners, and can measure static seals with pressurized sealing media inside. It can realize real-time observation of the actual contact situation of static seals and provide support for seal performance evaluation.

[0011] The present invention is achieved through the following technical solutions:

[0012] An optical-based real-time measurement device for actual contact in static seals, comprising a seal fixture assembly. The seal fixture assembly includes a fixture end plate, a transparent fixture plate, and fasteners. The seal to be measured is disposed between the fixture end plate and the transparent fixture plate, and the fasteners apply a pressure load to the seal to be measured. The seal fixture assembly is disposed on a support platform, and the support platform includes a bracket assembly and a platform assembly. The platform assembly includes a platform and a base. The bracket assembly includes a multi-point laser displacement sensor bracket, a light source bracket, and a camera bracket. The multi-point laser displacement sensor is disposed on the multi-point laser displacement sensor bracket, and the multi-point laser displacement sensor faces the seal fixture assembly directly, and is used to measure the actual thickness, compression ratio, and uniformity of the compression ratio distribution of the seal to be measured under the pressure load. A ring of light sources is disposed on the side surface of the transparent fixture plate, and the light sources are disposed on the light source bracket, so that the light sources are in stable contact with the side surface of the transparent fixture plate. A camera for photographing the seal to be measured is disposed directly opposite the transparent fixture plate, and the camera is disposed on the camera bracket. A seal medium inlet is opened on the fixture end plate, and the seal medium inlet is opened in the seal cavity formed by the seal to be measured, and the seal medium inlet is connected to a medium filling module. The medium filling module is used to fill the inside of the seal cavity with a seal medium.

[0013] Further, the fasteners include bolt-nut-washer fasteners. A bolt force sensor is sleeved on the bolt of the bolt-nut-washer fasteners. The upper end surface of the bolt force sensor is in contact with the fixture end plate, and a metal flat washer is disposed on the lower end surface.

[0014] Further, the medium filling module is an air filling module or a liquid filling module. The medium filling module is used to fill the inside of the seal cavity with a seal medium, and the seal medium is the medium sealed by the seal to be measured, including gas medium and liquid medium.

[0015] Further, according to the overall gray distribution of the image obtained by the camera, a brightness threshold I is extracted from the image. Pixel points with brightness higher than the threshold I are contact points, and pixel points with brightness lower than the threshold I are non-contact points. A binary method is used to obtain an actual contact area image.

[0016] Further, the position of the leakage point can be located using the binary image. Specifically, the leakage point appears at the continuous non-contact points on the seal line.

[0017] Further, image subtraction is used to compare the images obtained by the camera before and after applying the pressure load and before and after filling the seal medium, so as to judge the change of the actual contact situation.

[0018] Further, a data processing system is provided, and the bolt force sensor, the multi-point laser displacement sensor, and the camera are all signal-connected to the data processing system.

[0019] Furthermore, the data processing system records the actual thickness h of the seal to be tested, the compression ratio ε, the indication value of the bolt force sensor, and the images obtained by the camera.

[0020] Furthermore, the support platform is arranged inside the closed test chamber. The closed test chamber includes a test chamber frame and a black light-absorbing cloth covering the outer surface of the test chamber frame. The closed test chamber is used to isolate external light.

[0021] Furthermore, when setting the seal fixture assembly, if the transparent fixture plate is arranged below the fixture end plate, the transparent fixture plate is placed on the support platform, and the camera is arranged below the transparent fixture plate. The material of the platform is a high-rigidity transparent material, including float glass, tempered glass, plexiglass, and PAM board.

[0022] Furthermore, when setting the seal fixture assembly, if the fixture end plate is arranged below the transparent fixture plate, the fixture end plate is placed on the support platform, and the camera is arranged above the transparent fixture plate.

[0023] Compared with the prior art, the present invention has the following beneficial technical effects:

[0024] A real-time measurement device for actual contact in static sealing based on optics disclosed by the present invention is based on the principle of frustrated total internal reflection of light. When light travels from glass to air, total internal reflection occurs. When the seal contacts the glass, the total reflection condition at the contact point is destroyed, and light escapes to form a light spot, and the light spot characterizes the actual contact area.

[0025] In a light-shielding closed test chamber, the seal to be tested is placed in the seal fixture assembly, pressure is applied through fasteners, and the actual thickness of the seal to be tested under different pressure loads is measured by a multi-point laser displacement sensor, thereby calculating the compression ratio and determining whether the compression ratios at various positions of the seal are uniform. A certain pressure of sealing medium is filled into the sealed cavity formed by the seal to be tested through the medium filling module. The camera records the actual contact situation and the changes in the actual contact situation after the seal is pre-tightened, during the process of filling the sealing medium, and when the sealing medium stably exists in the sealed cavity at a certain pressure. It has auxiliary significance for studying the influence of fastener distribution, fastening force magnitude, seal structure, seal material aging, etc. on the static sealing effect in static sealing.

[0026] The present invention also has the following advantages:

[0027] 1. In many static sealing scenarios, a non-uniform loading method is used to pre-tighten the seal, such as bolted flanges, bolted end covers, etc.; in the present invention, a bolt-nut-washer fastener is used to apply the loading pressure, and the influence of the pressure distribution on the actual contact situation can be observed in-situ, the influence of stress concentration in some areas caused by the fastener distribution on the contact width of the actual contact surface can be judged, and the uniformity of the contact width distribution in the sealing length direction can be evaluated.

[0028] 2. Compared with the existing observation methods of actual contact, the present invention can observe the actual contact situation and the changes in the actual contact situation in real time after the seal is pre-tightened, during the process of filling the sealing medium, and when the sealing medium stably exists in the sealing cavity at a certain pressure; it is convenient to analyze the structural stability of the seal itself, judge whether the structure of the seal will become unstable, tilt, distort, or move due to pre-tightening and filling the medium; analyze the influence of the pressure of the sealing medium on the actual contact situation, and guide the selection of the pre-tightening force.

[0029] 3. When the seal is set in the fixture, the contact area of the seal is significantly smaller than the area of the sealing cavity, which is a contact problem of local small contact areas within a large range. In the present invention, an industrial camera with high pixels is used, and an industrial camera magnifying lens is equipped to improve the observation accuracy; and the image is processed according to the brightness threshold, binary method, and image subtraction to improve the image processing accuracy; at the same time, the position of the leakage point can be accurately located in the binary image, and the observation accuracy can reach the micron level.

[0030] 4. Using a light-shielding closed test chamber can reduce the influence of ambient light on the test results, improve the resolution ability between the actual contact area and the actual non-contact area, and improve the measurement accuracy of the actual contact area.

[0031] 5. Using a multi-point laser displacement sensor to obtain multi-point data on the distance between the seal fixture assembly and the multi-point laser displacement sensor, the actual thickness of the seal to be measured can be measured after pre-tightening, during the process of filling the sealing medium, and when the sealing medium stably exists in the sealing cavity at a certain pressure, and the compression ratio and the uniformity of the compression ratio distribution can be calculated. Description of the Drawings

[0032] Figure 1 It is a schematic diagram of the overall structure of Embodiment 1.

[0033] Figure 2 It is a schematic diagram of the overall structure of Embodiment 2.

[0034] Figure 3 It is a schematic diagram of the composition structure of the inflation module.

[0035] Figure 4 It is a schematic diagram of the composition structure of the liquid filling module.

[0036] Figure 5This is the actual contact situation after applying a pressure load to the sample part.

[0037] Figure 6 This is the actual contact situation after inflating the sample part, where there is a leakage point, which is circled with a white circle.

[0038] In the figure, 1 - transparent fixture plate, 2 - seal to be tested, 3 - fixture end plate, 4 - light source, 5 - platform, 6 - base, 7 - seal medium inlet, 8 - medium filling module, 9 - support assembly, 901 - light source support, 902 - camera support, 903 - multi - point laser displacement sensor support, 10 - camera, 11 - multi - point laser displacement sensor, 12 - fastener, 13 - bolt force sensor, 14 - closed test chamber, 15 - data processing system.

[0039] 16 - gas source, 17 - pressure reducing valve, 18 - inflation valve, 19 - pressure gauge.

[0040] 20 - liquid storage tank, 21 - pressure regulating valve, 22 - liquid inlet valve, 23 - pressure gauge. Specific implementation mode

[0041] The following further describes the present invention in detail with reference to the accompanying drawings and specific embodiments, the content of which is an explanation rather than a limitation of the present invention:

[0042] An optical - based real - time measurement device for actual contact in static sealing, as Figure 1 shown

[0043] An optical-based real-time measurement device for actual contact in static seals, comprising a seal fixture assembly. The seal fixture assembly includes a fixture end plate 3, a transparent fixture plate 1, and a fastener 12. The seal under test 2 is disposed between the fixture end plate 3 and the transparent fixture plate 1, and the fastener 12 applies a pressure load to the seal under test 2. The seal fixture assembly is disposed on a support platform, and the support platform includes a bracket assembly 9 and a platform assembly. The platform assembly includes a platform 5 and a base 6. The bracket assembly 9 includes a multi-point laser displacement sensor bracket 903, a light source bracket 901, and a camera bracket 902. The multi-point laser displacement sensor 11 is disposed on the multi-point laser displacement sensor bracket 903, and the multi-point laser displacement sensor 11 faces the seal fixture assembly, and is used to measure the actual thickness, compression ratio, and uniformity of the compression ratio distribution of the seal under test 2 under the pressure load. The measurement accuracy of the multi-point laser displacement sensor 11 is not greater than 1 / 3 of the allowable error of the compression ratio of the seal under test 2. A ring of light sources 4 is disposed on the side surface of the transparent fixture plate 1, and the light sources 4 are disposed on the light source bracket 901, so that the light sources 4 are in stable contact with the side surface of the transparent fixture plate 1. Preferably, the light sources 4 include LED light sources, the light sources 4 are connected to a power supply, and the color of the light sources 4 is blue, green, or purple. A camera 10 for photographing the seal under test 2 is disposed opposite the transparent fixture plate 1, and the camera 10 is disposed on the camera bracket 902. A seal medium inlet 7 is opened on the fixture end plate 3, and the seal medium inlet 7 is opened in the closed seal cavity formed by the seal under test 2, and the seal medium inlet 7 is connected to a medium filling module 8. The medium filling module 8 is used to fill the inside of the seal cavity with a seal medium.

[0044] The fastener 12 includes a bolt-nut-washer fastener. A bolt force sensor 13 is sleeved on the bolt of the bolt-nut-washer fastener. The upper end surface of the bolt force sensor 13 is in contact with the fixture end plate 3, and a metal flat washer is disposed on the lower end surface of the bolt force sensor 13.

[0045] The medium filling module 8 is an inflation module or a liquid filling module. The medium filling module 8 is used to fill the inside of the seal cavity with a seal medium. The seal medium is the medium sealed by the seal under test, including a gas medium and a liquid medium. The inflation module includes a gas source 16, a pressure reducing valve 17, an inflation valve 18, and a pressure gauge 19. The liquid filling module includes a liquid storage tank 20, a pressure regulating valve 21, a liquid inlet valve 22, and a pressure gauge 23.

[0046] A data processing system 15 is provided. The bolt force sensor 13, the multi-point laser displacement sensor 11, and the camera 10 are all signal-connected to the data processing system 15. The actual thickness h, compression ratio ε, the indication value of the bolt force sensor 13, and the image obtained by the camera 10 of the seal under test 2 are recorded through the data processing system 15.

[0047] Among them, the calculation method of the actual thickness h is as follows: The multi-point laser displacement sensor 11 is directly opposite to the seal fixture assembly. When the fastener 12 is not fastened, the multi-point initial distance A between the multi-point laser displacement sensor 11 and the seal fixture assembly is measured; after fastening the fastener 12 with the pre-tightening pressure load value, the multi-point distance B between the multi-point laser displacement sensor 11 and the seal fixture assembly is measured. The actual thickness h of the seal 2 to be measured under the pre-tightening pressure load is obtained according to the formula h = A - B.

[0048] The calculation method of the compression ratio ε is as follows: The compression ratio ε of the seal 2 to be measured is calculated according to the actual thickness h of the seal 2 to be measured under the pre-tightening pressure load. The calculation formula is ε = h / h0, where h0 is the initial thickness of the seal 2 to be measured; if the error of the compression ratio ε calculated at multiple points is greater than the allowable range of the seal compression ratio error, it indicates that the uniformity of the compression ratio distribution is poor.

[0049] During the process of filling the sealing medium and when the sealing medium stably exists in the sealing cavity at a certain pressure, the multi-point distances between the multi-point laser displacement sensor 11 and the seal fixture assembly are recorded respectively, and the changes of the actual thickness h and the compression ratio ε of the seal with the process of filling the sealing medium are obtained.

[0050] According to the overall gray-scale distribution of the image obtained by the camera 10, the brightness threshold I is extracted from the image. The pixel points with brightness higher than the threshold I are contact points, and the pixel points with brightness lower than the threshold I are non-contact points. The actual contact area image is obtained using the binary method; the images obtained by the camera before and after applying the pressure load and before and after filling the sealing medium are compared using image subtraction to judge the changes in the actual contact situation.

[0051] The support platform is arranged inside the closed test chamber 14. The closed test chamber 14 includes a test chamber frame and a black light-absorbing cloth covering the outer surface of the test chamber frame. The closed test chamber 14 is used to isolate external light; preferably, the test chamber frame is built using aluminum profiles.

[0052] The present invention will be further described below in conjunction with specific embodiments and the accompanying drawings.

[0053] Embodiment 1:

[0054] As Figure 1 shown, when setting the seal fixture assembly, the fixture end plate 3 is arranged below the transparent fixture plate 1. The fixture end plate 3 is placed on the support platform. The camera 10 is arranged above the transparent fixture plate 1, and the multi-point laser displacement sensor 11 is arranged above the transparent fixture plate 1.

[0055] Preferably, the camera 10 uses an industrial camera with 10 million pixels and is equipped with a 25-fold industrial camera magnifying lens, and the observation accuracy can reach the micron level. Preferably, the light source 4 is a green LED light source.

[0056] The material of the base 6 needs to ensure the stable support of the platform 5. In this embodiment, the base 6 is an aluminum alloy bracket, and triangular stiffeners are installed at the bottom of the bracket. The platform 5 is made of wood board.

[0057] In this embodiment, the seal to be tested 2 is a rectangle with rounded corners in the length direction of the seal line, with an initial thickness of 1.5 mm and an allowable error of 1% in the compression ratio. Preferably, the measurement accuracy of the multi-point laser displacement sensor 11 is 5 μm.

[0058] As Figure 3 shown, the sealing medium is compressed air, and the medium filling module 8 is an inflation module, including a compressed air gas source 16, a pressure reducing valve 17, an inflation valve 18, and a pressure gauge 19.

[0059] As Figure 5 shown, the light spot image at the contact between the seal and the transparent fixture plate 1 is obtained by the camera 10. According to the overall gray distribution of the image obtained by the camera 10, the brightness threshold I = 108 is extracted for the image. The pixel points with brightness higher than the threshold 108 are the contact points, and the pixel points with brightness lower than the threshold 108 are the non-contact points. The binary method is used to obtain the image of the actual contact area, where white represents the contact area and black represents the non-contact area.

[0060] The binary image can be used to locate the position of the leakage point. Specifically, the leakage point appears at the continuous non-contact points on the seal line; after filling the seal cavity with 300 kPa of compressed air for 3 minutes, the image of the actual contact area is obtained. As Figure 6 shown, Figure 6 there are obvious discontinuous contact points in [], which are marked with white circles, and this is the leakage position.

[0061] Embodiment 2:

[0062] As Figure 2 shown, the difference between Embodiment 2 and Embodiment 1 is that when setting the seal fixture assembly, the transparent fixture plate 1 is arranged below the fixture end plate 3. The transparent fixture plate 1 is placed on the support platform, the camera 10 is arranged below the transparent fixture plate 1, and the multi-point laser displacement sensor 11 is arranged below the transparent fixture plate 1. The material of the platform 5 is plexiglass to ensure the light transmittance of the platform 5.

[0063] The usage method of the present invention is as follows:

[0064] Clean the surfaces of the transparent fixture plate 1, the seal to be tested 2, and the fixture end plate 3. Place the seal to be tested 2 between the transparent fixture plate 1 and the fixture end plate 3. Pass the fastener 12 through the bolt holes on the transparent fixture plate 1 and the fixture end plate 3, and sleeve the bolt force sensor 13 onto the bolt. Turn on the multi-point laser displacement sensor 11 and record the multi-point initial spacing A between the multi-point laser displacement sensor 11 and the seal fixture assembly. Fasten the fastener 12 to the target pre-tightening force, record the multi-point spacing B between the multi-point laser displacement sensor 11 and the seal fixture assembly, turn on the light source 4, and at the same time, the data processing system 15 records the actual thickness h, compression ratio ε of the seal to be tested 2, the indication value of the bolt force sensor 13, and the image obtained by the camera 10. Set the camera 10 to the continuous shooting mode, open the valve of the medium filling module 8, and fill a certain pressure of sealing medium into the sealing cavity of the seal to be tested 2. Record the actual contact image and the change of the compression ratio ε during and after the filling of the sealing medium. Gradually increase the pre-tightening force of the fastener 12 and conduct the above tests. Obtain the relationship between the actual contact situation and the changes of the pressure load, sealing medium, and sealing medium pressure, obtain the influence of the pressure mutation in the sealing cavity during the filling of the sealing medium on the actual contact situation, and obtain the evaluation of the structural stability of the seal to be tested 2.

[0065] The beneficial effects of the present invention are as follows:

[0066] In many medium and low-pressure static seals, the pressing force is provided by fasteners, such as bolt flanges, bolt end covers, etc. The present invention can obtain the influence of the stress concentration in some areas caused by the actual fastener distribution position on the contact width of the actual contact surface, evaluate the uniformity of the contact width distribution in the sealing length direction, and judge the sealing reliability.

[0067] The present invention has auxiliary significance for studying the influence of fastener distribution, fastening force magnitude, seal structure, seal material aging, etc. on the static seal effect in static seals.

[0068] The present invention can obtain the actual contact situation and the change of the actual contact situation in real time after the seal is pre-tightened, during the filling of the sealing medium, and after the filling of the sealing medium is completed, can evaluate the structural stability of the seal, and evaluate the sealing ability of the seal for a certain pressure of sealing medium.

[0069] The present invention can improve the recognition accuracy of the actual contact area according to the brightness threshold, binary method, and image subtraction; can accurately locate the position of the leakage point through the binary image processing of the actual contact situation.

[0070] It should be noted that the above description is only a part of the embodiments of the present invention. Equivalent changes made to the system described according to the present invention are all included in the protection scope of the present invention. Those skilled in the art of the present invention can make similar alternative ways to the specific examples described, as long as they do not deviate from the structure of the present invention or exceed the scope defined by this claim book, they all belong to the protection scope of the present invention.

Claims

1. An optical-based real-time measurement device for actual contact in static seals, characterized in that: It includes a seal fixture assembly, and the seal fixture assembly includes a fixture end plate (3), a transparent fixture plate (1), and a fastener (12); the seal to be tested (2) is arranged between the fixture end plate (3) and the transparent fixture plate (1), and the fastener (12) applies a pressure load to the seal to be tested (2); a ring of light sources (4) is arranged on the side surface of the transparent fixture plate (1); a seal medium filling port (7) is opened on the fixture end plate (3), and the seal medium filling port (7) is opened in the seal cavity formed by the seal to be tested (2), and the seal medium filling port (7) is connected to a medium filling module (8) for real-time measurement of the actual contact when filling the pressurized seal medium into the seal cavity; the seal fixture assembly is arranged on a support platform, and the support platform includes a bracket assembly (9) and a platform assembly; the platform assembly includes a platform (5) and a base (6); the bracket assembly (9) includes a light source bracket (901), a camera bracket (902), and a multi-point laser displacement sensor bracket (903); a camera (10) for photographing the seal to be tested (2) is arranged opposite to the transparent fixture plate (1), and the camera (10) is arranged on the camera bracket (902); the light source (4) is arranged on the light source bracket (901), and the light source bracket (901) is used to make the light source (4) stably contact with the side surface of the transparent fixture plate (1); a multi-point laser displacement sensor (11) is arranged on the multi-point laser displacement sensor bracket (903), the multi-point laser displacement sensor (11) is opposite to the seal fixture assembly, and the multi-point laser displacement sensor (11) is used to measure the actual thickness and compression ratio of the seal to be tested (2).

2. The real-time measurement device for actual contact in an optical-based static seal according to claim 1, characterized in that: The fastener (12) includes a bolt-nut-washer fastener, a bolt force sensor (13) is sleeved on the bolt, the upper end surface of the bolt force sensor (13) contacts with the fixture end plate (3), and a metal flat washer is arranged on the lower end surface of the bolt force sensor (13).

3. The real-time measurement device for actual contact in an optical-based static seal according to claim 1, characterized in that: According to the overall gray distribution of the image obtained by the camera (10), a brightness threshold I is extracted from the image. The pixel points with brightness higher than the threshold I are contact points, and the pixel points with brightness lower than the threshold I are non-contact points. The binary method is used to obtain the actual contact area image. The images obtained by the camera (10) before and after applying the pressure load and before and after filling the seal medium are compared using image subtraction to judge the change of the actual contact situation.

4. The real-time measurement device for actual contact in an optical-based static seal according to claim 1, wherein: A data processing system (15) is provided, and the bolt force sensor (13), the multi-point laser displacement sensor (11), and the camera (10) are all signal-connected to the data processing system (15).

5. The real-time measurement device for actual contact in an optical-based static seal according to claim 1, wherein: The medium filling module (8) is an air filling module or a liquid filling module. The medium filling module (8) is used to fill the seal medium into the interior of the seal cavity, and the seal medium is the medium sealed by the seal to be tested (2), including gas medium and liquid medium.

6. The real-time measurement device for actual contact in an optical-based static seal according to claim 1, wherein: A closed test chamber (14) is provided. The closed test chamber (14) includes a test chamber frame and a black light-absorbing cloth covering the outer surface of the test chamber frame. The support platform is arranged inside the closed test chamber (14), and the closed test chamber (14) is used to isolate external light.

Images