An automated, controlled-atmosphere testing device and method

Abstract

The application relates to the technical field of sealing test equipment, and discloses an air tightness experimental device and method controlled automatically. The air tightness experimental device controlled automatically comprises a testing machine main body, a test platform, an end sealing mechanism and a control end. A supporting piece for supporting a measured pipeline is arranged on a test station on the test platform. The end sealing mechanism is arranged on the test station correspondingly and is used for mechanically sealing two ends of the measured pipeline. The end sealing mechanism comprises two sealing clamps, a displacement driving unit, a position adjusting unit, a pressure sensing unit, a posture recognition unit and a sealing property pre-checking unit. Through the arrangement of the end sealing mechanism, intelligent and accurate centering of the sealing clamp and the pipeline port is realized. In combination with pressure sensing and servo closed-loop control, the clamping pressure can be self-adaptively adjusted according to the actual contact state, the uniformity and reliability of the sealing interface are ensured, and the test result is more accurate.

Description

Technical Field

[0001] This invention relates to the field of sealing test equipment technology, and more specifically, to an automated control airtightness test apparatus and method. Background Technology

[0002] In the field of pipeline production and installation, airtightness testing is a crucial step in ensuring the safe and reliable operation of pipeline systems. Traditional pipeline airtightness testing equipment typically includes a testing machine body, a test connector for connecting short pipe sections, and a pipeline support and sealing device. During testing, both ends of the pipeline must first be sealed, the test connector connected, and a vacuum drawn. Leakage is determined by detecting changes in internal pressure.

[0003] While existing equipment can perform basic airtightness tests, there is a risk of uneven sealing due to pipe tolerances during actual use. For example, in the process of sealing the pipe port with the driving clamp, existing equipment generally directly and rigidly clamps the pipe port according to a preset stroke and pressure. However, due to manufacturing tolerances in the pipe itself (such as the port end face not being perpendicular to the axis, or center deviation), and slight positional deviations that may exist after loading and positioning, this simple rigid clamping can easily lead to uneven force on the sealing gasket. If the local pressure is too low, leakage channels will be created, affecting the test results; while if the local pressure is too high, it may accelerate the wear of the sealing ring or even damage the pipe port.

[0004] Therefore, although existing technologies have automated the testing process, they still fall short in ensuring sealing reliability and the uniqueness of test results. There is an urgent need for a highly reliable airtightness testing device that can achieve intelligent adaptive sealing and perform online self-verification of the sealing effect. Summary of the Invention

[0005] The purpose of this invention is to provide an automated control airtightness testing device and method to solve the aforementioned technical problems.

[0006] The present invention solves the above-mentioned technical problems through the following technical solutions:

[0007] This invention provides an automated control airtightness testing device, comprising: a testing machine body, a testing platform, an end sealing mechanism, and a control terminal;

[0008] The test station on the test platform is equipped with support components for supporting the pipe under test;

[0009] The end sealing mechanism is correspondingly installed on the test station and is used to mechanically seal both ends of the pipe under test.

[0010] The end sealing mechanism includes:

[0011] Two sealing clamps are arranged opposite each other to seal the two ports of the pipe under test; and each sealing clamp is connected to a linear expansion source.

[0012] The displacement drive unit is connected to two sealing clamps and is used to drive them to move synchronously towards or away from each other.

[0013] Position adjustment unit, used to adjust the spatial position of the sealing clamp;

[0014] The pressure sensing unit is used to detect the contact pressure between the sealing clamp and the port of the pipe being tested;

[0015] The attitude recognition unit is used to identify the position of the port of the pipe being tested;

[0016] The sealing pre-test unit is used to check the sealing status at the joint between the sealing clamp and the pipe port under test after the sealing clamp is connected, and before the main body of the testing machine performs the formal airtightness test.

[0017] The control terminal is communicatively connected to the linear telescopic source, displacement drive unit, position adjustment unit, pressure sensing unit, attitude recognition unit, and sealing pre-inspection unit, and is configured to execute the following logic:

[0018] Based on the posture information of the pipe port obtained by the posture recognition unit, the position adjustment unit is controlled to align the sealing clamp with the pipe port;

[0019] The displacement control unit drives the two sealing clamps to synchronously approach both ends of the pipe.

[0020] Each linear expansion source is controlled to operate independently, driving the sealing clamp to press the pipe port, and maintaining the contact pressure within the set range based on the feedback from the pressure sensing unit;

[0021] After the set pressure is reached, the sealing pre-inspection unit is activated to detect the sealing interface; if leakage is detected, the linear expansion source is controlled to adjust the clamping force and re-inspect until the seal is qualified or the adjustment limit is reached.

[0022] Preferably, the sealing pre-inspection unit includes a jetting structure for uniformly spraying detection gas into the mating gap between the sealing clamp and the port of the pipe under test, and a detection sensor for detecting whether there is any leakage of detection gas.

[0023] Preferably, the jet structure includes a jet head mounted on the end face of the sealing clamp, and a gas supply device for supplying detection gas to the jet head.

[0024] Preferably, the leak detection sensor is a plurality of gas concentration sensors arranged circumferentially on the outside of the sealing fixture.

[0025] Preferably, the displacement drive unit includes a servo motor, a lead screw connected to the output end of the servo motor, and two symmetrically threaded movable seats mounted at both ends of the lead screw.

[0026] Preferably, the position adjustment unit includes two cross slides correspondingly mounted on the movable base, and the linear telescopic source is mounted on the cross slides.

[0027] Preferably, the attitude recognition unit is a vision sensor installed on the test platform, which is used to acquire the three-dimensional coordinates of the port of the pipe under test.

[0028] Preferably, the pressure sensing unit is a contact pressure sensor mounted on the sealing clamp.

[0029] Preferably, the linear telescopic source is a servo electric cylinder, and its telescopic end is connected to the sealing clamp.

[0030] An automated control method for airtightness testing includes the following steps:

[0031] S100: Place the pipe to be tested at the test station;

[0032] S200: Based on attitude recognition information, adjust the position of the sealing clamp to align with the pipe port;

[0033] S300: Drives two sealing clamps to synchronously approach both ends of the pipe;

[0034] S400: Independently drives each sealing clamp to press the pipe port, and maintains the contact pressure at the set value based on pressure feedback;

[0035] S500: Perform a pre-inspection of the sealing interface under the set pressure; if leakage is detected, adjust the clamping force and perform the pre-inspection again until it passes the test.

[0036] S600: After the sealing pre-inspection is passed, the inside of the pipe under test is evacuated and a formal airtightness test is performed.

[0037] The beneficial effects of this invention are as follows:

[0038] This invention achieves intelligent and precise alignment between the sealing clamp and the pipe port by setting an end sealing mechanism. Combined with pressure sensing and servo closed-loop control, the clamping pressure can be adaptively adjusted according to the actual contact state, ensuring the uniformity and reliability of the sealing interface and making the test results more accurate.

[0039] In addition, by setting up a sealing pre-inspection unit, the present invention can proactively detect and eliminate leaks in the device's own seals before formal testing, thereby clearly distinguishing between leaks at the test interface and leaks in the pipeline body, reducing the probability of misjudgment, and further improving the reliability of the airtightness test and the uniqueness of the test results. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of an automated control airtightness test device according to the present invention;

[0041] Figure 2 This is a schematic diagram of the structure between the test platform and the end sealing mechanism in an automated control airtightness test device of the present invention;

[0042] Figure 3 This is a schematic diagram of the structure between the movable seat, the cross slide, and the sealing clamp in an automated control airtightness test device of the present invention.

[0043] Figure 4 This is a right view of the moving seat, cross slide, and sealing fixture in an automated control airtightness test device of the present invention.

[0044] Figure 5 This is a block diagram showing the relationship between the control end and the end sealing mechanism in an automated control airtightness test device of the present invention.

[0045] Figure 6 This is a flowchart of an automated control method for airtightness testing according to the present invention.

[0046] In the diagram: 10. Main body of the testing machine; 20. Testing platform; 201. Support component; 30. End sealing mechanism; 301. Sealing fixture; 302. Servo electric cylinder; 303. Jet nozzle; 304. Gas supply device; 305. Gas concentration sensor; 306. Servo motor; 307. Lead screw; 308. Moving seat; 309. Cross slide; 310. Vision sensor; 311. Pressure sensor; 40. Pipe under test. Detailed Implementation

[0047] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed merely to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the discussed elements without departing from the scope of this specification. Various processes or units may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0048] Please refer to the following: Figures 1 to 6 An automated airtightness testing device includes: a testing machine body 10, a testing platform 20, an end sealing mechanism 30, and a control terminal (not shown in the figure, see [reference]). Figure 5(Block diagram); The main body 10 of the testing machine contains a vacuum pump, a vacuum gauge, and a gas valve assembly, which are existing technologies and are specifically marked in the figure; The testing platform 20 has multiple test stations arranged side by side at equal intervals. In this invention, four stations are provided, which can realize the simultaneous testing of multiple pipelines, greatly improving the testing efficiency. Each test station is equipped with two pairs of V-shaped support members 201 to support the pipeline 40 under test and keep it in a horizontal position.

[0049] The end sealing mechanism 30 is set across the test station, and its main structure includes: a displacement driving unit, a position adjustment unit, and a sealing pre-inspection unit.

[0050] The displacement drive unit includes a servo motor 306, and a bidirectional lead screw 307 is connected to the output end of the servo motor 306. The two ends of the lead screw 307 are respectively machined with threads of opposite directions, and each is fitted with a movable seat 308. The bottom of the movable seat 308 slides in cooperation with the top surface of the test platform 20.

[0051] The position adjustment unit is mainly used to adjust the spatial position of the sealing fixture 301. It can be two cross slides 309 correspondingly mounted on the moving base 308. Each cross slide 309 consists of a pair of horizontal (X-axis) linear modules and a pair of vertical (Y-axis) linear modules, and is driven by a stepper motor. A servo cylinder 302 is mounted on the support plate of each cross slide 309 as a linear extension source. A sealing fixture 301 is connected to the front end of the piston rod of the servo cylinder 302. Between the sealing fixture 301 and the front end of the piston rod of the servo cylinder 302, a pressure sensing unit is integrated, which can be a high-precision piezoelectric pressure sensor 311; and the front end face of the sealing fixture 301 is embedded with an O-ring rubber sealing gasket.

[0052] The vacuum pump in the main body 10 of the testing machine is connected to four retractable vacuum lines through a four-way pipe. One end of the vacuum line is connected to a sealing clamp 301 near its side. When the sealing clamp 301 seals the port of the pipe under test 40 and performs vacuuming, the gas inside the pipe under test 40 flows out through the vacuum line.

[0053] The sealing pre-test unit is used to check the sealing status at the joint between the sealing fixture 301 and the port of the pipe under test 40 after they are connected, and before the formal airtightness test is performed on the main body 10 of the testing machine. It includes a jet nozzle 303 fixedly installed at the center of the sealing fixture 301, with jet holes evenly distributed on its outer side. A gas supply device 304 connected to the jet nozzle 303 is also provided on the testing platform 20. This device communicates with the jet nozzle 303 via a flexible gas tube. The gas supply device 304 includes a gas storage tank, and a precision pressure regulating valve and a solenoid valve assembly are provided at the outlet end of the gas storage tank. Four semiconductor gas concentration sensors 305 are evenly installed on the outer circumference of the sealing fixture 301 as leak detection sensors.

[0054] An industrial camera (CCD vision sensor 310) is installed on the side column of the test platform 20. Its field of view covers the pipe port area and serves as an attitude recognition unit.

[0055] The control terminal typically employs an industrial PLC controller, which, through digital and analog input / output modules, connects to the drivers of the servo motor 306, the stepper motor driver of the cross slide 309, the driver of the servo cylinder 302, the pressure sensor 311, the gas concentration sensor 305, the image processing unit of the industrial camera, and the vacuum pump start / stop and vacuum gauge signals of the main body 10 of the testing machine. Furthermore, the solenoid valve assembly of the jet structure is also controlled by this control terminal.

[0056] The specific working process of the automated control airtightness test device designed in this invention is as follows:

[0057] Step 1, Pipe loading: The pipe to be tested 40 is hoisted onto the support 201;

[0058] Step 2, visual recognition: The industrial camera captures images of both ends of the pipe, and the internal image processing unit calculates the actual three-dimensional coordinates (X, Y, Z) of the center of the two ends and the direction of the end face normal, which is then sent to the control terminal.

[0059] Step 3, Automatic Alignment: The control unit compares the coordinates measured by vision with the preset ideal coordinates and calculates the displacement that each of the two cross slides 309 needs to compensate in the X and Y directions. Then, the control unit starts to control the stepper motors of the two cross slides 309 to move the servo cylinders 302 and the sealing clamps 301 on them until the central axis of the sealing clamps 301 coincides with the port axis of the pipe.

[0060] Step 4, Synchronous Approach: After alignment is completed, the control terminal starts the servo motor 306, which drives the bidirectional lead screw 307 to rotate, so that the two moving seats 308, together with all the aligned units on them, move synchronously towards each other until the sealing clamp 301 stops at a preset distance from the pipe port.

[0061] Step 5, Precision clamping: The control terminal simultaneously commands the two servo electric cylinders 302 to extend. When the pressure sensor 311 detects that the contact force is greater than the preset pressure value (this pressure value needs to be set according to the actual use requirements), it indicates that contact has been made. The control terminal then switches to force control mode, using the target pressure value as the set point, and uses a PID closed-loop algorithm to adjust the output force of the servo electric cylinders 302 in real time until the pressure stabilizes within the target value range.

[0062] Step Six, Pre-sealing Inspection and Adjustment: After the pressure stabilizes, the control unit opens the precision pressure regulating valve and the solenoid valve, and introduces dry nitrogen into the jet head 303 for a period of time (generally 2-5 seconds). At the same time, the values ​​of the four gas concentration sensors 305 are read. If all sensor readings are below the leakage threshold, the seal is deemed qualified. If any sensor reading exceeds the threshold, the control unit determines that there is a leak. At this time, the control unit increases the current target pressure value according to the preset gradient (such as 5%, 10%, 15%), and re-executes the force-controlled pressing process of Step Five, and then performs the jet detection of Step Six again. This cycle is repeated a maximum of three times. If a leak is still detected after three times, the control unit triggers an audible and visual alarm and displays "Automatic sealing at the workstation failed" on the human-machine interface, requiring manual intervention for adjustment.

[0063] Step 7, Formal Airtightness Test: Only after the pre-sealing inspection is qualified will the control terminal send an instruction to the main body 10 of the testing machine. The main body 10 of the testing machine opens the vacuum valve and begins to evacuate the inside of the pipe under test 40 to the specified negative pressure. Then the valve is closed and the pressure is maintained. During the pressure maintenance period, the control terminal monitors the pressure rise value through the high-precision vacuum gauge of the main body 10 of the testing machine. If it is lower than the standard threshold, the airtightness of the pipe is judged to be qualified; otherwise, it is unqualified.

[0064] Through the above process, this invention achieves automated and intelligent control of pipeline airtightness testing, solving the problem of uneven force on the sealing gasket caused by pipeline manufacturing tolerances and material positioning deviations during the sealing process in traditional equipment. This invention uses visual recognition technology to accurately obtain the three-dimensional coordinates and end face normal direction of the pipeline port, thereby controlling the cross slide 309 to automatically align, ensuring precise docking between the sealing clamp 301 and the pipeline port. During the clamping process, a PID closed-loop algorithm is used to adjust the output force of the servo cylinder 302 in real time, stabilizing the contact pressure within the target range. This avoids leakage channels caused by insufficient local pressure and prevents excessive local pressure from accelerating seal wear or damaging the pipeline port. Furthermore, this invention introduces a sealing pre-inspection and adjustment mechanism. By introducing dry nitrogen into the jet head 303 and detecting the value of the gas concentration sensor 305, the sealing status is judged in real time, and the clamping force is automatically adjusted when leakage is detected until the seal is qualified. This improves the reliability of the airtightness test and the uniqueness of the test results.

[0065] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention, all of which are within the protection scope of the present invention.

Claims

1. An automated control airtightness testing device, characterized in that, include: The main body of the testing machine, the testing platform, the end sealing mechanism, and the control terminal; The test station on the test platform is equipped with support components for supporting the pipe under test; The end sealing mechanism is correspondingly installed on the test station and is used to mechanically seal both ends of the pipe under test. The end sealing mechanism includes: Two sealing clamps are arranged opposite each other to seal the two ports of the pipe under test; and each sealing clamp is connected to a linear expansion source. The displacement drive unit is connected to two sealing clamps and is used to drive them to move synchronously towards or away from each other. Position adjustment unit, used to adjust the spatial position of the sealing clamp; The pressure sensing unit is used to detect the contact pressure between the sealing clamp and the port of the pipe being tested; The attitude recognition unit is used to identify the position of the port of the pipe being tested; The sealing pre-test unit is used to check the sealing status at the joint between the sealing clamp and the pipe port under test after the sealing clamp is connected, and before the main body of the testing machine performs the formal airtightness test. The control terminal is communicatively connected to the linear telescopic source, displacement driving unit, position adjustment unit, pressure sensing unit, attitude recognition unit, and sealing pre-inspection unit, and is configured to execute the following logic: Based on the posture information of the pipe port obtained by the posture recognition unit, the position adjustment unit is controlled to align the sealing clamp with the pipe port; The displacement control unit drives the two sealing clamps to synchronously approach both ends of the pipe. Each linear expansion source is controlled to move independently, driving the sealing clamp to press the pipe port, and maintaining the contact pressure within the set range based on the feedback from the pressure sensing unit; After the set pressure is reached, the sealing pre-inspection unit is activated to detect the sealing interface; if leakage is detected, the linear expansion source is controlled to adjust the clamping force and re-inspect until the seal is qualified or the adjustment limit is reached. The sealing pre-inspection unit includes a jetting structure for uniformly spraying detection gas into the mating gap between the sealing clamp and the port of the pipe under test, and a detection sensor for detecting whether there is leakage of detection gas. The leakage detection sensor consists of multiple gas concentration sensors arranged circumferentially on the outside of the sealing clamp, which can actively detect and eliminate the device's own sealing leakage before formal testing, thereby clearly distinguishing the leakage of the test interface from the leakage of the pipe body.

2. The automated control airtightness testing device according to claim 1, characterized in that, The jet structure includes a jet head mounted on the end face of the sealing clamp, and a gas supply device for supplying detection gas to the jet head.

3. The automated control airtightness testing device according to claim 1, characterized in that, The displacement drive unit includes a servo motor, a lead screw connected to the output end of the servo motor, and two symmetrically threaded movable seats installed at both ends of the lead screw.

4. The automated control airtightness testing device according to claim 3, characterized in that, The position adjustment unit includes two cross slides correspondingly mounted on the movable base, and the linear telescopic source is mounted on the cross slides.

5. The automated control airtightness testing device according to claim 1, characterized in that, The attitude recognition unit is a vision sensor installed on the test platform, which is used to acquire the three-dimensional coordinates of the port of the pipe under test.

6. The automated control airtightness testing device according to claim 1, characterized in that, The pressure sensing unit is a contact pressure sensor installed on the sealing clamp.

7. The automated control airtightness testing device according to claim 1, characterized in that, The linear telescopic source is a servo electric cylinder, and its telescopic end is connected to a sealing clamp.

8. An automated control method for airtightness testing, using an automated control method for airtightness testing as described in any one of claims 1-7, characterized in that, The following steps are included: S100: Place the pipe to be tested at the test station; S200: Based on attitude recognition information, adjust the position of the sealing clamp to align with the pipe port; S300: Drives two sealing clamps to synchronously approach both ends of the pipe; S400: Independently drives each sealing clamp to press the pipe port, and maintains the contact pressure at the set value based on pressure feedback; S500: Perform a pre-inspection on the sealing interface under the set pressure; if leakage is detected, adjust the clamping force and perform the pre-inspection again until it passes the test. S600: After the sealing pre-inspection is passed, the inside of the pipe under test is evacuated and a formal airtightness test is performed.

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