Automatic helium mass spectrum leak detection device

Abstract

The invention relates to the technical field of helium leak detection, in particular to an automatic helium mass spectrometer leak detection device which comprises a rack, a vacuum pumping assembly, a helium mass spectrometer leak detector and a sliding scanning module moving in the axial direction of a workpiece to be detected. The sliding scanning module is sequentially provided with a differential pressure sensor and a rear helium injection detection unit in the scanning direction. In the scanning process, the differential pressure sensor detects airflow abnormity on the surface of a workpiece in advance according to the aerodynamic principle; if the large leakage rate defect is detected, the control system immediately locks a helium channel of the rear helium injection detection unit; and if the large leakage is not detected, the rear helium injection detection unit is controlled to carry out trace pulse helium injection and synchronous recovery detection. According to the invention, through a dual-mode hierarchical scanning mechanism, leakage detector poisoning caused by large leakage is effectively prevented, and through coaxial spraying and suction and on-demand helium injection, millimeter-level accurate positioning of leakage points and extremely low consumption of helium resources are realized.

Description

Technical Field

[0001] This invention relates to the field of helium leak detection technology, and in particular to an automated helium mass spectrometry leak detection device. Background Technology

[0002] Helium mass spectrometry leak detection technology, as a highly sensitive and non-destructive method for testing sealing performance, is widely used in aerospace, refrigeration and air conditioning, automotive parts, and vacuum electronics industries. Its basic principle involves evacuating the workpiece to a vacuum state and connecting it to a helium mass spectrometer leak detector, followed by spraying helium gas onto the exterior of the workpiece. When leak pores exist on the workpiece surface, helium gas is drawn into the workpiece under the influence of atmospheric pressure difference, and is then detected by the mass spectrometer chamber of the leak detector, thus determining whether a leak exists. Traditional leak detection methods primarily use a spray gun method, where a manual or mechanical handheld spray gun is used to spray helium gas onto specific areas.

[0003] Although the aforementioned traditional methods are mature, they still have the following significant drawbacks under the requirements of automation, high precision, and low-cost operation. First, existing equipment typically cannot effectively distinguish between large leaks and micro-leaks before helium injection. When a workpiece has large leak defects such as cracks or fractures, a large amount of helium will instantly flood into the vacuum system, causing ion source saturation in the mass spectrometer chamber. This results in persistent background noise that cannot be reduced for a long time, and in severe cases, even damages the filament, leading to prolonged production line shutdowns for cleaning and extremely high maintenance costs. Second, the utilization efficiency of helium is insufficient. In the spray gun method, most of the helium directly escapes into the workshop air, resulting in excessively high detection costs. Furthermore, although the spray gun method can locate the leak location, due to the rapid diffusion speed and low density of helium, the injected helium is prone to drift, causing false positive alarms in nearby areas. It is difficult to achieve millimeter-level precise positioning, failing to meet the coordinate accuracy requirements of subsequent automated repairs. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides an automated helium mass spectrometry leak detection device.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An automated helium mass spectrometry leak detection device includes a frame and a support base for mounting the workpiece to be tested. The support base is disposed on the frame. The device also includes a vacuum pumping assembly, a helium mass spectrometer leak detector, a sliding scanning module, and a control unit. The vacuum pumping assembly is airtightly connected to the inner cavity of the workpiece to be tested. The sampling port of the helium mass spectrometer leak detector is connected to the pipeline of the vacuum pumping assembly. The sliding scanning module is disposed on the frame and is driven to reciprocate along the axial extension direction of the workpiece to be tested by a linear drive mechanism. A surrounding housing is disposed on the linear drive mechanism. The surrounding housing has a central through hole for the workpiece to be tested to pass through. A scanning gap is reserved between the inner wall of the surrounding housing and the outer surface of the workpiece to be tested. The inner wall of the surrounding housing has a first detection chamber, an isolation groove and a second detection chamber sequentially opened along the scanning direction. The first detection chamber is connected to a differential pressure sensor through a pipeline and serves as a coarse inspection area for detecting the presence of large leaks. The second detection chamber is equipped with a helium injection assembly controlled by a solenoid valve and serves as a fine inspection area for injecting helium. The isolation groove is equipped with a high-pressure gas source and a gas source recovery assembly for separating the first and second detection chambers with a spray gas wall. The control unit is electrically connected to the linear drive mechanism, the differential pressure sensor and the solenoid valve respectively.

[0006] Furthermore, several gas static pressure throttling holes are distributed on the inner wall of the surrounding housing. The gas static pressure throttling holes are connected to a high-pressure gas source through a pressure equalization channel located inside the isolation groove. The outlet end of the gas static pressure throttling holes faces the outer surface of the workpiece to be tested.

[0007] Furthermore, the isolation groove is located on the inner wall of the housing between the first and second detection chambers. The isolation groove is an annular groove extending circumferentially along the inner wall of the housing, and the bottom of the annular groove has an opening for the high-pressure gas source to eject gas. The first detection chamber is considered the coarse inspection area, and the second detection chamber is considered the fine inspection area. By constructing a continuously ejected high-pressure gas wall between the first and second detection chambers, this gas wall spreads to both sides, physically cutting off the lateral communication of the airflow. This prevents the strong suction airflow generated by a large leak in the first detection chamber from affecting the second detection chamber, ensuring the stability of the flow field in the helium injection area; it also prevents the helium released from the second detection chamber from drifting forward into the first detection chamber or being carried away by the airflow, ensuring that the helium only acts on the current test point.

[0008] Furthermore, the high-pressure gas source and gas source recovery assembly are respectively arranged on both circumferential sides of the surrounding shell, forming a surrounding air wall by spraying gas between the surrounding shell and the workpiece to be tested. After the high-pressure gas enters the isolation groove 802, it is drawn by the negative pressure recovery assembly on the opposite side, flows along the annular groove and is discharged, thereby protecting the stability of the helium flow field. The circumferential flow forms a dynamic pressure ring. Compared with a stationary high-pressure gas mass, the flowing gas can better remove micro-dust or impurities in the gaps, playing an additional role in cleaning the surface to be tested.

[0009] Furthermore, the high-pressure gas source's nozzle is equipped with a circumferentially guiding vane, which has multiple guiding grooves to cover the gas within the isolation groove, forming a surrounding gas wall. Ordinary direct injection nozzles tend to create high-pressure points near the nozzle, while low-pressure blind zones form between two nozzles. The guiding vane directs the gas circumferentially, resulting in a continuous, uninterrupted, uniform gas wall across the entire 360-degree circumference.

[0010] Furthermore, the gas pressure of the gas wall injected by the high-pressure gas source and the helium flow generated by the helium injection assembly are the same. Specifically, the absence of a pressure difference between the gas wall and the helium flow can avoid or reduce lateral gas flow. Simultaneously, it can prevent the injected gas from the gas wall from disturbing adjacent gases and disrupting the stability of the helium flow field.

[0011] Furthermore, the helium injection assembly within the second detection chamber includes a helium injection nozzle and an annular suction channel surrounding the nozzle. The helium injection nozzle is connected to the outlet of the solenoid valve, and the annular suction channel is connected to a negative pressure recovery pump via a recovery pipeline. The helium injection nozzle releases tracer gas, while the surrounding annular suction channel utilizes negative pressure to create a strong recovery flow field. This ensures that the ejected helium, upon contact with the workpiece surface, is immediately recovered and carried away if not drawn into the leak, limiting the helium's diffusion radius. This not only achieves efficient helium recycling but also prevents the accumulation of helium in the workshop environment, which would increase background noise, ensuring detection sensitivity during continuous long-term operation.

[0012] Furthermore, the frame is also equipped with a through slot arranged along the axis of the sliding scanning module. This through slot is vertically continuous, allowing conduits to pass through, and the helium injection assembly is connected to a helium cylinder via a conduit. Since the sliding scanning module needs to travel along the entire length of the workpiece being measured, its connected gas pipes and cables must move accordingly. The vertically continuous through slot provides an interference-free channel for the pipelines, and in conjunction with the cable chain system, effectively prevents the pipelines from becoming tangled, knotted, or subject to friction and wear against the frame during movement. This results in a cleaner overall layout of the equipment, conforms to safe operating procedures in industrial settings, and reduces maintenance difficulty.

[0013] Furthermore, the machine frame is equipped with a rotatable and adjustable bent-tube sealing fixture, which is connected to the vacuum pumping assembly and sealed to the inner cavity of the workpiece to be tested. The bent-tube sealing fixture can be rotated and finely adjusted according to the actual orientation of the workpiece port, ensuring that the vacuum interface and the workpiece port are always coaxially and precisely aligned. This flexible connection not only ensures the high airtightness of the vacuum system and prevents misjudgments caused by leakage at the connection, but also reduces clamping auxiliary time.

[0014] Furthermore, the sliding scanning module includes a linear guide rail arranged parallel to the axial direction of the workpiece under test and a servo motor that drives the linear drive mechanism. The servo motor is coaxially connected to a position encoder, and the signal output of the position encoder is connected to the control unit. The servo motor, in conjunction with the linear guide rail, ensures that the scanning module operates at a stable speed, eliminating the influence of speed fluctuations on the flow detection signal. The coaxially connected position encoder can provide real-time feedback to the control unit on the module's current absolute coordinates along the workpiece's axial direction. This allows the system to map the time-series signal acquired by the helium mass spectrometer leak detector to the spatial position information on the workpiece under test, i.e., the coordinates of the leak point.

[0015] Furthermore, the inner wall of the surrounding housing is also equipped with a marking nozzle, which is located behind the traveling end of the second detection chamber. The control end of the marking nozzle is electrically connected to the control unit, and the nozzle of the marking nozzle is positioned facing the surface of the workpiece to be tested. When the control unit confirms that the second detection chamber has detected a leak signal and calculates the accurate coordinates based on the position encoder, the marking nozzle is triggered to spray a label as the linear drive mechanism continues to move forward past that coordinate point. This converts the invisible helium leak detection data into a visible physical mark, directly marking the defect location on the surface of the workpiece to be tested. This facilitates subsequent rework processes, allowing workers to intuitively locate leaks and perform repair welding without consulting computer records, avoiding incorrect or missed repairs due to information transmission errors, and significantly improving production efficiency.

[0016] Furthermore, the width of the first detection cavity along the scanning direction is L1, the width of the isolation groove is L2, and the width of the second detection cavity is L3; The center distance between the first detection cavity and the second detection cavity is L4; The control unit is equipped with a time delay logic module. The time delay logic module calculates the time difference T = L4 / V based on the real-time moving speed V of the linear drive mechanism, and controls the opening and closing of the helium injection component based on the time difference T.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention sets a differential pressure sensor at the front end of the scanning module and uses aerodynamic principles instead of helium tracer to first physically detect the large flow rate of helium inhalation on the surface of the workpiece. Once a large leak is detected, the control system forcibly closes the helium injection channel at the rear end in a short time. This avoids the technical problem of the leak detector stopping due to excessive helium inhalation caused by a large leak in the prior art, and significantly improves the operational stability and service life of the equipment. 2. When detecting micro-leakage, this invention injects only a small amount of helium into the tiny local gap and then recovers it through the annular intake channel. Combined with a closed-loop separation and purification system, it realizes on-demand supply and immediate injection and recovery of helium, solving the problems of serious helium waste and high operating costs in the prior art. Theoretically, helium consumption can be reduced by more than 90%. 3. This invention utilizes a sliding scanning module and an air-floating micro-gap design to physically confine the detection area within a very small dynamic microcavity. Combined with a position encoder and a delay logic algorithm, it enables coordinate tracking of the leak point. At the same time, the negative pressure isolation air curtain between the front-viewing unit and the rear-injection unit effectively cuts off airflow interference, allowing the device to accurately mark the specific location of the leak point, facilitating subsequent targeted welding or repair. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the surrounding shell; Figure 3 This is a partial structural diagram of the surrounding shell; Figure 4 This is a schematic diagram of the sliding scanning module; Figure labels: 1-Frame, 2-Workpiece to be tested, 3-Support base, 4-Vacuum pumping assembly, 5-Helium mass spectrometer leak detector, 6-Sliding scanning module, 7-Linear drive mechanism, 8-Circular housing, 801-First detection chamber, 802-Isolation groove, 803-Second detection chamber, 9-Differential pressure sensor, 10-Helium injection assembly, 1001-Helium injection nozzle, 1002-Annular suction channel, 11-Gas static pressure throttling orifice, 12-High pressure gas source, 13-Passage groove, 14-Helium cylinder, 15-Bent pipe sealing clamp, 16-Marking nozzle. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0020] Example 1, as Figures 1-4 As shown, the present invention discloses an automated helium mass spectrometry leak detection device, including a frame 1 and a support base 3 for mounting the workpiece 2 to be tested. The support base 3 is disposed on the frame 1. The device also includes a vacuum pumping assembly 4, a helium mass spectrometer leak detector 5, a sliding scanning module 6, and a control unit. The vacuum pumping assembly 4 is airtightly connected to the inner cavity of the workpiece 2 to be tested. The sampling port of the helium mass spectrometer leak detector 5 is connected to the pipeline of the vacuum pumping assembly 4. The sliding scanning module 6 is disposed on the frame 1 and is driven to reciprocate along the axial extension direction of the workpiece 2 to be tested by a linear drive mechanism 7. A surrounding housing 8 is disposed on the linear drive mechanism 7. The surrounding housing 8 has a central through hole through which the workpiece 2 to be tested passes. A scanning gap is reserved between the inner sidewall of the surrounding housing 8 and the outer surface of the workpiece 2 to be tested. The inner sidewall of the surrounding housing 8 is provided with a first detection chamber 801, an isolation groove 802 and a second detection chamber 803 in sequence along the scanning direction. The first detection chamber 801 is connected to a differential pressure sensor 9 through a pipeline and serves as a coarse inspection area for detecting the presence of large leaks. The second detection chamber 803 is provided with a helium injection assembly 10 controlled by a solenoid valve and serves as a fine inspection area for injecting helium. The isolation groove 802 is provided with a high-pressure gas source 12 and a gas source recovery assembly for separating the first detection chamber 801 and the second detection chamber 803 by a jet gas wall. The control unit is electrically connected to the linear drive mechanism 7, the differential pressure sensor 9 and the solenoid valve respectively.

[0021] Specifically, the differential pressure sensor 9 is located within the first detection chamber 801. Based on aerodynamic principles, when scanning over large leak defects such as cracks or fractures on the surface of the workpiece 2, the vacuum pumping assembly creates a negative pressure inside the workpiece, causing an instantaneous influx of external airflow. The differential pressure sensor 9 is responsible for real-time monitoring and capturing the pressure surge signal caused by the large-flow intake. Once an abnormal pressure is detected, the differential pressure sensor 9 sends a signal to the control unit as a trigger signal for subsequent control actions. By detecting large leaks in advance, the control system can close the solenoid valve before the large leak point moves to the helium injection assembly at the rear, preventing a large amount of helium from instantly flooding into the vacuum system and preventing the ion source of the helium mass spectrometer leak detector 5 from becoming saturated.

[0022] The inner wall of the surrounding housing 8 is also provided with a number of gas static pressure throttling holes 11. The gas static pressure throttling holes 11 are connected to the high pressure air source 12 through the pressure equalization channel provided inside the isolation groove 802. The air outlet of the gas static pressure throttling holes 11 faces the outer surface of the workpiece 2 to be tested.

[0023] The isolation groove 802 is located on the inner wall of the housing between the first detection chamber 801 and the second detection chamber 803. The isolation groove 802 is an annular groove extending circumferentially along the inner wall of the housing, and the bottom of the annular groove has an opening for the high-pressure gas source 12 to eject gas. Specifically, the first detection chamber 801 is considered as the coarse inspection area, and the second detection chamber 803 is considered as the fine inspection area. By constructing a continuously ejected high-pressure gas wall between the first detection chamber 801 and the second detection chamber 803, and this gas wall spreads to both sides, the lateral communication of the airflow is physically cut off. This prevents the strong suction airflow generated by a large leak in the first detection chamber 801 from affecting the second detection chamber 803, ensuring the stability of the flow field in the helium injection area; it also prevents the helium released from the second detection chamber 803 from drifting forward to the first detection chamber 801 or being carried away by the airflow, ensuring that the helium only acts on the current test point. The active pneumatic isolation design is more adaptable to dynamic scanning environments than traditional physical partitions. Even if there are slight unevennesses on the workpiece surface, the air curtain can adaptively fill the gap, achieving area segmentation without blind spots.

[0024] The high-pressure gas source 12 and the gas source recovery assembly are respectively arranged on both sides of the circumferential structure of the surrounding housing 8, forming a surrounding gas wall between the surrounding housing 8 and the workpiece 2 under test. Specifically, after the high-pressure gas enters the isolation groove 802, it is drawn by the negative pressure recovery assembly on the opposite side, flows along the annular groove and is discharged, thereby protecting the stability of the helium flow field. The circumferential flow forms a dynamic pressure ring. Compared with a static high-pressure gas mass, the flowing gas can better remove micro-dust or impurities in the gaps, playing an additional role in cleaning the surface under test.

[0025] The high-pressure gas source 12 is equipped with a circumferentially guiding vane at its nozzle. This vane has multiple guiding grooves to cover the gas within the isolation groove 802, forming a surrounding air wall. Specifically, ordinary direct injection nozzles tend to create high-pressure points near the nozzle, while low-pressure blind zones form between the two nozzles. The guiding vane guides the gas circumferentially, creating a continuous, uninterrupted, uniform air wall across the entire 360-degree circumference. Unlike existing technologies that use rubber seals or mechanical baffles for area isolation, traditional physical isolation methods require a strict match between the inner diameter of the isolation component and the outer diameter of the workpiece. If the workpiece has ellipticity, straightness deviations, or diameter tolerance fluctuations, the physical baffle is prone to sealing failure due to excessive gaps, or surface scratches and increased frictional resistance due to interference fits. The high-pressure air wall isolation technology used in this application utilizes the expandability and compressibility of fluids to construct a flexible gas barrier.

[0026] The gas wall ejected by the high-pressure gas source 12 and the helium flow generated by the helium injection assembly 10 have the same gas pressure. Specifically, the absence of a pressure difference between the gas wall and the helium flow can avoid or reduce lateral gas flow. Simultaneously, it can prevent the ejected gas from the gas wall from disturbing adjacent gases and disrupting the stability of the helium flow field.

[0027] The helium injection assembly 10 within the second detection chamber 803 includes a helium injection nozzle 1001 and an annular suction channel 1002 surrounding the nozzle 1001. The nozzle 1001 is connected to the outlet of the solenoid valve, and the annular suction channel 1002 is connected to a negative pressure recovery pump via a recovery pipeline. Specifically, the helium injection nozzle 1001 releases tracer gas, while the surrounding annular suction channel 1002 utilizes negative pressure to create a strong recovery flow field. This ensures that the ejected helium, upon contact with the workpiece surface, is immediately recovered and carried away if not drawn into a leak, limiting the helium's diffusion radius. This not only achieves efficient helium recycling but also prevents the accumulation of helium in the workshop environment, thus avoiding increased background noise and ensuring detection sensitivity during continuous long-term operation. Preferably, a proportional control valve and a flow sensor are installed on the pipeline connecting the annular suction channel 1002 to the negative pressure recovery pump. The control unit adjusts the proportional control valve to maintain the pressure within the annular suction channel 1002 at a set value slightly below atmospheric pressure. As long as the flow rate at the intake port is slightly greater than the flow rate at the helium injection nozzle, an inward-facing enveloping flow field can be formed to prevent helium from overflowing, while also avoiding excessive negative pressure that could draw in outside air and cause turbulence. The opening direction of the gas static pressure throttling orifice 11 is inclined at 15°-30° away from the second detection chamber 803. Utilizing the directionality of momentum vectors, the high-pressure exhaust gas is guided to preferentially flow towards the first detection chamber 801 (coarse detection area) or the outside, actively avoiding the helium injection area. This resolves the disturbance of the helium by the injected gas, ensuring the accuracy of detection information and data acquisition.

[0028] The frame 1 is also equipped with a through slot 13 arranged along the axis of the sliding scanning module 6. The through slot 13 is vertically through, allowing conduits to pass through, and the helium injection assembly 10 is connected to the helium cylinder 14 through the conduit. Specifically, since the sliding scanning module 6 needs to travel along the entire length of the workpiece 2 to be measured, its connected gas pipes and cables must move accordingly. The vertically through slot 13 provides an interference-free pipeline following channel, which, together with the cable chain system, can effectively prevent the pipelines from getting tangled, knotted, or rubbing against the frame during movement. This makes the overall layout of the equipment neater, conforms to the safety operation specifications of industrial sites, and reduces maintenance difficulty.

[0029] The frame 1 is equipped with a rotatable and adjustable bent pipe sealing clamp 15, which is connected to the vacuum pumping assembly 4 and sealed to the inner cavity of the workpiece 2 to be tested. Specifically, the bent pipe sealing clamp 15 can be rotated and its posture finely adjusted according to the actual orientation of the workpiece port, ensuring that the vacuum interface and the workpiece port are always coaxial and precisely aligned without stress. This flexible connection not only ensures the high airtightness of the vacuum system and prevents misjudgment due to leakage at the connection, but also reduces clamping auxiliary time, allowing the same equipment to quickly switch to meet the testing needs of various specifications and models of pipes.

[0030] The sliding scanning module 6 includes a linear guide rail parallel to the axis of the workpiece 2 under test and a servo motor that drives the linear drive mechanism 7. A position encoder is coaxially connected to the servo motor, and the signal output of the position encoder is connected to the control unit. Specifically, the servo motor, in conjunction with the linear guide rail, ensures that the scanning module operates at a stable speed, eliminating the influence of speed fluctuations on the flow detection signal. The coaxially connected position encoder can provide real-time feedback to the control unit on the module's current absolute coordinates along the workpiece axis. This allows the system to map the time-series signal acquired by the helium mass spectrometer leak detector 5 to the spatial position information on the workpiece 2 under test, i.e., the coordinates of the leak point.

[0031] The inner wall of the surrounding housing 8 is also provided with a marking nozzle 16. The marking nozzle 16 is located behind the traveling end of the second detection chamber 803. The control end of the marking nozzle 16 is electrically connected to the control unit. The nozzle of the marking nozzle 16 is positioned facing the surface of the workpiece 2 to be tested. Specifically, when the control unit confirms that the second detection chamber 803 has detected a leak signal and calculates the accurate coordinates according to the position encoder, the marking nozzle 16 is triggered to spray a label when the linear drive mechanism 7 continues to move forward past the coordinate point. This converts the invisible helium leak detection data into a visible physical mark, directly marking the defect location on the surface of the workpiece 2 to be tested. This facilitates subsequent rework processes, allowing workers to intuitively find the leak point for repair welding without consulting computer records, avoiding incorrect or missed repairs due to information transmission errors, and significantly improving production efficiency.

[0032] Example 2, based on Example 1, proposes a specific time control principle for an automated helium mass spectrometer leak detection device.

[0033] The width of the first detection cavity 801 along the scanning direction is L1, the width of the isolation groove 802 is L2, and the width of the second detection cavity 803 is L3. The center distance between the first detection cavity 801 and the second detection cavity 803 is L4; ; That is, center-to-center distance It is equal to the sum of the latter half of the first detection cavity 801, the total length of the isolation groove 802, and the first half of the second detection cavity 803.

[0034] When L1 detects a large leak, the control system has sufficient time to utilize the blank stroke of L2. The valve must be closed before the leak reaches L3 (the helium injection zone). If L4 is too small (i.e., L2 is short), the scan speed V must be very slow to ensure the valve closes in time. However, by properly setting L2 using this formula, the device can operate at a higher speed V because... It provides a sufficient reaction time window.

[0035] The control unit is equipped with a time delay logic module. The time delay logic module calculates the time difference T = L4 / V based on the real-time moving speed V of the linear drive mechanism 7, and controls the opening and closing of the helium injection component 10 based on the time difference T.

[0036] Specifically, when the differential pressure sensor 9 in the first detection chamber 801 is at time... When a pressure surge signal is detected (i.e., a large leak is identified), the logic module calculates the theoretical lag time T between the large leak point and the arrival at the second detection chamber 803 (i.e., the location of the helium injection assembly 10) using the formula T = L4 / V. Based on this calculation, the control unit executes an early latch-up command at time [time value missing]. Close the solenoid valve of helium injection assembly 10, and at time... Reopen the solenoid valve.

[0037] in, L4 refers to the absolute time when the differential pressure sensor 9 in the first detection chamber 801 first detects abnormal pressure fluctuations; L4 refers to the fixed physical distance between the geometric center line of the first detection chamber 801 and the geometric center line of the second detection chamber 803 on the sliding scanning module 6; and V represents the instantaneous speed at which the linear drive mechanism 7 drives the sliding scanning module 6 to move along the axial direction of the workpiece 2 under test. This is a preset safety lead time (used to compensate for the mechanical response delay of the solenoid valve). This is a safety hysteresis (used to ensure that large leaks are completely removed from the helium injection area). This indicates the execution time when the control unit sends a shut-off command to the helium injection assembly solenoid valve. This indicates the execution time when the control unit sends the opening command to the helium injection assembly solenoid valve.

[0038] Example 3: Based on Example 2, this example proposes a specific control logic optimization scheme for an automated helium mass spectrometer leak detection device.

[0039] The control unit is configured to receive the real-time displacement signal fed back by the position encoder and set the solenoid valve of the helium injection assembly 10 to distance trigger mode. That is, regardless of how the moving speed V of the linear drive mechanism 7 changes (including the start-up acceleration phase, constant speed phase, and stop-deceleration phase), the control unit will adjust the displacement increment based on the preset displacement increment output by the position encoder. The solenoid valve is opened by a fixed short pulse duration. Furthermore, the control unit is pre-programmed with secondary verification logic. When the helium mass spectrometer leak detector 5 detects a leak signal exceeding the warning threshold at a certain coordinate point, the control unit immediately controls the linear drive mechanism 7 to pause and retract to the front of that coordinate point, subsequently performing a verification at a speed lower than the normal scanning speed. The area is then re-injected with helium for confirmation; the marking nozzle 16 is triggered to perform physical marking only if both detections trigger an alarm.

[0040] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. An automated helium mass spectrometer leak detection device, comprising a rack table (1) and a support seat (3) for mounting a workpiece (2) to be tested, the support seat (3) being arranged on the rack table (1), characterized in that: Also include a vacuum pumping assembly (4), helium mass spectrometer leak detector (5), slip scanning module (6) and control unit, the vacuum pumping assembly (4) and the inner cavity of the workpiece (2) to be measured is airtight connection, the sampling port of the helium mass spectrometer leak detector (5) is communicated with the pipeline of vacuum pumping assembly (4), the slip scanning module (6) is arranged on the rack table (1), and is driven to reciprocate along the axial extension direction of the workpiece (2) to be measured by the linear drive mechanism (7), the linear drive mechanism (7) is provided with a circumferential shell (8); The circumferential shell (8) is provided with a central through hole for the workpiece (2) to be measured to pass through, and a scanning gap is reserved between the inner side wall of the circumferential shell (8) and the outer surface of the workpiece (2) to be measured, the inner side wall of the circumferential shell (8) is sequentially provided with a first detection cavity (801), an isolation groove (802) and a second detection cavity (803) along the scanning direction, the first detection cavity (801) is connected with a differential pressure sensor (9) through a pipeline, which is used as a rough detection area for detecting whether there is a large leak, the second detection cavity (803) is provided with a helium injection assembly (10) controlled by a solenoid valve, which is used as a fine detection area for injecting helium, the isolation groove (802) is provided with a high-pressure gas source (12) and a gas source recovery assembly for spraying gas wall to separate the first detection cavity (801) and the second detection cavity (803), and the control unit is electrically connected with the linear drive mechanism (7), the differential pressure sensor (9) and the solenoid valve respectively.

2. The automated helium mass spectrometer leak detection apparatus of claim 1, wherein: The inner side wall of the circumferential shell (8) is also circumferentially distributed with a plurality of gas static pressure orifices (11), the gas static pressure orifices (11) are connected to the high-pressure gas source (12) through the pressure equalizing flow channel arranged in the isolation groove (802), and the gas outlet end of the gas static pressure orifice (11) faces the outer surface of the workpiece (2) to be measured.

3. The automated helium mass spectrometer leak detection apparatus of claim 2, wherein: The isolation groove (802) is an annular groove extending along the circumferential wall of the shell, and the bottom of the annular groove is provided with an opening for the high-pressure gas source (12) to spray gas.

4. The automated helium mass spectrometer leak detection apparatus of claim 3, wherein: The high-pressure gas source (12) and the gas source recovery assembly are arranged on the two sides of the circumferential shell (8) respectively, and a circumferential gas wall is formed between the circumferential shell (8) and the workpiece (2) to be measured.

5. The automated helium mass spectrometer leak detection apparatus of claim 4, wherein: The gas injection port of the high-pressure gas source (12) is also provided with a circumferential flow guide vane, and a plurality of flow guide grooves are arranged on the flow guide vane for covering the gas in the isolation groove (802) to form a circumferential gas wall.

6. The automated helium mass spectrometer leak detection apparatus of claim 5, wherein: The gas wall sprayed by the high-pressure gas source (12) and the helium gas flow generated by the helium injection assembly (10) have the same gas pressure.

7. The automated helium mass spectrometer leak detection apparatus of claim 1, wherein: The helium injection assembly (10) in the second detection cavity (803) includes a helium injection nozzle (1001) and an annular gas suction channel (1002) surrounding the periphery of the helium injection nozzle (1001), the helium injection nozzle (1001) is communicated with the gas outlet end of the solenoid valve, and the annular gas suction channel (1002) is connected with a negative pressure recovery pump through a recovery pipeline.

8. The automated helium mass spectrometer leak detection apparatus of claim 1, wherein: The rack table (1) is further provided with a through groove (13) arranged along the axis direction of the sliding scanning module (6), the through groove (13) vertically penetrates for the catheter, and the helium injection assembly (10) is communicated with the helium bottle (14) through the catheter.

9. The automated helium mass spectrometer leak detection apparatus of claim 1, wherein: The rack table (1) is provided with a rotatable adjustable elbow sealing clamp (15), the elbow sealing clamp (15) is communicated with the vacuum air pumping assembly (4), and is sealingly communicated with the inner cavity of the workpiece (2) to be detected.

10. The automated helium mass spectrometer leak detection apparatus of claim 1, wherein: The sliding scanning module (6) comprises a linear guide rail arranged in parallel to the workpiece (2) to be detected and a servo motor driving a linear driving mechanism (7) to move, the servo motor is coaxially connected with a position encoder, and a signal output end of the position encoder is connected with the control unit.

11. The automated helium mass spectrometer leak detection apparatus of claim 1, wherein: The inner side wall of the surrounding shell (8) is further provided with a marking spray head (16), the marking spray head (16) is located behind the travel end of the second detection cavity (803), a control end of the marking spray head (16) is electrically connected with the control unit, and a nozzle of the marking spray head (16) is arranged towards the surface side of the workpiece (2) to be detected.

12. The automated helium mass spectrometer leak detection apparatus of claim 1, wherein: The width of the first detection cavity (801) along the scanning travel direction is L1, the width of the isolation groove (802) is L2, the width of the second detection cavity (803) is L3, and the center distance between the first detection cavity (801) and the second detection cavity (803) is L4. The formula corresponding to the relationship is: .

13. The automated helium mass spectrometer leak detection apparatus of claim 12, wherein: The control unit is preprovided with a delay logic module, the delay logic module calculates a time difference T = L4 / V according to the real-time moving speed V of the linear driving mechanism (7), and controls the opening and closing of the helium injection assembly (10) based on the time difference T.

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