An on-line device and method for detecting the wall thickness of an ultra-long pipe

Abstract

The application relates to an ultra-long pipe wall thickness on-line detection device and method, which comprises a measuring head mounting seat, a clamping assembly, a active guiding distance adjusting assembly, a distance measuring feedback unit, a measuring assembly and a control display unit; the active guiding distance adjusting unit is arranged in the clamping unit, and the front end of the active guiding distance adjusting unit is connected with the measuring head mounting seat; the distance measuring feedback unit is arranged on the front end side wall of the measuring head mounting seat; the measuring assembly is arranged in the middle region of the front end of the measuring head mounting seat; and the control display unit is connected with the distance measuring feedback unit, the active guiding distance adjusting assembly and the measuring assembly. The application can realize non-contact active distance adjusting and wall thickness on-line detection in the turning field with much iron filings, easy absorption of the measuring head to the iron filings and high-speed rotation of the pipe, and can effectively solve the problems of offline thickness detection lag, difficult stable lifting distance in on-line measurement, easy blocking of the contact type protective wheel by the iron filings and easy absorption of the strong magnetic measuring head to the metal filings in the turning process of the ultra-long pipe.

Description

Technical Field

[0001] This invention relates to the field of pipe testing technology, and in particular to an online device and method for detecting the wall thickness of ultra-long pipes. Background Technology

[0002] Extra-long heavy-duty metal pipes are widely used in heavy machinery, new energy equipment, petrochemicals, aerospace, and large-scale infrastructure. These pipes are long and heavy, and their machining typically requires external turning on a lathe. For pipes with lengths ranging from several meters to over ten meters, large outer diameter spans, and wide variations in wall thickness, wall thickness measurement must not only meet accuracy requirements but also adapt to the continuous machining cycle of the turning process.

[0003] Existing offline wall thickness measurement methods mostly employ post-processing sampling or stop-machine point measurement, such as using a conventional ultrasonic thickness gauge to measure at predetermined points. Although this method uses simple equipment, it requires stopping processing or waiting until processing is completed before measurement can be performed. It cannot detect problems such as wall thickness deviation, local out-of-tolerance, or insufficient machining allowance during turning, and the test results lack real-time feedback for the ongoing processing.

[0004] While existing online measurement devices can be deployed near machine tools for follow-up measurement, they still have significant limitations in ultra-long pipe turning scenarios: First, the high-speed rotation of the pipe generates radial runout and local oscillation, causing the lift-off distance between the probe and the pipe surface to constantly change, and non-contact thickness measurement signals are highly sensitive to this lift-off distance; Second, there are many metal chips in the machining environment, and thickness probes often contain strong magnetic structures, making it easy for metal chips to be attracted to the probe tip, causing measurement signal attenuation, false triggering, or probe surface contamination; Third, cutting fluid, spatter, and high-temperature debris can directly impact the probe and sensor, leading to a reduction in the lifespan of front-end components.

[0005] To maintain the measurement distance, some online measuring devices use contact-type limiting elements such as protective wheels or casters to stay close to the pipe surface, allowing the probe to move with the outer contour of the pipe. However, in machining environments with dense metal chips, the protective wheels can easily trap metal chips and become stuck, and the contact point may also scratch the pipe surface due to the adhered metal chips. When the pipe has a large outer diameter, long length, and large moment of inertia, the impact and vibration experienced by the protective wheels can also affect the stability of the probe mounting base.

[0006] If contact-type limit switches are completely eliminated, and the probe mounting base is directly driven by a regular linear motor or electric actuator, new mechanical problems will arise. The front end of the probe mounting base simultaneously bears the probe, distance sensor, protective structure, and cleaning air path; the load is not an ideal coaxial load. If the output end of the linear motor directly bears off-center loads, bending moments, and circumferential disturbances, it can easily cause uneven wear of the actuator, movement stagnation, and changes in probe posture, thereby affecting the distance measurement direction and thickness measurement stability.

[0007] Therefore, the core challenge faced by existing pipe wall thickness measurement devices and methods in ultra-long pipe turning is not simply the thickness measurement principle, but rather how to stably control the probe lift-off distance, protect the front-end components, and maintain the stability of the motion mechanism under conditions such as strong magnetic chip attraction, iron chip splashing, pipe jumping, inability to contact the pipe, and the need for continuous online detection. Summary of the Invention

[0008] The purpose of this invention is to provide an online detection device and method for ultra-long pipe wall thickness, aiming to solve problems such as the lag in existing offline measurement, easy jamming of contact-type online limiters, difficulty in stabilizing the lifting distance of non-contact probes, easy adsorption of iron filings by strong magnetic probes, and insufficient anti-eccentric load capacity of linear drive mechanisms.

[0009] The technical solution adopted in this invention is as follows:

[0010] The present invention proposes an online wall thickness detection device for ultra-long pipes, comprising a probe mounting base, a clamping assembly, an active guide adjustment assembly, a distance feedback unit, a measurement assembly, and a control and display unit; the active guide adjustment unit is disposed inside the clamping assembly, and its front end is connected to the probe mounting base; the distance feedback unit is disposed on the front side wall of the probe mounting base; the measurement assembly is disposed inside the middle area of ​​the front end of the probe mounting base; and the control and display unit is connected to the distance feedback unit, the active guide adjustment assembly, and the measurement assembly.

[0011] Furthermore, the clamping assembly includes a clamping square tube and an anti-bending joint; the anti-bending joint is disposed at the tail end of the clamping square tube and communicates with the inner cavity of the clamping square tube.

[0012] Furthermore, the active guide adjustment assembly includes a hollow linear motor, an output push rod, a reducing connector, a spline sleeve, and a hollow spline shaft; the spline sleeve is fixedly connected to the front interior of the clamping square tube; the hollow spline shaft is slidably fitted inside the spline sleeve; the hollow linear motor is fixedly connected to the rear interior of the clamping square tube; the output push rod is fixedly connected to the output end of the hollow linear motor; the front end of the output push rod is connected to the rear end of the hollow spline shaft through the reducing connector; the front end of the hollow spline shaft is fixedly connected to the probe mounting base; and the hollow linear motor is connected to the control and display unit.

[0013] Furthermore, the measuring component includes a probe, a probe connecting cable, and a thickness measuring host; the probe is disposed inside the middle area of ​​the front end of the probe mounting base; the probe connecting cable passes sequentially through the probe mounting base, a hollow spline shaft, a reducing joint, and a hollow linear motor before connecting to the external thickness measuring host; the thickness measuring host is connected to the control and display unit.

[0014] Furthermore, the hollow linear motor, the reducing joint, and the hollow spline shaft are all provided with axial through holes for the probe connection wire to pass through.

[0015] Furthermore, the ranging feedback unit is a distance sensor, which is arranged perpendicularly to the pipe to be measured; the distance sensor is provided with a protective shell on its outer side, and a protective cover is provided at its front end; the protective cover is provided with a light-transmitting protective window at the corresponding position of the ranging optical path.

[0016] Furthermore, a probe protective cover is provided at the front end of the probe; an air nozzle is fixedly connected to one side of the probe mounting base; the air jet hose is installed on the upper surface of the probe mounting base; the output end of the air nozzle is connected to the air jet hose; the output end of the air jet hose is located at the front side of the probe.

[0017] A method for online detection of the wall thickness of ultra-long pipes, the method comprising the following steps: S1. Install the control box near the lathe tool post, and connect the control display unit to the distance feedback unit, the hollow linear motor and the thickness measuring host respectively; S2. Clamp the square tube in the secondary tool slot of the lathe, and adjust the position of the probe mounting seat so that the probe and the distance feedback unit face the outer surface of the tube being measured. S3. Set the normal lift-off distance between the probe and the surface of the pipe being tested to 1.5~2mm in the control display unit; S4. After starting the lathe, the distance feedback unit detects the distance between itself and the surface of the pipe being measured in real time and sends the distance signal to the control display unit. The front end of the distance feedback unit is flush with the front end of the probe so that the distance signal corresponds to the lifting distance between the probe and the surface of the pipe being measured. S5. The control display unit judges the distance signal. When the lifting distance between the probe and the surface of the pipe being measured is less than 1.5mm, the hollow linear motor is controlled to move backward. When the lifting distance is greater than 2mm, the hollow linear motor is controlled to move forward. When the lifting distance is within the range of 1.5~2mm, the hollow linear motor is controlled to maintain the current position. S6. The hollow linear motor drives the hollow spline shaft to slide axially along the spline sleeve through the reducing joint. The hollow spline shaft drives the probe mounting seat to move closer to or away from the surface of the pipe being tested. S7. The lathe tool post drives the measuring component to feed along the turning direction of the pipe being measured. The probe measures the pipe wall thickness at the passing position in a non-contact state, and the thickness measurement host feeds back to the control display unit.

[0018] Furthermore, during the testing process, all components remain in a non-contact state with the surface of the pipe being tested.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. Non-contact ranging replaces contact-based mechanical limiting. The device can determine the lifting distance without the protective wheel needing to be in contact with the pipe, effectively avoiding problems such as iron filings getting stuck in the protective wheel, roller jamming, and scratches on the pipe surface.

[0020] 2. The active pitch adjustment and spline guidance have clearly defined roles. The hollow linear motor is responsible for forward and backward adjustment, while the spline sleeve and hollow spline shaft are responsible for guidance, anti-rotation, and anti-eccentric load, preventing the probe mounting base from shifting its posture during pitch adjustment.

[0021] 3. Adaptable to machining environments where strong magnetic probes easily attract chips. The probe protection structure, sensor protection structure, and pneumatic cleaning work together to effectively reduce the impact of iron chip adsorption, accumulation, and splashing impact on thickness and distance signals.

[0022] 4. Built-in cable protection. The probe connection cable is led out through the internal channels of the hollow linear motor, reducing the risk of exposed cables being damaged by iron filings or getting caught in the moving parts of the machine tool.

[0023] 5. Suitable for online inspection of ultra-long pipes during turning. The device can be clamped in the secondary tool slot of the lathe and feeds along the axial direction of the pipe with the tool post, achieving online detection and real-time display of wall thickness in a non-contact state. Attached Figure Description

[0024] Figure 1 This is an overall structural diagram of the present invention; Figure 2 This is a cross-sectional structural diagram of the active guiding and adjusting unit in this invention; Figure 3 This is a schematic diagram of the distance measuring and protection structure at the front end of the probe mounting base in this invention; Figure 4 This is a schematic diagram of the active distance control process of the present invention; Figure 5 This is a schematic diagram illustrating the application scenario of the present invention.

[0025] In the attached drawings, the following reference numerals are used: 1-Clamping square tube; 2-Anti-bending joint; 3-Hollow linear motor; 4-Output push rod; 5-Reducing diameter joint; 6-Spline sleeve; 7-Hollow spline shaft; 8-Probe mounting base; 9-Probe; 10-Probe connecting line; 11-Distance feedback unit; 12-Protective housing; 13-Sensor protective cover; 14-Air nozzle; 15-Air jet hose; 16-Control and display unit; 17-Thickness measuring host; 18-Probe protective cover; 19-Tested pipe. Detailed Implementation

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] It should be noted that in the description of this invention, the terms "upper", "lower", "top", "bottom", "one side", "the other side", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not mean that the device or element must have a specific orientation, or be constructed and operated in a specific orientation.

[0028] See appendix Figures 1-3 The present invention proposes an online wall thickness detection device for ultra-long pipes, comprising a probe mounting base 8, a clamping assembly, an active guide adjustment assembly, a distance measurement feedback unit 11, a measurement assembly, and a control and display unit 16. The active guide adjustment unit is disposed inside the clamping assembly, and its front end is connected to the probe mounting base 8. Two sets of distance measurement feedback units 11 are respectively fixed to the left and right side walls of the front end of the probe mounting base 8. The measurement assembly is disposed inside the middle area of ​​the front end of the probe mounting base 8. The control and display unit 16 is connected to the distance measurement feedback unit 11, the active guide adjustment assembly, and the measurement assembly.

[0029] like Figure 1 and Figure 2 As shown, the clamping assembly includes a clamping square tube 1 and an anti-bending joint 2; the anti-bending joint 2 is located at the tail end of the clamping square tube 1 and communicates with the inner cavity of the clamping square tube 1.

[0030] The active guide adjustment assembly includes a hollow linear motor 3, an output push rod 4, a reducing connector 5, a spline sleeve 6, and a hollow spline shaft 7. The spline sleeve 6 is fixedly connected to the front interior of the clamping square tube 1. The hollow spline shaft 7 is slidably fitted inside the spline sleeve 6. The hollow linear motor 3 is fixedly connected to the rear interior of the clamping square tube 1. The output push rod 4 is coaxially fixedly connected to the output end of the hollow linear motor 3. The front end of the output push rod 4 is connected to the rear end of the hollow spline shaft 7 through the reducing connector 5. The front end of the hollow spline shaft 7 is fixedly connected to the probe mounting base 8. The hollow linear motor 3 is connected to the control and display unit 16.

[0031] The hollow linear motor 3 is responsible for outputting forward or backward displacement, while the spline sleeve 6 and the hollow spline shaft 7 are responsible for axial guidance, circumferential limiting and anti-eccentric load, so that the probe mounting seat 8 maintains a stable posture during the adjustment process.

[0032] In this invention, the interior of the clamping square tube 1 is provided with a stepped hole along the axial direction, the spline sleeve 6 is fixedly installed in the stepped hole at the front section of the clamping square tube 1, and the hollow spline shaft 7 passes through the spline sleeve 6 and can slide axially relative to the spline sleeve 6.

[0033] The reducing joint 5 is used to achieve coaxial connection and diameter transition between the output end of the hollow linear motor 3 and the hollow spline shaft 7.

[0034] The hollow linear motor 3, the reducing joint 5, and the hollow splined shaft 7 are all provided with axial through holes for the cable to pass through. This reduces cable exposure and lowers the risk of the cable being cut by metal filings or caught in the moving parts of the machine tool.

[0035] The measuring assembly includes a probe 9, a probe connecting cable 10, and a thickness measuring host 17; the probe 9 is fixedly installed inside the middle area of ​​the front end of the probe mounting base 8; the probe connecting cable 10 is led out through the hollow channel of the probe mounting base 8, the hollow spline shaft 7, the reducing connector 5, and the hollow linear motor 3, and then connected to the external thickness measuring host 17; the thickness measuring host 17 is connected to the control and display unit 16.

[0036] The probe 9 is an electromagnetic ultrasonic probe or a non-contact thickness probe containing magnetic components.

[0037] The ranging feedback unit 11 is a distance sensor, which is arranged perpendicularly to the pipe being measured, such as... Figure 3 As shown; the ranging feedback unit 11 is connected to the control display unit 16; a protective shell 12 is provided on the outside of the distance sensor, and a sensor protective cover 13 is provided at its front end; the thickness of the sensor protective cover 13 is 1mm. The sensor protective cover 13 is used to protect the ranging feedback unit 11, and is only used to prevent chips, cutting fluid and splashes from impacting the sensor, and is not used to limit the lift-off distance between the probe 9 and the pipe 19 being measured.

[0038] The ranging feedback unit 11 is preferably a laser triangular displacement sensor, the front end of which is flush with the front end of the probe 9, and is used to detect the lifting distance between the front end of the probe 9 and the surface of the pipe 19 being measured; the ranging feedback unit 11 may also be an eddy current displacement sensor or other non-contact displacement sensor.

[0039] When the ranging feedback unit 11 is a laser displacement sensor or an electro-optical ranging sensor, the sensor protective cover 13 is provided with a light-transmitting protective window at the position corresponding to the transmitting optical path and the receiving optical path, or is set as an obstacle avoidance structure that does not block the ranging optical path.

[0040] In this invention, a probe protective cover 18 is provided at the front end of the probe 9; an air nozzle 14 is fixedly connected to one side of the probe mounting base 8; an air jet hose 15 is connected to the output end of the air nozzle 14; the air jet hose is installed on the upper surface of the probe mounting base 8, and its input end is connected to the output end of the air nozzle 14; the output end of the air jet hose 15 is located at the front side of the probe 9. The air nozzle 14 and the air jet hose 15 are connected through the internal air passage of the probe mounting base 8, and external high-pressure gas is blown through the air jet hose 15 towards the area in front of the probe 9 and the ranging feedback unit 11, forming a cleaning airflow to reduce the adhesion of metal chips and cutting fluid at the front end of the probe 9.

[0041] The control display unit 16 is equipped with a touch screen on its surface, which is used to receive feedback signals, set and display various parameters, and control the actions of corresponding components.

[0042] A method for online detection of the wall thickness of ultra-long pipes, the method comprising the following steps: S1. Install the control box near the lathe tool post, and connect the control display unit 16 to the distance feedback unit 11, the hollow linear motor 3 and the thickness measuring host 17 respectively. S2. Clamp the square tube 1 in the secondary tool slot of the lathe, and adjust the position of the probe mounting seat 8 so that the probe 9 and the distance feedback unit 11 face the outer surface of the tube 19 being measured. S3. Set the normal lift-off distance range between the probe 9 and the surface of the pipe 19 being measured to 1.5~2mm in the control display unit 16; S4, such as Figure 4 As shown, after the lathe is started, the distance feedback unit 11 detects the distance between itself and the surface of the pipe 19 being measured in real time and sends the distance signal to the control display unit 16. The front end of the distance feedback unit 11 is flush with the front end of the probe 9 so that the distance signal corresponds to the lifting distance between the probe 9 and the surface of the pipe 19 being measured. S5. The control display unit 16 judges the distance signal. When the lifting distance between the probe 9 and the surface of the pipe 19 being measured is less than 1.5mm, it controls the hollow linear motor 3 to move backward. When the lifting distance is greater than 2mm, it controls the hollow linear motor 3 to move forward. When the lifting distance is within the range of 1.5~2mm, it controls the hollow linear motor 3 to maintain the current position. S6. The hollow linear motor 3 drives the hollow spline shaft 7 to slide axially along the spline sleeve 6 through the reducing joint 5. The hollow spline shaft 7 drives the probe mounting seat 8 to approach or move away from the surface of the pipe 19 being tested. S7. The lathe tool post drives the measuring component to feed along the turning direction of the pipe 19 being measured. The probe 9 measures the pipe wall thickness at the passing position in a non-contact state, and the thickness measurement host 17 feeds it back to the control display unit 16.

[0043] During online inspection, the ranging feedback unit 11, probe 9, probe mounting base 8, sensor protective cover 13, probe protective cover 18, air nozzle 14, and air jet hose 15 all maintain a non-contact state with the surface of the pipe 19 being inspected. Therefore, this invention enables non-contact active ranging and online wall thickness inspection in machining environments with abundant metal filings, where the probe easily attracts metal filings, and where the pipe rotates at high speeds.

[0044] Matters not covered in this invention are common knowledge.

[0045] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An online detection device for the wall thickness of ultra-long pipes, characterized in that: The device includes a probe mounting base, a clamping assembly, an active guiding distance adjustment assembly, a distance measurement feedback unit, a measurement assembly, and a control and display unit. The active guiding distance adjustment unit is disposed inside the clamping assembly, and its front end is connected to the probe mounting base. The distance measurement feedback unit is disposed on the front side wall of the probe mounting base. The measurement assembly is disposed inside the middle area of ​​the front end of the probe mounting base. The control and display unit is connected to the distance measurement feedback unit, the active guiding distance adjustment assembly, and the measurement assembly.

2. The online wall thickness detection device for ultra-long pipes according to claim 1, characterized in that: The clamping assembly includes a clamping square tube and an anti-bending joint; the anti-bending joint is located at the tail end of the clamping square tube and communicates with the inner cavity of the clamping square tube.

3. The online wall thickness detection device for ultra-long pipes according to claim 2, characterized in that: The active guide adjustment assembly includes a hollow linear motor, an output push rod, a reducing connector, a spline sleeve, and a hollow spline shaft. The spline sleeve is fixedly connected to the front interior of the clamping square tube. The hollow spline shaft is slidably fitted inside the spline sleeve. The hollow linear motor is fixedly connected to the rear interior of the clamping square tube. The output push rod is fixedly connected to the output end of the hollow linear motor. The front end of the output push rod is connected to the rear end of the hollow spline shaft through the reducing connector. The front end of the hollow spline shaft is fixedly connected to the probe mounting base. The hollow linear motor is connected to the control and display unit.

4. The online wall thickness detection device for ultra-long pipes according to claim 3, characterized in that: The measuring assembly includes a probe, a probe connecting cable, and a thickness measuring host; the probe is located inside the middle area of ​​the front end of the probe mounting base; the probe connecting cable passes sequentially through the probe mounting base, a hollow spline shaft, a reducing joint, and a hollow linear motor before connecting to the external thickness measuring host; the thickness measuring host is connected to the control and display unit.

5. The online wall thickness detection device for ultra-long pipes according to claim 4, characterized in that: The hollow linear motor, the reducing joint, and the hollow spline shaft are all provided with axial through holes for the probe connection wire to pass through.

6. The online wall thickness detection device for ultra-long pipes according to claim 1, characterized in that: The ranging feedback unit is a distance sensor, which is arranged perpendicularly to the pipe to be measured; the distance sensor is provided with a protective shell on the outside and a protective cover at its front end; the protective cover has a light-transmitting protective window at the corresponding position of the ranging optical path.

7. The online wall thickness detection device for ultra-long pipes according to claim 4, characterized in that: The probe is equipped with a probe protective cover at its front end; an air nozzle is fixedly connected to one side of the probe mounting base; the output end of the air nozzle is connected to an air jet hose; the air jet hose is installed on the upper surface of the probe mounting base, and its input end is connected to the output end of the air nozzle; the output end of the air jet hose is located on the front side of the probe.

8. A method for online detection of the wall thickness of ultra-long pipes, implemented based on the device described in claim 7, characterized in that, The method includes the following steps: S1. Install the control box near the lathe tool post, and connect the control display unit to the distance feedback unit, the hollow linear motor and the thickness measuring host respectively; S2. Clamp the square tube in the secondary tool slot of the lathe, and adjust the position of the probe mounting seat so that the probe and the distance feedback unit face the outer surface of the tube being measured. S3. Set the normal lift-off distance between the probe and the surface of the pipe being tested to 1.5~2mm in the control display unit; S4. After starting the lathe, the distance feedback unit detects the distance between itself and the surface of the pipe being measured in real time and sends the distance signal to the control display unit. The front end of the distance feedback unit is flush with the front end of the probe so that the distance signal corresponds to the lifting distance between the probe and the surface of the pipe being measured. S5. The control display unit judges the distance signal. When the lifting distance between the probe and the surface of the pipe being measured is less than 1.5mm, the hollow linear motor is controlled to move backward. When the lifting distance is greater than 2mm, the hollow linear motor is controlled to move forward. When the lifting distance is within the range of 1.5~2mm, the hollow linear motor is controlled to maintain the current position. S6. The hollow linear motor drives the hollow spline shaft to slide axially along the spline sleeve through the reducing joint. The hollow spline shaft drives the probe mounting seat to move closer to or away from the surface of the pipe being tested. S7. The lathe tool post drives the measuring component to feed along the turning direction of the pipe being measured. The probe measures the pipe wall thickness at the passing position in a non-contact state, and the thickness measurement host feeds back to the control display unit.

9. The method for online detection of wall thickness of ultra-long pipes according to claim 8, characterized in that: During the testing process, all components remain in a non-contact state with the surface of the pipe being tested.

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