CN115451777A - Method for measuring wall thickness of pipe end of steel pipe - Google Patents
Method for measuring wall thickness of pipe end of steel pipe Download PDFInfo
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- CN115451777A CN115451777A CN202110643372.6A CN202110643372A CN115451777A CN 115451777 A CN115451777 A CN 115451777A CN 202110643372 A CN202110643372 A CN 202110643372A CN 115451777 A CN115451777 A CN 115451777A
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- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B5/00—Measuring arrangements characterised by the use of mechanical techniques
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- G01B5/06—Measuring arrangements characterised by the use of mechanical techniques for measuring length, width or thickness for measuring thickness
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Abstract
The invention discloses a method for measuring the wall thickness of a steel pipe end, which comprises the following steps: 1. obtaining steel pipe parameters; 2. controlling a first distance sensor (81) to be positioned inside a measuring section of the steel pipe (2), and controlling a second distance sensor (82) to be positioned outside the measuring section; 3. calculating the rotation angular velocity of the rotating arm and the translation velocity of the horizontal moving mechanism; 4. setting a sampling period, and simultaneously executing steps 5 and 6; 5. the wall thickness calculating unit controls the rotating arm and the horizontal moving mechanism to move so that the two distance sensors move from one end of the measuring section to the other end in a spiral manner; 6. the wall thickness calculating unit collects wall thickness data and calculates the average wall thickness, namely the wall thickness of the pipe end; 7. whether the measurement is finished or not, if so, finishing the measurement; if not, returning to the step 1. The invention can carry out spiral scanning measurement on the pipe end measuring section of the steel pipe through the pair of distance sensors, and calculate the wall thickness of the pipe end, has high measuring precision, and can realize non-contact on-line measurement of the wall thickness of the pipe end of the steel pipe.
Description
Technical Field
The invention relates to a quality detection method for steel pipe production, in particular to a method for measuring the wall thickness of a pipe end of a steel pipe.
Background
The pipe end wall thickness of the steel pipe refers to the radial thickness between the inner circle and the outer circle of a part of steel pipe or a pipe section within the specified length range of the two end heads of the steel pipe, the pipe end wall thickness is one of the most important control parameters in the production of the steel pipe, and is also an important index of the quality of the steel pipe product, and the pipe end wall thickness has definite technical requirements at home and abroad. Different standards have different specifications for the length range of pipe ends, such as those set forth in the American Petroleum Institute (API) standards for pipeline steel: the length range of the pipe end is the length range of each end of the steel pipe 100mm (4.0 in) away from the end.
With the continuous progress of the pipeline on-site welding construction technology, the quality requirement on the steel pipe is continuously improved, and particularly the requirement on the wall thickness of the pipe end is extremely strict. When two steel pipes are welded in the field or in the sea, if the wall thickness of the pipe end meets the requirement, the welding can be smoothly finished; on the contrary, the butt welding of the two pipes is difficult, and even if the two pipes can be welded together, a large residual stress can be generated, so that the mechanical performance of the welding seam is reduced, and the safety of the pipeline is reduced. Due to the limitation of the production process, the steel pipes with unqualified pipe end wall thickness still exist, and qualified steel pipes need to be strictly screened out.
The measurement of the wall thickness of a pipe end is actually the measurement of the distance between the inner wall and the outer wall of the cross section of the pipe end of a steel pipe, the measurement methods in the prior art mainly comprise measurement means such as a ray method, a magnetic leakage method, a vortex method, ultrasonic thickness measurement and the like, and production and measurement cannot be effectively matched due to the influence of the state of a production line, the production rhythm and the like. Therefore, the measurement of the wall thickness of the pipe end in actual production still depends on manual measurement, the manual measurement generally adopts a wall thickness micrometer and a go-no go gauge which are used for manual measurement, but is greatly influenced by factors such as production environment, measuring tool accuracy, operator experience and the like, the measurement accuracy is low, the speed is low, the efficiency is low, the labor intensity of workers is high, and the measurement data points are limited, so that the real condition of the wall thickness of the pipe end cannot be fully reflected.
The chinese patent application CN202011593379.3 discloses a method for measuring the inner and outer walls and the wall thickness of a steel pipe based on a visual micrometer, and specifically discloses: firstly, for the same batch of steel pipes, adjusting the spatial position of a visual micrometer to enable the center of a view field of the visual micrometer, the surface of an entity or a virtual scale and the central plane of the steel pipe to be in the same plane, wherein the steel pipe is not a complete rotating body due to ovality and the edge of the outer wall of the steel pipe is vertical to the scale; determining a lens used, the magnification factor and the depth of field of the lens, and adjusting the working distance of the lens; measuring the distance between the whole visual micrometer and the end face of the steel pipe before measuring the wall thickness and the inner and outer diameters of the steel pipe each time by using the laser displacement sensor, and controlling the visual micrometer to move to a scale in the system and the distance between the front surface of the base to meet the working conditions of a camera and a lens; step four, the visual micrometer moves under the control of the driving motor, the camera simultaneously acquires images in the moving process, the images are processed in the image processing unit, and the visual micrometer stops moving when the edge position of the steel pipe is identified; step five, the image processing unit processes the acquired image; and step six, calculating the ovality of the end face of the steel pipe. The method can be only used for measuring the wall thickness of the end face of the steel pipe, can only be used for quality inspection of common steel pipe products, but cannot be used for measuring the wall thickness of the interior of the end face of the steel pipe, namely the wall thickness of the interior of the end face of the steel pipe within a certain distance range from the end face, and the wall thickness of the steel pipe detected by the method cannot meet the requirements of API (application program interface) standards or national standards on the wall thickness of the end of the steel pipe. When the method is used in actual applications such as welding of steel pipes, if the welding of the steel pipes does not meet the requirements, the pipe ends of the welded parts need to be sawn off and welded again, but the method cannot determine whether the wall thickness of the end faces of the steel pipes after sawing meets the standard requirements, and the steel pipes can not be used. Meanwhile, due to the influence of a plurality of factors such as ambient light, the edge positions of the inner wall and the outer wall of the steel pipe cannot be accurately distinguished and analyzed in the image collected by the camera, the measurement precision cannot be guaranteed, and the method is not suitable for detection of steel pipe products with high precision requirements.
Disclosure of Invention
The invention aims to provide a method for measuring the wall thickness of the pipe end of a steel pipe, which can carry out spiral scanning measurement on a measuring section of the pipe end of the steel pipe through a pair of distance sensors and calculate the wall thickness of the pipe end, has high measurement precision and can realize non-contact on-line measurement of the wall thickness of the pipe end of the steel pipe.
The invention is realized by the following steps:
a method for measuring the wall thickness of a steel pipe end is realized based on a device for measuring the wall thickness of the steel pipe end, and the device for measuring the wall thickness of the steel pipe end comprises a horizontal moving mechanism arranged on one side of a steel pipe, an up-down lifting mechanism arranged on the horizontal moving mechanism, a rotation control mechanism arranged on the up-down lifting mechanism, two distance sensors arranged on the rotation control mechanism and a wall thickness calculating unit;
the method for measuring the wall thickness of the pipe end of the steel pipe comprises the following steps:
step 1: the wall thickness calculation unit obtains steel pipe parameters;
step 2: the rotating arm is a Y-shaped structure formed by connecting a straight rod and a bending rod, and the straight rod and the bending rod are respectively provided with a first distance sensor and a second distance sensor which are oppositely arranged; the wall thickness calculating unit controls the up-down lifting mechanism to lift up and down, and controls the horizontal moving mechanism to move horizontally at the same time, so that the first distance sensor is positioned inside the measuring section of the steel pipe, and the second distance sensor is positioned outside the measuring section of the steel pipe;
and step 3: the wall thickness calculating unit calculates the rotation angular velocity w of a rotating arm of the rotation control mechanism and the translation velocity v of the horizontal moving mechanism according to the steel pipe parameters;
and 4, step 4: setting a sampling period delta theta, and simultaneously executing the step 5 and the step 6;
and 5: the wall thickness calculation unit controls the rotating arm to rotate around the axial direction of the steel pipe at a rotation angular velocity w, and simultaneously controls the horizontal movement mechanism to translate parallel to the axial direction of the steel pipe at a translation velocity v, so that the first distance sensor and the second distance sensor move spirally from one end of the measuring section to the other end of the measuring section;
and 6: the wall thickness calculating unit collects 360 n/delta theta groups of wall thickness data and calculates the average wall thickness of the steel pipe measuring section according to the wall thickness data, wherein the average wall thickness is the pipe end wall thickness of the steel pipe;
wherein n is the number of rotation turns of the rotating arm;
and 7: the wall thickness calculating unit judges whether the measurement is finished or not, if so, the measurement is finished, and the next steel pipe is waited; if not, returning to the step 1.
The step 1 comprises the following steps:
step 1.1: arranging an in-place signal detector on a measuring station of the steel pipe, judging whether the steel pipe reaches the station by the in-place signal detector, if so, executing the step 1.2, and if not, continuing to wait for the steel pipe;
step 1.2: the input end of the wall thickness calculating unit is connected with the output end of the process signal interface unit, the input end of the process signal interface unit is connected to a control system of the steel pipe production line, and the wall thickness calculating unit acquires steel pipe parameters from the control system of the steel pipe production line through the process signal interface unit.
The steel pipe parameters comprise the specification size and the detection standard of the steel pipe.
In the step 2, the first distance sensor is positioned on the central axis of the steel pipe.
The step 6 comprises the following steps:
step 6.1: each set of said wall thickness data including (s, θ, r1, r 2);
wherein s is the translation distance of the horizontal moving mechanism at the current moment, is acquired by a distance sensor connected with the horizontal moving mechanism, and is more than or equal to 0 and less than or equal to the length of the measuring section;
theta is the rotation angle of the rotating arm at the current moment and is acquired by an angle sensor connected with the rotation control mechanism;
r1 is the distance between the first distance sensor and the inner wall of the steel pipe at the current moment and is acquired by the first distance sensor;
r2 is the distance between the second distance sensor and the outer wall of the steel pipe at the current moment, and is acquired by the second distance sensor;
step 6.2: and calculating the wall thickness D of each group of wall thickness data, wherein the calculation formula is as follows:
d = L-r1-r1 equation (1)
Wherein L is the distance between the first distance sensor and the second distance sensor;
step 6.3: recording the maximum wall thickness Dmax and the minimum wall thickness Dmin in the 360 n/delta theta group of wall thickness data, and calculating the average wall thickness Davg;
step 6.4: judging the stability and consistency of the wall thickness data, and setting a judgment parameter p and a judgment threshold p;
the calculation formula of the evaluation parameter p is as follows: p = (Dmax-Dmin)/Davg equation (2)
When p is less than or equal to p, the stability and consistency of wall thickness data are good, and the average wall thickness Davg is used as the wall thickness of the pipe end of the steel pipe; when p > p, the stability and consistency of the wall thickness data is poor, and the wall thickness data is re-measured.
The method for re-measuring the wall thickness data comprises the following steps:
step 6.4.1: the wall thickness calculating unit controls the rotating arm and the horizontal moving mechanism to do reverse return movement with the rotation and the translation in the step 5, so that the first distance sensor and the second distance sensor return to one end of the measuring section from the other end of the measuring section in a spiral shape, and wall thickness data at the positions of the maximum wall thickness Dmax and the minimum wall thickness Dmin are measured again in the return process;
step 6.4.2: recalculating the new maximum wall thickness Dmax1, the new minimum wall thickness Dmin1 and the new average wall thickness Davg1 according to the remeasured wall thickness data;
step 6.4.3: calculating a new judgment parameter p1 according to the new maximum wall thickness Dmax1, the new minimum wall thickness Dmin1 and the new average wall thickness Davg1, and judging the stability and consistency of the wall thickness data, wherein the calculation formula of the new judgment parameter p1 is as follows:
p1= (Dmax 1-Dmin 1)/Davg formula (3)
When p1 is not more than p, the stability and consistency of wall thickness data are good, and the average wall thickness Davg is used as the wall thickness of the pipe end of the steel pipe; when p1 is greater than p, the stability and consistency of the wall thickness data are poor, a new maximum wall thickness Dmax1, a new minimum wall thickness Dmin1 and a new average wall thickness Davg1 are recorded, and an alarm signal is output.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention adopts the distance sensors for determining the installation distance to acquire the distance between the distance sensors and the inner wall and the outer wall of the steel pipe, and can simply and quickly calculate the wall thickness value of the steel pipe at any measuring point, so that the wall thickness distribution condition in the pipe end area of the steel pipe, namely the measuring section, can be known in the displacement process of the distance sensors, and the wall thickness of the pipe end of the steel pipe can be obtained by processing the wall thickness data.
2. The invention adopts the horizontal moving mechanism and the up-down lifting mechanism to control the rotation and translation of the pair of distance sensors, so that the measuring ranges of the pair of distance sensors can cover the whole pipe end area of the steel pipe, namely a measuring section, and the quantity of wall thickness data can be controlled by adjusting the rotating speed, the translation speed and the acquisition frequency, thereby controlling the measuring precision, meeting the detection requirements of different steel pipes and improving the product quality of the steel pipes.
3. According to the invention, because the evaluation parameters and the evaluation threshold are set, the consistency of the wall thickness data can be evaluated by comparing the evaluation parameters with the evaluation threshold, and the measurement precision of the wall thickness data is further improved, so that the real wall thickness of the pipe end of the steel pipe can be more accurately reflected.
The invention carries out spiral scanning measurement on the steel pipe end measuring section based on the pair of rotatable and translational distance sensors to obtain the wall thickness distribution condition in the steel pipe end area, namely the measuring section, and under the condition of higher data consistency, the wall thickness of the pipe end is obtained by calculation, the measuring precision is high, the data processing is simple, the quantity is small, the efficiency is high, and the non-contact type on-line measurement of the wall thickness of the steel pipe end can be realized.
Drawings
FIG. 1 is a flowchart of a method of measuring a wall thickness of a pipe end of a steel pipe according to the present invention;
FIG. 2 is a front view of a measuring apparatus used in the method of measuring the wall thickness of the end of a steel pipe according to the present invention;
FIG. 3 is a diagram showing the state of movement of the rotating arm in the method for measuring the wall thickness of the end of a steel pipe according to the present invention;
FIG. 4 is a schematic diagram showing the acquisition of wall thickness data in the method for measuring the wall thickness of the end of a steel pipe according to the present invention.
In the figure, a V-shaped support 1, a steel pipe 2, a horizontal moving mechanism 3, an up-down lifting mechanism 4, a rotation control mechanism 5, a straight rod 51, a bending rod 52, a displacement sensor 6, an angle sensor 7, a first distance sensor 81, a second distance sensor 82, an in-place signal detector 9, a process signal interface unit 10 and a wall thickness calculating unit 11 are arranged.
Detailed Description
The invention is further described with reference to the following figures and specific examples.
A measuring method of the wall thickness of a steel pipe end is realized based on a measuring device of the wall thickness of the steel pipe end, please refer to figure 2, the measuring device comprises a V-shaped support 1 which is arranged at a measuring station and supports a steel pipe 2, a horizontal moving mechanism 3 which is arranged at one side of the steel pipe 2, an up-down lifting mechanism 4 which is arranged on the horizontal moving mechanism 3, a rotary control mechanism 5 which is arranged on the up-down lifting mechanism 4, a displacement sensor 6 which is connected with the horizontal moving mechanism 3, an angle sensor 7 which is connected with the rotary control mechanism 5, a first distance sensor 81 and a second distance sensor 82 which are arranged on a rotating arm of the rotary control mechanism 5, an in-position signal detector 9 which is arranged at the measuring station, a process signal interface unit 10 which is connected with a steel pipe production line control system, and a wall thickness calculating unit 11, wherein the wall thickness calculating unit 11 is electrically connected with the process signal interface unit 10, the in-position signal detector 9, the first distance sensor 81, the second distance sensor 82, the angle sensor 7, the displacement sensor 6, the rotary control mechanism 5, the up-down lifting mechanism 4 and the horizontal moving mechanism 3.
Preferably, the horizontal moving mechanism 3 can be implemented based on a sliding rail, a sliding block and a motion control device thereof in the prior art, the up-down lifting mechanism 4 can be implemented based on a hydraulic/pneumatic rod and a motion control device thereof in the prior art, the rotation control mechanism 5 can be implemented based on a motor in the prior art, and the moving directions of the horizontal moving mechanism 3, the up-down lifting mechanism 4 and the rotation control mechanism 5 are shown as arrow directions in fig. 2. The first distance sensor 81 and the second distance sensor 82 can use a laser sensor in the prior art to measure the distance between the first distance sensor and the wall of the steel pipe 2 at a certain sampling frequency. The wall thickness calculation unit 11 may employ computer equipment of the prior art and be integrated with the relevant data calculation model.
Referring to fig. 1 and 2, the method for measuring the wall thickness of the pipe end of the steel pipe comprises the following steps:
step 1: the wall thickness calculation unit 11 obtains steel pipe parameters.
Step 1.1: and arranging an in-place signal detector 9 on a measuring station of the steel pipe 2, wherein the in-place signal detector 9 judges whether the steel pipe 2 reaches the station, namely the steel pipe 2 is placed on the V-shaped support 1, if so, executing the step 1.2, and if not, continuing to wait for the steel pipe 2. Preferably, the in-place signal detector 9 can be arranged among a plurality of V-shaped brackets 1 of a certain station and used for detecting whether a steel pipe 2 exists on the station.
Step 1.2: the input end of the wall thickness calculating unit 11 is connected with the output end of the process signal interface unit 10, the input end of the process signal interface unit 10 is connected to a control system of the steel pipe production line, and the wall thickness calculating unit 11 obtains steel pipe parameters from the control system of the steel pipe production line through the process signal interface unit 10. The specification and model of the process signal interface unit 10 should be matched with the control system of the steel pipe production line to ensure reliable transmission of the steel pipe parameter information.
The steel pipe parameters comprise the specification size and the detection standard of the steel pipe 2. The specification and size of the steel tube 2 are used for determining the height position of the central axis of the steel tube 2 when the steel tube 2 is placed on the measuring station, so that the lifting adjusting distance of the up-down lifting mechanism 4 is determined. The detection standard comprises the length range of the measured section of the steel pipe 2, the detection precision, the requirements and the like.
And 2, step: the rotating arm is a Y-shaped structure formed by connecting a straight rod 51 and a bending rod 52, and a first distance sensor 81 and a second distance sensor 82 which are oppositely arranged are respectively arranged on the straight rod 51 and the bending rod 52. The wall thickness calculating unit 11 calculates the lifting distance of the lifting mechanism 4 according to the steel pipe parameters, controls the lifting mechanism 4 to lift up and down according to the lifting distance, and controls the horizontal moving mechanism 3 to move horizontally, so that the first distance sensor 81 is positioned inside the measuring section of the steel pipe 2, and the second distance sensor 82 is positioned outside the measuring section of the steel pipe 2.
Preferably, the first distance sensor 81 is located on the central axis of the steel pipe 2.
And step 3: the wall thickness calculation means 11 calculates the rotational angular velocity w of the rotating arm of the rotation control mechanism 5 and the translational velocity v of the horizontal movement mechanism 3 from the steel pipe parameters.
The rotational angular velocity w and the translational velocity v are determined according to the length of the measuring section of the steel pipe 2, the pipe diameter of the steel pipe 2, the detection precision and requirements and the like, the inner diameters of the steel pipes 2 with different specifications are different, the detection standards and requirements are also different, and in order to ensure the measurement precision and consistency, the measuring points on the radial direction of the steel pipe 2 need to be uniformly distributed, namely the included angle between the two measuring points, namely delta theta, is equal, and meanwhile, a sufficient number of measuring data points need to be provided. Under the condition that the measuring frequency of the first distance sensor 81 and the second distance sensor 82 is constant, the included angle between the two measuring points is determined by the rotation angular velocity w of the rotating arm, so the required number of measuring points and the included angle between the measuring points are determined according to different specifications and detection standard requirements of the steel pipe 2, and the rotation angular velocity w is calculated.
And 4, step 4: the sampling period Δ θ is set, and step 5 and step 6 are performed simultaneously. The sampling period Δ θ means that the first distance sensor 81 and the second distance sensor 82 acquire distance data once every time the rotary arm rotates by the angle θ. The sampling period delta theta is determined by the rotation angular velocity w, the higher the detection standard and requirement of the steel pipe 2 are, the smaller the rotation angular velocity w is, and the smaller the sampling period delta theta is; as the specification of the steel pipe 2 is larger, the rotational angular velocity w is smaller and the sampling period Δ θ is also smaller in order to ensure the measurement accuracy.
Referring to fig. 3, in fig. 3, a solid line indicates a position of the rotating arm at a certain time, and a dotted line indicates a position of the rotating arm at a certain time after rotating by a certain angle.
And 5: the wall thickness calculating unit 11 controls the rotation arm to rotate around the axial direction of the steel pipe 2 at a rotation angular velocity w (as shown by an arc arrow in fig. 3), and controls the horizontal movement mechanism 3 to translate parallel to the axial direction of the steel pipe 2 at a translation velocity v (as shown by a straight arrow in fig. 3), so that the first distance sensor 81 and the second distance sensor 82 move spirally from one end of the measurement section (i.e. the measurement start position) to the other end of the measurement section (i.e. the measurement end position), and the measurement range is ensured to cover the length range of the measurement section, i.e. the pipe end, of the steel pipe 2.
And 6: the wall thickness calculation unit 11 acquires 360n/Δ θ sets of wall thickness data through the distance sensor 6 and the angle sensor 7, and calculates the average wall thickness of the measured section of the steel pipe 2 according to the 360n/Δ θ sets of wall thickness data, wherein the average wall thickness is the pipe end wall thickness of the steel pipe 2. Wherein n is the number of rotation turns of the rotating arm.
Please refer to fig. 4, step 6.1: each set of wall thickness data includes (s, θ, r1, r 2).
Wherein s is the translation distance of the horizontal moving mechanism 3 at the current moment, and is acquired by the distance sensor 6, and s is more than or equal to 0 and less than or equal to the length of the measuring section;
theta is the rotation angle of the rotating arm at the current moment and is collected by an angle sensor 7;
r1 is the distance between the first distance sensor 81 and the inner wall of the steel pipe 2 at the current moment, and is acquired by the first distance sensor 81;
r2 is the distance between the second distance sensor 82 and the outer wall of the steel pipe 2 at the present moment, and is collected by the second distance sensor 82.
Step 6.2: and calculating the wall thickness D of each group of wall thickness data, wherein the calculation formula is as follows:
d = L-r1-r2 formula (1).
Where L is the distance between the first distance sensor 81 and the second distance sensor 82.
Step 6.3: the maximum wall thickness Dmax and the minimum wall thickness Dmin in the 360 n/[ Delta ] theta set of wall thickness data are recorded, and the average wall thickness Davg in the 360 n/[ Delta ] theta set of data is calculated.
Step 6.4: and judging the stability and consistency of the wall thickness data, setting a judgment parameter p and a judgment threshold p, determining the design requirements of steel pipes with different grades, and preferably, setting the value range of the judgment threshold p to be 5-10%.
The calculation formula of the evaluation parameter p is as follows: p = (Dmax-Dmin)/Davg formula (2).
When p is less than or equal to p, the stability and consistency of the wall thickness data are good, and the average wall thickness Davg is used as the wall thickness of the pipe end of the steel pipe 2; when p > p, the stability and consistency of the wall thickness data is poor, and the wall thickness data is re-measured.
The method for re-measuring the wall thickness data comprises the following steps:
step 6.4.1: the wall thickness calculating unit 11 controls the rotating arm and the horizontal moving mechanism 3 to perform a reverse return movement corresponding to the rotation and translation in step 5, i.e. returning from the measurement ending position to the measurement starting position, wherein the rotating angular velocity w and the translation velocity v of the straight rod 51 are consistent in magnitude and opposite in direction to the advancing time, so that the first distance sensor 81 and the second distance sensor 82 spirally return to one end of the measurement section from the other end of the measurement section, and the wall thickness data at the positions of the maximum wall thickness Dmax and the minimum wall thickness Dmin are measured again in the return movement. The location of the maximum wall thickness Dmax and the location of the minimum wall thickness Dmin may be determined from s and θ of the set of wall thickness data.
Step 6.4.2: the new maximum wall thickness Dmax1, the new minimum wall thickness Dmin1 and the new average wall thickness Davg1 are recalculated from the re-measured wall thickness data.
Step 6.4.3: calculating a new judgment parameter p1 according to the new maximum wall thickness Dmax1, the new minimum wall thickness Dmin1 and the new average wall thickness Davg1, and judging the stability and consistency of wall thickness data, wherein the calculation formula of the new judgment parameter p1 is as follows:
p1= (Dmax 1-Dmin 1)/Davg formula (3).
When p1 is not more than p, the stability and consistency of wall thickness data are good, and the average wall thickness Davg is used as the wall thickness of the pipe end of the steel pipe 2; when p1 is greater than p, the stability and consistency of the wall thickness data are poor, a new maximum wall thickness Dmax1, a new minimum wall thickness Dmin1 and a new average wall thickness Davg1 are recorded, and an alarm signal is output.
And 7: the wall thickness calculating unit 11 judges whether the measurement is finished, if so, the measurement is finished, and the next steel pipe 2 is waited for; if not, returning to the step 1, and according to the requirement of detection precision, repeatedly measuring some steel pipes 2 for multiple times, and realizing circular measurement by returning to the step 1. The data acquisition precision and parameter setting for repeated measurements may be different, so that when returning to step 1, the wall thickness calculation unit 11 controls the horizontal movement mechanism 3, the up-down lifting mechanism 4 and the rotation control mechanism 5 to synchronously return to the initial state before detection.
Example 1:
the steel pipe 2 to be detected is horizontally placed on the measuring station, the in-place signal detector 9 detects that the steel pipe 2 arrives at the station, and the steel pipe end wall thickness measuring device is started. The wall thickness calculation unit 11 acquires the steel pipe parameters such as the specification size and the detection standard of the steel pipe 2 on the current station to be detected through the process signal interface 10.
The wall thickness calculating unit 11 controls the vertical lifting mechanism 4 to lift up and down according to the specification and size information of the measured steel pipe 2, and adjusts the height of the straight rod 51 of the rotating arm, so that the central line of the straight rod 51 and the central axis of the current measured steel pipe 2 are at the same height. After the up-down position adjustment is completed, the wall thickness calculating unit 11 controls the horizontal moving mechanism 3 to drive the up-down lifting mechanism 4 and the rotation control mechanism 5 to move towards the pipe end of the steel pipe 2, so that the first distance sensor 81 and the second distance sensor 82 completely enter the end area of the steel pipe 2, the two distance sensors are guaranteed to be over against a certain section of the end of the steel pipe 2, the first distance sensor 81 is located inside the steel pipe 2 and used for measuring the distance between the inner wall of the steel pipe 2, and the second distance sensor 82 is located outside the steel pipe 2 and used for measuring the distance between the outer wall of the steel pipe 2.
The pipe end of the steel pipe 2 to be measured is within a length range of 100mm from the end face of the steel pipe 2 in the length direction of the steel pipe 2, that is, the length of the measurement section is 100mm, and the pipe diameter of the steel pipe 2 to be measured is 120mm. The thickness calculating means 11 calculates the rotational angular velocity w of the rotary arm to be 90 °/s, the translational velocity v of the horizontal movement mechanism 3 to be 20mm, s, and Δ θ =0.5 °. The wall thickness calculating unit 11 controls the rotation of the rotary arm and the horizontal movement of the horizontal movement mechanism 3, so that the first distance sensor 81 and the second distance sensor 82 move spirally from the outer end to the inner end of the measuring section.
The first distance sensor 81 and the second distance sensor 82 collect a set of wall thickness data every time when rotating for 0.5 degrees in the moving process, 720 sets of wall thickness data (s, theta, r1 and r 2) are collected every time when the straight rod 51 rotates for one circle, and all the wall thickness data are sent to the wall thickness calculating unit 11. The wall thickness calculation unit 11 calculates the wall thickness D at each measurement point according to the formula (1), calculates an average wall thickness Davg =5.5mm from all the wall thicknesses D, and counts a maximum wall thickness Dmax =5.61mm and a minimum wall thickness Dmin =5.42mm.
Setting a judgment threshold p × =10%, calculating a judgment parameter p =0.034 according to formula (2), namely 3.4% < 10%, and the wall thickness data has high consistency. The average wall thickness Davg was defined as the pipe end wall thickness of the steel pipe 2.
Example 2:
the steel pipe 2 to be detected is horizontally placed on a measuring station, the in-place signal detector 9 detects that the steel pipe 2 arrives at the station, and the steel pipe end wall thickness measuring device is started. The wall thickness calculating unit 11 acquires the steel pipe parameters such as the specification and the size of the steel pipe 2 on the current station to be detected, the detection standard and the like through the process signal interface 10.
The wall thickness calculating unit 11 controls the vertical lifting mechanism 4 to lift up and down according to the specification and size information of the measured steel pipe 2, and adjusts the height of the straight rod 51 of the rotating arm, so that the central line of the straight rod 51 and the central axis of the current measured steel pipe 2 are at the same height. After the up-down position adjustment is completed, the wall thickness calculation unit 11 controls the horizontal movement mechanism 3 to drive the up-down lifting mechanism 4 and the rotation control mechanism 5 to move towards the pipe end of the steel pipe 2, so that the first distance sensor 81 and the second distance sensor 82 completely enter the end area of the steel pipe 2, the two distance sensors are guaranteed to be over against a certain section of the end of the steel pipe 2, the first distance sensor 81 is located inside the steel pipe 2 and used for measuring the distance between the inner wall of the steel pipe 2, and the second distance sensor 82 is located outside the steel pipe 2 and used for measuring the distance between the outer wall of the steel pipe 2.
The pipe end of the steel pipe 2 to be measured is within a length range of 100mm from the end face of the steel pipe 2 in the length direction of the steel pipe 2, that is, the length of the measurement section is 100mm, and the pipe diameter of the steel pipe 2 to be measured is 70mm. The wall thickness calculating unit 11 calculates a rotational angular velocity w of the rotary arm to be 120 °/s, a translational velocity v of the horizontal movement mechanism 3 to be 15mm/s, and Δ θ =0.5 °. The wall thickness calculating unit 11 controls the rotation of the rotary arm and the horizontal movement of the horizontal movement mechanism 3, so that the first distance sensor 81 and the second distance sensor 82 move spirally from the outer end to the inner end of the measuring section.
The first distance sensor 81 and the second distance sensor 82 acquire a group of wall thickness data every time the first distance sensor and the second distance sensor rotate by 0.3 degrees in the moving process, 1200 groups of wall thickness data (s, theta, r1 and r 2) are acquired every time the straight rod 51 rotates by one circle, and all the wall thickness data are sent to the wall thickness calculating unit 11. The wall thickness calculation unit 11 calculates the wall thickness D at each measurement point according to the formula (1), calculates an average wall thickness Davg =3.5 mm from all the wall thicknesses D, and counts the maximum wall thickness Dmax = 3.64mm and the minimum wall thickness Dmin =3.42 mm.
Setting a judgment threshold value p × =5%, calculating a judgment parameter p =0.063, namely 6.3% >5%, according to formula (2), and the conformity of the wall thickness data is not satisfactory.
The wall thickness calculating unit 11 controls the rotating arm and the horizontal movement mechanism 3 to perform a backward movement in a reverse direction to the rotation and translation in step 5, so that the first distance sensor 81 and the second distance sensor 82 spirally return to one end of the measuring section from the other end of the measuring section, and wall thickness data at the positions of the maximum wall thickness Dmax and the minimum wall thickness Dmin are measured again during the backward movement. The new maximum wall thickness Dmax1=3.63, the new minimum wall thickness Dmin1=3.42 and the new average wall thickness Davg1=3.51 are recorded. And (4) calculating a new judgment parameter p1=0.060>5% according to the formula (3), wherein the consistency still does not meet the requirement, and outputting an alarm signal.
The present invention is not limited to the above embodiments, and therefore, any modifications, equivalents, improvements, etc. within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (6)
1. A method for measuring the wall thickness of a pipe end of a steel pipe is characterized by comprising the following steps: the measuring method is realized based on a steel pipe end wall thickness measuring device, and the steel pipe end wall thickness measuring device comprises a horizontal moving mechanism (3) arranged on one side of a steel pipe (2), an up-down lifting mechanism (4) arranged on the horizontal moving mechanism (3), a rotation control mechanism (5) arranged on the up-down lifting mechanism (4), two distance sensors arranged on the rotation control mechanism (5) and a wall thickness calculating unit (11);
the method for measuring the wall thickness of the pipe end of the steel pipe comprises the following steps:
step 1: a wall thickness calculation unit (11) obtains steel pipe parameters;
and 2, step: the rotating arm is a Y-shaped structure formed by connecting a straight rod (51) and a bending rod (52), and the straight rod (51) and the bending rod (52) are respectively provided with a first distance sensor (81) and a second distance sensor (82) which are arranged oppositely; the wall thickness calculating unit (11) controls the vertical lifting mechanism (4) to lift vertically and controls the horizontal moving mechanism (3) to move horizontally at the same time, so that the first distance sensor (81) is positioned inside the measuring section of the steel pipe (2), and the second distance sensor (82) is positioned outside the measuring section of the steel pipe (2);
and step 3: a wall thickness calculation unit (11) calculates the rotation angular velocity w of the rotating arm of the rotation control mechanism (5) and the translation velocity v of the horizontal movement mechanism (3) according to the steel pipe parameters;
and 4, step 4: setting a sampling period delta theta, and simultaneously executing the step 5 and the step 6;
and 5: the wall thickness calculating unit (11) controls the rotating arm to rotate around the axial direction of the steel pipe (2) at a rotation angular velocity w, and simultaneously controls the horizontal moving mechanism (3) to translate parallel to the axial direction of the steel pipe (2) at a translation velocity v, so that the first distance sensor (81) and the second distance sensor (82) move from one end of the measuring section to the other end of the measuring section in a spiral shape;
and 6: the wall thickness calculating unit (11) collects 360 n/delta theta groups of wall thickness data, and calculates the average wall thickness of the measured section of the steel pipe (2) according to the wall thickness data, wherein the average wall thickness is the pipe end wall thickness of the steel pipe (2);
wherein n is the number of rotation turns of the rotating arm;
and 7: the wall thickness calculating unit (11) judges whether the measurement is finished, if so, the measurement is finished, and the next steel pipe (2) is waited; if not, returning to the step 1.
2. The method of measuring a wall thickness of a pipe end of a steel pipe according to claim 1, wherein: the step 1 comprises the following steps:
step 1.1: arranging an in-place signal detector (9) on a measuring station of the steel pipe (2), judging whether the steel pipe (2) reaches the station by the in-place signal detector (9), if so, executing the step 1.2, and if not, continuing to wait for the steel pipe (2);
step 1.2: the input end of the wall thickness calculating unit (11) is connected with the output end of the process signal interface unit (10), the input end of the process signal interface unit (10) is connected to a control system of the steel pipe production line, and the wall thickness calculating unit (11) acquires steel pipe parameters from the control system of the steel pipe production line through the process signal interface unit (10).
3. The method of measuring the wall thickness of the pipe end of a steel pipe according to claim 1 or 2, wherein: the steel pipe parameters comprise the specification size and the detection standard of the steel pipe (2).
4. The method for measuring the wall thickness of the end of a steel pipe according to claim 1, wherein: in the step 2, the first distance sensor (81) is positioned on the central axis of the steel pipe (2).
5. The method of measuring a wall thickness of a pipe end of a steel pipe according to claim 1, wherein: the step 6 comprises the following steps:
step 6.1: each set of said wall thickness data including (s, θ, r1, r 2);
wherein s is the translation distance of the horizontal moving mechanism (3) at the current moment, and is acquired by a distance sensor (6) connected with the horizontal moving mechanism (3), and s is more than or equal to 0 and less than or equal to the length of the measuring section;
theta is the rotation angle of the rotating arm at the current moment and is acquired by an angle sensor (7) connected with the rotation control mechanism (5);
r1 is the distance between the first distance sensor (81) and the inner wall of the steel pipe (2) at the current moment, and is acquired by the first distance sensor (81);
r2 is the distance between the second distance sensor (82) and the outer wall of the steel pipe (2) at the current moment, and is acquired by the second distance sensor (82);
step 6.2: and calculating the wall thickness D of each group of wall thickness data, wherein the calculation formula is as follows:
d = L-r1-r1 equation (1)
Wherein L is the distance between the first distance sensor (81) and the second distance sensor (82);
step 6.3: recording the maximum wall thickness Dmax and the minimum wall thickness Dmin in the 360 n/delta theta group of wall thickness data, and calculating the average wall thickness Davg;
step 6.4: judging the stability and consistency of the wall thickness data, and setting a judgment parameter p and a judgment threshold p;
the calculation formula of the evaluation parameter p is as follows: p = (Dmax-Dmin)/Davg formula (2)
When p is less than or equal to p, the stability and consistency of the wall thickness data are good, and the average wall thickness Davg is used as the wall thickness of the pipe end of the steel pipe (2); when p > p, the stability and consistency of the wall thickness data is poor, and the wall thickness data is re-measured.
6. The method of measuring a wall thickness of a pipe end of a steel pipe according to claim 5, wherein: the method for re-measuring the wall thickness data comprises the following steps:
step 6.4.1: the wall thickness calculating unit (11) controls the rotating arm and the horizontal moving mechanism (3) to do reverse return movement with the rotation and translation in the step 5, so that the first distance sensor (81) and the second distance sensor (82) return to one end of the measuring section from the other end of the measuring section in a spiral shape, and wall thickness data at the positions of the maximum wall thickness Dmax and the minimum wall thickness Dmin are measured again in the return process;
step 6.4.2: recalculating the new maximum wall thickness Dmax1, the new minimum wall thickness Dmin1 and the new average wall thickness Davg1 according to the remeasured wall thickness data;
step 6.4.3: calculating a new judgment parameter p1 according to the new maximum wall thickness Dmax1, the new minimum wall thickness Dmin1 and the new average wall thickness Davg1, and judging the stability and consistency of wall thickness data, wherein the calculation formula of the new judgment parameter p1 is as follows:
p1= (Dmax 1-Dmin 1)/Davg formula (3)
When p1 is not more than p, the stability and consistency of wall thickness data are good, and the average wall thickness Davg is used as the wall thickness of the pipe end of the steel pipe (2); and when p1 is greater than p, the stability and consistency of the wall thickness data are poor, a new maximum wall thickness Dmax1, a new minimum wall thickness Dmin1 and a new average wall thickness Davg1 are recorded, and an alarm signal is output.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116336949A (en) * | 2022-12-29 | 2023-06-27 | 深圳市志奋领科技有限公司 | Measurement method, device, equipment and medium based on laser displacement |
| CN116718146A (en) * | 2023-08-08 | 2023-09-08 | 潍柴动力股份有限公司 | System and method for measuring pipe wall thickness |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116336949A (en) * | 2022-12-29 | 2023-06-27 | 深圳市志奋领科技有限公司 | Measurement method, device, equipment and medium based on laser displacement |
| CN116336949B (en) * | 2022-12-29 | 2024-02-13 | 深圳市志奋领科技有限公司 | Measurement method, device, equipment and medium based on laser displacement |
| CN116718146A (en) * | 2023-08-08 | 2023-09-08 | 潍柴动力股份有限公司 | System and method for measuring pipe wall thickness |
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