A non-contact automatic detection device and method for straightness of sucker rod

Abstract

This application relates to the field of sucker rod straightness detection technology, specifically disclosing a non-contact automatic detection device and method for sucker rod straightness, including a base, multiple support plates with circular grooves, a limiting mechanism, and a detection mechanism. The limiting mechanism drives the limiting plates to slide radially via hydraulic pressure, automatically centering sucker rods of different diameters. The detection mechanism first emits a laser beam along the generatrix of the sucker rod to a light-transmitting plate to form a light spot. After the camera captures the image, the controller performs a preliminary straightness judgment based on the integrity and circularity of the light spot distribution. If it fails to meet the standard, multiple rangefinders on the ring frame are controlled to scan axially, measuring the radial distance of each cross-section, calculating the eccentricity between the actual center and the theoretical center, and accurately locating the bent part.

Description

Technical Field

[0001] This application relates to the technical field of sucker rod straightness detection, and in particular to a non-contact automatic detection device and method for sucker rod straightness. Background Technology

[0002] Sucker rods are key transmission components in oil extraction machinery. Their straightness directly affects the working efficiency and service life of the oil pump. Once the sucker rod is bent and deformed, the stress on the inner side of the bend will increase during operation. Long-term action will cause fatigue fracture of the sucker rod, which will seriously affect the normal operation of oilfield production. The method of directly contacting the sucker rod is often used to test it, but the test data is incomplete and the accuracy is poor.

[0003] Therefore, in order to increase the accuracy of sucker rod detection, some researchers have tried to introduce machine vision technology into the field of sucker rod straightness detection. For example, the measurement method based on array camera can perform straightness analysis by acquiring images of the sucker rod edge contour, which can realize non-contact measurement. For example, patent application No. 2023235965635 discloses a rotary drilling rod straightness detection fixture, which includes a detection table and a support seat and support frame fixed on it. The screw is rotated by a rotating rod driving a conical tooth group, which drives the limiting plates to move towards each other, clamping the two ends of the drill rod to achieve stable limiting, preventing shaking or falling during detection, ensuring the detection effect, and can adapt to drill rods of different sizes.

[0004] The rotary drilling rods and sucker rods mentioned above both belong to the field of metal rods. Therefore, the above-mentioned existing technologies can also be used to inspect sucker rods. However, the following problems still exist: Sucker rods rely on a single-sided laser measuring device for data acquisition. If the sucker rod as a whole bends and shifts to the opposite side of the laser measuring instrument, and the generatrix of the sucker rod surface directly opposite the laser measuring instrument has no obvious deformation, the laser measuring instrument can only collect the contour data of the side currently facing it. It cannot capture the bending deviation of the sucker rod on the other side, which can easily cause the straightness data to be missed, ultimately resulting in a large detection error and reducing the accuracy and reliability of the sucker rod straightness detection results. Summary of the Invention

[0005] To address the aforementioned technical problem of missed detection of straightness data, this application provides a non-contact automatic detection device and method for sucker rod straightness, employing the following technical solution: In a first aspect, a non-contact automatic detection device for the straightness of a sucker rod is characterized by comprising: Base.

[0006] Multiple support plates are provided, which are arranged on the base along the length of the base. The support plates are provided with circular grooves for placing sucker rods.

[0007] The limiting mechanism is set on the support plate and is used to support and limit the sucker rod.

[0008] The testing mechanism is mounted on the base and includes: A laser pointer, located at one end of the base, is used to emit a laser beam along the generatrix of the sucker rod.

[0009] A light-transmitting plate is located at the other end of the base and is used to receive the laser beam and form a light spot.

[0010] A camera is set up in conjunction with the light-transmitting panel and is used to capture images of the light spots.

[0011] The detection assembly includes an annular frame disposed between two adjacent support plates, with multiple rangefinders evenly installed along its circumference on the inner sidewall of the annular frame.

[0012] The controller is connected to the signals of the camera and the rangefinder, respectively, and is used to receive and process data from the camera and the rangefinder.

[0013] Preferably, the limiting mechanism includes: An annular groove is formed inside the support plate, and the annular groove is coaxial with the circular groove.

[0014] Multiple limiting plates are provided, and the multiple limiting plates are slidably disposed on the support plate along the radial direction of the circular groove, with one end of the limiting plate extending into the interior of the circular groove.

[0015] The oil inlet channel is located inside the support plate and is connected to the annular groove.

[0016] The elastic telescopic rod is installed inside the support plate. The fixed end of the elastic telescopic rod is installed inside the annular groove, and the telescopic end of the elastic telescopic rod is installed on the limiting plate.

[0017] Preferably, the limiting mechanism further includes: The slide groove is located in the part of the support plate between the annular groove and the circular groove. The slide groove is connected to both the annular groove and the circular groove, and the limiting plate is slidably set in the slide groove.

[0018] The oil inlet pipes are installed on multiple support plates, and the oil inlet pipes are connected to the oil inlet channels on the corresponding support plates.

[0019] Preferably, the testing institutions also include: An extension rod is mounted on the limiting plate. The extension rod extends along the axis of the circular groove. A connecting plate is mounted on the end of the extension rod away from the limiting plate. The laser pointer is mounted on the connecting plate.

[0020] Spacer blocks are symmetrically installed on the side of the limiting plate away from the annular groove. A clearance gap is formed between two spacer blocks on the same limiting plate, and the laser beam emitted by the laser pointer passes through the clearance gap.

[0021] Preferably, the testing institutions also include: A support rod is installed on the top of the base, away from the laser pointer, and a light-transmitting plate is installed on top of the support rod.

[0022] A connecting rod is mounted on a support rod, and the camera is mounted on the end of the connecting rod furthest from the support rod.

[0023] Preferably, the testing institutions also include: The movable slots are symmetrically opened on the top of the base along the width direction of the base.

[0024] The movable rod is slidably positioned inside the movable groove.

[0025] The support frame has its bottom mounted on a movable rod and its top mounted on a ring frame.

[0026] The drive motor is mounted on one end of the base.

[0027] The lead screw extends along the length of the base. One end of the lead screw is connected to the output shaft of the drive motor, and the bottom end of the moving rod is provided with a threaded hole that mates with the lead screw.

[0028] Preferably, the annular frame and the circular groove are arranged coaxially, and multiple rangefinders are evenly installed inside the annular frame along its circumference.

[0029] Preferably, the central axis of the camera lens coincides with the central normal of the light-transmitting plate.

[0030] Preferably, the rangefinder is a laser displacement sensor, the signal output terminal of the rangefinder is electrically connected to the signal input terminal of the controller, and the signal output terminal of the controller is electrically connected to the signal input terminal of the drive motor.

[0031] Secondly, a non-contact automatic detection method for the straightness of a sucker rod includes the following steps: S1: Place the sucker rod in the circular groove of multiple support plates, and support and limit the sucker rod through the limiting mechanism.

[0032] S2: Control the laser pointer to emit a laser beam along the generatrix of the sucker rod. After passing through the clearance gap, the laser beam is projected onto the light-transmitting plate to form a light spot. The camera captures the image of the light spot and transmits it to the controller. After preprocessing the received image, the controller determines the straightness of the sucker rod based on the integrity and circularity of the light spot.

[0033] S3: When the initial inspection fails, the controller controls the drive motor to drive the lead screw to rotate, which in turn drives the moving rod and the ring frame to move step by step along the length of the base. At each preset axial section position during the movement, the controller controls each rangefinder to simultaneously measure the radial distance to the surface of the sucker rod and transmit the data back to the controller.

[0034] S4: The controller uses the installation position of the rangefinder as a reference, calculates the actual center of each preset axial section position by combining the radial distance, and then compares the actual center with the theoretical center determined by the axis of the circular groove one by one to calculate the eccentricity of each section, and determines the bending part of the sucker rod based on the eccentricity.

[0035] In summary, this application includes at least one of the following beneficial technical effects: 1. The laser pointer designed in this invention emits rays that pass through the clearance gap and are projected onto the light-transmitting plate. After the camera captures the light spot image, the controller makes a dual judgment based on the number of light spots and whether the distribution circles are coaxial, thus achieving rapid screening of overall straightness defects. If the first round of judgment fails, multiple rangefinders evenly distributed on the ring frame scan axially. The controller calculates the eccentricity of the actual center of each section relative to the theoretical center and plots the change curve, thereby accurately locating the axial position of the section with the most severe bending. Thus, by combining the above two steps, the problem that single-sided laser measurement cannot capture the bending deviation of the sucker rod on the opposite side can be solved, avoiding missed detection of straightness data and improving the accuracy of the detection results.

[0036] 2. The support plate designed in this invention has an annular groove coaxial with the circular groove inside. Hydraulic oil is pumped into the annular groove through the oil inlet channel, which pushes multiple limit plates to slide synchronously in the radial direction, so that sucker rods of different diameters are automatically aligned and coaxial with the circular groove, ensuring the consistency of the detection benchmark.

[0037] 3. This invention relies on laser beams and laser displacement sensors to complete the test, eliminating the need for direct contact with the sucker rod surface and avoiding rod damage and human reading errors caused by contact testing. After the initial pass inspection, the sucker rod is rotated multiple preset angles by an external rotation drive mechanism for repeated testing. This avoids the situation where the bent part is located in the detection blind zone between adjacent laser beams at a single angle. Only when all angles are qualified is the final pass inspection determined, further ensuring the accuracy of the test results and providing a guarantee for sucker rod quality control. Attached Figure Description

[0038] Figure 1 This is a three-dimensional installation structure diagram of the present invention and the sucker rod.

[0039] Figure 2 This is a schematic diagram of the support plate structure of the present invention (viewed along the length of the base).

[0040] Figure 3 This is the present invention. Figure 2 A magnified view of part A.

[0041] Figure 4 This is a schematic diagram of the first three-dimensional structure of the present invention.

[0042] Figure 5This is a three-dimensional installation structure diagram of the support plate, limiting plate, extension rod, and detection components of the present invention.

[0043] Figure 6 This is a schematic diagram of the three-dimensional installation structure between the support plate, the limiting plate, and the extension rod of the present invention.

[0044] Figure 7 This is the present invention. Figure 6 A magnified view of section B.

[0045] Figure 8 This is the present invention. Figure 6 A magnified view of a portion of point C.

[0046] Figure 9 This is a schematic diagram of the three-dimensional installation structure between the ring frame and the rangefinder of the present invention.

[0047] Figure 10 This is a schematic diagram of the second three-dimensional structure of the present invention.

[0048] Figure 11 This is a schematic diagram of the three-dimensional installation structure between the support rod, the light-transmitting plate, and the camera of the present invention.

[0049] Explanation of reference numerals in the attached drawings: 1. Base; 2. Support plate; 3. Circular groove; 4. Limiting mechanism; 5. Detection mechanism; 41. Annular groove; 42. Limiting plate; 43. Elastic telescopic rod; 44. Oil inlet channel; 45. Oil inlet pipe; 51. Extension rod; 52. Connecting plate; 53. Laser pointer; 54. Support rod; 55. Light-transmitting plate; 56. Connecting rod; 57. Camera; 58. Detection component; 59. Spacer block; 581. Annular frame; 582. Rangefinder; 583. Moving rod; 584. Support frame. Detailed Implementation

[0050] The following is in conjunction with the appendix Figures 1 to 11 This application will be described in further detail.

[0051] This application discloses a non-contact automatic detection device and method for sucker rod straightness. First, the overall straightness of the sucker rod is detected. If there is a problem with the straightness of the sucker rod, a second straightness detection is performed to determine the specific bending position of the sucker rod.

[0052] A non-contact automatic detection device for the straightness of a sucker rod includes a base 1, on which a plurality of support plates 2 are evenly arranged along its length. The support plates 2 are provided with circular grooves 3 for placing the sucker rod. The support plates 2 are provided with a limiting mechanism 4 that cooperates with the sucker rod, and a detection mechanism 5 for detecting the straightness of the sucker rod.

[0053] The testing agency 5 can complete the first round of preliminary testing of the sucker rod, and make a preliminary judgment on whether the entire sucker rod has straightness defects such as bending deformation. During the testing process, the support plate 2 and the limiting mechanism 4 cooperate with each other to position and support the sucker rod on the one hand, and divide the entire sucker rod into several independent testing sections along its length on the other hand.

[0054] When the initial inspection determined that the sucker rod had straightness issues such as bending, the testing agency 5 immediately conducted secondary straightness tests on each independent testing section to determine the exact location of the bending deformation of the sucker rod.

[0055] To ensure the stability of the sucker rod during testing, the limiting mechanism 4 provided by this invention can support and limit sucker rods of different diameters. Specifically, the limiting mechanism 4 includes: an annular groove 41 opened inside the support plate 2 and coaxial with the circular groove 3; multiple limiting plates 42 installed on the inner wall of the circular groove 3 and slidably arranged radially thereon; a sliding groove that cooperates with the limiting plates 42 is opened in the part of the support plate 2 between the annular groove 41 and the circular groove 3; and the end of the sliding groove away from the circular groove 3 is connected to the annular groove 41. An elastic telescopic rod 43 is provided inside the sliding groove. The fixed end of the elastic telescopic rod 43 is installed inside the annular groove 41, and the telescopic end of the elastic telescopic rod 43 is installed on the limiting plate 42. An oil inlet channel 44 is also opened inside the support plate 2 and is connected to the annular groove 41.

[0056] In the initial position, the annular groove 41 is filled with hydraulic oil. During operation, an existing feeding mechanism (not shown in the figure, such as a conveyor belt) is used to place the sucker rod on the support plate 2 through the circular groove 3. Hydraulic oil is pumped into the annular groove 41 through the oil inlet 44. As the hydraulic oil continues to enter the annular groove 41, the volume of hydraulic oil inside the annular groove 41 increases and applies pressure to the limiting plate 42. After being subjected to pressure, the limiting plate 42 slides along the chute, at which point the elastic telescopic rod 43 is stretched.

[0057] During the movement of the limiting plate 42, the sucker rod is supported and limited, so that the sucker rod is coaxial with the circular groove 3, thereby completing the support and limiting treatment of the sucker rod and ensuring stability in the subsequent testing process.

[0058] It should be noted that the limiting plate 42 and the sliding groove are in a clearance fit, and a sealing ring is embedded in the mating surface to prevent hydraulic oil from leaking from the sliding gap. The elastic telescopic rod 43 is a return spring, which is covered with a bellows sealing sleeve to prevent hydraulic oil from entering the spring and affecting its elastic performance.

[0059] An oil inlet pipe 45 is installed on the support plate 2, and the oil inlet pipe 45 is connected to the corresponding oil inlet channel 44 on the support plate 2.

[0060] When it is necessary to continuously pump hydraulic oil into the annular groove 41, connect the outlet of the existing oil pump (not shown in the figure) to the inlet pipe 45. At this time, the oil pump can continuously pump hydraulic oil into the inlet pipe 45, and the hydraulic oil flows into the annular groove 41 through the inlet pipe 45.

[0061] After the sucker rod is supported and limited, the straightness of the sucker rod is tested by the detection mechanism 5. Specifically, the detection mechanism 5 includes: an extension rod 51 extending along the axis of the circular groove 3 is installed on the limiting plate 42 corresponding to the support plate 2 at any end of the base 1. A connecting plate 52 is installed on the end of the extension rod 51 away from the corresponding limiting plate 42. A laser pointer 53 is installed on the connecting plate 52.

[0062] On the side of the limiting plate 42 away from the corresponding annular groove 41, spacer blocks 59 are symmetrically installed along the axis of the corresponding extension rod 51. A clearance gap is formed between the spacer blocks 59 corresponding to the same limiting plate 42 to make way for the laser beam emitted by the laser pointer 53.

[0063] The spacer block 59 has an arc-shaped clamping surface on the side near the circular groove 3. The radius of curvature of the arc-shaped clamping surface is adapted to the outer diameter of the sucker rod to be tested. The surface of the arc-shaped clamping surface is embedded with anti-slip rubber pads through a vulcanization process to increase the clamping friction and adapt to sucker rods of different diameters, and to avoid scratching the surface of the rod.

[0064] A support rod 54 is installed on the top side of the base 1 away from the laser pointer 53. A light-transmitting plate 55 is installed on the top of the support rod 54. A connecting rod 56 is also installed on the support rod 54. A camera 57 is installed on the end of the connecting rod 56 away from the support rod 54.

[0065] The light-transmitting plate 55 is made of frosted glass, and its surface is set perpendicular to the laser emission direction of the laser pointer 53; the central axis of the lens of the camera 57 coincides with the central normal of the light-transmitting plate 55, and the signal output terminal of the camera 57 is electrically connected to the signal input terminal of the controller through a data cable.

[0066] It should be noted that the vertical distance from the laser emitter to the sucker rod body is used as the maximum allowable straightness error threshold of the sucker rod. If the actual deformation offset of the sucker rod exceeds this vertical distance, the straightness test of the sucker rod is deemed unqualified. If the actual offset of the sucker rod does not exceed this distance, the straightness test of the sucker rod is deemed qualified. The laser emitted by the laser pointer 53 always passes through the clearance gap. In specific operation, during the sucker rod support and limiting process, the corresponding limiting plate 42 drives the laser pointer 53 to move synchronously through the extension rod 51, so that the distance between the laser pointer 53 and the sucker rod is always maintained at the maximum allowable straightness error threshold of the sucker rod.

[0067] After the sucker rod support limit is completed, the laser pointer 53 also moves to the working position and is turned on. The laser pointer 53 then emits a beam along the sucker rod, which eventually falls on the light-transmitting plate 55 to form a light spot. The camera receives the light spot signal and transmits the light spot signal to the controller. If the number of light spots falling on the light-transmitting plate 55 is the same as the number of laser pointers 53 and the lines connecting the light spots form a complete circle, it indicates that the straightness of the sucker rod is qualified; otherwise, it is unqualified.

[0068] Specifically, after receiving the light spot image, the controller first preprocesses the image to eliminate ambient light interference. Then, it counts the number of effective light spots in the image and calculates the coordinates of the center point of each light spot as the basis for subsequent judgment. The image preprocessing includes grayscale processing and median filtering denoising algorithm.

[0069] After completing the above data processing, the controller makes a logical decision based on the following two conditions: The first judgment is the integrity judgment of the light spot: the number of valid light spots obtained by statistics is compared with the total number of laser pointers 53. If the two are consistent, it means that all laser beams are not blocked by the sucker rod and the laser propagation path is unobstructed; if the numbers are inconsistent, it means that at least one beam is blocked by the bent rod and the corresponding light spot is missing.

[0070] The second judgment is the uniformity of the light spot distribution: the center points of each light spot are connected in circumferential order, and a circle is fitted to each connection point. The degree of deviation of each point from the fitted circle is calculated to obtain the roundness deviation value. If the deviation value is less than the preset threshold, it indicates that the line connecting each light spot forms a complete circle and the sucker rod has not undergone overall eccentric shift; if the deviation value exceeds the standard, it indicates that the rod body has eccentric bending.

[0071] The controller performs a comprehensive logical operation on the above two judgment results: if and only if the number of light spots is complete and the roundness deviation of the light spot distribution is within the allowable range, the straightness of the sucker rod is judged to be qualified; otherwise, it is judged to be unqualified.

[0072] It should be noted that the camera 57 is always on. In addition, as a specific way to automatically turn on the laser pointer 53, in this embodiment, a normally open limit switch is connected in series on the power supply circuit of the laser pointer 53. The limit switch is fixedly installed on the base 1, and its contact is located at the end of the moving path of the connecting plate 52. When the limit plate 42 is driven by hydraulic oil to move the extension rod 51 and the connecting plate 52 to the final working position, the connecting plate 52 just presses down and triggers the limit switch, so that the power supply circuit is turned on, and the laser pointer 53 automatically lights up and maintains a continuous light-emitting state.

[0073] As an alternative way to automatically turn on the laser pointer 53, a photoelectric proximity sensor is installed on the base 1 near the end of the moving path of the connecting plate 52. The signal output terminal of the sensor is connected to the input terminal of the controller. The output terminal of the controller is connected to a relay for controlling the power supply of the laser pointer 53. When the connecting plate 52 moves to the preset working position with the limit plate 42, the photoelectric proximity sensor detects the signal of the connecting plate 52 in position and transmits it to the controller. The controller then sends a closing command to the relay. After the relay is energized, the power supply circuit of the laser pointer 53 is connected, realizing the automatic turning on of the laser pointer 53.

[0074] The controller is an industrial control computer or programmable logic controller (PLC) with conventional configuration in the field. Its specific model and internal circuit structure are not the design focus of this application. The same applies to other existing electrical components, so they will not be described in detail here.

[0075] When the straightness of the sucker rod is not up to standard, the specific bending position of the sucker rod is determined by the detection component 58. Specifically, the detection mechanism 5 also includes a detection component 58 for determining the specific bending position of the sucker rod, including an annular frame 581 coaxial with the circular groove 3, and the annular frame 581 is arranged between adjacent support plates 2. Multiple rangefinders 582 are evenly installed in the annular frame 581 along its circumference.

[0076] The base 1 has a symmetrically arranged movable groove on its top along its width direction. A movable rod 583 is slidably arranged inside the movable groove. A support frame 584 that cooperates with the ring frame 581 is symmetrically arranged on the top of the base 1 along its width direction. The bottom of the support frame 584 is installed on the movable rod 583 on the corresponding side. The end of the support frame 584 away from the corresponding movable rod 583 is installed on the corresponding ring frame 581.

[0077] One end of the base 1 is fixedly equipped with a drive motor. The output shaft of the drive motor is connected to a lead screw through a coupling. The lead screw extends along the length of the base 1. The bottom end of the moving rod 583 is provided with a threaded hole that mates with the lead screw. The signal input end of the drive motor is electrically connected to the signal output end of the controller. The above-mentioned existing components are existing technology, so they will not be described in detail or shown in the figure.

[0078] The rangefinder 582 uses a laser displacement sensor. During the movement of the moving rod 583, the ring frame 581 moves synchronously through the support frame 584. During the movement of the ring frame 581, the rangefinder 582 moves synchronously, and the travel of the rangefinder 582 does not exceed the distance between two adjacent support plates 2.

[0079] During the movement of the rangefinder 582, the controller starts each rangefinder 582 to synchronously measure the distance to the detection point on the surface of the sucker rod and transmits the data back. The controller uses the installation position of the rangefinder 582 as a reference, combines the distance measurement data to calculate the spatial coordinates of the detection point, and then uses the least squares circle fitting algorithm to fit the actual center position of each cross section. The actual center of each cross section is compared with the theoretical center (determined by the axis of the circular groove 3) one by one to calculate the eccentricity and eccentricity vector of each cross section.

[0080] The specific calculation method is as follows: taking the theoretical center of the ring frame 581 as the origin, the fixed installation angle of each rangefinder 582 is known, and the polar coordinates of each detection point are obtained by combining the distance measurement value. Then, they are converted into rectangular coordinates, and the actual center coordinates of the cross section are fitted by the least squares method.

[0081] The controller plots a curve along the length of the sucker rod with the axial position as the x-axis and the eccentricity as the y-axis. It identifies the section with the largest eccentricity, which is the part with the most severe bending. The controller calculates the axial position of the bending based on the calibrated position of the section, stores the calculated bending position information in the controller's memory, and outputs it through the display screen or alarm.

[0082] The bending position can then be determined based on the coordinates.

[0083] It should be noted that after the sucker rod is deemed qualified, the limiting plate 42 is reset to one end distance so that the spacer block 59 no longer squeezes the sucker rod. At this time, the sucker rod is rotated by an external rotation drive mechanism (such as an electric chuck or roller rotation support device set at the end of the base 1) at multiple preset angles (90°, 180° and 270°, etc.) and then tested separately. This allows for comprehensive multi-angle testing of the sucker rod, avoiding missed detections caused by the bent part of the sucker rod being located in the detection blind zone between adjacent laser beams during single-angle testing. This further ensures the accuracy and reliability of the sucker rod straightness test.

[0084] Once all preset angles have passed the test, the controller will determine that the straightness of the sucker rod is qualified. If any angle fails the test, the straightness of the sucker rod will be determined to be unqualified, and the above steps for determining the straightness of the sucker rod will be repeated to determine the specific location of the sucker rod bending.

[0085] Finally, the present invention also provides a non-contact automatic detection method for the straightness of sucker rods, comprising the following steps: S1: The sucker rod is hoisted and placed into the circular groove 3 of each support plate 2, and the hydraulic oil pump is started to pump hydraulic oil into the annular groove 41. The hydraulic oil pushes the limiting plate 42 to slide synchronously towards the center along the radial direction of the slide groove until the arc-shaped clamping surface of each limiting plate 42 simultaneously and tightly adheres to the outer wall of the sucker rod, so that the axis of the sucker rod coincides with the axis of the circular groove 3, thus completing the centering and limiting.

[0086] S2: When the limiting plate 42 moves to the clamping position, the extension rod 51 drives the connecting plate 52 to move synchronously and triggers the limit switch. The laser pointer 53 automatically turns on and emits a laser beam along the direction of the sucker rod generatrix. The laser beam passes through the clearance gap between the limiting plates 42 and is projected onto the light-transmitting plate 55 to form a light spot. The camera 57 collects the light spot image and transmits it to the controller. After performing grayscale and median filtering preprocessing on the image, the controller counts the number of effective light spots and compares it with the total number of laser pointers 53. At the same time, it fits the roundness deviation value of the center point of each light spot. If the number of light spots is complete and the roundness deviation value is ≤0.05mm, the sucker rod is judged to be initially qualified and jumps to S4; otherwise, it is judged to be unqualified and S3 is executed.

[0087] S3: The controller starts the drive motor to drive the lead screw to rotate. The lead screw drives the moving rod 583 and the ring frame 581 to move at equal intervals from one end of the support plate 2 to the other end. During the movement, each rangefinder 582 synchronously measures the radial distance to each detection point on the surface of the sucker rod and transmits the data back. The controller uses the installation position of the rangefinder 582 as a reference, combines the distance measurement data to calculate the actual center coordinates of each axial section, and then compares them with the theoretical center of the circular groove 3 one by one to calculate the eccentricity of each section. The axial position and eccentricity change curve is plotted, and the axial section position corresponding to the maximum eccentricity is taken and marked as the bending part of the sucker rod.

[0088] S4: The controller controls the external rotary drive mechanism to rotate the sucker rod around its axis by a certain angle in sequence. S2 and S3 are repeated at each rotation angle. If the preliminary inspection and secondary fine inspection at all rotation angles are deemed qualified, the straightness of the sucker rod is finally deemed qualified. If it is deemed unqualified at any rotation angle, it is finally deemed unqualified, and the position information of the bent part marked in S3 is output.

[0089] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0090] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A non-contact automatic detection device for the straightness of sucker rods, characterized in that, include: Base (1); Support plate (2) is provided in multiple ways. Multiple support plates (2) are provided on the base (1) along the length direction of the base (1). The support plate (2) is provided with a circular groove (3) for placing the sucker rod. The limiting mechanism (4) is set on the support plate (2) and is used to support and limit the sucker rod; The testing mechanism (5) is mounted on the base (1) and includes: A laser pointer (53) is set at one end of the base (1) and is used to emit a laser beam along the generatrix of the sucker rod; A light-transmitting plate (55) is disposed at the other end of the base (1) and is used to receive the laser beam and form a light spot; A camera (57) is set in correspondence with a light-transmitting plate (55) and is used to capture images of light spots; The detection component (58) includes an annular frame (581) disposed between two adjacent support plates (2), and multiple rangefinders (582) are uniformly installed on the inner side wall of the annular frame (581) along its circumference. The controller is connected to the camera (57) and the rangefinder (582) respectively, and is used to receive and process data from the camera (57) and the rangefinder (582).

2. The non-contact automatic detection device for the straightness of sucker rods according to claim 1, characterized in that, The limiting mechanism (4) includes: An annular groove (41) is formed inside the support plate (2), and the annular groove (41) and the circular groove (3) are coaxial; Multiple limiting plates (42) are provided. Multiple limiting plates (42) are slidably disposed on the support plate (2) along the radial direction of the circular groove (3). One end of the limiting plate (42) extends into the interior of the circular groove (3). An oil inlet channel (44) is opened inside the support plate (2), and the oil inlet channel (44) is connected to the annular groove (41). The elastic telescopic rod (43) is set inside the support plate (2). The fixed end of the elastic telescopic rod (43) is installed inside the annular groove (41), and the telescopic end of the elastic telescopic rod (43) is installed on the limiting plate (42).

3. The non-contact automatic detection device for the straightness of sucker rod according to claim 2, characterized in that, The limiting mechanism (4) also includes: The slide groove is located in the part of the support plate (2) between the annular groove (41) and the circular groove (3). The slide groove is connected to both the annular groove (41) and the circular groove (3). The limiting plate (42) is slidably disposed in the slide groove. The oil inlet pipe (45) is installed on multiple support plates (2), and the oil inlet pipe (45) is connected to the oil inlet channel (44) on the corresponding support plate (2).

4. The non-contact automatic detection device for the straightness of sucker rod according to claim 2, characterized in that, The testing agency (5) also includes: An extension rod (51) is installed on a limiting plate (42). The extension rod (51) extends along the axis of the circular groove (3). A connecting plate (52) is installed at the end of the extension rod (51) away from the limiting plate (42). A laser pointer (53) is installed on the connecting plate (52). Spacer blocks (59) are symmetrically installed on the side of the limiting plate (42) away from the annular groove (41). A clearance gap is formed between two spacer blocks (59) on the same limiting plate (42), and the laser beam emitted by the laser pointer (53) passes through the clearance gap.

5. The non-contact automatic detection device for the straightness of sucker rod according to claim 4, characterized in that, The testing agency (5) also includes: A support rod (54) is installed on the top of the base (1) on the side away from the laser pointer (53), and a light-transmitting plate (55) is installed on the top of the support rod (54); A connecting rod (56) is mounted on a support rod (54), and a camera (57) is mounted on the end of the connecting rod (56) away from the support rod (54).

6. The non-contact automatic detection device for the straightness of sucker rod according to claim 1, characterized in that, The testing agency (5) also includes: The movable slot is symmetrically opened on the top of the base (1) along the width direction of the base (1); The movable rod (583) is slidably disposed inside the movable groove; The support frame (584) is mounted on the bottom of the moving rod (583) and on the top of the ring frame (581). A drive motor is installed at one end of the base (1); The lead screw extends along the length of the base (1), with one end connected to the output shaft of the drive motor, and the bottom end of the moving rod (583) is provided with a threaded hole that mates with the lead screw.

7. The non-contact automatic detection device for the straightness of a sucker rod according to claim 6, characterized in that, The ring frame (581) and the circular groove (3) are arranged coaxially, and multiple rangefinders (582) are evenly installed inside the ring frame (581) along the circumference of the ring frame (581).

8. The non-contact automatic detection device for the straightness of sucker rod according to claim 1, characterized in that, The central axis of the lens of the camera (57) coincides with the central normal of the light-transmitting plate (55).

9. The non-contact automatic detection device for the straightness of sucker rod according to claim 1, characterized in that, The rangefinder (582) is a laser displacement sensor. The signal output terminal of the rangefinder (582) is electrically connected to the signal input terminal of the controller, and the signal output terminal of the controller is electrically connected to the signal input terminal of the drive motor.

10. A non-contact automatic detection method for the straightness of sucker rods, employing the detection device as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1: Place the sucker rod in the circular groove (3) of multiple support plates (2), and support and limit the sucker rod through the limiting mechanism (4); S2: Control the laser pointer (53) to emit a laser beam along the direction of the sucker rod. After the laser beam passes through the clearance gap, it is projected onto the light-transmitting plate (55) to form a light spot. The camera (57) collects the image of the light spot and transmits it to the controller. After the controller preprocesses the received image, it judges the straightness of the sucker rod based on the integrity and distribution roundness of the light spot. S3: When the initial inspection is deemed unqualified, the controller controls the drive motor to drive the screw to rotate, which in turn drives the moving rod (583) and the ring frame (581) to move step by step along the length of the base (1). At each preset axial section position during the movement, the controller controls each rangefinder (582) to simultaneously measure the radial distance from it to the surface of the sucker rod and transmit it back to the controller. S4: The controller uses the installation position of the rangefinder (582) as a reference, calculates the actual center of each preset axial section position by combining the radial distance, and then compares the actual center with the theoretical center determined by the axis of the circular groove (3) one by one to calculate the eccentricity of each section, and determines the bending part of the sucker rod according to the eccentricity.

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