Pipe inner diameter detection equipment and method based on laser measurement technology

Abstract

The invention relates to the technical field of pipe size detection, in particular to a pipe inner diameter detection device and method based on a laser measurement technology. The pipe inner diameter detection equipment comprises a self-positioning supporting platform and a detection device. The detection device comprises a control system, a feeding device and a detection head; the detection head is conical or truncated cone-shaped, is internally provided with a laser emission unit, and is externally provided with a receiving unit; the feeding device is supported by two symmetrical four-bar mechanisms; during detection, the detection head is inserted into the end of a detected pipe, and the control system calculates and obtains an inner diameter value based on signals fed back by the receiving unit. The pipe inner diameter detection equipment can ensure that the detection head is highly overlapped with the central axis of the detected pipe, and the inner diameter measurement precision is remarkably improved; the position adjustment of the detection head and the inner diameter measurement process are automatically completed, time and labor are saved, and high efficiency and rapidness are achieved. Under the condition of not increasing significant cost, additional functions such as outer diameter detection and end face detection can be achieved, and high cost performance and practical significance are achieved.

Description

Technical Field

[0001] This invention relates to the field of workpiece size detection technology, and in particular to a device and method for detecting the inner diameter of pipes based on laser measurement technology. Background Technology

[0002] In the pipe manufacturing process, to ensure that products meet industry standards and quality control requirements, it is necessary to inspect the inner diameter of the pipes. Previously, handheld inner diameter measuring devices were typically used as the main inspection tool, with the inspection performed manually. This was cumbersome, and the standard operating procedures were complex, resulting in low inspection efficiency and significant manual errors, making it difficult to meet actual production requirements. Automated pipe inner diameter inspection equipment is the future trend. For example, the invention patent with publication number CN119354080B discloses an inner diameter inspection device for BWFRP power pipes, which achieves automatic inner diameter inspection based on an automated structural design. However, this inner diameter inspection device lacks a precise centering mechanism, making it impossible to ensure that the two inner clamping plates are symmetrically distributed on both sides of the central axis of the inspected pipe during the inspection process. This can cause a significant deviation between the distance measured by the laser rangefinder and the actual inner diameter value. Especially when inspecting the inner diameter of pipes made of low-strength and easily deformable plastics and rubber, the clamping of the pipe wall by the inner and outer clamping plates during the inspection process can lead to local deformation of the pipe ends, severely reducing the inspection accuracy.

[0003] Furthermore, pipes made of plastic or rubber, as well as thin-walled metal pipes, have lower structural strength. During placement, under external forces such as gravity or compression, the pipe ends are prone to deformation, resulting in a non-standard circular structure. However, this does not affect practical application and is not considered a quality issue. Because the pipe ends are not perfectly circular, the inner diameter of the pipe cannot be accurately measured using existing testing methods. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a pipe inner diameter detection device and method based on laser measurement technology, aiming to solve the technical problems that the current pipe inner diameter detection mainly relies on manual labor, resulting in low measurement accuracy and detection efficiency.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a pipe inner diameter detection device based on laser measurement technology, comprising a self-positioning support platform and a detection device; the self-positioning support platform makes the central axis of the pipe under inspection horizontal and located in a vertical detection plane; the detection device includes a feeding device controlled by a control system, a detection head, and two driving devices; the detection head is conical or frustum-shaped, with a pointed front end facing one end of the pipe under inspection, and is driven by the feeding device to move back and forth; a laser emitting unit for emitting a parallel beam is fixed inside the detection head, a light-transmitting groove is opened on the side wall, and a receiving unit is fixed outside; the upper side of the feeding device is provided with an upper... The upper and lower beams are connected by two linkages to form a parallel four-bar linkage mechanism. A lower beam is provided below the feeding device, which is also connected by two linkages to form another parallel four-bar linkage mechanism. The two parallel four-bar linkage mechanisms are symmetrical about the central axis of the detection head. The upper and lower beams are driven by two drive devices to move up and down. Contact sensors are installed on the upper and lower beams via forward-extending probe arms. When the two contact sensors contact the upper and lower sides of the pipe being inspected, respectively, the detection head coincides with the central axis of the pipe being inspected. During inspection, the detection head is inserted into the end of the pipe being inspected and makes close contact. The control system calculates the inner diameter value based on the signal fed back by the receiving unit.

[0007] In a preferred embodiment, during the up-and-down movement of the upper and lower beams, the two parallel four-bar linkages deform symmetrically within the detection plane.

[0008] In a preferred embodiment, two rows of parallel and spaced roller groups are installed on the self-positioning support platform. The two roller groups support the lower ends of the pipe to be inspected on both sides. When the pipe to be inspected is placed on the upper side of the two roller groups, the pipe to be inspected rolls automatically to adapt to the detection plane based on its own weight.

[0009] In a preferred embodiment, the self-positioning support platform is equipped with two symmetrically arranged inclined surfaces. When the pipe to be inspected is placed between the two inclined surfaces, the pipe to be inspected automatically adapts to the inspection plane based on its own weight.

[0010] In a preferred embodiment, both the driving device and the feeding device are linear drive mechanisms.

[0011] In a preferred embodiment, the two drive devices are mounted and fixed on the machine body, with the drive device providing drive for the upper beam frame located on the upper side of the upper beam frame and the drive device providing drive for the lower beam frame located on the lower side of the lower beam frame.

[0012] In a preferred embodiment, two laser emitting units are fixed inside the detection head, and the two laser emitting units emit parallel beams in opposite directions; correspondingly, two light-transmitting slots and two receiving units are provided, distributed on opposite sides of the detection head; furthermore, the control system compares the two inner diameter values ​​obtained from the two receiving units to determine whether the end face of the inspected pipe meets the requirements, thereby realizing the end face detection function.

[0013] In a preferred embodiment, the pipe inner diameter detection device further includes a positioning mechanism, which includes a lifting device and a limiting plate. The limiting plate is driven by the lifting device to move up and down. The control system can control the operating state of the lifting device. When the limiting plate is in the raised state, it can position the axial position of the pipe being inspected. When the limiting plate is in the lowered state, it does not obstruct the detection operation.

[0014] In a preferred embodiment, the front end of the probe arm is provided with a bent portion that bends toward the direction of the other probe arm, and the contact sensor is mounted and fixed on the opposite ends of the two bent portions.

[0015] In a preferred embodiment, a load sensor is installed inside the feeding device. The load sensor monitors the working load of the feeding device and feeds the signal back to the control system. When the feeding device drives the detection head to move forward, if the working load of the feeding device increases suddenly, the control system stops the feeding device.

[0016] In a preferred embodiment, the detection head has a plug-in portion on its rear side and the drive device has a telescopic portion on its front side that can move back and forth. The telescopic portion and the plug-in portion are plugged into each other and can move relative to each other in the front and back direction without disengaging. A thrust spring is provided between the telescopic portion and the plug-in portion to drive them away from each other. During the process of the feed device driving the detection head to move forward, when the feedback signal of the receiving unit no longer changes, the control system stops the feed device.

[0017] In a preferred embodiment, a first measuring point is provided on the upper beam frame, and a second measuring point is provided on the lower beam frame. The first measuring point is located directly above the second measuring point. A laser ranging element for measuring the vertical distance between the first and second measuring points is installed and fixed on the upper or lower beam frame. The laser ranging element can feed back a signal to the control system. The control system calculates the vertical distance between the two contact sensors based on the signal fed back by the laser ranging element. The vertical distance is the value of the outer diameter of the pipe being inspected.

[0018] Secondly, the present invention provides a method for detecting the inner diameter of a pipe, which uses the pipe inner diameter detection equipment to detect the inner diameter of the pipe, comprising the following steps:

[0019] S1: Under the control of the control system, the detection device is initialized to ensure that the two contact sensors are located on the front side of the detection head and that there is enough space between the two contact sensors to accommodate the end of the pipe being inspected.

[0020] S2: Place the pipe to be inspected on the self-positioning support platform so that the end of the pipe to be inspected that is facing the inspection head is in a suspended state;

[0021] S3: Under the control of the control system, the two contact sensors contact the upper and lower sides of the pipe being inspected, respectively, and the detection head moves forward so that the detection head is inserted into the end of the pipe being inspected and makes close contact.

[0022] S4: The laser emitting unit and the receiving unit work together. The control system calculates the inner diameter of the inspected pipe based on the signal or data fed back by the receiving unit.

[0023] Compared with existing technologies, the pipe inner diameter detection equipment and method based on laser measurement technology disclosed in this invention have the following beneficial technical effects:

[0024] When this pipe inner diameter testing equipment is in operation, the self-positioning support platform can position the pipe to be inspected in the testing plane. The testing device uses two parallel four-bar linkages to center the testing head and the pipe to be inspected, ensuring that the central axes of the testing head and the pipe to be inspected coincide. Furthermore, the pipe to be inspected will not deform due to clamping during the testing process, thus significantly improving the accuracy of inner diameter measurement and enhancing testing precision. During operation, the position adjustment of the testing head and the inner diameter measurement process can be automatically completed based on the control system and preset programs, saving time and effort, and achieving high efficiency and speed, avoiding errors caused by improper manual operation. Based on its structural design, this pipe inner diameter testing equipment has significant functional expansion potential. Additional functions such as outer diameter testing and end face testing can be implemented without significantly increasing costs, making this pipe inner diameter testing equipment highly cost-effective and practical. When measuring the inner diameter of pipes made of plastic or rubber, as well as thin-walled metal pipes, even if there is some deformation at the pipe opening, the detection head can be inserted into the pipe to restore the pipe opening to a standard circular structure, thereby achieving the purpose of inner diameter detection and ensuring detection accuracy. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0026] Figure 1 This is a schematic diagram of the self-positioning support platform in the embodiment.

[0027] Figure 2This is a schematic diagram of the detection device in the embodiment.

[0028] Figure 3 This is a schematic diagram of the detection device in another direction in the embodiment.

[0029] Figure 4 This is a schematic diagram of the feeding device and detection head in the embodiment.

[0030] Figure 5 This is a schematic diagram showing the coordinated state of the detection head, laser emitting unit, and receiving unit in the embodiment.

[0031] Figure 6 This is a side view of a pipe inner diameter testing device.

[0032] Figure 7 This is a schematic diagram showing the status of the pipe inner diameter testing equipment after the pipe being inspected has been installed.

[0033] Figure 8 This is a schematic diagram of the state of a pipe inner diameter detection device when a contact sensor comes into contact with the pipe being inspected.

[0034] Figure 9 This is a schematic diagram of the pipe inner diameter detection equipment when two contact sensors are in contact with the pipe being inspected.

[0035] Figure 10 This is a schematic diagram showing the status of the pipe inner diameter testing equipment during the testing of the pipe material.

[0036] Figure 11 This is a three-dimensional structural diagram of the pipe inner diameter testing equipment used to test the pipe material.

[0037] Figure 12 This is a schematic diagram of the mating structure between the testing head and the pipe being tested.

[0038] Figure 13 A reference diagram illustrating the principle of calculating the inner diameter of the pipe being inspected using a pipe inner diameter testing device.

[0039] Figure 14 This is a schematic diagram of the cooperation structure between the detection head and the feeding device in another embodiment.

[0040] Figure label:

[0041] 1-Self-positioning support platform; 2-Idler roller group; 3-Lower beam frame; 4-Feeding device; 5-Connecting rod; 6-Upper beam frame; 7-Drive device; 8-Machine body; 9-Probe arm; 10-Bending part; 11-Contact sensor; 12-Receiving unit; 13-Detection head; 14-Light transmission groove; 15-Limiting plate; 16-Lifting device; 17-Laser emitting unit; 18-Detection plane; 19-Second measuring point; 20-Laser ranging element; 21-First measuring point; 22-Thrust spring; 23-Telescopic part; 24-Plug-in part. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0043] See Figures 1 to 2 As shown in the figure, the embodiment discloses a pipe inner diameter detection device based on laser measurement technology, including a self-positioning support platform 1 and a detection device.

[0044] Among them, such as Figure 1 , Figure 6 As shown, the self-positioning support platform 1 can support and position the inspected pipe, extending its central axis horizontally and positioning it within a predetermined vertical plane, namely the detection plane 18. Support platforms with these functions are common in the field of pipe processing technology. For example, two rows of parallel and spaced roller groups 2 are installed on the self-positioning support platform 1, supporting the lower ends of the inspected pipe on both sides. Thus, when the inspected pipe is placed on the roller groups 2, it rolls under its own weight, automatically adapting to the detection plane 18, achieving the intended positioning. Alternatively, two symmetrically arranged inclined surfaces can be installed on the self-positioning support platform 1. When the inspected pipe is placed between the two inclined surfaces, it can also automatically adapt to the detection plane 18 under its own weight.

[0045] Among them, see Figures 2 to 6The detection device includes a control system, a feeding device 4, a detection head 13, and two driving devices 7, all controlled by the control system. The detection head 13 is mounted on the feeding device 4 and is driven by the feeding device 4 to move back and forth. The control system can control the operation of the feeding device 4 to adjust the horizontal position of the detection head 13. The detection head 13 is conical or frustum-shaped, with its central axis extending horizontally in the front-back direction and located in the detection plane 18. Its front end is a pointed tip and faces one end of the pipe being inspected. A laser emitting unit 17 is fixed inside the detection head 13. The laser emitting unit 17 is controlled by the control system and can emit a parallel beam. The parallel beam consists of beams that are parallel to each other and densely arranged along the axial direction of the detection head 13. The emission direction of the parallel beam is perpendicular to the central axis of the detection head 13. A light-transmitting groove 14 is provided on the side wall of the detection head 13 along the axial direction to allow the parallel beam to pass through. Specifically, the laser emitting unit 17 emits a monochromatic, single-frequency laser beam through a built-in laser diode or HeNe laser, and the laser beam is amplified by a convex lens or optical system. The beam is converged into a parallel beam to ensure its uniformity and consistency. A receiving unit 12 is fixed externally to the detection head 13 to receive the parallel beam, and the receiving unit 12 feeds back the reception status of the parallel beam to the control system. An upper beam frame 6 is provided on the upper side of the feeding device 4, and the two are connected by two connecting rods 5 to form a parallel four-bar linkage. A lower beam frame 3 is provided on the lower side of the feeding device 4, and the two are connected by two connecting rods 5 to form another parallel four-bar linkage. The upper beam frame 6 and the lower beam frame 3 are driven by two driving devices 7 respectively. The control system can only move in the vertical direction and can control the operation of the two drive devices 7 to adjust the vertical position of the upper beam 6 and the lower beam 3. During the vertical movement of the upper beam 6 and the lower beam 3, the two parallel four-bar linkages deform in the detection plane 18 and remain symmetrical with respect to the central axis of the detection head 13. As a result, the detection head 13 will move in the detection plane 18 with the deformation of the parallel four-bar linkages. When the detection head 13 is in different positions, the central axis always remains horizontal and is located in the middle of the two parallel four-bar linkages.

[0046] like Figure 2 , Figure 3 , Figures 7 to 12As shown, the upper beam frame 6 and lower beam frame 3 are each equipped with contact sensors 11 via forward-extending probe arms 9. The two contact sensors 11 are located in the detection plane 18 and distributed on the upper and lower sides of the end of the pipe being inspected. The control system can control the operation of the drive device 7 based on the signals fed back from the contact sensors 11 to adjust the position of the lower beam frame 3. Specifically, during the downward movement of the upper beam frame 6, when the corresponding contact sensor 11 contacts the upper side of the pipe being inspected, it feeds a signal back to the control system. The control system then stops the corresponding drive device 7, thereby adjusting the upper beam frame 6 to the corresponding position. Similarly, the lower beam frame 3... During the upward movement of frame 3, when the corresponding contact sensor 11 contacts the lower side of the pipe, the control system stops the corresponding drive device 7, thereby adjusting the lower beam frame 3 to the corresponding position. When the two contact sensors 11 contact the upper and lower sides of the pipe under inspection respectively, the two parallel four-bar linkages are symmetrically distributed around the central axis of the pipe under inspection, thereby aligning the detection head 13 with the pipe under inspection, that is, the central axes of the detection head 13 and the pipe under inspection coincide. After that, the detection head 13 is driven forward by the feed device 4, which can drive the detection head 13 to insert into the end of the pipe under inspection and make the detection head 13 in close contact with the end of the pipe under inspection.

[0047] See Figure 5 , Figure 13 As shown, during inner diameter measurement, the detection head 13 is inserted into the end of the pipe being tested, and the two are in close contact. The laser emitting unit 17 emits a parallel laser beam. Part of the parallel beam is blocked by the pipe being tested and cannot be received by the receiving unit 12. Depending on the inner diameter of the pipe being tested, the receiving state of the receiving unit 12 for the parallel beam is also different. Based on this characteristic, the control system can calculate the inner diameter value of the pipe being tested based on the signal fed back by the receiving unit 12. In the existing laser measurement technology, the blocking method, also known as the parallel light method, is a commonly used laser measurement technology. When the parallel beam illuminates the object being tested, the object blocks part of the laser, and the blocked area forms a "shadow" on the receiving unit 12. By measuring the width of the shadow, the relevant dimensions of the object being tested can be obtained. In this invention, during the inner diameter measurement process, the end of the pipe being tested will block part of the parallel beam to form a shadow in the receiving unit 12. Based on the width of the shadow, the relative position between the end face of the pipe being tested and the detection head 13 can be determined. Combined with the shape and size parameters of the detection head 13, the inner diameter value of the pipe being tested can obviously be calculated.

[0048] For specific calculation methods, please refer to the following:

[0049] like Figure 13As shown, in the longitudinal section of the detection head 13, there is a right triangle composed of line segments A, B, and C. The shape and size of the right triangle are clear and fixed. Based on the receiving state of the receiving unit 12 for the parallel beam, the value of line segment A1 can be determined, and then the value of A2 can be obtained. The value of angle α is determined. Based on the definition of trigonometric functions, tanα = R / A2, the value of R can be obtained, which is the inner diameter of the pipe being inspected.

[0050] See Figures 7 to 12 As shown, the specific method and working principle of using the pipe inner diameter detection equipment to detect the inner diameter of the pipe are as follows:

[0051] S1: Under the control of the control system, the detection device is initialized; specifically, the detection head 13 moves backward, the upper beam 6 moves upward, and the lower beam 3 moves downward; to ensure that the two contact sensors 11 are located in front of the detection head 13, and that there is sufficient space between the two contact sensors 11 to accommodate the end of the pipe being inspected.

[0052] S2: Place the pipe to be inspected on the self-positioning support platform 1, so that the end of the pipe to be inspected that faces the detection head 13 is in a suspended state and is within the working range of the detection head 13 and the contact sensor 11.

[0053] S3: Under the control of the control system, the upper beam 6 moves downward and the lower beam 3 moves upward, so that the two contact sensors 11 contact the upper and lower sides of the pipe to be inspected respectively, thereby completing the centering operation and ensuring that the central axis of the detection head 13 and the pipe to be inspected coincides; the feeding device 4 drives the detection head 13 to move forward, so that the detection head 13 is inserted into the end of the pipe to be inspected and makes close contact.

[0054] S4: The laser emitting unit 17 works in conjunction with the receiving unit 12. The control system calculates the inner diameter value of the pipe under inspection based on the signal or data fed back by the receiving unit 12, and determines whether it meets the requirements. Thus, the inner diameter detection work is completed.

[0055] S5: Under the control of the control system, the detection device is reset to the initialization state and the pipe to be inspected is removed from the self-positioning support platform 1.

[0056] When this pipe inner diameter testing equipment is working, the self-positioning support platform 1 can position the pipe to be tested in the testing plane 18. The testing device can center the testing head 13 with the pipe to be tested through two parallel four-bar linkages, thereby ensuring that the central axis height of the testing head 13 and the pipe to be tested coincides, which significantly improves the accuracy of inner diameter measurement and enhances the accuracy of testing.

[0057] When this pipe inner diameter testing equipment is working, the positioning function of the self-positioning support platform 1 and the centering function of the testing device are not affected by the diameter of the pipe being tested. The testing head 13 adopts a conical or frustum-shaped design, which can also be applied to pipes with different inner diameters, making this pipe inner diameter testing equipment highly applicable and with a large inner diameter measurement range.

[0058] When this pipe inner diameter testing equipment is working, the position adjustment of the testing head 13 and the inner diameter measurement process can be automatically completed based on the control system and preset program, saving time and effort, and being highly efficient and fast.

[0059] In a specific embodiment of this pipe inner diameter detection equipment, both the drive device 7 and the feed device 4 are linear drive mechanisms, and can be devices such as hydraulic cylinders, air cylinders, electric push rods, and linear motors.

[0060] like Figure 2 , Figure 3 As shown, in a specific embodiment of this pipe inner diameter testing equipment, in order to optimize the structural layout, the two drive devices 7 are installed and fixed on the machine body 8. The drive device 7 that provides drive for the upper beam frame 6 is located on the upper side of the upper beam frame 6, and the drive device 7 that provides drive for the lower beam frame 3 is located on the lower side of the lower beam frame 3.

[0061] like Figure 4 , Figure 5 As shown, in a preferred embodiment of this pipe inner diameter detection device, two laser emitting units 17 are fixed inside the detection head 13, and the two laser emitting units 17 emit parallel beams in opposite directions; correspondingly, two light-transmitting slots 14 and two receiving units 12 are provided, distributed on opposite sides of the detection head 13. Thus, based on the cooperation of the two laser emitting units 17 and the two receiving units 12, the control system can measure the inner diameter values ​​from opposite sides of the pipe being inspected, and can eliminate measurement errors by taking the average value, thereby further improving the accuracy of inner diameter measurement. Furthermore, based on the above working characteristics, the control system can compare the two inner diameter values ​​to determine whether the end face of the pipe being inspected meets the requirements, making the functions of this pipe inner diameter detection device more comprehensive and significantly improving its cost-effectiveness. Specifically, a deviation threshold can be set according to actual processing requirements. If the deviation between the two inner diameter data is not greater than the threshold, it indicates that the end face is relatively neat and meets the requirements; if the deviation between the two inner diameter data is greater than the threshold, it indicates that the end face of the pipe being inspected is severely tilted and does not meet the product processing requirements.

[0062] See Figure 2 , Figure 3 , Figure 7 , Figure 8As shown, in a preferred embodiment of the pipe inner diameter testing equipment, the equipment further includes a positioning mechanism. This positioning mechanism includes a lifting device 16 and a limiting plate 15. The limiting plate 15 is driven by the lifting device 16 and can move up and down. The control system can control the operating state of the lifting device 16 to adjust the height of the limiting plate 15. When the limiting plate 15 is in the raised state, it can position the axial position of the pipe being tested, reducing the difficulty of placing the pipe and ensuring the effective cooperation between the pipe and the testing device. Specifically, after the pipe being tested is placed on the self-positioning support platform 1 and its end abuts against the limiting plate 15, the axial position of the pipe being tested meets the testing requirements. When the limiting plate 15 is in the lowered state, it does not obstruct the testing operation.

[0063] See Figure 2 , Figure 3 , Figure 7 As shown, in a specific embodiment of this pipe inner diameter detection device, the front end of the probe arm 9 is provided with a bent portion 10 that bends toward the direction of the other probe arm 9, and the contact sensor 11 is installed and fixed on the opposite ends of the two bent portions 10 to facilitate contact and cooperation between the contact sensor 11 and the pipe being inspected.

[0064] When this pipe inner diameter testing equipment measures the inner diameter, the testing head 13 needs to be inserted into the end of the pipe being tested, and the two need to be in close contact. In order to achieve the above-mentioned fitting requirements more automatically and accurately, this invention provides two specific technical approaches:

[0065] Firstly, during the process of the feeding device 4 driving the detection head 13 to move forward, when the detection head 13 comes into close contact with the end of the pipe being inspected, the workload of the feeding device 4 will increase sharply. Therefore, a load sensor (not shown) can be installed inside the feeding device 4. The load sensor monitors the workload of the feeding device 4 and feeds the signal back to the control system. When the feeding device 4 drives the detection head 13 to move forward, when the workload of the feeding device 4 increases sharply, the control system stops the feeding device 4, thereby enabling the detection head 13 and the pipe being inspected to meet the above-mentioned matching requirements.

[0066] Secondly, such as Figure 14As shown, the detection head 13 has a plug-in portion 24 on its rear side, and the drive device 7 has a telescopic portion 23 on its front side that can move back and forth. The telescopic portion 23 and the plug-in portion 24 are plugged into each other, and the telescopic portion 23 and the plug-in portion 24 can move relative to each other in the front and back direction but will not disengage. A thrust spring 22 is provided between the telescopic portion 23 and the plug-in portion 24 to drive them away from each other. During the process of the feed device 4 driving the detection head 13 to move forward, when the receiving state of the receiving unit 12 for the parallel light beam no longer changes, it indicates that the detection head 13 has made close contact with the end of the inspected pipe, making it impossible for the detection head 13 to continue moving forward. At this time, the feedback signal of the receiving unit 12 no longer changes, and the control system stops the feed device 4. In the above process, the force applied by the drive device 7 to the detection head 13 is buffered by the thrust spring 22, which can avoid the detection head 13 applying too much force to the inspected pipe and causing deformation of the end of the inspected pipe, so as to ensure detection accuracy.

[0067] like Figure 9 As shown, during the inner diameter measurement process of this pipe inner diameter detection equipment, the control system adjusts the vertical positions of the upper beam 6 and lower beam 3 so that the two contact sensors 11 contact the upper and lower sides of the pipe being inspected, respectively. Since the central axes of the two contact sensors 11 and the pipe being inspected are all located in the detection plane 18, the vertical distance between the two contact sensors 11 is essentially the outer diameter of the pipe being inspected. Based on the above characteristics, a relatively economical method can be used to achieve the outer diameter measurement function. Specifically:

[0068] The upper beam 6 is provided with a first measuring point 21, and the lower beam 3 is provided with a second measuring point 19. The first measuring point 21 is located directly above the second measuring point 19. A laser ranging element 20 for measuring the vertical distance between the first measuring point 21 and the second measuring point 19 is installed and fixed on the upper beam 6 or the lower beam 3. The laser ranging element 20 can feed the signal back to the control system. Since the relative position of the first measuring point 21 and the corresponding contact sensor 11 is fixed, and the relative position of the second measuring point 19 and the corresponding contact sensor 11 is also fixed, when the two contact sensors 11 are in contact with the upper and lower sides of the pipe under test, respectively, the control system can calculate the vertical distance between the two contact sensors 11 by adding or subtracting a constant based on the distance between the first measuring point 21 and the second measuring point 19. This vertical distance is the outer diameter value of the pipe under test.

Claims

1. A pipe inner diameter detection device based on laser measurement technology, comprising a self-positioning support platform and a detection device; characterized in that: The self-positioning support platform ensures that the central axis of the inspected pipe is horizontal and located in the vertical detection plane. The detection device includes a feeding device controlled by a control system, a detection head, and two driving devices. The detection head is conical or frustum-shaped, with a pointed front end facing one end of the inspected pipe. The detection head is driven by the feeding device and can move back and forth. A laser emitting unit for emitting a parallel beam is fixed inside the detection head, and a light-transmitting groove is provided on the side wall. A receiving unit is fixed externally. An upper beam frame is provided on the upper side of the feeding device, and the two are connected by two connecting rods to form a parallel four-bar linkage mechanism. A lower beam is provided on the lower side of the device, and the two are connected by two linkages to form another parallel four-bar linkage mechanism. The two parallel four-bar linkage mechanisms are symmetrical about the central axis of the detection head. The upper beam and the lower beam are driven by two drive devices and can move up and down. The upper beam and the lower beam are respectively equipped with contact sensors through forward-extending probe arms. When the two contact sensors contact the upper and lower sides of the pipe being inspected, the detection head coincides with the central axis of the pipe being inspected. During detection, the detection head is inserted into the end of the pipe being inspected and makes close contact. The control system calculates the inner diameter value based on the signal fed back by the receiving unit.

2. The pipe inner diameter testing equipment according to claim 1, characterized in that: During the up-and-down movement of the upper and lower beams, the two parallel four-bar linkages deform symmetrically within the detection plane.

3. The pipe inner diameter testing equipment according to claim 1, characterized in that: Both the drive device and the feed device are linear drive mechanisms.

4. The pipe inner diameter testing equipment according to claim 1, characterized in that: The detection head has two fixed laser emitting units inside, which emit parallel beams in opposite directions; there are two light-transmitting slots and two receiving units, which are distributed on opposite sides of the detection head.

5. The pipe inner diameter testing equipment according to claim 4, characterized in that: The control system will compare two inner diameter values ​​obtained from two receiving units to determine whether the end face of the inspected pipe meets the requirements.

6. The pipe inner diameter testing equipment according to claim 1, characterized in that: It also includes a positioning mechanism, which includes a lifting device and a limiting plate. The limiting plate is driven by the lifting device and can move up and down. The control system can control the operating status of the lifting device.

7. The pipe inner diameter testing equipment according to claim 1, characterized in that: The feeding device is equipped with a load sensor. The load sensor monitors the working load of the feeding device and feeds the signal back to the control system. When the feeding device drives the detection head to move forward, if the working load of the feeding device increases suddenly, the control system will stop the feeding device.

8. The pipe inner diameter testing equipment according to claim 1, characterized in that: The detection head has a plug-in part on its rear side and a telescopic part that can move back and forth on its front side. The telescopic part and the plug-in part are plugged into each other and can move relative to each other in the front and back direction without disengaging. A thrust spring is provided between the telescopic part and the plug-in part to drive them away from each other. When the feedback signal from the receiving unit no longer changes during the process of the feeding device driving the detection head forward, the control system stops the feeding device.

9. The pipe inner diameter testing equipment according to claim 1, characterized in that: The upper beam is provided with a first measuring point, and the lower beam is provided with a second measuring point. The first measuring point is located directly above the second measuring point. A laser ranging element for measuring the vertical distance between the first and second measuring points is installed and fixed on the upper or lower beam. The laser ranging element can feed back the signal to the control system. The control system calculates the vertical distance between the two contact sensors based on the signal fed back by the laser ranging element. The vertical distance is the outer diameter value of the pipe being inspected.

10. A method for detecting the inner diameter of a pipe, characterized in that: The method of measuring the inner diameter of a pipe using the pipe inner diameter measuring device according to any one of claims 1-9 includes the following steps: S1: Under the control of the control system, the detection device is initialized to ensure that the two contact sensors are located on the front side of the detection head and that there is enough space between the two contact sensors to accommodate the end of the pipe being inspected. S2: Place the pipe to be inspected on the self-positioning support platform so that the end of the pipe to be inspected that is facing the inspection head is in a suspended state; S3: Under the control of the control system, the two contact sensors contact the upper and lower sides of the pipe being inspected, respectively, and the detection head moves forward so that the detection head is inserted into the end of the pipe being inspected and makes close contact. S4: The laser emitting unit and the receiving unit work together. The control system calculates the inner diameter of the pipe being inspected based on the signal or data fed back by the receiving unit.

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