A metal tube online metallographic detection method

Abstract

The present invention provides an online metallographic inspection method for metal pipes, including an online metallographic inspection device for metal pipes. The online metallographic inspection device for metal pipes includes: an industrial robot; a pipe fixing device for fixing the metal pipe within the working radius of the industrial robot; a track device positioned parallel to the axis of the metal pipe fixed by the pipe fixing device and capable of reciprocating movement, the industrial robot being fixedly connected to the track device and moving with the track device; and a detection device, which is the end effector of the industrial robot and is configured to polish the outer wall of the metal pipe. The present invention has a simple structure and reliable operation, and can utilize the deadweight of DN1000-3000 cast pipes to perform online metallographic inspection by the industrial robot; the track device enables the actuator installed at the end of the industrial robot to complete inspection at any position along the axis of the metal pipe; and the industrial robot utilizes the joint rotation function and the double-headed electric spindle to quickly cut rings for rough grinding and polishing.

Description

Technical Field

[0001] The invention belongs to the technical field of metal pipe processing and relates to a metallographic detection device, in particular to an online outer wall metallographic detection device for medium and large-sized metal pipes. Background Art

[0002] Metallographic testing and analysis is one of the important means of testing and researching metal materials. It adopts the principle of quantitative metallography and determines the three-dimensional spatial morphology of the alloy structure by measuring and calculating the metallographic microstructure of the ground surface of two-dimensional metallographic specimens or thin films, thereby establishing a quantitative relationship between alloy composition, structure and performance. The usual testing process includes body sampling - test block mounting - rough grinding - fine grinding - polishing - corrosion - observation.

[0003] Metal pipes, particularly ductile iron pipes, also require metallographic testing and analysis during production. Currently, metallographic testing of the surface of large-scale hot-molded cast iron pipes is performed entirely manually, with workers using handheld angle grinders to manually grind and inspect the metallographic inspection points on the pipe surface. The hot-molded cast pipe production process requires that each large-scale pipe be subjected to metallographic testing at five or more points evenly distributed along the axial direction. This process must be repeated for each point.

[0004] The inventors found in their research on the prior art that:

[0005] Manual inspection greatly increases the workload of personnel. More importantly, due to equipment limitations, portable microscopes can only observe metallographic structures in real time, and cannot retain microscopic photos of metallographic inspection, making it impossible to preserve cast pipe quality information and conduct quality re-inspections of cast pipes. Summary of the Invention

[0006] In order to overcome the defects in the prior art, reduce the labor utilization rate and improve labor productivity, the present invention uses industrial robots and specific tooling and methods to realize online metallographic detection of metal pipes.

[0007] The technical solution adopted by the present invention is: an online metallographic detection method for metal pipes, including an online metallographic detection device for metal pipes, the online metallographic detection device for metal pipes comprising:

[0008] Industrial robots, with four or more degrees of freedom;

[0009] A pipe fixing device, fixing the metal pipe within the working radius of the industrial robot;

[0010] a track device, positioned parallel to the axial direction of the metal pipe fixed by the pipe fixing device, and the industrial robot is fixedly connected to the track device;

[0011] A detection device, which is the end effector of the industrial robot, grinds the outer wall of the metal tube and detects the metallographic structure of the ground portion of the metal tube;

[0012] A control system for controlling the movements of the industrial robot, track device, and detection device, and transmitting and storing detection data;

[0013] The track device comprises:

[0014] A slide track, which is parallel to the axial direction of the metal tube fixed by the tube fixing device, and the slide track is fixed to one of the ground, the vertical wall, the top wall or the frame;

[0015] A movable slide is slidably connected to the slide track and reciprocates along the slide track;

[0016] A slide drive device, fixed to the movable slide, providing driving force for the movable slide;

[0017] The industrial robot is fixed on the movable slide.

[0018] The detection device comprises:

[0019] A connecting portion, fixedly connected to the end of the industrial robot;

[0020] The support portion is a hollow shell with one side or more being open, and the outer side is fixedly connected to the connecting portion;

[0021] a floating cylinder fixed inside the support portion, with a telescopic end protruding from the open side of the support portion;

[0022] The double-headed electric spindle has a housing fixedly connected to the telescopic end of the floating cylinder, and the accessories at both ends of the double-headed electric spindle are polishing parts;

[0023] The grinding parts of the accessories at both ends of the double-headed electric spindle are a first grinding part and a second grinding part, the first grinding part is a grinding wheel; the second grinding part is a soft-bristled polishing wheel;

[0024] A metallographic detection component is fixed on the support portion and detects the metallographic structure of the outer wall of the polished metal tube;

[0025] A spraying assembly is fixed to the outside of the support portion and sprays liquid required for polishing or metallographic testing onto the polished portion of the metal pipe;

[0026] The metallographic detection component includes:

[0027] A microscope fixing frame, fixed to the outside of the support portion;

[0028] A microscope telescopic shaft, one end of which is fixed to the microscope fixing frame and the other end of which is telescopic;

[0029] A metallographic microscope is fixed to the telescopic end of the telescopic shaft of the microscope, and the direction of the lens is consistent with the axial direction of the telescopic shaft of the microscope;

[0030] The axial extension direction of the telescopic axis of the microscope is perpendicular to the main axis of the double-headed electric spindle;

[0031] The nominal diameter of the metal pipe is DN1000 to DN3000;

[0032] And a detection method using the metal tube online metallographic detection device, the detection method comprising the following steps:

[0033] The control system sends specification information of the metal pipe to be polished to the industrial robot;

[0034] The industrial robot approaches the outer surface of the metal pipe according to the specification information of the metal pipe;

[0035] The industrial robot controls the first grinding piece to gradually approach the outer surface of the metal pipe and complete the first grinding;

[0036] The industrial robot gradually moves away from the outer surface of the metal pipe;

[0037] The wrist axis of the industrial robot rotates to rotate the double-headed electric spindle 180°;

[0038] The industrial robot controls the second polishing member to gradually approach the outer surface of the metal pipe;

[0039] The spraying assembly sprays abrasive liquid onto the outer surface of the metal tube after being polished by the first polishing member before the second polishing member touches the outer surface of the metal tube;

[0040] The industrial robot controls the second grinding piece to gradually approach the outer surface of the metal pipe and complete the second grinding;

[0041] The spraying assembly sprays the corrosive liquid onto the outer surface of the metal pipe after being polished by the second polishing member;

[0042] The wrist axis of the industrial robot rotates 90 degrees so that the distance between the lens of the metallographic microscope and the outer surface of the metal tube after being polished by the second polishing member is 15 mm to 25 mm;

[0043] The metallographic microscope transmits metallographic images to the control system for analysis.

[0044] Furthermore, the first grinding piece is a diamond grinding wheel with a mesh size of 250 to 350, and the second grinding piece is a wool polishing wheel.

[0045] Furthermore, the spraying assembly includes:

[0046] A magnetic base, fixed to the outside of the support portion;

[0047] A universal nozzle, fixedly connected to the magnetic base, with the nozzle end facing the grinding position of the metal pipe;

[0048] A storage box, mounted on the industrial robot or fixedly mounted on a track device and moving with the industrial robot;

[0049] A delivery pipeline connects the storage tank and the universal nozzle.

[0050] Furthermore, the spraying components are divided into two groups, one group sprays the grinding liquid with a mesh size of 8000 or above required for polishing, and the other group sprays the chemical etching liquid required for metallographic detection.

[0051] Furthermore, the industrial robot controls the second grinding piece to gradually approach the outer surface of the metal tube in a state of bevel tangency.

[0052] Furthermore, the spraying assembly sprays the grinding fluid synchronously when the second grinding member touches the outer surface of the metal tube.

[0053] Furthermore, the method further comprises the following steps:

[0054] When the metallographic conclusion after the control system analysis does not meet the detection requirements, the first grinding and the second grinding are repeated in sequence.

[0055] Compared with the prior art, the present invention has the following beneficial effects: the present invention has a simple structure and reliable operation, and can utilize the deadweight of DN1000-3000 specification cast pipes to enable an industrial robot to complete online metallographic inspection work; the track device enables the actuator installed at the end of the industrial robot to complete inspection at any position along the axial direction of the metal pipe; the industrial robot joint rotation function and the double-head electric spindle are used in combination to quickly cut the ring, rough grind and polish; the metallographic microscope is perpendicular to the main axis of the double-head electric spindle, so that the metallographic inspection and polishing are integrated in the tooling position, and the inspection and polishing functions do not interfere with each other and are efficiently converted; the information obtained by the metallographic microscope can be directly saved and used for quality traceability. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a top view of the online metallographic detection device for metal pipes of the present invention;

[0057] Figure 2 This is a side view of the online metallographic detection device for metal pipes of the present invention;

[0058] Figure 3 This is a front view of the industrial robot and track device of the present invention;

[0059] Figure 4This is a front view of the detection device of the present invention;

[0060] Figure 5 It is a side view of the detection device of the present invention;

[0061] Figure 6 A top view of the metallographic detection assembly of the present invention;

[0062] Among them, 100-industrial robot; 200-track device; 210-movable slide; 220-slide drive device; 230-slide track; 300-fixed pipe device; 400-detection device; 410-connecting part; 420-floating cylinder; 430-double-head electric spindle; 431-first polishing part; 432-second polishing part; 440-support part; 450-metallographic detection component; 451-metallographic microscope; 452-microscope telescopic axis; 453-microscope fixing frame; 460-spraying component; 461-magnetic base; 462-universal nozzle; 463-delivery pipeline; 464-storage box; 500-metal pipe. DETAILED DESCRIPTION

[0063] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0064] Please see the attached Figure 1 To the attached Figure 6 An online metallographic inspection device for metal pipes includes an industrial robot 100 having four or more degrees of freedom. ISO 8373 defines industrial robots as "robots possessing automatic control, reprogrammability, and multi-purpose capabilities. The robot manipulator has three or more programmable axes (degrees of freedom of the robot mechanism, referred to as DOF). In industrial automation applications, the robot base can be either fixed or movable." Three-axis, four-axis, five-axis dual-arm, and six-axis industrial robots are currently the most commonly used. The number of axes depends on the specific application. The wrist of the industrial robot 100 of the present invention needs to be able to control the rotation of the end effector, and a six-axis industrial robot is optimal.

[0065] The system also includes: a pipe-fixing device 300, which fixes the metal pipe 500 within the working radius of the industrial robot 100. The pipe-fixing device 300 can be a conveyor chain with accessories, a V-shaped bracket, a roller, etc., to fix the relative position of the metal pipe 100. A track device 200 is positioned parallel to the axis of the metal pipe 500 fixed by the pipe-fixing device 300, and the industrial robot 100 is fixedly connected to the track device 200; a detection device 400, which is the end effector of the industrial robot 100 and polishes the outer wall of the metal pipe 500 and detects the metallographic structure of the polished area of ​​the metal pipe 500; and a control system, which controls the movement of the industrial robot 100, the track device 200, and the detection device 400, and transmits and stores detection data. The control system controls the movement of the industrial robot 100, the reciprocating motion of the track device 200, the start and stop of the detection device 400, and the transmission of detection images.

[0066] In this embodiment, the track device 200 includes: a slide track 230, a track axially parallel to the metal pipe 500 fixed by the fixed pipe device 300, and the slide track 230 is fixed to one of the ground, the vertical wall, the top wall or the frame; a mobile slide 210, which is slidably connected to the slide track 230 and reciprocates along the slide track 230; a slide drive device 220, which is fixed on the mobile slide 210 to provide driving force for the movement of the mobile slide 210; and the industrial robot 100 is fixed on the mobile slide 210.

[0067] In this embodiment, the detection device 400 includes: a connecting part 410, which is fixedly connected to the end of the industrial robot 100; a supporting part 440, which is a hollow shell with one side or more being open, and the outer side is fixedly connected to the connecting part 410; a floating cylinder 420, which is fixed inside the supporting part 440, and the telescopic end protrudes from the open side of the supporting part 440; a double-headed electric spindle 430, the outer shell of which is fixedly connected to the telescopic end of the floating cylinder 420, and the accessories at both ends of the spindle of the double-headed electric spindle 430 are polishing parts; a metallographic detection component 450, which is fixed on the supporting part 440, and detects the metallographic structure of the outer wall of the metal pipe 500 after polishing; a spraying component 460, which is fixed on the outer side of the supporting part 440, and sprays the liquid required for polishing or metallographic detection onto the polished part of the metal pipe 500.

[0068] In another preferred embodiment, the polishing members attached to both ends of the double-ended electric spindle 430 are a first polishing member 431 and a second polishing member 432. The first polishing member 431 is a grinding wheel, and the second polishing member 432 is a soft-bristled polishing wheel. Furthermore, the first polishing member 431 is a 250-350 mesh diamond wheel, and the second polishing member 432 is a wool polishing wheel, or alternatively, a felt wheel.

[0069] In this embodiment, the metallographic inspection assembly 450 includes: a microscope mounting frame 453, fixed to the outside of the support portion 440; a microscope telescopic shaft 452, one end of which is fixed to the microscope mounting frame 453 and the other end of which is retractable; and a metallographic microscope 451, fixed to the telescopic end of the microscope telescopic shaft 452, with the lens direction aligned with the axial direction of the microscope telescopic shaft 452. The microscope is an autofocus metallographic microscope. During execution, the industrial robot 100 positions the objective lens about 20 mm from the polished surface for metallographic microscopic observation and automatically focuses the image, taking a photo and outputting an electronic metallographic structure photograph. The metallographic photograph is transmitted to a computer via a data cable, and then metallographic analysis software is used to grade and determine the metallographic composition of the cast pipe, and a metallographic structure analysis report is output, thereby achieving complete automation of the metallographic inspection work on the surface of large-scale cast pipes.

[0070] Preferably, in another embodiment, the axial extension direction of the microscope telescopic shaft 452 is perpendicular to the main axis of the double-headed electric spindle 430. The metallographic microscope is perpendicular to the main axis of the double-headed electric spindle, so that metallographic inspection and polishing are integrated in the tooling position, and the inspection and polishing functions do not interfere with each other and are efficiently converted.

[0071] In this embodiment, the spraying assembly 460 includes: a magnetic base 461, fixed to the outside of the support part 440; a universal nozzle 462, fixedly connected to the magnetic base 461, with the nozzle end facing the polishing part of the metal pipe 500; a storage box 464, mounted on the industrial robot 100 or fixedly installed on the track device 200 and moving with the industrial robot 100; a conveying pipeline 463, connecting the storage box 464 and the universal nozzle 462.

[0072] In this embodiment, the spraying components 460 are divided into two groups, one group sprays the grinding liquid with a mesh size of 8000 or above required for polishing, and the other group sprays the chemical etching liquid required for metallographic testing.

[0073] In this embodiment, the nominal diameter of the metal pipe 500 ranges from DN1000 to DN3000. During research, the inventors discovered that the weight of metal pipes 500 larger than DN800 can provide sufficient stability for the workpiece during grinding. Of course, the present invention can also be used during online metallographic testing of metal pipes 500 with diameters between DN80 and DN600, but this requires adding circumferential restraint to the metal pipe 500.

[0074] The specific operating method of the present invention includes the following steps: (1) According to the specifications and models of the metal tube 500, the industrial robot 100 moves the detection device 400 to the vicinity of the surface of the metal tube 500 along a set trajectory. (2) The double-headed electric spindle 430 is powered on and operated. (3) The end face of the diamond grinding wheel of the detection device 400 is directly facing the surface of the metal tube 500 for rough grinding, and then the double-headed electric spindle 430 is turned 180 degrees, and a wool polishing wheel is vertically pressed on the rough-ground point for rotary polishing. Before and during polishing, it is necessary to adjust the angle between the wool polishing wheel and the polishing surface so that there is a certain angle gap between the felt wheel and the polishing surface. Then, the universal nozzle 462 sprays the polishing liquid onto the polishing surface, and then the rotary polishing operation is carried out. (4) After polishing is completed, the spraying component 460 sprays the etching liquid onto the polished surface through the control system to perform mirror etching, and then adjusts the end of the industrial robot 100 to rotate to a certain angle so that the metallographic detection component 450 is aligned with the polished and corroded mirror surface to perform microscopic observation of the metallographic structure, and transmits the metallographic microscopic electronic photograph to the computer, automatically analyzes it through the metallographic analysis software, and outputs an analysis report.

[0075] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A metal tube online metallographic detection method, characterized in that: The invention comprises an online metallographic detection device for a metal tube (500), wherein the online metallographic detection device for the metal tube (500) comprises: Industrial robot (100) having four or more degrees of freedom; A pipe fixing device (300) for fixing the metal pipe (500) within a working radius of the industrial robot (100); A track device (200) is positioned parallel to the axis of the metal pipe (500) fixed by the pipe fixing device (300), and the industrial robot (100) is fixedly connected to the track device (200); A detection device (400), which is an end effector of the industrial robot (100), grinds the outer wall of the metal tube (500) and detects the metallographic structure of the ground portion of the metal tube (500); A control system for controlling the movements of the industrial robot (100), the track device (200), and the detection device (400), and transmitting and storing detection data; The track device (200) comprises: a slide rail (230) which is parallel to the axial direction of the metal pipe (500) fixed by the pipe fixing device (300), and the slide rail (230) is fixed to one of the ground, the vertical wall, the top wall or the frame; A movable slide (210) is slidably connected to the slide rail (230) and reciprocates along the slide rail (230); A slide drive device (220) is fixed on the movable slide (210) and provides a driving force for the movement of the movable slide (210); The industrial robot (100) is fixed on the movable slide (210); The detection device (400) comprises: A connecting portion (410) fixedly connected to the end of the industrial robot (100); The support portion (440) is a hollow shell with one side or more being open, and the outer side is fixedly connected to the connecting portion (410); A floating cylinder (420) is fixed inside the support portion (440), and a telescopic end protrudes from the open side of the support portion (440); A double-headed electric spindle (430), the outer shell of which is fixedly connected to the telescopic end of the floating cylinder (420), and the accessories at both ends of the main shaft of the double-headed electric spindle (430) are grinding parts; The grinding pieces attached to both ends of the main shaft of the double-headed electric spindle (430) are a first grinding piece (431) and a second grinding piece (432), wherein the first grinding piece (431) is a grinding wheel; and the second grinding piece (432) is a soft-bristled polishing wheel; A metallographic detection component (450) is fixed on the support portion (440) and detects the metallographic structure of the outer wall of the polished metal tube (500); A spraying assembly (460) is fixed to the outside of the support portion (440) and sprays liquid required for polishing or metallographic testing onto the polished portion of the metal tube (500); The metallographic detection component (450) comprises: A microscope fixing frame (453) is fixed to the outside of the support portion (440); A microscope telescopic shaft (452), one end of which is fixed to the microscope fixing frame (453) and the other end of which is telescopic; A metallographic microscope (451) is fixed to the telescopic end of the microscope telescopic shaft (452), and the direction of the lens is consistent with the axial direction of the microscope telescopic shaft (452); The axial extension direction of the microscope telescopic shaft (452) is perpendicular to the main axis of the double-headed electric spindle (430); The metal pipe (500) has a nominal diameter of DN1000 to DN3000; And a detection method using the metal tube (500) online metallographic detection device, the detection method comprising the following steps: The control system sends specification information of the metal pipe (500) to be polished to the industrial robot (100); The industrial robot (100) approaches the outer surface of the metal pipe (500) according to the specification information of the metal pipe (500); The industrial robot (100) controls the first grinding piece (431) to gradually approach the outer surface of the metal pipe (500) and complete the first grinding; The industrial robot (100) gradually moves away from the outer surface of the metal pipe (500); The wrist axis of the industrial robot (100) rotates, causing the double-headed electric spindle (430) to rotate 180°; The industrial robot (100) controls the second polishing member (432) to gradually approach the outer surface of the metal pipe (500); The spraying component (460) sprays abrasive liquid onto the outer surface of the metal tube (500) after being polished by the first polishing member (431) before the second polishing member (432) touches the outer surface of the metal tube (500); The industrial robot (100) controls the second grinding piece (432) to gradually approach the outer surface of the metal pipe (500) and complete the second grinding; The spraying component (460) sprays a corrosive liquid onto the outer surface of the metal tube (500) after being polished by the second polishing member (432); The wrist axis of the industrial robot (100) rotates 90 degrees, so that the distance between the lens of the metallographic microscope (451) and the outer surface of the metal tube (500) after being polished by the second polishing member (432) is 15 mm to 25 mm; The metallographic microscope (451) transmits the metallographic image to the control system for analysis.

2. The online metallographic detection method for metal pipes according to claim 1, characterized in that: The first grinding piece (431) is a diamond grinding wheel with a mesh size of 250 to 350, and the second grinding piece (432) is a wool polishing wheel.

3. The online metallographic detection method for metal pipes according to claim 1, characterized in that: The spraying assembly (460) includes: A magnetic base (461) is fixed to the outside of the support portion (440); A universal nozzle (462) is fixedly connected to the magnetic base (461), with the nozzle end facing the grinding position of the metal tube (500); A storage box (464) is mounted on the industrial robot (100) or fixedly mounted on a track device (200) and moves with the industrial robot (100); The delivery pipeline (463) is connected to the storage tank (464) and the universal nozzle (462).

4. The online metallographic detection method for metal pipes according to claim 3, characterized in that: The spraying components (460) are divided into two groups, one group sprays the grinding liquid with a mesh size of 8000 or above required for polishing, and the other group sprays the chemical etching liquid required for metallographic detection.

5. The online metallographic detection method for metal pipes according to claim 1, characterized in that: The industrial robot (100) controls the second grinding piece (432) to gradually approach the outer surface of the metal tube (500) in a bevel tangent state.

6. The online metallographic detection method for metal pipes according to claim 5, characterized in that: The spraying assembly (460) sprays the grinding fluid synchronously when the second grinding member (432) touches the outer surface of the metal tube (500).

7. The online metallographic detection method for metal pipes according to claim 1, characterized in that: The following steps are also included: When the metallographic conclusion after the control system analysis does not meet the detection requirements, the first grinding and the second grinding are repeated in sequence.

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