CN103978310B - A kind of hardware surface fine crack restorative procedure and device - Google Patents

Abstract

The invention relates to a method and a device for repairing micro-cracks on the surface of metal structural parts, and relates to a method and a device for repairing micro-cracks on the metal surface. The repair method adopts the laser heating optical path and the observation optical path to form a coaxial optical path, uses the image acquisition device and the distance sensor to detect the crack, uses the temperature sensor to monitor the temperature of the crack repair area in real time, and uses the laser to heat and repair the crack. The overall appearance of the repairing device adopts a gun-shaped structure, including three parts: the gun body, the detection system and the powder feeding device. The device integrates crack location, repairing laser beam and powder feeding. The device is small in size and light, and is not limited by the shape and position of cracks when used, and the repair process has little damage to the base material. The repair method can quickly and accurately determine the location of tiny cracks and repair them, and is especially suitable for in-situ repair of tiny and irregular cracks in special positions that cannot be implemented by conventional laser repair methods due to the limitation of the spatial position of the defect.

Description

A method and device for repairing micro-cracks on the surface of metal structural parts

technical field

The invention belongs to the technical field of defect repairing of metal structural parts, and relates to a method and a device for repairing tiny cracks on metal surfaces.

Background technique

Metal structural parts inevitably produce various microscopic cracks in the process of manufacturing and service, such as welding cracks, heat treatment cracks, grinding cracks, electrical machining cracks, electric spark cracks, metal fatigue cracks, laser cladding cracks, etc., with the service time The increase of microscopic cracks will continue to expand, resulting in the failure of mechanical parts, and even sudden catastrophic accidents, causing huge losses to the country and people's property. Since the early expansion of microscopic cracks mostly occurs in a local area, the early repair of local micro cracks in metal structural parts that have not yet reached the design life, especially the parts of major mechanical equipment, is particularly important for saving resources and prolonging the life of equipment.

At present, the crack repair methods of metal structural parts mainly include conventional welding technology, laser filler welding and laser cladding technology based on laser technology. Adopt conventional welding technique to use welding torch more, as application number is " portable welding torch " of CN90222738 and application number is " double mouth portable welding torch " of CN89203471, carries out the manual repair welding of crack defect position. Since the repair process requires the operator to judge the location, timing, repair time and parameters based on experience, the repair quality is difficult to control. Using laser filler welding and laser cladding technology based on laser technology, such as Wang Dingjiang et al. "A new process for repairing cracks in aero-engine turbine blades based on laser cladding technology", New Technology and New Technology, 2010, (8): 72-74. Although the repair quality is fully guaranteed, the existing laser welding and laser cladding equipment is bulky, requires complex numerical control systems and drive components, and the equipment costs are high; and laser welding and laser cladding equipment are usually aimed at one or a type of workpiece Repairing according to a specific programming path has poor versatility, limited repair locations, inability to repair irregular cracks on site, and poor repair quality.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior art and to invent a method and device for repairing micro-cracks on the surface of metal structural parts. The device integrates crack positioning, repairing laser beams and powder delivery, and can quickly and accurately determine the position of micro-cracks It is especially suitable for the in-situ repair of small and irregular cracks in special positions that cannot be implemented by conventional laser repair methods due to the limitation of the spatial position of the defect.

The technical solution adopted in the present invention is a method and device for repairing tiny cracks on the surface of metal structural parts. The repair method uses a laser heating optical path and an observation optical path to form a coaxial optical path, and uses an image acquisition device and a distance sensor to detect cracks. Monitor the temperature of the crack repair area, use lasers to heat and repair cracks. The repair method is divided into two steps: detection and repair. The detection step is: the image acquisition device is composed of a CCD industrial camera and a coaxial optical circuit, and the image signal is collected and amplified to determine The position of tiny cracks on the surface of metal structural parts; the distance from the nozzle of the crack repair device to the crack is detected by the distance sensor. When the distance is within the set focal length range of the laser lens, the laser is turned on to heat the crack area to be repaired; the temperature sensor detects the crack in real time Monitor the temperature of the crack repair area until the laser heating temperature reaches the softening point of the material; the repair steps are: when the temperature of the laser heating crack repair area reaches the material softening point, turn on the air compressor, and use a certain high-pressure gas to pump the metal in the powder storage tank The powder is transported to the crack repair area, and the flow meter controls the amount of metal powder delivery; at the end of the repair process, the pneumatic piston is used to drive the ejector rod to hit and compact the material sprayed on the repair area to ensure that the material added to the crack is consistent with the repaired part The base metal is fully combined to improve the repair reliability and repair quality.

Using the above technology to repair cracks, the overall shape of the repair device used is a gun-shaped structure, including three parts: the gun body, the detection system and the powder feeding device: in the gun body, one end of the laser focusing module 10 is connected to the laser input end 11 , and the other end is connected with the second L-shaped connector 9; from the laser focus module 10, a first laser focus fixing ring 26, a collimating mirror 27, a second laser focus fixing ring 28 are installed sequentially from left to right, Focusing mirror 29, the third laser focus fixing ring 30; a dichroic mirror 8 is installed between the second connector 9 of the L shape and the first connector 5 of the L shape, and the angle between it and the laser optical axis OO' is 45°; the left end of the nozzle 1 is installed on the first connector 5 through the positioning boss; the upper connector plate 7 is installed above the first connector 5 and the second connector 9, and the upper connector plate 7 is installed with Cylinder bracket 6 and cylinder 4; Connector lower connecting plate 24 is installed below the first connector 5 and the second connector 9, and handle 22 is connected on the gun body by screw 23; Have nozzle opening a, nozzle 1 on the nozzle 1 Ejector channel c, temperature sensor channel e, and powder feeding channel b and d, and the above-mentioned channels intersect at the same point on the optical axis; the right main shell 40 and the left main shell 41 are installed outside the overall structure after the above assembly, and the front cover 2 and the rear cover 12 are respectively mounted on the front and rear ends of the right main housing 40 and the left main housing 41; the laser heating optical path consists of a laser input terminal 11, a laser focusing module 10, a dichroic mirror 8 and a nozzle 1;

In the detection system, the observation optical path is composed of nozzle 1, dichroic mirror 8, reflection channel 38, reflector 21, CCD magnifying lens group 32 and CCD industrial camera 31, and the observation optical path and laser heating optical path constitute a coaxial optical path; the distance sensor 25 is installed Below the nozzle 1; the temperature sensor 39 is installed on the right side of the nozzle 1 through the temperature sensor channel e of the nozzle 1; one end of the reflection channel 38 is installed on the left side of the first connector 5, and the other end is connected with the upper reflector box 19 and the lower reflector The mirror box 20 is connected, and the mirror 21 is installed between the upper mirror box 19 and the lower mirror box 20, and the included angle with the laser optical axis OO' is 45°; one end of the CCD magnifying lens group 32 is connected to the upper mirror box through a positioning groove. The reflector box 19 is connected with the lower reflector box 20, and the other end of the CCD magnifying lens group 32 is connected with the CCD industrial camera 31 by threads; the first camera magnifying lens fixing ring is installed successively from right to left in the CCD magnifying lens group 32 37, the first camera magnifying lens 36, the second camera magnifying lens fixing ring 35, the second camera magnifying lens 34, the third camera magnifying lens fixing ring 33; the large L-shaped side shell 17 and the side shell 18 are installed up and down on The outside of CCD industrial camera 31, CCD magnifying lens group 32, upper reflector box 19, lower reflector box 20 and reflection passage 38, and are connected together by screw;

In the powder feeding device, the two ends of the powder storage tank 14 located on both sides of the laser focusing module 10 are respectively connected with an air supply pipe 13 and a flow meter 15; one end of the powder feeding pipe 16 is connected to the flow meter 15, and the other end passes through the nozzle 1 The powder feeding channels b and d are used to feed powder; the powder storage tank is designed in the repair device, which reduces the loss of metal powder along the way and avoids the waste of metal powder.

Nozzle 1 is made of silicon nitride material, and the whole nozzle is designed as a whole. There are ejector channel c, temperature sensor channel e, powder feeding channel b and d on it, and the above channels intersect at the same point on the optical axis; ejector rod 3 passes through The ejector channel c is used for guidance and support, and can accurately strike the repaired part to ensure that the metal powder is fully combined with the base material of the part at the crack repaired site, improving the reliability of the repair; the laser input terminal 11, the laser focusing module 10, the dichroic mirror 8 and the The laser heating optical path composed of nozzle 1 and the crack observation optical path composed of nozzle 1, dichroic mirror 8, reflection channel 38, mirror 21, CCD magnifying lens group 32 and CCD industrial camera 31 form a coaxial optical path.

The beneficial effects of the present invention are: the overall appearance of the device adopts a gun-shaped structure, which has flexibility and portability; adopts a coaxial optical amplification system based on a CCD industrial camera, can quickly and accurately determine the position of a tiny crack; adopts a temperature sensor, a distance sensor and The flowmeter measures parameters such as the temperature of the crack repair center, the distance from the workpiece to the nozzle, and the amount of metal powder delivered during the crack repair process in real time, and establishes communication between the sensor and the computer to facilitate the control of repair quality; the powder storage tank is designed in the repair device, Reduce the loss of metal powder along the way; at the end of the repair process, the pneumatic piston is used to drive the ejector rod to compact the material sprayed on the repaired area, which can ensure that the material added to the crack is fully combined with the base material of the repaired part, improving the repair reliability and Repair quality. The repair device is small in size and light, and is not limited by the shape and position of cracks when used. The repair process has little damage to the base material, and can achieve rapid, equal-strength and in-situ repair of cracks. The repair process is economical and environmentally friendly. It has broad application prospects and economic value for repairing cracks on the surface of metal structural parts and prolonging their life.

Description of drawings

Fig. 1 is a three-dimensional view of the overall structure of the present invention.

Fig. 2 is an A-A view of the overall structure of the present invention.

Figure 3 is an end view of the nozzle in the H direction.

Fig. 4 is a B-B view of the overall structure of the present invention.

In the figure: 1. Nozzle, 2. Front cover, 3. Ejector rod, 4. Cylinder, 5. First connector, 6. Cylinder bracket, 7. Connector upper connecting plate, 8. Dichroic mirror, 9. Second Connector, 10. Laser focusing module, 11. Laser input end, 12. Rear cover, 13. Air supply pipe, 14. Powder storage tank, 15. Flow meter, 16. Powder supply pipe, 17. On the side shell, 18. Under the side shell, 19. Upper reflector box, 20. Lower reflector box, 21. Reflector, 22. Handle, 23. Screw, 24. Connector lower connecting plate, 25. Distance sensor, 26. First laser focus Fixed ring, 27. Collimating mirror, 28. The second laser focus fixed ring, 29. Focus mirror, 30. The third laser focus fixed ring, 31. CCD industrial camera, 32. CCD magnifying lens group, 33. The third camera magnifying lens fixing ring, 34. second camera magnifying lens fixing ring, 35. second camera magnifying lens fixing ring, 36. first camera magnifying lens fixing ring, 37. first camera magnifying lens fixing ring, 38. reflection channel, 39. temperature sensor , 40. right main shell, 41. left main shell.

Detailed ways

The specific implementation of the present invention will be described in detail below in conjunction with the accompanying drawings and technical solutions.

The working process of the whole device is as follows: firstly, the operator holds the device vertically to the repaired surface, moves the device to find the crack position by observing the image displayed on the computer screen; When the distance is within the focal length range set by the laser lens, start the laser, and the laser beam is projected onto the surface of the workpiece through the laser focusing module 10 and the dichroic mirror 8 to heat the crack repair; at the same time, the temperature sensor 39 is used to monitor the temperature of the crack repair center in real time, when the temperature When the softening point of the material is reached, start the air compressor to deliver the metal powder to the crack repair, and use the flowmeter 15 to measure the amount of powder delivered to the preset value; Hit the crack repair part to ensure that the added material at the crack is fully combined with the base material of the part to ensure the quality of the repair.

As shown in FIG. 1 , the laser input end 11 of the repairing device is connected to a continuous laser through an optical fiber. As shown in Figures 2 and 4, the central axis OO' of the crack repair device is the path of the laser used for repair; , the dichroic mirror 8, the reflection channel 38, the reflection mirror 21, the CCD magnifying lens group 32 and the CCD industrial camera 31 form the crack observation optical path to form a coaxial optical path. The laser beam is focused on one point by the laser focusing module 10, and is emitted through the nozzle opening a on the nozzle 1, and then irradiates the crack on the surface of the workpiece to be repaired, and heats the crack area to be repaired; the dichroic mirror 8 has the special performance of allowing light of a specific wavelength to pass through , that is, the laser beam is allowed to pass through and still propagate along the original route; the reflected light at the crack enters through the nozzle opening a on the nozzle 1 and then changes direction through the 45° dichroic mirror 8 to enter the reflection channel 38 on the left, and then passes through 45° The mirror 21 enters the CCD magnifying lens group 32 and the CCD industrial camera 31 at the rear, and the collected images will be sent to the computer for processing, and the operator can observe the crack location and related information. When working, the operator holds the device vertically, and by observing the movement of the image displayed on the display screen, the location of the crack can be found and repaired.

As shown in Figures 3 and 4, during the laser heating process on the crack surface, the temperature sensor 39 installed in the temperature sensor channel e of the nozzle 1 is used to monitor the temperature of the crack repair center in real time, and when the temperature reaches the softening point of the material, the air compression is started machine, conveying metal powder to the crack repairing place, and measuring the amount of powder feeding to a preset value with a flow meter 15; The channel c pops up, and the crack repair part is hit with a certain force to ensure that the added material at the crack is fully combined with the base material of the part, thereby ensuring the repair quality.

The tiny crack repairing device includes a set of powder feeding device, as shown in Figures 1 and 3, the powder storage tank 14 located on both sides of the laser focusing module 10 is filled with the same metal powder as the material of the cracked part. When feeding powder, the high-speed output airflow of the air compressor takes the quantitative powder in the powder storage tank 14 out of the tank through the air supply pipe 13, and the mixed gas of metal powder and gas enters the powder supply pipe 16 through the flow meter 15, and is passed through the powder supply pipe 16. Through the powder feeding channels b and d of the nozzle 1, the powder is sent to the focus of the laser beam. The powder storage tank is designed in the repair device, which can reduce the loss of metal powder along the way and avoid the waste of metal powder.

As shown in Figures 1 and 4, the first connector 5 and the second connector 9 are the key to connecting the device together, and the first connector 5 and the second connector 9 are divided into two parts along the diagonal: the first connection A dichroic mirror 8 is installed between the connector 5 and the second connector 9. Since it is not conducive to assembly and positioning after being divided into two parts along the diagonal, a square boss is respectively provided on the upper and lower surfaces of the first connector 5 and the second connector 9, and the upper connecting plate 7 and the connecting plate on the connector are designed. The lower connecting plate 24 is used to locate and fix the two bosses of the connector. One side of the upper connecting plate 7 of the connector is designed with a square pit matching the connector to position the first connector 5 and the second connector 9, and fasten the connectors by screw connection; the other side is a long strip Shaped bosses are convenient for positioning with the cylinder bracket 6; in the same way, the lower connecting plate 24 of the connector is connected with the handle 22 by screws. The sides of the first connector 5 and the second connector 9 are interfaces connected with the nozzle 1 , the reflection channel 38 and the laser focusing module 10 respectively. The interface is mainly composed of two parts, namely the annular boss for positioning and the threaded hole for fastening. The annular surface on the outside of the boss cooperates with the annular positioning surface of parts such as nozzles.

The invention integrates crack location, repairing laser beam and powder feeding, and can quickly and accurately determine the position of tiny cracks and repair them, especially suitable for small special positions in large equipment that cannot be implemented by conventional laser repair methods due to the limitation of defect space. In-situ repair of irregular cracks, and less damage to the base metal during the repair process, economical and environmentally friendly, will help to prolong the life of large equipment and save resources.

Claims (3)

1. A method for repairing micro-cracks on the surface of a metal structure, characterized in that the repair method adopts a laser heating optical path and an observation optical path to form a coaxial optical path, detects cracks with an image acquisition device and a distance sensor, and monitors the crack repair area in real time with a temperature sensor The temperature of the laser is used to heat and repair the crack; the repair method is divided into two steps of detection and repair, and the specific steps are as follows: Detection steps: (1) An image acquisition device composed of a CCD industrial camera and a coaxial optical circuit collects and amplifies image signals to determine the position of tiny cracks on the surface of metal structural parts; (2) The distance from the nozzle of the crack repair device to the crack is detected by the distance sensor. When the distance is within the set focal length range of the laser lens, the laser is turned on to heat the crack area to be repaired; (3) The temperature in the crack repair area is monitored in real time by the temperature sensor until the laser heating temperature reaches the softening point of the material; Repair steps: (1) After the temperature of the laser heating crack repair area reaches the softening point of the material, the air compressor is turned on, and the metal powder in the powder storage tank is transported to the crack repair area with a certain high-pressure gas, and the delivery amount of the metal powder is controlled by the flow meter; (2) At the end of the repair process, the pneumatic piston is used to drive the ejector rod to hit and compact the material sprayed on the repaired area to ensure that the material added to the crack is fully combined with the base material of the repaired part. 2. The method for repairing micro-cracks on the surface of a metal structure according to claim 1, wherein the overall shape of the device used in the method adopts a gun-shaped structure, including three parts: a gun body, a detection system and a powder feeding device; In the gun body, one end of the laser focusing module (10) is connected to the laser input terminal (11), and the other end is connected to the L-shaped second connector (9); From left to right, the first laser focus fixed ring (26), the collimator mirror (27), the second laser focus fixed ring (28), the focus mirror (29), and the third laser focus fixed ring (30); A dichroic mirror (8) is installed between the L-shaped second connector (9) and the L-shaped first connector (5), and the angle between it and the laser optical axis OO' is 45°; the nozzle (1) The left end of the left end is installed on the first connector (5) through the positioning boss; the upper connector plate (7) is installed above the first connector (5) and the second connector (9), and the upper connector plate ( 7) The cylinder bracket (6) and the cylinder (4) are installed on the top; the lower connecting plate (24) of the connector is installed under the first connector (5) and the second connector (9), and is connected by screws (23) The handle (22) is connected to the gun body; the nozzle (1) is provided with a nozzle opening (a), an ejector rod channel (c), a temperature sensor channel (e), a first powder feeding channel (b) and a second powder feeding channel channel (d), and the channels intersect at the same point on the optical axis; the right main housing (40) and the left main housing (41) are installed outside the overall structure after the above assembly, the front cover (2) and the rear cover (12) Installed on the front and rear ends of the right main casing (40) and the left main casing (41) respectively; the laser heating optical path is the laser input end (11), the laser focusing module (10), the dichroic mirror (8) and the nozzle (1) constitute; In the detection system, the observation light path is composed of nozzle (1), dichroic mirror (8), reflection channel (38), mirror (21), CCD magnifying lens group (32) and CCD industrial camera (31). The observation light path and The laser heating optical path constitutes a coaxial optical path; the distance sensor (25) is installed under the nozzle (1); the temperature sensor (39) is installed on the right side of the nozzle (1) through the temperature sensor channel (e) of the nozzle (1); One end of the channel (38) is installed on the left side of the first connector (5), the other end is connected with the upper reflector box (19) and the lower reflector box (20), and the reflector (21) is installed in the upper reflector box (19 ) and the lower mirror box (20), the angle with the laser optical axis is 45°; one end of the CCD magnifying lens group (32) is connected with the upper mirror box (19) and the lower mirror box ( 20) connection, the other end of the CCD magnifying lens group (32) is connected to the CCD industrial camera (31) through threads; the first camera magnifying lens fixing ring (37) is installed in sequence from right to left in the CCD magnifying lens group (32) ), the first camera magnifying lens (36), the second camera magnifying lens fixing ring (35), the second camera magnifying lens (34), the third camera magnifying lens fixing ring (33); on the large L-shaped side shell ( 17) and the lower side shell (18) are installed up and down on the outside of the CCD industrial camera (31), the CCD magnifying lens group (32), the upper mirror box (19), the lower mirror box (20) and the reflection channel (38) , and connected together by screws; In the powder feeding device, the two ends of the powder storage tank (14) located on both sides of the laser focusing module (10) are respectively connected with an air supply pipe (13) and a flow meter (15); The meter (15) is connected, and the other end passes through the first powder feeding channel (b) and the second powder feeding channel (d) in the nozzle (1) to feed powder. 3. A method for repairing micro-cracks on the surface of metal structural parts according to claim 1, characterized in that, in the device used in the method, the nozzle (1) is made of silicon nitride material, and the whole nozzle is made as a whole, and the nozzle ( 1) There are ejector channel (c), temperature sensor channel (e), first powder feeding channel (b) and second powder feeding channel (d) on the top, and the above channels intersect at the same point on the optical axis.