Device and method for measuring residual stress of automobile lightweight composite board

Abstract

The invention relates to the technical field of measuring devices, and provides a device and a method for measuring residual stress of materials such as automobile lightweight metal materials, non-metal materials, plates, profiled bars and composite plates. In the detection process, relative alignment operation is formed relative to materials such as automobile light-weight metal materials, non-metal materials, plates, profiled bars and composite plates, movement of the materials such as the automobile light-weight metal materials, the non-metal materials, the plates, the profiled bars and the composite plates is reduced, and the overall integrity of the automobile light-weight body structure is good; in addition, stripping detection points are formed in an electrolytic corrosion mode, introduction of milling stress in the milling machining process is reduced, the accuracy of detection data is guaranteed, moving adjustment and switching adjustment operation of an operation system is more convenient, practicability and operation convenience are good, and the device comprises a base, a crawler vehicle body and the operation system. The base is installed on a crawler vehicle body, and a middle supporting column is rotationally connected into the base.

Description

Technical Field

[0001] The present invention relates to the technical field of measuring devices, and in particular to a measuring device and method for residual stress of lightweight composite plates of automobiles, which can measure the residual stress of lightweight metal materials, non-metallic materials, plates, special-shaped materials, composite plates and other materials of automobiles. Background Art

[0002] As we all know, residual stress is the stress that exists in the object to maintain balance when there is no external factor acting on the object. Residual stress can cause warping of the object. For lightweight composite panels of automobiles, serious residual stress may even affect the overall quality of the automobile. In order to detect the residual stress in lightweight composite panels of automobiles, we propose a measuring device and method for residual stress of lightweight composite panels of automobiles.

[0003] After searching, the invention patent with Chinese patent application number CN202310186838.3 discloses a test device and test method for the internal residual stress distribution of a plate, which is roughly described as including a base with multiple mounting holes reserved, at least two support columns vertically installed on the base, and the tops of the at least two support columns form a horizontal plane for placing plate samples, side limit blocks vertically installed on the base, used to limit the horizontal position of the plate sample, and a deflection test micrometer vertically installed on the base, with the pointer vertically upward and the tip intended to contact the center point of the bottom surface of the plate sample, for testing the deflection of the sample. When in use, the sample is cut from a 60mm thick aluminum alloy plate. The sample length is 400mm and the width is 50mm. The sample is prepared by conventional solid solution-quenching. It can be considered that the residual stress is symmetrically distributed along the thickness direction. The sample is milled by half the thickness, and the number of peeling layers is determined to be 10 times. The thickness of each milling layer is 3mm, and it is measured by a micrometer.

[0004] Although the above-mentioned existing technical solution can realize the test of residual stress distribution inside the plate, the premise of its operation is that the plate needs to be cut to obtain a plate sample, which has a great impact on the integrity of the plate. In addition, after the plate is cut, structural changes and force changes will be introduced, thereby affecting the detection of the original stress condition of the plate. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the present invention provides a device and method for measuring the residual stress of lightweight composite panels of automobiles. During the detection process, relative alignment operations are formed with respect to lightweight metal materials, non-metallic materials, plates, special-shaped materials, composite panels and other materials of automobiles, thereby reducing the movement of lightweight metal materials, non-metallic materials, plates, special-shaped materials, composite panels and other materials of automobiles. The overall integrity of the lightweight body structure of the automobile is better, and the formation of the peeling detection point is achieved by electrolytic corrosion, thereby reducing the introduction of milling stress during milling processing, thereby ensuring the accuracy of the detection data, and the movement adjustment and switching adjustment operations of the operating system are more convenient, and the practicality and ease of operation are better.

[0007] (II) Technical solution

[0008] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a residual stress measuring device for automobile lightweight composite panels, comprising a base and a crawler body, and also comprising an operating system, wherein the crawler body is provided with an installation middle opening, the base is installed in the installation middle opening, a middle pillar is rotatably connected in the base, the top of the middle pillar is fixedly connected with an adjustment frame, a translation support wheel, a long support wheel and a short support wheel are installed on the adjustment frame, a storage belt is transmission-connected between the translation support wheel, the long support wheel and the short support wheel, six external racks are provided on the storage belt, the six external racks are rotatably connected with a rotating part, the bottom ends of the six rotating parts are all provided with an electric telescopic rod, the operating system comprises an ultrasonic cleaning head, a mechanical grinding head, a pickling treatment head, an electrolytic corrosion head, and a glue coating head and an X-ray stress measuring instrument, the ultrasonic cleaning head, mechanical grinding head, pickling head, electrolytic corrosion head, glue coating head and X-ray stress measuring instrument are all equipped with connecting brackets, six connecting brackets are connected with connecting balls, and six connecting brackets are all equipped with limiting structures, the six limiting structures are respectively matched with the six connecting balls, the tops of the six connecting balls are all fixedly connected with lifting rods, the six lifting rods are respectively connected with the telescopic rods of the six electric telescopic rods, the pickling head, electrolytic corrosion head and glue coating head are all equipped with feeding pipes, four storage bottles are fixedly connected in the crawler body, four feeding pumps are installed in the crawler body, the suction ends of the four feeding pumps are respectively connected with the four storage bottles, and the output ends of the four feeding pumps are respectively connected with the four feeding pipes.

[0009] Preferably, the adjusting frame includes a middle frame, a telescopic frame, an upper swing frame and a lower swing frame, the middle frame is fixedly connected to the top end of the middle pillar, the telescopic frame is slidably connected to the middle frame, and a threaded rod is rotatably connected in the telescopic frame, a threaded sleeve is threadedly connected on the threaded rod, and the threaded sleeve is fixedly connected in the middle frame, the upper swing frame and the lower swing frame are both rotatably connected to the middle frame, the upper swing frame and the lower swing frame are both connected to elastic springs, and the two elastic springs are connected to the middle frame, the translation support wheel is rotatably connected to the bottom end of the telescopic frame, the long support wheel is rotatably connected to the bottom end of the upper swing frame, and the short support wheel is rotatably connected to the bottom end of the lower swing frame.

[0010] Preferably, the middle frame is rotatably connected to two rotating blocks, the two rotating blocks are respectively fixedly connected to the two elastic springs, the upper swing frame and the lower swing frame are respectively rotatably connected to a short bracket and a long bracket, and the short bracket and the long bracket are respectively fixedly connected to the two elastic springs.

[0011] Preferably, a vertical shaft is rotatably connected inside the telescopic frame, the vertical shaft is fixedly connected to the translation support wheel, an upper hand wheel is fixedly connected to the top end of the vertical shaft, and the upper hand wheel is located above the telescopic frame.

[0012] Preferably, a clamping groove is provided on the round head at the front end of the telescopic frame, a rotating frame is rotatably connected in the clamping groove, a vertical hole for the vertical axis to pass through is provided on the rotating frame, the rotating frame is rotatably connected to a horizontal axis, the horizontal axis is transmission-connected to a torque rope, and the torque rope is transmission-connected to the threaded rod.

[0013] Preferably, a strip-shaped opening is provided on the telescopic frame, a connecting plate is fixedly connected to the threaded sleeve, the connecting plate is fixedly connected to the middle frame, and the threaded sleeve and the two connecting plates are both located in the strip-shaped opening.

[0014] Preferably, the limiting structure includes a rotating bracelet, which is rotatably connected to the connecting bracket, and a fan-shaped cavity is opened in the connecting bracket, an extrusion block is arranged in the fan-shaped cavity, the extrusion block is fixedly connected to the rotating bracelet, a gradient groove is arranged on the extrusion block, the gradient groove matches the connecting ball, a return spring is connected in the fan-shaped cavity, and the return spring is connected to the extrusion block.

[0015] Preferably, a fixed wristband is fixedly connected to the connecting bracket.

[0016] Preferably, a servo motor is installed in the crawler vehicle body, a driving gear is installed on the output shaft of the servo motor, the driving gear is meshed with a driven gear ring, and the driven gear ring is fixedly connected to the bottom end of the middle support.

[0017] A method for measuring residual stress of a lightweight composite plate of an automobile comprises the following steps:

[0018] S1. Surface treatment: The surface of the metal composite plate is polished and cleaned. The surface treatment method of the metal composite plate is to firstly perform ultrasonic cleaning on the surface of the metal composite plate through an ultrasonic cleaning head, then perform mechanical polishing on the surface of the metal composite plate through a mechanical polishing head, and then perform pickling treatment on the surface of the metal composite plate through a pickling treatment head to achieve the effect of removing rust and oil stains on the surface and high-pressure cleaning. After cleaning, the surface of the metal composite plate is dried, and the measuring position is kept as flat as possible. Finally, the surface is wiped clean with alcohol;

[0019] S2. Paste the ceramic tube cup body: select the measurement position in a distributed manner along the rolling direction and the transverse direction of the metal composite plate, and then paste a plurality of ceramic tube cup bodies with through holes at the bottom to the measurement position. The pasting position of the ceramic tube cup body is distributed along the rolling direction and the transverse direction of the metal composite plate. Glue is applied in the space between the ceramic tube cup body and the metal composite plate by a glue coating head, and the periphery of the bottom through hole of the ceramic tube cup body is tightly pasted with the metal composite plate without leaving any gap, so as to ensure that the electrolyte used in the corrosion process will not leak from the gap at the bottom of the cup, and align the through hole at the bottom of the ceramic tube cup body with the measurement point, and then wait for the glue to dry. The ceramic tube cup body is a special ceramic tube with an inner diameter of 30mm-50mm, a height of 30mm-50mm, a wall thickness of 1mm-5mm, a bottom through hole diameter of 4-12mm, and a through hole arranged at the bottom center of the ceramic tube cup body. The number of the ceramic tubes is less than or equal to 5;

[0020] S3, electrolytic corrosion: the electrolytic corrosion stripping method is selected, and the specific operation includes: the electrolytic corrosion head used in the electrolytic corrosion stripping method is composed of a voltage-stabilized power supply, positive and negative electrodes, a ceramic tube, a graphite rod and a test material, and an electrolyte of two-thirds of the depth is added to the ceramic tube cup body pasted on the metal composite plate, and the electrolyte is a saturated NaCl solution, and then one end of the graphite rod is connected to one end of the negative electrode, and the other end of the graphite rod is inserted into the electrolyte in the ceramic tube cup body, and the other end of the negative electrode is connected to the negative electrode of the voltage-stabilized power supply, and one end of the positive electrode is directly connected to the test material, and the other end is connected to the positive electrode of the voltage-stabilized power supply through a wire, and the metal composite plate at the bottom through hole of the ceramic tube cup body is locally electrolytically stripped layer by layer by using a matching power supply device;

[0021] S4. Corrosion depth measurement: Keep the corrosion current constant, change the corrosion time, measure the corrosion depth at different corrosion times, and obtain the variation law of the corrosion depth of the corroded material with the corrosion time;

[0022] S5, stress detection: measure each corrosion position, ensure that the measurement position and direction of the metal composite plate are consistent during each measurement, and then loop through steps S2-S5 until the corrosion depth reaches the required depth and the stress detection is completed. The parameters of the X-ray stress meter are as follows: the X-ray wavelength is determined according to the selected target material, the residual stress of the composite plate is measured by the tilt method, the measurement starting angle is 150°-154°, the end angle is 155°-160°, the measurement step width is 0.04°, and the test time of each step width is 0.1s-0.3s. At this time, the X-ray stress meter sets the measurement tube voltage to 10kV-25kV and the tube current to 5mA-40mA. The parameters of the above X-ray stress meter can be appropriately adjusted according to different corroded metal materials.

[0023] (III) Beneficial effects

[0024] Compared with the prior art, the present invention provides a device and method for measuring residual stress of lightweight composite panels for automobiles, which has the following beneficial effects:

[0025] 1. In the present invention, the traveling support system of the device for measuring residual stress of lightweight composite plates for automobiles is formed by the cooperation of the base, the middle pillar and the crawler body, which facilitates the relative position adjustment with respect to the metal composite plate.

[0026] 2. In the present invention, the installation space of the operating system is formed by the cooperation of the adjustment frame, the translation support wheel, the long support wheel, the short support wheel and the storage belt, and the relative displacement adjustment of different functional components in the operating system is convenient, and the subsequent use and adjustment of the actual detection operation of the metal composite plate is convenient.

[0027] 3. In the present invention, through the configuration of the operating system, the tools required for each step of the process of surface treatment, ceramic tube cup bonding, electrolytic corrosion, corrosion depth measurement and stress detection adapted to the metal composite plate are provided.

[0028] 4. In the present invention, the design of the limit structure facilitates the adjustment of the relative postures of the components in the operating system, and the auxiliary limit after adjustment makes the operation more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall three-dimensional structure of the present invention;

[0030] Figure 2 For the present invention Figure 1 A schematic diagram of the local enlarged structure at point A in the middle;

[0031] Figure 3 For the present invention Figure 1 A schematic diagram of the local enlarged structure at B in the middle;

[0032] Figure 4 For the present invention Figure 1 A schematic diagram of the local enlarged structure at C in the middle;

[0033] Figure 5 It is a schematic diagram of the three-dimensional structure of the present invention as a whole from another angle;

[0034] Figure 6 For the present invention Figure 5 A schematic diagram of the local enlarged structure at D in the middle;

[0035] Figure 7 For the present invention Figure 5 A schematic diagram of the local enlarged structure at E in the middle;

[0036] Figure 8 It is a schematic diagram of a partially cutaway three-dimensional structure of the rotating frame, the vertical hole and the horizontal axis of the present invention;

[0037] Fig. 9 It is a schematic diagram of the three-dimensional structure of the coupling frame, the threaded sleeve and the connecting plate in the present invention;

[0038] Fig.10 It is a schematic diagram of the three-dimensional structure of the connecting bracket, the connecting ball and the lifting rod of the present invention;

[0039] Fig.11 For the present invention Fig.10 A schematic diagram of the local enlarged structure at F in the middle;

[0040] Fig.12 It is a schematic diagram of the three-dimensional structure of the rotating bracelet and the extrusion block of the present invention;

[0041] Fig.13 It is a schematic diagram of the overall three-dimensional structure of the present invention when viewed from above;

[0042] Fig.14 For the present invention Fig.13 Schematic diagram of the local enlarged structure at G in the middle;

[0043] Fig.15 For the present invention Fig.13 Schematic diagram of the local enlarged structure at H in the middle.

[0044] In the figure: 1. base; 2. crawler body; 3. middle pillar; 4. translation support wheel; 5. long support wheel; 6. short support wheel; 7. storage belt; 8. external rack; 9. rotating part; 10. electric telescopic rod; 11. ultrasonic cleaning head; 12. mechanical grinding head; 13. pickling head; 14. electrolytic corrosion head; 15. glue coating head; 16. X-ray stress measuring instrument; 17. connecting rack; 18. connecting ball; 19. lifting rod; 20. feeding pipe; 21. storage bottle; 22. feeding pump; 23. middle rack; 24. telescopic rack; 25. Upper swing frame; 26, lower swing frame; 27, threaded rod; 28, threaded sleeve; 29, elastic spring; 30, rotating block; 31, short bracket; 32, long bracket; 33, vertical axis; 34, upper hand wheel; 35, clamping groove; 36, rotating frame; 37, vertical hole; 38, horizontal axis; 39, torque rope; 40, strip mouth; 41, connecting plate; 42, rotating wrist ring; 43, fan-shaped cavity; 44, extrusion block; 45, gradual groove; 46, reset spring; 47, fixed wrist ring; 48, servo motor; 49, driving gear; 50, driven gear ring. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] Example

[0047] See also Figure 1-Figure 15A measuring device for residual stress of lightweight composite plates of automobiles, comprising a base 1 and a crawler body 2, and also comprising an operating system, wherein the crawler body 2 is provided with an installation middle opening, the base 1 is installed in the installation middle opening, a middle pillar 3 is rotatably connected in the base 1, and a traveling support system of the measuring device for residual stress of lightweight composite plates of automobiles is formed through the cooperation of the base 1, the middle pillar 3 and the crawler body 2, so as to facilitate the relative position adjustment relative to the metal composite plate, an adjusting frame is fixedly connected to the top of the middle pillar 3, a translation support wheel 4, a long support wheel 5 and a short support wheel 6 are installed on the adjusting frame, a storage belt 7 is transmission-connected between the translation support wheel 4, the long support wheel 5 and the short support wheel 6, the adjusting frame comprises a middle link frame 23, a telescopic frame 24, an upper swing frame 25 and a lower swing frame 26, and a middle support frame 27 is provided on the adjusting frame. The coupling frame 23 is fixedly connected to the top of the middle pillar 3, the telescopic frame 24 is slidably connected to the middle coupling frame 23, and a threaded rod 27 is rotatably connected in the telescopic frame 24, and a threaded sleeve 28 is threadedly connected on the threaded rod 27, and the threaded sleeve 28 is fixedly connected in the middle coupling frame 23. The upper swing frame 25 and the lower swing frame 26 are both rotatably connected to the middle coupling frame 23, and the upper swing frame 25 and the lower swing frame 26 are both connected to elastic springs 29, and the two elastic springs 29 are connected to the middle coupling frame 23. The translation support wheel 4 is rotatably connected to the bottom end of the telescopic frame 24, the long support wheel 5 is rotatably connected to the bottom end of the upper swing frame 25, and the short support wheel 6 is rotatably connected to the bottom end of the lower swing frame 26. There are two rotating blocks 30 rotatably connected to the middle coupling frame 23, and the two rotating blocks 30 are respectively fixedly connected to the two elastic springs 29. The movable frame 25 and the lower swing frame 26 are rotatably connected with the short bracket 31 and the long bracket 32 ​​respectively, and the short bracket 31 and the long bracket 32 ​​are fixedly connected with the two elastic springs 29 respectively. Through the cooperation of the adjustment frame, the translation support wheel 4, the long support wheel 5, the short support wheel 6 and the storage belt 7, the installation space of the operating system is formed, and at the same time, the relative displacement adjustment of different functional components in the operating system is convenient, and the subsequent use and adjustment of the actual detection operation of the metal composite plate are convenient. The telescopic frame 24 is rotatably connected with the vertical shaft 33, and the vertical shaft 33 is fixedly connected with the translation support wheel 4. The top of the vertical shaft 33 is fixedly connected with the upper hand wheel 34, and the upper hand wheel 34 is located above the telescopic frame 24. The rotation drive of the vertical shaft 33 can be realized by rotating the upper hand wheel 34, and the rotation of the vertical shaft 33 can realize the rotation of the translation support wheel 4 Dynamic drive, and then form the motion drive of the storage belt 7, so as to form the switching adjustment of the six functional components in the operating system. A clamping groove 35 is provided on the round head at the front end of the telescopic frame 24, and a rotating frame 36 is rotatably connected in the clamping groove 35. A vertical hole 37 for the vertical axis 33 to pass through is provided on the rotating frame 36, and a horizontal axis 38 is rotatably connected to the rotating frame 36. The horizontal axis 38 is transmission-connected with a torque rope 39, and the torque rope 39 is transmission-connected with the threaded rod 27 to facilitate the rotation drive of the threaded rod 27. A strip opening 40 is provided on the telescopic frame 24, and a connecting plate 41 is fixedly connected to the threaded sleeve 28. The connecting plate 41 is fixedly connected to the middle frame 23, and the threaded sleeve 28 and the two connecting plates 41 are all located in the strip opening 40, forming a display of the specific connection structure between the threaded sleeve 28 and the middle frame 23.

[0048] It should be further explained that six external racks 8 are arranged on the storage belt 7, and the six external racks 8 are rotatably connected to the rotating parts 9, and the bottom ends of the six rotating parts 9 are installed with electric telescopic rods 10. The operating system includes an ultrasonic cleaning head 11, a mechanical grinding head 12, a pickling treatment head 13, an electrolytic corrosion head 14, a glue coating head 15 and an X-ray stress measuring instrument 16. The ultrasonic cleaning head 11, the mechanical grinding head 12, the pickling treatment head 13, the electrolytic corrosion head 14, the glue coating head 15 and the X-ray stress measuring instrument 16 are installed with connecting racks 17, and the six connecting racks 17 are connected with connecting balls 18, and the six connecting racks 17 are installed with limiting structures, and the six limiting structures are respectively connected to the six connecting balls 18. Matching, the top ends of the six connecting balls 18 are fixedly connected with lifting rods 19, and the six lifting rods 19 are respectively connected to the telescopic rods of the six electric telescopic rods 10, the pickling treatment head 13, the electrolytic corrosion head 14 and the glue coating head 15 are all equipped with a feeding pipe 20, and four storage bottles 21 are fixedly connected in the crawler body 2, and four feeding pumps 22 are installed in the crawler body 2. The suction ends of the four feeding pumps 22 are respectively connected to the four storage bottles 21, and the output ends of the four feeding pumps 22 are respectively connected to the four feeding pipes 20. Through the configuration of the operating system, the tools required for each step of the process of surface treatment, pasting ceramic tube cups, electrolytic corrosion, corrosion depth measurement and stress detection adapted to the metal composite plate are provided, and the limit joint The structure includes a rotating bracelet 42, which is rotatably connected to the connecting bracket 17, and a fan-shaped cavity 43 is opened in the connecting bracket 17, and an extrusion block 44 is arranged in the fan-shaped cavity 43, and the extrusion block 44 is fixedly connected to the rotating bracelet 42, and a gradual groove 45 is arranged on the extrusion block 44, and the gradual groove 45 matches the connecting ball 18. A return spring 46 is connected in the fan-shaped cavity 43, and the return spring 46 is connected to the extrusion block 44. Through the design of the limiting structure, the relative posture adjustment of each component in the operating system and the auxiliary limit after adjustment are convenient, and the operation convenience is better. A fixed bracelet 47 is fixedly connected to the connecting bracket 17, which is convenient for the operation hand of the connecting bracket 17. A servo motor 48 is installed in the crawler body 2. The servo motor A driving gear 49 is installed on the output shaft of the machine 48, and the driving gear 49 is meshed with a driven gear ring 50. The driven gear ring 50 is fixedly connected to the bottom end of the middle pillar 3, so that the middle pillar 3 can be electrically driven relative to the tracked body 2. At the same time, the rotation drive of the horizontal axis 38 and the vertical axis 33 can also be introduced into the motor to form corresponding electric drive and control. The tracked body 2 is equipped with a battery, and the battery provides power for the tracked body 2, the servo motor 48, the electric telescopic rod 10 and the feeding pump 22. The tracked body 2, the servo motor 48 and the electric telescopic rod 10 are equipped with a dragging teaching end, and the matching operation of the tracked body 2, the servo motor 48 and the electric telescopic rod 10 can be realized by dragging the teaching end.

[0049] The feeding pump 22, servo motor 48, electric telescopic rod 10, ultrasonic cleaning head 11, mechanical grinding head 12, pickling head 13, electrolytic corrosion head 14, glue coating head 15, X-ray stress measuring instrument 16 and drag teaching end in this embodiment are all conventional equipment purchased on the market and well known to technical personnel in this field. In the present invention, we only use them and do not improve their structure and function. For technical personnel in this field, their setting method, installation method and electrical connection method only need to be debugged and operated according to the requirements of their instruction manual, and they will not be described in detail here.

[0050] In summary, the working principle and working process of the residual stress measuring device and method for automobile lightweight composite panels are as follows: when in use, surface treatment is first performed: the surface of the metal composite panel is polished and cleaned, and the surface treatment method of the metal composite panel is to firstly perform ultrasonic cleaning on the surface of the metal composite panel through an ultrasonic cleaning head 11, and then perform mechanical polishing on the surface of the metal composite panel through a mechanical polishing head 12, and then perform pickling treatment on the surface of the metal composite panel through a pickling treatment head 13, so as to achieve the effect of removing rust, oil stains and high-pressure cleaning on the surface, and after the cleaning is completed, the metal composite panel is cleaned. The surface of the plate is dried, and the measuring position is kept as flat as possible. Finally, the surface is wiped clean with alcohol, and then the ceramic tube cup body is pasted: the measuring position is selected in a distributed manner along the rolling direction and the transverse direction of the metal composite plate, and then a plurality of ceramic tube cup bodies with through holes at the bottom are pasted to the measuring position. The pasting positions of the ceramic tube cup bodies are distributed along the rolling direction and the transverse direction of the metal composite plate. Glue is applied in the space between the ceramic tube cup body and the metal composite plate through the glue coating head 15, and the area around the bottom through hole of the ceramic tube cup body is tightly pasted to the metal composite plate without leaving any gaps to ensure corrosion resistance. The electrolyte used in the etching process will not leak out from the gap at the bottom of the cup, and the through hole at the bottom of the ceramic tube cup body is aligned with the measuring point, and then wait for the glue to dry. The ceramic tube cup body is a special ceramic tube with an inner diameter of 30mm-50mm, a height of 30mm-50mm, a wall thickness of 1mm-5mm, and a bottom through hole diameter of 4-12mm. The through hole is set at the bottom center of the ceramic tube cup body. The number of ceramic tubes is less than or equal to 5, and then electrolytic corrosion is performed: the electrolytic corrosion stripping method is selected, and the specific operations include: the electrolytic corrosion head 14 used in the electrolytic corrosion stripping method is composed of a voltage-stabilizing electrode The method is composed of a power source, positive and negative electrodes, a ceramic tube, a graphite rod and a test material. An electrolyte is added to a two-thirds depth into a ceramic tube cup body pasted on a metal composite plate. The electrolyte is a saturated NaCl solution. Then one end of the graphite rod is connected to one end of the negative electrode. The other end of the graphite rod is inserted into the electrolyte in the ceramic tube cup body. The other end of the negative electrode is connected to the negative electrode of the voltage-stabilized power supply. One end of the positive electrode is directly connected to the test material, and the other end is connected to the positive electrode of the voltage-stabilized power supply through a wire. The metal composite plate at the bottom through hole of the ceramic tube cup body is locally electrolytically stripped layer by layer using a matching power supply device.

[0051] Further, the corrosion depth is measured: the corrosion current is unchanged, the corrosion time is changed, the corrosion depth at different corrosion times is measured, and the variation law of the corrosion depth of the corroded material with the corrosion time is obtained. Finally, the stress detection is started: each corrosion position is measured, and the measurement position and direction of the metal composite plate are kept consistent during each measurement, and then steps S2-S5 are looped until the corrosion depth reaches the required depth and the stress detection is completed. The parameters of the X-ray stress measuring instrument 16 are: the X-ray wavelength is determined according to the selected target material, the tilt method is used to measure the residual stress of the composite plate, the measurement starting angle is 150°-154°, the end angle is 155°-160°, the measurement step width is 0.04°, and the test time of each step width is 0.1s-0.3s, at this time, the X-ray stress measuring instrument 16 sets the measuring tube voltage to 10kV-25kV and the tube current to 5mA-40mA. The above-mentioned X-ray stress measuring instrument 16 is a DST-177 model with high resolution function. The parameters of the X-ray stress measuring instrument 16 can be appropriately adjusted according to the different corroded metal materials. This method can measure the residual stress of the metal composite plate at various depths within 2mm from the surface. During the corresponding use of the ultrasonic cleaning head 11, the mechanical grinding head 12, the pickling treatment head 13, the electrolytic corrosion head 14, the glue coating head 15 and the X-ray stress measuring instrument 16, by installing the drag teaching end on the corresponding middle bracket 23, the operator can operate The dragging teaching end forms the movement of the corresponding track body 2, and then the relative position of the entire connecting frame 17 relative to the metal composite plate is adjusted. Then, the relative position of the telescopic frame 24 relative to the middle frame 23 is adjusted by rotating the threaded rod 27, so that the translation support wheel 4 can be extended relative to the track body 2 to adapt to the operation of different spans of the metal composite plate. Due to the configuration of the elastic spring 29, the long support wheel 5 and the short support wheel 6 will form a follow-up position change to achieve the adjustment of the storage belt 7. Then, by rotating the upper hand wheel 34, the synchronous adjustment of multiple connecting frames 17 is achieved, so that the corresponding components of the operating system to be used are adjusted to the front of the translation support wheel 4, and then the dragging teaching end is removed from the middle pillar 3 and It is installed on the connecting bracket 17 adjusted to the front of the translation support wheel 4, and then the corresponding telescopic adjustment of the electric telescopic rod 10 can be achieved by operating and dragging the teaching end, so that the operating system has an adaptive height relative to the metal composite plate to be processed, and the rotating hand ring 42 is rotated and adjusted relative to the fixed hand ring 47 to achieve the rotation drive of the extrusion block 44 on the rotating rotating hand ring 42, so that the relative extrusion effect of the gradual groove 45 and the connecting ball 18 is invalid, and then the connecting bracket 17 can be adjusted relative to the connecting ball 18. After the adjustment is completed, the rotation drive of the rotating hand ring 42 is relaxed. Under the elastic reset action of the reset spring 46, the rotating hand ring 42 is rotated and reset relative to the connecting bracket 17, so that the extrusion block 44 will also The connection ball 18 is rotated and reset to achieve the relative limit of the connection bracket 17 relative to the connection ball 18 again, so as to facilitate the corresponding operation of the operation system relative to the metal composite plate to be processed. When the ultrasonic cleaning head 11, pickling treatment head 13, electrolytic corrosion head 14 and glue coating head 15 in the operation system are in practical operation, the corresponding feeding pump 22 will be powered on to realize the pumping of the required materials. When the overall size of the metal composite plate is large and the overall position is not easy to change, there is no need to assist in clamping and positioning the metal composite plate. When the overall position of the metal composite plate is easy to change, it is necessary to assist in clamping and positioning the metal composite plate through the external position to ensure the stability of the position of the metal composite plate during the operation.

[0052] Furthermore, although the measurement device for residual stress of automobile lightweight composite panels focuses on matching use with automobile lightweight composite panels of larger size, it can also be used for matching detection with automobile lightweight composite panels of smaller size. In this case, the measurement device for residual stress of automobile lightweight composite panels can be adjusted and moved relative to the automobile lightweight composite panels, and the automobile lightweight composite panels can also be adjusted and moved relative to the measurement device for residual stress of automobile lightweight composite panels to facilitate the alignment of the automobile lightweight composite panels relative to the operating system in the measurement device for residual stress of automobile lightweight composite panels. Since automobile lightweight composite panels are easier to move after being reduced in size than automobile lightweight composite panels of sufficiently large size, in order to ensure the positional stability of automobile lightweight composite panels during the detection process, external auxiliary fixtures can be further introduced to achieve auxiliary positioning of the smaller automobile lightweight composite panels, such as the attached Fig.10 As shown, the connection between the connecting bracket 17 and the lifting rod 19 is formed by the connecting ball 18, which enriches the adjustment range and angle of the connecting bracket 17 relative to the lifting rod 19. Since the automobile lightweight composite panel is in a flat state at the beginning of the product and becomes a finished sheet metal after a specific process, or even becomes a white body after a welding process, the size, structure and position of the automobile lightweight composite panel will inevitably change during this process. In this case, during the detection, the structure formed by the connecting bracket 17, the connecting ball 18 and the lifting rod 19 enables the operating system to form a larger matching adjustment relative to the detection points at different spatial positions on the sheet metal or even the white body, so as to achieve the effect of enriching the detection position range. The finished product structure on the market is also adopted for the crawler body 2. For the travel control of the crawler body 2, on the one hand, the corresponding movement and steering control can be achieved through the matching control handheld setting, and on the other hand, it can also be selected to connect to the system matching the drag teaching end. By dragging The teaching end is used in conjunction with the dragging teaching end, and the dragging teaching end adopts the form of a suction cup, which is convenient for the switching installation and use of a single dragging teaching end relative to multiple devices such as the crawler body 2, the servo motor 48 and the electric telescopic rod 10. The number of external racks 8 on the storage belt 7 can be appropriately installed according to the specific situation to cooperate with the mounting use of operation terminals such as welding, cutting, drilling and riveting, so as to achieve the effect of expanding the function of the measuring device for the residual stress of the lightweight composite plate of the automobile. At the same time, when the measuring device for the residual stress of the lightweight composite plate of the automobile is equipped with a small-sized metal composite plate for detection, considering that it is easier to move the small-sized metal composite plate, the small-sized metal composite plate can also be moved relative to the measuring device for the residual stress of the lightweight composite plate of the automobile for detection. If necessary, in order to maintain the relative position stability of the small-sized metal composite plate, an external clamp can be used to assist in achieving the position stability of the small-sized metal composite plate.

[0053] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A residual stress measuring device for a lightweight composite plate of an automobile, comprising a base (1) and a tracked vehicle body (2), characterized in that: The invention also comprises an operating system, wherein the crawler vehicle body (2) is provided with an installation middle opening, the base (1) is installed in the installation middle opening, a middle pillar (3) is rotatably connected in the base (1), the top of the middle pillar (3) is fixedly connected with an adjustment frame, a translation support wheel (4), a long support wheel (5) and a short support wheel (6) are installed on the adjustment frame, a storage belt (7) is transmission-connected between the translation support wheel (4), the long support wheel (5) and the short support wheel (6), and a storage belt (7) is provided on the storage belt (7). There are six external racks (8), each of which is rotatably connected to a rotating member (9), and each of which is equipped with an electric telescopic rod (10) at the bottom end of each of the six rotating members (9). The operating system comprises an ultrasonic cleaning head (11), a mechanical grinding head (12), a pickling treatment head (13), an electrolytic corrosion head (14), a glue coating head (15) and an X-ray stress measuring instrument (16). The ultrasonic cleaning head (11), the mechanical grinding head (12), the pickling treatment head (13) 3) The electrolytic corrosion head (14), the glue coating head (15) and the X-ray stress measuring instrument (16) are all equipped with a connecting bracket (17), and the six connecting brackets (17) are all connected with a connecting ball (18), and the six connecting brackets (17) are all equipped with a limiting structure, and the six limiting structures are matched with the six connecting balls (18) respectively, and the tops of the six connecting balls (18) are all fixedly connected with lifting rods (19), and the six lifting rods (19) are respectively connected with the six electric The telescopic rod (10) is connected to the telescopic rod, the pickling head (13), the electrolytic corrosion head (14) and the glue coating head (15) are all equipped with a feeding pipe (20), four storage bottles (21) are fixedly connected in the crawler body (2), and four feeding pumps (22) are installed in the crawler body (2), the suction ends of the four feeding pumps (22) are respectively connected to the four storage bottles (21), and the output ends of the four feeding pumps (22) are respectively connected to the four feeding pipes (20).

2. A residual stress measuring device for lightweight composite panels of automobiles according to claim 1, characterized in that: The adjustment frame comprises a middle frame (23), a telescopic frame (24), an upper swing frame (25) and a lower swing frame (26); the middle frame (23) is fixedly connected to the top end of the middle support (3); the telescopic frame (24) is slidably connected to the middle frame (23); a threaded rod (27) is rotatably connected inside the telescopic frame (24); a threaded sleeve (28) is threadedly connected to the threaded rod (27); the threaded sleeve (28) is fixedly connected inside the middle frame (23); The upper swing frame (25) and the lower swing frame (26) are both rotatably connected to the middle frame (23); the upper swing frame (25) and the lower swing frame (26) are both connected to elastic springs (29); the two elastic springs (29) are both connected to the middle frame (23); the translation support wheel (4) is rotatably connected to the bottom end of the telescopic frame (24); the long support wheel (5) is rotatably connected to the bottom end of the upper swing frame (25); and the short support wheel (6) is rotatably connected to the bottom end of the lower swing frame (26).

3. A residual stress measuring device for lightweight composite panels of automobiles according to claim 2, characterized in that: The middle link frame (23) is rotatably connected to two rotating blocks (30), and the two rotating blocks (30) are respectively fixedly connected to the two elastic springs (29). The upper swing frame (25) and the lower swing frame (26) are respectively rotatably connected to a short bracket (31) and a long bracket (32), and the short bracket (31) and the long bracket (32) are respectively fixedly connected to the two elastic springs (29).

4. The residual stress measuring device for lightweight composite panels of automobiles according to claim 3 is characterized in that: A vertical shaft (33) is rotatably connected inside the telescopic frame (24), the vertical shaft (33) is fixedly connected to the translation support wheel (4), the top end of the vertical shaft (33) is fixedly connected to an upper hand wheel (34), and the upper hand wheel (34) is located above the telescopic frame (24).

5. The residual stress measuring device for lightweight composite panels of automobiles according to claim 4 is characterized in that: A clamping groove (35) is provided on the round head at the front end of the telescopic frame (24); a rotating frame (36) is rotatably connected in the clamping groove (35); a vertical hole (37) is provided on the rotating frame (36) for the vertical shaft (33) to pass through; the rotating frame (36) is rotatably connected to a horizontal shaft (38); the horizontal shaft (38) is transmission-connected to a torque rope (39); and the torque rope (39) is transmission-connected to the threaded rod (27).

6. The residual stress measuring device for lightweight composite panels of automobiles according to claim 5, characterized in that: The telescopic frame (24) is provided with a strip-shaped opening (40), the threaded sleeve (28) is fixedly connected with a connecting plate (41), the connecting plate (41) is fixedly connected to the middle frame (23), and the threaded sleeve (28) and the two connecting plates (41) are both located in the strip-shaped opening (40).

7. The residual stress measuring device for lightweight composite panels of automobiles according to claim 6, characterized in that: The limiting structure comprises a rotating hand ring (42), the rotating hand ring (42) is rotatably connected to the connecting bracket (17), and a fan-shaped cavity (43) is provided in the connecting bracket (17), an extrusion block (44) is provided in the fan-shaped cavity (43), the extrusion block (44) is fixedly connected to the rotating hand ring (42), a gradual groove (45) is provided on the extrusion block (44), the gradual groove (45) matches the connecting ball (18), a return spring (46) is connected in the fan-shaped cavity (43), and the return spring (46) is connected to the extrusion block (44).

8. The residual stress measuring device for lightweight composite panels of automobiles according to claim 7, characterized in that: A fixed wristband (47) is fixedly connected to the connecting bracket (17).

9. The residual stress measuring device for lightweight composite panels of automobiles according to claim 8, characterized in that: A servo motor (48) is installed in the crawler vehicle body (2), a driving gear (49) is installed on the output shaft of the servo motor (48), the driving gear (49) is meshed with a driven gear ring (50), and the driven gear ring (50) is fixedly connected to the bottom end of the middle pillar (3).

10. A method for measuring residual stress of lightweight composite panels for automobiles, characterized in that: A device for measuring residual stress of a lightweight composite plate for an automobile according to any one of claims 1 to 9 is used, comprising the following steps: S1. Surface treatment: The surface of the metal composite plate is polished and cleaned. The surface treatment method of the metal composite plate is to firstly perform ultrasonic cleaning on the surface of the metal composite plate through an ultrasonic cleaning head (11), then perform mechanical polishing on the surface of the metal composite plate through a mechanical polishing head (12), and then perform pickling treatment on the surface of the metal composite plate through a pickling treatment head (13) to achieve the effect of removing rust and oil stains on the surface and high-pressure cleaning. After cleaning, the surface of the metal composite plate is dried and the measuring position is kept as flat as possible. Finally, the surface is wiped clean with alcohol; S2, pasting the ceramic tube cup body: selecting the measurement position in a distributed manner along the rolling direction and the transverse direction of the metal composite plate, and then pasting a plurality of ceramic tube cup bodies with through holes at the bottom to the measurement position. The pasting positions of the ceramic tube cup bodies are distributed along the rolling direction and the transverse direction of the metal composite plate. Gluing is applied in the space between the ceramic tube cup body and the metal composite plate by a glue coating head (15), and the periphery of the through hole at the bottom of the ceramic tube cup body is tightly pasted to the metal composite plate without leaving any gap, so as to ensure that the electrolyte used in the corrosion process will not leak from the gap at the bottom of the cup, and the through hole at the bottom of the ceramic tube cup body is aligned with the measurement point, and then the glue is allowed to dry. The ceramic tube cup body is a special ceramic tube with an inner diameter of 30mm-50mm, a height of 30mm-50mm, a wall thickness of 1mm-5mm, a bottom through hole diameter of 4-12mm, and a through hole arranged at the bottom center of the ceramic tube cup body. The number of the ceramic tubes is less than or equal to 5; S3, electrolytic corrosion: an electrolytic corrosion stripping method is selected, and the specific operation includes: the electrolytic corrosion head (14) used in the electrolytic corrosion stripping method is composed of a voltage-stabilized power supply, positive and negative electrodes, a ceramic tube, a graphite rod and a test material, an electrolyte is added to a ceramic tube cup body pasted on the metal composite plate to a depth of two-thirds, and the electrolyte is a saturated NaCl solution, and then one end of the graphite rod is connected to one end of the negative electrode, and the other end of the graphite rod is inserted into the electrolyte in the ceramic tube cup body, the other end of the negative electrode is connected to the negative electrode of the voltage-stabilized power supply, one end of the positive electrode is directly connected to the test material, and the other end is connected to the positive electrode of the voltage-stabilized power supply through a wire, and the metal composite plate at the bottom through hole of the ceramic tube cup body is locally electrolytically stripped layer by layer by using a matching power supply device; S4. Corrosion depth measurement: Keep the corrosion current constant, change the corrosion time, measure the corrosion depth at different corrosion times, and obtain the variation law of the corrosion depth of the corroded material with the corrosion time; S5, stress detection: measuring each corrosion position, ensuring that the measurement position and direction of the metal composite plate are consistent during each measurement, and then looping through steps S2 to S5 until the corrosion depth reaches the required depth and the stress detection is completed. The parameters of the X-ray stress measuring instrument (16) are as follows: the X-ray wavelength is determined according to the selected target material, the residual stress of the composite plate is measured by the tilt method, the measurement start angle is 150°-154°, the end angle is 155°-160°, the measurement step width is 0.04°, and the test time of each step width is 0.1s-0.3s. At this time, the X-ray stress measuring instrument (16) sets the measurement tube voltage to 10kV-25kV and the tube current to 5mA-40mA. The parameters of the above-mentioned X-ray stress measuring instrument (16) can be appropriately adjusted according to different corroded metal materials.

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