A detection tool for heat exchange coil

Abstract

This invention relates to the field of heat exchange equipment testing technology, specifically a testing fixture for heat exchange coils. It includes an operating support, with a longitudinal mounting plate fixedly connected to its rear end. The front end of the longitudinal mounting plate is equipped with a moving mechanism for driving the testing feed. The moving mechanism includes a top plate, and the front end of the top plate is equipped with a testing mechanism for the heat exchange coil. A first motor drives a locking rod and a threaded rod, coordinating with the movement of the threaded sleeve's threaded pair to achieve a helical feeding motion matching the pitch of the heat exchange coil, driving the testing mechanism to continuously move along the outer spiral wall of the coil. Simultaneously, a third motor drives an open annular plate to reciprocate circumferentially via a synchronous belt, causing a laser contour sensor surrounding the inner wall to scan the tube wall in segments. The helical feeding and circumferential oscillation are linked, allowing for the fitting of a complete tube wall cross-sectional contour, completely eliminating the testing blind spots caused by the open structure.

Description

Technical Field

[0001] This invention relates to the field of heat exchange equipment testing technology, specifically a testing fixture for heat exchange coils. Background Technology

[0002] As the core heat transfer component of heat exchange equipment, heat exchange coils are widely used in many industrial production fields such as chemical, petroleum, pharmaceutical, refrigeration and air conditioning, food processing, and power. Their helical geometry determines that dimensional parameters such as the coil's outer diameter, ellipticity, pitch, and surface profile accuracy directly affect heat exchange efficiency and equipment safety. Therefore, accurate geometric dimension testing of the helical section of the heat exchange coil is a crucial step in the manufacturing process.

[0003] Currently, the mainstream methods for dimensional inspection of spiral heat exchanger coils are divided into two categories: manual fixed-point inspection and fixed optical inspection. Manual inspection often uses a handheld laser rangefinder to sample multiple points on the coil, which is inefficient and can only obtain dimensional data from a limited number of locations, failing to cover the entire spiral section wall. This makes it easy to miss minor defects such as local dents and elliptical deformations, and it is difficult to guarantee the consistency and accuracy of the inspection. Fixed optical inspection often uses a closed-loop laser inspection frame, which needs to be inserted segment by segment from the end of the coil to complete the inspection. The loading and unloading process is cumbersome and cannot be adapted to finished coils with straight pipe sections at both ends. At the same time, this type of inspection frame can only move up and down in a straight line, which cannot match the spiral angle of the coil wall. During the inspection process, the incident direction of the laser sensor continuously deviates from the tube wall normal, resulting in systematic measurement deviations and failing to meet the requirements of high-precision metrology.

[0004] In addition, after the spiral heat exchange coil is bent and formed, the surface generally has residual oil, oxide scale and processing dust. Moreover, the metal tube wall has strong specular reflection characteristics. When laser detection is performed directly, the surface deposits and stray reflections will seriously interfere with the stability of the optical path, resulting in large fluctuations in sampling data and low effective recognition rate. Most existing detection equipment does not integrate matching cleaning and light-shielding structures, requiring a separate pre-treatment process, which lengthens the overall detection process and reduces production detection efficiency.

[0005] On the other hand, the specifications of heat exchange coils used under different operating conditions vary greatly, with different parameter requirements for tube diameter, pitch, and number of turns. The existing testing fixtures have limited adaptability and adjustment range. When changing workpiece specifications, the main structure of the testing frame needs to be disassembled and modified, resulting in high replacement costs and long cycles, making it difficult to meet the flexible testing needs of multi-variety, small-batch coils. Summary of the Invention

[0006] The purpose of this invention is to provide a testing fixture for heat exchange coils, which aims to solve the problems of existing equipment being unable to achieve continuous laser dimension testing around the entire circumference, lacking integrated cleaning and anti-interference structures, and being inconvenient for changing specifications.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a testing fixture for a heat exchanger coil, comprising an operating support, a longitudinal mounting plate fixedly connected to the rear end of the operating support, a moving mechanism for driving the testing feed provided at the front end of the longitudinal mounting plate, the moving mechanism comprising a top plate, a testing mechanism for testing the heat exchanger coil provided at the front end of the top plate, the testing mechanism comprising a testing component for adapting to the spiral outer wall of the heat exchanger coil, and a cleaning component for cleaning the outer wall of the heat exchanger coil.

[0008] Preferably, the moving mechanism includes a first motor installed at the rear end of the longitudinal mounting plate. The output shaft of the first motor is fixedly connected to a locking bar via a coupling. Multiple locking bars are fixedly connected around the outer wall of the locking bar. A threaded rod is slidably connected to the outer side of the locking bar. A cavity is formed on the inner side of the threaded rod. A spring is provided inside the cavity of the threaded rod. One end of the spring is fixedly connected to the locking bar, and the other end of the spring is fixedly connected to the threaded rod. The front end of the threaded rod is fixedly connected to the top plate.

[0009] Preferably, a fixing frame is fixedly connected to the front end of the longitudinal mounting plate, and a threaded sleeve is fixedly connected to the inner side of the fixing frame, with the inner side of the threaded sleeve being threadedly connected to the threaded rod.

[0010] Preferably, a connecting bracket is provided at the front end of the top plate, a second motor is installed at the front end of the connecting bracket, a rotating sleeve is fixedly connected to the output shaft of the second motor, a fixed rotating shaft is fixedly connected to the inner side of the rotating sleeve, and a first electric push rod is installed at both ends of the fixed rotating shaft through connecting blocks.

[0011] Preferably, the output shafts of the two first electric actuators are fixedly connected to an open plate. A plurality of limiting shafts are rotatably connected to one side of the open plate. A limiting baffle is provided on the outer side of the limiting shafts. An open annular plate is rotatably connected to the outer side of the plurality of limiting shafts. A plurality of laser contour sensors are installed around the inner wall of the open annular plate. A retaining tooth is provided around the outer wall of the open annular plate.

[0012] Preferably, a third motor is installed on one side of the opening plate, and the output shaft of the third motor is fixedly connected to a first pulley. A timing belt is rotatably connected to the outer side of the first pulley, and a plurality of second pulleys are rotatably connected to the inner side of the timing belt. One end of each second pulley is rotatably connected to the inner side of the opening plate via a rotating shaft. The plurality of second pulleys are arranged around the outer side of the opening annular plate, and the outer wall of the timing belt is provided with teeth, and the outer side of the timing belt meshes with the outer side of the opening annular plate.

[0013] Preferably, a plurality of assembly blocks are fixedly connected around the other side of the opening plate, a fourth motor is installed on one side of the assembly block, a cavity rod is fixedly connected to the output shaft of the fourth motor, a plurality of flexible sponge strips are provided on the side of the plurality of cavity rods that are close to each other, and a laser ranging sensor is installed on the side of the plurality of assembly blocks that are close to each other.

[0014] Preferably, a toothed rack is slidably connected to the inner side of the cavity rod, and multiple limiting rods are rotatably connected to both sides of the toothed rack. Multiple gears are meshed with the outer side of the toothed rack, and the two ends of the gears are rotatably connected to the inner side of the cavity rod through a rotating shaft. The same end of the multiple gears is fixedly connected to the corresponding flexible sponge strip.

[0015] Preferably, a second electric actuator is installed on one side of the cavity rod, the output shaft of the second electric actuator is fixedly connected to the rack, a limit baffle is fixedly connected to the other end of the rack, and a pressure sensor is provided on the inner side of the second electric actuator.

[0016] Preferably, a horizontal mounting plate is fixedly connected to the inner side of the operating bracket, a third electric push rod is mounted on the inner side of the horizontal mounting plate, a connecting rod is fixedly connected to the output shaft of the third electric push rod, electric clamps are mounted on both ends of the connecting rod, a straight tube of a heat exchange coil is provided on the inner side of the two electric clamps, and two guide telescopic rods are fixedly connected to the inner side of the horizontal mounting plate, and the telescopic shafts of the two guide telescopic rods are respectively fixedly connected to the housing of the corresponding electric clamp above.

[0017] Compared with the prior art, the beneficial effects of the embodiments of the present invention are: 1. The first motor drives the clamping rod and threaded rod transmission, which, in conjunction with the conversion of the threaded sleeve, achieves a spiral feed motion that matches the pitch of the heat exchange coil, driving the detection mechanism to continuously move along the outer wall of the coil spiral. Simultaneously, the third motor drives the open annular plate to reciprocate circumferentially via a synchronous belt, causing the laser contour sensor surrounding the inner wall to scan the tube wall in segments. The spiral feed and circumferential oscillation are linked, which can fit a complete tube wall cross-sectional contour, completely eliminating the detection blind zone caused by the open structure, and realizing uninterrupted continuous detection of the entire wall surface of the heat exchange coil spiral section. This solves the problems of incomplete coverage and high missed detection rate of traditional fixed-point sampling inspection.

[0018] Simultaneously, the cleaning component is arranged in front of the inspection station along with the traveling mechanism, completing the pretreatment of the pipe wall before inspection: flexible sponge strips repeatedly wipe away surface oil, oxide scale, and dust impurities, preventing these deposits from interfering with the laser beam path; multiple sets of surrounding flexible sponge strips also form a local light-shielding enclosure around the inspection area, reducing stray reflections from the pipe wall and minimizing interference from ambient light on the laser profile sensor and laser range sensor, effectively improving the data stability and inspection accuracy of optical measurements. Combined with real-time calibration of the coaxiality of the opening plate and the coil using the laser range sensor, the inspection benchmark can be further standardized, reducing system measurement errors.

[0019] 2. Both the open plate and the open annular plate adopt an open structure design, which can directly insert the heat exchange coil from the side without having to insert it section by section from the tube end. This greatly simplifies the workpiece loading and unloading process, reduces the difficulty of clamping operations, and improves the efficiency of inspection operations.

[0020] The radial feed distance of the opening plate can be adjusted via the first electric actuator. Combined with the second motor driving the opening plate to deflect via a rotating sleeve and fixed shaft, the inclination angle of the ring plane can be flexibly adjusted to accommodate heat exchange coils of different pipe diameters. For heat exchange coils with different thread pitches, only the corresponding threaded rod and threaded sleeve need to be replaced, along with adjustments to the deflection angle and feed stroke of the opening plate, to complete the equipment changeover. No modification to the overall machine structure is required, resulting in strong equipment versatility, low changeover costs, and high efficiency. Furthermore, the electric clamping device, combined with the lifting and positioning method using the third electric actuator, can quickly align the workpiece's inspection reference, adapting to heat exchange coils with different straight pipe lengths, providing flexible and efficient clamping and positioning.

[0021] 3. The spring installed inside the threaded rod cavity provides continuous axial preload, effectively eliminating the fit clearance of the threaded pair, avoiding swerving, jamming, and reverse dead zones during the helical feed process, improving the smoothness of the travel process, and ensuring the continuous stability of the detection benchmark.

[0022] Multiple sets of limiting pivots provide radial and axial bidirectional limiting support for the open annular plate. Combined with multiple sets of second pulleys for tensioning and guiding the synchronous belt, this ensures the stability of the open annular plate during its reciprocating oscillation, preventing radial wobble and axial movement, and maintaining the positional accuracy of the laser detection element. The guide telescopic rod provides linear guidance and constraint for the lifting and lowering motion of the electric fixture, ensuring that the axis remains vertical during workpiece lifting and lowering, avoiding interference and detection reference offset caused by coil skew. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional view of the overall structure of the present invention; Figure 3 This is a schematic diagram of the overall structure of the moving mechanism and the detection mechanism of the present invention; Figure 4 This is a cross-sectional schematic diagram of the overall structure of the moving mechanism of the present invention; Figure 5 This is a schematic diagram of the overall structure of the detection mechanism of the present invention; Figure 6 This is a cross-sectional view of the overall structure of the testing mechanism of the present invention. Figure 1 ; Figure 7 This is a cross-sectional view of the overall structure of the testing mechanism of the present invention. Figure 2 ; Figure 8 This is a cross-sectional view of the overall structure of the testing mechanism of the present invention. Figure 3 .

[0024] In the diagram: 1. Operating bracket; 2. Longitudinal mounting plate; 3. Moving mechanism; 31. First motor; 32. Clamping bar; 33. Threaded rod; 34. Spring; 35. Fixing frame; 36. Threaded sleeve; 37. Top plate; 4. Detection mechanism; 41. Detection assembly; 411. Connecting bracket; 412. Second motor; 413. Rotating sleeve; 414. Fixed rotating shaft; 415. First electric push rod; 416. Opening plate; 417. Limiting rotating shaft; 418. Opening annular plate; 419. Laser wheel 4110, First pulley; 4111, Synchronous belt; 4112, Second pulley; 4113, Third motor; 42, Cleaning assembly; 421, Assembly block; 422, Fourth motor; 423, Laser rangefinder; 424, Cavity rod; 425, Flexible sponge strip; 426, Gear rack; 427, Limiting rod; 428, Gear; 429, Second electric actuator; 5, Lateral mounting plate; 6, Third electric actuator; 7, Connecting rod; 8, Electric clamp; 9, Guide telescopic rod. Detailed Implementation

[0025] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0026] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0027] Please see Figures 1-8In this embodiment of the invention, a testing fixture for a heat exchanger coil includes an operating support 1. A longitudinal mounting plate 2 is fixedly connected to the rear end of the operating support 1. A moving mechanism 3 for driving the testing feed is provided at the front end of the longitudinal mounting plate 2. The moving mechanism 3 includes a top plate 37. A testing mechanism 4 for testing the heat exchanger coil is provided at the front end of the top plate 37. The testing mechanism 4 includes a testing component 41 for adapting to the spiral outer wall of the heat exchanger coil and a cleaning component 42 for cleaning the outer wall of the heat exchanger coil.

[0028] Furthermore, the moving mechanism 3 includes a first motor 31 installed at the rear end of the longitudinal mounting plate 2. The output shaft of the first motor 31 is fixedly connected to a retaining bar 32 via a coupling. Multiple retaining bars are fixedly connected around the outer wall of the retaining bar 32. A threaded rod 33 is slidably connected to the outer side of the retaining bar 32. A cavity is opened on the inner side of the threaded rod 33. A spring 34 is provided inside the cavity of the threaded rod 33. One end of the spring 34 is fixedly connected to the retaining bar 32, and the other end of the spring 34 is fixedly connected to the threaded rod 33. The front end of the threaded rod 33 is fixedly connected to the top plate 37.

[0029] The first motor 31, serving as the power source for the moving mechanism 3, is installed at the rear end of the longitudinal mounting plate 2 and outputs rotational driving force. The clamping bar 32 is fixedly connected to the output shaft of the first motor 31 via a coupling. Multiple clamping bars arranged around its outer wall are used for sliding cooperation with the inner wall of the cavity of the threaded rod 33, transmitting torque while allowing axial relative sliding. The threaded rod 33 is sleeved on the outside of the clamping bar 32, and the cavity opened on its inner side provides sliding space for the clamping bar 32. Through the cooperation of the external thread with the threaded sleeve 36, the rotational motion is converted into axial lifting motion, driving the detection mechanism 4 to move axially along the coil. The spring 34 is set inside the cavity of the threaded rod 33, with one end fixed to the clamping bar 32 and the other end fixed to the threaded rod 33. It is used to provide axial preload to eliminate the meshing gap of the threaded pair, improve the smoothness of movement, and provide auxiliary pulling force for the threaded rod 33 to descend and reset. The top plate 37 is fixed to the front end of the threaded rod 33 and serves as the power output end to transmit the lifting motion of the threaded rod 33 to the detection mechanism 4.

[0030] Furthermore, a fixing bracket 35 is fixedly connected to the front end of the longitudinal mounting plate 2, and a threaded sleeve 36 is fixedly connected to the inner side of the fixing bracket 35. The inner side of the threaded sleeve 36 is threadedly connected to the threaded rod 33.

[0031] The fixed frame 35 is fixedly connected to the front end of the longitudinal mounting plate 2, serving as the mounting base for the threaded sleeve 36. The threaded sleeve 36 is fixed inside the fixed frame 35, and its inner thread meshes with the outer thread of the threaded rod 33. When the threaded rod 33 rotates, its rotational motion is converted into axial linear motion through the meshing action of the thread pair. It is the core mating component for the moving mechanism 3 to achieve spiral lifting.

[0032] Furthermore, a connecting bracket 411 is provided at the front end of the top plate 37, a second motor 412 is installed at the front end of the connecting bracket 411, a rotating sleeve 413 is fixedly connected to the output shaft of the second motor 412, a fixed rotating shaft 414 is fixedly connected to the inner side of the rotating sleeve 413, and a first electric push rod 415 is installed at both ends of the fixed rotating shaft 414 through connecting blocks.

[0033] A connecting bracket 411 is located at the front end of the top plate 37 and is used to install the second motor 412 and provide support. The second motor 412 is installed at the front end of the connecting bracket 411 and is used to drive the rotating sleeve 413 to rotate, serving as the power source for the angle deflection of the opening plate 416. The rotating sleeve 413 is fixedly connected to the output shaft of the second motor 412, and a fixed rotating shaft 414 is fixed on its inner side to transmit the rotational torque of the second motor 412 to the fixed rotating shaft 414. The fixed rotating shaft 414 is located inside the rotating sleeve 413, and first electric push rods 415 are installed at both ends through connecting blocks. This is used to drive the first electric push rods 415 and the opening plate 416 to deflect as a whole, so that the plane inclination angle of the opening plate 416 matches the local spiral rise angle of the heat exchange coil. The first electric push rods 415 are installed on the connecting blocks at both ends of the fixed rotating shaft 414, and their output shafts are fixedly connected to the opening plate 416. This is used to drive the opening plate 416 to move radially closer to or away from the spiral tube, thereby adjusting the radial distance between the detection component 41 and the outer wall of the coil.

[0034] Furthermore, the output shaft of the first electric actuator 415 is fixedly connected to an open plate 416. A plurality of limiting shafts 417 are rotatably connected around one side of the open plate 416. A limiting baffle is provided on the outer side of the limiting shafts 417. An open annular plate 418 is rotatably connected to the outer side of the plurality of limiting shafts 417. A plurality of laser contour sensors 419 are installed around the inner wall of the open annular plate 418. A retaining tooth is provided around the outer wall of the open annular plate 418.

[0035] The open plate 416, as the basic support component of the detection mechanism 4, is fixedly connected to the output shaft of the first electric push rod 415. Multiple limiting shafts 417 arranged around one side of the open plate 416 are used to provide radial and axial bidirectional limiting support for the open annular plate 418. The limiting shafts 417 are rotatably connected to one side of the open plate 416, and the limiting baffles arranged on the outer side are used to constrain the axial movement of the open annular plate 418, ensuring the stability of the open annular plate 418 during swinging. The open annular plate 418 is rotatably connected to the outer side of the multiple limiting shafts 417, and the retaining teeth arranged around its outer wall are used to engage with the synchronous belt 4111. Under the support of the limiting shafts 417, it swings back and forth in the circumferential direction, serving as a rotating carrier for swinging scanning with the laser profile sensor 419. The laser profile sensor 419 is installed around the inner wall of the open annular plate 418 and is used to perform segmented scanning of the outer wall of the coil during the swinging process of the open annular plate 418, collecting the profile data of the pipe wall cross section, and realizing full-circumferential dimension detection after data fitting.

[0036] Furthermore, a third motor 4113 is installed on one side of the opening plate 416. The output shaft of the third motor 4113 is fixedly connected to a first pulley 4110. A synchronous belt 4111 is rotatably connected to the outer side of the first pulley 4110. Multiple second pulleys 4112 are rotatably connected to the inner side of the synchronous belt 4111. One end of the second pulley 4112 is rotatably connected to the inner side of the opening plate 416 through a rotating shaft. Multiple second pulleys 4112 are arranged around the outer side of the opening annular plate 418. The outer wall of the synchronous belt 4111 is surrounded by teeth, and the outer side of the synchronous belt 4111 meshes with the outer side of the opening annular plate 418.

[0037] The third motor 4113 is mounted on one side of the open plate 416 and is used to drive the first pulley 4110 to rotate, serving as the power source for the reciprocating oscillation of the open annular plate 418. The first pulley 4110 is fixedly connected to the output shaft of the third motor 4113 and is used to transmit the motor torque to the synchronous belt 4111. The synchronous belt 4111 is a double-tooth synchronous belt, which is rotatably connected to the outside of the first pulley 4110. Multiple second pulleys 4112 are rotatably connected to its inner side, and a retaining clip is arranged around its outer wall. The teeth engage with the retaining teeth on the outer wall of the open annular plate 418 to synchronously transmit the power of the first pulley 4110 to multiple second pulleys 4112 and drive the open annular plate 418 to swing back and forth around its center. The second pulleys 4112 are arranged around the outside of the open annular plate 418, and one end of them is rotatably connected to the inside of the open plate 416 through a rotating shaft. They are used to tension and guide the running path of the synchronous belt 4111 to ensure that the meshing transmission between the synchronous belt 4111 and the open annular plate 418 is smooth and reliable.

[0038] Furthermore, multiple assembly blocks 421 are fixedly connected around the other side of the opening plate 416. A fourth motor 422 is installed on one side of the assembly block 421. The output shaft of the fourth motor 422 is fixedly connected to a cavity rod 424. Multiple flexible sponge strips 425 are provided on the side of the multiple cavity rods 424 that are close to each other. A laser rangefinder sensor 423 is installed on the side of the multiple assembly blocks 421 that are close to each other.

[0039] Assembly block 421 is fixedly connected to the other side of opening plate 416, and is used to install fourth motor 422 and laser range sensor 423, providing an installation position for cleaning component 42; fourth motor 422 is installed on one side of assembly block 421, and its output shaft is fixedly connected to cavity rod 424, used to drive cavity rod 424 to deflect in the direction of coil, realizing the contact and release action of flexible sponge strip 425; laser range sensor 423 is installed on the side of assembly block 421 close to it, used to detect cavity rod 424 and flexible sponge in real time. The radial distance between the flexible sponge strip 425 and the outer wall of the coil is used to achieve precise contact and positioning of the flexible sponge strip 425; the cavity rod 424 is fixedly connected to the output shaft of the fourth motor 422, and the flexible sponge strip 425 and transmission components are provided on its inner side, serving as the execution arm of the cleaning component 42; the flexible sponge strip 425 is set on the side where multiple cavity rods 424 are close to each other, and is used to remove surface oil, oxide scale and dust by reciprocating wiping after contacting the outer wall of the coil, and also serves as a local light shielding function to reduce the interference of external stray reflections on laser measurement.

[0040] Furthermore, a rack 426 is slidably connected to the inner side of the cavity rod 424, and multiple limiting rods 427 are rotatably connected to both sides of the rack 426. Multiple gears 428 are meshed with the outer side of the rack 426. The two ends of the gears 428 are rotatably connected to the inner side of the cavity rod 424 through a rotating shaft, and the same end of the multiple gears 428 is fixedly connected to the corresponding flexible sponge strip 425.

[0041] The rack 426 is slidably connected to the inner side of the cavity rod 424, and its outer teeth mesh with multiple gears 428. It is used to slide back and forth along the length of the cavity rod 424 under the drive of the second electric push rod 429, converting linear motion into reciprocating rotational motion of the gears 428. The limiting rod 427 is rotatably connected to both sides of the rack 426 and abuts against the inner wall of the cavity rod 424. It is used to linearly guide and constrain the sliding direction of the rack 426 to ensure its linearity. The gears 428 are meshed and connected to the outer side of the rack 426. Both ends are rotatably connected to the inner side of the cavity rod 424 through rotating shafts. The same end is fixedly connected to the corresponding flexible sponge strip 425. It is used to rotate back and forth under the drive of the rack 426, driving the flexible sponge strip 425 to synchronously reciprocate and deflect to wipe, thereby realizing the cleaning action of the pipe wall.

[0042] Furthermore, a second electric actuator 429 is installed on one side of the cavity rod 424. The output shaft of the second electric actuator 429 is fixedly connected to the rack 426. A limit baffle is fixedly connected to the other end of the rack 426. A pressure sensor is provided on the inner side of the second electric actuator 429.

[0043] The second electric push rod 429 is installed on one side of the cavity rod 424. Its output shaft is fixedly connected to the toothed rack 426 and is used to drive the toothed rack 426 to slide back and forth linearly along the inner side of the cavity rod 424. It is the power source for the wiping action of the cleaning component 42. The pressure sensor is set inside the second electric push rod 429 to monitor the clamping force when the flexible sponge strip 425 is against the tube wall, so as to avoid excessive wiping pressure and damage to the surface of the coil, and ensure the safety and controllability of the cleaning process.

[0044] Furthermore, a horizontal mounting plate 5 is fixedly connected to the inner side of the operating bracket 1, a third electric push rod 6 is installed on the inner side of the horizontal mounting plate 5, a connecting rod 7 is fixedly connected to the output shaft of the third electric push rod 6, electric clamps 8 are installed at both ends of the connecting rod 7, a straight tube of the heat exchange coil is provided on the inner side of the two electric clamps 8, and two guide telescopic rods 9 are fixedly connected to the inner side of the horizontal mounting plate 5, and the telescopic shafts of the two guide telescopic rods 9 are fixedly connected to the housing of the corresponding electric clamps 8 above.

[0045] The horizontal mounting plate 5 is fixed inside the operating bracket 1 to install the third electric push rod 6 and provide support. The third electric push rod 6 is installed inside the horizontal mounting plate 5, and its output shaft is fixedly connected to the connecting rod 7. It is used to drive the electric clamp 8 to rise and fall vertically, thereby adjusting the overall station height of the heat exchange coil. The connecting rod 7 is fixedly connected to the output shaft of the third electric push rod 6, and electric clamps 8 are installed at both ends of the connecting rod 7 to synchronously transmit the single-point driving force of the third electric push rod 6 to the two electric clamps 8, ensuring synchronous rising and falling at both ends. The electric clamps 8 are installed at both ends of the connecting rod 7, and their inner sides clamp the straight pipe section of the heat exchange coil to clamp and fix the workpiece, ensuring the positioning stability of the workpiece during the inspection process. The guide telescopic rod 9 is fixed inside the horizontal mounting plate 5, and its telescopic shaft is fixedly connected to the housing of the corresponding electric clamp 8 above. It is used to guide and constrain the rising and falling direction of the electric clamp 8, ensuring that the heat exchange coil rises and falls linearly in the vertical direction and that the central axis of the spiral part is aligned with the center line of the inspection station.

[0046] Working principle: Step 1: Place the heat exchange coil to be tested above the operating bracket 1. Adjust the position of the heat exchange coil so that the straight pipe sections at both ends are aligned with the clamping ports of the two electric clamps 8. Activate the two electric clamps 8 to clamp and fix the straight pipe sections of the heat exchange coil. Then, activate the third electric push rod 6 inside the horizontal mounting plate 5. Its output shaft extends and pushes the two electric clamps 8 upwards simultaneously through the connecting rod 7. During this process, the two guide telescopic rods 9 extend synchronously with the electric clamps 8, guiding and constraining the lifting direction of the electric clamps 8 to ensure that the heat exchange coil rises in a straight vertical direction. This aligns the central axis of the spiral part of the heat exchange coil with the center line of the testing station of the moving mechanism 3 and the testing mechanism 4, completing the benchmark positioning before testing. Step two: Start the first motor 31 installed at the rear end of the longitudinal mounting plate 2. Its output shaft drives the retaining bar 32 to rotate circumferentially through a coupling. The retaining bar 32 transmits torque through the engagement of the outer wall retaining bar with the inner wall of the cavity of the threaded rod 33, causing the threaded rod 33 to rotate synchronously. The threaded rod 33 engages with the threaded sleeve 36 on the inner side of the fixing frame 35. During rotation, it generates axial upward displacement synchronously. At the same time, the threaded rod 33 and the retaining bar 32 slide axially relative to each other, stretching the spring 34 inside the cavity. The spring 34 provides axial preload to the threaded rod 33, eliminating the fit clearance of the threaded pair and improving the smoothness of movement. On the other hand, it provides auxiliary pulling force for subsequent reset. The threaded rod 33 drives the detection mechanism 4 to rise as a whole through the top plate 37 at the front end. After the opening plate 416 is aligned with the starting position of the lower end of the spiral section of the heat exchange coil, the first motor 31 stops. Then the first electric push rod 415 is started, and its output shaft drives the opening plate 416 to be radially fed towards the coil. During the process, the laser range sensor 423 on each assembly block 421 detects the radial distance between the opening plate 416 and the outer wall of the coil in real time to ensure that the opening center of the opening plate 416 is roughly aligned with the axis of the spiral tube. After coaxial calibration is completed, the second motor 412 on the connecting bracket 411 is started. Its output shaft drives the fixed rotating shaft 414 to deflect through the rotating sleeve 413, and then drives the opening plate 416 to deflect by the connecting block and the first electric push rod 415. This makes the plane tilt angle of the opening plate 416 match the local spiral rise angle of the heat exchange coil, ensuring that the ring body and the tube wall maintain an adaptive posture throughout the subsequent spiral movement without any hard interference. Step 3: Restart the first motor 31 to drive the threaded rod 33 to rotate continuously and rise axially. The nominal pitch of the threaded rod 33 is consistent with the pitch of the heat exchange coil to be tested. Therefore, the combined helical motion of the rotation of the threaded rod 33 and the axial rise provides the detection mechanism 4 with the main motion reference matching the spiral lead of the coil. The top plate 37 can drive the opening plate 416 to move synchronously along the outer wall of the heat exchange coil, maintaining an appropriate posture and moving upward along the spiral trajectory of the coil. During the movement, the first electric push rod 415 adjusts the radial feed amount in real time according to the feedback of the laser range sensor 423 to compensate for the radial distance change caused by the offset of the rotation center. The second motor 412 synchronously adjusts the deflection angle of the opening plate 416 to match the local spiral rise angle of the tube wall. The two work together to ensure that the opening annular plate 418 always moves smoothly and continuously along the outer wall of the coil, ensuring the stability of the laser detection reference. During the movement, the third motor 4113 is started synchronously, and its output shaft drives the first pulley 4110 to rotate. The first pulley 4110 drives the multiple second pulleys 4112 arranged around it to rotate synchronously through the synchronous belt 4111. The outer wall teeth of the synchronous belt 4111 mesh with the outer wall teeth of the open annular plate 418, causing the open annular plate 418 to swing back and forth in the circumferential direction under the limiting support of multiple limiting shafts 417. A laser profile sensor 419, arranged around the inner wall of the open annular plate 418, oscillates synchronously with the annular body, completing segmented scanning along the circumference of the tube wall. Combined with the overall helical axial feed of the open plate 416, the multi-segment scanning data can fit a complete tube wall cross-sectional profile, eliminating the detection blind zone caused by the open structure and achieving continuous full-circumference detection of the outer diameter, roundness, and surface shape and position deviations of the heat exchange coil. The limiting shaft 417 provides radial and axial bidirectional limiting for the open annular plate 418, ensuring the stability of the annular body's posture during oscillation and maintaining the reference accuracy of the laser measurement. Step 4: During the detection process, the cleaning component 42 moves synchronously with the opening plate 416 and is located in front of the laser contour sensor 419, completing the pipe wall cleaning before the detection station. The cleaning action is as follows: the fourth motor 422 on one side of each assembly block 421 is started, driving the cavity rod 424 to deflect towards the coil, so that the flexible sponge strip 425 on the cavity rod 424 is attached to the outer wall of the coil; the attachment process is positioned in real time by the laser range sensor 423, and the pressure sensor built into the second electric push rod 429 monitors the clamping force to ensure that the sponge strip is properly attached to the tube wall and avoids damage to the surface of the workpiece; Then the second electric actuator 429 is activated, and its output shaft drives the rack 426 inside the cavity rod 424 to reciprocate linearly; the limit rod 427 guides the rack 426 to slide, ensuring its linearity. When the rack 426 slides back and forth, the multiple gears 428 meshing with the outer side rotate synchronously back and forth, thereby driving the flexible sponge strips 425 connected to each gear 428 to deflect back and forth and wipe, removing oil, oxide scale and dust impurities attached to the surface of the coil, and avoiding interference from the attachments with laser measurement; at the same time, the multiple sets of flexible sponge strips 425 arranged around form a local light-shielding enclosure around the detection area, weakening stray reflections on the surface of the tube wall, reducing interference with the detection accuracy of the laser profile sensor 419 and the laser range sensor 423, and improving the optical measurement stability and data accuracy of the laser profile sensor 419; while the cleaning component 42 is cleaning the surface of the spiral tube or after cleaning, the scanning detection action in step three continues to run, so that the laser profile sensor 419 can perform a complete measurement on the cleaned tube wall surface and obtain the full wall geometric dimension data of the spiral part of the heat exchange coil; After the entire coil is inspected, the third motor 4113 drives the open annular plate 418 to swing and reset, aligning the opening with the opening of the open plate 416 and offsetting it from the tube wall. The first electric push rod 415 drives the open plate 416 to retract radially, disengaging it from the outer wall of the coil. Subsequently, the first motor 31 reverses, and the threaded rod 33 rotates and descends under the auxiliary pulling force of the thread engagement and the spring 34, driving the entire inspection mechanism 4 to reset to its initial position. The electric clamp 8 releases the workpiece, and the next set of coils can be inspected. For heat exchange coils with different pitches and tube diameters, the threaded rod 33 and threaded sleeve 36 with the corresponding pitch specifications can be replaced by a coupling. By adjusting the deflection angle and feed stroke of the open plate 416, the inspection adaptation of different workpiece models can be completed.

Claims

1. A testing fixture for heat exchanger coils, comprising an operating support (1), characterized in that, The rear end of the operating bracket (1) is fixedly connected to a longitudinal mounting plate (2). The front end of the longitudinal mounting plate (2) is provided with a moving mechanism (3) for driving the detection feed. The moving mechanism (3) includes a top plate (37). The front end of the top plate (37) is provided with a detection mechanism (4) for detecting the heat exchange coil. The detection mechanism (4) includes a detection component (41) for adapting to the spiral outer wall of the heat exchange coil. The detection mechanism (4) includes a cleaning component (42) for cleaning the outer wall of the heat exchange coil.

2. The testing fixture for a heat exchange coil according to claim 1, characterized in that, The moving mechanism (3) includes a first motor (31) installed at the rear end of the longitudinal mounting plate (2). The output shaft of the first motor (31) is fixedly connected to a retaining rod (32) via a coupling. Multiple retaining bars are fixedly connected around the outer wall of the retaining rod (32). A threaded rod (33) is slidably connected to the outer side of the retaining rod (32). A cavity is opened on the inner side of the threaded rod (33). A spring (34) is provided on the inner side of the cavity of the threaded rod (33). One end of the spring (34) is fixedly connected to the retaining rod (32), and the other end of the spring (34) is fixedly connected to the threaded rod (33). The front end of the threaded rod (33) is fixedly connected to the top plate (37).

3. The testing fixture for a heat exchange coil according to claim 1, characterized in that, The front end of the longitudinal mounting plate (2) is fixedly connected to a fixing bracket (35), and the inner side of the fixing bracket (35) is fixedly connected to a threaded sleeve (36), and the inner side of the threaded sleeve (36) is threadedly connected to the threaded rod (33).

4. The testing fixture for a heat exchanger coil according to claim 1, characterized in that, The top plate (37) is provided with a connecting bracket (411) at the front end. A second motor (412) is installed at the front end of the connecting bracket (411). The output shaft of the second motor (412) is fixedly connected to a rotating sleeve (413). A fixed rotating shaft (414) is fixedly connected to the inner side of the rotating sleeve (413). Both ends of the fixed rotating shaft (414) are equipped with a first electric push rod (415) through a connecting block.

5. The testing fixture for a heat exchange coil according to claim 4, characterized in that, The output shafts of the two first electric actuators (415) are fixedly connected to an open plate (416). A plurality of limiting shafts (417) are rotatably connected around one side of the open plate (416). A limiting baffle is provided on the outer side of the limiting shafts (417). An open annular plate (418) is rotatably connected to the outer side of the plurality of limiting shafts (417). A plurality of laser contour sensors (419) are installed around the inner wall of the open annular plate (418). A retaining tooth is provided around the outer wall of the open annular plate (418).

6. The testing fixture for a heat exchange coil according to claim 5, characterized in that, A third motor (4113) is installed on one side of the opening plate (416). The output shaft of the third motor (4113) is fixedly connected to a first pulley (4110). A synchronous belt (4111) is rotatably connected to the outer side of the first pulley (4110). A plurality of second pulleys (4112) are rotatably connected to the inner side of the synchronous belt (4111). One end of the second pulley (4112) is rotatably connected to the inner side of the opening plate (416) through a rotating shaft. The plurality of second pulleys (4112) are arranged around the outer side of the opening annular plate (418). The outer wall of the synchronous belt (4111) is surrounded by teeth. The outer side of the synchronous belt (4111) meshes with the outer side of the opening annular plate (418).

7. The testing fixture for a heat exchanger coil according to claim 5, characterized in that, Multiple assembly blocks (421) are fixedly connected around the other side of the opening plate (416). A fourth motor (422) is installed on one side of the assembly block (421). A cavity rod (424) is fixedly connected to the output shaft of the fourth motor (422). Multiple flexible sponge strips (425) are provided on the side of the multiple cavity rods (424) that are close to each other. A laser rangefinder (423) is installed on the side of the multiple assembly blocks (421) that are close to each other.

8. The testing fixture for a heat exchanger coil according to claim 7, characterized in that, A toothed rack (426) is slidably connected to the inner side of the cavity rod (424). Multiple limiting rods (427) are rotatably connected to both sides of the toothed rack (426). Multiple gears (428) are meshed with the outer side of the toothed rack (426). The two ends of the gears (428) are rotatably connected to the inner side of the cavity rod (424) through a rotating shaft. The same end of the multiple gears (428) is fixedly connected to the corresponding flexible sponge strip (425).

9. The testing fixture for a heat exchanger coil according to claim 8, characterized in that, A second electric actuator (429) is installed on one side of the cavity rod (424). The output shaft of the second electric actuator (429) is fixedly connected to the rack (426). A limit baffle is fixedly connected to the other end of the rack (426). A pressure sensor is provided on the inner side of the second electric actuator (429).

10. The testing fixture for a heat exchange coil according to claim 1, characterized in that, The operating bracket (1) is fixedly connected to a horizontal mounting plate (5). A third electric push rod (6) is installed on the inner side of the horizontal mounting plate (5). A connecting rod (7) is fixedly connected to the output shaft of the third electric push rod (6). Electric clamps (8) are installed at both ends of the connecting rod (7). A straight tube of a heat exchange coil is provided on the inner side of the two electric clamps (8). Two guide telescopic rods (9) are fixedly connected to the inner side of the horizontal mounting plate (5). The telescopic shafts of the two guide telescopic rods (9) are fixedly connected to the housing of the corresponding electric clamps (8) above.

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