A device and method for measuring the diameter of metal pipe fittings

Abstract

This invention relates to the field of pipe diameter measurement, specifically to a device and method for measuring the diameter of metal pipe fittings. The device includes a frame with an air pump mounted on one side, the air pump's outlet connected to an air supply pipe. The frame is equipped with a clamping mechanism to hold the pipe fitting and prevent displacement during measurement. Inside the pipe fitting, a measuring mechanism for measuring its inner diameter is installed. A fastening mechanism is connected to the tail of the pipe fitting, and the tail of the fastening mechanism is connected to the air supply pipe. The air supply pipe delivers gas to the measuring mechanism via the air pump, propelling the measuring mechanism within the pipe fitting to complete the inner diameter measurement. By designing the measuring mechanism with a compact structure, it can easily enter the interior of slender pipe fittings. Combined with a gas-driven method, it propels the measuring instrument along the inner wall of the pipe fitting, solving the problems of traditional laser equipment's inability to detect the inner wall and the inability of large robots to enter. This achieves full-length inner diameter measurement of long pipe fittings, filling a technological gap in the industry.

Description

Technical Field

[0001] This invention relates to the field of pipe diameter measurement, specifically to a device and method for measuring the diameter of metal pipes. Background Technology

[0002] In precision manufacturing, petrochemical, and aerospace industries, the diameter accuracy of metal pipe fittings directly affects the assembly precision and operational safety of equipment. Therefore, pipe fitting diameter measurement is a core process in production and inspection. Currently, the technology for measuring the outer diameter of pipe fittings is relatively mature. Equipment such as laser scanners and optical projectors can quickly achieve accurate non-contact inspection. For conventional pipe fittings with an inner diameter greater than 20cm and a length less than 1m, pipe inspection robots carrying sensors can also enter the interior to complete the inner diameter measurement, meeting basic industrial needs.

[0003] However, in fields such as nuclear power equipment, medical devices, and micro-precision instruments, a large number of slender metal pipes with an inner diameter of less than 20 cm and a length of more than 1 m are used. Measuring the inner diameter of these pipes faces multiple technical challenges:

[0004] External inspection equipment such as laser scanners cannot penetrate the outer wall of pipe fittings to obtain internal wall dimension data. Existing pipe inspection robots are large, with a minimum outer diameter generally exceeding 20cm, making it impossible to enter the interior of slender pipe fittings. Furthermore, micro-robots have poor mobility in confined spaces, making it difficult to complete long-distance continuous measurements. When the measuring instrument moves inside slender pipe fittings, the gas supply pipe must be pulled in simultaneously. As the length of the gas supply pipe increases, the resistance generated by its own weight and friction with the pipe wall gradually increases, easily causing the measuring instrument to detach from the gas supply pipe, interrupting the measurement process. After the measurement is completed, the measuring instrument and gas supply pipe must be removed from the pipe fitting. Traditional devices have complex connection structures between the measuring mechanism and the gas supply pipe, requiring a significant amount of time for disassembly, especially for pipe fittings longer than 1m, resulting in low disassembly and assembly efficiency and severely impacting inspection efficiency. Summary of the Invention

[0005] To address the problems in the prior art, the present invention provides a device and method for measuring the diameter of metal pipe fittings.

[0006] The technical solution adopted by the present invention to solve its technical problem is as follows: a metal pipe diameter measuring device, including a frame, an air pump is provided on one side of the frame, and an air supply pipe is connected to the air outlet of the air pump; a clamping mechanism is provided on the frame for clamping the pipe to prevent displacement of the pipe during measurement; a measuring mechanism for measuring the inner diameter of the pipe is installed inside the pipe; a fastening mechanism is connected to the tail of the pipe, and the tail of the fastening mechanism is connected to the air supply pipe, and the air supply pipe delivers gas to the measuring mechanism through the air pump to push the measuring mechanism to move inside the pipe and complete the inner diameter measurement.

[0007] Preferably, the measuring mechanism includes a measuring instrument, which is equipped with a measuring head for measuring the inner diameter of the pipe fitting; the outer wall of the measuring instrument is provided with a plurality of sliding balls that slide along the inner wall of the pipe fitting, and the sliding balls are connected to the measuring instrument through flexible rods.

[0008] Preferably, the measuring mechanism further includes an air chamber inside the measuring instrument, the air chamber having a plurality of annularly distributed end holes, each end hole having a corresponding waist hole, the waist hole having a tail hole at its end, and the diameter of the waist hole being smaller than the diameter of the end holes and the tail hole; the waist hole having a plurality of capillary holes extending into the groove for mounting the fastening mechanism.

[0009] Preferably, the measuring instrument has a slot at its tail end, and a slidable blocking block is provided in the slot; sliders are provided on both sides of the blocking block, and an elastic element is provided below the slider in the slot, the elastic element being used to push the slider to reset; one end of the blocking block is used to block the tail hole, and the other end is used to limit the fastening mechanism; when gas is discharged from the tail hole, the blocking block moves to open the tail hole and engage with the fastening mechanism; when the gas supply stops, the elastic element drives the blocking block to move out of the fastening mechanism.

[0010] Preferably, the fastening mechanism includes a connector that is inserted into the internal slot of the measuring instrument. The connector is provided with an annular pad and has a blocking groove that slides with the blocking block. The annular pad is made of a flexible material and its diameter is larger than that of the connector in the initial state.

[0011] Preferably, the frame is provided with an electrical control box, a motor and a gearbox, the motor is used to drive the gearbox to rotate, the output end of the gearbox is provided with a gear, the gear meshes with the clamping mechanism; the frame is provided with a plurality of guide frames for supporting the clamping mechanism.

[0012] Preferably, the clamping mechanism includes a turntable disposed above the frame, the turntable having multiple clearance slots, each corresponding to a clamping rod, and the turntable being rotatable relative to the clamping rods; the turntable having a gear plate with teeth meshing with gears; the clamping rods having clamping heads for clamping pipe fittings, and guide posts on the clamping rods; the turntable having guide grooves, which, when rotated, push the guide posts to move, causing the guide posts to bring the clamping rods closer together to clamp the pipe fittings.

[0013] Preferably, the motor is a synchronous motor, and the clamping mechanism is equipped with a pressure sensor for feedback of clamping force; when the clamping head just clamps the pipe, the pressure sensor triggers the motor to stop working.

[0014] Preferably, the connection between the capillary pore and the waist hole is inclined forward. When gas flows through the waist hole, the capillary pore can generate an adsorption force to adsorb the outer wall of the annular pad. Furthermore, the air pump can change the magnitude of the adsorption force of the capillary pore by adjusting the output air pressure.

[0015] A method for measuring the diameter of a metal pipe fitting as described above includes the following steps:

[0016] Step 1: Pass the pipe to be measured through the inside of the two turntables, start the motor, the motor drives the gear to rotate through the gearbox, the gear drives the toothed disc to rotate, and the toothed disc drives the guide groove to rotate.

[0017] Step 2: During the rotation of the guide groove, the guide column on the clamping rod is pushed to move linearly along the direction of the guide frame, so that the clamping rod drives the clamping head to move closer to the pipe fitting; when the pressure sensor feedback that the clamping head just clamps the pipe fitting, the motor stops working, and the pipe fitting is limited;

[0018] Step 3: Insert the connector of the fastening mechanism into the slot of the measuring instrument to seal the end of the capillary hole with the annular gasket; turn on the air pump, and the air pump will input gas into the air chamber through the air delivery pipe;

[0019] Step 4: The gas in the gas chamber flows through the end hole and waist hole in sequence, and is discharged from the tail hole. During the gas discharge process, the capillary pores generate an adsorption force due to Bernoulli's principle to adsorb the outer wall of the annular pad. At the same time, the gas pushes the blocking block to slide in the block groove, so that one end of the blocking block is stuck into the blocking groove of the connector, thereby fixing the measuring instrument and the connector.

[0020] Step 5: Place the measuring instrument inside the pipe fitting. The gas continuously discharged from the tail hole pushes the measuring instrument to move along the inner wall of the pipe fitting. The measuring head measures the inner diameter of the pipe fitting in real time. When the measuring instrument goes deeper into the pipe fitting, causing the length of the gas delivery pipe to increase, the air pump appropriately increases the output air pressure to increase the capillary adsorption force and prevent the connector from detaching from the measuring instrument.

[0021] Step 6: After the measurement is completed, turn off the air pump to stop the air supply, and the capillary adsorption force disappears; the elastic element pushes the slider to reset the blocking block, so that the blocking block moves out of the blocking groove; pull the connector to separate it from the measuring instrument, and then pull the air supply tube from the air pump to remove the measuring instrument from the tube, thus completing the measurement.

[0022] Beneficial effects:

[0023] By designing the measuring mechanism into a compact structure, it can easily enter the interior of slender pipes with an inner diameter of less than 20cm. Combined with a gas-driven method, it propels the measuring instrument along the inner wall of the pipe, solving the problems that traditional laser equipment cannot detect the inner wall and that robots are too large to enter. It realizes the full-length inner diameter measurement of slender pipes with a length greater than 1m, filling a technological gap in the industry.

[0024] The dual-fixation structure ensures measurement stability. Firstly, utilizing Bernoulli's principle, the gas flow through the waist hole creates a capillary suction force, firmly adhering the annular pad of the fastening mechanism to the measuring instrument's slot, forming initial fixation. Secondly, the gas pushes the blocking block into the blocking groove of the connector, forming a mechanical limiting fixation. This dual-fixation structure effectively prevents the measuring instrument from detaching from the gas supply pipe during measurement. Furthermore, the air pump can increase the suction force by adjusting the air pressure to adapt to changes in resistance caused by the increased length of the gas supply pipe, ensuring stable and reliable measurement throughout the entire process.

[0025] Furthermore, once the measurement is complete, simply turn off the air pump to stop the air supply, and the capillary adsorption force will immediately disappear. The elastic element will push the blocking block to automatically reset and disengage from the blocking groove. At this point, pulling the connector will allow the measuring instrument to be quickly separated from the fastening mechanism. Then, pulling the air supply pipe from the air pump end will allow the measuring instrument to be pulled out from inside the pipe. The entire disassembly and assembly process does not require complicated tools, which improves efficiency compared to traditional devices and significantly reduces testing time.

[0026] The sliding ball on the outer wall of the measuring instrument is connected by a flexible rod, which can slide smoothly along the inner wall of the pipe, greatly reducing the frictional resistance and avoiding the deviation of the measuring instrument due to friction. The clamping mechanism is driven by a synchronous motor and, together with the pressure sensor, provides feedback on the clamping force, which can accurately control the clamping force of the clamping head on the pipe, preventing the pipe from shifting and avoiding excessive squeezing that could cause the pipe to deform, thus further ensuring the measurement accuracy. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 This is a partial cross-sectional view of the present invention;

[0030] Figure 3 for Figure 2 Enlarged structural diagram at point A in the diagram;

[0031] Figure 4 for Figure 2 Enlarged structural diagram at point B in the diagram;

[0032] Figure 5 for Figure 2 Enlarged structural diagram at point C;

[0033] Figure 6 This is a schematic diagram showing the connection between the measuring mechanism and the fastening mechanism of the present invention;

[0034] Figure 7 This is a schematic diagram of the fastening mechanism of the present invention;

[0035] Figure 8This is a partial structural cross-sectional view of the measuring mechanism;

[0036] Figure 9 This is a schematic diagram of the blocking block structure;

[0037] Figure 10 This is a schematic diagram of the clamping mechanism.

[0038] Figure 11 for Figure 10 A sectional view.

[0039] In the diagram: 1. Frame; 11. Electrical control box; 12. Support frame; 13. Guide frame; 14. Motor; 15. Gearbox; 16. Limit sleeve; 17. Gear; 100. Pipe fitting; 2. Air pump; 21. Air supply pipe; 3. Clamping mechanism; 31. Turntable; 32. Gear plate; 33. Relief groove; 34. Clamping head; 35. Clamping rod; 36. Guide column; 37. Guide groove; 4. Measuring mechanism; 41. Measuring instrument; 42. Measuring head; 43. Air chamber; 44. End hole; 45. Waist hole; 46. Capillary hole; 47. Tail hole; 48. Sliding ball; 49. Blocking block; 410. Block groove; 411. Elastic element; 412. Slider; 5. Fastening mechanism; 51. Connector; 52. Annular pad; 53. Blocking groove. Detailed Implementation

[0040] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0041] In one embodiment, please refer to the appendix to the specification. Figure 1-11 As shown, the present invention discloses a metal pipe diameter measuring device, comprising a frame 1, an air pump 2 disposed on one side of the frame 1, and an air supply pipe 21 connected to the air outlet of the air pump 2; a clamping mechanism 3 for clamping the pipe 100 to prevent displacement of the pipe 100 during measurement is provided on the frame 1; a measuring mechanism 4 for measuring the inner diameter of the pipe 100 is installed inside the pipe 100; a fastening mechanism 5 is connected to the tail of the pipe 100, and the tail of the fastening mechanism 5 is connected to the air supply pipe 21. The air supply pipe 21 supplies gas to the measuring mechanism 4 through the air pump 2 to push the measuring mechanism 4 to move inside the pipe 100 and complete the inner diameter measurement.

[0042] The slender metal tube 100 to be measured is passed through the center hole of the two turntables 31. The position of the tube 100 is adjusted so that the axis of the tube 100 is consistent with the moving direction of the measuring mechanism 4 to avoid deviation during measurement.

[0043] When the pressure signal reaches the preset threshold, the electrical control box 11 automatically controls the motor 14 to stop working, thus completing the limit fixation of the pipe fitting 100.

[0044] Connect the air outlet of the air pump 2 to the tail of the connector 51 of the fastening mechanism 5 through the air supply pipe 21, and seal it with a clamp to ensure that there is no gas leakage in the air path; test the air pressure regulation function of the air pump 2 through the electrical control box 11 to confirm that the air pressure can be stably adjusted within the range of 0.3-0.8MPa.

[0045] The measuring mechanism 4 includes a measuring instrument 41, which is equipped with a measuring head 42 for measuring the inner diameter of the pipe fitting 100; the outer wall of the measuring instrument 41 is provided with a plurality of sliding balls 48 that slide along the inner wall of the pipe fitting 100, and the sliding balls 48 are connected to the measuring instrument 41 through flexible rods.

[0046] The measuring mechanism 4 also includes an air chamber 43 inside the measuring instrument 41. The air chamber 43 has a plurality of annularly distributed end holes 44. Each end hole 44 has a corresponding waist hole 45 at one end. Each waist hole 45 has a tail hole 47 at its end. The diameter of the waist hole 45 is smaller than the diameter of the end holes 44 and the tail hole 47. Each waist hole 45 has a plurality of capillary holes 46, which extend into the groove for mounting the fastening mechanism 5.

[0047] The measuring instrument 41 has a slot 410 at its tail end, and a slidable blocking block 49 is provided in the slot 410. Slider blocks 412 are provided on both sides of the blocking block 49. An elastic element 411 located below the slider 412 is provided in the slot 410. The elastic element 411 is used to push the slider 412 to reset. One end of the blocking block 49 is used to block the tail hole 47, and the other end is used to limit the fastening mechanism 5. When gas is discharged from the tail hole 47, the blocking block 49 moves to open the tail hole 47 and lock into the fastening mechanism 5. When the gas supply stops, the elastic element 411 drives the blocking block 49 to move out of the fastening mechanism 5.

[0048] The fastening mechanism 5 includes a connector 51 that inserts into the internal slot of the measuring instrument 41. The connector 51 has an annular pad 52 and a blocking groove 53 that slides with the blocking block 49. The annular pad 52 is made of a flexible material, and its initial diameter is larger than that of the connector 51. An elastic element 411 and the blocking block 49 are installed in the block slot 410 of the measuring instrument 41, ensuring that the sliders 412 on both sides of the blocking block 49 slide smoothly against the inner wall of the block slot 410 without jamming. The connector 51 of the fastening mechanism 5 is then fitted with the annular pad 52. The annular pad 52 is preferably made of nitrile rubber, which has good elasticity and sealing properties.

[0049] The frame 1 is equipped with an electrical control box 11, a motor 14 and a reduction gearbox 15. The motor 14 is used to drive the reduction gearbox 15 to rotate. The output end of the reduction gearbox 15 is equipped with a gear 17, which meshes with the clamping mechanism 3. The frame 1 is equipped with a plurality of guide frames 13 for supporting the clamping mechanism 3.

[0050] Fix the electrical control box 11, motor 14, gearbox 15 and guide frame 13 in the preset position of the frame 1, ensuring that the output shaft of motor 14 is coaxially connected with the input shaft of gearbox 15, and that the gear 17 on the output shaft of gearbox 15 is aligned with the gear plate 32 of clamping mechanism 3 to ensure smooth meshing and no jamming.

[0051] Preferably, a limiting sleeve 16 is provided on the frame 1, the limiting sleeve 16 is connected to the support frame 12, and the limiting sleeve 16 plays the role of stabilizing the support frame 12; the support frame 12 plays the role of guiding and supporting the gas pipeline 21.

[0052] The clamping mechanism 3 includes a turntable 31 disposed above the frame 1. The turntable 31 has multiple clearance slots 33, and clamping rods 35 are correspondingly disposed in each clearance slot 33. The turntable 31 can rotate relative to the clamping rods 35. The turntable 31 is provided with a toothed disc 32, and the toothed disc 32 is provided with teeth that mesh with gears 17. The clamping rods 35 are provided with clamping heads 34 for clamping the pipe fitting 100, and the clamping rods 35 are provided with guide posts 36. The turntable 31 is provided with a guide groove 37. When the guide groove 37 rotates, it pushes the guide post 36 to move, so that the guide post 36 drives the clamping rods 35 to move closer to each other to achieve clamping of the pipe fitting 100.

[0053] The turntable 31 is mounted on the guide frame 13 via bearings, allowing the turntable 31 to rotate flexibly; a clamping rod 35 is inserted into the relief groove 33 of the turntable 31, ensuring that the guide post 36 on the clamping rod 35 is fully embedded in the guide groove 37 of the turntable 31, and the clamping head 34 at the end of the clamping rod 35 faces the clamping center of the pipe fitting 100.

[0054] The motor 14 is started by the electrical control box 11. The motor 14 is a synchronous motor to ensure that the two turntables 31 rotate synchronously and prevent uneven force on the pipe fitting 100. The power of the motor 14 is reduced by the reduction box 15 and then transmitted to the gear 17. The gear 17 drives the gear plate 32 to rotate, and the gear plate 32 drives the turntable 31 to rotate synchronously.

[0055] When the turntable 31 rotates, the guide groove 37 pushes the guide column 36 on the clamping rod 35 to move linearly along the direction of the guide frame 13, so that multiple clamping rods 35 move closer to the pipe fitting 100 in a synchronized manner; the pressure sensor on the clamping mechanism 3 collects the contact pressure between the clamping head 34 and the outer wall of the pipe fitting 100 in real time and transmits the signal to the electrical control box 11.

[0056] The motor 14 is a synchronous motor, and the clamping mechanism 3 is equipped with a pressure sensor for feedback of clamping force; when the clamping head 34 just clamps the pipe 100, the pressure sensor triggers the motor 14 to stop working.

[0057] The connection between the capillary pore 46 and the waist hole 45 is inclined forward. When the gas flows through the waist hole 45, the capillary pore 46 can generate an adsorption force to adsorb the outer wall of the annular pad 52. The air pump 2 can change the magnitude of the adsorption force of the capillary pore 46 by adjusting the output air pressure.

[0058] Align the connector 51 of the fastening mechanism 5 with the slot at the tail of the measuring instrument 41 and insert it slowly. Since the initial diameter of the annular pad 52 is larger than the diameter of the connector 51, the annular pad 52 will be slightly compressed during the insertion process. Finally, the annular pad 52 fits tightly against the inner wall of the slot, completely sealing the end of the capillary pore 46 and forming an initial seal.

[0059] Start the air pump 2, set the initial air pressure, and the air pump 2 delivers gas into the connector 51 through the air supply pipe 21. The gas enters the air chamber 43 of the measuring instrument 41 smoothly.

[0060] The gas in the air chamber 43 is evenly distributed to multiple end holes 44 and flows into the corresponding waist holes 45. Since the diameter of the waist holes 45 is smaller than that of the end holes 44 and the tail holes 47, the gas flow rate in the waist holes 45 is accelerated. According to Bernoulli's principle, the air pressure at the waist holes 45 is reduced, causing the capillary pores 46 to generate an adsorption force, which firmly adsorbs the outer wall of the annular pad 52 onto the inner wall of the groove, thus achieving the initial fixation of the measuring instrument 41 and the connector 51.

[0061] Meanwhile, the gas in the waist hole 45 continues to flow to the tail hole 47 and is discharged outward. During the gas flow, it generates a continuous thrust on the arc-shaped end face of the blocking block 49, pushing the blocking block 49 to overcome the elastic force of the elastic element 411 and slide downward in the block groove 410. When the upper end of the blocking block 49 is completely inserted into the blocking groove 53 of the connector 51, the blocking block 49 stops sliding and forms a mechanical limit fixation. At this time, the tail hole 47 maintains a stable exhaust state, and the fixed structure is assembled.

[0062] Holding the gas delivery tube 21, slowly insert the measuring instrument 41 into one end of the fitting 100, ensuring that the sliding ball 48 on the outer wall of the measuring instrument 41 is in complete contact with the inner wall of the fitting 100; the sliding ball 48 is connected by a flexible rod, which can adapt to the slight unevenness of the inner wall of the fitting 100, reduce the frictional resistance of movement, and avoid scratching the inner wall of the fitting.

[0063] The gas continuously discharged from the tail hole 47 forms a stable pressure difference at the tail of the measuring instrument 41, which pushes the measuring instrument 41 to move slowly along the inner wall of the pipe fitting 100. During the movement, the measuring head 42 (preferably a laser displacement sensor with an accuracy of ±0.001mm) on the measuring instrument 41 collects the diameter data of the inner wall of the pipe fitting 100 in real time and wirelessly transmits the data to the display screen of the electrical control box 11 to realize real-time data display, storage and abnormal alarm.

[0064] When the measuring instrument 41 penetrates into the pipe fitting 100, the weight of the air supply pipe 21 and the frictional resistance with the pipe wall increase. At this time, the output air pressure of the air pump 2 is appropriately increased through the electrical control box 11. The increased air pressure further accelerates the gas flow rate in the waist hole 45, and the adsorption force of the capillary pore 46 increases accordingly, ensuring that the connector 51 does not detach from the measuring instrument 41. At the same time, the increased exhaust thrust can offset the resistance and ensure that the measuring instrument 41 moves continuously and stably.

[0065] Until the measuring instrument 41 extends out from the other end of the pipe fitting 100, the electrical control box 11 automatically records the complete inner diameter measurement data of the pipe fitting 100, including the diameter values ​​at different locations, the maximum diameter, the minimum diameter, and the average diameter, generates a measurement report, and completes the measurement process.

[0066] Preferably, the gas supply pipe 21 is an elastic pipe that can be appropriately extended or retracted.

[0067] Working principle: During measurement, the pipe fitting 100 is first passed through the interior of the two turntables 31. Two motors 14, preferably synchronous motors, are then started. The motors 14 drive the gear 17 to rotate via a reducer. The gear 17 drives the gear disc 32 to rotate, which in turn drives the guide groove 37 to rotate. The rotation of the guide groove 37 causes the guide post 36 on the clamping rod 35 to slide along the position of the guide groove 37. The guide post 36 slides linearly along the direction of the guide frame 13 (see attached instruction manual). Figure 1-2 (As shown in Figure 4); the clamping force is fed back by a pressure sensor. When the clamping head 34 on the clamping rod 35 just clamps the pipe fitting 100, the motor 14 stops working; at this time, the pipe fitting 100 is limited.

[0068] Because the annular pad 52 is made of a flexible material, such as rubber, it has a certain degree of elasticity. Initially, the diameter of the annular pad 52 is larger than the diameter of the connector 51. During installation, there will be a feeling of resistance when the annular pad 52 enters the interior of the connector 51. The connector 51 is installed with its orifice aligned with the interior of the slot. When the measuring instrument 41 and the connector 51 are installed, the annular pad 52 will seal the end of the capillary tube. Then, the air pump 2 is turned on, and the air pump 2 introduces gas into the interior of the air chamber 43. The gas inside the air chamber 43 needs to be discharged outwards. The gas will first flow through the end hole 4. 4. The gas enters the interior of the waist hole 45 and exits from the end of the tail hole 47. At this time, because the end of the capillary tube is inclined forward at the connection with the waist hole 45, the capillary tube will generate an adsorption force due to Bernoulli's principle, adsorbing the outer wall of the annular pad 52. When the gas is discharged, it will push the blocking block 49 to move. The blocking block 49 slides inside the block groove 410. The structure of the blocking block 49 sealing the tail hole 47 is an arc-shaped structure, which facilitates the gas discharged from the tail hole 47 to push the blocking block 49 downward. The other end of the blocking block 49 enters the interior of the blocking groove 53, making... The connector 51 and the measuring instrument 41 will not detach. At this point, after the gas discharged from the tail hole 47 stabilizes, the measuring instrument 41 is placed inside the pipe fitting 100. Because the tail hole 47 continuously discharges gas, the pipe fitting 100 is in a fixed state. Multiple sliding balls 48 contact the inner wall of the pipe fitting 100, effectively reducing friction. Gas discharged from the tail hole 47 pushes the measuring instrument 41 to move inside the pipe fitting 100, thereby achieving the measurement of the inner diameter of the slender pipe fitting 100. As the measuring instrument 41 enters the pipe fitting 100, the gas delivery pipe 21 that the measuring instrument 41 needs to pull also... When the pump body increases the gas pressure appropriately, the increased gas pressure makes the capillary suction force stronger, preventing the connector 51 from detaching from the measuring instrument 41. When the measuring instrument 41 passes through the pipe fitting 100, simply stop the gas supply. The capillary will not generate suction force. At the same time, the blocking block 49 will reset under the action of the elastic element 411, so that the blocking block 49 will no longer limit the blocking groove 53. Pull the connector 51, and the connector 51 will separate from the measuring instrument 41. Then pull the connecting pipe from the air pump 2, so that the connecting pipe moves out from the port that initially entered the pipe fitting 100.

[0069] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A metal pipe diameter measuring device, comprising a frame (1), one side of the frame (1) is provided with an air pump (2), the air outlet of the air pump (2) is connected with a gas conveying pipe (21); characterized in that, The rack (1) is provided with a clamping mechanism (3) for clamping the pipe (100) to prevent displacement of the pipe (100) during measurement; the pipe (100) is internally provided with a measuring mechanism (4) for measuring the inner wall diameter of the pipe (100); the tail of the pipe (100) is connected with a fastening mechanism (5), the tail of the fastening mechanism (5) is connected with a gas conveying pipe (21), the gas conveying pipe (21) conveys gas to the inside of the measuring mechanism (4) through a gas pump (2), so as to drive the measuring mechanism (4) to move in the pipe (100) and complete the inner diameter measurement; The measuring mechanism (4) comprises a measuring instrument (41), the measuring instrument (41) is provided with a measuring head (42) for measuring the inner wall diameter of the pipe (100); the outer wall of the measuring instrument (41) is provided with a plurality of sliding balls (48) sliding along the inner wall of the pipe (100), the sliding balls (48) are connected with the measuring instrument (41) through flexible rods; The measuring mechanism (4) further comprises a gas chamber (43) opened in the measuring instrument (41), the gas chamber (43) is provided with a plurality of annularly distributed end holes (44), one end of each of the end holes (44) is provided with a waist hole (45) in one-to-one correspondence, the end of the waist hole (45) is provided with a tail hole (47), and the diameter of the waist hole (45) is smaller than the diameters of the end hole (44) and the tail hole (47); the waist hole (45) is provided with a plurality of capillary holes (46), the capillary holes (46) extend into the hole groove for mounting the fastening mechanism (5); The tail of the measuring instrument (41) is provided with a block groove (410), the block groove (410) is provided with a slidable blocking block (49); the blocking block (49) is provided with sliding blocks (412) on both sides, the block groove (410) is provided with elastic members (411) below the sliding blocks (412), the elastic members (411) are used to push the sliding blocks (412) to reset; one end of the blocking block (49) is used to block the tail hole (47), and the other end is used to limit the fastening mechanism (5); when the tail hole (47) has gas discharged, the blocking block (49) moves to open the tail hole (47) and is clamped into the fastening mechanism (5); when the gas supply is stopped, the elastic members (411) drive the blocking block (49) to move out of the fastening mechanism (5); The fastening mechanism (5) comprises a connecting head (51) inserted into the hole groove in the measuring instrument (41), the connecting head (51) is provided with an annular pad (52), and the connecting head (51) is provided with a blocking groove (53) in sliding cooperation with the blocking block (49); the annular pad (52) is made of flexible material, and in the initial state, the diameter of the annular pad (52) is larger than the diameter of the connecting head (51).

2. The metal pipe fitting diameter measuring device of claim 1, wherein, The rack (1) is provided with an electric control box (11), a motor (14) and a speed reducer (15), the motor (14) is used to drive the speed reducer (15) to rotate, the output end of the speed reducer (15) is provided with a gear (17), the gear (17) is engaged with the clamping mechanism (3); the rack (1) is provided with a plurality of guide frames (13) for supporting the clamping mechanism (3).

3. The metal pipe fitting diameter measuring device of claim 2, wherein, The clamping mechanism (3) comprises a rotating disc (31) arranged above the frame (1), a plurality of accommodation grooves (33) are formed in the rotating disc (31), a clamping rod (35) is arranged in each of the accommodation grooves (33) in a one-to-one correspondence, and the rotating disc (31) is rotatable relative to the clamping rod (35); a gear disc (32) is arranged on the rotating disc (31), and a clamping tooth of the gear disc (32) is engaged with a gear (17); a clamping head (34) for clamping the pipe (100) is arranged on the clamping rod (35), and a guide column (36) is arranged on the clamping rod (35); a guide groove (37) is arranged on the rotating disc (31), and the guide groove (37) drives the guide column (36) to move when rotating, so that the guide column (36) drives the clamping rod (35) to move close to each other to clamp the pipe (100).

4. The metal pipe fitting diameter measuring device of claim 2, wherein, The motor (14) is a synchronous motor, and a pressure sensor for feeding back the clamping force is arranged on the clamping mechanism (3); when the clamping head (34) clamps the pipe (100), the pressure sensor triggers the motor (14) to stop working.

5. The metal pipe fitting diameter measuring device of claim 1, wherein, The connecting part between the capillary hole (46) and the waist hole (45) is inclined forward, and when the gas flows through the waist hole (45), the capillary hole (46) can generate an adsorption force to adsorb the outer wall of the annular pad (52); and the air pump (2) can change the adsorption force of the capillary hole (46) by adjusting the output air pressure.

6. A measuring method of the metal pipe fitting diameter measuring apparatus according to any one of claims 1 to 5, characterized by, The method comprises the following steps: Step 1: the pipe (100) to be measured is inserted into the two rotating discs (31), the motor (14) is started, the motor (14) drives the gear (17) to rotate through the speed reducer (15), the gear (17) drives the gear disc (32) to rotate, and the gear disc (32) drives the guide groove (37) to rotate; Step 2: during the rotation of the guide groove (37), the guide column (36) on the clamping rod (35) moves linearly along the guide frame (13), so that the clamping rod (35) drives the clamping head (34) to move close to the pipe (100); when the pressure sensor feeds back that the clamping head (34) clamps the pipe (100), the motor (14) stops working, and the pipe (100) is limited; Step 3: the connecting head (51) of the fastening mechanism (5) is inserted into the hole groove of the measuring instrument (41), so that the annular pad (52) blocks the end part of the capillary hole (46); the air pump (2) is opened, and the air pump (2) inputs the gas into the air chamber (43) through the gas conveying pipe (21); Step 4: the gas in the air chamber (43) flows through the end hole (44), the waist hole (45) and the tail hole (47) in sequence; During the gas discharge process, the capillary hole (46) generates an adsorption force to adsorb the outer wall of the annular pad (52), and the gas drives the blocking block (49) to slide in the block groove (410), so that one end of the blocking block (49) is clamped into the blocking groove (53) of the connecting head (51), and the measuring instrument (41) and the connecting head (51) are fixed. Step 5: Put the measuring instrument (41) into the pipe (100), the gas continuously discharged from the tail hole (47) pushes the measuring instrument (41) to move along the inner wall of the pipe (100), and the measuring head (42) measures the diameter size of the inner wall of the pipe (100) in real time; when the measuring instrument (41) is deeply put into the pipe (100), the length of the gas conveying pipe (21) is increased, the air pump (2) appropriately increases the output air pressure, the adsorption force of the capillary hole (46) is increased, and the connection head (51) and the measuring instrument (41) are prevented from being separated; Step 6: After the measurement is completed, the air pump (2) is turned off to stop gas conveying, the adsorption force of the capillary hole (46) disappears; the elastic element (411) pushes the sliding block (412) to drive the blocking block (49) to reset, so that the blocking block (49) moves out of the blocking groove (53); the connection head (51) is pulled to separate from the measuring instrument (41), the gas conveying pipe (21) is pulled from the air pump (2), the measuring instrument (41) is taken out from the pipe (100), and the measurement is completed.

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