A Measuring Method and Detection Device for the Axial Position Deviation of Pipe Materials

Abstract

The present invention provides a method and a detection device for measuring the deviation of the axis position of a pipe, comprising a workbench, a three-axis sliding table mechanism, a positioning device for a workpiece to be measured, and a detection device; the detection device is installed at the sliding end of the three-axis sliding table mechanism and points to the positioning device for the workpiece to be measured; the detection device includes a base, a detection claw, a bending generating device, and a sensing device. The detection claw bends towards the pipe under the action of the bending generating device, and the sensing device converts the bending amount into an electrical signal output. Through the relationship between the displacement variable and the electrical signal amount, the offset amount of the pipe axis can be obtained. The present invention provides a method and a detection device for measuring the deviation of the axis position of a pipe, which can be applied to the measurement of the axis deviation of pipes arranged in an array, and has the advantages of high measurement accuracy and simple operation.

Description

Technical Field

[0001] The present invention relates to the technical field of pipe detection devices, and particularly relates to a method for measuring the deviation of the axial center position of a pipe and a detection device therefor. Background Art

[0002] In production applications, after pipes are assembled according to dimensions, they are prone to deformation due to subsequent special processes, and the axial center position of their ends will deviate from the original design position. However, they still need to be assembled with other parts in subsequent applications. For example, in the production process of an air-conditioning heat exchanger, after copper pipes are assembled with multiple fins, an expansion joint process is required. The expansion joint process will cause the copper pipes to deform, causing the ports of the copper pipes to deviate from the preset positions. Each expanded copper pipe still needs to be assembled with other parts, and the air-conditioning heat exchanger has multiple arrayed copper pipes, further increasing the detection difficulty. Therefore, obtaining the deviation amount between the actual axial center position and the design position of the pipe end is of great significance for realizing the automation of pipe port assembly.

[0003] Existing detection methods for the axial center position of pipes are divided into two categories: contact measurement and non-contact measurement. Contact measurement mostly uses mechanical structures for hard contact. For example, a measurement tool for the axial center deviation of a valve seat hole plane disclosed in Chinese Patent CN203454961U uses a lever-type mechanical structure to directly contact the object to be measured, and then uses a dial indicator to read the offset of the probe to achieve the detection of the axial center. Although this tool has a simple structure and is easy to operate, it requires manual measurement using instruments such as a dial indicator, has a large measurement error, and is not suitable for measuring pipes with a small diameter.

[0004] Non-contact measurement often uses light, electromagnetic, and sound waves as media for measurement. For example, Chinese Patent CN 105423946 discloses an axial center measurement device and measurement calibration method for a journal based on a laser displacement sensor, which uses two movable laser displacement sensors at a certain angle in a plane to measure the axial center of a cylindrical part. This method has higher accuracy and better safety than contact measurement. However, since light is easily blocked by objects, this method cannot measure the axial centers of pipes arranged in an array simultaneously, especially not suitable for the determination of the arrayed copper pipes in an air-conditioning heat exchanger.

[0005] Therefore, designing a device with high measurement accuracy and capable of measuring the axial center deviation of pipes arranged in an array has important significance and application value. Summary of the Invention

[0006] The present invention provides a method for measuring the deviation of the axial center position of a pipe and a detection device therefor, which is applicable to the measurement of the axial center deviation of pipes arranged in an array and has the advantages of high measurement accuracy and simple operation.

[0007] To achieve the above technical objectives and obtain the above technical effects, the present invention solves the above problems through the following technical solutions:

[0008] A detecting device for the axial position deviation of a pipe, comprising a workbench, a three-axis sliding table mechanism, a positioning device for a workpiece to be measured, and a detecting device; the three-axis sliding table mechanism and the positioning device for the workpiece to be measured are oppositely arranged on the workbench, and the detecting device is installed at the sliding end of the three-axis sliding table mechanism; the detecting device includes a base, and a plurality of detecting claws arranged in a circumferential array on the side wall of the base; the tail end of the detecting claw is fixedly connected to the base, the front end points to the side where the positioning device for the workpiece to be measured is located, an induction groove is formed between the front and rear ends, and a sensing device for measuring the bending degree of the detecting claw is arranged in the groove; a bending generating device for bending the front end of the detecting claw inward is installed at the front end of the base, and the workpiece to be measured is detachably installed on the positioning device for the workpiece to be measured.

[0009] In the above solution, the bending generating device attracts the detecting claw to make the front end of the detecting claw bend and contact the side wall of the pipe. The sensing device can obtain the bending variable of the detecting claw and convert it into an electrical signal for output. Calibrate the relationship between the displacement of the front end of the detecting claw in the direction of the axis of the detecting device and the electrical signal, and substitute the measured change value of the electrical signal to obtain the deviation of the axis of the pipe relative to the axis of the standard pipe. The device can obtain a high measurement accuracy through the measurement of multiple sensors. And the detecting claw has a large bending range and can be applied to the deviation measurement of pipes with different diameters.

[0010] Further, the three-axis sliding table mechanism includes an X-axis sliding table, a Y-axis sliding table and a Z-axis sliding table stacked from bottom to top. The Y-axis sliding table is slidably arranged on the X-axis sliding table, the Z-axis sliding table is slidably arranged on the Y-axis sliding table, and the base is fixedly connected to the slider of the Z-axis sliding table.

[0011] Further, the bending generating device includes a central rod with the tail end fixedly connected to the base, and an energized coil arranged at the front end of the central rod; the detecting claw is made of a ferromagnetic material, or a permanent magnet is arranged at the front part of the detecting claw, and the ferromagnetic material and the permanent magnet can be adsorbed by the electromagnetic field of the energized coil.

[0012] Further, the detecting claws are arranged in pairs, and the two claws of each pair of detecting claws are symmetrically arranged on both sides of the base. The detecting claws adopt a paired and symmetrical structure, and the two claws arranged oppositely are convenient for measuring and checking the displacement in the same direction.

[0013] Further, an arc-shaped convex platform in line contact with the outer wall of the pipe to be measured is arranged on the inner wall of the front end of the detecting claw. The arc-shaped convex platform can reduce the bending amount required for the claw piece during work, avoid interference between the claw piece and the bending generating device, and the arc-shaped convex platform can increase the stiffness of the front end of the claw piece to ensure that the front end of the claw piece is in tangential contact with the outer circle of the circular pipe, which is convenient for the conversion of detection data.

[0014] Further, the induction groove is arranged on the outer wall of the detecting claw, and the sensing device can adopt a resistance strain gauge.

[0015] Further, the workpiece to be measured positioning device is provided with a positioning groove for the workpiece to be measured to slide in and a positioning and locking device is provided.

[0016] A method for measuring the axial center position deviation of a pipe includes the following steps:

[0017] S1: Calibrate the relationship between the displacement of the front end of each detection claw in the direction of the base axis of the detection device and the electrical signal quantity of the sensing device caused by the bending deformation of the detection claw respectively;

[0018] S2: Install the standard workpiece on the workpiece to be measured positioning device, so that the rod material with the same outer diameter as the pipe on the standard workpiece extends into the detection device, and the axis of the rod material coincides with the base axis of the detection device;

[0019] S3: Use the bending generating device to bend each detection claw until the inner wall of the front end of each detection claw contacts the rod material, and record the electrical signals A1~An output by the sensing device on each detection claw;

[0020] S4: Install the workpiece to be measured on the workpiece to be measured positioning device, move the detection device through the three-axis sliding table mechanism, make the base axis of the detection device coincide with the axis position where the original design size of the pipe is located, and the pipe end extends into the detection device;

[0021] S5: Start the bending generating device to bend each detection claw, make the inner wall of the front end of each detection claw contact the pipe, and record the electrical signals B1~Bn output by the sensing device on each detection claw;

[0022] S6: Substitute the differences between the electrical signal quantities A1~An and B1~Bn into the calibration relationship between the displacement of the front end of the detection claw and the electrical signal quantity for calculation, the offset amounts of the pipe axis corresponding to multiple directions can be obtained, and by summing multiple offset vectors, the total offset amount of the pipe axis can be obtained;

[0023] S7: Control the three-axis sliding table mechanism and the detection device through the control device, and the individual measurement of the array pipes can be completed in sequence.

[0024] The present invention has the following beneficial effects:

[0025] 1. A plurality of pairs of detection claws are symmetrically arranged along the circumference. The front end of the detection claw bends inward through the bending generating device to contact the pipe port. The sensing device converts the bending amount into an electrical signal output. According to the relationship between the electrical signal and the displacement amount, the displacement amount of the front end of the detection claw can be calculated. By comparing the pipe displacement amount with the standard part displacement amount, the deviation of the pipe axis position can be obtained.

[0026] The device uses sensors to measure variables, with complete data and high measurement accuracy. The detection claws are arranged in a circular array, capable of radially multi-point positioning of the pipe material to obtain sufficient measurement data. The detection claws are arranged in pairs symmetrically. The symmetrically arranged detection claws can double-check the displacement in the same direction, and the data is accurate and reliable.

[0027] 2. The detection device adopts a bending contact measurement method with detection claws. The detection claws have a large bending space, enabling the device to be applicable to the measurement of pipe materials within a certain diameter range. Moreover, the detection claws bend to the measurement state in contact with the pipe material through the magnetic force of the induced magnetic field, and each claw does not interfere with each other, and the data is reliable.

[0028] 3. The tail base of the detection device is fixedly connected to the three-axis slide table mechanism, and the displacements in the X, Y, and Z directions can be completed through the three-axis slide table. When a workpiece with an array of pipe materials is installed on the workpiece positioning device to be measured, the movement of the three-axis slide table mechanism can be controlled by program setting for continuous measurement. Description of the Drawings

[0029] Figure 1 It is a schematic structural diagram of a pipe material axis position deviation detection device according to the present invention.

[0030] Figure 2 It is a schematic structural diagram of the detection device.

[0031] Figure number identification: 1. Workbench, 2. Three-axis slide table mechanism, 21. X-axis slide table, 22. Y-axis slide table, 23. Z-axis slide table, 3. Workpiece positioning device to be measured, 31. Positioning groove, 32. Positioning and locking device, 4. Detection device, 41. Base, 42. Detection claw, 421. Arc-shaped convex platform, 43. Sensing device, 44. Bending generating device, 441. Central rod, 442. Energized coil, 443. Permanent magnet. Detailed Embodiment

[0032] Next, in combination with the drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. The specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0033] A pipe material axis position deviation detection device described in this embodiment, as shown in the attached Figure 1 figure, the main body includes a workbench 1, a three-axis slide table mechanism 2, a workpiece positioning device 3 to be measured, and a detection device 4. The three-axis slide table mechanism 2 and the workpiece positioning device 3 to be measured are arranged on the workbench 1, and the detection device 4 is installed at the movable end of the three-axis slide table mechanism 2, and its front end points to the side where the workpiece positioning device 3 to be measured is located.

[0034] The three-axis slide table mechanism 2 includes an X-axis slide table 21, a Y-axis slide table 22, and a Z-axis slide table 23 stacked from bottom to top. In the embodiment, the slide table is a ball screw slide table, including a slide table base, a screw rod rotatably connected to the slide table base, a drive motor for driving the screw rod to rotate, and a slider threadedly connected to the screw rod. The drive motor circuit is connected to the control device circuit. The tail end of the detection device 4 is fixedly connected to the slider of the Z-axis slide table 23 and can slide along the X / Y / Z axes with the three-axis slide table mechanism 2.

[0035] As shown in the attached Figure 2 figure, the detection device 4 includes a base 41, a detection claw 42, a sensing device 43, and a bending generation device 44. In the embodiment, the base 41 has a square cross-section block structure, and the base 41 is fixedly connected to the Z-axis slide table 23 through fasteners. The four detection claws 42 respectively correspond to the four side walls of the base 41. The tail end of the claw body is fixedly connected to the base 41, and the front end points to the workpiece positioning device 3 to be measured. An installation groove for placing the sensing device 43 is provided on the outer wall of each detection claw 42. The sensing device 43 is a resistance strain gauge, and the resistance strain gauge can convert the bending variable of the detection claw 42 into an electrical signal output. By processing and analyzing the electrical signal, the bending amount of the detection claw can be known.

[0036] The front end of the detection claw 42 is bent through the bending generation device 44. The bending generation device 44 includes a central rod 441 with its tail end fixedly connected to the base 41, a current-carrying coil 442 wound around the front end of the central rod 441, and a permanent magnet 443 fixed to the inner wall of the front end of the central rod 441. The central rod 441 has a screw rod structure, and the base 41 is provided with a central through hole. The tail end of the central rod 441 passes through the central hole and is positioned by front and rear nuts. When the current-carrying coil 442 is energized, an induced magnetic field is generated, and the permanent magnet 443 drives the detection claw 42 to bend inward under the action of the magnetic field until it abuts against the end wall of the pipe to be measured. The detection claw 42 has a large bending range and can be used for measuring the axial center deviation of pipes within a certain diameter range.

[0037] The workpiece positioning device 3 to be measured is fixedly connected to the workbench 1. The workpiece to be measured is a pipe part with an array arrangement. The workpiece to be measured is installed in the positioning groove 31 of the workpiece positioning device 3 to be measured and is fixed by a positioning locking device 32 provided on the side wall of the positioning chute. In the embodiment, the workpiece to be measured is an air conditioner heat exchanger equipped with multiple U-shaped pipes, as shown in the attached Figure 1 figure. By setting the control device, the three-axis slide table mechanism 2 can carry the detection device 4 to sequentially complete the continuous measurement of multiple pipes on the air conditioner heat exchanger.

[0038] A method for measuring the axial center position deviation of a pipe, based on a device for detecting the axial center position deviation of a pipe, the measurement includes the following steps:

[0039] S1: Calibrate the relationship between the displacement of the front end of each detection claw 42 in the direction of the base axis of the detection device 4 and the electrical signal quantity of the sensing device 43 caused by the bending deformation of the detection claw 42 respectively;

[0040] S2: Install the standard workpiece on the workpiece positioning device 3 to be measured, so that the bar stock with the same outer diameter as the pipe on the standard workpiece extends into the detection device 4, and the axis of the bar stock coincides with the base axis of the detection device 4;

[0041] S3: Use the bending generating device 44 to bend each detection claw 42 until the inner wall of the front end of each detection claw 42 contacts the bar stock, and record the electrical signals A1~An output by the sensing device 43 on each detection claw 42;

[0042] S4: Install the workpiece to be measured on the workpiece positioning device 3 to be measured, move the detection device 4 through the three-axis slide mechanism 2, and make the base axis of the detection device 4 coincide with the axis position where the original design size of the pipe is located, and the pipe end extends into the detection device;

[0043] S5: Start the bending generating device 44 to bend each detection claw 42 so that the inner wall of the front end of each detection claw 42 contacts the pipe, and record the electrical signals B1~Bn output by the sensing device 43 on each detection claw 42;

[0044] S6: Substitute the differences between the electrical signal quantities A1~An and B1~Bn into the calibration relationship between the displacement of the front end of the detection claw 42 and the electrical signal quantity for calculation, and the offset amounts of the pipe axis corresponding to multiple directions can be obtained. By summing multiple offset vectors, the total offset amount of the pipe axis can be obtained;

[0045] S7: Control the three-axis slide mechanism 2 and the detection device 4 through the control device, and the individual measurements of the array pipes can be completed in sequence.

[0046] The above has described the embodiments of the present invention in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. Without departing from the principle and spirit of the present invention, various changes, modifications, substitutions, and variations to these embodiments still fall within the protection scope of the present invention.

Claims

1. A device for detecting the axial position deviation of a pipe, characterized in that: It includes a workbench (1), a three-axis slide mechanism (2), a workpiece to be measured positioning device (3), and a detection device (4); the three-axis slide mechanism (2) and the workpiece to be measured positioning device (3) are oppositely arranged on the workbench (1), and the detection device (4) is installed at the sliding end of the three-axis slide mechanism (2). The detection device (4) includes a base (41) and a plurality of detection claws (42) circumferentially arrayed on the side wall of the base (41); the tail ends of the detection claws (42) are fixedly connected to the base (41), the front ends point to the side where the workpiece to be measured positioning device (3) is located, an induction groove is opened between the front and rear ends, and a sensing device (43) for measuring the bending degree of the detection claws (42) is arranged in the groove; the induction groove is arranged on the outer wall of the detection claws (42), and the sensing device (43) uses a resistance strain gauge. A bending generating device (44) capable of bending the front ends of the detection claws (42) inward is installed at the front end of the base (41), and the workpiece to be measured is detachably installed on the workpiece to be measured positioning device (3); the bending generating device (44) includes a central rod (441) with its tail end fixedly connected to the base (41) and an energized coil (442) arranged at the front end of the central rod (441); the detection claws (42) are made of ferromagnetic materials, or a permanent magnet (443) is arranged at the front part of the detection claws (42), and the ferromagnetic materials and the permanent magnet (443) can be adsorbed by the electromagnetic field of the energized coil (442); the workpiece to be measured positioning device (3) is provided with a positioning groove (31) for the workpiece to be measured to slide into and a positioning locking device (32). The detection claws (42) are arranged in pairs, and the two claws of each pair of detection claws (42) are symmetrically arranged on both sides of the base (41); the front ends of the detection claws (42) are bent inward by the bending generating device (44) to contact the pipe port, and the sensing device (43) converts the bending amount into an electrical signal for output; the relationship between the displacement amount of the front end of the detection claw towards the axis of the detection device base and the electrical signal is calibrated, and the measured change value of the electrical signal is substituted to obtain the deviation of the pipe axis relative to the axis of the standard pipe.

2. The pipe axis position deviation detection device according to claim 1, characterized in that: The three-axis slide mechanism (2) includes an X-axis slide (21), a Y-axis slide (22), and a Z-axis slide (23) stacked from bottom to top. The Y-axis slide (22) is slidably arranged on the X-axis slide (21), the Z-axis slide (23) is slidably arranged on the Y-axis slide (22), and the base (41) is fixedly connected to the slider of the Z-axis slide (23).

3. The pipe axis position deviation detection device according to claim 1, characterized in that: An arc-shaped convex platform (421) in line contact with the outer wall of the pipe to be measured is arranged on the inner wall of the front end of the detection claw (42).

4. A method for measuring the deviation of the axial center position of a pipe is implemented by the detection device according to any one of claims 1 to 3, characterized in that It includes the following steps: S1: Calibrate the relationship between the displacement amount of the front end of each detection claw (42) towards the axis of the detection device (4) and the electrical signal amount of the sensing device (43) caused by the bending deformation of the detection claw (42) respectively. S2: Install the standard workpiece on the workpiece to be measured positioning device (3), insert the bar with the same outer diameter as the pipe into the detection device (4), and make the axis of the bar coincide with the axis of the detection device (4). S3: Use the bending device (44) to bend each detection claw (42) until the inner wall of the front end of each detection claw (42) contacts the bar stock, and record the electrical signals A1~A output by the sensing device (43) on each detection claw (42). n ; S4: Mount the workpiece to be measured on the workpiece positioning device to be measured (3), move the detection device (4) through the three-axis slide mechanism (2), align the base axis of the detection device (4) with the axis position where the original design dimensions of the pipe are located, and extend the pipe end into the detection device; S5: Activate the bending generation device (44) to bend each detection claw (42) so that the inner wall of the front end of each detection claw (42) contacts the pipe, and record the electrical signals B1~B output by the sensing device (43) on each detection claw (42). n ; S6: Substitute the differences between the electrical signal quantities A1 to A n , B1 to B n into the calibration relationship between the displacement at the front end of the detection claw (42) and the electrical signal quantity for calculation, and the offset amounts of the pipe axis corresponding to multiple directions can be obtained. By summing up multiple offset vectors, the total offset amount of the pipe axis can be obtained; S7: Control the three-axis slide mechanism (2) and the detection device (4) through the control device to sequentially complete the individual measurement of the array of pipes.

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