Method for preventing clamp deformation of an elongated tubular and detection device

Abstract

The present disclosure provides a method for preventing clamping deformation of an elongated pipe and a detection device, belonging to the field of mechanical processing. The method for preventing clamping deformation comprises: obtaining reference positions of centers of cross sections corresponding to different axial positions of the pipe; detecting actual positions of centers of cross sections corresponding to a clamping tool after the clamping tool is clamped at one of the axial positions; determining a deformation degree of the pipe according to the actual positions and the reference positions; and adjusting a clamping state of the clamping tool according to the deformation degree of the pipe until the deformation degree of the pipe after the clamping tool is clamped is within a preset range. The present disclosure can reduce the deformation of the pipe caused by clamping.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the field of mechanical processing, and particularly relates to a method for preventing clamping deformation of an elongated pipe and a detection device. BACKGROUND

[0002] For an elongated pipe (such as a pipe with a length of more than 10 m), due to its long length and narrow inner cavity, the overall straightness of the pipe is required to be relatively high (within 1 mm).

[0003] In the related art, before the pipe is processed by a machine tool, in order to reduce the influence of deformation caused by clamping on the processing precision, a machine tool spindle is generally used to set up a dial gauge to detect the straightness of the pipe, and then the pipe is clamped by a plurality of fixtures arranged along the axial direction of the pipe, and the straightness is re-detected. When the straightness detected twice meets the requirements, the pipe is processed.

[0004] However, clamping the pipe by the fixture may cause deformation of the pipe. Therefore, after the pipe is processed, the fixture is loosened, and the straightness of the pipe is checked again, which may not meet the requirements. SUMMARY

[0005] The embodiments of the present disclosure provide a method for preventing clamping deformation of an elongated pipe and a detection device, which can reduce the deformation of the pipe caused by clamping. The technical solutions are as follows:

[0006] The embodiments of the present disclosure provide a method for preventing clamping deformation of an elongated pipe, and the method comprises the following steps: obtaining reference positions of centers of cross sections corresponding to different axial positions of the pipe; detecting actual positions of centers of cross sections corresponding to fixtures in a plurality of axial positions after the fixtures are clamped; determining a deformation degree of the pipe according to the actual positions and the reference positions; and adjusting clamping states of the fixtures according to the deformation degree of the pipe until the deformation degree of the pipe after the fixtures are clamped is within a preset range.

[0007] In another implementation manner of the present disclosure, the obtaining of the reference coordinates of the centers of the cross sections of the pipe corresponding to different axial positions comprises: determining axial positions of a plurality of fixtures clamping the pipe; and detecting straightness of an inner cavity of the pipe to obtain the reference positions of the centers of the cross sections of the pipe corresponding to different axial positions.

[0008] In another implementation manner of the present disclosure, the detecting of the straightness of the inner cavity of the pipe comprises: detecting the straightness of the inner cavity of the pipe by a laser tracker and a target ball.

[0009] In still another implementation form of the disclosure, the detecting the straightness of the inner cavity of the pipe by the laser tracker and the target ball comprises: arranging the laser tracker at an end of the pipe; arranging the target ball at an axial position of the pipe and connecting the target ball with an inner sidewall of the pipe; controlling the laser tracker to emit laser light towards the target ball; controlling the pipe to move along an axial direction of the pipe; and determining a three-dimensional coordinate of the target ball in the axial direction of the pipe according to reflected light received by the laser tracker, the three-dimensional coordinate being the reference position.

[0010] In still another implementation form of the disclosure, the detecting the actual position of the center of the cross section of the pipe at the axial position where each of the fixtures is clamped comprises: clamping one of the fixtures at the axial position of the pipe; and detecting the actual position of the center of the cross section of the pipe at the axial position where the fixture is clamped by the laser tracker and the target ball.

[0011] In still another implementation form of the disclosure, the reference coordinate and the actual coordinate each comprise three coordinate values, the three coordinate values comprising a first coordinate value, a second coordinate value and a third coordinate value, the first coordinate value being a coordinate value in an axial direction of the pipe, and the second coordinate value and the third coordinate value being coordinate values in two directions perpendicular to each other in a cross section of the pipe.

[0012] The determining the deformation degree of the pipe after each of the fixtures is clamped comprises: calculating a first difference between the second coordinate value of the reference position and the second coordinate value of the actual position, and a second difference between the third coordinate value of the reference position and the third coordinate value of the actual position, the first difference and the second difference being used to indicate the deformation degree.

[0013] In still another implementation form of the disclosure, the first difference and the second difference used to indicate the deformation degree comprise: if the first difference and the second difference are both not greater than 0.1 mm, the deformation degree is 0.

[0014] In still another implementation form of the disclosure, the adjusting the clamping state of the fixture according to the deformation degree of the pipe until the deformation degree of the pipe after the fixture is clamped is within the preset range comprises: when all the fixtures are clamped on the pipe, detecting the straightness of the inner cavity of the pipe to obtain spatial positions of the pipe at each axial position; and determining whether the pipe is deformed according to all the reference coordinates and corresponding spatial positions.

[0015] In yet another implementation manner of the present disclosure, the determining whether the pipe is deformed according to all the reference positions and corresponding spatial positions comprises: if the deviations between the spatial coordinates and corresponding reference coordinates are all within a preset range, it is determined that the pipe is not deformed.

[0016] In yet another implementation manner of the present disclosure, a detection device for preventing clamping deformation of an elongated pipe is also provided, which is applicable to the above-mentioned method for preventing clamping deformation. The detection device comprises a fixing table, a detection assembly and a processing unit. The fixing table has a support plane for supporting the pipe. The detection assembly comprises a laser tracker and a target ball. The laser tracker is located on the support plane and connected with the fixing table. The laser tracker is located at one end of the pipe. The target ball is located at the axial position of the pipe and connected with the inner wall of the pipe. The target ball is located on the same straight line as the emitting end of the laser tracker. The processing unit is electrically connected with the laser tracker to determine whether the pipe is deformed after clamping according to the detection result of the laser tracker.

[0017] The technical scheme provided by the embodiments of the present disclosure has the following beneficial effects:

[0018] When the pipe is corrected by the method for preventing clamping deformation provided by the present disclosure, the reference positions of the centers of the cross sections corresponding to different axial positions of the pipe are first obtained, so that the positions of the centers of the square holes at different axial positions of the pipe can be reflected by the reference positions. Then, the fixtures are clamped in sequence at the axial positions, and the actual coordinates of the centers of the cross sections corresponding to the fixtures are detected after each fixture is clamped. Then, the deformation degree of the pipe after each fixture is clamped is determined according to the actual positions and the reference positions. In this way, the actual positions of the centers of the cross sections at the axial positions corresponding to the fixtures after the fixtures are clamped are compared with the reference positions before the fixtures are clamped, so as to ensure that the deformation degree of the pipe after the fixtures are clamped is within a preset range, reduce the deformation degree of the pipe, and facilitate subsequent processing. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical scheme in the embodiments of the present disclosure, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 is a structural schematic diagram of the pipe provided by the embodiments of the present disclosure;

[0021] Figure 2 is Figure 1A cross-sectional view along the AA direction;

[0022] Figure 3 A flowchart illustrating a method for preventing clamping deformation of slender tubular components, provided as an embodiment of this disclosure;

[0023] Figure 4 A flowchart illustrating another method for preventing clamping deformation of slender tubular components provided in this disclosure embodiment;

[0024] Figure 5 An embodiment of this disclosure provides a detection device for preventing clamping deformation of slender tubular components;

[0025] Figure 6 for Figure 5 Side view.

[0026] The symbols in the diagram represent the following meanings:

[0027] 1. Fixed platform; 10. Supporting plane;

[0028] 2. Detection components; 21. Laser tracker; 22. Target ball; 3. Processing unit;

[0029] 100. Pipe fittings; 101. Top plate; 102. Bottom plate; 103. Left side plate; 104. Right side plate;

[0030] 200. Tooling; 201. First clamping assembly; 2011. Connecting rod; 2012. Clamping block; 202. Second clamping assembly. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0032] To clearly illustrate the anti-clamping deformation method for slender tubes provided in the embodiments of this disclosure, the basic structure of the slender tubes will be described first.

[0033] like Figure 1 As shown, the slender tube 100 described in this disclosure has a length of 10m and is a cuboid structure.

[0034] Figure 2 yes Figure 1 The cross-sectional view along the AA direction, combined with Figure 2 The slender tubular fitting 100 includes an upper top plate 101, a lower bottom plate 102, a left side plate 103, and a right side plate 104. The upper top plate 101 and the lower bottom plate 102 are arranged in parallel, and the left side plate 103 and the right side plate 104 are located between the upper top plate 101 and the lower bottom plate 102 at intervals, and the left side plate 103 and the right side plate 104 are welded to the upper top plate 101 and the lower bottom plate 102, respectively.

[0035] A square hole is defined between the top plate 101, the bottom plate 102, the left side plate 103, and the right side plate 104. The length and width of the square hole are both 200 mm.

[0036] The length direction of the square hole is: when the slender tube 100 is placed horizontally, the direction parallel to the cross-section and parallel to the horizontal plane is the horizontal direction. See [reference needed]. Figure 2 The X-axis direction in the diagram.

[0037] The width direction of the square hole is: the direction perpendicular to the length direction of the square hole when the slender tube 100 is placed horizontally, see [reference]. Figure 2 The Y-axis direction in the diagram.

[0038] In other words, the slender tube provided in this embodiment is a composite part. Because of its long length and narrow inner cavity (which is a square hole), the overall straightness requirement of the tube is relatively high (within 1mm).

[0039] After the pipe fittings are transferred to the corresponding machine tool, the straightness of the pipe fittings needs to be corrected and clamped before processing. Since multiple clamping fixtures are used to clamp the pipe fittings before processing, in order to reduce the impact of the deformation caused by clamping on the processing accuracy, this disclosure proposes a method for preventing clamping deformation for slender pipe fittings.

[0040] This disclosure provides a method for preventing clamping deformation of slender tubular fittings, such as... Figure 3 As shown, methods to prevent clamping deformation include:

[0041] S301: Obtain the reference position of the center of the cross section corresponding to different axial positions of the pipe fitting.

[0042] In this embodiment, the reference position mentioned above can be represented by three-dimensional coordinates. The three-dimensional coordinates include a first coordinate value, a second coordinate value, and a third coordinate value. The first coordinate value is used as the coordinate value in the axial direction of the pipe fitting, and the second and third coordinate values ​​are coordinate values ​​in two mutually perpendicular directions in a cross-section of the pipe fitting.

[0043] In other words, three-dimensional coordinates include coordinates along the X-axis, Y-axis, and Z-axis. The X-axis, Y-axis, and Z-axis are all perpendicular to each other.

[0044] Since the pipe fittings need to be horizontally clamped on the machine tool during processing, meaning that the axial direction of the pipe fittings is parallel to the horizontal plane during processing, for ease of recording, in this embodiment of the disclosure, the X-axis direction is set to be parallel to the paper plane and pointing to the right, the Y-axis direction is set to be parallel to the paper plane and pointing upwards, and the Z-axis direction is perpendicular to the paper plane.

[0045] The X-axis mentioned above refers to the length of the square hole, the Y-axis refers to the width of the square hole, and the Z-axis refers to the axial direction of the fitting. In other words, the reference coordinates can be (z, x, y).

[0046] The axial position mentioned above refers to the position of each tooling relative to the axis of the pipe fitting. For example, according to the axis of the pipe fitting, tooling can be set at different axial positions of the pipe fitting, that is, different tooling can be used to clamp the pipe fitting at different axial positions. The different axial positions can be represented by z, that is, the z in the coordinate position is recorded as 0m, 2m, 6m, 8m, etc.

[0047] S302: Clamp the fixture sequentially at each axial position, and after each fixture is clamped, detect the actual position of the center of the cross section corresponding to the fixture.

[0048] Similarly, the actual position can also be represented by the actual coordinate position, which is (x, y, z).

[0049] S303: Determine the degree of deformation of the pipe fitting after each tooling clamp is installed, based on the actual position and the reference position.

[0050] By comparing the actual position with the reference position, it can be determined whether the pipe fitting is deformed. If the actual position matches the corresponding reference position, the pipe fitting is considered not to be deformed.

[0051] S304: Adjust the clamping state of the tooling according to the degree of deformation of the pipe fitting until the degree of deformation of the pipe fitting is within the preset range after all the tooling is clamped.

[0052] When correcting pipe fittings using the anti-clamping deformation method provided in this disclosure, the method first obtains the reference position of the center of the cross-section corresponding to different axial positions of the pipe fitting. This allows the reference position to reflect the center position of the square hole at different axial positions of the pipe fitting. Then, fixtures are clamped sequentially at each axial position, and after each fixture is clamped, the actual coordinates of the center of the cross-section corresponding to the fixture are detected. Based on the actual position and the reference position, the degree of deformation of the pipe fitting after clamping each fixture is determined. This allows the actual position of the center of the cross-section at the corresponding axial position of each fixture after clamping to be compared with the reference position before clamping, thereby ensuring that the degree of deformation of the pipe fitting after clamping is within a preset range, reducing the degree of deformation of the pipe fitting for subsequent processing.

[0053] On the other hand, this disclosure also provides another method for preventing clamping deformation of slender tubular fittings, such as... Figure 4 As shown, the method includes:

[0054] S401: Determine the axial position of multiple tooling fixtures for clamping the pipe fitting.

[0055] Alternatively, S401 can be implemented in the following ways:

[0056] 4011: The tooling is positioned at intervals along the axial direction of the pipe fitting on both sides of the pipe fitting's axis.

[0057] like Figure 5 As shown in this embodiment, each tooling 200 includes a first clamping assembly 201 and a second clamping assembly 201, which are located on both sides of the pipe's axis. The first clamping assembly 201 and the second clamping assembly 201 are simultaneously clamped on both sides of the pipe, thus clamping and positioning the pipe.

[0058] The first clamping assembly 201 and the second clamping assembly 201 described above have the same structure. The first clamping assembly 201 includes a connecting rod 2011 and a clamping block 2012. The clamping block 2012 is threaded onto the outside of the connecting rod 2011, and one side of the clamping block 2012 has a clamping surface for fitting against the outer wall of the pipe fitting. Thus, by manually adjusting the connecting rod 2011 or the clamping block 2012, the clamping block 2012 can be moved toward the pipe fitting to clamp it.

[0059] Of course, the first clamping assembly 201 can also be of other structures, such as a telescopic and clamping block connected together. The clamping block can be controlled to clamp the pipe by controlling the amount of extension and retraction of the telescopic rod. When the telescopic rod extends, the clamping block moves towards the pipe to clamp it; when the telescopic rod retracts, the clamping block moves away from the pipe to release it.

[0060] 4012: Mark the axial position of each tool along the pipeline axis.

[0061] In this embodiment, the tooling provided by this disclosure can be 20 pieces, and the distance between any two adjacent tooling pieces is the same.

[0062] Therefore, the axial positions mentioned above can be recorded as 0m, 0.5m, 1m, 1.5m, 2m, 2.5m, 3m, 3.5m, ..., 20m, etc., according to the axis direction of the pipe fitting.

[0063] S402: The straightness of the inner cavity of the pipe fitting is checked to obtain the reference position of the center of the pipe fitting cross-section corresponding to different axial positions.

[0064] Alternatively, S402 can be implemented in the following ways:

[0065] The straightness of the inner cavity of the pipe fitting is detected using a laser tracker and a target ball.

[0066] In this embodiment, the straightness detection of the inner cavity of the pipe using a laser tracker and a target ball, as mentioned above, can be performed according to the following steps:

[0067] Step 1: Place the laser tracker at the end of the pipe fitting.

[0068] In this embodiment, a laser tracker is used to emit light and receive the reflected light. Then, the position of the reflected light is identified based on the reflected light.

[0069] Step 2: Place the target ball on the axis of the pipe and connect it to the inner wall of the pipe.

[0070] In this embodiment, the target ball is slidably connected to the inside of the tube via a connecting assembly. The target ball is a steel ball with an outer diameter of 3 mm or less. The target ball is used to reflect the light emitted by the laser tracker.

[0071] Step 3: Control the laser tracker to emit lasers toward the target ball.

[0072] Step 4: Control the pipe fitting to move along its own axis.

[0073] In this embodiment, since the target ball is movably connected to the inner wall of the pipe, that is, relative sliding can occur between the target ball and the pipe, the target ball does not move when the pipe moves along the axial direction.

[0074] Step 5: Determine the three-dimensional coordinates of the target ball along the axial direction of the pipe based on the reflected light received by the laser tracker.

[0075] The three-dimensional coordinates are (z, x, y) as mentioned above.

[0076] In this embodiment, the unit of the value corresponding to z is m. The units of the values ​​corresponding to x and y are mm.

[0077] To facilitate recording x and y, the center position of any cross-section of the pipe fitting is marked as the origin, that is, the coordinates of the X-axis and Y-axis corresponding to the center position of the cross-section are (0, 0).

[0078] S403: Clamp one of the multiple tooling fixtures at the corresponding axial position of the pipe fitting.

[0079] In this embodiment, one of the tooling fixtures can be clamped at the corresponding axial position of the pipe fitting. For example, the first tooling fixture can be clamped at the first axial position of the pipe fitting. The first axial position can be the position corresponding to 0m mentioned earlier. Similarly, the second axial position is the position corresponding to 0.5m, and the third axial position is the position corresponding to 1m.

[0080] For ease of recording, the first tooling can be used to clamp and position the first axial position of the pipe fitting.

[0081] S404: The actual position of the center of the cross-section of the pipe fitting at the axial position of the tooling after clamping is detected by a laser tracker and a target ball.

[0082] The above detection process is the same as step S402 in the previous text, and will not be repeated here.

[0083] S405: Determine the degree of deformation of the pipe fitting after each tooling clamp is installed, based on the actual position and the reference position.

[0084] In this embodiment, by comparing the reference position with the actual position at the same axial position, it can be determined whether the tooling at that axial position will cause the pipe to deform after clamping.

[0085] In this embodiment, S405 is implemented in the following way:

[0086] Calculate a first difference between the second coordinate value of the reference position and the second coordinate value of the actual position, and a second difference between the third coordinate value of the reference position and the third coordinate value of the actual position, wherein the first difference and the second difference are used to indicate the degree of deformation.

[0087] If both the first difference and the second difference are not greater than 0.1 mm, then the degree of deformation is 0.

[0088] For example, the reference coordinates at a certain axial position are (1, 0, 0), while the actual reference coordinates are (1, 0.5, -0.2). By comparing the x and y values, it can be seen that the actual position of this axial position deviates from the reference position by 0.5 in the X-axis direction and by 0.2 in the Y-axis direction, both of which are greater than 0.1 mm.

[0089] In other words, the first difference mentioned above includes deviations in both positive and negative directions along the X-axis, and the second difference also includes deviations in both positive and negative directions.

[0090] S406: Repeat steps S403-S405.

[0091] In this embodiment, by repeating the above steps S403-S405, each tool can be clamped at different axial positions of the pipe fitting, and the actual position corresponding to the different axial positions of the pipe fitting after each clamping can be detected. At the same time, the deviation between the actual position after each clamping and the reference position can be compared to see if it is within a preset range.

[0092] If the position is not within the preset range, the tooling at the axial position will be reinstalled until the deviation between the actual position and the reference position is within the preset range after the tooling is clamped.

[0093] By clamping the tooling at each axial position in this way, the deformation of the pipe fitting can be zero after each tooling is clamped.

[0094] In other words, after each fixture is clamped onto the pipe fitting, a laser tracker and a target ball are used to detect the actual position of the center of the pipe fitting's cross-section at the axial position of the clamped fixture. The actual position is then compared with the corresponding reference position to check for any deviation. If the deviation is within a preset range, the assembly of the next fixture continues. If the deviation exceeds the preset range, the clamping state of the fixture is readjusted, and the check is repeated until the deviation between the actual position and the corresponding standard position is within the preset range.

[0095] S407: After all the tooling is clamped onto the pipe fitting, the straightness of the inner cavity of the pipe fitting is checked to obtain the spatial position of each axial position of the pipe fitting.

[0096] In this embodiment, the spatial position of each axial position of the pipe is re-measured, and then the deformation of the pipe can be determined based on the spatial position and the reference position.

[0097] S408: Determine whether the pipe fitting is deformed based on all reference coordinates and corresponding spatial positions.

[0098] In this embodiment, S408 is implemented in the following way:

[0099] If the deviations between the spatial coordinates and the corresponding reference coordinates are both within the preset range, then it is determined that the pipe fitting is not deformed.

[0100] By comparing the reference position with the spatial position, the deviation between the overall straightness of the pipe fitting after all the tooling is clamped and its straightness before clamping can be determined. If the deviation between the overall straightness of the pipe fitting and its straightness before clamping is no greater than 0.1, it is determined that the pipe fitting is not deformed. Conversely, if the deviation between the overall straightness of the pipe fitting and its straightness before clamping is greater than 0.1, it is determined that the pipe fitting is deformed, and in this case, the clamping state of the tooling needs to be readjusted.

[0101] On the other hand, this disclosure also provides a detection device for preventing clamping deformation of slender tubular fittings, such as... Figure 5 and 6 As shown, the detection device is applicable to the above-mentioned methods for preventing clamping deformation.

[0102] The detection device includes a fixed platform 1, a detection component 2, and a processing unit 3.

[0103] The fixed platform 1 has a support plane 10 for supporting the pipe fitting. The detection component 2 includes a laser tracker 21 and a target ball 22. The laser tracker 21 is located on the support plane 10 and connected to the fixed platform 1. The laser tracker 21 is located at one end of the pipe fitting. The target ball 22 is located on the axis of the pipe fitting 100 and connected to the inner wall of the pipe fitting 100. The target ball 22 and the emitting end of the laser tracker 21 are on the same straight line.

[0104] The processing unit 3 is electrically connected to the laser tracker 21 to determine whether the pipe has deformed after clamping based on the detection results of the laser tracker 21.

[0105] The above testing device can be used to obtain the reference position of the pipe fitting and the actual position of the tooling after clamping. This makes it easy to compare the reference position with the actual position to determine whether the tooling will cause deformation of the pipe fitting after clamping.

[0106] In addition, the laser tracker 21 mentioned above is used to emit lasers and receive the reflected light from the target ball, thereby obtaining the corresponding actual position or reference position by the position of the reflected light.

[0107] During testing, the target ball 22 is pre-connected to the center of the first end face of the pipe fitting 100, and the laser tracker 21 is positioned on the second end face of the pipe fitting 100 away from the first end face, with the emitting end of the laser tracker 21 and the target ball 22 on the same straight line. At this time, the reference position at the first axial position (z = 0m) can be detected through the laser tracker's emitting line.

[0108] Then, the control fitting 100 is moved along the direction from the second end face to the first end face, and the moving distance of the fitting 100 is 0.5m. At this time, the reference position of the second axial position (at z = 0.5m) can be detected.

[0109] By continuing to control the movement of pipe fitting 100, the reference position corresponding to the various axial positions can be obtained.

[0110] Similarly, after the tooling is clamped onto the pipe fitting, the corresponding actual position and spatial position can be detected using the above methods.

[0111] In this embodiment, the processing unit 3 includes a processor and a display, etc. The processor records and calculates the position coordinates of the target ball detected by the laser tracker 21, and then transmits the calculation results to the display for display, so that the staff can view them directly.

[0112] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A method for preventing clamping deformation of slender tubular fittings, characterized in that, The method for preventing clamping deformation includes: Obtain the reference position of the center of the cross section corresponding to different axial positions of the pipe fitting; The fixtures are sequentially clamped at each of the axial positions, and after each fixture is clamped, the actual position of the center of the cross section of the pipe corresponding to the fixture position is detected. The reference position and the actual position both include a first coordinate value, a second coordinate value and a third coordinate value. The first coordinate value is the coordinate value in the axial direction of the pipe, and the second coordinate value and the third coordinate value are the coordinate values ​​in two mutually perpendicular directions in a cross section of the pipe. Calculate a first difference between the second coordinate value of the reference position and the second coordinate value of the actual position, and a second difference between the third coordinate value of the reference position and the third coordinate value of the actual position. The first difference and the second difference are used to indicate the degree of deformation. The first difference includes deviations in both positive and negative directions, and the second difference includes deviations in both positive and negative directions. According to the degree of deformation of the pipe fitting, the clamping state of the tooling is adjusted accordingly until the degree of deformation of the pipe fitting is within the preset range after all the tooling is clamped. After all the tooling is clamped on the pipe fitting, the straightness of the inner cavity of the pipe fitting is tested to obtain the spatial position of each axial position of the pipe fitting. Based on all the reference positions and the corresponding spatial positions, determine whether the pipe fitting is deformed.

2. The method for preventing clamping deformation according to claim 1, characterized in that, The step of obtaining the reference position of the center of the cross-section corresponding to different axial positions of the pipe fitting includes: Determine the axial position of multiple tooling fixtures for clamping the pipe fitting; The straightness of the inner cavity of the pipe fitting is tested to obtain the reference position of the center of the cross-section of the pipe fitting corresponding to different axial positions.

3. The method for preventing clamping deformation according to claim 2, characterized in that, The process of detecting the straightness of the inner cavity of the pipe fitting includes: The straightness of the inner cavity of the pipe is detected using a laser tracker and a target ball.

4. The method for preventing clamping deformation according to claim 3, characterized in that, The method of detecting the straightness of the inner cavity of the pipe fitting using a laser tracker and a target ball includes: The laser tracker is positioned at the end of the pipe fitting; The target ball is positioned on the axial side of the pipe and connected to the inner wall of the pipe. The laser tracker is controlled to emit a laser beam toward the target sphere; Control the pipe fitting to move along its own axis; Based on the reflected light received by the laser tracker, the three-dimensional coordinates of the target ball along the axial direction of the pipe are determined, and the three-dimensional coordinates are the reference position.

5. The method for preventing clamping deformation according to claim 1, characterized in that, After the fixture is clamped at each of the axial positions, the actual position of the center of the cross-section corresponding to the fixture is detected, including: One of the plurality of tooling fixtures is clamped at the axial position corresponding to the pipe fitting; The actual position of the center of the cross-section of the pipe at the axial position of the tooling after clamping is detected by a laser tracker and a target ball.

6. The method for preventing clamping deformation according to claim 1, characterized in that, The first difference and the second difference are used to indicate the degree of deformation, including: If both the first difference and the second difference are not greater than 0.1 mm, then the degree of deformation is 0.

7. The method for preventing clamping deformation according to claim 1, characterized in that, The step of determining whether the pipe fitting is deformed based on all the reference positions and the corresponding spatial positions includes: If the deviations between the spatial coordinates and the corresponding reference coordinates are both within a preset range, then it is determined that the pipe fitting is not deformed.

8. A detection device for preventing clamping deformation of slender tubular fittings, characterized in that, The detection device is applicable to the anti-clamping deformation method according to any one of claims 1-7; The detection device includes a fixed platform (1), a detection component (2), and a processing unit (3). The fixed platform (1) has a support plane (10) for supporting the pipe fitting. The detection component (2) includes a laser tracker (21) and a target ball (22). The laser tracker (21) is located on the support plane (10) and connected to the fixed platform (1). The laser tracker (21) is located at one end of the pipe fitting (100). The target ball (22) is located on the axis of the pipe fitting (100) and connected to the inner wall of the pipe fitting (100). The target ball (22) and the emitting end of the laser tracker (21) are on the same straight line. The processing unit (3) is electrically connected to the laser tracker (21) to determine whether the pipe fitting (100) has deformed after clamping based on the detection result of the laser tracker (21).

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