Method for detecting radian of steel pipe

Abstract

The invention discloses a method for detecting the radian of a steel pipe. The method comprises the following steps: lofting a section of arc line of the radian of the steel pipe to be measured according to the proportion of 1: 1; connecting two end points of the arc line into a straight line as a chord line; equally dividing the chord line into a plurality of equal parts to obtain each equal division point of the chord line; drawing vertical lines perpendicular to the chord line by taking each equal division point as a starting point, and extending vertexes of all the vertical lines to an arc line; measuring theoretical lengths of all vertical lines; the end points of all the vertical lines are smoothly connected to obtain an arc line with the required radian; a chord line, a vertical line and an arc line are made into a real object as a radian measuring scale by adopting a hard material; the radian of the measuring scale is adjusted out and the radian of the measuring edge is fixed and shaped, then the measuring edge of the radian measuring scale is placed on the inner wall of the steel pipe to be tightly attached to the pipe wall, and whether the radian of the steel pipe and the designed radian meet requirements or not can be known according to the attaching condition and the gap between the measuring edge of the measuring scale and the inner wall of the steel pipe. The method can meet roundness detection of various pipe diameters.

Description

Technical Field

[0001] The invention relates to the field of detection devices, and in particular to a method for detecting the curvature of a steel pipe. Background Art

[0002] In recent years, many offshore wind power projects have emerged at home and abroad, involving large-diameter steel pipe structures such as marine pipes and structural pipes. Large-diameter steel pipes are generally made of multiple pipe sections that are rolled and spliced ​​together. When manufacturing a single pipe section, it is necessary to strictly control the roundness of the pipe section. The roundness of the steel pipe is a must-check item to determine whether the product manufacturing is qualified. At present, the general operation of testing the roundness of steel pipes is to make specific arc templates according to different pipe diameters for measurement, and stick the template on the inner wall of the steel plate to see whether the plate wall fits the template. Because the detection of the curvature of different pipe diameters requires the production of templates that match the curvature, one template can only measure one curvature, but cannot measure the curvature of other pipe diameters. Summary of the invention

[0003] The purpose of the present invention is to provide a method for testing the curvature of a steel pipe, which can adjust various curvatures and realize the detection of the roundness of the inner wall of steel pipes of various diameters.

[0004] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical scheme:

[0005] A method for testing the curvature of a steel pipe comprises the following steps:

[0006] Step A, first lay out an arc of the steel pipe to be measured at a ratio of 1:1;

[0007] Step B, connecting the two end points of the arc in step A into a straight line as the chord length line;

[0008] Step C, dividing the chord length line in step B into several equal parts to obtain equal division points of the chord length line;

[0009] Step D, taking each equally divided point in step C as a starting point, draw a vertical line perpendicular to the chord length line in step B, and extend the vertices of all the vertical lines to the arc in step A;

[0010] Step E, measuring the theoretical lengths of all vertical lines in step D;

[0011] Step F, smoothly connecting the endpoints of all the vertical lines in step E to obtain an arc of the required curvature;

[0012] Step G, using hard materials to make physical objects of the chord length line, the vertical line, and the arc line as an arc measuring ruler;

[0013] Step H, call out the curvature of the measuring ruler in step G and fix the curvature of the measuring edge, then put the measuring edge of the curvature measuring ruler on the inner wall of the steel pipe close to the pipe wall, and according to the fit and gap between the measuring edge of the measuring ruler and the inner wall of the steel pipe, it can be known whether the curvature of the steel pipe meets the design curvature requirements.

[0014] Further technology of the present invention:

[0015] Preferably, the arc measuring ruler comprises a support frame made along the chord length line, a measuring edge made along the arc line and an adjustment rod made along the vertical line;

[0016] The support frame is provided with a plurality of lockable positioning frames, the adjustment rods are inserted into the positioning frames, and the adjustment rods are moved up and down or fixed in the positioning frames;

[0017] The measuring edge is hinged with a plurality of adjusting rods, and the measuring edge can obtain various radian curves by extending and retracting the adjusting rods to different lengths.

[0018] Preferably, the support frame of the device is a square frame, on which two rows of lockable positioning frames are provided, and each adjustment rod passes through the two rows of positioning frames.

[0019] Preferably, the measuring edge is a bendable steel bar or aluminum plate.

[0020] The beneficial effects of the present invention are:

[0021] The method is simple and clear. It uses a comparison method to lay out the size of the steel pipe to be measured and prepare an arc measuring ruler. The corresponding arc can be adjusted according to different pipe diameters. One detection device can meet the roundness detection of various pipe diameters. There is no need to make different arc plates for different pipe diameters, which saves production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 Schematic diagram of the method of the present invention.

[0024] Figure 2 This is a schematic diagram of the structure of the arc measuring ruler.

[0025] Figure 3 This is a schematic diagram of the operation of the arc measuring ruler.

[0026] The symbols in the figure are: 1 supporting frame, 2 measuring edge, 3 adjusting rod, 4 positioning frame, 5 fastening screw, 6 steel pipe. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be further described in detail below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention but not all. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] like Figure 1 This embodiment provides a method for testing the curvature of a steel pipe, comprising the following steps:

[0029] Step A, first lay out an arc Arn of the steel pipe to be measured at a ratio of 1:1;

[0030] Step B, connecting the two end points of the arc Arn in step A into a straight line as the chord length line L1;

[0031] Step C, dividing the chord length line L1 in step B into several equal parts to obtain equal division points of the chord length line;

[0032] Step D, taking each equally divided point in step C as a starting point, draw a vertical line Hn perpendicular to the chord length line L1 in step B, and extend the vertices of all vertical lines Hn to the arc line Arn in step A;

[0033] Step E, measuring the theoretical lengths of all vertical lines Hn in step D;

[0034] Step F, smoothly connecting the endpoints of all the vertical lines Hn in step E to obtain the arc Arn of the required curvature;

[0035] Step G, using hard materials to make objects of the chord length line L1, the vertical line Hn, and the arc line Arn as arc measuring rulers;

[0036] Step H, call out the curvature of the measuring ruler in step G and fix the curvature of the measuring edge, then put the measuring edge of the curvature measuring ruler on the inner wall of the steel pipe close to the pipe wall, and according to the fit and gap between the measuring edge of the measuring ruler and the inner wall of the steel pipe, it can be known whether the curvature of the steel pipe meets the design curvature requirements.

[0037] In the above, the arc measuring ruler is as follows Figure 2 , including a supporting frame made along the chord line, a measuring edge made along the arc line and an adjusting rod made along the vertical line.

[0038] The support frame 1 is provided with a plurality of lockable positioning frames 4, and the adjusting rods 3 are inserted in the positioning frames 4. Each adjusting rod 3 can be moved up and down and fixed in the positioning frames 4 to achieve the extension and retraction of the adjusting rod 3. In this embodiment, the positioning frames 4 are provided with fastening screws 5 to fix the adjusting rods 3.

[0039] The measuring edge 2 is hinged to a plurality of adjusting rods 3 , and the measuring edge 2 can obtain various curvature curves by extending and retracting the adjusting rods 3 to different lengths.

[0040] The support frame 1 of the device is a square frame, which plays a supporting and shaping role. The square frame is provided with two rows of lockable positioning frames 4, and each adjusting rod 3 passes through the two rows of positioning frames 4. The two positioning frames 4 prevent the adjusting rod 3 from deviating during the telescopic movement.

[0041] The measuring edge 2 is a bendable steel bar or aluminum plate.

[0042] like Figure 3 Specifically, first draw the roundness arc to be measured on the ground or paper at a ratio of 1:1, then place the measuring edge 2 of the detection device close to the roundness arc, and then adjust the adjustment rods 3 to make the outer edge line of the measuring edge 2 coincide with the roundness arc;

[0043] After the measuring edge 2 matches the roundness arc, each adjusting rod 3 is locked, so that the supporting frame 1, the measuring edge 2 and the adjusting rod 3 of the whole device form a rigid fixation as a whole, and no deformation or displacement occurs. At this time, the roundness measuring device is completed;

[0044] Place the adjusted measuring edge 2 of the detection device against the inner wall of the steel pipe 6, and by observing the gap between the inner wall of the steel pipe 6 and the measuring edge 2 of the detection device, it can be determined whether the roundness of the steel pipe 6 meets the requirements.

[0045] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for testing the curvature of a steel pipe, characterized in that: The following steps are involved: Step A, first lay out an arc of the steel pipe to be measured at a ratio of 1:1; Step B, connecting the two end points of the arc in step A into a straight line as the chord length line; Step C, dividing the chord length line in step B into several equal parts to obtain equal division points of the chord length line; Step D, taking each equally divided point in step C as a starting point, draw a vertical line perpendicular to the chord length line in step B, and extend the vertices of all the vertical lines to the arc in step A; Step E, measuring the theoretical lengths of all vertical lines in step D; Step F, smoothly connecting the endpoints of all the vertical lines in step E to obtain an arc of the required curvature; Step G, using hard materials to make physical objects of the chord length line, the vertical line, and the arc line as an arc measuring ruler; Step H, call out the curvature of the measuring ruler in step G and fix the curvature of the measuring edge, then put the measuring edge of the curvature measuring ruler on the inner wall of the steel pipe close to the pipe wall, and according to the fit and gap between the measuring edge of the measuring ruler and the inner wall of the steel pipe, it can be known whether the curvature of the steel pipe meets the design curvature requirements.

2. A method for testing the curvature of a steel pipe according to claim 1, characterized in that: The arc measuring ruler comprises a support frame made along the chord length line, a measuring edge made along the arc line and an adjustment rod made along the vertical line; The support frame is provided with a plurality of lockable positioning frames, the adjustment rods are inserted into the positioning frames, and the adjustment rods are moved up and down or fixed in the positioning frames; The measuring edge is hinged with a plurality of adjusting rods, and the measuring edge can obtain various radian curves by extending and retracting the adjusting rods to different lengths.

3. A method for testing the curvature of a steel pipe according to claim 2, characterized in that: The supporting frame of the device is a square frame, on which two rows of lockable positioning frames are arranged, and each adjusting rod passes through the two rows of positioning frames.

4. A method for testing the curvature of a steel pipe according to claim 2, characterized in that: The measuring edge is a bendable steel bar or aluminum plate.

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