Fire curved angle steel first hole after bending process

Abstract

The application discloses a fire curve angle steel hole-making and bending process, which comprises the following steps: firstly, determining the gravity center line of the fire curve angle steel; secondly, calculating the compensation size according to the fire curve angle and the distance between the gravity center line and the edge of the angle steel; thirdly, calculating the cutting length according to the length of the connecting angle steel and the compensation size; fourthly, making holes; and finally, bending and correcting. Compared with the process of making holes after bending, the process of making holes before bending is adopted, and the holes are made on the plane angle steel in the order of cutting, hole-making and bending, so that the holes can be made by using the conventional hole-making process and equipment, and the bending is made after reasonable calculation. Compared with the process of making holes on the irregular surface angle steel after bending, the production cost is saved, and the work efficiency is improved.

Description

Technical Field

[0001] This invention relates to the process of using fire-curled inner steel for connecting the main materials of the upper and lower slope sections of transmission line towers and broadcast communication towers, and the process of making holes in angle steel before bending it, which belongs to the field of fire-curled angle steel processing technology. Background Technology

[0002] The variable slope of the upper and lower sections of the iron tower is usually designed with an inner steel cladding and an outer connecting plate to connect the main materials of the upper and lower sections. This connection method has high requirements for the calculation of the deformation of the inner steel cladding and the quality of the processing accuracy. Therefore, the hot-bent angle steel is an important key link in the processing of iron towers. At present, there are two main forms: one is to hot-bend first and then make the hole, and the other is to make the hole first and then hot-bend.

[0003] The method of first bending the angle steel and then drilling the hole requires cutting the material first. The angle steel is bent into a curve and then the hole is drilled on one side of the tower body before bending it. The hole on the other side of the curve is drilled according to the plate to which it is connected. This method produces angle steel with high hole accuracy and high installation performance. However, because the other side of the curve needs to be drilled, the production efficiency is low and the processing cost is high.

[0004] The method of drilling holes before bending angle steel involves machining the angle steel according to the cutting length, hole positions, and bending angles indicated on the part drawing. The workpiece is then trial-assembled with related plates. Based on the assembly results, the length, hole positions, and bending positions of the angle steel are adjusted before subsequent mass production. This method is currently the most commonly used method in tower factories. However, without accurate calculations, the holes on the bent angle steel cannot be connected to the holes connecting the main angle steel and the outer connecting plate. Furthermore, during production, it was found that holes closer to the bending curve undergo some deformation after bending, which also prevents the holes on the bent angle steel from connecting to the connecting angle steel, making trial assembly impossible and compromising machining accuracy. Summary of the Invention

[0005] The purpose of this invention is to provide a process for pre-drilling holes and then bending fire-curved angle steel. By calculating reasonable compensation dimensions and adopting the method of pre-drilling holes and then bending, processing costs are saved, processing efficiency is improved, and the technical problem of mismatched hole positions after bending is avoided.

[0006] The above-mentioned technical objective of this invention is achieved through the following technical solution: a process for pre-drilling holes and then bending fire-curved angle steel, comprising the following steps:

[0007] Step 1: Cutting: First, determine the length of connecting angle steel I as L①, the length of connecting angle steel II as L②, the curved angle ∠θ, and the thickness T of the curved angle steel leg. Then, determine the position of the core line of the curved angle steel. The position of the core line of the curved angle steel is the translation line of the outer edge of the angle steel towards the rolling edge. The specific translation distance is one-quarter of the width of the curved angle steel leg L④ plus 0.345T and the compensation distance 3.5T. The distance between the curved core line and the translation distance is L③=L④ / 4+0.345T+3.5T. Therefore, the cutting length of the curved angle steel L⑤=L①+L②+L③*tan∠θ.

[0008] Step 2: Hole making: First, take the intersection point a of the outer ridge lines of connecting angle steel I and connecting angle steel II as the reference. After the holes on connecting angle steel I and connecting angle steel II are perpendicular to the outer ridge lines, they form an intersection point b. Determine the distance between intersection point a and intersection point b as L⑥. The hole position compensation length is L⑦=L③*tan∠(θ / 2)=(L④ / 4+0.345T+3.5T)*tan∠(θ / 2). Determine the distance between the hole position on the fire-curved angle steel and the fire curve as L⑧=L⑦+L⑥. According to the value of L⑧, make holes on the fire-curved angle steel.

[0009] Step 3: Bending: First, determine the position of the fire curve as L⑨=L① or L②+L⑦, and the fire curve angle ∠θ before bending.

[0010] Step 4: Calibration: Verify the roundness and position of each hole on the curved angle steel. If the hole positions and diameters of connecting angle steel I and connecting angle steel II are inconsistent, perform secondary hole making correction.

[0011] Preferably, in step two, when the hole position fire separation curve is greater than 50mm, the hole diameter is made in accordance with the hole diameter corresponding to the hole position of connecting angle steel I and connecting angle steel II.

[0012] By adopting the above technical solution, the compensation dimensions of the angle steel were calculated to ensure the accurate dimensions of the angle steel after bending and to guarantee the overall strength of the profile. The compensation dimensions of the processing hole diameter were also calculated to ensure the correctness of the hole position and to make the hole position of the angle steel correspond to the hole position on the connecting steel plate. Most importantly, special hole-making treatment was performed on the hole positions close to the bending curve to avoid deformation of the hole positions after bending the angle steel.

[0013] The present invention is further configured such that: in step two, when the hole position fire separation curve is greater than 50mm, the hole diameter is made in accordance with the hole diameter corresponding to the hole position of connecting angle steel I and connecting angle steel II.

[0014] Using the above technical solution, it was found in the actual production and processing process that only when the hole position is close to the fire curve, drilling the hole first and then bending it will cause a certain degree of lateral stretching of the hole position that is close to the fire curve, thus causing deformation. Conversely, the hole position that is far from the fire curve has a weak impact and will not cause deformation. After testing, it was found that when the hole diameter is more than 50mm away from the fire curve, the impact is small, and the hole can be drilled according to the actual hole diameter, that is, the hole is drilled in accordance with the hole diameter corresponding to the connecting angle steel I and connecting angle steel II.

[0015] The present invention is further configured such that, in step two, when the hole position is no more than 50 mm away from the fire curve, the hole diameter is shaped as an ellipse during hole making.

[0016] Using the above technical solution, it was found through testing that when the distance between the aperture and the fire curve is less than 80mm, the fire-curved angle steel will cause the aperture to stretch laterally and deform. Therefore, the aperture is set to an ellipse to allow for a certain dimensional margin after bending. After bending, the aperture can be stretched into a circle to avoid secondary processing.

[0017] The invention is further configured such that the elliptical hole has the following specific shape: the major axis of the elliptical hole is perpendicular to the core line, and the minor axis of the elliptical hole coincides with the core line.

[0018] Using the above technical solution, the hole shape is set to an elliptical hole. After bending, it will affect the dimension in the short axis direction, but the dimension in the long axis direction will be slightly affected. Setting this diameter difference allows for a certain margin in the bending process.

[0019] The present invention is further configured such that: when the flame angle satisfies: 1°≦∠θ≤6°, the difference between the major and minor axes of the elliptical hole is 0.5mm; when the flame angle satisfies: 6°<∠θ≤10°, the difference between the major and minor axes of the elliptical hole is 1.0mm; and when the flame angle satisfies: ∠θ>10°, the difference between the major and minor axes of the elliptical hole is 1.5mm.

[0020] Using the above technical solution, actual measurements show that the size of the flame angle directly affects the stretching length of the hole. The smaller the flame angle, the shorter the stretching length, the smaller the allowance required, and the shorter the distance difference between the major and minor axes. Conversely, the larger the flame angle, the longer the stretching length, the larger the allowance required, and the longer the distance difference between the major and minor axes.

[0021] The present invention is further configured such that: in step 4, when the minor axis and major axis of the elliptical hole are not equal, correction is performed, that is, a second hole is made so that the minor axis and major axis are the same size, and the hole is a circular hole.

[0022] Using the above technical solution, there are certain calculation or processing errors in the actual production process, which inevitably makes the hole diameter obtained after hole making and bending inconsistent with the expected diameter. However, sufficient margin is left in step 3. When the inconsistency exceeds the reasonable error, it can be corrected.

[0023] The beneficial effects achieved by this invention are:

[0024] The process involves drilling holes first and then bending them. Following the sequence of material cutting, drilling, and bending, since the holes are drilled on flat angle steel, conventional drilling processes and equipment can be used to complete the process. Finally, after reasonable calculation, bending is performed. Compared with drilling holes on irregular angle steel after bending, this method saves production costs, improves work efficiency, and leaves sufficient compensation dimensions during processing, which facilitates calibration. Attached Figure Description

[0025] The invention will be further understood from the following description taken in conjunction with the accompanying drawings. The components in the drawings are not necessarily drawn to scale, but rather the emphasis is on illustrating the principles of the embodiments. In different views, the same reference numerals designate corresponding parts.

[0026] Figure 1 This is a schematic diagram of the structure of the present invention;

[0027] Figure 2 This is a schematic diagram showing the position of the angle steel in the structure of this invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Other systems, methods, and / or features of this embodiment will become apparent to those skilled in the art after reviewing the following detailed description. All such additional systems, methods, features, and advantages are intended to be included within this specification, within the scope of the invention, and protected by the appended claims. Further features of the disclosed embodiments are described in detail below, and these features will become apparent from the following detailed description.

[0029] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the mechanism or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0030] This invention provides a technical solution: a process for pre-drilling holes and then bending fire-curved angle steel, comprising the following steps:

[0031] Step 1: Cutting: First, determine the length of connecting angle steel I as L①, the length of connecting angle steel II as L②, the curved angle ∠θ, and the thickness T of the curved angle steel leg. Then, determine the position of the core line of the curved angle steel. The position of the core line of the curved angle steel is the translation line of the outer edge of the angle steel towards the rolling edge. The specific translation distance is one-quarter of the width of the curved angle steel leg L④ plus 0.345T and the compensation distance 3.5T. The distance between the curved core line and the translation distance is L③=L④ / 4+0.345T+3.5T. Therefore, the cutting length of the curved angle steel L⑤=L①+L②+L③*tan∠θ.

[0032] Step 2: Hole making: First, take the intersection point a of the outer ridge lines of connecting angle steel I and connecting angle steel II as the reference. After the holes on connecting angle steel I and connecting angle steel II are perpendicular to the outer ridge lines, they form an intersection point b. Determine the distance between intersection point a and intersection point b as L⑥. The hole position compensation length is L⑦=L③*tan∠(θ / 2)=(L④ / 4+0.345T+3.5T)*tan∠(θ / 2). Determine the distance between the hole position on the fire-curved angle steel and the fire curve as L⑧=L⑦+L⑥. According to the value of L⑧, make holes on the fire-curved angle steel.

[0033] Step 3: Bending: First, determine the position of the fire curve as L⑨=L① or L②+L⑦, and the fire curve angle ∠θ before bending.

[0034] Step 4: Calibration: Verify the roundness and position of each hole on the curved angle steel. If the hole positions and diameters of connecting angle steel I and connecting angle steel II are inconsistent, perform secondary hole making correction.

[0035] Example 1: First, determine the length of connecting angle steel I as L①, the length of connecting angle steel II as L②, the bend angle ∠θ, and the thickness T of the bend angle steel leg. Then, determine the position of the core line of the bend angle steel. The position of the core line of the bend angle steel is the translation line of the outer edge of the angle steel towards the rolling edge. The specific translation distance is one-quarter of the width L④ of the bend angle steel leg plus 0.345T and a compensation distance of 3.5T. The distance between the bend core line and the translation distance is L③ = L④ / 4 + 0.345T + 3.5T. Therefore, the blanking length of the bend angle steel L⑤ = L① + L② + L③ * tan∠θ. Then, make the hole: First, take the outer edge of connecting angle steel I and connecting angle steel II as the reference line. Using intersection point a as a reference, the holes on connecting angle steel I and connecting angle steel II, perpendicular to the outer rib line, form intersection point b. The distance between intersection point a and intersection point b is determined as L⑥, and the hole position compensation length is L⑦ = L③ * tan∠(θ / 2) = (L④ / 4 + 0.345T + 3.5T) * tan∠(θ / 2). The distance from the hole position on the curved angle steel to the fire curve is determined as L⑧ = L⑦ + L⑥. Based on the value of L⑧, holes are made on the curved angle steel. When the value of L⑧ is not less than 50mm, holes are made on the curved angle steel. At this time, the hole diameter is consistent with the hole diameter on the connecting angle steel, and no hole diameter compensation operation is required. Next, bending is performed: bending is performed according to the fire curve and the fire curve angle ∠θ. Finally, calibration: the dimensions of each hole on the curved angle steel are checked. When it is found that the hole diameter is inconsistent with the corresponding hole diameter of connecting angle steel I and connecting angle steel II, a second hole-making correction is performed.

[0036] Example 2:

[0037] In Example 1, the material cutting steps remain unchanged. After material cutting but before hole making, if the distance between the hole position on the fire-curved angle steel and the fire curve L⑧ is found to be less than 50mm, the size of the fire curve angle needs to be considered simultaneously. When the fire curve angle satisfies: 1°≦∠θ≤6°, the hole position for the hole position with a distance of less than 50mm from the fire curve L⑧ is elliptical. Specifically, the major axis of the elliptical hole position is perpendicular to the core line, the minor axis of the elliptical hole position coincides with the core line, and the difference between the major and minor axes of the elliptical hole position is 0.5mm. After hole making, the subsequent bending is performed as in Example 1. During the final calibration, it is necessary not only to calibrate whether the hole diameter is consistent with the hole diameter corresponding to the connecting angle steel I and connecting angle steel II, but also to check whether the minor and major axes of the hole position with a distance of less than 50mm from the fire curve L⑧ are the same after bending. If they are inconsistent, a second hole making correction is required.

[0038] Example 3:

[0039] In Example 2, the material cutting steps remain unchanged. After material cutting and before hole making, when the distance between the hole position on the L⑧ fire-curved angle steel and the fire curve L⑧ is less than 50mm, and the fire curve angle satisfies: 6° < ∠θ ≤ 10°, when making the hole, for the hole position where the distance between the hole position and the fire curve L⑧ is less than 50mm, the hole position is elliptical. Specifically, the major axis of the elliptical hole position is perpendicular to the core line, the minor axis of the elliptical hole position coincides with the core line, and the difference between the major axis and minor axis of the elliptical hole position is 1.0mm. After hole making, the subsequent bending and calibration are performed in the same way as in Example 2.

[0040] Example 4:

[0041] In Example 2, the blanking process remains unchanged. After blanking and before drilling, when the distance L⑧ from the hole position on the fire-curved angle steel is less than 50mm, and the fire-curved angle satisfies ∠θ>10°, the hole position for the hole position with a distance L⑧ less than 50mm from the fire-curved angle is elliptical. Specifically, the major axis of the elliptical hole position is perpendicular to the core line, and the minor axis of the elliptical hole position coincides with the core line. The difference between the major and minor axes of the elliptical hole position is 1.5mm. After drilling, the subsequent bending and calibration are performed in the same manner as in Example 2.

Claims

1. A process for pre-drilling holes and then bending fire-curved angle steel, characterized by: Includes the following steps: Step 1: Material cutting: First, determine the length of connecting angle steel I as L①, the length of connecting angle steel II as L②, the curved angle ∠ɵ, and the thickness T of the curved angle steel leg. Then, determine the position of the core line of the curved angle steel. The position of the core line of the curved angle steel is the translation line of the outer edge of the angle steel towards the rolling edge. The specific translation distance is one-quarter of the width of the curved angle steel leg L④ plus 0.345T and the compensation distance 3.5T. The distance between the curved core line and the translation distance is L③ = L④ / 4 + 0.345T + 3.5T. Therefore, the cutting length of the curved angle steel L⑤ = L① + L② + L③ * tan∠ɵ; Step 2: Hole Making: First, using the intersection point a of the outer ridge lines of connecting angle steel I and connecting angle steel II as a reference, the holes on connecting angle steel I and connecting angle steel II are perpendicular to the outer ridge lines, forming an intersection point b. The distance between intersection point a and intersection point b is determined as L⑥, and the hole position compensation length is L⑦ = L③ * tan∠(ɵ / 2) = (L④ / 4 + 0.345T + 3.5T) * tan∠(ɵ / 2). The distance from the hole position to the fire curve on the curved angle steel is determined as L⑧ = L⑦ + L⑥. Based on the value of L⑧, holes are made on the curved angle steel. When the distance from the hole position to the fire curve is greater than 50mm, the hole diameter is determined according to the distance from connecting angle steel I. The hole diameter is consistent with that of the connecting angle steel II. When the fire curve of the hole position does not exceed 50mm, the hole shape is machined as an ellipse. The specific shape of the elliptical hole position is as follows: the major axis of the elliptical hole position is perpendicular to the core line, and the minor axis of the elliptical hole position coincides with the core line. When the fire curve angle satisfies: 1°≦∠ɵ≤6°, the difference between the major and minor axes of the elliptical hole position is 0.5mm; when the fire curve angle satisfies: 6°<∠ɵ≤10°, the difference between the major and minor axes of the elliptical hole position is 1.0mm; when the fire curve angle satisfies: ∠ɵ>10°, the difference between the major and minor axes of the elliptical hole position is 1.5mm. Step 3: Bending: First, determine the position of the fire curve as L⑨ = L① + L⑦ or L② + L⑦, and the fire curve angle ∠ɵ before bending; Step 4: Calibration: Verify the roundness and position of each hole on the curved angle steel. When the hole positions and diameters of connecting angle steel I and connecting angle steel II are inconsistent, perform secondary hole making correction. When the minor axis and major axis dimensions of the elliptical hole are not equal, perform correction, that is, perform secondary hole making to make the minor axis and major axis dimensions the same, and make the hole a circular hole.

Images