Process for preventing punching deviation of blade root of wind power blade

Abstract

The application provides a process method for preventing punching deviation of a blade root of a wind power blade, and the method can perform multi-level protection in a blade root punching process through methods such as binding and fixing of the blade, axial shallow hole full hole trial drilling of the blade, and installation of a blade root armor. When an extreme abnormal condition occurs in the blade punching process, the blade root armor can still protect the blade, so that the blade can be ensured to be free of any damage caused by punching deviation in the punching link, thereby completely solving the risk of blade scrapping caused by punching deviation of the blade root, realizing prevention of punching deviation in the whole process of the blade root punching process, and greatly reducing the operation quality loss of the company.

Description

Technical Field

[0001] This invention relates to the field of wind turbine blade technology, and in particular to a process method for preventing deviation in the root drilling of wind turbine blades. Background Technology

[0002] Wind turbine blades are the core components of wind turbines that convert natural wind energy into electrical energy, and they are also the main basis for measuring the design and technical level of wind turbines.

[0003] There are currently two common methods for connecting wind turbine blade roots: one is to pre-embed bolt sleeves during the blade layup process, and the other is to drill holes at the root end after the blade is formed. Drilling is the more common method in the industry. The root drilling process is a critical step; any deviation in drilling will cause irreversible damage to the blade. The common practice in the industry for blades with drilling deviations is to scrap them, and blades scrapped for this reason occur frequently in the industry. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the present invention provides a process method for preventing root drilling deviation of wind turbine blades, so as to solve the technical problem that wind turbine blades are prone to deviation during the drilling process, resulting in irreversible damage.

[0005] This invention provides a process method for preventing root perforation deviation in wind turbine blades, comprising:

[0006] S1. Place the wind turbine blades onto the bracket and align the centerline of the wind turbine blades;

[0007] S2. Fix the wind turbine blade and pre-cut the root end face of the wind turbine blade;

[0008] S3. Set a tapered pin in the axial direction of the drill bit of the drilling machine, align the tapered pin with the horizontal 3 o'clock and 9 o'clock directions and the vertical 6 o'clock and 12 o'clock directions of the blade root end face, and measure the distance between the tip of the tapered pin and the outer edge of the blade root end face.

[0009] S4. Compare the two horizontal distance data and the two vertical distance data. If the deviation is greater than 1mm, adjust the bracket and repeat S3 until the deviation of the two horizontal distance data and the two vertical distance data is not greater than 1mm.

[0010] S5. Align the conical ejector pins with the center of the structural adhesive layer thickness in the parting line areas of the wind turbine blade's leading and trailing edges, respectively, and record the leading edge parting line angle α and the trailing edge parting line angle β, and calculate the starting drilling angle.

[0011] S6. Replace the conical pin on the drilling machine with a drill bit, and perform a full-hole test drilling of the axial hole on the blade root end face;

[0012] S7. Perform secondary cutting on the leaf root end face and mill the leaf root end face;

[0013] S8. Axial and radial holes are drilled on the blade root end face, and the blade root end face armor is fixedly installed through the axial and radial holes.

[0014] Optionally, placing the wind turbine blades onto the bracket includes:

[0015] A first bracket, a second bracket, and a third bracket are respectively provided for the root, tip, and middle part of the wind turbine blade. The wind turbine blade is hoisted to the first bracket, the second bracket, and the third bracket by a crane.

[0016] Optionally, the process of correcting the centerline of the wind turbine blade includes:

[0017] Before the center line of the ground faceted drilling machine is reached, the wind turbine blade is moved so that its center line is aligned with the center line of the drilling machine.

[0018] Optionally, the fixed wind turbine blade includes:

[0019] At least two tension straps are used to bind and secure the wind turbine blades to the first bracket, the second bracket, and the third bracket, respectively.

[0020] Optionally, the pre-cutting of the root end face of the wind turbine blade includes:

[0021] Based on the reserved length at the leaf root end, the leaf root end is pre-cut after leaving at least 25mm of margin, and the excess part is removed.

[0022] Optionally, the step of recording the leading edge parting line angle α and the trailing edge parting line angle β and calculating the starting drill angle includes:

[0023] The starting drill angle is calculated based on the leading edge parting line angle α and the trailing edge parting line angle β. The calculation formula is as follows:

[0024]

[0025] Optionally, the secondary cutting of the leaf root end face includes:

[0026] Leave a 1mm margin and cut off the excess part at the root end of the leaf.

[0027] Optionally, the secondary cutting of the leaf root end face includes:

[0028] The blade root end face is milled using the milling unit of the drilling machine, with a milling depth of less than 1 mm.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] This invention provides a process for preventing root drilling deviation in wind turbine blades. Through methods such as blade binding and fixing, full-hole trial drilling of shallow axial holes, and installation of root armor, multi-layered protection can be provided during the root drilling process. Even in extreme abnormal situations during blade drilling, the root armor still protects the blade, ensuring that the blade will not be damaged by drilling deviation. This completely eliminates the risk of blade scrapping due to root drilling deviation, achieving full-process prevention of drilling deviation in the blade root drilling process and significantly reducing operational quality losses for the company. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the process of the present invention;

[0032] Figure 2 This is a schematic diagram of the placement and fixing of wind turbine blades in this invention;

[0033] Figure 3 This is a schematic diagram of the perforation structure at the root end of the blade in this invention;

[0034] Figure 4 This is a schematic diagram of the root end armor installation at the blade root end in this invention;

[0035] Figure 5 This is a schematic diagram showing the connection between the root end armor fixing bolt and the spur head nut in this invention.

[0036] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0037] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the technical solutions of this invention are further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0038] See Figure 1 This invention provides a process method for preventing root perforation deviation in wind turbine blades, comprising:

[0039] S1. Place the wind turbine blades onto the bracket and align the centerline of the wind turbine blades;

[0040] In this embodiment, the wind turbine blade is hoisted onto the drilling machine bracket using a two-point overhead crane. A first bracket, a second bracket, and a third bracket are respectively provided at the blade root, blade tip, and middle section of the wind turbine blade. The wind turbine blade is hoisted onto these brackets using the overhead crane. Furthermore, conformal protective plates are placed at the leading and trailing edges of the blade root and blade tip hoisting points for protection. The blade tip hoisting point requires the use of a strut or chordal lifting beam for hoisting to prevent damage to the blade during hoisting.

[0041] The projection line of the drilling machine's centerline on the ground is marked before project production. Different centerline lengths are selected based on the requirements of different wind turbine blade shapes; for example, a 70m long blade has its centerline suspended at 45m, and an 80m long blade at 50m. This varies with the blade shape. A plumb line is suspended at the centerline marking line of the wind turbine blade (this marking line needs to be engraved on the surface of the main mold so that the marking line remains on the surface after vacuum casting. The specific engraving position is confirmed based on the actual blade shape and design for axial and chordal positioning). This plumb line is compared with the projection of the drilling machine's centerline marked on the ground. If there is a deviation, the blade needs to be moved to make the plumb line coincide with the ground projection line.

[0042] S2. Fix the wind turbine blade and pre-cut the root end face of the wind turbine blade;

[0043] See Figure 2 In this embodiment, tension straps are used to bind and fix the wind turbine blades to each bracket. Two or more tension straps are used for binding and fixing, increasing the friction between the blade surface and the bracket surface, preventing relative movement between the blade and the bracket. This step avoids displacement of the blade relative to the bracket towards the blade tip due to frequent contact and collision between the axial hole drill bit and the blade root end face during the drilling process, thus preventing deviations in the drilling position of the radial holes.

[0044] Based on the desired length at the leaf root tip, pre-cut the leaf root tip after leaving approximately 25mm of margin, removing the excess portion. After cutting off 3 / 4 of the circumference, clamp the cut-off portion at the 12 o'clock position and use slings to assist in removing it after the cutting is complete. This step prevents the cut-off portion from sagging prematurely due to gravity before the pre-cutting of the root tip is finished, thus avoiding tearing of the uncut portion and causing fiber delamination on the leaf root end face.

[0045] S3. Set a tapered pin in the axial direction of the drill bit of the drilling machine, align the tapered pin with the horizontal 3 o'clock and 9 o'clock directions and the vertical 6 o'clock and 12 o'clock directions of the blade root end face, and measure the distance between the tip of the tapered pin and the outer edge of the blade root end face.

[0046] In this embodiment, a tapered ejector pin is installed at the axial drill bit position of the drilling machine. The drilling machine arm is rotated, and the distance between the ejector pin tip and the outer surface of the wind turbine blade is measured at the horizontal 3 o'clock and 9 o'clock positions, and the vertical 6 o'clock and 12 o'clock positions. Note that when measuring the distance from the outer surface of the wind turbine blade at the horizontal 3 o'clock and 9 o'clock positions (i.e., the front and rear edge parting line areas), the measurement of the external reinforcement must be avoided (after the wind turbine blade is demolded, the edge reinforcement fabric is applied at the front and rear edge parting line positions, so when measuring the distance from the outer surface of the blade, the thickness of this applied edge reinforcement must be excluded).

[0047] S4. Compare the two horizontal distance data and the two vertical distance data. If the deviation is greater than 1mm, adjust the bracket and repeat S3 until the deviation of the two horizontal distance data and the two vertical distance data is not greater than 1mm.

[0048] In this embodiment, the two values ​​in the horizontal direction and the two values ​​in the vertical direction are compared. The deviation is required to be ≤1mm. If it is greater than this requirement, the first bracket needs to be adjusted. After the bracket is adjusted, the above step S3 needs to be repeated until it is confirmed that the deviation of the values ​​in the two horizontal directions and the two vertical directions is ≤1mm.

[0049] S5. Align the conical ejector pins with the center of the structural adhesive layer thickness in the parting line areas of the wind turbine blade's leading and trailing edges, respectively, and record the leading edge parting line angle α and the trailing edge parting line angle β, and calculate the starting drilling angle.

[0050] In this embodiment, a tapered ejector pin is installed at the axial drill bit position of the drilling machine. The drilling machine arm is rotated, and the ejector pin is aligned with the center position of the structural adhesive layer thickness in the parting line area of ​​the blade's front and rear edges, respectively. The front edge parting line angle α and the rear edge parting line angle β are recorded respectively. The general formula for calculating the starting drill angle is:

[0051]

[0052] S6. Replace the conical pin on the drilling machine with a drill bit, and perform a full-hole test drilling of the axial hole on the blade root end face;

[0053] See Figure 3In this embodiment, an axial hole drill bit is installed on the drilling machine. Based on the calculated starting angle, one shallow axial hole is drilled above and below the parting line at both the front and rear edges. The differences in hole diameter, distance between adjacent hole walls, and distance from the hole to the parting line are measured to ensure they meet technical requirements (these vary depending on the blade type, blade root size, number of holes, and hole diameter). The drilling machine program is then set to perform a full-hole test drill of the shallow axial hole on the blade root end face, with a depth of 3-5 mm. After the shallow hole test drill is completed, the blade root end face is inspected and confirmed. The full-hole test drill of the shallow axial hole helps identify cumulative deviation problems caused by insufficient lubrication of the drilling machine slider or other reasons, which are usually not identifiable through a single hole test drill.

[0054] S7. Perform secondary cutting on the leaf root end face and mill the leaf root end face;

[0055] In this embodiment, referring to the marking line reserved on the outer surface of the blade root (the marking line needs to be engraved on the surface of the main mold so that the marking line is left on the surface after the blade is vacuum-injected), a 1mm margin is reserved, the excess part of the blade root end is cut off, and the blade root end is milled using a drilling and milling unit to a milling depth of about 1mm to ensure that the blade flatness meets the requirements.

[0056] S8. Axial and radial holes are drilled on the blade root end face, and the blade root end face armor is fixedly installed through the axial and radial holes.

[0057] See Figure 4 and Figure 5 In this embodiment, a pair of axial and radial holes are drilled, and a trial assembly is performed using double-ended bolts and stud nuts of the corresponding blade design dimensions. If the double-ended bolts can be fully screwed into the threaded holes of the stud nuts, it indicates that the axial and radial holes meet the alignment requirements. Before drilling the radial holes, the distance between the radial hole drill bit and the blade root end face needs to be measured to ensure it meets the requirements. After the alignment of the first pair of holes is confirmed to be satisfactory, a second pair of axial and radial holes is drilled at approximately 180° intervals (this must be the normal drilling position) for the installation of blade root armor. Figure 4 The white area is the leaf root tip armor;

[0058] Using a single-roller crane, the blade root end cap is hoisted to the blade root position, ensuring it is flush against the blade end face. Bolts and stub nuts are used to secure the fixture to the blade root at the two pairs of axial and radial holes drilled previously. The blade root end cap is constructed from welded steel, with a recommended steel thickness of approximately 10mm. Laser CNC machining is used to cut and drill holes in the steel structure, creating holes in the blade root face and blade cavity. The number and position of these holes must match the dimensions of the axial and radial holes on the blade (perceived by a tolerance of ±0.5mm).

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A process for preventing root perforation deviation in wind turbine blades, characterized in that, include: S1. Place the wind turbine blades onto the bracket and align the centerline of the wind turbine blades; S2. Fix the wind turbine blade and pre-cut the root end face of the wind turbine blade; S3. Set a tapered pin in the axial direction of the drill bit of the drilling machine, align the tapered pin with the horizontal 3 o'clock and 9 o'clock directions and the vertical 6 o'clock and 12 o'clock directions of the blade root end face, and measure the distance between the tip of the tapered pin and the outer edge of the blade root end face. S4. Compare the two horizontal distance data and the two vertical distance data. If the deviation is greater than 1mm, adjust the bracket and repeat S3 until the deviation of the two horizontal distance data and the two vertical distance data is not greater than 1mm. S5. Align the conical ejector pins with the center of the structural adhesive layer thickness in the parting line areas of the wind turbine blade's leading and trailing edges, respectively, and record the leading edge parting line angle α and the trailing edge parting line angle β, and calculate the starting drilling angle. S6. Replace the conical pin on the drilling machine with a drill bit, and perform a full-hole test drilling of the axial hole on the blade root end face; S7. Perform secondary cutting on the leaf root end face and mill the leaf root end face; S8. Axial and radial holes are drilled on the blade root end face, and the blade root end face armor is fixedly installed through the axial and radial holes.

2. The process method for preventing root perforation deviation in wind turbine blades as described in claim 1, characterized in that, The placement of the wind turbine blades onto the bracket includes: A first bracket, a second bracket, and a third bracket are respectively provided for the root, tip, and middle part of the wind turbine blade. The wind turbine blade is hoisted to the first bracket, the second bracket, and the third bracket by a crane.

3. The process method for preventing root perforation deviation in wind turbine blades as described in claim 2, characterized in that, The process of correcting the centerline of the wind turbine blades includes: The center line of the drilling machine is marked on the ground in advance, and the wind turbine blade is moved so that its center line is aligned with the center line of the drilling machine.

4. The process method for preventing root perforation deviation in wind turbine blades as described in claim 2, characterized in that, The fixed wind turbine blade includes: At least two tension straps are used to bind and secure the wind turbine blades to the first bracket, the second bracket, and the third bracket, respectively.

5. The process method for preventing root perforation deviation in wind turbine blades as described in claim 1, characterized in that, The pre-cutting of the root end face of the wind turbine blade includes: Based on the reserved length at the leaf root end, the leaf root end is pre-cut after leaving at least 25mm of margin, and the excess part is removed.

6. The process method for preventing root perforation deviation in wind turbine blades as described in claim 1, characterized in that, The process of recording the leading edge parting line angle α and the trailing edge parting line angle β and calculating the starting drill angle includes: The starting drill angle is calculated based on the leading edge parting line angle α and the trailing edge parting line angle β. The calculation formula is as follows:

7. The process method for preventing root perforation deviation in wind turbine blades as described in claim 1, characterized in that, The secondary cutting of the leaf root end face includes: Leave a 1mm margin and cut off the excess part at the root end of the leaf.

8. The process method for preventing root perforation deviation in wind turbine blades as described in claim 1, characterized in that, The secondary cutting of the leaf root end face includes: The blade root end face is milled using the milling unit of the drilling machine, with a milling depth of less than 1 mm.

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