A method for manufacturing a wind tunnel full model test section wall panel

Abstract

This invention discloses a method for manufacturing wall panels of a wind tunnel full-model test section, belonging to the field of wall panel processing and manufacturing technology. The processing method includes the following steps: material preparation, using the inner wall panel of the wind tunnel full-model test section; marking, setting a coordinate system on the inner wall panel and marking the positions to be drilled on the coordinates; rough milling; annealing; semi-finish milling and finish milling; drilling; finish milling; fitter work, used for deburring and chamfering; inspection and warehousing, checking the machining accuracy of the inclined holes in the inner wall panel. If it meets the set value, it is put into storage; if it does not meet the set value, it is reprocessed. This invention uses an imported high-precision gantry moving boring and milling machining center or a universal swing milling head of a Siegfried gantry milling machine, combined with CNC programming to process the inclined holes. A U-drill is used to drill the pilot hole first, and then a precision boring tool is used for precision boring, which fully guarantees the positional dimensions, hole spacing dimensions, and angular accuracy of 30°±0.1° of the inclined holes.

Description

Technical Field

[0001] This invention belongs to the field of wall panel processing and manufacturing technology, and specifically relates to a method for manufacturing wall panels for a wind tunnel full-model test section. Background Technology

[0002] The full-scale test section (hereinafter referred to as the test section) is one of the core equipment for conducting tests. It has the characteristics of large motion range of model support mechanism and three-degree-of-freedom full decoupling, and fine zoning of test area wall panel opening rate. It has comparative advantages such as "multiple functions, good flow field, high efficiency and accurate data".

[0003] The inner wall panel structure is the core structural component that determines the flow field of the test section. From the perspective of panel structure, it can be divided into perforated walls and solid walls. The four walls of the perforated wall all use 60° inclined holes. The diameter and distribution of the holes mainly depend on the functional zones. The upper and lower wall panels are fixedly installed on the frame structure, while the left and right wall panels are installed on the frame structure using suspension support devices and auxiliary support devices. The wall panel inlet is fixedly connected to the inlet flange. The expansion angle of the left and right wall panels is adjusted using an elastic plate structure and an expansion angle adjustment mechanism. The upper and lower walls of the solid wall are also fixedly installed on the frame structure, using an inclined plate design to achieve the transition from the test section inlet to the test section outlet. The left and right solid walls, also known as left and right adjusting plates, are hinged to the frame structure. An ejector slit adjustment mechanism allows them to rotate around the hinge point, thereby adjusting the width of the gap (i.e., ejector slit) between the front end of the left and right adjusting plates and the rear edge of the left and right wall panels.

[0004] However, existing panel processing technology has the problem of difficulty in machining oblique holes. Since the hole spacing of oblique holes is not easy to guarantee, the hole opening is not a complete circle, and conventional drilling is prone to drilling deviation of oblique holes. Furthermore, the method of milling flat and then drilling will produce a gap at the junction of milling and drilling, and the milled hole is prone to being too large. Summary of the Invention

[0005] The purpose of this invention is to provide a method for manufacturing wall panels for a full-scale wind tunnel test section, addressing the aforementioned problems and aiming to improve the difficulty in ensuring the spacing of the inclined holes in existing wall panels, which is also a major challenge in processing.

[0006] The technical solution adopted in this invention is as follows: A method for manufacturing a wall panel for a full-scale wind tunnel test section, the processing method including the following:

[0007] Material preparation: The inner wall panels of the wind tunnel full-model test section are used;

[0008] Mark the lines, set up a coordinate system on the inner wall plate, and mark the positions where holes need to be drilled on the coordinates; the types of holes include square holes and oblique holes;

[0009] Rough milling: The inner wall panel is divided into an airflow surface and a mounting surface. The mounting surface and both ends of the four sides of the inner wall panel are machined into straight surfaces. Rough milling is performed on the airflow surface and the mounting surface.

[0010] Annealing is performed twice, and the inner wall panel is leveled.

[0011] Semi-finish milling and finish milling: First, semi-finish milling and finish milling are performed on the airflow surface and the mounting surface. Using a universal milling head, oblique holes and square holes are drilled according to coordinate dimensions. After drilling is completed, semi-finish milling and finish milling are performed on the airflow surface and the mounting surface.

[0012] A fitter is used to remove burrs after drilling holes in the inner wall panel and to chamfer the edges of beveled and square holes.

[0013] Upon receiving the product, check the machining accuracy of the oblique and square holes on the inner wall panel. If the accuracy meets the set values, proceed with the receiving process; otherwise, reprocess the product.

[0014] It should be noted that the setting value should be set according to the actual use needs. In this application, it is set to between 15mm and 20mm.

[0015] Furthermore, the rough milling step is performed using a high-speed CNC boring and milling machine, and the specific steps include:

[0016] With the airflow surface facing down and the mounting surface facing up, place it on the adjusting shim. Use the side-top fastening method to align the workpiece according to the line (that is, place the workpiece in the correct position). After evenly fastening the inner wall plate, machine the two ends of the rough milled mounting surface and the four sides into straight surfaces, and leave a margin at the two ends of the mounting surface and the four sides.

[0017] Rough mill the square hole, leaving a margin around the four sides of the square hole to ensure that all the inclined holes around it can be drilled out.

[0018] Turn the part over so that the mounting surface is facing down and place it on the self-milling leveling pad. Check the contact by pulling out paper. Use the side-top fastening method to evenly tighten the inner wall plate. Loosen and press the clamps several times in the middle. If the part does not deform, rough mill the airflow surface and leave a margin around the airflow surface. If the part deforms, rough mill it again.

[0019] It should be noted that the high-speed CNC boring and milling machine uses the JOMAX265×140 model; the workpiece alignment line is a pre-set scribing line, which makes it easy to accurately locate the center position of the workpiece.

[0020] Furthermore, the annealing process includes two annealing processes: the first annealing is performed after rough milling, and the second annealing is performed after semi-finish milling and finish milling; during the second annealing, the inner wall plate is leveled so that it can evenly support the parts, and no other parts are placed on the upper part of the inner wall plate.

[0021] Furthermore, the semi-finish milling and finish milling steps are performed using a high-speed CNC boring and milling machine, including:

[0022] Place the inner wall panel with the airflow side facing down on the adjusting shims, align the workpiece according to the line, and evenly tighten the inner wall panel before semi-finish milling the mounting surface.

[0023] Turn it over so that the mounting surface is facing down, place it on the self-milling leveling pad, check the contact by pulling out paper, tighten the inner wall plate evenly, loosen and press it several times in the middle, if the part is not deformed, semi-finish mill the airflow surface;

[0024] Using a universal milling head, drill oblique and square holes according to the coordinate dimensions, leaving allowance on the three straight edges and the airflow surface. Program the milling of the end bevel, and semi-finish mill and finish mill each square hole; flip it over with the airflow surface facing down, place it on the self-milling leveling pad, check the contact with paper, and evenly tighten the inner wall plate. Then semi-finish mill and finish mill the mounting surface; flip it over with the mounting surface facing down, place it on the self-milling leveling pad, check the contact with paper, and evenly tighten the inner wall plate. Loosen and tighten the clamps several times in the middle. If the part is not deformed, semi-finish mill and finish mill the airflow surface and the remaining three perimeters.

[0025] Furthermore, in the drilling process, when machining the inclined hole, a high-precision gantry milling and boring machine or the universal oscillating milling head of the Siegfried gantry milling machine is used for CNC programming and machining. A U-drill is used to drill the bottom hole first, and after machining, a precision boring tool is used to finish boring to ensure the hole diameter.

[0026] It should be noted that the high-precision gantry-type moving boring and milling machining center is model JOMAX265.

[0027] Furthermore, a stainless steel milling cutter disc is used during the processing, and the inner wall panel is flipped multiple times during the process to release the processing stress.

[0028] Furthermore, a side-top fastening method is used during processing, and the upper and lower planes of the inner wall panel are symmetrically and evenly de-loaded.

[0029] Furthermore, the airflow surface of the inner wall plate is semi-finish milled with a margin, and then the oblique hole of a set diameter is first machined, and then the airflow surface is finely milled.

[0030] Furthermore, the flatness of the wall panels is checked using a laser tracker during the warehousing process, and the diameter and spacing of each inclined hole are also checked.

[0031] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0032] This invention uses an imported high-precision gantry-type boring and milling machining center or a universal oscillating milling head from a Siegfried gantry milling machine, combined with CNC programming to process inclined holes. It uses a U-drill to drill the pilot hole first and then a precision boring tool to finish boring, which fully guarantees the positional dimensions, hole spacing dimensions, and angular accuracy of 30°±0.1° for the inclined holes. Furthermore, this invention performs semi-finish milling and finish milling after drilling, making the drilled area even more precise. Attached Figure Description

[0033] Figure 1 This is a flowchart of the method of the present invention;

[0034] Figure 2 This is a schematic diagram of the wall panel of the present invention;

[0035] Figure 3 This is a schematic diagram of the oblique hole structure of the present invention.

[0036] Reference numerals: 1. Inner wall plate; 2. Square hole; 3. Angled hole. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings.

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0039] The existing wall panel processing technology has the following problems:

[0040] 1. Difficulty in machining inclined hole 3: Since the hole spacing of inclined hole 3 is not easy to guarantee, the hole opening is not a complete circle. Conventional drilling is prone to drilling deviation of inclined hole 3. Furthermore, the method of milling flat and then drilling will produce a gap at the junction of milling and drilling, and the milled hole is prone to being too large.

[0041] 2. Flatness and parallelism control is difficult: The wall panel is a large-sized thin-walled part. The flatness requirement of the airflow surface is 0.2mm, and the parallelism requirement of the two sides is 0.3mm. The precision requirements are extremely high relative to its large size. It is very easy to deform during processing, making it difficult to guarantee the precision.

[0042] 3. Deformation problem during hole processing: Most of the oblique holes 3 on the wall panel are broken holes. If the outer shape is processed first and then the oblique holes 3 are processed, it will not only be difficult to process, but also easily lead to deformation of the parts.

[0043] 4. Deformation during lifting and flipping: The wall panels are large in size and thin in thickness (only 18mm), making them prone to deformation during lifting and flipping.

[0044] The method of the present invention can effectively solve the above problems and produce the following effects:

[0045] 1. Machining accuracy of inclined hole 3: Using a high-precision gantry milling and boring center (such as the Italian JOMAX265) or the universal swing milling head of the Siegfried gantry milling machine, combined with CNC programming, the inclined hole 3 is machined. The U-drill is used to drill the bottom hole first and then the precision boring tool is used for precision boring, which fully guarantees the positional dimensions, hole spacing dimensions and angular accuracy of 30°±0.1° of the inclined hole 3.

[0046] 2. Flatness and parallelism meet the standards: By using a high-feed stainless steel special milling cutter, and employing a high-speed, small-cutting-weight, and fast-feed machining method, the machine is flipped multiple times during the machining process to release stress; roughing and finishing are carried out separately, and a side-top fastening and clamping method is used to remove excess material symmetrically and evenly on the upper and lower planes; after roughing, annealing is performed to improve internal stress, etc., so that the flatness of the airflow surface of the middle support and the parallelism between the mounting surface and the airflow surface meet the set requirements.

[0047] 3. Deformation control during hole breaking: By leaving allowance for the hole breaking parts (the oblique holes and square holes to be processed), and processing the square holes 2 to the drawing requirements after the oblique holes 3 are processed, the processing difficulties and deformation problems caused by processing the wall panel shape first and then processing the oblique holes 3 are avoided.

[0048] 4. Prevention of deformation during lifting and flipping: By designing special tooling for lifting and flipping, deformation of the wall panels during the lifting and flipping process is effectively prevented.

[0049] 5. Controllable quality: Flatness is checked by laser trackers (API RADIAN / R-50, AT930), the diameter of the oblique holes is checked by φ18H7 plug gauges, and the hole spacing of the oblique holes is checked by self-made inspection fixtures. These methods ensure the processing accuracy and quality of the wall panels. The final products meet the design requirements and are successfully put into storage.

[0050] Example 1

[0051] like Figure 1 As shown, one embodiment of the present invention is a method for manufacturing a wall panel for a wind tunnel full-model test section, the processing method including the following steps:

[0052] Step S100: Material preparation, using the inner wall panel 1 of the wind tunnel full-model test section;

[0053] Step S200: Marking lines, setting up a coordinate system on the inner wall plate 1, and marking the positions where holes need to be drilled on the coordinate system; the types of holes include square holes 2 and oblique holes 3;

[0054] Step S300: Rough milling; The rough milling step is performed using a high-speed CNC boring and milling machine, and the specific steps include:

[0055] Place the airflow surface downwards on the adjusting shim, use the side-top fastening method to align the workpiece according to the line, and evenly fasten the inner wall plate 1. Then, machine the rough milling mounting surface and the two ends of the four sides of the inner wall plate into straight surfaces, leaving a 10mm allowance. Leave a 6mm allowance on the other surfaces, and grind the roughness of the mounting surface to Ra3.2.

[0056] Rough mill the square hole 2, leaving a margin around the four sides to ensure that all the oblique holes 3 around the perimeter can be drilled out;

[0057] Turn the plate over so that the mounting surface is facing down and place it on the self-milling leveling pad. Check the contact by pulling out paper. Use the side-top fastening method to evenly tighten the inner wall plate 1. Loosen the clamps several times in the middle. If the part is not deformed, rough mill the airflow surface and leave a 6mm allowance.

[0058] Step S400: Annealing; Annealing includes two annealing processes. During the second annealing, the inner wall plate 1 is leveled so that it can evenly support the parts. No other parts are placed on the upper part of the inner wall plate 1.

[0059] Step S500: Semi-finish milling and finish milling; the semi-finish milling and finish milling steps are performed using a high-speed CNC boring and milling machine, including:

[0060] Place the inner wall panel 1 with the airflow facing downwards on the adjusting shim, align the workpiece according to the line, tighten it evenly, and then semi-finish mill the mounting surface, leaving a 1mm allowance. The roughness is Ra3.2, which means that the arithmetic mean of the absolute value of the profile offset of the mounting surface within the sampling length is 3.2 micrometers.

[0061] Turn it over so that the mounting surface is facing down, place it on the self-milling leveling pad, pull out paper to check the contact, tighten it evenly, loosen and press it several times in the middle. If the part is not deformed, semi-finish mill the airflow surface, leaving a 1mm allowance, mill three straight edges, leaving a 1mm allowance.

[0062] Using a universal milling head, drill oblique holes 3 and square holes 2 according to the coordinate dimensions, leaving a 1mm allowance on the three straight edges and a 1mm allowance on the airflow surface. Program the milling of the end bevel, and semi-finish mill and finish mill each of the square holes 2. Turn the part over so that the airflow surface is facing down and place it on the self-milling leveling pad. Check the contact with paper. After evenly tightening, semi-finish mill and finish mill the mounting surface to a roughness of Ra1.6. Turn the part over so that the mounting surface is facing down and place it on the self-milling leveling pad. Check the contact with paper. If the paper cannot be inserted between the mounting surface and the leveling pad, the contact is good. Evenly tighten the mounting surface and the leveling pad, loosening and tightening several times in the middle. If the part is not deformed, semi-finish mill and finish mill the airflow surface and the remaining three perimeters.

[0063] Step S600: Drilling; In the drilling step, when machining the inclined hole 3, a high-precision gantry moving boring and milling machining center or the universal swing milling head of the Siegfried gantry milling machine is used for CNC programming and machining. A U-drill is used to drill the bottom hole first, and after machining, a fine boring tool is used to finely bore the hole to ensure the hole diameter size.

[0064] Step S700: Fitter, used to remove burrs after drilling the inner wall plate 1, and to chamfer the edges of the oblique holes 3 and the square holes 2.

[0065] Step S800: Check the warehousing process. Check the machining accuracy of the oblique hole 3 of the inner wall plate 1. If it meets the set value of 18mm, then put it into storage; if it does not meet the set value, then re-process it.

[0066] During the machining process, a high-feed stainless steel special milling cutter head is used, and a machining method with high speed, small cutting depth, and fast feed is employed. The inner wall plate is flipped multiple times during the machining process to release the machining stress.

[0067] Specialized tooling is used when lifting and flipping the wall panels; when inspecting the flatness of the wall panels upon entry into the warehouse, a laser tracker of model API RADIAN / R-50 or AT930 is used for testing; the diameter of each of the three inclined holes is tested using a plug gauge of model φ18H7; and the distance between each of the three inclined holes is tested using a self-made testing tool, where φ is the diameter.

[0068] Example 2

[0069] like Figures 2-3 As shown, another embodiment of the present invention adopts the following setting method. Since the hole spacing of the inclined hole 3 is not easy to guarantee and the hole opening is not a complete circle, the conventional drilling process of the inclined hole 3 is prone to drilling off-center. Therefore, the method of milling flat and then drilling will produce deviation at the junction of milling and drilling. Generally, the milled hole is too large.

[0070] In this embodiment, the lower wall plate of the inner wall panel 1 is machined using the universal oscillating milling head of the Italian JOMAX265 (high-precision gantry milling and boring machine) or Siegfried gantry milling machine, with CNC programming to machine the inclined holes 3. This ensures the positional dimensions and hole spacing of the inclined holes 3. A U-drill is used to drill the pilot hole first, and then a precision boring tool is used to finish the hole diameter. This ensures that the diameter of the inclined holes 3 is relatively uniform, and the hole spacing is also similar, thus guaranteeing the drilling accuracy.

[0071] Example 3

[0072] Another embodiment of the present invention adopts the following configuration: since the flatness requirement of the airflow surface of the inner wall plate 1 is 0.2 mm and the parallelism of the two sides is 0.3 mm, this accuracy requirement is very high relative to the size of the part in this embodiment, and it is an ultra-large thin-walled part, which is very easy to deform during processing.

[0073] Therefore, this embodiment uses a high-feed stainless steel special milling cutter head, a high-speed, small-cut, and fast-feed machining method, and flips the cutter multiple times during the machining process to release machining stress. The machining is divided into roughing and finishing, and a side-top fastening clamping method is used. At the same time, the upper and lower planes are uniformly and symmetrically removed. The annealing treatment after roughing can improve the internal stress and is beneficial to the dimensional stability of finishing. The semi-finish milling of the airflow surface of the hole plate assembly leaves a 1mm allowance. The Φ18 oblique hole 3 is machined first, and then the airflow surface is finished milled to reduce the deformation caused by drilling.

[0074] Example 4

[0075] like Figures 2-3As shown, another embodiment of the present invention adopts the following arrangement: when the inner wall plate 1 is processed to make oblique holes 3, many oblique holes 3 are not qualified and are called broken holes. If the outer shape of the inner wall plate 1 is processed first and then the broken holes are processed into oblique holes 3, it is not only difficult to process, but also very easy to deform.

[0076] Therefore, in this embodiment, the perforation portion is left unprocessed, and after the oblique hole 3 is processed, the perforation portion is processed into a square hole 2; alternatively, the square hole 2 portion can be left unprocessed, and after the oblique hole 3 is processed, the perforation and square hole 2 can be processed into place.

[0077] Example 5

[0078] Another embodiment of the present invention employs the following configuration: due to the large size and thin wall thickness of the inner wall panel 1 (only 18mm), it is extremely prone to deformation during lifting and flipping.

[0079] By designing specialized tooling for lifting and flipping, deformation of the wall panels during the lifting and flipping process is effectively prevented.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for manufacturing wall panels for a full-scale wind tunnel test section, characterized in that, The processing methods include the following: Material preparation: The inner wall panels of the wind tunnel full-model test section are used; Mark the lines, set up a coordinate system on the inner wall plate, and mark the positions where holes need to be drilled on the coordinates; the types of holes include square holes and oblique holes; Rough milling: The inner wall panel is divided into an airflow surface and a mounting surface. The mounting surface and both ends of the four sides of the inner wall panel are machined into straight surfaces. Rough milling is performed on the airflow surface and the mounting surface. The rough milling step is performed using a high-speed CNC boring and milling machine. The specific steps include: With the airflow surface facing down and the mounting surface facing up, place it on the adjusting shim. Use the side-top fastening method to align the workpiece according to the line. After evenly fastening the inner wall plate, machine the two ends of the rough milled mounting surface and the four sides into straight surfaces, leaving a margin at both ends of the mounting surface and the four sides. Rough mill the square hole, leaving a margin around the four sides of the square hole to ensure that all the inclined holes around the perimeter are drilled; Turn it over so that the mounting surface is facing down and place it on the self-milling leveling pad. Check the contact by pulling out paper. Use the side-top fastening method to evenly tighten the inner wall plate. Loosen and press the clamps several times in the middle. If the part is not deformed, rough mill the airflow surface and leave a margin around the airflow surface. Annealing is performed twice, and the inner wall panel is leveled. Semi-finish milling and finish milling: First, semi-finish milling and finish milling are performed on the airflow surface and the mounting surface. Using a universal milling head, oblique holes and square holes are drilled according to coordinate dimensions. After drilling is completed, semi-finish milling and finish milling are performed on the airflow surface and the mounting surface. The semi-finish milling and finish milling steps are performed using a high-speed CNC boring and milling machine, including: Place the inner wall panel with the airflow side facing down on the adjusting shims, align the workpiece according to the line, and evenly tighten the inner wall panel before semi-finish milling the mounting surface. Turn it over so that the mounting surface is facing down, place it on the self-milling leveling pad, check the contact by pulling out paper, tighten the inner wall plate evenly, loosen and press it several times in the middle, if the part is not deformed, semi-finish mill the airflow surface; Using a universal milling head, drill oblique and square holes according to the coordinate dimensions, leaving allowance on the three straight edges and the airflow surface. Program the milling of the end bevel, and semi-finish mill and finish mill each square hole; flip it over with the airflow surface facing down, place it on the self-milling leveling pad, check the contact with paper, and evenly tighten the inner wall plate. Then semi-finish mill and finish mill the mounting surface; flip it over with the mounting surface facing down, place it on the self-milling leveling pad, check the contact with paper, and evenly tighten the inner wall plate. Loosen and tighten the clamps several times in the middle. If the part is not deformed, semi-finish mill and finish mill the airflow surface and the remaining three perimeters. A fitter is used to remove burrs after drilling holes in the inner wall panel and to chamfer the edges of beveled and square holes. Upon receiving the product, check the machining accuracy of the oblique and square holes on the inner wall panel. If the accuracy meets the set values, proceed with the receiving process; otherwise, reprocess the product.

2. The method for manufacturing a wall panel for a full-scale wind tunnel test section according to claim 1, characterized in that, Annealing includes two annealing processes. The first annealing is performed after rough milling, and the second annealing is performed after semi-finish milling and finish milling. During the second annealing, the inner wall plate is leveled so that it can evenly support the parts, and no other parts are placed on the upper part of the inner wall plate.

3. The method for manufacturing a wall panel for a full-scale wind tunnel test section according to claim 1, characterized in that, During the drilling process, when machining the inclined hole, a high-precision gantry milling and boring machine or the universal oscillating milling head of the Siegfried gantry milling machine is used for CNC programming and machining. A U-drill is used to drill the bottom hole first, and after machining, a fine boring tool is used to finish boring to ensure the hole diameter.

4. The method for manufacturing a wall panel for a full-scale wind tunnel test section according to claim 1, characterized in that, Stainless steel milling cutter discs are used during the processing, and the inner wall panel is flipped multiple times during the process to release the processing stress.

5. The method for manufacturing a wall panel for a full-scale wind tunnel test section according to claim 1, characterized in that, The side-top fastening clamping method used during processing involves symmetrically and evenly removing excess material from the upper and lower planes of the inner wall panel.

6. The method for manufacturing a wall panel for a full-scale wind tunnel test section according to claim 3, characterized in that, Leave a margin when semi-finish milling the airflow surface of the inner wall plate. First, machine it into an oblique hole of a set diameter, and then finish mill the airflow surface.

7. The method for manufacturing a wall panel for a full-scale wind tunnel test section according to claim 1, characterized in that, When inspecting the panels upon entry into the warehouse, the flatness of the panels is checked using a laser tracker, and the diameter and spacing of each inclined hole are also checked.

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