A high-pressure airbag-assisted thin-wall component precision milling method

Abstract

The present invention discloses a method for precision milling of thin-walled components assisted by a high-pressure airbag, wherein the thin-walled component to be processed is placed on a supporting membrane and fixed; a pressurized medium is continuously filled into the interior of the high-pressure airbag auxiliary device and discharged through the outlet of the high-pressure airbag, so that the processing area of ​​the thin-walled component is completely in contact with the supporting membrane; the high-pressure airbag auxiliary device moves synchronously with the milling cutter, and the high-pressure airbag and the pressurized medium jointly apply pressure to the thin-walled component, and the milling cutter performs milling processing on the thin-walled component to remove the part. The present invention uses a gas or liquid with adjustable pressure as a restraining medium, and the pressure can reach 10MPa or even higher, thereby avoiding the problem of insufficient clamping force. The present invention uses a high-pressure airbag auxiliary device to make the auxiliary pressure move synchronously with the milling cutter, thereby suppressing deformation of the processing area of ​​the thin-walled component, ensuring the precision of the thin-walled component during milling, and improving processing efficiency.

Description

Technical Field

[0001] The invention relates to a precision machining method for a thin-wall component, and in particular to a precision milling machining method for a thin-wall component assisted by a high-pressure air bag. Background Art

[0002] In recent years, with the rapid development of advanced manufacturing technology, thin-walled components, as an important structural form for achieving high-performance and lightweight equipment, account for an increasing proportion in the actual application of today's engineering, and are widely used in the fields of aviation, automobiles, chemical machinery, construction and marine engineering. For example, there are many types of thin-walled parts used in aircraft, with different shapes and performances, and different structural and process characteristics. They mainly include thin-walled parts in the aircraft fuselage structure, thin-walled parts such as frame shells for assembling airborne equipment, and thin-walled parts in the aircraft engine structure. The single-direction size of the thin-walled parts of the fuselage plane exceeds 3000mm, while the wall thickness is only 2-3mm, and the dimensional accuracy in the thickness direction reaches ±0.1mm.

[0003] Thin-walled components are usually manufactured by combining forming and cutting (or chemical milling): one solution is to first perform cutting (or chemical milling) on ​​the blank to obtain characteristic structures such as reinforcing ribs, and then use roll bending or press bending to obtain the integral wall panel; another solution is to first perform roll bending or press bending on the blank to obtain the integral wall panel, and then use cutting or (chemical milling) to obtain characteristic structures such as reinforcing ribs. When chemical milling is used to process the characteristic structures of thin-walled components, dissolution will also occur on the side of the unprocessed position, and an arc will be formed between the processed bottom surface and the side surface, making it difficult to process the designed sharp corners or deep grooves. At the same time, the solution after chemical milling is also polluted, which cannot meet the requirements of precision processing and the development of green manufacturing. Therefore, such characteristic structures of thin-walled components often need to be completed by milling.

[0004] In milling, it is necessary to place the flat or curved thin-walled components made by roll bending or press bending on the supporting membrane, fix them on the membrane by using a pressure plate, and then the milling cutter starts milling at a local position of the thin-walled component and gradually completes the process. Due to the complex structure, weak rigidity, and high removal rate of thin-walled components, they are very easy to deform during the milling process, resulting in uneven wall thickness and dimensional tolerance of thin-walled components, and even damage to the tool or machine tool and scrapping of the thin-walled component. Therefore, in the milling of thin-walled components, a device or method to suppress machining deformation is often required.

[0005] At present, the main methods for suppressing the deformation of thin-walled components are as follows: (1) Processing parameter and path optimization to suppress component deformation technology. First, the processing deformation of thin-walled components under different cutting parameters and paths is obtained, and then the minimum deformation and optimal path are obtained through the optimization algorithm; (2) High-speed cutting to suppress component deformation technology. It mainly increases the tool speed and feed rate significantly and reduces the cutting thickness, so as to achieve the purpose of slowing down the temperature rise of thin-walled components and reducing the deformation of thin-walled components during the processing; (3) CNC compensation to suppress component deformation technology. The tool position is monitored and controlled in real time by special equipment to compensate for the tool clearance caused by deformation, reduce deformation, and ensure the processing accuracy of thin-walled components; (4) Auxiliary support to suppress component deformation technology, mainly including vacuum suction cups, mirror milling, fixed pressure medium cavity milling and other technical methods. Vacuum suction cup technology sets multiple vacuum suction cups on the other side of the thin-walled component to be milled, and the thin-walled component is firmly fixed by vacuum pressure. Mirror milling technology sets a support unit on the other side of the milling cutter. The control system makes the support unit and the milling cutter have the same feed speed, and the support unit will change its position in real time with the movement of the tool. The fixed pressure medium cavity milling technology (a pressure-assisted thin-walled blank precision machining method, patent number: ZL 201510341829.2) is to place the pressure medium cavity on the thin-walled component to be processed, adjust the pressure in the medium cavity (the pressure can be much greater than 0.1MPa) so that the thin-walled component to be processed is close to the supporting membrane, and the milling process is completed in the pressure medium cavity.

[0006] However, these methods have the following problems: (1) The technology of suppressing component deformation by optimizing machining parameters and paths requires a lot of time to calculate or test the best results. The larger the size of the thin-walled component, the more time it takes. (2) The technology of suppressing component deformation by high-speed cutting requires high spindle speed and rigidity of the equipment, and there are high acceleration and deceleration stages at the start and end stages, which causes rapid wear on the guide rails, ball screws and spindle bearings, and the maintenance cost is high. (3) The technology of suppressing component deformation by numerical control compensation requires a dedicated monitoring system and analysis system, and the system is complex and costly. (4) The technology of suppressing component deformation by auxiliary support uses a vacuum suction cup to make the thin-walled component to be processed stick to the support membrane, but the maximum pressure of the vacuum suction cup is only 0.1MPa (1 atmosphere), which is often not enough to make the thin-walled component to be processed completely stick to the support membrane. The control system of mirror milling technology is complex and the manufacturing cost is high. The operation of the milling technology in a fixed pressure medium cavity is not flexible. The pressure medium cavity cannot move synchronously with the milling cutter. After completing the processing of a certain area, the pressure medium cavity needs to be moved to another area to be processed. For large-sized thin-walled components, the pressure medium cavity often needs to be clamped repeatedly.

[0007] In order to solve the problems of existing thin-walled component processing methods, such as high technical difficulty, high maintenance cost, low production efficiency, complex control system, and poor versatility for parts of different sizes, a new thin-walled component precision milling method is needed. Summary of the invention

[0008] The purpose of the present invention is to propose a new thin-walled component precision milling method to solve the problems of high technical difficulty, high maintenance cost, low production efficiency, complex control system, and poor versatility for parts of different sizes in the existing thin-walled component processing equations.

[0009] The technical solution adopted by the present invention to solve the above problems is:

[0010] A high-pressure airbag-assisted thin-wall component precision milling method, the steps are as follows:

[0011] Step 1: The upper part of the high-pressure airbag auxiliary device 3 is connected to the telescopic connecting rod 8 through the bolt 9, and the telescopic connecting rod 8 is further connected to the vertical milling machine 7; the lower part of the high-pressure airbag auxiliary device 3 is connected to the high-pressure airbag 11 through the bolt 9, and the two are in communication; the upper surface of the high-pressure airbag auxiliary device 3 is provided with a medium inlet 10, and the medium inlet 10 is connected to the medium conduit 4, and the pressurized medium 12 is rushed into the high-pressure airbag auxiliary device 3 through the medium conduit 4; the milling cutter 5 is connected to the vertical milling machine 7, and a square hole is left at the center of the high-pressure airbag auxiliary device 3 for the milling cutter 5 to extend into;

[0012] Step 2: Place the thin-walled component 2 to be processed on the supporting membrane 6, and fix the outer edge of the thin-walled component 2 with the pressing plate 1;

[0013] Step 3: The pressurized medium 12 is continuously filled into the interior of the high-pressure airbag auxiliary device 3 through the medium conduit 4 and the medium inlet 10, and discharged through the outlet of the high-pressure airbag 11, so that the processing area of ​​the thin-walled component 2 is completely fitted with the supporting fetal membrane 6; the pressure value of the pressurized medium 12 increases with the increase of the strength and size of the thin-walled component 2, and the pressure value that forms a pressure equilibrium state between the high-pressure airbag auxiliary device 3 and the thin-walled component 2 is determined through experiments;

[0014] Step 4: The high-pressure airbag auxiliary device 3 and the milling cutter 5 move synchronously, the high-pressure airbag 11 and the pressure medium 12 jointly apply pressure to the thin-walled component 2, and the milling cutter 5 performs milling processing on the thin-walled component 2 to obtain the final required parts;

[0015] Step 5: Stop charging the pressurized medium 12, remove the high-pressure airbag auxiliary device 3, the milling cutter 5 and the pressing plate 1, and take out the parts.

[0016] The beneficial effects of this invention are:

[0017] 1. The high-pressure airbag-assisted thin-walled component precision milling method of the present invention can apply pressure to the to-be-processed area on the surface of the thin-walled component through a flexible airbag, so that the processing area of ​​the thin-walled component is completely fitted with the supporting fetal membrane. The high-pressure airbag can apply uniform pressure to the processing area of ​​thin-walled components of different shapes, avoiding the problem of only applying concentrated pressure to a part of the thin-walled component when using a rigid pressing plate or fixture.

[0018] 2. The present invention adopts a high-pressure airbag auxiliary device, which can make the auxiliary pressure move synchronously with the milling cutter, suppress the deformation of the processing area of ​​the thin-walled component, and ensure the accuracy of the thin-walled component during milling. At the same time, when processing parts of the same batch, the pressure auxiliary device only needs to be clamped once, which improves the processing efficiency.

[0019] 3. The present invention uses gas or liquid with adjustable pressure as the restraining medium, and the pressure can reach 10MPa or even higher, thereby avoiding the problem of insufficient pressing force when using traditional methods (such as using vacuum suction cups).

[0020] Fourth, the present invention uses pressurized medium and high-pressure airbag as working medium, and the working materials are easy to obtain and low in price, which is conducive to reducing the time cycle and economic cost of maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the present invention using a high-pressure airbag-assisted method to perform milling on a thin-walled component;

[0022] Figure 2 It is a schematic diagram of the high-pressure airbag auxiliary device of the present invention;

[0023] Figure 3 It is a cross-sectional schematic diagram of the high-pressure airbag auxiliary device of the present invention;

[0024] Figure 4 It is a schematic bottom view of the high-pressure airbag auxiliary device of the present invention.

[0025] In the figure: 1 pressure plate, 2 thin-walled component, 3 high-pressure airbag auxiliary device, 4 medium conduit, 5 milling cutter, 6 supporting fetal membrane, 7 vertical milling machine, 8 telescopic connecting rod, 9 bolt, 10 medium inlet, 11 high-pressure airbag, 12 pressurized medium. DETAILED DESCRIPTION

[0026] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0027] Example 1

[0028] Combination Figures 1 to 4 It is explained that the high-pressure airbag-assisted thin-walled component precision milling processing method proposed in the present invention is implemented according to the following steps:

[0029] Step 1, the main body of the high-pressure airbag auxiliary device 3 is connected by bolts 9, the upper part is connected to the telescopic connecting rod 8 by bolts 9, the lower part is connected to the high-pressure airbag 11, the telescopic connecting rod 8 of the high-pressure airbag auxiliary device is connected to the vertical milling machine 7, the medium inlet 10 is connected to the medium conduit 4, and the milling cutter 5 is connected to the vertical milling machine 7;

[0030] Step 2: placing the thin-walled component 2 to be processed on the supporting membrane 6, and fixing the thin-walled component 2 with the pressing plate 1;

[0031] Step 3: The pressurized medium 12 is continuously filled into the high-pressure airbag auxiliary device 3 through the medium conduit 4 and the medium inlet 10, and is discharged through the outlet of the high-pressure airbag 11, so that a pressure balance state is formed between the high-pressure airbag auxiliary device 3 and the thin-walled component 2;

[0032] Step 4: The high-pressure airbag auxiliary device 3 moves synchronously with the milling cutter 5, and the high-pressure airbag 11 and the pressure medium 12 jointly apply pressure to the thin-walled component 2, while the milling cutter 5 performs milling processing on the thin-walled component 2 to obtain the final required parts;

[0033] Step 5: Stop charging the pressurized medium 12, remove the high-pressure airbag auxiliary device 3, the milling cutter 5 and the pressing plate 1, and take out the parts.

[0034] Example 2

[0035] Combination Figure 1 , Figure 2 , Figure 3 Note that in steps 1 to 4 of this embodiment, the high-pressure airbag auxiliary device 3 is connected to the vertical milling machine 7 in a detachable manner, such as a threaded connection, and the high-pressure airbag auxiliary device 3 and the milling cutter 5 remain relatively stationary. Other steps and parameters are the same as those in the first embodiment.

[0036] The beneficial effect of this embodiment is that when processing the same batch of parts, the high-pressure airbag auxiliary device 3 only needs to be clamped once and works simultaneously with the milling cutter 5. During the milling process, there is no need to consider multiple clamping of the high-pressure airbag auxiliary device 3, and no extra time is consumed during the entire processing process, thereby improving the processing efficiency.

[0037] Example 3

[0038] Combination Figure 2 , Figure 3 , Figure 4 It is noted that in steps 1 to 4 of this embodiment, the high-pressure airbag 11 is a tape product, which is filled with a pressure medium 12 to apply uniform pressure to the surface of the thin-walled component 2. The other steps and parameters are the same as those in the first embodiment.

[0039] The beneficial effects of this embodiment are: the high-pressure airbag 11 is filled with a pressure medium 12 to form a local pressure field, which generates a certain lifting force at the bottom of the high-pressure airbag 11, so that a small gap is formed between the high-pressure airbag auxiliary device 3 and the thin-walled component 2, and a pressure balance state is achieved. During processing and movement, the direct contact between the high-pressure airbag 11 and the thin-walled component 2 is reduced or avoided, the friction force is reduced, and the friction damage of the high-pressure airbag 11 is reduced.

[0040] Example 4

[0041] Combination Figure 1 , Figure 2 , Figure 3 It is noted that the telescopic connecting rod 8 in step three of this embodiment can adjust the distance between the high-pressure airbag auxiliary device 3 and the thin-walled component 2, and change the pressure value of the pressurized medium 12. Other steps and parameters are the same as those in the first embodiment.

[0042] The beneficial effect of this embodiment is that the distance from the thin-walled component 2 and the size of the pressure medium 12 can be changed according to the milling processing parameters to adjust the pressure value on the surface of the thin-walled component 2 to meet the pressure value required during milling of thin-walled components 2 of different materials and thicknesses.

Claims

1. A high-pressure airbag-assisted thin-wall component precision milling method, characterized in that: Here are the steps: Step 1: The upper part of the high-pressure airbag auxiliary device (3) is connected to the telescopic connecting rod (8) through a bolt (9), and the telescopic connecting rod (8) is further connected to the vertical milling machine (7); the lower part of the high-pressure airbag auxiliary device (3) is connected to the high-pressure airbag (11) through a bolt (9), and the two are in communication; a medium inlet (10) is arranged on the upper surface of the high-pressure airbag auxiliary device (3), and the medium inlet (10) is connected to the medium conduit (4), and a pressurized medium (12) is rushed into the high-pressure airbag auxiliary device (3) through the medium conduit (4); the milling cutter (5) is connected to the vertical milling machine (7), and a square hole is reserved at the center of the high-pressure airbag auxiliary device (3) for the milling cutter (5) to extend into; Step 2: placing the thin-walled component (2) to be processed on the supporting membrane (6), and fixing the outer edge of the thin-walled component (2) with a pressing plate (1); Step 3: The pressurized medium (12) is continuously filled into the interior of the high-pressure airbag auxiliary device (3) through the medium conduit (4) and the medium inlet (10), and discharged through the outlet of the high-pressure airbag (11), so that the processed area of ​​the thin-walled component (2) and the supporting fetal membrane (6) are completely in contact with each other; the pressure value of the pressurized medium (12) increases as the strength and size of the thin-walled component (2) increase, and the pressure value at which a pressure equilibrium state is formed between the high-pressure airbag auxiliary device (3) and the thin-walled component (2) is determined through experiments; Step 4: The high-pressure airbag auxiliary device (3) and the milling cutter (5) move synchronously, the high-pressure airbag (11) and the pressure medium (12) jointly apply pressure to the thin-walled component (2), and the milling cutter (5) performs milling processing on the thin-walled component (2) to obtain the final required parts; Step 5: Stop charging the pressurized medium (12), remove the high-pressure airbag auxiliary device (3), the milling cutter (5) and the pressing plate (1), and take out the parts.

2. The high-pressure airbag-assisted thin-wall component precision milling method according to claim 1, characterized in that: The high-pressure airbag auxiliary device (3) is connected to the vertical milling machine (7) in a detachable manner.

3. The high-pressure airbag-assisted thin-wall component precision milling method according to claim 1, characterized in that: The high-pressure airbag (11) is a tape product.

4. The high-pressure airbag-assisted thin-wall component precision milling method according to claim 1, characterized in that: A telescopic connecting rod (8) is used to adjust the distance between the high-pressure airbag auxiliary device (3) and the thin-walled component (2).

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