Method for machining using unsaturated resins

Abstract

The application discloses a method for machining using unsaturated resin, and applies the unsaturated resin to machining, wherein the method comprises the following steps: cutting the unsaturated resin into unsaturated resin blocks, bonding the unsaturated resin blocks to positions prone to vibration during machining of a part, milling the bonded resin blocks, making the surface of the resin blocks flush with a positioning reference surface of the part, machining the part, and removing the unsaturated resin blocks after machining is completed. The method can fix the unsaturated resin blocks to positions prone to vibration of the part by bonding, and can prevent machining vibration, thereby improving machining stability of the part and ensuring machining quality of the part.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of mechanical processing method, and relates to a method for mechanical processing using unsaturated resin. BACKGROUND

[0002] At present, the field of mechanical processing in the aviation manufacturing industry increasingly appears the processing of thin-walled parts. Such parts have poor processing rigidity due to the decrease of wall thickness, and vibration occurs during mechanical processing, which easily causes phenomena such as chatter, poor finish and even wall thickness out-of-tolerance, seriously affecting the delivery of parts.

[0003] The current measures to solve this problem are to use gypsum as a filler to enhance the rigidity of the part processing or to use a vacuum suction clamp to enhance stability.

[0004] During on-site operation, the gypsum filling process needs to go through the operations of transporting gypsum, making gypsum slurry, filling gypsum, waiting for gypsum to solidify, milling the gypsum reference surface, removing the gypsum after processing, cleaning the site, etc. This method mainly has the following shortcomings:

[0005] a) The operation is complicated, and the waiting time for gypsum solidification is long. Especially for large-size parts, the longest time for single part coating is about 8 hours, and the shortest time is also 2 hours, resulting in low efficiency;

[0006] b) The surface of the part is prone to rust;

[0007] c) After the numerical control processing procedure of the part is completed, the gypsum needs to be removed by knocking the part, which may easily cause defects in the part if not handled properly;

[0008] d) It is easy to pollute the environment. Since gypsum is used only once, the used gypsum needs to be recycled. If it is directly mixed with household garbage or leaks during transportation, it will cause environmental pollution. In addition, the coating site is prone to environmental chaos, affecting the 6S management of the site;

[0009] e) The labor intensity of workers is large. When coating gypsum, the workers need to go through the operations of adding water and stirring, cleaning the part and applying anti-rust oil, pouring into the cavity of the part, waiting for solidification, repairing the reference surface, and decomposing the gypsum, resulting in a large labor intensity of workers.

[0010] The vacuum suction method needs to go through the operations of transporting and installing the vacuum suction tooling, aligning the vacuum suction tooling, checking the air source, checking the suction reliability, and tooling into the warehouse, mainly having the following shortcomings:

[0011] a) The design cycle of the vacuum clamp is long, and the cost is high;

[0012] b) Once the structure of the part is changed, the clamp needs to be repaired or newly manufactured;

[0013] c) Using the fixture, the machine tool must be required to have vacuum suction, the adaptation surface is narrow;

[0014] d) For small batch production, considering the production cost, the number of special vacuum fixtures is less.

[0015] At present, in the processing of thin-walled parts, in order to prevent chatter during processing, ensure the size of the part web and the surface finish, the main method used in actual production site is to apply plaster. SUMMARY

[0016] The purpose of the present application is to provide a method of mechanical processing using unsaturated resin, which replaces plaster with unsaturated resin in mechanical processing, and has the advantages of simple operation, environmental protection and no pollution in the processing process, and solves the problems of chatter and unstable quality in the mechanical processing of thin-walled parts.

[0017] The technical scheme adopted by the present application is a method of mechanical processing using unsaturated resin, which applies unsaturated resin to mechanical processing, cuts the unsaturated resin into unsaturated resin blocks, bonds the unsaturated resin blocks to the parts prone to vibration during processing, mills the bonded resin blocks, makes the surface of the resin blocks flush with the positioning reference surface of the parts, then processes the parts, and removes the unsaturated resin blocks after processing.

[0018] The present application also has the following characteristics:

[0019] The thickness of the unsaturated resin block is greater than or equal to the distance from the bonding surface of the unsaturated resin block to the positioning reference surface of the part to be processed.

[0020] The unsaturated resin block is bonded to the web area of the part to be processed, and at least one unsaturated resin block is bonded to the center position of the web area.

[0021] The length, width and distance between the resin blocks are related to the thickness δ of the part web, specifically:

[0022] When δ≥4mm, the distance between the resin blocks is 150mm-200mm, and the size of the resin block is 50mm×50mm;

[0023] When 3mm≤δ<4mm, the distance between the resin blocks is 100mm-150mm, and the size of the resin block is 50mm×50mm;

[0024] When 2.5mm≤δ<3mm, the distance between the resin blocks is 80mm-100mm, and the size of the resin block is 60mm×60mm;

[0025] When 2mm≤δ<2.5mm, the distance between the resin blocks is ≤80mm, and the size of the resin block is 80mm×80mm;

[0026] When 1mm≤δ<2mm, the area of the resin block is equal to the area of the part web.

[0027] The unsaturated resin block is bonded to the side wall area of the part to be processed.

[0028] The unsaturated resin block and the part to be processed are bonded using AB glue, and the volume ratio of A glue to B glue in the AB glue is 1:1.

[0029] The specific process of milling the resin block is as follows: an end mill is used, the milling tool material is cemented carbide, the cutting depth is 3mm-5mm, the cutting width is less than or equal to 0.8 times the diameter of the tool, the rotation speed is 3000-4000r / min, and the feed per tooth is 0.2-0.3mm / z.

[0030] The specific steps for removing the unsaturated resin block are as follows: the side surface of the bonded unsaturated resin block is lightly tapped with a wooden hammer, the angle between the tapping direction of the wooden hammer and the bonding surface is not greater than 30°, and the unsaturated resin block and the part can be separated.

[0031] The beneficial effects of the present application are as follows:

[0032] The method of the present application applies unsaturated resin to mechanical processing, and uses bonding to fix the unsaturated resin block at the part of the part that is prone to vibration, which can effectively prevent processing vibration and improve the processing stability of the part, thereby ensuring the processing quality of the part.

[0033] (1) Simple and convenient operation

[0034] Whether it is a vacuum suction method or a gypsum filling process, the operation is relatively complicated, and the method of the present application uses unsaturated resin instead of the vacuum suction tooling or gypsum filling process, which only needs to use AB glue to paste the unsaturated resin block to the part of the part that is prone to vibration, and then mill off the excess unsaturated resin, which is relatively convenient to operate.

[0035] (2) Low cost

[0036] The cost of unsaturated resin material is much lower than that of gypsum and special tooling fixtures, especially for small-batch production parts, which can significantly reduce the processing cost of the parts.

[0037] Compared with the special tooling fixture, the cost of the special tooling fixture is one-time investment, but the design cost, material cost, processing cost, measurement cost, management cost and repair cost of the tooling fixture result in large one-time investment of the tooling fixture, especially for large aviation structural parts, the cost is as high as tens of thousands or even hundreds of thousands of yuan. If the parts are small batch production, the special tooling fixture cannot recover the tooling cost in a short period of time, which affects the economic benefit of the enterprise. The unsaturated resin process does not need a large amount of early economic investment, only needs to use some unsaturated resin blocks as support to play a similar role as the vacuum fixture. For small batch production parts, the cost of all unsaturated resin blocks is also much lower than that of the special tooling fixture.

[0038] Compared with the gypsum process, the unsaturated resin process is also suitable for small batch production parts, and the cost of the unsaturated resin is lower than that of the gypsum for the same volume. When filling the parts, the gypsum process generally fills the whole cavity of the part with gypsum, and needs more gypsum, while the unsaturated resin process only needs to use unsaturated resin blocks, and selectively paste several parts according to the rigidity requirement, without filling the cavity of the part, and the used unsaturated resin can be used on other parts, while the gypsum can only be used once. Therefore, the volume of the unsaturated resin used is relatively small compared with the gypsum. It can be seen that the unsaturated resin process has lower cost compared with the gypsum process.

[0039] (3) Environmentally friendly and pollution-free

[0040] Compared with the gypsum process, the unsaturated resin process has obvious environmental advantages. After use, the gypsum process becomes gypsum slurry solidification, which has no value and needs to be treated uniformly. If mixed with household garbage, it will pollute the surrounding soil and groundwater after being washed by rain. While the unsaturated resin used after use is still an unsaturated resin block, which can be used on other parts again, realizing recycling, so the waste is less, and it is more environmentally friendly. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is a schematic diagram of the size selection of the unsaturated resin block in the method of the present application;

[0042] Figure 2 is a structural schematic diagram of the unsaturated resin block adhered to the web area of the part, wherein figure a is a structural schematic diagram, and figure b is a sectional view in the direction of A-A in figure a;

[0043] Figure 3 is a structural schematic diagram of the unsaturated resin block adhered to the side wall area of the part, wherein the unsaturated resin block in figure a is integral, and the unsaturated resin block in figure b is formed by adhering a plurality of small blocks;

[0044] Figure 4 This is a schematic diagram of bonding unsaturated resin blocks using AB glue in the method of the present invention, wherein Figure a is a front view, Figure b is a cross-sectional view along the AA direction in Figure a, and Figure c is a top view;

[0045] Figure 5 Figure a is a schematic diagram of the unsaturated resin block bonding method in Example 1, wherein Figure a is a schematic diagram and Figure b is an enlarged schematic diagram of Figure a;

[0046] Figure 6 Figures a and b in the figure are schematic diagrams of the unsaturated resin block bonding method in Example 2;

[0047] Figure 7 This is a schematic diagram of the unsaturated resin block bonding method in Example 3.

[0048] In the diagram, 1. Part, 2. Unsaturated resin block, 3. Part positioning reference surface, 4. AB glue, 5. Wood substitute block. Detailed Implementation

[0049] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0050] This invention relates to a method for machining with unsaturated resin. The method involves applying unsaturated resin to machining processes, including selecting the size of the unsaturated resin, bonding, milling, and removing it. Specifically, it is implemented according to the following steps:

[0051] Step 1: Determine the size of the unsaturated resin block

[0052] Unsaturated resin primarily serves a supporting role in machining; therefore, the thickness of the unsaturated resin block should be greater than or equal to the distance from its bonding surface to the part's positioning reference surface. For example... Figure 1 As shown, taking part 1, which is machined on both sides, as an example, after the first side is machined, in order to enhance the machining stability of the web of the second side of the part, an unsaturated resin block 2 is bonded to the machined web surface on the first side. After bonding, the unsaturated resin block 2 is higher than the part positioning reference surface 3. In this way, after milling the higher unsaturated resin block 2 with the part positioning reference surface 3, it can be ensured that the plane of the unsaturated resin block 2 and the part positioning reference surface 3 are on the same plane. When the second side of the part is machined, the unsaturated resin block 2 can play a good supporting role.

[0053] The length of the unsaturated resin block is generally 50mm to 80mm. The specific size is related to the thickness of the web of the part. See Table 1 in step 2 for details.

[0054] Step 2: Bond the unsaturated resin blocks

[0055] (1) Determine the distance between the bonding location and the unsaturated resin block.

[0056] The bonding location of the unsaturated resin block should be selected based on the vibration prevention requirements of the parts during processing, such as... Figure 2 As shown, unsaturated resin block 2 can be bonded to the web area of ​​part 1; as Figure 3 As shown, unsaturated resin block 2 can also be bonded to the side wall area of ​​part 1, such as... Figure 3 As shown in a and 3b respectively, the unsaturated resin block 2 can be a single piece or a combination formed by pasting multiple unsaturated resin blocks together.

[0057] When unsaturated resin blocks are bonded to the web surface, the selection of web thickness, maximum bonding distance of unsaturated resin blocks, and length of unsaturated resin blocks is detailed in Table 1.

[0058] Table 1. Relationship between part thickness and bonding distance / length of unsaturated resin block

[0059] Part web thickness δ (mm) Distance between blocks of unsaturated resin (mm) Size of blocks of unsaturated resin (mm) δ≥4 150～200 50×50 3≤δ<4 100～150 50×50 2.5≤δ<3 80～100 60×60 2≤δ<2.5 ≤80 80×80 1≤δ<2 / Selection according to part web size

[0060] As shown in Table 1, the selection of the number and size of unsaturated resin blocks is related to the area and thickness of the web of the part. For parts with a web thickness ≥ 4 mm and a web length and width ≤ 200 mm, the web has good machining rigidity and can be machined directly without unsaturated resin, achieving ideal machining conditions. However, when the web size is large, the vibration during machining increases, requiring unsaturated resin for auxiliary machining. Generally, when using unsaturated resin, such as... Figure 2 As shown, an unsaturated resin block needs to be placed at the very center of the web surface of the part, and the remaining areas should be equipped with unsaturated resin blocks according to the dimensions shown in Table 1. For parts with a web surface thickness of 1mm ≤ δ < 2mm, the size of the unsaturated resin block at the very center of the web surface can be increased; ideally, the entire web surface should be supported by unsaturated resin. For parts with a web surface thickness of δ < 1mm, although using unsaturated resin to assist in machining can significantly improve the machining conditions, it is difficult to guarantee that the surface roughness meets the requirements; therefore, the use of unsaturated resin is not recommended.

[0061] (2) Adhesion method

[0062] AB glue is used to bond unsaturated resin blocks and parts to be processed, wherein the volume ratio of A glue to B glue is 1:1.

[0063] like Figure 4 The diagram shows the bonding method for the unsaturated resin block. Since the unsaturated resin block will be removed from the part after processing, only general adhesive force is needed between them. During bonding, an inverted triangular AB glue 4 bonding area is formed at the four edges of the contact surface between the unsaturated resin block 2 and the part 1.

[0064] Step 3, milling the unsaturated resin block

[0065] After the unsaturated resin block is bonded, the surface thereof is higher than the positioning reference surface of the part, and the unsaturated resin block needs to be milled so that the two surfaces are in the same plane. The machining parameters of the numerical control milling of the unsaturated resin block are shown in Table 2. The top surface of the milled unsaturated resin block is preferably 0.03mm-0.05mm higher than the positioning reference surface of the part.

[0066] Table 2 Milling parameter list

[0067]

[0068] Step 4, removing the unsaturated resin block

[0069] The side surface of the bonded unsaturated resin block is lightly tapped with a wooden hammer, the angle between the tapping direction of the wooden hammer and the bonding surface is not greater than 30°, and the unsaturated resin block can be separated from the part. After separation, the residual AB glue on the part can be removed using industrial acetone or other degreasing agents that do not corrode the part.

[0070] The method of the present application pastes the unsaturated resin block to the part web or side wall and other parts that are prone to vibration during mechanical processing, which can improve the processing conditions and reduce the vibration during mechanical processing. The method has been applied to aircraft structural frame parts, thin-walled box-shaped parts and other parts, and good results have been achieved.

[0071] Example 1

[0072] As shown in Figure 5 , the part 1 to be processed in this embodiment is a certain aircraft door frame part, and the specific size of the part 1 is about 1200mmx800mmx110mm. The part 1 is processed using a horizontal milling equipment when the side wall is processed, and the bottom edge of a Φ20R3 alloy end mill is selected to process the side wall of the part. The thickness of the side wall of the part is 2.5mm, and the part 1 is prone to tool chatter during processing, which makes it difficult to ensure the size and surface finish of the side wall. In order to improve the processing conditions, unsaturated resin is used for auxiliary mechanical processing. The selected unsaturated resin is wood substitute, and the size of the wood substitute block 5 is 150mmx50mmx50mm, and the number of blocks is 4, as shown in Figure 5 , the wood substitute block 5 is pasted to the area of the part 1 side wall where the tool chatter is prone to occur, and the distance between the wood substitute blocks 5 is distributed according to the tool chatter position. The wood substitute block 5 is bonded using Kraft strong AB glue, and after bonding, it is milled. During milling, the bottom edge of a Φ20R3 alloy end mill is still used to process the other side wall, and after processing is completed, the wood substitute block 5 is removed. The use of unsaturated resin for auxiliary mechanical processing in this example can well improve the processing conditions and improve the processing stability and quality of the part.

[0073] Example 2

[0074] As Figure 6 shown, the part to be processed in this embodiment is a box-shaped part in a certain aircraft structure, and the specific size of the part 1 is about 600mmx600mmx80mm, and the web size of the part 1 is 3mm. Nine unsaturated resin blocks 2 are selected, and the size of the resin block is 50mmx50mm, and the number of blocks is 9, as shown in Figure 6 shown, one of the unsaturated resin blocks 2 is pasted on the center area of the side wall of the part, and then the distance between the resin blocks is about 110mm, the resin blocks are adhered using Kraft strong AB glue, after the adhesion, the upper surface of the resin block is milled to be flush with the first surface of the raw material reference surface, and the specific parameters of the milling are: processing tool Φ40 face milling cutter, cutting width 30mm, cutting depth 5mm, and cutting amount per tooth 0.25mm / z. After the reference processing is completed, the second surface is milled, and after the processing is completed, the resin block is removed. Compared with the part processed without using resin block auxiliary processing, the quality of the part is greatly improved.

[0075] Embodiment 3

[0076] As Figure 7 shown, the part to be processed in this embodiment is a certain rib position edge strip part of a certain aircraft, and the specific size of the part 1 is about 5000mmx110mmx95mm, and the part has a 3mm inclined rib. A five-coordinate numerical control milling machine is used for processing, and when the 3mm inclined rib is processed, the part processing stiffness is reduced, and the quality problem caused by chatter is prone to occur. Unsaturated resin is selected as a wood substitute, and the size of the wood substitute block 5 is 50mmx50mmx50mm, and the number of blocks is 1, as shown in Figure 7 shown, one of the wood substitute blocks 5 is pasted on the side wall of the part 1 using Kraft strong AB glue, and after the adhesion, the part inclined rib opening side is processed, and after the processing is completed, the wood substitute block 5 is removed, which can well solve the problem of unstable quality of the inclined rib processing.

Claims

1. A method for mechanical processing using unsaturated resins, characterized in that, The unsaturated resin is applied to mechanical processing by cutting the unsaturated resin into blocks, bonding the blocks to positions prone to vibration during part processing, milling the bonded blocks to make the block surface flush with the part positioning reference surface, and then processing the part, and removing the blocks after processing is completed. The unsaturated resin blocks are bonded to the web area of the part to be processed, and at least one unsaturated resin block is bonded to the center position of the web area. The length, width and distance between the blocks are related to the web thickness δ of the part, specifically: When δ≥4mm, the distance between the blocks is 150mm~200mm, and the size of the blocks is 50mm×50mm; When 3mm≤δ<4mm, the distance between the blocks is 100mm~150mm, and the size of the blocks is 50mm×50mm; When 2.5mm≤δ<3mm, the distance between the blocks is 80mm~100mm, and the size of the blocks is 60mm×60mm; When 2mm≤δ<2.5mm, the distance between the blocks is ≤80mm, and the size of the blocks is 80mm×80mm; When 1mm≤δ<2mm, the area of the blocks is equal to the area of the part web.

2. The method of machining using unsaturated resin according to claim 1, characterized by, The thickness of the unsaturated resin blocks is greater than or equal to the distance from the bonding surface of the blocks to the part positioning reference surface.

3. The method of machining using unsaturated resin according to claim 1, characterized by, The unsaturated resin blocks are bonded to the side wall area of the part to be processed.

4. The method of machining using unsaturated resin according to claim 1, characterized by, AB glue is used to bond the unsaturated resin blocks and the part to be processed, and the volume ratio of A glue to B glue in the AB glue is 1:

1.

5. The method of machining using unsaturated resin according to claim 1, characterized by, The specific process for milling the blocks is: using an end mill, the mill material is cemented carbide, the cutting depth is 3mm~5mm, the cutting width is ≤0.8 times the diameter of the tool, the speed is 3000~4000r / min, and the feed per tooth is 0.2~0.3mm / z.

6. The method of claim 1, wherein the unsaturated resin is a vinyl ester resin. The specific steps for removing the unsaturated resin blocks are: gently knock the side of the bonded unsaturated resin blocks with a wooden hammer, the angle between the knocking direction of the wooden hammer and the bonding surface is not greater than 30°, and the unsaturated resin blocks can be separated from the part.

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