Square open-end frame type thin-walled part and processing method

Abstract

The application discloses a square open-end frame type thin-wall part and a machining method, and relates to the field of machining.The main steps of the machining method are as follows: step one, three-dimensional scanning is performed on a casting blank to confirm the machining allowance of the inner cavity shape;step two, the connecting rib is cut off to release deformation;step three, mounting holes are drilled on the cut connecting rib, and a connecting plate is used for connection and fixation;step four, the end face and the contour are machined with the aid of the connecting rib;and step five, the four-axis tooling is used for mounting and machining.The method combines three-dimensional scanning to verify the casting blank, releases stress deformation with the aid of the connecting rib, and is used for auxiliary clamping, so that the clamping difficulty in the machining process is solved, the machining performance of the workpiece is enhanced, the machining deformation in the machining process is reduced, and the machining process qualification rate of the product is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mechanical processing, and relates to a square open-end frame type thin-walled part and a processing method. BACKGROUND

[0002] The processing of thin-walled parts is always a difficult problem in mechanical processing because of the easy deformation. Among them, the open-end part is prone to large deformation and contour out-of-tolerance because of poor clamping stability and poor structural rigidity. The processing deformation of the part to be processed on both sides may also cause one side to be over-processed, resulting in the rejection of the workpiece due to thin wall. For the processing of such workpieces, measures need to be taken to control the deformation of the workpiece to improve the processing quality. SUMMARY

[0003] The technical problem solved by the present application is to overcome the shortcomings of the prior art and provide a processing method for a square open-end frame type thin-walled part. The processing stress of the workpiece during machining is overcome by using means such as increasing support, releasing stress and making tooling to control the deformation of the workpiece during the processing of the thin-walled workpiece.

[0004] Specifically, the method increases the cast rib to enhance the structural rigidity and reduce the deformation of the casting; the clamping performance is optimized by the cast rib, and the stress deformation is released by cutting; the four-axis support tooling is used to process the shape, thereby reducing the deformation amount during processing. Finally, the deformation amount of the thin-walled area of the end frame, especially the open position, during the machining process is reduced, and the processing quality of the workpiece is improved.

[0005] The technical scheme provided by the present application is as follows:

[0006] A processing method for a square open-end frame type thin-walled part, comprising:

[0007] S1: One end of the casting blank is a closed end, the other end is an open end, and the side surface of the casting blank has an opening. The opening of the side surface is in communication with the opening of the open end. The casting blank is provided with a connecting rib at the opening position of the side surface, and the connecting rib is close to the open end. The connecting rib connects the structures on both sides of the open end together; the casting blank is three-dimensionally scanned to confirm the machining allowance of the inner cavity shape, and the machining allowance of the whole casting blank is determined according to the machining allowance of the inner cavity shape. If the whole casting blank has machining allowance, S2 is performed;

[0008] S2: The connecting rib is cut off;

[0009] S3: A mounting hole is drilled at the end of the cut connecting rib, and a connecting plate is used for connection and fixation to obtain an intermediate casting blank;

[0010] S4: The intermediate casting blank is fixed to the surface of the machine tool, and the end face and the inner contour of the end face are processed to obtain a processed casting blank.

[0011] S5: Install the turntable at the closed end and the blocking plate at the open end. Install the turntable and the blocking plate on the machine tool and use the machine tool to process the circumferential features of the processed casting blank.

[0012] In step S2, the connecting rib is cut off at the middle position; the cutting length of the connecting rib from the middle position is 10%-15% of the length of the connecting rib.

[0013] In S2, the connecting plate is connected to the side of the connecting rib facing the inside of the open end.

[0014] In step S3, drilling mounting holes at the ends of the cut connecting ribs and connecting and fixing them with connecting plates to obtain intermediate casting blanks includes: drilling a mounting hole at the end of the cut connecting ribs, and connecting and fixing the connecting plate and the ends of the two disconnected connecting ribs with bolts and connecting holes to obtain intermediate casting blanks.

[0015] In S4, the processed casting blank has a groove on the end face of the closed end away from the open end.

[0016] In S5, a recessed block is provided on one side of the turntable, and the recessed block cooperates with the groove.

[0017] In S5, the hole structure is formed by the open end of the machined casting blank, the connecting ribs, and the connecting plate; the plug plate fits into the hole structure, and the plug plate transitions into the hole structure.

[0018] The casting blank is an aluminum alloy casting.

[0019] A square open-end frame type thin-walled part, the casting blank is processed according to any of the above-described processing methods for a square open-end frame type thin-walled part.

[0020] In summary, this application includes at least the following beneficial technical effects:

[0021] To address the difficulty in machining open, thin-walled structural components, cast ribs are added for support and clamping during machining. Stress is released by cutting the ribs during machining, reducing deformation in the open areas after rib removal. This enhances the workpiece's machinability, reduces machining deformation, and improves overall machining quality. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the end frame structure.

[0023] Figure 2 A schematic diagram of adding connecting ribs to a casting.

[0024] Figure 3 This is a schematic diagram of the connecting plate after the reinforcing bars have been cut.

[0025] Figure 4 This is a schematic diagram of a four-axis tooling.

[0026] The reference numerals in the attached figures are as follows: 1. Casting blank; 11. Closed end; 12. Open end; 13. Connecting rib; 2. Connecting plate. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments disclosed in the present invention will be described in further detail below with reference to the accompanying drawings.

[0028] This application discloses a method for processing a square open-end frame type thin-walled part, such as... Figure 1 As shown, the selected test part is a fuel tank end frame for a certain type of aerospace product. The material is cast aluminum alloy, and the structure is a square hollow shell with an open rear and top surface. The thin-walled area has a wall thickness of 1.5 mm. The blank is cast, with envelope dimensions of 440 mm × 230 mm × 215 mm. The product structure is as follows. Figure 1 As shown. The specific implementation method is as follows:

[0029] (1) Perform a three-dimensional scan on the casting blank, confirm the scan fitting results, and ensure that the workpiece has sufficient internal and external allowances.

[0030] One end of the casting blank 1 is a closed end 11 and the other end is an open end 12. The side of the casting blank 1 is open and the open end is connected to the open end. The casting blank is provided with a connecting rib 13 at the open end position on the side and the connecting rib 13 is close to the open end. The connecting rib connects the two sides of the open end structure together.

[0031] During the confirmation of the scanning results, the main focus is on the machining allowance of the workpiece's internal cavity. Because machining the outer surface of the workpiece is relatively easy while machining the internal cavity is more difficult, only a small allowance is left in the internal cavity during casting to compensate for deformation. Therefore, it is necessary to ensure that the machining allowance meets the requirements before machining. Due to the instability of open structures, connecting ribs are added at the rear end during casting, such as... Figure 2 As shown.

[0032] The key areas for attention regarding the wall thickness allowance of this workpiece are: ① the square step inside the cavity; ② the cylindrical through groove; ③ the inner walls of the left and right sides.

[0033] (2) Cut the connecting ribs to release the deformation.

[0034] Cutting or removing the connecting ribs will release stress and cause the workpiece to deform again. This must be done before processing to avoid severe deformation of the open area caused by cutting them after processing.

[0035] (3) Machining threaded holes in the connecting ribs and making connecting plates to fix both ends.

[0036] Here, cast ribs are used again. After connection, they strengthen the workpiece's structural rigidity and facilitate clamping of the workpiece using a clamping plate during machining, thus simplifying subsequent processing. For example... Figure 3 As shown.

[0037] (4) Features of the machined end face.

[0038] At this point, the machining end face and contour features, and the inner contour need to be used to mate with the four-axis tooling, and the machining tolerance requirements are high.

[0039] In this step, the end frame and connecting ribs are clamped using a pressure plate, and the features of both end faces are machined; after machining, the casting blank has a groove on the end face of the closed end away from the open end.

[0040] (5) Fabricate a four-axis machining fixture, and install it by fitting the end face contour features to machine the external shape and internal cavity features from all sides. For example... Figure 4 As shown.

[0041] Specifically, a four-axis tooling is fabricated, comprising a turntable and a blocking plate. These are installed using the inner contours of the two end faces machined in step four to perform circumferential machining of the workpiece. One side of the turntable has a recessed block that mates with a groove. The machined open end of the casting blank, connecting ribs, and connecting plate form a hole structure. The blocking plate mates with the hole structure, and the connection between the blocking plate and the hole structure has a transition fit. The side of the blocking plate opposite the closed end has a groove that mates with the machine tool's ejector pin structure. The turntable is connected to the machine tool's drive shaft.

[0042] This invention provides a machining method for thin-walled square open-end frame parts. Addressing the issues of structural rigidity and post-machining deformation in the open area of ​​this type of end frame, the method adds casting ribs to release stress, thereby strengthening structural rigidity and clamping stability. A four-axis tooling is then fabricated to complete the feature machining. This method makes the casting and machining processes more stable, reduces the risk of workpiece deformation during machining, and improves the product's pass rate during machining. Currently, this method has been applied in actual production and has broad application prospects.

[0043] The contents not described in detail in this application specification are common knowledge to those skilled in the art.

[0044] The present application has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present application. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and implementation methods of the present application without departing from the spirit and scope of the present application, and all such modifications and improvements fall within the scope of the present application. The scope of protection of the present application is determined by the appended claims.

Claims

1. A method for processing a square open-end frame type thin-walled part, characterized in that, include: S1: One end of the casting blank (1) is a closed end (11) and the other end is an open end (12). The side of the casting blank is open and the open end (12) is connected. The casting blank is provided with a connecting rib (13) at the open end (12) and the connecting rib (13) is close to the open end (12). The connecting rib (13) connects the two sides of the open end (12) together. The casting blank is three-dimensionally scanned to confirm the machining allowance of the inner cavity. Based on the machining allowance of the inner cavity, the machining allowance of the casting blank is determined. If the casting blank has a machining allowance, proceed to S2. S2: Cut the connecting rib (13); S3: Drill mounting holes at the ends of the cut connecting ribs (13) and use connecting plates (2) to connect and fix them to obtain intermediate casting blanks; S4: Fix the intermediate casting blank onto the machine tool surface, and perform machining on the end face and inner contour of the end face to obtain the machined casting blank; S5: Install the turntable at the closed end (11), install the blocking plate at the open end (12), install the turntable and the blocking plate on the machine tool, and use the machine tool to process the circumferential features of the processed casting blank.

2. The processing method for a square open-end (12) frame-type thin-walled part according to claim 1, characterized in that: In S2, the connecting rib (13) is cut off at the middle position; the cutting length of the connecting rib (13) from the middle position is 10%-15% of the length of the connecting rib (13).

3. The processing method for a square open-end (12) frame-type thin-walled part according to claim 1, characterized in that: In S2, the connecting plate (2) is connected to the side of the connecting rib (13) facing the inside of the open end (12).

4. The processing method for a square open-end (12) frame-type thin-walled part according to claim 1, characterized in that, In S3, a mounting hole is drilled at the end of the cut connecting rib (13), and a connecting plate (2) is used to connect and fix it to obtain an intermediate casting blank. This includes: drilling a mounting hole at the end of the cut connecting rib (13), and connecting and fixing the connecting plate (2) and the ends of the two disconnected connecting ribs (13) through bolts and connecting holes to obtain an intermediate casting blank.

5. The processing method for a square open-end (12) frame-type thin-walled part according to claim 1, characterized in that: In S4, the processed casting blank has a groove on the end face of the closed end (11) away from the open end (12).

6. A method for processing a square open-end (12) frame-type thin-walled part according to claim 5, characterized in that: In S5, a recessed block is provided on one side of the turntable, and the recessed block cooperates with the groove.

7. A method for processing a square open-end (12) frame-type thin-walled part according to claim 1, characterized in that: In S5, the hole structure is formed by the open end (12), connecting rib (13) and connecting plate (2) of the processed casting blank; the plug plate is matched with the hole structure, and the plug plate is matched with the hole structure in a transitional manner.

8. A method for processing a square open-end (12) frame-type thin-walled part according to claim 1, characterized in that: The casting blank is an aluminum alloy casting.

9. A square open-end frame type thin-walled part, characterized in that, The casting blank is processed by the processing method of a square open-end (12) frame-type thin-walled part according to any one of claims 1-8.

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