Method and apparatus for partial forming of large flange

Abstract

The present application belongs to the field of machining method, and particularly relates to a method and device for local forming of large flange edge, which is used for forming the shape of large flange edge box-shaped part and the box-shaped area. The method comprises the following steps: step 1, extracting the shape of the part; step 2, identifying whether the part is a flange edge box-shaped part; step 3, if the part is a flange edge box-shaped part, calculating the machining difficulty of four corner areas and sorting; step 4, pre-forming the corner areas of the part according to the machining difficulty order, first forming the one with the largest machining difficulty, and finally forming the one with the smallest machining difficulty. The present application saves a large amount of manpower, and compared with the original deep drawing forming, the time for trimming the part is shortened from two hours to twenty minutes to thirty minutes.

Description

Technical Field

[0001] This invention relates to machining methods, and more particularly to a method and apparatus for partial forming of a large flange edge. Background Technology

[0002] Sheet metal box-shaped parts are widely used in aircraft components and are classified as typical deep-drawn parts according to their processing method. Deep drawing refers to a pressing process that uses a die to apply force to a metal sheet, shaping it into a three-dimensional hollow part. The hollow part is formed by the shrinkage and flow of material at the outer edge of the blank. However, aircraft sheet metal parts include a type of large-flange box-shaped part, which differs from ordinary box-shaped parts in the following ways: 1. It is larger than ordinary box-shaped parts, with a longer flange edge, resulting in poor material flowability. If deep drawing is used, bulges and wrinkles will appear, making manual reshaping very difficult. 2. High precision is required in terms of shape. 3. Large structural dimensions, relatively small thickness, and poor rigidity. Summary of the Invention

[0003] Purpose of the invention: To provide a method and apparatus for partial forming of a large flange edge, used to form the shape of a box-shaped part and the box-shaped area of ​​a large flange edge.

[0004] Technical solution: A method for local forming of a large flange edge, comprising:

[0005] Step 1: Extract the outline of the part;

[0006] Step 2: Identify whether the part is a flange-side box type;

[0007] Step 3: If the part is a flange box type, calculate and sort the machining difficulty of the four corner areas;

[0008] Step 4: Pre-form each corner area of ​​the part according to the order of processing difficulty, forming the most difficult area first and the easiest area last.

[0009] include:

[0010] The specific criteria for identifying whether the part is a flange box type in step 2 are as follows:

[0011] Collect the column radius R and the opening radius r at the top of the column of the part. When r / R < 1, it means that the part is a flange box type part.

[0012] Step 3 includes:

[0013] Measure the bend heights H1, H2, H3, and H4 at the four corners within the cylindrical area of ​​the part.

[0014] Measure the corner radii e1, e2, e3, e4 of the four corners within the cylindrical area of ​​the part.

[0015] Calculate the forming difficulty coefficient β of the four corner areas of the part:

[0016] The difficulty coefficient of forming a corner part is β1 = H1 / e1;

[0017] The difficulty coefficient of forming the corner of the part is β2=H2 / e2;

[0018] The difficulty coefficient of forming the corner of the part is β3=H3 / e3;

[0019] The difficulty coefficient for forming the corner of the part is β4 = H4 / e4;

[0020] Compare the magnitudes of β1, β2, β3, and β4.

[0021] Also includes:

[0022] Step 5: After smoothing out the bulges and wrinkles, shape all the curved edges until they completely fit the mold.

[0023] Step 2 also includes: when r = 0, the box-shaped component is closed, and the column in the box-shaped area is regarded as a reinforcing recess.

[0024] The reinforcing recess was then hydraulically formed using the same method as for forming navigation mark holes.

[0025] Step 2 also includes: when r / R = 1, the box-shaped part is regarded as a bend relief hole.

[0026] The box-shaped component was subsequently formed by die stamping or hydraulic forming.

[0027] A device for partial forming of a large flange edge, which is formed by the method of claim 1.

[0028] Beneficial effects:

[0029] 1. Compared with existing box-shaped parts forming methods, the present invention not only significantly reduces the bulging, loosening and wrinkling phenomena at the bottom of the box-shaped parts during heat treatment, but also completely solves the problem of residual bulging and loosening at the bottom of the box-shaped parts.

[0030] 2. It saves a lot of manpower. Compared with the original deep drawing process, the time for trimming parts is reduced from two hours to twenty to thirty minutes.

[0031] 3. Significantly improves the surface quality of parts. Attached Figure Description

[0032] Figure 1 This is a top view of the part according to the present invention.

[0033] Figure 2 This is a 3D view of the part.

[0034] Figure 3This is a partial schematic diagram of the forming tooling for the flange box type component. Detailed Implementation

[0035] The invention will now be further described with reference to the accompanying drawings.

[0036] The processing method of the present invention is as follows:

[0037] Step 1: Use 3D design software to extract the shape of the part and confirm parameters such as the height of the cylinder, the radius of the cylinder, and the opening radius of the top of the cylinder within the box-shaped area of ​​the part.

[0038] H---- Height of the column within the box-shaped area

[0039] R----Relative of the cylinder

[0040] r ---- Radius of the opening at the top of the cylinder

[0041] e---- Radius of the corner inside the cylinder

[0042] Step 2: Calculate and analyze each parameter

[0043] ① When r = 0, the box-shaped part is closed. The column in the box-shaped area can be approximated as a reinforcing recess. The reinforcing recess is then formed by hydraulic forming according to the forming method of the beacon hole.

[0044] ② When r / R = 1, it means that the box-shaped part can be regarded as a bending edge relief hole, which can be formed by die stamping or hydraulic forming;

[0045] ③ When r / R < 1, it means that the part is a flange box type part, which cannot be formed by deep drawing. It is necessary to manufacture a local mold for hydraulic forming of the column, and then manually form the shape of the part and open the bottom hole.

[0046] Measure the bend heights H1, H2, H3, and H4 at the four corners within the cylindrical area of ​​the part.

[0047] Measure the corner radii e1, e2, e3, e4 of the four corners within the cylindrical area of ​​the part.

[0048] Calculate the forming difficulty coefficient β of the four corner areas of the part.

[0049] The difficulty coefficient of forming a corner part is β1 = H1 / e1

[0050] Difficulty coefficient of part corner forming β2=H2 / e2

[0051] Difficulty coefficient of forming corner parts β3=H3 / e3

[0052] The difficulty coefficient of forming the corner of the part is β4 = H4 / e4

[0053] Compare the magnitudes of β1, β2, β3, and β4.

[0054] Step 3: Pre-form the corner areas of the part in order of difficulty, starting with the area with the largest β and ending with the area with the smallest β.

[0055] The key to this step lies in selecting the areas for initial shaping. These areas must meet three criteria: first, they must be areas that cannot be shaped after quenching, meaning they can only be shaped before quenching; second, shaping them must not affect the release of bottom stress; and third, shaping them must increase the rigidity and three-dimensionality of the sheet metal. Fourth, in the past, if workers processed the less difficult corner radii first, followed by the more difficult ones, this processing order would affect the surface quality and shape of the parts at the first less difficult corner radii. This would require workers to rework and adjust the first corner radii, increasing processing time and impacting the surface quality of the parts.

[0056] Step 4: After smoothing out the bulges and wrinkles, shape all the curved edges until they completely fit the mold.

[0057] Example

[0058] like Figure 1 As shown, the processing method of the present invention is as follows:

[0059] Step 1: Use 3D design software to extract the shape of the part and confirm parameters such as the height of the cylinder, the radius of the cylinder, and the opening radius of the top of the cylinder within the box-shaped area of ​​the part.

[0060] H---- Height of the column within the box-shaped area

[0061] R----Relative of the cylinder

[0062] r ---- Radius of the opening at the top of the cylinder

[0063] R = 83.5, r = 65,

[0064] Step 2: Calculate and analyze each parameter

[0065] ① When r = 0, the box-shaped part is closed. The column in the box-shaped area can be approximated as a reinforcing recess. Then, prepare the hydraulic forming of the reinforcing recess according to the navigation mark.

[0066] ② When r / R = 1, it means that the box-shaped part can be regarded as a bending edge relief hole, which can be formed by die stamping or hydraulic forming;

[0067] ③ When r / R < 1, it means that the part is a flange box type part, which cannot be formed by deep drawing. It is necessary to manufacture a local mold for hydraulic forming of the column, and then manually form the shape of the part and open the bottom hole.

[0068] As can be seen from the parameters in step one, this part is a flange box type part, which requires the manufacture of a local mold for hydroforming and then manual forming of the part's shape, and the drilling of the bottom hole.

[0069] ④ Measure the bend heights H1, H2, H3, and H4 at the four corners within the cylindrical area of ​​the part.

[0070] H1=7.5, H2=7, H3=8.5, H4=8

[0071] like Figure 2 As shown, the corner radii e1, e2, e3, e4 of the four corners within the cylindrical area of ​​the part are measured, where e1 = 5, e2 = 6, e3 = 5, and e4 = 6.

[0072] Calculate the forming difficulty coefficient β of the four corner areas of the part.

[0073] The difficulty coefficient for forming the corner of the part is β1 = H1 / e1 = 1.5

[0074] The difficulty coefficient of forming the corner of the part is β2 = H2 / e2 = 1.16

[0075] The difficulty coefficient for forming the corner of the part is β3 = H3 / e3 = 1.7

[0076] The difficulty coefficient for forming the corner of the part is β4 = H4 / e4 = 1.33

[0077] The comparison results show that β3 > β1 > β4 > β2

[0078] Step 3: Pre-form the corner areas of the part in order of difficulty (e.g., Figure 3 As shown), first form the one with the largest β, and finally form the one with the smallest β.

[0079] The key to this step lies in selecting the areas for initial shaping. These areas must meet three criteria: first, they must be areas that cannot be shaped after quenching, meaning they can only be shaped before quenching; second, shaping them must not affect the release of bottom stress; and third, shaping them must increase the rigidity and three-dimensionality of the sheet metal. Fourth, in the past, if workers processed the less difficult corner radii first, followed by the more difficult ones, this processing order would affect the surface quality and shape of the parts at the first less difficult corner radii. This would require workers to rework and adjust the first corner radii, increasing processing time and impacting the surface quality of the parts.

[0080] Step 4: After smoothing out the bulges and wrinkles, shape all the curved edges until they completely fit the mold.

Claims

1. A method for local forming of a large flange edge, characterized in that, include: Step 1: Extract the shape of the part: Use 3D design software to extract the shape of the part, and confirm the height of the cylinder, the radius of the cylinder, the opening radius of the top of the cylinder, and the corner radius of the cylinder within the box-shaped area of ​​the part; Step 2: Identify whether the part is a flange-side box type. The specific criteria for identifying whether the part is a flange-side box type are as follows: Collect the column radius R and the opening radius r at the top of the column. When r / R < 1, it means that the part is a flange-side box type. When r = 0, the box type is closed. Approximately regard the column in the box type area as a reinforcing recess, and then hydraulically form the reinforcing recess according to the forming method of the beacon hole. When r / R = 1, regard the box type as a bending edge relief hole, and form it by die stamping or hydraulic forming. Step 3: If the part is a flange box type, calculate and sort the machining difficulty of the four corner areas; Step 4: Pre-form each corner area of ​​the part according to the order of processing difficulty, forming the most difficult area first and the easiest area last.

2. The method for partial forming of a large flange edge as described in claim 1, characterized in that, Step 3 includes: Measure the bend heights H1, H2, H3, and H4 at the four corners within the cylindrical area of ​​the part. Measure the corner radii e1, e2, e3, e4 of the four corners within the cylindrical area of ​​the part. Calculate the forming difficulty coefficient β of the four corner areas of the part: The difficulty coefficient of forming a corner part is β1 = H1 / e1; The difficulty coefficient of forming the corner of the part is β2=H2 / e2; The difficulty coefficient of forming the corner of the part is β3=H3 / e3; The difficulty coefficient for forming the corner of the part is β4 = H4 / e4; Compare the magnitudes of β1, β2, β3, and β4.

3. The method for partial forming of a large flange edge as described in claim 1, characterized in that, Also includes: Step 5: After smoothing out the bulges and wrinkles, shape all the curved edges until they completely fit the mold.

4. The method for partial forming of a large flange edge as described in claim 1, characterized in that, Step 2 also includes: when r = 0, the box-shaped component is closed, and the column in the box-shaped area is regarded as a reinforcing recess.

5. The method for partial forming of a large flange edge as described in claim 4, characterized in that, The reinforcing recess was then hydraulically formed using the same method as for forming navigation mark holes.

6. The method for partial forming of a large flange edge as described in claim 1, characterized in that, Step 2 also includes: when r / R = 1, the box-shaped part is regarded as a bend relief hole.

7. The method for partial forming of a large flange edge as described in claim 6, characterized in that, The box-shaped component is then formed by die stamping or hydraulic forming.

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