Universal bending method for sheet metal bracket

Abstract

The present invention discloses a universal bending method for sheet metal brackets, comprising calculating the R value at the bend of a sheet metal bracket part and the bending angle between two bending surfaces to form a series consisting of R values ​​and bending angles, processing multiple bending tools corresponding to the R values, and processing bending cavities corresponding to the bending angles and R values ​​on the same bending die base. The sheet metal bracket part is then designed for unfolding, and the two bending surfaces of the sheet metal bracket part in the sheet metal bracket part drawing are flipped along the bending line until they are coplanar to form a bending body. Positioning blocks and connecting blocks are also designed, and the sheet metal bracket part is cut and blanked according to the designed unfolding shape. The part is then bent using a bending tool and a bending die base, and finally cut at the connecting block. The present invention is suitable for processing sheet metal bracket parts of various sizes, and is particularly suitable for a multi-variety, small-batch production organization model, with low processing costs and high processing efficiency.

Description

Technical Field

[0001] The invention belongs to the field of aero-engine sheet metal forming, and in particular relates to a universal bending die for a sheet metal bracket and a bending method thereof. Background Art

[0002] The structure of aircraft engines is complex, and the connection methods between various structures are mainly non-detachable welding and detachable stud nut connection. Sheet metal brackets are the main accessories of threaded nut connection and are currently indispensable in aircraft engines. Their typical parts structure is as follows: Figure 1 As shown. Usually, this type of parts has many part numbers, different shapes, simple structures but high dimensional accuracy requirements. Generally speaking, there are two process solutions:

[0003] The first method is to bend the sheet metal to the required angle of the bracket, and then use a five-axis laser cutting machine to process its shape and bottom hole. For holes with higher precision requirements, wire cutting is used to process the holes to the final required size.

[0004] The second method is to calculate the blanking size according to the size of the bracket and cut the material, and then use a special bending mold to bend it to obtain the part.

[0005] Both of the above solutions are uneconomical. Solution 1 involves five-axis machining, while Solution 2 requires a dedicated mold for each part number and has a long processing cycle.

[0006] In order to improve the processing efficiency of parts and reduce costs, it is urgent to study a universal processing device and method for processing radius bracket parts. Summary of the Invention

[0007] The present invention aims to provide a universal bending method for sheet metal brackets, which is suitable for processing sheet metal bracket parts of various sizes, and is particularly suitable for a multi-variety and small-batch production organization mode, with low processing cost and high processing efficiency.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] A universal bending method for a sheet metal bracket comprises the following steps:

[0010] S1, count the R value of the bending part of the sheet metal bracket and the bending angle between the two bending surfaces to form a series consisting of R value and bending angle;

[0011] S2, processing bending tools and bending mold bases, processing a series of bending tools with tool head profiles equal to the corresponding R values ​​according to the R value series in S1, processing multiple bending cavities with corresponding R values ​​and bending angles on the same bending mold base according to the R value series and bending angle series in S1, and processing positioning holes on the mold surface outside the bending cavities;

[0012] S3, sheet metal bracket part unfolding shape design, the sheet metal bracket part in the sheet metal bracket part drawing along the bending line to flip the two bending surfaces until they are coplanar, forming a bending body, and then perform the following two operations:

[0013] Case 1: If the multiple sheet metal bracket parts to be processed are exactly the same, then add positioning blocks on the same side of the multiple bending bodies. The side of the positioning block corresponding to the bending body is the positioning bevel. All positioning bevels are parallel to each other. Each bending body and the positioning bevel are connected by a connecting block, and the positioning block has a positioning hole.

[0014] Case 2: If the multiple sheet metal bracket parts to be processed are not exactly the same, a positioning block is added on the same side of the multiple bending bodies. The side of the positioning block corresponding to the bending body is the positioning bevel. The positioning bevel is not completely parallel, so that the bending lines of different sheet metal bracket parts are collinear. Each bending body and the positioning bevel are connected by a connecting block, and a positioning hole is opened on the positioning block;

[0015] S4, cutting and blanking of the sheet metal bracket parts, cutting on the sheet metal according to the unfolded shape of the sheet metal bracket parts designed in S3, to obtain a rough material including multiple curved bodies, a positioning block and multiple connecting blocks;

[0016] S5, Bending, select the corresponding bending tool and bending die base according to the R value series and bending angle series, put the blank prepared in S4 into the bending die base, fix the blank through the positioning holes on the bending die base and the positioning holes on the blank positioning block, and press the tool head of the bending tool into the bending cavity of the bending die base to complete the bending of the sheet metal bracket part;

[0017] S6, trimming, lift the bending tool, take the sheet metal bracket part out of the bending die base, cut off the connection with the positioning block from the connecting block, and obtain the final sheet metal bracket part.

[0018] As an option, in S2, the bending mold base is a cube, and the four surfaces of the cube are all processed with curved cavities.

[0019] As an option, in S2, the surface of the bending mold base without the bending cavity is connected to a handle hanging ear.

[0020] As an option, in S4, laser cutting is adopted, and burrs on the edge of the rough material are removed after cutting.

[0021] As an option, in S6, the connection block is removed by grinding.

[0022] Compared to existing technologies, the processing method provided by the present invention can process multiple identical or non-identical parts at once. All parts can be processed by simply changing the shape and size of the sheet metal bracket part during the unfolding shape design process. Processing different sheet metal bracket parts does not require the investment of new molds, nor does it involve five-axis machining. This can significantly reduce the tooling cost and processing cycle for developing sheet metal bracket parts. If only one sheet metal bracket part is required, it can even process several different sheet metal bracket parts at once, fully utilizing every piece of material and reducing material costs. The present invention is particularly suitable for high-variety, low-batch production organizations. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a typical structural diagram of a sheet metal bracket part;

[0024] Figure 2 This is a schematic diagram of the universal bending die base and bending tool;

[0025] Figure 3 It is a schematic diagram of a universal bending die mechanical bending equipment;

[0026] Figure 4 This is a schematic diagram of blanking when multiple sheet metal bracket parts are exactly the same;

[0027] Figure 5 This is a schematic diagram of blanking when multiple sheet metal bracket parts are not exactly the same;

[0028] In the figure, 1-connecting block, 2-positioning block, 3-bent body, 4-positioning bevel, 5-positioning hole. DETAILED DESCRIPTION

[0029] The present invention is further described below with reference to specific embodiments. However, it should not be understood that the scope of the subject matter described in the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various modifications, substitutions and changes made according to common technical knowledge and customary means in the field are included in the scope of the present invention.

[0030] like Figures 2-3 As shown, the universal bending device designed for the present invention includes a bending die base, a bending tool and a mechanical bending device.

[0031] The basic idea of ​​the universal bending method of the sheet metal bracket of the present invention is as follows:

[0032] 1. Calculate the R value and bending angle of the bent sheet metal bracket parts;

[0033] 2. According to the statistical R value and angle size, press Figure 2As shown, bending tools with different R values ​​(the tool head profile corresponds to the R pointer) and bending die bases are processed;

[0034] 3. Design the shape and size of the raw material for the bent sheet metal bracket parts drawing (i.e. Figure 1 The expanded view in the lower right middle part shows that the two bending surfaces have been flattened into one plane) and the raw material is referenced Figure 4 or Figure 5 There are two ways to draw the raw material cutting diagram;

[0035] 4. Cut the material along Figure 4 、 Figure 5 Cut the outline of the dimensions shown and remove the burrs;

[0036] 5. According to the R value of the sheet metal bracket parts and the bending angles of the two bending surfaces, select the corresponding bending mold base and bending tool, press Figure 3 As shown, the bending die base is clamped to the base of the mechanical bending equipment (i.e., the press), the sheet metal bracket parts are clamped to the bending die base, the screws at the positioning holes are tightened, the bending tool is installed to the actuating mechanism of the mechanical bending equipment, and then the sheet metal bracket parts are bent using the mechanical bending equipment;

[0037] 6. Remove the sheet metal bracket parts from the positioning edge of the rough material, then cut off the connecting block part and keep the sheet metal bracket parts.

[0038] A more detailed processing method implementation process is given below:

[0039] 1. Count the R value of the bending part of the sheet metal bracket and the bending angle between the two surfaces of the bending bracket (commonly used R values ​​are 4mm, 6mm and 10mm, and the angles are 90° and 82°).

[0040] 2. According to the statistical R value of the bending part of the sheet metal bracket parts and the angle size between the two bending surfaces, process bending tools of different sizes (that is, three types of bending tools with tool head R values ​​of 4mm, 6mm and 10mm respectively) and bending mold bases (that is, a total of 6 bending cavities including [4mm, 90°], [4mm, 82°], [6mm, 90°], [6mm, 82°], [10mm, 90°], and [10mm, 82°] are processed on one mold base, and the 6 bending cavities are distributed in a straight line), and mark the bending tool and the bending mold base (that is, the corresponding R value and bending angle). The bending mold base is a cube, and all four sides of it can be used to process bending cavities, which is suitable for bending sheet metal brackets of different sizes and saves investment costs. Handle ears are added on both sides of the bending mold base for easy use, and positioning holes are processed outside the surface of the bending cavity to fix the parts.

[0041] 3. Design the shape and size of the raw material for the sheet metal bracket parts of a single specification, and refer to the raw material Figure 4 The method is to use two 2mm wide connection blocks 1 to connect with the positioning blocks 2. If the sheet metal bracket parts are of different specifications, Figure 5 In the method shown, the front and rear position and rotation angle of each bending body 3 (ie the final sheet metal bracket part) need to be adjusted so that Figure 5 The bending lines of each bending body 3 are adjusted to be collinear (or at the same level) and consistent with the bending lines in the bending cavity of the bending mold base. The length of the positioning bevel 4 and the diameter of the positioning hole 5 on the positioning block are fixed sizes, making it easy to replace parts.

[0042] 4. Use laser cutting to cut materials, such as Figure 4 、 Figure 5 As shown, laser cutting is performed according to the contour lines in the figure and the burrs generated by laser cutting are removed.

[0043] 5. According to the R value of the sheet metal bracket parts to be processed and the bending angle of the two bending surfaces, select the corresponding bending mold base and bending tool, press Figure 3 As shown, the bending die base is clamped to the base of the mechanical bending equipment and fixed, the rough material is clamped to the bending die base, the screws of the three positioning holes 3 are tightened, and the three bending tools are installed to the actuating mechanism of the mechanical bending equipment (hydraulic press) through the tool holder. The three bending tools are clamped in a straight line, and the actuating mechanism of the mechanical bending equipment is operated, that is, moved downward to bend the rough material.

[0044] 6. After the bending is completed, remove the sheet metal bracket part (bending body 3) and the positioning block 2 from the bending mold base, and then grind off the connecting block part to obtain the sheet metal bracket part.

[0045] Any matters not described in detail in the present specification are prior art known to those skilled in the art. Although the above description of the present invention is based on illustrative embodiments to facilitate understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the specific embodiments. As long as various modifications are within the spirit and scope of the present invention as defined and determined by the appended claims, such modifications will be obvious to those skilled in the art, and all inventions and creations utilizing the concepts of the present invention are protected.

Claims

1. A universal bending method for sheet metal brackets, characterized in that: The following steps are involved: S1, count the R value of the bending part of the sheet metal bracket and the bending angle between the two bending surfaces to form a series consisting of R value and bending angle; S2, processing bending tools and bending mold bases, processing a series of bending tools with tool head profiles equal to the corresponding R values ​​according to the R value series in S1, processing multiple bending cavities with corresponding R values ​​and bending angles on the same bending mold base according to the R value series and bending angle series in S1, and processing positioning holes on the mold surface outside the bending cavities; S3, sheet metal bracket part unfolding shape design, the sheet metal bracket part in the sheet metal bracket part drawing along the bending line to flip the two bending surfaces until they are coplanar, forming a bending body, and then perform the following two operations: Case 1: If the multiple sheet metal bracket parts to be processed are exactly the same, then add positioning blocks on the same side of the multiple bending bodies. The side of the positioning block corresponding to the bending body is the positioning bevel. All positioning bevels are parallel to each other. Each bending body and the positioning bevel are connected by a connecting block, and the positioning block has a positioning hole. Case 2: If the multiple sheet metal bracket parts to be processed are not exactly the same, a positioning block is added on the same side of the multiple bending bodies. The side of the positioning block corresponding to the bending body is the positioning bevel. The positioning bevel is not completely parallel, so that the bending lines of different sheet metal bracket parts are collinear. Each bending body and the positioning bevel are connected by a connecting block, and a positioning hole is opened on the positioning block; S4, cutting and blanking of the sheet metal bracket parts, cutting on the sheet metal according to the unfolded shape of the sheet metal bracket parts designed in S3, to obtain a rough material including multiple curved bodies, a positioning block and multiple connecting blocks; S5, Bending, select the corresponding bending tool and bending die base according to the R value series and bending angle series, put the blank prepared in S4 into the bending die base, fix the blank through the positioning holes on the bending die base and the positioning holes on the blank positioning block, and press the tool head of the bending tool into the bending cavity of the bending die base to complete the bending of the sheet metal bracket part; S6, trimming, lift the bending tool, take the sheet metal bracket part out of the bending die base, cut off the connection with the positioning block from the connecting block, and obtain the final sheet metal bracket part.

2. A universal bending method for sheet metal brackets according to claim 1, characterized in that: In S2, the base of the bending mold is a cube, and the four surfaces of the cube are all processed with curved cavities.

3. A universal bending method for sheet metal brackets according to claim 2, characterized in that: In said S2, the surface of the bending mold base without the bending cavity is connected with a handle hanging ear.

4. A universal bending method for sheet metal brackets according to claim 1, characterized in that: In the above-mentioned S4, laser cutting is adopted, and burrs on the edges of the rough material are removed after cutting.

5. The universal bending method for sheet metal brackets according to claim 1, characterized in that: In S6, the connection block is removed by grinding.

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