A method and device for bending a spaceflight L-shaped frame plate with a notch

Abstract

The application discloses a segmented bending forming device and method for a notched L-shaped arc frame plate for aerospace, relates to the field of aerospace sheet metal part machining, and solves the problems of long process, low efficiency and manual correction of parts in a traditional "blanking-bending-rolling-bending gap punching" process. The device comprises a die handle, upper and lower dies, a guide top rod and a guide top piece block with an arc step and a positioning cylindrical pin. The upper and lower dies are vertically staggered and the arc surface gap is adapted to the thickness of the blank. The method comprises the following steps of synchronously machining the gap through blanking, positioning clamping, segmented bending of the upper die, resetting and taking the part, and repeatedly completing the forming. The application simplifies the process to "blanking-segmented bending", improves the efficiency by about 50%, guarantees the size consistency and surface quality of the parts, and can be adapted to different specifications of products by only replacing the upper die, thereby reducing the cost of production change.

Description

Technical Field

[0001] This invention belongs to the field of aerospace sheet metal processing, specifically relating to a method and apparatus for segmented bending and forming of an L-shaped arc frame plate with notches for aerospace applications. Background Technology

[0002] Sheet metal parts are widely used in the structure of liquid rocket bodies. The parts involved in this invention are core load-bearing structural components of the rocket body, which together with stringers and other components—commonly referred to in the industry as "frame plates"—and are one of the key radial load-bearing components of the rocket body.

[0003] The raw material for this type of frame plate component is primarily aluminum sheet. Due to the need for precise assembly with the stringers, different sized notches need to be cut into the plate frame according to assembly requirements, providing space for stringer assembly. In summary, the core structural features of this type of frame plate component are: a combination of curved edges and notches of specific dimensions. See the attached diagram for a detailed structural illustration. Figure 8 .

[0004] Currently, the forming of such frame plate parts generally adopts the traditional process route of "material cutting → bending → rolling → punching notches". The limitations of this process are clear from the process flow: on the one hand, the process chain is long, which directly leads to low production efficiency; on the other hand, the parts are prone to dimensional deviations after forming, requiring a lot of manual correction to meet the accuracy requirements of rocket body assembly, which further increases the complexity of the production process. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method and apparatus for segmented bending forming of L-shaped arc frame plates with notches for aerospace applications. This forming method and apparatus improves part production efficiency and product consistency, thereby increasing the product qualification rate and solving the problems of low efficiency and poor product consistency in the current blanking → bending → rolling → punching notch method.

[0006] To achieve the above objectives, the present invention employs the following technical solutions:

[0007] A segmented bending forming device for L-shaped arc frame plates with notches for aerospace applications, characterized in that it includes a mold handle, an upper mold, a lower mold, a guide ejector block, a guide ejector rod, a lower template, hexagonal head screws, and positioning cylindrical pins.

[0008] The mold handle is connected to the drive unit of the press, the lower mold plate is installed on the worktable of the press, and the guide rod is installed above the air bladder of the press.

[0009] The lower end of the mold shank is threadedly connected to the upper mold. The lower mold is fixedly connected to the upper end of the lower template by an internal hexagon head screw. The lower mold and the upper mold are staggered in the vertical direction, and the staggered surfaces of the lower mold and the upper mold are both arc surfaces. One end of the guide rod passes through the lower template and is threadedly connected to the guide ejector block. The guide ejector block is located directly below the upper mold and is adapted to the arc surface of the lower mold. A positioning cylindrical pin is also installed at the upper end of the guide ejector block.

[0010] Further preferably, the upper surface of the guide top block is provided with an arc-shaped step, and the radius of the step is adapted to the unfolded inner diameter of the blank to be formed; the upper end of the guide top block is also equipped with a positioning cylindrical pin, and the notch of the blank to be formed matches the positioning cylindrical pin.

[0011] In a further preferred embodiment, the upper mold has a cylindrical pin clearance hole corresponding to the position of the positioning cylindrical pin.

[0012] As a preferred embodiment, there is a gap between the intersecting surfaces of the upper and lower dies, and the size of the gap is equal to the thickness of the blank to be formed.

[0013] A method for segmented bending forming of an L-shaped arc frame plate with notches for aerospace applications includes the following steps:

[0014] S1: Draw the unfolded drawing of the blank to be formed according to the sheet metal unfolding method, and cut the blank by laser cutting. During the blanking process, a notch is simultaneously processed on the blank, and the size of the notch is adapted to the positioning cylindrical pin.

[0015] S2: Install the forming device on the press and adjust the guide ejector rod to make the device in the initial state - that is, the upper end face of the guide ejector block is flush with the upper end face of the lower die.

[0016] S3: Place the section of the blank to be formed in the arc step of the guide top block, and then clamp and position it by cooperating with the positioning cylindrical pin through the notch of the blank; control the press to drive the mold handle to drive the upper mold to move downward. After the upper mold contacts the blank, it continues to move downward, pushing the guide top block to move downward synchronously with the guide top rod, so that the section of blank is bent and formed in the arc gap between the upper and lower molds.

[0017] S4: Once the guide top block descends to fully fit the upper surface of the lower template, control the press to drive the upper mold to reset, the guide top block moves upward to reset, and the semi-finished part is removed;

[0018] S5: Using the next notch in the blank as the positioning reference, repeat steps S3~S4 to bend and shape the remaining segments in sequence until the entire blank is bent into an L-shaped arc to obtain an L-shaped arc frame plate part with a notch.

[0019] Compared to the traditional forming process of "material preparation → bending → roll bending → punching notch" for L-shaped curved frame parts, this invention significantly optimizes the process, and its beneficial effects are as follows:

[0020] 1. Streamlined process and significantly improved efficiency: This invention simplifies the forming process to "material cutting → segmented bending," and completes the notch processing simultaneously during the material cutting stage, directly eliminating the two subsequent processes of "rolling bending" and "notch punching" in the traditional process. Actual production verification shows that this improvement increases production efficiency by approximately 50% compared to the original forming method, effectively shortening the production cycle.

[0021] 2. Excellent part consistency, improved surface quality and labor efficiency: This invention uses a rigid mold for forming, which ensures the dimensional consistency and curvature accuracy of the L-shaped arc frame parts from the source of the process. It completely avoids the large amount of manual correction work required in the traditional rolling process due to the part curvature not meeting the standard. This not only significantly reduces the labor intensity of operators, but also effectively avoids problems such as surface scratches and deformation by reducing manual contact and correction links, thus ensuring that the formed parts of this invention have better consistency and surface quality.

[0022] 3. The device is highly versatile and has low production changeover costs: The forming device described in this invention has strong adaptability. It does not require adjustment of other core structures of the device. It can quickly switch to forming production of L-shaped arc frame plate parts of different specifications by simply changing the upper mold. This greatly reduces the production changeover time and equipment modification costs for multi-specification products and improves the overall utilization efficiency of the device. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the initial state and component installation positions of a segmented bending and forming device for L-shaped arc frame plates with notches used in aerospace applications.

[0024] Figure 2 This is a schematic diagram of the final state structure of a segmented bending and forming device for an L-shaped arc frame plate with notches used in aerospace applications.

[0025] Figure 3 This is a schematic diagram of the lower mold of a segmented bending forming device for L-shaped arc frame plates with notches used in aerospace applications.

[0026] Figure 4 This is a schematic diagram of the upper mold of a segmented bending forming device for L-shaped arc frame plates with notches used in aerospace applications.

[0027] Figure 5 This is a schematic diagram of the guide top block of a segmented bending and forming device for L-shaped arc frame plates with notches used in aerospace applications.

[0028] Figure 6 This is a schematic diagram of the guide rod of a segmented bending and forming device for L-shaped arc frame plates with notches used in aerospace applications.

[0029] Figure 7 This is a schematic diagram of the sheet metal unfolding of the blank to be formed.

[0030] Figure 8 This is a schematic diagram of the formed part.

[0031] In the diagram: 1-lower template, 2-lower mold, 3-mold handle, 4-upper mold, 6-guide ejector block, 7-guide ejector rod, 8-positioning cylindrical pin, 9-internal hex head screw, 10-formed blank. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings.

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0034] Examples, such as Figures 1 to 8 As shown:

[0035] A segmented bending forming device for L-shaped arc frame plate with notch for aerospace applications includes a mold handle 3, an upper mold 4, a lower mold 2, a guide ejector block 6, a guide ejector rod 7, a lower template 1, an internal hexagon head screw 9, and a positioning cylindrical pin 8.

[0036] The mold shank 3, connected to the press drive unit, is used to assemble the forming parts and provide power; the lower mold plate 1, installed on the press worktable, is used to support the lower mold 2 and other components; and the guide ejector 7, installed above the press airbag, can provide power for the reset of the guide ejector block 6.

[0037] The lower end of the mold handle 3 is threaded to the upper mold 4. The lower mold 2 is fixedly connected to the lower template 1 by the internal hex head screw 9. The lower mold 2 and the upper mold 4 are staggered in the vertical direction. Under the drive of the press drive unit, the blank 10 to be formed can be pressed into an L shape. The staggered surfaces of the two are both arc surfaces, which can press the blank 10 to be formed into a section with a certain arc to meet the design requirements. The guide rod 7 passes through one end of the lower template 1 and is threaded to the guide ejector block 6. The guide ejector block 6 is located directly below the upper mold 4 and is adapted to the arc surface of the lower mold 2. The guide ejector block 6 can be reset by the guide rod 7 under the drive of the air bladder of the press. The upper end of the guide ejector block 6 is equipped with a positioning cylindrical pin 8 to lock the notch of the blank 10 to be formed.

[0038] The upper surface of the guide top block 6 is provided with an arc-shaped step, and the radius of the step is adapted to the unfolded inner diameter of the blank 10 to be formed. This device is suitable for blanks 10 to be formed with an inner arc radius between 999mm and R1499mm. In this case, the radius of the step = the inner arc radius of the blank + 1mm. The positioning cylindrical pin 8 at the upper end of the guide top block 6 has a threaded section radius that is equal to the fillet radius of the notch position of the blank 10 to be formed. The positioning cylindrical pin 8, in conjunction with the arc-shaped step, can clamp the blank 10 to be formed, thereby realizing the clamping and positioning of the blank 10 to be formed.

[0039] The upper mold 4 has a cylindrical pin clearance hole at the position corresponding to the positioning cylindrical pin 8, which can avoid interference with the positioning cylindrical pin 8 during the forming process.

[0040] There is a gap between the intersecting surfaces of the upper mold 4 and the lower mold 2, and the size of the gap is equal to the thickness of the blank 10 to be formed. This device is suitable for forming parts with a thickness between 2 mm and 7 mm.

[0041] A segmented bending forming method for an aerospace L-shaped arc frame plate with notches includes the following steps: S1: Draw the unfolded drawing of the blank 10 to be formed according to the sheet metal unfolding method, cut the blank by laser cutting, and simultaneously process the notch of the blank during the blanking process. The size of the notch is adapted to the positioning cylindrical pin 8. The blank after cutting is polished to remove burrs until the surface is smooth.

[0042] S2: Install the forming device on the press as described above, and adjust the up and down position of the guide rod 7 so that the device is in the initial state - that is, the upper end face of the guide rod block 6 is flush with the upper end face of the lower mold 2.

[0043] S3: Place the section of the blank 10 to be formed into the arc step of the guide top block 6 (at this time, the distance from the lower surface of the upper mold 4 to the upper surface of the lower mold 2 is greater than the thickness of the blank 10 to be formed). Then, install the two positioning cylindrical pins 8 on the upper end of the guide top block 6 through the two notches of the blank 10 to be formed, so as to achieve the clamping and positioning of the blank 10 to be formed. Then, control the press to drive the mold handle 3 to drive the upper mold 4 to move downward. After the upper mold 4 contacts the blank (i.e. the blank 10 to be formed), it continues to move downward, pushing the guide top block 6 to move downward synchronously with the guide top rod 7, so that the section of the blank 10 to be formed is bent and formed in the arc gap between the upper mold 4 and the lower mold 2.

[0044] S4: When the guide top block 6 descends to fully fit the upper surface of the lower template 1 (final position), control the press to drive the upper mold 4 to reset. The guide top block 6 moves upward under the push of the air bladder of the press below, and then completes the reset, and the semi-finished part is taken out.

[0045] S5: Using the next notch connected to the formed blank segment (i.e. the formed segment of the blank 10 to be formed) in step S3 as the positioning reference, re-clamp the unformed blank segment (i.e. the unformed segment of the blank 10 to be formed) in the same direction (clockwise or counterclockwise), repeat steps S3 to S4, and bend the remaining segments in sequence until the entire blank (i.e. the blank 10 to be formed) completes the L-shaped arc bending, and obtains the L-shaped arc frame plate part with notch.

[0046] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A method for segmented bending and forming of an L-shaped arc frame plate with notches for aerospace applications, based on a device for segmented bending and forming of an L-shaped arc frame plate with notches for aerospace applications, characterized in that: The forming device includes a mold handle, an upper mold, a lower mold, a guide ejector block, a guide ejector rod, a lower template, an internal hexagon head screw, and a positioning cylindrical pin; The mold handle is connected to the drive unit of the press, the lower mold plate is installed on the worktable of the press, and the guide rod is installed above the air bladder of the press. The lower end of the mold shank is threadedly connected to the upper mold. The lower mold is fixedly connected to the upper end of the lower template by an internal hexagon head screw. The lower mold and the upper mold are staggered in the vertical direction, and the staggered surfaces of the lower mold and the upper mold are both arc surfaces. One end of the guide rod passes through the lower template and is threadedly connected to the guide ejector block. The guide ejector block is located directly below the upper mold and is adapted to the arc surface of the lower mold. A positioning cylindrical pin is installed at the upper end of the guide ejector block. The upper surface of the guide top block is provided with an arc-shaped step, and the radius of the step is adapted to the inner diameter of the blank to be formed, and the notch of the blank to be formed is matched with the positioning cylindrical pin. The upper mold has a cylindrical pin clearance hole corresponding to the position of the positioning cylindrical pin; The forming method includes the following steps: S1: Draw the unfolded drawing of the blank to be formed according to the sheet metal unfolding method, and cut the blank by laser cutting. During the blanking process, a notch is simultaneously processed on the blank, and the size of the notch is adapted to the positioning cylindrical pin. S2: Install the forming device on the press and adjust the guide ejector rod to make the device in the initial state - that is, the upper end face of the guide ejector block is flush with the upper end face of the lower die. S3: Place the section of the blank to be formed in the arc step of the guide top block, and then clamp and position it by cooperating with the positioning cylindrical pin through the notch of the blank; control the press to drive the mold handle to drive the upper mold to move downward. After the upper mold contacts the blank, it continues to move downward, pushing the guide top block to move downward synchronously with the guide top rod, so that the section of blank is bent and formed in the arc gap between the upper and lower molds. S4: Once the guide top block descends to fully fit the upper surface of the lower template, control the press to drive the upper mold to reset, the guide top block moves upward to reset, and the semi-finished part is removed; S5: Using the next notch in the blank as the positioning reference, repeat steps S3~S4 to bend and shape the remaining segments in sequence until the entire blank is bent into an L-shaped arc to obtain an L-shaped arc frame plate part with a notch.

2. The method for segmented bending and forming of an L-shaped arc frame plate with a notch for aerospace applications according to claim 1, characterized in that: There is a gap between the intersecting surfaces of the upper and lower dies, and the size of the gap is equal to the thickness of the blank to be formed.

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