Skin forming device

Abstract

The utility model belongs to the technical field of aircraft manufacturing, and discloses a skin forming device which comprises an upper die and a lower die, the upper die is provided with an arc-shaped extrusion face, the lower die is arranged opposite to the upper die in the first direction, a forming space used for containing a skin is formed between the arc-shaped extrusion face and the lower die, and the lower die is used for elastically supporting the skin. The upper die can move close to or away from the lower die in the first direction, when the upper die moves close to the lower die, the arc-shaped extrusion face can be matched with the lower die to extrude the skin, and when the lower die capable of elastically supporting the skin is arranged, the lower die deforms and can apply multiple upward flexible supporting force to the skin when the skin is extruded; and the phenomenon of'bone exposure 'can be effectively avoided.

Description

Technical Field

[0001] The utility model relates to aircraft manufacturing technology, in particular to a skin forming device. Background Art

[0002] In aviation manufacturing technology, the forming of variable thickness skin (thin sheet aluminum alloy) is composed of two parts. One part is installed on the aircraft bending machine to ensure that the lower surface of the skin is arc-shaped and smooth; the other part is installed on the upper surface of the variable thickness skin to ensure that the upper surface of the skin is evenly stressed. Variable thickness skin is an important structural part of the aircraft. It is made of a whole plate blank through cutting, forming and other processes. There is a variable thickness area on the inner surface. It has the advantages of light weight, smooth surface, high structural strength, good rigidity, and aerodynamic shape. It has been widely used in aviation structural parts.

[0003] In order to reduce weight, a large number of thinning structures are used in the design of large variable thickness skins. In order to form the curvature of the skin, the elastic pad bending technology is used, that is, an elastic pad with a shape opposite to the skin's concave and convex is laid on the thinned skin surface to fill the thinned area of ​​the skin, and then a bending machine is used as a forming device to cooperate with rigid upper and lower molds to gradually form the skin. The function of the elastic pad is to evenly distribute the bending force on the skin through the elastic pad to obtain the required curvature. The principle is three-point bending, that is, the upper mold applies a downward pressure P, and the skin elastic pad and skin are deformed accordingly. The edge of the mold generates two supporting forces P', which causes plastic deformation of the part of the upper mold in contact with the part.

[0004] When the thickness difference of the thinned area is not large, the yield strength difference of the two adjacent thicknesses is not large, and the curvature of the skin can be formed evenly through the elastic pad bending technology; however, if there is a feature with a large thickness difference on the skin, the yield strength of the thinner area is much smaller than that of the thicker area, and the difference in yield strength between the two is large, that is, the thinner area is over-formed, and the thicker area is not formed in place, and an obvious crease will be produced at the junction where the thickness difference is large, commonly known as the "exposed" phenomenon. When using the shape card to measure the curvature of the skin, the curvature of the skin cannot fit the shape template, and the required curvature of the skin cannot be obtained. The "exposed" area increases the workload of the shape correction, and in severe cases, it may cause the skin surface to be orange peel or even cracked. The "exposed" phenomenon is a common defect in the elastic pad assisted bending forming technology. Utility Model Content

[0005] The utility model aims to provide a skin forming device to solve the problem of exposed skin in the prior art.

[0006] As conceived above, the technical solution adopted by the utility model is:

[0007] The skin forming device comprises:

[0008] An upper die, wherein the upper die has an arc-shaped extrusion surface;

[0009] The lower mold is arranged opposite to the upper mold in a first direction, and a forming space for placing the skin is formed between the arc-shaped extrusion surface and the lower mold. The lower mold is used to elastically support the skin, and the arc-shaped extrusion surface can cooperate with the lower mold to extrude the skin to form the skin.

[0010] Further, the lower mold includes a lower mold base and an elastic component, the lower mold base is provided with a forming groove on the surface facing the upper mold in the first direction, the bottom of the forming groove is arc-shaped, the elastic component is arranged on the side of the lower mold base facing the upper mold, and at least part of the elastic component is located in the forming groove, the elastic component is used to elastically support the skin, and the elastic component cooperates with the upper mold to form the forming space.

[0011] Furthermore, the shape of the arc-shaped extrusion surface matches the shape of the groove bottom of the forming groove.

[0012] Furthermore, the notch of the forming groove is provided with an arc chamfer.

[0013] Further, the elastic component includes a first elastic pad, the surface of the first elastic pad facing the lower mold base is an arc surface matching the bottom of the forming groove, and the surface of the first elastic pad facing the lower mold base contacts the bottom of the forming groove.

[0014] Furthermore, a surface of the first elastic pad facing away from the lower mold base is a plane.

[0015] Furthermore, an edge of the first elastic pad extends to a surface of the lower mold base facing the upper mold.

[0016] Furthermore, the elastic component also includes a second elastic pad, which is arranged on a side of the first elastic pad away from the lower mold base, and the hardness of the second elastic pad is greater than the hardness of the first elastic pad.

[0017] Furthermore, the skin forming device also includes a third elastic pad, which is used to contact the surface of the skin facing the upper mold, and the third elastic pad is provided with a matching structure, which is used to match with the groove or protrusion of the skin.

[0018] Furthermore, the third elastic pad and the second elastic pad are both made of nylon, and the first elastic pad is made of rubber or silicone.

[0019] The skin forming device proposed by the utility model comprises: an upper die and a lower die, the upper die has an arc-shaped extrusion surface, the lower die is arranged opposite to the upper die in a first direction, a forming space for placing the skin is formed between the arc-shaped extrusion surface and the lower die, the lower die is used to elastically support the skin, the upper die can move towards or away from the lower die in the first direction, when the upper die moves towards the lower die, the arc-shaped extrusion surface can cooperate with the lower die to extrude the skin, by providing a lower die that can elastically support the skin, when the skin is extruded, the deformation of the lower die can exert multiple upward flexible supporting forces on the skin, which can effectively avoid the occurrence of the "bone exposed" phenomenon. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a skin forming device provided in an embodiment of the utility model;

[0021] Figure 2 It is a structural schematic diagram of the lower mold provided by an embodiment of the utility model;

[0022] Figure 3 It is a reference diagram of the use state of the skin forming device provided by the embodiment of the utility model;

[0023] Figure 4 It is a structural schematic diagram of a partial skin forming device provided in an embodiment of the utility model.

[0024] In the figure:

[0025] 1. Upper die; 11. Arc-shaped extrusion surface; 2. Lower die; 21. Lower die base; 211. Forming groove; 2111. Arc-shaped chamfer; 22. First elastic pad; 3. Second elastic pad; 4. Third elastic pad; 5. Skin. DETAILED DESCRIPTION

[0026] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the present invention are further described below in conjunction with the accompanying drawings and through specific implementation methods. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings, rather than all of them.

[0027] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0029] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0030] This embodiment provides a skin forming device to avoid the occurrence of the "bone exposure" phenomenon during the skin forming process and improve the forming quality of the skin.

[0031] like Figure 1-Figure 4 As shown, the skin forming device includes an upper die 1 and a lower die 2. The upper die 1 has an arc-shaped extrusion surface 11, and the lower die 2 is arranged opposite to the upper die 1 in a first direction. A forming space for placing the skin 5 is formed between the arc-shaped extrusion surface 11 and the lower die 2. The arc-shaped extrusion surface 11 can cooperate with the lower die 2 to extrude the skin 5, so as to realize the forming of the skin 5.

[0032] Specifically, the lower die 2 is used to elastically support the skin 5, and the upper die 1 can move toward or away from the lower die 2 in a first direction. When the upper die 1 moves toward the lower die 2, the arc-shaped extrusion surface 11 can cooperate with the lower die 2 to extrude the skin 5 to form the skin 5. During the extrusion process, the lower die 2 can undergo elastic deformation, thereby applying multiple upward flexible supporting forces to the skin 5, which can effectively avoid the occurrence of the "bone exposure" phenomenon.

[0033] Optionally, there may be multiple ways for the lower mold 2 to elastically support the skin 5. This embodiment exemplarily provides two achievable ways, but is not limited to these two achievable ways.

[0034] In some achievable ways, the lower mold 2 is made of elastic material as a whole, that is, the lower mold 2 is an integrated structure, such as rubber, silicone, nylon, etc. The lower mold 2 is made of elastic material, so that the lower mold 2 can elastically support the skin 5. In the process of squeezing the skin 5, the lower mold 2 can be elastically deformed, thereby applying multiple upward flexible supporting forces to the skin 5.

[0035] In another achievable manner, the lower mold 2 is a split structure, such as Figure 2 As shown, the lower mold 2 includes a lower mold base 21 and an elastic component (not shown in the figure). A forming groove 211 is provided on the surface of the lower mold base 21 facing the upper mold 1, and the bottom of the forming groove 211 is arc-shaped. The elastic component is arranged on the side of the lower mold base 21 facing the upper mold 1, and at least part of the elastic component is located in the forming groove 211. The elastic component is used to elastically support the skin 5, and the elastic component cooperates with the upper mold 1 to form a forming space. It should be noted that the lower mold base 21 is a plastic structure, that is, the lower mold base 21 will not undergo elastic deformation, so that the forming groove 211 on the lower mold base 21 can cooperate with the upper mold 1 to better shape the skin 5, ensuring that the shape of the skin 5 can meet the requirements.

[0036] It can be understood that by setting a forming groove 211 on the surface of the lower mold base 21 facing the upper mold 1, and at the same time setting an elastic component on the side of the lower mold base 21 facing the upper mold 1, when the arc extrusion surface 11 moves along the first direction close to the lower mold 2 to extrude the skin 5, the elastic component is compressed. While the elastic component is compressed, it provides multiple upward flexible supporting forces to the skin 5, which can effectively avoid the occurrence of the "bone exposure" phenomenon.

[0037] Alternatively, if Figure 2 As shown, the elastic component includes a first elastic pad 22, and the surface of the first elastic pad 22 facing the lower mold base 21 is a curved surface that matches the bottom of the forming groove 211. The surface of the first elastic pad 22 facing the lower mold base 21 contacts the bottom of the forming groove 211, that is, at least part of the first elastic pad 22 is located in the forming groove 211 and matches the shape of the forming groove 211. It can be understood that when the first elastic pad 22 is compressed, since at least part of the first elastic pad 22 is located in the forming groove 211 and matches the shape of the forming groove 211, the first elastic pad 22 moves toward the forming groove 211, which is conducive to improving the stability of the first elastic pad 22 applying a flexible supporting force to the skin 5. In this embodiment, the material of the first elastic pad 22 is rubber or silicone.

[0038] Furthermore, the thickness of the middle portion of the first elastic pad 22 in the first direction is greater than the thickness of the edge of the first elastic pad 22 in the first direction, so that the middle portion of the first elastic pad 22 is thicker. When the first elastic pad 22 is compressed, it can better support the skin 5 and stably apply multiple upward flexible supporting forces to the skin 5, thereby improving the forming effect.

[0039] Alternatively, if Figure 2 As shown, the surface of the first elastic pad 22 on the side away from the lower mold base 21 is a plane. Such a configuration can ensure that the first elastic pad 22 stably supports the skin 5, so that the first elastic pad 22 and the skin 5 have a large contact area, and the supporting force is evenly applied to the skin 5, which can avoid the uneven surface of the first elastic pad 22 on the side away from the lower mold base 21, which may cause the skin 5 to be "exposed" when being formed.

[0040] Optionally, the edge of the first elastic pad 22 extends to the outside of the forming groove 211, that is, the edge of the first elastic pad 22 extends to the surface of the lower mold base 21 facing the upper mold 1, that is, the size of the first elastic pad 22 in the second direction is larger than the size of the forming groove 211 in the second direction, and the second direction is perpendicular to the first direction, so that the first elastic pad 22 can cover the forming groove 211, thereby preventing the skin 5 from directly contacting the edge of the forming groove 211 when being squeezed, and forming a hard contact with the edge of the forming groove 211, thereby avoiding damage to the surface quality of the skin 5 or even the "bone exposure" phenomenon.

[0041] In this embodiment, the first elastic pad 22 is used to elastically support the skin 5. During processing, the skin 5 can be directly placed on the first elastic pad 22 without overlapping the edge of the mold. There is no situation where the overlapping part cannot be formed into place, that is, there is no bending allowance, and forming without bending allowance can be achieved.

[0042] Alternatively, if Figure 4 As shown, in order to further improve the forming quality of the skin 5, the notch of the forming groove 211 is provided with an arc chamfer 2111. It can be understood that even when the skin 5 is extruded, the first elastic pad 22 is elastically deformed and compressed, because the notch of the forming groove 211 is provided with an arc chamfer 2111, the first elastic pad 22 can be prevented from being cut by the lower mold base 21, and the skin 5 will not be damaged, thereby improving the yield rate.

[0043] In order to further improve the forming effect of the skin 5, in this embodiment, Figure 4As shown, the shape of the arcuate extrusion surface 11 matches the shape of the forming groove 211, that is, the radius of the arcuate extrusion surface 11 is the same as the radius of the groove bottom of the forming groove 211. With such a configuration, when the arcuate extrusion surface 11 and the lower die 2 extrude the skin 5, the movement of the arcuate extrusion surface 11 close to the lower die 2 will not be interfered by the forming groove 211, and the skin 5 will not abut against the edge of the forming groove 211, thereby ensuring that the shape of the skin 5 after forming meets the requirements.

[0044] Alternatively, if Figure 1 and Figure 3 As shown, the elastic component also includes a second elastic pad 3, which is arranged on the side of the first elastic pad 22 away from the lower mold base 21. In this embodiment, the hardness of the second elastic pad 3 is greater than the hardness of the first elastic pad 22. The two can cooperate to apply a flexible supporting force to the skin 5 while preventing the skin 5 from deforming too quickly during the forming process, thereby improving the forming quality of the skin 5. It should be noted that the hardness of a material refers to the ability of the material to locally resist hard objects from pressing into its surface. The greater the hardness, the stronger the ability to resist hard objects from pressing into its surface.

[0045] like Figure 1 and Figure 3 As shown, the skin forming device further includes a third elastic pad 4 , which is used to contact the surface of the skin 5 facing the upper mold 1 to avoid hard contact between the upper mold 1 and the skin 5 , thereby avoiding damage to the skin 5 .

[0046] In this embodiment, the third elastic pad 4 is provided with a matching structure, specifically, the matching structure is provided on the side of the third elastic pad 4 facing the skin 5, and the matching structure is used to match with the groove or protrusion on the skin 5. It can be understood that by providing the matching structure on the third elastic pad 4 to match with the groove or protrusion on the skin 5, the side of the skin 5 close to the upper mold 1 forms a plane, and when the skin 5 is extruded, the pressure applied by the upper mold 1 is evenly distributed through the third elastic pad 4 to act on the skin 5 to obtain the required curvature, thereby meeting the forming requirements of the skin 5 with a special-shaped structure.

[0047] Exemplarily, when the surface of the skin 5 facing the third elastic pad 4 has a groove, the matching structure is a protrusion that can fill the groove; when the surface of the skin facing the third elastic pad 4 has a protrusion, the matching structure is a groove that can accommodate the protrusion.

[0048] like Figure 3As shown, in the first direction, by respectively arranging the third elastic pad 4 and the second elastic pad 3 on both sides of the skin 5, and arranging the first elastic pad 22 below the second elastic pad 3, elastic support for the skin 5 is achieved while clamping the skin 5. When the skin 5 is extruded, not only can a plurality of upward flexible supporting forces be applied to the skin 5, which can effectively avoid the "exposed bone" phenomenon, but also the forming stability of the skin 5 can be improved, and the forming effect is better.

[0049] Optionally, the third elastic pad 4 and the second elastic pad 3 are made of nylon, and the first elastic pad 22 is made of rubber or silicone. It is understandable that the hardness of nylon is greater than that of rubber and silicone. By setting the third elastic pad 4 and the second elastic pad 3 to be made of nylon, the skin 5 can be better clamped, and the elastic deformation of the first elastic pad 22 can be better achieved, so that multiple upward flexible supporting forces can be better applied to the skin 5.

[0050] like Figure 1 and Figure 3 As shown, in this embodiment, the skin 5 is a skin with grooves or protrusions. During operation, first ensure that the upper mold 1 and the lower mold 2 are in a state of being away from each other in the first direction, so as to facilitate the installation of the elastic pad and the skin 5 in the forming space, and then place the first elastic pad 22 on the side of the lower mold base 21 facing the upper mold 1, and make it at least partially located in the forming groove 211. Then lay the second elastic pad 3 on the side of the first elastic pad 22 away from the lower mold base 21, and then place the skin 5 on the side of the second elastic pad 3 away from the first elastic pad 22, the second elastic pad 3 supports the skin 5, and then set the third elastic pad 4 on the side of the skin 5 close to the upper mold 1, the matching structure on the third elastic pad 4 matches with the groove or protrusion on the skin 5, so that the side of the skin 5 close to the upper mold 1 forms a plane, the second elastic pad 3 and the third elastic pad 4 clamp the skin 5, and then drive the upper mold 1 moves along the first direction close to the lower die 2, the arc-shaped extrusion surface 11 of the upper die 1 and the lower die 2 cooperate to extrude the skin 5 to realize the forming of the skin 5. When the skin 5 is extruded, the first elastic pad 22 to the third elastic pad 4 and the skin 5 are deformed. During the deformation process, the first elastic pad 22 and the second elastic pad 3 exert multiple upward flexible supporting forces on the skin 5, thereby avoiding the occurrence of the "exposed" phenomenon. After forming, the upper die 1 is driven to move along the first direction away from the lower die 2, and then the skin 5 is translated, and the forming of the skin 5 is completed.

[0051] The above embodiments are only to illustrate the basic principles and characteristics of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and modifications, which are within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. Skin forming device, characterized in that: include: An upper die (1), wherein the upper die (1) has an arc-shaped extrusion surface (11); A lower mold (2), the lower mold (2) is arranged opposite to the upper mold (1) in a first direction, a forming space for placing the skin (5) is formed between the arc-shaped extrusion surface (11) and the lower mold (2), the lower mold (2) is used to elastically support the skin (5), and the arc-shaped extrusion surface (11) can cooperate with the lower mold (2) to extrude the skin (5) so as to shape the skin (5).

2. The skin forming device according to claim 1, characterized in that: The lower mold (2) comprises a lower mold base (21) and an elastic component. The lower mold base (21) is provided with a forming groove (211) on its surface facing the upper mold (1) in the first direction. The bottom of the forming groove (211) is arc-shaped. The elastic component is arranged on a side of the lower mold base (21) facing the upper mold (1), and at least a part of the elastic component is located in the forming groove (211). The elastic component is used for elastically supporting the skin (5), and the elastic component cooperates with the upper mold (1) to form the forming space.

3. The skin forming device according to claim 2, characterized in that: The shape of the arc-shaped extrusion surface (11) matches the shape of the groove bottom of the forming groove (211).

4. The skin forming device according to claim 2, characterized in that: The notch of the forming groove (211) is provided with an arc-shaped chamfer (2111).

5. The skin forming device according to claim 2, characterized in that: The elastic component comprises a first elastic pad (22), the surface of the first elastic pad (22) facing the lower die base (21) is an arc surface matching the bottom of the forming groove (211), and the surface of the first elastic pad (22) facing the lower die base (21) contacts the bottom of the forming groove (211).

6. The skin forming device according to claim 5, characterized in that: The surface of the first elastic pad (22) facing away from the lower mold base (21) is a plane.

7. The skin forming device according to claim 5, characterized in that: The edge of the first elastic pad (22) extends to the surface of the lower mold base (21) facing the upper mold (1).

8. The skin forming device according to claim 5, characterized in that: The elastic component further comprises a second elastic pad (3), the second elastic pad (3) being arranged on a side of the first elastic pad (22) away from the lower mold base (21), and the hardness of the second elastic pad (3) being greater than the hardness of the first elastic pad (22).

9. The skin forming device according to claim 8, characterized in that: The skin forming device also includes a third elastic pad (4), which is used to contact the surface of the skin (5) facing the upper mold (1), and the third elastic pad (4) is provided with a matching structure, which is used to match with the groove or protrusion of the skin (5).

10. The skin forming device according to claim 9, characterized in that: The third elastic pad (4) and the second elastic pad (3) are both made of nylon, and the first elastic pad (22) is made of rubber or silicone.

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