Skin auxiliary drawing die and using method thereof

Abstract

The invention relates to the technical field of skin forming, and particularly discloses a skin auxiliary drawing die and a using method thereof.The skin auxiliary drawing die comprises a first pressing die, a second pressing die, a cushion block and a pressing plate; the first pressing die and the second pressing die are oppositely arranged in the vertical direction. The side, facing the second pressing die, of the first pressing die is convexly provided with a crimping bulge, the side, facing the first pressing die, of the second pressing die is concavely provided with a crimping groove, and the crimping bulge can crimp a to-be-stretched skin into the crimping groove; the number of the cushion blocks is at least two, the at least two cushion blocks are arranged on the side, away from the crimping protrusion, of the first pressing die, and one of the at least two cushion blocks and the crimping protrusion are oppositely arranged in the vertical direction. The pressing plate is arranged on the other side, away from the first pressing die, of the cushion block. According to the method, the reverse warping phenomenon of the skin to be stretched in the stretching process can be avoided, so that the negative-curvature double-curved-surface skin is formed in place at a time, reworking is avoided, and the production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of skin forming technology, in particular to a skin auxiliary stretching die and a method thereof. BACKGROUND

[0002] The aircraft skin refers to the skin member which is surrounded outside the aircraft framework structure and is fixed on the framework by adhesive or rivet to form the aerodynamic shape of the aircraft. The skin structure formed by the aircraft skin and the framework has large bearing capacity and stiffness, and the self-weight is very light, which plays a role of bearing and transferring aerodynamic load. The aircraft skin commonly includes metal skin, composite laminated skin, sandwich skin and integral panel skin.

[0003] In the aircraft skin, there is a kind of large local double curved surface skin with negative curvature which needs to be stretched longitudinally. The existing technology uniformly pressurizes the mold and then stretches and forms. However, in the forming process using this kind of mold, the negative curvature surface of the aircraft skin will appear uncontrollable reverse warping phenomenon, so it is difficult to accurately stretch and form in place at one time, which further causes rework and affects production efficiency. SUMMARY

[0004] The purpose of the present application is to provide a skin auxiliary stretching die and a method thereof, so as to solve the problem that the negative curvature surface forming of the aircraft skin in the prior art will appear uncontrollable reverse warping phenomenon, so it is difficult to accurately stretch and form in place at one time, which further causes rework and affects production efficiency.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] On the one hand, the present application provides a skin auxiliary stretching die for pressure bonding a skin to be stretched, which comprises:

[0007] A first die and a second die are oppositely arranged along a vertical direction, and the skin to be stretched can be arranged between the first die and the second die. The side of the first die facing the second die is provided with a pressure bonding protrusion, and the side of the second die facing the first die is provided with a pressure bonding groove. The pressure bonding protrusion can pressure bond the skin to be stretched in the pressure bonding groove, so that the skin to be stretched forms a negative curvature double curved surface after stretching.

[0008] The spacer comprises at least two, and one of the at least two spacers is oppositely arranged with the pressure bonding protrusion along the vertical direction.

[0009] The pressing plate is arranged on the other side of the spacer away from the first die.

[0010] As an optional solution of the skin auxiliary stretching die, the outer surface of the pressing protrusion comprises a middle surface and first and second side surfaces arranged on both sides of the middle surface, and the first side surface is arranged on the side close to the edge of the first pressing die; one of the at least two pads is arranged opposite to the middle surface in the vertical direction, or one of the at least two pads is arranged opposite to the first side surface in the vertical direction.

[0011] As an optional solution of the skin auxiliary stretching die, the extension direction of the pad is parallel to the extension direction of the pressing protrusion.

[0012] As an optional solution of the skin auxiliary stretching die, the at least two pads are symmetrically arranged relative to the middle position of the pressing plate.

[0013] As an optional solution of the skin auxiliary stretching die, the skin auxiliary stretching die further comprises a counterweight, and the counterweight can be arranged at the middle position of the pressing plate.

[0014] As an optional solution of the skin auxiliary stretching die, the skin auxiliary stretching die further comprises a counterweight, and the counterweight can be arranged on the pressing plate; the counterweight is provided with at least two, and the at least two counterweights are arranged one by one in the vertical direction corresponding to the at least two pads.

[0015] As an optional solution of the skin auxiliary stretching die, the pressing plate is a metal plate.

[0016] On the other hand, the application provides a use method of the skin auxiliary stretching die, which is completed by using the skin auxiliary stretching die as described above, and the use method of the skin auxiliary stretching die comprises the following steps:

[0017] Arranging the skin to be stretched between the first pressing die and the second pressing die;

[0018] Arranging the at least two pads on the first pressing die, and arranging one of the at least two pads opposite to the pressing protrusion of the first pressing die in the vertical direction;

[0019] Arranging the pressing plate on the at least two pads, and applying pressure to the pressing plate while applying tension to both ends of the skin to be stretched.

[0020] As an optional solution of the use method of the skin auxiliary stretching die, the step of arranging the skin to be stretched between the first pressing die and the second pressing die further comprises:

[0021] Clamping both ends of the skin to be stretched by a stretching clamp.

[0022] The skin to be stretched is moved so that the negative curvature hyperboloid forming part of the skin to be stretched is arranged opposite the pressing protrusion of the first pressing mold along the vertical direction.

[0023] As an optional solution of the method for using the skin auxiliary stretching mold, the pressing plate is arranged on at least two of the pads, and the pressing plate is pressed, and the method further comprises:

[0024] The position of the pressing plate is adjusted so that the at least two pads are symmetrically arranged relative to the middle position of the pressing plate;

[0025] The middle position of the pressing plate is pressed, or the same pressure is applied to the positions of the pressing plate corresponding to the at least two pads.

[0026] The skin auxiliary stretching mold has the following advantages:

[0027] The skin auxiliary stretching mold comprises a first pressing mold, a second pressing mold, pads, and a pressing plate. The first pressing mold and the second pressing mold are arranged opposite along the vertical direction, and the skin to be stretched can be arranged between the first pressing mold and the second pressing mold, so that the first pressing mold and the second pressing mold can be close to each other to press the skin to be stretched. The side of the first pressing mold facing the second pressing mold is provided with a pressing protrusion, and the side of the second pressing mold facing the first pressing mold is provided with a pressing groove. The pressing protrusion can press the skin to be stretched into the pressing groove, so that the skin to be stretched forms a negative curvature hyperboloid skin after stretching, and the product is formed. Meanwhile, the pads comprise at least two, and the at least two pads are arranged on the side of the first pressing mold away from the pressing protrusion. One of the at least two pads is arranged opposite the pressing protrusion along the vertical direction, and the pressing plate is arranged on the other side of the pad away from the first pressing mold. Therefore, after the pressing plate is pressed, the pressure can be transmitted to the first pressing mold through the pad, so that the first pressing mold and the second pressing mold can press the skin to be stretched. Since one of the pads is arranged opposite the pressing protrusion along the vertical direction, the pressure can be accurately transmitted to the pressing protrusion, thereby avoiding the phenomenon of reverse warping of the skin to be stretched during stretching, so that the negative curvature hyperboloid skin is formed in place at one time, rework is avoided, and the production efficiency is improved.

[0028] The method for using the skin auxiliary stretching mold is completed by using the skin auxiliary stretching mold as described above. The method for using the skin auxiliary stretching mold is simple and convenient to use. The position of pressure transmission can be changed by arranging the pressing plate and the pad, and the pressure can be concentrated on the pressing protrusion, thereby avoiding the phenomenon of reverse warping of the skin to be stretched during stretching, so that the negative curvature hyperboloid skin is formed in place at one time, rework is avoided, and the production efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1A structural schematic diagram of a skin auxiliary stretching die provided by an embodiment of the present application;

[0030] Figure 2 A flowchart of a method for using the skin auxiliary stretching die provided by an embodiment of the present application.

[0031] In the drawings:

[0032] 1, first pressing die; 11, crimping protrusion; 111, middle surface; 112, first side surface; 113, second side surface; 2, second pressing die; 21, crimping groove; 3, cushion block; 4, pressing plate; 5, skin to be stretched. DETAILED DESCRIPTION

[0033] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0034] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", are only for the purpose of description, and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and moreover, the "above", "above" and "above" of the first feature on the second feature include the first feature above and obliquely above the second feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature on the second feature include the first feature below and obliquely below the second feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0035] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0037] Example 1

[0038] This embodiment provides a skin auxiliary stretching die for pressing a skin to be stretched, so that the skin to be stretched is stretched into a negative curvature hyperbolic skin.

[0039] like Figure 1 As shown, the skin auxiliary stretching die includes a first die 1, a second die 2, a spacer 3 and a pressing plate 4. The first die 1 and the second die 2 are arranged relative to each other in the vertical direction, and the skin to be stretched 5 can be arranged between the first die 1 and the second die 2, so that the first die 1 and the second die 2 can approach each other to press the skin to be stretched 5. Among them, the first die 1 is provided with a crimping protrusion 11 on the side facing the second die 2, and the second die 2 is provided with a crimping groove 21 on the side facing the first die 1. The crimping protrusion 11 can crimp the skin to be stretched 5 into the crimping groove 21, so that the skin to be stretched 5 forms a negative curvature hyperboloid skin after stretching, thereby realizing the molding of the product.

[0040] At the same time, the pads 3 include at least two, at least two of which are arranged on the side of the first die 1 away from the crimping protrusion 11, at least one of the two pads 3 is arranged opposite to the crimping protrusion 11 in the vertical direction, and the pressure plate 4 is arranged on the other side of the pad 3 away from the first die 1, so that after the pressure plate 4 is subjected to pressure, the pressure can be transmitted to the first die 1 through the pad 3, so that the first die 1 and the second die 2 can press the skin to be stretched 5, and since one of the pads 3 is arranged opposite to the crimping protrusion 11 in the vertical direction, the pressure can be accurately transmitted to the crimping protrusion 11, thereby avoiding the warping phenomenon of the skin to be stretched 5 during the stretching process, so that the negative curvature hyperbolic skin is formed in place at one time, avoiding rework and improving production efficiency.

[0041] Specifically, the extension direction of the spacer 3 is parallel to the extension direction of the crimping protrusion 11, so that the spacer 3 can transmit pressure to the entire crimping protrusion 11, preventing parts of the skin 5 to be stretched from not receiving concentrated pressure and thus warping after stretching. Optionally, the pressure plate 4 is a metal plate with a certain compressive strength, which can prevent the pressure plate 4 from deforming after being subjected to force, resulting in a change in the force transmission direction and affecting the one-time stretching and forming of the negative curvature hyperboloid skin.

[0042] Further, the outer surface of the crimping protrusion 11 comprises a middle surface 111 and first and second side surfaces 112 and 113 located on both sides of the middle surface 111, the first side surface 112 is located on the side close to the edge of the first pressing die 1, and one of the at least two pads 3 is arranged opposite to the middle surface 111 in the vertical direction, so that the pressure is concentrated on the center of the crimping protrusion 11, or one of the at least two pads 3 is arranged opposite to the first side surface 112 in the vertical direction, so that the pressure is concentrated on the side of the crimping protrusion close to the edge of the first pressing die 1. In this way, while ensuring that the to-be-stretched skin 5 will not have a reverse warping phenomenon after stretching, the positioning difficulty of the pads 3 when installed on the first pressing die 1 can also be reduced.

[0043] Further, the at least two pads 3 are symmetrically arranged relative to the middle position of the pressing plate 4, so that the center of gravity of the pressing plate 4 is located at the middle position between the two pads 3, thereby avoiding the influence of the weight of the pressing plate 4 itself on the accuracy of pressure transmission. In an embodiment, the skin auxiliary stretching die further comprises a counterweight, which can be arranged at the middle position of the pressing plate 4, so that the pressing force of the pressing plate 4 on the two pads 3 can be equal, so that both sides of the to-be-stretched skin 5 can be subjected to concentrated pressure, facilitating the slow and uniform stretching of the to-be-stretched skin 5. In another embodiment, the skin auxiliary stretching die further comprises a counterweight, which can be arranged on the pressing plate 4, and the counterweight is provided with at least two, and the at least two counterweights are arranged in one-to-one correspondence with the at least two pads 3 in the vertical direction, so that by arranging the counterweights on the pressing plate 4 corresponding to the positions of the two pads 3, the pressing force of the pressing plate 4 on the two pads 3 can also be equal, so that both sides of the to-be-stretched skin 5 can be subjected to concentrated pressure, facilitating the slow and uniform stretching of the to-be-stretched skin 5.

[0044] Embodiment Two

[0045] The embodiment also provides a use method of the skin auxiliary stretching die, which is completed by using the skin auxiliary stretching die in the embodiment one, as shown in the following. Figure 2 As shown, the use method of the skin auxiliary stretching die comprises the following steps:

[0046] arranging the to-be-stretched skin 5 between the first pressing die 1 and the second pressing die 2;

[0047] arranging the at least two pads 3 on the first pressing die 1, and arranging one of the at least two pads 3 opposite to the crimping protrusion 11 of the first pressing die 1 in the vertical direction;

[0048] arranging the pressing plate 4 on the at least two pads 3, and applying pressure to the pressing plate 4, while applying tension to both ends of the to-be-stretched skin 5.

[0049] The method for using the skin auxiliary stretching die is simple and convenient in use, the setting of the pressing plate 4 and the cushion block 3 can change the position of pressure transmission, and the pressure can be concentrated on the pressing protrusion 11, so that the phenomenon of reverse warping of the skin 5 to be stretched during the stretching process is avoided, the negative curvature hyperboloid skin is formed in place at one time, the rework is avoided, and the production efficiency is improved.

[0050] Further, the skin 5 to be stretched is arranged between the first pressing die 1 and the second pressing die 2, and the both ends of the skin 5 to be stretched are clamped by the stretching clamp, and the skin 5 to be stretched is moved, so that the negative curvature hyperboloid forming part of the skin 5 to be stretched is arranged opposite to the pressing protrusion 11 of the first pressing die 1 in the vertical direction, so that the forming precision of the negative curvature hyperboloid skin is improved.

[0051] Further, the pressing plate 4 is arranged on the at least two cushion blocks 3, and the pressing plate 4 is applied with pressure, and the position of the pressing plate 4 is adjusted, so that the at least two cushion blocks 3 are symmetrically arranged relative to the middle position of the pressing plate 4, so that the influence of the weight of the pressing plate 4 itself on the precision of pressure transmission is avoided, and the middle position of the pressing plate 4 is applied with pressure, or the positions corresponding to the at least two cushion blocks 3 of the pressing plate 4 are applied with pressure of the same size, so that the pressure applied by the pressing plate 4 to the two cushion blocks 3 is equal, and the both sides of the skin 5 to be stretched can be applied with concentrated pressure, so that the skin 5 to be stretched is stretched slowly and uniformly.

[0052] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the implementation modes of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the implementation modes are not required or can not be exhausted. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the claims of the present application.

Claims

1. A skin auxiliary stretching die for pressing a front stretched skin (5), characterized in that: The skin auxiliary stretching mold includes: A first die (1) and a second die (2), wherein the first die (1) and the second die (2) are arranged relative to each other in a vertical direction, and the skin to be stretched (5) can be arranged between the first die (1) and the second die (2); a crimping protrusion (11) is convexly provided on the side of the first die (1) facing the second die (2), and a crimping groove (21) is concavely provided on the side of the second die (2) facing the first die (1), and the crimping protrusion (11) can crimp the skin to be stretched (5) into the crimping groove (21), so that the skin to be stretched (5) forms a negative curvature hyperbolic skin after stretching; A pad (3), comprising at least two pads (3), at least two of which are arranged on a side of the first die (1) facing away from the crimping protrusion (11), and at least one of the two pads (3) is arranged opposite to the crimping protrusion (11) along the vertical direction; A pressing plate (4), the pressing plate (4) being arranged on the other side of the cushion block (3) away from the first pressing die (1).

2. The skin auxiliary stretching die according to claim 1, characterized in that: The outer surface of the crimping protrusion (11) includes a middle surface (111) and a first side surface (112) and a second side surface (113) arranged on both sides of the middle surface (111), wherein the first side surface (112) is located on a side close to the edge of the first die (1); at least one of the two pads (3) is arranged opposite to the middle surface (111) along the vertical direction, or at least one of the two pads (3) is arranged opposite to the first side surface (112) along the vertical direction.

3. The skin auxiliary stretching mold according to claim 1, characterized in that: The extending direction of the cushion block (3) is parallel to the extending direction of the crimping protrusion (11).

4. The skin auxiliary stretching die according to claim 1, characterized in that: At least two of the cushion blocks (3) are symmetrically arranged relative to the middle position of the pressure plate (4).

5. The skin auxiliary stretching die according to claim 4, characterized in that: The skin auxiliary stretching mold also includes a counterweight block, and the counterweight block can be arranged in the middle position of the pressure plate (4).

6. The skin auxiliary stretching die according to claim 4, characterized in that: The skin auxiliary stretching mold further comprises a counterweight block, which can be arranged on the pressure plate (4); at least two counterweight blocks are provided, and at least two counterweight blocks and at least two cushion blocks (3) are arranged in a one-to-one correspondence along the vertical direction.

7. The skin auxiliary stretching die according to any one of claims 1 to 6, characterized in that: The pressing plate (4) is a metal plate.

8. A method for using a skin auxiliary stretching die, characterized in that: The method for using the skin auxiliary stretching die is completed using the skin auxiliary stretching die according to any one of claims 1 to 7, and the method for using the skin auxiliary stretching die comprises the following steps: The skin to be stretched (5) is arranged between the first pressing die (1) and the second pressing die (2); At least two of the pads (3) are arranged on the first pressing die (1), and one of the at least two pads (3) is arranged opposite to the crimping protrusion (11) of the first pressing die (1) along the vertical direction; A pressure plate (4) is arranged on at least two of the pads (3), and pressure is applied to the pressure plate (4), while simultaneously applying tension to both ends of the skin to be stretched (5).

9. The method for using the skin auxiliary stretching mold according to claim 8, characterized in that: The method of placing the skin to be stretched (5) between the first die (1) and the second die (2) further comprises: clamping both ends of the skin (5) to be stretched by a stretching clamp; The skin to be stretched (5) is moved so that the negative curvature hyperboloid forming portion of the skin to be stretched (5) and the crimping protrusion (11) of the first pressing die (1) are arranged opposite to each other along the vertical direction.

10. The method for using the skin auxiliary stretching mold according to claim 8, characterized in that: The method of placing a pressure plate (4) on at least two of the cushion blocks (3) and applying pressure to the pressure plate (4) further comprises: Adjusting the position of the pressing plate (4) so ​​that at least two of the pads (3) are symmetrically arranged relative to the middle position of the pressing plate (4); Pressure is applied to the middle position of the pressure plate (4), or pressure of the same magnitude is applied to the positions of the pressure plate (4) corresponding to at least two of the cushion blocks (3).

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