Filling method for cavity between matching surfaces of R angle and right angle

Abstract

The invention relates to a method for filling a cavity between an R angle and a right angle matching surface, which comprises the following steps: fitting a part with an R angle with a side pressing plate, and enabling the top end of the part with the R angle to be flush with the top end of the side pressing plate so as to form a cavity similar to a triangle; polystyrene foam is cut into a uniform-section cylinder with the same length as the triangular-like cavity; the sectional area of the polystyrene foam is calculated, and the polystyrene foam is cut according to the calculation result so that the polystyrene foam can be matched with the triangle-like cavity; the foaming rubber is stuffed into the similar triangular cavity, and the top pressing plate covers the top ends of the part with the R angle and the side pressing plate; feeding the combined part with the R angle, the side pressing plate, the top pressing plate and the polystyrene foam into a drying oven for curing the polystyrene foam; and the two ends of the cured polystyrene foam are cut, so that the cured polystyrene foam is as long as the triangle-like cavity. According to the invention, twisted strips are not needed, a good filling effect is ensured, the production cost is reduced, the production period is shortened, and the filling efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of cavity filling technology, and in particular to a method for filling a cavity between a right-angle mating surface and a radius-angle mating surface. Background Technology

[0002] In the molding process of sandwich composite parts, there are often scenarios where parts with rounded corners (R-angles) and right-angled parts fit together at their right angles. For example, in the aerospace field, a U-shaped frame with rounded corners is often embedded between two skins in a sandwich structure. This U-shaped frame also fits into the honeycomb core material already embedded between the two skins. Because a right angle is formed between the inner wall of the skin and the outer wall of the honeycomb core material, the rounded corner of the U-shaped frame forms a triangular cavity between the inner wall of the skin and the outer wall of the honeycomb core material. If this triangular cavity is not filled, the skin, during the curing process (since the skin is flexible before curing), is easily subjected to external pressure, causing depressions or wrinkles in the cavity, leading to a loss of overall strength. Therefore, it is necessary to fill this triangular cavity to ensure the continuity and straightness of the skin and to avoid overall strength loss.

[0003] Currently, the common method for filling the interior of such triangular cavities is to use "twisted strips." For example, first, fiber prepreg is rolled into long, thin strips (i.e., the aforementioned twisted strips), then the prepared twisted strips are inserted into the triangular cavity, and finally, a skin is applied, allowing the twisted strips, skin, honeycomb core material, and U-shaped frame to cure together, thereby filling the interior of the triangular cavity. However, this method has at least the following drawbacks: 1. Because parameters such as the compactness and shape of the filling of the twist have a critical impact on the quality of the final product, it is difficult to accurately assess the filling amount of the twist, resulting in an unsatisfactory filling effect.

[0004] 2. Making twisted slivers requires specialized twisting forming equipment (or tooling), which increases the additional production cycle and production cost, while also reducing filling efficiency.

[0005] 3. Due to the soft texture and high stickiness of the twisted strip, it is difficult to operate during filling. In addition, after filling, the twisted strip is prone to local accumulation and bulging due to its high stickiness, resulting in an unsatisfactory filling effect.

[0006] Therefore, there is an urgent need for a method that does not require filling the triangular cavity between the R-angle and right-angle mating surfaces of the twisted strip, in order to solve the aforementioned defects. Summary of the Invention

[0007] The purpose of this invention is to provide a method for filling the cavity between the R-angle and the right-angle mating surface, so as to solve the problems existing in the prior art.

[0008] To achieve the above objectives, the present invention provides the following solution: This invention provides a method for filling the cavity between a right-angle mating surface and a radius (R-angle), the method comprising at least the following steps: S1. Fit the sidewall of the part with the rounded corner to the sidewall of the side pressure plate, and make the top of the part with the rounded corner flush with the top of the side pressure plate to form a triangular cavity. S2. Cut the expanding foam into a column with the same cross-section as the length of the triangular cavity; calculate the cross-sectional area of ​​the expanding foam, and cut the expanding foam a second time according to the calculation result so that the volume of the expanding foam matches the volume of the triangular cavity. S3. Insert the foam adhesive obtained after step S2 into the triangular cavity, and cover the top of the part with the rounded corner and the top of the side pressure plate with the bottom of the top pressure plate. S4. The assembled R-corner part, the side pressure plate, the top pressure plate and the foam are sent into an oven to cure the foam. S5. Cut both ends of the cured foam to make the length of the cured foam the same as that of the triangular cavity.

[0009] According to one embodiment of the present invention, both the side pressure plate and the top pressure plate are cuboid structures.

[0010] According to one embodiment of the present invention, in step S2, the expanding foam is cut into a right quadrangular prism.

[0011] According to one embodiment of the present invention, in step S2, the expanding foam is cut first and second using scissors.

[0012] According to an embodiment of the present invention, in step S2, the formula for calculating the cross-sectional area of ​​the expanding foam is: in: S is the cross-sectional area of ​​the expanding foam, in mm². r is the radius of the R-angle on the part with the R-angle, in mm; n is the expansion ratio of the foaming adhesive; k is the fill factor, and its value ranges from 1.2 to 2.5.

[0013] According to one embodiment of the present invention, the value of k is 1.5.

[0014] According to one embodiment of the present invention, a release cloth is provided between the side wall of the side pressure plate and the side wall of the part with the R-angle, and between the bottom end of the top pressure plate and the top end of the part with the R-angle.

[0015] According to one embodiment of the present invention, the release cloth between the side wall of the side pressure plate and the side wall of the part with the R-angle is connected to the side pressure plate, and the release cloth between the bottom end of the top pressure plate and the top end of the part with the R-angle is connected to the top pressure plate.

[0016] According to an embodiment of the present invention, in steps S1 and S3, the side wall of the part with the R-angle is clamped to the side wall of the side pressure plate, and the bottom end of the top pressure plate is clamped to the top end of the part with the R-angle by a clamping mechanism.

[0017] According to one embodiment of the present invention, after step S5 is completed, the cured foam is sanded and cleaned.

[0018] Beneficial effects This invention has at least the following technical effects: The method disclosed in this invention can use expanding foam to fill the triangular-like cavity between the R-angle and right-angle mating surfaces of parts with R-angles. Therefore, it is not necessary to use twisting strips to fill the triangular-like cavity, thus ensuring a good filling effect, reducing additional production costs and production cycle, and improving filling efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of the R-corner part, the triangular cavity, the side pressure plate, and the top pressure plate in this invention; Figure 2 for Figure 1 A schematic diagram of the overall structure after the triangular cavity is filled with expanding foam. Figure 3 for Figure 2 A schematic diagram of the overall structure of the expanding foam after it has finished foaming in the triangular cavity; Figure 4 This is a schematic diagram of the overall structure of the side pressure plate and top pressure plate pressing on the U-shaped frame body in this invention; Figure 5 This is a schematic diagram of the overall structure of the skin body, the U-shaped frame body, and the honeycomb core material body in this invention.

[0021] Explanation of reference numerals in the attached figures: 1. Parts with rounded corners; 2. Triangular cavity; 3. Side pressure plate; 4. Top pressure plate; 5. Foam; 6. Skin body; 7. U-shaped frame body; 8. Honeycomb core material body. Detailed Implementation

[0022] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and to exemplify the principles of the present invention, and are not configured to limit the present invention. In addition, the structural components in the drawings are not necessarily drawn to scale. For example, the dimensions of some structural components or regions in the drawings may be enlarged for other structural components or regions to aid in the understanding of the embodiments of the present invention.

[0023] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of the embodiments of the present invention. In the description of the present invention, it should be noted that, unless otherwise stated, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0024] Furthermore, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a structure or component that includes a list of elements includes not only those elements but also other structural elements that are not expressly listed or inherent to the structure or component. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the article or apparatus that includes the element.

[0025] Spatial relation terms such as "below," "under," "under," "low," "above," "on," and "high" are used for descriptive convenience to explain the positioning of one element relative to a second element, indicating that these terms are intended to cover different orientations of the device, in addition to those different from those shown in the figure. Furthermore, phrases such as "one element on / below another element" can indicate that two elements are in direct contact, or that there are other elements between the two elements. In addition, terms such as "first" and "second" are also used to describe individual elements, areas, parts, etc., without specifically indicating order or sequence, and should not be considered restrictive. Similar terms are used throughout the description to represent similar elements.

[0026] It will be apparent to those skilled in the art that the present invention can be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention.

[0027] Example 1 like Figures 1-3 As shown, the present invention provides a method for filling the cavity between a right-angle mating surface and a radius-angle mating surface, the method comprising at least the following steps: Step S1, as follows Figure 1 As shown, the sidewall of part 1 with R-angle (such as...) Figure 1 and Figure 2 The right side wall of the part with R-angle 1 and the side wall of the side pressure plate 3 (such as...) Figure 1 and Figure 2 The left side wall of the middle side pressure plate 3 is attached to the side pressure plate 3, and the top of the part with the R-angle is flush with the top of the side pressure plate 3, thereby forming a triangular cavity 2.

[0028] In this embodiment, the cross-section of the triangular cavity 2 can be regarded as a triangular shape with two right-angled sides and an arc-shaped hypotenuse (i.e., an arc at the R-angle).

[0029] Step S2: Cut the expanding foam 5 into a uniform cross-section cylinder with the same length as the triangular cavity 2 (i.e., the same axial length as the triangular cavity 2). After this step, calculate the cross-sectional area of ​​the expanding foam 5, and cut it a second time based on the calculation results to make the volume of the expanding foam 5 fit the volume of the triangular cavity 2.

[0030] In step S2, the specific shape of the cross-section of the equal-section prism cut from the foam 5 for the first time is not particularly limited. For example, the foam 5 can be cut into a triangular prism with a triangular cross-section, or it can be cut into a right square prism with a rectangular cross-section, depending on the actual situation.

[0031] In step S2, tools known in the art, such as scissors, that can cut the expanding foam 5 can be used to make the first cut and the second cut of the expanding foam 5, without any particular limitation.

[0032] It should be understood that the cross section referred to in the above-mentioned uniform cross section column is not the cross section along the axial direction of the expanding foam 5, but rather the cross section perpendicular to the axial direction of the expanding foam 5 (that is, the cross section of the expanding foam 5).

[0033] It should be understood that the expanding foam 5 is a known material in the art, and will not be described in detail here. In this embodiment, the expanding foam 5 may also be preferably a expanding foam with a compressive strength greater than or equal to (≥) 10 MPa, which is known in the art, and is not particularly limited here.

[0034] In step S2, the formula for calculating the cross-sectional area of ​​the expanding foam 5 can be: in: S is the cross-sectional area of ​​expanding foam 5, that is, the cross-sectional area of ​​expanding foam 5 that needs to be calculated, in mm². r is the radius of the R-angle on part 1 with R-angle, which is the radius of the circle when the arc-shaped R-angle on part 1 with R-angle is extended into a full circle, and the unit is mm; n is the expansion ratio of foam adhesive 5, which is the ratio of the original volume of foam adhesive 5 before foaming to the volume of foam after foaming, or the ratio of the original weight of foam adhesive 5 to the weight of its foam. k is the fill factor, and its value ranges from 1.2 to 2.5.

[0035] Step S3: Insert the foam 5 from step S2 into the triangular cavity 2, and cover the top of the top plate 4 with the bottom end of the top of the part with the R-angle 1 and the top of the side plate 3 (that is, cover the top of the triangular cavity 2 with the bottom end of the top plate 4).

[0036] If the volume of the expanding foam 5 inserted into the triangular cavity 2 is too small relative to the volume of the triangular cavity 2, the expanding foam 5 will not be able to fill the triangular cavity 2 completely. If the volume of the expanding foam 5 inserted into the triangular cavity 2 is too large relative to the volume of the triangular cavity 2, the expanding foam 5 will easily overflow from the contact point between the side pressure plate 3 and the top pressure plate 4 during the later foaming process, resulting in a waste of resources. Furthermore, since the radius of the R-angle on the R-angle part 1 directly affects the curvature of the R-angle on the R-angle part 1, it will affect the cross-sectional area and volume of the triangular cavity 2. Therefore, by calculating the cross-sectional area of ​​the expanding foam 5 in step S2, the cross-sectional area of ​​the expanding foam 5 can be determined based on the radius of the R-angle on the R-angle part 1. This allows the volume of the expanding foam 5 inserted into the triangular cavity 2 to be determined, ensuring that the expanding foam 5 completely fills the triangular cavity 2 without overflowing from the contact point between the side pressure plate 3 and the top pressure plate 4 during the later foaming process, thus avoiding waste of resources.

[0037] In step S2, the preferred value of k is 1.5. Extensive testing has verified that when k (the aforementioned filling coefficient) is 1.5, the volume of the expanding foam 5 best matches the volume of the triangular cavity 2. Specifically, when k is 1.5, the expanding foam 5 perfectly fills the interior of the triangular cavity 2 after foaming, achieving the best filling effect. The state of the expanding foam 5 after filling the triangular cavity 2 can be seen by referring to... Figure 3 .

[0038] Step S4: The assembled (i.e., completed step S3) parts 1 with R-corners, side pressure plate 3, top pressure plate 4 and expanding foam 5 are sent into an oven (not shown in the figure) to cure the expanding foam 5.

[0039] In this embodiment, the oven is a known existing component in the art, which is capable of drying and curing the foam 5, and will not be described in detail here.

[0040] Step S5: Cut both ends of the cured foam 5 (i.e., after step S4) so ​​that the cured foam 5 is once again the same length as the triangular cavity 2.

[0041] Since the expanding foam 5 at both ends of the triangular cavity 2 is not sealed in this embodiment, after the expanding foam 5 has finished expanding inside the triangular cavity 2, the axial length of the expanding foam 5 will be slightly longer than the axial length of the triangular cavity 2. At this time, the cured expanding foam 5 can be recut to the same length as the triangular cavity 2 using a cutting tool or other tool known in the art that can cut the expanding foam 5.

[0042] It should be understood that the excess foam at both ends of the expanding foam 5 is negligible compared to the overall foaming of the expanding foam 5, and therefore will not affect the foaming and filling of the expanding foam 5 inside the triangular cavity 2.

[0043] In this embodiment, as Figures 1-3 As shown, both the side pressure plate 3 and the top pressure plate 4 can be cuboid structures.

[0044] Furthermore, after the foam 5 has cured, in order to prevent the foam 5 from sticking to the side pressure plate 3 and the top pressure plate 4 and to achieve a better demolding effect, a release cloth (not shown in the figure) is provided between the side wall of the side pressure plate 3 and the side wall of the part with the R-angle 1, and between the bottom end of the top pressure plate 4 and the top end of the part with the R-angle 1.

[0045] In this embodiment, the release cloth can be a Teflon material known in the art, and is not particularly limited herein.

[0046] Specifically, the release cloth between the side wall of the side pressure plate 3 and the side wall of the part with R-angle 1 can be connected to the side pressure plate 3, and the release cloth between the bottom end of the top pressure plate 4 and the top end of the part with R-angle 1 can be connected to the top pressure plate 4.

[0047] More specifically, the release cloth between the side wall of the side pressure plate 3 and the side wall of the part with the R-angle 1 can be connected to the side pressure plate 3 by a high-temperature adhesive known in the art, and the release cloth between the bottom end of the top pressure plate 4 and the top end of the part with the R-angle 1 can also be connected to the top pressure plate 4 by a high-temperature adhesive known in the art.

[0048] Alternatively, the side plate 3 can be placed on the side wall near the end of the part with the R-angle 1 (i.e. Figure 1 The left side wall of the middle side pressure plate 3 and the bottom end of the top pressure plate 4 (i.e., Figure 1 The bottom of the top and middle pressure plates 4 are coated with a release agent known in the art (not shown in the figure), which can also prevent the foam 5 from sticking to the side pressure plates 3 and the top pressure plate 4, so as to achieve a better demolding effect.

[0049] Furthermore, to ensure a more secure fit between the side pressure plate 3 and the part with the rounded corner 1, and between the top pressure plate 4 and the part with the rounded corner 1, in steps S1 and S3, clamping mechanisms (not shown in the figure) can be used to clamp the side wall of the part with the rounded corner 1 to the side wall of the side pressure plate 3, and the bottom end of the top pressure plate 4 to the top end of the part with the rounded corner 1. That is, the clamping mechanism clamps the side wall of the part with the rounded corner 1 to the side wall of the side pressure plate 3, and simultaneously, other clamping mechanisms clamp the bottom end of the top pressure plate 4 to the top end of the part with the rounded corner 1.

[0050] Specifically, the clamping mechanism can be any known high-pressure clamp in the art, and no particular limitation is made here.

[0051] Furthermore, after completing step S5, the cured foam 5 is sanded and cleaned.

[0052] In this embodiment, the burrs on the cured foam 5 can be polished and cleaned using sandpaper known in the art. No particular limitation is made here, which can make the surface of the cured foam 5 smoother and flatter.

[0053] Example 2 In this embodiment, as Figure 4 As shown, the R-corner part 1 is taken as an example of the U-shaped frame body 7, and the R-corner on the U-shaped frame body 7 is located at the two bends of the U-shaped frame body 7.

[0054] like Figure 5 As shown, when the U-shaped frame body 7 is embedded between two adjacent (i.e., sandwich structure) skin bodies 6, a triangular cavity 2 is generated between the R-corner of the U-shaped frame body 7 and the outer wall of the honeycomb core material body 8 already embedded between the two adjacent skin bodies 6 and the inner wall of the skin body 6. Therefore, this triangular cavity 2 needs to be filled to ensure the continuity and straightness of the skin body 6, thereby avoiding the formation of depressions or wrinkles in the triangular cavity 2. At this time, according to the steps in Embodiment 1, cured expanding foam 5 can be formed at the R-corner of the U-shaped frame body 7. Then, the cured expanding foam 5 can be used to perfectly fill the triangular cavity 2 between the R-corner of the U-shaped frame body 7, the outer wall of the honeycomb core material body 8, and the inner wall of the skin body 6, thereby ensuring the continuity and straightness of the skin body 6 and avoiding the formation of depressions or wrinkles in the triangular cavity 2.

[0055] It should be understood that the above-described embodiments or examples of the present invention can be combined with each other and have corresponding technical effects.

[0056] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for filling the cavity between a right-angle mating surface and a radius-angle mating surface, characterized in that, Includes the following steps: S1. The side wall of the R-angle part (1) is attached to the side wall of the side pressure plate (3), and the top of the R-angle part (1) is flush with the top of the side pressure plate (3) to form a triangular cavity (2). S2. Cut the expanding foam (5) into a column with the same cross-section as the triangular cavity (2) for the first time; calculate the cross-sectional area of ​​the expanding foam (5), and cut the expanding foam (5) a second time according to the calculation results so that the volume of the expanding foam (5) matches the volume of the triangular cavity (2); S3. Insert the foam (5) after step S2 into the triangular cavity (2), and cover the top of the top plate (4) and the top of the side plate (3) with the bottom end of the top plate (4). S4. The assembled R-corner part (1), the side pressure plate (3), the top pressure plate (4) and the foam (5) are sent into the oven for curing treatment of the foam (5). S5. Cut both ends of the cured foam (5) so that the length of the cured foam (5) is the same as that of the triangular cavity (2).

2. The method for filling the cavity between the R-angle and the right-angle mating surface according to claim 1, characterized in that, Both the side pressure plate (3) and the top pressure plate (4) are rectangular parallelepiped structures.

3. The method for filling the cavity between the R-angle and the right-angle mating surface according to claim 1, characterized in that, In step S2, the foam (5) is cut into a straight quadrangular prism.

4. The method for filling the cavity between the R-angle and the right-angle mating surface according to claim 3, characterized in that, In step S2, the expanding foam (5) is cut first and then cut second using scissors.

5. The method for filling the cavity between the R-angle and the right-angle mating surface according to claim 1, characterized in that, In step S2, the formula for calculating the cross-sectional area of ​​the expanding foam (5) is: in: S is the cross-sectional area of ​​the foam (5), in mm². r is the radius of the R-angle on the part (1) with R-angle, in mm; n is the expansion ratio of the foaming adhesive (5); k is the fill factor, and its value ranges from 1.2 to 2.

5.

6. The method for filling the cavity between the R-angle and the right-angle mating surface according to claim 5, characterized in that, The value of k is 1.

5.

7. The method for filling the cavity between the R-angle and the right-angle mating surface according to claim 1, characterized in that, A release cloth is provided between the side wall of the side pressure plate (3) and the side wall of the part with R-angle (1), and between the bottom end of the top pressure plate (4) and the top end of the part with R-angle (1).

8. The method for filling the cavity between the R-angle and the right-angle mating surface according to claim 7, characterized in that, The release cloth between the side wall of the side pressure plate (3) and the side wall of the part with R-angle (1) is connected to the side pressure plate (3), and the release cloth between the bottom end of the top pressure plate (4) and the top end of the part with R-angle (1) is connected to the top pressure plate (4).

9. The method for filling the cavity between the R-angle and the right-angle mating surface according to claim 1, characterized in that, In steps S1 and S3, the side wall of the part with the R-angle (1) is clamped to the side wall of the side pressure plate (3) and the bottom end of the top pressure plate (4) is clamped to the top end of the part with the R-angle (1) by the clamping mechanism.

10. The method for filling the cavity between the R-angle and the right-angle mating surface according to claim 1, characterized in that, After completing step S5, the cured foam adhesive (5) is sanded and cleaned.

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