Forming mold and manufacturing method of enveloping type composite material rib

Abstract

The invention discloses a forming die and a manufacturing method of an enveloping type composite material rib, and two sets of pressure pad forming dies in the forming die are an enveloping type pressure pad forming die and a rib edge strip pressure pad forming die which are used for preparing an enveloping type rib end pressure pad through the enveloping type pressure pad forming die. Rib edge strip pressure pads correspondingly attached to the outer sides of the rib edge strips b on the two sides are prepared through a rib edge strip pressure pad forming die; an upper die and a lower die in the enveloping type composite material rib forming die are respectively designed and formed on the basis of appearance surfaces of an upper part and a lower part divided by a horizontal central plane of an enveloping type composite material rib, and are respectively used for paving preformed bodies of the upper part and the lower part. The mold structure can adapt to and improve the problem that the pressure pad is not matched due to deformation of the part in the curing process, a cavity between the pressure pad and the part is eliminated, and the problems that in the manufacturing process of the enveloping type composite material rib, pressure conduction is uneven, and fiber buckling occurs on the surface of the part are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of composite parts manufacturing technology, and in particular to a molding die and manufacturing method for an envelope-type composite material rib. Background Technology

[0002] Currently, with the development of aircraft manufacturing technology, the proportion of composite material ribs used is increasing, the rib structure is becoming more complex, and the manufacturing difficulty is gradually increasing. Among them, the enveloping composite material rib is a relatively complex type of composite material rib structure, with a closed enveloping structure at the rib end, rather than the open structure found in common composite material ribs.

[0003] In conventional composite rib manufacturing, a combination of male mold placement and integral pressure pad curing is mostly used. However, for complex or enveloping irregular rib structures, the manufacturing process of enveloping composite ribs involves twisting the preforms laid separately with upper and lower molds during mold closing. To ensure the flatness of the twisted area, a rigid composite pressure pad is required. However, the preforms deform and slip during curing, causing the pressure pad to shift, reducing the fit between the pressure pad and the preform and creating cavities. Therefore, uneven pressure transmission during autoclaving leads to internal porosity in the part. Furthermore, poor matching between the preform surface and the pressure pad causes localized compression, resulting in fiber buckling in the final manufactured part, affecting both internal and surface quality and failing to meet delivery quality requirements. Therefore, ensuring uniform pressure transmission during curing and effectively improving the fit between the pressure pad and the part are key challenges in the manufacturing process of enveloping composite ribs. Summary of the Invention

[0004] The purpose of this invention is to provide a molding die and manufacturing method for an envelope-type composite material rib, so as to solve the problem that uneven pressure transmission during the manufacturing process of the envelope-type composite material rib leads to fiber buckling on the surface, which affects the internal and surface quality of the part and fails to meet the quality requirements of the delivered part.

[0005] The technical solution of the present invention is as follows: In the first aspect, the present invention provides a molding die for an enveloping composite material rib, wherein the enveloping composite material rib 1 includes: a rib web a, rib flanges b fixedly connected to both sides of the rib web a, and an enveloping rib end c connected to one end of the two rib flanges b and forming an enveloping structure; the molding die includes: two sets of pressure pad molding dies and one set of enveloping composite material rib molding die. The two sets of pressure pad forming molds are an envelope-type pressure pad forming mold and a rib strip pressure pad forming mold, which are used to prepare an envelope-type rib end pressure pad through the envelope-type pressure pad forming mold and to prepare a rib strip pressure pad corresponding to the outer side of the two rib strips b through the rib strip pressure pad forming mold. The enveloping composite material rib forming mold includes an upper mold 7 and a lower mold 8; the upper mold 7 and the lower mold 8 are respectively designed based on the outer surface of the upper part and the lower part divided by the horizontal center plane of the enveloping composite material rib, and are used to lay the preforms of the upper part and the lower part respectively.

[0006] Optionally, in the molding die for the envelope-type composite rib as described above, The molding die for the envelope-type composite material rib is used to lay the upper and lower preforms of the composite material rib through the molding die and form the preform of the envelope-type composite material rib by closing the mold. Before making the vacuum bag, the pressure pad at the end of the envelope-type rib prepared by the molding die is fixed at the end of the envelope-type rib of the preform with a release cloth. Two pressure pads prepared by the rib edge pressure pad molding die are placed on the outside of the rib edge strips on both sides of the preform. During the curing process of the preform, the three segmented pressure pads adhere to the relative structure of the preform to keep the outer surface of the envelope-type composite material rib consistent with the theoretical surface and effectively and evenly transfer the can pressure.

[0007] Optionally, in the molding die for the envelope-type composite rib as described above, The enveloping pressure pad forming mold is used to simultaneously prepare multiple sets of enveloping rib end pressure pads. The enveloping pressure pad forming mold includes: a forming male mold 2 with a cross-section of a T-shaped structure, and handles 3 fixedly set at both ends of the forming male mold 2. The handles 3 are set as detachable structures and are connected to the forming male mold 2 by threads, and are removed before entering the can for curing. The cross-section of the molding male mold 2 is prepared based on the cross-section of the end of the envelope-type composite material rib. The molding male mold 2 has a uniform cross-section structure in its length direction. It is used to prepare a strip-shaped U-shaped envelope-type pressure pad by laying and curing a convex mold body, and to cut it to form an envelope-type rib end pressure pad with the same width as the end of the envelope-type rib.

[0008] Optionally, in the molding die for the envelope-type composite material rib as described above, the rib edge pressure pad molding die includes: a molding die body 4, a base 5, and a hanger 6; Among them, two identical molding molds 4 are fixedly mounted on the base 5, and hanging 6 are installed at the four corners of the base 5 to facilitate the handling of the tooling. The ribbed pressure pad forming mold is used to lay and cure two ribbed pressure pads through two forming mold bodies 4 respectively.

[0009] Optionally, in the molding die for the envelope-type composite material rib as described above, both the upper die 7 and the lower die 8 are configured as frame structures. The enveloping composite material rib forming mold further includes: cover plates 9 disposed on both end faces of the upper mold 7 and the lower mold 8; by disposing of cover plates 9, the shape of the enveloping composite material rib forming mold is maintained during the curing process of the preform, so as to prevent the vacuum bag from being sucked into the frame structure of the upper mold 7 and the lower mold 8, thereby causing air leakage and damage.

[0010] Optionally, in the molding die for the envelope-type composite rib as described above, The prepared rib end pressure pad and the pressure pads of the two side rib strips are cut to form a sloping overlap structure. The sloping overlap structure inhibits the slippage of the rib end pressure pad and the pressure pads of the two side rib strips, which would cause quality defects in the side ribs.

[0011] Optionally, in the molding die for the envelope-type composite rib as described above, Both the rib end pressure pad and the rib edge pressure pad are made of rigid carbon fiber prepreg pressure pads; the cutting positions of the rib end pressure pad and the rib edge pressure pad are cut according to the curvature inflection point of the part, and the angle between the inclined planes of the mating sections of the rib end pressure pad and the two side rib edge pressure pads is 15°~20°.

[0012] In a second aspect, the present invention also provides a method for manufacturing an envelope-type composite material rib, wherein the envelope-type composite material rib is prepared using a molding die for an envelope-type composite material rib as described in any of the above claims, and the manufacturing method includes: Step 1, Preparation of enveloping rib end pressure pad: The enveloping rib end pressure pad is prepared using an enveloping pressure pad molding die; Step 2, Preparation of ribbed pressure pad: The ribbed pressure pad is prepared using a ribbed pressure pad forming mold; Step 3, Material Laying: Carbon fiber prepreg is laid on the upper mold 7 and lower mold 8 of the enveloping composite material rib forming mold according to the layup. Step 4, Mold assembly: After the tiling is completed, the upper mold 7 and the lower mold 8 are combined. The upper and lower molds are connected and locked by positioning pins and bolts located inside the frame. Step 5, Twisting: After the mold is closed, according to the mold closing section of the upper mold 7 and the lower mold 8, cut strips of prepreg of different widths in sequence, add them one by one to the twisting area until the V-shaped cavity is filled, and compact them; Step 6, Place pressure pads: Place the rib end envelope type rib end pressure pad and the rib edge strip pressure pad respectively, overlap the pressure pads with an angle of 15°~20°, and fix them with tape; Step 7, Vacuum bag making: Place the release film and breathable felt on the laid carbon fiber prepreg, and then make a vacuum bag; Step 8, Curing: Before entering the autoclave, check for vacuum leaks. Once the requirements are met, proceed with curing in the autoclave. Step 9, Demolding: Remove the part after curing; Step 10, Cutting and Trimming: Use a pneumatic cutter to cut and trim the parts along the cutting line.

[0013] Optionally, in the forming method of the envelope-type composite material rib as described above, such as Figure 2 As shown, step 1, preparing the envelope-type rib end pressure pad, includes: Step 11, Material laying: Lay 6 layers of carbon fiber fabric prepreg on the surface 2 of the rib end envelope pressure pad forming mold; Step 12, Vacuum bag making: Place the release film and breathable felt on the laid carbon fiber prepreg, and then make a vacuum bag; Step 13, Curing: Before entering the autoclave, check for vacuum leaks. Once the requirements are met, proceed with curing in the autoclave. Step 14, Demolding: Remove the cured rib end envelope structure pressure pad from the surface 2 of the rib end envelope type pressure pad molding mold, and remove the burrs on the edge of the pressure pad with sandpaper. Step 15, Cutting: According to Figure 6 As shown, at the pressure pad division position, a grinder, cutter and other tools are used to process the mating position of the rib end envelope type pressure pad into a bevel with an included angle of 15°~20°; at the non-pressure pad division position, a grinder, cutter and other tools are used to cut the rib end envelope type pressure pad along the outer shape line of the rib end.

[0014] Optionally, in the forming method of the envelope-type composite material rib as described above, such as Figure 3 As shown, step 3, manufacturing the ribbed pressure pad, includes the following steps: Step 21, Material laying: Lay 6 layers of carbon fiber prepreg on the surface 2 of the rib pressure pad forming mold; Step 22, making vacuum bags: Place the release film and breathable felt on the laid carbon fiber prepreg, and then make vacuum bags; Step 23, Curing: Before entering the autoclave, check for vacuum leaks. Once the requirements are met, proceed with curing in the autoclave. Step 24, Demolding: Remove the cured ribbed pressure pad from the surface 4 of the ribbed pressure pad molding mold, and remove the burrs on the edge of the pressure pad with sandpaper; Step 25, Cutting: According to Figure 6 As shown, at the pressure pad division position, use tools such as grinders and cutters to process the mating position of the rib edge pressure pad into a bevel with an included angle of 15°~20°; at the non-pressure pad division position, use tools such as grinders and cutters to cut the rib end envelope type pressure pad along the outer rib profile line. Step 26, Check Status: According to Figure 6 As shown, at the pressure pad division position, check the beveled fit of the pressure pad of the rib end envelope structure and the pressure pad of the rib edge strip. If there is a gap, use sandpaper to polish and repair the fit until there is no gap.

[0015] The beneficial effects of this invention are as follows: This invention provides a molding die and manufacturing method for an envelope-type composite material rib. The segmented pressure pad structure effectively improves the fit between the pressure pad and the part. The pressure pad joint section adopts a sloping lap structure to suppress pressure pad slippage and cause web quality defects. It can effectively solve the problems of uneven pressure transmission and fiber buckling on the surface of the part during the manufacturing process of envelope-type composite material ribs, ensuring good internal quality of the part and a smooth and defect-free surface. It is used to achieve precise manufacturing and molding of envelope-type composite material ribs. The molding die can be used to lay up the upper and lower preforms of the composite material rib through the enveloping composite material rib molding die, and then form the enveloping composite material rib preform by closing the mold. Before making the vacuum bag, the enveloping rib end pressure pad prepared by the enveloping pressure pad molding die is fixed at the end position of the enveloping rib of the preform and secured with a release cloth. Two pressure pads prepared by the rib edge pressure pad molding die are placed on the outside of the rib edge strips on both sides of the preform. During the curing process of the preform, the three segmented pressure pads adhere to the relative structure of the preform to keep the outer surface of the enveloping composite material rib consistent with the theoretical surface and effectively and uniformly transfer the can pressure. The technical solution provided by this invention has the following beneficial effects: First, the molding die provided by the present invention uses a hard composite material pressure pad, which can effectively compact the twisting area of ​​the part and ensure the undamaged quality and surface quality of the twisting area.

[0016] Secondly, the pressure pad in the molding die provided by the present invention is segmented and the butt joint section adopts a sloping lap structure to improve the matching degree between the pressure pad and the part, suppress the pressure pad slippage that causes web quality defects. This structure can adapt to and improve the pressure pad mismatch problem caused by the deformation of the part during the curing process, eliminate the cavity between the pressure pad and the part, and effectively solve the problems of uneven pressure transmission and fiber buckling on the surface of the part during the manufacturing process of the envelope-type composite material rib. Attached Figure Description

[0017] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0018] Figure 1 This is a schematic diagram of an envelope-type composite material rib structure; Figure 2 This is a schematic diagram of an envelope-type pressure pad forming mold provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the ribbed pressure pad forming mold provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of an envelope-type composite material rib forming mold provided in an embodiment of the present invention.

[0019] Figure 5 This is a schematic diagram of the overlapping structure of the butt joint cross-section of the rib edge pressure pad and the rib end envelope type pressure pad in an embodiment of the present invention; the figure shows that the butt joint cross-section of the rib edge pressure pad and the rib end envelope type pressure pad adopts an overlapping method with a slope of 15°~20°. Figure 6 This is a schematic diagram showing the segmentation position of the two pressure pad structures of the envelope-type composite material rib in an embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures: 1. Enveloping composite rib; 2. Forming male mold; 3. Handle; 4. Forming mold body; 5. Base; 6. Hanger; 7. Upper mold; 8. Lower mold; 9. Cover plate. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

[0022] As explained in the background section above, uneven pressure transmission during the manufacturing process of envelope-type composite ribs can lead to fiber buckling on the surface, affecting the internal and surface quality of the parts and failing to meet the quality requirements for part delivery.

[0023] Existing technologies typically disclose molding dies and manufacturing methods for composite ribs with conventional configurations. However, the preparation technology for envelope-type composite ribs, especially how to achieve uniform and effective pressure transmission during the curing process, remains undeveloped. Therefore, there is an urgent need for a reliable molding die and manufacturing method to solve the problems of uneven pressure transmission and fiber buckling on the part surface during the manufacturing of envelope-type composite ribs, thereby improving the quality of delivered parts.

[0024] To address the aforementioned needs, this invention provides a molding die and manufacturing method for an enveloping composite material rib. The segmented pressure pad structure effectively improves the fit between the pressure pad and the part. The pressure pad joint profile adopts a sloping lap structure to suppress pressure pad slippage and cause web quality defects. This effectively solves the problems of uneven pressure transmission and fiber buckling on the part surface during the manufacturing process of the enveloping composite material rib, ensuring good internal quality and a smooth, defect-free surface. It is used to achieve precise manufacturing and molding of the enveloping composite material rib.

[0025] The present invention provides the following specific embodiments, which can be combined with each other. For the same or similar concepts or processes, they may not be described again in some embodiments.

[0026] The present invention provides a molding die for forming envelope-type composite material ribs, used for forming envelope-type composite material ribs, such as... Figure 1 As shown, the structure of the enveloping composite material rib 1 includes: a rib web a, rib flanges b fixedly connected to both sides of the rib web a, and rib ends c for connecting to one end of the two rib flanges b to form an enveloping structure.

[0027] like Figures 2 to 5 As shown, the manufacturing method of the envelope-type composite material rib provided by the present invention requires the use of three sets of molds, namely, the three sets of molding molds included in the molding mold of the envelope-type composite material rib provided by the present invention: two sets of pressure pad molding molds and one set of envelope-type composite material rib molding mold.

[0028] In this embodiment of the invention, the two sets of pressure pad forming molds are an envelope-type pressure pad forming mold and a rib strip pressure pad forming mold, which are used to prepare an envelope-type rib end pressure pad by means of the envelope-type pressure pad forming mold and to prepare a rib strip pressure pad corresponding to the outer side of the two rib strips b by means of the rib strip pressure pad forming mold.

[0029] like Figure 2 The enveloping pressure pad forming mold shown can be used to prepare multiple sets of enveloping rib end pressure pads at the same time. The enveloping pressure pad forming mold includes: a forming male mold 2 with a cross-section of a T-shaped structure, and handles 3 fixedly set at both ends of the forming male mold 2. The handles 3 are detachable and are connected to the forming male mold 2 by threads for easy handling and removal during canning.

[0030] In one embodiment, the cross section of the molding male mold 2 is prepared according to the cross section of the end of the envelope-type composite material rib. The molding male mold 2 has a uniform cross section structure in its length direction, which is used to prepare a strip-shaped U-shaped envelope-type pressure pad by laying and curing a convex mold body, and to cut it to form an envelope-type rib end pressure pad with the same width as the end of the envelope-type rib.

[0031] like Figure 3The ribbed pressure pad forming mold shown is used to prepare ribbed pressure pads. The forming mold includes: a forming mold body 4, a base 5, and a hanger 6. The forming mold body 4 is fixed on the base 5, and the hanger 6 facilitates the handling of the tooling.

[0032] In one embodiment, a ribbed pressure pad forming mold is used to form two ribbed pressure pads by respectively laying and curing two forming mold bodies 4.

[0033] like Figure 4 The enveloping composite rib forming mold shown is used to prepare enveloping composite ribs. The forming mold includes an upper mold 7 and a lower mold 8. The upper mold 7 and the lower mold 8 are respectively designed based on the outer surface of the upper part and the lower part divided by the horizontal center plane of the enveloping composite rib, and are used to lay the preforms of the upper part and the lower part.

[0034] In one implementation, both the upper mold 7 and the lower mold 8 are configured as frame structures; The enveloping composite material rib forming mold further includes: cover plates 9 disposed on both end faces of the upper mold 7 and the lower mold 8; by disposing of cover plates 9, the shape of the enveloping composite material rib forming mold is maintained during the curing process of the preform, so as to prevent the vacuum bag from being sucked into the frame structure of the upper mold 7 and the lower mold 8, thereby causing air leakage and damage.

[0035] The molding die for the envelope-type composite material rib provided by this invention involves laying down the upper and lower preforms of the composite material rib and forming the preform of the envelope-type composite material rib by closing the mold. Before making the vacuum bag, the preform will be... Figure 2 The enveloping rib end pressure pad, prepared by the enveloping pressure pad molding mold shown, and the enveloping rib end position set on the preform and fixed with a release cloth, will be used... Figure 3 The two pressure pads prepared by the rib strip pressure pad molding die shown are placed on the outer sides of the rib strips on both sides of the preform. During the curing process of the preform, the three segmented pressure pads adhere to the relative structure of the preform to keep the outer surface of the enveloped composite material rib consistent with the theoretical surface and effectively and evenly transfer the can pressure. This ensures that the appearance of the enveloped composite material rib is flat and wrinkle-free, and that the internal structure is free of defects such as voids and delamination.

[0036] Using the molding die for the envelope-type composite material rib provided by this invention, the mating section of the prepared rib end pressure pad and the pressure pads of the two side rib edges is cut to form a sloping overlap structure. The mating section of the sloping overlap structure suppresses the slippage of the rib end pressure pad and the pressure pads of the two side rib edges, which would cause quality defects in the side edges.

[0037] In one implementation scheme, such as Figure 5As shown, both the rib end pressure pad and the rib edge pressure pad are rigid carbon fiber prepreg pressure pads; the cutting positions of the rib end pressure pad and the rib edge pressure pad are cut according to the curvature inflection point of the part, and the angle between the inclined planes of the mating sections of the rib end pressure pad and the two side rib edge pressure pads is 15°~20°.

[0038] This invention provides a molding die and manufacturing method for an envelope-type composite material rib. Two types of pressure pads in segmented form are prepared using an envelope-type pressure pad molding die and a rib edge strip pressure pad molding die, respectively. The segmented pressure pad structure effectively improves the fit between each segment of the pressure pad and the envelope-type composite material rib. The mating section between the rib end pressure pad and the pressure pads on both sides of the rib edge strip adopts a sloping overlap structure to suppress slippage of the rib end pressure pad and the pressure pads on both sides of the rib edge strip, which could cause quality defects in the side edge strips. This effectively solves the problem of fiber buckling on the surface of the part caused by uneven pressure transmission during the manufacturing process of the envelope-type composite material rib, ensuring good internal quality and a smooth, defect-free surface. This method is used to achieve precise manufacturing and molding of the envelope-type composite material rib.

[0039] This invention is based on Figure 1 Taking the forming process of the envelope-type composite material rib shown as an example, the specific method is as follows: Step 1, Preparation of Enveloping Rib End Pressure Pads: Enveloping rib end pressure pads are prepared using an enveloping pressure pad molding die, such as... Figure 2 As shown, step 1, manufacturing the enveloping rib end pressure pad, includes the following steps: Step 11, Material laying: Lay 6 layers of carbon fiber fabric prepreg on the surface 2 of the rib end envelope pressure pad forming mold; Step 12, Vacuum bag making: Place the release film and breathable felt on the laid carbon fiber prepreg, and then make a vacuum bag; Step 13, Curing: Before entering the autoclave, check for vacuum leaks. Once the requirements are met, proceed with curing in the autoclave. Step 14, Demolding: Remove the cured rib end envelope structure pressure pad from the surface 2 of the rib end envelope type pressure pad molding mold, and remove the burrs on the edge of the pressure pad with sandpaper. Step 15, Cutting: According to Figure 6 As shown, at the pressure pad division position, a grinder, cutter and other tools are used to process the mating position of the rib end envelope type pressure pad into a bevel with an included angle of 15°~20°; at the non-pressure pad division position, a grinder, cutter and other tools are used to cut the rib end envelope type pressure pad along the outer shape line of the rib end. Step 2, Preparation of the ribbed pressure pad: The ribbed pressure pad is prepared using a ribbed pressure pad molding die; such as... Figure 3 As shown, step 2, manufacturing the ribbed pressure pad, includes the following steps: Step 21, Material laying: Lay 6 layers of carbon fiber prepreg on the surface 2 of the rib pressure pad forming mold, with the prepreg having the same width as the tooling surface; Step 22, making vacuum bags: Place the release film and breathable felt on the laid carbon fiber prepreg, and then make vacuum bags; Step 23, Curing: Before entering the autoclave, check for vacuum leaks. Once the requirements are met, proceed with curing in the autoclave. Step 24, Demolding: Remove the cured ribbed pressure pad from the surface 4 of the ribbed pressure pad molding mold, and remove the burrs on the edge of the pressure pad with sandpaper; Step 25, Cutting: According to Figure 6 As shown, at the pressure pad division position, use tools such as grinders and cutters to process the mating position of the rib edge pressure pad into a bevel with an included angle of 15°~20°; at the non-pressure pad division position, use tools such as grinders and cutters to cut the rib end envelope type pressure pad along the outer rib profile line. Step 26, Check Status: According to Figure 6 As shown, at the pressure pad division position, check the beveled fit of the pressure pad of the rib end envelope structure and the pressure pad of the rib edge strip. If there is a gap, use sandpaper to polish and repair the fit until there is no gap.

[0040] Step 3, Material Laying: Carbon fiber prepreg is laid on the upper mold 7 and lower mold 8 of the enveloping composite material rib forming mold according to the layup. Step 4, Mold assembly: After the tiling is completed, the upper mold 7 and the lower mold 8 are combined. The upper and lower molds are connected and locked by positioning pins and bolts located inside the frame. Step 5, Twisting: After the mold is closed, according to the mold closing section of the upper mold 7 and the lower mold 8, cut strips of prepreg of different widths in sequence, add them one by one to the twisting area until the V-shaped cavity is filled, and compact them; Step 6, Place the pressure pad: Place the rib end enveloping rib end pressure pad at rib end a position, place the rib edge strip pressure pad at rib edge c position, overlap the 15°~20° beveled area of ​​the pressure pad, and fix it with tape; Step 7, Vacuum bag making: Place the release film and breathable felt on the laid carbon fiber prepreg, and then make a vacuum bag; Step 8, Curing: Before entering the autoclave, check for vacuum leaks. Once the requirements are met, proceed with curing in the autoclave. Step 9, Demolding: After curing, first remove the rib end envelope pressure pad and rib edge strip pressure pad, then remove the part; Step 10, Cutting and Trimming: Use a pneumatic cutter to cut and trim the parts along the cutting line.

[0041] This invention provides a molding die and manufacturing method for an envelope-type composite material rib. The segmented pressure pad structure effectively improves the fit between the pressure pad and the part. The pressure pad joint section adopts a sloping overlap structure to suppress pressure pad slippage and cause web quality defects. It can effectively solve the problems of uneven pressure transmission and fiber buckling on the surface of the part during the manufacturing process of envelope-type composite material ribs, ensuring good internal quality and a smooth and defect-free surface of the part. It is used to achieve precise manufacturing and molding of envelope-type composite material ribs. The molding die can be used to lay up the upper and lower preforms of the composite material rib through the enveloping composite material rib molding die, and then form the enveloping composite material rib preform by closing the mold. Before making the vacuum bag, the enveloping rib end pressure pad prepared by the enveloping pressure pad molding die is fixed at the end position of the enveloping rib of the preform and secured with a release cloth. Two pressure pads prepared by the rib edge pressure pad molding die are placed on the outside of the rib edge strips on both sides of the preform. During the curing process of the preform, the three segmented pressure pads adhere to the relative structure of the preform to keep the outer surface of the enveloping composite material rib consistent with the theoretical surface and effectively and uniformly transfer the can pressure. The technical solution provided by this invention has the following beneficial effects: First, the molding die provided by the present invention uses a hard composite material pressure pad, which can effectively compact the twisting area of ​​the part and ensure the undamaged quality and surface quality of the twisting area.

[0042] Secondly, the pressure pad in the molding die provided by the present invention is segmented and the butt joint section adopts a sloping lap structure to improve the matching degree between the pressure pad and the part, suppress the pressure pad slippage that causes web quality defects. This structure can adapt to and improve the pressure pad mismatch problem caused by the deformation of the part during the curing process, eliminate the cavity between the pressure pad and the part, and effectively solve the problems of uneven pressure transmission and fiber buckling on the surface of the part during the manufacturing process of the envelope-type composite material rib.

[0043] While the embodiments disclosed in this invention are as described above, they are merely illustrative of the embodiments to facilitate understanding of the invention and are not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A molding die for an envelope-type composite material rib, characterized in that, The enveloping composite material rib (1) includes: a rib web a, rib flanges b fixedly connected to both sides of the rib web a, and an enveloping rib end c connected to one end of the two rib flanges b and forming an enveloping structure; the molding die includes: two sets of pressure pad molding dies and one set of enveloping composite material rib molding die. The two sets of pressure pad forming molds are an envelope-type pressure pad forming mold and a rib strip pressure pad forming mold, which are used to prepare an envelope-type rib end pressure pad through the envelope-type pressure pad forming mold and to prepare a rib strip pressure pad corresponding to the outer side of the two rib strips b through the rib strip pressure pad forming mold. The enveloping composite material rib forming mold includes an upper mold (7) and a lower mold (8); the upper mold (7) and the lower mold (8) are respectively designed based on the outer surface of the upper part and the lower part divided by the horizontal center plane of the enveloping composite material rib, and are used to lay the preforms of the upper part and the lower part respectively.

2. The molding die for the envelope-type composite material rib according to claim 1, characterized in that, The forming mold for the envelope-type composite material rib is used to lay the upper and lower preforms of the composite material rib through the forming mold and form the preform of the envelope-type composite material rib by closing the mold. Before making the vacuum bag, the pressure pad at the end of the envelope-type rib prepared by the forming mold is fixed at the end of the envelope-type rib of the preform with a release cloth. Two pressure pads prepared by the rib edge pressure pad forming mold are placed on the outside of the rib edge strips on both sides of the preform. During the curing process of the preform, the three segmented pressure pads adhere to the relative structure of the preform to keep the outer surface of the envelope-type composite material rib consistent with the theoretical surface and effectively and evenly transfer the can pressure.

3. The molding die for the envelope-type composite material rib according to claim 1, characterized in that, The enveloping pressure pad forming mold is used to simultaneously prepare multiple sets of enveloping rib end pressure pads. The enveloping pressure pad forming mold includes: a forming male mold (2) with a cross-section of a T-shaped structure, and handles (3) fixedly set at both ends of the forming male mold (2). The handles (3) are set as detachable structures and are connected to the forming male mold (2) by threads. They are removed before entering the can for curing. The cross section of the molding male mold (2) is prepared according to the cross section of the end of the envelope rib of the envelope composite material rib. The molding male mold (2) has a uniform cross section structure in its length direction. It is used to prepare a strip-shaped U-shaped envelope pressure pad by laying and curing the convex mold body, and cut it to form an envelope rib end pressure pad with the same width as the end of the envelope rib.

4. The molding die for the envelope-type composite material rib according to claim 1, characterized in that, The ribbed pressure pad forming mold includes: a forming mold body (4), a base (5), and a hanger (6); Among them, two identical molding molds (4) are fixedly set on the base (5), and hanging devices (6) are installed at the four corners of the base (5) to facilitate the handling of the tooling; The ribbed pressure pad forming mold is used to lay and cure two ribbed pressure pads respectively through two forming mold bodies (4).

5. The molding die for the envelope-type composite material rib according to any one of claims 1 to 4, characterized in that, In the enveloping composite material rib forming mold, both the upper mold (7) and the lower mold (8) are set as frame structures; The enveloping composite material rib forming mold further includes: cover plates (9) set on both ends of the upper mold (7) and the lower mold (8); by setting the cover plates (9), the shape of the enveloping composite material rib forming mold is maintained during the curing process of the preform, so as to prevent the vacuum bag from being sucked into the frame structure of the upper mold (7) and the lower mold (8) and thus causing air leakage and damage.

6. The molding die for the envelope-type composite material rib according to any one of claims 1 to 4, characterized in that, The prepared rib end pressure pad and the pressure pads of the two side rib strips are cut to form a sloping overlap structure. The sloping overlap structure inhibits the slippage of the rib end pressure pad and the pressure pads of the two side rib strips, which would cause quality defects in the side ribs.

7. The molding die for the envelope-type composite material rib according to claim 6, characterized in that, Both the rib end pressure pad and the rib edge pressure pad are made of rigid carbon fiber prepreg pressure pads; the cutting positions of the rib end pressure pad and the rib edge pressure pad are cut according to the curvature inflection point of the part, and the angle between the inclined planes of the mating sections of the rib end pressure pad and the two side rib edge pressure pads is 15°~20°.

8. A method for manufacturing an envelope-type composite material rib, characterized in that, The enveloping composite rib is prepared using a molding die according to any one of claims 1 to 7, and the manufacturing method includes: Step 1, Preparation of enveloping rib end pressure pad: The enveloping rib end pressure pad is prepared using an enveloping pressure pad molding die; Step 2, Preparation of ribbed pressure pad: The ribbed pressure pad is prepared using a ribbed pressure pad forming mold; Step 3, material laying: carbon fiber prepreg is laid on the upper mold (7) and lower mold (8) of the enveloping composite material rib forming mold according to the layup; Step 4, Mold assembly: After the paving is completed, the upper mold (7) and the lower mold (8) are combined. The upper and lower molds are connected and locked by positioning pins and bolts located inside the frame. Step 5, Twisting: After the mold is closed, according to the mold closing section of the upper mold (7) and the lower mold (8), cut prepreg strips of different widths in sequence, add them one by one to the twisting area until the V-shaped cavity is filled, and compact them; Step 6, Place pressure pads: Place the rib end envelope type rib end pressure pad and the rib edge strip pressure pad respectively, overlap the pressure pads with an angle of 15°~20°, and fix them with tape; Step 7, Vacuum bag making: Place the release film and breathable felt on the laid carbon fiber prepreg, and then make a vacuum bag; Step 8, Curing: Before entering the autoclave, check for vacuum leaks. Once the requirements are met, proceed with curing in the autoclave. Step 9, Demolding: Remove the part after curing; Step 10, Cutting and Trimming: Use a pneumatic cutter to cut and trim the parts along the cutting line.

9. The method for manufacturing the envelope-type composite material rib according to claim 8, characterized in that, Step 1 includes: Step 11, Material laying: Lay 6 layers of carbon fiber fabric prepreg on the surface 2 of the rib end envelope pressure pad forming mold; Step 12, Vacuum bag making: Place the release film and breathable felt on the laid carbon fiber prepreg, and then make a vacuum bag; Step 13, Curing: Before entering the autoclave, check for vacuum leaks. Once the requirements are met, proceed with curing in the autoclave. Step 14, Demolding: Remove the cured rib end envelope structure pressure pad from the surface 2 of the rib end envelope type pressure pad molding mold, and remove the burrs on the edge of the pressure pad with sandpaper. Step 15, Cutting: At the pressure pad division position, use a grinder, cutter and other tools to process the mating position of the rib end envelope type pressure pad into a bevel with an included angle of 15°~20°; at the non-pressure pad division position, use a grinder, cutter and other tools to cut the rib end envelope type pressure pad along the outer shape line of the rib end.

10. The method for manufacturing the envelope-type composite material rib according to claim 8, characterized in that, Step 2 includes: Step 21, Material laying: Lay 6 layers of carbon fiber prepreg on the surface 2 of the rib pressure pad forming mold; Step 22, making vacuum bags: Place the release film and breathable felt on the laid carbon fiber prepreg, and then make vacuum bags; Step 23, Curing: Before entering the autoclave, check for vacuum leaks. Once the requirements are met, proceed with curing in the autoclave. Step 24, Demolding: Remove the cured ribbed pressure pad from the surface 4 of the ribbed pressure pad molding mold, and remove the burrs on the edge of the pressure pad with sandpaper; Step 25, Cutting: At the pressure pad division position, use a grinder, cutter and other tools to process the mating position of the rib edge pressure pad into a bevel with an included angle of 15°~20°; at the non-pressure pad division position, use a grinder, cutter and other tools to cut the rib end envelope type pressure pad along the outer rib shape line. Step 26, check the status: At the pressure pad division position, check the beveled fit of the pressure pad of the rib end envelope structure and the pressure pad of the rib edge strip. If there is a gap, use sandpaper to sand and repair the fit until there is no gap.

Images