An eVTOL aircraft flat tail beam forming die

Abstract

The utility model discloses a kind of eVTOL aircraft flat tail beam forming die, including mould base, mould main part and drill die. Mould main part includes flat tail front beam mould main body and flat tail rear beam mould main body, and flat tail front beam mould main body and flat tail rear beam mould main body are all composed of fixed mould and several inserts. The fixed mould of flat tail front beam mould main body includes top plate and side plate, and the fixed mould of flat tail rear beam mould main body includes bottom plate fixed on the upper end surface of mould base. Insert is detachably arranged on top plate and bottom plate, and drill die is detachably arranged on top plate and bottom plate. The mould base and fixed mould of the utility model can be welded using sectional material or flat plate, then a small amount of machining is carried out, while the insert is divided into multiple sections, the size of each section is smaller, which can effectively reduce the size of raw material block, the processing amount is smaller, the cost is low, while the precision of small-size insert processing is also higher, and the precision of mould is high after splicing into a whole.

Description

Technical Field

[0001] This utility model relates to the field of molding die technology, specifically to a molding die for the horizontal tail boom of an eVTOL aircraft. Background Technology

[0002] eVTOL (Electric Vertical Takeoff and Landing) aircraft can take off and land vertically, eliminating the need for long runways and enabling takeoff and landing operations within limited spaces. This significantly improves the flexibility and accessibility of air transport, making them suitable for scenarios such as urban air mobility. Powered by electricity, they produce no pollutants such as carbon dioxide and nitrogen oxides during operation, meeting the zero-carbon vision and environmental requirements. They also significantly reduce noise, enhancing the passenger experience and comfort. The overall configuration allows for various innovative integrated aerodynamic propulsion designs and unconventional aerodynamic layouts, including multi-rotor, compound, and vector propulsion types, to meet diverse travel needs. Their structure is relatively simple, maintenance requirements are low, and electricity costs are typically lower than fuel costs, suggesting the potential for lower operating costs after large-scale commercial operation.

[0003] The horizontal stabilizer spars of eVTOL aircraft are generally made of carbon fiber composite materials. Therefore, molds are required to lay the carbon fiber prepreg on the molds and then heat, pressurize, and vacuum cure them. The front and rear spars of the eVTOL aircraft's horizontal stabilizer run through the entire horizontal stabilizer. Following the shape trend of the eVTOL aircraft's horizontal stabilizer, it is a three-dimensional structure, and the parts have negative demolding angles. When designing the molds, it is necessary to consider the requirements of low cost, high quality, and fast production pace. Priority is given to using a common mold for the front and rear spars of the eVTOL aircraft's horizontal stabilizer, producing two parts at a time to meet the requirements of a single aircraft.

[0004] Reference 1: Chinese patent document with publication number CN115609802A.

[0005] Reference 1 discloses a molding die and molding method for a composite material beam. The front beam of a helicopter tail section has a complex shape, numerous assembly surfaces, high precision requirements, and is difficult to demold. The molding die of this invention includes a main mold body assembly, an upper mold body assembly, and a side plate assembly. The main mold body assembly consists of a main mold body, a right main mold body segment, and a left main mold body segment. The main mold body includes a base plate and protruding structures on the base plate. The upper mold body assembly consists of an upper mold body, a left upper mold segment, and a right upper mold segment. The left and right upper mold segments, after being combined with the upper mold body on both sides, form an overall shape that matches the groove shape on the other side of the front beam and is slightly smaller in size. The side plate assembly consists of a left side plate and a right side plate, which have the shape of the side of the front beam. This ensures precise machining of the part's shape and meets the precision requirements for product dimensions. Simultaneously, the mold assembly and disassembly process is convenient, resulting in high processing efficiency.

[0006] However, the above mold is composed of many modules, which are relatively complex to combine and have many assembly sequences. When molding large three-dimensional parts, it will face problems such as large individual block size, large amount of main mold processing and large amount of raw materials used. Utility Model Content

[0007] The purpose of this invention is to solve the above-mentioned technical problems existing in the prior art and to provide a molding die for the horizontal tail boom of an eVTOL aircraft.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a molding die for an eVTOL aircraft horizontal tail boom, comprising a die base, a die body, and a drill jig.

[0009] The mold body includes a flat tail front beam mold body and a flat tail rear beam mold body, both of which are composed of a fixed mold and several inserts.

[0010] The fixed mold of the flat tail front beam mold body includes a top plate and side plates. The top plate includes a central horizontal section and inclined sections located at both ends of the central horizontal section along its length. The two side plates are respectively set on both sides of the top plate to provide support for the top plate.

[0011] The fixed mold of the flat tail rear beam mold body includes a base plate fixed to the upper end face of the mold base;

[0012] The insert is detachably mounted on the top plate and the bottom plate, and the insert is provided with a first fixing hole and a first positioning hole;

[0013] The drill jig is detachably mounted on the top plate and the bottom plate, and the drill jig is provided with a second fixing hole, a second positioning hole and a drill bit guide hole.

[0014] As a further optimization of the eVTOL aircraft horizontal tail boom forming mold of this utility model: the mold base is a steel frame structure welded from steel profiles and steel plates.

[0015] As a further optimization of the eVTOL aircraft horizontal tail beam forming mold of this utility model: the fixed mold of the main body of the horizontal tail beam mold also includes a support plate, which is set in the cavity surrounded by the top plate and the side plate and connected to the bottom surface of the top plate.

[0016] As a further optimization of the eVTOL aircraft horizontal tail boom forming mold of this utility model: the upper surface of the top plate and the bottom plate are provided with a web plate whose shape is adapted to the aircraft horizontal tail boom, and a number of inserts are arranged around the web plate.

[0017] As a further optimization of the eVTOL aircraft horizontal tail beam forming mold of this utility model: the side plate of the main body of the horizontal tail beam mold is provided with a vacuum bag sealing area.

[0018] As a further optimization of the eVTOL aircraft horizontal tail boom forming mold of this utility model: the side plate is provided with ventilation holes.

[0019] As a further optimization of the eVTOL aircraft horizontal tail beam forming mold of this utility model: the top plate and the bottom plate are provided with screw holes around the web plate, the insert is detachably connected to the top plate and the bottom plate by bolts, and the drill jig is detachably connected to the top plate and the bottom plate by bolts.

[0020] As a further optimization of the eVTOL aircraft horizontal tail beam forming mold of this utility model: the drill mold is a gantry structure, which forms an insert avoidance area inside. The two side walls of the drill mold extend outward and are provided with support plates. The second fixing hole and the second positioning hole are set on one of the support plates, and the drill bit guide hole is set on the other support plate.

[0021] As a further optimization of the eVTOL aircraft horizontal tail beam forming mold of this utility model: the main body of the horizontal tail front beam mold has 24 inserts.

[0022] As a further optimization of the eVTOL aircraft horizontal tail boom forming mold of this utility model: the material of the insert is 6061 aluminum alloy.

[0023] This utility model has the following beneficial effects:

[0024] 1. The mold base of this utility model is made of metal profiles and metal plates welded together, with gaps between the profiles. When the parts are solidified, hot air can flow effectively between the metal profiles to heat the mold base and the mold body, making the heating uniform and the surface temperature of the parts more uniform, which is beneficial to product molding.

[0025] 2. The mold body of this utility model is welded to the flat plate of the mold base. During curing, a vacuum bag wraps the mold body and parts inside. The flat plate area of ​​the mold base 1 on the outside of the mold body is the sealing area of ​​the vacuum bag. The entire sealing strip is sealed on the flat surface, which can effectively prevent air leakage. At the same time, ventilation holes are designed on the side plate of the mold body to discharge the gas inside the fixed mold welded from the steel plate, so that the product can be better compacted and the quality of the molded product is good.

[0026] 3. The mold base and the fixed mold of this utility model are both welded from profiles or flat plates and then machined in a small amount. At the same time, the insert is divided into multiple segments, making the size of each segment smaller. This can effectively reduce the size of the raw material block. The smaller size also means less processing and lower cost. The small-sized insert is also processed with higher precision. After being assembled into a whole, the mold has high precision. Attached Figure Description

[0027] Figure 1 This is an isometric view of the molding die of this utility model;

[0028] Figure 2 This is an exploded view of the molding die of this utility model;

[0029] Figure 3 This is an exploded view of the main body of the mold in the molding die of this utility model;

[0030] Figure 4 This is an isometric view of the upper part of the fixed mold in the molding die of this utility model;

[0031] Figure 5 This is an isometric view of the lower part of the fixed mold in the molding die of this utility model;

[0032] Figure 6 This is an isometric view of the insert in the molding die of this utility model;

[0033] Figure 7 This is an isometric view of the drill jig in the molding die of this utility model;

[0034] Figure 8 This is a cross-sectional view of the main body of the mold in the molding die of this utility model;

[0035] The diagram is labeled as follows: 1. Mold base; 2. Mold body; 21. Fixed mold; 211. Top plate; 212. Side plate; 213. Insert fixing area; 214. Support plate; 215. Bottom plate; 22. Insert; 221. First fixing hole; 222. First positioning hole; 3. Drill jig; 31. Drill bit guide hole; 32. Second positioning hole; 33. Second fixing hole; 34. Insert clearance area. Detailed Implementation

[0036] To better understand this utility model, the following embodiments further illustrate the content of this utility model, but the content of this utility model is not limited to the following embodiments.

[0037] like Figure 1-3 As shown, an eVTOL aircraft horizontal tail boom forming mold consists of a mold base 1, a mold body 2, and a drill jig 3. The mold base 1 serves as the support for the entire mold, giving the mold body 2 a certain height, which facilitates the laying of carbon fiber prepreg by workers during the horizontal tail boom forming process.

[0038] The mold base 1 is a hollow structure welded from steel profiles and steel plates. The steel profiles support the steel plates, bear the pressure of the mold body 2, and keep the upper steel plates flat. The steel profiles of the mold base 1 are made of Q235 steel, and the steel plates are made of 45# steel.

[0039] The mold body 2 includes a front tail beam mold body and a rear tail beam mold body, both of which are composed of a fixed mold 21 and several inserts 22. The fixed mold 21 of the front tail beam mold body includes a top plate 211 and side plates 212. The top plate 211 includes a horizontal section in the middle and inclined sections located at both ends of the horizontal section in the length direction. The two side plates 212 are respectively arranged on both sides of the top plate 211 to provide support for the top plate 211. The fixed mold 21 of the rear tail beam mold body includes a bottom plate 215 fixed to the upper surface of the mold base 1.

[0040] The mold body 2 is welded to the steel plate of the mold base 1. The steel plate is larger than the mold body 2, and a large flat area is reserved on the outside of the mold body 2. This allows the vacuum bag to seal this area during molding, ensuring that the entire mold body 2 is inside the vacuum bag and reducing the risk of air leakage. The drill jig 3 is a detachable structure. It can be disassembled during part molding without hindering the part molding process. After the part has cured, the drill jig is installed to drill holes in the part. The drilling positions are relatively precise and serve as positioning holes for the next assembly process, positioning the flat tail beam to ensure that the flat tail beam is installed in the correct position. In this example, a single mold is used to mold the front and rear beams of the flat tail, which can effectively improve production efficiency and save raw material dimensions. Since the shapes of the front and rear beams are similar, this example only describes the front beam of the flat tail; the structure of the rear beam is similar.

[0041] Because the flat-tail beam is a three-dimensional structure, the mold needs to be designed to conform to its shape. To save costs, the fixed mold 21 is a three-dimensional structure welded from multiple steel plates. The inserts are divided into multiple parts, which reduces the size of each insert, saving raw material size and CNC machining. In this example, the front beam mold inserts are divided into 24 pieces, which solves the problem of the flat-tail front beam being demolded and undercut, while saving costs. The individual inserts are small in size and have high machining accuracy. After assembly, the overall mold accuracy is high. In this example, the inserts are made of aluminum alloy. Since aluminum alloy is relatively soft, the machining cost is low. The preferred aluminum alloy material is 6061, and the preferred heat treatment state is T3. Considering the difference in thermal expansion coefficients between aluminum alloy and steel, the inserts 22 and the fixed mold 21 in this example are scaled according to their respective thermal expansion coefficients and the difference between room temperature and curing temperature, so that the theoretical size is achieved during molding.

[0042] like Figure 4 and 5As shown, the fixed mold 21 is welded from steel plates 211, 212, and 214. In this example, the steel plates are 45# steel. Considering that there may be gaps in the weld during welding, the air inside the cavity formed by the top plate 211, side plate 212, support plate 214 and mold base 1 may slowly leak. If the gap is very small, the leakage rate will be very slow. When the mold body 2 is wrapped inside a vacuum bag and vacuuming is performed, the vacuum level will not meet the standard, causing defects in the parts. Therefore, a vent hole is designed on the side plate 212 so that the enclosed gas can be quickly removed during vacuuming. Considering the negative pressure of vacuuming the vacuum bag and the fact that the vacuum bag is soft, if the vent hole is designed to be too large, it may suck the vacuum bag into the hole, damaging the vacuum bag and causing leakage. Therefore, in order to achieve a balance between venting and protecting the vacuum bag, the diameter of the hole should not be too large or too small. In this example, the diameter is 6mm. To conform to the shape of the horizontal tail beam, the top plate 211 is made of steel plate that has been bent and then CNC machined to ensure a tight fit with the insert 22. This reduces the amount of machining required and saves on processing costs. The top plate 211 has an insert fixing area 213, which is fixed to the insert 22 with bolts. The holes on the top plate 211 that connect to the bolts are threaded to facilitate thread engagement with the bolts.

[0043] like Figure 6 As shown, the insert 22 is fixed to the fixed mold 21 by bolts (not shown), and positioned by locating pins (not shown). The insert 22 has a first fixing hole 221 and a first positioning hole 222. The first fixing hole 221 is for bolt connection, and the first positioning hole 222 is for locating pin connection. During demolding, the bolts are removed, allowing the insert 22 to be separated from the fixed mold 21, and then the insert 22 can be separated from the flat-tail front beam. The main body shape of the insert 22 is machined according to the shape of the flat-tail front beam in the area where the insert 22 is located.

[0044] like Figure 7 As shown, the fixing method of drill jig 3 is similar to that of insert 22. It is designed with a second fixing hole 33 and a second positioning hole 32, which are connected to bolts and positioning pins. The drill bit guide hole 31 is designed according to the coordinates of the positioning points required for the next assembly process. After the part is formed, the drill bit is used to process the part along the drill bit guide hole 31 to ensure the accurate position of the machined hole and meet the assembly positioning requirements. Simultaneously, according to the shape of insert 22, an insert clearance area 34 is designed to prevent interference with insert 22 during installation. During drilling, torque is applied to the hole; therefore, positioning pins and bolts are required for fixing, at least two, to prevent the drill jig position from shifting during drilling. Drill jig 3 is machined from a steel block, and the material is 45# steel.

[0045] like Figure 8As shown, in order to reduce the amount of machining required for the insert 22, the mold surface of the flat-tail front beam formed by the insert 22 and the top plate 211 is divided into two sections on both sides of the web plate. The web plate is a small step extending from the top plate 211. In this way, as long as the outer side of the step of the top plate 211 is machined to a very shallow depth, the width of the insert 22 can be reduced. After being combined with the small step, the surface of the flat-tail front beam is formed. Considering that the vacuum bag wraps the mold body 2 inside, there is no need to worry about air leakage at the seam.

[0046] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this utility model.

Claims

1. A molding die for forming the horizontal tail boom of an eVTOL aircraft, characterized in that: Includes mold base (1), mold body (2), and drill jig (3): The mold body (2) includes a flat-tail front beam mold body and a flat-tail rear beam mold body. Both the flat-tail front beam mold body and the flat-tail rear beam mold body are composed of a fixed mold (21) and several inserts (22). The fixed mold (21) of the main body of the flat tail front beam mold includes a top plate (211) and side plates (212). The top plate (211) includes a middle horizontal section and inclined sections located at both ends of the length direction of the middle horizontal section. The two side plates (212) are respectively set on both sides of the top plate (211) to provide support for the top plate (211). The fixed mold (21) of the main body of the flat tail beam mold includes a base plate (215) fixed to the upper end face of the mold base (1); The insert (22) is detachably mounted on the top plate (211) and the bottom plate (215), and the insert (22) is provided with a first fixing hole (221) and a first positioning hole (222); The drill jig (3) is detachably mounted on the top plate (211) and the bottom plate (215). The drill jig (3) is provided with a second fixing hole (33), a second positioning hole (32) and a drill bit guide hole (31).

2. The eVTOL aircraft horizontal tail boom forming mold as described in claim 1, characterized in that: The mold base (1) is a steel frame structure welded from steel profiles and steel plates.

3. The eVTOL aircraft horizontal tail boom forming mold as described in claim 1, characterized in that: The fixed mold (21) of the flat tail front beam mold body (2) also includes a support plate (214), which is set in the cavity surrounded by the top plate (211) and the side plate (212) and is connected to the bottom surface of the top plate (211).

4. The eVTOL aircraft horizontal tail boom forming mold as described in claim 1, characterized in that: The top plate (211) and the bottom plate (215) are both provided with a web plate whose shape is adapted to the horizontal tail beam of the aircraft, and a number of inserts (22) are arranged around the web plate.

5. The eVTOL aircraft horizontal tail boom forming mold as described in claim 1, characterized in that: The side plate (212) of the main body of the flat tail front beam mold is provided with a vacuum bag sealing area.

6. The eVTOL aircraft horizontal tail boom forming mold as described in claim 5, characterized in that: The side plate (212) is provided with ventilation holes.

7. The eVTOL aircraft horizontal tail boom forming mold as described in claim 4, characterized in that: The top plate (211) and bottom plate (215) are provided with screw holes around the web. The insert (22) is detachably connected to the top plate (211) and bottom plate (215) by bolts. The drill jig (3) is detachably connected to the top plate (211) and bottom plate (215) by bolts.

8. The eVTOL aircraft horizontal tail boom forming mold as described in claim 1, characterized in that: The drill jig (3) is a gantry structure with an insert clearance area (34) inside. The two side walls of the drill jig (3) extend outward and are provided with support plates. The second fixing hole (33) and the second positioning hole (32) are provided on one of the support plates, and the drill bit guide hole (31) is provided on the other support plate.

9. The eVTOL aircraft horizontal tail boom forming mold as described in claim 1, characterized in that: The main body of the flat-tail front beam mold has 24 inserts (22).

10. The eVTOL aircraft horizontal tail boom forming mold as described in claim 1, characterized in that: The material of the insert (22) is 6061 aluminum alloy.

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