A wet winding method for a composite shell of a rain enhancement and hail suppression projectile engine

Abstract

The application discloses a wet winding method for a rain enhancement and hail prevention bomb engine composite shell, and relates to the technical field of winding processes.The shell thread part is directly integrally formed on a mold through a mold with threads; bidirectional carbon fiber cloth is adopted in the middle winding process of the thread part, the strength of the thread part is improved, and a stepped angle spiral winding process is adopted; the winding gap of z1 is filled by z2 winding, the winding gap of z2 is filled by z3 winding, the shell stiffness is improved with the change of the angle, and the wet winding method for the rain enhancement and hail prevention bomb engine composite shell can make the obtained shell bear 18MPa strength in a static test, even reach 21MPa, and ensure the strength and quality of the shell, so that the shell will not be broken or appear pressure leakage during the launching of the rain enhancement and hail prevention bomb.

Description

Technical Field

[0001] This invention relates to the field of winding technology, specifically a wet winding method for a composite casing of a rain-inducing and hail-prevention projectile engine. Background Technology

[0002] In meteorological bureaus' rain enhancement operations, rain-enhancing and hail-suppressing munitions are required. The engine casing stamping device is a key structural component of these munitions, responsible for containing the propellant combustion and generating high-temperature expanding gases. These expanding gases are accelerated through engine spraying, thereby generating thrust for the rain-enhancing and hail-suppressing munitions. The casing is required to have high tensile strength, good heat resistance, and lightweight characteristics.

[0003] The pressure generated by the combustion of the tail flame of rain-inducing and hail-suppressing projectiles is 12-16 MPa. The pressure generated by the longitudinal combustion of the tail flame in the shell is mainly supported by the longitudinal strength of the shell. If the longitudinal strength is insufficient, there is a risk of shell breakage. In order to ensure the strength and quality of the shell, the design strength of the shell generally needs to reach 1.5 times the maximum pressure of the tail flame jet, so that the shell can withstand the strength requirement of 18 MPa. However, the current rain-inducing and hail-suppressing projectile engine shell requires threaded connection at both ends, and the strength at the threaded part of the shell is the weakest, generally only reaching 0.75 times that of the pure shell. Therefore, how to enhance the strength at the threaded part and obtain a rain-inducing and hail-suppressing projectile engine shell with high overall strength has become the key to prevent pressure leakage in the shell.

[0004] The existing molds for the composite housing of rain-inducing and hail-preventing projectile engines are all uniform cylinders. After demolding, the housing needs to be machined to form threads. Taking a 10mm thick housing as an example, the housing is machined with a 2.3mm thick thread with a length of 36mm. The strength of the housing at the threaded part decreases by about 25%, which seriously affects the overall strength of the composite housing. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a wet winding method for the composite casing of a rain-enhancing and hail-prevention projectile engine.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] A wet winding method for a composite casing of a rain-inducing and hail-prevention projectile engine includes the following steps:

[0008] ① Prepare a mold, the mold including a cylindrical shaft, the cylindrical shaft having external threads at both ends;

[0009] ② Wrap glass fiber around the threaded area to fill the unevenness of the threaded area, and obtain the threaded connection filling circumferential layer 11;

[0010] ③ An ablation-resistant layer 12 is laid on the cylindrical shaft within the threads at both ends. The ablation-resistant layer 12 is composed of glass fiber and an ablation-resistant substrate sprayed on the glass fiber. The thickness of the glass fiber is 0.12-0.18 mm, and the thickness of the ablation-resistant layer is 0.6-0.9 mm. The material of the ablation-resistant substrate layer is a modified epoxy resin coating.

[0011] ④ Glass fiber is wound circumferentially on the ablation-resistant substrate to achieve a flatness error of ≤0.1mm at the threaded part, thus obtaining the first circumferential compression layer 13;

[0012] ⑤ The mold is spirally wound with glass fiber at an angle of z1 = 45 to 50°. After completion, the mold is circumferentially wound with glass fiber to compact and fill the circumferential gap, thus obtaining the first spiral layer 14.

[0013] ⑥ Lay a layer of bidirectional carbon fiber cloth along the circumferential winding direction at both sides of the thread to obtain the bidirectional carbon fiber cloth layer 15 at the thread; use glass fiber to circumferentially wind and compact the mold to obtain the second circumferential compression layer 16.

[0014] ⑦ Wrap the mold with glass fiber at an angle of z2 = 45 to 40° for 2 layers to obtain the second spiral layer 17. After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the third circumferential compression layer 18.

[0015] ⑧ Wrap the mold with glass fiber at an angle of z3 = 35~30° for 2 layers to obtain the third spiral layer 19. After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the fourth circumferential compression layer 20.

[0016] In steps ⑤, ⑦, and ⑧, z1 > z2 > z3;

[0017] ⑨ Use glass fiber to circumferentially compress the threaded area to obtain the threaded compression layer 21.

[0018] Preferably, the mold includes a mold body 1 and a threaded sleeve 2. The mold body 1 includes two cylinders with different diameters. The end of the larger diameter cylinder away from the smaller diameter cylinder is provided with a first external thread 3. The outer diameter of the threaded sleeve 2 is the same as the outer diameter of the larger diameter cylinder of the mold body 1. The inner diameter of the threaded sleeve 2 matches the outer diameter of the smaller diameter cylinder of the mold body 1. The threaded sleeve 2 is fitted around the outer periphery of the smaller diameter cylinder of the mold body 1. The side of the threaded sleeve 2 closest to the larger diameter cylinder of the mold body 1 is provided with a second external thread 4.

[0019] Preferably, the biaxial carbon fiber cloth has a specification of 200g-T450. 200g is the weight per square meter of the biaxial carbon fiber cloth, and T450 is the maximum tensile strength of 4500MPa.

[0020] Preferably, in step ⑥, the biaxial carbon fiber cloth extends longitudinally for another 55-65 mm towards the root of the thread.

[0021] Preferably, the glass fiber has a specification of 50g. The weight of the glass fiber per square meter is 50g.

[0022] Preferably, z1-z2 > 3°, z2-z3 > 3°.

[0023] Preferably, z1 = 45°, z2 = 40°, and z3 = 35°.

[0024] The present invention has the following advantages over the prior art:

[0025] The wet winding method for the composite casing of the rain-inducing and hail-suppressing projectile engine of the present invention produces a casing that can withstand a strength of 18MPa, or even up to 21MPa, in static tests, ensuring the strength and quality of the casing. When the rain-inducing and hail-suppressing projectile is launched, the casing will not break or leak pressure.

[0026] The wet winding method for the composite casing of the rain-enhancing and hail-suppressing projectile engine of the present invention firstly uses a threaded mold to integrally form the threaded part of the casing directly on the mold, which improves the strength of the threaded part. The integral winding of the thread solves the strength damage problem caused by machining the thread. The strength of the casing thread is increased by about 10% compared with the strength of the machined thread. Secondly, bidirectional carbon fiber cloth is used in the intermediate winding process of the threaded part to improve the strength of the threaded part. Furthermore, a stepped angle spiral winding process is adopted. By changing the angle of the winding direction z1-z2-z3, the winding gap of z2 fills the winding gap of z1, and the winding gap of z3 fills the winding gap of z2. With the change of angle, the rigidity of the casing is improved. Finally, the casing is layered with circumferential and spiral layers by a winding machine, which has high tension. The stepped spiral winding is used to make up the gap of each longitudinal winding layer, and the circumferential winding is used to compact the spiral winding and prevent the finished casing from having leakage pressure. Attached Figure Description

[0027] Figure 1 A 3D view of the mold;

[0028] Figure 2 for Figure 1 The main view;

[0029] Figure 3 This is a perspective view of the composite housing and mold of the rain-enhancing and hail-preventing projectile engine after wet winding according to the present invention;

[0030] Figure 4 for Figure 3 The main view;

[0031] Figure 5A three-dimensional view of the composite casing of the rain-inducing and hail-preventing projectile engine after the mold has been removed;

[0032] Figure 6 for Figure 4 Enlarged view of section I in the middle.

[0033] Figure label:

[0034] 1. Mold body; 2. Threaded sleeve; 3. First external thread; 4. Second external thread; 5. Composite housing of rain-inducing and hail-preventing projectile engine; 11. Threaded connection filling circumferential layer; 12. Ablation-resistant layer; 13. First circumferential compression layer; 14. First spiral layer; 15. Bidirectional carbon fiber cloth layer at the thread; 16. Second circumferential compression layer; 17. Second spiral layer; 18. Third circumferential compression layer; 19. Third spiral layer; 20. Fourth circumferential compression layer; 21. Threaded compression layer. Detailed Implementation

[0035] The purpose of this invention is to provide a wet winding method for the composite casing of a rain-enhancing and hail-suppressing projectile engine, which is achieved through the following technical solution:

[0036] A wet winding method for a composite casing of a rain-inducing and hail-prevention projectile engine includes the following steps:

[0037] ① Prepare a mold, the mold including a cylindrical shaft, the cylindrical shaft having external threads at both ends;

[0038] ② Wrap glass fiber around the threaded area to fill the unevenness of the threaded area, and obtain the threaded connection filling circumferential layer 11;

[0039] ③ An ablation-resistant layer 12 is laid on the cylindrical shaft within the threads at both ends. The ablation-resistant layer 12 is composed of glass fiber and an ablation-resistant substrate sprayed on the glass fiber. The thickness of the glass fiber is 0.12-0.18 mm, and the thickness of the ablation-resistant layer is 0.6-0.9 mm. The material of the ablation-resistant substrate layer is a modified epoxy resin coating.

[0040] ④ Glass fiber is wound circumferentially on the ablation-resistant substrate to achieve a flatness error of ≤0.1mm at the threaded part, thus obtaining the first circumferential compression layer 13;

[0041] ⑤ The mold is spirally wound with glass fiber at an angle of z1 = 45 to 50°. After completion, the mold is circumferentially wound with glass fiber to compact and fill the circumferential gap, thus obtaining the first spiral layer 14.

[0042] ⑥ Lay a layer of bidirectional carbon fiber cloth along the circumferential winding direction at both sides of the thread to obtain the bidirectional carbon fiber cloth layer 15 at the thread; use glass fiber to circumferentially wind and compact the mold to obtain the second circumferential compression layer 16.

[0043] ⑦ Wrap the mold with glass fiber at an angle of z2 = 45 to 40° for 2 layers to obtain the second spiral layer 17. After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the third circumferential compression layer 18.

[0044] ⑧ Wrap the mold with glass fiber at an angle of z3 = 35~30° for 2 layers to obtain the third spiral layer 19. After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the fourth circumferential compression layer 20.

[0045] In steps ⑤, ⑦, and ⑧, z1 > z2 > z3;

[0046] ⑨ Use glass fiber to circumferentially compress the threaded area to obtain the threaded compression layer 21.

[0047] Preferably, the mold includes a mold body 1 and a threaded sleeve 2. The mold body 1 comprises two cylinders with different diameters. The end of the larger diameter cylinder away from the smaller diameter cylinder has a first external thread 3. The outer diameter of the threaded sleeve 2 is the same as the outer diameter of the larger diameter cylinder of the mold body 1, and the inner diameter of the threaded sleeve 2 matches the outer diameter of the smaller diameter cylinder of the mold body 1. The threaded sleeve 2 is fitted onto the outer circumference of the smaller diameter cylinder of the mold body 1. A second external thread 4 is provided on the side of the threaded sleeve 2 closest to the larger diameter cylinder of the mold body 1. This two-part mold design is ingenious and facilitates demolding.

[0048] Preferably, the biaxial carbon fiber cloth has a specification of 200g-T450. 200g is the weight per square meter of the biaxial carbon fiber cloth, T450 is the maximum tensile strength of 4500MPa, the length can cover the thread length and extend it by 50mm, and the width can cover a circumference of the mold, so that the strength of the threaded part is greatly improved.

[0049] Preferably, in step ⑥, the biaxial carbon fiber cloth extends longitudinally for another 55-65mm to the root of the thread; in this way, the biaxial carbon fiber cloth can cover part of the root of the thread, and when the rain-inducing and hail-preventing projectile is launched, the root of the housing thread will not break, thus ensuring that the quality of the engine housing will not endanger personal safety.

[0050] Preferably, the glass fiber has a specification of 50g, and the weight of the glass fiber per square meter is 50g.

[0051] Preferably, z1-z2 > 3°, and z2-z3 > 3°. The greater the difference in gradient angles, the greater the final shell strength, and the better the results in the static pressure test.

[0052] Preferably, z1 = 45°, z2 = 40°, and z3 = 35°.

[0053] The present invention will be further described below with reference to specific embodiments.

[0054] The modified epoxy resin coating used in this invention can be any general-purpose modified epoxy resin ablation resistant coating.

[0055] Example 1

[0056] A wet winding method for a composite casing of a rain-inducing and hail-prevention projectile engine includes the following steps:

[0057] ① Prepare a mold, the mold including a cylindrical shaft, the cylindrical shaft having external threads at both ends;

[0058] ② Wrap glass fiber around the threaded area to fill the unevenness of the threaded area, and obtain the threaded connection filling circumferential layer 11;

[0059] ③ An ablation-resistant layer 12 is laid on the cylindrical shaft within the outer circumferential threads at both ends. The ablation-resistant layer 12 is composed of glass fiber and an ablation-resistant substrate sprayed on the glass fiber. The thickness of the glass fiber is 0.12 mm, and the thickness of the ablation-resistant layer 12 is 0.6 mm. The material of the ablation-resistant substrate layer is a modified epoxy resin coating.

[0060] ④ Glass fiber is wound circumferentially on the ablation-resistant substrate to achieve a flatness error of ≤0.1mm at the threaded part, thus obtaining the first circumferential compression layer 13;

[0061] ⑤ The mold is spirally wound with glass fiber at an angle of z1 = 50°. After completion, the mold is circumferentially wound with glass fiber to compact and fill the circumferential gap, thus obtaining the first spiral layer 14.

[0062] ⑥ Lay a layer of bidirectional carbon fiber cloth along the circumferential winding direction at both sides of the thread to obtain the bidirectional carbon fiber cloth layer 15 at the thread; use glass fiber to circumferentially wind and compact the mold to obtain the second circumferential compression layer 16.

[0063] ⑦ Wrap the mold with glass fiber at an angle of z2 = 45° for 2 layers to obtain the second spiral layer 17. After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the third circumferential compression layer 18.

[0064] ⑧ Wrap the mold with glass fiber at an angle of z3 = 35° for 2 layers to obtain the third spiral layer 19. After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the fourth circumferential compression layer 20.

[0065] ⑨ Use glass fiber to circumferentially compress the threaded area to obtain the threaded compression layer 21.

[0066] Example 2

[0067] A wet winding method for a composite casing of a rain-inducing and hail-prevention projectile engine includes the following steps:

[0068] ① Prepare a mold, the mold including a cylindrical shaft, the cylindrical shaft having external threads at both ends;

[0069] ② Wrap glass fiber around the threaded area to fill the unevenness of the threaded area, and obtain the threaded connection filling circumferential layer 11;

[0070] ③ An ablation-resistant layer 12 is laid on the cylindrical shaft within the outer circumferential threads at both ends. The ablation-resistant layer 12 is composed of glass fiber and an ablation-resistant substrate sprayed on the glass fiber. The thickness of the glass fiber is 0.18 mm, and the thickness of the ablation-resistant layer is 0.9 mm. The material of the ablation-resistant substrate layer is a modified epoxy resin coating.

[0071] ④ Glass fiber is wound circumferentially on the ablation-resistant substrate to achieve a flatness error of ≤0.1mm at the threaded part, thus obtaining the first circumferential compression layer 13;

[0072] ⑤ The mold is spirally wound with glass fiber at an angle of z1 = 45°. After completion, the mold is circumferentially wound with glass fiber to compact and fill the circumferential gap, thus obtaining the first spiral layer 14.

[0073] ⑥ Lay a layer of bidirectional carbon fiber cloth along the circumferential winding direction at both sides of the thread to obtain the bidirectional carbon fiber cloth layer 15 at the thread; use glass fiber to circumferentially wind and compact the mold to obtain the second circumferential compression layer 16.

[0074] ⑦ Wrap the mold with glass fiber at an angle of z2 = 40° for 2 layers to obtain the second spiral layer 17. After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the third circumferential compression layer 18.

[0075] ⑧ Wrap the mold with glass fiber at an angle of z3 = 30° for 2 layers to obtain the third spiral layer 19. After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the fourth circumferential compression layer 20.

[0076] ⑨ Use glass fiber to circumferentially compress the threaded area to obtain the threaded compression layer 21.

[0077] Example 3

[0078] A wet winding method for the composite casing of a rain-enhancing and hail-prevention projectile engine, such as... Figures 1-4 , Figure 6 As shown, it includes the following steps:

[0079] ① Prepare the mold, such as Figures 1-2As shown, the mold includes a mold body 1 and a threaded sleeve 2. The mold body 1 includes two cylinders with different diameters. The end of the larger diameter cylinder away from the smaller diameter cylinder is provided with a first external thread 3. The outer diameter of the threaded sleeve 2 is the same as the outer diameter of the larger diameter cylinder of the mold body 1. The inner diameter of the threaded sleeve 2 matches the outer diameter of the smaller diameter cylinder of the mold body 1. The threaded sleeve 2 is fitted around the outer circumference of the smaller diameter cylinder of the mold body 1. The side of the threaded sleeve 2 closest to the larger diameter cylinder of the mold body 1 is provided with a second external thread 4.

[0080] ② Wrap glass fiber around the threaded area to fill the unevenness of the threaded area, and obtain the threaded connection filling circumferential layer 11;

[0081] ③ An ablation-resistant layer 12 is laid on the cylindrical shaft within the outer circumferential threads at both ends. The ablation-resistant layer 12 is composed of glass fiber and an ablation-resistant substrate sprayed on the glass fiber. The thickness of the glass fiber is 0.15 mm, and the thickness of the ablation-resistant layer is 0.7 mm. The material of the ablation-resistant substrate layer is a modified epoxy resin coating.

[0082] ④ Glass fiber is wound circumferentially on the ablation-resistant substrate to achieve a flatness error of ≤0.1mm at the threaded part, thus obtaining the first circumferential compression layer 13;

[0083] ⑤ The mold is spirally wound with glass fiber at an angle of z1 = 46°. After completion, the mold is circumferentially wound with glass fiber to compact and fill the circumferential gap, thus obtaining the first spiral layer 14.

[0084] ⑥ Lay a layer of bidirectional carbon fiber cloth along the circumferential winding direction at both sides of the thread, and extend it longitudinally for 60mm to the root of the thread to obtain the bidirectional carbon fiber cloth layer 15 at the thread; use glass fiber to circumferentially wind and compact the mold to obtain the second circumferential compression layer 16.

[0085] ⑦ Wrap the mold with glass fiber at an angle of z2 = 41° for 2 layers to obtain the second spiral layer 17. After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the third circumferential compression layer 18.

[0086] ⑧ Wrap the mold with glass fiber at an angle of z3 = 34° for 2 layers to obtain the third spiral layer 19. After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the fourth circumferential compression layer 20.

[0087] ⑨ Use glass fiber to circumferentially compress the threaded area to obtain the threaded compression layer 21.

[0088] Example 4

[0089] A wet winding method for the composite casing of a rain-enhancing and hail-prevention projectile engine, such as... Figures 1-4 , Figure 6 As shown, it includes the following steps:

[0090] ① Prepare the mold, such as Figures 1-2 As shown, the mold includes a mold body 1 and a threaded sleeve 2. The mold body 1 includes two cylinders with different diameters. The end of the larger diameter cylinder away from the smaller diameter cylinder is provided with a first external thread 3. The outer diameter of the threaded sleeve 2 is the same as the outer diameter of the larger diameter cylinder of the mold body 1. The inner diameter of the threaded sleeve 2 matches the outer diameter of the smaller diameter cylinder of the mold body 1. The threaded sleeve 2 is fitted around the outer circumference of the smaller diameter cylinder of the mold body 1. The side of the threaded sleeve 2 closest to the larger diameter cylinder of the mold body 1 is provided with a second external thread 4.

[0091] ② Wrap glass fiber around the threaded area to fill the unevenness of the threaded area, and obtain the threaded connection filling circumferential layer 11;

[0092] ③ An ablation-resistant layer 12 is laid on the cylindrical shaft within the outer circumferential threads at both ends. The ablation-resistant layer 12 is composed of glass fiber and an ablation-resistant substrate sprayed on the glass fiber. The thickness of the glass fiber is 0.16 mm, and the thickness of the ablation-resistant layer is 0.8 mm. The material of the ablation-resistant substrate layer is a modified epoxy resin coating.

[0093] ④ Glass fiber is wound circumferentially on the ablation-resistant substrate to achieve a flatness error of ≤0.1mm at the threaded part, thus obtaining the first circumferential compression layer 13;

[0094] ⑤ The mold is spirally wound with glass fiber at an angle of z1 = 48°. After completion, the mold is circumferentially wound with glass fiber to compact and fill the circumferential gap, thus obtaining the first spiral layer 14.

[0095] ⑥ Lay a layer of bidirectional carbon fiber cloth along the circumferential winding direction at both sides of the thread, and extend it longitudinally for 60mm to the root of the thread to obtain the bidirectional carbon fiber cloth layer 15 at the thread; use glass fiber to circumferentially wind and compact the mold to obtain the second circumferential compression layer 16.

[0096] ⑦ Wrap the mold with glass fiber at an angle of z2 = 44° for 2 layers to obtain the second spiral layer 17. After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the third circumferential compression layer 18.

[0097] ⑧ Wrap the mold with glass fiber at an angle of z3 = 34° for 2 layers to obtain the third spiral layer 19. After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the fourth circumferential compression layer 20.

[0098] ⑨ Use glass fiber to circumferentially compress the threaded area to obtain the threaded compression layer 21.

[0099] Example 5

[0100] A wet winding method for the composite casing of a rain-enhancing and hail-prevention projectile engine, such as... Figures 1-4 , Figure 6 As shown, it includes the following steps:

[0101] ① Prepare the mold, such as Figures 1-2 As shown, the mold includes a mold body 1 and a threaded sleeve 2. The mold body 1 includes two cylinders with different diameters. The end of the larger diameter cylinder away from the smaller diameter cylinder is provided with a first external thread 3. The outer diameter of the threaded sleeve 2 is the same as the outer diameter of the larger diameter cylinder of the mold body 1. The inner diameter of the threaded sleeve 2 matches the outer diameter of the smaller diameter cylinder of the mold body 1. The threaded sleeve 2 is fitted around the outer circumference of the smaller diameter cylinder of the mold body 1. The side of the threaded sleeve 2 closest to the larger diameter cylinder of the mold body 1 is provided with a second external thread 4.

[0102] ② Wrap glass fiber around the threaded area to fill the unevenness of the threaded area, and obtain the threaded connection filling circumferential layer 11;

[0103] ③ An ablation-resistant layer 12 is laid on the cylindrical shaft within the outer circumferential threads at both ends. The ablation-resistant layer 12 is composed of glass fiber and an ablation-resistant substrate sprayed on the glass fiber. The thickness of the glass fiber is 0.15 mm, and the thickness of the ablation-resistant layer is 0.9 mm. The material of the ablation-resistant substrate layer is a modified epoxy resin coating.

[0104] ④ Glass fiber is wound circumferentially on the ablation-resistant substrate to achieve a flatness error of ≤0.1mm at the threaded part, thus obtaining the first circumferential compression layer 13;

[0105] ⑤ The mold is spirally wound with glass fiber at an angle of z1 = 45°. After completion, the mold is circumferentially wound with glass fiber to compact and fill the circumferential gap, thus obtaining the first spiral layer 14.

[0106] ⑥ Lay a layer of bidirectional carbon fiber cloth along the circumferential winding direction at both sides of the thread, and extend it longitudinally for 65mm to the root of the thread to obtain the bidirectional carbon fiber cloth layer 15 at the thread; use glass fiber to circumferentially wind and compact the mold to obtain the second circumferential compression layer 16.

[0107] ⑦ Wrap the mold with glass fiber at an angle of z2 = 40° for 2 layers to obtain the second spiral layer 17. After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the third circumferential compression layer 18.

[0108] ⑧ Wrap the mold with glass fiber at an angle of z3 = 35° for 2 layers to obtain the third spiral layer 19. After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the fourth circumferential compression layer 20.

[0109] ⑨ Use glass fiber to circumferentially compress the threaded area to obtain the threaded compression layer 21.

[0110] After employing the wet winding method for the composite casing of the rain-enhancing and hail-suppressing projectile engine as described in Examples 1-5, the composite casing and mold of the rain-enhancing and hail-suppressing projectile engine need to be cured and demolded to obtain the composite casing of the rain-enhancing and hail-suppressing projectile engine, as shown below. Figure 5 As shown, the final rain-inducing and hail-preventing projectile engine casing is a combination of epoxy resin and glass fiber. Epoxy resin, as the adhesive for solidifying and connecting glass fiber filaments, has a stepped curing time, and different resin-adhesive ratios result in different curing curves.

[0111] While conventional demolding processes are slower than traditional shell demolding, they eliminate the machining time required for the threaded parts of traditional shells. Traditional threads require the shell to be machined into the thread shape on a machine tool after demolding, which damages the strength of the pipe body, reduces the strength of the threaded parts, and increases safety hazards.

[0112] Examples 3-5 use a mold consisting of a mold body 1 and a threaded sleeve 2. During demolding, the threaded sleeve 2 is unscrewed first for demolding, and then the mold body 1 is demolded. Compared with an integrated mold, the demolding time is greatly shortened.

[0113] After employing the wet winding method for the composite housing of the rain-inducing and hail-suppressing projectile engine as described in Examples 4 and 5, the composite housing is cured and demolded to obtain the rain-inducing and hail-suppressing projectile engine composite housing. The thickness of the composite housing is set to 10 mm, the thread thickness is 2.3 mm, and the lengths of the first and second external threads are both 36 mm.

[0114] Comparative Example

[0115] The traditional process first obtains a shell with a thickness of 10mm. The shell material and shape are the same as those in this application. It is also a combination of epoxy resin and glass fiber. However, the threads are made using a traditional turning process, which turns the shell to a thickness of 2.3mm, with a thread length of 36mm at both ends.

[0116] Static hydrostatic tests were conducted on the composite casings of the rain-inducing and hail-suppressing projectile engines obtained in Examples 1-5 and the casings obtained using conventional processes. The process is as follows:

[0117] Tests were performed on the shell and the threads separately. For the shell test, the two ends of the shell were sealed with a tool. During the sealing, a threaded cap with a pipe hole was tightened on the threads at both ends of the shell. Water was injected through the pipe hole to increase the pressure for the test. The circumferential tensile strength of the threads was tested using the method GB / T1458-2023.

[0118] Sampling tests were conducted on the obtained composite casing of the rain-inducing and hail-suppressing projectile engine, and the results are shown in Table 1. The comparison of circumferential tensile strength at the threads of different processes is shown in Table 2.

[0119] Table 1 Comparison of Static Hydraulic Pressure Intensity under Different Processes

[0120]

[0121]

[0122] Table 2 Comparison of circumferential tensile strength at threads with different processes

[0123] 285 212 296 240 287 225 288 230 292 232 290 246

[0124] As can be seen from Table 1, the static water pressure strength of the composite shell obtained by the process of the present invention is between 18 and 22 MPa, while the static water pressure strength of the composite shell obtained by the conventional process in the comparative example is only 8 to 14 MPa, which is much smaller than that of the composite shell obtained by the process of the present invention.

[0125] The technical specification of the engine housing is a circumferential tensile strength > 235 MPa. As can be seen from the results in Table 2, the circumferential tensile strength of the threaded portion of the housing obtained by the present invention is all above 280 MPa, which far exceeds the technical specification of the engine housing. However, the strength of the threaded portion produced by the traditional method may not meet the technical specification requirements of the engine housing.

Claims

1. A wet winding method for a composite casing of a rain-inducing and hail-preventing projectile engine, characterized in that: Includes the following steps: ① Prepare a mold, the mold including a cylindrical shaft, the cylindrical shaft having external threads at both ends; ② Wrap glass fiber around the thread to fill the unevenness of the thread and obtain the threaded connection filling circumferential layer (11). ③ An ablation-resistant layer (12) is laid on the cylindrical shaft inside the outer circumferential threads at both ends. The ablation-resistant layer (12) is composed of glass fiber and an ablation-resistant matrix sprayed on the glass fiber. The thickness of the glass fiber is 0.12-0.18 mm, and the thickness of the ablation-resistant layer is 0.6-0.9 mm. The material of the ablation-resistant matrix layer is a modified epoxy resin coating. ④ Glass fiber is wound circumferentially on the ablation-resistant substrate to achieve a flatness error of ≤0.1mm at the threaded part, thus obtaining the first circumferential compression layer (13). ⑤ Use glass fiber to spirally wind the mold at an angle of z1 = 45~50°. After completion, use glass fiber to circumferentially wind the mold to compact and fill the circumferential gap, thus obtaining the first spiral layer (14). ⑥ Lay a layer of bidirectional carbon fiber cloth along the circumferential winding direction at both sides of the thread to obtain a bidirectional carbon fiber cloth layer at the thread (15); use glass fiber to circumferentially wind and compact the mold to obtain a second circumferential compression layer (16). ⑦ Wrap the mold with glass fiber at an angle of z2 = 45 to 40° for 2 layers to obtain the second spiral layer (17). After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the third circumferential compression layer (18). ⑧ Wrap the mold with glass fiber at an angle of z3 = 35~30° for 2 layers to obtain the third spiral layer (19). After completion, wrap and compact the mold with glass fiber in a circumferential direction to obtain the fourth circumferential compression layer (20). In steps ⑤, ⑦, and ⑧, z1 > z2 > z3; ⑨ Use glass fiber to circumferentially compress the threaded area to obtain a threaded compression layer (21).

2. The wet winding method for the composite casing of a rain-enhancing and hail-suppressing projectile engine according to claim 1, characterized in that: The mold includes a mold body (1) and a threaded sleeve (2). The mold body (1) includes two cylinders with different diameters. The end of the cylinder with a larger diameter away from the cylinder with a first external thread (3) is provided. The outer diameter of the threaded sleeve (2) is the same as the outer diameter of the cylinder with a larger diameter in the mold body (1). The inner diameter of the threaded sleeve (2) matches the outer diameter of the cylinder with a smaller diameter in the mold body (1). The threaded sleeve (2) is fitted around the outer periphery of the cylinder with a smaller diameter in the mold body (1). The threaded sleeve (2) is provided with a second external thread (4) on the side of the cylinder with a larger diameter in the mold body (1) that is close to the cylinder with a larger diameter in the mold body (1).

3. The wet winding method for the composite casing of a rain-enhancing and hail-suppressing projectile engine according to claim 1, characterized in that: The biaxial carbon fiber cloth has a specification of 200g-T450.

4. The wet winding method for the composite casing of a rain-enhancing and hail-suppressing projectile engine according to claim 1, characterized in that: In step ⑥, the biaxial carbon fiber cloth extends longitudinally for another 55-65 mm towards the root of the thread.

5. The wet winding method for the composite casing of a rain-enhancing and hail-suppressing projectile engine according to claim 1, characterized in that: The glass fiber has a specification of 50g.

6. The wet winding method for the composite casing of a rain-enhancing and hail-suppressing projectile engine according to claim 1, characterized in that: z1-z2>3°, z2-z3>3°.

7. The wet winding method for the composite casing of a rain-enhancing and hail-suppressing projectile engine according to claim 1, characterized in that: z1 = 45°, z2 = 40°, z3 = 35°.

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