A projectile separation fairing and its design method

Abstract

This invention relates to a projectile separation fairing and its design method. The projectile separation fairing of this invention optimizes the center of mass position through the layout of structural components, ensuring symmetry between the two half-fairings and maximally consistent separation attitude, significantly reducing the risk of collision with the final stage. Uniquely designed embedded parts, combined with reinforcing ribs, can withstand the impact load generated during fairing separation, distributing the impact load across the skin to prevent localized damage to the fairing. This design allows for weight reduction through honeycomb construction while maintaining the fairing's impact resistance and structural integrity, thus solving the problem of honeycomb sandwich structures being susceptible to impact damage. The design of the separation mechanism and its base ensures that after the actuating rod separates from the actuating cylinder, it is limited after rotating a small angle around the base of the separation mechanism, preventing the actuating rod from colliding with the payload. During separation, the linear guide area of ​​the end frame, in conjunction with the guide rod, effectively prevents the left and right half-fairings from rotating relative to the rocket body, avoiding collisions with the internal structure of the fairing.

Description

Technical Field

[0001] This invention belongs to the field of launch vehicle technology, specifically relating to a horizontally projectile separation fairing and its design method. Background Technology

[0002] When a launch vehicle flies through the atmosphere, the fairing protects the payload from harmful environmental factors such as aerodynamic heating and acoustic vibration. When the launch vehicle reaches an altitude where the atmosphere is thinner, the fairing must separate. The jettison separation method involves first unlocking the fairing from the rocket's final stage, then unlocking the two halves of the fairing, and finally, using a separation mechanism installed inside the fairing to peel the fairing apart from above the final stage.

[0003] During fairing separation, the fairing's inertia, deviations in the force applied by the separation device, and the dimensional and positional tolerances of the separation device can all cause the fairing to collide with the payload. In addition, the attitudes of the two half-fairings are uncontrolled during traditional fairing separation, resulting in a high risk of separation. Furthermore, in traditional designs, to prevent aerodynamic heat and ablation, the entire end cap is fixed to the half-fairing shell. This structural form leads to an asymmetry in the fairing's center of mass, resulting in a large difference in the separation attitudes of the two half-fairings, which is not conducive to fairing separation.

[0004] Meanwhile, the honeycomb sandwich structure, which has the advantages of being lightweight and highly designable, has been widely used in rocket fairings. However, the lateral impact force during fairing separation can easily cause damage and deformation to the shell of the honeycomb sandwich structure, which will affect the normal operation of the fairing structure and separation mechanism.

[0005] In summary, there are still many shortcomings in the structural design of the fairing. Designing a fairing jettison technology that can meet the requirements of high overload environments and a fairing structure that can withstand lateral impacts are the challenges faced in rocket fairing design. Summary of the Invention

[0006] The purpose of this invention is to provide a flat-projectile separation fairing and its design method. The design of this invention can reduce the weight of the fairing, ensure its impact resistance, improve separation safety, and solve the problem of heat sealing of the flat-projectile separation fairing.

[0007] To achieve the above technical objectives, the present invention provides a horizontal projectile separation fairing, comprising a first half-fairing and a second half-fairing, wherein the first half-fairing includes a first end cap, a shell, reinforcing ribs disposed on the shell, embedded parts, and a first separation mechanism base;

[0008] The second half-cover includes a second end cap, a housing, reinforcing ribs disposed on the housing, embedded parts, a base for the second separation mechanism, and pyrotechnic components;

[0009] The embedded part is provided with a weight-reducing groove and two symmetrical lugs. The embedded part is connected to the reinforcing rib. The first separation mechanism base and the second separation mechanism base are fixed on the embedded part.

[0010] The horizontal jet separation fairing also includes a separation mechanism, which includes an actuating rod, a lateral support, a piston, a rear end cover, and an actuating cylinder. The actuating cylinder is disposed on the rear end cover, the lateral support is disposed on the inner side wall of the housing to support the actuating cylinder, the actuating rod is disposed inside the actuating cylinder, and the piston is slidably disposed at the bottom of the actuating cylinder.

[0011] The first separation mechanism base is provided with a hinge hole, and the first separation mechanism base is hinged to the actuating rod; the rear end cover is fixedly connected to the second separation mechanism base.

[0012] Furthermore, the base of the first separation mechanism is hinged to one end of the actuating rod, and a limit mechanism is provided at the hinge to restrict the rotation of the actuating rod on the base of the first separation mechanism.

[0013] Furthermore, the lower part of the horizontal jet separation fairing is provided with a docking end frame. The horizontal jet separation fairing is docked and installed on the rocket's final stage through the docking end frame. The rocket's final stage is provided with a limit rod. The docking end frame has a linear guide area. During the fairing separation process, the limit rod limits the linear guide area, so that the first half of the fairing and the second half of the fairing move in a straight line during separation.

[0014] Furthermore, the guide rod is made of stainless steel and coated with grease to reduce the friction of the linear guide area of ​​the cover during separation. During assembly, a gap of 0-1mm is preferably left between the guide rod and the linear guide area.

[0015] Furthermore, the shape of the embedded part is adapted to the curved surface of the fairing, and the lugs at both ends are connected to the reinforcing ribs; a weight reduction groove is provided in the middle area on the back of the embedded part, and a screw steel sleeve is inlaid around the weight reduction groove as the installation interface of the separation mechanism base.

[0016] The weight-reducing groove cannot be installed through the entire embedded part, because if it is installed through the entire embedded part, the area that the embedded part can bear will be reduced, which will not meet the requirements. In addition, if the weight-reducing groove is installed through the entire embedded part, it will affect the rigidity of the embedded part.

[0017] Furthermore, the first half-cover is provided with an end baffle and a shell baffle strip. The end baffle is recessed and installed in the end cap, and the shell baffle strip is installed on the edge of the first half-cover shell.

[0018] Furthermore, the end baffle is made of an ablation-resistant material, such as fiberglass or high-temperature alloy steel.

[0019] Furthermore, the shell adopts a honeycomb sandwich structure, using aramid paper-based honeycomb, with skins covering both the inner and outer sides of the honeycomb. The skins are made of carbon fiber material, and the reinforcing ribs are bonded to the skins. Where reinforcing ribs are required, the honeycomb can be removed first, and then the reinforcing ribs can be inserted, with the gaps between the honeycomb and the reinforcing ribs filled with expanding foam.

[0020] Furthermore, the embedded part is made of aluminum alloy or titanium alloy.

[0021] This invention also provides a design method for the projectile separation fairing as described above, characterized in that it includes:

[0022] pass The centroid positions of the left and right halves of the fairing were calculated, and the centroid positions were optimized by the layout of structural components.

[0023] In the formula, m is the total mass of the half-coverage, and x i y i z i These are the x, y, and z coordinates of each component, m i The mass of each component is used; the coordinate system for calculation is based on the theoretical apex of the fairing as the origin, the axis of symmetry of the section as the X-axis, pointing towards the tail as positive, and the Y-axis pointing towards the separation direction of the second half of the fairing. X, Y, and Z satisfy the right-hand rule of right angles.

[0024] The dimensions and structural form of the embedded parts are designed according to the magnitude of the impact force of the separation mechanism and the shape and size of the fairing; the location and size of the weight reduction groove are designed according to the magnitude of the impact force.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] By optimizing the position of the center of mass through the layout of structural components, the centers of mass of the two half-shells are made symmetrical, ensuring that the separation attitude is as consistent as possible and greatly reducing the risk of collision with the final stage.

[0027] The uniquely designed embedded parts, combined with reinforcing ribs, can withstand the impact load generated by fairing separation, distributing the impact load onto the skin and preventing local damage to the fairing. This allows for the use of honeycomb to reduce the weight of the fairing while ensuring its impact resistance and structural integrity, thus solving the problem of honeycomb sandwich structures being not impact-resistant.

[0028] The design of the separation mechanism and its base ensures that after the actuating rod separates from the actuating cylinder, it is limited after rotating slightly around the base of the separation mechanism, preventing the actuating rod from colliding with the effective load. During the separation process, the straight guide area of ​​the end frame can cooperate with the guide rod to guide, effectively preventing the left and right halves of the cover from rotating relative to the arrow body and avoiding collisions with the internal structure of the cover. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the projectile separation fairing.

[0030] Figure 2 A bottom view of the projectile separation fairing;

[0031] Figure 3 for Figure 2 Sectional view along direction A;

[0032] Figure 4 This is a schematic diagram of the first half-cover structure;

[0033] Figure 5 This is a schematic diagram of the second half-cover structure;

[0034] Figure 6 This is a schematic diagram of the embedded component structure;

[0035] Figure 7 This is a schematic diagram of the separation mechanism.

[0036] Figure 8 for Figure 7 Sectional view from direction B;

[0037] Figure 9 A three-dimensional view of the separation mechanism;

[0038] Figure 10 This is a schematic diagram of the base of the first separation mechanism;

[0039] Figure 11 Schematic diagram of the base of the second separation mechanism;

[0040] Figure 12 A schematic diagram of the straight guide area and guide rod of the docking end frame;

[0041] Figure 13 This is a schematic diagram of the end baffle.

[0042] Symbol Explanation: 1-First half-cover, 11-First end cap, 111-End baffle, 12-First separation mechanism base, 121-Pin, 122-Hinge hole, 2-Second half-cover, 21-Second end cap, 22-Second separation mechanism base, 3-Dating end frame, 31-Linear guide area, 4-Embedded part, 41-Ear, 411-Screw hole, 42-Weight reduction groove, 43-Screw steel sleeve, 5-Pyrotechnics, 51-Pipeline, 6-Separation mechanism, 61-Actuating rod, 611-Protrusion, 62-Actuating cylinder, 63-Side support, 64-Rear end cover, 65-Piston, 7-Outer shell, 71-Outer shell baffle strip, 8-Rocket final stage, 81-Guide rod, 9-Reinforcing rib. Detailed Implementation

[0043] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0044] The present invention provides a horizontal projectile separation fairing, such as... Figure 1-5 As shown, it includes a first half-cover and a second half-cover;

[0045] The first half-cover includes a first end cap, a shell, reinforcing ribs, embedded parts, and a base for the first separation mechanism;

[0046] The second half-cover includes a second end cap, a shell, reinforcing ribs, embedded parts, a base for the second separation mechanism, and pyrotechnic components;

[0047] The shell adopts a honeycomb sandwich structure, which can effectively reduce the weight of the fairing. Specifically, it uses aramid paper-based honeycomb, with skin covering both the inner and outer sides of the honeycomb. The skin is made of carbon fiber, and the reinforcing ribs are bonded to the skin. During manufacturing, the honeycomb is removed first where reinforcing ribs are needed, and then the reinforcing ribs are filled in. The gaps between the honeycomb and the reinforcing ribs are filled with expanding foam.

[0048] The shape of the embedded parts is adapted to the curved surface of the fairing, such as... Figure 6 As shown, the embedded part has a weight-reducing groove and two symmetrical lugs. The embedded part is connected to the reinforcing rib through the two lugs. Specifically, the lugs have screw holes, and the two lugs are connected to the reinforcing rib by screws. In this embodiment, the weight-reducing groove is located in the middle area of ​​the back of the embedded part, and a total of two weight-reducing grooves are opened. A screw steel sleeve is inlaid at equal intervals around the weight-reducing groove. The screw steel sleeve is a steel sleeve with internal threads. In this design, no threaded holes are directly opened in the embedded part because the base of the separation mechanism may need to be repeatedly disassembled and assembled. The embedded part is preferably made of aluminum alloy. If threaded holes are set on aluminum alloy, the threaded holes are easily damaged under repeated disassembly and assembly. Therefore, this design embeds a steel sleeve with a threaded hole in the embedded part, which is not easily damaged under repeated disassembly and assembly. Preferably, a screw steel sleeve is also inlaid in the center of the two weight-reducing grooves, so that the middle area of ​​the base of the separation mechanism can also be fixed to the embedded part, ensuring firmness and reliability.

[0049] The embedded parts are symmetrically arranged on the first and second half-covers, such as... Figure 2 As shown, there are a total of 8 embedded parts. Two embedded parts of the same height but different half-covers are symmetrical with the splicing surface of the first half-cover and the second half-cover as the symmetrical plane.

[0050] In this embodiment, the embedded part is made of aluminum alloy, while in other embodiments, the embedded part is made of titanium alloy.

[0051] The weight-reducing groove cannot be installed through the entire embedded part, because if it is installed through the entire embedded part, the area that the embedded part can bear will be reduced, which will not meet the requirements. In addition, if the weight-reducing groove is installed through the entire embedded part, it will affect the rigidity of the embedded part.

[0052] The horizontal separation fairing also includes a separation mechanism, such as... Figure 7-9As shown, the separation mechanism includes an actuating rod, a lateral support, a piston, a rear end cover, and an actuating cylinder; the actuating cylinder is disposed on the rear end cover, and the two are connected by threads; the lateral support is disposed on the inner side wall of the housing to support the actuating cylinder, and the actuating rod is disposed inside the actuating cylinder; in this embodiment, the actuating cylinder and the actuating rod are respectively the cylinder barrel and the cylinder rod.

[0053] The first separation mechanism base and the second separation mechanism base have through holes that match the pre-embedded part screw sleeves, and are fixed to the pre-embedded part with screws; such as Figure 10 As shown, the first separation mechanism base is provided with a hinge hole for hinge connection with the actuating rod. The hinge end of the actuating rod is also provided with a through hole. During installation, the through hole of the actuating rod is aligned with the hinge hole of the first separation mechanism base, and then a pin is inserted to fix the actuating rod on the first separation mechanism base; as shown. Figure 11 As shown, a screw sleeve is provided on the base of the second separation mechanism, and the rear end cover has a through hole that matches the screw sleeve of the base of the second separation mechanism. The rear end cover and the base of the second separation mechanism are fixedly connected by screws.

[0054] The base of the first separation mechanism is hinged to one end of the actuating rod, and a limit mechanism is provided at the hinge. The limit mechanism is as follows: Figure 9 As shown, the actuator rod extends with a protrusion. When the actuator rod rotates, the protrusion comes into contact with the base of the first separation mechanism, restricting the rotation of the actuator rod on the base of the first separation mechanism. In this embodiment, the actuator rod is restricted to rotating downwards by only 3°. In another embodiment, its maximum rotation angle can be restricted to 1°, 2°, 4°, 5°, 8° or 10°.

[0055] The pyrotechnic device is mounted on the second half of the enclosure and connected to the actuating cylinder via a pipe, providing a power source for the separation mechanism. Since the separation mechanism uses the pyrotechnic device as its power source, the actuating cylinder must be fixedly connected to the base. Therefore, the base of the second separation mechanism is a fixed design, and the actuating cylinder is mounted on it and cannot move.

[0056] The two half-shells are connected by a conventional radial end frame. The separation mechanism is arranged close to the radial end frame of the fairing to reduce the deformation of the radial end frame under impact overload and make full use of the space structure without occupying too much envelope space of the fairing.

[0057] The lower part of the jet propulsion separation fairing is equipped with a docking end frame. The jet propulsion separation fairing is docked and installed on the rocket's final stage through the docking end frame, such as... Figure 12 As shown, a limit rod is installed on the rocket's final stage, and the docking end frame has a linear guide area. During the fairing separation process, the limit rod limits the linear guide area, so that the first half of the fairing and the second half of the fairing move in a straight line during separation.

[0058] The guide rod is made of stainless steel with high hardness and is coated with grease to reduce the friction of the linear guide area of ​​the cover during separation. During assembly, a gap of 0-1mm is preferably left between the guide rod and the linear guide area. In this embodiment, a gap of 0.8mm is left.

[0059] Optional, such as Figure 4 and 13 As shown, the first half-cover is equipped with an end baffle and a shell baffle strip. The end baffle is recessed and installed in the end cap, effectively reducing the impact of the end baffle on the aerodynamic shape of the fairing. Both the end baffle and the shell baffle strip are installed at the edge of the separation surface of the first half-cover. To adjust the weight of the two half-covers, the end baffle and the shell baffle strip are set on the first half-cover. The end baffle and the shell baffle strip only need to block the joint between the two half-covers to prevent high-speed airflow from directly scouring the joint. Therefore, the end baffle and the shell baffle strip are only fixed to one half-cover, and extending a portion into the other half-cover is sufficient to meet the requirements. In this embodiment, both the end baffle and the shell baffle strip are installed on the first half-cover using countersunk screws.

[0060] Optionally, a sealing structure can be set at the mating surface of the two half-covers, specifically using a silicone rubber sheet for sealing. The shell baffle strip is set at the outermost layer of the mating point to prevent high-speed airflow from scouring the silicone rubber sheet.

[0061] The nose cone deflector and shell deflector strips are made of ablation-resistant materials, such as fiberglass or high-temperature alloy steel. This minimizes the ablation of the nose cone by the aerodynamic heat of the rocket's high-speed flight and prevents high-speed airflow from entering the fairing.

[0062] The fairing also includes axial explosive bolts and radial explosive bolts. Using explosive bolts to separate the fairing from the rocket's final stage and the two fairing halves is a conventional technique in this field, and will not be elaborated upon here.

[0063] The fairing separation process is as follows:

[0064] The axial and radial explosive bolts are unlocked, and the separation mechanism pushes the first and second half-covers to move in parallel and opposite directions. During the movement of the first and second half-covers, the straight guide area is limited by the guide rod to ensure that the fairing separates in a straight direction. The actuator cylinder and the actuator rod separate from each other, and the half-cover continues to move by inertia until it is completely separated from the separation body.

[0065] The present invention also provides a design method for a horizontal projectile separation fairing, comprising:

[0066] pass The positions of the center of mass of the left and right halves of the fairing were calculated, and the positions of the center of mass were optimized by the layout of the structural components. The mass and center of mass of the first and second halves of the fairing were made symmetrical, ensuring that the separation attitude was as consistent as possible and greatly reducing the risk of collision with the rocket's final stage.

[0067] In the formula, m is the mass of half the cover, and x i y i z i These are the x, y, and z coordinates of each component, m i The mass of each component; the subscript i takes the value 1-n, where n is the number of all components contained in the half-cover; the coordinate system for calculation is based on the theoretical cusp of the fairing as the origin, the axis of symmetry of the section as the X-axis, pointing towards the tail as positive, and the Y-axis pointing towards the separation direction of the second half-cover, and XYZ satisfy the right-hand rule of right angles;

[0068] The dimensions and structural form of the embedded parts are designed according to the magnitude of the impact force of the separation mechanism and the shape and size of the fairing; the location and size of the weight reduction groove are designed according to the magnitude of the impact force.

[0069] In this embodiment, the embedded part designed through simulation is a cube with dimensions of 200mm×120mm×15mm (excluding the lugs). Each embedded part is equipped with two weight-reducing grooves, each with dimensions of 70mm×70mm×12mm. The lugs of the embedded part are connected to the annular reinforcing ribs to distribute the impact load of the separation mechanism to the surrounding area and the inner and outer skins. This embedded part structure has high efficiency and meets the requirements of repeated disassembly and assembly of the separation mechanism base.

Claims

1. A projectile separation fairing, comprising a first half-fairing and a second half-fairing, characterized in that, The first half-cover includes a first end cap, a housing, reinforcing ribs disposed on the housing, embedded parts, and a base for a first separation mechanism; The second half-cover includes a second end cap, a housing, reinforcing ribs disposed on the housing, embedded parts, a base for the second separation mechanism, and pyrotechnic components; The embedded part is provided with a weight reduction groove and two ear pieces. The embedded part is connected to the reinforcing rib. The first separation mechanism base and the second separation mechanism base are fixed on the embedded part. It also includes a separation mechanism, which includes an actuating rod, a lateral support, a piston, a rear end cover, and an actuating cylinder; the actuating cylinder is disposed on the rear end cover, the lateral support is disposed on the inner side wall of the housing for supporting the actuating cylinder, the actuating rod is disposed inside the actuating cylinder, and the piston is slidably disposed at the bottom of the actuating cylinder; The first separation mechanism base is provided with a hinge hole, and the first separation mechanism base is hinged to the actuating rod; the rear end cover is fixedly connected to the second separation mechanism base.

2. The projectile separation fairing according to claim 1, characterized in that, The base of the first separation mechanism is hinged to one end of the actuating rod, and a limit mechanism is provided at the hinge to restrict the rotation of the actuating rod on the base of the first separation mechanism.

3. The projectile separation fairing according to claim 1, characterized in that, The lower part of the horizontal projectile separation fairing is provided with a docking end frame. The horizontal projectile separation fairing is docked and installed on the rocket's final stage through the docking end frame. The rocket's final stage is provided with a limit rod. The docking end frame has a linear guide area. During the fairing separation process, the limit rod limits the linear guide area, so that the first half of the fairing and the second half of the fairing move in a straight line during separation.

4. The projectile separation fairing according to claim 3, characterized in that, The limiting rod is made of stainless steel and coated with grease.

5. A projectile separation fairing according to claim 1, characterized in that, The shape of the embedded part is adapted to the curved surface of the fairing. A weight reduction groove is provided in the middle area of ​​the back of the embedded part. A screw steel sleeve is inlaid around the weight reduction groove, which serves as the installation interface for the base of the separation mechanism.

6. The projectile separation fairing according to claim 1, characterized in that, The first half-cover is provided with an end baffle and a shell baffle strip. The end baffle is recessed and installed in the end cap, and the shell baffle strip is installed on the edge of the first half-cover shell.

7. A projectile separation fairing according to claim 6, characterized in that, The end baffle and the shell baffle strip are made of ablation-resistant materials, including fiberglass or high-temperature alloy steel.

8. A projectile separation fairing according to any one of claims 1-7, characterized in that, The shell adopts a honeycomb sandwich structure, which is made of aramid paper-based honeycomb. The inner and outer sides of the honeycomb are covered with skin, which is made of carbon fiber. The reinforcing ribs are bonded to the skin.

9. A projectile separation fairing according to any one of claims 1-7, characterized in that, The embedded parts are made of aluminum alloy or titanium alloy.

10. A design method for a projectile separation fairing as described in any one of claims 1-9, characterized in that, include: pass The centroid positions of the left and right halves of the fairing were calculated, and the centroid positions were optimized by the layout of structural components. In the formula, m is the total mass of the half-mask, and x i y i z i These are the x, y, and z coordinates of each component, m i The mass of each component is calculated; the coordinate system is based on the theoretical apex of the fairing as the origin, the axis of symmetry of the section as the X-axis, pointing towards the tail as positive, and the Y-axis pointing towards the separation direction of the second half of the fairing. XYZ satisfies the right-hand rule of right angles. The dimensions and structural form of the embedded parts are designed according to the magnitude of the impact force of the separation mechanism and the shape and size of the fairing; the location and size of the weight reduction groove are designed according to the magnitude of the impact force.

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