Variable throat solid rocket engine jet pipe blanking cap structure

Abstract

The invention discloses a variable throat solid rocket engine jet pipe blanking cap structure which comprises a front cap body, a rear cap body, a plugging body and an adjusting screw rod, the plugging body is of a rotary body structure made of an elastic material, and an outward protruding section is formed in the middle of the side wall of the plugging body; the front end and the rear end of the plugging body are provided with interfaces, and the front cover body and the rear cover body are respectively matched and sealed at the front end and the rear end of the plugging body through the interfaces; one end of the adjusting screw rod is movably assembled on the inner side of the front cover body, and the other end of the adjusting screw rod penetrates through a through hole in the rear cover body and is provided with a pressing nut. The distance between the front cover body and the rear cover body is adjusted through the pressing nut, so that the radial deformation quantity of the plugging body is adjusted, and the protruding section of the plugging body is made to be matched with engine nozzle throats with different inner diameters. The nozzle plug can be freely adjusted to meet different throat sealing and ignition work requirements, the problem that a nozzle plug cover structure is difficult to replace when reaching the service life can be effectively solved, and the storage life of the whole engine is effectively prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of solid rocket engines, and particularly relates to a nozzle plug structure of a variable-throat solid rocket engine. Background Art

[0002] Solid rocket engines have a wide range of applications due to their advantages such as simple structure, reliability, convenience, and long-term storage. As a key part of the design of solid rocket engines, the nozzle plug design plays a crucial role in the reliable ignition of the engine. Traditional nozzle plug designs for solid rocket engines usually use rubber plugs, aluminum plugs, foamed bead nozzles, and metal-nonmetal composite structure plugs. These plugs are usually cured and formed to be only applicable to a single model of engine nozzle structure with one throat diameter or one profile, and are not applicable to the nozzle plugs of different nozzle structures or engine nozzles with similar throat diameter sizes during the scientific research and trial production stage. Re-producing and processing not only increases the production cost and extends the production and delivery cycle, but also the previously produced nozzle plug structures are difficult to match with other models of engines as the structure changes, and can only be scrapped, resulting in a large amount of resource waste. Different nozzle plug structures can only be applicable to a single model of engine, and cannot be mass-produced using the same mold. The mold processing cost is high, the processing progress is slow, and the unit cost is relatively high.

[0003] At the same time, traditional nozzle plug structures are usually bonded and cured to the converging section of the nozzle using adhesives. Solid rocket engines for tactical weapons have a long storage time, and it is relatively difficult to replace the seal plug structure after its service life, resulting in the inability to reasonably and effectively extend the service life of solid rocket engines. Summary of the Invention

[0004] The purpose of the invention is to provide a nozzle plug structure of a variable-throat solid rocket engine to overcome problems such as poor adaptability and inconvenient installation of existing plugs, and to meet the sealing of multi-diameter nozzles and allow for replacement at any time.

[0005] To achieve the above tasks, the invention adopts the following technical solutions:

[0006] A nozzle plug structure of a variable-throat solid rocket engine includes a front cover body, a rear cover body, a plug body, and an adjusting screw rod, wherein:

[0007] The plug body is a rotary body structure made of an elastic material, and a protruding section is formed outwardly in the middle of the side wall of the plug body; interfaces are provided at the front end and the rear end of the plug body, and the front cover body and the rear cover body are respectively sealed to the front end and the rear end of the plug body through the interfaces; one end of the adjusting screw rod is movably assembled inside the front cover body, and the other end passes through a through hole on the rear cover body and is equipped with a compression nut; by adjusting the compression nut, the distance between the front cover body and the rear cover body is adjusted, thereby adjusting the radial deformation amount of the plug body, so that the protruding section of the plug body adapts to the throat of the engine nozzle with different inner diameters.

[0008] Furthermore, the plugging body is made of ethylene propylene diene monomer (EPDM) rubber material.

[0009] Furthermore, in the natural state without external force, both the inner and outer surfaces of the convex section in the axial cross-section of the plugging body are arcs, and the central angle range corresponding to the inner arc is 60° - 120°.

[0010] Furthermore, the thickness of the plugging body is kept consistent, or:

[0011] The end points of the convex section of the plugging body are the minimum thickness, and along the end points of the convex section to both sides, the thickness of the plugging body gradually increases; the change trend is linear or non-linear.

[0012] Furthermore, the minimum thickness of the plugging body shall not be less than 3 mm, and the axial length range of the plugging body is 10 - 60 mm.

[0013] Furthermore, when adjusting the outward deformation of the plugging body through the compression nut, the convex section of the plugging body will be in contact with the throat surface of the engine nozzle in a surface contact or line contact; the straight section of the engine nozzle throat has an axial length of at least 2 - 3 mm, and the inner diameter of the nozzle throat is 20 - 200 mm.

[0014] Furthermore, the interfaces provided at the front end and the rear end of the plugging body are annular steps formed on the inner circumferences of the front end and the rear end of the plugging body; the front cover body and the rear cover body are respectively assembled into the annular steps at the front and rear ends, and the sealing and curing connection of the front and rear ends of the plugging body is realized by applying an adhesive at the assembly parts.

[0015] Furthermore, a threaded hole is provided on the inner side of the front cover body, and the front end of the adjusting screw is installed in the threaded hole; by rotating the compression nut, the compression nut can be made to push the rear cover body to move axially along the adjusting screw, thereby increasing or shortening the distance between the front cover body and the rear cover body, changing the axial deformation of the plugging body, and adjusting the maximum outer diameter of the plugging body to make it adapt to different engine nozzle throats.

[0016] Furthermore, during use, first clean the inner surface of the engine nozzle, the outer surface of the plugging body, the interfaces at the front and rear ends, and clean the external threads of the adjusting screw;

[0017] Assemble the front end of the adjusting screw into the threaded hole on the inner side of the front cover body and tighten it. Then, assemble the front cover body onto the interface at the front end of the plugging body and apply adhesive. After that, pass the rear end of the adjusting screw through the through hole on the rear cover body, and then assemble the rear cover body onto the interface at the rear end of the plugging body and apply adhesive. Finally, assemble the compression nut at the rear end of the adjusting screw, and then place the entire plugging cover structure at the throat of the engine nozzle. After the adjusting screw is coaxial with the engine nozzle, rotate the compression nut according to the inner diameter of the engine nozzle throat to adjust the radial deformation amount and the installation tightness of the plugging body, and finally realize the assembly of the plugging cover structure.

[0018] A variable-throat solid rocket engine nozzle that uses the plugging cover structure described above.

[0019] Compared with the prior art, the present invention has the following technical characteristics:

[0020] 1. Provide a plugging cover structure for a solid rocket engine nozzle with a simple structure and reliable sealing, and meet the needs of engineering applications.

[0021] 2. The plugging cover structure of the nozzle can be applied to the sealing design of nozzles with different throat diameters / structures, and can match the plugging covers of multiple types of engine nozzles. Mass production can be achieved through a set of molds, thereby effectively reducing costs.

[0022] 3. The size of the plugging cover structure of the nozzle is adjustable. When the seal fails after the storage life expires, it can be replaced for the second time, effectively extending the sealed storage life of the engine. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of the installation of the plugging cover structure of the present invention;

[0024] Figure 2 It is a schematic diagram of the plugging cover structure of the present invention;

[0025] Figure 3 It is a schematic diagram of the plugging cover structure of the present invention during the installation process.

[0026] Explanation of the reference numerals in the figure: 1 nozzle, 2 front cover body, 21 threaded hole, 3 adjusting screw, 4 plugging body, 41 convex section, 42 interface, 5 rear cover body, 6 compression nut. Detailed Embodiment

[0027] The design concept of the present invention is to provide a plug cover structure with adjustable outer diameter, enabling it to adapt to the throat of engine nozzles within a certain inner diameter range and achieve adaptation to different types of engine nozzles. The factors to be considered in the design of the present invention are as follows: Considering the convenience of disassembly and assembly, curing connection methods such as adhesives are not used; considering the problem of convenient assembly; considering the universality and replaceability of products; considering the cost issue; in this case, it is also necessary to ensure that after the plug cover structure is installed, it can meet the requirements of the plug-breaking pressure. Under the joint limitation of these factors, the present invention provides a variable-throat solid rocket engine nozzle plug cover structure, which utilizes the characteristics of rubber being soft and squeezable and deformable, and realizes the requirements of plug cover sealing for nozzles with similar-sized throat diameters / structures and replaceability of end-of-life sealing plug covers by adjusting the depth of the compression nut, so as to achieve mass production and reduce production costs.

[0028] See the appendix Figure 1 , the present invention provides a variable-throat solid rocket engine nozzle plug cover structure, including a front cover body 2, a rear cover body 5, a plugging body 4, and an adjusting screw 3, wherein:

[0029] The plugging body 4 is a rotary body structure made of elastic material, and an outward protruding section 41 is formed in the middle of the side wall of the plugging body 4; interfaces 42 are provided at the front end and the rear end of the plugging body 4, and the front cover body 2 and the rear cover body 5 are respectively sealed to the front end and the rear end of the plugging body 4 through the interfaces 42; one end of the adjusting screw 3 is movably assembled inside the front cover body 2, and the other end passes through a through hole on the rear cover body 5 and is assembled with a compression nut 6; by adjusting the distance between the front cover body 2 and the rear cover body 5 through the compression nut 6, the radial deformation amount of the plugging body 4 is adjusted, so that the protruding section 41 of the plugging body fits the throat of the engine nozzle 1 with different inner diameters.

[0030] Among them, the plugging body 4 is made of rubber material; in an embodiment of the present invention, the rubber material of the plugging body is ethylene propylene diene monomer rubber, which has excellent high-temperature resistance and can provide sufficient elasticity.

[0031] When designing the plugging body 4, the inventor team gave a set of design parameters through a large number of calculations and experimental verifications:

[0032] In the natural state without external force, both the inner and outer surfaces of the protruding section 41 in the axial cross-section of the plugging body 4 are arcs, and the central angle range of the inner arc is 60° to 120°, so that the plugging body 4 can have a certain range of adjustment margin and ensure the elastic force of the plugging, and at the same time, during the usual maintenance process, the aging phenomenon of the plugging body 4 can also be determined by measuring its angle to avoid using unqualified plugging bodies 4.

[0033] In terms of thickness design, the thickness of the plugging body 4 can be kept consistent, or a more preferred method is as follows:

[0034] The end point of the convex section 41 of the plugging body 4 has the minimum thickness. Along the end points of the convex section 41 to both sides, the thickness of the plugging body 4 gradually increases; the change trend is a linear change; or parts with the same thickness can be left at both ends of the plugging body 4.

[0035] This design with a gradually changing thickness enables the convex section 41 of the plugging body 4 to closely contact the throat of the engine nozzle 1 after deformation, maintaining the contact elastic force, which is beneficial for the plugging body 4 to better meet the plug-breaking pressure of the engine nozzle 1; among them, the minimum thickness of the plugging body 4 shall not be less than 3 mm.

[0036] Regarding the axial length of the plugging body 4, in cooperation with the above design parameters of the present invention, through the design and verification of the inventor team, when the axial length range of the plugging body 4 is 10 - 60 mm, the plugging body 4 has relatively excellent use performance and can generate a deformation amount of about 5 mm at most in the radial direction.

[0037] For the use scenario of the present invention, generally the plug-breaking pressure of the engine nozzle 1 is 2 - 3 Mpa. Through the above design of the plugging body 4 of the present invention and verification, it can fully meet the requirements of the plug-breaking pressure; at the same time, the unique advantage of the present invention compared with the existing plug structures is:

[0038] The existing plugs are generally fixedly installed using adhesives, etc.; the solution of the present invention can adjust the outward deformation amount of the plugging body 4 through the compression nut 6, thereby adjusting the elastic force of the contact between the plugging body 4 and the throat of the engine nozzle 1, and the change of the elastic force affects the frictional force on the wall surface, and finally it is reflected that the plugging pressure can be adjusted, so as to better adapt to the plug-breaking pressure requirements of different models of engine nozzles 1.

[0039] In this solution, when adjusting the outward deformation amount of the plugging body 4 through the compression nut 6, the convex section 41 of the plugging body 4 will be in surface contact or line contact with the throat surface of the engine nozzle 1; generally, in order to assemble the plug, a straight section will be designed at the throat of the engine nozzle 1; in order to better adapt to this solution, it is preferably recommended that the axial length of the straight section is at least 2 - 3 mm, and the inner diameter of the throat of the nozzle 1 is 20 - 200 mm, so that the plugging body 4 can closely contact the throat of the nozzle 1.

[0040] In this solution, the front cover body 2 and the rear cover body 5 are circular cover bodies, and they can be made of, for example, 45# steel plate.

[0041] Interfaces 42 are provided at the front end and the rear end of the plugging body 4, and the interfaces 42 are annular steps formed on the inner circumferences at the front end and the rear end of the plugging body 4; see Figure 2, during installation, the front cover body 2 and the rear cover body 5 are respectively assembled into the annular steps at the front and rear ends, and the front and rear ends of the plugging body 4 are sealed and cured by applying an adhesive at the assembly parts.

[0042] For the installation of the adjusting screw 3, refer to Figure 2 , a threaded hole 21 is provided on the inner side of the front cover body 2, and the front end of the adjusting screw 3 is installed in the threaded hole 21; a through hole is opened in the middle of the rear cover body 5, the adjusting screw 3 passes through the through hole, and a pressing nut 6 is assembled thereon; by rotating the pressing nut 6, the pressing nut 6 can be made to push the rear cover body 5 to move axially along the adjusting screw 3, so as to increase or shorten the distance between the front cover body 2 and the rear cover body 5, change the axial deformation amount of the plugging body 4, and adjust the maximum outer diameter of the plugging body 4, so that it fits different throats of the engine nozzle 1, and meets the use requirements for sealing and pressure building of the throat of the engine nozzle 1 and the secondary replacement of the plug structure.

[0043] When the present invention is in use, first clean the inner surface of the engine nozzle 1 to ensure that there is no excess; then check the outer surface of the plugging body 4 and the interfaces 42 at the front and rear ends, there should be no burrs, flash, excess, etc.; clean the external thread of the adjusting screw 3.

[0044] Assemble the front end of the adjusting screw 3 into the threaded hole 21 on the inner side of the front cover body 2 and tighten it, then assemble the front cover body 2 onto the interface 42 at the front end of the plugging body 4 and apply an adhesive; then pass the rear end of the adjusting screw 3 through the through hole on the rear cover body 5, and then assemble the rear cover body 5 onto the interface 42 at the rear end of the plugging body 4 and apply an adhesive; finally, assemble the pressing nut 6 at the rear end of the adjusting screw 3, and then place the entire plug structure at the throat of the engine nozzle 1, after making the adjusting screw 3 coaxial with the engine nozzle 1, as Figure 3 shown, rotate the pressing nut 6 according to the inner diameter of the throat of the engine nozzle 1 to adjust the radial deformation amount and the installation tightness of the plugging body 4, and finally realize the assembly of the plug structure.

[0045] The present invention can be applied to the plugging and sealing of nozzles 1 with different throat diameters / structures of various models of engines. This plug structure realizes that the plugging can be freely adjusted to meet the requirements of different throat seals and ignition operations, greatly reducing the production and trial cost. This plug structure can be disassembled and replaced as a whole, effectively solving the problem that it is difficult to replace the plug structure of the nozzle 1 when it reaches its service life, and effectively extending the storage life of the entire engine.

[0046] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A variable throat solid rocket engine nozzle plug structure, characterized in that It includes a front cover body (2), a rear cover body (5), a plugging body (4) and an adjusting screw rod (3), wherein: The plugging body (4) is a rotary body structure made of elastic material, and an outward protruding section (41) is formed in the middle of the side wall of the plugging body (4); interfaces (42) are arranged at the front end and the rear end of the plugging body (4), and the front cover body (2) and the rear cover body (5) are respectively hermetically fitted to the front end and the rear end of the plugging body (4) through the interfaces (42); one end of the adjusting screw rod (3) is movably assembled inside the front cover body (2), and the other end passes through a through hole on the rear cover body (5) and is equipped with a compression nut (6); by adjusting the compression nut (6), the distance between the front cover body (2) and the rear cover body (5) is adjusted, so as to adjust the radial deformation amount of the plugging body (4), and make the protruding section (41) of the plugging body adapt to the throats of engine nozzles (1) with different inner diameters.

2. The variable throat solid rocket engine nozzle plug structure according to claim 1, characterized in that, The plugging body (4) is made of ethylene propylene diene monomer (EPDM) rubber material.

3. The variable-throat solid rocket engine nozzle plug structure according to claim 1, characterized in that, In the natural state without external force, both the inner and outer surfaces of the protruding section (41) in the axial cross-section of the plugging body (4) are an arc, and the central angle range corresponding to the inner arc is 60° to 120°.

4. The variable-throat solid rocket engine nozzle plug structure according to claim 1, characterized in that The thickness of the plugging body (4) is kept consistent, or: The thickness of the plugging body (4) is the smallest at the end points of the protruding section (41), and gradually increases from the end points of the protruding section (41) to both sides; the change trend is linear or non-linear.

5. The variable throat solid rocket motor nozzle plug structure according to claim 1, characterized in that, The minimum thickness of the plugging body (4) cannot be less than 3 mm, and the axial length range of the plugging body (4) is 10 to 60 mm.

6. The variable throat solid rocket engine nozzle plug structure according to claim 1, characterized in that, When adjusting the outward deformation amount of the plugging body (4) through the compression nut (6), the protruding section (41) of the plugging body (4) will be in surface contact or line contact with the throat surface of the engine nozzle (1); the straight section of the throat of the engine nozzle (1) has an axial length of at least 2 - 3 mm, and the inner diameter of the throat of the nozzle 1 is 20 to 200 mm.

7. The variable-throat solid rocket engine nozzle plug structure according to claim 1, characterized in that, The interfaces (42) arranged at the front end and the rear end of the plugging body (4) are annular steps formed on the inner circumferences at the front end and the rear end of the plugging body (4); the front cover body (2) and the rear cover body (5) are respectively assembled into the annular steps at the front and rear ends, and the front and rear ends of the plugging body (4) are hermetically sealed and cured by applying an adhesive at the assembly parts.

8. The variable-throat solid rocket engine nozzle plug structure according to claim 1, wherein A threaded hole (21) is arranged inside the front cover body (2), and the front end of the adjusting screw rod (3) is installed in the threaded hole (21); by rotating the compression nut (6), the compression nut (6) can be made to push the rear cover body (5) to move axially along the adjusting screw rod (3), so as to increase or shorten the distance between the front cover body (2) and the rear cover body (5), change the axial deformation amount of the plugging body (4), and adjust the maximum outer diameter of the plugging body (4) to make it adapt to the throats of different engine nozzles (1).

9. The variable throat solid rocket engine nozzle plug structure according to claim 1, characterized in that, During use, first clean the inner surface of the engine nozzle (1), the outer surface of the plugging body (4), the interfaces (42) at the front and rear ends, and clean the external threads of the adjusting screw rod (3); Assemble the front end of the adjusting screw (3) into the threaded hole (21) inside the front cover body (2) and tighten it. Then, assemble the front cover body (2) onto the interface (42) at the front end of the plugging body (4) and apply adhesive. After that, pass the rear end of the adjusting screw (3) through the through hole in the rear cover body (5), and then assemble the rear cover body (5) onto the interface (42) at the rear end of the plugging body (4) and apply adhesive. Finally, assemble the compression nut (6) at the rear end of the adjusting screw (3). Then, place the entire plugging cover structure at the throat of the engine nozzle (1). After making the adjusting screw (3) coaxial with the engine nozzle (1), rotate the compression nut (6) according to the inner diameter of the throat of the engine nozzle (1) to adjust the radial deformation amount and the installation tightness of the plugging body (4), and finally complete the assembly of the plugging cover structure.

10. A variable throat solid rocket motor nozzle, characterized in that, The nozzle adopts the plugging cover structure according to any one of claims 1-9.

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