Engine medicine baffle assembly and preparation process

Abstract

The invention provides an engine medicine baffle assembly and a preparation process, the engine medicine baffle assembly comprises a metal base, the metal base is provided with a medicine baffle buffer layer, and the medicine baffle buffer layer is prepared from the following raw materials: liquid silicone rubber, a flexibilizer, silica powder, zirconium boride, carbon fibers, quartz fibers and polyimide fibers. According to the process, integrated compression molding of the medicine baffle assembly of the engine is achieved through a special mold. The invention provides the silicone rubber-based explosive baffle assembly with good comprehensive performance and mold pressing fluidity, and reliable support for the explosive column and the ignition device can be realized. According to the engine medicine baffle assembly, the problems that in the prior art, when a medicine baffle buffer layer is made of organic materials such as polyurethane and ethylene propylene diene monomer or inorganic coatings such as silicate and zirconium oxide, the steps are tedious, the material performance cannot meet the requirement, or the cost is high are effectively solved.

Description

Technical Field

[0001] The invention belongs to the technical field of solid rocket engines and relates to a drug baffle assembly, and in particular to an engine drug baffle assembly and a preparation process thereof. Background Art

[0002] The charge baffle assembly is an important component of a solid rocket engine based on free-loading charges. Its main function is to limit the propellant column and fix the ignition cartridge, support, buffer and resist ablation of the charge and ignition cartridge, prevent the charge or its fragments from entering the nozzle, protect the structural integrity of the engine, and ensure the normal flow of high-temperature combustion gas generated by the propellant. In order to ensure the normal and reliable operation of the engine, the charge baffle assembly must have the following characteristics: good mechanical properties and ablation resistance to support the charge and ignition cartridge, while resisting the scouring and ablation of high-temperature, high-speed combustion gas and particles generated during the combustion of the propellant; relatively low overall density to avoid negative mass; good processing technology, which can be easily molded and manufactured. The charge baffle assembly must be able to withstand the scouring and ablation of high-temperature, high-speed combustion gas rich in particles up to 3600K.

[0003] At present, the commonly used materials or structural schemes of the medicine baffle assembly mainly include: high-hardness alloy, high-temperature resistant alloy, metal base + ablation-resistant layer. Among them, the first two both lead to a large negative weight of the medicine baffle. At the same time, during the operation, the particles or droplets formed by melt peeling and ablation are easy to clog the nozzle, and even directly affect the stability of the combustion surface. In addition, high-temperature resistant alloys also have problems such as high manufacturing cost and difficulty in processing. The bottom of the metal base + ablation-resistant layer medicine baffle assembly can use economical steel, and the surface can be bonded, paved, and coated with ablation-resistant organic or inorganic materials, such as ablation-resistant nitrile, ablation-resistant EPDM, phenolic resin-based composite materials or inorganic coatings.

[0004] The Chinese patent with application number CN201320430843.6 proposes a propellant column fixing device for rocket engines, which is mainly composed of a sealing ring, an elastic retaining ring and a positioning body, and can achieve reliable fixation of the propellant column. The Chinese patent with application number CN201710699645.2 proposes a thermal barrier coating drug baffle structure based on a double-layer hollow structure metal substrate. The structure requires an MCrAlY alloy bonding layer and a ZrO2 coating, which needs to be processed by high-temperature plasma spraying, which is costly and complex. However, on the one hand, traditional non-metallic materials often have problems of low strength or high-temperature embrittlement / carbonization peeling. On the other hand, when the surface of the drug baffle assembly is more complex (for example, a special-shaped structure containing a large number of corners, concave cavities or straight edges), the use of a pressing and then bonding or coating process has the problem of difficult control of bonding surface quality or high cost, and sometimes it is even difficult to manufacture a complex surface ablation-resistant layer. It can be seen that the ablation-resistant layer or buffer layer materials involved in the drug baffle assembly often cannot simultaneously meet the comprehensive requirements of good mechanics, ablation resistance, low density and easy processing. Summary of the invention

[0005] In view of the deficiencies in the prior art, an object of the present invention is to provide an engine medicine baffle assembly to solve the technical problem that the reliability of the material of the engine medicine baffle assembly in the prior art needs to be further improved.

[0006] The purpose of the present invention is to provide a preparation process of an engine medicine baffle assembly, so as to solve the technical problem that the processability of the preparation process of the engine medicine baffle assembly in the prior art needs to be further improved.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0008] An engine drug baffle assembly comprises a metal base, on which a drug baffle buffer layer is arranged, and the drug baffle buffer layer is made of the following raw materials: liquid silicone rubber, toughening agent, silicon micropowder, zirconium boride, carbon fiber, quartz fiber and polyimide fiber.

[0009] The present invention also has the following technical features:

[0010] Specifically, the drug baffle buffer layer is composed of the following raw materials, measured by weight: 100 parts of liquid silicone rubber, 2 to 5 parts of toughening agent, 14 to 30 parts of silicon micropowder, 3 to 11 parts of zirconium boride, 3 to 8 parts of carbon fiber, 0.5 to 3 parts of quartz fiber, and 0.5 to 2 parts of polyimide fiber.

[0011] Preferably, the drug baffle buffer layer material is composed of the following raw materials in parts by weight: 100 parts of liquid silicone rubber, 5 parts of toughening agent, 30 parts of silicon micropowder, 10 parts of zirconium boride, 8 parts of carbon fiber, 2 parts of quartz fiber, and 2 parts of polyimide fiber.

[0012] The present invention also protects a preparation process of the engine medicine baffle assembly as described above, which realizes the integrated compression molding of the engine medicine baffle assembly through a special mold; the special mold includes a center seat, a center axis is coaxially arranged on the center seat, a detachable positioning ring is coaxially mounted on the center axis, a detachable retaining ring is coaxially mounted on the center seat outside the positioning ring, and a detachable pressure cover is installed between the retaining ring and the positioning ring.

[0013] The cavity surrounded by the center seat, the center shaft, the positioning ring, the retaining ring and the pressure cover is the medicine retaining plate assembly cavity.

[0014] Specifically, the process includes the following steps:

[0015] Step 1: Processing of metal base:

[0016] Step 2: Pretreatment of metal base:

[0017] The surface to be bonded of the metal base obtained in step 1 is processed.

[0018] Step three, prepare the raw materials for the buffer layer of the medicine baffle.

[0019] Step 4: Molding the rough blank of the medicine retaining plate assembly:

[0020] Place the metal base in the cavity of the medicine baffle assembly of the special mold, install a retaining ring on the outside of the metal base, install a positioning ring on the central axis, load the raw material of the medicine baffle buffer layer into the cavity of the medicine baffle assembly, press tightly, so that the raw material of the medicine baffle buffer layer is evenly spread on the surface to be bonded of the metal base; then cover it with the pressure cover of the special mold.

[0021] The matching parts consisting of the special mold, the metal base and the raw materials of the medicine baffle plate buffer layer are placed on a flat vulcanizer, molded, and then heat-insulated, solidified, cooled and demoulded to obtain a rough blank of the medicine baffle plate assembly.

[0022] Step 5: Shape the rough blank of the medicine baffle assembly:

[0023] The rough blank of the medicine baffle plate assembly is shaped to obtain the medicine baffle plate assembly.

[0024] Preferably, in step four, during the heat preservation and curing stage, the center seat and the positioning ring are locked by a first bolt; the center seat, the retaining ring and the pressure cover are locked by a second bolt; and the locked mating parts are then placed in an oven or a curing furnace for heating and curing.

[0025] Preferably, in step four, the process conditions of the compression molding are: molding at 80±5℃, 2MPa for 4±0.5h or molding at 120℃±5℃, 2MPa for 2±0.5h; the process conditions of heat preservation and curing are: heat preservation at 80±5℃, 2MPa for 4±0.5h or heat preservation at 120℃±5℃, 2MPa for 2±0.5h.

[0026] Preferably, in step 2, the pretreatment steps include: pickling, alkali washing, cleaning, drying, sandblasting, cleaning and primer coating.

[0027] Preferably, the specific process of step three includes the following steps:

[0028] Step 301, the liquid silicone rubber is a two-component liquid silicone rubber including component A and component B; the component A and component B are used in a mass ratio of 1:1; a toughening agent, silicon micropowder and zirconium boride are added to component A of the liquid silicone rubber and mixed evenly to obtain a paste-like rubber material.

[0029] Step 302, adding carbon fiber, quartz fiber and polyimide fiber to the paste-like rubber material obtained in step 1 and dispersing them evenly to obtain a lump-like rubber material.

[0030] Step 303, adding the B component of the liquid silicone rubber to the lump rubber material obtained in step 2, and mixing the materials evenly to obtain the raw material of the buffer layer of the drug blocking plate.

[0031] Compared with the prior art, the present invention has the following technical effects:

[0032] (I) The present invention proposes a silicone rubber-based drug baffle assembly with good comprehensive performance and molded fluidity, which can achieve reliable support for drug columns and ignition devices.

[0033] (II) The engine drug baffle assembly of the present invention effectively overcomes the problems in the prior art of using organic materials such as polyurethane and EPDM rubber for the drug baffle buffer layer, or using inorganic coatings such as silicate and zirconium oxide, such as complicated steps, material performance that cannot meet the requirements, or high costs.

[0034] (III) The engine medicine baffle assembly special mold of the present invention can be used by direct molding and curing, or it can be transferred to an oven or a curing furnace for heating and curing after tightening the screws.

[0035] (IV) The preparation process of the drug baffle assembly of the present invention can be quickly prepared and formed. While achieving material properties that meet design requirements, it has the effects of simple operation, low supporting process cost and strong process adaptability, and provides a new idea for the controllable, reliable and low-cost manufacturing of the drug baffle assembly of solid rocket engines based on free-loading charges, which is common in the fields of aerospace and weapon equipment manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the overall structure of the medicine baffle assembly.

[0037] Figure 2 for Figure 1 Schematic cross-sectional view of .

[0038] Figure 3 A schematic diagram of the structure of a special mold for a medicine baffle assembly.

[0039] Figure 4 Schematic diagram of the assembly of the special mold for the medicine baffle assembly.

[0040] Figure 5 This is the physical appearance picture of the medicine baffle assembly.

[0041] The meanings of the numbers in the figure are: 1-metal base, 2-medicine baffle buffer layer, 3-special mold.

[0042] 301 - center seat, 302 - center axis, 303 - positioning ring, 304 - retaining ring, 305 - pressure cover, 306 - medicine retaining plate assembly cavity, 307 - first bolt, 308 - second bolt.

[0043] The specific contents of the present invention are further described in detail below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0044] It should be noted that, unless otherwise specified, all components and materials in the present invention are components and materials known in the prior art.

[0045] In accordance with the above technical scheme, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical scheme of this application fall within the protection scope of the present invention.

[0046] Embodiment 1:

[0047] This embodiment provides an engine medicine baffle assembly, such as Figure 1 and Figure 2 As shown, it comprises a metal base 1 on which a drug baffle buffer layer 2 is arranged.

[0048] In this embodiment, the structure of the drug baffle assembly is generally a disc-shaped structure with flower holes, and its specific structure is determined in the overall design stage of the engine. In this embodiment, the development of a drug baffle assembly in a small solid rocket engine is used as an example for explanation.

[0049] In this embodiment, the shape and material of the metal base 1 are usually determined by the overall design of the engine, and the processing method is achieved through common metal processing technology.

[0050] The drug baffle buffer layer 2 is composed of the following raw materials by weight: 100 parts of liquid silicone rubber, 5 parts of toughening agent, 30 parts of silicon micropowder, 10 parts of zirconium boride, 8 parts of carbon fiber, 2 parts of quartz fiber and 2 parts of polyimide fiber.

[0051] As a preferred solution of this embodiment, the liquid silicone rubber is a two-component liquid silicone rubber including component A and component B; the two-component liquid silicone rubber adopts a known commercially available two-component liquid silicone rubber, wherein component A contains a platinum catalyst and component B contains methyl hydrogen siloxane. Component A and component B are used in a mass ratio of 1:1.

[0052] In this embodiment, the toughening agent is an epoxy resin toughening agent modified by epoxy-terminated hyperbranched polyester; further, the toughening agent is a CYH-277 hyperbranched polyester toughening agent.

[0053] In this embodiment, the silicon micropowder is silicon dioxide silicon micropowder modified by silane coupling agent A151. Silane coupling agent A151 is vinyl triethoxysilane; the specific modification method can be a commonly used modification method known in the art, and the particle size of the silicon micropowder is 375 mesh. Further, the silicon micropowder in this embodiment can also be silicon dioxide silicon micropowder modified by silane coupling agent A171 or silicon dioxide silicon micropowder modified by hexamethyldisilazane; the specific modification method can be a commonly used modification method known in the art, and silane coupling agent A171 is vinyl trimethoxysilane. The particle size of the silicon micropowder is 375 mesh.

[0054] In this embodiment, the carbon fiber and the quartz fiber are both chopped fibers, and the specifications of the carbon fiber and the quartz fiber are both 4-6 mm.

[0055] In this embodiment, the polyimide fiber is a pulp-type polyimide fiber, which is a known commercially available pulp-type polyimide fiber.

[0056] Embodiment 2:

[0057] This embodiment provides a preparation process of the engine medicine baffle assembly provided in Embodiment 1, and the process realizes the integrated compression molding of the engine medicine baffle assembly through a special mold 3; Figure 3As shown, the special mold 3 includes a center seat 301, a center axis 302 is coaxially arranged on the center seat 301, a detachable positioning ring 303 is coaxially mounted on the center axis 302, a detachable retaining ring 304 is coaxially mounted on the center seat 301 outside the positioning ring 303, and a detachable pressure cover 305 is installed between the retaining ring 304 and the positioning ring 303.

[0058] like Figure 3 As shown, the cavity surrounded by the center seat 301 , the center shaft 302 , the positioning ring 303 , the retaining ring 304 and the pressure cover 305 is the medicine retaining plate assembly cavity 306 .

[0059] The process specifically includes the following steps:

[0060] Step 1: Processing of metal base:

[0061] The metal base 1 is processed according to the design requirements.

[0062] Step 2: Pretreatment of metal base:

[0063] The surface to be bonded of the metal base 1 obtained in step 1 is treated, and the pretreatment steps include: pickling, alkali washing, cleaning, drying, sandblasting, cleaning and primer coating.

[0064] Step 3: Prepare the raw materials for the buffer layer of the drug baffle:

[0065] Step 301, adding toughening agent, silicon powder and zirconium boride to component A of liquid silicone rubber, and mixing them evenly by high-speed stirring, kneading, internal mixing or three-roll grinding to obtain a paste-like rubber material.

[0066] Step 302, adding carbon fiber, quartz fiber and polyimide fiber to the paste-like rubber material obtained in step 1, and uniformly dispersing the carbon fiber, quartz fiber and polyimide fiber by high-speed dispersion, vertical kneading or planetary mixing to obtain a mass-like rubber material.

[0067] Step 303 , adding the B component of the liquid silicone rubber to the lump rubber material obtained in step 2 , and mixing the materials evenly by vertical kneading or planetary mixing to obtain the raw material of the drug baffle buffer layer 2 .

[0068] Step 4: Molding the rough blank of the medicine retaining plate assembly:

[0069] The metal base 1 is placed in the cavity 306 of the medicine baffle assembly of the special mold 3, the retaining ring 304 is mounted on the outside of the metal base 1, and the positioning ring 303 is mounted on the central axis 302. The raw material of the medicine baffle buffer layer 2 is loaded into the cavity 306 of the medicine baffle assembly and pressed tightly so that the raw material of the medicine baffle buffer layer 2 is evenly spread on the surface to be bonded of the metal base 1; then the pressure cover 305 of the special mold 3 is covered.

[0070] The mating parts composed of the special mold 3, the metal base 1 and the raw materials of the medicine baffle plate buffer layer 2 are placed on a flat vulcanizer, molded, and then heat-insulated, solidified, cooled and demoulded to obtain a rough blank of the medicine baffle plate assembly.

[0071] In step 4, the process conditions for compression molding are: molding at 120°C ± 5°C, 2MPa for 2±0.5h; the process conditions for heat preservation and curing are: heat preservation at 120°C ± 5°C, 2MPa for 2±0.5h.

[0072] In step 4, preferably, the heat preservation and curing stage is as follows: Figure 4 As shown, the center seat 301 and the positioning ring 303 are locked by a first bolt 307; the center seat 301, the retaining ring 304 and the pressure cover 305 are locked by a second bolt 308; and the locked mating parts are then placed in an oven or a curing furnace for heating and curing.

[0073] Step 5: Shape the rough blank of the medicine baffle assembly:

[0074] The rough blank of the medicine baffle assembly is shaped according to the product design requirements to obtain the medicine baffle assembly.

[0075] In this embodiment, the actual appearance photo of the prepared drug blocking plate assembly is shown in Figure 5 .

[0076] This embodiment simultaneously tests the physical and chemical properties of the drug baffle buffer layer material, and the test values ​​are shown in Table 1. From Table 1, it can be seen that the drug baffle buffer layer material prepared according to the present invention has low density, low ablation rate, and excellent comprehensive performance.

[0077] Table 1 Physical and chemical properties of the drug baffle buffer layer material

[0078] Serial number project unit Measured value Test Method 1 density <![CDATA[g / cm 3 ]]> 1.38 GB / T 533-2008 2 Tensile Strength MPa 5.8 GB / T 528-2009 3 Elongation ％ 15.0 GB / T 528-2009 4 Hardness(Shore A) / 65 GBT 531.1-2008 5 Bonding strength (to metal) MPa 2.2 GB / T 13936-2014 6 Line ablation rate mm / s 0.07 GJB 323B-2018 7 Thermal conductivity W / (m·K) 0.45 GB / T 11205-2009

Claims

1. An engine drug baffle assembly, comprising a metal base (1), a drug baffle buffer layer (2) being arranged on the metal base (1), characterized in that: The drug baffle buffer layer (2) is made of the following raw materials: liquid silicone rubber, toughening agent, silicon micropowder, zirconium boride, carbon fiber, quartz fiber and polyimide fiber.

2. The engine pill plate assembly according to claim 1, characterized in that: The drug baffle buffer layer (2) is composed of the following raw materials in parts by weight: 100 parts of liquid silicone rubber, 2-5 parts of toughening agent, 14-30 parts of silicon micropowder, 3-11 parts of zirconium boride, 3-8 parts of carbon fiber, 0.5-3 parts of quartz fiber, and 0.5-2 parts of polyimide fiber.

3. The engine pill plate assembly according to claim 1, characterized in that: The drug baffle buffer layer (2) is composed of the following raw materials in parts by weight: 100 parts of liquid silicone rubber, 5 parts of toughening agent, 30 parts of silicon micropowder, 10 parts of zirconium boride, 8 parts of carbon fiber, 2 parts of quartz fiber, and 2 parts of polyimide fiber.

4. A process for preparing an engine medicine baffle assembly according to any one of claims 1 to 3, characterized in that: The process realizes integrated compression molding of an engine medicine baffle assembly by using a special mold (3); the special mold (3) comprises a center seat (301), a center shaft (302) is coaxially arranged on the center seat (301), a detachable positioning ring (303) is coaxially mounted on the center shaft (302), a detachable retaining ring (304) is coaxially mounted on the center seat (301) outside the positioning ring (303), and a detachable pressure cover (305) is installed between the retaining ring (304) and the positioning ring (303); The cavity enclosed by the center seat (301), the center shaft (302), the positioning ring (303), the retaining ring (304) and the pressure cover (305) is the medicine retaining plate assembly cavity (306).

5. The process for preparing the engine medicine baffle assembly according to claim 4, characterized in that: The process specifically includes the following steps: Step 1: Processing of metal base: Step 2: Pretreatment of metal base: Treating the surface to be bonded of the metal base (1) obtained in step 1; Features: Step three, configuring the buffer layer material of the drug baffle; Step 4: Molding the rough blank of the medicine baffle assembly: The metal base (1) is placed in the cavity (306) of the medicine baffle assembly of the special mold (3), a retaining ring (304) is mounted on the outside of the metal base (1), a positioning ring (303) is mounted on the central axis (302), the raw material of the medicine baffle buffer layer (2) is loaded into the cavity (306) of the medicine baffle assembly, and pressed tightly so that the raw material of the medicine baffle buffer layer (2) is evenly spread on the surface to be bonded of the metal base (1); and then the pressure cover (305) of the special mold (3) is covered; Placing the matching parts composed of the special mold (3), the metal base (1) and the raw materials of the drug baffle plate buffer layer (2) on a flat vulcanizer, molding them, and then heat-insulating, curing, cooling and demoulding to obtain a rough blank of the drug baffle plate assembly; Step 5: Shape the rough blank of the medicine baffle assembly: The rough blank of the medicine baffle plate assembly is shaped to obtain the medicine baffle plate assembly.

6. The process for preparing the engine medicine baffle assembly according to claim 5, characterized in that: In step 4, the process conditions of the compression molding are: molding at 80±5℃, 2MPa for 4±0.5h or molding at 120℃±5℃, 2MPa for 2±0.5h; the process conditions of thermal insulation and curing are: thermal insulation at 80±5℃, 2MPa for 4±0.5h or thermal insulation at 120℃±5℃, 2MPa for 2±0.5h.

7. The process for preparing the engine medicine baffle assembly according to claim 5, characterized in that: In step 4, during the heat preservation and curing stage, the center seat (301) and the positioning ring (303) are locked by a first bolt (307); the center seat (301) and the retaining ring (304) and the pressure cover (305) are locked by a second bolt (308); and the locked mating parts are then placed in an oven or a curing furnace for heating and curing.

8. The process for preparing the engine medicine baffle assembly according to claim 5, characterized in that: In step 2, the pretreatment steps include: pickling, alkali washing, cleaning, drying, sandblasting, cleaning and primer coating.

9. The process for preparing the engine medicine baffle assembly according to claim 5, characterized in that: The specific process of step three includes the following steps: Step 301, the liquid silicone rubber is a two-component liquid silicone rubber including component A and component B; the component A and component B are used in a mass ratio of 1:1; a toughening agent, silicon micropowder and zirconium boride are added to component A of the liquid silicone rubber and mixed evenly to obtain a paste-like rubber material; Step 302, adding carbon fiber, quartz fiber and polyimide fiber to the paste-like rubber material obtained in step 1 and dispersing them evenly to obtain a lump-like rubber material; Step 303, adding the B component of the liquid silicone rubber to the lump rubber material obtained in step 2, and mixing the materials evenly to obtain the drug blocking plate buffer layer (2) material.

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