阅读说明：本技术 喷管热防护层成型方法 (Method for forming thermal protection layer of spray pipe ) 是由 金秀秀 王付青云 舒威 佘平江 于 2020-12-03 设计创作，主要内容包括：本发明公开了一种喷管热防护层成型方法,所述喷管包括喷管本体和热防护层,包括出片、剪形-贴片装模-真空预压-硫化。通过热防护材料贴片模压成型方法,所制备的热防护层尺寸和外观满足使用要求,解决了传统短纤维增强酚醛树脂热防护材料压力机模压成型不适用于复杂结构喷管热防护层成型的问题。同时通过采用真空箱真空预压整形方法,使热防护材料在硫化前基本定型,防止硫化过程中局部缺料从而在热防护层表面形成缺陷,提高了模压后热防护层的表观质量。成型过程中依靠模具本体和喷管壳体之间的连接结构对热防护层进行加压,因此不需要借助压力机,同时控制热防护层尺寸,模具结构简单,成本低,能够很好的实现定位和脱模,操作方便。(The invention discloses a method for forming a thermal protection layer of a spray pipe, wherein the spray pipe comprises a spray pipe body and the thermal protection layer and comprises the steps of sheet discharging, shearing, surface mounting and mold filling, vacuum preloading and vulcanization. By the thermal protection material patch compression molding method, the size and the appearance of the prepared thermal protection layer meet the use requirements, and the problem that the traditional short fiber reinforced phenolic resin thermal protection material press compression molding is not suitable for the molding of the thermal protection layer of the spray pipe with the complex structure is solved. Meanwhile, the vacuum box vacuum preloading shaping method is adopted, so that the thermal protection material is basically shaped before vulcanization, defects are prevented from being formed on the surface of the thermal protection layer due to local material shortage in the vulcanization process, and the apparent quality of the thermal protection layer after mould pressing is improved. Rely on the connection structure between mould body and the spray tube casing to pressurize the thermal protection layer in the forming process, consequently need not be with the help of the press, the thermal protection layer size of simultaneous control, mould simple structure, it is with low costs, realization location and drawing of patterns that can be fine, convenient operation.)

1. A method for forming a thermal protection layer of a spray pipe, wherein the spray pipe comprises a spray pipe body and the thermal protection layer, and is characterized in that: the molding method comprises the following steps:

1) sheet-out and shear shape

1a) Rolling the thermal protection layer rubber material on an open mill to obtain a sheet;

1b) placing the film into the spray pipe shell, and carrying out shearing according to the molded surface of the thermal protection layer;

2) paster die

2a) Cleaning and airing the molding surface of the mold for later use; cleaning and airing the surface of the spray pipe shell for later use;

2b) coating an adhesive on the surface of the thermal protection layer forming part of the spray pipe shell and the surface of the thermal protection layer film, and drying the adhesive;

2c) carrying out thermal protection layer film pasting on the surface of the thermal protection layer forming part of the spray pipe shell;

2d) after the surface mounting is finished, the spray pipe shell is placed into a mold;

3) vacuum prepressing

Putting the integrally matched spray pipe into a vacuum drying box for vacuumizing and prepressing;

4) and (4) vulcanizing.

2. The method for forming a thermal protection layer of a nozzle according to claim 1, wherein: in the step 1a), the thickness of the film is 0.1-0.3 mm thicker than the theoretical thickness of the thermal protection layer.

3. The method for forming a thermal protection layer of a nozzle according to claim 1, wherein: in the step 1b), the parts which cannot be completely covered are spliced.

4. The method for forming a thermal protection layer of a nozzle according to claim 1, wherein: in the step 2d), the die filling process specifically comprises the following steps: firstly, the unloading module is placed into the die body, then the spray pipe shell and the die body are fixedly connected through bolts, a gap is reserved, and finally the core rod is placed into the die body.

5. The method for forming a thermal protection layer of a nozzle according to claim 1, wherein: and in the step 3), if the part with the material shortage is subjected to glue filling according to the shape of the material shortage position, repeating the step 2) and the step 3) until the surface glue material of the sprayer shell is complete, and vulcanizing after integrally assembling the sprayer shell.

6. The method for forming a thermal protection layer of a nozzle according to claim 1, wherein: in the step 3a), the pre-pressing specifically comprises the following steps: pumping the pressure to-30 KPa to-50 KPa, and keeping the pressure for 30min +/-10 min.

7. The method for forming a thermal protection layer of a nozzle according to claim 1, wherein: the step 4) comprises the following specific vulcanization process:

4a) the mould is stably placed into an oven, and the temperature is raised to 80 +/-10 ℃ along with the oven, and is kept for 30-40 min;

4b) taking out the die, screwing the bolt, detecting the gap between the spray pipe shell and the die body by using a feeler gauge to ensure that the circumferential gap difference is not more than 0.1mm, and then putting the die body into an oven to continuously heat up to 140 +/-10 ℃ for 80-100 min;

4c) and after heat preservation is finished, cutting off the power, discharging the steel plate out of the furnace along with the temperature of the furnace reduced to below 60 ℃, opening the die, and cleaning the flash of the part.

Technical Field

The invention relates to the technical field of manufacturing of thermal protection layers of spray pipes, in particular to a forming method of a thermal protection layer of a spray pipe.

Background

The solid rocket engine jet pipe belongs to a non-cooling structure, is the worst part in the engine for bearing the thermal environment, and needs to rely on an ablation and heat insulation structure to ensure the structural integrity, the change of an inner profile and the temperature control of an outer wall surface within a required range. Due to the complex structure form and the bad working condition, the high requirement is provided for the thermal protection, and the forming method is complex.

The traditional thermal protection layer of the spray pipe is usually formed by die pressing of short fiber reinforced phenolic resin composite materials, the forming process needs to be carried out on a press machine, and larger pressure is needed. However, due to the structural limitation of the nozzle shell, the short fiber reinforced phenolic resin thermal protection layer cannot be formed on the surface of the nozzle shell, or the forming process is complex, and the quality of the thermal protection layer cannot meet the use requirement.

Disclosure of Invention

The invention aims to provide a method for forming a thermal protection layer of a spray pipe, which is convenient to operate and good in quality of the thermal protection layer, and is suitable for forming the thermal protection layer of a structural complex part.

In order to achieve the above object, the present invention provides a method for forming a thermal protection layer of a nozzle, the nozzle including a nozzle body and a thermal protection layer, the method comprising the steps of:

1) sheet-out and shear shape

1a) Rolling the thermal protection layer rubber material on an open mill to obtain a sheet;

1b) placing the film into the spray pipe shell, and carrying out shearing according to the molded surface of the thermal protection layer;

2) paster die

2a) Cleaning and airing the molding surface of the mold for later use; cleaning and airing the surface of the spray pipe shell for later use;

2b) coating an adhesive on the surface of the thermal protection layer forming part of the spray pipe shell and the surface of the thermal protection layer film, and drying the adhesive;

2c) carrying out thermal protection layer film pasting on the surface of the thermal protection layer forming part of the spray pipe shell;

2d) after the surface mounting is finished, the spray pipe shell is placed into a mold;

3) vacuum prepressing

Putting the integrally matched spray pipe into a vacuum drying box for vacuumizing and prepressing;

4) and (4) vulcanizing.

Further, in the step 1a), the thickness of the film is 0.1-0.3 mm thicker than the theoretical thickness of the thermal protection layer.

Further, in the step 1b), the parts which cannot be completely covered are spliced.

Further, in the step 2d), the die filling process specifically includes: firstly, the unloading module is placed into the die body, then the spray pipe shell and the die body are fixedly connected through bolts, a gap is reserved, and finally the core rod is placed into the die body.

Further, in the step 3), if the part with the material shortage is subjected to glue filling according to the shape of the material shortage position, repeating the step 2) and the step 3) until the glue material on the surface of the sprayer shell is complete, and vulcanizing after integrally assembling the mould.

Further, in the step 3a), the pre-pressing specifically comprises the following steps: pumping the pressure to-30 KPa to-50 KPa, and keeping the pressure for 30min +/-10 min.

Further, the specific vulcanization process in the step 4) is as follows:

4a) the mould is stably placed into an oven, and the temperature is raised to 80 +/-10 ℃ along with the oven, and is kept for 30-40 min;

4b) taking out the die, screwing the bolt, detecting the gap between the spray pipe shell and the die body by using a feeler gauge to ensure that the circumferential gap difference is not more than 0.1mm, and then putting the die body into an oven to continuously heat up to 140 +/-10 ℃ for 80-100 min;

4c) and after heat preservation is finished, cutting off the power, discharging the steel plate out of the furnace along with the temperature of the furnace reduced to below 60 ℃, opening the die, and cleaning the flash of the part.

Compared with the prior art, the invention has the following advantages: according to the invention, by the hot protective material patch compression molding method, the size and the appearance of the prepared hot protective layer meet the use requirements, and the problem that the traditional short fiber reinforced phenolic resin hot protective material press compression molding is not suitable for the molding of the hot protective layer of the spray pipe with the complex structure is solved. Meanwhile, the vacuum box vacuum preloading shaping method is adopted, so that the thermal protection material is basically shaped before vulcanization, defects are prevented from being formed on the surface of the thermal protection layer due to local material shortage in the vulcanization process, and the apparent quality of the thermal protection layer after mould pressing is improved. Rely on the connection structure between mould body and the spray tube casing to pressurize the thermal protection layer in the forming process, consequently need not be with the help of the press, the thermal protection layer size of simultaneous control, mould simple structure, it is with low costs, realization location and drawing of patterns that can be fine, convenient operation.

Drawings

FIG. 1 is a schematic view of a nozzle configuration;

fig. 2 is a schematic view of the mold installation.

Detailed Description

The invention is described in further detail below with reference to the figures and the specific embodiments.

A method for forming a thermal protection layer of a spray pipe comprises a spray pipe body 2 and the thermal protection layer 1 as shown in figure 1, and specifically comprises the following steps:

1) sheet-out and shear shape

1a) Rolling the thermal protection layer rubber material on an open mill to obtain a film, and ensuring that the thickness of the film is 0.1-0.3 mm thicker than the theoretical thickness of the thermal protection layer; the thermal protection layer rubber material adopts ethylene propylene diene monomer material or 5-III material;

1b) and (4) placing the film into the spray pipe shell, shearing according to the molded surface of the thermal protection layer, and splicing the part which cannot be completely covered.

2) Mounting a piece and die assembling:

2a) cleaning and airing the molding surface of the mold for later use; meanwhile, the surface of the spray pipe shell is cleaned and dried for later use;

2b) coating an adhesive on the surface of the thermal protection layer forming part of the spray pipe shell and the surface of the thermal protection layer film, and drying the adhesive; the adhesive is prepared from Kernel, 730 adhesive and other adhesives matched with the thermal protective layer material;

2c) carrying out thermal protection layer film pasting on the surface of the thermal protection layer forming part of the spray pipe shell;

2d) after the surface mounting is finished, the unloading module 4 is firstly placed into the die body 3, then the spray pipe shell and the die body 3 are fixedly connected through the bolt 6, a gap is reserved, and finally the core rod 5 is placed into the die body, as shown in fig. 2;

3) vacuum prepressing

3a) Putting the integrally matched spray pipe into a vacuum drying box for vacuumizing, pumping the pressure to-30 KPa to-50 KPa, maintaining the pressure for 30min +/-10 min, then taking out the spray pipe, and cleaning redundant rubber materials;

3b) if the part with the material shortage is subjected to glue filling according to the shape of the material shortage position, repeating the step 2) and the step 3) until the surface of the sprayer shell is complete in glue, and integrally assembling the sprayer shell and then vulcanizing;

by adopting a vacuum preloading method, the thermal protection material is basically shaped before vulcanization, and the apparent quality of the thermal protection layer after mould pressing is improved.

4) Vulcanization

4a) The mould is stably placed into an oven, and the temperature is raised to 80 +/-10 ℃ along with the oven, and is kept for 30-40 min;

4b) taking out the die, screwing the bolt, detecting the gap between the spray pipe shell and the die body by using a feeler gauge to ensure that the circumferential gap difference is not more than 0.1mm, and then putting the die body into an oven to continuously heat up to 140 +/-10 ℃ for 80-100 min;

4c) and after heat preservation is finished, cutting off the power, discharging the steel plate out of the furnace along with the temperature of the furnace reduced to below 60 ℃, opening the die, and cleaning the flash of the part.

The mould comprises a core rod, a mould body and a disassembling module, and is simple in structure, low in cost, convenient to operate, and capable of achieving positioning and demoulding well.

According to the invention, by the hot protective material patch compression molding method, the size and the appearance of the prepared hot protective layer meet the use requirements, and the problem that the traditional short fiber reinforced phenolic resin hot protective material press compression molding is not suitable for the molding of the hot protective layer of the spray pipe with the complex structure is solved. Meanwhile, the vacuum box vacuum preloading shaping method is adopted, so that the thermal protection material is basically shaped before vulcanization, defects are prevented from being formed on the surface of the thermal protection layer due to local material shortage in the vulcanization process, and the apparent quality of the thermal protection layer after mould pressing is improved. Rely on the connection structure between mould body and the spray tube casing to pressurize the thermal protection layer in the forming process, control the thermal protection layer size simultaneously, mould simple structure, it is with low costs, realization location and drawing of patterns that can be fine, convenient operation.