CN115384083A - Method for manufacturing full-opening composite material shell - Google Patents

Abstract

The invention discloses a method for manufacturing a full-opening composite material shell in the technical field of space engines, which comprises the following steps: 1) Manufacturing a composite material joint, and processing the composite material joint into a necking end joint and an opening end joint; 2) Manufacturing a core mold; 3) Paving and sticking a heat insulating layer; 4) Preforming a heat insulating layer; 5) Installing a connector; 6) Winding the inner side, namely winding the carbon fiber soaked with the medium-temperature epoxy resin, adopting a winding mode of alternately winding in a longitudinal direction and winding in a circumferential direction, adjusting and controlling the tension of the fiber before winding, and adjusting and controlling the tension according to the requirement of gradually decreasing the tension from inside to outside in a gradient manner; 7) Winding the outer side, winding the carbon fiber soaked with the medium-temperature epoxy resin on the inner winding layer again, adopting a hoop winding mode, adjusting and controlling the tension of the fiber before winding, and adjusting and controlling the tension according to the requirement of gradually gradient-type decreasing from the inner tension to the outer tension; 8) Curing; 9) Demolding; 10 Detection; the invention improves the strength of the casing with full opening.

Description

Method for manufacturing full-opening composite material shell

Technical Field

The invention relates to the technical field of aerospace engines, in particular to a method for manufacturing an engine shell.

Background

In the 21 st century, an engine shell is a main power device of various missile weapons, is widely applied to the field of aerospace, and has the characteristics of simple structure, and is very suitable for the requirements of modern wars and aerospace industry due to a series of advantages of mobility, reliability, easy maintenance and the like.

In the 60's of the 20 th century, composite engine casings were used on American rocket engines, and then, a great deal of research work was carried out in all countries, most of the rocket engines at present adopt carbon fiber wound epoxy resin composite materials, but parts such as flange joints and the like of the rocket engines still adopt metal materials, so that space for further improving weight reduction is provided, and the bonding strength of the metal joints, the ablation-resistant heat-insulating layers and the winding layers is always a technical problem in the industry.

At present, the full-opening engine shell is mainly made of metal materials, the density of the metal materials is high, the manufactured engine shell is heavy in weight and has large influence on the range and the speed of a rocket, the fuel consumption of the metal engine shell is large, and the demand of commercial satellites is higher and higher at present, so that the demand of the rocket engine shell with light weight, high performance and low cost is higher and higher. In order to realize weight reduction, a common full-open engine shell in the prior art generally adopts a mode of matching a composite material cylinder body with a metal joint, because metal and composite materials have thermal expansion mismatching and large modulus difference, the joint of the metal and the composite materials has deformation mismatching under temperature change or stress change, and in addition, the joint of the metal and the composite materials generally needs to be thickened and has heavier weight.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a method for manufacturing a full-opening composite material shell, which changes the situation that the bonding strength between a metal joint and a composite layer is not high in the prior art, and uses the composite material joint to bond with the composite shell, so that the strength of a body and the bonding strength are improved, and the problem that the full-opening composite material shell is difficult to produce and process on the premise of ensuring the reliability and the strength is solved.

The purpose of the invention is realized as follows: a manufacturing method of a full-opening composite shell comprises the following steps:

step 1) manufacturing a composite material joint, and processing the composite material joint into a necking end joint and an opening end joint;

step 2), manufacturing a core mold;

step 3), paving and pasting a heat insulating layer, and paving and pasting a heat insulating layer on the surface of the core mold;

step 4), performing heat insulation layer, and performing vacuum pumping and pressurizing on the heat insulation layer;

step 5), installing a connector, namely installing a necking end connector and an opening end connector at corresponding positions on the core mold;

step 6), winding the inner side, namely winding the carbon fiber soaked in the medium-temperature epoxy resin, adopting a winding mode of alternately winding in a longitudinal direction and winding in a circumferential direction, adjusting and controlling the tension of the fiber before winding, and adjusting and controlling the tension according to the requirement of gradually decreasing the tension from inside to outside in a gradient manner;

step 7) outer winding, namely winding the carbon fiber soaked with the medium-temperature epoxy resin on the winding layer on the inner side of the opening end again, adjusting and controlling the tension of the fiber before winding in a hoop winding mode, and adjusting and controlling the tension according to the requirement of gradual gradient type decreasing from inner tension to outer tension;

step 8), curing, namely heating and curing at normal pressure, and jointly curing the shell winding layer and the heat insulating layer;

step 9), demolding, namely detaching the shell from the core mold;

and step 10) detection, including size detection, nondestructive detection, airtight detection and water pressure detection.

As a further limitation of the invention, in the winding process of the step 6), the polar hole connected with the joint and the end socket is reinforced, and a reinforcing layer is laid between the adjacent longitudinal layers.

As a further limitation of the present invention, the reinforcing layer is made of plain cloth made of glass fiber material.

As a further limitation of the present invention, the reinforcement is specifically: during reinforcement, the equipment keeps rotating, and by taking two sides of the end socket column section as starting points, the reinforcing layer is laid and attached in the annular direction along the equator towards polar holes on two sides.

As a further limitation of the present invention, when wrinkles are formed during the process of laying the reinforcing layer, the region close to the column section is not cut, and the region far from the column section is cut with a knife.

As a further limitation of the present invention, in step 5), an elastic layer is applied to the surface of the joint during the installation of the joint.

The method comprises the following steps of 6) and 7), firstly, adjusting and controlling the fiber tension before winding to achieve the specified tension precision, and specifically comprises the following steps:

in the actual winding process, if tension is not detected and adjusted, the tension of the fiber layer is gradually reduced layer by layer, so that the situation of internal looseness and external tightness can occur, because the fiber wound on the fiber layer after winding can cause the fiber layer wound firstly and the inner layer to contract and deform together due to the tension effect, the fiber on the inner layer becomes loose, if proper tension is not tested in advance, the situation of internal looseness and external tightness of the fiber on the shell can be caused, the initial stress of the fiber on the surface and the fiber on the inner layer is greatly different, the fiber cannot be uniformly stressed when the container is pressurized, and serious people can cause the buckling situations of wrinkle, liner bubbling, deformation and the like of the fiber on the inner layer, so that the strength and the fatigue function of the shell are greatly reduced; therefore, the winding fiber is ensured to meet the requirement by detecting the tension before winding, the condition of internal looseness and external tightness is avoided, specifically, whether the tension of the fiber meets the requirement or not is detected, the tension can be adjusted according to the requirement subsequently, but the tension detection is carried out on the premise, if no tension detection link exists, the subsequent adjustment cannot be realized, and thus all winding layers have the same deformation and initial tension from inside to outside; when the shell container is pressurized, the fibers can still be stressed, so that the strength of the container is improved, and the strength of the fibers can be better improved.

In order to simultaneously ensure the volume content and the fiber performance coefficient of the fiber and reduce the abrasion degree of the fiber as much as possible, the winding tension of the fiber layer by layer is controlled, when the inner layer is wound, the longitudinal winding layer and the circumferential winding layer are alternately carried out, and the gradient tension can enable the fibers of all layers of the winding shell from inside to outside to have the same prestress, so that the shell can play the whole effect of the composite material when working, the fiber performance coefficient of the whole shell wound by the same tension is generally about 70 percent from the practical shrinkage shell blasting experience, and the fiber performance coefficient of the system design gradient tension shell blasting strength can reach more than 85 percent.

In order to ensure that the seal head has uniform and symmetrical thickness distribution, a reinforcing layer is paved between the adjacent longitudinal layers; the glass fiber cloth is used as a reinforcing layer instead of the weftless cloth; the longitudinal direction and the latitudinal direction near the polar hole of the end socket can be strengthened, and the reinforcement is local, namely the reinforcement is only limited near the polar hole connected with the end socket; considering convenient process implementation, the overall reinforcement of the whole end socket is difficult, the reinforcement near the equator brings inconvenience to the upper skirt construction, and the strength of the whole end socket is mainly completed by adjusting the thickness of the end socket, namely adjusting the stress balance coefficient ks; the glass fiber has higher fracture strain and fracture toughness, although the strength is lower than that of the carbon fiber, the mixed positive effect can be realized, and the carbon fiber shell end socket is reinforced by the glass cloth, so that the defect that the carbon fiber is easy to break can be overcome.

And determining reinforcing areas of the front and rear seal heads according to the rigidity difference of the joint structure part in the area with larger strain in the shell and the accuracy of the practical executable operation position, wherein the two sides of the column section of the front and rear seal heads are taken as starting points and the reinforcement is carried out along the equator to the polar hole directions of the two sides.

Compared with the prior art, the invention has the beneficial effect that.

The adoption of the shell made of the full composite material reduces the weight and improves the efficiency of the container.

The heat insulation layer is adopted, and the layer is paved after the joint is installed, so that the joint is ensured to be bonded with the heat insulation, and the influence of the traditional compression molding pressure of the seal head on the joint is avoided.

The full-opening carbon fiber composite material is optimized in structure, the end socket and the opening are reinforced, the weight of the combustion chamber is reduced, the overall performance of a product is improved, and the overall connection strength of the shell is improved.

Because the metal and the composite material have thermal expansion mismatch and large modulus difference, the joint of the metal and the composite material has deformation mismatch under the temperature change or stress change, in addition, the joint of the metal and the composite material generally needs to be thickened and has heavier weight, the shell of the invention changes the condition that the bonding strength of the metal joint and the composite layer is not high in the prior art, and the composite material joint and the composite bonding are used, so that the body strength and the bonding strength are improved.

According to the size of the opening of the combustion chamber shell, the diameter of the column section and the like, the winding angle and the number of winding layers are provided, and the joint of the closing-up section and the opening section is subjected to reinforcement design, so that the mechanical property index requirement is met.

Through process selection and optimization, tension application and tension gradient design are controlled, the quality of a winding layer product is improved, the quality and the production efficiency of the product are improved through mold design optimization, the weight is reduced, and the cost is reduced; compared with the traditional shell, the weight of the shell can be reduced by more than 40% under the conditions of the volume and the strength of the cylinder.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a cross-sectional view of the housing of the present invention.

Fig. 2 is a schematic illustration of the various regions of the housing of the present invention.

FIG. 3 is a schematic view of the present invention.

FIG. 4 is a schematic view of the joint of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The existing fiber winding technology and mature technology are combined with the material selection experience of various winding shells and launching tube products, a T700 fiber reinforced epoxy resin system is selected for a carbon fiber winding part, the material is selected according to the design requirements of a joint, and the performance data of the material system is as follows:

for the characteristics of the product, the full-open carbon fiber composite combustion chamber adopts a metal core mold, 2 full-open carbon fiber composite combustion chambers are formed by one-time winding (the forming schematic diagram is shown in figure 3), and after the forming is finished, the middle part of the formed combustion chamber is cut open, so that 2 independent full-open carbon fiber composite combustion chambers can be obtained by demolding.

The joint at the necking end can be directly embedded into the composite material before the first winding; the open end is reinforced through carrying out axial shop's layer reinforcement and hoop winding reinforcement, and the joint strength can be guaranteed through calculating the combined material screw thread to machine behind the product drawing of patterns with the combined material screw thread.

The process route of the invention is as follows:

composite material joint manufacturing = > core mould manufacturing = > thermal insulation layer laying = > thermal insulation preforming = > interface machining = > reduced-mouth joint installation = > joint surface elastic layer laying = > fiber winding = > hoop winding reinforcement = > curing = > demoulding = > detection = > product delivery.

The section of the completed shell half is shown in fig. 1, and the description of each area of the section is shown in fig. 2.

Example 1

A manufacturing method of a full-opening composite shell comprises the following steps:

step 1) manufacturing a composite material joint:

a. selecting a carbon fiber unidirectional prepreg and a carbon fiber plain prepreg;

b. blanking according to the designed shape and quantity of the expanded drawings, and numbering;

c. carrying out layering operation on a mould according to a designed layering process, wherein the laying is 60 to 90 percent, the whole package of layering is 10 to 40 percent, and the time is 4 hours, and the interval of vacuumizing, exhausting and compacting is about every 10 layers;

d. after the layering is finished, closing the die, heating and pressurizing on a hot press, and compacting and solidifying the product;

e. and machining the cooled and demoulded joint blank to the required size according to the design drawing requirements for later use.

Step 2) core mold manufacturing: the core mould is manufactured according to the design and the surface is sprayed with a polytetrafluoroethylene coating (anti-sticking).

Step 3), paving and pasting a heat insulating layer: laying and sticking ethylene propylene diene monomer rubber with the thickness of 1.2mm, and coating a special adhesive for ethylene propylene diene monomer at the lap joint of the green sheet; cleaning and airing the surface of the bonding part; paving and sticking column section rubber, adhering the column section rubber and the lap joint of the front end socket and the rear end socket by using a rubber adhesive, compacting and expelling air; and (4) size detection, namely performing size detection on the rubber seal head according to the requirement of a drawing.

Step 4), heat insulating layer preforming: performing vacuum-pumping and pressurizing preforming on the heat insulating layer; because the metal mold has better structural strength, the scheme of vacuumizing and pressurizing in an autoclave can be adopted to perform heat insulation, and the heat insulation molding is reliable.

Step 5), joint processing: selecting materials according to a drawing and processing the necking end joint and the opening end joint.

Step 6), installing a necking end connector: and after sand blasting is carried out on the bonding surface of the necking end joint and the ethylene propylene diene monomer adhesive is coated, the necking end joint is installed at the corresponding position of the core mould, the flange surfaces of the front joint and the rear joint are positioned by adopting a special tool, and the axial displacement and the radial displacement of the joints are restrained.

Step 7), paving and pasting an elastic layer on the surface of the joint: the surface of the joint is covered with a 0.5mm elastic layer.

Step 8) winding: the inner side winding is longitudinally and annularly alternated, the outer side winding adopts the whole annular direction, and the outer side winding is mainly at the opening end; the inner winding and the outer winding are wound by adopting T700/12k carbon fiber soaking medium-temperature epoxy resin, the number of yarn sheets is 1, the unfolding width of the yarn sheets is 1.5mm, the number of longitudinal winding layers is 6 (T1, T2 and T3 are longitudinal layers, one longitudinal layer is 2), the number of hoop winding layers is 2 (H1, H2, H3, H4, H5 and H6 are hoop layers), the volume content of the fiber is controlled by about 60%, and the rubber content is mainly controlled by the tension of the winding fiber of a winding machine.

The temperature (24 +/-10) DEG C and the relative humidity of the cylinder body winding environment are required, and the temperature and the humidity of each day are recorded every 3 h.

In order to control the volume content of the fibers to be 59 +/-1 percent and control the content of glue solution, the glue solution overflowing from the front and rear end enclosures and the column sections is manually scraped during winding.

Before winding, firstly adjusting the fiber tension, measuring the fiber tension by using a tensioner, and adjusting a tension control mechanism to achieve the tension precision specified by a file; setting linear winding according to design requirements, adjusting a gum dipping device at any time, controlling the gum amount of a fiber tape, scraping redundant gum solution on the surface of a product at any time during winding, observing yarn arrangement conditions, and stopping in time if yarn sheets slip, overlap or gaps occur; and (3) continuously adding new glue solution in the winding process, removing yarn wool on the rubber roll and the glue solution dripped on winding equipment, keeping the cleanness and sanitation of the whole produced wire, and realizing civilized production.

In order to simultaneously ensure the volume content and the exertion coefficient of the fiber and reduce the abrasion degree of the fiber as much as possible, the winding tension of the fiber layer by layer is controlled, the longitudinal winding layer and the circumferential winding layer are alternately carried out, the gradient tension can enable the fiber of each layer of the winding shell from inside to outside to have the same prestress, so that the shell can exert the integral effect of the composite material when working, the fiber exertion coefficient of the whole shell wound by the same tension is generally about 70 percent from the practical scaling shell blasting experience, the system design gradient tension shell blasting strength fiber exertion coefficient can reach more than 85 percent, and the shell tension gradiometer of the type is shown in the following table;

the tension successive layer gradient of fibrous layer is decreased progressively and is appeared the circumstances of interior pine external tightness, this is because the fibrous layer that twines after can make earlier twined together with the inlayer seize the contraction deformation because tension effect of one deck fibre, make inlayer fibre pine, if do not test proper tension in advance, the fibre that will lead to on the casing in appears the interior pine external tightness situation, make the fibrous initial stress in table and interior have very big difference, fibre can not even atress when the container pressurizes, serious person can make the interior fiber attack rugosity, inside lining bubble, the condition of buckling such as deformation, will greatly reduce casing intensity and tired function like this.

Therefore, the winding fiber is ensured to meet the requirement by detecting the tension before winding, the condition of internal looseness and external tightness is avoided, specifically, whether the tension of the fiber meets the requirement or not is detected, the tension can be adjusted according to the requirement subsequently, but the tension detection is carried out on the premise, if no tension detection link exists, the subsequent adjustment cannot be realized, and thus all winding layers have the same deformation and initial tension from inside to outside; when the shell container is pressurized, the fiber can be stressed, so that the strength of the container is improved, and the strength of the fiber can be better developed.

Step 9), winding reinforcement: through the summarization and analysis of practical experience, some problems can be clearly judged from the qualitative point of view, for example;

(1) In order to ensure that the thickness distribution of the end socket is uniform and symmetrical, the 'need to be compensated when the end socket is stretched', namely 1 reinforcing layer is paved between adjacent longitudinal layers;

(2) Carbon cloth or glass cloth is used as a reinforcing layer instead of the weftless cloth; thus, the warp direction and the weft direction near the end socket polar hole can be strengthened, and the occurrence of a failure mode 2 and a failure mode 3 can be prevented at the same time;

(3) The reinforcement is local, namely limited to the vicinity of a polar hole connected with the end socket by the connector; considering convenient process implementation, the overall reinforcement of the whole end enclosure is difficult, and the reinforcement near the equator brings inconvenience to the upper skirt construction; the strength problem of the whole end socket is mainly solved by adjusting the thickness of the end socket, namely adjusting a stress balance coefficient ks;

(4) Although the glass fiber has higher fracture strain and fracture toughness and lower strength than the carbon fiber, if the hybrid positive effect can be realized, the defect that the carbon fiber is easy to break can be overcome if the carbon fiber shell end socket is reinforced by the glass cloth.

And determining reinforcing areas of the front and rear end enclosures according to the difference of the rigidity of the joint structure part in the areas with larger strain indicated in the cylinder strength analysis report and the accuracy of the practical executable operation position, wherein the reinforcing areas adopt domestic T700-grade plain cloth for reinforcing by taking two sides of the column section of the front and rear end enclosures as starting points and along the equator towards polar holes at two sides.

According to the calculation result, the opening of the joint needs to be reinforced by Hmm thickness, and H/0.2 layers are calculated; during reinforcement, the equipment keeps rotating, the rotating speed is 2-3%, two sides of the front and rear end socket column sections are used as starting points, the two sides of the front and rear end socket column sections are in polar hole directions along the equator, domestic T700-grade and 12k plain cloth is adopted for reinforcement, and H/0.2 layer of reinforcement is paved and attached together; reinforcement is supplemented from 20mm of the pole hole to 40mm (layer 1 is longitudinally forward), 30mm (layer 1 is longitudinally forward), 20mm (layer 1 is longitudinally backward), 10mm (layer 1 is longitudinally backward) and 0mm (layer 2 is longitudinally backward) of the cross-equator line respectively; when wrinkles exist, a region close to the column section is not cut, and a knife is cut at the other side and is not cut off; the lapping width is 10 to 20mm; the weight of the reinforcement cloth was weighed for each reinforcement and recorded in a winding card.

Before winding, firstly adjusting the fiber tension, measuring the fiber tension by using a tensioner, and adjusting a tension control mechanism to achieve the tension precision specified by a file; setting linear winding according to design requirements, observing yarn arrangement conditions, and stopping in time if yarn sheets slip, overlap or gaps occur; keeping the whole production line clean and sanitary, realizing civilized production, measuring the outer diameter when the winding is about to be finished, stopping the machine when the outer diameter meets the requirement, unloading the product, and transferring the product into a curing furnace; after the winding in the skirt is finished, the skirt is installed on the winding cylinder body by utilizing the upper skirt tool.

Step 10) curing: the shell is wound by using T700 carbon fiber and epoxy resin, and as the epoxy resin system is adopted, normal-pressure heating curing is adopted in the curing process, and the shell winding layer and the heat insulation rubber layer are cured together; the specific parameters are as follows: keeping the temperature of room temperature to 80 ℃ for 2h; the heating rate is 25-30 ℃/h; keeping the temperature for 2 hours at 80-150 ℃; the heating rate is 25-30 ℃/h; closing the heat source at 150 to 60 +/-5 ℃, opening the blast, and taking out of the oven at 60 ℃; in the curing process, equipment maintenance personnel are equipped to ensure the normal operation of the equipment in the curing process.

Step 11), demolding: the product is taken off from the mould, and the mould can be repeatedly used due to the adoption of the metal mould.

Step 12) detection

a) Detecting the size; the dimension of the shell is checked by using a measuring tool with the requirement on the dimensional precision, and the form and position tolerance of the shell is detected by using a three-coordinate measuring instrument;

b) Nondestructive testing; ultrasonic detection and ultrasonic flaw detection, wherein when the composite material product is detected by ultrasonic, the composite material product is used for detecting pores and cracks and detecting the defects of pores, crack layering, foreign matter inclusion and the like, and the gel content of the product is measured; and measuring the gel content of the product, etc.; ultrasonic detection can also be used for debonding and flaw detection of the composite material shell and the heat-insulating layer, and the delamination and debonding of the first interface of the engine shell can be basically and correctly judged; ray detection including X-ray, fluoroscope, neutron ray, and gamma ray detection, etc.; they are often used to detect defects such as cracks, hole drying, delamination, foreign matter inclusion, and the like; the X-ray method is used for detecting the pores, cracks, delamination and foreign matters in various heat insulation parts of the shell, is very effective, and can directly observe the internal defects of the product from images or photos; because the size and the structural thickness of the shell of the table are smaller, A-scan is mainly adopted for detection;

c) Detecting air tightness; the test is carried out according to the specification of QJ1658A, the pressure of an inner cavity is 0.3Mpa, and the pressure is maintained for 1 hour without pressure drop, so that the air tightness requirement is met;

d) Carrying out hydrostatic test; the concrete operation of the hydraulic blasting experiment test is executed according to the specification of Q/Nt 015;

step 13) product delivery.

Example 2

A manufacturing method of a full-opening composite shell comprises the following steps:

step 1) preparing a joint;

cleaning a mold: cleaning residues on a mold forming surface and the like by using tools such as a blade and the like to avoid scratching the mold forming surface, then soaking a small amount of acetone in a clean cloth tape to wipe the mold, cleaning residues which affect a product such as a small amount of residual glue and the like, and drying the residues;

a. firstly, mounting a lower die plate, an inner die ring and an outer die ring of a half die, and mounting an upper die plate of the die after layering is finished; selecting a carbon fiber unidirectional prepreg and a carbon fiber plain prepreg;

b. blanking according to the designed shape and quantity of the expanded drawings, and numbering;

c. carrying out layering operation on a mould according to a designed layering process, wherein the laying is 60%, and the whole package of layering is 40%;

d. as shown in fig. 4, dividing the joint into 4 areas, laying whole-package areas ii and I, wherein the area I is firstly unfolded outwards, then laying the area iii, then laying the area iv, and finally turning the area I onto the laying area iii; the area III is a side cladding layer, and the areas II and I are whole cladding layers; firstly, paving a whole cladding, and then paving a side cladding, wherein the two are crossed and layered; after the first layer of the whole cladding layer is paved, vacuumizing for 5min for one time so as to compact the corners;

paving the area III and paving the area IV; when laying the IV, after the height reaches 4/5, turning over the area I, and crossly laying with the IV, wherein the upper layer and the lower layer are staggered and form a butt joint; after the flanging is finished, 2 layers of plain cloth are laid on the outermost surface;

in the paving process, air bubbles are removed and compacted by a driving plate, and the time is 4 hours after the air bubbles are pumped, exhausted and compacted into 8 layers at intervals; if necessary, the paving and pasting can be ensured to be smooth and not overhead by a method of filling carbon wires;

flanging the side bag, building a layer of the side bag on a unidirectional layer, and paving a layer of plain cloth after each layer of the side bag is turned;

after a release agent is applied to the upper cover plate, die assembly is carried out to ensure that the die assembly is in place;

joint curing: (1) putting the tool into a press, enabling a heating plate on the press to be attached to the die, setting the heating temperature to be 70 ℃, and recording the curing starting time; (2) when the temperature of the thermocouple reaches 70 +/-5 ℃, starting pressurization, keeping the temperature for 2 hours and keeping the pressure for 2.5MPa, wherein the pressure is 2.5MPa; (3) setting the heating temperature to 130 ℃ after the heat preservation at 70 +/-5 ℃, setting the heating rate to 30 ℃/h, preserving the heat at 130 +/-5 ℃ for 0.5h, pressurizing to 12MPa, preserving the heat for 1h, and maintaining the pressure at 12MPa; (4) after the heat preservation at the temperature of 130 +/-5 ℃ is finished, setting the heating temperature to be 160 ℃, the heating rate to be 30 ℃/h, preserving the heat for 3h, and maintaining the pressure to be 12MPa; (5) setting the heating temperature to be 180 ℃ after the heat preservation at 160 +/-5 ℃, setting the heating rate to be 30 ℃/h, and preserving the heat for 1.5h when the temperature of the thermocouple reaches 180 +/-5 ℃; (6) closing the heating device, and naturally cooling to room temperature; the pressure of the press can be released when the temperature of the thermocouple is lower than 60 ℃; in the curing process, recording the pressure and the temperature once every 30min, and taking a picture of the abnormal phenomenon; and machining the joint according to the drawing of the product after the solidification is finished, and machining the joint into a necking end joint and an opening end joint.

Step 2) core mold manufacturing: the core mould is manufactured according to the design and the surface is sprayed with a polytetrafluoroethylene coating (anti-sticking).

Step 3), heat insulation paving: and (3) paving ethylene propylene diene monomer rubber with the diameter of 1.2mm on the surface of the core mould, and brushing an adhesive on the lap joint part.

Step 4) adiabatic pre-curing: after the heat insulation layer is laid, vacuumizing the heat insulation layer by using an isolation film and a medium-temperature vacuum bag, pressurizing the heat insulation layer by using an autoclave at 0.2MPa, and precuring the heat insulation layer for 2 hours at 120 ℃; and (3) heat insulation polishing: after the heat insulating layer is pre-cured, polishing the lap joint part, wherein the polishing is required to be smooth and the step height is not more than 0.2mm, and cleaning the lap joint part by using ethyl acetate after polishing

Step 5), installing a connector: installing a front connector before winding, cleaning the inner surface and the outer surface of the front connector and the outer surface of the rear connector by ethyl acetate, brushing a layer of interface adhesive after cleaning, drying for 2h at 50 ℃, continuously drying for 2h at 50 ℃ after brushing a layer of interface adhesive, then installing the connectors, paving a layer of heat-insulating rubber on the surfaces of the connectors, vacuumizing and compacting.

Step 6) adopting carbon fiber yarns to pre-wind the surface of the rubber core mold according to a normal winding program, and checking the linear state after the carbon fiber yarns are wound for 1 circle; the debugged fibers are required to be not overlapped and separated from the seam, and are uniformly distributed on the surface of the core mold, so that the fibers are stable on the surface of the core mold and do not slip;

removing fiber yarns on the surface of the heat insulation core mold, cleaning the heat insulation surface by using ethyl acetate, taking a picture and recording, wherein the surface is required to be clean and free of dust, fibers and other redundancies; before winding, drying the used carbon fiber yarns, and putting the fiber yarns into a drying oven to preserve heat for 6 hours at the temperature of 60-70 ℃; mixing glue, weighing, stirring for ten minutes, ensuring that the glue is uniformly stirred, introducing winding resin into a glue groove, uniformly penetrating fiber yarns through a yarn comb, and ensuring that the fiber yarns are fully impregnated in the glue groove; the fiber yarn passes through the middle row of yarn combs, and the interval between two yarns is 1 yarn space; before each layer is wound, testing the tension of front row fiber yarns, measuring by using an electronic tensiometer, and keeping the tension gradient according to a winding table; controlling the tension gradient, wherein the error range is within +/-2N; before the winding, brush one deck winding resin on the surface and call vertical and hoop winding procedure, twine according to winding table order, carry out every layer of winding of reinforcement in joint department and end, carry out the frictioning to the surface, it does not have obvious glue solution to require the fibre surface to remain winding environment and does not have dust, temperature range: the temperature and the humidity are monitored every 1h at the temperature of 14-34 ℃ and the relative humidity is less than or equal to 60%, and a multi-angle handheld dust remover is required to remove dust for the whole winding room before winding; wrapping the surface of the shell by using skinning cloth, an isolating membrane and an air-permeable felt after the winding is finished, and winding a layer of glass fiber in a longitudinal direction and a layer of a circumferential direction for curing;

step 7) curing:

keeping the temperature at room temperature of 80 ℃ below zero for 2 hours; the heating rate is 25-30 ℃/h;

keeping the temperature for 2h at 80-150 ℃; the heating rate is 25-30 ℃/h;

closing the heat source at 150-60 +/-5 ℃, opening the blast and discharging from the oven at 60 ℃;

in the curing process, equipment maintenance personnel are equipped to ensure the normal operation of the equipment in the curing process.

Step 8), demolding: and removing the glass fiber, the breathable felt, the isolating membrane and the peeling cloth on the surface of the shell, cutting along the middle of the shell, and screwing the round nuts at the two ends to remove the two small shells from the two sides.

Step 9), machining: and machining the rear end threads of the product which is wound and solidified inside by the shell drawing.

The winding product adopting the metal die has better quality, and is beneficial to reducing weight; the metal die can be used repeatedly, so that the cost is reduced; 2 full-opening carbon fiber composite combustion chambers formed by winding at one time can also reduce the cost; the necking end joint is directly embedded into the composite material by adopting a composite material joint, so that the technology is mature; the connector ladder of the opening end is inserted into the composite material, and axial layering reinforcement and hoop winding reinforcement are carried out, so that the connection strength can be ensured.

The joint, the winding layer and the ablation resistant layer are all made of composite materials, and pass all cold and heat tests to reach the usable state; the Xinyang company researches various composite internal threads and external threads, and the connection strength can reach 50MPa.

The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims (6)

1. A manufacturing method of a full-opening composite material shell is characterized by comprising the following steps:

step 1) manufacturing a composite material joint, and processing the composite material joint into a necking end joint and an opening end joint;

step 2), manufacturing a core mold;

step 3), paving and pasting a heat insulating layer, and paving and pasting a heat insulating layer on the surface of the core mold;

step 4), performing heat insulation layer, and performing vacuum pumping and pressurizing on the heat insulation layer;

step 5), installing a connector, namely installing a necking end connector and an opening end connector at corresponding positions on the core mold;

step 6), winding the inner side, namely winding the carbon fiber soaked in the medium-temperature epoxy resin, adopting a winding mode of alternately winding in a longitudinal direction and winding in a circumferential direction, adjusting and controlling the tension of the fiber before winding, and adjusting and controlling the tension according to the requirement of gradually decreasing the tension from inside to outside in a gradient manner;

step 7), winding the outer side, winding the carbon fiber soaked with the medium-temperature epoxy resin on the inner winding layer again, adjusting and controlling the fiber tension before winding in a hoop winding mode, and adjusting and controlling the fiber tension according to the requirement that the tension gradually decreases in a gradient manner from inside to outside;

step 8), curing, namely heating and curing at normal pressure, and jointly curing the shell winding layer and the heat insulating layer;

step 9), demolding, namely detaching the shell from the core mold;

and step 10) detection, including size detection, nondestructive detection, airtight detection and water pressure detection.

2. The method for manufacturing the full-open composite shell according to claim 1, wherein the polar holes connected with the joints and the end sockets are reinforced in the winding process in the step 6), and a reinforcing layer is laid between the adjacent longitudinal layers.

3. The method for manufacturing the full-open composite shell according to claim 2, wherein the reinforcing layer is made of plain cloth made of glass fiber material.

4. The method for manufacturing a full-open composite shell according to claim 2, wherein the reinforcement is specifically: during reinforcement, the equipment keeps rotating, and by taking two sides of the end socket column section as starting points, the reinforcing layer is laid and attached in the annular direction along the equator towards polar holes on two sides.

5. The method of claim 2 wherein the stiffening layer is applied with wrinkles by removing the knife from the area of the post section and removing the knife from the area of the post section.

6. The manufacturing method of the full-open composite shell according to any one of claims 1 to 5, wherein an elastic layer is laid on the surface of the joint in the step 5) when the joint is installed.

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