阅读说明：本技术 一种双脉冲发动机燃烧室壳体及成型方法 (Double-pulse engine combustion chamber shell and forming method ) 是由 郏保琪 冯彬彬 张雄军 周永江 袁金 胡旭辉 于 2020-07-03 设计创作，主要内容包括：本发明公开了一种双脉冲发动机燃烧室壳体及成型方法,通过对双脉冲发动机燃烧室壳体和隔离装置设计,经过材料优选,工艺和结构优化,选择复合材料作为隔离装置和燃烧室壳体的材质,成型时,先成型复合材料隔离装置,然后整体灌注一体成型燃烧室壳体。制备得到的双脉冲发动机燃烧室壳体,质量轻、隔离装置中心无开孔,不需要再添加其他密封结构,密封严密,另外隔离装置也为整体复合材料结构,质量轻,耐高内压/低压溃压强的工作环境,稳定可靠。保证隔离装置分别对双脉冲两燃烧室壳体的密封性能,消除间隙,密封严密,成型方式简单,质量轻、高可靠、成本低,隔离装置与壳体一同成型后,减少后期安装步骤,提高装机效率。(The invention discloses a double-pulse engine combustion chamber shell and a forming method, wherein the double-pulse engine combustion chamber shell and an isolation device are designed, through material optimization, process and structure optimization, a composite material is selected as a material of the isolation device and the combustion chamber shell, and during forming, the composite material isolation device is formed firstly, and then the combustion chamber shell is integrally poured. The prepared double-pulse engine combustion chamber shell is light in weight, the center of the isolation device is not provided with an opening, other sealing structures are not needed to be added, the sealing is tight, in addition, the isolation device is also of an integral composite material structure, the weight is light, the working environment of high internal pressure/low pressure collapse pressure is resisted, and the double-pulse engine combustion chamber shell is stable and reliable. The sealing performance of the isolation device to the shells of the double-pulse combustion chambers is guaranteed, gaps are eliminated, sealing is tight, the forming mode is simple, the weight is light, high reliability and low cost are achieved, after the isolation device and the shells are formed together, later-stage installation steps are reduced, and the assembly efficiency is improved.)

1. A kind of double pulse engine combustion chamber shell, characterized by: the method comprises the following steps:

the device comprises an I-stage combustion chamber shell (11), a rear connecting metal piece (15), a II-stage combustion chamber shell (5), a front connecting metal piece (4) and an isolating device (9);

the I-stage combustion chamber shell (11) is provided with a rear opening and is connected with the spray pipe through a rear connecting metal piece (15);

the second-stage combustion chamber shell (5) is provided with a front opening; is connected with the bullet body through a front connecting metal (4);

the isolating device (9) is positioned in the middle of the double-pulse engine combustion chamber shell, the double-pulse engine combustion chamber shell is isolated into a first-order combustion chamber shell (11) and a second-order combustion chamber shell (5), an inner insulating layer (10) of the isolating device and an outer insulating layer (8) of the isolating device are respectively integrally formed with a first-order combustion chamber shell insulating layer (14) and a second-order combustion chamber shell insulating layer (6), and independent inner cavities are respectively formed;

the pulse amount of the I-stage combustion chamber and the II-stage combustion chamber is adjusted by the position change of the isolation device (9).

2. The method of forming a combustor casing for a dipulse engine as set forth in claim 1, wherein: the method comprises the following steps:

1) structural design:

according to the difference of the combustion impulse of the combustion chamber shell of the double-pulse engine in different stages to the load, the air flow temperature and the ablation time of the combustion chamber shell (11) of the I order, the combustion chamber shell (5) of the II order and the isolating device (9), the whole structure is divided into two parts, namely a bearing layer and a heat insulating layer;

carrying out analog simulation analysis on the internal pressure born by the I-order combustion chamber shell (11) and the II-order combustion chamber shell (5) and the internal pressure born by the isolating device (9) and the external pressure burst pressure by using abaqus analog simulation software, wherein the I-order combustion chamber shell (11) and the II-order combustion chamber shell (5) are required to bear high internal pressure and the isolating device (9) bears high internal pressure under the action of I-order pulses, and the II-order pulses are damaged under the action of low pressure burst pressure, and calculating the fiber layer angle and the thickness of the parts of the I-order combustion chamber shell (11) and the II-order combustion chamber shell (5) and the isolating device (9);

2) selecting materials:

the heat insulating layer is made of ethylene propylene diene monomer or nitrile rubber;

the reinforcing material is one of carbon fiber cloth, glass fiber cloth and quartz fiber cloth;

the matrix is selected from one of ester ring family epoxy resin, phenolic resin, polyaryl acetylene and cyanate ester resin ablation heat-proof resin;

the material system consists of a reinforcing material and a matrix, wherein the fiber content is 70-78%;

3) the molding process comprises the following steps:

preparing a sand core mold:

preparing a first-order combustion chamber shell sand core (13) and a second-order combustion chamber shell sand core (7), and processing the sand cores;

molding the isolation device:

the arc surface of the I-stage combustion chamber shell sand core (13) is used for molding, ethylene propylene diene monomer or nitrile rubber is laid firstly, then fiber cloth is laid, and the outer surface is coated with stripping cloth, a flow guide net and a vacuum bag film to ensure sealing and vacuumizing;

pouring resin, curing, cleaning after curing, processing to remove redundant parts, polishing the surface of the isolation device by using abrasive paper, cleaning by using a volatile solvent, coating a coupling agent on the surface, and paving a heat insulation layer;

forming the I-order combustion chamber shell and the II-order combustion chamber shell:

assembling a first-order combustion chamber shell sand core (13) and a second-order combustion chamber shell sand core (7) together, wherein an isolation device (9) is positioned between the two sand cores, the two sand cores are erected, one end of the two sand cores is fixed, the other end of the two sand cores is tightly propped, and the two sand cores are adjusted to be in the same axial degree through meter making;

heat insulation materials (6) and (14) are laid on the surface of the sand core, the heat insulation layer (14) of the combustion chamber shell with the I step is bonded with the heat insulation layer (10) in the isolation device, and the heat insulation layer (6) of the combustion chamber shell with the II step is bonded with the heat insulation layer (8) outside the isolation device;

the front connecting metal piece (4) and the rear connecting metal piece (15) are subjected to sand blasting treatment, a volatile solvent is used for wiping the sand clean, a coupling agent is coated, the front connecting metal piece (4) is bonded with the heat insulating layer at the left end of the II-order combustion chamber shell sand core (7), and the rear connecting metal piece (15) is bonded with the heat insulating layer at the right end of the I-order combustion chamber shell sand core (13); the front connecting metal piece (4) is firmly fixed by the front connecting metal piece fixing tool (3) and the front connecting metal piece positioning tool (2); the rear connecting metal piece (15) is firmly fixed by a rear connecting metal piece fixing tool (17) and a rear connecting metal piece positioning tool (16);

wiping the surface with the heat insulation layer with a volatile solvent, brushing a coupling agent, and laying the fiber cloth cut by an automatic fabric cutting machine according to a designed fiber angle;

coating a piece of membrane removing cloth, a flow guide net and a vacuum bag membrane, and integrally vacuumizing;

resin is poured;

putting the mixture into a curing oven for curing;

and cleaning surface auxiliary materials after solidification is finished, washing the sand core (13) of the I-order combustion chamber shell and the sand core (7) of the II-order combustion chamber shell by using a high-pressure hot water gun, carefully drawing out the forming core shaft-1 (1) and the forming core shaft-2 (12) from two sides respectively, cleaning, and forming the I-order combustion chamber shell and the II-order combustion chamber shell to obtain the double-pulse engine combustion chamber shell.

3. The method of forming a combustor casing for a double pulse engine as set forth in claim 2, wherein: the high internal pressure in the step 1) is more than or equal to 40MPa, and the low pressure is less than or equal to 1.5 MPa.

4. The method of forming a combustor casing for a double pulse engine as set forth in claim 2, wherein: the method adopts abaqus simulation software to carry out simulation analysis on the internal pressure born by the I-order combustion chamber shell (11) and the II-order combustion chamber shell (5) and the internal pressure born by the isolating device (9) and the external pressure collapse pressure, and comprises the following steps: the method is characterized in that abaqus software is adopted to carry out simulation analysis on loads borne by a first-order combustion chamber shell (11), a second-order combustion chamber shell (5) and an isolation device (9), the first-order combustion chamber shell (11) and the second-order combustion chamber shell (5) are required to bear the high internal pressure after the ammunition point combustion and not to be damaged, the isolation device (9) bears the high internal pressure after the ammunition of the first-order combustion chamber shell (11) is ignited, the second-order combustion chamber shell (5) is instantaneously damaged under the low-pressure condition after the ignition, and the thickness, the direction and the number of fiber layers in each direction of a structural layer fiber layer are calculated.

5. The method of forming a combustor casing for a double pulse engine as set forth in claim 2, wherein: calculating the fiber layering angles and the thicknesses of the parts of the I-order combustion chamber shell (11) and the II-order combustion chamber shell (5) and the isolating device (9) in the step 1), wherein the calculation means that: the thickness of the heat insulation layer is selected to be 0.5-10mm, the fiber angle of the paving layer is adjusted to be one or more of 0 degree, 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees and 90 degrees according to the design requirement of each part, the thickness of the paving layer is 0.2-10mm, and the fiber angle is realized by using an automatic cloth cutting machine.

6. The method of forming a combustor casing for a double pulse engine as set forth in claim 2, wherein: the reinforcing material in the step 2) is one selected from T700 carbon fiber cloth and T800 carbon fiber cloth, and the areal density is 200-800 TEX.

7. The method of forming a combustor casing for a double pulse engine as set forth in claim 2, wherein: the material system in the step 2) is one/ester ring epoxy system resin selected from T700 carbon fiber cloth and T800 carbon fiber cloth, the density of the carbon fiber cloth is 200-800TEX, the angle is 0-90 degrees, the whole vacuum pumping is carried out to ensure that the vacuum degree is less than-0.085 Mpa, and the fiber content is 70-78 percent.

8. The method of forming a combustor casing for a double pulse engine as set forth in claim 2, wherein: the molding of the isolating device in the step 3) comprises the following steps:

the method comprises the steps of forming an arc surface of a sand core of a shell of the I-order combustion chamber, firstly laying ethylene propylene diene monomer or nitrile rubber with the thickness of 0.5-5mm, then laying fiber cloth with the thickness of 0.2-10mm and the angle of 0 degree, 15 degrees, -15 degrees, 30 degrees, -30 degrees, 45 degrees, -45 degrees, 60 degrees, -60 degrees, 75 degrees, -75 degrees and 90 degrees, coating the outer surface with de-filming cloth, a flow guide net and a vacuum bag film, ensuring sealing and vacuumizing, ensuring the vacuum degree to be-0.085-1.0 MPa, and not dropping pressure for 30 min;

pouring resin, wherein the resin system is resin, curing agent and accelerator, and the mass ratio is 100: 80-120: 0.5-2.5; the curing temperature is 1.5h at 90 ℃, 2h at 120 ℃ and 4h at 160 ℃, and the heating rate is 1-2 ℃/min; cleaning after curing is finished, processing to remove redundant parts, polishing the surface of the isolation device by using abrasive paper, cleaning by using a volatile solvent, brushing a coupling agent on the surface, and paving a heat insulation layer;

step 3) the I-order combustion chamber shell and the II-order combustion chamber shell are molded, and the molding process comprises the following steps:

assembling a first-order combustion chamber shell sand core (13) and a second-order combustion chamber shell sand core (7) together, wherein an isolation device (9) is positioned between the two sand cores, the two sand cores are erected, one end of the two sand cores is fixed, the other end of the two sand cores is tightly propped, and the two sand cores are adjusted to be in the same axial degree through meter making;

heat insulation materials (6) and (14) are laid on the surface of the sand core, the heat insulation layer (14) of the combustion chamber shell with the I step is bonded with the heat insulation layer (10) in the isolation device, and the heat insulation layer (6) of the combustion chamber shell with the II step is bonded with the heat insulation layer (8) outside the isolation device;

the front connecting metal piece (4) and the rear connecting metal piece (15) are subjected to sand blasting treatment, the adopted compressed air pressure is 0.4-1.0MPa, a volatile solvent is used for wiping the front connecting metal piece (4) and the rear connecting metal piece (15) cleanly, a coupling agent is coated, the front connecting metal piece (4) is bonded with the heat insulating layer at the left end of the II-order combustion chamber shell sand core (7), and the rear connecting metal piece (15) is bonded with the heat insulating layer at the right end of the I-order combustion chamber shell sand core (13); the front connecting metal piece (4) is firmly fixed by the front connecting metal piece fixing tool (3) and the front connecting metal piece positioning tool (2); the rear connecting metal piece (15) is firmly fixed by a rear connecting metal piece fixing tool (17) and a rear connecting metal piece positioning tool (16); (ii) a

Wiping the surface with the heat insulation layer with a volatile solvent, brushing a coupling agent, and laying the fiber cloth cut by an automatic fabric cutting machine according to a designed fiber angle;

coating a piece of membrane removing cloth, a flow guide net and a vacuum bag membrane, and integrally vacuumizing to ensure that the vacuum degree is less than-0.085 to-1.0 MPa, and the pressure is not dropped for 30 min;

pouring resin, wherein the resin system is epoxy resin, curing agent and accelerator, and the mass ratio is 100: 80-120: 0.5-2.5;

putting the mixture into a curing furnace for curing, wherein the curing system comprises the following steps: the heating rate is 1-2 ℃/min, the temperature is 1.5h at 90 ℃, 2h at 120 ℃ and 4h at 160 ℃;

and cleaning surface auxiliary materials after solidification, flushing the I-order combustion chamber shell sand core (13) and the II-order combustion chamber shell sand core (7) by using a high-pressure hot water gun, carefully drawing out the forming core shaft-1 (1) and the forming core shaft-2 (12) from two sides respectively, cleaning, and forming the I-order combustion chamber shell and the II-order combustion chamber shell to obtain the double-pulse engine combustion chamber shell.

9. The method of forming a combustor casing for a double pulse engine as set forth in claim 8, wherein: the curing agent in the step 3) is selected from ammonia curing agents, and the accelerator is selected from benzylamine; the volatile solvent is selected from one of acetone, alcohol and ethyl acetate; the coupling agent is selected from silane coupling agents.

Technical Field

The invention belongs to the technical field of aerospace, and particularly relates to a double-pulse engine combustion chamber shell and a forming method.

Background

The double-pulse engine utilizes the isolating device to divide a combustion chamber of the solid engine into two parts, carries out ignition twice, reasonably distributes thrust and two-pulse interval time, realizes the optimal control of the flying trajectory of the missile and the optimal management of the energy of the engine, and comprehensively improves the performance of various tactical missile systems. At present, a combustion chamber shell of the double-pulse engine is divided into an integral steel structure and an integral fiber winding structure, and an I-order pulse explosive column and a II-order pulse explosive column of the double-pulse engine are separated by an isolating device.

The existing double-pulse engine combustion chamber structure is characterized in that a shell and an isolating device are respectively molded, the shell and the isolating device are connected and installed in the later period, the assembling is inconvenient, the bonding of the shell and the assembling part of the isolating device is not firm, and the problems of I-order and II-order sealing are caused.

For example, chinese patent application CN201910769142.7 discloses a double-pulse solid engine, which adopts a manufacturing method of integral interlayer type double pulse, and divides the interlayer into an axial interlayer and a radial interlayer, the axial interlayer and the housing are integrally formed, and the radial interlayer and the axial interlayer are connected by bonding. However, the bonding position is a weak part, so that the quality is unstable, and the bonding part is easy to break or leak under the condition of bearing internal pressure.

For example, chinese patent application CN201811628188.9 discloses a radial interlayer type double pulse engine, which is a manufacturing method of a radial interlayer type double pulse engine, wherein an inner cavity of a housing of a second-order combustion chamber is divided into a first-order combustion chamber and a second-order combustion chamber by an interlayer, but the interlayer is composed of a heat insulation sleeve and a metal connecting sleeve, and has a heavy mass, which increases the inertia weight of the engine.

Also, as in chinese patent application CN201811628177.0, a double-pulse engine with integrated chemical winding structure and a manufacturing method thereof are disclosed, wherein the interlayer is a soft interlayer, and the combustion chamber is divided into two parts by the soft interlayer, but the forming process is complicated, the soft interlayer is not easy to be directly formed, the operation is inconvenient, and the soft interlayer cannot bear the larger internal pressure of the i-stage pulse.

Therefore, the development of an integrated double-pulse engine combustion chamber shell which has a simple structure and light weight and can bear I-stage pulse high internal pressure and II-stage pulse low external pressure is urgently needed.

Disclosure of Invention

The invention provides a double-pulse engine combustion chamber shell and a forming method thereof, aiming at the defects that the double-pulse engine combustion chamber shell is heavy in weight, an isolating device is not easy to seal, and cannot bear large high internal pressure/low pressure collapse pressure ratio and the like in the prior art, composite materials are selected as materials of the isolating device and the combustion chamber shell according to the bearing requirements of the double-pulse engine combustion chamber shell and the isolating device, ethylene propylene diene monomer or nitrile butadiene rubber is used as a bearing structure, carbon fiber/epoxy composite materials are used as the bearing structure, the isolating device divides the combustion chamber shell into two parts, and the isolating device meets the application environments of I-stage pulse high internal pressure and II-stage pulse low pressure collapse pressure, so that the inertia weight of an engine is reduced, and the effective range of a missile is increased.

The invention relates to a double-pulse engine combustion chamber shell, which comprises:

the device comprises a first-order combustion chamber shell, a rear connecting metal piece, a second-order combustion chamber shell, a front connecting metal piece and an isolating device;

the first-stage combustion chamber shell is provided with a rear opening and is connected with the spray pipe through a rear connecting metal piece;

the second-stage combustion chamber shell is provided with a front opening; is connected with the bullet body through a front connecting metal piece;

the isolating device is positioned in the middle of the double-pulse engine combustion chamber shell and isolates the double-pulse engine combustion chamber shell into an I-order combustion chamber shell and a II-order combustion chamber shell, and an inner heat insulating layer and an outer heat insulating layer of the isolating device are respectively integrally formed with the heat insulating layer of the I-order combustion chamber shell and the heat insulating layer of the II-order combustion chamber shell to respectively form independent inner cavities;

the pulse amount of the I-stage combustion chamber and the II-stage combustion chamber is adjusted by the position change of the isolating device.

The forming method of the double-pulse engine combustion chamber shell comprises the following steps:

1) structural design:

according to the difference of the load, the air flow temperature and the ablation time of the I-order combustion chamber shell, the II-order combustion chamber shell and the isolating device of the double-pulse engine on the basis of the combustion impulse of the combustion chamber shell of the double-pulse engine at different stages, the whole structure is divided into two parts, namely a bearing layer and a heat insulating layer;

carrying out analog simulation analysis on the internal pressure borne by the I-order combustion chamber shell and the II-order combustion chamber shell of the double-pulse engine and the internal pressure borne by the isolating device and the external pressure burst pressure by using abaqus simulation software, wherein the high internal pressure borne by the I-order combustion chamber shell and the II-order combustion chamber shell of the double-pulse engine is required, the high internal pressure borne by the isolating device under the action of I-order pulse, the high internal pressure borne by the isolating device under the action of II-order pulse and the low pressure burst pressure borne by the isolating device under the action of II-order pulse are required, and the fiber layer laying angles and thicknesses of the I-order combustion chamber shell, the II-order combustion chamber shell;

2) selecting materials:

the heat insulating layer is made of ethylene propylene diene monomer or nitrile rubber;

the reinforcing material is one of carbon fiber cloth, glass fiber cloth and quartz fiber cloth;

the matrix is selected from one of ester ring family epoxy resin, phenolic resin, polyaryl acetylene and cyanate ester resin ablation heat-proof resin;

the material system consists of a reinforcing material and a matrix, wherein the fiber content is 70-78%;

3) the molding process comprises the following steps:

preparing a sand core mold:

preparing a first-order combustion chamber shell sand core and a second-order combustion chamber shell sand core, and processing the sand cores;

molding the isolation device:

forming by utilizing the circular arc surface of the sand core of the I-stage combustion chamber shell, firstly laying an inner heat insulation layer of an isolation device, then laying fiber cloth, coating demoulding cloth, a flow guide net and a vacuum bag film on the outer surface, ensuring sealing and vacuumizing;

pouring resin, curing, cleaning after curing, processing to remove redundant parts, polishing the surface of the isolation device by using abrasive paper, cleaning by using a volatile solvent, coating a coupling agent on the surface, and laying an outer heat insulation layer of the isolation device;

forming the I-order combustion chamber shell and the II-order combustion chamber shell:

assembling a first-order combustion chamber shell sand core and a second-order combustion chamber shell sand core together, wherein a formed isolation device is positioned between the two sand cores, the two sand cores are erected, one end of the two sand cores is fixed, the other end of the two sand cores is tightly propped, and the two sand cores are adjusted to be in the same axial degree through meter making;

heat insulation layers are laid on the surfaces of the I-order combustion chamber shell sand core and the II-order combustion chamber shell sand core, the I-order combustion chamber shell heat insulation layer is bonded with the inner side of the heat insulation layer in the isolation device, and the II-order combustion chamber shell heat insulation layer is bonded with the outer heat insulation layer of the isolation device;

the front connecting metal piece and the rear connecting metal piece are subjected to sand blasting treatment, a volatile solvent is used for wiping the front connecting metal piece and the rear connecting metal piece, a coupling agent is coated, the front connecting metal piece is bonded with the heat insulating layer at the left end of the sand core of the II-order combustion chamber shell, and the rear connecting metal piece is bonded with the heat insulating layer at the right end of the sand core of the I-order combustion chamber shell; the front connecting metal piece is firmly fixed by the front connecting metal piece fixing tool and the front connecting metal piece positioning tool; the rear connecting metal piece is firmly fixed by a rear connecting metal piece fixing tool and a rear connecting metal piece positioning tool;

wiping the surface with the heat insulation layer with a volatile solvent, brushing a coupling agent, and laying the fiber cloth cut by an automatic fabric cutting machine according to a designed fiber angle;

coating a piece of membrane removing cloth, a flow guide net and a vacuum bag membrane, and integrally vacuumizing;

resin is poured;

putting the mixture into a curing oven for curing;

and cleaning surface auxiliary materials after solidification is finished, flushing the I-order combustion chamber shell sand core and the II-order combustion chamber shell sand core by using a high-pressure hot water gun, carefully drawing out the forming mandrel-1 and the forming mandrel-2 from two sides respectively, cleaning, and forming the I-order combustion chamber shell and the II-order combustion chamber shell to obtain the double-pulse engine combustion chamber shell.

The high internal pressure in the step 1) of the invention is more than or equal to 40MPa, and the low pressure is less than or equal to 1.5 MPa.

The step 1) of adopting abaqus simulation software to carry out simulation analysis on the internal pressure borne by the I-order combustion chamber shell and the II-order combustion chamber shell of the double-pulse engine and the internal pressure and external pressure crushing pressure borne by the isolating device comprises the following steps: and (3) carrying out simulation analysis on the loads borne by the I-order combustion chamber shell, the II-order combustion chamber shell and the isolating device by using abaqus software, wherein the I-order combustion chamber shell and the II-order combustion chamber shell are required to bear high internal pressure after the ammunition point combustion and not to be damaged, the isolating device bears high internal pressure after the ammunition of the I-order combustion chamber shell is ignited, the II-order combustion chamber shell is instantaneously damaged under the condition of low pressure after the ignition, and the thickness and the direction of the structural layer fiber layering and the number of the fiber layering layers in each direction are calculated.

In the simulation process of the abaqus software, drawing and storing a three-dimensional graph through three-dimensional drawing software such as UG, guiding the graph into STP (standard transfer protocol) or IGS (integrated standard system) formats, guiding the graph into the abaqus software, then entering a grid dividing module, dividing a model into a plurality of areas for dividing a high-quality grid, carrying out grid division on the model by adopting an SC8R continuous shell unit, and assigning a material stacking direction; after grid division is completed, entering an attribute module, defining material attributes (such as material parameters including strength, modulus, Poisson ratio and the like), and assigning a layering angle; the example to be analyzed is introduced into the assembly module, the load module defines boundary conditions and loads (such as internal pressure 40MPa), and load requirements are input to the I-stage combustion chamber shell, the II-stage combustion chamber shell and the isolation device.

Calculating the fiber layering angle and thickness of the shell part and the isolating device in the step 1), adjusting the fiber angle of layering to be one or more of 0 degree, 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees and 90 degrees according to the design requirement, wherein the layering thickness is 0.2-10mm, and the fiber angle is realized by using an automatic cloth cutting machine.

Calculating the fiber layering angles, thicknesses and layers of the I-order combustion chamber shell, the II-order combustion chamber shell and the isolating device in the step 1), wherein the fiber layering angles are one or more (defined according to the axial direction) of 0 degree, 15 degrees, -15 degrees, 30 degrees, -30 degrees, 45 degrees, -45 degrees, 60 degrees, -60 degrees, 75 degrees, -75 degrees and 90 degrees according to the design requirements of the structural layers, and the fiber cloth is cut by an automatic cloth cutting machine in an advanced manner to obtain the required angle and shape; when the paving is carried out, the position of the needed paving layer is designed according to the designed aspect ratio, and the paving layer is inserted at different positions for 90 degrees. The thickness of the fiber cloth layer is 0.2-10 mm. The heat insulating layer is selected according to the propellant gas property, the inner cavity aerodynamic force and other environments, the thickness of the heat insulating layer is designed according to the high temperature born by different parts and the strain born by the shell and the propellant grain, the shell of the combustion chamber is guaranteed not to be burnt out, the shell of the combustion chamber is guaranteed not to be overheated, and the thickness is 0.5mm-10 mm.

Selecting one of T700 carbon fiber cloth and T800 carbon fiber cloth as the reinforcing material in the step 2), wherein the surface density is 200-800 TEX;

selecting one/ester ring epoxy system resin of T700 carbon fiber cloth and T800 carbon fiber cloth from the material system in the step 2), wherein the cloth surface density of the carbon fiber cloth is 200-800TEX, the angle is 0-90 degrees, and the whole vacuum pumping is carried out to ensure that the vacuum degree is less than-0.085 Mpa and the fiber content is 70-78 percent.

The molding of the isolating device in the step 3) comprises the following steps:

the method comprises the steps of forming an arc surface of a sand core of a shell of the I-order combustion chamber, firstly laying ethylene propylene diene monomer or nitrile rubber with the thickness of 0.5-5mm, then laying fiber cloth with the thickness of 0.2-10mm and the angle of 0 degree, 15 degrees, -15 degrees, 30 degrees, -30 degrees, 45 degrees, -45 degrees, 60 degrees, -60 degrees, 75 degrees, -75 degrees and 90 degrees, coating the outer surface with de-filming cloth, a flow guide net and a vacuum bag film, ensuring sealing and vacuumizing, ensuring the vacuum degree to be-0.085-1.0 MPa, and not dropping pressure for 30 min;

pouring resin, wherein the resin system is resin, curing agent and accelerator, and the mass ratio is 100: 80-120: 0.5-2.5; the curing temperature is 1.5h at 90 ℃, 2h at 120 ℃ and 4h at 160 ℃, and the heating rate is 1-2 ℃/min; cleaning after curing, processing to remove redundant parts, polishing the inner surface and the outer surface of the isolation device by using sand paper, cleaning by using a volatile solvent, coating a coupling agent on the surface, and paving a heat insulation layer.

Step 3) the I-order combustion chamber shell and the II-order combustion chamber shell are molded, and the molding process comprises the following steps:

assembling a first-order combustion chamber shell sand core and a second-order combustion chamber shell sand core together, wherein an isolation device is positioned between the two sand cores, the two sand cores are erected, one end of each sand core is fixed, the other end of each sand core is tightly propped, and the sand cores are adjusted to be in the same axial degree through meter making;

laying a heat insulation layer on the surface of the sand core, bonding the heat insulation layer of the combustion chamber shell of the I step with the heat insulation layer in the isolation device, and bonding the heat insulation layer of the combustion chamber shell of the II step with the heat insulation layer outside the isolation device; the front connecting metal piece and the rear connecting metal piece are subjected to sand blasting treatment, the adopted compressed air pressure is 0.4-1.0MPa, the front connecting metal piece and the rear connecting metal piece are wiped cleanly by using a volatile solvent, the front connecting metal piece is bonded with the heat insulating layer at the left end of the sand core of the II-order combustion chamber shell, and the rear connecting metal piece is bonded with the heat insulating layer at the right end of the sand core of the I-order combustion chamber shell; the front connecting metal piece is firmly fixed by the front connecting metal piece fixing tool and the front connecting metal piece positioning tool; the rear connecting metal piece is firmly fixed by a rear connecting metal piece fixing tool and a rear connecting metal piece positioning tool;

wiping the surface with the heat insulation layer with a volatile solvent, brushing a coupling agent, and laying the fiber cloth cut by an automatic fabric cutting machine according to a designed fiber angle;

coating a piece of membrane removing cloth, a flow guide net and a vacuum bag membrane, and integrally vacuumizing to ensure that the vacuum degree is less than-0.085 to-1.0 MPa, and the pressure is not dropped for 30 min;

pouring resin, wherein the resin system is epoxy resin, curing agent and accelerator, and the mass ratio is 100: 80-120: 0.5-2.5;

putting the mixture into a curing furnace for curing, wherein the curing system comprises the following steps: the heating rate is 1-2 ℃/min, the temperature is 1.5h at 90 ℃, 2h at 120 ℃ and 4h at 160 ℃;

and cleaning surface auxiliary materials after solidification is finished, flushing the I-order combustion chamber shell sand core and the II-order combustion chamber shell sand core by using a high-pressure hot water gun, carefully drawing out the forming mandrel-1 and the forming mandrel-2 from two sides respectively, cleaning, and forming the I-order combustion chamber shell and the II-order combustion chamber shell to obtain the double-pulse engine combustion chamber shell.

The curing agent in the step 3) is selected from ammonia curing agents, and the accelerator is selected from benzylamine; the volatile solvent is selected from one of acetone, alcohol and ethyl acetate; the coupling agent is a silane coupling agent, and the coupling agent is coated to increase the bonding strength with rubber.

Compared with the prior art, the invention has the following advantages:

1. according to the invention, through designing the double-pulse engine combustion chamber shell and the isolation device, according to the designability of the composite material, through material optimization, process and structure optimization, the composite material is selected as the material of the isolation device and the combustion chamber shell, the isolation device is made of the carbon fiber composite material, and the two surfaces of the isolation device are bonded with the heat insulation layers which are respectively connected with the heat insulation layers of the I-stage combustion chamber shell and the II-stage combustion chamber shell, so that the sealing and heat insulation in the two shells are ensured.

2. The double-pulse engine combustion chamber shell prepared by the invention is light in weight, the center of the isolation device is not provided with an opening and is integrally formed, the isolation device is pre-formed by adopting a vacuum infusion process, the coaxiality of two sand cores of the I-stage combustion chamber shell and the II-stage combustion chamber shell is adjusted, the carbon fiber cloth is paved together with the pre-formed isolation device after the heat insulation layer is paved on the surface of the isolation device, the isolation device is integrally formed by adopting the vacuum infusion process, other sealing structures are not required to be added, the sealing is tight, in addition, the isolation device is also of an integral composite material structure, the weight is light, and the high internal pressure/low pressure collapse pressure resistant.

3. The invention relates to a method for molding a combustion chamber shell of a double-pulse engine, which comprises the steps of molding a composite material isolation device firstly and then integrally filling and molding the combustion chamber shell, wherein the center of the isolation device of the combustion chamber shell of the double-pulse engine is in a molding mode without an opening, the combustion chamber shell and the isolation device are integrally molded, the isolation device is made of composite materials and is tightly sealed, the isolation device can bear a larger high internal pressure/low pressure collapse pressure ratio, the sealing performance of the isolation device on the two combustion chamber shells of the double-pulse engine respectively is ensured, a gap is eliminated, the sealing is tight, in addition, the molding mode is simple, the quality is light, high reliability and low cost are realized, after the isolation device and the shells are molded together, the later-stage installation steps are reduced.

Drawings

FIG. 1 is a schematic structural diagram of a combustion chamber housing of a double pulse engine prepared according to an embodiment of the invention.

FIG. 2 is a schematic view of a forming structure of an I-stage combustion chamber shell and an isolating device of a double-pulse engine combustion chamber shell prepared by the embodiment of the invention.

FIG. 3 is a schematic view of a II-stage combustion chamber shell forming structure of a double-pulse engine combustion chamber shell prepared according to an embodiment of the invention.

FIG. 4 is a schematic product structure diagram of a double pulse engine combustion chamber shell prepared according to an embodiment of the invention.

In fig. 1 to 4: 1. forming a mandrel-1; 2. the front connecting metal piece fixes the tool; 3. a front connecting metal piece positioning tool; 4. a front connecting metal piece; 5. a second stage combustor housing; 6. a II-stage combustion chamber heat insulation layer; 7. a second-order combustion chamber shell sand core; 8. an insulating layer outside the isolation device; 9. an isolation device; 10. an insulating layer inside the isolation device; 11. a first stage combustor housing; 12. forming a mandrel-2; 13. i-stage combustion chamber shell sand core; 14. i-stage combustion chamber heat insulation layer; 15. then connecting a metal piece; 16. a rear connecting metal piece positioning tool; 17. and fixing the tool by the rear connecting metal piece.

Detailed Description

The present invention is described in further detail below by way of examples, which should not be construed as limiting the invention thereto.