Composite material solid rocket engine heat insulation layer 3D printing system and operation method

Abstract

The invention relates to the technical field of thermal protection layer forming, in particular to a composite solid rocket engine heat insulation layer 3D printing system and an operation method. The printing system comprises a feeding system and a mechanical arm system, the feeding system further comprises a material storage device, a mixing device and a hydraulic device, the mixing device is connected with the material storage device through a pipeline, and the hydraulic device conveys a heat insulation material in the material storage device to the mixing device through a pipeline; the mechanical arm system further comprises a mechanical arm and a control unit, the head of the mechanical arm is provided with a mixing device and a printing head, and the mixing device is connected with the printing head. The control unit has a heat insulation layer model slicing function and controls the mechanical arm to move and the printing head to print; the head of the mechanical arm is further provided with a curing device and a thickness measuring device. The thickness measuring device can measure the thickness of the heat insulation structure, the mechanical arm system automatically adjusts technological parameters according to the measuring result, the area with the thickness not meeting the requirement continues to be printed, the printing effect is fully guaranteed, and the reliability of the heat insulation layer is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal protection layer forming, in particular to a composite solid rocket engine insulation layer 3D printing system and operation method. BACKGROUND

[0002] The inner insulation layer of a solid rocket engine is one of the core components of a solid rocket engine. According to statistics, more than 70% of rocket launch failures are caused by engine thermal protection failure. Poor thermal protection technology will lead to engine combustion chamber burnout. The most famous case is the explosion of the American Hercules IV rocket after launch in 1993. The analysis result points out that the explosion is caused by the burnout of the engine back head insulation.

[0003] The existing composite solid rocket engine inner insulation layer usually follows the following process technology route: (1) head molding: the insulation material sheet is laid in the head mold, and high temperature and high pressure molding is adopted, then the head is sleeved on the core mold; (2) column segment patching: the insulation material sheet is laid on the core mold column segment by hand, and the joint of the head and the column segment is bonded with adhesive. However, the head molding needs manual laying of the material sheet in the mold, which often causes air entrapment, increases the risk of insulation structure fire burning, and the manual laying of the material sheet is low in efficiency and increases the labor cost. The head molding also needs molding mold and high temperature and high pressure vulcanization equipment, which increases the cost of mold and equipment; the column segment patching is also a manual operation, which is prone to problems such as uneven thickness of insulation material sheet and poor quality consistency; the column segment and the head are in a segmented structure, and the joint is bonded with adhesive, which reduces the integrity of the insulation structure and the reliability of the insulation layer.

[0004] The above process technology has the problems of low manual operation efficiency, easy air entrapment, uneven thickness, poor quality consistency, high mold and equipment cost, etc.; and cannot meet the development requirements of high performance, low cost, high reliability and high efficiency of solid rocket.

[0005] From the existing patent scheme, a solid rocket engine inner insulation layer 3D printing system and method (CN202010323345.6) proposes a micro-jet printing insulation layer method, with a single printing thickness of hundreds of microns, which greatly limits the printing efficiency of the insulation layer. The system has no detection system, cannot detect during printing, cannot obtain insulation layer thickness data in time, and cannot adjust the 3D printing parameters for thickness compensation during the process; and the patent does not describe the specific operation method of the solid rocket engine inner insulation layer printing.

[0006] A 3D printing forming device for a solid rocket engine insulation layer (CN109501256A) proposes a 3D printing device inside the engine shell. This method is limited by the size of the printing head assembly and cannot be used for 3D printing inside a small caliber shell. In addition, the low-illumination narrow space inside the shell also increases the difficulty of insulation layer thickness detection. After the insulation layer is printed, it is transferred to the oven for heating and curing. There is a risk of sticking and taking away the unsolidified insulation layer during printing. When printing a large thickness of insulation structure, there is a risk of unsolidified insulation layer dripping.

[0007] A 3D printing solid propellant / insulation layer formula and its integrated preparation method (CN111559948A) proposes a method for synchronously printing propellant and insulation layer. This method is suitable for engines with free-filling charging mode and cannot be used for composite material engines with wall-pasting pouring charging mode. At the same time, this system also has no thickness detection system. SUMMARY

[0008] Based on the above, the purpose of the present application is to provide a composite solid rocket engine insulation layer 3D printing system and operation method that can balance efficiency and accuracy, realize insulation layer thickness detection and thickness compensation during printing, and prevent unsolidified insulation layer from being stuck and taken away and dripping.

[0009] To achieve the above purpose, the present application adopts the following technical solutions:

[0010] A composite solid rocket engine insulation layer 3D printing system, comprising:

[0011] A feeding system comprising a storage device, a mixing device, and a hydraulic device. The storage device has multiple storage devices. The mixing device is connected to the multiple storage devices through pipelines. The hydraulic device transports the insulation material in the storage device to the mixing device through the pipeline.

[0012] A mechanical arm system comprising a mechanical arm and a control unit. The head of the mechanical arm is provided with the mixing device and the printing head. The mixing device is connected to the printing head. The control unit has an insulation layer model slicing function and controls the movement of the mechanical arm and the printing of the printing head. The head of the mechanical arm is also provided with a curing device and a thickness measuring device.

[0013] As a preferred scheme of a composite solid rocket engine insulation layer 3D printing system, a metering device is arranged at the pipeline between the mixing device and the storage device.

[0014] As a preferred scheme of a composite solid rocket engine insulation layer 3D printing system, a cooling system is arranged on the outer surface of the mixing device.

[0015] As a preferred scheme of the 3D printing system of the composite solid rocket engine insulation layer, the nozzle of the printing head has different shapes and sizes, the nozzle shape of the printing head is rectangular, parallelogram, triangle, trapezoid, circle and ellipse, the nozzle thickness of the printing head is 0.1mm-5mm, and the width is 5mm-100mm.

[0016] As a preferred scheme of the 3D printing system of the composite solid rocket engine insulation layer, the direction of the energy emitted by the curing device is consistent with the output direction of the printing head, and the energy emitted by the curing device can be selected in three forms, including microwave, ultraviolet light or infrared light.

[0017] As a preferred scheme of the 3D printing system of the composite solid rocket engine insulation layer, the thickness measuring device is specifically a three-dimensional scanner or a thickness gauge, and the orientation of the three-dimensional scanner or the thickness gauge is consistent with the output direction of the printing head.

[0018] As a preferred scheme of the 3D printing system of the composite solid rocket engine insulation layer, it further comprises a rotating tool for fixing and rotating a solid rocket engine core mold, the core mold is composed of end caps and a column segment in the middle, the shape of the end caps is a partial hemisphere, the shape of the column segment is a cylinder, and the diameter of the bottom of the end cap is equal to the diameter of the column segment.

[0019] A 3D printing operation method of a composite solid rocket engine insulation layer, the operation method is applied to the 3D printing system of the composite solid rocket engine insulation layer, and comprises the following steps:

[0020] S1: fixing the solid rocket engine core mold on the rotating tool, setting the rotating speed of the rotating tool, inputting the three-dimensional model of the insulation layer into the mechanical arm system, setting the single-layer slice thickness, and generating a slice graph by the control unit for the insulation layer;

[0021] S2: placing different insulation materials after defoaming in a plurality of storage devices, setting the mixing ratio, opening the cooling system of the mixing device, and controlling the feeding speed of the hydraulic device through the metering device.

[0022] S3: selecting the nozzle shape and size of the printing head, starting the feeding system for trial, until the nozzle of the printing head uniformly discharges, and closing the feeding system.

[0023] S4: setting the walking angle and speed of the mechanical arm through the control unit, and the mechanical arm drives the printing head to walk and print the insulation layer on the core model surface.

[0024] S5: after the print head prints 1 layer, the curing device is started, a curing mode is selected, the mechanical arm drives the curing device to walk along the surface of the core model, and the thermal insulation layer is cured;

[0025] S6: S4 and S5 are repeated, every 5 layers are printed, the thickness measuring device is started, the thickness of the thermal insulation layer is detected, and is compared with the three-dimensional model of the thermal insulation layer, the comparison result is transmitted to the mechanical arm system, the area that does not meet the requirement in thickness continues to be printed, and the above operation is repeated until the size of the thermal insulation layer meets the requirement.

[0026] As a preferred scheme of the 3D printing operation method of the thermal insulation layer of the composite solid rocket engine, the nozzle shape and size of the print head are selected, for the thermal insulation layer with large thickness, a large-size nozzle is used for printing in the early stage, and when the printing approaches the required size, a small-size nozzle is switched to for printing.

[0027] As a preferred scheme of the 3D printing operation method of the thermal insulation layer of the composite solid rocket engine, the mechanical arm drives the print head to walk along the surface of the core model to print the thermal insulation layer, the included angle between the print head and the core model is a walking angle, and the walking angle is 30°-90°.

[0028] As a preferred scheme of the 3D printing operation method of the thermal insulation layer of the composite solid rocket engine, the diameter (D) of the core model is controlled during the printing process, the rotation speed (V R ) of the rotating tool, the nozzle cross-sectional area (S) of the print head and the feeding speed (V1) of the feeding system are matched with each other, the walking speed (V2) of the print head along the axial direction of the core model, the rotation speed (V R ) of the rotating tool and the nozzle width (L) of the print head are matched with each other, and the following formula needs to be met:

[0029]

[0030] Z is the shortest distance between the printing position and the column segment when the print head prints on the head of the core model, and therefore D z is the diameter of the cross section circle where the printing position is located; when the print head prints on the column segment, Z=0, and D z =D, and the above two formulas can be simplified as:

[0031]

[0032] The 3D printing operation method of the thermal insulation layer of the composite solid rocket engine has the following beneficial effects:

[0033] ​(1) Adopting the feeding system and the mechanical arm system instead of manual work, quantitatively controlling the walking speed, the rotating speed and the walking angle of the printing head, avoiding the air entrapment problem of manual laying of the material sheet, and reducing the labor cost;

[0034] (2) The scheme carries out 3D printing of the heat insulation layer on the surface of the core mold in situ, the heat insulation layer and the core mold are completely attached, the gap problem between the traditional mold pressing head and the core mold is solved, the risk of poor bonding between the heat insulation layer and the composite shell is further avoided, and the mold pressing mold and the high-temperature vulcanization equipment are saved, thereby saving the mold cost and the vulcanization equipment cost;

[0035] (3) The head and the column segment heat insulation are formed by 3D printing without manual operation, the walking speed, the angle, the walking angle, the diameter (D) of the core mold, the rotating speed (V R ) of the rotating tool, the nozzle cross-sectional area (S) of the printing head and the feeding speed (V1) of the feeding system are matched with each other, the uniformity of the heat insulation layer printing thickness can be effectively controlled, and the quality consistency is improved; the walking speed (V2) of the printing head along the axial direction of the core mold, the rotating speed (V R ) of the rotating tool and the nozzle width (L) of the printing head are matched with each other, and the wrinkles and burrs of the heat insulation layer overlap are prevented;

[0036] (4) The column segment and the head are continuously 3D printed, which is an overall structure, and does not need to use adhesive to bond, compared with the traditional manual patching process, the reliability of the heat insulation structure is improved;

[0037] (5) The curing device is arranged, after printing each layer, the heat insulation layer can be cured in situ by using the curing device, so as to prevent the heat insulation layer of the previous layer from being adhered and taken away when printing the next layer, the heat insulation layer is cured in situ during the printing process, the time for secondary curing of the heat insulation layer is reduced, the manufacturing period of the heat insulation layer is shortened, and the risk of sagging during printing is eliminated;

[0038] (6) The three-dimensional scanner or the thickness gauge is arranged on the head of the mechanical arm, the thickness of the heat insulation structure is measured, and the measurement result is compared with the heat insulation structure model, the comparison result is transmitted to the mechanical arm system, the process parameters are automatically adjusted by the mechanical arm system, the area with a thickness not meeting the requirements is continuously printed, and the above operation is repeated until the size of the heat insulation structure meets the requirements, so that the printing effect is fully guaranteed, and the reliability of the heat insulation layer is improved. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the description of the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the contents of the embodiments of the present application and these drawings.

[0040] Figure 1 is a three-dimensional structure schematic view of a composite material solid rocket engine insulation layer 3D printing system provided by the present application;

[0041] Figure 2 is Figure 1 is a partial enlarged view of A in FIG.

[0042] Figure 3 is a top view of a composite material solid rocket engine insulation layer 3D printing system provided by the present application;

[0043] Figure 4 is Figure 3 is a partial enlarged view of B in FIG.

[0044] Figure 5 is a side view of a composite material solid rocket engine insulation layer 3D printing system provided by the present application;

[0045] Figure 6 is Figure 5 is a partial enlarged view of C in FIG.

[0046] Figure 7 is a sectional view of a core mold in a composite material solid rocket engine insulation layer 3D printing system provided by the present application.

[0047] Reference signs:

[0048] 1 - storage device; 2 - mixing device; 3 - hydraulic device; 4 - mechanical arm; 4a - support disc; 5 - printing head; 6 - curing device; 7 - thickness measuring device; 8 - metering device; 9 - cooling system; 10 - rotating tool; 11 - core mold; 11a - end cap; 11b - column segment; 12 - operation table; 13 - base; 14 - wire slot wiring board. DETAILED DESCRIPTION

[0049] The present application will be further described below in conjunction with the drawings and examples. It can be understood that the specific examples described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, but not all the structures.

[0050] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0051] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0052] In the description of the present embodiment, the terms "up", "down", "left", "right" and other orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more. In addition, the terms "first", "second" are only used to distinguish in the description, and have no special meaning.

[0053] The present embodiment provides a kind of composite material solid rocket engine heat insulation layer 3D printing system, as shown in Fig. Figures 1 to 6 It includes:

[0054] Feeding system, including storage device 1, mixing device 2 and hydraulic device 3, storage device 1 is provided with multiple, for storing different heat insulation materials, and the heat insulation layer is composed of a plurality of heat insulation materials mixed;Mixing device 2 is connected with a plurality of storage devices 1 pipeline, and the hydraulic device 3 transports the heat insulation material in the storage device 1 to the mixing device 2 through the pipeline, so as to realize the mixing of different heat insulation materials;

[0055] Mechanical arm system, including mechanical arm 4 and control unit, the head of mechanical arm 4 is provided with mixing device 2 and printing head 5, and mixing device 2 is connected with printing head 5;Control unit has heat insulation layer model slicing function and controls the movement of mechanical arm 4 and the printing of printing head 5;As Figure 2As shown, the head of the mechanical arm 4 is also provided with a curing device 6 and a thickness measuring device 7, as Figure 2 and Figure 4 As shown, the print head 5, the curing device 6 and the thickness measuring device 7 are all arranged on the support disc 4a of the head of the mechanical arm 4, and the output direction of the print head 5, the direction of energy emission of the curing device 6 and the orientation of the thickness measuring device 7 are all consistent and the same as the axial direction of the support disc 4a.

[0056] In the present embodiment, the storage device 1 is specifically a material barrel, and there are two material barrels, and the two material barrels are respectively filled with two different thermal insulation materials, and the thermal insulation materials are in liquid or paste state before curing; in some other embodiments, the storage device 1 is a multi-barrel, and the specific number of barrels can be 3, 4, 5, etc., which is suitable for printing of multi-layer composite thermal insulation structure.

[0057] Specifically, the thermal insulation material used by the printing system can be one or more of liquid silicone rubber system, liquid ethylene-propylene-diene rubber system, liquid nitrile rubber system, liquid polyurethane system, liquid polyurea system, etc. with liquid or paste system form.

[0058] Further, a set of hydraulic devices 3 is arranged above each material barrel, and the core structure of each set of hydraulic devices 3 is a plunger pump, which sucks the thermal insulation material in the material barrel into the pipeline and delivers it to the mixing device 2. The plunger pump is a conventional technology, and therefore will not be described in detail herein.

[0059] Further, as shown in Figure 5 The pipeline between the mixing device 2 and the storage device 3 is provided with a metering device 8, which monitors and controls the flow or mass of the thermal insulation material in the pipeline in real time. Specifically, according to the flow or mass measured by the metering device 8, the metering pump in the metering device 8 controls the mass or volume of different thermal insulation materials delivered per unit time, so as to quantitatively control the proportion of different thermal insulation materials, so as to realize the mixing and production of the thermal insulation layer according to the preset ratio; it can also accurately control the extrusion rate of the mixed thermal insulation material, prevent the occurrence of material breakage or plug, and ensure the stability of the thermal insulation material forming.

[0060] Preferably, a cooling system 9 is arranged on the outer surface of the mixing device 2, which is a cooling water system in the present embodiment, for absorbing the heat generated by the thermal insulation material during the mixing process, preventing the temperature of the thermal insulation layer from being too high, and causing the viscosity to rise or solidify in the mixing device 2.

[0061] Preferably, the nozzles of the print head 5 have different shapes and sizes, and the shapes of the nozzles of the print head 5 are rectangular, parallelogram, triangular, trapezoidal, circular and elliptical. Different shapes of nozzles can adapt to different printing needs, and can also solve the problems of adhesion at the printing overlap and size precision control. For example, circular and rectangular nozzles are the most common. The circular nozzle extrudes a wire in the shape of a nearly cylindrical shape, which is suitable for general printing. The rectangular nozzle extrudes a wire that is wide and thin, which is suitable for large-area filling. The parallelogram nozzle can reduce the overlapping area between adjacent wires, reduce the local over-thickness caused by boundary accumulation, make the printing effect more uniform, and increase the boundary adhesion area with high bonding strength. The thickness of the nozzle of the print head 5 is 0.1mm-5mm, and the width is 5mm-100mm. In some other embodiments, the thickness of the nozzle of the print head 5 is 2.5mm, and the width is 50mm. The print head nozzle with high thickness and large width is a large-size nozzle, which is suitable for early-stage large-thickness thermal insulation layer printing. The print head nozzle with low thickness and small width is a small-size nozzle, which is suitable for later-stage high-precision thermal insulation layer printing.

[0062] Specifically, as shown in Figure 2 、 Figure 4 and Figure 6 , the direction of the energy emitted by the curing device 6 is consistent with the output direction of the print head 5. The energy emitted by the curing device 6 can be selected in three forms, including microwave, ultraviolet light or infrared light, which realizes in-situ curing of the thermal insulation layer by irradiating the surface of the thermal insulation layer. In actual application, the curing device 6 can be used to cure the thermal insulation layer in-situ after the printing system prints 1 layer, so as to prevent the adhesion of the previous layer of thermal insulation layer from being taken away when printing the next layer. In-situ curing of the thermal insulation layer is realized during the printing process, which reduces the time for secondary curing of the thermal insulation layer and shortens the manufacturing cycle of the thermal insulation layer.

[0063] More specifically, the curing operation is divided into four modes, including normal temperature curing, microwave curing, ultraviolet light curing and infrared heating curing. Normal temperature curing is realized by adjusting the proportion of the curing agent in the thermal insulation material. When normal temperature curing is selected, printing and curing are performed synchronously, and the curing device 6 does not participate in the curing operation. When microwave curing, ultraviolet light curing and infrared heating curing are selected, printing and curing are performed separately, and the curing device 6 stops working after being started.

[0064] Specifically, the thickness measuring device 7 is specifically a three-dimensional scanner or a thickness gauge, as shown in Figure 2 、 Figure 4 and Figure 6 , the orientation of the three-dimensional scanner or the thickness gauge is consistent with the output direction of the print head. The thickness measuring device 7 can measure the thickness of the currently printed thermal insulation layer, and compare it with the three-dimensional model of the thermal insulation layer. The comparison result is transmitted to the mechanical arm system, which automatically adjusts the process parameters. The areas with thickness not meeting the requirements are printed again, and the above operation is repeated until the size of the thermal insulation structure meets the requirements, so as to ensure the printing effect of the thermal insulation layer.

[0065] More specifically, the three-dimensional scanner or the thickness gauge both adopt existing technologies: the three-dimensional scanner can be a FreeScan Trak Pro2 industrial three-dimensional scanner, which generates a three-dimensional point cloud map by laser scanning the heat insulation profile before and after molding, and obtains the heat insulation layer thickness by comparing the three-dimensional point cloud maps; the thickness gauge can be a Keyence LJ-X8000 laser measuring instrument, which diffuses laser into linear laser through a cylindrical lens, projects it on the target object surface to form diffuse reflection, and then images the reflected light on the CMOS, and measures the heat insulation layer thickness by detecting the position and shape changes. In this embodiment, the thickness measuring device 7 is selected as a thickness gauge.

[0066] Specifically, the composite solid rocket engine heat insulation layer 3D printing system further comprises a rotating tool 10 for fixing and rotating the solid rocket engine core mold 11, as shown in the figure. Figure 7 As shown in the figure, the core mold 11 is composed of end caps 11a at both ends and a column segment 11b in the middle. The shape of the end cap 11a is a partial hemisphere, and the shape of the column segment 11b is a cylinder. The diameter of the bottom of the end cap 11a is equal to the diameter of the column segment 11b. The rotating tool 10 fixes and rotates the end cap 11a of the core mold 11 from both ends.

[0067] More specifically, the control of the hydraulic device 3, the mechanical arm system and the rotating tool 10 is carried out on the operation table 12. Optionally, a control panel touch screen is arranged on the operation table 12 for actual control.

[0068] Optionally, the solid rocket engine core mold 11 can be a plaster core mold, a sand core mold or a metal core mold. After the heat insulation layer and the outer shell are made, the plaster core mold is knocked out to be demolded, the sand core mold is washed with water to be demolded, and the metal core mold is demolded through a detachable structure.

[0069] Optionally, a wire slot wiring board 14 is arranged on the base 13 where the composite solid rocket engine heat insulation layer 3D printing system is located. The cables for connecting the power supply or other external devices of the printing system are laid in the inner slots of the wire slot wiring board 14, so as to avoid various safety hazards caused by direct exposure of the cables and improve the safety of the system.

[0070] A composite solid rocket engine heat insulation layer 3D printing operation method is applied to a composite solid rocket engine heat insulation layer 3D printing system, and comprises the following steps:

[0071] S1: fixing the solid rocket engine core mold 11 to the rotating tool 10, the diameter of the core mold 11 is 50 cm, the rotating speed of the rotating tool 10 is set to 20 r / min, the three-dimensional model of the heat insulation layer is input into the mechanical arm system, the single-layer slice thickness is set to 0.1-1 mm, and the control unit generates a slice map by slicing the heat insulation layer layer by layer;

[0072] S2: After defoaming, different thermal insulation materials are placed in multiple storage devices 1, the mixing ratio is set to 1:1, the cooling system 9 of the mixing device 2 is opened, the water temperature of the cooling water system is controlled to be ≤10℃, and the feeding speed of the hydraulic device 3 is controlled by the metering device 8 to be 471 cm / min. 3

[0073] S3: The nozzle shape and size of the print head 5 are selected, the nozzle shape of the print head 5 is a parallelogram with a thickness of 1 mm and a width of 15 mm, the feeding system is started for trial, until the nozzles of the print head 5 are uniformly discharged, and then the feeding system is turned off.

[0074] S4: The walking angle and speed of the mechanical arm 4 are set by the control unit, the mechanical arm 4 drives the print head 5 to walk on the surface of the core model to print the thermal insulation layer, and the printing is performed in the order of head 11a-column segment 11b-head 11a.

[0075] S5: After printing 1 layer by the print head 5, the curing device 6 is started, the infrared heating and curing mode is selected, the infrared heating lamp is turned on, the heating temperature is controlled to be 80-120℃, the mechanical arm 4 drives the curing device 6 to walk on the surface of the core model to heat and cure the thermal insulation layer, and at this time the axial walking speed of the mechanical arm 4 is 30 cm / min.

[0076] S6: Repeat S4 and S5, start the thickness measuring device 7 every 5 layers to detect the thickness of the thermal insulation layer, compare it with the three-dimensional model of the thermal insulation layer, and transmit the comparison result to the mechanical arm system. The area that does not meet the thickness requirement is continuously printed, and the above operation is repeated until the size of the thermal insulation layer meets the requirement.

[0077] Preferably, in the foregoing operation method, "selecting the nozzle shape and size of the print head 5" means that for a large-thickness thermal insulation layer, a large-size nozzle is used for printing in the early stage, and when the printing approaches the required size, a small-size nozzle is switched to for printing.

[0078] Specifically, in the foregoing operation method, "the print head 5 walks on the surface of the core model" means that the print head 5 walks along the shape of the solid rocket engine core model 11, and the print head 5 always maintains a fixed walking angle with the surface of the core model 11. Walking on the surface of the core model by the print head can generate a certain pressure on the thermal insulation layer, thereby improving the compactness and interlayer bonding strength of the thermal insulation layer.

[0079] More specifically, the mechanical arm 4 drives the print head 5 to walk on the surface of the core model to print the thermal insulation layer, the included angle between the print head 5 and the core model 11 is the walking angle, and the walking angle is 30°-90°. When the walking angle is less than 90°, the print head 5 generates a certain pressure while printing the thermal insulation material, which is beneficial to improving the interlayer bonding strength of the thermal insulation material.

[0080] ​In practical applications, the diameter (D) of the mandrel 11 and the rotational speed (V) of the rotating fixture 10 need to be controlled during the printing process. R The nozzle cross-sectional area (S) of the printhead 5 and the feeding speed (V1) of the feeding system are matched to prevent the insulation layer from being too thick or too thin in some areas; it is also necessary to control the axial travel speed (V2) of the printhead 5 along the core mold 11 and the rotation speed (V1) of the rotating tooling 10. R The width (L) of the nozzle of the printhead 5 and the nozzle width of the printhead 5 must be matched to prevent wrinkles and burrs from forming at the overlap of the insulation layer. The above two matching relationships must satisfy the following formula:

[0081]

[0082] in like Figure 7 As shown, Z is the shortest distance between the printing position and the column segment 11b when the print head 5 prints on the end cap 11a of the mandrel 11. Therefore, D z The diameter of the cross-sectional circle where the printing position is located; when the print head 5 prints on column segment 11b, Z = 0, D z =D, formulas (1) and (2) can be simplified to:

[0083]

[0084] When printing in the order of head 11a - column segment 11b - head 11a, Z first gradually decreases to 0, then remains constant, and then gradually increases. z The corresponding value gradually increases to D, then remains constant, and then gradually decreases. The dynamic adjustment during this period is achieved by adjusting the rotational speed (V) of the rotating fixture 10. R )accomplish.

[0085] Specifically, formulas (1) and (3) refer to the fact that within the time range during which the rotating fixture 10 rotates the core mold 11 one revolution, the volume of the heat insulation material output by the print head 5 is equal to the volume of the heat insulation material covering the core mold 11 one revolution, thereby ensuring that the heat insulation material is printed evenly on the surface of the core mold 11; formulas (2) and (4) refer to the fact that the time during which the rotating fixture 10 rotates the core mold 11 one revolution is equal to the time during which the print head 5 moves axially by the width of a nozzle, thereby ensuring that there are no gaps between adjacent printing areas when rotating to print the insulating material.

[0086] Based on the specific data provided in the operating instructions, taking the printing process of the column segment area as an example: feeding speed V1 = 471cm 3 / min, rotational speed V of rotating fixture 10 R =20r / min, π = 3.14, core mold 11 diameter D = 50cm, S = 1 × 15 = 15mm 2 (0.15cm2 ), the width L of the print head 5 is 15 mm (1.5 cm), and the axial walking speed V2 is 30 cm / min, it can be calculated by substituting into formula (3) and formula (4) that both satisfy; it is also found that when the diameter D of the core mold 11 and the nozzle width L of the print head 5 are too different in value, (πD) 2 and L 2 are more different in value, L 2 can be ignored, and formula (3) for the column segment printing can be further simplified as:

[0087]

[0088] When the diameter D of the core mold 11 and the nozzle width L of the print head 5 are relatively close in value, the influence of the nozzle width L on the calculation result needs to be considered, and the matching relationship is still calculated by using formula (3).

[0089] Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses or adaptations of the disclosure other than those expressly disclosed herein. The specification and examples are to be regarded as illustrative only, and the true scope and spirit of the disclosure are indicated by the following claims.

[0090] It should be understood that the present disclosure is not limited to the precise structures herein described and illustrated in the drawings, and that various modifications and changes can be made without departing from its scope. The scope of the present disclosure is limited only by the claims that follow.

Claims

1. A composite solid rocket motor insulation 3D printing system, characterized in that, The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer.

2. The composite solid rocket motor insulation 3D printing system according to claim 1, wherein, The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer.

3. The composite solid rocket motor insulation 3D printing system according to claim 1, wherein, The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer.

4. The composite solid rocket motor insulation 3D printing system of claim 1, wherein, The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer.

5. The composite solid rocket motor insulation 3D printing system according to claim 1, wherein, The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer.

6. The composite solid rocket motor insulation 3D printing system according to claim 2, wherein, The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer.

7. A method of 3D printing of a composite solid rocket motor insulation layer, characterized in that, The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for a composite solid rocket engine heat-insulating layer. The application relates to a 3D printing system for S4: setting the walking angle and speed of the mechanical arm (4) by the control unit, the mechanical arm (4) driving the printing head (5) to walk on the core model surface to print the thermal insulation layer; S5: after the printing head (5) prints one layer, starting the curing device (6), selecting the curing mode, the mechanical arm (4) driving the curing device (6) to walk on the core model surface to cure the thermal insulation layer; S6: repeating S4 and S5, every 5 layers, starting the thickness measuring device (7), detecting the thickness of the thermal insulation layer, comparing with the three-dimensional model of the thermal insulation layer, and transmitting the comparison result to the mechanical arm system, continuing to print the area that does not meet the requirements, repeating the above operation until the size of the thermal insulation layer meets the requirements.

8. The 3D printing operation method of a composite material solid rocket engine insulation layer according to claim 7, characterized in that, The nozzle shape and size of the printing head (5) are selected, for large thickness thermal insulation layer, large size nozzle is used for printing in the early stage, and when the size approaches the required size, small size nozzle is switched to print.

9. The 3D printing operation method of a composite material heat shield for a solid rocket engine according to claim 7, characterized in that, The mechanical arm (4) drives the printing head (5) to walk on the core model surface to print the thermal insulation layer, the included angle between the printing head (5) and the core model (11) is the walking angle, and the walking angle is 30°~90°.

10. The 3D printing operation method of a composite material solid rocket engine insulation layer according to claim 7, characterized in that, The diameter (D) of the core (11), the rotation speed (V R ) of the rotating tool (10), the nozzle cross-sectional area (S) of the printing head (5) and the feeding speed (V1) of the feeding system are matched with each other during the printing process; the axial walking speed (V2) of the printing head (5) along the core (11), the rotation speed (V R ) of the rotating tool (10) and the nozzle width (L) of the printing head (5) are matched with each other, and the following formula is met: ， wherein Z is the shortest distance between the printing position and the column segment (11b) when the printing head (5) prints on the head (11a) of the core (11), thus D is the diameter of the cross section where the printing position is located; when the printing head (5) prints on the column segment (11b), Z = 0, D = D, and the above two formulas can be simplified as: 。

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