CN117962368A - Inflatable mandrel and method for preparing continuous variable-section composite material by using same - Google Patents
Inflatable mandrel and method for preparing continuous variable-section composite material by using same Download PDFInfo
- Publication number
- CN117962368A CN117962368A CN202410161070.9A CN202410161070A CN117962368A CN 117962368 A CN117962368 A CN 117962368A CN 202410161070 A CN202410161070 A CN 202410161070A CN 117962368 A CN117962368 A CN 117962368A
- Authority
- CN
- China
- Prior art keywords
- mandrel
- die
- inflatable
- composite
- mold
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000002131 composite material Substances 0.000 title claims abstract description 104
- 238000000034 method Methods 0.000 title claims abstract description 25
- 239000000463 material Substances 0.000 claims abstract description 33
- 239000000835 fiber Substances 0.000 claims abstract description 19
- 238000002360 preparation method Methods 0.000 claims abstract description 16
- 238000001746 injection moulding Methods 0.000 claims abstract description 6
- 238000000748 compression moulding Methods 0.000 claims abstract description 5
- 239000002994 raw material Substances 0.000 claims abstract 2
- 238000000465 moulding Methods 0.000 claims description 18
- 229920001971 elastomer Polymers 0.000 claims description 15
- 239000003292 glue Substances 0.000 claims description 15
- 238000003825 pressing Methods 0.000 claims description 15
- 238000002347 injection Methods 0.000 claims description 11
- 239000007924 injection Substances 0.000 claims description 11
- 238000009954 braiding Methods 0.000 claims description 8
- 150000001875 compounds Chemical class 0.000 claims description 8
- 238000009940 knitting Methods 0.000 claims description 8
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 4
- 239000011347 resin Substances 0.000 claims description 4
- 229920005989 resin Polymers 0.000 claims description 4
- 239000000741 silica gel Substances 0.000 claims description 4
- 229910002027 silica gel Inorganic materials 0.000 claims description 4
- 238000009941 weaving Methods 0.000 claims description 4
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- 238000005520 cutting process Methods 0.000 claims description 3
- 239000004744 fabric Substances 0.000 claims description 3
- 239000003365 glass fiber Substances 0.000 claims description 3
- 238000005086 pumping Methods 0.000 claims description 3
- 229920002379 silicone rubber Polymers 0.000 claims description 3
- 239000011343 solid material Substances 0.000 claims description 3
- 238000005507 spraying Methods 0.000 claims description 3
- 238000007599 discharging Methods 0.000 claims description 2
- 239000011344 liquid material Substances 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 abstract description 7
- 238000007789 sealing Methods 0.000 description 19
- 238000000926 separation method Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 229920002430 Fibre-reinforced plastic Polymers 0.000 description 4
- 230000013011 mating Effects 0.000 description 4
- 229920000049 Carbon (fiber) Polymers 0.000 description 3
- 244000043261 Hevea brasiliensis Species 0.000 description 3
- 239000004917 carbon fiber Substances 0.000 description 3
- 238000001125 extrusion Methods 0.000 description 3
- 229920003052 natural elastomer Polymers 0.000 description 3
- 229920001194 natural rubber Polymers 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000004073 vulcanization Methods 0.000 description 2
- 229920002943 EPDM rubber Polymers 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000012938 design process Methods 0.000 description 1
- 238000007723 die pressing method Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 229910052602 gypsum Inorganic materials 0.000 description 1
- 239000010440 gypsum Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 239000004945 silicone rubber Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000004753 textile Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/68—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts by incorporating or moulding on preformed parts, e.g. inserts or layers, e.g. foam blocks
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/68—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts by incorporating or moulding on preformed parts, e.g. inserts or layers, e.g. foam blocks
- B29C70/681—Component parts, details or accessories; Auxiliary operations
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/68—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts by incorporating or moulding on preformed parts, e.g. inserts or layers, e.g. foam blocks
- B29C70/681—Component parts, details or accessories; Auxiliary operations
- B29C70/682—Preformed parts characterised by their structure, e.g. form
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Composite Materials (AREA)
- Mechanical Engineering (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
- Moulding By Coating Moulds (AREA)
Abstract
The application provides an inflatable mandrel and a method for preparing a continuous variable cross-section composite material by using the same, and belongs to the technical field of fiber composite materials. The method comprises the steps of taking a selected mandrel material as a raw material, taking a mandrel die and a block combined type inner die as a forming die, placing the block combined type inner die in the mandrel die, filling the mandrel material between the mandrel die and the forming die, and then obtaining the inflatable mandrel in a compression molding or injection molding mode, wherein the shape of the inflatable mandrel meets the requirement that the section continuously changes along the axial direction, wherein the outer surface of the block combined type inner die forms the shape of the inner wall of the inflatable mandrel, and the shape of a forming groove of the mandrel die is the same as the shape of the inflatable mandrel. The application can realize the low-cost high-precision preparation of the continuous variable-section inflatable mandrel and the high-efficiency high-precision manufacture and demoulding of the special-shaped composite pipe fitting, can meet the production requirement of the high-performance low-cost composite material, and promotes the wide application of the special-shaped woven composite material.
Description
Technical Field
The application relates to an inflatable mandrel and a method for preparing a continuous variable cross-section composite material by using the same, and belongs to the technical field of fiber composite materials.
Background
The three-dimensional braided composite material has the excellent characteristics of light weight, high strength, good structural designability, easiness in molding complex components and the like, and is widely applied to the fields of aerospace, transportation, military energy and the like, such as rocket throat liners, propeller blades, engine spray pipes, missile nose cones, carbon fiber frames and the like. The corresponding three-dimensional braiding technology has the advantages of less material loss, high automation degree and the like, so that one-step forming of complex components can be realized, and the three-dimensional braiding technology is very suitable for forming various curved surfaces and special-shaped structural components. The mandrel is a necessary component for preparing the hollow composite pipe fitting, and is a precondition and foundation for guaranteeing the stable forming of the braided composite preform. Therefore, the material selection and preparation process of the mandrel with the complex shape are very important.
Common mandrel materials include wax, gypsum, hydrosol/Dan Yingsha and the like, but the materials have the defects of intolerance to high temperature or repeated mandrel preparation and the like, and the existence of the defects seriously influences the performance of the mandrel and further influences the production efficiency of the composite material.
In order to improve the utilization rate of the mandrel and reduce the repeated preparation process of the mandrel, an inflatable/deflatable soft mandrel is developed in the industry. However, most of the current inflatable mandrels can only be used for preparing straight-tube-shaped or axially uniformly-changed special-shaped composite material components, the mandrels are easy to realize unidirectional demolding, and the preparation of the spindle-shaped and other continuous variable-section composite material components cannot be realized.
Disclosure of Invention
In view of the above, the application firstly provides an inflatable mandrel capable of realizing continuous variable cross-section special-shaped composite material preparation, and the composite material preparation is realized by controlling inflation pressure.
Specifically, the application is realized by the following scheme:
an inflatable mandrel is prepared from the chosen mandrel material, mandrel mould and sectional combined internal mould through putting the sectional combined internal mould in the mandrel mould, filling the mandrel material between them, die pressing or injection moulding to obtain the shape of internal wall of inflatable mandrel, shaping slot of mandrel mould, and axially and continuously changing its shape,
The block combined internal mold comprises an internal mold head, an internal mold block and an internal mold core, wherein the internal mold block and the internal mold core are respectively connected with the internal mold head, so that the internal mold block surrounds and is attached to the periphery of the internal mold core,
The inner die is of a split type structure formed by splicing a plurality of module units, and the inner wall of each module unit is respectively attached to the outer wall of the inner die core.
The inflatable mandrel obtained by the scheme can be processed with the aid of the matching of the segmented combined inner die and the mandrel die, and the inflatable mandrel with axial continuous change can be endowed with specific strength, hardness and elasticity by selecting the mandrel material. The block combined type internal mold facilitates demolding of the inflatable mandrel, and when the inflatable mandrel is prepared, the internal mold head, the internal mold block and the internal mold core can be disassembled sequentially to realize easy demolding, so that the molding effect of the inflatable mandrel is prevented from being greatly influenced by the demolding difficulty. When the composite material is used for preparing the continuous variable cross-section composite material, the outer surface of the inflatable mandrel forms the basic shape of the composite material, the molding stability and the molding density of the composite material are realized by means of the inflation pressure of the inflatable mandrel, and when the molding is finished, the composite material is deflated, so that the composite material can be rapidly demolded.
Further, as preferable:
The inflatable mandrel is of a thick structure at two ends and a thin structure at the middle or a thick structure at the middle of two ends. The spindle-type special-shaped structure with the thick middle thick two ends or the thin middle two ends is the most commonly applied composite material shape, and the inflatable mandrel with the shape can meet the processing requirements of most composite materials.
The module units are four groups, the four groups of module units are mutually spliced to obtain the segmented combined internal mold, the section of the inner wall of the segmented combined internal mold is the same as the section of the internal mold core, and the shape of the outer wall of the segmented combined internal mold is consistent with that of the outer wall of the inflatable mandrel. If the inner mold core is of a cylindrical structure, the block combined type inner mold is formed by splicing four groups of module units, the inner wall of each group of module units is at right angles, and the outer wall of each group of module units is arranged into four unit shapes corresponding to the shape of the inflatable mandrel, so that the block combined type inner mold is convenient to splice.
The mandrel material is a solid material and is suitable for compression molding, at the moment, the mandrel material is positioned between a mandrel die and a block combined internal die, and an inlet and an outlet for exhausting are arranged on the mandrel die; or the mandrel material is a liquid material and is suitable for injection molding, at the moment, the inlet and the outlet on the mandrel die are glue injection/glue outlet, and the mandrel material is injected between the mandrel die and the segmented combined inner die through the inlet and the outlet. The core shaft material is rubber, silicon rubber or a composite material of silica gel/rubber and glass fiber cloth. The mandrel material needs to meet the requirements of high strength (more than or equal to 40 MPa), high hardness (shore hardness more than or equal to 50) and high elastic modulus (more than or equal to 20 MPa), and the optional mandrel material comprises rubber, silicone rubber, a composite material of silica gel/rubber and glass fiber cloth, and the like. When rubber is selected as the mandrel material, the inflatable mandrels with the temperature resistance of 100 ℃, 200 ℃ and 300 ℃ can be respectively selected from natural rubber, ethylene propylene diene monomer rubber and perfluorinated rubber, and the heat resistance of the silica gel is enough, and only the strength and the hardness are considered.
A second object of the applicant is to provide a method for preparing a continuous variable cross-section composite material, comprising the steps of:
step one, connecting a support shaft with an inflation device, sleeving an inflation mandrel on the outer side of the support shaft and fixing the inflation mandrel with the inflation device, after the inflation device inflates the inflation mandrel, weaving a formed fiber prefabricated member on the inflation mandrel,
Spraying a release agent in the composite material forming die, placing the inflatable mandrel and the fiber prefabricated member in the step one in the composite material forming die, fixing, closing the die, continuously inflating the inflatable mandrel to a proper positive pressure through an inflating device, vacuumizing the die, injecting resin into the die through a glue injection port of the composite material forming die,
And thirdly, after curing, opening the die, taking out the inflatable mandrel, removing the inflatable device after pumping the inflatable mandrel to negative pressure through the inflatable device, taking down the cured product and cutting the redundant end part to obtain the continuous variable cross-section composite material.
The process realizes the VARTM process molding of the fiber preform, positive pressure is filled in the inflatable mandrel in the molding stage, and negative pressure is pumped in the inflatable mandrel in the demolding stage.
Preferably, the method comprises the steps of,
In the first step:
The inflatable device comprises an air vent, a raised flange and a connector, wherein the supporting shaft is installed on the inflatable device through threaded connection with the connector, the inflatable mandrel is connected with the inflatable device through the raised flange, an air channel is arranged in the inflatable device, and the air channel is communicated between the inflatable mandrel and the air vent. More preferably, the separation ring sealing device is arranged at the convex flange, the separation ring sealing device is provided with an extrusion notch, the extrusion notch corresponds to the convex flange, and the inflatable mandrel is fixed at the convex flange in a sealing way through the separation ring sealing device.
The knitting forming process mainly comprises the type, fineness and knitting parameters of the used fiber, and the knitting parameters of the knitting forming meet the formulaAnd/>Wherein θ is the braiding angle, R is the average radius of the inflatable mandrel, R is the radius of the guiding ring of the braiding machine, H is the convergence domain length, w is the angular velocity of the braiding machine, and V is the advancing velocity of the mechanical arm.
In the second step:
The composite material forming die comprises a pressing table, a bottom plate, an upper composite die and a lower composite die, wherein the upper composite die is arranged on the pressing table, the lower composite die is arranged on the bottom plate, the inflatable mandrel and the fiber prefabricated member are positioned between the upper composite die and the lower composite die,
The glue injection port is arranged on the upper composite die,
The end parts of the upper compound die and the lower compound die are respectively provided with a matching groove matched with the air charging device.
The composite material forming die needs to consider the thickness of the manufactured composite material, the reasonable distribution of the glue injection port and the glue outlet, the air tightness and the matching with the air charging device in the design process. In this case, the composite material forming mold may be a VARTM mold, preferably:
and the lower composite die is provided with a positioning hole.
The pressing table and the bottom plate are respectively provided with a connecting piece, the connecting piece is provided with a supporting frame, and the connecting piece is matched with the supporting frame to install the upper compound die on the pressing table and install the lower compound die on the bottom plate.
The beneficial effects of the invention are as follows:
The invention provides a method for forming an inflatable mandrel by adopting a block combined type internal mold, wherein the method can realize multiple high-precision manufacturing of the inflatable mandrel by processing only one set of block combined type internal mold; the block combined internal mold and the mandrel mold form a molding mold for injection molding and compression molding, which can be applicable to different types of materials and is beneficial to researching the molding process of the inflatable mandrel; the inflation device can be conveniently combined with the mechanical arm and the VARTM die, and the inflation and the air extraction of the inflation mandrel can ensure the high-efficiency and high-precision manufacturing of the final composite material; the inflatable mandrel provided by the invention can be repeatedly used, the manufacturing process of the special-shaped woven composite material is easy to realize automation, and the production cost is reduced on the premise of ensuring the product quality.
Drawings
FIG. 1 is a schematic view of an inflatable mandrel in accordance with the present application;
FIG. 2 is a schematic diagram of a block combined inner mold according to the present application;
FIG. 3 is a schematic view of a split structure according to the present application;
FIG. 4 is a schematic view of the structure of the end side A in FIG. 3;
FIG. 5 is a schematic view of the structure of the B-side in FIG. 3;
FIG. 6 is a schematic diagram of an assembly structure of a segmented composite inner mold and a mandrel mold;
FIG. 7 is a schematic illustration of the assembly of an inflatable mandrel with an inflatable device;
FIG. 8 is a schematic diagram showing the assembly relationship of the inflatable mandrel with the inflatable device and the support shaft in a disassembled state;
FIG. 9 is a schematic diagram of the assembly relationship of the inflatable mandrel with the inflatable device and the split ring seal device in a split state;
FIG. 10 is a schematic illustration of the assembly relationship of an inflatable mandrel, an inflatable device, and a fiber preform;
FIG. 11 is a schematic diagram of the cooperation structure of the inflator, the mandrel mold and the composite molding mold according to the present application.
Reference numerals in the drawings: 1. an inflatable mandrel; 2. a block combined internal mold; 21. an inner die head; 22. an inner module; 221. a first module unit; 222. a second module unit; 221. a third module unit; 222. a fourth module unit; 23. an inner mold core; 3. a mandrel mold; 31. a mandrel upper die; 311. an access opening; 312. an upper connection hole; 32. a mandrel lower die; 321. a sealing rubber strip groove; 322. a first positioning hole; 323. a lower connection hole; 33. a handle; 4. an inflator; 41. a vent hole; 42. a vent passage; 43. a raised flange; 44. a connector; 5. a support shaft; 51. a connection hole; 6. a split ring seal; 61. extruding the notch; 7. a composite die is arranged; 71. a pressing table; 72. a glue injection port; 73. an upper mating groove; 74. an upper connecting piece; 8. a lower composite die; 81. a bottom plate; 82. a second positioning hole; 83. a lower mating groove; 84. a lower connecting piece; 85. a support frame; 86. a clamping groove; 9. a fiber preform; m, mandrel materials; and N, continuously variable cross-section composite materials.
Detailed Description
The technical scheme of the specific embodiment of the present invention will be clearly and completely described below with reference to the accompanying drawings of the specification, the specific embodiment is only one case of the present invention, and other embodiments obtained by those skilled in the art without any creative effort on the basis of the preparation and the use method of the inflatable mandrel for continuously variable-section woven composite material provided by the present invention are all within the protection scope of the present invention.
Example 1
In this embodiment, as shown in fig. 1, the structure of the inflatable mandrel 1 is a spindle structure with a thin middle and thick two ends, specifically, the inflatable mandrel 1 has a decreasing trend from two ends to the middle in the z-axis direction, and has an increasing trend from two ends to the middle in the y-axis direction, that is, the front view in fig. 1 changes regularly to be thick and thin in the x-direction, the top view changes regularly to be thin and thin, the outer diameter from the necking to the supporting shaft 5 is designed to be 25mm near the-x end (the left end in fig. 1), the necking to the outer diameter of the inflatable device 4 is designed to be 50mm near the x-end (the right end in fig. 1), and the design thickness of the inflatable mandrel 1 is 5mm.
In the preparation of the inflatable mandrel 1, the following steps are carried out:
step one, determining a mandrel material, wherein in the embodiment, an inflatable mandrel with the temperature resistant of 80 ℃ is prepared as an example, and solid raw rubber (high-strength natural rubber) is selected as the mandrel material.
Step two, after the continuous variable cross-section shape parameters of the inflatable mandrel 1 are determined, designing a block combined type internal mold 2 of the inflatable mandrel 1, as shown in fig. 2 and 3: the block combined type internal mold 2 comprises an internal mold head 21, an internal mold head 22 and an internal mold core 23, wherein the internal mold head 21 is positioned in a mandrel mold, the internal mold head 22 forms the inner surface of the inflatable mandrel 1, the internal mold core 23 mainly plays a supporting role, and the internal mold head 22 and the internal mold core 23 are respectively connected with the internal mold head 21, so that the internal mold head 22 surrounds and is attached to the periphery of the internal mold core 23.
As a specific scheme: referring to fig. 4 and 5, the inner module 22 is a split structure formed by splicing a first module unit 221, a second module unit 222, a third module unit 223 and a fourth module unit 224, and the split combined inner mold 2 is formed by four module units, an inner mold core 23 and an inner mold head 21, and the inner wall of each module unit is respectively attached to the outer wall of the inner mold core 23.
In addition, a mandrel mold 3 is designed according to the block combined type internal mold 2, the two molds are matched to realize compression molding and injection molding integrated forming, the mandrel mold 3 comprises a mandrel upper mold 31 and a mandrel lower mold 32, forming grooves which respectively correspond to the shapes (an upper half part and a lower half part) of the inflatable mandrel 1 are respectively arranged on the mandrel upper mold 31 and the mandrel lower mold 32, the mandrel upper mold 31 is provided with an upper connecting hole 312, a sealing rubber strip groove and an inlet and outlet 311 for injecting glue/discharging glue/exhausting, and the mandrel lower mold 32 is provided with a sealing rubber strip groove 321, a first positioning hole 322 and a lower connecting hole 323; the sealing rubber strip groove 321 is positioned at the end part of the forming groove, and when the block combined type internal mold 2 is assembled, the internal mold head 21 is clamped into the sealing rubber strip grooves of the mandrel upper mold 31 and the mandrel lower mold 32 to realize positioning; the upper connecting hole 312 is arranged corresponding to the lower connecting hole 323, and screws and the like are arranged to realize the threaded connection of the mandrel lower die 31 and the mandrel upper die 32; for convenient installation, a first positioning hole 322 can be arranged at the end parts of the mandrel upper die 31 and the mandrel lower die 32 to assist positioning.
Handles 33 can be respectively arranged at two ends of the mandrel upper die 31 and the mandrel lower die 32, so that the mandrel upper die 31 and the mandrel lower die 32 can be conveniently transferred.
Step three, because the solid material, namely the high-strength natural rubber, is selected as the mandrel material, the inflatable mandrel is prepared by adopting a mould pressing vulcanization method during molding: the mandrel material M is repeatedly slit to a long shape with a length x width x thickness of 1400mm x 12mm x 5mm, and referring to fig. 6, a quantity of about half of the length direction of the mandrel material M is laid on the surface of the mandrel lower die 32, then the segmented combined inner die 2 assembled in the manner shown in fig. 2 is put on (the inner die 21 is clamped into the sealing rubber groove), then the other half of the mandrel material M is laid and covers all the segmented combined inner die 2, the mandrel upper die 31 is closed, the redundant mandrel material M is removed by pre-molding, and then the inflated mandrel is formed by a vulcanization process.
In the forming process, the outer surface of the block combined type inner mold 2 forms the shape of the inner wall of the inflatable mandrel 1, and the shape of a forming groove of the mandrel mold 3 is the same as the shape of the inflatable mandrel 1, so that the inflatable mandrel 1 with the shape which meets the requirement that the section continuously changes along the axial direction is obtained.
After the molding is finished, the mold is opened to obtain the inflatable mandrel 1 with the block combined type internal mold 2, and the hollow inflatable mandrel 1 can be obtained by sequentially disassembling the internal mold head 21, the internal mold core 23 and the internal mold 22.
In the scheme, the processing of the inflatable mandrel 1 with axial continuous change can be realized by means of the matching of the segmented combined inner die 2 and the mandrel die 3, and the selection of the mandrel material can endow the inflatable mandrel 1 with specific strength, hardness and elasticity. The block combined type internal mold 2 facilitates the demolding of the inflatable mandrel 1, and when the inflatable mandrel 1 is prepared, the internal mold head 21, the internal mold 22 and the internal mold core 23 can be disassembled in sequence to realize easy demolding, so that the molding effect of the inflatable mandrel 1 is prevented from being greatly influenced by the demolding difficulty.
When the inflatable mandrel 1 prepared as described above is used for the preparation of a continuous variable cross-section composite material, the outer surface of the inflatable mandrel 1 forms the basic shape of the composite material, and the molding stability and the molding density of the composite material are realized by means of the inflation pressure of the inflatable mandrel 1.
Example 2
The preparation of the continuous variable cross-section composite material is carried out according to the embodiment, and the steps are as follows:
Step one, step two and step three can be set up with reference to example 1 to obtain the inflatable mandrel 1.
Step four, an air charging device 4, a supporting shaft 5 and a separation type sealing device 6 are designed, and after being assembled in a mode shown in fig. 9, the air charging device is connected into an air compressor to test the air tightness of the whole device and the pressure resistance of the air charging mandrel 1, wherein the air tightness is good, and the pressure resistance of the air charging mandrel 1 can be 0.1MPa.
In which, referring to fig. 7 and 8, a connecting hole 51 is provided at one end of the support shaft 5. The inflator 4 is provided with a vent hole 41, a vent passage 42 is provided in the inflator 4, one end of the vent passage 41 is communicated with the vent hole 41, the other end penetrates to the end of the inflator 4, a connector 44 is provided at the end (the connector 44 is not mutually interfered with the end outlet of the vent passage 41), a connecting hole 51 is in threaded connection with the connector 44, and the support shaft 5 is mounted at the end of the inflator 4; the side wall of the inflator 4 near the end is provided with a raised flange 43, the inflator mandrel 1 is mounted such that one end is fitted over the support shaft 5 and the other end is fitted over the raised flange 43 of the inflator 4, and at this time, the inflator 4, the support shaft 5 and the inflator mandrel 1 are positioned in the inflator mandrel 1as shown in fig. 7. The separable sealing device 6 is assembled, the separable sealing device 6 is composed of an upper portion and a lower portion, the inner wall of which is provided with a pressing notch 61, and the pressing notch 61 is provided corresponding to the projecting flange 43. When the assembly of the inflation device 4, the support shaft 5 and the separation type sealing device 6 is completed, the extrusion notch 61 is buckled on the periphery of the inflation mandrel 1 corresponding to the convex flange 43, so that the inflation mandrel 1 and the inflation device 4 are sealed and fixed.
Step five, taking 12k carbon fibers as an example to weave a fiber prefabricated member 9: according to the formulaAnd(Large-size special-shaped structure mandrel knitting strategy, yarn track prediction, li Qiyang, etc., textile journal, 10 months of 2023, 44 th roll, 10 th phase, p 188-194) to determine the knitting process. In this example, θ=45°, w=0.332 rad/s, r=110 mm, r≡38mm, h=103 mm, v=12.62 mm/s; after the weaving process parameters are determined, the mechanical arm is used for connecting the inflation mandrel 1, the pressure in the inflation mandrel 1 is inflated to 0.08MPa through the inflation device 4, and the inflation mandrel 1 is woven in a reciprocating mode according to the thickness (2 mm) of the designed special-shaped woven composite material under the air pressure, for example, three layers of carbon fibers are woven on the inflation mandrel 1 to form a fiber prefabricated body 9, and after the weaving is finished, the relationship among the inflation mandrel 1, the inflation device 4 and the fiber prefabricated body 9 is shown in fig. 10, and at the moment, the inflation mandrel 1 completely covers the fiber prefabricated body 9.
Step six, designing a composite material VARTM mould, wherein the mould design needs to consider the thickness of the manufactured composite material, the reasonable distribution of the glue injection port and the glue outlet, the air tightness and the matching with an air charging device. In this embodiment, referring to fig. 11, the composite forming mold includes an upper composite mold 7 and a lower composite mold 8, where the upper composite mold 7 and the lower composite mold 8 are respectively provided with a composite forming groove corresponding to the shape (upper half and lower half) of the fiber preform 9, one end of the composite forming groove is closed, and the other end is respectively provided with a sealing groove, and an upper mating groove 73 (located on the upper composite mold 7) and a lower mating groove 83 (located on the lower composite mold 8), where the sealing groove corresponds to the raised flange 43, and the upper composite mold 7 is further provided with a glue injection port 72.
Spraying a release agent in the composite forming grooves of the upper composite die 7 and the lower composite die 8, dismantling the separation type sealing device 6, placing the fiber prefabricated member 9, the inflatable mandrel 1 and the inflatable device 4 in the lower composite die 8 and fixing, at the moment, the inflatable device 4 is buckled at the lower matching groove 83, the convex flange 43 is buckled in the sealing groove, and the sealing groove is matched with the convex flange 43 to fix and seal the inflatable mandrel 1; closing the upper composite die 7 to finish the die closing of the upper composite die 7 and the lower composite die 8; after the inflation mandrel 1 was continuously inflated to 0.1MPa through the vent hole 41 of the inflator 4, the injection port 72 was connected to a vacuum pump (not shown in the figure, conventional structure), other outlets of the upper composite mold 7 were closed, the air tightness of the mold was checked, the vacuum pump was removed, and the mold was closed through the injection port 72, and the resin was injected into the mold and cured.
And seventhly, after curing is completed, opening the mould, taking out the inflatable mandrel 1 (comprising molding resin, the fiber prefabricated member 9 and the inflatable device 4), connecting the vent holes 41 with a vacuum pump, pumping the inflatable mandrel 1 to negative pressure to complete demoulding, rotating to take out the inflatable device 4 and the inflatable mandrel 1, and cutting off redundant parts at two ends of the composite material to obtain the continuous variable-section composite material N.
In the process, the inflatable mandrel 1 is pressurized in the forming stage, and negative pressure is pumped in the demolding stage.
As an alternative, the composite material forming mold further comprises a pressing table 71 and a bottom plate 81, wherein an upper connecting piece 74 is installed on the pressing table 71 through a clamping groove, an upper supporting frame (not marked in the figure) is arranged below the upper connecting piece 74, and the upper composite mold 7 is installed on the pressing table 71 through the upper supporting frame and the upper connecting piece 74; the bottom plate 8 is provided with a plurality of groups of clamping grooves 86, a group of lower connecting pieces 84 are arranged on the bottom plate 8 through the clamping grooves 86, a supporting frame 85 is arranged at the top of the lower connecting pieces 84, and the lower composite die 8 is arranged on the bottom plate 81 through the supporting frame 85 and the lower connecting pieces 84.
A second positioning hole 82 may be provided on the lower composite mold 8 to assist in positioning and mounting the upper composite mold 7 and the lower composite mold 8.
Claims (10)
1. An inflatable mandrel, characterized in that: the method comprises the steps of taking a selected mandrel material as a raw material, taking a mandrel mold and a segmented combined inner mold as a forming mold, placing the segmented combined inner mold in the mandrel mold, filling the mandrel material between the mandrel mold and the segmented combined inner mold, and then forming in a compression molding or injection molding mode to obtain an inflatable mandrel, wherein the shape of the inflatable mandrel meets the requirement that the section continuously changes along the axial direction, wherein the outer surface of the segmented combined inner mold forms the shape of the inner wall of the inflatable mandrel, the shape of a forming groove of the mandrel mold is the same as the shape of the inflatable mandrel,
The block combined internal mold comprises an internal mold head, an internal mold block and an internal mold core, wherein the internal mold block and the internal mold core are respectively connected with the internal mold head, so that the internal mold block surrounds and is attached to the periphery of the internal mold core,
The inner die is of a split type structure formed by splicing a plurality of module units, and the inner wall of each module unit is respectively attached to the outer wall of the inner die core.
2. An inflatable mandrel as claimed in claim 1 wherein: the inflatable mandrel is of a thick structure at two ends and a thin structure at the middle or a thick structure at the middle of two ends.
3. An inflatable mandrel as claimed in claim 1 wherein: the module units are four groups, the four groups of module units are mutually spliced to obtain the segmented combined internal mold, the section of the inner wall of the segmented combined internal mold is the same as the section of the internal mold core, and the shape of the outer wall of the segmented combined internal mold is consistent with that of the outer wall of the inflatable mandrel.
4. An inflatable mandrel as claimed in claim 1 wherein: the mandrel material is a solid material and is positioned between the mandrel die and the block combined internal die, and an inlet and an outlet for exhausting are arranged on the mandrel die; or the mandrel material is a liquid material, an inlet and an outlet for injecting/discharging glue are arranged on the mandrel upper die, and the mandrel material is injected between the mandrel die and the block combined inner die through the inlet and the outlet.
5. An inflatable mandrel as claimed in claim 1 wherein: the core shaft material is rubber, silicon rubber or a composite material of silica gel/rubber and glass fiber cloth.
6. A method of using the inflatable mandrel of claim 1 for continuous variable cross-section composite preparation, comprising the steps of:
step one, connecting a support shaft with an inflation device, sleeving an inflation mandrel on the outer side of the support shaft and fixing the inflation mandrel with the inflation device, after the inflation device inflates the inflation mandrel, weaving a formed fiber prefabricated member on the inflation mandrel,
Spraying a release agent in the composite material forming die, placing the inflatable mandrel and the fiber prefabricated member in the step one in the composite material forming die, fixing, closing the die, continuously inflating the inflatable mandrel through the inflating device, vacuumizing the die, injecting resin into the die through the glue injection port of the composite material forming die,
And thirdly, after curing, opening the die, taking out the inflatable mandrel, removing the inflatable device after pumping air from the inflatable mandrel through the inflatable device, taking down the cured product and cutting the redundant end part to obtain the continuous variable cross-section composite material.
7. A method for continuous variable cross-section composite material preparation using an inflatable mandrel as claimed in claim 6 wherein: in the first step, the knitting parameters of the knitting molding satisfy the formulaAnd/>Wherein θ is the braiding angle, R is the average radius of the inflatable mandrel, R is the radius of the guiding ring of the braiding machine, H is the convergence domain length, w is the angular velocity of the braiding machine, and V is the advancing velocity of the mechanical arm.
8. A method for continuous variable cross-section composite material preparation using an inflatable mandrel as claimed in claim 6 wherein: in the second step, the composite material forming die comprises a pressing table, a bottom plate, an upper composite die and a lower composite die, wherein the upper composite die is arranged on the pressing table, the lower composite die is arranged on the bottom plate, the inflatable mandrel and the fiber prefabricated member are positioned between the upper composite die and the lower composite die,
The glue injection port is arranged on the upper composite die,
The end parts of the upper compound die and the lower compound die are respectively provided with a matching groove matched with the air charging device.
9. A method for continuous variable cross-section composite preparation using an inflatable mandrel as claimed in claim 8 wherein: and the lower composite die is provided with a positioning hole.
10. A method for continuous variable cross-section composite preparation using an inflatable mandrel as claimed in claim 8 wherein: the pressing table and the bottom plate are respectively provided with a connecting piece, the connecting piece is provided with a supporting frame, and the connecting piece is matched with the supporting frame to install the upper compound die on the pressing table and install the lower compound die on the bottom plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410161070.9A CN117962368A (en) | 2024-02-05 | 2024-02-05 | Inflatable mandrel and method for preparing continuous variable-section composite material by using same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410161070.9A CN117962368A (en) | 2024-02-05 | 2024-02-05 | Inflatable mandrel and method for preparing continuous variable-section composite material by using same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117962368A true CN117962368A (en) | 2024-05-03 |
Family
ID=90847701
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410161070.9A Pending CN117962368A (en) | 2024-02-05 | 2024-02-05 | Inflatable mandrel and method for preparing continuous variable-section composite material by using same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117962368A (en) |
-
2024
- 2024-02-05 CN CN202410161070.9A patent/CN117962368A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109895418B (en) | Processing method of special-shaped hollow structure composite material part forming core mold | |
| EP0491650B1 (en) | Conformal composite molding | |
| CN104070687A (en) | Method for forming composite material pipe mold element by pressurizing air bags with assistance of resin film transfer | |
| CN104589670B (en) | A kind of gas path design method of composite cavity structure air bag shaping | |
| CN101932432A (en) | Method for producing fuselage cell sections for aircraft with composite fibre materials, and a device | |
| CN101489768A (en) | Method of manufacturing composite part | |
| CN109774199B (en) | Forming method of carbon fiber composite rudder-shaped structure | |
| CN113427793B (en) | High-strength high-temperature-resistant composite material air inlet channel and forming method thereof | |
| CN112848381B (en) | Composite component and preparation method thereof | |
| CN105690791A (en) | Barrel-shaped composite structural member overall molding method capable of achieving easy demolding | |
| CN104476782A (en) | Manufacturing process of propeller and large efficient blade propeller of fan | |
| CN108501397A (en) | It is used to prepare the inner core die of thin-walled arc composite material tube and the preparation method of curved pipe | |
| CN111086128A (en) | Core mold for manufacturing solid rocket engine and forming method thereof | |
| CN117962368A (en) | Inflatable mandrel and method for preparing continuous variable-section composite material by using same | |
| CN108864995B (en) | Multi-axial composite material bent pipe and preparation method thereof | |
| CN112895233B (en) | Method for forming solid rocket engine combustion chamber shell | |
| CN115111060A (en) | Aircraft engine air inlet duct and integrated forming process thereof | |
| CN213564306U (en) | Mold opening device for injection blow mold | |
| US20220126535A1 (en) | Tool for preforming a fibrous preform and method for preforming a fibrous preform | |
| CN113001834A (en) | Recyclable core mold for molding composite material part with complex structure | |
| JPS642048B2 (en) | ||
| CN115716275B (en) | C-shaped multi-rib cavity tubular mechanical arm made of carbon fiber composite material and manufacturing method | |
| CN221021934U (en) | Combined die for molding closed composite material bracket | |
| CN212826327U (en) | Rubber riding wheel die for module belt | |
| CN113910637B (en) | Forming method of composite material complex special-shaped air inlet channel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |