An internal inflatable mold for weaving a preform of a composite material shell

Abstract

The application discloses an inner expansion mold for weaving a composite material shell preform, which comprises a main shaft, a plurality of contraction plates and a contraction driving device. The contraction plates and filling plates are alternately arranged to form a cylindrical outer wall, and are sleeved outside the main shaft. The two ends of the cylindrical outer wall are provided with end covers which are sleeved on the main shaft. The contraction plates and the filling plates are positioned by the end covers. The contraction driving device is used for driving the contraction plates to move away from or close to the main shaft. The end cover is made of water-soluble material. The contraction plates and the filling plates are bonded by water-soluble adhesive material. After the water-soluble adhesive material is dissolved, the filling plates are separated from the contraction plates. The contraction driving device is contracted after the end cover and the water-soluble adhesive material are dissolved. The problem of difficult demolding of a traditional core mold is solved. After the preform is completed on the mold, the water-soluble material can be washed away by water. The water-soluble adhesive material between the end cover and the gap is dissolved together. The inner expansion mold is contracted. The gap is formed between the filling plates. The inner expansion mold and the filling plates can be taken out from the polar hole respectively and individually.

Description

TECHNICAL FIELD

[0001] The present application relates to composite weaving, in particular to an internal expansion mold for weaving a composite shell preform. BACKGROUND

[0002] The shell is a solid rocket engine filled with solid propellant tank, which is the combustion site of the propellant. In addition to bearing the internal pressure of high temperature and high pressure gas flow and the axial pressure of load, the shell also bears the action of other mechanical loads. Advanced composite materials have the advantages of high specific strength, high specific modulus, designability, fatigue resistance, impact resistance, corrosion resistance and other advantages, which meet the technical requirements of high bearing capacity and low structure mass of solid rocket engine shell, and have been widely used in the development of various engine shells, such as Japanese M-5 rocket engine and European Space Agency Vega rocket engine.

[0003] The shell is an important part of the solid rocket engine, and the use of high specific strength, high specific modulus and winding forming composite materials to develop high performance shell is an effective way to improve the performance of solid rocket engine. However, with the development of reusable and reusable technology of launch vehicle, the performance of engine needs to be further improved, and the existing winding technology still has many shortcomings and cannot be accurately and high performance. The development of composite weaving technology provides a new direction for this, which can "weave" carbon fiber bundle into engine shell preform to realize the integrated preparation of composite shell preform. The existing composite core mold has poor adaptability, low reuse rate, high cost, cannot be disassembled and is difficult to demold. SUMMARY

[0004] The purpose of the present application is to provide an internal expansion mold for weaving a composite shell preform, which can automatically shrink and demold.

[0005] Technical scheme: In order to solve the above problems, the present application adopts an internal expansion mold for weaving a composite shell preform, which comprises a main shaft, a shrinkage assembly, a plurality of filling plates, the shrinkage assembly comprises a plurality of shrinkage plates and a shrinkage driving device, the shrinkage plates and the filling plates are alternately arranged to form a cylindrical outer wall, and are sleeved on the outside of the main shaft, the two ends of the cylindrical outer wall are provided with end caps sleeved on the main shaft, the shrinkage plates and the filling plates are positioned by the end caps, the shrinkage driving device is arranged on the main shaft, and the shrinkage driving device is used for driving the shrinkage plates away from or close to the main shaft, the end caps are made of water-soluble material, and the shrinkage plates and the filling plates are bonded by water-soluble adhesive material, the filling plates are separated from the shrinkage plates after the water-soluble adhesive material is dissolved, and the shrinkage driving device is shrunk after the end caps and the water-soluble adhesive material are dissolved.

[0006] Further, the contraction driving device comprises a slider moving along the main shaft, a linkage group, each contraction plate is connected with the slider through a linkage group, the linkage group comprises a plurality of linkages and driving rods, the linkages are hingedly connected in a scissors type, one end of the hingedly connected linkages is respectively hingedly connected with two sliders, the other end is respectively hingedly connected with two driving rods, the other end of the two driving rods is hingedly connected with a point on the contraction plate, when the two sliders are close to each other, the contraction plate is away from the main shaft, when the two sliders are away from each other, the contraction plate is close to the main shaft. The contraction plate is provided with a contraction driving device at both ends and is connected with the main shaft. The main shaft is provided with two groups of threads corresponding to the two ends of the contraction plate, each group of threads comprises two thread units in opposite directions, the two sliders at the same end are respectively screw-connected with the two thread units, when the main shaft rotates, the two sliders move in opposite directions.

[0007] Further, the water-soluble material adopts water-soluble sand, and the water-soluble sand is prepared from PVP or PVAL and quartz sand.

[0008] Advantages: Compared with the prior art, the present application has the following advantages: 1. The problem of difficult demolding of the traditional core mold is solved. After the composite material preform is prepared on the mold, the sealing head of the water-soluble material can be washed away with water, the inner expansion mold shrinks, and can be pulled out from the polar hole of the shell. The water-soluble adhesive material in the gap dissolves together with the sealing head, the gap between the filling plates is formed, and the filling plates can be taken out from the polar hole. 2. The reuse rate is improved, and the cost is reduced. The inner expansion metal mold shrinkage assembly and the filling plate can be reused, the sealing head of the water-soluble sand has low cost and is easy to prepare. 3. The adaptability of the core mold is improved. By adjusting the diameter of the inner expansion metal mold, the present application can be used for the preparation of most cylindrical shell preforms and can be widely used in various equipment. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 Fig. 1 shows the overall structure of the inner expansion mold in the present application;

[0010] Figure 2 Fig. 2 shows the structure of the contraction assembly in the open state in the present application;

[0011] Figure 3 Fig. 3 shows the structure of the contraction assembly after contraction in the present application;

[0012] Figure 4 Fig. 4 shows the structure of the contraction driving device in the present application;

[0013] Figure 5 Fig. 5 shows the structure of the linkage group in the present application;

[0014] Figure 6 Fig. 6 shows the connection between the sealing head and the contraction plate and the filling plate in the present application;

[0015] Figure 7 The diagram shown illustrates the connection between the shrink plate and the filler plate in this invention. Detailed Implementation

[0016] like Figure 1 and Figure 2 As shown, an internal expansion mold for weaving composite material shell preforms in this embodiment includes a metal spindle 34, two water-soluble sand heads 1, an internal expansion metal mold shrinkage assembly 3, and eight filler plates 2. The internal expansion metal mold shrinkage assembly includes eight metal shrinkage plates 31, two sets of sixteen identical four-bar linkages 32, and four sliders 33. The four-bar linkage includes connecting rod I 321, connecting rod II 322, connecting rod III 323, and connecting rod IV 324. The upper through hole 321a of connecting rod I is hinged to the upper through hole 322a of connecting rod II and connected to the left / right lifting lugs of the metal shrinkage plates. The lower through hole 322b of connecting rod II is hinged to the upper through hole 323a of connecting rod III. 321b is hinged to the through hole 324a on the upper part of connecting rod IV, and the through hole 323c in connecting rod III is hinged to the through hole 324c in connecting rod IV. Finally, the lower through holes 323b in connecting rod III and 324b in connecting rod IV are respectively connected to the lifting lugs on the slider to form a telescopic four-bar assembly. The metal shrinkage plate 31 is installed on the slider 33 through the four-bar telescopic assembly 32 and then sleeved on the metal main shaft 34 to form the internal expansion metal mold assembly 3. The two sliders connecting the four-bar have opposite threads, which respectively cooperate with two opposite threads on the main shaft. When the main shaft rotates, the two sliders move relative to each other, so that the four-bar has telescopic movement. The telescopic movement of the four-bar causes the metal shrinkage plate to open or close relative to the main shaft. With this setting, the mold can be opened before the preform is prepared and the end cap and filling plate are installed to form a complete mold. After the preparation is completed, it can be closed for easy demolding.

[0017] The water-soluble sand head 1 is made of PVP or PVAL and quartz sand. After molding, it is trimmed according to installation needs. During mold forming, it is installed at both ends of the mold by fitting the stop with the inner surface of the metal shrink plate to form a complete mold. After the preform is prepared, it can be removed with a high-pressure water gun.

[0018] After the internal expansion metal mold opens, the water-soluble sand head 1 and the filling plate 2 are designed with stop edges on both sides. When the internal expansion mold opens, it cooperates with the stop edges of the metal shrinkage plates on both sides, and is then bonded by water-soluble sand. It fits tightly with the gap to form a complete mold, ensuring the shape accuracy of the preform.

[0019] The working principle of the inner expansion mold is as follows: the driving slider 33, the connecting rod I, the connecting rod II, the connecting rod III and the connecting rod IV form a four-connecting-rod crank slider mechanism. When the composite material preform is prepared, the metal shrinkage plate 31, the water-soluble sand sealing head 1 and the filling plate 2 are in a close-fitting state, so that the integrity of the mold is ensured. After the preparation of the preform is completed, the water-soluble sand sealing head 1 is washed away by using a high-pressure water gun. The two sliders 33 connected by the four connecting rods are provided with opposite threads, and are respectively screwed on two sections of the shaft. When the main shaft rotates, the two sliders move relatively, so that the four-connecting-rod mechanism 32 is retracted. The retraction of the four-connecting-rod mechanism 32 causes the metal shrinkage plate 31 to retract inward relative to the metal main shaft 34, and the inner expansion metal mold 3 is retracted completely. The gap between the filling plates 2 is formed, and the preform can be taken out from the shell hole. When the preform needs to be prepared again, the driving slider 33 moves reversely, the inner expansion metal mold 3 is opened, and the sealing head 1 and the filling plate 2 are installed in the gap and at both ends, so that the complete mold is formed again.

Claims

1. An internal inflatable mold for weaving a preform of a composite material shell, characterized in that, The application relates to a preform preparation device, which comprises a main shaft (34), a shrink assembly (3), a plurality of filling plates (2) and two end caps (1), the shrink assembly (3) comprises a plurality of shrink plates (31) and shrink driving devices, the shrink plates (31) and the filling plates (2) are alternately arranged to form a cylindrical outer wall, and are sleeved outside the main shaft to form the cylindrical outer wall, the two ends of the cylindrical outer wall are provided with the end caps (1) sleeved on the main shaft (34), the shrink plates (31) and the filling plates (2) are positioned by the end caps, the shrink driving devices are arranged on the main shaft (34), and the shrink driving devices are used for driving the shrink plates (31) to move away from or close to the main shaft (34), the end caps (1) are made of water-soluble materials, and the shrink plates (31) and the filling plates (2) are bonded by water-soluble bonding materials, when a preform is prepared, the shrink plates, the end caps and the filling plates are in close cooperation to ensure the integrity of a mold; after the preform is prepared, the filling plates (2) are separated from the shrink plates (31) after the water-soluble bonding materials are dissolved, and the shrink driving devices are used for shrinking after the end caps and the water-soluble bonding materials are dissolved, and the filling plates can be taken out from the polar holes of the shell preform.

2. The internal expansion mold according to claim 1, wherein The shrink driving devices are arranged at the two ends of the shrink plates, the shrink driving devices comprise two sliders (33) moving along the main shaft (34) and a linkage assembly, each shrink plate is connected with the sliders through the linkage assembly, the linkage assembly comprises a plurality of linkages and driving rods, the linkages are hingedly connected in a scissors type, one end of each linkage is hingedly connected with the two sliders respectively, and the other end of each linkage is hingedly connected with the two driving rods respectively, the other ends of the two driving rods are hingedly connected to a point on the shrink plate (31), and the shrink plate moves away from the main shaft when the two sliders move close to each other.

3. The internal expansion mold according to claim 2, wherein Two groups of threads are arranged at the two ends of the main shaft corresponding to the shrink plates, each group of threads comprises two thread units with opposite directions, the two sliders at the same end are threadedly connected with the two thread units corresponding to the sliders respectively, and the two sliders move in opposite directions when the main shaft rotates.

4. The internal expansion mold according to claim 1, wherein The water-soluble material is water-soluble sand, and the water-soluble sand is prepared from PVP or PVAL and quartz sand.

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