TW201325879A - Composite tube having middle necking three-dimensional woven structure and its manufacturing method - Google Patents

Abstract

This invention discloses a composite tube having middle necking and its manufacturing method. The composite tube includes a three-dimensional woven inner layer and a fiber bundle outer layer disposed on the outer surface of the three-dimensional woven inner layer. During the manufacturing, the three-dimensional woven inner layer is woven on an assembly-type mold core first, and then outer fiber bundle layer is wound on the outer surface of the three-dimensional woven inner layer, and an appropriate pull force is applied during the winding of outer fiber bundle layer so as to push the three-dimensional woven inner layer moving closely to the assembly-type mold core. After that, it is infiltrated with resin and heated for curing the resin to complete the composite tube. By this way, the composite tube will have a very high circumferential strength due to the mutual winding of the three-dimensional woven inner layer and the outer fiber bundle layer so that it is capable of sharing the tension stress of the metal shell, such that the thickness of the metal shell can be reduced to achieve the efficacy of weight reduction.

Description

Composite pipe fitting with intermediate shrinkage three-dimensional braiding structure and manufacturing method thereof

The present invention relates to a tubular three-dimensional braided composite, and in particular, to a composite tubular member having an intermediate necked three-dimensional braided construction and a method of making the same.

According to the knitting technique, the weaving technique is originally used for fabrics, which are formed by interlacing the threads by a specific weaving method to form a flat cloth. In composite structures, fabrics are often used as reinforcements and have been widely used in various fields, such as automotive, aerospace, marine, aerospace or medical.

The composite material with laminated woven fabric as reinforcing material is generally called two-dimensional laminated type composite material, and its interlayer strength is not a major disadvantage; for example, in a rocket nozzle, the heat insulating layer is in a high temperature airflow environment above 2000 ° C, Under the action of scouring force and thermal stress, the design function of decomposition and cooling is often not achieved, that is, lamination and stripping have occurred to accelerate the ablation. Therefore, the lamination angle must be specially designed, especially to avoid parallel or perpendicular fiber to airflow.

The composite material of the three-dimensional structure type can greatly improve the disadvantage of insufficient strength between the two-dimensional structure layers by adding a reinforcing material in the thickness direction. For example, U.S. Patent No. 4,519,290 discloses a three-dimensional technique that utilizes carbon fiber rods to enhance the strength of the wall thickness of the rocket propeller nozzle insulation layer. However, most of the three-dimensional techniques including this patent tend to sacrifice the structural strength of the in-plane in order to enhance the strength in the thickness direction due to a decrease in fiber content.

The woven fabric woven by three-dimensional weaving technology has a fiber volume content of the composite material much higher than that of the general three-dimensional structure type, so that the structure can not only maintain the plane direction strength, but also greatly improve the interlayer strength. The problem.

There have been three-dimensional weaving techniques that can be woven with a solid structure. However, this technique is not suitable for a hollow tubular braided structure such as a rocket thruster nozzle insulation layer.

While the typical rocket propeller nozzle 100 (as in Figure 1) clearly indicates its direction, the rocket thruster portion 110 is shown. Like a typical nozzle, the nozzle 100 includes a converging section 120, a throat 130, and a diverging section 140, which is substantially a tubular structure having an intermediate constriction and a larger inner diameter at both ends. The inner layer of the nozzle 100 is a heat insulating layer 150 that functions to reduce heat transfer by ablation decomposition, thereby protecting the outer casing structure 160. A heat insulating layer (not shown) may be selectively disposed between the outer casing structure 160 and the inner layer heat insulating layer to further cool down.

Referring to FIG. 2 again, it is schematically shown that the heat insulating layer 150 of the first figure is to be fabricated on a core 200 by a three-dimensional weaving technique, and the fiber bundle 210 cannot be applied to the surface of the core under the action of the weaving force 250. . As illustrated, the convergent section 220, the throat 230, and the diverging section 240 of the core 200 correspond to 120, 130, and 140 of the first figure, respectively. As can be seen from the figure, the fiber bundle 210 cannot be applied to the core, especially in the convergent section 220, and is slightly shallow in the diverging section 240.

Although a general-purpose three-dimensional knitting machine is proposed in U.S. Patent No. 6,439,096, it is possible to woven rods or tubular structures of various cross sections, but it is not suitable for knitting round tubes.

According to the Patent Application No. 097147865 of the Republic of China, a three-dimensional weaving machine is proposed, which can be used for three-dimensional weaving of straight pipe or cone pipe structure, but the use of this technique to weave the tubular structure of the intermediate necking has encountered difficulties in practice. It is the tensile force of the fiber bundle during the weaving process that makes it unable to be applied to the core, resulting in a too large throat diameter of the braided preform. For the rocket thruster nozzle, the thrust will be greatly affected. In other words, the three-dimensional braided composite pipe fittings which are manufactured by conventional methods cannot meet the design requirements, and therefore must be segmented, separately solidified, separately processed, and then combined, and the pass is very cumbersome.

Accordingly, it is an object of the present invention to provide a composite tubular member having an intermediate necked three-dimensional woven construction to solve the above problems.

The main object of the present invention is to enable the composite pipe member to be entangled with the outer layer of the fiber bundle by using the three-dimensional woven inner layer, and has a high hoop strength, which can share the tensile stress of the metal casing, so the thickness of the metal casing. Can be thinned to achieve weight loss.

In order to achieve the above object, the present invention is a composite pipe member having an intermediate necked three-dimensional braided structure and a manufacturing method thereof, the composite pipe member comprising a three-dimensional braided inner layer and a fiber bundle outer layer disposed on the outer surface of the three-dimensional braided inner layer .

In the above embodiment of the present invention, one end of the composite pipe member is provided with a converging section, and the other end is provided with a diverging section, and an intermediate constriction is provided between the converging section and the diverging section.

In the above embodiments of the present invention, the three-dimensional braided inner layer may be a carbon fiber/epoxy three-dimensional braided composite.

In the above embodiments of the present invention, the three-dimensional braided inner layer may be a three-dimensional braided carbon/carbon composite.

In the above embodiments of the present invention, the outer layer of the fiber bundle may be a carbon fiber/epoxy winding composite.

In the above embodiments of the present invention, the outer layer of the fiber bundle may be a fiber wound carbon/carbon composite material.

In the above embodiment of the invention, the three-dimensional braided inner layer has a fiber pre-tension.

In the above embodiment of the invention, the outer layer of the fiber bundle has a pre-tension.

In addition, the method for manufacturing a composite pipe fitting of the present invention comprises at least the following steps;

Step 1: provide a combined core having a core upper half and a lower core half, and knit the inner layer of the three-dimensional braid in the upper half of the core, and then use the tightening device to make the three-dimensional The braided inner layer is clamped to the large diameter end and the small diameter end of the upper half of the core.

Step 2: The lower half of the core is combined with the upper half of the core, and the fixing device is used to prevent loosening, and the three-dimensional braided inner layer is clamped to the lower half of the core by other tightening devices.

Step 3: Remove the tightening device near the center of the three-dimensional braid inner layer, and wind the fiber bundle from the center of the three-dimensional braid inner layer to the ends to the other unremovable tightening device, and on the outer surface of the three-dimensional braid inner layer An outer layer of fiber bundles is formed.

Step 4: infiltrating the combined three-dimensional braided inner layer and the outer layer of the fiber bundle with a resin, and heating to cure the resin to obtain a composite pipe member.

In the above embodiment of the present invention, one end of the composite pipe member is provided with a converging section, and the other end is provided with a diverging section, and an intermediate constriction is provided between the converging section and the diverging section.

In the above embodiments of the present invention, the resin may be an epoxy resin, a phenol resin or a furan resin.

In the above embodiment of the present invention, the resin is infiltrated into the bonded three-dimensionally woven inner layer and the outer layer of the fiber bundle by a resin transfer molding method.

In the above embodiment of the present invention, the resin is infiltrated into the bonded three-dimensional woven inner layer and the outer layer of the fiber bundle by vacuum assisted resin transfer molding.

In the above embodiment of the invention, the resin is infiltrated into the combined three-dimensional braided inner layer and the outer layer of the fiber bundle by a pressure vessel at a high pressure.

In the above embodiments of the present invention, the composite pipe member can be further subjected to a densification/curing/carbonization densification process to a desired density to become a carbon/carbon composite material.

The spirit of the present invention, as well as the foregoing and other advantages, will be more apparent from the following detailed description of the invention.

Please refer to FIG. 3 to FIG. 8 , which are schematic diagrams showing the cross-sectional state of the composite pipe fitting of the present invention, a schematic diagram of the first step of the present invention, a schematic diagram of the second step of the present invention, a schematic diagram of the third step of the present invention, and the present invention. A schematic diagram of step four. As shown in the figure, the present invention is a composite pipe member having a three-dimensional braided structure with an intermediate neck and a manufacturing method thereof. The composite pipe member 300 comprises a three-dimensional braided inner layer 310 and a fiber disposed on the outer surface of the three-dimensional braided inner layer 310. The outer layer 320 is bundled, and one end of the composite pipe member 300 is provided with a converging section 330, and the other end is provided with a diverging section 350, and an intermediate constricting 340 is disposed between the converging section 330 and the diverging section 350.

The three-dimensional braided inner layer 310 may be a carbon fiber/epoxy three-dimensional braided composite material or a three-dimensional braided carbon/carbon composite material, and the three-dimensional braided inner layer 310 has a fiber pre-tensioning force; and the fiber bundle outer layer 320 is It may be a carbon fiber/epoxy winding composite, or a fiber wound carbon/carbon composite, and the fiber bundle outer layer 320 has a pre-tension.

In order to facilitate the subsequent description of FIG. 3, when the composite pipe fitting 300 of FIG. 3 is used as the nozzle of the rocket propeller, the direction is opposite to that of FIG. 1 (conventional technology), that is, the converging section. 330 is downward, the divergent section 350 is upwards, because the invention is first woven from the diverging section of the fiber bundle which can be applied to the core, and the knitting machine used in the case is woven from top to bottom, so After the outer layer 320 of the fiber bundle of the present invention is combined with the three-dimensional braided inner layer 310, the subsequent osmosis process can be performed together, so that the three-dimensional woven inner layer 310 can be tightly clamped all the time, so that it is always applied to the mold core without looseness. Take it off.

When the composite pipe member 300 of the present invention is produced (please cooperate with the figures 4 to 8), at least the following steps may be included (although the figures are basically axisymmetric, for the sake of clarity, the figures are in section Present; it must be stated that the weave thickness should change with the pipe diameter, but for the sake of simplicity, each figure is expressed in equal thickness):

Step 1: provide a combined core 410 having a core upper half 411 and a lower mold half 412. First, the upper half 411 of the combined mold core 410 is fixed to the socket 400 of the knitting machine. It may be a threaded lock or any detachable form; and the lower half of the mold core 412 is first retracted to a position that does not interfere with the weaving of the upper half 411 of the core, and then three-dimensionally woven in the upper half 411 of the core. The weaving of the inner layer 310 causes the length of the three-dimensional braided inner layer 310 to exceed the molded composite tube member 300. Since the lower mold half 412 does not interfere with the three-dimensional braided inner layer 310 in this step, even three-dimensional Under the action of the woven inner layer 310 pulling force 460, the three-dimensional woven inner layer 310 can still be mostly applied to the upper core portion 411, and the three-dimensional woven inner layer is woven by the tightening devices 430, 440, 450. 310 is clamped to the large diameter end and the small diameter end of the upper half 411 of the core (as shown in Fig. 4).

Step 2: Push the lower half 412 of the core upward to be combined with the upper half 411 of the core, and attach the fixing device 500 to prevent the lower half 412 of the core from separating from the upper half 411 of the core. The three-dimensional braided inner layer 310 is then clamped to the lower core half 412 by other tightening devices 510, 520, and the position of the braiding machine socket 400 can be adjusted up and down during the tightening process, so that the knitting machine is applied to the knitting machine. The tension of the fiber bundle 530 is lower than the original tensile force 460, so that the tightening force can clamp the three-dimensional braided inner layer 310 to the combined core 410, and after the three-dimensional braided inner layer 310 is fixed, the tension 530 is released, and The three-dimensional braided inner layer 310 is removed from the three-dimensional braiding machine socket 400 (as shown in FIG. 5), and is mounted on a winding machine (not shown), and the winding machine can be manufactured. A dedicated fiber bundle winding machine for a high pressure gas cylinder, or the like, does not depart from the scope of the invention.

Step 3: Remove the tightening device 430 near the center of the three-dimensional braid inner layer 310 (ie, at the position of the intermediate constriction 340 shown in the third figure), and wind the fiber bundle from the center of the three-dimensional braid inner layer 310 to the other ends. The unwound tightening device 440, 510 forms a fiber bundle outer layer 320 on the outer surface of the three-dimensional braided inner layer 310, and the winding process applies an appropriate pulling force to the fiber bundle to make the three-dimensional braided inner layer 310 adhere to the combined mold. The core 410 is placed, and the tightening devices 440, 510 can be selectively removed as needed, and the carbon fiber bundles are continuously wound to both ends, as shown in Figs. 6 and 7.

Step 4: The combined three-dimensional braided inner layer 310 and the fiber bundle outer layer 320 together with the combined mold core 410 (as shown in FIG. 7) are immersed in a pressure barrel containing resin, wherein the resin may be epoxy resin or phenolic resin. Or furan resin (not shown), after sealing, applying high pressure to infiltrate the resin into the three-dimensional braid inner layer 310 and the fiber bundle outer layer 320, and in the case of soaking the resin, heating to 120 ° C to make the resin semi-cured. Then, it is taken out from the pressure tank and placed in a vacuum bag (not shown), and is vacuumed and simultaneously heated to 150 ° C or higher to cure the resin (and the resin infiltration and curing process can also be carried out by resin transfer). Resin Transfer Molding, or vacuum assisted resin transfer molding, and then the fixing device 500 is removed, and the upper half 411 and the lower half 412 are withdrawn from both ends to obtain a composite pipe embryo. Body 300a (as shown in Figure 8); finally, the composite pipe body 300a is slowly heated to 800-900 ° C in an oxygen-free environment, carbonizing the phenol resin, then slowly dropping to room temperature, and then repeating the infiltration Glue/curing/carbonization densification process Order, to achieve the required density, become a carbon / carbon composite material, and finally can be further graphitized at a high temperature of 2600 ° C or higher, further improve the ablation resistance, the pre-tension of the three-dimensional braided inner layer 310 and the fiber bundle outer layer 320 Further, after the resin is cured and the self-assembled mold core 410 is released, the pre-tensioning force causes the pre-compressive stress of the cured resin, so that the tensile stress generated by the heating and carbonization process can be offset, and thus the crack can be avoided. Produced, and can reduce the process rejection rate; after the foregoing densification procedure is completed, the composite pipe body 300a can be processed and intercepted, and the nozzle of the rocket propeller, for example, the portion between the A and the B is intercepted. For the composite pipe fitting 300 as shown in the third figure, or when the outer casing and the heat insulating layer are required, the nozzle insulating layer must be divided into front and rear sections for assembly, in which case the composite can be compounded anywhere between C or B. The material tube 300 is cut into two segments.

Thus, the intermediate shrinkage 340 of the present invention adopts the composite pipe member 300 composed of the three-dimensional braided inner layer 310 and the fiber bundle outer layer 320, so as to reduce the ablation rate and maintain the necessary thrust when used as a nozzle of the rocket thruster, The low erosion rate maintains the strength of the intermediate constriction 340 so as not to expand, and allows the composite pipe member 300 of the present invention to have a high hoop strength by winding the fiber bundle outer layer 320, thereby sharing the tensile stress of the metal casing. Therefore, the thickness of the metal casing can be thinned to achieve the effect of weight reduction; thereby making the invention more progressive, more practical, and more in line with the needs of the consumer, and indeed meets the requirements of the invention patent application, patent application.

However, the above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto; therefore, the simple equivalent changes and modifications made in accordance with the scope of the present invention and the contents of the invention are modified. All should remain within the scope of the invention patent.

(customized part)

100. . . Rocket propeller nozzle

110. . . Rocket propeller

120. . . Convergent section

130. . . Throat

140. . . Diverging section

150. . . Insulation layer

160. . . Shell structure

200. . . Mould

210. . . Fiber bundle

220. . . Convergence segment

230. . . Throat

240. . . Divergent segment

250. . . Braiding force

(part of the invention)

300. . . Composite pipe fittings

300a. . . Composite pipe body

310. . . Three-dimensional braided inner layer

320. . . Fiber bundle outer layer

330. . . Convergence segment

340. . . Intermediate shrinkage

350. . . Divergent segment

400. . . Braiding machine socket

410. . . Combined core

411. . . Upper half of the mold

412. . . Lower half of the mold

430, 440, 450, 510, 520. . . Tightening device

460, 530. . . pull

500. . . Fixtures

Figure 1 is a schematic view of a conventional rocket propeller nozzle.

Figure 2 is a schematic view of the weaving state of the conventional use.

Figure 3 is a schematic view showing the cross-sectional state of the composite pipe member of the present invention.

Figure 4 is a schematic view of the first step of the present invention.

Figure 5 is a schematic view of the second step of the present invention.

Figures 6 and 7 are schematic views of the third step of the present invention.

Figure 8 is a schematic view of the fourth step of the present invention.

300. . . Composite pipe fittings

310. . . Three-dimensional braided inner layer

320. . . Fiber bundle outer layer

330. . . Convergence segment

340. . . Intermediate shrinkage

350. . . Divergent segment

Claims (10)

A composite tubular member having an intermediate necked three-dimensional braided structure, the composite tubular member comprising a three-dimensional braided inner layer and an outer layer of wound fiber bundles disposed on an outer surface of the three-dimensional braided inner layer. A composite tubular member having an intermediate necked three-dimensional braided structure according to claim 1, wherein the three-dimensional braided inner layer has a fiber pre-tension. A composite tubular member having an intermediate necked three-dimensional braided structure according to claim 1, wherein the outer layer of the fiber bundle has a pre-tension. The composite pipe fitting having an intermediate necked three-dimensional braiding structure according to claim 1, wherein the three-dimensional braided inner layer is a carbon fiber/epoxy three-dimensional braided composite material. A composite tubular member having an intermediate necked three-dimensional braided structure according to claim 1, wherein the three-dimensional braided inner layer is a three-dimensional braided carbon/carbon composite. The composite pipe fitting having the intermediate necking three-dimensional braiding structure according to the first aspect of the patent application, wherein the fiber bundle outer layer is a carbon fiber/epoxy wire wound composite material. A composite pipe member having an intermediate necked three-dimensional braided structure according to claim 1, wherein the fiber bundle outer layer is a fiber wound carbon/carbon composite material. A composite pipe fitting manufacturing method with an intermediate shrinkage three-dimensional braiding structure, comprising the following steps: Step 1: providing a combined core having a core upper half and a lower half of the core, in the upper half of the core The three-dimensional braided inner layer is woven, and the three-dimensional braid inner layer is clamped to the large-diameter end and the small-diameter end of the upper half of the core by the tightening device after the knitting; step two: the lower half of the mold core The upper half of the core is combined with the fixing device to prevent loosening, and the three-dimensional woven inner layer is clamped to the lower half of the core by other tightening devices; Step 3: Unloading near the center of the three-dimensional woven inner layer The device is tightened, and the fiber bundle is wound from the center of the three-dimensional braid inner layer to the two ends to the other unremovable tightening device, and an outer layer of the fiber bundle is formed on the outer surface of the three-dimensional braid inner layer; Step 4: infiltrating the resin with the resin The combined three-dimensional braided inner layer and the outer layer of the fiber bundle are heated to cure the resin to obtain a composite pipe member. The method for manufacturing a composite pipe fitting having an intermediate necking three-dimensional braiding structure according to claim 8 , wherein one end of the composite pipe fitting is provided with a converging section, and the other end is provided with a diverging section, and is converged in the converging section and diverging. There is an intermediate constriction between the segments. A method of manufacturing a composite pipe member having an intermediate necked three-dimensional braided structure according to claim 8 wherein the resin is epoxy resin, phenol resin or furan resin.