An integrated molding process method for a large deformation structure of a composite material

Abstract

The present invention relates to an integrated molding process method for a large deformation structure of a composite material. An ultra-long oven and an ultra-long core mold are designed. The ultra-long oven and the ultra-long core mold are installed on a guide rail. The length of the guide rail is greater than the length of the oven base. First, the entire layer is laid on the core mold. After the laying is completed, it is packaged with felt and vacuum bag film, cured in an ultra-long oven, and then demolded, that is, the entire structure is cured and molded in the oven at one time. The present invention solves the problem of integral molding of large deformation structures above 30m level and avoids the curing defects caused by segmented molding. When the core mold is heated in the oven, thermal expansion deformation occurs. The change in its length dimension can be quickly released by the sliding of the support frame on the guide rail, avoiding bending of the mold, affecting the straightness of the large deformation structure of the composite material, and improving the preparation accuracy of the structure.

Description

Technical Field

[0001] The invention belongs to the field of composite materials and relates to an integrated molding process method for a large deformation structure of a composite material. Background Art

[0002] Future spacecraft are trending toward larger and more powerful structures, reaching dimensions exceeding hundreds or even kilometers. These payloads, such as 100-meter deployable antennas, kilometer-scale solar power plants, and solar sails, are crucial due to the size constraints of rocket fairing envelopes. Carbon fiber / resin-based high-deformation composite structures are crucial for carrying these payloads. Their advantages include lightweight, high load-bearing ratios, strong design flexibility, and the ability to manufacture in extremely long lengths, making them the preferred choice for future large-scale deployable structures.

[0003] Currently, the molding of this type of structure has the following problems: (1) The required length of the composite material large deformation structure exceeds 30m, but the actual manufacturing length is limited by the length of conventional autoclaves and ovens, which is generally within 10m, and it is impossible to manufacture it in an ultra-long length; (2) After heating, the ultra-long mold has a large thermal expansion, which causes the mold to bend and deform, resulting in an excessive straightness of the composite material large deformation structure. Summary of the Invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the existing technology and propose an integrated molding process method for large-deformation composite material structures, so as to solve the problem that large-deformation composite material structures are subject to the size limitations of conventional autoclaves, ovens, molds, etc., making it difficult to mold more than 30m and having poor molding straightness.

[0005] The solution of the present invention is:

[0006] An integrated molding process for a composite material large deformation structure, comprising:

[0007] Arrange 4 guide rails on the ground according to the length of the composite material large deformation structure, of which the two inner guide rails are used to install the core mold support frame, and the two outer guide rails are used to install the oven base;

[0008] The oven base is composed of a number of oven base modules, which are arranged in sequence and installed on the guide rails. Adjacent oven base modules are connected by quick clamps without any gaps. After being installed in place, the oven base can slide freely on the guide rails.

[0009] Pass the core mold support frame through the oven base and install it on the guide rail;

[0010] The core mold is composed of several core mold modules. Each core mold module is installed on the corresponding core mold support frame. The core mold modules are connected with fasteners, the outer circles are aligned, and the core mold straightness is measured and adjusted using a laser tracker.

[0011] Install the laser projector directly above the core mold and adjust the projection line until it is directly above the core mold.

[0012] Single layers of prepreg are stacked sequentially on the platform, and finally a layer of fluorine cloth is laid on the inner and outer surfaces to prepare the prepreg layer. A reference line is drawn on the outer surface of the fluorine cloth of the prepreg layer, and the prepreg layer is wound on a paper tube;

[0013] Spray release agent on the surface of the core mold;

[0014] Lay the prepreg layer on the core mold surface in a C-shaped structure, with the C-shaped opening located directly below the core mold. Adjust the position of the prepreg layer on the core mold so that the reference line of the prepreg layer is aligned with the laser projection line, and compact it;

[0015] The outer surface of the prepreg layer is sealed with vacuum bag film, and vacuum is tested to ensure there is no air leakage;

[0016] Wrap the outer surface of the vacuum bag film with heat-expandable silicone rubber, then install a limiting metal tube on the heat-expandable silicone rubber, and the heat-expandable silicone rubber and the metal limiting tube completely wrap the prepreg layer;

[0017] Each oven base module is equipped with a U-shaped upper cover, which is installed on the corresponding oven base module with the opening downward. The U-shaped upper cover is connected to the oven base module with a quick clamp, and the U-shaped upper covers are also connected to each other with a quick clamp;

[0018] Install sealing plates at both ends of the oven, start the oven, and complete the curing;

[0019] After curing, disconnect the quick clamp, lift off the U-shaped upper cover in turn, remove the metal limit tube, thermal expansion silicone rubber, and packaging material, and expose the large deformation structure of the cured composite material;

[0020] Demolding, trimming, and product preparation are completed.

[0021] Preferably, the length of the guide rail is greater than the length of the oven base, and the length of the guide rail on one side is more than 1 meter greater than the length of the oven base.

[0022] Preferably, the length of one side of the oven base exceeds the large deformation structure by more than 1 m.

[0023] Preferably, a heat insulating pad is provided between the oven base and the sliders on the two outer guide rails.

[0024] Preferably, a core mold support frame and a partial protrusion of the core mold module are placed in the middle of each oven base module. When the U-shaped upper cover opening is installed on the corresponding oven base module downward, the protrusion is embedded in the upper cover to form a matching section.

[0025] Preferably, the length of the core mold module is consistent with the length of the oven base module.

[0026] Preferably, a heat insulating pad is provided between the core mold support frame and the sliders on the two inner guide rails.

[0027] Preferably, the method of stacking single layers of prepreg in sequence on the platform is as follows:

[0028] First, single-layer prepregs with ±45° and 0° are pre-laid in a flat state, where the length of the 0° layer is not less than the product length, and the width of the single-layer prepreg is consistent with the circumference of the C-shaped structural section.

[0029] Preferably, when a reference line is drawn on the outer surface of the fluorine cloth of the prepreg ply, the reference line is along the length direction of the prepreg ply and is located at the center of the width direction of the prepreg ply.

[0030] Preferably, the connection point between the core mold module and the core mold support frame is located directly below the core mold module.

[0031] The beneficial effects of the present invention compared with the prior art are:

[0032] (1) The integrated molding process method for ultra-long composite material large deformation structures adopted by the present invention solves the problem of integral molding of large deformation structures above 30m, and avoids the curing defects caused by segmented molding.

[0033] (2) The present invention realizes the release of mold thermal deformation, solves the problem of curing bending of ultra-long deformed rods caused by thermal expansion deformation of ultra-long core molds, and improves the preparation accuracy of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of a large deformation structure of a composite material involved in the present invention;

[0035] Figure 2 Schematic diagram of the integrated molding oven and core mold of the present invention;

[0036] Figure 3 Schematic diagram of the oven module and core mold module of the present invention;

[0037] Figure 4 This is a schematic diagram of the installation of the core mold and oven on the guide rail. DETAILED DESCRIPTION

[0038] The present invention will be further described below with reference to the accompanying drawings.

[0039] like Figure 1 As shown, the composite material large deformation structure involved in the present invention is a carbon fiber / resin-based composite material laminate structure, whose cross section is C-shaped and long rod-shaped, and the length can reach more than 30m.

[0040] like Figure 2As shown, the large deformation structure of the composite material of the present invention adopts an integrated molding process, and an ultra-long oven and an ultra-long core mold are designed. First, the entire layer is laid on the mold. After the laying is completed, it is packaged with felt and vacuum bag film, cured in the ultra-long oven, and then demolded, that is, the entire layer is cured and formed in the oven at one time.

[0041] like Figure 3 As shown, the oven is a modular combination structure, consisting of several oven module units of standard length. The length of the oven module can be set to 5m. The number of modules can be increased or decreased according to the length of the product to meet the total length requirement of the product curing.

[0042] The oven module consists of a U-shaped cover and a base module. Several base modules form the oven base. The base is mounted on long guide rails on the floor and can slide freely along the length of the core. As the oven temperature rises and falls during heating, changes in the oven's length due to thermal expansion are quickly released by sliding on the rails. The U-shaped cover is mounted on the base and can be quickly connected using a quick-release clamp.

[0043] The core mold is a modular combination structure, consisting of several core mold module units of standard length. The length of the core mold module is consistent with the length of the oven and can be set to 5m. The core mold can increase or decrease the number of modules according to the length of the product to meet the total length requirements of the product layer.

[0044] The specific molding process steps are as follows:

[0045] Step 1: Arrange four guide rails on the ground according to the length of the large deformation structure of the composite material and adjust the accuracy. The two inner guide rails are used to install the core mold support frame, and the guide rails on both sides are used to install the oven base. The length of the guide rails should be more than 1m longer than the length of the oven module on one side;

[0046] Step 2: Install the oven base modules on the guide rails. Arrange the oven base modules in sequence, exceeding the maximum deformation length of the structure. Reserve at least 1m on one side. After installation, the oven base can slide freely on the guide rails. Use quick clamps to connect the base modules without gaps.

[0047] Step 3: Install several core mold support frames through the oven base and onto the guide rails;

[0048] Step 4: Install the core mold module on the corresponding core mold support frame, connect the modules with fasteners, align the outer circles, and use a laser tracker to measure and adjust the straightness of the core mold;

[0049] Step 5: Install the laser projector directly above the core mold and adjust the projection line position until the projection line is directly above the core mold;

[0050] Step 6: Stack the single layers of prepreg on the platform in sequence, and finally lay a layer of fluorine cloth on the inner and outer surfaces to prepare the prepreg layer. Draw a reference line on the outer surface of the fluorine cloth of the prepreg layer, and wind the prepreg layer on a paper tube with a diameter of 300mm.

[0051] Step 7: Spray release agent on the surface of the core mold;

[0052] Step 8: Place the prepreg layer on the surface of the core mold, with the C-shaped opening of the large deformation structure directly below. Adjust the position of the prepreg layer on the core mold so that the reference line of the prepreg layer is aligned with the laser projection line, and compact it;

[0053] Step 9: Wrap the outer surface of the prepreg layer with vacuum bag film and try to draw a vacuum to ensure there is no air leakage.

[0054] Step 10: Wrap the outer surface of the vacuum bag film with heat-expandable silicone rubber, and then install the limiting metal tube. The heat-expandable silicone rubber and the metal limiting tube completely wrap the prepreg layer.

[0055] Step 11: Install the U-shaped upper cover of the oven on the base in sequence. Use quick clamps to connect the U-shaped upper cover and the base. Use quick clamps to connect the U-shaped upper cover and the U-shaped upper cover.

[0056] Step 12: Install sealing plates at both ends of the oven, start the oven, and complete the curing;

[0057] Step 13: After curing, disconnect the quick clamp, lift off the U-shaped upper cover in sequence, remove the metal limit tube, thermal expansion silicone rubber, packaging materials, etc., and expose the large deformation structure of the cured composite material;

[0058] Step 14: Demolding, trimming, and completing product development.

[0059] like Figure 4 The figure shows the installation diagram of the core mold and oven on the guide rail.

[0060] An insulation pad is installed between the oven base module and the sliders on the two outer guide rails, which can quickly dissipate the heat conducted out of the oven and prevent the guide rail temperature from rising too much and causing large thermal deformation.

[0061] The oven cover is U-shaped and can be buckled on the base. The protrusion on the base can be embedded in the oven cover to form a matching section, reducing heat loss from the joint.

[0062] The core mold module is a round tube laying mold, wherein one end of the core mold support frame is connected to the round tube laying mold, and the other end is connected to the guide rail slider outside the oven through an opening on the oven base module.

[0063] The size of the opening in the oven base meets the displacement size requirements of the support legs of the core mold support frame.

[0064] The guide rail of the core mold support frame is located inside the oven. A thermal insulation pad is installed between the core mold support frame and the guide rail slider to block heat and prevent the guide rail temperature from rising. During the oven heating process, the guide rail remains at room temperature and there is no significant thermal expansion length change.

[0065] When the core mold is heated in the oven, thermal expansion deformation occurs. The change in its length dimension can be quickly released by the sliding of the support frame on the guide rail, avoiding bending of the mold and affecting the straightness of the large deformation structure of the composite material.

[0066] The connection point between the core mold and the support frame is located at the C-shaped opening of the composite material large deformation rod, and the connection point is located directly below the core mold.

[0067] A heat-expandable silicone rubber layer and a metal limiting tube are provided on the outer surface of the core mold to pressurize the prepreg layer during the curing process.

[0068] The method of laying prepregs for large deformation composite materials is to lay single layers of prepregs such as ±45° and 0° in a flat state in advance, and the laying order is [+45° / -45° / 0° n / -45° / +45°], 0° n This indicates multiple layers of 0° ply. The length of the 0° ply must be no less than the product length, and the width of a single prepreg layer must match the perimeter of the C-shaped structural section. Fluorine cloth is applied to the inner and outer surfaces of the prepreg ply. After layup, the prepreg ply is wound onto a 300mm diameter paper tube.

[0069] Draw a reference line on the prepreg ply. The reference line is along the length direction of the prepreg ply and is located in the center of the width direction of the prepreg ply.

[0070] Laser projection is used to project a straight line at the center of the upper surface of the extra-long mold. When the prepreg layers are laid on the mold, the reference line of the center of the layer is aligned with the projection line, thereby controlling the layup accuracy.

[0071] The composite material large deformation structure curing process is to first seal a vacuum bag film on the surface of the prepreg ply, evacuate the vacuum, and after it is leak-proof, wrap the outer surface with heat-expandable silicone rubber, and then install a metal limit tube on the surface so that the heat-expandable silicone rubber can only expand toward the surface of the prepreg ply, thereby applying curing pressure.

[0072] Parts of the present invention that are not described in detail belong to common knowledge among those skilled in the art.

Claims

1. An integrated molding process for a large deformation structure of a composite material, characterized in that: include: Arrange 4 guide rails on the ground according to the length of the composite material large deformation structure, of which the two inner guide rails are used to install the core mold support frame, and the two outer guide rails are used to install the oven base; The oven base is composed of a number of oven base modules, which are arranged in sequence and installed on the guide rails. Adjacent oven base modules are connected by quick clamps without any gaps. After being installed in place, the oven base can slide freely on the guide rails. Pass the core mold support frame through the oven base and install it on the guide rail; The core mold is composed of several core mold modules. Each core mold module is installed on the corresponding core mold support frame. The core mold modules are connected with fasteners, the outer circles are aligned, and the core mold straightness is measured and adjusted using a laser tracker. Install the laser projector directly above the core mold and adjust the projection line until it is directly above the core mold. Single layers of prepreg are stacked sequentially on the platform, and finally a layer of fluorine cloth is laid on the inner and outer surfaces to prepare the prepreg layer. A reference line is drawn on the outer surface of the fluorine cloth of the prepreg layer, and the prepreg layer is wound on a paper tube; Spray release agent on the surface of the core mold; Lay the prepreg layer on the core mold surface in a C-shaped structure, with the C-shaped opening located directly below the core mold. Adjust the position of the prepreg layer on the core mold so that the reference line of the prepreg layer is aligned with the laser projection line, and compact it; The outer surface of the prepreg layer is sealed with vacuum bag film, and vacuum is tested to ensure there is no air leakage; Wrap the outer surface of the vacuum bag film with heat-expandable silicone rubber, then install a limiting metal tube on the heat-expandable silicone rubber, and the heat-expandable silicone rubber and the metal limiting tube completely wrap the prepreg layer; Each oven base module is equipped with a U-shaped upper cover, which is installed on the corresponding oven base module with the opening downward. The U-shaped upper cover is connected to the oven base module with a quick clamp, and the U-shaped upper covers are also connected to each other with a quick clamp; Install sealing plates at both ends of the oven, start the oven, and complete the curing; After curing, disconnect the quick clamp, lift off the U-shaped upper cover in turn, remove the metal limit tube, thermal expansion silicone rubber, and packaging material, and expose the large deformation structure of the cured composite material; Demolding, trimming, and product preparation are completed.

2. The integrated molding process of a composite material large deformation structure according to claim 1, characterized in that: The length of the guide rail is greater than the length of the oven base, and the length of one side of the guide rail is more than 1m greater than the length of the oven base.

3. The integrated molding process of a composite material large deformation structure according to claim 1, characterized in that: The length of one side of the oven base exceeds the maximum deformation structure by more than 1m.

4. The integrated molding process of a composite material large deformation structure according to claim 1, characterized in that: A heat insulation pad is provided between the oven base and the sliders on the two outer guide rails.

5. The integrated molding process of a composite material large deformation structure according to claim 1, characterized in that: A core mold support frame and a partial protrusion of the core mold module are placed in the middle of each oven base module. When the U-shaped upper cover opening is installed downward on the corresponding oven base module, the protrusion is embedded in the upper cover to form a matching section.

6. The integrated molding process of a composite material large deformation structure according to claim 1, characterized in that: The length of the core mold module is consistent with the length of the oven base module.

7. The integrated molding process of a composite material large deformation structure according to claim 1, characterized in that: A heat insulation pad is arranged between the core mold support frame and the sliders on the two inner guide rails.

8. The integrated molding process of a composite material large deformation structure according to claim 1, characterized in that: The method of stacking single layers of prepreg on the platform is as follows: First, single-layer prepregs with ±45° and 0° are pre-laid in a flat state, where the length of the 0° layer is not less than the product length, and the width of the single-layer prepreg is consistent with the circumference of the C-shaped structural section.

9. The integrated molding process of a composite material large deformation structure according to claim 1, characterized in that: When drawing a reference line on the outer surface of the fluorine cloth of the prepreg ply, the reference line is along the length direction of the prepreg ply and is located at the center of the width direction of the prepreg ply.

10. The integrated molding process of a composite material large deformation structure according to claim 1, characterized in that: The connection point between the core mold module and the core mold support frame is located directly below the core mold module.

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