Integrated forming process method of composite material large-deformation structure

Abstract

The invention relates to an integrated forming process method of a composite material large-deformation structure, which comprises the following steps: designing a super-long drying oven and a super-long core mold, mounting the super-long drying oven and the super-long core mold on a guide rail which is longer than a base of the drying oven, firstly, integrally laying on the core mold, packaging with a felt and a vacuum bag film after laying, curing in the super-long drying oven, and then demolding to obtain the composite material large-deformation structure. And carrying out one-time integral curing molding in a drying oven. According to the method, the integral forming problem of a large-deformation structure of more than 30m level is solved, and the curing defect caused by segmented forming is avoided. When the core mold is heated in the drying oven, thermal expansion deformation is generated, the change of the length size of the core mold can be quickly released through sliding of the supporting frame on the guide rail, mold bending is avoided, the straightness of a large-deformation structure of a composite material is prevented from being affected, and the preparation precision of the structure is improved.

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] In the future, spacecraft will develop in the direction of large-scale and high-power, with a size of hundreds of meters or even kilometers. For example, payloads such as hundred-meter-class deployable antennas, kilometer-class solar power stations, and solar sails are extremely important due to the size limit of the rocket fairing envelope. Carbon fiber / resin-based large deformation composite material structures are the key load-bearing structures for the above loads. They have the advantages of light weight, high load-bearing ratio, strong designability, and ultra-long manufacturing, and are the first choice for future large-scale deployable structures.

[0003] The current molding of this type of structure has the following problems: (1) The required length of the large deformation structure of the composite material exceeds 30m, but the actual manufacturing length is limited by the length of conventional autoclaves and ovens, which is generally less than 10m and cannot be manufactured 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 excessive straightness of the large deformation structure of the composite material. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and propose an integrated molding process method for a large deformation structure of a composite material, so as to solve the problem that the large deformation structure of the composite material is subject to the size limitations of conventional autoclaves, ovens, molds, etc., and is difficult to be molded for more than 30m and has poor molding straightness.

[0005] The solution of the present invention is:

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

[0007] According to the length of the large deformation structure of the composite material, four guide rails are arranged on the ground, 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 plurality 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 of which is installed on a corresponding core mold support frame, and the core mold modules are connected with fasteners, the outer circles are aligned, and the straightness of the core mold is measured and adjusted using a laser tracker;

[0011] Install a laser projector directly above the core mold and adjust the projection line position until the projection line is directly above the core mold;

[0012] Single-layer prepregs are stacked sequentially on the platform, and finally a layer of fluorine cloth is laid on the inner and outer surfaces to prepare a 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] Spraying mold release agent on the surface of the core mold;

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

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

[0016] Wrap the outer surface of the vacuum bag film with heat-expandable silicone rubber, then set 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] A U-shaped upper cover is configured for each oven base module, and the U-shaped upper cover 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] Demoulding, 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 greater than 1 m of 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 arranged 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, and 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.

[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 arranged between the core mold support frame and the sliding blocks on the two inner guide rails.

[0027] Preferably, the method of stacking the single-layer prepregs sequentially on the platform is as follows:

[0028] First, single-layer prepregs of ±45° and 0° are pre-laid in a flat state, wherein 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 of the ultra-long composite material large deformation structure adopted by the present invention solves the problem of overall 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 A schematic diagram of a large deformation structure of a composite material involved in the present invention;

[0035] Figure 2 It is a schematic diagram of the integrated forming oven and the core mold of the present invention;

[0036] Figure 3 It is a schematic diagram of the oven module and the 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 in conjunction with the accompanying drawings.

[0039] like Figure 1 As shown, a composite material large deformation structure involved in the present invention is a carbon fiber / resin-based composite material laminated 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 an 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, which is composed 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 upper cover and an oven base module, and several oven base modules constitute the oven base. The oven base is installed on a long rail on the ground and can slide freely along the length of the core mold on the rail. During the oven heating process, as the oven temperature rises and falls, the length change caused by thermal expansion of the oven is quickly released by sliding on the rail. The U-shaped upper cover is installed on the base and can be quickly connected by a quick clamp.

[0043] The core mold is a modular combination structure, which is composed 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 requirement of the product layer.

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

[0045] Step 1: Arrange 4 guide rails on the ground according to the length of the large deformation structure of the composite material, 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 rail is longer than the length of the oven module on one side by more than 1m;

[0046] Step 2: Install the oven base module on the guide rail. The oven base modules are arranged in sequence, exceeding the length of the large deformation structure, and the single-side length is at least 1m. After installation, the oven base can slide freely on the guide rail, and the base modules are connected with quick clamps without gaps;

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

[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-layer prepregs in sequence on the platform, and finally lay a layer of fluorine cloth on the inner and outer surfaces to prepare the prepreg ply, draw a reference line on the outer surface of the fluorine cloth of the prepreg ply, and wind the prepreg ply on a paper tube with a diameter of 300 mm;

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

[0052] Step 8: Spread the prepreg ply 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 ply on the core mold, align the reference line of the prepreg ply with the laser projection line, and compact;

[0053] Step 9: Encapsulate the outer surface of the prepreg layer with a vacuum bag film and try to draw a vacuum to ensure there is no 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. The U-shaped upper cover and the base are connected by a quick clamp, and the U-shaped upper covers are also connected by a quick clamp;

[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 turn, 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 product development are completed.

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

[0060] An insulation pad is arranged between the oven base module and the sliders on the two outer guide rails, so that the heat conducted out of the oven by heat conduction can be quickly dissipated, thereby preventing the temperature of the guide rails 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, thereby 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 supporting legs of the core mold support frame.

[0064] The guide rail of the core mold support frame is located inside the oven. A heat insulation pad is installed between the core mold support frame and the guide rail slider to block heat and prevent the temperature of the guide rail from rising. During the heating process of the oven, the guide rail remains at room temperature without significant thermal expansion length changes.

[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 to avoid bending of the mold and affect 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 large deformation rod of the composite material, and the connection point is located directly below the core mold.

[0067] A heat expansion 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 structures of composite materials is to first lay single-layer prepregs of ±45°, 0°, etc. in a flat state, and the laying order is [+45° / -45° / 0° n / -45° / +45°], 0° n It means that there are multiple layers of 0° ply. The length of the 0° ply is not less than the length of the product, and the width of a single layer of prepreg is consistent with the circumference of the C-shaped structural section. Fluorine cloth is pasted on the inner and outer surfaces of the prepreg ply. After the ply is completed, the prepreg ply is wound on a paper tube with a diameter of 300mm.

[0069] Draw a reference line on 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.

[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 layer 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 no leakage, 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 composite material large deformation structure, characterized in that: include: According to the length of the large deformation structure of the composite material, four guide rails are arranged on the ground, 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 plurality 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 of which is installed on a corresponding core mold support frame, and the core mold modules are connected with fasteners, the outer circles are aligned, and the straightness of the core mold is measured and adjusted using a laser tracker; Install a laser projector directly above the core mold and adjust the projection line position until the projection line is directly above the core mold; Single-layer prepregs are stacked sequentially on the platform, and finally a layer of fluorine cloth is laid on the inner and outer surfaces to prepare a 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; Spraying mold release agent on the surface of the core mold; Lay the prepreg ply on the surface of the core mold in a C-shaped structure, with the C-shaped opening located directly below the core mold. Adjust the position of the prepreg ply on the core mold so that the reference line of the prepreg ply is aligned with the laser projection line, and compact it. The outer surface of the prepreg layer is sealed with a vacuum bag film, and a vacuum test is conducted to ensure that there is no air leakage; Wrap the outer surface of the vacuum bag film with heat-expandable silicone rubber, then set 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; A U-shaped upper cover is configured for each oven base module, and the U-shaped upper cover 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; Demoulding, trimming and product preparation are completed.

2. The integrated forming 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 forming process of a composite material large deformation structure according to claim 1, characterized in that: The single side of the oven base exceeds the length of the large 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 insulating pad is arranged 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 forming 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 insulating pad is arranged between the core mold support frame and the sliding blocks on the two inner guide rails.

8. The integrated forming 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 of ±45° and 0° are pre-laid in a flat state, wherein 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 forming 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 forming 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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