Manufacturing method of large-size oval pipe and oval pipe

Abstract

The invention belongs to the technical field of pipe body manufacturing, and particularly relates to a manufacturing method of a large-size oval pipe and the oval pipe. The large-size oval pipe is made of a composite material and is high in bending resistance and compression resistance, not prone to deformation, long in service life, good in fatigue resistance and corrosion resistance and flexible in designability; the stability and the reliability of mechanical equipment can be effectively improved; according to the large-size oval pipe, on the premise that the working intensity is guaranteed, the overall weight of mechanical equipment is reduced, and the production efficiency of the mechanical equipment is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of tube manufacturing, and in particular relates to a manufacturing method of a large-size oval tube and the oval tube. Background Art

[0002] With the continuous development of mechanical equipment design and manufacturing technology, the shapes and performance requirements of its structural components are becoming increasingly diversified. Traditional pipe fittings mostly adopt circular structures and metal materials. They are generally used for the connection structure or load-bearing structure of mechanical equipment. However, in some cases they may not meet specific needs, such as mechanical equipment working performance, weight requirements and installation requirements.

[0003] The oval tube has a unique geometric shape, while the composite material is light, high-strength and has good weather resistance. The combination of the two can make the large-sized oval tube have higher bending resistance, compressive strength, lighter weight, and flexible designability, thereby improving the stability and reliability of mechanical equipment, reducing the overall weight of the equipment, and improving production efficiency.

[0004] Therefore, a method for manufacturing a large-size oval tube and the oval tube are proposed. Summary of the invention

[0005] The object of the present invention is to provide a method for manufacturing a large-size oval tube and an oval tube to solve the above problems.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A method for manufacturing a large-size oval tube comprises the following steps:

[0008] Prepare the core mold and the metal joint, pre-treat the core mold and the metal joint, assemble and fix the core mold and the metal joint, clamp the core mold on the winding machine / taping machine, fill the joint between the embedded part of the metal joint and the core mold with carbon fiber prepreg, wrap the surface of the embedded part with adhesive film, tape the carbon fiber prepreg layer by layer on the surface of the core mold and the embedded part, and pre-compact the carbon fiber prepreg. After the tape is wrapped, a semi-finished product is formed, tape is wrapped on the layup surface of the semi-finished product, a uniform pressure plate is placed on the flat area of ​​the semi-finished product and fixed, the semi-finished product is vacuum-packaged with auxiliary materials, and then placed in a curing furnace for curing. After the curing is completed, wait for the semi-finished product to cool down, remove the auxiliary materials after cooling, and then demold, and post-process the obtained finished product to obtain a large-sized elliptical tube.

[0009] Preferably, the pretreatment process of the core mold is: treating the surface of the core mold and applying a release agent on the surface of the core mold.

[0010] Preferably, the pretreatment process of the metal joint is: grinding the outer side of the metal joint and brushing a release agent on the inner side of the metal joint.

[0011] Preferably, when the carbon fiber prepreg is wrapped layer by layer on the surface of the core mold and the embedded part, the carbon fiber prepreg does not cover the connection area of ​​the metal joint.

[0012] Preferably, when the carbon fiber prepreg is wrapped layer by layer on the surface of the core mold and the embedded part, the inner layer and the main layer use carbon fiber unidirectional prepreg, the plying direction of the carbon fiber unidirectional prepreg is designed to be 0° plying and 90° plying, and the ratio of 0° plying to 90° plying is 4:1, and the outer layer uses carbon fiber fabric prepreg.

[0013] Preferably, when pre-compacting the carbon fiber prepreg, after the first layer of carbon fiber prepreg is wrapped and compacted by BOPP tape / PET tape, wrapping and compacting are performed every 5-8 layers.

[0014] Preferably, the auxiliary materials include an isolation film, a breathable felt, and a vacuum bag film arranged in sequence from the inside to the outside. When the semi-finished product is vacuum-packaged, the isolation film, the breathable felt, and the vacuum bag film are sequentially wrapped on the outside of the semi-finished product. After the vacuum bag is pasted, it is evacuated and the vacuum degree is -0.092 to -0.1 MPa.

[0015] A large-size oval tube is manufactured by the manufacturing method of the large-size oval tube.

[0016] Preferably, the large-sized oval tube includes a large-sized oval tube body, an embedded part is arranged in the large-sized oval tube body, the embedded part is close to one end of the large-sized oval tube body, a connecting area is fixedly connected to the outer side of the embedded part, the connecting area extends out of the large-sized oval tube body, and a plurality of bolt holes are opened on the connecting area.

[0017] Preferably, the length of the large-size elliptical tube is greater than or equal to 3 m.

[0018] Compared with the prior art, the present invention has the following advantages and technical effects:

[0019] The large-size elliptical tube of the present invention adopts a composite material, has strong bending and compression resistance, is not easy to deform, has a long service life, good fatigue resistance, good corrosion resistance, and flexible designability, and can effectively improve the stability and reliability of mechanical equipment; the large-size elliptical tube of the present invention can reduce the overall weight of mechanical equipment and improve the production efficiency of mechanical equipment while ensuring the working strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor:

[0021] Figure 1 It is an overall schematic diagram of a large-sized oval tube in the present invention;

[0022] Figure 2 It is a schematic diagram of the internal structure of the large-sized oval tube in the present invention;

[0023] Figure 3 It is an overall schematic diagram of the metal joint in the present invention;

[0024] Figure 4 It is an overall schematic diagram of the core mold in the present invention;

[0025] Among them, 2. Metal joint; 3. Large-size oval tube; 4. Bolt hole; 5. Embedded part; 6. Connection area. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] The invention discloses a method for manufacturing a large-size oval tube, comprising the following steps:

[0029] Prepare a core mold and a metal joint 2, pre-treat the core mold and the metal joint 2, assemble and fix the core mold and the metal joint 2, clamp the core mold on a winding machine / taping machine, fill the joint between the embedded part 5 of the metal joint 2 and the core mold with carbon fiber prepreg, wrap the surface of the embedded part 5 with adhesive film, wrap the carbon fiber prepreg layer by layer on the surface of the core mold and the embedded part 5, and pre-compact the carbon fiber prepreg. After the wrapping is completed, a semi-finished product is formed, the layup surface of the semi-finished product is wrapped, a uniform pressure plate is placed on the flat area of ​​the semi-finished product and fixed, the semi-finished product is vacuum-packaged with auxiliary materials, and then placed in a curing furnace for curing. After the curing is completed, wait for the semi-finished product to cool down, remove the auxiliary materials after cooling, and then demold, and post-process the resulting finished product to obtain a large-sized elliptical tube.

[0030] The outer edge of the metal joint 2 is flush with the outer side wall of the core mold, thereby ensuring the flatness of the large-sized oval tube obtained;

[0031] According to the further optimization scheme, the pretreatment process of the core mold is as follows: treating the surface of the core mold and applying a release agent on the surface of the core mold.

[0032] According to a further optimization scheme, the pretreatment process of the metal joint 2 is as follows: grinding the outer side of the metal joint 2 and applying a release agent on the inner side of the metal joint 2 .

[0033] According to a further optimization scheme, when the carbon fiber prepreg is wrapped layer by layer on the surface of the core mold and the embedded part 5 , the carbon fiber prepreg does not cover the connection area 6 of the metal joint 2 .

[0034] A further optimization scheme is to wrap the carbon fiber prepreg layer by layer on the surface of the core mold and the embedded part 5, and the inner layer and the main layer use carbon fiber unidirectional prepreg, and the ply directions of the carbon fiber unidirectional prepreg are designed to be 0° ply and 90° ply, and the ratio of 0° ply and 90° ply is 4:1, and the outer layer uses carbon fiber fabric prepreg.

[0035] To further optimize the solution, when pre-compacting the carbon fiber prepreg, after the first layer of carbon fiber prepreg is compacted by wrapping with BOPP tape / PET tape, wrapping and compacting is performed every 5-8 layers.

[0036] To further optimize the plan, auxiliary materials include isolation film, breathable felt and vacuum bag film arranged in sequence from the inside to the outside. When the semi-finished product is vacuum-packaged, the isolation film, breathable felt and vacuum bag film are sequentially wrapped on the outside of the semi-finished product. After the vacuum bag is pasted, it is evacuated and the vacuum degree is -0.092 to -0.1MPa.

[0037] A large-size oval tube is manufactured by a large-size oval tube manufacturing method.

[0038] A further optimized solution is that the large-sized elliptical tube includes a large-sized elliptical tube body 3, an embedded part 5 is arranged inside the large-sized elliptical tube body 3, the embedded part 5 is close to one end of the large-sized elliptical tube body 3, a connecting area 6 is fixedly connected to the outer side of the embedded part 5, the connecting area 6 extends out of the large-sized elliptical tube body 3, and a plurality of bolt holes 4 are opened on the connecting area 6.

[0039] According to a further optimization scheme, the length of the large-sized elliptical tube body 3 is greater than or equal to 3 m.

[0040] One specific example:

[0041] Preparation method:

[0042] Step 1: Prepare the core mold and treat the surface of the core mold. Use a clean cloth dipped in acetone or alcohol to wipe the surface of the mold to remove dust and debris on the surface of the mold, so that the surface of the core mold is clean and smooth;

[0043] Heat the core mold, use an oven or autoclave to heat the mold at 80°C for at least 2 hours; apply a release agent on the surface of the core mold at least 3 times, with an interval of at least 15 minutes between each application;

[0044] Step 2: Prepare the metal joint 2, treat the surface of the metal joint 2, first remove the oil and impurities on the surface of the metal joint 2, then use sandpaper to roughen the surface of the embedded part of the metal joint 2, and then use a dust-removing rag to wipe it clean. The surface of the metal joint 2 includes the outer surface and the inner surface, and apply a release agent on the inner surface of the metal joint 2;

[0045] Step 3: Fix the metal joint 2 at the preset position on the core mold. The structural diagram of the core mold is as follows: Figure 4 As shown;

[0046] Step 4: Clamp the core mold onto the tape wrapping machine / winding machine and make sure that the core mold is clamped in place and firmly;

[0047] Step 5: Fill the joint between the embedded part 5 and the core mold with carbon fiber prepreg, the carbon fiber prepreg at the joint between the embedded part 5 and the core mold is tightly attached and flush with the embedded part 5 and the outer surface of the core mold;

[0048] Step 6: Wrap the surface of the embedded part 5 with a film to improve the bonding strength between the embedded part 5 and the carbon fiber ply;

[0049] Step 7: wrap carbon fiber prepreg layer by layer on the surface of the core mold and the embedded part 5, and perform pre-compacting of the wrapping; wherein, the inner layer and the main layer are both made of carbon fiber unidirectional prepreg, and the laying direction of the carbon fiber unidirectional prepreg is designed to be 0° laying and 90° laying, and the ratio of 0° laying and 90° laying is 4:1, and the outer layer is a layer of carbon fiber fabric prepreg; when manually laying, the carbon fiber prepreg needs to open a hole in the connection area 6, and when the machine is laid, the carbon fiber prepreg avoids the connection area 6, so that the connection area 6 extends out of the large-size elliptical tube body 3; during the laying process, use BOPP tape or PET tape to perform pre-compacting of the wrapping after the first layer of wrapping, and then perform pre-compacting of the wrapping every 5-8 layers;

[0050] The inner layer, main layer and outer layer are divided according to the laying order from inside to outside.

[0051] Specifically: the inner layer is 10 layers of T700 carbon fiber unidirectional prepreg with a single layer thickness of 0.1mm, the main layer is 20 layers of T700 carbon fiber unidirectional prepreg with a single layer thickness of 0.2mm, the outer layer is 1 layer of T300 carbon fiber fabric prepreg with a single layer thickness of 0.25mm, and the inner layer, main layer and outer layer constitute a 5.25mm thick tube body layer.

[0052] Step 8: After the tape is wrapped, a semi-finished product is formed. The tape is wrapped around the outside of the semi-finished product, and a pressure plate is placed and fixed on the flat area of ​​the semi-finished product;

[0053] Step nine: Sequentially wrap the outside of the semi-finished product with an isolation film, a breathable felt, and a vacuum bag film, paste the vacuum bag film to form a vacuum bag, and evacuate the vacuum bag to a vacuum degree of -0.092 to -0.1 MPa;

[0054] Step 10: Place a layer of breathable felt on the curing platform, place the vacuum-packed semi-finished product on the breathable felt, put the curing platform into a curing furnace / autoclave, level the core mold, arrange the thermocouple, and then evacuate, heat and pressurize to cure the large-sized oval tube 3 and the metal joint 2 into an integrated structure;

[0055] Step 11: After the semi-finished product is cured, it is naturally cooled, and demoulding is performed after removing the isolation film, breathable felt, and vacuum bag film;

[0056] Step 12: Grind, cut to length and drill holes on the demoulding material according to usage requirements to obtain the required large-sized oval tube.

[0057] The obtained large-size oval tube structure is as follows Figure 1 to Figure 2 As shown, Figure 3 It is a schematic diagram of the structure of the metal joint 2 in the present invention.

[0058] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0059] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for manufacturing a large-size oval tube, characterized in that: The following steps are involved: A core mold and a metal joint (2) are prepared, the core mold and the metal joint (2) are pre-treated, the core mold and the metal joint (2) are assembled and fixed, the core mold is clamped on a winding machine / taping machine, the joint between the embedded part (5) of the metal joint (2) and the core mold is filled with carbon fiber prepreg, the surface of the embedded part (5) is wrapped with a film, the carbon fiber prepreg is taped layer by layer on the surface of the core mold and the embedded part (5), and the carbon fiber prepreg is pre-compacted, the taping is completed to form a semi-finished product, the layer surface of the semi-finished product is taped, a uniform pressure plate is placed on the plane area of ​​the semi-finished product and fixed, the semi-finished product is vacuum-sealed with auxiliary materials, and then placed in a curing furnace for curing, and the semi-finished product is cooled after the curing is completed, the auxiliary materials are removed after the cooling is completed, and then the mold is demoulded, and the obtained finished product is post-processed to obtain a large-sized elliptical tube.

2. The method for manufacturing a large-size oval tube according to claim 1, characterized in that: The pretreatment process of the core mold is: treating the surface of the core mold and brushing a release agent on the surface of the core mold.

3. The method for manufacturing a large-size oval tube according to claim 1, characterized in that: The pretreatment process of the metal joint (2) is as follows: grinding the outer side of the metal joint (2) and brushing a release agent on the inner side of the metal joint (2).

4. The method for manufacturing a large-size oval tube according to claim 1, characterized in that: When the carbon fiber prepreg is wrapped layer by layer on the surface of the core mold and the embedded part (5), the carbon fiber prepreg does not cover the connection area (6) of the metal joint (2).

5. The method for manufacturing a large-size oval tube according to claim 1, characterized in that: When the carbon fiber prepreg is wrapped layer by layer on the surface of the core mold and the embedded part (5), the inner layer and the main layer use carbon fiber unidirectional prepreg, the plying direction of the carbon fiber unidirectional prepreg is designed to be 0° plying and 90° plying, and the ratio of 0° plying to 90° plying is 4:1, and the outer layer uses carbon fiber fabric prepreg.

6. The method for manufacturing a large-size oval tube according to claim 1, characterized in that: When pre-compacting the carbon fiber prepreg, after the first layer of carbon fiber prepreg is taped and compacted by BOPP tape / PET tape, the taping and compaction is performed every 5-8 layers.

7. The method for manufacturing a large-size oval tube according to claim 1, characterized in that: The auxiliary materials include an isolation film, a breathable felt, and a vacuum bag film which are arranged in sequence from the inside to the outside. When the semi-finished product is vacuum-packaged, the isolation film, the breathable felt, and the vacuum bag film are sequentially wrapped on the outside of the semi-finished product. After the vacuum bag is pasted, it is evacuated and the vacuum degree is -0.092 to -0.1MPa.

8. A large-size oval tube, characterized in that: The large-size oval tube is manufactured by the manufacturing method of any one of claims 1 to 7.

9. A large-size oval tube according to claim 8, characterized in that: The invention comprises a large-sized elliptical tube body (3), wherein a pre-embedded portion (5) is arranged inside the large-sized elliptical tube body (3), wherein the pre-embedded portion (5) is close to one end of the large-sized elliptical tube body (3), and a connecting area (6) is fixedly connected to the outer side of the pre-embedded portion (5), wherein the connecting area (6) extends out of the large-sized elliptical tube body (3), and a plurality of bolt holes (4) are provided on the connecting area (6).

10. The large-size oval tube according to claim 9, characterized in that: The length of the large-size elliptical tube (3) is greater than or equal to 3 m.

Images