Anchoring head moulding device, method and anchoring head

Abstract

The application discloses an anchor head mould pressing forming device and method and an anchor head. The anchor head mould pressing forming device comprises an initial pressing half mould, a first cavity of the anchor head is formed on a mould closing surface of the initial pressing half mould, an injection pressing half mould, the injection pressing half mould comprises an outer mould and a core mould, the outer mould is provided with a through hole with the same size as the first cavity of the anchor head on the mould closing surface, the outer mould comprises a base body and a second cavity of the anchor head arranged in the base body, the base body is matched with the through hole, the initial pressing half mould and the outer mould are relatively moved along a first guide, the core mould and the outer mould are relatively moved along a second guide, and the first cavity of the anchor head and the second cavity of the anchor head form a forming cavity with the same size as the anchor head to be formed when the core mould and the initial pressing half mould are closed. The mould pressing device has the advantages of convenient mould closing, bidirectional symmetrical compression, high mould pressing precision, no damage to the cable and the like. The mould pressing device is also suitable for the mould pressing forming of other shape composite materials by changing the shape of the inner cavity of the mould, and has wide applicability.

Description

TECHNICAL FIELD

[0001] The application relates to a winding type FRP cable conical anchor head mold forming technology and belongs to the winding type FRP cable conical anchor head mold forming technical field. BACKGROUND

[0002] Fiber-reinforced polymer or plastics (FRP) is a high-performance material composed of fibers and resin matrix, has excellent performance such as light weight, high tensile strength, corrosion resistance and fatigue resistance, and is considered to be an ideal alternative material for solving the defects of heavy weight and easy corrosion of traditional bridge steel cables. Therefore, scholars at home and abroad have developed various cable anchoring systems, the purpose of which is to maximize the tensile strength of the FRP cable body.

[0003] According to the different forming methods of the load transfer medium in the anchoring area, the anchoring system can be divided into the clamping type, the bonding (grouting) type and the winding type. The forming process of the load transfer medium of the clamping type and the bonding (grouting) type is relatively mature after a long period of development and improvement. Compared with the first two methods, the winding type load transfer medium is a new type of anchoring method. The method is first proposed by the inventor of the patent based on the homologous material design concept. Specifically, the continuous fiber soaked with resin is wound into a conical anchor head in the anchoring area of the FRP cable, and the winding anchor head is integrated with the FRP cable through the mold pressing method. The advantages of the method are as follows: 1) the FRP cable and the load transfer medium have reliable interfacial bonding and mechanical biting effect, so that the FRP cable will not be pulled out under the action of fatigue, impact and other loads; 2) the FRP cable and the load transfer medium belong to fiber reinforced resin materials, and have good coordination performance. The realization of the above technical effects is closely related to the level of the preparation process. Therefore, it is necessary and urgent to break through the two technical difficulties of fiber winding and mold forming in the process of preparing the anchor head.

[0004] (1) Fiber winding

[0005] To address the fiber entanglement problem, the inventors previously developed a method for preparing a wound FRP cable anchor head (ZL201911393971.6). The preparation steps can be summarized as follows: 1) The FRP cable is segmented and fixed using a segmented multi-hole clamp and a metal disc. This step achieves several benefits, including increasing the bending stiffness of the FRP cable, enabling free lifting and movement of the FRP cable, and maintaining its straight shape during molding; 2) The metal disc is brought into contact with a circular tube. Rotation of the tube drives the metal disc to rotate, thereby rotating the entire FRP cable and achieving fiber entanglement; 3) This winding method effectively avoids early damage such as twisting, misalignment, and wear during FRP cable preparation; 4) Adjusting the rotation speed of the FRP cable and the fiber tension during the winding of the impregnated yarn allows for variations in fiber content to meet different application requirements. In conclusion, the winding method proposed by the inventors effectively solves the fiber entanglement problem.

[0006] (2) Compression molding

[0007] The finished conical anchor head needs to be molded before it can be used. However, conventional molding methods cannot meet the requirements for manufacturing conical anchor heads. The main technical defects are summarized as follows:

[0008] 1) Constant sizing method one (two symmetrical half-molds)

[0009] When the volume of the wound anchor head is greater than the volume of the mold cavity, material leakage and leakage will occur during the molding process, causing the symmetrical half mold to fail to close. When the volume of the wound anchor head is smaller than or close to the volume of the mold cavity, pressure cannot be applied to the loose wound anchor head, resulting in the anchor head being too small and the density not meeting the usage requirements.

[0010] 2) Standard Molding Method Two (Two Half-Molds + Injection Section)

[0011] By introducing an injection molding section, that is, adding a straight injection molding cavity inside one half of the mold, the problem of two symmetrical half molds being unable to close can be solved. However, this method still has four shortcomings:

[0012] ① When one half of the mold comes into contact with the straight section of another half of the mold, the mold closing gap between the two half of the mold is very small, making it very difficult to close the mold. This causes the sharp corners at both ends of one half of the mold to break when they come into contact with the straight section of the other half of the mold.

[0013] ② Increasing the mold closing gap can solve the problem of mold sharp corner damage ①, but increasing the mold closing gap will cause the two semi-conical anchor heads to be misaligned after mold closing, that is, the two semi-conical anchor heads cannot form a complete symmetrical structure, which will greatly affect the cable anchoring effect.

[0014] ③ During the mold closing process, one mold is always pressing against the other, causing the internal cable of the anchor head to shift in center position or even be damaged.

[0015] ④ After the anchor head is molded and cured, the overflowing resin will stick to the inner wall of the mold, making it very difficult to demold the anchor head, and may even damage the anchor head during the demolding process.

[0016] To fundamentally solve the above-mentioned technical bottlenecks and promote the widespread application of the winding anchoring method in cable structures, it is necessary to further develop a molding method with technical advantages such as easy mold closing, high molding accuracy, bidirectional symmetrical molding, and easy demolding, based on the shape and molding characteristics of the conical winding anchor head. Summary of the Invention

[0017] The technical problem to be solved by the present invention is to provide an anchor head molding device, method and anchor head that reduces the difficulty of mold closing and improves the accuracy of mold closing.

[0018] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0019] This invention first provides an anchor head molding apparatus, comprising:

[0020] The initial pressing half mold has an anchor head first cavity on its mating surface;

[0021] The injection molding half mold includes an outer mold and a core mold; the outer mold has a through hole of the same size as the first cavity of the anchor head on the mold mating surface; the outer mold includes a base and a second cavity of the anchor head disposed in the base, the base being matched with the through hole;

[0022] The initial pressure half-mold and the outer mold move relative to each other along the first guide, and the core mold and the outer mold move relative to each other along the second guide; when the core mold and the initial pressure half-mold are closed, the first cavity and the second cavity of the anchor head form a forming cavity with the same size as the anchor head to be formed.

[0023] Heating devices are provided on the initial pressure half mold, outer mold and core mold.

[0024] The heating device includes a thermocouple and / or a heating rod.

[0025] A base plate is provided at the lower part of the core mold base, and a limiting screw is provided on the base plate to restrict the movement range of the core mold within the outer mold.

[0026] The first guide is a tie rod; the second guide is a guide post.

[0027] The initial pressure half-mold is set on the first mold connecting block, and the core mold is set on the second mold connecting block.

[0028] A first heat insulation plate is provided between the initial pressure half mold and the first mold connecting block, and a second heat insulation plate is provided between the core mold and the second mold connecting block.

[0029] The first cavity of the anchor head located on the initial pressure half-mold closing surface is a semi-conical cavity, and a semi-cylindrical groove communicating with the semi-conical cavity is also provided on the closing surface; the second cavity of the anchor head located on the outer mold is a semi-conical cavity; the through hole located in the outer mold is a trapezoidal through hole with the same shape as the bottom surface of the semi-conical cavity.

[0030] The present invention also provides a method for molding an anchor head, wherein the molding device provided above is used for molding.

[0031] The present invention also provides an anchor head, which is formed by compression molding using the compression molding device described above.

[0032] Compared with similar molding technologies, the present invention has the following advantages:

[0033] (1) Convenient mold closing, high molding accuracy, avoidance of material leakage, and good performance. Before formal molding, the core mold is moved to provide sufficient injection section for the injection material. Then, the initial molding half and the injection half mold are closed, which can completely seal the slightly larger injection material in the mold cavity and avoid material leakage during the molding process. The core mold and the outer mold fit tightly, and the movement of the core mold always takes place inside the outer mold, which greatly reduces the difficulty of mold closing and significantly improves the mold closing accuracy.

[0034] (2) Easy demolding, and no damage to the anchor head and cable during the demolding process. When demolding, the initial pressure half mold is first separated from the anchor head to release the contact stress between them; then the outer mold is moved under the drive of the tie rod to separate the core mold from the anchor head and release the contact stress on the other side of the anchor head. At this point, there is no adhesive contact between the anchor head and the mold, and the anchor head and cable can be easily peeled off from the inner wall of the mold.

[0035] (3) Simple structure and controllable cost. The device of the present invention has few parts, simple structure, easy processing, and can be reused, which greatly saves the cost of use. Attached Figure Description

[0036] Figure 1 This is mold connecting block 1.

[0037] Figure 2 Insulation panel 2.

[0038] Figure 3 For the initial pressing half mold 3.

[0039] Figure 4 For the outer mold 4.

[0040] Figure 5 For core mold 5.

[0041] Figure 6 51 is a rectangular steel plate with through holes.

[0042] Figure 7 52 is an isosceles trapezoidal block with a cylindrical internal cavity.

[0043] Figure 8 It is lever 6.

[0044] Figure 9 For guide post 7.

[0045] Figure 10 The limit screw is 8.

[0046] Figure 11 This is the complete mold after assembly.

[0047] Figure 12 For placing tapered fiber-wound anchor heads and molds.

[0048] Figure 13 Demolding is performed after the anchor head has cured.

[0049] The components include: 1. Mold connecting block; 2. Heat insulation board; 3. Initial pressing half mold; 4. Outer mold; 5. Core mold; 6. Tie rod; 7. Guide post; 8. Limiting screw; 9. Fiber-wound anchor head; 10. Cable. Detailed Implementation

[0050] The technical solution of the present invention will be further explained in detail below with reference to the accompanying drawings. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art fall within the scope defined by the appended claims.

[0051] The embodiments of this invention mainly include component preparation, component assembly, mold closing, and demolding. These steps will be described in detail below.

[0052] The first step is to prepare the parts.

[0053] ① Mold connecting block 1

[0054] like Figure 1 As shown, there are two mold connecting blocks 1, made of high-strength, high-hardness mold steel. The length × width × height of each block is 450 × 348 × 50 mm. There are nine through holes 11 with varying diameters in the plane formed by the length and width. The purpose of these holes is to ensure that the tightened nut does not protrude from the mold connecting block 1 and affect the contact force between the mold connecting block 1 and the molding machine.

[0055] ②Insulation board 2

[0056] like Figure 2As shown, there are a total of 2 heat insulation boards 2, each with dimensions of 450×248×10mm (length×width×height). Nine through holes 21 with a diameter of Φ14.5 are opened in the plane formed by the length and width, and the center of each through hole is aligned with the mold connecting block 1.

[0057] ③ Initial pressing half mold 3

[0058] like Figure 3 As shown, there is one initial pressure half-mold 3, with dimensions of 450×248×99mm (length×width×height). Nine M14 holes 31, each 15mm deep, are formed on the surface in contact with the heat insulation plate 2, and the center of each hole is aligned with the openings in the heat insulation plate 2 and the mold connecting block 1. Within this plane, four through holes 32 with a diameter of Φ25 and four through holes 33 with varying diameters (the through hole with a diameter of Φ16.5 has a length of 20mm, and the through hole with a diameter of Φ25 has a length of 79mm) are also formed. The through holes 32 are used to pass through the guide post 7 with an outer diameter of Φ24, while the four through holes 33 are used to connect the tie rod 6. A semi-conical cavity 34 is formed on the surface in contact with the outer mold 4. The diameters of the top and bottom circles of the cone are 54.9mm and 138.4mm, respectively, with a cone height of 340mm and a taper of 7°. At both ends of the semi-cylindrical cone, there are six Φ12.5mm deep circular holes 35, two Φ14.5mm deep circular holes 36, and two Φ50mm semi-cylindrical through holes 37. The circular holes 35 are used to house the heating rod, the Φ14 holes are used to house the thermocouple 36 to control the temperature of the heating rod, and the semi-cylindrical through holes 37 are used to house the cable. The diameter of the semi-cylindrical groove is larger than the outer diameter of the cable, with a difference of 5-15mm.

[0059] ④ Outer mold 4

[0060] like Figure 4 As shown, there is one outer mold 4, with dimensions of 450×248×99mm (length×width×height). On the surface in contact with the initial pressure half-mold 3, there are four guide post through holes 41, four limit screw through holes 42, four connecting rod through holes 43, one trapezoidal hole 44, two semi-cylindrical holes 45, and two thermocouple holes 46. The specifications of each type of hole are as follows:

[0061] a. The diameter of the guide post through hole 41 is Φ30. In order to reduce the friction between the guide post and the hole wall, a copper sleeve with an outer diameter of 30mm and a wall thickness of 3mm is installed inside the guide post through hole.

[0062] b. The limit screw through hole 42 is a variable diameter through hole, wherein the through hole with a diameter of Φ16.5 has a length of 20mm (away from the side of the initial pressure half mold), and the through hole with a diameter of Φ24.5 has a length of 79mm (closer to the side of the initial pressure half mold).

[0063] c. The connecting rod through hole 43 is a variable diameter through hole, wherein the through hole with a diameter of Φ25 has a length of 79mm (away from the side of the initial pressure half mold), and the through hole with a diameter of Φ16.5 has a length of 20mm (close to the side of the initial pressure half mold).

[0064] d. The trapezoidal hole 44 is an isosceles trapezoid with upper and lower base lengths of 54.9 mm and 138.4 mm, respectively, and two interior angles of 97° and 83°, respectively.

[0065] e. The outer mold 4 also has a semi-cylindrical hole 45 and a thermocouple hole 46. The semi-cylindrical hole 45 is 50mm deep and Φ50mm in diameter, and the thermocouple hole 46 is 70mm deep and Φ14 in diameter.

[0066] ⑤ Core mold 5

[0067] like Figure 5 As shown, to reduce processing difficulty and lower processing costs, the core mold 5 is composed of a rectangular steel plate 51 with through holes and an isosceles trapezoidal block 52 with a cylindrical inner cavity, connected as a whole by screws. Figure 6 As shown, the rectangular steel plate 51 has a length × width × height of 450 × 248 × 30 mm. Its pressure-bearing surface has 4 guide post through holes 511, 4 limit screw through holes 512, 12 through holes 513 for fixing the isosceles trapezoidal block, and 9 screw holes 514 for fixing the heat insulation plate and the mold connecting plate 1.

[0068] a. The diameter of the guide post through hole 511 is Φ24.2.

[0069] b. The limit screw through hole 512 is an M16 screw hole with a hole depth of 20mm.

[0070] c. The diameter of the through hole 513 of the fixed isosceles trapezoidal block is Φ10.5.

[0071] d. The nine screw holes 514 for fixing the heat insulation plate 2 and the mold connecting plate 1 are of specification M14 and have a depth of 15mm.

[0072] like Figure 7 As shown, the isosceles trapezoidal block 52 with a cylindrical inner cavity has an upper base and a lower base length of 54.9 mm and 138.4 mm, respectively, two interior angles of 97° and 83°, and a height of 99 mm. A semi-conical cavity 521 (half of the anchor head) is carved out inside, and 12 M10 wire holes 522 are opened at the bottom with a depth of 15 mm.

[0073] ⑥ Pull rod 6

[0074] like Figure 8 As shown, there are a total of 4 tie rods 6, each consisting of 1 hollow steel tube 61, 2 hex socket screws 62, and 2 annular bushings 63. The dimensions of each part are as follows:

[0075] a. The hollow steel pipe 61 has a length of 150mm, an outer diameter of Φ16, and an inner diameter of M8.

[0076] b. 62 socket head cap screws are M8.

[0077] c. The outer diameter and inner diameter of the annular bushing 63 are 24 mm and 8.5 mm, respectively, and the thickness is 10 mm.

[0078] ⑦ Guide post

[0079] like Figure 9 As shown, the guide post 7 has an outer diameter of 24mm, a length of 200mm, and is made of high-strength steel. Every 15mm interval, a 1mm deep arc-shaped groove 71 is engraved on the post body. The purpose of these grooves is to store lubricating oil and reduce friction during the sliding process of the guide post 7. To create a mechanical anchoring effect between the guide post 7 and the rectangular steel plate, one end of the guide post 7 also has an enlarged end 72 (approximately 30mm in length), whose diameter is slightly larger than the diameter of the guide post hole in the rectangular steel plate. This allows one end of the guide post 7 to be secured to the steel plate after passing through it, thus forming a mechanical anchoring effect.

[0080] ⑧ Limit screw 8 (see) Figure 8 )

[0081] like Figure 10 As shown, the length of the limit screw 8 threaded rod is 80mm, the nut is an internal hexagonal shape, and the material is 12.9 grade high-strength steel.

[0082] The second step is component assembly.

[0083] ① Assemble the initial pressure half mold 3 and the outer mold 4. Place the initial pressure half mold 3 and the outer mold 4 on their sides and connect them with 4 tie rods 6 to form a whole.

[0084] ② Assemble the heat insulation plate 2 and mold connecting block 1 at the initial pressing half mold 3. Place the heat insulation plate 2 and mold connecting block 1 onto the initial pressing half mold 3 in sequence, and fix them with 9 M14 screws to connect the three into a whole.

[0085] ③ Assemble the guide posts 7 and the rectangular steel plate. Pass the four guide posts 7 through the rectangular steel plate in sequence. The position of the guide posts 7 is limited on the rectangular steel plate by the enlarged end 72 at one end of each guide post 7.

[0086] ④ Assemble the trapezoidal block and rectangular steel plate. Use 12 M10 high-strength screws to connect the trapezoidal block and rectangular steel plate into a whole.

[0087] ⑤ Assemble the heat insulation plate 2 and the mold connecting block 1 at the rectangular steel plate. Place the heat insulation plate 2 and the mold connecting block 1 onto the rectangular steel plate in sequence, and connect them with 9 M14 screws of grade 12.9 to form a whole.

[0088] ⑥ Pass the limiting screw 8 through the outer mold 4 and screw it onto the initial pressing half mold 3.

[0089] At this point, the molding device is fully assembled, as follows: Figure 11 As shown.

[0090] This embodiment provides a method for continuous fiber winding anchor head compression molding, the specific steps of which are as follows:

[0091] Before molding, a continuous fiber wound injection anchor head with a conical shape is prepared using the integrated continuous fiber winding technology previously developed by the inventor (Patent No.: ZL201911393971.6).

[0092] The injection material is continuous fiber impregnated with resin.

[0093] The continuous fiber is carbon fiber, basalt fiber, glass fiber, aramid fiber, ultra-high molecular weight polyethylene fiber, polyester fiber, nylon fiber, or a mixture of different types of fibers.

[0094] The resin type is epoxy resin, vinyl resin, or polyurethane resin.

[0095] Placement of tapered fiber-wound anchor head and mold closing (see) Figure 12 ).

[0096] The molding device is placed vertically on the molding machine. The mold connecting plate 1 is fixed using the molding machine's clamping device. The mold is pulled open to allow the anchor head 9 and cable 10 to be placed into the mold cavity. The initial mold half 3 is slowly moved by the molding machine's hydraulic device, with the movement trajectory controlled by the guide post 7, so that the initial mold half 3 first closes with the outer mold 4. The hydraulic clamp continues to move downward, causing the initial mold half 3 and the outer mold 4 to move downward together, gradually reducing the injection section length, and finally achieving the closing of the core mold 5 with the outer mold 4. At this point, the molding process is complete. The prepared heating rod and thermocouple are placed into the round hole inside the mold. By increasing the mold temperature, the resin curing time is shortened, thereby improving the preparation efficiency of the fiber-wound anchor head 9.

[0097] Step 4, demolding (see...) Figure 13 ).

[0098] After the fiber-wound anchor head 9 is cured, the mold connecting block 1 is moved upward by the molding press, so that the initial pressing half mold 3 is demolded from the fiber-wound anchor head 9 first; then the tie rod 6 is used to drive the outer mold 4 to move upward, so that the core mold 5 is demolded from the fiber-wound anchor head 9, and the movement displacement of the outer mold 4 is controlled by the limit screw 8.

[0099] At this point, the fiber-wound anchor head 9 has been successfully prepared.

Claims

1. An anchor head molding device, characterized in that, include: The initial pressing half mold has an anchor head first cavity on its mating surface; The injection molding half mold includes an outer mold and a core mold; the outer mold has a through hole of the same size as the first cavity of the anchor head on the mold closing surface; the core mold includes a base and a second cavity of the anchor head disposed in the base, the base being matched with the through hole; The initial pressure half-mold and the outer mold move relative to each other along the first guide, and the core mold and the outer mold move relative to each other along the second guide; when the core mold and the initial pressure half-mold are closed, the first cavity and the second cavity of the anchor head form a forming cavity with the same size as the anchor head to be formed; Heating devices are provided on the initial pressure half mold, outer mold, and core mold; A base plate is provided at the lower part of the core mold base, and a limiting screw is provided on the base plate to limit the movement range of the core mold within the outer mold; The first cavity of the anchor head located on the initial mold half-mold closing surface is a semi-conical cavity, and a semi-cylindrical groove communicating with the semi-conical cavity is also provided on the mold closing surface; the second cavity of the anchor head located on the outer mold is a semi-conical cavity; the through hole located in the core mold is a trapezoidal through hole with the same shape as the bottom surface of the semi-conical cavity.

2. The molding apparatus according to claim 1, characterized in that, The heating device includes a thermocouple and / or a heating rod.

3. The molding apparatus according to claim 1, characterized in that, The first guide is a tie rod; the second guide is a guide post.

4. The molding apparatus according to claim 1, characterized in that, The initial pressure half-mold is set on the first mold connecting block, and the core mold is set on the second mold connecting block.

5. The molding apparatus according to claim 4, characterized in that, A first heat insulation plate is provided between the initial pressure half mold and the first mold connecting block, and a second heat insulation plate is provided between the core mold and the second mold connecting block.

6. A method for molding an anchor head, characterized in that, The molding process is performed using the molding apparatus described in any one of claims 1-5.

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