Strip-shaped RTM (Resin Transfer Molding) resin transfer heating forming mold

Abstract

The utility model relates to the technical field of RTM (Resin Transfer Molding) resin forming molds, in particular to a strip-shaped RTM resin transfer heating forming mold. The problems that an existing mold is difficult to demold and products are scrapped due to volume expansion in the forming process are solved. According to the technical scheme, the die comprises a rectangular die body composed of a lower die, an upper die and blocking flat plates arranged on the two sides. A die cavity is formed in the upper surface of the lower die in the length direction, strip-shaped sealing grooves are formed in the two sides of the die cavity respectively, strip-shaped protrusions matched with the die cavity are arranged on the lower surface of the upper die in a protruding mode, concentric-square-shaped sealing grooves are formed in the inner surfaces of the two blocking flat plates, sealing rings are arranged in the sealing grooves, and the sealing grooves, the lower die and the upper die are sealed through the sealing rings. The mold is simple in structure and convenient to demold.

Description

Technical Field

[0001] The utility model relates to the technical field of RTM resin molding dies, in particular to a strip-shaped RTM resin transfer heating molding die. Technical Background

[0002] Strip RTM resin transfer molding dies are used to form the thermal insulation layer of the external fairing of hypersonic weapons in the aviation industry. Hypersonic weapons experience severe surface heat erosion during flight, with maximum surface temperatures reaching approximately 1500°C. The importance of the fairing insulation layer is evident in its ability to protect internal cables from damage even at 1500°C. Due to the product's unique application scenario and high raw material costs, extremely high requirements are placed on both product quality and yield.

[0003] The RTM process is a closed-mold molding technology developed from hand lay-up. With increasing performance requirements for composite materials and environmental regulations restricting open-mold molding processes, RTM has gradually gained attention and developed as a closed-mold molding process. The basic principle is to lay a reinforcement material (such as glass fiber or carbon fiber) into a closed mold cavity. A low-viscosity resin is then injected into the cavity under pressure, allowing the resin to penetrate the reinforcement material and finally solidify to form the part.

[0004] The RTM molding process has the characteristics of high product performance, great cost and efficiency advantages, environmental and health friendliness, mature material technology, and the ability to prepare large and complex components. It is mostly used to manufacture parts for satellites and missiles. Its application in the aerospace field has an important technical background and broad prospects.

[0005] The primary factor that determines the quality of RTM products is the mold. Since RTM molds generally use the male-female mold matching method, improving the mold's surface quality and dimensional accuracy and designing a reasonable demoulding structure are the key to ensuring product quality.

[0006] Existing strip-shaped resin transfer thermoforming molds require a completely sealed cavity during operation. To ensure this, conventional molds often feature a relatively closed cavity. With the exception of the removable upper mold on the upper surface, the remaining cavity surfaces are integral. This integral structure makes it difficult to remove the product from the mold. Furthermore, the product expands during the molding process, particularly in the longitudinal direction, making demolding difficult and, in severe cases, potentially resulting in product failure. Utility Model Content

[0007] In view of this, the present invention provides a strip-shaped RTM resin transfer heating molding mold to solve the problem that the existing mold expands in volume during the molding process, resulting in difficulty in demoulding and causing product scrapping.

[0008] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: a strip-shaped RTM resin transfer heating molding mold, characterized in that it includes a rectangular mold body consisting of a lower mold, an upper mold and blocking plates arranged on both sides;

[0009] A mold cavity is provided on the extension direction of the upper surface of the lower mold, and a strip-shaped sealing groove 1 is provided on both sides of the mold cavity, and a sealing strip is provided in the sealing groove 1; the lower surface of the upper mold is protruded with a strip-shaped protrusion that matches the mold cavity, and a circular sealing groove 2 is provided on the inner surfaces of the two sealing plates, and a sealing ring is provided in the sealing groove 2, which is sealed with the lower mold and the upper mold through the sealing ring.

[0010] Furthermore, the sealing rings are overlapped at an oblique angle, and the overlapped portions are bonded with silicone rubber.

[0011] Furthermore, the lower die and the upper die are connected by screws.

[0012] Furthermore, the lower mold, the upper mold and the sealing plates on both sides are connected by screws.

[0013] Furthermore, the lower die is also provided with pin holes for positioning.

[0014] Furthermore, the mold body material is 45# steel material, with a length of 2100-2300 mm, a width of 230-250 mm, and a height of 140-160 mm.

[0015] Furthermore, the width of the sealing groove 1 and the sealing groove 2 is 5 mm and the depth is 3 mm.

[0016] Compared with the prior art, the advantages of this utility model are:

[0017] 1) The utility model provides blocking plates on both sides of the mold. When the product is demoulded, the blocking plates on both sides are removed to relieve the force generated by the volume expansion in the longitudinal direction during the product molding process, thereby facilitating demoulding.

[0018] 2) The utility model is provided with sealing strips on the lower mold and the sealing plates on both sides to prevent the glue from flowing out during glue injection and achieve a sealing effect.

[0019] 3) The utility model is provided with threaded holes and pin holes on the upper and lower molds respectively, which ensure positioning and fix the connection at the same time.

[0020] 4) The sealing ring of the utility model adopts an oblique overlap method, and silicone rubber is applied at the overlap to effectively reduce the risk of mold leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural diagram of the present utility model.

[0022] Figure 2Schematic diagram of the structure of the lower mold;

[0023] Figure 3 It is the side view of the lower die;

[0024] Figure 4 Schematic diagram of the structure of the upper die;

[0025] Figure 5 Schematic diagram of the structure of the plugging plate;

[0026] Figure 6 Schematic diagram of the structure of the sealing ring.

[0027] Marking instructions: 1. Lower mold; 2: Upper mold; 3: Sealing plate; 4: Threaded hole; 5: Mold cavity; 6: Pin hole; 7: Sealing groove 1; 8: Protrusion; 9: Through hole; 10: Sealing groove 2. DETAILED DESCRIPTION

[0028] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or internal communication between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0029] 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 embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0030] like Figures 1-4 As shown, this embodiment is a strip-shaped RTM resin transfer heating molding mold, comprising a lower mold 1, an upper mold 2, and left and right blocking plates 3, forming a rectangular mold formed by the left and right blocking plates and the upper and lower molds. A mold cavity 5 is provided on the upper surface of the lower mold 1 in the extension direction, and two blocking plates 3 are screwed to both sides of the lower mold 1. A fiber preform is placed in the mold cavity, and sealing strips are provided in the strip-shaped sealing grooves 7 on both sides of the mold cavity 5. A strip-shaped protrusion 8 protrudes from the lower surface of the upper mold 2, and the strip-shaped protrusion 8 covers the mold cavity 5. The upper and lower molds are connected by screws, and resin is injected into the mold cavity through the injection hole, and the resin is cured by heating.

[0031] As an implementation method in this embodiment, the inner surfaces of the two blocking plates 3 are provided with a circular sealing groove 2 10, and a sealing ring is provided in the sealing groove 2 10, which is sealed with the lower mold 1 and the upper mold 2 through the sealing ring. The sealing ring is overlapped and the overlap is bonded by silicone rubber, such as Figure 5 and Figure 6 shown.

[0032] As an implementation method in this embodiment, the lower mold 1 is further provided with a pin hole 6 for positioning.

[0033] As an implementation method in this embodiment, the mold body material is 45# steel material, with a length of 2100-2300mm, a width of 230-250mm, and a height of 140-160mm. On the basis of the traditional upper and lower molds, the length direction is opened up, and a sealing plate combined with M10 bolts is used for sealing. A sealing groove with a width of 5mm and a depth of 3mm is added to the lower mold and the sealing plates at both ends, and a Ø5.5mm silicone rubber sealing strip is installed to solve the mold sealing problem. The above utility model solves the problem of demolding difficulties in the traditional upper and lower mold structure mold.

[0034] The working process of this utility model:

[0035] When assembling the mold, first install a Ø5.5mm sealing ring in the sealing groove of the lower mold and the sealing plate (note: the seal connection part adopts an angled overlap method, and silicone rubber is applied at the overlap), then load the fiber preform into the mold cavity of the lower mold, install the upper mold, insert the positioning pins and tighten the bolts, then install the sealing plates at both ends of the mold, insert the positioning pins and tighten the bolts.

[0036] When demolding, first remove the sealing plates at both ends of the mold, and then remove the upper mold. At this time, the force generated by the expansion of the product in the mold cavity during heating and molding is completely eliminated. By prying the upper surface and two end faces of the product in the length direction, it can be easily demolded.

[0037] Many specific details are set forth in the above description to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed above.

[0038] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A strip RTM resin transfer heating molding mold, characterized in that: It comprises a rectangular mold body consisting of a lower mold (1), an upper mold (2) and blocking plates (3) arranged on both sides; A mold cavity (5) is provided on the upper surface of the lower mold (1) in an extension direction, and strip-shaped sealing grooves (7) are provided on both sides of the mold cavity (5), and a sealing strip is provided in the sealing groove (7); a strip-shaped protrusion (8) is provided on the lower surface of the upper mold (2) to match the mold cavity (5), and a circular sealing groove (10) is provided on the inner surface of the two blocking plates (3), and a sealing ring is provided in the sealing groove (10), which is sealed with the lower mold (1) and the upper mold (2) through the sealing ring.

2. The strip-shaped RTM resin transfer heating molding mold according to claim 1, characterized in that: The sealing rings are overlapped at an oblique angle, and the overlapped portions are bonded by silicone rubber.

3. A strip-shaped RTM resin transfer heating molding die according to claim 1 or 2, characterized in that: The lower die (1) and the upper die (2) are connected via screws.

4. The strip-shaped RTM resin transfer heating molding mold according to claim 3, characterized in that: The lower mold (1), the upper mold (2) and the blocking plates (3) on both sides are connected by screws.

5. The strip-shaped RTM resin transfer heating molding mold according to claim 4, characterized in that: The lower die (1) is also provided with a pin hole (6) for positioning.

6. The strip-shaped RTM resin transfer heating molding mold according to claim 5, characterized in that: The mold body is made of 45# steel, with a length of 2100-2300 mm, a width of 230-250 mm, and a height of 140-160 mm.

7. The strip-shaped RTM resin transfer heating molding die according to claim 6, characterized in that: The width of the sealing groove 1 (7) and the sealing groove 2 (10) is 5 mm and the depth is 3 mm.

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