Ejector-rod-free mold for SMC glass fiber reinforced plastic porous panel

Abstract

The utility model discloses an SMC (Sheet Molding Compound) glass fiber reinforced plastic porous panel ejector-rod-free mold which comprises an upper pressure part, a lower pressure part, a forming frame and a pull cylinder, the upper pressure part and the lower pressure part are fixedly connected to upper and lower workbenches of the hydraulic machine tool respectively; the forming frame is movably arranged in the lower film, and the outer wall of the forming frame is tightly attached to the inner wall of the lower film. The pull cylinder comprises an outer cylinder and an inner rod, the outer cylinder is connected with the upper pressure component, the inner rod is connected with an outer cylinder movable rod, and one end of the bottom of the inner rod is fixedly connected with the forming frame; an inclined reverse demolding area is arranged on the side, close to the bottom, of the inner wall of the forming frame. According to the design, through the synergistic effect of the reverse demolding area and the pull cylinder, the problems of indentation and deformation caused by direct contact of a traditional ejector rod with the surface of a product are solved, and the product quality is improved.

Description

A mold for SMC fiberglass porous panels without top rods Technical Field

[0001] This utility model belongs to the technical field of sheet molding compound products, specifically a mold for SMC fiberglass multi-hole panels without top rods. Background Technology

[0002] SMC (Sheet Molding Compound) fiberglass porous panels are widely used in automotive parts (such as battery box separators and ventilation covers), architectural decoration (such as soundproof wall panels and translucent ceilings), and electrical equipment (such as electrical distribution cabinet insulation panels) due to their advantages of being lightweight, high-strength, corrosion-resistant, having excellent insulation properties, and simple molding processes. These panels are typically manufactured through compression molding, and the mold structure design directly affects the dimensional accuracy, surface quality, and production efficiency of the finished product. In SMC compression molding, the demolding mechanism is a core component, and its design must balance molding accuracy and demolding reliability. This is especially true for porous panels, where the integrity of the hole structure, the smoothness of the edge transition areas, and the overall deformation control of the panel are key technical challenges.

[0003] Traditional SMC molding dies often employ ejector pin demolding structures, where ejector pins directly act on the back of the product to push the molded panel out of the mold cavity. This demolding method relies on the contact force transmission between the ejector pins and the product, requiring evenly distributed ejector pins and consistent ejection force; otherwise, uneven stress on the product can easily lead to deformation or breakage. For porous panels, the internal porous structure creates hollow areas with relatively weak mechanical strength. If the ejector pins directly act on the thin-walled areas between the holes or the edges of the panel, it can easily cause localized indentations, damage, or tearing, severely affecting the product yield. Furthermore, ejector pin demolding requires a complex ejector pin drive system (such as hydraulic cylinders and return springs) in the mold, which not only increases the difficulty and cost of mold manufacturing but may also cause demolding jamming and decreased accuracy due to frictional wear between the ejector pins and the mold hole walls, thus affecting production efficiency.

[0004] A patent application with application number CN202420304272.X discloses a molding die for SMC (Surface Mounted Molding) air-raid shelter doors with a multi-piece splicing mechanism. While this prior art utilizes a multi-piece splicing structure to optimize mold maintainability, it still employs a traditional multi-ejector mechanism. During use, the straight ejector rods must directly act on the back of the SMC air-raid shelter door. The contact area between the ejector rod end face and the product is small, and the SMC material has a high adhesion force after curing, resulting in concentrated contact stress during ejection. This easily leads to indentations or localized dents on the product surface. Therefore, this type of mold is prone to causing localized indentations, damage, or tearing of the product, affecting product quality. Summary of the Invention

[0005] The purpose of this utility model is to provide a pinless mold for SMC fiberglass porous panels, so as to solve the following technical problems mentioned in the background art:

[0006] In existing technologies, ejector pins are typically used for demolding. These ejector pins act directly on the thin-walled areas between holes or the edges of the panel, which can easily cause localized indentations, damage, or tearing, affecting the quality of the product.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0008] A mold for SMC fiberglass porous panels without top rods includes an upper pressure component, a lower pressure component, a forming frame, and a pull cylinder. The upper and lower pressure components are respectively fixed to the upper and lower worktables of a hydraulic press. The forming frame is movably disposed inside the lower mold, and the outer wall of the forming frame is tightly fitted with the inner wall of the lower mold. The pull cylinder includes an outer cylinder and an inner rod. The outer cylinder is connected to the upper pressure component, and the inner rod is connected to the movable rod of the outer cylinder. One bottom end of the inner rod is fixed to the forming frame. An inclined reverse demolding area is provided on the inner wall of the forming frame near the bottom.

[0009] Furthermore, the upper pressure component includes an upper heating plate and an upper mold. The upper heating plate is fixedly connected to the upper worktable of the hydraulic machine tool, and the upper mold and the upper heating plate are detachably connected.

[0010] Furthermore, the upper mold is made of P20H mold steel and is used to form the upper part of the perforated panel and the main structure of the holes in the perforated panel.

[0011] Furthermore, the lower pressure component includes a lower heating plate and a lower die. The lower heating plate is fixedly connected to the lower worktable of the hydraulic machine tool, while the lower die and the lower heating plate are detachably connected.

[0012] Furthermore, the lower mold is made of P20H mold steel. The lower mold is used to form the lower half of the perforated panel and to round the openings of the holes in the perforated panel.

[0013] Furthermore, a mounting platform is provided on the top of the outer cylinder, through which the outer cylinder is connected to the upper pressure component.

[0014] Furthermore, four pull cylinders are provided. In each pull cylinder, the outer wall of the inner rod is provided with two symmetrical guide protrusions along the axial direction, and the inner wall of the outer cylinder is provided with corresponding guide grooves. The guide protrusions and guide grooves are fitted with a clearance.

[0015] Furthermore, the inclination angle of the reverse demolding area of ​​the molded frame relative to the vertical plane is 3°-7°.

[0016] Furthermore, a wear-resistant layer is provided on the outer surface of the molded frame.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This invention, through the synergistic effect of the reverse demolding zone and the pull cylinder, avoids the indentation and deformation problems caused by direct contact between the ejector pin and the product surface, thus improving product quality. The mechanical linkage between the pull cylinder and the forming frame replaces the complex ejector pin drive system, reducing mold manufacturing costs and simplifying the demolding process. The tight fit between the forming frame and the lower mold, and the inclined design of the reverse demolding zone, ensure the forming accuracy of the porous panel sides and achieve stability in the demolding process through controllable friction. Attached Figure Description

[0019] Figure 1 is a schematic diagram of the overall structure of this utility model;

[0020] Figure 2 is a front view of this utility model;

[0021] Figure 3 is a cross-sectional schematic diagram of this utility model;

[0022] Figure 4 is an enlarged schematic diagram of part A in Figure 3;

[0023] Figure 5 is a schematic diagram of the internal structure of the pull tube of this utility model.

[0024] The markings in the diagram are: 1-perforated panel, 2-lower pressure component, 3-forming frame, 4-upper pressure component, 5-pull cylinder, 6-upper hot plate, 7-upper mold, 8-lower mold, 9-lower hot plate, 10-reverse demolding area, 11-inner rod, 12-limiting component, 13-guide groove, 14-hanging platform, 15-outer cylinder. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] Example:

[0027] A mold for SMC fiberglass porous panels without top rods, as shown in Figure 1, includes an upper pressure component 4, a lower pressure component 2, a forming frame 3, and a pull cylinder 5. The upper pressure component 4 and the lower pressure component 2 are respectively fixed to the upper and lower worktables of a hydraulic press. The forming frame 3 is movably disposed within the lower mold 8, and the outer wall of the forming frame 3 is tightly fitted to the inner wall of the lower mold 8. The pull cylinder 5 includes an outer cylinder 15 and an inner rod 11. The outer cylinder 15 is connected to the upper pressure component 4, and the inner rod 11 is movably connected to the outer cylinder 15. One bottom end of the inner rod 11 is fixed to the forming frame 3. As shown in Figure 4, an inclined reverse demolding area 10 is provided on the inner wall of the forming frame 3 near the bottom. A limiting component 12 is also provided between the inner rod 11 and the outer cylinder 15. The limiting component 12 is used to limit the range of motion of the inner rod 11 and prevent the inner rod 11 from detaching from the outer cylinder 15.

[0028] The molding frame 3 is tightly fitted to the inner wall of the lower mold 8, forming a complete molding cavity. During use, the SMC molding compound is filled into the cavity formed by the upper mold 7, lower mold 8, and molding frame 3. The upper pressure component 4 and lower pressure component 2 heat the mold through an internal heating structure, such as using an electric heating tube. The SMC molding temperature is typically 130-170℃, and the electric heating tube can be heated to 150℃. The molding compound solidifies under high temperature and pressure to form a porous panel 1. After molding, the mold is opened by using a hydraulic press to lift the upper worktable, which moves the upper pressure component 4 upwards, separating it from the lower pressure component 2. Because the reverse demolding area 10 near the bottom of the inner wall of the molding frame 3 is inclined, the friction between the molded porous panel 1 and the inner wall of the molding frame 3 is greater than its adhesion to the upper mold 7. Therefore, the porous panel 1 does not detach with the upper mold 7 but is forcibly retained in the combined structure of the lower mold 8 and molding frame 3. The upper worktable continues to rise, and the pull cylinder 5 pulls the forming frame 3 through the inner rod 11, forcing the forming frame 3 to separate from the lower mold 8 and move upward. During the upward movement of the forming frame 3, the porous panel 1 moves synchronously with it; when the forming frame 3 is completely separated from the lower mold 8, the adhesion between the porous panel 1 and the forming frame 3 is reduced due to the inclined structure of the reverse demolding zone 10. At this time, the porous panel 1 can be separated from the forming frame 3 by manually blowing compressed air or mechanical assistance, thus completing the final demolding.

[0029] In a preferred embodiment, as shown in Figures 1-3, the upper pressure component 4 includes an upper heating plate 6 and an upper mold 7. The upper heating plate 6 is fixedly connected to the upper worktable of the hydraulic press, and the upper mold 7 is detachably connected to the upper heating plate 6. Further optimized, the upper mold 7 is made of P20H mold steel and is used to form the upper half of the porous panel 1 and the main structure of the holes in the porous panel 1. The upper heating plate 6, fixedly connected to the upper worktable of the hydraulic press, provides stable support and pressure transmission; the detachable connection of the upper mold 7 facilitates maintenance and replacement. P20H mold steel has high strength and good wear resistance, ensuring that the upper mold 7 does not deform during high-temperature and high-pressure forming, accurately forming the upper half of the porous panel 1 and the main structure of the holes, ensuring the dimensional accuracy and surface quality of the product.

[0030] In a preferred embodiment, as shown in Figures 1-3, the lower pressure component 2 includes a lower heating plate 9 and a lower mold 8. The lower heating plate 9 is fixedly connected to the lower worktable of the hydraulic press, and the lower mold 8 is detachably connected to the lower heating plate 9. Further optimized, the lower mold 8 is made of P20H mold steel. The lower mold 8 is used to form the lower half of the porous panel 1 and to round the openings of the holes in the porous panel 1. The lower heating plate 9 is fixedly connected to the lower worktable of the hydraulic press, providing stable support and pressure transmission; the detachable connection of the lower mold 8 facilitates maintenance and replacement. P20H mold steel has high strength and excellent wear resistance, ensuring that the lower mold 8 maintains precision during high-temperature and high-pressure forming, accurately forming the lower half of the porous panel 1 and the rounded corners of the holes, improving the structural strength and surface smoothness of the product.

[0031] In a preferred embodiment, as shown in Figures 1-3, a mounting platform 14 is provided on the top of the outer cylinder 15, and the outer cylinder 15 is connected to the upper pressure component 4 through the mounting platform 14. When the upper worktable of the hydraulic press is lifted, the outer cylinder 15 moves upward with the upper pressure component 4, generating tension, which is transmitted to the forming frame 3 through the inner rod 11, causing it to separate from the lower mold 8, achieving demolding without ejector pins and ensuring a stable and reliable process.

[0032] In a preferred embodiment, as shown in Figure 5, four pull cylinders 5 are provided. The outer wall of the inner rod 11 of each pull cylinder 5 has two symmetrical guide protrusions along the axial direction, and the inner wall of the outer cylinder 15 has corresponding guide grooves 13. The guide protrusions and guide grooves 13 are fitted with a clearance fit. The four pull cylinders 5 evenly distribute the pulling force, preventing uneven force distribution on the forming frame 3. The cooperation between the guide protrusions and grooves restricts the circumferential rotation of the inner rod 11, ensuring linear motion accuracy and stable force transmission during demolding, preventing deviation or jamming.

[0033] In a preferred embodiment, the inclination angle of the reverse demolding area 10 of the molded frame 3 relative to the vertical plane is 3°-7°. In this embodiment, 3°, 4°, 5°, 6°, and 7° are optional. The inclination angle balances the friction between the porous panel 1 and the molded frame 3: when the mold is opened, the panel remains in the lower mold 8 due to sufficient friction; when demolding, the pulling force of the pull cylinder 5 can overcome the friction, avoiding excessive angle that would cause demolding difficulties, and ensuring smooth demolding.

[0034] In a preferred embodiment, a wear-resistant layer is provided on the outer surface of the molding frame 3. The wear-resistant layer on the outer surface of the molding frame 3 can reduce frictional wear with the inner wall of the lower mold 8, improve the service life of the component, ensure long-term fitting accuracy, prevent SMC material from overflowing due to wear gaps during the molding process, and ensure stable molding quality.

[0035] In the description of this utility model, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "other end", "upper", "side", "top", "inner", "front", "center", "both ends", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0036] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0037] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A mold for SMC fiberglass porous panels without ejector pins, characterized in that: It includes an upper pressure component (4), a lower pressure component (2), a forming frame (3), and a pull cylinder (5); the upper pressure component (4) and the lower pressure component (2) are respectively fixed to the upper and lower worktables of the hydraulic machine tool; the forming frame (3) is movably set in the lower mold (8) and the outer wall of the forming frame (3) is tightly fitted with the inner wall of the lower mold (8); the pull cylinder (5) includes an outer cylinder (15) and an inner rod (11), the outer cylinder (15) is connected to the upper pressure component (4), the inner rod (11) is movably connected to the outer cylinder (15), and one bottom end of the inner rod (11) is fixed to the forming frame (3); an inclined reverse demolding area (10) is provided on the side of the inner wall of the forming frame (3) near the bottom.

2. The SMC fiberglass multi-hole panel mold without ejector pin according to claim 1, characterized in that: The upper pressure component (4) includes an upper heating plate (6) and an upper mold (7). The upper heating plate (6) is fixedly connected to the upper worktable of the hydraulic machine tool, and the upper mold (7) and the upper heating plate (6) are detachably connected.

3. The SMC fiberglass multi-hole panel mold without top pin according to claim 2, characterized in that: The upper mold (7) is made of P20H mold steel. The upper mold (7) is used to form the upper part of the perforated panel (1) and the main structure of the holes of the perforated panel (1).

4. The SMC fiberglass multi-hole panel mold without ejector pin according to claim 1, characterized in that: The lower pressure component (2) includes a lower heating plate (9) and a lower mold (8). The lower heating plate (9) is fixedly connected to the lower worktable of the hydraulic machine tool, and the lower mold (8) and the lower heating plate (9) are detachably connected.

5. The SMC fiberglass multi-hole panel mold without top pin according to claim 4, characterized in that: The lower mold (8) is made of P20H mold steel. The lower mold (8) is used to form the lower half of the perforated panel (1) and to round the opening of the holes in the perforated panel (1).

6. The SMC fiberglass multi-hole panel mold without ejector pin according to claim 1, characterized in that: The top of the outer cylinder (15) is provided with a hanging platform (14), and the outer cylinder (15) is connected to the upper pressure component (4) through the hanging platform (14).

7. The SMC fiberglass multi-hole panel mold without ejector pin according to claim 1, characterized in that: There are four pull cylinders (5). In the pull cylinder (5), the outer wall of the inner rod (11) is provided with two symmetrical guide protrusions along the axial direction, and the inner wall of the outer cylinder (15) is provided with corresponding guide grooves (13). The guide protrusions and guide grooves (13) are fitted with a clearance.

8. The SMC fiberglass multi-hole panel mold without ejector pin according to claim 1, characterized in that: The angle of inclination of the reverse demolding area (10) of the molding frame (3) relative to the vertical plane is 3°-7°.

9. The SMC fiberglass multi-hole panel mold without ejector pin according to claim 1, characterized in that: The outer surface of the molded frame (3) is provided with a wear-resistant layer.

Images