A composite core for a plastic mold

Abstract

The utility model relates to the core technical field, especially guide positioning's plastic mould composite core, including body, high temperature resistance layer and the protection layer between body and high temperature resistance layer, be provided with guide positioning structure on the body, the high temperature resistance layer is gradient coating structure, the gradient coating structure reduces gradually in the direction away from the protection layer's thermal conductivity. The core of this application is high in positioning precision, and the high temperature resistance performance is excellent.

Description

Technical Field

[0001] This utility model relates to the field of core technology, and in particular to a guide and positioning composite core for plastic molds. Background Technology

[0002] A core is a prefabricated component used in the casting process to form the internal cavity or complex structure of a casting. In processes such as investment casting and sand casting, the core works in conjunction with the mold to form the complete cavity of the casting.

[0003] Traditional cores are typically made of resin sand or ordinary ceramics, which have low bending strength and are easily deformed or broken by mold pressure during mold closing. Furthermore, the core is subjected to instantaneous impact during high-speed mold closing; if not securely fixed, micro-displacement can occur, and temperature changes during the casting process can easily cause instability in the core's dimensions. All of these factors can affect the quality of the casting. Utility Model Content

[0004] To address the problems mentioned above, this invention provides a guide-positioning composite core for plastic molds, which has high positioning accuracy, good high-temperature resistance, and long service life.

[0005] The solution adopted by this utility model to solve its technical problem is: a plastic mold composite core for guiding and positioning, including a body, a high-temperature resistant layer, and a protective layer located between the body and the high-temperature resistant layer. The body is provided with a guiding and positioning structure; the high-temperature resistant layer is a gradient coating structure, and the thermal conductivity of the gradient coating structure gradually decreases in the direction away from the protective layer.

[0006] Furthermore, the guiding and positioning structure includes trapezoidal dovetail grooves symmetrically arranged on both sides of the body, and an annular guide groove located at the top of the body.

[0007] Furthermore, a wave spring sheet is embedded at the bottom of the annular guide groove.

[0008] Furthermore, the gradient coating structure includes an adhesive layer, a composite coating, and an isolation layer arranged sequentially outwards, with the adhesive layer attached to the outside of the protective layer.

[0009] Furthermore, the adhesive layer, composite coating, and isolation layer are respectively made of FeCrAlY, Al2O3-SiO2, and CSZ materials.

[0010] Furthermore, a cooling channel is provided inside the main body, and a sintered heat pipe is provided inside the cooling channel. Thermally conductive silicone grease is filled between the cooling channel and the sintered heat pipe.

[0011] Furthermore, the protective layer comprises phenolic resin, wherein boron nitride nanotubes and silicon micropowder are uniformly distributed within the phenolic resin.

[0012] In summary, the beneficial effects of this utility model are as follows:

[0013] 1. This application improves the mold closing positioning accuracy through a guide positioning structure, and optimizes thermal management through a gradient coating structure to enhance high temperature resistance. The two work together to reduce thermal-mechanical fatigue damage to the core, thereby extending its service life.

[0014] 2. The guiding and positioning structure includes a trapezoidal dovetail groove and an annular guide groove. A wave spring is embedded at the bottom of the annular guide groove. The wave spring can absorb the instantaneous impact force of mold closing through compression deformation to prevent core breakage. At the same time, its elastic properties allow the core and mold to undergo micro-scale relative displacement at high temperature, which can alleviate stress concentration caused by the difference in thermal expansion coefficients and reduce the risk of jamming.

[0015] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this embodiment;

[0017] Figure 2 This is a bottom view of this embodiment;

[0018] Figure 3 This is a cross-sectional view of this embodiment.

[0019] In the diagram: 1. Body; 2. Protective layer; 3. High-temperature resistant layer; 4. Trapezoidal dovetail groove; 5. Annular guide groove; 6. Wave spring sheet; 7. Cooling channel; 8. Sintered heat pipe. Detailed Implementation

[0020] To make the content of this utility model easier to understand, the present utility model will be further described below with reference to specific embodiments and accompanying drawings.

[0021] It should be noted that the terms "center," "upper," "lower," "front," "rear," "left," "right," "inner," and "outer" used herein to indicate the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and 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, and therefore should not be construed as a limitation of this utility model. Unless otherwise stated, "a plurality of" means two or more.

[0022] Unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] like Figures 1 to 3 As shown, a plastic mold composite core for guiding and positioning includes a body 1, a high-temperature resistant layer 3, and a protective layer 2 located between the body 1 and the high-temperature resistant layer 3. A guiding and positioning structure is provided on the body 1.

[0024] In this embodiment, the core body 1 is a metal composite material, which includes a metal matrix and ceramic particles uniformly distributed in the metal matrix.

[0025] like Figure 1 As shown, the guiding and positioning structure of this embodiment includes trapezoidal dovetail grooves 4 symmetrically arranged on both sides of the body 1, and an annular guide groove 5 located at the top of the body 1. The annular guide groove 5 is located on the working surface at the top of the core and cooperates with the mold core for positioning. Through the above scheme, the design of both the trapezoidal dovetail grooves 4 and the annular guide groove 5 is beneficial to the positioning of the core.

[0026] like Figure 3 As shown, a wave spring plate 6 is embedded at the bottom of the annular guide groove 5. Specifically, in this embodiment, the wave spring plate 6 is made of beryllium copper alloy, which can compensate for gap changes caused by thermal expansion. The spring plate is completely embedded in the groove and does not protrude from the core surface. Two symmetrical positioning recesses are machined at the bottom of the annular guide groove 5, and these recesses cooperate with the protrusions stamped on the spring plate. In this embodiment, the spring plate only contacts the bottom of the groove, and its top maintains a 0.1-0.2mm gap with the working surface of the guide groove. During mold closing, the mold core presses against the core guide surface, and then the spring plate is compressed, generating elastic force. This elastic force pushes the core back through the bottom of the groove, thereby achieving dynamic compensation.

[0027] Through the above design, the elastic properties of the wave spring sheet 6 allow the core and mold to undergo micro-scale relative displacement at high temperatures, alleviating stress concentration caused by the difference in thermal expansion coefficients, thereby reducing the risk of the core and mold getting stuck.

[0028] In this embodiment, the high-temperature resistant layer 3 is a gradient coating structure, which includes an adhesive layer, a composite coating, and an isolation layer arranged sequentially outwards. The adhesive layer is attached to the outside of the protective layer 2. Specifically, the adhesive layer, composite coating, and isolation layer are FeCrAlY, Al2O3-SiO2, and CSZ materials, respectively, with the thermal conductivity of FeCrAlY, Al2O3-SiO2, and CSZ materials gradually decreasing. Through this scheme, when heat is transferred from the high-temperature side—the isolation layer—to the low-temperature side—the adhesive layer, the decreasing thermal conductivity forms a nonlinear temperature field, causing thermal stress to be evenly distributed within the coating, avoiding spalling caused by stress concentration at the interface, and improving the high-temperature resistance of the core.

[0029] like Figure 2 As shown, a cooling channel 7 is provided inside the main body 1, and a sintered heat pipe 8 is provided inside the cooling channel 7. Thermally conductive silicone grease is filled between the cooling channel 7 and the sintered heat pipe 8. The thermally conductive silicone grease can fill the gap between the cooling channel 7 and the sintered heat pipe 8, prevent the existence of microscopic gaps between the sintered heat pipe 8 and the inner wall of the cooling channel 7, and form an air insulation layer.

[0030] The protective layer 2 in this embodiment includes phenolic resin, within which boron nitride nanotubes and silicon powder are uniformly distributed. The amount of boron nitride nanotubes added is 0.5-1 wt%, and its combination with silicon powder can reduce the manufacturing cost of the protective layer 2 while ensuring its compressive strength and high-temperature resistance.

[0031] The embodiments described above are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and modifications made by those skilled in the art based on this utility model shall fall within the scope of protection of this utility model.

Claims

1. A composite core for guiding and positioning plastic molds, characterized in that, It includes a body (1), a high-temperature resistant layer (3), and a protective layer (2) located between the body (1) and the high-temperature resistant layer (3). The body (1) is provided with a guiding and positioning structure. The high-temperature resistant layer (3) is a gradient coating structure, and the thermal conductivity of the gradient coating structure gradually decreases in the direction away from the protective layer (2).

2. The plastic mold composite core for guiding and positioning according to claim 1, characterized in that, The guiding and positioning structure includes trapezoidal dovetail grooves (4) symmetrically arranged on both sides of the main body (1) and an annular guide groove (5) located at the top of the main body (1).

3. The plastic mold composite core for guiding and positioning according to claim 2, characterized in that, The bottom of the annular guide groove (5) is embedded with a wave spring sheet (6).

4. The plastic mold composite core for guiding and positioning according to claim 1, characterized in that, The gradient coating structure includes an adhesive layer, a composite coating and an isolation layer arranged outwardly in sequence, with the adhesive layer attached to the outside of the protective layer (2).

5. A guide and positioning composite core for plastic molds according to claim 4, characterized in that, The adhesive layer, composite coating, and isolation layer are respectively made of FeCrAlY, Al2O3-SiO2, and CSZ materials.

6. The plastic mold composite core for guiding and positioning according to claim 1, characterized in that, The main body (1) is provided with a cooling channel (7), and a sintered heat pipe (8) is provided in the cooling channel (7). Thermally conductive silicone grease is filled between the cooling channel (7) and the sintered heat pipe (8).

7. A composite core for guiding and positioning plastic molds according to claim 1, characterized in that, The protective layer (2) includes phenolic resin, in which boron nitride nanotubes and silicon micropowder are uniformly distributed.

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