Mold exhaust nail based on bionic loofah sponge structure and preparation method of mold exhaust nail

Abstract

The invention discloses a mold exhaust nail based on a bionic loofah sponge structure and a preparation method thereof, and the mold exhaust nail comprises an insert nail which is tubular and is used for embedding and penetrating through a mold; the inner core is embedded in the opening position of the insert nail, the inner core is of a three-dimensional interconnected multi-stage pore structure and is arranged in a loofah sponge shape, pores in the inner core comprise a main channel and a secondary channel, the pore diameter of the main channel ranges from 0.5 mm to 3 mm, and the pore diameter of the secondary channel ranges from 10 [mu] m to 200 [mu] m; and the baffle ring is arranged in the inlaying nail and is used for supporting the inner core. The invention has the following advantages and effects: by arranging the inner core with the loofah sponge structure, the characteristics of light weight, high specific surface area and strong permeability are achieved, the interwoven network shape can efficiently transmit load and promote gas exchange, the problems of uneven heat dissipation, stress concentration and easy blockage are avoided, and meanwhile, the mechanical strength and the air-permeable and glue-leakage-free performance are considered.

Description

Technical Field

[0001] This invention relates to the field of molds, and in particular to a mold venting nail based on a biomimetic loofah structure and its preparation method. Background Technology

[0002] Mold venting pins are special components used to solve the problem of air venting from inside molds. In molding processes such as injection molding and die casting, when molten material is injected into the mold cavity, the air inside the cavity needs to be vented in time. Otherwise, it will lead to problems such as air bubbles, insufficient filling or surface defects in the product. Mold venting pins help solve these problems by providing additional venting paths.

[0003] Traditional mold venting pins are mostly simple single-hole structures, which suffer from problems such as heavy weight, uneven heat dissipation, stress concentration, and easy clogging. Although conventional multi-hole mold venting pin structures (such as honeycomb structures) can reduce weight, the uniform pore distribution makes it difficult to balance mechanical strength and breathability without glue leakage, and therefore needs improvement. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a mold exhaust nail based on a biomimetic loofah structure, which has the effect of efficiently transferring loads and promoting gas exchange.

[0005] The above-mentioned technical objective of this invention is achieved through the following technical solution: a mold venting nail based on a biomimetic loofah structure, comprising: The studs are tubular in shape and are used for embedding and penetrating molds; The inner core is embedded in the opening of the insert. The inner core is a three-dimensional interconnected multi-level porous structure and is arranged in a loofah-like shape. The pores inside the inner core include main channels and secondary channels, wherein the pore diameter of the main channel is 0.5mm-3mm and the pore diameter of the secondary channel is 10μm-200μm. A retaining ring is disposed inside the insert and is used to support the inner core.

[0006] In a preferred embodiment, the present invention can be further configured such that the porosity inside the core is gradient-distributed and decreases from bottom to top, wherein the porosity at the head of the core is 50%-70% and the porosity at the tail is 80%-90%.

[0007] In a preferred embodiment, the present invention may be further configured such that the outer wall of the inner core is provided with a fiber layer, wherein the fiber layer is a carbon fiber, ceramic fiber, or nanoscale metal structure layer.

[0008] In a preferred embodiment, the present invention may be further configured such that the pores inside the core are filled with a phase change material.

[0009] In a preferred embodiment, the invention may be further configured such that the outer wall of the insert is provided with a wear-resistant coating.

[0010] In a preferred embodiment, the present invention can be further configured such that: the insert includes a thick pipe section, a thin pipe section, and a connecting pipe section, wherein the inner diameter and outer diameter of the thick pipe section are both larger than the inner diameter and outer diameter of the thin pipe section, the inner core is located inside the thick pipe, and the connecting pipe section is disposed between the thick pipe section and the thin pipe section and is configured in a constricted shape.

[0011] In a preferred embodiment, the present invention can be further configured such that the lower end of the thin tube segment has a constricted outer wall.

[0012] Another objective of this invention is to provide a method for preparing a mold exhaust nail based on a biomimetic loofah structure, which has the effect of facilitating production and processing.

[0013] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a method for preparing a mold venting nail based on a biomimetic loofah structure, comprising the following steps: S1, setting fabrication, using the lost-wax casting method to achieve the setting process, and then coating or electroplating a wear-resistant coating on the outer wall of the setting; S2, the inner core is made using 3D printing technology, using 316L stainless steel powder, and the inner core with a porous gradient structure is laser printed using SLM technology. S3, inner core processing, a fiber layer is deposited on the porous surface of the outer wall of the inner core, wherein the thickness of the fiber layer is 50μm; S4, heat treatment: the inner core is placed in a heating furnace and heated to 490°C. The temperature is then kept constant for 2 hours, and then it is taken out and air-cooled. S5, Polishing process: Place the inner core in a magnetic polishing machine and polish for 3 minutes. S6, Assembly and processing, using a hydraulic press or hammer to press the inner core into the insert; S7, Filling process: The insert is degassed and the end of the insert is inserted into the phase change material filler to achieve the suction of the filler, so that the filler is attached to the pores of the inner core. Then the insert is heated at a low temperature of 40°C for 10 minutes to remove the excess filler.

[0014] In summary, the present invention has the following beneficial effects: 1. By setting the inner core in the shape of a loofah sponge, it has the characteristics of light weight, high specific surface area and strong permeability. Its interwoven network can efficiently transfer load and promote gas exchange, avoiding problems such as uneven heat dissipation, stress concentration and easy blockage, while taking into account mechanical strength and breathability without glue leakage. 2. By setting the pores inside the core to a gradient shape, it is possible to adapt to the temperature and mechanical requirements of different areas of the mold, thereby reducing the risk of thermal deformation; 3. By setting a fiber layer on the outer wall of the inner core, the tensile strength and fatigue resistance are improved. At the same time, the pores of the inner core are filled with phase change material filler, and the mold temperature is regulated by heat absorption and heat release. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of Example 1; Figure 2 This is a schematic diagram of the internal structure of Example 1; Figure 3 This is a schematic diagram of the inner core of Example 1.

[0016] Reference numerals: 1. Insert; 11. Thick pipe section; 12. Thin pipe section; 13. Connecting pipe section; 2. Inner core; 3. Retaining ring; 4. Wear-resistant coating; 5. Fiber layer; 6. Filler. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings.

[0018] Example 1: like Figure 1 , Figure 2 As shown, a mold exhaust nail based on a biomimetic loofah structure includes a nail 1, an inner core 2, and a retaining ring 3.

[0019] like Figure 2 , Figure 3 As shown, the insert 1 is tubular and is used for embedding and penetrating the mold. The outer wall of the insert 1 is provided with a wear-resistant coating 4, which is CrN or DLC, to improve corrosion resistance and service life.

[0020] like Figure 2 , Figure 3 As shown, the insert 1 includes a thicker pipe section 11, a thinner pipe section 12, and a connecting pipe section 13. The lower end of the thinner pipe section 12 has a constricted outer wall to facilitate insertion of the insert 1 into the hole of the mold. The inner and outer diameters of the thicker pipe section 11 are both larger than those of the thinner pipe section 12. The connecting pipe section 13 is located between the thicker pipe section 11 and the thinner pipe section 12 and is also constricted.

[0021] Therefore, during the installation of the insert 1, the insert 1 can be inserted into the hole of the mold from the inside out. At this time, under the action of the shape and structure of the connecting pipe section 13, the insert 1 is restricted from continuing to slide outward, thereby realizing the snap-fit ​​fixation of the insert 1 from the inside out. No other fasteners are needed, realizing the automatic installation and fixation of the insert 1. Moreover, the greater the internal pressure, the tighter the insert 1 is snapped, realizing the rapid assembly and rapid application of the insert 1.

[0022] like Figure 2 , Figure 3 As shown, the inner core 2 is located at the opening of the coarse pipe, and the retaining ring 3 is set inside the coarse pipe and is used to support the inner core 2, so as to realize the snap-fit ​​fixation after the inner core 2 is embedded.

[0023] like Figure 2 , Figure 3 As shown, the inner core 2 has a three-dimensional interconnected multi-level porous structure arranged in a loofah-like pattern. The pores inside the inner core 2 include main channels and secondary channels, wherein the pore diameter of the main channels is 0.5mm-3mm, and the pore diameter of the secondary channels is 10μm-200μm.

[0024] like Figure 2 , Figure 3 As shown, the porosity inside the inner core 2 is distributed in a gradient and decreases from bottom to top. The porosity at the head of the inner core 2 is 50%-70%, and the porosity at the tail is 80%-90%, in order to match the heat dissipation requirements of different areas of the mold.

[0025] like Figure 2 , Figure 3 As shown, the outer wall of the inner core 2 is provided with a fiber layer 5, which is a carbon fiber, ceramic fiber, or nanoscale metal structure layer, to improve tensile strength and fatigue resistance. The pores inside the inner core 2 are filled with a phase change material filler 6, which is a silica composite material, and can regulate the mold temperature by absorbing and releasing heat.

[0026] Therefore, by setting the inner core 2 in the shape of a loofah sponge, it has the characteristics of light weight, high specific surface area and strong permeability. Its interwoven network can efficiently transfer load and promote gas exchange, avoiding problems such as uneven heat dissipation, stress concentration and easy blockage, while taking into account mechanical strength and breathability without glue leakage performance.

[0027] Example 2: A method for preparing a mold venting nail based on a biomimetic loofah sponge structure, characterized by the following steps: S1, the nail 1 is made by casting the nail 1 using the lost-wax casting method, and then the outer wall of the nail 1 is coated or electroplated with a wear-resistant coating 4.

[0028] S2, the inner core 2, is made using 3D printing technology, using 316L stainless steel powder, and the inner core 2 with a porous gradient structure is laser printed using SLM technology.

[0029] S3, inner core 2 processing, a fiber layer 5 is deposited on the porous surface of the outer wall of the inner core 2 by spraying, wherein the thickness of the fiber layer 5 is 50μm.

[0030] S4, heat treatment: place the inner core 2 in a heating furnace, heat it to 490°C, then keep the temperature constant and hold it for 2 hours, and then take it out for air cooling.

[0031] S5, Polishing treatment: Place the inner core 2 in the magnetic polishing machine and polish for 3 minutes.

[0032] S6, Assembly and processing: Use a hydraulic press or hammer to press the inner core 2 into the insert 1.

[0033] S7, filling process: the insert 1 is degassed and the end of the insert 1 is inserted into the phase change material filler 6 to achieve the suction of the filler 6, so that the filler 6 is attached to the pores of the inner core 2. Then the insert 1 is heated at a low temperature of 40°C for 10 minutes to make the excess filler 6 fall off.

[0034] The specific embodiments are merely illustrative of the present invention and are not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A mold venting nail based on a biomimetic loofah sponge structure, characterized in that: include: The stud (1) is tubular in shape and is used for embedding and penetrating the mold; The inner core (2) is embedded in the opening of the insert (1). The inner core (2) is a three-dimensional interconnected multi-level porous structure and is arranged in a loofah-like shape. The pores inside the inner core (2) include a main channel and a secondary channel. The pore diameter of the main channel is 0.5mm-3mm, and the pore diameter of the secondary channel is 10μm-200μm. A retaining ring (3) is disposed inside the insert (1) and is used to support the inner core (2).

2. The mold venting nail based on a biomimetic loofah structure according to claim 1, characterized in that: The porosity inside the inner core (2) is distributed in a gradient and decreases from bottom to top, wherein the porosity at the head of the inner core (2) is 50%-70% and the porosity at the tail is 80%-90%.

3. The mold venting nail based on a biomimetic loofah structure according to claim 1, characterized in that: The outer wall of the inner core (2) is provided with a fiber layer (5), which is a carbon fiber, ceramic fiber or nanoscale metal structure layer.

4. The mold venting nail based on a biomimetic loofah structure according to claim 1, characterized in that: The pores inside the core (2) are filled with a phase change material filler (6).

5. A mold venting nail based on a biomimetic loofah structure according to claim 1, characterized in that: The outer wall of the insert (1) is provided with a wear-resistant coating (4).

6. A mold venting nail based on a biomimetic loofah structure according to claim 1, characterized in that: The insert (1) includes a thick pipe section (11), a thin pipe section (12) and a connecting pipe section (13). The inner diameter and outer diameter of the thick pipe section (11) are both larger than the inner diameter and outer diameter of the thin pipe section (12). The inner core (2) is located inside the thick pipe. The connecting pipe section (13) is disposed between the thick pipe section (11) and the thin pipe section (12) and is arranged in a constricted shape.

7. A mold venting nail based on a biomimetic loofah structure according to claim 6, characterized in that: The lower end of the thin tube section (12) is designed with a constricted outer wall.

8. A method for preparing a mold venting nail based on a biomimetic loofah sponge structure, characterized in that: Includes the following steps: S1, the nail (1) is made by casting the nail (1) using the lost-wax casting method, and then the outer wall of the nail (1) is coated or electroplated with a wear-resistant coating (4); S2, the inner core (2) is made using 3D printing technology, using 316L stainless steel powder, and the inner core (2) with a porous gradient structure is laser printed using SLM technology. S3, inner core (2) processing, a fiber layer (5) is sprayed onto the pore surface on the outer wall of the inner core (2), wherein the thickness of the fiber layer (5) is 50 μm; S4, heat treatment: place the inner core (2) in a heating furnace, heat it to 490°C, then keep the temperature constant and keep it warm for 2 hours, and then take it out for air cooling; S5, polishing treatment: place the inner core (2) in the magnetic polishing machine and start the polishing treatment for 3 minutes; S6, Assembly and processing: Use a hydraulic press or hammer to press the inner core (2) into the insert (1); S7, filling process, the insert (1) is degassed and the end of the insert (1) is inserted into the phase change material filler (6) to achieve the suction of the filler (6) so that the filler (6) is attached to the pores of the inner core (2). Then the insert (1) is heated at a low temperature of 40°C for 10 minutes to make the excess filler (6) fall off.

Images