A mold conforming cooling water channel structure with a lattice structure

Abstract

The application discloses a mold core conformal cooling water channel structure with a lattice structure, characterized in that the conformal water channel structure comprises a double-helix water channel structure and a lattice structure. The double-helix structure is used for cooling the side wall of the mold core, and a runway-shaped cross section is adopted; the top of the mold core adopts the lattice structure, and a cylindrical hole is arranged in the center of the mold core. Cooling water enters from two water inlets of the double-helix water channel, and flows out from the cylindrical hole after passing through the lattice structure. The lattice structure is formed by a unit cell array with a large porosity; the interfaces between the double-helix water channel and the lattice region are water inlets, and the included angle between the water flow emission angle and the horizontal angle is 30°. In order to facilitate powder cleaning and cooling water outflow, an inclined surface is arranged below the lattice region, the included angle between the inclined surface and the horizontal plane is 20°-30°, and the cylindrical hole simultaneously serves as a powder cleaning channel and a cooling water outlet.

Description

Technical Field

[0001] This invention relates to the field of mold design, and in particular to a mold conformal cooling water channel structure with a lattice structure. Background Technology

[0002] Precision molded plastic parts require higher precision and quality than those produced by general molds. The cooling system significantly impacts the quality of these molded parts; therefore, a suitable cooling system can yield higher-quality parts. Currently, most conformal cooling channels have regular cross-sections. While this allows for uniform cooling of most of the core, uneven cooling occurs in areas where channels cannot be placed or are inconvenient to install. This leads to significant temperature differences in these areas during cooling, potentially causing warping and deformation of the plastic part. Furthermore, these areas cool more slowly than other parts, prolonging the overall molding cycle and reducing efficiency. Therefore, modifying the cooling channel structure is crucial for improving the cooling efficiency of precision molds and the quality of the molded parts.

[0003] With societal development, people have higher requirements for the quality and appearance of plastic parts. For tall, narrow parts—plastic parts whose height is several times greater than their width, such as the caps of spray cosmetics—the double-helix water channel structure can effectively cool the outer wall. Its racetrack-shaped cross-section provides a large heat exchange area on the sides, allowing for uniform and rapid cooling of the core's sides. However, this can lead to localized areas of excessively high temperature at the top. 3D printing technology allows for more diverse conformal water channel structures to meet the requirements of high-quality plastic parts. A lattice structure is a structure composed of an array of unit cells, where each unit cell is composed of multiple columnar support rods. It can be placed in areas where water channels cannot be or are inconvenient to install, or at the top of the core where uneven cooling may occur. This structure increases the disturbance to the cooling medium while simultaneously increasing the heat exchange area of ​​the coolant, improving the mold's cooling effect. Furthermore, the lattice structure has sufficient structural strength to ensure the mold's lifespan, and it also achieves lightweighting, saving materials and improving printing efficiency. Furthermore, the powder remaining in the cavity after 3D printing also needs to be removed. This invention designs a structure for convenient powder removal, with the lower part of the lattice region designed as a sloping structure and a circular hole at the center. During powder removal, the two water inlets of the double-helix water channel structure blow air, while the powder removal hole draws in air, thus removing the powder. Simultaneously, the cylindrical hole can serve as a water outlet; in use, water enters through the double-helix water channel structure and exits through the cylindrical hole, improving cooling efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a mold conformal cooling channel structure with a lattice structure. In areas where local cooling channels cannot be arranged or are inconvenient to arrange, or in locations where uneven cooling may occur, such as the top of the core, a lattice structure replaces the traditional channels. This structure increases disturbance, enlarges the heat exchange area of ​​the coolant, and improves the cooling effect of the mold. Simultaneously, it possesses sufficient strength to ensure the mold's service life. Furthermore, the lattice structure is also a method for achieving lightweighting in additive manufacturing, reducing core weight, saving material, and improving printing efficiency. The core sides utilize traditional double-helix conformal cooling channels, which can uniformly cool the sides of the core. In addition, a conformal cooling channel structure with a lattice structure is designed, with the lower part of the lattice area designed as a sloping structure and a cylindrical hole at the center. During powder removal, the two water inlets of the double-helix channel structure blow air, while the cylindrical hole draws air in, effectively removing powder. Simultaneously, the cylindrical hole can also serve as a water outlet; during use, water enters through the double-helix channel structure and exits through the cylindrical hole, improving cooling efficiency.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A mold conformal cooling channel structure with a lattice structure is characterized by comprising a lattice structure, a double-helix channel structure, and a structure for easy powder cleaning. The double-helix channel structure is used to cool the sidewalls of the core; the top of the core adopts a lattice structure, and a cylindrical hole is provided at the center of the core. Cooling water enters from the two inlets of the double-helix channel, flows out from the cylindrical hole after passing through the lattice structure.

[0007] In the preferred embodiment, the double helix structure is used to cool the side of the core, and the distance from the helix to the cavity surface should be equal to ensure uniform cooling.

[0008] In a further preferred embodiment, the cooling water channel of the double helix structure has a racetrack-shaped cross-section. The racetrack-shaped cross-section has a large side heat exchange area, which can enhance the cooling effect of the core wall.

[0009] In a preferred embodiment, the lattice structure is formed by filling a unit cell array with a large porosity to form a lattice region, and the unit cells are connected by columnar support rods.

[0010] In an optional configuration, the support rod of the unit cell with higher porosity can be either straight or arc-shaped.

[0011] In the preferred embodiment, the rod diameter of the unit cell should not exceed 1 / 4 of the side length of the unit cell to ensure sufficient clearance for water flow.

[0012] In the preferred embodiment, the height of the lattice region is 2-3 times the diameter of the equivalent circular cross-section of the double-helix water channel.

[0013] In the preferred embodiment, the structure for easy powder cleaning is designed with a sloping structure below the lattice region. Typically, the angle of repose of metal powder used in 3D printing is around 30°. Considering that the two inlets of the double helix water channel structure blow air and the cylindrical hole draws air during powder cleaning, the angle between the sloping surface and the horizontal plane is 20°-30°, which can remove the powder during cleaning.

[0014] In the preferred embodiment, the interface between the double helix water channel structure and the lattice region is the water inlet, and the angle between the water jet angle and the horizontal angle is 30° to make the water jet speed larger. At the same time, the cylindrical hole serves as the water outlet, and the inclined structure can further facilitate the water flow.

[0015] In a preferred embodiment, the diameter of the cylindrical hole is 1.5 to 2 times the diameter of the equivalent cross-section of the racetrack-shaped section.

[0016] In the preferred embodiment, the double helix waterway structure and the lattice structure waterway need to be fabricated using SLM 3D printing technology.

[0017] Compared with existing technologies, the beneficial effects of this invention are as follows: Compared with other cooling channel structure designs, the cooling channel of this invention can not only cool the sides of the core, but also enhance the cooling of the top of the core, so as to achieve uniform cooling of the entire core, prevent micro-cracks caused by uneven local cooling, and shorten the cooling cycle; the lattice structure has a certain structural strength, which can ensure the service life of the mold; using a lattice structure instead of a solid structure can reduce the use of materials, which can not only save costs, but also reduce printing time. In addition, setting the bottom of the lattice area as a sloping structure and adding powder removal holes can more easily remove residual powder in the cavity, preventing water channel blockage caused by powder residue during later use. At the same time, the cylindrical hole can also serve as a water outlet, and the sloping surface can further facilitate water flow. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the metal 3D printed mold core in the embodiment.

[0019] Figure 2 This is a schematic diagram of a double helix waterway structure.

[0020] Figure 3 This is a partial sectional view of the top of the core.

[0021] Figure 4 This is a schematic diagram of the crystal lattice structure.

[0022] Figure 5 for Figure 4 The diagram shows a unit cell structure with straight support rods.

[0023] Figure 6 for Figure 4The diagram shows a unit cell structure with a circular arc as the support rod.

[0024] Figure label:

[0025] In the figure, 1 is a metal 3D printing mold, 2 is a double helix water channel, 3 is a lattice structure, 4 and 5 are the two inlets of the double helix water channel structure, 6 is the region of the lattice structure, 7 is a cylindrical hole, 8 is a racetrack-shaped cross section, and 9 and 10 are the interface between the double helix water channel structure and the lattice structure. Detailed Implementation

[0026] The technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0027] The following is in conjunction with the appendix Figure 1-4 The invention will be further described with reference to specific examples.

[0028] In this embodiment, the core of a spray cosmetic cap is used, such as... Figure 1 As shown, this embodiment of the invention discloses a conformal cooling water channel structure for a mold core, including a double-helix water channel 2, a lattice structure 3, and a circular hole 7 disposed on the mold core 1. L is the side length of the unit cell, D is the diameter of the unit cell rod, H is the height of the lattice region, α is the angle between the inclined plane and the horizontal plane, and β is the angle between the angle of water jetting and the horizontal plane.

[0029] The following provides further explanation of the above embodiments:

[0030] In this embodiment, a lattice structure 3 is used instead of a cooling water pipe and is placed on top of the metal 3D printing mold core 1 to replace the cooling water pipe.

[0031] Furthermore, such as Figure 2 As shown, the double-helix water channel 2 is a double-helix structure. The interfaces 9 and 10 of the double-helix water channel structure and the lattice structure are symmetrically distributed at 180 degrees to ensure that the cooling water can fill the lattice structure region. The distance from the central spiral line of the spiral water channel to the cavity should be equal to ensure uniform cooling.

[0032] Furthermore, when the cooling water is ejected from the inlets 4 and 5 of the portion where the conformal cooling water channel 2 connects to the crystal structure, the angle between the water flow direction and the horizontal plane is 30° to ensure a large velocity.

[0033] Furthermore, the cross-section of the conformal cooling channel 2 is racetrack-shaped. Compared to a circular cross-section, the racetrack-shaped cross-section has a larger lateral area, which can enhance the cooling of the sides.

[0034] Furthermore, the cell rod diameter D should not exceed 1 / 4 of the cell side length L to ensure that the lattice structure 3 has sufficient gaps so that cooling water with a sufficient flow rate can pass smoothly through the gaps in the lattice structure 3 to achieve sufficient cooling, while preventing clogging when used due to insufficient porosity.

[0035] Furthermore, the rod diameter type of the unit cell structure can be linear or circular.

[0036] Furthermore, the height of the lattice region is 2-3 times the diameter of the equivalent circular cross-section of the double-helix water channel to ensure the cooling effect.

[0037] Furthermore, a sloping structure is formed below the lattice region, with an angle of 20°-30° to the horizontal plane, to facilitate powder cleaning and the outflow of cooling water.

[0038] Furthermore, a cylindrical hole 7 is provided in the center of the inclined surface. During powder removal, the two inlets 4 and 5 of the double-helix structure cooling water channel 2 blow air, and the cylindrical hole 7 draws in air, which can remove the powder. The cylindrical hole 7 serves as the water outlet during subsequent cooling, and together with the inclined surface, it can better facilitate the water flow.

[0039] Furthermore, the mold core conformal cooling channel structure is realized using SLM 3D printing technology.

[0040] Compared with existing technologies, the beneficial effects of this invention are as follows: Compared with other cooling channel structure designs, the cooling channel of this invention can not only cool the sides of the core, but also enhance the cooling of the top of the core, so as to achieve uniform cooling of the entire core, prevent micro-cracks caused by uneven local cooling, and shorten the cooling cycle; the lattice structure has a certain structural strength, which can ensure the service life of the mold core; in addition, using a lattice structure instead of a solid structure can reduce the use of materials, which can not only save costs, but also reduce printing time.

[0041] The implementation method of this invention first designs a core, then designs a double-helix conformal cooling water channel to ensure that the distance from the center line of the water channel to the side is equal, then selects a part of the top area of ​​the core and fills it with a cell array to form a lattice structure, then exports the model as an STL format to the process data software for setting printing parameters, and finally imports the printing data into the SLM 3D printing equipment for printing.

[0042] After printing is completed, the 3D printed mold core 1 needs to be cut off from the printing substrate using a wire cutting device. Then, it needs to be cleaned, heat treated, and sandblasted before it can be put into use.

[0043] The embodiments of the present invention are not limited to the limitations of the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A mold core conformal cooling water channel structure with a lattice structure, characterized in that: The conformal water channel structure includes a double-helix water channel structure and a lattice structure. The double-helix water channel structure is used to cool the sidewalls of the core. The top of the core adopts the lattice structure, which is composed of a unit cell array. A cylindrical hole is set in the center of the core. The area below the lattice structure is designed with a sloping structure. The angle between the sloping structure and the horizontal plane is 20°-30°. The cylindrical hole serves as both a powder cleaning channel and a cooling water outlet. The interface between the areas of the double-helix water channel structure and the lattice structure are both water inlets. The angle of water jetting out is 30° with the horizontal plane. Cooling water enters from the two water inlets of the double-helix water channel, passes through the lattice structure, and flows out from the cylindrical hole.

2. The conformal cooling water channel structure of a mold core with a lattice structure as described in claim 1, characterized in that: The distance from the center of the cooling water pipe in the double helix water channel structure to the cavity wall is equal.

3. The conformal cooling water channel structure of a mold core with a lattice structure as described in claim 1, characterized in that: The cross-section of the double helix waterway structure is racetrack shaped.

4. The conformal cooling water channel structure of a mold core with a lattice structure as described in claim 1, characterized in that: The lattice structure is used to cool the upper portion of the core.

5. The conformal cooling water channel structure of a mold core with a lattice structure as described in claim 4, characterized in that: The unit cell is composed of multiple columnar support rods.

6. The conformal cooling water channel structure of a mold core with a lattice structure as described in claim 3, characterized in that: The region height of the lattice structure is 2-3 times the diameter of the equivalent circular cross-section of the racetrack-shaped section.

7. The conformal cooling water channel structure of a mold core with a lattice structure as described in claim 5, characterized in that: The diameter of the support rod does not exceed 1 / 4 of the side length of the unit cell, ensuring sufficient gaps for water to flow out.

8. The conformal cooling water channel structure of a mold core with a lattice structure as described in claim 5, characterized in that: The side length of the unit cell is less than the height of the region of the lattice structure.

9. The conformal cooling water channel structure of a mold core with a lattice structure as described in claim 3, characterized in that: The diameter of the cylindrical hole is 1.5-2 times the diameter of the equivalent cross-section of the racetrack-shaped section.

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