Optical mirror injection molding mold and manufacturing method

Abstract

The invention relates to an optical mirror surface injection molding mold and a manufacturing method in the technical field of injection molding molds, the optical mirror surface injection molding mold comprises a mold body, a molded surface is formed on one side of the mold body, a three-dimensional groove is formed in the other side of the mold body, and the three-dimensional groove is designed in a shape following mode based on the molded surface; the closed water path is arranged in the three-dimensional groove, and a water inlet and a water outlet are formed in the two ends of the closed water path respectively; the water path supporting structure is combined to the side, provided with the closed water path, of the mold body, and the water path supporting structure is formed on the mold body in a 3D printing mode through a 3D printing material. According to the optical mirror surface injection molding mold and the manufacturing method, the injection molding mold has the optical mirror surface, high heat conduction efficiency and high temperature uniformity, and the quality and performance of the injection molding mold are improved.

Description

Technical Field

[0001] This application relates to the technical field of injection molding dies, and particularly to an optical mirror surface injection molding die and a manufacturing method thereof. Background Art

[0002] The water channel system of an injection molding die undertakes the heat conduction function in the injection molding process. Before the melt is injected into the die, the water channel system provides heat to the die, maintains the die at the process required temperature, and ensures the quality of product molding. After the melt is injected into the die, the water channel system quickly conducts out the heat of the high-temperature plastic melt, so that the plastic melt is quickly and uniformly cooled to the demolding temperature and solidified in the die.

[0003] Currently, the water channels of injection molding dies are mostly processed by drilling. Therefore, the water channel structure can only be composed of straight water holes. The distance between the straight water channels and the curved surface of the die is uneven. And when combining straight water holes into a curved water channel, it is necessary to block the water holes at the turning positions to generate stagnant water cavities, which have an adverse impact on the heat conduction efficiency of the die and the temperature uniformity of the die surface. There is also a method of processing 3D grooves by numerical control machining and then assembling them into the whole die by splicing. This method will leak water due to different thermal expansion amounts on both sides of the water channel, and has a short service life due to the die repeatedly experiencing the process of thermal expansion and contraction. In addition, there is also a method of directly forming the die and 3D water channels by 3D printing. However, since it has not undergone repeated purification and forging during the manufacturing of mirror die steel, its tissue uniformity is poor and it cannot meet the requirements of mirror polishing. Summary of the Invention

[0004] In view of the problems existing in the background art, this application provides an optical mirror surface injection molding die and a manufacturing method thereof, which can make the injection molding die have both an optical mirror surface and high heat conduction efficiency and high temperature uniformity, and improve the quality and performance of the injection molding die.

[0005] According to one aspect of the present invention, there is provided an optical mirror surface injection molding die, including: a die body, on one side of the die body, a surface is formed, and on the other side, a three-dimensional groove is formed, and the three-dimensional groove is designed to follow the shape of the surface; a closed water channel, the closed water channel is arranged in the three-dimensional groove, and water inlets and outlets are respectively formed at both ends of the closed water channel; a water channel support structure, the water channel support structure is combined with the side of the die body with the closed water channel, and the water channel support structure is formed on the die body by 3D printing with 3D printing materials.

[0006] By using the optical mirror injection molding die in the present technical solution, taking the conventional die body as the substrate for the 3D printing process, forming a three-dimensional groove conforming to the mold surface on the die body and arranging a closed water channel, and then using a suitable 3D printing material to form a water channel support structure on the die body and the closed water channel by 3D printing, not only a high-grade optical mirror mold surface can be obtained on the die body, but also by forming a three-dimensional groove conforming to the mold surface and a closed water channel on the die body, the heat conduction efficiency and temperature uniformity of the injection molding die can be ensured. At the same time, by forming the water channel support structure by 3D printing, the injection molding die has better integrity and further seals the closed water channel, thereby improving the quality and performance of the injection molding die and increasing its service life.

[0007] In some embodiments of the present invention, the closed water channel is formed by a heat exchange water pipe embedded in the three-dimensional groove.

[0008] In some embodiments of the present invention, the closed water channel is formed by covering the three-dimensional groove with a cover plate, and the closed space formed by the cover plate and the three-dimensional groove constitutes the closed water channel.

[0009] In some embodiments of the present invention, the cover plate is designed to conform to the three-dimensional groove, and the cover plate is fixed to the die body by welding.

[0010] In some embodiments of the present invention, the number of the closed water channels is more than one.

[0011] In some embodiments of the present invention, the materials of the die body and the water channel support structure are the same.

[0012] In some embodiments of the present invention, the material is selected from mirror die steel.

[0013] According to another aspect of the present invention, there is provided a manufacturing method of the above-mentioned optical mirror injection molding die, including the following steps: preparing the substrate of the die body; performing preliminary processing on the back surface of the substrate according to the mold surface design of the die body to form a reference surface; performing further processing on the reference surface of the substrate to obtain a three-dimensional groove conforming to the mold surface, and preparing a closed water channel in the three-dimensional groove; using 3D printing technology to form a 3D printing material on one side of the substrate with the closed water channel to form a water channel support structure; after forming the water channel support structure on the back surface of the substrate, performing processing on the front surface of the substrate according to the mold surface design of the die body to form a mold surface; obtaining the optical mirror injection molding die.

[0014] In some embodiments of the present invention, the size of the substrate is larger than the design size of the optical mirror injection molding die.

[0015] In some embodiments of the present invention, after forming a waterway support structure on the back surface of the substrate, the whole of the substrate and the waterway support structure is first heat-treated, and then the front surface of the substrate is processed according to the surface profile design of the mold body to form a surface profile. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0017] Figure 1 is a schematic diagram of the overall structure of the optical mirror injection molding die of the present invention;

[0018] Figure 2 is a sectional view of the optical mirror injection molding die of the present invention;

[0019] Figure 3 is a schematic diagram of the structure of the mold body of the present invention;

[0020] Figure 4 is a schematic diagram of the heat exchange water pipe of the present invention as a closed waterway;

[0021] Figure 5 is a schematic diagram of the cover plate of the present invention covering the three-dimensional groove as a closed waterway.

[0022] The reference numerals in the drawings are represented as follows: 1. Mold body; 2. Three-dimensional groove; 3. Closed waterway; 4. Waterway support structure; 5. Heat exchange water pipe; 6. Cover plate; 7. Surface profile. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope of protection of the present application.

[0024] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are only examples of the devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0025] In the description of the present application, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances. In addition, in the description of the present application, unless otherwise specified, "a plurality" means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0026] An embodiment of the present application discloses an optical mirror injection molding die. As Figures 1-3 shown, the optical mirror injection molding die includes a die body 1, a closed water channel 3, and a water channel support structure 4.

[0027] Among them, a molding surface 7 is formed on one side of the die body 1, and a three-dimensional groove 2 is formed on the other side. The three-dimensional groove 2 is designed according to the shape of the molding surface 7; the closed water channel 3 is arranged in the three-dimensional groove 2, and water inlets and outlets are respectively formed at both ends of the closed water channel 3; the water channel support structure 4 is combined with the side of the die body 1 with the closed water channel 3, and the water channel support structure 4 is formed on the die body 1 by 3D printing with a 3D printing material.

[0028] It should be understood that the molding surface 7 of the die body 1 in the present invention is designed and processed according to the profile data of the workpiece. The relative distances between the positions of the three-dimensional groove 2 and the corresponding positions of the molding surface 7 are close or equal. The three-dimensional groove 2 is shaped according to the molding surface 7, that is, the three-dimensional groove 2 is processed according to the external shape structure of the workpiece, so as to obtain a closed water channel 3 structure that changes with the external shape of the workpiece on the die body 1.

[0029] By using the optical mirror injection molding die in this technical solution, taking the conventional die body 1 as the base of the 3D printing process, first a three-dimensional groove 2 conforming to the shape of the mold surface 7 is formed on the die body 1, then a closed water channel 3 is formed based on the three-dimensional groove 2, and then a water channel support structure 4 is formed on the die body 1 and the closed water channel 3 by 3D printing using a suitable 3D printing material. Not only can the die body 1 obtain a mold surface 7 of a high-grade optical mirror after rough machining, semi-finishing, finishing and polishing based on its conventional die material, but also by forming the three-dimensional groove 2 conforming to the shape of the mold surface 7 and the closed water channel 3 on the die body 1, the heat conduction efficiency and temperature uniformity of the injection molding die can be ensured. At the same time, by forming the water channel support structure 4 on the die body 1 and the closed water channel 3 by 3D printing, not only is the bonding effect with the die body 1 good and the support stability for the closed water channel 3 high, but also the water channel support structure 4 can be completely bonded to each position on the side surface of the die body 1, and can play a further isolation role for each adjacent section of the closed water channel 3 and the outermost periphery of the closed water channel 3. Cooperating with the closed water channel 3 structure formed in the three-dimensional groove 2 in advance, it effectively avoids the occurrence of water leakage caused by reasons such as the thermal expansion differences of each structure of the injection molding die or repeated thermal expansion and contraction, thereby greatly improving the quality and performance of the injection molding die, increasing its service life, and further enabling high-precision, high-appearance-quality and high-optical-quality parts to be obtained with this injection molding die.

[0030] In some embodiments of the present invention, as Figure 4 shown, the closed water channel 3 is formed by a heat exchange water pipe 5 embedded in the three-dimensional groove 2.

[0031] It should be understood that the heat exchange water pipe 5 is a whole water pipe, and it can be partially or completely embedded in the three-dimensional groove 2 in a bent manner according to the trend of the three-dimensional groove 2 to form the closed water channel 3.

[0032] In this embodiment, the heat exchange water pipe 5 can adopt a water pipe with high thermal conductivity and high temperature resistance, such as a stainless steel water pipe, to ensure the heat exchange efficiency between the heat exchange working medium in the heat exchange water pipe 5 and the die body 1.

[0033] Furthermore, the part of the heat exchange water pipe 5 located in the three-dimensional groove 2 is completely attached to the groove wall of the three-dimensional groove 2, which can reduce the gap and further improve the heat exchange effect of the heat exchange water pipe 5.

[0034] By laying the heat exchange water pipe 5 in the three-dimensional groove 2 to form a closed water circuit 3, and then forming the water circuit support structure 4 on the mold body 1 and the heat exchange water pipe 5 by 3D printing, and applying the 3D printing material layer by layer in an additive manufacturing manner, the water circuit support structure 4 can form a dense coverage of the heat exchange water pipe 5, ensuring that there are no other voids between the mold body 1 and the water circuit support structure 4 except for the cavity where the heat exchange working medium flows in the heat exchange water pipe 5, making the heat exchange water pipe 5 in full contact with the mold body 1 and the water circuit support structure 4, effectively ensuring the heat conduction efficiency and temperature uniformity of the injection molding mold.

[0035] In some embodiments of the present invention, as Figure 4 shown, when using the heat exchange water pipe 5 to form the closed water circuit 3, a partial length at both ends of the heat exchange water pipe 5 can extend a certain distance away from the mold body 1. After 3D printing the water circuit support structure 4, both ends of the heat exchange water pipe 5 are located outside, used to form the inlet and outlet for the heat exchange working medium to flow through.

[0036] In some embodiments of the present invention, as Figure 5 shown, the closed water circuit 3 is formed by covering the three-dimensional groove 2 with a cover plate 6, and is composed of the closed space formed by the cover plate 6 and the three-dimensional groove 2.

[0037] In this embodiment, the cover plate 6 can be designed as a whole piece or in sections. The cover plate 6 is designed to follow the shape of the three-dimensional groove 2 and can be made from a whole plate by cutting. According to the trend of the three-dimensional groove 2, it is only necessary to ensure that the three-dimensional groove 2 is completely covered and sealed from one end to the other end.

[0038] In this embodiment, the cover plate 6 can be made of a material with high thermal conductivity and high temperature resistance, such as a metal plate like a stainless steel plate, and is fixed to the mold body 1 by welding.

[0039] In addition, in this embodiment, after 3D printing the water circuit support structure 4, at the positions corresponding to both ends of the three-dimensional groove 2 on the water circuit support structure 4, the inlet and outlet holes communicating with the three-dimensional groove 2 can be processed by drilling from the outside to the inside for the heat exchange working medium to flow through.

[0040] By welding the cover plate 6 on the surface of the mold body 1 to hermetically cover the three-dimensional groove 2 to form a closed water circuit 3, and then forming the water circuit support structure 4 on the mold body 1 and the cover plate 6 by 3D printing, and applying the 3D printing material layer by layer in an additive manufacturing manner, the water circuit support structure 4 can form a dense coverage of the cover plate 6, ensuring that there are no other voids between the mold body 1 and the water circuit support structure 4 except for the cavity where the heat exchange working medium flows in the three-dimensional groove 2, making the heat exchange working medium in full contact with the mold body 1 and the water circuit support structure 4, effectively ensuring the heat conduction efficiency and temperature uniformity of the injection molding mold.

[0041] In some embodiments of the present invention, such as Figure 4 and Figure 5 shown, the number of the closed water channels 3 is more than one. For example, the number of the closed water channels 3 can be 1, 2, 3, 4, etc.

[0042] In this embodiment, the surface 7 can be reasonably divided into regions according to the heat exchange requirements of different regions of the workpiece, such as according to the size of the workpiece, the thickness difference of different regions, etc. Then, a three-dimensional groove 2 is respectively opened in the mold body 1 corresponding to each region, and a closed water channel 3 is respectively arranged, so as to effectively avoid the problem of poor heat exchange uniformity caused by the too long length of a single closed water channel 3, and further improve the temperature uniformity of the injection molding die.

[0043] Furthermore, the cross-sectional dimensions of each three-dimensional groove 2 and the corresponding closed water channel 3 on the mold body 1, and even the cross-sectional dimensions of different sections of a single closed water channel 3 can be reasonably designed according to the heat exchange requirements of different regions of the workpiece, so that the temperature uniformity of the injection molding die is more consistent.

[0044] In some embodiments of the present invention, the mold body 1 and the water channel support structure 4 can be made of the same or different materials. Preferably, the same material is used to effectively reduce the thermal expansion difference between the mold body 1 and the water channel support structure 4, and improve the stability of the overall structure formed by the mold body 1 and the water channel support structure 4.

[0045] In some embodiments of the present invention, the materials of the mold body 1 and the water channel support structure 4 can be mirror mold steel.

[0046] In other embodiments of the present invention, the materials of the mold body 1 and the water channel support structure 4 can also be other mold materials such as high-hardness steel, molybdenum steel, cemented carbide, stainless steel, etc., which have high hardness, good wear resistance, excellent polishing performance and low thermal expansion coefficient.

[0047] This embodiment also proposes a manufacturing method, which is used to prepare the above-mentioned optical mirror injection molding die. The manufacturing method includes the following steps:

[0048] S1. Prepare the substrate of the mold body.

[0049] In this embodiment, the substrate can select materials according to the service life of the injection molding die and product requirements, and is obtained by cutting and processing the blank parts.

[0050] Furthermore, the size of the substrate is larger than the design size of the optical mirror injection molding die to accommodate the deformation generated by the substrate in the subsequent manufacturing process.

[0051] S2. Rough machine the back surface of the substrate according to the surface design of the mold body to form a reference surface.

[0052] In this embodiment, according to the part drawing or 3D model, analyze the part structure, dimensions, material properties and forming requirements, design the injection molding die and its surface, generate 2D engineering drawings and 3D model data, and then rough machine the back surface of the substrate according to this data, such as using equipment like milling machines and planers to form a reference surface adapted to the surface.

[0053] S3. Re-machine on the reference surface of the substrate to obtain a three-dimensional groove that conforms to the surface design, and form a closed water circuit in the three-dimensional groove.

[0054] In this embodiment, first, based on the injection molding die and its surface parameters and part parameters, design the quantity and dimensions of the three-dimensional groove, generate machining data, and then re-machine the back surface of the substrate according to this data. For example, first rough machine using equipment like milling machines and planers, and then perform high-precision finish machining using a CNC machining center to ensure the dimensional and positional accuracy of the three-dimensional groove. Then, perform polishing treatment to ensure the surface finish, obtain three-dimensional grooves evenly distributed on the part surface, and finally form a closed water circuit by laying heat exchange water pipes or welding covers.

[0055] S4. Use 3D printing technology to form a 3D printing material on one side of the substrate with a closed water circuit to form a water circuit support structure.

[0056] In this embodiment, 3D printing technologies such as selective laser melting (SLM), selective laser sintering (SLS), and electron beam melting (EBM) can be used to deposit metal powder layer by layer on the substrate to form a water circuit support structure.

[0057] Further, after forming the water circuit support structure on the back surface of the substrate, first perform heat treatment on the whole of the substrate and the water circuit support structure to make the internal stress uniform and reach the required tissue state, and then perform subsequent surface machining.

[0058] S5. After forming the water circuit support structure on the back surface of the substrate, machine the front surface of the substrate according to the surface design of the mold body to form a surface.

[0059] In this embodiment, the surface can be obtained through processes such as rough machining, semi-finish machining, finish machining, and polishing treatment to obtain a high-precision optical mirror surface.

[0060] S6. Obtain an optical mirror injection molding die.

[0061] As described above, it is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An optical mirror injection molding mold, characterized in that: include: A mold body, wherein one side of the mold body forms a molding surface, and the other side forms a three-dimensional groove, wherein the three-dimensional groove is designed based on the molding surface; A closed waterway, wherein the closed waterway is arranged in the three-dimensional groove, and a water inlet and a water outlet are formed at two ends of the closed waterway respectively; A water channel support structure is combined with a side of the mold body with a closed water channel, and the water channel support structure is formed on the mold body by 3D printing using 3D printing materials.

2. The optical mirror injection molding mold according to claim 1, characterized in that: The closed water channel is formed by a hot water exchange pipe embedded in the three-dimensional groove.

3. The optical mirror injection molding mold according to claim 1, characterized in that: The closed waterway uses a cover plate to cover the three-dimensional groove, and is composed of a closed space formed by the cover plate and the three-dimensional groove.

4. The optical mirror injection molding mold according to claim 3, characterized in that: The cover plate is designed to conform to the three-dimensional groove, and the cover plate is fixed to the mold body by welding.

5. The optical mirror injection molding mold according to claim 1, characterized in that: The number of the closed water channels is more than one.

6. The optical mirror injection molding mold according to claim 1, characterized in that: The mold body and the water channel supporting structure are made of the same material.

7. The optical mirror injection molding mold according to claim 6, characterized in that: The material is selected from mirror mold steel.

8. A method for manufacturing an optical mirror injection molding mold according to any one of claims 1 to 7, characterized in that: The following steps are involved: Preparing a substrate for the mold body; Preliminary processing is performed on the back of the substrate according to the surface design of the mold body to form a reference surface; Further processing is performed on the reference surface of the substrate to obtain a three-dimensional groove designed in accordance with the profile surface, and a closed water channel is prepared in the three-dimensional groove; Using 3D printing technology to mold 3D printing materials on one side of the substrate with the closed waterway to form a waterway support structure; After forming the water channel support structure on the back of the base, processing the front of the base according to the profile design of the mold body to form a profile; The optical mirror surface injection molding mold is obtained.

9. The manufacturing method according to claim 8, characterized in that: The size of the base is larger than the design size of the optical mirror surface injection molding mold.

10. The manufacturing method according to claim 8, characterized in that: After the water channel support structure is formed on the back side of the substrate, the substrate and the water channel support structure are firstly heat treated as a whole, and then the front side of the substrate is processed according to the profile design of the mold body to form a profile.

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