Resin parts molding method
The method seals the liquid resin within submerged molds to prevent bubble formation, addressing the issue of voids in resin parts by ensuring molds remain submerged and sealed below the liquid surface, resulting in defect-free resin parts.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TOYOTA JIDOSHA KK
- Filing Date
- 2024-11-21
- Publication Date
- 2026-06-02
AI Technical Summary
Existing methods for molding resin parts using photocurable or thermosetting resins often generate bubbles in the liquid resin, leading to defects such as voids in the molded parts due to residual air bubbles.
A method involving sealing the liquid resin within a closed molding space using upper and lower molds submerged in the resin, clamping them together to prevent air bubbles from forming, and then curing the resin to form the part, followed by demolding and removal steps to ensure bubble-free resin parts.
Prevents air bubbles from mixing into the liquid resin during the molding process, thereby eliminating defects like voids in the final resin parts by ensuring the molds remain submerged and sealed below the liquid surface.
Smart Images
Figure 2026090100000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for molding resin parts from a liquid resin having photocurability or thermosetting properties.
Background Art
[0002] As this type of technology, for example, in Patent Document 1, after curing a liquid resin having photocurability stored in a tank to mold a part of a resin part, a part of the resin part is sedimented into the liquid resin, and a part of the resin part is similarly molded thereon. By repeating this, an integrated resin part is molded.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, in the technology described in Patent Document 1, in the process of sedimenting a part of the resin part into the liquid resin, bubbles are generated in the liquid resin. If the generated bubbles cannot be completely defoamed and bubbles remain in the liquid resin, there is a risk of defects such as voids in the molded resin part.
[0005] The present invention has been made in view of such points, and an object thereof is to provide a method for molding resin parts that can prevent bubbles from remaining in a liquid resin when curing the liquid resin for molding resin parts.
Means for Solving the Problems
[0006] In view of the above problems, the present invention provides a resin part molding method for molding a resin part in a tank containing a photocurable or thermocurable liquid resin, comprising: a sealing step of sealing the liquid resin in a molding space closed by the upper mold and the lower mold by raising the lower mold while fixing the upper mold and clamping the upper mold and the lower mold; a molding step of curing the liquid resin sealed in the molding space and molding the resin part; a demolding step of releasing the resin part by opening the upper mold and the lower mold; and a removal step of removing the resin part from the tank. [Effects of the Invention]
[0007] According to the present invention, the upper and lower molds are placed in the liquid resin, the lower mold is raised while the upper mold is fixed, and the upper and lower molds are clamped together to seal the liquid resin within the molding space. As a result, when the upper and lower molds are clamped together, both the upper and lower molds remain submerged in the liquid resin and do not rise above the liquid surface. Therefore, no air bubbles are generated on the liquid surface, preventing air bubbles from being mixed into the liquid resin when the upper and lower molds are clamped together. Consequently, when the sealed liquid resin hardens, it is possible to prevent air bubbles from remaining in the liquid resin, thus preventing defects such as voids caused by air bubbles from occurring in the molded resin parts. [Brief explanation of the drawing]
[0008] [Figure 1] This is a schematic diagram illustrating the configuration of a molding apparatus and its surroundings used in a resin part molding method according to an embodiment of the present invention, as well as the flow of the resin part molding method. [Figure 2] This is a schematic diagram illustrating the detailed configuration of a molding apparatus used in a resin parts molding method according to an embodiment of the present invention. [Figure 3]This is a flowchart of a resin part molding method according to an embodiment of the present invention. [Modes for carrying out the invention]
[0009] The resin parts molding method according to the present invention will be described in detail below with reference to Figures 1 to 3. Note that the embodiments shown below are only one aspect of the present invention and do not limit the technical scope of the present invention.
[0010] <Structure> Figure 1(A) is a schematic diagram illustrating the configuration of a molding apparatus 10 and its surroundings used in a resin part molding method according to an embodiment of the present invention. In this embodiment, the resin part 3 molded by the molding apparatus 10 has a substantially rectangular shape. Such a resin part 3 is molded by the molding apparatus 10 described below. The molding apparatus 10 includes an upper mold 41 and a lower mold 42 that can be clamped and opened. Of the surfaces 41a and 42a of the upper mold 41 and lower mold 42 that face each other, at least one of the surfaces 41a and 42a has a recess (not shown). A molding space S for molding the resin part 3 is formed by the wall surfaces of the recesses formed on each of the two surfaces 41a and 42a, or by the wall surface of the recess formed on one of the surfaces 41a and 42a and the other surface 41a and 42a that does not have a recess.
[0011] Furthermore, with the direction from the bottom surface 20 of the tank 2 containing the liquid resin 1 toward the liquid surface 11 of the liquid resin 1 being considered upward, the upper mold 41 and lower mold 42 are installed in the liquid resin 1 such that the upper mold 41 is positioned above the lower mold 42. Here, the liquid surface 11 is separated by a flat bubble escape prevention plate 6. Hereinafter, the tank 2 containing the liquid surface 11 on one side separated by the bubble escape prevention plate 6, where the upper mold 41 and lower mold 42 are installed and the resin part 3 is molded, will be called the molding tank 22, and the tank 2 containing the liquid surface 11 on the other side will be called the removal tank 21. The lower mold 42 is also freely able to rise from the bottom surface 20 toward the upper mold 41, which is achieved by the detailed configuration of the molding apparatus 10 shown in Figure 2(A).
[0012] As shown in Figure 2(A), the molding apparatus 10 includes an upper die 41 and a lower die 42, as well as a hydraulic press unit 81, a plurality of (e.g., two) hydraulic press rods 82, and a plurality of (e.g., two) guide posts 83, which are not shown in Figure 1(A). The hydraulic press rods 82 extend from the hydraulic press unit 81, passing through two corners of the upper die 41 to the lower die 42. The guide posts 83 extend from the hydraulic press unit 81, passing through two corners each of the upper die 41 and the lower die 42 to the bottom surface 20. When the hydraulic pressure in the hydraulic press unit 81 is increased or decreased, the hydraulic press rods 82 fixed to the lower die 42 extend and contract, causing the lower die 42 to move up and down along the guide posts 83. The hydraulic press unit 81 is located outside the tank 2 for ease of maintenance.
[0013] Furthermore, the lower die 42 can also be raised and lowered along the guide posts 83 by using the molding apparatus 100 shown in Figure 2(B) instead of the molding apparatus 10 shown in Figure 2(A). The molding apparatus 100 does not have a hydraulic press unit 81 and a hydraulic press rod 82, but instead has four guide posts 83. In addition, a pair of coils 9 are built into each of the upper die 41 and the lower die 42, and when current is passed through the coils 9, a magnetic force is generated in the coils 9, and this magnetic force allows the lower die 42 to be raised and lowered freely along the guide posts 83.
[0014] In this embodiment, the liquid resin 1 is an ultraviolet-curable resin, and as shown in Figure 1(A), the light source device 5 is mounted on the upper side of the upper mold 41. The upper mold 41 is made of a transparent material so that the liquid resin 1 can be cured by irradiating ultraviolet light into the molding space S from the light source device 5. Furthermore, since the liquid resin 1 that comes into contact with the light source device 5 hardens when the light source device 5 is placed in the liquid resin 1, it is preferable that the light source device 5 be fixed so that it is positioned above the liquid surface 11. In addition, although the light source device 5 is not shown in Figures 2(A) and 2(B), in Figure 2(A) the light source device 5 is positioned between the upper mold 41 and the hydraulic press unit 81, and in Figure 2(B) the light source device 5 is positioned on the upper side of the upper mold 41.
[0015] Alternatively, the liquid resin 1 may be a thermosetting resin. In this case, heating elements (not shown) are provided on either or both of the upper mold 41 and the lower mold 42 to prevent the liquid resin 1 outside the molding space S from hardening. Furthermore, the upper mold 41 and the lower mold 42 are made of a material with low thermal conductivity, such as rubber. Note that in this case, the upper mold 41 is not limited to being made of a transparent material, nor is it limited to the configuration in which the light source device 5 is attached to the upper side of the upper mold 41.
[0016] <Flowchart> The flow of the resin part molding method according to this embodiment will be described below with reference to Figure 3, and also to Figures 1(A) to 1(C). The resin part molding method according to this embodiment is a method of molding a resin part 3 by curing a liquid resin 1 that has photocurability in a tank 2 containing the liquid resin 1. In this method, first, in step S1, as shown in Figure 1(A), the upper mold 41 and the lower mold 42 are placed in the liquid resin 1 in the tank 2 such that the upper mold 41 is positioned above the lower mold 42. Then, as shown in Figure 1(B), with the upper mold 41 fixed, the lower mold 42 is raised along the guide post 83 and the upper mold 41 and the lower mold 42 are clamped together, thereby sealing the liquid resin 1 in the molding space S closed by the upper mold 41 and the lower mold 42. At this time, neither the upper mold 41 nor the lower mold 42 comes above the liquid surface 11 of the liquid resin 1. Therefore, as the upper mold 41 and lower mold 42 rise above the liquid surface 11, no bubbles 7 are generated at the liquid surface 11, thus preventing bubbles 7 from being mixed into the liquid resin 1 when the upper mold 41 and lower mold 42 are clamped together. Here, step S1 corresponds to the sealing step in the present invention.
[0017] Next, in step S2, the liquid resin 1 sealed in the molding space S is cured to form the resin part 3. In this embodiment, the liquid resin 1 is photocurable, and specifically, as shown in Figure 1(B), the liquid resin 1 is cured by irradiating ultraviolet light into the molding space S from a light source device 5 attached to the upper side of the upper mold 41 made of a transparent material. On the other hand, if the liquid resin 1 is thermosetting, the liquid resin 1 sealed in the molding space S formed by the upper mold 41 and lower mold 42 made of a material with low thermal conductivity such as rubber is cured by heating it with a heating element. In either case, since the sealing process prevents air bubbles 7 from being mixed into the liquid resin 1 sealed in the molding space S, defects such as voids caused by air bubbles 7 can be prevented from occurring in the molded resin part 3. Here, step S2 corresponds to the molding process in the present invention.
[0018] Next, in step S3, the lower mold 42 is lowered along the guide post 83, and the molds of the upper mold 41 and lower mold 42 are opened to release the molded resin part 3. Here, step S3 corresponds to the release step in the present invention. Steps S1 to S3 are performed in the molding tank 22 of the tank 2.
[0019] Finally, in step S4, the resin part 3 released in the molding tank 22 is moved to the extraction tank 21 through the gap C between the bubble outflow prevention plate 6 and the bottom surface 20, and the resin part 3 is taken out from the extraction tank 21. At this time, with the operation of putting an instrument such as tweezers into the extraction tank 21 to take out the resin part 3 and the operation of taking out the resin part 3 from the extraction tank 21, bubbles 7 may be generated in the vicinity of the liquid surface 11 of the liquid resin 1 in the extraction tank 21. However, the bubble outflow prevention plate 6 can prevent the bubbles 7 from moving into the molding tank 22 without passing through the gap C. This is because the specific gravity of the bubbles 7 is smaller than that of the liquid resin 1, and the bubbles 7 float in the liquid resin 1. Thereby, even when step S1 is executed again, it is possible to prevent the bubbles 7 from mixing into the liquid resin 1 sealed in the molding space S. Here, step S4 corresponds to the extraction process in the present invention.
Explanation of Reference Numerals
[0020] 1: Liquid resin, 11: Liquid surface, 2: Tank, 20: Bottom surface, 3: Resin part, 41: Upper mold, 42: Lower mold, 5: Light source device
Claims
[Claim 1] A method for molding resin parts, comprising molding resin parts in a tank containing a photocurable or thermocurable liquid resin, A sealing step is performed in which the upper mold and the lower mold are placed in the liquid resin in the tank such that the upper mold is positioned above the lower mold, with the direction from the bottom of the tank toward the liquid surface of the liquid resin being considered as upward, the lower mold is raised while the upper mold is fixed, and the upper mold and the lower mold are clamped together to seal the liquid resin within the molding space closed by the upper mold and the lower mold. A molding step in which the liquid resin sealed within the molding space is cured and the resin part is formed, A mold release step is performed by opening the upper mold and the lower mold to release the resin part, A method for molding resin parts, characterized by comprising a removal step of removing the resin parts from the tank.