Manufacturing method of resin molded products

Abstract

To provide a method for manufacturing a resin molded product, which can eliminate a trim step after resin molding and reduce waste of materials.SOLUTION: In a fixing step, an upper insert 170 is prepared, an outer edge 210 of a glass mat 200 is sandwiched between a lower mold 110 and the upper insert 170, and a position of the upper insert 170 is fixed with respect to the lower mold 110. After the fixing step, in a cutting step, a protruding part 220 of the outer edge 210 of the glass mat 200 that protrudes from a side surface 171 of the upper insert 170 is cut along the side surface 171 of the upper insert 170. After the cutting step, in an assembling step, an upper mold 130 is assembled to the lower mold 110 with a portion of the upper mold 130 in contact with the side surface 171 of the upper insert 170.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a method for producing a resin molded product. [Background technology]

[0002] Conventionally, a method has been proposed in which a glass mat made of glass fiber is placed between a lower mold and an upper mold, the lower mold and the upper mold are assembled, and resin is injected into the glass mat while drawing a vacuum between the lower mold and the upper mold, and then the resin is hardened and molded. This method is shown in, for example, Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-54034 Summary of the Invention [Problem to be solved by the invention]

[0004] Usually, when forming a resin molded product, the outer edge of the resin molded product is formed large in advance. This is because when the glass mat is sandwiched between the lower and upper dies and clamped, the glass mat that should be located at the outer edge of the resin molded product may shift from the die. For this reason, it is necessary to prepare a glass mat with a size that allows for some margin in advance, taking into account the shifting of the glass mat when clamping.

[0005] In addition, since the outer edge of the resin molded product is formed to be larger than necessary, unnecessary portions are generated at the outer edge of the resin molded product. As a result, after demolding, a trimming process is required to cut off the unnecessary portions of the outer edge of the resin molded product, and the cut portions are wasted.

[0006] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide a method for manufacturing a resin molded product that can eliminate a trimming step after resin molding and reduce waste of material. [Means for solving the problem]

[0007] In order to achieve the above object, the invention described in claim 1 includes a setting step of setting a glass mat (200) made of glass fiber between a lower mold (110) and an upper mold (130). It also includes a molding step of injecting resin into the glass mat while drawing a vacuum between the lower mold and the upper mold, and hardening the resin.

[0008] The installation process includes a fixing process, a cutting process, and an assembly process. In the fixing process, an upper insert (170) is prepared, an outer edge (210) of the glass mat is sandwiched between the lower mold and the upper insert, and the position of the upper insert is fixed relative to the lower mold.

[0009] In the cutting process, after the fixing process, a protruding portion (220) of the outer edge of the glass mat that protrudes from a side surface (171) of the upper insert is cut along the side surface of the upper insert. In the assembling process, after the cutting process, the upper insert is assembled to the lower insert with a part of the upper insert in contact with the side surface of the upper insert.

[0010] According to this, since the position of the outer edge of the glass mat is fixed in advance by the lower mold and the upper insert prior to the molding step, it is possible to prevent the glass mat from shifting.

[0011] In the cutting process, the protruding portion of the glass mat is cut along the side surface of the upper insert, so that the outer edge portion (310) of the resin molded product (300) can be adjusted in advance to match the shape of the side surface of the upper insert. This makes it possible to eliminate the need for a trimming process for cutting off unnecessary portions of the outer edge portion of the resin molded product after the molding process.

[0012] In addition, the size of the glass mat can be adjusted in advance so that the length of the protruding portion of the glass mat is shortened, which reduces the amount of the protruding portion to be cut off, thereby reducing waste of the glass mat and resin.

[0013] In addition, the reference symbols in parentheses for each means described in this column and in the claims indicate the correspondence with the specific means described in the embodiments described later. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is an exploded perspective view of a molding die according to one embodiment. [Diagram 2] FIG. 2 is a front view of the mold shown in FIG. [Diagram 3] FIG. 2 is a side view of the mold shown in FIG. [Figure 4] FIG. [Diagram 5] FIG. 5 is a cross-sectional view of FIG. 4 . [Figure 6] 1 is a side view showing a state in which a glass mat is sandwiched between an upper insert and a lower insert. FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. [Figure 9] FIG. 11 is a cross-sectional view showing a comparative example of a mold clamping portion. [Figure 10] FIG. 11 is a cross-sectional view showing a comparative example of a mold clamping portion. [Figure 11] FIG. 11 is a cross-sectional view showing a comparative example of a mold clamping portion. [Figure 12] FIG. 11 is a cross-sectional view showing a comparative example of a mold clamping portion. [Figure 13] 4 is a cross-sectional view showing a part of the resin molded product and a part of the runner after being demolded. FIG. [Figure 14] FIG. 11 is a cross-sectional view showing a modified example of the molding die. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] An embodiment will be described below with reference to the drawings. The method for manufacturing a resin molded product according to this embodiment can be applied to a process in which a resin is poured into a mold while evacuating the inside of the mold, the resin is cured, and then the resin molded product is demolded. In this embodiment, a silicon back method is adopted, in which an elastically deformable resin sheet is used as part of the mold.

[0016] The manufacturing method according to this embodiment can manufacture resin molded products used for, for example, in-vehicle parts, vehicle parts, medical equipment, ships, sporting goods, wind turbine blades, water purification tanks, bathtubs, railroad cars, etc. In the following, a frame for housing a refrigeration unit is manufactured as an in-vehicle part.

[0017] The manufacturing method of a resin molded product includes a setting step and a molding step. The setting step is a step of setting a sheet-like glass mat 200 made of glass fiber between the lower mold 110 and the upper mold 130 of the molding die 100 shown in Figs. 1 to 8. The glass mat 200 is a material that becomes the base material of the resin molded product. The setting step is a preparatory step prior to resin molding.

[0018] The molding process is a process in which, after the installation process, a vacuum is drawn between the lower mold 110 and the upper mold 130, and while the upper mold 130 is elastically deformed to conform to the shape of the lower mold 110, resin is injected into the glass mat 200 and the resin is hardened.

[0019] Next, the contents of each step and the devices used in each step will be described. First, in the setting step, the forming mold 100 and the glass mat 200 are prepared, and a fixing step of fixing the glass mat 200 to the forming mold 100 is performed.

[0020] 1 to 3 are prepared as the molding die 100. The lower die 110, the upper die 130, the lower insert 150, and the upper insert 170 may each be a separate component, or the lower die 110 may have the lower insert 150, for example.

[0021] The lower mold 110 is made of a material such as fiber reinforced plastic (FRP), thermosetting resin, resin such as rubber, metal, etc. The lower mold 110 has a mold portion 111 in which the outer shape of a resin molded product is formed in advance.

[0022] 4 is composed of an elastic sheet 131 made of elastic silicon that is elastically deformable. As shown in FIGS. 1 to 3, the upper mold 130 is formed in advance into a shape that matches the shape of the lower mold 110. That is, the upper mold 130 has a portion that corresponds to the shape of the mold portion 111 of the lower mold 110.

[0023] 4, the elastic sheet 131 constituting the upper mold 130 has a plurality of through holes 132 for injecting resin and drawing a vacuum. In this embodiment, for example, two through holes 132 for injecting resin are provided in an outer edge portion 133 of the elastic sheet 131. Also, three through holes 132 for drawing a vacuum are provided in the elastic sheet 131 at positions corresponding to the mold portion 111 of the lower mold 110. The number and positions of the through holes 132 are appropriately set depending on the type of resin molded product, etc.

[0024] The upper die 130 has a joint portion 134 provided in each through hole 132. The joint portion 134 is made of silicon having a different hardness from that of the elastic sheet 131. The joint portion 134 has a hardness that allows it to withstand the vacuum pressure during evacuation, maintain its shape, and facilitates processing to make the surface smooth. The Shore hardness of the joint portion 134 is, for example, 40 to 70.

[0025] The elastic sheet 131 is made of a material softer than the joint portion 134. The Shore hardness of the elastic sheet 131 is, for example, 10 or more. The elastic sheet 131 does not stick to the resin molded product and has solvent resistance and heat resistance.

[0026] 5, the joint portion 134 has a pipe portion 135 and a protrusion portion 136. The pipe portion 135 has an internal passage 135a through which evacuated air and resin pass. The internal passage 135a is a hollow portion of the pipe portion 135. The pipe portion 135 is, for example, hollow cylindrical. Note that the pipe portion 135 is not limited to being hollow cylindrical as long as it is cylindrical and has the internal passage 135a.

[0027] The protrusion 136 is a flange-shaped portion in which the outer wall of the tube portion 135 on the side of one end 137 protrudes. The cross-sectional shape of the protrusion 136 is not limited to a square shape, and may be a triangle or a trapezoid. The protrusion 136 may be disposed flush with the end face of the tube portion 135 on the side of one end 137, or may be disposed at a position between the end face of the tube portion 135 on the side of one end 137 and the end face of the other end 138.

[0028] Then, when the other end 138 side of the pipe portion 135 is inserted into the through hole 132, the protrusion 136 is caught on an edge portion 139 that constitutes the through hole 132. The edge portion 139 may be formed in advance into a shape into which the protrusion 136 fits. The other end portion 138 of the pipe portion 135 is exposed to the outside from the through hole 132.

[0029] Also, edge portion 139 is in contact with the outer wall of one end portion 137 side of pipe portion 135. One end portion 137 side of pipe portion 135 and edge portion 139 of elastic sheet 131 are simply in contact with each other and are not fixed with an adhesive or the like.

[0030] The protrusion 136 of the pipe portion 135 is provided to prevent the joint portion 134 from slipping out of the through hole 132. The protrusion 136 may be provided in a ring shape at one end 137 of the pipe portion 135, or may be provided intermittently at one end 137 of the pipe portion 135. In order to increase the contact area between the elastic sheet 131 and the joint portion 134, a protrusion may be provided on the surface of the outer circumferential surface of the pipe portion 135 that comes into contact with the edge portion 139.

[0031] A joint part 140 made of, for example, polypropylene (PP) is connected to the other end 138 of the joint part 134. That is, the joint part 140 is inserted into the internal passage 135a of the pipe part 135. A hose 141 is connected to the side of the joint part 140 opposite to the side of the joint part 134. The hose 141 is connected to a resin supplying machine (not shown) when the joint part 134 to which the hose 141 is connected is for resin injection, and is connected to a vacuum pump (not shown) when the joint part 134 to which the hose 141 is connected is for vacuum drawing.

[0032] 4, the upper mold 130 has a mold clamping portion 142. The mold clamping portion 142 is a portion for fixing the upper mold 130 to the lower mold 110 by vacuum drawing separate from the resin molding. The mold clamping portion 142 is provided continuously around the outer edge portion 133 of the elastic sheet 131.

[0033] The lower insert 150 and the upper insert 170 are parts that are disposed between the lower mold 110 and the upper mold 130 and that sandwich and fix the outer edge portion 210 of the glass mat 200. The lower insert 150 and the upper insert 170 are hard relative to the upper mold 130 and the lower mold 110. The lower insert 150 and the upper insert 170 have, for example, a Rockwell hardness of R25 or more.

[0034] In this way, by using hard materials for the lower insert 150 and the upper insert 170, it is possible to form a smooth surface in the portion of the resin molded product that is sandwiched between the lower insert 150 and the upper insert 170. Therefore, it is possible to ensure the surface precision of the outer edge of the resin molded product, which requires surface precision.

[0035] Moreover, the lower insert 150 and the upper insert 170 are made of polyacetal (POM). This ensures that the upper insert 170 and the lower insert 150 do not stick to the resin molded product after resin molding. In addition, this has the advantage of being solvent resistant and highly processable.

[0036] The lower insert 150 and the upper insert 170 may be formed from other materials such as polyethylene (PE), polypropylene, or fluororesin.

[0037] 1, the lower insert 150 has a ring-like shape with a part of it missing. On the other hand, the upper insert 170 has a ring-like shape. The lower insert 150 and the upper insert 170 only need to be able to sandwich a part of the outer edge 210 of the glass mat 200, and do not have to be ring-like.

[0038] The lower insert 150 and the upper insert 170 may be configured by combining multiple divided parts. Furthermore, the lower insert 150 and the upper insert 170 may be configured by disposing multiple parts intermittently. By configuring the lower insert 150 and the upper insert 170 from multiple divided parts, it is possible to improve workability.

[0039] The lower insert 150 is fitted into a tapered pin or a positioning pin (not shown) provided on the lower die 110. This positions the lower insert 150 relative to the lower die 110. The positioning of the lower insert 150 relative to the lower die 110 may be performed by a method based on the fitting shape of the lower insert 150 and the lower die 110, or by a method using a part other than the shaft.

[0040] 6, in the fixing process, the glass mat 200 is sandwiched between the lower insert 150 and the upper insert 170. At this time, the lower insert 150 and the upper insert 170 are used in such a shape that the side surface 171 of the upper insert 170 and the side surface 151 of the lower insert 150 are positioned on the same plane. This makes it possible to secure the space 101 next to the side surface 171 of the upper insert 170 and the side surface 151 of the lower insert 150 in the fixing process.

[0041] The lower nesting member 150 used has a groove 152 formed on a side surface 151. The groove 152 is a portion that serves as a demolding point for demolding the resin molded product from the lower die 110 after resin molding. The groove 152 is formed on the surface of the lower nesting member 150 that faces the lower die 110. For example, a tool such as a crowbar is inserted into the groove 152, and the crowbar is moved by the principle of leverage to demold the product. The groove 152 may be a hole formed in a part of the side surface 151 of the lower nesting member 150.

[0042] 7, the lower insert 150 has a magnet 153. The upper insert 170 has a magnet 172. Each of the magnets 153, 172 is, for example, a neodymium magnet. Each of the magnets 153, 172 provides each of the inserts 150, 170 with a function of positioning each of the inserts 150, 170 in a non-contact manner and a function of applying pressure to the glass mat 200 by each of the inserts 150, 170.

[0043] The magnet 172 is exposed on a surface of the upper insert part 170 that faces the lower insert part 150. Similarly, the magnet 153 is exposed on a surface of the lower insert part 150 that faces the upper insert part 170. The magnet 172 may be insert molded in the upper insert part 170. Similarly, the magnet 153 may be insert molded in the lower insert part 150.

[0044] It is sufficient that the magnets 153, 172 are able to attract each other without contacting each other. Therefore, the magnets 153, 172 are not limited to being solid, and may have any configuration as long as they can apply an attractive force in a non-contact state by being kneaded into the material of the nesting members 150, 170 and by being electromagnets.

[0045] 6, the outer edge 210 of the glass mat 200 is sandwiched between the lower insert 150 and the upper insert 170 so that the side surface 171 of the upper insert 170 and the side surface 151 of the lower insert 150 are positioned on the same plane. The position of the upper insert 170 relative to the lower insert 150 is fixed by the magnet 172 of the upper insert 170 and the magnet 153 of the lower insert 150.

[0046] As a result, a part of the outer edge 210 of the glass mat 200 protrudes as a protrusion 220 from the side surface 171 of the upper insert 170 and the side surface 151 of the lower insert 150 .

[0047] Subsequently, after the fixing step, a cutting step is performed in which the protruding portions 220 of the outer edge portion 210 of the glass mat 200 protruding from the respective side surfaces 151, 171 of the respective nesting members 150, 170 are cut along the respective side surfaces 151, 171 of the respective nesting members 150, 170 using a tool such as scissors.

[0048] Since the space 101 is provided next to each side surface 151, 171 of each of the nests 150, 170, i.e., the space for cutting the protruding portion 220 is provided, the protruding portion 220 of the glass mat 200 can be easily cut. No large-scale equipment such as a machine tool is required, and workability is improved.

[0049] Thereafter, in the assembly process, the upper die 130 is fixed to the lower die 110 with the protruding portion 136 of the joint portion 134 facing the glass mat 200. The upper die 130 is assembled to the lower die 110 with a part of the upper die 130 in contact with each of the side surfaces 151, 171 of the respective inserts 150, 170.

[0050] 7 and 8, the lower mold 110 has a recess 114 formed by recessing an outer edge 113 of an opposing surface 112 of the lower mold 110 facing the upper mold 130. The upper mold 130 has an opposing surface 143 facing the lower mold 110, where a portion corresponding to the recess 114 protrudes, and has a protrusion 144 that fits into the recess 114. As a result, the protrusion 144 of the upper mold 130 fits into the recess 114 of the lower mold 110, so that the upper mold 130 can be positioned with respect to the lower mold 110.

[0051] The lower mold 110 has a flat surface 115, the portion of which corresponding to the mold clamping portion 142 of the upper mold 130 is flat. The mold clamping portion 142 of the upper mold 130 has a vacuum passage 145 as a space formed by part of an outer edge portion 133 of the elastic sheet 131 being recessed on the side opposite to the flat surface portion 115 of the lower mold 110. As shown in FIG. 8, the vacuum passage 145 is evacuated via a joint portion 134 provided in the upper mold 130.

[0052] In this embodiment, in a state in which the upper mold 130 is fixed to the lower mold 110 by the mold clamping portion 142, the cross-sectional shape of the vacuum passage 145 in a direction perpendicular to both the direction in which the mold clamping portion 142 extends and the surface direction of the flat portion 115 is an inverted trapezoidal shape based on the surface of the flat portion 115. In other words, the upper base of the trapezoid faces the flat portion 115 side.

[0053] The inventors investigated by simulation the lifting of the outer edge portion 133 of the upper die 130 for the cases where the cross-sectional shape of the vacuum passage 145 is an inverse trapezoid as well as for the comparative examples shown in Figs.

[0054] 9 shows that a flange portion 146 that comes into contact with the flat portion 115 is provided in a portion of the mold clamping portion 142 that constitutes a vacuum passage 145. When the mold clamping portion 142 is evacuated, the flange portion 146 is lifted off the flat portion 115, and the portion indicated by the arrow in FIG.

[0055] 10, the cross-sectional shape of the vacuum passage 145 is rectangular. Due to the vacuuming of the mold clamping section 142, the part indicated by the arrow in FIG. 10 is raised up more from the opposing surface 112 of the lower mold 110 than in the case of the shape in FIG.

[0056] 11 shows a case in which a convex portion 147 provided on an upper mold 130 is fitted into a groove portion 116 provided on an opposing surface 112 of a lower mold 110, thereby forming a vacuum passage 145 in a gap between the bottom of the groove portion 116 and the convex portion 147. In this case, the part indicated by the arrow in FIG. 11 is raised up more from the opposing surface 112 of the lower mold 110 than in the case of the shape in FIG. 10 due to the vacuuming of the mold clamping portion 142.

[0057] 12, the cross-sectional shape of the vacuum passage 145 is circular. Due to the vacuuming of the mold clamping section 142, the part indicated by the arrow in FIG. 12 is raised up more than in the case of the shape in FIG.

[0058] 9 to 12, when the cross-sectional shape of the vacuum passage 145 is the inverse trapezoidal shape shown in Fig. 7 and Fig. 8, the outer edge portion 133 of the upper mold 130 does not float up. Therefore, by making the cross-sectional shape of the vacuum passage 145 an inverse trapezoidal shape, it is possible to prevent the part of the outer edge portion 133 of the upper mold 130 outside the mold clamping portion 142 from floating up from the lower mold 110 when the upper mold 130 is clamped to the lower mold 110 by the mold clamping portion 142.

[0059] The thickness of the part of the mold clamping part 142 constituting the vacuum passage 145 that faces the flat part 115 of the lower mold 110 is preferably 5 mm or more. If the thickness of this part is less than 5 mm, the amount of depression of this part increases when drawing a vacuum, making it difficult to suppress the lifting of the outer edge part 133 of the upper mold 130.

[0060] 7 and 8, a resin flow path 148 for supplying resin between the upper mold 130 and the lower mold 110 is provided on the outer edge 133 of the upper mold 130. A part of the convex portion 144 of the upper mold 130 is recessed, and a space formed by fitting the convex portion 144 of the upper mold 130 into the concave portion 114 of the lower mold 110 is configured as the resin flow path 148.

[0061] Resin flow path 148 is provided so as to go around outer edge portion 133 of upper mold 130. That is, resin flow path 148 is provided around the outer periphery of mold portion 111 of lower mold 110. Also, as shown in Fig. 7, resin flow path 148 includes a thin branch portion that extends to the gap between upper insert 170 and lower insert 150. A plurality of branch portions are provided in upper mold 130.

[0062] The upper mold 130 is provided with a resin flow path 148, but the lower mold 110 is not provided with a groove that serves as the resin flow path 148.

[0063] Next, a molding process is performed. In the molding process, a vacuum drawing process is first performed. In the vacuum drawing process, the mold clamping portion 142 of the upper mold 130 is vacuumed to perform the molding, and the mold portion 111 is vacuumed through the joint portion 134 for vacuum drawing of the upper mold 130.

[0064] When drawing a vacuum, edge 139 of elastic sheet 131 adheres closely to the outer wall of one end 137 of pipe portion 135 of joint portion 134. That is, since the inside of mold 100 is in a vacuum state and pressure is applied to the surface of mold 100 by the atmospheric pressure outside mold 100, elastic sheet 131 of upper mold 130 is in a vacuum-packed state. Therefore, elastic sheet 131 adheres tightly to joint portion 134.

[0065] Thereafter, in the resin injection step, resin is injected into the interior of the molding die 100 from the resin injection joint portion 134 and cured. Even if the resin overflows from the resin flow path 148 due to the resin injection pressure becoming greater than the vacuum pressure during resin injection, the resin is unlikely to overflow the side wall of the recess 114 of the lower die 110. Therefore, the mold clamping pressure of the mold clamping portion 142 located further outboard than the recess 114 can be ensured.

[0066] After the resin injection step, a demolding step is performed. For this purpose, the upper mold 130 is removed from the upper insert 170. Furthermore, the lower insert 150 is removed from the lower mold 110 with a tool inserted into the groove 152 of the lower insert 150, thereby demolding the resin molded product from the lower mold 110. During demolding, the tool comes into contact with the lower insert 150 but does not come into contact with the resin molded product. For this reason, the finished resin molded product can be demolded from the lower mold 110 without being damaged.

[0067] After demolding, as shown in Fig. 13, only thin runners 320 formed by hardened resin in the resin flow paths 148 of the upper mold 130 are formed at the outer edge 310 of the finished resin molded product 300. Therefore, the outer edge 310 of the resin molded product 300 can be completed by simply folding the runners 320 at the positions of the dashed lines shown in Fig. 13. Fig. 13 is a cross section corresponding to VII-VII in Fig. 4.

[0068] Therefore, in a post-process, the runner 320 of the resin molded product 300 is broken to separate the runner 320 from the resin molded product 300. In addition, the resin molded product 300 is subjected to a finishing process, a hole-making process, and the like. In this manner, the resin molded product 300 is completed.

[0069] By repeating the above steps, it is possible to manufacture a plurality of resin molded products 300 of the same shape. In other words, the joint portion 134 is repeatedly used. However, the joint portion 134 deteriorates as a result of repeated use.

[0070] For example, the joint portion 134 may change color from translucent to yellow and lose transparency, the joint portion 134 may lose elasticity, the joint portion 134 may be damaged by inserting and removing the joint portion 140, or the hardness of the outer wall of the joint portion 134 may change. In such cases, the joint portion 134 is replaced with a new one.

[0071] In this way, by replacing the joint portion 134 with a new one according to deterioration, it is possible to maintain the suppression of vacuum leakage. Moreover, since the joint portion 134 is only in contact with the elastic sheet 131 of the upper mold 130, the joint portion 134 can be easily removed from the through hole 132 of the elastic sheet 131. Therefore, the joint portion 134 can be easily replaced.

[0072] As described above, in this embodiment, prior to the molding step, the outer edge 210 of the glass mat 200 is fixed in advance by the lower insert 150 and the upper insert 170. This makes it possible to prevent the glass mat 200 from shifting when the resin is injected into the molding die 100.

[0073] In addition, in the cutting process, the protruding portion 220 of the glass mat 200 is cut along each side surface 151, 171 of each of the nesting members 150, 170. This allows the outer edge portion 310 of the resin molded product 300 to be preliminarily adjusted to a shape along each side surface 151, 171 of each of the nesting members 150, 170. Therefore, it is possible to eliminate the need for a trimming process for cutting unnecessary portions of the outer edge portion 310 of the resin molded product 300 after the demolding process.

[0074] Furthermore, since the glass mat 200 is sandwiched between the nests 150 and 170, the size of the glass mat 200 can be adjusted in advance. This makes it possible to reduce the portion of the outer edge 210 of the glass mat 200 that is cut. This makes it possible to reduce waste of the glass mat 200 and resin.

[0075] In this embodiment, a joint portion 134 for resin injection and vacuum drawing is used. This allows the elastic sheet 131, which is made of silicone with different hardness, and the joint portion 134 to adhere closely to each other. Therefore, the silicones adhere closely to each other when a vacuum is drawn, so that vacuum leakage from the joint portion 134 can be suppressed.

[0076] In addition, since the elastic sheet 131 is softer than the joint portion 134, the soft edge portion 139 is subjected to atmospheric pressure during evacuation, so that the edge portion 139 tightly adheres to the joint portion 134. That is, the surface contact between the edge portion 139 and the outer wall surface of the joint portion 134 becomes strong. Therefore, the joint portion 134 is tightly fastened by the edge portion 139, so that vacuum leakage can be further suppressed.

[0077] 14, the forming mold 100 may be composed of a lower mold 110, an upper mold 130, and an upper insert 170 without including a lower insert 150. In this case, the lower mold 110 has a magnet 117. The magnet 117 provides the lower mold 110 with a function of positioning the lower mold 110 and the upper insert 170 without contacting each other, and a function of pressing the glass mat 200 with the lower mold 110 and the upper insert 170. Also, instead of sandwiching the outer edge 210 of the glass mat 200 between the lower mold 110 and the upper insert 170, the outer edge 210 of the glass mat 200 is sandwiched between the lower mold 110 and the upper insert 170, and the position of the upper insert 170 relative to the lower mold 110 is fixed by the magnet 172 and the magnet 117. At this time, by arranging the side surface 118 of the lower mold 110 and the side surface 171 of the upper insert 170 on the same plane, it becomes easier to cut the protruding portion 220 of the glass mat 200 .

[0078] (Other embodiments) The manufacturing method of the resin molded product 300 shown in each of the above embodiments is merely an example, and the present invention is not limited to the above-described configurations, and other configurations are also possible that can realize the present invention.

[0079] For example, in the above embodiment, a method for manufacturing the resin molded product 300 using the respective inserts 150, 170 in the silicon back method has been described, but the resin molded product 300 can also be manufactured using the respective inserts 150, 170 in other molding methods such as the L-RTM molding method. The L-RTM molding method is a molding method in which a fiber reinforcement material is placed in a resin mold, the mold is closed, and a vacuum is created to inject resin at low pressure to integrate it with the reinforcing base material.

[0080] Furthermore, the side surface 171 of the upper insert 170 does not have to be flush with the side surface 151 of the lower insert 150 or the side surface 118 of the lower die 110. For example, the side surface 171 of the upper insert 170 may be located more inward than the side surface 151 of the lower insert 150 or the side surface 118 of the lower die 110. In this case, the protruding portion 220 of the glass mat 200 may be cut along the side surface 171 of the upper insert 170 using a tool such as a rotary cutter. [Explanation of symbols]

[0081] 110 Lower mold 130 Upper mold 150 Lower Nest 151 Side 152 Groove 153 Magnet 170 Upper nesting 171 Side 172 Magnet 200 Glass Mat 210 Outer edge 220 Protrusion

Claims

1. a step of placing a glass mat (200) made of glass fiber between the lower mold (110) and the upper mold (130); a molding step of injecting a resin into the glass mat while drawing a vacuum between the lower mold and the upper mold, and hardening the resin; Including, In the installation step, a fixing step of preparing an upper insert (170), sandwiching an outer edge portion (210) of the glass mat between the lower mold and the upper insert, and fixing the position of the upper insert relative to the lower mold; After the fixing step, a cutting step is performed in which a protruding portion (220) of the outer edge portion of the glass mat that protrudes from a side surface (171) of the upper insert is cut along the side surface of the upper insert. an assembling step of assembling the upper die to the lower die in a state in which a part of the upper die is in contact with the side surface of the upper insert after the cutting step; A method for producing a resin molded product comprising the steps of:

2. In the fixing step, an upper insert having a magnet (172) is prepared, and a lower insert having a magnet (153) and a lower insert having a groove (152) on a side surface (151) is prepared, and the outer edge of the glass mat is sandwiched between the lower insert and the upper insert, rather than between the lower insert and the upper insert, and the position of the upper insert is fixed relative to the lower insert by the magnet of the upper insert and the magnet of the lower insert. In the assembling step, the upper mold is assembled to the lower mold in a state in which a part of the upper mold is in contact with a side surface of the upper insert and a side surface of the lower insert; 2. The method for manufacturing a resin molded product according to claim 1, wherein the molding step includes a demolding step of, after hardening the resin, removing the lower insert from the lower mold with a tool inserted into a groove of the lower insert, thereby demolding the resin molded product (300) from the lower mold.

3. In the fixing step, when the outer edge of the glass mat is sandwiched between the lower insert and the upper insert, the position of the upper insert is fixed relative to the lower insert so that the side surfaces of the upper insert and the lower insert are positioned on the same plane; The method for producing a resin molded product according to claim 2 , wherein in the cutting step, the protruding portion of the glass mat is cut along a side surface of the upper insert and a side surface of the lower insert.

4. The method for manufacturing a resin molded product according to claim 2 or 3, wherein in the fixing step, the upper insert and the lower insert are made of hard materials relative to the upper mold and the lower mold.

5. 5. The method for producing a resin molded product according to claim 2, wherein the upper insert and the lower insert are made of polyacetal in the fixing step.

6. 6. The method for manufacturing a resin molded product according to claim 1, wherein in the installation process, an upper mold is used that has a resin flow path (148) for supplying the resin between the upper mold and the lower mold, and a lower mold is used that does not have the resin flow path.

7. 7. A method for manufacturing a resin molded product according to claim 1, wherein in the installation step, a lower mold is used that has a recess (114) formed in an outer edge portion (113) of an opposing surface (112) facing the upper mold, and a top mold is used that has a protrusion (144) that protrudes from an opposing surface (143) facing the lower mold and that fits into the recess.

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