Resin molded articles

Abstract

To provide a resin molding which makes a gate mark inconspicuous when a design surface is viewed.SOLUTION: A resin molding includes: a body part which has a first design surface; and an overhanging part which overhangs to a side opposite to the first design surface in a thickness direction of the body part from a peripheral edge part of the body part and the outside of the body part, and has a second design surface continuous to the first design surface, wherein the overhanging part has: a tip part in an overhanging direction; and a general part between the tip part and the body part, an outer surface of the tip part is positioned inside the body part rather than a definition line for determining the general part and the tip part, and has a gate mark formed at the tip part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a resin molded product.

Background Art

[0002] Patent Document 1 includes a first mold for molding a surface other than the fastening surface on one plate surface, and a second mold for molding the other plate surface of the foamed resin molded product. A cavity is formed between the first mold and the second mold, and the volume of the cavity can be expanded by separating the first mold and the second mold. A mold body is configured, and a portion for molding the fastening surface and a portion for molding the end surface are assembled to the mold body so as to be exposed to the cavity, and an insert for molding a corner portion is provided. A molding die made of a metal having a higher thermal conductivity than the mold body is disclosed, wherein the portion for molding the corner portion of the insert.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration described in Patent Document 1, when viewed from the design surface side, there is a risk that the design property may be deteriorated because the gate mark, which is the trace of the resin material injection port formed during molding, is visible.

[0005] An object of the present disclosure is to provide a resin molded product in which the gate mark is not conspicuous when the design surface is viewed.

Means for Solving the Problems

[0006] Means for solving the above problems include the following embodiments. <1> A main body portion having a first design surface, An overhang extending from the peripheral edge of the main body portion in the thickness direction of the main body portion on the opposite side of the first design surface and outward from the main body portion, and having a second design surface that is continuous with the first design surface, Equipped with, The protruding portion has a tip portion in the direction of protrusion and a general portion between the tip portion and the main body portion. The outer surface of the tip portion is located inside the main body portion beyond the defining line that determines the general portion and the tip portion. A gate mark is formed at the tip portion. Resin molded product. <2> The aforementioned defining line is defined as a step extending from the second design surface of the general part toward the inside of the main body. <1> The resin molded product described above. <3> In the second design surface, a parting line is formed on the defining line. <1> The resin molded product described above. <4> The demarcation line is located at a position of 0.5 mm to 2.0 mm from the tip of the protruding portion. <1> The resin molded product described above. <5> The tip of the protruding portion is arc-shaped. <1> from <4> A resin molded product as described in any one of the items. <6> The end of the gate trace connects to the end of the side of the protruding portion opposite to the second design surface. <1> from <5> A resin molded product as described in any one of the items. <7> A first resin foam region is formed inside the main body. A second resin foam region is formed inside the protruding portion, which is connected to the first resin foam region. <1> from <6> A resin molded product as described in any one of the items. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a resin molded product in which gate marks are not noticeable when viewed from a design perspective. [Brief explanation of the drawing]

[0008] [Figure 1] It is a cross-sectional view showing a part of a foamed resin molded product according to the first embodiment of the present disclosure. [Figure 2] It is a cross-sectional view of a mold according to the first embodiment of the present disclosure. [Figure 3] It is a cross-sectional view showing the periphery of the gate portion of the mold shown in FIG. 2. [Figure 4] It is a cross-sectional view showing a state where resin is filled in the mold shown in FIG. 2. [Figure 5] It is a cross-sectional view showing a state where the resin around the gate portion is filled in the mold shown in FIG. 4. [Figure 6] It is a cross-sectional view showing a state where the movable mold moves in the opening direction with respect to the fixed mold and the resin foams in the mold shown in FIG. 4. [Figure 7] It is a cross-sectional view showing a state where the resin around the gate portion foams in the mold shown in FIG. 6. [Figure 8] It is a cross-sectional view showing a state where the movable mold is moved in the opening direction and the foamed resin molded product is taken out in the mold shown in FIG. 6. [Figure 9] It is a cross-sectional view showing the periphery of the gate portion in the mold shown in FIG. 8. [Figure 10] It is a cross-sectional view showing a state where the movable mold moves in the opening direction and the resin foams in the mold of the comparative example. [Figure 11] It is a cross-sectional view showing a state where the resin around the gate portion foams in the mold of the comparative example shown in FIG. 10. [Figure 12] It is a cross-sectional view showing a state where the movable mold moves in the opening direction and the resin foams around the gate portion of the mold according to the second embodiment of the present disclosure. [Figure 13] It is a cross-sectional view showing a state where the movable mold is moved in the opening direction and the foamed resin molded product is taken out around the gate portion of the mold shown in FIG. 12. [Figure 14] It is a view showing a state where a foamed resin molded product molded using a mold according to the third embodiment of the present disclosure is visually recognized. [Figure 15]A cross-sectional view showing a state in which the protruding portion of the foamed resin molded product is gradually reduced toward the tip around the gate portion of the mold according to the third embodiment of the present disclosure. [Figure 16] FIG. 15 is a cross-sectional view showing a state in which the movable mold is moved in the opening direction to take out the foamed resin molded product around the gate portion of the mold shown in FIG. 15. [Figure 17] FIG. 6 is a view showing a state in which a foamed resin molded product molded using the mold according to the fourth embodiment of the present disclosure is visually recognized. [Figure 18] FIG. 9 is a cross-sectional view showing a state in which the gate of the foamed resin molded product is formed inside the width direction from the tip of the protruding portion around the gate portion of the mold according to the fourth embodiment of the present disclosure. [Figure 19] FIG. 18 is a cross-sectional view showing a state in which the movable mold is moved in the opening direction to take out the foamed resin molded product around the gate portion of the mold shown in FIG. 18. [Figure 20] FIG. 15 is a cross-sectional view showing a state in which a foamed resin molded product molded using the mold according to the fifth embodiment of the present disclosure is visually recognized. [Figure 21] FIG. 18 is a cross-sectional view showing a state in which the gate of the foamed resin molded product is formed in a flat shape around the gate portion of the mold according to the fifth embodiment of the present disclosure. [Figure 22] FIG. 22 is a cross-sectional view showing a state in which the movable mold is moved in the opening direction to take out the foamed resin molded product around the gate portion of the mold shown in FIG. 22.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments for carrying out the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the components are not essential unless otherwise specified. The same applies to numerical values and their ranges, which do not limit the present disclosure.

[0010] The arrow X shown in each figure indicates the width direction of the resin molded product 70, and the arrow Y indicates the opening and closing direction in which the movable mold 26 of the mold 10 opens and closes with respect to the fixed mold 20, which is a direction intersecting the width direction of the resin molded product 70.

[0011] [First Embodiment] [Resin molded product 70] A resin molded product according to the first embodiment of this disclosure comprises a main body having a first design surface, and an overhang extending from the peripheral edge of the main body on the opposite side of the first design surface in the thickness direction of the main body and outward from the main body, and having a second design surface connected to the first design surface, wherein a gate mark is formed at the tip of the overhang on the opposite side of the second design surface in the thickness direction of the overhang from the tip in the overhang direction. Specific examples of resin molded products will be described below with reference to the drawings, but this disclosure is not limited thereto.

[0012] As shown in Figure 1, the resin molded product 70 of this embodiment is a foamed resin molded product using foamed resin. The resin molded product 70 has a main body portion 72, an overhang portion 76, and a gate mark 80.

[0013] (Main body 72) The main body portion 72 is a flat plate-like portion that extends in the X direction. This main body portion 72 extends in the X direction, and at the peripheral edge portion 74 of the end in the X direction (the lower side in the drawing in Figure 1), an overhang portion 76 is formed that protrudes outward in the X direction.

[0014] (Protrusion 76) The protruding portion 76 extends in the protruding direction, which is the direction in which it protrudes from the peripheral portion 74. This protruding portion 76 has a general portion 78 and a tip portion 84. The tip portion 84 is the tip of the protruding portion 76 in the protruding direction. The general portion 78 is the part of the protruding portion 76 from the tip portion 84 to the main body portion 72. The thickness of this general portion 78 may be constant in the protruding direction or may increase or decrease.

[0015] The direction of the protrusion of the protruding portion 76 is indicated by arrow L in the figure. The direction of the thickness of the protruding portion 76, which is perpendicular to the direction of the protrusion of the protruding portion 76, is indicated by arrow T. In other words, the direction of arrow L in this disclosure is inclined outward with respect to the X direction.

[0016] As shown in Figure 1, the other side of the main body portion 72 in the Y direction (left side in Figure 1) is the first design surface 86A, which forms part of the design surface of the resin molded product 70. Also, one side of the protruding portion 76 in the T direction (lower left side in Figure 1) is the second design surface 86B, which forms part of the design of the resin molded product 70. The first design surface 86A and the second design surface 86B are connected.

[0017] Furthermore, the side of the protruding portion 76 opposite to the second design surface 86B is referred to as the opposite surface.

[0018] (Foaming area) The main body portion 72 of this embodiment has a first resin foam region (hereinafter referred to as the "first foam region") 88A inside. The first foam region 88A extends in the X direction.

[0019] The protruding portion 76 of this embodiment has a second resin foam region (hereinafter referred to as the "second foam region") 88B inside. The second foam region 88B may extend in the L direction. The first foam region 88A and the second foam region 88B may be connected or separate. In this embodiment, as shown in Figure 1, the first foam region 88A and the second foam region 88B are connected.

[0020] Furthermore, the average diameter of the bubbles in the first foaming region 88A and the second foaming region 88B may be, for example, 0.02 mm or more and 0.15 mm or less.

[0021] In this embodiment, a second foamed region 88B is formed inside the protruding portion 86, but the disclosure is not limited thereto, and a second foamed region 88B does not necessarily have to be formed inside the protruding portion 86. Furthermore, the second foamed region 88B may be divided in the L direction of the protruding portion 86, and its foaming rate may be lower than that of the first foamed region 88A.

[0022] (Tip 84) In this embodiment, the tip portion 84, as shown in Figure 1, is the tip-side portion of the protruding portion 76 defined by the defining line D from the general portion 78, and is thinner than the general portion 78. Furthermore, the tip side of the tip portion 84 (one side in the direction of arrow L) is arc-shaped, as shown in Figure 1, and has a gate mark 80 formed during molding. In addition, the general portion 78 and the tip portion 84 of the protruding portion 76 in this embodiment are defined by a step S, as shown in Figure 1. That is, the defining line D in this embodiment is the step S, and the tip portion 84 is the part that is thinner than the general portion 78 on one side in the direction of arrow L from the step S. Moreover, because the tip portion 84 is thin and is formed in the second cavity 64 where the volume expansion during core backing of the mold 10 is small, the amount of foaming is small, and there is little deformation of the shape due to foaming. Thus, the thickness of the foamed region formed inside the tip portion 84 of the protruding portion 76 is thinner than the foamed region formed inside the main body portion 72, and is less than or equal to the thickness of the foamed region formed inside the general portion 78 of the protruding portion 86.

[0023] In other words, in this embodiment, the protruding portion 76 can be said to have a base end where it connects to the peripheral edge 74 of the main body portion 72, and a tip end 84 on the opposite side.

[0024] (Gate remains 80) The gate mark 80 is a portion formed during the injection molding process described later, and is a rough fracture surface formed by the fracture of the resin material R. In this embodiment, the gate mark 80 is formed including the tip of the arc-shaped tip portion 84 in the protruding direction. In other words, the gate mark 80 is formed including the point (the vertex of the tip portion 84) that contacts the tangent F which is parallel to the T direction, which is the thickness direction of the protruding portion 76, and is in contact with the tip portion 84. In other words, the gate mark 80 is formed on the tip portion 84 from one side to the other in the T direction with respect to the vertex that coincides with the tangent F which is pointing in the T direction. In other words, the gate mark 80 is formed on the tip portion 84 on the side opposite to the second design surface 86B.

[0025] The length of the tip portion 84 in the direction of arrow L may be, for example, 0.5 mm or more and 2.0 mm or less.

[0026] Furthermore, the step S is formed overlapping with the parting line PL that was formed during molding, as will be described later.

[0027] Next, the mold 10 and manufacturing process used in the production of the resin molded product 70 according to this embodiment will be described.

[0028] [Mold 10] The mold according to the first embodiment of this disclosure comprises: a fixed mold as a first mold; a movable mold as a second mold, which is movable relative to the fixed mold in an opening and closing direction, and forms a first cavity that extends between itself and the fixed mold in a direction intersecting the opening and closing direction, and a second cavity that extends from the end of the first cavity in the intersecting direction toward the fixed mold in an opening direction toward the fixed mold, thereby increasing the volume of the first cavity and the second cavity by movement in the opening direction; and a sliding mold, which is movable relative to the fixed mold, forms the end of the second cavity in the opening direction, and maintains its relative position with respect to the volume expansion operation of the first cavity and the second cavity by the movable mold.Specific examples of the mold will be described below with reference to the drawings, but this disclosure is not limited thereto.

[0029] Figures 2 and 3 show a portion of a mold 10 according to the first embodiment. This mold 10 comprises a fixed mold 20, a movable mold 26, a first slide mold 34, a second slide mold 36, and a slide core 56. Figures 2 and 3 show portions of the same mold 10 in the depth direction of the drawing, respectively. The first slide mold 34, the second slide mold 36, and the slide core 56 are examples of slide molds according to this disclosure.

[0030] (Fixed type 20) The fixed mold 20 has a bottom portion 22 extending in the X direction, and a rising portion 24 rising from one side of the bottom portion 22 in the X direction (the lower side in the drawings in Figures 2 and 3) toward one side in the Y direction (the right side in the drawings in Figures 2 and 3). As shown in Figures 2 and 3, the fixed mold 20 has a concave shape due to the bottom portion 22 and the rising portion 24. This fixed mold 20 is fixed to an injection molding machine (not shown).

[0031] (Movable type 26) The movable mold 26 has a main body portion 72 extending in the X direction and a protruding portion 30 that protrudes from the inside of the main body portion 72 in the X direction to the other side in the Y direction (the left side in the drawings in Figures 2 and 3). As shown in Figures 2 and 3, the movable mold 26 has a convex shape due to the main body portion 72 and the protruding portion 30. This movable mold 26 is supported by an injection molding machine (not shown) so as to be movable in the Y direction. Note that since Figures 2 and 3 show a portion of the same mold 10 in the depth direction of the drawing, the movable mold 26 in Figure 2 and the movable mold 26 in Figure 3 move in the Y direction simultaneously. The movable mold 26 is also provided with a stepped through hole 32 whose diameter is enlarged on one side in the Y direction.

[0032] (First slide type 34) The first slide type 34 is an example of a slide type according to this disclosure, and as shown in Figure 2, it is positioned between the fixed type 20 and the movable type 26, surrounded by the movable type 26. The first slide type 34 is separate from the movable type 26 and is capable of moving in the Y direction at a different timing than the movable type 26.

[0033] Furthermore, as shown in Figure 2, the first slide mold 34 is pressed against the fixed mold 20 by a push pin 40 from one side in the Y direction when the movable mold 26 is in contact with the fixed mold 20 (mold closed state). The push pin 40 is inserted from one side in the Y direction into a stepped through hole 32 that penetrates the movable mold 26 in the Y direction, and is movable in the Y direction.

[0034] The push pin 40 has a flange portion 40C on one side in the Y direction. As shown in Figure 2, when the movable mold 26 is in contact with the fixed mold 20, it is pressed from one side in the Y direction by an injection molding apparatus (not shown) via a biasing member 50. The biasing member 50 is, for example, a coil spring. Also, in the state shown in Figure 2, i.e., when the fixed mold 20 and the movable mold 26 are in contact, the length to which the biasing member 50 is compressed from its natural length is longer than the travel length of the volume expansion operation described later.

[0035] (Second slide type 36) The second slide type 36 is another example of a slide type according to this disclosure, and as shown in Figure 3, it is positioned between the fixed type 20 and the movable type 26, surrounded by the movable type 26. The second slide type 36 is separate from the movable type 26 and is capable of moving in the Y direction at a different timing than the movable type 26. In this embodiment, the first slide type 34 and the second slide type 36 are separate in the depth direction of the paper in Figures 2 and 3.

[0036] The second slide type 36 has an angular pin 38 fixed to one side in the Y direction. This angular pin 38 penetrates the movable type 26 while moving in the Y direction and tilting in the X direction.

[0037] Furthermore, the second slide type 36 is provided with a stepped through hole 44 whose diameter is enlarged on one side in the Y direction.

[0038] (Slide core 56) As shown in Figure 3, the slide core 56 is positioned between the fixed mold 20 and the second slide mold 36 and is in contact with the fixed mold 20. The slide core 56 also has a gate 58 that opens toward the other side in the Y direction and a flow path C that connects the gate 58 to an injection molding apparatus (not shown). The flow path C is in the depth direction of the paper in Figure 3.

[0039] Furthermore, the slide core 56 has a push pin 42 fixed to one side in the Y direction. This push pin 42 has a flange portion 42C on one side in the Y direction that has a larger diameter than the reduced diameter portion 44B of the stepped through hole 44. Also, as shown in Figure 3, the flange portion 42C of the push pin 42 is located inside the enlarged diameter portion 44A of the stepped through hole 44 of the second slide mold 36 when the movable mold 26 is in contact with the fixed mold 20.

[0040] Furthermore, as shown in Figure 3, when the movable mold 26 is in contact with the fixed mold 20, the slide core 56 is pressed against the fixed mold 20 by the second slide mold 36 via the biasing member 50. The biasing member 50 is, for example, a coil spring. The surface where the fixed mold 20 and the slide core 56 come into contact is referred to as the dividing surface 68. Also, in the state shown in Figure 3, that is, when the fixed mold 20 and the movable mold 26 are in contact, the length to which the biasing member 50 is compressed from its natural length is longer than the travel length of the volume expansion operation described later.

[0041] (Cavity 60) Here, as shown in Figures 2 and 3, when the fixed mold 20 and the movable mold 26 are in contact, the cavity 60 is formed by the fixed mold 20, the movable mold 26, the first slide mold 34, the second slide mold 36, and the slide core 56. The cavity 60 has a first cavity 62 and a second cavity 64.

[0042] The first cavity 62 of cavity 60 extends in the X direction, as shown in Figures 2 and 3, and constitutes the majority of the resin molded product 70 in the X direction. The second cavity 64 is the portion that extends from one end of the first cavity 62 in the X direction toward one side in the X direction and one side in the Y direction (the lower right side in Figures 2 and 3). That is, the Y direction is also the opening and closing direction in this disclosure.

[0043] As will be described later, in this disclosure, the resin molded product 70 formed by injecting resin material R into the cavity 60 has a design surface on the side that contacts the fixed mold 20. That is, the resin material R injected into the first cavity 62 becomes the main body portion 72 having the first design surface 86A, and the resin material R injected into the second cavity 64 becomes the protruding portion 76 having the second design surface 86B.

[0044] As shown in Figure 2, in this embodiment, a step 66 is formed in the T direction between the rising portion 24 of the fixed mold 20 and the first sliding mold 34 at the tip of the second cavity 64.

[0045] Furthermore, as shown in Figure 2, in this embodiment, the step S in the resin molded product 70 becomes a defining line D that defines the general portion 78 and the tip portion 84 of the protruding portion 76 of the resin molded product 70. In other words, in this embodiment, the surface where the fixed mold 20 and the first slide mold 34 come into contact is also the portion where the defining line D in the resin molded product 70 is formed.

[0046] Furthermore, as shown in Figure 2, in this embodiment, at the contact surface between the fixed mold 20 and the first slide mold 34, the resin material R seeps out during resin injection (details to be described later), forming a parting line PL, which is a linear protrusion when viewed from the second design surface 86B side. In other words, the contact surface between the fixed mold 20 and the first slide mold 34 in this embodiment is also the area where the parting line PL is formed in the resin molded product 70.

[0047] As shown in Figure 3, in this embodiment, a step 66 is formed in the T direction between the rising portion 24 of the fixed mold 20 and the slide core 56 at the tip of the second cavity 64. This step 66 is positioned further inward in the X direction on the slide core 56 side of the dividing surface 68. In other words, the fixed mold 20 and the slide core 56 form the step S of the protruding portion 76. That is, the T direction is also the direction that intersects the opening and closing direction in this disclosure.

[0048] Furthermore, as shown in Figure 3, in this embodiment, the step S in the resin molded product 70 becomes a defining line D that defines the general portion 78 and the tip portion 84 of the protruding portion 76 of the resin molded product 70. In other words, in this embodiment, the surface in contact between the fixed mold 20 and the slide core 56 is also the portion where the defining line D is formed in the resin molded product 70.

[0049] Furthermore, as shown in Figure 3, in this embodiment, at the surface where the fixed mold 20 and the slide core 56 come into contact, the resin material R seeps out during resin injection, as described later, and a linear protrusion, or parting line PL, is formed on the second design surface 86B side. In other words, in this embodiment, the surface where the fixed mold 20 and the slide core 56 come into contact is also the area where the parting line PL is formed in the resin molded product 70.

[0050] In this embodiment, the tip portion 65 of the second cavity 64 is arc-shaped, as shown in Figures 2 and 3.

[0051] Furthermore, as shown in Figure 3, in this embodiment, the gate 58 of the slide core 56 is located near the tip of the second cavity 64. In other words, the fixed mold 20 and the slide core 56 form a gate mark 80 on the tip side of the step S of the protruding portion 76. In other words, the fixed mold 20 and the slide core 56 form a gate mark 80 on the side of the thickness direction of the protruding portion 76 opposite to the second design surface 86B.

[0052] (Volume expansion operation) Furthermore, as will be described later, the mold 10 in this disclosure allows the movable mold 26 to move slightly in the Y direction when the resin material R is injected into the cavity 60. That is, the mold 10 in this disclosure performs a volume expansion operation of the cavity 60, known as core back, by moving the movable mold 26 in the opening and closing direction. In addition, in the mold 10 in this disclosure, when the resin material R is injected into the cavity 60 and the volume of the cavity 60 expands, the resin material R inside the cavity 60 foams. Note that the surface of the resin material R in contact with the mold tends to harden (become solid) as the temperature drops, so when core back occurs, the surface of the resin material R does not foam easily, and foaming occurs internally. In resin molded products, the surface area with less foaming is generally called the skin area. Furthermore, depending on the opening direction of the movable mold 26, the volume expansion of the second cavity 64 (the cavity that forms the protruding portion 76) is less than the volume expansion of the first cavity 62, so the foaming rate of the second foaming region 88B tends to be lower than that of the first foaming region 88A. Also, the skin area of ​​the protruding portion 76 may be larger than that of the main body portion 72.

[0053] The aforementioned "slight" movement length may be, for example, 1.5 mm.

[0054] (Resin materials) The resin material R is preferably a resin material R containing a resin and a foaming agent, and may optionally contain other components such as additives.

[0055] The resin used for the resin material R includes at least one selected from the group consisting of polyethylene resins, polypropylene resins (PP), composite polypropylene resins (PPC), polystyrene resins, polyethylene terephthalate resins, polyvinyl alcohol resins, vinyl chloride resins, ionomer resins, polyamide resins, acrylonitrile-butadiene-styrene copolymer resins (ABS), polycarbonate resins, and polyphenylene sulfide resins (PPS). Among these, at least one selected from the group consisting of polypropylene resins (PP), composite polypropylene resins (PPC), and acrylonitrile-butadiene-styrene copolymer resins (ABS) is preferred.

[0056] Examples of foaming agents include organic foaming agents such as azodicarbonamide and inorganic foaming agents such as sodium bicarbonate (also known as sodium hydrogen carbonate or baking soda). In foam molding of automotive interior parts, organic foaming agents are preferred from the viewpoint of improving environmental testing performance and coating film performance (such as hot water resistance).

[0057] Examples of organic blowing agents include azodicarbonamide (ADCA), N,N-dinitrosopentamethylenetetramine (DPT), 4,4'-oxybisbenzenesulfonyl hydrazide (OBSH), and hydrazodicarbonamide (HDCA), with azodicarbonamide (ADCA) being preferred. In particular, when manufacturing outer packaging, it is preferable to use azodicarbonamide (ADCA) whose decomposition products contain almost no water.

[0058] The content of azodicarbonamide (ADCA) in the total amount of the blowing agent is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0059] The decomposition temperature of the foaming agent is preferably 50°C to 250°C, and more preferably 50°C to 220°C. Depending on the application, the decomposition temperature of the foaming agent may be 130°C to 250°C.

[0060] (injection molding process) Next, the injection molding process in this embodiment will be described with reference to Figures 4 to 9 as appropriate.

[0061] First, as shown in Figures 4 and 5, with the fixed mold 20 and the movable mold 26 in contact, molten resin material R flows from the injection molding apparatus (not shown) into the cavity 60 through the flow path C and gate 58. Note that, as shown in Figure 4, with the fixed mold 20 and the movable mold 26 in contact, the first slide mold 34 is in contact with the fixed mold 20, thus forming the tip portion 65 of the second cavity 64. Also, as shown in Figure 5, with the fixed mold 20 and the movable mold 26 in contact, the slide core 56 is in contact with the fixed mold 20, thus forming the tip portion 65 of the second cavity 64.

[0062] After a predetermined time has elapsed since the resin material R was injected into the cavity 60, the resin material R cools and hardens from the outside of the cavity 60 (the part that comes into contact with the fixed mold 20, the movable mold 26, the first slide mold 34, and the slide core 56). When the outside of the cavity 60 begins to harden, the movable mold 26 expands in volume to the state shown in Figures 6 and 7.

[0063] As shown in Figures 6 and 7, when the movable mold 26 performs a volume expansion operation, the volume inside the cavity 60 increases, and the pressure inside the cavity 60 decreases. In this state, the foaming agent mixed with the resin material R causes the resin material R to foam inside the first cavity 62 and the second cavity 64.

[0064] Here, as shown in Figure 6, when the movable mold 26 is in the volume expansion operation, the first slide mold 34 maintains its relative position with respect to the fixed mold 20 by the push pin 40 pressed by the biasing member 50. In other words, even when the movable mold 26 is in the volume expansion operation, the tip portion 65 of the cavity 60 formed by the first slide mold 34 maintains its shape from before the volume expansion operation. Therefore, since the amount of resin foaming inside the tip portion 84 of the molded resin product 70 is small, deformation of the tip portion 84 due to foaming is suppressed.

[0065] Furthermore, as shown in Figure 7, when the movable mold 26 is in a volume-expanding state, the slide core 56 is pressed by the biasing member 50, thereby maintaining its relative position with respect to the fixed mold 20. In other words, even when the movable mold 26 is in a volume-expanding state, the tip portion 65 of the cavity 60 formed by the slide core 56 maintains its shape from before the volume-expanding operation.

[0066] Then, as the resin material R in the cavity 60 is further cooled and the entire resin material R hardens, the movable mold 26 moves further in the Y direction to the state shown in Figures 8 and 9.

[0067] As shown in Figure 8, when the movable mold 26 moves further to one side in the Y direction than when it has performed the volume expansion operation, the biasing member 50 extends to its natural length, and the pressure on the push pin 40 by the biasing member 50 is relieved. Also, when the flange portion 40C of the push pin 40 catches on the stepped through hole 32 of the movable mold 26, the first slide mold 34 moves to one side in the Y direction together with the movable mold 26. As a result, as shown in Figure 8, contact between the first slide mold 34 and the fixed mold 20 is eliminated.

[0068] Furthermore, as shown in Figure 9, as the movable mold 26 moves further to one side in the Y direction than when it has performed the volume expansion operation, the biasing member 50 extends to its natural length, thus relieving the pressure exerted by the biasing member 50. In addition, the angular pin 38 of the second slide mold 36 is guided to one side in the X direction by the through hole of the movable mold 26 which moves to one side in the Y direction. As a result, the second slide mold 36 and the slide core 56 move to one side in the X direction.

[0069] Subsequently, as the slide core 56 moves further to one side in the X direction from the state shown in Figure 9, the hardened resin material R is cut at the gate 58. As a result, a rough fracture surface, known as the gate mark 80, is formed at the position corresponding to the gate 58 at the tip 84 of the cavity 60, as shown in Figure 1.

[0070] Then, as the movable mold 26 moves further to one side in the Y direction relative to the fixed mold 20, the hardened resin material R is removed from the fixed mold 20 as a resin molded product 70 as shown in Figure 1. As mentioned above, as shown in Figure 1, in this embodiment, the portion of the resin molded product 70 that was in contact with the fixed mold 20 in the cavity 60 is the design surface.

[0071] (Comparative example) Here, Figures 10 and 11 show a mold 110, which is a comparative example with mold 10 according to this embodiment, in a state where it has performed a volume expansion operation similar to mold 10 according to this embodiment.

[0072] As shown in Figure 10, in the comparative example mold 110, the portion corresponding to the first slide mold 34 according to this embodiment is part of the movable mold 125. In other words, when the volume expansion operation is performed, the tip portion 65 of the second cavity 64 moves to one side in the Y direction together with the movable mold 125.

[0073] Furthermore, as shown in Figure 11, in the comparative example mold 110, the parts corresponding to the second slide mold 36 and slide core 56 are integrally formed as a slide mold 130. Note that, unlike the slide core 56 in this embodiment, the slide mold 130 is not biased toward the fixed mold 120, and therefore does not come into contact with the fixed mold 120 when the volume expansion operation is performed. In other words, when the volume expansion operation is performed, the tip portion 65 of the second cavity 64 moves to one side in the Y direction together with the movable mold 125.

[0074] In this case, as shown in Figures 10 and 11, the movable mold 125 expands its volume, causing the tip of the second cavity 64 to be pulled by the movable mold 125 and the sliding mold 130 and move to one side in the Y direction. Since the resin material R has not hardened at the time of the volume expansion, the boundary between the bottom 22 of the cavity 60 and the second cavity 64 deforms toward one side in the Y direction. This deformation of the boundary reduces the aesthetic appearance of the design surface of the resin molded product 70.

[0075] (Mechanism of Action and Effects) In this embodiment, the mold 10 and the resin molded product 70 formed by the mold 10 can provide the following functions and effects.

[0076] In the mold 10 of this embodiment, the slide mold is pressed against the fixed mold 20 near the tip of the second cavity 64 in the opening and closing direction, and forms the tip of the second cavity 64 in the opening and closing direction in the cavity 60, and maintains the state of being pressed against the fixed mold 20 when the movable mold 26 moves in the opening and closing direction. As a result, when the movable mold 26 expands the volume of the cavity 60, the slide mold that forms the tip of the second cavity 64 does not move, so the design surface from the first cavity 62 to the second cavity 64 is less likely to deform when the movable mold 26 moves in the opening and closing direction.

[0077] Therefore, in the mold 10 of this embodiment, the possibility that the design surface will deform when forming the resin molded product 70, and that the design quality of the design surface of the formed resin molded product 70 will be impaired, can be reduced.

[0078] Furthermore, in the mold 10 of this embodiment, when the movable mold 26 expands the volume of the cavity 60, the sliding mold is pressed against the fixed mold 20. As a result, in the mold 10 of this embodiment, the possibility of deformation of the tip of the protruding portion 76 can be reduced compared to the case where the sliding mold is not pressed against the fixed mold 20.

[0079] Furthermore, in the mold 10 of this embodiment, the slide mold is pressed against the fixed mold 20 by a biasing member 50 provided on the movable mold 26. Therefore, when the distance between the fixed mold 20 and the movable mold 26 is narrow, the slide mold is pressed against the fixed mold 20, and when the distance between the fixed mold 20 and the movable mold 26 is wide, the pressure of the slide mold against the fixed mold 20 is released. This reduces the possibility of impairing the aesthetic appearance of the design surface and simplifies the configuration of the mold 10 in this embodiment.

[0080] Furthermore, in the mold 10 of this embodiment, the sliding mold has a gate 58 from which resin is injected from the tip in the opening and closing direction of the second cavity 64, and is movable outward in a direction intersecting the fixed mold 20. As a result, the gate marks 80 are difficult to see from a person viewing the design surface of the resin molded product 70 molded using the mold 10 of this embodiment.

[0081] Therefore, the possibility of the aesthetic appearance of the design surface of the resin molded product 70 formed by the mold 10 in this embodiment being impaired can be reduced.

[0082] Furthermore, in the resin molded product 70 of this embodiment, since it is formed using the mold 10 of this embodiment, the design surface is less likely to deform from the main body portion 72, which corresponds to the first cavity 62, to the protruding portion 76, which corresponds to the second cavity 64.

[0083] Therefore, in the resin molded product 70 of this embodiment, the possibility of the design quality of the design surface being impaired can be reduced compared to the resin molded product 70 formed without using the mold 10 of this embodiment.

[0084] Furthermore, in this embodiment, the resin molded product 70 has a gate mark 80 formed on the second design surface 86B side in the thickness direction of the tip 84 of the protruding portion 76, and the tip 84 is formed inside the main body portion 72 relative to the defining line D that defines the general portion 78 and the tip 84. That is, the gate mark 80 on the opposite side of the second design surface 86B from the general portion 78 on the second design surface 86B is easily blended in with the defining line D, so the gate mark 80 is not noticeable to a person looking at the design surface. Therefore, in this embodiment, the gate mark 80 is not noticeable relative to the design surface, thus reducing the possibility of the design quality of the design surface being impaired.

[0085] Furthermore, in this embodiment, the defining line D of the resin molded product 70 is a step S that extends inward from the second design surface 86B of the general part 78 towards the main body part 72. As a result, the defining line D of the resin molded product 70 is a step S, and the parting line PL is not noticeable to a person viewing the design surface, thus reducing the possibility of the design quality of the design surface being impaired.

[0086] Furthermore, in this embodiment, the resin molded product 70 has a parting line PL formed on the defining line D on the second design surface 86B.

[0087] Furthermore, in this embodiment, the resin molded product 70 has a parting line PL formed on the defining line D which is the boundary between the general part 78 and the tip part 84. Therefore, the parting line PL is not noticeable to a person viewing the design surface, thus reducing the possibility of the design quality of the design surface being impaired.

[0088] Furthermore, in this embodiment, the resin molded product 70 has a parting line PL located 0.5 mm to 2.0 mm from the tip of the protruding portion 76, so the parting line PL is not noticeable to a person viewing the design surface, thus reducing the possibility of the design quality of the design surface being impaired.

[0089] Furthermore, in this embodiment, since the tip portion 84 of the resin molded product 70 is arc-shaped, the gate marks 80 tend to be smaller during molding. Therefore, in this embodiment, the gate marks 80 are smaller compared to the case where the tip portion 84 is not arc-shaped, thus reducing the possibility of the design quality of the design surface being impaired.

[0090] Furthermore, in this embodiment, the end of the gate mark 80 of the resin molded product 70 connects to the end of the surface opposite to the second design surface 86B of the protruding portion 76, making the gate mark 80 difficult to see for a person viewing the design surface. Therefore, in this embodiment, the gate mark 80 is less noticeable compared to the case where the end of the gate mark 80 does not connect to the end of the surface opposite to the second design surface 86B of the protruding portion 76, thus reducing the possibility of the design quality of the design surface being impaired.

[0091] Furthermore, since the resin molded product 70 in this embodiment has a first foamed region 88A and a second foamed region 88B formed therein, the weight of the resin molded product can be reduced.

[0092] In this embodiment, the resin molded product 70 has a gate mark 80 formed at the tip 84 of the protruding portion 76, on the side opposite to the second design surface 86B in the thickness direction of the protruding portion 76, rather than at the tip in the protruding direction. Therefore, the gate mark 80 is difficult to see from a person looking at the design surface.

[0093] Therefore, in this embodiment, the gate marks 80 are difficult to see on the design surface of the resin molded product 70, thus reducing the possibility of the design quality of the design surface being impaired.

[0094] Furthermore, in this embodiment, since the tip portion 84 of the resin molded product 70 is arc-shaped, the gate marks 80 tend to be smaller during molding. Therefore, in this embodiment, the gate marks 80 are less visible compared to the case where the tip portion 84 is not arc-shaped, thus reducing the possibility of the design quality of the design surface being impaired.

[0095] Furthermore, in this embodiment, the end of the gate mark 80 of the resin molded product 70 connects to the end of the surface opposite to the second design surface 86B of the protruding portion 76, making it difficult for a person viewing the design surface to see the gate mark 80. Therefore, in this embodiment, the gate mark 80 is less visible compared to the case where the end of the gate mark 80 does not connect to the end of the surface opposite to the second design surface 86B of the protruding portion 76, thus reducing the possibility of the design quality of the design surface being impaired.

[0096] Furthermore, since the resin molded product 70 in this embodiment has a first foamed region 88A and a second foamed region 88B formed therein, the weight of the resin molded product 70 can be reduced.

[0097] (modified version) In the above explanation, the first slide type 34 and the second slide type 36 were described as separate components, but this is not the only option. For example, instead of being supported by an angular pin 38 against the movable type 26, the second slide type 36 may be pressed against the fixed type 20 by a push pin 40, similar to the first slide type 34. In this case, the first slide type 34 and the second slide type 36 may be considered as a single component.

[0098] Furthermore, although the slide core 56 was described as being separate from the second slide mold 36 in the above explanation, it is not limited to this, and the second slide mold 36 and the slide core 56 may be considered as the same entity.

[0099] Even in such cases, if the movable mold 26 expands in volume and the resin material R foams, and the parts corresponding to the first slide mold 34 and slide core 56 are in contact with the fixed mold 20, the same operation and effects as the mold 10 according to the first embodiment can be obtained.

[0100] Furthermore, in the above description, the defining line D and the parting line PL overlapped in the resin molded product 70 of this embodiment, but the design is not limited to this, and the defining line D and the parting line PL may not overlap. In this case, it is desirable that the parting line PL is formed on the tip side of the defining line D in the resin molded product. As a result, the parting line PL becomes less noticeable due to the defining line D and the step S, thus reducing the possibility of the design quality of the design surface being impaired.

[0101] In the above description, the present embodiment described a resin molded product 70 having a foamed region inside as an example of a resin molded product, but the technology in this disclosure is not limited to this. That is, it is also applicable to resin molded products that do not have a foamed region in the main body portion 72 and the protruding portion 76. In this case as well, similar to the resin molded product 70 in this embodiment, the gate marks 80 are not noticeable to a person viewing the design surface, thus reducing the possibility of the design quality of the design surface being impaired. Also, similar to the resin molded product 70 in this embodiment, the gate marks 80 are difficult to see on the design surface from a person viewing the design surface, thus reducing the possibility of the design quality of the design surface being impaired.

[0102] Next, a second embodiment of this disclosure will be described with reference to Figures 12 and 13 as appropriate. Note that, in this embodiment, components similar to those in the first embodiment will be denoted by the same reference numerals, and their specific descriptions may be omitted.

[0103] [Second Embodiment] Figure 12 shows the mold 10 according to the second embodiment in a volume expansion operation. In the mold 10 according to this embodiment, the slide core 56 is connected to the movable mold 26 by a slide actuator 54 that penetrates it from one side in the Y direction. That is, in this embodiment, the slide core 56 is pressed against the fixed mold 20 by the slide actuator 54 when the mold 10 is in a volume expansion operation.

[0104] The other components are the same as in the first embodiment.

[0105] In the mold 10 of this embodiment, as shown in Figure 13, when the fixed mold 20 moves further to one side in the Y direction than when it has performed a volume expansion operation, the slide core 56 is guided to one side in the X direction together with the second slide mold 36. As a result, in this embodiment as well, the movable mold 26 separates from the fixed mold 20, and the resin material R is cut at the gate 58.

[0106] (Mechanism of Action and Effects) Furthermore, as shown in Figure 12, in this embodiment, the sliding mold is pressed against the fixed mold 20 when the movable mold 26 expands its volume, not by the biasing member 50 but by the sliding actuator 54. In other words, even in this embodiment, the sliding mold does not lose contact with the fixed mold 20 when it expands its volume. As a result, in this embodiment as well, when the movable mold 26 expands the volume of the cavity 60, the sliding mold that forms the tip of the second cavity 64 does not move, and therefore the design surface from the first cavity 62 to the second cavity 64 is less likely to deform when the movable mold 26 moves in the opening and closing direction.

[0107] Therefore, even in the mold 10 of this embodiment, the possibility that the design surface will deform when forming the resin molded product 70, and that the design quality of the design surface of the formed resin molded product 70 will be impaired, can be reduced.

[0108] Furthermore, the other functions and effects obtained by the mold 10 in the first embodiment can be similarly obtained in this embodiment as well.

[0109] Next, a third embodiment of this disclosure will be described with reference to Figures 14 to 16 as appropriate. Note that, in this embodiment, components similar to those in the first embodiment will be denoted by the same reference numerals, and their specific descriptions may be omitted.

[0110] [Third Embodiment] (Resin molded product 70) Figure 14 shows a resin molded product 70 in the third embodiment. In this embodiment, compared to the resin molded product 70 of the first embodiment, a step S is not formed at the tip 284 of the protruding portion 76, and a tapering portion 92 is formed. Also, in the resin molded product 70 in this embodiment, the gate mark 80 is formed on one side in the T direction within the range in the T direction of the tip 284, and is located on one side in the T direction than the vertex on one side in the direction of arrow L. In other words, in this embodiment, the gate mark 80 is formed on one side in the T direction than the point (vertex of the tip 284) that contacts the tangent line F that is parallel to the T direction, which is the thickness direction of the protruding portion 276. In other words, in the resin molded product 70 in this embodiment, the gate mark 80 is not formed on the other side in the T direction than the vertex on one side in the direction of arrow L within the range in the T direction of the tip 284.

[0111] As shown in Figure 14, the tapering portion 92 is a part in which the thickness decreases from the parting line PL, which is the defining line D that defines the general portion 78 and the tip portion 284, toward one side in the direction of arrow L and toward the other side in the direction of T (towards the inside of the main body portion 72). In other words, the tapering portion 92 in this embodiment, like the step S in the first embodiment, gradually reduces the thickness of the protruding portion 76 by changing the thickness in the direction of T.

[0112] The shape of the other parts is the same as that of the resin molded product 70 according to the first embodiment.

[0113] Next, the mold 10 used to manufacture the resin molded product 70 according to this embodiment will be described.

[0114] Figure 15 shows the mold 10 in this embodiment. In the mold 10 in this embodiment, one side in the direction of arrow L from the dividing surface 68 where the fixed mold 20 and the slide core 56 come into contact is an inclined portion 266 in which the thickness of the protruding portion 76 decreases towards the other side in the direction T as the one side in the direction of arrow L moves.

[0115] Furthermore, as shown in Figure 15, in the mold 10 of this embodiment, the gate 258 is located on one side in the T direction rather than on the other side in the L direction of the cavity 60. In other words, in this embodiment, the gate 258 is located between the tapering portion 92 and the tip portion 265 of the cavity 60.

[0116] The other components are the same as in the first embodiment.

[0117] In this embodiment, as shown in Figure 16, when the slide core 56 moves to one side in the X direction, the hardened resin material R is cut at the gate 258 portion, and the gate mark 80 of the resin molded product 70 is formed.

[0118] (Mechanism of Action and Effects) In this embodiment as well, as shown in Figure 15, contact between the slide core 56 and the fixed mold 20 is maintained when the movable mold 26 is in a volume expansion state. This reduces the possibility that the design surface will deform when forming the resin molded product 70, and that the design quality of the design surface of the formed resin molded product 70 will be impaired, similar to the first embodiment.

[0119] Furthermore, in this embodiment as well, as shown in Figure 14, the gate mark 80 is formed on the second design surface 86B side in the thickness direction at the tip 284 of the protruding portion 76, and the tip 284 is formed inside the main body portion 72 relative to the defining line D that defines the general portion 78 and the tip 284. In other words, the gate mark 80 on the opposite side of the second design surface 86B from the general portion 78 is easily blended in with the defining line D, so the gate mark 80 is not noticeable to a person looking at the design surface. As a result, the formed resin molded product 70 does not have a noticeable gate mark 80 relative to the design surface, thus reducing the possibility of the design quality of the design surface being impaired.

[0120] Furthermore, the other functions and effects obtained by the mold 10 in the first embodiment can be similarly obtained in this embodiment as well.

[0121] Next, the fourth embodiment of this disclosure will be described with reference to Figures 17 to 19 as appropriate. Note that, in this embodiment, components similar to those in the first embodiment will be denoted by the same reference numerals, and their specific descriptions may be omitted.

[0122] [Fourth Embodiment] (Resin molded product 70) Figure 17 shows a resin molded product 70 in the fourth embodiment. In this embodiment, compared to the resin molded product 70 of the first embodiment, the gate mark 80 at the tip 384 of the protruding portion 76 is formed on the other side in the T direction from the vertex on one side in the L direction, within the range in the T direction of the tip 384. In other words, in this embodiment, the gate mark 80 is formed on the other side in the T direction from the point (vertex of the tip 384) that contacts the tangent line F that is parallel to the T direction, which is the thickness direction of the protruding portion 376. In other words, in the resin molded product 70 of this embodiment, the gate mark 80 is not formed on one side in the T direction from the vertex on one side in the L direction, within the range in the T direction of the tip 384.

[0123] The shape of the other parts is the same as that of the resin molded product 70 according to the first embodiment.

[0124] Next, the mold 10 used to manufacture the resin molded product 70 according to this embodiment will be described.

[0125] Figure 18 shows the mold 10 in this embodiment. In this embodiment, the gate 358 is located on the other side in the T direction than on the other side in the L direction of the cavity 60. In other words, in this embodiment, the gate 358 is located between the tip portion 365 of the cavity 60 and the protruding portion 30 of the movable mold 26.

[0126] The other components are the same as in the first embodiment.

[0127] In this embodiment, as shown in Figure 19, when the slide core 56 moves to one side in the X direction, the cured resin material R is cut at the gate 358 portion, and the gate mark 80 of the resin molded product 70 is formed.

[0128] (Mechanism of Action and Effects) In this embodiment as well, as shown in Figure 18, contact between the slide core 56 and the fixed mold 20 is maintained when the movable mold 26 is in a volume expansion state. This reduces the possibility that the design surface will deform when forming the resin molded product 70, and that the design quality of the design surface of the formed resin molded product 70 will be impaired, similar to the first embodiment.

[0129] Furthermore, in this embodiment as well, as shown in Figure 17, the gate mark 80 is formed at the tip 384 of the protruding portion 76, on the side opposite to the second design surface 86B in the thickness direction of the protruding portion 76, rather than at the tip in the protruding direction. That is, at the tip 384 of the protruding portion 76, it is formed on the side opposite to the second design surface 86B in the thickness direction of the protruding portion 76, rather than at the tip in the protruding direction, so the gate mark 80 is difficult to see from a person looking at the design surface. As a result, in this embodiment, the gate mark 80 is difficult to see from the design surface of the resin molded product 70, thus reducing the possibility of the design quality of the design surface being impaired.

[0130] Furthermore, the other functions and effects obtained by the mold 10 in the first embodiment can be similarly obtained in this embodiment as well.

[0131] Next, the fifth embodiment of this disclosure will be described with appropriate reference to Figures 20 to 22. Note that, in this embodiment, components similar to those in the first embodiment will be denoted by the same reference numerals, and their specific descriptions may be omitted.

[0132] [Fifth Embodiment] (Resin molded product 70) Figure 20 shows a resin molded product 70 in the fourth embodiment. In this embodiment, compared to the resin molded product 70 of the first embodiment, the tip shape of the tip portion 484 of the protruding portion 76 is straight rather than arc-shaped. In other words, the gate mark 80 is formed parallel to the T direction, which is the thickness direction of the protruding portion 76, and includes the point (the vertex of the tip portion 484) that contacts the tangent line F that is in contact with the tip portion 484. In other words, the gate mark 80 is formed within the range of the T direction of the tip portion 484, on one side of the vertex on one side of the L direction of arrow, and on the other side of the L direction of arrow.

[0133] The shape of the other parts is the same as that of the resin molded product 70 according to the first embodiment.

[0134] Next, the mold 10 used to manufacture the resin molded product 70 according to this embodiment will be described.

[0135] Figure 21 shows the mold 10 in this embodiment. In this embodiment, a step 66 is formed at the dividing surface 68 where the fixed mold 20 and the slide core 56 come into contact.

[0136] Furthermore, in this embodiment, as shown in Figure 21, the outermost side of the second cavity 64 in the cavity 60 in the direction of arrow L is parallel to the X direction. In other words, in this embodiment, the second cavity 64 is linear, and the gate 458 is located at the tip portion 465 of the second cavity 64.

[0137] The other components are the same as in the first embodiment.

[0138] In this embodiment, as shown in Figure 22, when the slide core 56 moves to one side in the X direction, the hardened resin material R is cut at the gate 458 portion, and the gate mark 80 of the resin molded product 70 is formed.

[0139] (Mechanism of Action and Effects) In this embodiment as well, as shown in Figure 22, contact between the slide core 56 and the fixed mold 20 is maintained when the movable mold 26 is in a volume expansion state. This reduces the possibility that the design surface will deform when forming the resin molded product 70, and that the design quality of the design surface of the formed resin molded product 70 will be impaired, similar to the first embodiment.

[0140] Furthermore, as shown in Figure 22 of this embodiment, as the slide core 56 moves to one side in the X direction, the cured resin material R is cut at the gate 458 portion, forming the gate mark 80 of the resin molded product 70.

[0141] Furthermore, in this embodiment as well, as shown in Figure 20, the gate mark 80 is formed at the tip 484 of the protruding portion 76, on the side opposite to the second design surface 86B in the thickness direction of the protruding portion 76, rather than at the tip in the protruding direction. That is, at the tip 484 of the protruding portion 76, it is formed on the side opposite to the second design surface 86B in the thickness direction of the protruding portion 76, rather than at the tip in the protruding direction, so the gate mark 80 is difficult to see from a person looking at the design surface. As a result, in the resin molded product in this embodiment, the gate mark 80 is difficult to see from the design surface, thus reducing the possibility of the design quality of the design surface being impaired.

[0142] In other words, in this embodiment as well, as shown in Figure 20, the gate mark 80 is formed on the second design surface 86B side in the thickness direction at the tip 484 of the protruding portion 76, and the tip 484 is formed inside the main body portion 72 relative to the defining line D that defines the general portion 78 and the tip 484. That is, the gate mark 80 on the opposite side of the second design surface 86B from the general portion 78 is easily blended in with the defining line D, so the gate mark 80 is not noticeable to a person looking at the design surface. As a result, in this embodiment, the gate mark 80 is not noticeable relative to the design surface of the resin molded product, and therefore the possibility of the design quality of the design surface being impaired is reduced.

[0143] While embodiments of this disclosure have been described above with reference to the attached drawings, it is clear that any person with ordinary skill in the art to which this disclosure belongs could conceive of various modifications or applications within the scope of the technical idea described in the claims, and these too are naturally understood to fall within the technical scope of this disclosure. [Explanation of symbols]

[0144] 10 molds 20 Fixed type 22 Bottom 24. Rising section 26 Movable type 30 Protruding part 32 stepped through holes 34 First slide type 36. Second slide type 38 Angulapine 40 push pins 42 Pushpins 44 stepped through holes 50 biasing member 52 Biasing member 54 Slide Actuator 56 slide core Gates 58, 258, 358, and 458 60 Cavity 65, 265, 365, 465 Tip part 66 steps 68 Split plane 70 Resin molded products 72 Main body 74 Peripheral area 76 Overhang 78 General section 80 Gate ruins 84, 284, 384, 484 Tip 86A First design surface 86B Second design surface 88A First Resin Foaming Area 88B Second Resin Foaming Area 92. Gradual Decrease 266 Slope

Claims

1. A main body having a first design surface, An overhang extending from the peripheral edge of the main body portion in the thickness direction of the main body portion on the opposite side of the first design surface and outward from the main body portion, and having a second design surface that is continuous with the first design surface, Equipped with, The protruding portion has a tip portion in the direction of protrusion and a general portion between the tip portion and the main body portion. The outer surface of the tip portion is located inside the main body portion beyond the defining line that determines the general portion and the tip portion. A gate mark is formed at the tip portion. Resin molded product.

2. The resin molded product according to claim 1, wherein the defining line is a step extending from the second design surface of the general part toward the inside of the main body part.

3. The resin molded article according to claim 1, wherein a parting line is formed on the defining line in the second design surface.

4. The resin molded product according to claim 1, wherein the defining line is located at a position of 0.5 mm or more and 2.0 mm or less from the tip of the protruding portion.

5. The resin molded product according to claim 1, wherein the shape of the tip of the protruding portion is arc-shaped.

6. The resin molded product according to claim 1, wherein the end of the gate mark connects to the end of the surface opposite to the second design surface in the protruding portion.

7. A first resin foam region is formed inside the main body. The resin molded article according to any one of claims 1 to 6, wherein a second resin foam region connected to the first resin foam region is formed inside the protruding portion.

Images