Resin molded article

Abstract

This resin molded article is provided with: a main body section having a first design surface; and a protruding section that protrudes from the peripheral edge of the main body section to the outside of the main body section on the opposite side to the first design surface in the thickness direction of the main body section, and that has a second design surface that is continuous with the first design surface. The protruding portion has a front end portion in a protruding direction and a general portion between the front end portion and the main body portion, an outer surface of the front end portion is located on an inner side of the main body portion compared with a demarcation line determining the general portion and the front end portion, and a gate trace is formed on the front end portion.

Description

Technical Field

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

[0002] In Japanese Patent Application Laid-Open No. 2019-181874, a molding die is disclosed, which includes: a die body configured to include a first die that molds a surface other than the fastening surface in one plate surface and a second die that molds the other plate surface of the foamed resin molded product, a cavity being formed between the first die and the second die, and the volume of the cavity being capable of being enlarged by separating the first die and the second die; and an insert assembled to the die body such that a portion for molding the fastening surface and a portion for molding the end surface are exposed in the cavity and the corners are molded, and a portion of the corners of the molding insert is made of a metal having a higher thermal conductivity than the die body. Summary of the Invention

[0003] Problems to be Solved by the Invention

[0004] In the configuration described in Japanese Patent Application Laid-Open No. 2019-181874, since the gate mark, which is a trace of the resin material injection port formed during molding, can be visually recognized when viewed from the design surface side, the designability may be reduced.

[0005] An object of the present disclosure is to provide a resin molded product in which the gate mark is inconspicuous when the design surface is observed.

[0006] Means for Solving the Problems

[0007] Means for solving the above problems include the following embodiments.

[0008] [1] A resin molded product, comprising:

[0009] a main body portion having a first design surface; and

[0010] a protruding portion protruding from a peripheral portion of the main body portion toward a side opposite to the first design surface in a thickness direction of the main body portion and outside the main body portion, and having a second design surface connected to the first design surface,

[0011] the protruding portion having a front end portion in a protruding direction and a general portion between the front end portion and the main body portion,

[0012] an outer surface of the front end portion being located inside the main body portion as compared with a delimiting line that defines the general portion and the front end portion,

[0013] a gate mark being formed in the front end portion.

[0014] [2] The resin molded product according to [1], wherein the demarcation line is a step from the second design surface of the general portion toward the inside of the main body portion.

[0015] [3] The resin molded product according to [1], wherein in the second design surface, a parting line is formed on the demarcation line.

[0016] [4] The resin molded product according to [1], wherein the demarcation line is located at a position greater than or equal to 0.5 mm and less than or equal to 2.0 mm from the front end of the protruding portion.

[0017] [5] The resin molded product according to any one of [1] to [4], wherein the shape of the front end portion of the protruding portion is an arc shape.

[0018] [6] The resin molded product according to any one of [1] to [5], wherein the end of the gate mark is connected to the end of the surface of the protruding portion on the side opposite to the second design surface.

[0019] [7] The resin molded product according to any one of [1] to [6], wherein a first resin foaming region is formed inside the main body portion,

[0020] and a second resin foaming region connected to the first resin foaming region is formed inside the protruding portion.

[0021] Advantageous Effects of the Invention

[0022] According to the present disclosure, it is possible to provide a resin molded product in which a gate mark is inconspicuous when viewed from the design surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a cross-sectional view showing a part of a foamed resin molded product according to a first embodiment of the present disclosure.

[0024] Figure 2 is a cross-sectional view of a mold according to a first embodiment of the present disclosure.

[0025] Figure 3 is a view showing Figure 2 a cross-sectional view around a gate portion of the mold shown.

[0026] Figure 4 is a view showing a case where resin is filled in the mold shown in Figure 2 a cross-sectional view of the case.

[0027] Figure 5 is a view showing a case where resin around the gate portion is filled in the mold shown in Figure 4 a cross-sectional view of the case.

[0028] Figure 6 is a view showing a case whereFigure 4 In the mold shown, the movable mold moves in the opening direction relative to the fixed mold, and a cross-sectional view of the case where the resin has foamed.

[0029] Figure 7 It shows the case where Figure 6 In the mold shown, a cross-sectional view of the case where the resin around the gate portion has foamed.

[0030] Figure 8 It shows the case where Figure 6 In the mold shown, a cross-sectional view of the case where the movable mold is moved in the opening direction and the foamed resin molded product is taken out.

[0031] Figure 9 It shows Figure 8 A cross-sectional view of the vicinity of the gate portion in the mold shown.

[0032] Figure 10 It is a cross-sectional view showing the case where, in the mold of the comparative example, the movable mold moves in the opening direction and the resin has foamed.

[0033] Figure 11 It shows the case where Figure 10 In the mold of the comparative example shown, a cross-sectional view of the case where the resin around the gate portion has foamed.

[0034] Figure 12 It is a cross-sectional view showing the case where, around the gate portion of the mold of the second embodiment of the present disclosure, the movable mold moves in the opening direction and the resin has foamed.

[0035] Figure 13 It shows the case where Figure 12 In the vicinity of the gate portion of the mold shown, a cross-sectional view of the case where the movable mold is moved in the opening direction and the foamed resin molded product is taken out.

[0036] Figure 14 It is a view showing the case of visually recognizing the foamed resin molded product molded using the mold of the third embodiment of the present disclosure.

[0037] Figure 15 It is a cross-sectional view showing the case where, around the gate portion of the mold of the third embodiment of the present disclosure, the foamed resin molded product is molded such that the protruding portion gradually decreases toward the front end.

[0038] Figure 16 It shows the case where Figure 15 In the vicinity of the gate portion of the mold shown, a cross-sectional view of the case where the movable mold is moved in the opening direction and the foamed resin molded product is taken out.

[0039] Figure 17 It is a view showing the case of visually recognizing the foamed resin molded product molded using the mold of the fourth embodiment of the present disclosure.

[0040] Figure 18 This is a cross-sectional view showing a case where the gate of the foamed resin molded product is formed on the inner side in the width direction compared to the front end of the protruding portion around the gate portion of the mold in the fourth embodiment of the present disclosure.

[0041] Figure 19 It shows a case where Figure 18 The movable mold is moved in the opening direction around the gate portion of the mold shown in the figure, and the foamed resin molded product is taken out. This is a cross-sectional view.

[0042] Figure 20 This is a cross-sectional view showing a case where the foamed resin molded product molded using the mold of the fifth embodiment of the present disclosure is visually recognized.

[0043] Figure 21 This is a cross-sectional view showing a case where the gate of the foamed resin molded product is formed in a flat shape around the gate portion of the mold in the fifth embodiment of the present disclosure.

[0044] Figure 22 It shows a case where Figure 21 The movable mold is moved in the opening direction around the gate portion of the mold shown in the figure, and the foamed resin molded product is taken out. This is a cross-sectional view. Detailed Embodiment

[0045] Hereinafter, the embodiments for implementing the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, unless otherwise specified, the constituent elements are not essential. The same applies to numerical values and their ranges, which do not limit the present disclosure.

[0046] The arrow X shown in each figure represents the width direction of the resin molded product 70, and the arrow Y represents 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 and intersects the width direction of the resin molded product 70.

[0047] [First Embodiment]

[0048] [Resin Molded Product 70]

[0049] The resin molded product of the first embodiment of the present disclosure includes: a main body portion having a first design surface; and a protruding portion protruding from the peripheral portion of the main body portion to the side opposite to the first design surface in the thickness direction of the main body portion and outside the main body portion, and having a second design surface connected to the first design surface. At the front end portion of the protruding portion, a gate mark is formed closer to the side opposite to the second design surface in the thickness direction of the protruding portion than the front end in the protruding direction. Hereinafter, a specific example of the resin molded product will be described with reference to the drawings, but the present disclosure is not limited thereto.

[0050] As Figure 1 shown, the resin molded product 70 of the present embodiment is a foamed resin molded product using foamed resin. The resin molded product 70 has a main body portion 72, a protruding portion 76, and a gate mark 80.

[0051] (Main body portion 72)

[0052] The main body portion 72 is a flat plate-shaped portion extending in the X direction. The main body portion 72 extends in the X direction, and a protruding portion 76 protruding outward in the X direction is formed at the peripheral portion 74 at the end in the X direction ( Figure 1 the lower side of the drawing in).

[0053] (Protruding portion 76)

[0054] The protruding portion 76 extends in the protruding direction, that is, the direction in which it protrudes from the peripheral portion 74. The protruding portion 76 has a general portion 78 and a front end portion 84. It should be noted that the front end portion 84 is the front end portion in the protruding direction of the protruding portion 76. The general portion 78 is the portion of the protruding portion 76 from the front end portion 84 to the main body portion 72. The thickness of the general portion 78 may be constant in the protruding direction or may increase or decrease.

[0055] It should be noted that the protruding direction of the protruding portion 76 is indicated by an arrow L in the drawing. In addition, the direction orthogonal to the protruding direction of the protruding portion 76, that is, the thickness direction of the protruding portion 76, is indicated by an arrow T. That is, the direction of the arrow L in the present disclosure is inclined outward with respect to the X direction.

[0056] As Figure 1 shown, the other side in the Y direction in the main body portion 72 ( Figure 1 the left side of the drawing in) is a first design surface 86A which is a part of the design surface of the resin molded product 70. In addition, one side in the T direction of the protruding portion 76 ( Figure 1 the lower left side of the drawing in) is a second design surface 86B which is a part of the design surface of the resin molded product 70. The first design surface 86A and the second design surface 86B are connected.

[0057] In addition, the surface on the opposite side of the second design surface 86B in the protruding portion 76 is called the opposite surface.

[0058] (Foaming region)

[0059] The main body portion 72 of the present embodiment has a first resin foaming region (hereinafter appropriately referred to as the "first foaming region") 88A inside. The first foaming region 88A extends in the X direction.

[0060] The protrusion 76 of the present embodiment has a second resin foam region (hereinafter appropriately referred to as "second foam region") 88B inside. The second foam region 88B may also extend in the L direction. In addition, the first foam region 88A and the second foam region 88B may be connected or separated. In the present embodiment, as Figure 1 shown, the first foam region 88A is connected to the second foam region 88B.

[0061] In addition, the average diameter of the bubbles in the first foam region 88A and the second foam region 88B may be, for example, greater than or equal to 0.02 mm and less than or equal to 0.15 mm.

[0062] It should be noted that in the present embodiment, the second foam region 88B is formed inside the protrusion 86, but the present disclosure is not limited thereto, and the second foam region 88B may not be formed inside the protrusion 86. In addition, the second foam region 88B may be divided in the L direction of the protrusion 86, and the foaming ratio may also be lower than that of the first foam region 88A.

[0063] (Front end portion 84)

[0064] As Figure 1 shown, the front end portion 84 in the present embodiment is the front end side portion of the protrusion 76 delimited by the general portion 78 and the delimiting line D, and is thinner (thinner) than the general portion 78. In addition, the front end side (the side in the direction of arrow L) of the front end portion 84 is formed in an arc shape as Figure 1 shown, and has a gate mark 80 formed during molding. In addition, as Figure 1 shown, the general portion 78 and the front end portion 84 of the protrusion 76 in the present embodiment are delimited by a step S. That is, the delimiting line D in the present embodiment is the step S, and the front end portion 84 is the portion (the thin portion) closer to the direction of arrow L than the step S and having a thickness smaller than that of the general portion 78. It should be noted that the front end portion 84 is formed by the second mold cavity 64 having a small thickness (thin) and a small volume expansion when the mold 10 is demolded, so the foaming amount is small and the shape collapse caused by foaming is small. In this way, the thickness of the foam region formed inside the front end portion 84 of the protrusion 76 is thinner than the foam region formed inside the main body portion 72, and is less than or equal to the foam region formed inside the general portion 78 of the protrusion 86.

[0065] In addition, in other words, in the protrusion 76 of the present embodiment, it can also be said that the portion connected to the peripheral portion 74 of the main body portion 72 is the base end portion, and the opposite side thereof is the front end portion 84.

[0066] (Gate mark 80)

[0067] The gate mark 80 is a part formed in the subsequent injection molding process and is a rough fracture surface formed by the fracture of the resin material R. In the present embodiment, the gate mark 80 is formed to include the front end in the protruding direction of the arc-shaped front end portion 84. In other words, the gate mark 80 is formed to include the point (the vertex of the front end portion 84) in contact with the tangent line F, and the tangent line F is parallel to the T direction which is the thickness direction of the protruding portion 76 and is tangent to the front end portion 84. In other words, the gate mark 80 is formed at the front end portion 84 from one side to the other side of the T direction with respect to the vertex overlapping with the tangent line F facing the T direction. In other words, the gate mark 80 is formed on the side opposite to the second design surface 86B at the front end portion 84.

[0068] It should be noted that the length of the front end portion 84 in the arrow L direction may be set, for example, to a length greater than or equal to 0.5 mm and less than or equal to 2.0 mm.

[0069] In addition, as described later, the step S is formed overlapping the parting line PL formed during molding.

[0070] Next, the mold 10 and the manufacturing process used in the manufacture of the resin molded product 70 of the present embodiment will be described.

[0071] [Mold 10]

[0072] The mold of the first embodiment of the present disclosure includes: a fixed mold as the first mold; a movable mold as the second mold, which can move relative to the fixed mold in the opening and closing direction, and forms a first mold cavity extending in a direction crossing the opening and closing direction between the fixed mold and a second mold cavity extending from the end of the first mold cavity in the crossing direction toward the opening direction with respect to the fixed mold, and the volumes of the first mold cavity and the second mold cavity are enlarged by the movement in the opening direction; and a sliding mold, which can move relative to the fixed mold, forms the end of the second mold cavity in the opening direction, and maintains the relative position with the fixed mold for the volume enlargement operation of the first mold cavity and the second mold cavity based on the movable mold. Hereinafter, a specific example of the mold will be described with reference to the drawings, but the present disclosure is not limited thereto.

[0073] Figure 2 and Figure 3 is a view showing a part of the mold 10 of the first embodiment. The mold 10 includes a fixed mold 20, a movable mold 26, a first sliding mold 34, a second sliding mold 36, and a sliding core 56. It should be noted that Figure 2 and Figure 3 respectively show a part of the depth direction of the drawing in the same mold 10. It should be noted that the first sliding mold 34, the second sliding mold 36, and the sliding core 56 are examples of the sliding mold of the present disclosure.

[0074] (Fixed mold 20)

[0075] The fixed mold 20 has: a bottom 22 extending in the X direction; and a rising portion 24 rising from one side of the bottom 22 in the X direction ( Figure 2 and Figure 3 the lower side of the drawing in) toward one side in the Y direction ( Figure 2 and Figure 3 the right side of the drawing in). As Figure 2 and Figure 3 shown, the fixed mold 20 is concave-shaped by the bottom 22 and the rising portion 24. The fixed mold 20 is fixed to an injection molding device (not shown).

[0076] (Movable mold 26)

[0077] The movable mold 26 has a main body portion 72 extending in the X direction and a protruding portion 30 protruding from the inner side of the main body portion 72 in the X direction toward the other side in the Y direction ( Figure 2 and Figure 3 the left side of the drawing in). As Figure 2 and Figure 3 shown, the movable mold 26 is convex-shaped by the main body portion 72 and the protruding portion 30. The movable mold 26 is supported by the injection molding device (not shown) so as to be able to open and close in the Y direction. It should be noted that, Figure 2 and Figure 3 show a part of the drawing depth direction of the same mold 10, so Figure 2 the movable mold 26 in Figure 3 and the movable mold 26 in

[0078] (First sliding mold 34)

[0079] The first sliding mold 34 is an example of the sliding mold of the present disclosure. As Figure 2 shown, it is disposed between the fixed mold 20 and the movable mold 26 so as to be surrounded by the movable mold 26. In addition, the first sliding mold 34 is separate from the movable mold 26 and can move in the Y direction at a different timing from the movable mold 26.

[0080] In addition, as Figure 2 shown, in a state where the movable mold 26 is in contact with the fixed mold 20 (closed mold state), the first sliding mold 34 is pressed against the fixed mold 20 by a pressing pin 40 from one side in the Y direction. The pressing 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 can move in the Y direction.

[0081] It should be noted that the pressing pin 40 has a flange portion 40C on one side in the Y direction. AsFigure 2 As shown, in a state where the movable mold 26 is in contact with the fixed mold 20, it is pressed from one side in the Y direction via a biasing member 50 by an injection molding device (not shown). Note that, as an example, the biasing member 50 is a coil spring. Additionally, in Figure 2 the state shown, i.e., the state where the fixed mold 20 is in contact with the movable mold 26, the length by which the biasing member 50 is compressed from its natural length is longer than the moving length of the volume expansion operation described later.

[0082] (Second sliding mold 36)

[0083] The second sliding mold 36 is another example of the sliding mold of the present disclosure. As Figure 3 shown, it is disposed between the fixed mold 20 and the movable mold 26 so as to be surrounded by the movable mold 26. Additionally, the second sliding mold 36 is separate from the movable mold 26 and can move in the Y direction at a different timing from the movable mold 26. Note that, in the present embodiment, the first sliding mold 34 and the second sliding mold 36 are separate in the Figure 2 and Figure 3 paper depth direction of the drawing.

[0084] The lifter pin 38 of the second sliding mold 36 is fixed to one side in the Y direction. The lifter pin 38 penetrates the movable mold 26 obliquely in the X direction and toward the Y direction.

[0085] Additionally, a stepped through-hole 44 having an enlarged diameter on one side in the Y direction is provided in the second sliding mold 36.

[0086] (Sliding core 56)

[0087] As Figure 3 shown, the sliding core 56 is disposed between the fixed mold 20 and the second sliding mold 36 and is in contact with the fixed mold 20. Additionally, the sliding core 56 has a gate 58 that opens to the other side in the Y direction and a flow path C that connects the gate 58 to an injection molding device (not shown). Note that the flow path C is connected in the Figure 3 paper depth direction in the drawing.

[0088] Additionally, in the sliding core 56, a pressing pin 42 is fixed to one side in the Y direction. The pressing pin 42 has a flange portion 42C on one side in the Y direction that has a diameter larger than the reduced-diameter portion 44B of the stepped through-hole 44. Additionally, as Figure 3 shown, the flange portion 42C of the pressing pin 42 is located inside the enlarged-diameter portion 44A of the stepped through-hole 44 of the second sliding mold 36 in a state where the movable mold 26 is in contact with the fixed mold 20.

[0089] Additionally, as Figure 3As shown, in a state where the movable mold 26 is in contact with the fixed mold 20, the sliding core 56 is pressed against the fixed mold 20 by the second sliding mold 36 via the biasing member 50. It should be noted that, as an example, the biasing member 50 is a coil spring. It should be noted that the surface where the fixed mold 20 contacts the sliding core 56 is referred to as the parting surface 68. In addition, in Figure 3 the state shown, that is, in a state where the fixed mold 20 is in contact with the movable mold 26, the length by which the biasing member 50 is compressed from its natural length is longer than the moving length of the volume expansion operation described later.

[0090] (Mold cavity 60)

[0091] Here, as Figure 2 and Figure 3 shown, in a state where the fixed mold 20 is in contact with the movable mold 26, a mold cavity 60 is formed by the fixed mold 20, the movable mold 26, the first sliding mold 34, the second sliding mold 36, and the sliding core 56. The mold cavity 60 has a first mold cavity 62 and a second mold cavity 64.

[0092] As Figure 2 and Figure 3 shown, the first mold cavity 62 of the mold cavity 60 extends in the X direction and is a part that constitutes most of the X direction of the resin molded product 70. In addition, the second mold cavity 64 is a part that extends from an end portion on one side in the X direction of the first mold cavity 62 toward one side in the X direction and the Y direction ( Figure 2 and Figure 3 the lower right side of the drawing in). That is, the Y direction is also the opening and closing direction in the present disclosure.

[0093] It should be noted that, as described later, in the present disclosure, in the resin molded product 70 formed by injecting the resin material R into the mold cavity 60, the side in contact with the fixed mold 20 is the design surface. That is, the resin material R injected into the first mold cavity 62 forms a main body portion 72 having a first design surface 86A, and the resin material R injected into the second mold cavity 64 forms a protruding portion 76 having a second design surface 86B.

[0094] It should be noted that, as Figure 2 shown, in the present embodiment, a step 66 is formed in the T direction between the upright portion 24 of the fixed mold 20 and the first sliding mold 34 at the front end of the second mold cavity 64.

[0095] In addition, as Figure 2 shown, in the present embodiment, the step S in the resin molded product 70 becomes a demarcation line D that demarcates the general portion 78 and the front end portion 84 in the protruding portion 76 of the resin molded product 70. That is, in the present embodiment, the surface where the fixed mold 20 contacts the first sliding mold 34 is also a part of the resin molded product 70 where the demarcation line D is formed.

[0096] In addition, asFigure 2 As shown, in the present embodiment, on the surface where the fixed mold 20 contacts the first sliding mold 34, when the resin is injected (during injection) as described later, the resin material R oozes out, so that a parting line PL in the form of a linear protrusion is formed when viewed from the second design surface 86B side. That is, the surface where the fixed mold 20 contacts the first sliding mold 34 in the present embodiment is also the part of the resin molded product 70 where the parting line PL is formed.

[0097] It should be noted that, as Figure 3 shown, in the present embodiment, at the front end of the second cavity 64, a step 66 is formed between the upright portion 24 of the fixed mold 20 and the sliding core 56 along the T direction. Regarding this step 66, on the dividing surface 68, the sliding core 56 side is closer to the inner side in the X direction. In other words, a step S of the protruding portion 76 is formed by the fixed mold 20 and the sliding core 56. That is, the T direction is also a direction intersecting the opening and closing direction in the present disclosure.

[0098] In addition, as Figure 3 shown, in the present embodiment, the step S in the resin molded product 70 becomes a demarcation line D that demarcates the general portion 78 and the front end portion 84 of the protruding portion 76 of the resin molded product 70. That is, in the present embodiment, the surface where the fixed mold 20 contacts the sliding core 56 is also the part of the resin molded product 70 where the demarcation line D is formed.

[0099] In addition, as Figure 3 shown, in the present embodiment, on the surface where the fixed mold 20 contacts the sliding core 56, when the resin is injected as described later, the resin material R oozes out, so that a parting line PL in the form of a linear protrusion is formed on the second design surface 86B side. That is, the surface where the fixed mold 20 contacts the sliding core 56 in the present embodiment is also the part of the resin molded product 70 where the parting line PL is formed.

[0100] It should be noted that, in the present embodiment, as Figure 2 and Figure 3 shown, the front end portion 65 of the second cavity 64 is arc-shaped.

[0101] In addition, as Figure 3 shown, in the present embodiment, the gate 58 of the sliding core 56 is located near the front end of the second cavity 64. In other words, through the fixed mold 20 and the sliding core 56, a gate mark 80 is formed at a position closer to the front end side than the step S of the protruding portion 76. In other words, through the fixed mold 20 and the sliding core 56, a gate mark 80 is formed on the side opposite to the second design surface 86B in the thickness direction of the protruding portion 76.

[0102] (Volume expansion operation)

[0103] It should be noted that, as described later, in the state where the resin material R is injected into the mold cavity 60 in the mold 10 of the present disclosure, the movable mold 26 can slightly move in the Y direction. That is, in the mold 10 of the present disclosure, the volume expansion operation of the mold cavity 60, which is called so-called core pulling, is performed by the movable mold 26 moving in the opening and closing direction. In addition, in the mold 10 of the present disclosure, the resin material R is injected into the mold cavity 60, and when the volume of the mold cavity 60 expands, the resin material R in the mold cavity 60 foams. It should be noted that the surface of the resin material R in contact with the mold is likely to have its temperature decreased and solidified (hardened), so when core pulling, the surface of the resin material R is not easily foamed, but foams inside. In a resin molded product, the surface portion with less foaming amount is generally also called the skin area. In addition, according to the opening direction of the movable mold 26, compared with the volume expansion of the first mold cavity 62, the volume expansion of the second mold cavity 64 (the mold cavity for forming the protruding portion 76) is less, so the foaming rate of the second foaming region 88B tends to be lower than that of the first foaming region 88A. In addition, the proportion of the skin area of the protruding portion 76 can also be larger than that of the main body portion 72.

[0104] It should be noted that, as an example, the length of the above-mentioned "slightly" movement can also be set to 1.5 mm.

[0105] (Resin material)

[0106] The resin material R is preferably a resin material R containing a resin and a foaming agent, and may also contain other components such as additives as needed.

[0107] As the resin used in the resin material R, at least one selected from the group consisting of polyethylene-based resins, polypropylene-based resins (PP), composite polypropylene-based resins (PPC), polystyrene-based resins, polyethylene terephthalate-based resins, polyvinyl alcohol-based resins, vinyl chloride-based resins, ionomer-based resins, polyamide-based resins, acrylonitrile-butadiene-styrene copolymer resins (ABS), polycarbonate-based resins, and polyphenylene sulfide resins (PPS) can be cited. Among them, at least one selected from the group consisting of polypropylene-based resins (PP), composite polypropylene-based resins (PPC), and acrylonitrile-butadiene-styrene copolymer resins (ABS) is preferred.

[0108] In addition, as the foaming agent, organic foaming agents such as azodicarbonamide and inorganic foaming agents such as sodium bicarbonate (alias: sodium hydrogen carbonate, baking soda) can be cited. In the foam molding of automotive interior parts, organic foaming agents are preferred from the viewpoints of improving environmental test performance, coating film performance (such as hot water resistance), etc.

[0109] Examples of organic foaming agents include azodicarbonamide (ADCA), N,N-dinitrosopentamethylenetetramine (DPT), 4,4'-oxybis(benzenesulfonylhydrazide) (OBSH), hydrazinedicarboxamide (HDCA), etc., with azodicarbonamide (ADCA) being preferred. Especially in the case of manufacturing exterior ornaments, azodicarbonamide (ADCA) with almost no water in its decomposition products is preferably used.

[0110] The content rate of azodicarbonamide (ADCA) in the total amount of the foaming agent is preferably greater than or equal to 50% by mass, more preferably greater than or equal to 80% by mass, still more preferably greater than or equal to 90% by mass, and particularly preferably greater than or equal to 95% by mass.

[0111] The decomposition temperature of the foaming agent is preferably greater than or equal to 50°C and less than or equal to 250°C, more preferably greater than or equal to 50°C and less than or equal to 220°C. Depending on the usage method, the decomposition temperature of the foaming agent can also be greater than or equal to 130°C and less than or equal to 250°C.

[0112] (Injection molding process)

[0113] Next, with appropriate reference to Figures 4 to 9 the injection molding process in this embodiment will be described.

[0114] First, as Figure 4 and Figure 5 shown, in the state where the fixed mold 20 is in contact with the movable mold 26, the molten resin material R flows into the mold cavity 60 from an injection molding device (not shown) through the flow path C and the gate 58. It should be noted that, as Figure 4 shown, in the state where the fixed mold 20 is in contact with the movable mold 26, the first sliding mold 34 is in contact with the fixed mold 20, so the front end portion 65 of the second mold cavity 64 is formed. In addition, as Figure 5 shown, in the state where the fixed mold 20 is in contact with the movable mold 26, the sliding core 56 is in contact with the fixed mold 20, so the front end portion 65 of the second mold cavity 64 is formed.

[0115] If a predetermined time elapses from when the resin material R is injected into the inside of the mold cavity 60, the resin material R is cooled and solidified from the outside of the mold cavity 60 (the part in contact with the fixed mold 20, the movable mold 26, the first sliding mold 34, and the sliding core 56). In the state where solidification starts on the outside of the mold cavity 60, the movable mold 26 performs a volume expansion action to become the state shown in Figure 6 and Figure 7 shown.

[0116] As Figure 6 and Figure 7As shown, when the movable mold 26 performs a volume expansion operation, the volume inside the mold cavity 60 expands, so the pressure inside the mold cavity 60 decreases. In this state, due to the foaming agent mixed in the resin material R, the resin material R foams inside the first mold cavity 62 and the second mold cavity 64.

[0117] Here, as Figure 6 shown, when the movable mold 26 performs a volume expansion operation, the first sliding mold 34 maintains its relative position with respect to the fixed mold 20 by the pressing pin 40 pressed by the biasing member 50. In other words, even when the movable mold 26 performs a volume expansion operation, the front end portion 65 of the mold cavity 60 formed by the first sliding mold 34 can maintain the shape before the volume expansion operation. Therefore, inside the front end portion 84 of the molded resin molded product 70, the amount of foaming of the resin is small, so the shape collapse caused by the foaming of the front end portion 84 can be suppressed.

[0118] In addition, as Figure 7 shown, when the movable mold 26 performs a volume expansion operation, the sliding core 56 is pressed by the biasing member 50 to maintain its relative position with respect to the fixed mold 20. In other words, even when the movable mold 26 performs a volume expansion operation, the front end portion 65 of the mold cavity 60 formed by the sliding core 56 can maintain the shape before the volume expansion operation.

[0119] Then, the resin material R inside the mold cavity 60 is further cooled. In the state where the entire resin material R is cured, the movable mold 26 further moves in the Y direction to become the Figure 8 and Figure 9 shown state.

[0120] As Figure 8 shown, by moving the movable mold 26 further to one side in the Y direction from the state where the volume expansion operation has been performed, the biasing member 50 extends to its natural length, so the pressing of the biasing member 50 on the pressing pin 40 is released. In addition, by the flange portion 40C of the pressing pin 40 being stuck in the stepped through-hole 32 of the movable mold 26, the first sliding mold 34 moves to one side in the Y direction together with the movable mold 26. Thus, as Figure 8 shown, the contact between the first sliding mold 34 and the fixed mold 20 is released.

[0121] In addition, as Figure 9 shown, by moving the movable mold 26 further to one side in the Y direction from the state where the volume expansion operation has been performed, the biasing member 50 extends to its natural length, so the pressing based on the biasing member 50 is released. In addition, the second sliding mold 36 guides the angled guide pin 38 to one side in the X direction through the through-hole of the movable mold 26 that moves to one side in the Y direction. Thus, the second sliding mold 36 and the sliding core 56 move to one side in the X direction.

[0122] After that, by sliding the core 56 to move further to one side in the X direction from the Figure 9 state shown, the cured resin material R is cut at the gate 58 portion. As a result, at the position of the gate 58 corresponding to the front end portion 84 in the cavity 60 as the trace of the cut, a rough fracture surface called the so-called gate mark 80 is formed. Figure 1 shown.

[0123] Then, by further moving the movable mold 26 relative to the fixed mold 20 to one side in the Y direction, the cured resin material R is taken out from the fixed mold 20 in the form of the Figure 1 resin molded product 70 shown. It should be noted that, as described above, as Figure 1 shown, the portion in the cavity 60 of the resin molded product 70 in the present embodiment that contacts the fixed mold 20 is the design surface.

[0124] (Comparative Example)

[0125] Here, Figure 10 and Figure 11 show a state in which the mold 110 as a comparative example of the mold 10 of the present embodiment has performed a volume expansion operation in the same manner as the mold 10 of the present embodiment.

[0126] As Figure 10 shown, in the mold 110 of the comparative example, the portion corresponding to the first sliding mold 34 of the present embodiment is a part of the movable mold 125. In other words, in the state where the volume expansion operation has been performed, the front end portion 65 of the second cavity 64 moves to one side in the Y direction together with the movable mold 125.

[0127] In addition, as Figure 11 shown, in the mold 110 of the comparative example, the portions corresponding to the second sliding mold 36 and the sliding core 56 are integrally formed as a sliding mold 130. It should be noted that the sliding mold 130 is different from the sliding core 56 of the present embodiment and is not biased toward the fixed mold 120, so it does not contact the fixed mold 120 in the state where the volume expansion operation has been performed. In other words, in the state where the volume expansion operation has been performed, the front end portion 65 of the second cavity 64 moves to one side in the Y direction together with the movable mold 125.

[0128] In this case, as Figure 10 and Figure 11As shown, the volume expansion operation is performed by the movable mold 125, so that the front end of the second cavity 64 is stretched by the movable mold 125 and the sliding mold 130 and moves to one side in the Y direction. At the moment when the volume expansion operation is performed, the resin material R is not cured, so the boundary portion between the bottom 22 of the cavity 60 and the second cavity 64 deforms toward one side in the Y direction. Due to the deformation of this boundary portion, the designability of the design surface of the resin molded product 70 is reduced.

[0129] (Function and effect)

[0130] In the case of the mold 10 of the present embodiment and the resin molded product 70 formed by the mold 10, the following functions and effects can be obtained.

[0131] In the mold 10 of the present embodiment, the sliding mold is pressed against the fixed mold 20 near the front end in the opening and closing direction of the second cavity 64, and the front end in the opening and closing direction of the second cavity 64 in the cavity 60 is formed. When the movable mold 26 moves in the opening and closing direction, the state of being pressed against the fixed mold 20 is maintained. Thus, when the movable mold 26 expands the volume of the cavity 60, the sliding mold forming the front end of the second cavity 64 does not move. Therefore, when the movable mold 26 moves in the opening and closing direction, the design surface is not easily deformed from the first cavity 62 to the second cavity 64.

[0132] Therefore, in the case of the mold 10 of the present embodiment, it is possible to reduce the possibility that the designability of the design surface of the resin molded product 70 formed due to the deformation of the design surface during the formation of the resin molded product 70 is impaired.

[0133] In addition, in the case of the mold 10 of the present embodiment, when the movable mold 26 expands the volume of the cavity 60, the sliding mold is pressed against the fixed mold 20. Thus, in the case of the mold 10 of the present embodiment, compared with the case where the sliding mold is not pressed against the fixed mold 20, the possibility of the front end of the protruding portion 76 deforming can be reduced.

[0134] In addition, in the case of the mold 10 of the present embodiment, the sliding mold is pressed against the fixed mold 20 by the urging member 50 provided on the movable mold 26. Therefore, when the interval between the fixed mold 20 and the movable mold 26 is narrow, the sliding mold is pressed against the fixed mold 20, and when the interval between the fixed mold 20 and the movable mold 26 is wide, the pressing of the sliding mold against the fixed mold 20 is released. Thus, the configuration of the mold 10 in the present embodiment that can reduce the possibility of the designability of the design surface being impaired can be simplified.

[0135] In addition, in the case of the mold 10 of the present embodiment, the sliding mold has a gate 58 for injecting resin from the front end in the opening and closing direction of the second cavity 64, and can move relative to the fixed mold 20 toward the outside in the crossing direction. Thus, for a person viewing the design surface of the resin molded product 70 molded using the mold 10 in the present embodiment, it is difficult to visually recognize the gate mark 80.

[0136] Therefore, it is possible to reduce the possibility that the designability of the design surface of the resin molded product 70 formed by the mold 10 in the present embodiment is impaired.

[0137] In addition, in the case of the resin molded product 70 of the present embodiment, since it is formed using the mold 10 of the present embodiment, the design surface is less likely to deform from the portion corresponding to the first cavity 62, i.e., the main body portion 72, to the portion corresponding to the second cavity 64, i.e., the protruding portion 76.

[0138] Therefore, compared with the resin molded product 70 formed without using the mold 10 of the present embodiment, the resin molded product 70 of the present embodiment can reduce the possibility that the designability of the design surface is impaired.

[0139] In addition, in the resin molded product 70 of the present embodiment, the front end portion 84 of the protruding portion 76 has a gate mark 80 formed on the side of the second design surface 86B in the thickness direction of the front end portion 84 of the protruding portion 76, and the front end portion 84 is formed inside the main body portion 72 compared with the demarcation line D that demarcates the general portion 78 and the front end portion 84. That is, in the second design surface 86B, the gate mark 80 located on the opposite side of the second design surface 86B closer to the general portion 78 is likely to be confused with the demarcation line D, so the gate mark 80 is not conspicuous to a person viewing the design surface. Therefore, the gate mark 80 of the resin molded product 70 in the present embodiment is not conspicuous with respect to the design surface, and thus the possibility that the designability of the design surface is impaired is reduced.

[0140] In addition, in the resin molded product 70 of the present embodiment, the demarcation line D is a step S that is inward of the main body portion 72 compared with the second design surface 86B of the general portion 78. Thus, the demarcation line D of the resin molded product 70 becomes the step S, and the parting line PL is not conspicuous to a person viewing the design surface. Therefore, the possibility that the designability of the design surface is impaired is reduced.

[0141] In addition, in the resin molded product 70 of the present embodiment, a parting line PL is formed on the demarcation line D in the second design surface 86B.

[0142] In addition, in the resin molded product 70 of the present embodiment, a parting line PL is formed on the demarcation line D that is the boundary between the general portion 78 and the front end portion 84. The parting line PL is not conspicuous to a person viewing the design surface. Therefore, the possibility that the designability of the design surface is impaired is reduced.

[0143] In addition, in the resin molded product 70 of the present embodiment, the parting line PL is located at a position that is greater than or equal to 0.5 mm and less than or equal to 2.0 mm from the front end of the protruding portion 76. From the perspective of a person viewing the design surface, the parting line PL is not conspicuous. Therefore, the possibility of damage to the designability of the design surface is reduced.

[0144] In addition, in the resin molded product 70 of the present embodiment, since the shape of the front end portion 84 is an arc shape, the gate mark 80 is likely to become smaller during molding. Therefore, compared with the case where the shape of the front end portion 84 of the resin molded product 70 of the present embodiment is not an arc shape, the gate mark 80 becomes smaller, and thus the possibility of damage to the designability of the design surface is reduced.

[0145] In addition, in the resin molded product 70 of the present embodiment, since the end portion of the gate mark 80 is connected to the end portion of the surface of the protruding portion 76 on the side opposite to the second design surface 86B, the gate mark 80 is not easily visually recognized from the perspective of a person viewing the design surface. Therefore, compared with the case where the end portion of the gate mark 80 is not connected to the end portion of the surface of the protruding portion 76 on the side opposite to the second design surface 86B in the resin molded product 70 of the present embodiment, the gate mark 80 becomes inconspicuous, and thus the possibility of damage to the designability of the design surface is reduced.

[0146] In addition, in the resin molded product 70 of the present embodiment, since the first foaming region 88A and the second foaming region 88B are formed, the weight of the resin molded product can be reduced.

[0147] In the resin molded product 70 of the present embodiment, since the gate mark 80 is formed in a portion of the front end portion 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 compared to the front end in the protruding direction, the gate mark 80 is not easily visually recognized from the perspective of a person viewing the design surface.

[0148] Therefore, in the resin molded product 70 of the present embodiment, the gate mark 80 is not easily visually recognized with respect to the design surface, and thus the possibility of damage to the designability of the design surface is reduced.

[0149] In addition, in the resin molded product 70 of the present embodiment, since the shape of the front end portion 84 is an arc shape, the gate mark 80 is likely to become smaller during molding. Therefore, compared with the case where the shape of the front end portion 84 is not an arc shape, the gate mark 80 is not easily visually recognized, and thus the possibility of damage to the designability of the design surface is reduced.

[0150] In addition, in the resin molded product 70 of the present embodiment, since the end of the gate mark 80 is connected to the end of the surface of the protruding portion 76 on the side opposite to the second design surface 86B, the gate mark 80 is less likely to be visually recognized by a person viewing the design surface. Therefore, compared with the case where the end of the gate mark 80 in the resin molded product 70 of the present embodiment is not connected to the end of the surface of the protruding portion 76 on the side opposite to the second design surface 86B, the gate mark 80 is less likely to be visually recognized, and thus the possibility of damage to the designability of the design surface is reduced.

[0151] In addition, since the resin molded product 70 of the present embodiment is formed with the first foaming region 88A and the second foaming region 88B, the weight of the resin molded product 70 can be reduced.

[0152] (Modification example)

[0153] It should be noted that in the above description, the first sliding die 34 and the second sliding die 36 are separate, but this is not limited thereto. For example, the second sliding die 36 may be pressed against the fixed die 20 by the pressing pin 40 in the same manner as the first sliding die 34 instead of being supported by the angled pin 38 on the movable die 26. In addition, in this case, the first sliding die 34 and the second sliding die 36 may also be integrated.

[0154] In addition, in the above description, the sliding core 56 and the second sliding die 36 are separate, but this is not limited thereto, and the second sliding die 36 and the sliding core 56 may also be integrated.

[0155] In such a case, as long as the movable die 26 performs a volume expansion action and the portions corresponding to the first sliding die 34 and the sliding core 56 come into contact with the fixed die 20 when the resin material R foams, the same functions and effects as those of the mold 10 of the first embodiment can be obtained.

[0156] In addition, in the above description, in the resin molded product 70 of the present embodiment, the demarcation line D overlaps with the parting line PL, but this is not limited thereto, and it may also be formed in a shape where the demarcation line D and the parting line PL do not overlap. In this case, it is preferable that the parting line PL is formed at a position closer to the front end side than the demarcation line D of the resin molded product. Thereby, the parting line PL becomes less conspicuous due to the demarcation line D and the step S, and therefore, the possibility of damage to the designability of the design surface is reduced.

[0157] Note that in the above description, in the present embodiment, as an example of the resin molded product, a resin molded product 70 having a foamed region inside is formed, but the technology of the present disclosure is not limited thereto. That is, it is equally applicable to a resin molded product that does not have a foamed region in the main body portion 72 and the protruding portion 76. In this case, similar to the resin molded product 70 in the present embodiment, from the perspective of a person viewing the design surface, the gate mark 80 is not conspicuous with respect to the design surface, so the possibility of damage to the designability of the design surface is reduced. In addition, similar to the resin molded product 70 in the present embodiment, from the perspective of a person viewing the design surface, the gate mark 80 is not easily visually recognizable with respect to the design surface, so the possibility of damage to the designability of the design surface is reduced.

[0158] Next, with appropriate reference to Figure 12 and Figure 13 the second embodiment in the present disclosure will be described. Note that in the configuration of the present embodiment, the same reference numerals are given to the same configurations as those in the first embodiment, and the detailed description may be omitted sometimes.

[0159] [Second Embodiment]

[0160] Figure 12 The case where the mold 10 of the second embodiment performs a volume expansion operation is shown. In the mold 10 of the present embodiment, for the sliding core 56, a sliding actuator 54 is connected through the movable mold 26 from one side in the Y direction. That is, in the present embodiment, the sliding core 56 is pressed against the fixed mold 20 by the sliding actuator 54 in a state where the mold 10 performs a volume expansion operation.

[0161] Other configurations are the same as those in the first embodiment.

[0162] In the mold 10 of the present embodiment, as Figure 13 shown, when the fixed mold 20 further moves to one side in the Y direction from the state where the volume expansion operation has been performed, the sliding core 56 and the second sliding mold 36 are guided to one side in the X direction. Thus, in the present embodiment, when the movable mold 26 is separated from the fixed mold 20, the resin material R is cut at the gate 58 portion.

[0163] (Function and Effect)

[0164] In addition, as Figure 12As shown, in the present embodiment, the sliding die is pressed against the fixed die 20 when the movable die 26 performs a volume expansion action not by the force applying member 50 but by the sliding actuator 54. In other words, in the present embodiment, the sliding die does not release contact with the fixed die 20 at the moment of performing the volume expansion action. Thus, in the present embodiment, when the volume of the mold cavity 60 is expanded by the movable die 26, the sliding die forming the front end of the second mold cavity 64 does not move. Therefore, when the movable die 26 moves in the opening and closing direction, the design surface is not easily deformed from the first mold cavity 62 to the second mold cavity 64.

[0165] Therefore, in the mold 10 of the present embodiment, it is also possible to reduce the possibility that the designability of the design surface of the resin molded product 70 formed is impaired due to deformation of the design surface when the resin molded product 70 is formed.

[0166] It should be noted that other functions and effects obtained by the mold 10 in the first embodiment can also be obtained in the same manner in the present embodiment.

[0167] Next, with appropriate reference Figures 14 to 16 The third embodiment in the present disclosure will be described. It should be noted that in the configuration of the present embodiment, the same reference numerals are given to the same configurations as those in the first embodiment, and the specific description may be omitted sometimes.

[0168] [Third Embodiment]

[0169] (Resin Molded Product 70)

[0170] Figure 14 FIG. shows the resin molded product 70 in the third embodiment. In the present embodiment, compared with the resin molded product 70 in the first embodiment, a tapered portion 92 is formed at the front end portion 284 of the protruding portion 76 without forming a step S. In addition, in the resin molded product 70 of the present embodiment, the gate mark 80 is formed at a position closer to the T direction side than the vertex on the L arrow direction side within the range of the T direction of the front end portion 284. In other words, in the present embodiment, the gate mark 80 is formed at a position closer to the T direction side than the point of contact with the tangent line F (the vertex of the front end portion 284), and the tangent line F is parallel to the T direction which is the thickness direction of the protruding portion 276 and is tangent to the front end portion 284. In other words, in the resin molded product 70 of the present embodiment, the gate mark 80 is not formed at a position closer to the other side in the T direction than the vertex on the L arrow direction side within the range of the T direction of the front end portion 284.

[0171] As Figure 14As shown, the tapered portion 92 is a portion where the thickness decreases toward the other side in the T direction (the inner side of the main body portion 72) as it goes from the parting line PL, which is the demarcation line D demarcating the general portion 78 and the front end portion 284, toward the side in the direction of arrow L. In other words, similar to the step S in the first embodiment, the tapered portion 92 in the present embodiment changes the thickness of the protruding portion 76 in the T direction to gradually reduce the thickness.

[0172] The shapes of the other parts are the same as those of the resin molded product 70 in the first embodiment.

[0173] Next, the mold 10 for manufacturing the resin molded product 70 of the present embodiment will be described.

[0174] Figure 15 FIG. shows the mold 10 in the present embodiment. In the mold 10 of the present embodiment, on the side in the direction of arrow L from the parting surface 68 where the fixed mold 20 contacts the sliding core 56, there is an inclined portion 266 where the thickness of the protruding portion 76 decreases toward the other side in the T direction as it goes toward the side in the direction of arrow L.

[0175] In addition, as Figure 15 shown, in the mold 10 of the present embodiment, the gate 258 is located at a position closer to the side in the T direction than the side closest to the direction of arrow L in the cavity 60. In other words, in the present embodiment, the gate 258 is located between the tapered portion 92 and the front end portion 265 of the cavity 60.

[0176] The other configurations are the same as those in the first embodiment.

[0177] It should be noted that, in the present embodiment, as Figure 16 shown, by moving the sliding core 56 to the side in the X direction, the cured resin material R is cut at the gate 258 portion to form the gate mark 80 of the resin molded product 70.

[0178] (Function and Effect)

[0179] In the present embodiment, as Figure 15 shown, even in a state where the movable mold 26 has performed a volume expansion operation, the contact between the sliding core 56 and the fixed mold 20 can be maintained. Thus, similar to the first embodiment, when forming the resin molded product 70, the possibility that the designability of the designed surface of the resin molded product 70 is impaired due to deformation of the designed surface can be reduced.

[0180] In addition, in the present embodiment, as Figure 14As shown, the front end portion 284 of the protruding portion 76 of the gate mark 80 has the gate mark 80 formed on the side of the second design surface 86B in the thickness direction of the front end portion 284 of the protruding portion 76, and the front end portion 284 is formed at a position closer to the inside of the main body portion 72 than the demarcation line D that demarcates the general portion 78 and the front end portion 284. That is, at the second design surface 86B, the gate mark 80 located at a position closer to the opposite side of the second design surface 86B than the general portion 78 is likely to be confused with the demarcation line D. Therefore, from the perspective of a person viewing the design surface, the gate mark 80 is not conspicuous. Thus, in the formed resin molded product 70, since the gate mark 80 is not conspicuous with respect to the design surface, the possibility of impairment of the designability of the design surface is reduced.

[0181] It should be noted that other functions and effects obtained by the mold 10 in the first embodiment can also be obtained in the same manner in this embodiment.

[0182] Next, with appropriate reference to Figures 17 to 19 The fourth embodiment in the present disclosure will be described. It should be noted that in the configuration of this embodiment, the same reference numerals are given to the same configurations as those in the first embodiment, and the specific description may sometimes be omitted.

[0183] [Fourth Embodiment]

[0184] (Resin Molded Product 70)

[0185] Figure 17 FIG. shows the resin molded product 70 in the fourth embodiment. In this embodiment, compared with the resin molded product 70 in the first embodiment, at the front end portion 384 of the protruding portion 76, the gate mark 80 is formed at a position closer to the other side in the T direction than the vertex on the one side in the direction of arrow L within the range of the T direction of the front end portion 384. In other words, in this embodiment, the gate mark 80 is formed at a position closer to the other side in the T direction than the point of contact with the tangent line F (the vertex of the front end portion 384), and the tangent line F is parallel to the T direction which is the thickness direction of the protruding portion 376 and is tangent to the front end portion 384. In other words, in the resin molded product 70 of this embodiment, the gate mark 80 is not formed at a position closer to the one side in the T direction than the vertex on the one side in the direction of arrow L within the range of the T direction of the front end portion 384.

[0186] The shapes of other parts are the same as those of the resin molded product 70 in the first embodiment.

[0187] Next, the mold 10 for manufacturing the resin molded product 70 of this embodiment will be described.

[0188] Figure 18This is a view showing the mold 10 in the present embodiment. In the present embodiment, in the mold 10 of the present embodiment, the gate 358 is located on the other side closer to the T direction than the side closest to the arrow L direction in the cavity 60. In other words, in the present embodiment, the gate 358 is located between the front end portion 365 of the cavity 60 and the protrusion 30 of the movable mold 26.

[0189] Other configurations are the same as those in the first embodiment.

[0190] It should be noted that, in the present embodiment, as Figure 19 shown, by moving the sliding core 56 to one side in the X direction, the cured resin material R is cut at the gate 358 portion, forming the gate mark 80 of the resin molded product 70.

[0191] (Function and effect)

[0192] In the present embodiment, as Figure 18 shown, in the state where the movable mold 26 has performed the volume expansion operation, the contact between the sliding core 56 and the fixed mold 20 can also be maintained. Thus, similarly to the first embodiment, when forming the resin molded product 70, the possibility that the designability of the designed surface of the resin molded product 70 is impaired due to the deformation of the designed surface can be reduced.

[0193] In addition, in the present embodiment, as Figure 17 shown, the gate mark 80 is formed at the front end portion 384 of the protrusion 76 on the side closer to the side opposite to the second designed surface 86B in the thickness direction of the protrusion 76 than the front end in the protruding direction. That is, at the front end portion 384 of the protrusion 76, it is formed at a portion closer to the side opposite to the second designed surface 86B in the thickness direction of the protrusion 76 than the front end in the protruding direction. Therefore, from the perspective of a person viewing the designed surface, the gate mark 80 is not easily visually recognizable. Thus, in the resin molded product 70 in the present embodiment, the gate mark 80 is not easily visually recognizable with respect to the designed surface, so the possibility that the designability of the designed surface is impaired is reduced.

[0194] It should be noted that other functions and effects obtained by the mold 10 in the first embodiment can also be obtained similarly in the present embodiment.

[0195] Next, with appropriate reference to Figures 20 to 22 the fifth embodiment of the present disclosure will be described. It should be noted that, in the configuration of the present embodiment, for the same configurations as those in the first embodiment, the same reference numerals are used, and specific descriptions may sometimes be omitted.

[0196] [Fifth Embodiment]

[0197] (Resin Molded Product 70)

[0198] Figure 20 This is a view showing the resin molded product 70 in the fourth embodiment. In this embodiment, compared with the resin molded product 70 in the first embodiment, at the front end portion 484 of the protruding portion 76, the front end shape is not arc-shaped but linear. In other words, the gate mark 80 is formed to include the point of contact with the tangent line F (the vertex of the front end portion 484), and this tangent line F is parallel to the T direction which is the thickness direction of the protruding portion 76 and is tangent to the front end portion 484. In other words, the gate mark 80 is formed at a position closer to the T direction than the vertex on the side of the arrow L direction within the T direction range of the front end portion 484, and is formed at a position closer to the other side of the T direction than the vertex on the side of the arrow L direction.

[0199] The shapes of other parts are the same as those of the resin molded product 70 in the first embodiment.

[0200] Next, the mold 10 for manufacturing the resin molded product 70 of this embodiment will be described.

[0201] Figure 21 This is a view showing the mold 10 in this embodiment. In this embodiment, a step 66 is formed on the parting surface 68 where the fixed mold 20 contacts the sliding core 56.

[0202] In addition, in this embodiment, as Figure 21 shown, the side closest to the arrow L direction in the second cavity 64 in the cavity 60 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 front end portion 465 of the second cavity 64.

[0203] Other configurations are the same as those in the first embodiment.

[0204] It should be noted that, in this embodiment, as Figure 22 shown, by moving the sliding core 56 to one side in the X direction, the cured resin material R is cut at the gate 458 portion, and the gate mark 80 of the resin molded product 70 is formed.

[0205] (Function and effect)

[0206] In this embodiment, as Figure 22 shown, in the state where the movable mold 26 has performed the volume expansion operation, the contact between the sliding core 56 and the fixed mold 20 can also be maintained. Thus, similarly to the first embodiment, when forming the resin molded product 70, the possibility that the designability of the designed surface of the resin molded product 70 is impaired due to deformation of the designed surface can be reduced.

[0207] In addition, in this embodiment, as Figure 22As shown, by moving the sliding core 56 to one side in the X direction, the cured resin material R is cut at the gate 458 portion, forming a gate mark 80 of the resin molded product 70.

[0208] In addition, in the present embodiment, as Figure 20 shown, the gate mark 80 is formed at the front end portion 484 of the protruding portion 76 closer to the side opposite to the second design surface 86B in the thickness direction of the protruding portion 76 than the front end in the protruding direction. That is, at the front end portion 484 of the protruding portion 76, the portion formed closer to the side opposite to the second design surface 86B in the thickness direction of the protruding portion 76 than the front end in the protruding direction, so that the gate mark 80 is not easily visually recognized by a person viewing the design surface. Thus, in the resin molded product of the present embodiment, the gate mark 80 is not easily visually recognized with respect to the design surface, and thus the possibility of impairment of the designability of the design surface is reduced.

[0209] In other words, in the present embodiment, as Figure 20 shown, with respect to the gate mark 80, the front end portion 484 of the protruding portion 76 has the gate mark 80 formed on the second design surface 86B side in the thickness direction of the front end portion 484 of the protruding portion 76, and the front end portion 484 is formed inside the main body portion 72 compared to the demarcation line D that demarcates the general portion 78 and the front end portion 484. That is, at the second design surface 86B, the gate mark 80 located closer to the opposite side of the second design surface 86B than the general portion 78 is likely to be confused with the demarcation line D, so that the gate mark 80 is not conspicuous to a person viewing the design surface. Thus, in the resin molded product of the present embodiment, since the gate mark 80 is not conspicuous with respect to the design surface, the possibility of impairment of the designability of the design surface is reduced.

[0210] As described above, the embodiments of the present disclosure have been described with reference to the drawings. However, it is obvious that those having ordinary knowledge in the technical field to which the present disclosure pertains can conceive of various modification examples or application examples within the scope of the technical idea described in the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure.

[0211] It should be noted that the entire disclosure content of Japanese Patent Application No. 2022-174980 filed on October 31, 2022 is incorporated herein by reference.

[0212] All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as when each document, patent application, and technical standard is specifically and separately described as being incorporated by reference.

Claims

1. A resin molded article, comprising: a main body portion having a first designed surface; and a protruding portion that protrudes from a peripheral portion of the main body portion toward a side opposite to the first designed surface in the thickness direction of the main body portion and outside the main body portion, and has a second designed surface connected to the first designed surface, the protruding portion having a front end portion in the protruding direction and a general portion between the front end portion and the main body portion, an outer surface of the front end portion being located inside the main body portion as compared with a demarcation line that defines the general portion and the front end portion, a gate mark being formed in the front end portion.

2. The resin molded article according to claim 1, wherein the demarcation line is a step from the second designed surface of the general portion toward the inside of the main body portion.

3. The resin molded article according to claim 1, wherein a parting line is formed in the second designed surface at the demarcation line.

4. The resin molded article according to claim 1, wherein the demarcation line is located at a position that is greater than or equal to 0.5 mm and less than or equal to 2.0 mm from the front end of the protruding portion.

5. The resin molded article according to claim 1, wherein a shape of the front end portion of the protruding portion is an arc shape.

6. The resin molded article according to claim 1, wherein an end of the gate mark is connected to an end of a surface of the protruding portion opposite to the second designed surface.

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

Images