JP2010155355A - Injection molding mold and method for producing resin molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection molding mold which can prevent gate flight when second resin injection is carried out into an insert sheet, and to provide a method for producing a resin molding. <P>SOLUTION: The injection molding mold is provided with: a first mold 1 in which a first cavity surface 1a is formed; a second mold 2 in which a second cavity surface 2a is formed; a first gate 6 for injecting a first resin into a first cavity 22 formed by relatively moving the first mold 1 and the second mold 2 on which the insert sheet S is arranged; and a second gate 7 for injecting a second resin into a second cavity 24 through a gate space 25, both formed by relatively moving the first mold 1 and the second mold 2. The gate space 25 receives a projected piece 10 of the insert sheet S and can arrange the projected piece 10 to contact the first mold 1 therealong. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an injection mold that can be used for manufacturing a resin molded product in which an insert sheet is embedded between a first resin portion and a second resin portion.

Conventionally, there is a resin molded product in which a core material as an insert portion is embedded.
An injection mold that can be used for manufacturing the resin molded product includes a first mold in which a first cavity surface corresponding to one surface side of the core material is formed, and a first mold corresponding to the other surface side of the core material. A second mold having a two-cavity surface, a slide mold capable of moving in and out of the second mold in the mold clamping direction, and a gate for injecting resin located on the side of the core material are provided. .
A resin molded product is manufactured using the injection mold. Specifically, first, the first mold and the second mold are opened to place the core material at a predetermined position. Next, the first mold and the second mold are clamped to sandwich the end portion of the core material. Advance the slide mold to hold the core material. At this time, a first cavity is formed between the one surface of the core material and the first cavity surface, and a second cavity is formed between the other surface of the core material and the second cavity surface. Thereafter, when the resin is injected from the gate, the injected resin is divided into the first cavity and the second cavity and filled. The slide mold is retracted while the injected resin is melted. Resin is injected from the gate for the volume of the slide mold retired. After the resin is solidified, the first mold and the second mold are opened and the resin molded product is taken out. In this way, a resin molded product in which the core material is embedded is manufactured. (For example, refer to Patent Document 1).

  However, when the insert portion is an insert sheet with low rigidity, when the resin is injected from the gate, the injected resin is divided into the first cavity and the second cavity and filled. At this time, the insert sheet is pulled by the resin passing simultaneously on one side and the other side of the insert sheet, and the insert sheet is displaced or wrinkled. For this reason, when the insert portion is an insert sheet with low rigidity, it is difficult to manufacture a molded product in which the insert sheet is embedded.

  Therefore, an injection mold for manufacturing a resin molded product in which an insert sheet is embedded has been previously proposed by the present applicant. Specifically, the injection mold includes a first mold in which a first cavity surface corresponding to the surface of the first resin portion is formed, and a second cavity surface corresponding to the surface of the first resin portion. The second mold, a first gate for injecting the first resin, and a second gate for injecting the second resin are provided. A first cavity is formed between the first surface of the insert sheet and the first cavity surface by relatively moving the first mold and the second mold in which the insert sheet is disposed along the second cavity surface. A first resin is injected from the first gate into the first cavity to form a first resin portion. An insert sheet adheres to the formed first resin portion. Thereafter, the second mold is formed between the other surface of the insert sheet and the second cavity surface by relatively moving the first mold and the second mold holding the fixed first resin portion. The second resin is directly flowed from the second gate toward the portion of the insert sheet to which the first resin is fixed and injected into the second cavity, or the first resin is injected from the second gate to the outside of the end of the insert sheet. And the second resin is injected into the second cavity through the integrated part. After the second resin is solidified, the first mold and the second mold are opened and the resin molded product is taken out. In this manner, a resin molded product in which the insert sheet is embedded is manufactured.

Japanese Patent Laid-Open No. 4-16316

In the improved technique, the first resin passes on one surface of the insert sheet disposed on the second cavity surface, and then the second resin passes on the other surface of the insert sheet fixed to the first resin portion. Therefore, it is possible to prevent the insert sheet from being pulled and the insert sheet from being displaced or wrinkled as compared with the case where the resin passes through one side and the other side of the insert sheet at the same time. For this reason, it has the advantage which can respond also when the insert part is an insert sheet. However, when the second resin is injected, the insert sheet is melted by the heat of the second resin, so that a phenomenon called so-called gate jump may occur, and there is still room for improvement.
That is, when the high-temperature second resin directly hits a part of the insert sheet at the time of injection, the heat of the second resin is transmitted to a part of the insert sheet, while the heat-insulating action of the first resin fixed to the insert sheet causes The heat applied to a part does not escape, and the insert sheet becomes hot and melts.

  Accordingly, an object of the present invention is to provide an injection mold and a method for producing a resin molded product that can solve the above-described problems and prevent gate jumping when the second resin is injected into the insert sheet. .

The mold for injection molding of the present invention can be used for manufacturing a resin molded product in which an insert sheet is embedded between the first resin portion and the second resin portion,
The first characteristic configuration includes a first mold in which a first cavity surface corresponding to the surface of the first resin portion is formed, and a second mold in which a second cavity surface corresponding to the surface of the first resin portion is formed. Type,
A first cavity corresponding to the first resin portion is formed by relatively moving the first mold and the second mold on which the insert sheet is disposed along the second cavity surface. Corresponding to the second resin portion by relatively moving the first gate for injecting the first resin into the cavity, the first die for holding the first resin portion to which the insert sheet is fixed, and the second die. A second cavity configured to form a second cavity that is connected to the second cavity, and a second gate that injects a second resin into the second cavity through the gate space. The projecting piece of the insert sheet projecting outward from one resin part is received, and the projecting piece is configured to be arranged so as to contact along the first mold.

Further, in the method for producing a resin molded product of the present invention, an insert sheet is embedded between the first resin portion and the second resin portion,
The first characteristic means includes the insert sheet in the opened state so that the protruding piece protrudes into the gate space while contacting the surface of the first mold when the second cavity is formed. A step of arranging along the two cavities, a step of clamping the arranged second mold and the first mold to form the first cavity, and the first gate in the formed first cavity. Injecting the first resin from the first resin portion and forming the first resin portion, and after the insert sheet is fixed to the formed first resin portion, the first mold is held by the first mold. The step of forming the second cavity by moving the first mold and the second mold relative to each other, and the second gate so as to flow through the upper surface of the protruding piece into the formed second cavity. From the gate space It is in that a step of forming the second resin portion by injecting a second resin through.

  According to the present invention, when the second resin is injected, the second resin contacts the insert sheet through the gate space. A portion in the vicinity of the protruding piece in the insert sheet is likely to become high temperature, and the insert sheet is likely to melt. However, in this configuration, the heat in the vicinity of the protruding piece is diffused to the first mold through the protruding piece, thereby preventing the insert sheet from being overheated and preventing the insert sheet from melting.

  According to a second characteristic configuration of the present invention, the gate space includes a step portion in which a tip of the protruding piece is accommodated so as to retreat from the flow of the second resin.

  According to the present invention, it is possible to avoid the second resin from directly hitting the tip of the protruding piece when the second resin is injected. As a result, it is possible to prevent the insert sheet from being displaced and the insert sheet from being lifted or turned up.

  A third characteristic configuration of the present invention is that the gate space is configured such that a cross-sectional area when cut along a plane orthogonal to the flow direction of the second resin is substantially constant over the entire length. .

  For example, when a bottleneck having a small cross-sectional area exists in a part of the gate space, the flow rate of the second resin passing through the bottleneck is increased, and the insert sheet is likely to be lifted or turned up. Further, shear heat is generated in the second resin passing through the portion having a small cross-sectional area, and the insert sheet is easily melted. However, since the cross-sectional area of the gate space is substantially equal over the entire length, it is possible to prevent melting of the insert sheet and lifting and turning of the insert sheet.

  According to a fourth aspect of the present invention, there is provided a fixing means for fixing the protruding piece disposed so as to come into contact with the surface of the first mold when the second resin is injected. .

  According to the present invention, the state in which the protruding piece is brought into contact with the surface of the first mold by the fixing means is maintained, so that the position of the insert sheet is shifted during the injection of the second resin, and the insert sheet is lifted and turned up It can be prevented from occurring.

  A fifth characteristic configuration of the present invention has a parting surface with respect to the first mold, the second mold slides in the mold clamping direction inside, and a part of the inner peripheral wall is on the surface of the second resin portion. A third mold that constitutes a corresponding third cavity surface is further provided.

  According to the present invention, when the insert sheet is disposed on the second mold and the first mold, the second mold, and the third mold are clamped, the parting surfaces of the first mold and the third mold are in close contact with each other. A first cavity is formed between the first cavity surface of the mold and one surface of the insert sheet disposed in the second mold. A first resin is injected into the first cavity to form a first resin portion. When the second mold slides inside the third mold, the other surface of the insert sheet fixed to the first resin portion held by the first mold, the second cavity surface of the second mold, and the third cavity of the third mold A second cavity is formed between the surfaces. Therefore, the outer shape of the second resin portion can be made smaller than the outer shape of the first mold when viewed from the mold clamping direction.

[First embodiment]
Hereinafter, the injection mold according to the present invention will be described.
With the injection mold according to the present invention, a resin molded product in which the insert sheet S is embedded between the first resin portion 23 and the second resin portion 26 can be manufactured as shown in FIG.
As shown in FIGS. 1 to 4, the injection mold is provided in a state facing the fixed mold 1 and the fixed mold 1 (an example of the first mold) on which the first parting surface 1 b is formed. A movable part formed with a slide part 2 (an example of a second part) and a second parting surface 3a (an example of a parting face) provided opposite to the fixed mold 1 and surrounding the slide mold 2 A mold 3 (an example of a third mold). A concave portion 4 is formed at the center of the surface of the fixed die 1 on the slide die 2 side, and the surface of the concave portion 4 constitutes a first cavity surface 1 a corresponding to the surface of the first resin portion 23. A surface of the slide mold 2 on the fixed mold 1 side constitutes a second cavity surface 2 a corresponding to the surface of the second resin portion 26. An end of the inner peripheral wall 3b of the movable mold 3 on the fixed mold 1 side constitutes an annular third cavity surface corresponding to the surface of the second resin portion 26.

  FIG. 1A is a diagram showing the fixed mold 1 in plan view. FIG. 1B is a cross-sectional side view taken along the arrow I-I in FIG. FIG. 2B is a diagram showing the slide mold 2 and the movable mold 3 surrounding the slide mold 2 in plan view. FIG. 2A is a cross-sectional side view taken along the arrow I-I in FIG. FIG. 3 shows a perspective view of the main part of the slide mold 2 and the movable mold 3. Specifically, for the slide mold 2, the second cavity surface 2a formed on one side of the slide mold 2 from obliquely below. The movable mold 3 is a diagram showing a second parting surface 3a formed on one side of the movable mold 3 from obliquely below. FIG. 4 shows a perspective view of the main part of the fixed mold 1. Specifically, for the fixed mold 1, the first cavity surface 1 a and the first party formed on the other side of the fixed mold 1 from obliquely above. FIG.

  As shown in FIGS. 1 to 4, the fixed mold 1 is configured in a substantially rectangular parallelepiped shape, and has a recess 4 formed at the center of the other surface (the surface facing the slide mold 2 and the movable mold 3), and the like. And a rectangular parallelepiped-shaped convex portion 5 formed at the center of the side portion of the direction. Thereby, the first step portion 31 (between the first side surface 5a on the concave portion 4 side of the convex portion 5 and the first portion 1c sandwiched between the concave portion 4 and the convex portion 5 on the first parting surface 1b. An example of a stepped portion is formed. The surface of the recess 4 constitutes the cavity surface 1a. The first cavity surface 1a is provided with a first gate 6 for injecting a first resin. The convex part 5 is provided with a second gate 7 for injecting the second resin.

  As shown in FIGS. 2 and 3, the slide mold 2 is configured by providing a protruding portion 9 having a rectangular cross-sectional shape along the mold clamping direction at the center of the side surface of the substantially rectangular parallelepiped body portion 8. . A second cavity surface 2 a is formed on one side of the main body 8. A first surface 9a connected to the second cavity surface 2a, a second surface 9b connected in a state orthogonal to the first surface 9a, and a second surface 9b connected in a state orthogonal to the second surface 9b are connected to one side of the protrusion 9. Three surfaces 9c are formed. Thereby, the 2nd step part 32 is formed between the 1st surface 9b and the 3rd surface 9c. The second cavity surface 2a and the first surface 9a are preferably flush with each other so that the first resin flows smoothly. The other surface of the insert sheet S is in contact with the second cavity surface 2a, and the other surface on the proximal end side of the protruding piece 10 of the insert sheet S is disposed in contact with the first surface 9a. The width of the protruding piece 10 is set to be the same as or slightly smaller than the width of the protruding portion 9. A slide pin 11 (an example of a fixing unit) that can protrude from the third surface 9c in the mold clamping direction is provided. As the slide operation mechanism of the slide pin 11, for example, a piston cylinder attached to the slide mold 2, an interlocking mechanism interlocking with the fixed mold 1, or the like can be used.

  As shown in FIGS. 2, 3, 7, and 8, the movable mold 3 is formed in a substantially rectangular parallelepiped shape, and the slide mold 2 is configured to be slidable in the mold clamping direction in the internal space. A part of the inner peripheral wall 3 b of the movable mold 3 constitutes a third cavity surface 3 c corresponding to the surface (side surface) of the second resin portion 26. The inner peripheral wall 3b of the movable mold 3 is provided with a concave groove 12 having a rectangular cross-sectional shape along the mold clamping direction so that the protruding portion 9 can be accommodated. A cutout 13 having a rectangular cross-sectional shape connected to the end of the groove 12 is provided on one side of the movable mold 3.

The insert sheet S is configured by forming a pattern layer (not shown) on a base sheet (not shown).
The base sheet is made of a material such as a resin sheet such as polyethylene terephthalate (PET), polypropylene (PP), or acrylic (PMMA), a metal foil, glassine paper, coated paper, a cellulosic sheet such as cellophane.
The pattern layer is formed of a colored ink containing a resin as a binder and a colorant such as a pigment or dye. Resins used as binders are polyvinyl resin, polyamide (PA) resin, polyester resin, acrylic (PMMA) resin, polyurethane resin, polyvinyl acetal resin, polyester urethane resin, cellulose ester resin, alkyd Examples thereof include resins. The pattern layer is printed on the base sheet by gravure printing, screen printing, offset printing, or the like. When it is desired to express metallic luster as a pattern, the pattern layer is constituted by a metal thin film layer formed by a vacuum deposition method, a sputtering method, an ion plating method, a plating method or the like. The symbol layer is set entirely or partially depending on the symbol to be expressed. In addition to the design layer, for example, a protective layer for protecting the design layer or a functional layer for improving interlayer adhesion may be provided.

  Next, a method for producing a resin molded product according to the present invention will be described.

[Insert sheet placement process]
As shown in FIG. 2, when the second cavity 24 is formed with the fixed mold 1, the slide mold 2, and the movable mold 3 opened by a robot apparatus (not shown) or manually, the protruding piece 10 is fixed to the fixed mold 1. The insert sheet S is disposed so as to contact the second cavity surface 2a so as to protrude into the gate space 25 while being in contact with the first portion 1c. At this time, since the width of the projecting piece 10 is the same as or slightly smaller than the width of the projecting portion 9, the projecting piece 10 abuts on the concave groove 12 of the movable mold 3 to shift the insert sheet S. regulate. Thereby, positioning and arrangement | positioning of the insert sheet S can be performed easily. The insert sheet S is sucked from a suction port (not shown) provided on the second cavity surface 2a of the slide mold 2 by suction means (not shown), and the insert sheet S is fixed to the second cavity surface 2a. Also good.

[First cavity forming process]
The fixed mold 1, the slide mold 2 and the movable mold 3 are clamped. At this time, as shown in FIG. 5, the upper surface 5 b of the convex portion 5 of the fixed die 1 contacts the notch 13 of the movable die 3 and the third surface 9 c of the protruding portion 9 of the slide die 2. The first portion 1c of the fixed mold 1 is in contact with the first surface 9a of the protruding portion 9 of the slide mold 2 via the base end side of the protruding piece 10 of the insert sheet S. A gap d <b> 2 is formed between the first side surface 5 a of the convex portion 5 of the fixed mold 1 and the second surface 9 b of the protruding portion 9 of the slide mold 2. Thereby, a rectangular parallelepiped space 21 surrounded by the first portion 1c, the first side surface 5a, the second surface 9b, and the third surface 9c is formed. As shown in FIGS. 1 to 4, the first parting surface 1 b of the fixed mold 1 is in contact with the second parting surface 3 a of the movable mold 3. Thereby, the 1st cavity 22 is formed between the one side of the insert sheet S, and the 1st cavity surface 1a. In this embodiment, the slide pin 11 holds the protruding piece 10 of the insert sheet S. However, the slide pin 11 does not necessarily need to hold the protruding piece 10 of the insert sheet S, and the slide pin 11 does not necessarily hold the protruding piece 10. It may not be in contact with. At this time, when a positioning pin (not shown) is provided in the first portion 1c of the fixed mold 1, and a hole (not shown) that can be fitted to the protruding piece 10 corresponding to the positioning pin is provided, the insert sheet In addition to being able to easily position and arrange S, it is possible to prevent the insert sheet S from being lifted or turned up during the injection of the second resin described later.

[First resin part forming step]
As shown in FIG. 6, the first resin is injected from the first gate 6 into the first cavity 22 through the first resin flow path 33. The first resin injected over time is cooled and solidified, and the first resin portion 23 is formed on one side of the insert sheet S. The insert sheet S is fixed to the first resin portion 23 and is held until the hardness of the first resin portion 23 reaches a predetermined hardness. The insert sheet S may be disposed in a direction in which the surface on which the design layer is formed is fixed to the first resin portion 23 or in the opposite direction.

[Second cavity forming step]
As shown in FIGS. 7 and 8, after the insert sheet S is fixed to the first resin portion 23, the slide die 2 is moved to the other side with the first resin portion 23 held by the fixed die 1. The state in which the slide pin 11 protrudes with the movement of the slide mold 2 and one surface of the protruding piece 10 contacts the first portion 1c is maintained. At this time, a second cavity 24 surrounded by the other surface of the insert sheet S, the second cavity surface 2a, and the third cavity surface 3c is formed, and the second cavity 24 and the second gate 7 are connected to each other. A communicating gate space 25 is formed. Between the upper surface 5b of the convex part 5 of the fixed mold 1 and the third surface 9c of the projecting part 9 of the slide mold 2, the first part 1c of the fixed mold 1 and the first surface 9a of the projecting part 9 of the slide mold 2 are provided. Are formed with a gap d1 and a gap d3, respectively. The gap d2 between the first side surface 5a of the convex portion 5 of the fixed mold 1 and the second surface 9b of the protruding portion 9 of the slide mold 2 does not change. As a result, the width of the gap d2 is made substantially equal to the width of the gaps d1 and d3 (the core back amount of the slide mold 2). For this reason, the cross-sectional area of the gate space 25 becomes substantially equal over the entire length. The tip of the protruding piece 10 is housed in a first step portion 31 formed between the first side surface 5a and the first portion 1c.

[Second resin part forming step]
As shown in FIG. 8, the second resin is injected into the second cavity 24 from the second gate 7 through the gate space 25 through the second resin flow path 34. At this time, the second resin passes through a gap d3 sandwiched between the protruding piece 10 and the first surface 9a. Even if the heat of the high-temperature second resin is conducted to the protruding piece 10, since the one surface of the protruding piece 10 is in contact with the first portion 1 c, the heat diffuses to the fixed mold 1. For this reason, the insert sheet S does not overheat, and the base sheet and the design layer of the insert sheet S can be prevented from melting. And since the front-end | tip of the protrusion piece 10 is accommodated in the 1st step part 31 formed between the 1st side surface 5a and the 1st part 1c, it is that the 2nd resin hits the front-end | tip of the protrusion piece 10 directly. Can be avoided. As a result, it is possible to prevent the insert sheet S from being displaced and the insert sheet S from being lifted or turned up when the second resin is injected. In addition, for example, if the width of the gap d2 is narrower than the widths of the gaps d1 and d3, the flow rate of the second resin passing through the gap d2 is increased, and the insert sheet S is likely to be lifted and turned up. Further, shear heat is generated in the second resin passing through the gap d2, and the base sheet and the design layer of the insert sheet S are easily melted. However, since the widths of the gaps d1 to d3 are substantially equal, it is possible to prevent the base sheet and the design layer of the insert sheet S from being melted and the insert sheet S from being lifted or turned up. The second resin injected as time passes cools and solidifies, and the second resin portion 26 is formed on the other side of the insert sheet S. The insert sheet S is fixed to the second resin portion 26 and is held until the hardness of the second resin portion 26 reaches a predetermined hardness.

  The first resin and the second resin may be resins of the same color, the same hardness, and the same material, but may be resins of different colors, different hardness, and different materials. In short, the first resin and the second resin may be the same resin, but may be different resins. For example, the first resin may be polycarbonate resin, ABS resin, an alloy of polycarbonate resin and ABS resin, and the second resin may be acrylic (PMMA) resin. In particular, when the first resin is an ABS resin and the second resin is an acrylic (PMMA) resin, the ABS resin has high moldability, so that two-material molding can be performed satisfactorily. Moreover, even if the softening temperature of the ABS resin is lower than the softening temperature of the acrylic (PMMA) resin, the presence of the insert sheet S can suppress deformation of the ABS resin when the acrylic (PMMA) resin is injected.

[Resin molded product removal process]
The fixed mold 1, the slide mold 2 and the movable mold 3 are opened, and the first resin portion 23 is formed on one surface of the insert sheet S, and the second resin portion 26 is formed on the other surface of the insert sheet S. Take out the resin molded product. A resin molded product is continuously manufactured by repeating the above steps. The injection mold according to the present invention includes a fixed mold 1 and a slide mold 2, and in addition to being able to manufacture a resin molded product with a simple configuration by simply backing the slide mold 2, a large resin molded product can be easily manufactured. Has the advantage that it can be manufactured.

[Another embodiment]
(1) In the said embodiment, the structure which manufactures the resin molded product in which the 1st resin part 23 was formed in the one side of the insert sheet S, and the 2nd resin part 26 was formed in the other side of the insert sheet S is illustrated. did. However, it is not limited to such a configuration, the first resin portion 23 is formed on one surface of the insert sheet S, the second resin portion 26 is formed on the other surface of the insert sheet S, and the second resin portion. It is good also as a structure which manufactures the resin molded product in which the 3rd resin part was formed in the other side of 26. In short, the present invention can also be applied to a method of manufacturing a multi-material molded article by injecting multi-material resin.

(2) In the above embodiment, the configuration in which the fixing means 11 is the slide pin 11 that protrudes in the mold clamping direction and fixes the edge of the protruding piece 10 when the second cavity 24 is formed is illustrated. However, the present invention is not limited to such a configuration, and the fixing means 11 is a slide piece that is housed in the gate space 25 and presses and fixes the edge of the protruding piece 10 to the fixed mold 1 side. The projecting piece 10 may be sucked from a suction port provided in the first portion 1 c of the fixed mold 1, and suction means for fixing the projecting piece 10 to the fixed mold 1 may be used. Furthermore, the fixing means 11 may be configured by sandwiching the edge of the protruding piece 10 between the slide mold 2 and the fixed mold 1.

(3) In the above embodiment, the configuration in which the first gate 6 is provided on the first cavity surface 1a of the fixed mold 1 is exemplified. However, the present invention is not limited to this configuration, and the first gate 6 may be provided on the first parting surface 1b of the fixed die 1 or the first gate 6 may be provided on the slide die 2 or the movable die 3. May be.

(4) In the above embodiment, the configuration including the fixed mold 1, the slide mold 2, the movable mold 3, etc. is illustrated, but the movable mold 3 may not be provided. Specifically, as shown in FIG. 9, a protruding portion 27 that protrudes from the peripheral portion to one side in a state where the slide die 2 is in contact with the side surface of the fixed die 1 may be provided. When the insert sheet S is arranged on the slide mold 2 and the slide mold 2 is slid, the one side of the insert sheet S arranged on the slide mold 2 and the first of the fixed mold 1 are shown in FIG. A first cavity 22 is formed between the cavity surface 1a. The first resin is injected into the first cavity 22 to form the first resin portion 23. When the slide mold 2 is slid, as shown in FIG. 9B, the other surface of the insert sheet S fixed to the second cavity surface 2a of the slide mold 2 and the first resin portion 23 held by the fixed mold 1 is obtained. The second cavity 24 is formed between the two. Thus, the first cavity 22 and the second cavity 24 can be formed with a simple configuration in which the protrusion 27 is provided on the slide mold 2 and with a simple operation in which the slide mold 2 is slid.

(5) In the above embodiment, the configuration in which the space 21 has a rectangular parallelepiped shape is illustrated, but the space 21 may have a columnar shape with a parallelogram in cross section. In short, it is sufficient if the space 21 is such that the cross-sectional area of the gate space 25 is substantially equal over the entire length of the gate space 25.

  The present invention can be applied to various injection molds that can be used for manufacturing a resin molded product in which an insert sheet is embedded.

Plan view and side sectional view of fixed mold Plan view and side sectional view of slide type and movable type Perspective view of main part of slide type and movable type Perspective view of main part of fixed type Side view of fixed type, slide type and movable type Side view of fixed type, slide type and movable type Side view of fixed type, slide type and movable type Side view of fixed type, slide type and movable type Side sectional view of fixed type and slide type in another embodiment

Explanation of symbols

Reference Signs List 1a First cavity surface 2a Second cavity surface 3a Parting surface 3b Inner peripheral wall 3c Third cavity surface 6 First gate 7 Second gate 11 Fixing means 21 Space 22 First cavity 23 First resin portion 24 Second cavity 25 Gate Space 26 Second resin part 31 Step part 1 First mold 2 Second mold 3 Third mold S Insert sheet

Claims (6)

An injection mold that can be used for manufacturing a resin molded product in which an insert sheet is embedded between a first resin portion and a second resin portion,
A first mold formed with a first cavity surface corresponding to the surface of the first resin portion;
A second mold in which a second cavity surface corresponding to the surface of the first resin portion is formed;
A first cavity corresponding to the first resin portion is formed by relatively moving the first mold and the second mold on which the insert sheet is disposed along the second cavity surface. A first gate for injecting a first resin into the cavity;
The first mold holding the first resin part to which the insert sheet is fixed and the second mold are moved relative to each other so as to be connected to the second cavity corresponding to the second resin part and the second cavity. A gate space is formed, and a second gate that injects a second resin into the second cavity through the gate space,
The gate space is configured to receive the protruding piece of the insert sheet that protrudes outward from the first resin portion, and is configured to be arranged so that the protruding piece contacts the first mold. Mold.   2. The injection mold according to claim 1, wherein the gate space includes a step portion in which a tip of the protruding piece is accommodated so as to retreat from the flow of the second resin.   The injection mold according to claim 2, wherein the gate space is configured such that a cross-sectional area when cut along a plane orthogonal to the flow direction of the second resin is substantially constant over the entire length. .   4. The apparatus according to claim 1, further comprising a fixing unit configured to fix the projecting piece disposed so as to come into contact with the surface of the first mold when the second resin is injected. 5. The mold for injection molding as described.   It has a parting surface for the first mold, the second mold slides in the mold clamping direction inside, and a part of the inner peripheral wall constitutes a third cavity surface corresponding to the surface of the second resin part. The injection mold according to any one of claims 1 to 4, further comprising a third mold. A method for producing a resin molded product, wherein an insert sheet is embedded between a first resin part and a second resin part, using the injection mold according to any one of claims 1 to 5. ,
In a state where the mold is opened, the insert sheet is disposed along the second cavity so that the projecting piece projects into the gate space while contacting the surface of the first mold when the second cavity is formed. Process,
Forming the first cavity by clamping the arranged second mold and the first mold;
Injecting the first resin from the first gate into the formed first cavity to form the first resin portion;
After the insert sheet is fixed to the formed first resin portion, the first die and the second die are moved relative to each other while the first resin portion is held by the first die. Forming two cavities;
And a step of injecting the second resin from the second gate through the gate space to form the second resin portion in the formed second cavity so as to flow on the upper surface of the protruding piece. The manufacturing method of a resin molded product.

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