JP2010137521A - Injection-molding die, and color-changing method for injection-molded article using the molding die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection-molding die which can greatly reduce labor and time required for a color changing. <P>SOLUTION: This injection-molding die includes: a nozzle touch block 10 on which introduction ports I<SB>1</SB>and I<SB>2</SB>for introducing molding materials M<SB>1</SB>and M<SB>2</SB>from an injection unit 60 are installed; a manifold 20 in which hot runners R<SB>10</SB>and R<SB>20</SB>for respectively independently guiding the molding materials M<SB>1</SB>and M<SB>2</SB>which have respectively been introduced from the introduction ports I<SB>1</SB>and I<SB>2</SB>are installed; and a supporting means 30 for supporting the nozzle touch block 10 in a manner to be movable to the manifold 20. Then, the hot runner which is used makes the hot runner R<SB>10</SB>and the hot runner R<SB>20</SB>switchable by switching the introduction port which is connected with the nozzle 61 between the introduction port I<SB>1</SB>and the introduction port I<SB>2</SB>by moving the nozzle touch block 10 to the manifold 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an injection mold used for injection molding and a method for changing the color of a product (injection molded product) injection-molded with the injection mold.

  For example, in the injection molding of a thermoplastic resin, an injection mold is used so that the molten thermoplastic resin derived from the nozzle of the injection unit can be kept in a molten state up to the cavity in the injection mold. The resin passage (runner) connecting the portion connected to the nozzle (inlet port) and the portion connected to the cavity (gate) is heated with a heater. This resin passage is called a hot runner, and an injection mold having the hot runner is used for molding various resin products such as automobile interior materials.

  By the way, many of the old automobiles have a single interior material color. However, in recent years, automobiles have been designed to meet the needs of diversifying consumers. There are many colors that can be selected from multiple colors. For this reason, a company that manufactures automotive interior materials, for example, injection-molds black thermoplastic resin with an injection mold and then injection-molds beige thermoplastic resin with the same injection mold. For example, there is an urgent need to take measures such as injection molding of products of a plurality of colors using the same injection mold.

However, in a conventional injection mold, when the color of a product to be injection-molded is switched from one color (A color) to another color (B color), the injection mold After finishing injection molding of A color product with mold,
[1] The injection unit and the injection mold are separated, and the A-color thermoplastic resin remaining inside the screw cylinder of the injection unit is completely removed from the nozzle of the injection unit.
[2] A B-color thermoplastic resin is charged into the screw cylinder, and the screw of the injection unit is driven until the thermoplastic resin derived from the nozzle is completely switched to the B color.
[3] Stop the screw and reconnect the injection unit and the injection mold.
[4] The screw is driven again to supply B-color thermoplastic resin from the nozzle of the injection unit to the injection port of the injection mold, and trial driving is performed until the product is completely switched to B-color.
[5] Perform injection molding of a B-color product.
As a result, the following problems occurred.

  That is, in the conventional mold for injection molding, the A-color thermoplastic resin inside the hot runner is replaced with the B-color thermoplastic resin in the step (4). Since the thermoplastic resin staying in the vicinity cannot be easily removed, it was necessary to make trial hits many times before the product was completely switched to B color. For this reason, the thermoplastic resin and time were consumed wastefully. For example, when two interior panels for automobile doors are injection-molded at a time, it is necessary to perform trial strikes about 15 times (30 in number of products, about 15 minutes in terms of time) when changing colors.

  In view of such a situation, until now, a plurality of hot runners have been provided independently, and the hot runner to be used can be switched according to the color of the product to be injection molded. A mold (see, for example, Patent Document 1 and Patent Document 2. In the following, this type of injection mold may be referred to as a “hot runner switching mold”). . Thereby, even when the same injection mold is used, the color of the injection-molded product can be changed without going through the step (4). It becomes possible to greatly reduce the consumption of the thermoplastic resin.

  However, in the conventional hot runner switching type injection mold described in Patent Document 1 and Patent Document 2, when the color of an injection molded product is changed, the nozzle of the injection unit is used for injection molding. Since it was necessary to move the entire mold, a large device such as a crane was required. For this reason, the conventional hot runner switching type injection mold can suppress wasteful consumption of the thermoplastic resin, but is not always effective in terms of reducing labor and time loss. It wasn't. In addition, the installation layout of the injection mold is greatly limited, such as a space for installing a crane or the like around the injection mold.

JP-A-57-105330 JP 2007-062085 A

  The present invention has been made to solve the above-described problems, and not only reduces wasteful consumption of molding materials associated with color change of injection molded products, but also requires a large apparatus such as a crane for color change. In addition, the present invention provides an injection mold that can significantly reduce the labor and time required for color change. It is also an object of the present invention to provide a method for changing the color of an injection molded product that can be suitably performed using this injection mold.

  The above-described problems include a nozzle touch block (a block forming the introduction port and its periphery in an injection molding die) provided with a plurality of introduction ports for introducing a molding material from the injection unit, and the respective introduction ports. The nozzle touch block includes a manifold provided with a plurality of hot runners for independently guiding the molding material introduced from the nozzle, and support means for movably supporting the nozzle touch block with respect to the manifold. This is solved by providing an injection molding die characterized in that the hot runner to be used is switched by moving the nozzle with respect to the manifold and switching the inlet connected to the nozzle.

  This makes it possible to change the color of injection-molded products without replacing the molding material inside the hot runner of the manifold with molding materials of other colors, thus reducing wasteful consumption of molding materials. Is possible. In addition, it is possible to switch hot runners used for injection molding by moving only the nozzle touch block without moving the entire injection mold, so there is no need to use a large device such as a crane. In addition, it is possible to change the color of an injection molded product. Therefore, it is possible to reduce labor and time required for color change.

  However, when the nozzle touch block and the manifold are separated from each other as in the injection mold of the present invention, the molding material introduced from the nozzle of the injection unit to the introduction port becomes the nozzle touch block and the manifold. There is a risk of leaking through the gap. For this reason, it is preferable to provide nozzle injection block pressing means for pressing the nozzle touch block to the manifold side in the injection mold of the present invention. Thereby, it becomes possible to make it difficult for the molding material to leak from the gap between the nozzle touch block and the manifold.

  Examples of the nozzle touch block pressing means include those provided with a surface α for pressing the nozzle touch block against the manifold as will be described later. The nozzle touch block pressing means may be provided integrally with the support means or may be a separate body. The nozzle touch block pressing means may use a screwing member such as a bolt or a nut.

  In the injection mold according to the present invention, the nozzle touch block and the support means may be configured so that the inlet connected to the nozzle can be switched by moving the nozzle touch block relative to the manifold. There is no particular limitation. For example, the support means may be a shaft body that rotatably supports the nozzle touch block, and the plurality of inlets may be arranged rotationally symmetrically about the shaft body. However, considering the ease of design and processing, etc., a plurality of inlets are provided in a row along the specific direction of the nozzle touch block, and the nozzle touch block is moved in the specific direction with respect to the manifold by the support means. It is preferable to support it.

  As described above, when the nozzle touch block is movable in the specific direction, the nozzle touch block pressing means has a surface α for pressing the nozzle touch block toward the manifold side. The nozzle touch block is provided with a pair of biting portions that bite into a gap between the surface α of the nozzle touch block pressing means and the surface β guiding the nozzle touch block in the manifold as it approaches the movement limit position in the specific direction. One inlet is connected to the nozzle when it is at one movement limit position in the specific direction, and the other inlet is the nozzle when the nozzle touch block is at the other movement limit position in the specific direction. It is preferable to be connected to.

  Thereby, while easily moving the nozzle touch block in the specific direction, when flowing the molding material introduced from the introduction port by moving the nozzle touch block to the movement limit position in the specific direction, The nozzle touch block can be strongly pressed against the manifold, and the molding material can be prevented from leaking from the gap between the nozzle touch block and the manifold.

  In this case, the inclination angle formed by the surface α of the nozzle touch block pressing means and the surface β of the manifold (hereinafter referred to as “inclination angle θ”) is larger than 0 ° and smaller than 90 °. If it does not specifically limit. However, if the inclination angle θ is too small, it is difficult to secure the pressing force applied from the nozzle touch block pressing means to the nozzle touch block, and the positioning accuracy of the nozzle touch block in the specific direction is lowered. There is also a risk. In addition, the nozzle touch block must be lengthened in the specific direction, which may increase the heat capacity of the nozzle touch block. Therefore, when a heater is provided in the nozzle touch block and the hot runner of the nozzle touch block is a hot hot runner, energy is likely to be wasted. For this reason, the inclination angle θ is normally set to 1 ° or more. The inclination angle θ is preferably 2 ° or more, and more preferably 3 ° or more.

  On the other hand, when the inclination angle θ is too large, it is still difficult to ensure the pressing force applied to the nozzle touch block from the nozzle touch block pressing means. In addition, the thickness of the nozzle touch block has to be increased, which may increase the heat capacity of the nozzle touch block. For this reason, the inclination angle θ is normally set to 60 ° or less. The inclination angle θ is preferably 45 ° or less, and more preferably 30 ° or less.

  In the injection mold of the present invention, the arrangement of the plurality of hot runners provided in the manifold is not particularly limited as long as the molding material can be guided to a desired gate, but the plurality of hot runners are arranged in the manifold thickness direction. It is preferable to arrange them in steps. Accordingly, the hot runners can be crossed so as not to collide with each other without bending the hot runners in a complicated manner. Therefore, processing of the manifold becomes easy.

  By the way, the above-mentioned problems are a plurality of nozzle touch blocks provided with a plurality of inlets for introducing the molding material from the injection unit, and a plurality for independently guiding the molding material introduced from each inlet. An injection mold having a manifold provided with a hot runner and a support means for movably supporting the nozzle touch block relative to the manifold is used, and the nozzle touch block is moved relative to the manifold. The problem can also be solved by providing a method for changing the color of an injection-molded product, wherein the hot runner to be used is switched according to the color of the molding material by switching the inlet connected to the nozzle. The purpose is the same as that of the injection mold described above.

  As described above, according to the present invention, not only the wasteful consumption of the molding material associated with the color change of the injection-molded product is reduced, but a large-scale device such as a crane is not required for the color change. It is possible to provide an injection mold that can significantly reduce the time. It is also possible to provide a method for changing the color of an injection-molded product that can be suitably performed using this injection mold.

A preferred embodiment of the injection mold of the present invention will be described more specifically with reference to the drawings. Figure 1 is a perspective view of a nozzle touch block 10 and the manifold 20 when the first molding material M ₁ using an injection mold of the present invention are injection molded. FIG. 2 is a diagram illustrating a state in which the nozzle touch block 10 and the manifold 20 in FIG. 1 are viewed from the negative side in the y-axis direction. Figure 3 is a diagram showing a state in which the injection mold of the present invention as viewed from the x-axis direction positive side when being injection molded one of the molding material M _1. FIG. 4 is a view showing a state in which the injection mold of the present invention in FIG. 3 is viewed from the positive side in the z-axis direction. Figure 5 is a perspective view of a nozzle touch block 10 and the manifold 20 when using an injection molding die of the present invention are injection molded other molding material M _2. FIG. 6 is a view showing a state in which the nozzle touch block 10 and the manifold 20 in FIG. 5 are viewed from the negative side in the y-axis direction. Figure 7 is a view of the injection mold of the present invention showing a state seen from the x-axis direction positive side when being injection molded other molding material M _2. FIG. 8 is a view showing a state of the injection mold of the present invention in FIG. 7 as viewed from the positive side in the z-axis direction. However, in FIGS. 1 to 8, the hot runners R ₁₀ and R ₂₀ and the molding materials M ₁ and M ₂ make it easy to understand the positional relationship between the hot runners R ₁₀ and R _{20 and} the route through which the molding materials M ₁ and M ₂ flow. Therefore, the hot runners R ₁₀ and R ₂₀ and the molding materials M ₁ and M ₂ are indicated by solid lines without using broken lines even if they are invisible.

As shown in FIGS. 4 and 8, the injection mold according to the present embodiment has two inlets I ₁ and I ₂ for introducing molding materials M ₁ and M ₂ led out from the nozzle 61 of the injection unit 60. _Two hot runners R ₁₀ , R for independently guiding the nozzle touch block 10 provided with I ₂ and the molding materials M ₁ , M ₂ introduced from the introduction ports I ₁ , I ₂ , respectively. _20, a support means 30 for movably supporting the nozzle touch block 10 with respect to the manifold 20, a first mold 40 fixed to the manifold 20, and a first mold 40 A second mold 41 that forms a cavity C in pairs is provided. As shown in FIGS. 3 and 7, the injection molding die moves the nozzle touch block 10 relative to the manifold 20, and introduces the inlets connected to the nozzle 61 into the inlet I ₁ and the inlet I ₂ . By switching at, the hot runner to be used can be switched between the hot runner R ₁₀ and the hot runner R ₂₀ .

As shown in FIG. ₁ , the introduction ports I ₁ and I ₂ are both provided on the front surface (the surface facing the negative side in the y-axis direction) of the nozzle touch block 10 and along the vertical direction (z-axis direction). It is arranged in one row. The nozzle touch block 10 is supported by a support means 30 using a pipe wrench or a hydraulic cylinder so as to be movable in the z-axis direction. For this reason, as shown in FIG. 3, when the nozzle touch block 10 is moved upward (z-axis direction positive side), the lower inlet I ₁ is connected to the nozzle 61 of the injection unit 60, and FIG. As shown in FIG. 7, when the nozzle touch block 10 is moved downward (on the negative side in the z-axis direction), the upper inlet I ₂ is connected to the nozzle 61 of the injection unit 60. .

The rear of the nozzle touch block 10 (the surface facing the y-axis positive direction side), FIG. 1 and as shown in FIG. 5, nozzle inlet I _1, I ₂ molding material is introduced from each of M _1, M ₂ Derivation ports O ₁ and O ₂ for deriving to the rear of the touch block 10 (positive side in the y-axis direction) are provided. The outlet port O ₁ and the outlet port O ₂ are arranged with their positions shifted in the x-axis direction and the z-axis direction, and a through hole connecting the inlet port I ₁ and the outlet port O ₁ , and the inlet port I _2. And the through hole connecting the outlet port O ₂ are both inclined with respect to the yz plane (see FIGS. 4 and 8). Therefore, as shown in FIG. 3, when the nozzle touch block 10 is moved to the positive side in the z-axis direction, the outlet port O ₁ of the nozzle touch block 10 is connected to the hot runner via the inlet port I ₁₀ of the manifold 20. It is adapted to be connected to R _10. On the other hand, as shown in FIG. 7, when the nozzle touch block 10 is moved to the negative side in the z-axis direction, the outlet port O ₂ of the nozzle touch block 10 is hot via the inlet port I ₂₀ of the manifold 20. It is adapted to be connected with the runner R _20.

Therefore, in the injection mold according to this embodiment, as shown in FIG. 3, the molding material is transferred from the nozzle 61 of the injection unit 60 to the inlet I ₁ in a state where the inlet I ₁ and the hot runner R ₁₀ are connected. When M ₁ is injected, the molding material M ₁ is guided by the hot runner R ₁₀ and passes through the outlets O _{10 to} O ₁₃ provided on the back side of the manifold 20 (the surface facing the positive side in the y-axis direction). It is injected into the cavity C from a gate provided on the back side of the mold 40. On the other hand, as shown in FIG. 7, when the molding material M ₂ is injected from the nozzle 61 of the injection unit 60 to the introduction port I ₂ in a state where the introduction port I ₂ and the hot runner R ₂₀ are connected, the molding material M ₂ becomes The hot runner R ₂₀ is guided, passes through outlets O _{20 to} O ₂₃ provided on the back side of the manifold 20, and is injected into the cavity C from the gate provided on the back side of the first mold 40. It has become. The molding materials M ₁ and M ₂ injected into the cavity C become a product P.

Gate for injecting a molding material _M 1, _{M 2} into the cavity C passes through the outlet _O 10 _{~O 13, O} 20 _~O position overlapping the ₂₃ (each outlet _{O 10 ~O 13, O 20 ~O} 23 y Provided at intersections between a plurality of straight lines parallel to the axis and the back surface of the first mold 40). The number and arrangement of the gates are appropriately determined according to the shape and dimensions of the cavity C. However, the position of the weld line formed on the product P when subjected to injection molding at a molding material M _1, and the position of the weld line formed on the product P when subjected to injection molding at a molding material M ₂ is If it is greatly deviated, the strength characteristics of the product P and the like may be non-uniform. Therefore, corresponding in a group of gates (injection mold of the present embodiment that the gate overlapping the gate and outlet O ₂₀ overlapping the outlet O _10, a gate overlying the outlet port O ₁₁ to outlet O ₂₁ gate overlapping a gate which overlaps the outlet _{O 12} gate and outlet _{O 22} overlapping the gate) which overlaps the gate and outlet _{O 23} overlapping the outlet _{O 13} is usually placed as close as possible. When the shape of the cavity C is complicated, the number and arrangement of the gates may be determined while evaluating the position of the weld line by simulation or the like.

The shape of the hot runners R ₁₀ and R ₂₀ is not particularly limited, but considering the ease of manufacturing the manifold 20 and the ease of flow of the molding materials M ₁ and M ₂ , it is preferable to have a simple shape with as few bends as possible. . In the injection mold according to the present embodiment, the hot runner R ₁₀ is z at a position advanced by a predetermined distance a (see FIG. 3) from the introduction port I ₁₀ toward the positive side in the y-axis direction, as shown in FIG. Branches in the axial direction, and further branches in the x-axis direction at the tip of each branch. Further, the hot runner R _{20 is} also branched in the z-axis direction at a location advanced by a predetermined distance b (see FIG. 3) from the introduction port I ₂₀ to the positive side in the y-axis direction, and further in the x-axis direction at the tip of each branch Branch to.

Here, the length of the backbone path of the hot runner _{R 10} (section connecting the first branch point and inlet _{I 10} in the hot runner _{R 10)} and (distance in FIG. 3 a), the backbone path of the hot runner _{R 20} ( The length (distance b in FIG. 3) of the section connecting the inlet I ₂₀ and the first branch point in the hot runner R ₂₀ may be set to be the same. branch of R ₁₀ and (first branch portions and the outlet _O 10 _{~ O 13} and the section connecting the in the hot runner _{R 10),} first branch portion and the outlet port in the branch passage (hot runner _{R 20} of the hot runner _{R 20} It is preferable that the section connecting O _{20 to} O ₂₃ is arranged in a step difference (see FIGS. 3 and 7) in the thickness direction (y-axis direction) of the manifold 20. Thus, as the injection mold of the present embodiment, by connecting a plurality of gates each hot runner R _10, R _20, to span go the branch passage in the hot runner R _10, R ₂₀ variety Even in such a case, the hot runners R ₁₀ and R ₂₀ are three-dimensional without locally detouring the hot runners R ₁₀ and R ₂₀ in places where the hot runners R ₁₀ and R ₂₀ overlap (for example, the locations S ₁ and S ₂ in FIG. ₂ ). Can be crossed. Therefore, the number of corners of the hot runners R ₁₀ and R ₂₀ can be reduced.

By the way, although the case where only the support means 30 supported the nozzle touch block 10 has been described so far, in this case, the nozzle touch block 10 is lifted from the manifold 20 and introduced from the nozzle 61 of the injection unit 60. The molding materials M ₁ and M ₂ introduced into the ports I ₁ and I ₂ may leak out from the gap between the nozzle touch block 10 and the manifold 20. For this reason, as shown in FIG. 9, it is preferable to provide nozzle touch block pressing means 50 for pressing the nozzle touch block 10 against the manifold 20 side. FIG. 9 shows the periphery of the nozzle touch block 10 in an injection mold according to another embodiment (an embodiment in which the nozzle touch block 10 is pressed against the manifold 20 side by the nozzle touch block pressing means 50) different from FIGS. It is the perspective view which showed the state expanded.

The nozzle touch block pressing means 50 will be described more specifically with reference to the drawings. FIG. 10 is a perspective view showing an enlarged state of the nozzle touch block pressing means 50 in FIG. FIG. 11 is a perspective view showing an enlarged state of the nozzle touch block 10 in FIG. FIG. 12 is a cross-sectional view showing a state in which the periphery of the nozzle touch block 10 when the nozzle touch block 10 shown in FIG. 9 is at an intermediate position in the z-axis direction is cut by a plane corresponding to the X ₁ -X ₁ plane. is there. FIG. 13 shows a state where the periphery of the nozzle touch block 10 is cut by a plane corresponding to the X ₁ -X ₁ plane when the nozzle touch block 10 shown in FIG. 9 is at the movement limit position on the positive side in the z-axis direction. It is sectional drawing. FIG. 14 shows a state in which the periphery of the nozzle touch block 10 is cut by a plane corresponding to the X ₁ -X ₁ plane when the nozzle touch block 10 shown in FIG. 9 is at the movement limit position on the negative side in the z-axis direction. It is sectional drawing.

As shown in FIG. 10, the nozzle touch block pressing means 50 is a left and right pair, each of which includes a pressing portion 51 for pressing the nozzle touch block 10 and a fixing for fixing the pressing portion 51 to the manifold 20. Part 52. The surface (surface A ₁ A ₂ A ₃ A ₄ and surface A ₃ A ₄ A ₅ A ₆ in FIG. 10) on the side facing the manifold 20 in the pressing portion 51 (surface A ₃ A ₄ A ₅ A ₆ in FIG. It is a surface α for pressing against the manifold 20 side. Among these, the upper surface α (surface A ₁ A ₂ A ₃ A ₄ ) is guided to the surface β of the manifold 20 (the nozzle touch block in the manifold 20 as it becomes the positive side in the z-axis direction, as shown in FIG. It is formed to be inclined with respect to the surface β so as to be away from the surface). On the other hand, the lower surface α (surface A ₃ A ₄ A ₅ A ₆ ) is formed so as to be inclined with respect to the surface β so as to move away from the surface β of the manifold 20 toward the negative side in the z-axis direction. . In the injection mold according to the present embodiment, the inclination angle θ (FIG. 12) formed by the surface α of the nozzle touch block pressing means 50 and the surface β of the manifold is either on the upper surface α or the lower surface α. Is also 5 °.

On the other hand, as shown in FIG. 11, a pair of biting portions 11 are provided on both side surfaces of the nozzle touch block 10 (a surface facing the positive side in the x-axis direction and a surface facing the negative side in the x-axis direction). It has been. When the nozzle touch block 10 reaches the movement limit position on the positive side in the z-axis direction, as shown in FIG. 13, the front side surface (surface facing the negative side in the y-axis direction) of each biting portion 11 is used. The surface B ₅ B ₆ B ₇ B ₈ (refer to FIG. 11) that contacts the lower surface α of the nozzle touch block pressing means 50 and the nozzle touch block 10 on the negative side in the z-axis direction as shown in FIG. When the movement limit position is reached, a surface γ is formed which includes a surface B ₁ B ₂ B ₃ B ₄ (see FIG. 11) that contacts the upper surface α of the nozzle touch block pressing means 50. When the nozzle touch block 10 reaches the movement limit position in the z axis direction positive side (FIG. 13) is connected to the outlet O ₁ and inlet I ₁₀ is, nozzle touch block 10 in the z-axis direction negative side When the movement limit position is reached (FIG. 14), the outlet O ₂ and the inlet I ₂₀ are connected.

Of the surface γ in the biting portion 11, the upper surface B ₁ B ₂ B ₃ B ₄ (see FIG. 11) is formed to be inclined so as to be parallel to the upper surface α, as shown in FIG. Has been. On the other hand, the lower surface B ₅ B ₆ B ₇ B ₈ (see FIG. 11) is formed to be inclined so as to be parallel to the lower surface α. Therefore, as the nozzle touch block 10 approaches the movement limit position (FIG. 13) on the positive side in the z-axis direction from the intermediate position (FIG. 12) in the z-axis direction, the lower portion of the biting portion 11 is formed with the lower surface α and the surface. It is designed to bite into the gap with β. On the other hand, as the nozzle touch block 10 approaches the movement limit position (FIG. 14) on the negative side in the z-axis direction from the intermediate position (FIG. 12) in the z-axis direction, the upper portion of the biting portion 11 becomes the upper surface α and surface β. And bite into the gap. A portion (surface B ₃ B ₄ B ₅ B ₆ in FIG. 11) parallel to the surface β is provided between the upper surface γ and the lower surface γ of the biting portion 11, and the nozzle touch block When 10 is near the middle position in the z-axis direction, the nozzle touch block 10 can be smoothly moved in the z-axis direction without resistance.

In this way, the nozzle touch block 10 is provided with the biting portion 11 and the nozzle touch block pressing means 50 is fixed to the manifold 20, so that when the nozzle touch block 10 is in the vicinity of the intermediate position in the z-axis direction, While the touch block 10 can be easily moved in the z-axis direction, the nozzle touch block 10 moves toward the manifold 20 as the nozzle touch block 10 is brought closer to the movement limit position on the positive side in the z-axis direction or the movement limit position on the negative side in the z-axis direction. It comes to be strongly pressed to the side. That is, as shown in FIG. 13, the nozzle touch block 10 is moved to the positive side in the z-axis direction by the support means 30, and the nozzle touch block 10 is reached to the movement limit position on the positive side in the z-axis direction. And the lower surface γ are brought into contact with each other, the nozzle touch block 10 has a force opposite to the z-axis direction positive side force applied from the support means 30 (the z-axis direction negative side). F is received (point D ₁ in FIG. 13). At this time, since the surface γ is inclined with respect to the xz plane, the component perpendicular to the surface γ of the force F acts as the normal force F _{1 on} the biting portion 11 of the nozzle touch block 10. Therefore, the nozzle touch block 10 is pressed to the side of the manifold 20 by the component F ₁ perpendicular to the plane β in the vertical effect F ₁ . On the other hand, as shown in FIG. 14, the nozzle touch block 10 is moved to the negative side in the z-axis direction by the support means 30, and the nozzle touch block 10 is reached to the movement limit position on the negative side in the z-axis direction. When the upper surface γ is brought into contact, the same phenomenon as in FIG. 13 occurs (see forces f, f ₁ and f ₂ in FIG. 14). Accordingly, when the molding materials M ₁ and M ₂ are injected from the introduction ports I ₁ and I ₂ (when the nozzle touch block 10 is at the movement limit position on the positive side in the z-axis direction or the movement limit position on the negative side in the z-axis direction). ), The molding materials M ₁ and M ₂ can be prevented from leaking from the gap between the nozzle touch block 10 and the manifold 20.

Up to this point, for convenience of explanation, the x-axis direction is the left-right direction, the y-axis direction is the front-rear direction, and the z-axis direction is the up-down direction. However, the direction in which the injection mold of the present invention is installed is limited to this. Not. The direction in which the injection mold is installed is appropriately determined according to the scale of the injection mold, the type of the product P to be injection molded, and the like. In addition, the injection mold shown in FIGS. 1 to 14 is provided with two sets of inlets of the nozzle touch block 10 and hot runners of the manifold 20, and two types of molding materials M ₁ and M ₂ are independently provided. However, the number of inlets of the nozzle touch block 10 and the number of hot runners of the manifold 20 are not limited to this. For example, by providing three or more sets of inlets in the nozzle touch block 10 and also providing three or more sets of hot runners in the manifold 20, three or more types of molding materials can be independently injection molded.

Then, the color change method of the product P (injection molded product) using the injection mold shown in FIGS. 1-8 is demonstrated. The injection mold shown in FIGS. 1 to 8 can change the color of the product P by repeating the following procedures [1] to [12].
[1] First, as shown in Figures 1-4, the nozzle touch block 10 is moved in the z-axis direction positive side, the outlet _{O 1} of the nozzle touch block 10 connected to the inlet _{O 10} of the manifold 20, The nozzle 61 of the injection unit 60 is connected to the inlet I ₁ of the nozzle touch block 10.
[2] In this state, the molding material M ₁ having a specific color from the injection unit 60 and injected, injecting a molding material M ₁ to the cavity C through the hot runner R ₁₀ of the manifold 20.
[3] When the molding material M _{1 of the} cavity C is cured to become the product P, the second mold 41 is moved backward in the y-axis direction positive side, and the product P is moved inside the first mold 40 or the second mold 41. Take out from.
[4] Then, in the case of performing the re-injection molding the molding material M ₁ comprises a first mold 40 by advancing the second mold 41 in the y-axis direction negative side second mold 42 and the mold clamping Then, the steps [2] to [4] are repeated.
[5] after the injection molding at a molding material M _1, in the case of performing injection molding at a molding material M ₂ in a color different from the molding material M _1, after the procedure of [3], y-axis the injection unit 60 The nozzle 61 is separated from the nozzle touch block 10 by moving backward in the negative direction.
[6] In this state, it was charged with molding material M ₂ to the injection unit 60, until the molding material injected from the nozzle 61 is completely switched to the molding material M ₂ from the molding material M _1, an injection in the injection unit 60 Do.
[7] During this time, the support means 30 is operated to move the nozzle touch block 10 to the negative side in the z-axis direction so that the outlet port O ₂ of the nozzle touch block 10 is connected to the inlet port O ₂₀ of the manifold 20. .
[8] When the molding material injected from the nozzle 61 is confirmed to have switched to the molding material M _2, the injection unit 60 is moved forward to the y-axis positive direction side, inlet I ₂₀ of the nozzle touch block 10 the nozzle 61 Connect to.
[9] In this state, injecting a molding material _{M 2} from the injection unit 60, injection of the molding material _{M 2} in the cavity C through the hot runner _{R 20} of the manifold 20 (see Figure 5-8).
[10] When the molding material M ₂ of the cavity C becomes a product P by curing inside the second mold 41 are retracted to the y-axis positive direction side, first mold the product P 40 or second mold 41 Take out from.
[11] Thereafter, when performing re-injection molding the molding material M ₂ comprises a first mold 40 by advancing the second mold 41 in the y-axis direction negative side second mold 42 and the mold clamping Then, the steps [9] to [11] are repeated.
After injection molding at [12] the molding material M _2, when performing a re-injection molding the molding material M _1, after the procedure of [10], retract the injection unit 60 to the y-axis direction negative side, the disconnect the nozzle 61 from the nozzle touch block 10, was charged with molding material M ₁ in the injection unit 60, an injection unit 60 to the forming material injected from the nozzle 61 is completely switched to the molding material M ₁ from the molding material M ₂ perform injection, the injection unit 60 is moved forward to the y-axis positive direction side and connect the nozzle 61 and the inlet port I ₁ of the nozzle touch block 10, following the procedure [2] or higher.

As described above, since the injection mold according to the present invention can change the color of the product P without performing trial hitting, it is possible to eliminate waste of the molding material. The types of molding materials M ₁ and M ₂ for injection molding using the injection molding die of the present invention are not particularly limited, but are usually polyolefins such as polypropylene, polyethylene, polybutene-1, and the like; ABS (acrylonitrile-butadiene- Styrene) such as styrene), MBS (methyl methacrylate-butadiene-styrene), polystyrene; acrylic resin such as polymethyl methacrylate; polycarbonate; polyvinyl chloride; polyester such as polybutylene terephthalate and polyethylene terephthalate; heat such as polyamide It is a plastic resin. The injection mold of the present invention can be suitably used for injection molding various products such as automobile interior materials.

It is the perspective view which showed the nozzle touch block and manifold when one molding material is injection-molded using the injection mold of this invention. It is the figure which showed the state which looked at the nozzle touch block and manifold in FIG. 1 from the y-axis direction negative side. It is the figure which showed the state which looked at the injection mold of this invention when injection-molding one molding material from the x-axis direction positive side. It is the figure which showed the state which looked at the injection die of this invention in FIG. 3 from the z-axis direction positive side. It is the perspective view which showed the nozzle touch block and manifold when other molding materials are injection-molded using the injection mold of this invention. It is the figure which showed the state which looked at the nozzle touch block and manifold in FIG. 5 from the y-axis direction negative side. It is the figure which showed the state which looked at the injection mold of this invention when injection-molding another molding material from the x-axis direction positive side. It is the figure which showed the state which looked at the injection die of this invention in FIG. 7 from the z-axis direction positive side. It is the perspective view which showed the state which expanded the periphery of the nozzle touch block in the injection die of another embodiment. It is the perspective view which showed the state which expanded the nozzle touch block press means in FIG. It is the perspective view which showed the state which expanded the nozzle touch block in FIG. FIG. 10 is a cross-sectional view showing a state in which the periphery of the nozzle touch block when the nozzle touch block shown in FIG. 9 is at an intermediate position in the z-axis direction is cut by a plane corresponding to the X ₁ -X ₁ plane. Nozzle touch block shown in FIG. 9 is a cross-sectional view of the periphery of the nozzle touch block showing a state taken along a plane corresponding to X ₁ -X ₁ side when in the movement limit position of the z-axis direction positive side. Nozzle touch block shown in FIG. 9 is a cross-sectional view of the periphery of the nozzle touch block showing a state taken along a plane corresponding to X ₁ -X ₁ side when in the movement limit position of the z-axis direction negative side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Nozzle touch block 11 Biting part 20 Manifold 30 Support means 40 1st metal mold | die 41 2nd metal mold | die 50 Nozzle touch block press means 51 Press part 52 Fixing part 60 Injection unit 61 Nozzle C Cavity I ₁ Inlet (molding material M Nozzle touch block side inlet for ₁ )
I ₁₀ inlet (manifold side inlet for molding material M ₁ )
I ₂ inlet (inlet on the nozzle touch block side for molding material M ₂ )
I ₂₀ inlet (manifold side inlet for molding material M ₂ )
M ₁ molding material M ₂ molding material O ₁ outlet (outlet on the nozzle touch block side for molding material M ₁ )
O ₂ outlet (outlet on the nozzle touch block side for molding material M ₂ )
O _{10 to} G ₁₃ outlet (manifold side outlet for molding material M ₁ )
O _{20 to} G ₂₃ outlet (manifold side outlet for molding material M ₂ )
R ₁₀ hot runner (forming material _{M 1)}
R ₂₀ hot runner (forming material _{M 2)}
P product

Claims (7)

  Nozzle touch block provided with multiple inlets for introducing molding material from the injection unit and multiple hot runners for independently guiding the molding material introduced from each inlet port are provided And a support means for movably supporting the nozzle touch block with respect to the manifold, and the nozzle touch block is moved with respect to the manifold to switch the inlet connected to the nozzle. An injection mold characterized in that the hot runner to be switched can be switched.   The injection mold according to claim 1, further comprising nozzle touch block pressing means for pressing the nozzle touch block toward the manifold.   The plurality of introduction ports are provided in one row along a specific direction of the nozzle touch block, and the support unit supports the nozzle touch block so as to be movable in the specific direction with respect to the manifold. Mold for injection molding.   The nozzle touch block pressing means having a surface α for pressing the nozzle touch block toward the manifold side is provided, and the nozzle touch block has a surface α in the nozzle touch block pressing means and a manifold in the manifold as it approaches the movement limit position in the specific direction. A pair of biting portions that bite into the gap with the surface β guiding the nozzle touch block are provided, and when the nozzle touch block is at one movement limit position in the specific direction, one inlet is connected to the nozzle 4. The injection mold according to claim 3, wherein when the nozzle touch block is at the other movement limit position in the specific direction, the other inlet is connected to the nozzle.   The injection mold according to claim 4, wherein an inclination angle formed by the surface α of the nozzle touch block pressing means and the surface β of the manifold is 1 to 60 °.   The mold for injection molding according to any one of claims 1 to 5, wherein a plurality of hot runners provided in the manifold are arranged in steps in the thickness direction of the manifold.   Nozzle touch block provided with multiple inlets for introducing molding material from the injection unit and multiple hot runners for independently guiding the molding material introduced from each inlet port are provided The nozzle touch block is moved with respect to the manifold and connected to the nozzle using an injection mold having a manifold and a support means for movably supporting the nozzle touch block with respect to the manifold. A method for changing the color of an injection-molded product, wherein the hot runner to be used is switched according to the color of the molding material by switching the introduction port.

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