Injection molding machine and operating method thereof

Abstract

The present invention relates to an injection molding machine and a method of operating the same. The injection molding machine according to the present invention is equipped with a foam injection molding machine and a general injection molding machine in pairs, and produces a final molded product by a secondary molding process in which the surface of a foam injection molded product, which is first molded by the foam injection molding machine, is overlaid by the general injection molding machine. According to the present invention, a smooth exterior quality can be secured even while being a foam injection molded product, thereby expanding the scope of application as an exterior material for products and enabling various types of injection molding required by the product.

Description

Technology Field

[0001] The present invention relates to an injection molding machine, and in particular to foam injection. Background Technology

[0003] An injection molding machine is equipment that produces molded products by injecting resin into a molding space formed by a mold.

[0004] Among injection molding machines, there are types that produce foamed products by incorporating an inert gas into the resin.

[0005] An injection molding machine that produces foamed products is equipped with a gas supply device for supplying gas at a pressure above a critical point.

[0006] When gas supplied by a gas supply device is mixed into the resin in a supercritical state (a state that is neither gas nor liquid) and injected into the molding space, the phase of the gas changes, and gas cells are formed inside the resin.

[0007] Figure 1 shows an example of a foamed molded article.

[0008] Foam molded products have the advantage of being lightweight and saving raw materials because they have many gas voids.

[0009] However, as shown in Fig. 1, foam molded products have the disadvantage of being less versatile because they are limited to use mainly as interior materials due to the projection of gas marks on the outer surface. Prior art literature

[0011] Republic of Korea Published Patent Application No. 10-2023-0129297 The problem to be solved

[0012] It is necessary to extend the scope of application to exterior products while retaining the advantages of foam molded products. means of solving the problem

[0014] An injection molding machine according to the first embodiment of the present invention comprises: a movable foam injection machine that injects a gas-mixed foamed resin; a movable plate positioned toward the foam injection machine and movable together with the foam injection machine; a moving mechanism that moves the foam injection machine and the movable plate together; a general injection machine provided in pair with the foam injection machine and injecting a general resin into a foamed product formed by injection of the foam injection machine; a fixed plate positioned toward the general injection machine and fixed in position; a rotating plate positioned between the movable plate and the fixed plate; and a rotating mechanism for rotating the rotating plate.

[0015] It includes a primary mold coupled to the movable plate; a secondary mold coupled to the fixed plate; and a pair of rotating molds each coupled to both sides of the rotating plate, facing the primary mold or the secondary mold depending on the rotational position of the rotating plate; wherein the volume of the second molding space formed by the secondary mold and the rotating mold is larger than the volume of the first molding space formed by the primary mold and the rotating mold.

[0016] The volume of the first molding space is 80% to 90% of the volume of the second molding space.

[0017] The above pair of rotary dies have identical molding parts.

[0018] The molding portion of the first mold and the molding portion of the second mold have different shapes.

[0019] The general resin injected by the above general injection molding machine is an opaque material.

[0020] The resin injected by the foam injection molding machine and the resin injected by the general injection molding machine are different types of resins.

[0021] The resin injected from the foam injection molding machine and the resin injected from the general injection molding machine are different colors.

[0023] An injection molding machine according to a second embodiment of the present invention comprises: a foam injection machine for injecting a gas-mixed foaming resin; a fixed mold plate positioned toward the foam injection machine and having a fixed position; a movable general injection machine provided in pair with the foam injection machine and injecting a general resin into a foamed product formed by the injection of the foam injection machine; a movable mold plate positioned toward the general injection machine and capable of moving together with the general injection machine; a moving mechanism for moving the general injection machine and the movable mold plate together; a rotating mold plate positioned between the fixed mold plate and the movable mold plate; and a rotating mechanism for rotating the rotating mold plate.

[0024] It includes a primary mold coupled to the fixed plate; a secondary mold coupled to the movable plate; and a pair of rotating molds each coupled to both sides of the rotating plate and facing the primary mold or the secondary mold as the rotating plate rotates, wherein the volume of the second molding space formed by the secondary mold and the rotating mold is larger than the volume of the first molding space formed by the primary mold and the movable mold.

[0025] The volume of the first molding space is 80% to 90% of the volume of the second molding space.

[0026] The above pair of rotary dies have identical molding parts.

[0027] The molding portion of the first mold and the molding portion of the second mold have different shapes.

[0028] The general resin injected by the above general injection molding machine is an opaque material.

[0029] The resin injected by the foam injection molding machine and the resin injected by the general injection molding machine are different types of resins.

[0030] The resin injected from the foam injection molding machine and the resin injected from the general injection molding machine are different colors.

[0032] The method of operating an injection molding machine according to the present invention comprises: a first molding step of injecting a foamed resin mixed with gas into a first molding space formed by a first mold and a rotary mold in a closed state; a mold rotation step of rotating the rotary mold in an open state after the first molding step; and a second molding step of injecting a general resin into a second molding space formed by a second mold and a rotary mold in a closed state after the mold rotation step, thereby injecting the general resin into a foamed molded product formed in the first molding step.

[0033] The above second molding step is performed together with the above first molding step.

[0034] A foam injection machine that injects foam resin moves to switch between the above-mentioned open state and the above-mentioned closed state.

[0035] A general injection molding machine that injects general resin moves to switch between the above-mentioned open state and the above-mentioned closed state. Effects of the invention

[0037] According to the present invention, a smooth exterior quality can be secured even while being a foam injection molded product, thereby expanding the scope of application as an exterior material for products and enabling various types of injection molding required by the product. Brief explanation of the drawing

[0039] FIG. 1 is a schematic diagram of an injection molding machine according to a first embodiment of the present invention. FIGS. 2 to 10 are reference drawings for explaining the injection molding machine of FIG. 1. FIG. 11 is a schematic diagram of an injection molding machine according to a second embodiment of the present invention. Specific details for implementing the invention

[0040] Preferred embodiments according to the present invention will be described with reference to the accompanying drawings, provided that for the sake of brevity, descriptions of well-known configurations are omitted or compressed as much as possible.

[0042] <제1실시예>

[0043] FIG. 2 is a schematic diagram of an injection molding machine (100) according to a first embodiment of the present invention.

[0044] The injection molding machine (100) according to the first embodiment includes a foam injection machine (110), a movable plate (120), a movable machine (130), a general injection machine (140), a fixed plate (150), a rotating plate (161), a rotating machine (162), a primary mold (170), a secondary mold (180), and a pair of rotating molds (191, 192), etc.

[0045] The foam injection machine (110) injects a foamed resin in which gas is mixed into the resin.

[0046] The foam injection machine (110) has a gas injector (111).

[0047] The gas injected into the interior of the barrel (112) by the gas injector (111) is mixed into the resin.

[0048] A foam injection molded product is formed from a foamable resin injected by a foam injection machine (110).

[0049] The foam injection machine (110) is configured to be movable along the X-axis.

[0050] The movable plate (120) is placed on the side of the foam injection machine (110).

[0051] The movable plate (120) is provided to be movable along the X-axis.

[0052] The foam injection machine (110) and the movable plate (120) move together along the X-axis.

[0053] The moving device (130) moves the foam injection machine (110) along the X-axis.

[0054] The mover (130) moves the movable plate (120) along the X-axis.

[0055] In the first embodiment, the mover (130) moves the foam injection machine (110) and the movable plate (120) together on the X-axis.

[0056] The general injection molding machine (140) injects general resin.

[0057] The general injection molding machine (140) is positioned to face the foam injection molding machine (110) in the X-axis direction.

[0058] The general injection molding machine (140) is provided in pair with the foam injection molding machine (110).

[0059] According to the present invention, a single injection molding machine (100) is equipped with both a foam injection machine (110) and a general injection machine (140).

[0060] The general resin injected by the general injection molding machine (140) is applied to the surface of the foamed molded product.

[0061] The general injection molding machine (140) has a fixed position.

[0062] The general injection molding machine (140) only needs to inject enough resin to cover the surface of the foamed product molded by the foam injection molding machine (110), so it can be configured to be smaller in size compared to the foam injection molding machine (110).

[0063] The fixed plate (150) is placed on the side of the general injection molding machine (140).

[0064] The fixed plate (150) is fixed in position.

[0065] The rotating plate (161) is positioned between the movable plate (120) and the fixed plate (150) on the X-axis.

[0066] The rotating plate (161) is configured to rotate 180 degrees forward and backward using the vertical line (V) as the axis of rotation.

[0067] The rotating plate (161) may be provided to rotate infinitely by 180 degrees in any rotational direction.

[0068] The rotating plate (161) is provided to be movable on the X-axis.

[0069] The rotating device (162) rotates the rotating plate (150) using the vertical line (V) as the axis of rotation.

[0070] The first mold (170) is connected to the movable plate (120).

[0071] The first mold (170) moves along the X-axis together with the movable plate (120).

[0072] A primary mold (170) has a primary molding portion (P1) formed therein.

[0073] The second mold (180) is connected to the fixed plate (150).

[0074] The second mold (180) is fixed in position.

[0075] A secondary molding portion (P2) is formed in the secondary mold (180).

[0076] The first mold (170) and the second mold (180) are arranged such that the first molding portion (P1) and the second molding portion (P2) face each other on the X-axis.

[0077] A pair of rotary molds (191, 192) are each connected to both sides of the rotary plate ((161).

[0078] The rotational forming portions (P0) in a pair of rotary molds (191, 192) are identical to each other.

[0079] A pair of rotating molds (191, 192) may face the primary mold (170) or the secondary mold (180) depending on the rotational position of the rotating plate (161).

[0080] When the rotary mold (191 / 192) comes into contact with the primary mold (170) as shown in FIG. 3 in the closed state, the primary molding area (P1) and the rotary molding area (P0) form a first molding space (M1).

[0081] When the rotating die (191 / 192) comes into contact with the secondary die (180) as shown in FIG. 4 in the closed state, the secondary molding area (P2) and the rotating molding area (P0) form a second molding space (M2).

[0082] The first molding space (M1) is filled with foamed resin.

[0083] The foamed resin filled in the first molding space (M1) becomes an intermediate product, a foamed molded product.

[0084] The second molding space (M2) is filled with general resin in the area other than the space occupied by the foamed molded product (hereinafter referred to as the 'surface area').

[0085] The general resin filled in the surface area in the second molding space (M2) forms the surface of the final molded product.

[0086] Since it is sufficient for a general resin to form the surface of the final molded product, it is sufficient to use only the minimum amount capable of forming and maintaining the surface of the final molded product.

[0087] Since it is sufficient to use only a minimum amount of general resin that can maintain commercial value as a final molded product, it is desirable that the volume of the first molding space (M1) be in the range of about 80% to 90% of the volume of the second molding space (M2).

[0088] It is desirable that the volume of the foamed molded product be in the range of about 80% to 90% of the volume of the second molding space (M2).

[0089] It is desirable that the volume of the foamed molded product be in the range of about 80% to 90% of the volume of the final molded product.

[0090] It is desirable to determine the volumes of the first molding space (M1) and the second molding space (M2) by comprehensively considering the type, hardness, elasticity, wear resistance, heat resistance, etc. of the resin used.

[0091] Since the rotational forming portions (P0) of both rotary molds (191, 192) must be identical to each other, the volumes of the first forming space (M1) and the second forming space (M2) must be different.

[0092] Since the volumes of the first molding space (M1) and the second molding space (M2) are different, the first molding portion (P1) and the second molding portion (P2) must have different shapes from each other.

[0093] For example, the first molded area (P1) and the second molded area (P2) may have a shape difference in which the depth of the second molded area (P2) is deeper than the depth of the first molded area (P1).

[0094] For example, the first molded area (P1) and the second molded area (P2) may have a shape difference in which the protrusion height of the second molded area (P2) is lower than the protrusion height of the first molded area (P1).

[0095] Next, the method of operating the injection molding machine (100) according to the first embodiment will be described.

[0096] In the open state as shown in FIG. 2, the moving device (130) operates to move the foam injection machine (110) and the moving plate (120) in the +X direction, thereby switching the injection molding machine (100) to the closed state as shown in FIG. 5. During this process, the rotating plate (161) also moves in the +X direction by being pushed by the moving plate (120).

[0097] In the closed state of Fig. 5, the first mold (170) and the first rotating mold (191) are in close contact, and the second mold (180) and the second rotating mold (192) are in close contact.

[0098] A first molding space (M1) is formed by the first mold (170) and the first rotating mold (191) coming into close contact, and a second molding space (M2) is formed by the second mold (180) and the second rotating mold (192) coming into close contact.

[0099] In the state of Fig. 5, the foam injection machine (110) operates to inject foamed resin into the first molding space (M1).

[0100] Since the injection molding machine (100) starts operating for the first time, general resin is not injected into the second molding space (M2).

[0101] As shown in FIG. 6, a first molding is performed by filling the first molding space (M1) with a foamed resin. Upon completion of the first molding, a foamed molded product (Mf) that fills the first molding space (M1) is formed.

[0102] When the foam molded product (Mf) is molded, the moving device (130) operates to move the foam injection machine (110) and the moving plate (120) in the -X direction, thereby converting the injection molding machine (100) into the mold opening state as shown in FIG. 7. In this process, when the moving plate (120) moves in the -X direction, the rotating plate (161) is also moved in the -X direction by a separate means and is implemented to return to its original position.

[0103] In the open state of Fig. 7, the foamed molded product (Mf) is separated from the primary mold (170) and adheres to the first rotary mold (191).

[0104] In the state of Fig. 7, the rotor (162) operates to rotate the movable plate (120) 180 degrees.

[0105] Due to the rotation of the movable plate (120), as shown in FIG. 8, the first rotating mold (191) is positioned in the +X direction relative to the vertical line (V), and the second rotating mold (192) is positioned in the -X direction. At the same time, the foamed molded product (Mf) attached to the first rotating mold (191) is also positioned in the +X direction.

[0106] Next, for secondary molding, the injection molding machine (100) is switched from the state of FIG. 8 back to the mold-closed state of FIG. 9.

[0107] In the closed state of Fig. 9, the first mold (170) and the second rotating mold (192) are in close contact, and the second mold (180) and the first rotating mold (191) are in close contact.

[0108] A first molding space (M1) is formed by the first mold (170) and the second rotating mold (192) coming into close contact, and a second molding space (M2) is formed by the second mold (180) and the first rotating mold (191) coming into close contact.

[0109] The second molding space (M2) is filled with 90% of the space by the foamed molded product (Mf), and the remaining 10% of the space (SS, hereinafter referred to as the 'surface space') is empty.

[0110] The surface space (SS) is a space for injecting and attaching general resin to the foam molded product (Mf).

[0111] When the general injection molding machine (140) is operated in the closed state of Fig. 9, a general resin is injected into the surface space (SS) of the second molding space (M2) as in Fig. 10, and a second molding is performed.

[0112] The injected general resin forms a surface layer (SF) of the final molded product (FM) by being applied to the surface of the foamed molded product (Mf).

[0113] In addition, in the closed state of Fig. 9, the foam injection machine (110) operates together, so that a primary molding process is also carried out in parallel, in which a foamed resin is injected into the first molding space (M1) as in Fig. 10.

[0114] When the first molding in the first molding space (M1) and the second molding in the second molding space (M2) are completed, the final molded product (FM), which has a surface formed of ordinary resin, is collected after switching to a mold-opened state. Afterwards, the rotation of the rotating plate (161), mold closing, first molding and second molding, mold opening, and collection of the final molded product (FM) are repeated sequentially, and the final molded product (FM) is continuously molded.

[0116] <제2실시예>

[0117] FIG. 11 is a schematic diagram of an injection molding machine (200) according to a second embodiment of the present invention.

[0118] The injection molding machine (200) according to the second embodiment includes a foam injection machine (210), a fixed mold plate (220), a general injection machine (230), a movable mold plate (240), a movable machine (250), a rotating mold plate (261), a rotating machine (262), a primary mold (270), a secondary mold (280), and a pair of rotating molds (291, 292), etc.

[0119] The foam injection machine (210) injects a foamed resin in which gas is mixed into the resin.

[0120] A foamed injection molded product (Mf) is formed with a foamed resin injected by a foaming injection machine (210).

[0121] The foam injection machine (210) is fixed in position.

[0122] The fixed plate (220) is positioned on the side of the foam injection machine (210) and its position is fixed.

[0123] The general injection molding machine (230) injects general resin.

[0124] The general injection molding machine (230) is positioned to face the foam injection molding machine (210) on the X-axis.

[0125] The general injection molding machine (230) is configured to be movable along the X-axis.

[0126] The movable plate (240) is placed on the side of the general injection molding machine (230).

[0127] The movable plate (240) is provided to be movable along the X-axis.

[0128] The general injection molding machine (230) and the movable plate (240) move together on the X-axis.

[0129] The moving device (250) moves the general injection molding machine (230) along the X-axis.

[0130] The mover (250) moves the movable plate (240) along the X-axis.

[0131] In the second embodiment, the mover (250) moves the general injection molding machine (230) and the movable plate (240) together on the X-axis.

[0132] The general injection molding machine (230) is smaller in size compared to the foam injection molding machine (210) because it injects a general resin that can fill only about 10% to 20% of the volume occupied by the final molded product (FM).

[0133] In addition, the general injection molding machine (230) does not have a separate gas injector that needs to be considered in the design of the moving structure.

[0134] Therefore, in some of the various cases, it may be better to move the general injection molding machine (230) rather than the foam injection molding machine (220).

[0135] The rotating plate (261) is positioned between the movable plate (220) and the fixed plate (240) on the X-axis.

[0136] The rotating plate (261) is configured to rotate 180 degrees forward and backward using the vertical line (V) as the axis of rotation.

[0137] The rotating plate (261) is provided to be movable on the X-axis.

[0138] The first mold (270) is joined to the fixed plate (220).

[0139] The first mold (270) is fixed in position.

[0140] The second mold (280) is connected to the movable plate (240).

[0141] The second mold (280) moves along the X-axis together with the movable plate (240).

[0142] A pair of rotating molds (291, 292) are each connected to both sides of the rotating plate (261).

[0143] The operation of the injection molding machine (200) according to the second embodiment is the same as that of the injection molding machine (100) of the first embodiment, except that the general injection machine (230) moves and switches between the mold closing and mold opening states, so a detailed description thereof is omitted.

[0145] According to the present invention, the surface of a foamed molded product produced by a foam injection molding machine (110, 210) is finished by a general injection molding machine to obtain a final molded product (FM).

[0146] Since the surface of the final molded product (FM) is formed with general resin, it is formed smoothly and elegantly.

[0147] Therefore, the injection molding machine (100, 200) according to the present invention can be used for injection molding of not only the interior materials of the product but also the exterior materials.

[0149] In the first embodiment, the foam injection machine (110) moves when transitioning between the open state and the closed state, and in the second embodiment, the foam injection machine (210) moves when transitioning between the open state and the closed state.

[0151] <추가적인 사항>

[0152] 1. When the final molded product (FM) is an exterior material, unsightly gas marks must not be visible on the exterior of the product, so the general resin must be an opaque material.

[0154] 2. If there is no problem with bonding the foamed resin and the general resin, different types of resins can be used.

[0155] Raw material costs can be reduced by using low-quality resins, such as recycled or low-cost resins, for foamed resins, and using high-quality resins with good marketability for general resins.

[0157] 3. It is also possible to use foamed resin and ordinary resin with different colors.

[0159] As described above, according to the present invention, various injection molded products can be molded through various combinations of foamed resin and general resin depending on the characteristics of the final molded product (FM).

[0161] 4. The injection molding machine (100, 200) may be delivered with the primary mold (170, 270), secondary mold (180, 280), and rotary mold (191, 192 / 291, 292) removed or installed, depending on the requirements of the customer.

[0163] The embodiments described above are merely preferred examples of the present invention and may have various applications. Therefore, the present invention should not be understood as being limited only to the contents described above. Instead, the scope of the present invention should be understood as the separately described claims and their equivalents. Explanation of the symbols

[0165] 100, 200 : Injection molding machine 110, 210 : Foam injection molding machine 120, 240 : Movable plate 130, 250 : Mover 140, 230 : General injection molding machine 150, 220 : Fixed plate 161, 261 : Rotating plate 162, 262 : Rotating machine 170, 270: 1st mold 180, 280: Secondary mold 191, 192, 291, 292: Rotary die

Claims

Claim 1 An injection molding machine comprising: a movable foam injection machine that injects a gas-mixed foamed resin; a movable plate positioned toward the foam injection machine and movable together with the foam injection machine; a mover that moves the foam injection machine and the movable plate together; a general injection machine provided in pair with the foam injection machine and injecting a general resin into a foamed product formed by injection of the foam injection machine; a fixed plate positioned toward the general injection machine and fixed in position; a rotating plate positioned between the movable plate and the fixed plate; and a rotor for rotating the rotating plate. Claim 2 An injection molding machine according to claim 1, comprising: a primary mold coupled to the movable plate; a secondary mold coupled to the fixed plate; and a pair of rotating molds each coupled to both sides of the rotating plate and facing the primary mold or the secondary mold depending on the rotational position of the rotating plate, wherein the volume of the second molding space formed by the secondary mold and the rotating mold is larger than the volume of the first molding space formed by the primary mold and the rotating mold. Claim 3 An injection molding machine comprising: a foam injection machine for injecting a gas-mixed foamed resin; a fixed mold plate positioned toward the foam injection machine and having a fixed position; a movable general injection machine provided in pair with the foam injection machine and injecting a general resin into a foamed molded product formed by the injection of the foam injection machine; a movable mold plate positioned toward the general injection machine and capable of moving together with the general injection machine; a mover for moving the general injection machine and the movable mold plate together; a rotating mold plate positioned between the fixed mold plate and the movable mold plate; and a rotor for rotating the rotating mold plate. Claim 4 An injection molding machine according to claim 3, comprising: a primary mold coupled to the fixed plate; a secondary mold coupled to the movable plate; and a pair of rotating molds each coupled to both sides of the rotating plate and facing the primary mold or the secondary mold depending on the rotation of the rotating plate, wherein the volume of the second molding space formed by the secondary mold and the rotating mold is larger than the volume of the first molding space formed by the primary mold and the movable mold. Claim 5 In paragraph 2 or 4, the injection molding machine wherein the volume of the first molding space is 80% to 90% of the volume of the second molding space. Claim 6 In paragraph 2 or 4, the above pair of rotary dies is an injection molding machine in which the molding parts are identical. Claim 7 In paragraph 2 or 4, the molding portion of the first mold and the molding portion of the second mold are different shapes in an injection molding machine. Claim 8 In paragraph 1 or 3, the general resin injected by the general injection machine is an injection molding machine of an opaque material. Claim 9 In claim 1 or 3, the resin injected in the foam injection machine and the resin injected in the general injection machine are different types of resins. Claim 10 In claim 1 or 3, the resin injected in the foam injection machine and the resin injected in the general injection machine are different index injection molding machines. Claim 11 A method of operating an injection molding machine comprising: a first molding step of injecting a gas-mixed foamed resin into a first molding space formed by a first mold and a rotary mold in a closed state; a mold rotation step of rotating the rotary mold in an open state after the first molding step; and a second molding step of injecting a general resin into a second molding space formed by a second mold and a rotary mold in a closed state after the mold rotation step, thereby injecting the general resin into a foamed molded product formed in the first molding step. Claim 12 In claim 11, the method of operating an injection molding machine in which the second molding step is performed together with the first molding step. Claim 13 In claim 11, a method of operating an injection molding machine in which a foam injection machine that injects foam resin for transitioning between the above-mentioned open state and the above-mentioned closed state moves. Claim 14 In claim 11, a method of operation of an injection molding machine in which a general injection machine that injects general resin moves to switch between the above-mentioned open state and the above-mentioned closed state.

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