JP5840459B2 - Three-sheet injection mold, injection molding apparatus and injection molding method - Google Patents

Description

  The present invention relates to an injection mold having a three-sheet structure in which an intermediate mold is moved in a mold opening / closing direction by a rack and pinion mechanism, an injection molding apparatus, and an injection molding method using the same.

  2. Description of the Related Art Conventionally, a stack mold (three-sheet injection molding) including a fixed mold attached to a fixed platen, a movable mold attached to a movable platen, and an intermediate mold provided between the fixed mold and the movable mold. (Mold) is known (see Patent Document 1). In the stack mold of Patent Document 1, a rack and pinion mechanism including a pair of racks and pinions is attached to the side surface thereof. Is configured to move in the mold opening and closing direction. The configuration in parentheses in the description relating to Patent Document 1 shows the configuration of the present invention that is considered to correspond to the configuration of the prior art immediately before the parenthesis for convenience of explanation, It does not imply that the configuration is the same or similar.

  As shown in FIG. 11A, a conventional rack and pinion mechanism such as that used in the stack mold of Patent Document 1 is configured to smoothly mesh the rack and pinion and rotate the pinion without trouble. Backlash α and β are provided between the teeth 111 and 113 of the racks 110 and 112 and the teeth 115a and 115b of the pinion 114, respectively, and the teeth 115a and 115b of the pinion 114 are bited into the teeth 111 and 113 of the racks 110 and 112, respectively. It is formed to avoid.

  On the other hand, foam molding for molding foam molded products from foamable molten resin has been conventionally performed for the purpose of weight reduction and deformation suppression of products, functionalization such as heat insulation characteristics and sound absorption characteristics, and cost reduction by reducing material consumption. It is done. As such foam molding, after injecting and filling foamable molten resin into the mold cavity, the mold is slightly opened to expand the volume of the mold cavity, and the foamable molten resin is expanded in the mold cavity. The expanded foam molding method that forms foamed molded products with foamed cells inside covered with an unfoamed skin layer by foaming and expanding is a molding with high foaming efficiency such as foam controllability and stabilization of foam quality. It is known as a law (see Patent Document 2).

  Conventionally, as an injection molding method for molding, for example, a glass resin molded product, a molten resin is injected and filled into a mold cavity whose volume has been expanded in advance by a predetermined amount, and then the volume of the mold cavity is reduced. By applying a clamping press force to the molten resin in the mold cavity, an injection press molding method that suppresses deformation of the molded product, and for the same purpose, by the molten resin pressure in the injection-filled mold cavity There is known a molding method such as an injection compression molding method in which the mold cavity volume is expanded by a predetermined amount, and then the mold cavity volume is reduced to apply a clamping compression force to the molten resin in the mold cavity. These injection press molding method and injection compression molding method are called compression molding methods.

JP 10-315281 A JP 2000-351142 A

  However, if an expansion foam molding method, an injection press molding method, or an injection compression molding method is performed with an injection mold having a three-sheet structure using a rack and pinion mechanism such as the stack mold of Patent Document 1, the effect of backlash increases. There is a problem in that it is impossible to perform mold opening and closing operations with high accuracy, and it is impossible to obtain a high-quality foam molded product, injection press molded product, or injection compression molded product.

  That is, in the stack mold (three-sheet injection mold) of Patent Document 1, the rack and pinion mechanism in the process of moving the movable mold and the intermediate mold in the mold closing direction from the mold open state and clamping the mold. The rack and pinion are considered to be in the state shown in FIG. Assuming this, in the movement of the movable mold and the intermediate mold in the mold opening direction, until the intermediate mold starts moving in the mold opening direction after the movable mold starts moving in the mold opening direction, From the state of FIG. 11A, as shown in FIG. 11B, until the teeth 111 of the lower rack 110 on the movable side come into contact with the teeth 115a on the lower side of the pinion 114 (that is, FIG. )), The lower rack 110 moves in the mold opening direction (in FIG. 11B, the white arrow indicates the movement direction of the lower rack 110, and the black arrow indicates the contact location. Show). After that, as shown in FIG. 11C, the teeth 111 of the lower rack 110 on the movable side push the teeth 115a on the lower side of the pinion 114 in the mold opening direction, so that the teeth 115b on the upper side of the pinion 114 become The pinion 114 rotates clockwise and the lower rack 110 moves in the mold opening direction until it comes into contact with the teeth 113 of the upper rack 112 on the fixed side (that is, by the backlash β in FIG. 11B). . Then, after such an operation, the upper teeth 115b of the pinion 114 push the teeth 113 of the upper rack 112 on the fixed side which is fixed and does not move in the direction of the fixed mold, thereby rotating the pinion 114 clockwise. The intermediate mold in which the rotation is continued and the pinion 114 is rotatably arranged starts to move in the direction of the movable mold (the mold opening direction) (in FIG. 11 (c), the white arrow indicates the lower rack 110). ) And the rotation / movement direction of the pinion 114, and a black arrow indicates a contact point). As described above, the stack mold of Patent Document 1 causes a difference in the mold opening amount of both mold cavities by a maximum α + β due to the backlash of the rack and pinion mechanism (see FIG. 11C). Also, during mold opening from the mold closed state or during mold closing from the mold open state, the pressure inside the mold cavity (for example, the pressure of the molten resin injected and filled or the foaming pressure of the foamable molten resin in the expanded foam molding method) Etc.), a force in the mold opening / closing direction corresponding to the difference acts on the intermediate mold, and the intermediate mold that is not restrained in the mold opening / closing direction other than meshing of the rack and pinion is moved between the rack and the pinion. The backlash of the mold suddenly moves in the mold opening and closing direction, resulting in a difference in the mold opening amount of both mold cavities, unstable mold opening speed and mold closing speed, etc. There is a problem that the mold opening operation and the mold closing operation cannot be performed. The backlash problem of such a rack and pinion mechanism is particularly an expansion that requires accurate micro mold opening amount and micro mold opening position maintenance, and stable mold opening speed and mold closing speed control. This is a problem in foam molding, injection press molding, and injection compression molding.

  Therefore, the present invention provides a three-sheet injection mold that can obtain a high-quality molded product in a three-sheet injection mold, an injection molding apparatus, and an injection molding method using a rack and pinion mechanism, An object of the present invention is to provide an injection molding apparatus and an injection molding method.

  In order to achieve the above object, an injection mold having a three-piece structure according to the present invention includes a fixed mold, a movable mold that is opposed to the fixed mold and is provided so as to be movable in a mold opening and closing direction, An intermediate mold provided between the fixed mold and the movable mold so as to be movable in a mold opening and closing direction and capable of forming a mold cavity between the fixed mold and the movable mold; , A pinion provided in the intermediate mold, and a rack provided in each of the fixed mold and the movable mold and having teeth that can mesh with the pinion, and the movable mold is moved in the mold opening / closing direction. And a rack-and-pinion mechanism that moves the intermediate mold in the mold opening / closing direction, and the rack-and-pinion mechanism includes the pinion that moves into the intermediate mold. How to open and close the mold A pinion moving mechanism capable of pressing the pinion against at least one of the fixed mold and the movable mold and pressing the pinion against the teeth of the rack. Thus, the intermediate mold can be moved in the mold opening / closing direction by the rack and pinion mechanism in a state where the pinion is pressed against the teeth of the rack.

  In the three-piece injection mold according to the present invention, the pinion moving mechanism is configured such that the pinion is moved to the fixed mold side or the movable mold when the fixed mold, the movable mold, and the intermediate mold are opened. It is preferable that the pinion is pressed to the movable mold side when the fixed mold, the movable mold, and the intermediate mold are closed.

  An injection molding apparatus according to a first example of the present invention is an injection molding apparatus including the above-described three-sheet injection mold, and a fixed platen to which the fixed mold can be attached, and the fixed platen. A movable plate capable of moving in the mold opening / closing direction with respect to the fixed plate and capable of attaching the movable mold, and a mold clamping device for moving the movable plate in the mold opening / closing direction and clamping the mold. It is characterized by providing.

  An injection molding apparatus according to a second example of the present invention includes a fixed part including a fixed mold and a movable mold facing the fixed mold, and is movable in a mold opening / closing direction with respect to the fixed part. Including an intermediate mold capable of forming a mold cavity between the movable part provided on the fixed mold and the fixed mold and between the movable mold, and opening and closing the mold between the fixed part and the movable part An intermediate portion provided movably in a direction, a mold clamping device for moving the movable portion in a mold opening / closing direction, and clamping, a pinion provided in the intermediate portion, and the fixed portion and the movable portion. An injection molding comprising a rack and a pinion mechanism, each of which is provided with a rack having teeth that can mesh with the pinion and moves the intermediate portion in the mold opening / closing direction in response to the movement of the movable portion in the mold opening / closing direction. A device comprising: The quan-pinion mechanism supports the pinion so as to be movable in the mold opening / closing direction with respect to the intermediate part, presses the pinion against at least one side of the fixed part and the movable part, and pushes the pinion to the rack. A pinion moving mechanism that can be pressed against teeth; and the intermediate portion can be moved in the mold opening and closing direction by the rack and pinion mechanism when the pinion is pressed against the teeth of the rack by the pinion moving mechanism. It is characterized by being. In the injection molding apparatus according to the second example of the present invention, the fixed part includes the fixed mold and a fixed plate to which the fixed mold can be attached, and the movable part includes the movable mold, A movable platen to which the movable mold can be attached, and the rack may be provided on each of the fixed platen and the movable platen.

  An injection molding method according to a first example of the present invention is an injection molding method in which expansion foam molding is performed using the above-described injection molding apparatus, wherein the first mold is clamped between the fixed mold and the intermediate mold. Forming a mold cavity and clamping the movable mold and the intermediate mold to form a second mold cavity; and after the clamping process, the first mold cavity and the mold cavity A foamable resin injection filling process for injecting and filling foamable molten resin into at least one of the second mold cavities, a mold clamping release process for releasing the mold clamping state after the foamable resin injection filling process, and the mold clamping release In parallel with or after the process, a mold opening correction pressing process for pressing the pinion to the fixed mold side by the pinion moving mechanism, and the pinion is pressed to the fixed mold side by the mold opening correction pressing process. The movable mold and the intermediate mold are slightly opened in a mold opening / closing direction with respect to the fixed mold by a predetermined amount, and the foamable molten resin injected and filled in the foamable resin injection filling step is A foaming mold opening step of foaming and expanding in the mold cavity. In the injection molding method according to the first example of the present invention, in the foamable resin injection filling step, after the mold clamping step, the foamable molten resin is applied to both the first mold cavity and the second mold cavity. It may be a process of injection filling.

  An injection molding method according to a second example of the present invention is an injection molding method in which injection press molding is performed using the injection molding apparatus, and the pinion is moved toward the movable mold by the pinion moving mechanism. A mold closing correction pressing step and a state in which the pinion is pressed toward the movable mold by the mold closing correction pressing step, and between the fixed mold and the intermediate mold, and the movable mold and the intermediate mold. The fixed mold, the movable mold, and the intermediate mold are closed to a position where a predetermined amount is opened between the fixed mold and the intermediate mold, and the first mold cavity is interposed between the fixed mold and the intermediate mold. Forming a second mold cavity between the movable mold and the intermediate mold, and after the mold closing process, the first mold cavity and the second mold cavity At least An injection filling process in which molten resin is injected and filled, and in conjunction with the injection filling process or after the injection filling process, the fixed mold, the movable mold, and the intermediate mold are pressed with a predetermined clamping force. And an injection press step of applying the mold clamping press force to at least one of the molten resin in the first mold cavity and the second mold cavity.

  Furthermore, an injection molding method according to a third example of the present invention is an injection molding method for performing injection compression molding using the above-described injection molding apparatus, wherein the fixed mold, the movable mold, and the intermediate mold are arranged. A mold closing step of forming a first mold cavity between the fixed mold and the intermediate mold and forming a second mold cavity between the movable mold and the intermediate mold; In parallel with or after the mold closing process, a mold closing correction pressing process for pressing the pinion toward the movable mold by the pinion moving mechanism and a mold opening correction pressing for pressing the pinion toward the fixed mold At least one of the first mold cavity and the second mold cavity during the continuation of any one of the correction pressing process and the mold closing correction pressing process and the mold opening correction pressing process. Melting The movable mold and the intermediate mold are slightly opened in the mold opening / closing direction by a predetermined amount by an injection filling process of injecting and filling the resin and a molten resin pressure injected and filled in the mold cavity. After the micro mold opening process and the micro mold opening process, the fixed mold, the movable mold, and the intermediate mold are clamped with a predetermined clamping compression force, and the inside of the first mold cavity and the second mold An injection compression step of applying the mold clamping compression force to at least one of the molten resins in the mold cavity.

  In the injection molding method according to the second and third examples of the present invention, in the injection filling step, the molten resin is injected and filled into both the first mold cavity and the second mold cavity after the mold clamping step. It may be a process to perform.

  According to the present invention, in a three-sheet injection mold using a rack and pinion mechanism, an injection molding apparatus and an injection molding method, a three-sheet injection mold that can obtain a high-quality molded product, An injection molding apparatus and an injection molding method can be provided.

It is a front view which shows schematic structure of the injection molding apparatus which concerns on one Embodiment of this invention. It is a schematic sectional drawing in alignment with the AA 'line of FIG. It is a front view which shows schematic structure of the pinion movement mechanism of the injection molding apparatus which concerns on this embodiment. It is a schematic sectional drawing in alignment with the BB 'line of FIG. FIG. 4 is a schematic cross-sectional view taken along the line CC ′ of FIG. 3. It is a front view which shows schematic structure of the alternative example of the injection molding apparatus which concerns on one Embodiment of this invention. It is explanatory drawing for demonstrating the process of the expansion foam molding method which concerns on this embodiment. It is explanatory drawing for demonstrating operation | movement of the rack and pinion at the time of the mold opening in the injection molding apparatus which concerns on this embodiment. It is explanatory drawing for demonstrating the process of the injection press molding method which concerns on this embodiment. It is explanatory drawing for demonstrating the process of the injection compression molding method which concerns on this embodiment. It is explanatory drawing for demonstrating operation | movement of the rack and pinion at the time of the mold opening in the conventional rack and pinion mechanism.

  Next, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings. 1 and 2 are a front view and a sectional view showing a schematic configuration of the injection molding apparatus according to the present embodiment. 3 to 5 are a front view and a cross-sectional view showing a schematic configuration of the pinion moving mechanism in the present embodiment. FIG. 6 is a front view showing a schematic configuration of an alternative example of an injection molding apparatus according to an embodiment of the present invention. The injection molding apparatus 1 according to the present embodiment schematically includes a stationary part 100 including a stationary platen 3 and a stationary mold 12 fixed to the base 2, and is movable in the mold opening / closing direction with respect to the stationary part 100. A movable part 102 having the movable platen 4 and the movable mold 14 provided, an intermediate part 104 having an intermediate mold 16 movably provided in the mold opening / closing direction between the fixed part 100 and the movable part 102, and movable. The mold of the movable part 102 is moved in a state in which the backlash generated between the mold clamping device 6, the pinion 22, and the teeth 25 and 27 of the racks 24 and 26 is moved in the mold opening and closing direction to zero. The rack and pinion mechanism 20 moves the intermediate portion 104 in the mold opening / closing direction in response to (in conjunction with) movement in the opening / closing direction. Hereinafter, a specific configuration of the injection molding apparatus 1 according to the present embodiment will be described with reference to FIGS. 1 to 6.

  As shown in FIG. 1, the injection molding apparatus 1 according to the present embodiment is provided with a fixed platen 3 fixed to a base 2 and facing the fixed platen 3, and moves in a mold opening / closing direction with respect to the fixed platen 3. A movable platen 4 that can be configured, a tie bar 5 that protrudes from the four corners of the fixed platen 3 so as to pass through the four corners of the movable platen 4 and guides the movement of the movable platen 4 in the mold opening / closing direction, and the movable platen 4 Is moved in the mold opening / closing direction along the tie bar 5 and can be clamped, and a three-piece injection mold 10 provided between the fixed plate 3 and the movable plate 4 and fixed. An injection unit 7 is provided on the back side of the panel 3 and injects molten resin into a mold cavity formed by a three-sheet injection mold 10. In the injection molding apparatus 1 according to the present embodiment, the mold opening / closing direction refers to the direction in which the three-layer injection mold 10 is opened and closed, that is, a fixed mold 12, a movable mold 14, and an intermediate position described later. A direction in which the molds 16 face each other.

  The fixed platen 3 has a through-hole (not shown) through which a nozzle (not shown) of the injection unit 7 can be inserted from the back side (the side opposite to the surface facing the movable platen 4) to the front side (the surface facing the movable platen 4). (Not shown) is formed. The injection unit 7 is detachably provided on the back side of the fixed platen 3, and a nozzle for injecting the molten resin is provided on the back side of the fixed die 12, which will be described later, through the through hole of the fixed platen 3. The molten resin is injected and filled into the mold cavity of the three-sheet injection mold 10 via the resin flow path of the three-sheet injection mold 10. .

  As shown in FIGS. 1 and 2, the three-piece injection mold 10 includes a fixed mold 12, a movable mold 14 that is opposed to the fixed mold 12 and is movable in the mold opening and closing direction. An intermediate mold 16 movably provided in the mold opening / closing direction between the fixed mold 12 and the movable mold 14 and an intermediate mold corresponding to (in conjunction with) movement of the movable mold 14 in the mold opening / closing direction. A rack and pinion mechanism 20 that moves the mold 16 in the mold opening and closing direction is provided. The three-mold injection mold 10 is configured such that the fixed mold 12 and the movable mold 14 are detachably attached to the fixed plate 3 and the movable plate 4, respectively, so that the fixed plate 3 and the movable plate 4 are mounted. It is attached so that it can be removed and replaced. In the rack and pinion mechanism 20 according to this embodiment, the movement of the intermediate mold 16 in the mold opening / closing direction corresponding to the movement of the movable mold 14 in the mold opening / closing direction will be described later. By movement of the rack 26 in the mold opening / closing direction, a pinion 22 described later provided in the intermediate mold 16 rotates, and meshes with teeth 25 of a rack 24 described later provided in the fixed mold 12 while the pinion 22 rotates. The intermediate mold 16 is moved in the mold opening / closing direction by linearly moving in the mold opening / closing direction.

  The three-piece injection mold 10 has mold dividing surfaces between the fixed mold 12 and the intermediate mold 16 and between the movable mold 14 and the intermediate mold 16. The mold dividing surfaces of the fixed mold 12, the movable mold 14 and the intermediate mold 16 are respectively positioned between the fixed mold 12 and the intermediate mold 16 as well as the movable mold 14 and the intermediate mold when they are aligned. The mold cavities having the same shape (hereinafter referred to as “first mold cavity C1” and “second mold cavity C2”, respectively) are formed between the sixteen. Further, these mold dividing surfaces have a shear edge structure in which the resin injected and filled in the first mold cavity C1 and the second mold cavity C2 does not leak when each of the mold dividing surfaces is opened slightly. ing. This shear edge structure is called a squeezing structure, an inlay structure, or the like, and is a structure generally known as a structure of a fitting portion that forms a mold dividing surface. This shear edge structure is filled in the mold cavity by forming a fitting part that extends in the mold opening and closing direction and can be inserted and removed while sliding with each other between the mold dividing surfaces. The resin can be prevented from leaking out of the mold even when the mold is opened by a predetermined amount. In the three-sheet injection mold 10 according to the present embodiment, each mold dividing surface has a shear edge structure, but is not limited thereto.

  Between the fixed mold 12 and the intermediate mold 16 and between the movable mold 14 and the intermediate mold 16, guide pins 18a to 18d for guiding the movement of the intermediate mold 16 in the mold opening / closing direction (in FIG. Guide pins 18c and 18d are provided). That is, a pair of guide pins 18 a and 18 d that protrude toward the movable mold 14 and the intermediate mold 16 and pass through the intermediate mold 16 are provided at two diagonal positions of the four corners of the fixed mold 12. Yes. In addition, a pair of guide pins 18b and 18c protruding from the movable mold 14 are housed in two positions on the diagonal opposite to the side where the pair of guide pins 18a and 18d are provided, among the four corners of the fixed mold 12. Possible storage holes 19a (in FIG. 1, the rear-side storage holes 19a are not shown) are formed. Of the four corners of the movable mold 14, two diagonal positions that do not face the guide pins 18 a and 18 d protruding from the fixed mold 12 protrude toward the fixed mold 12 and the intermediate mold 16, and the intermediate mold 16. A pair of guide pins 18b, 18c are provided. Also, a pair of guide pins 18a and 18d protruding from the fixed mold 12 are housed in two locations on the diagonal opposite to the side where the pair of guide pins 18b and 18c are provided, among the four corners of the movable mold 14. Possible storage holes 19b (in FIG. 1, the rear side storage hole 19b is not shown) are formed.

  The guide pins 18a to 18d have a mold opening limit position of the three-mold injection mold 10, that is, a mold opening amount between the molds 12, 14, and 16 constituting the three-mold injection mold 10. The intermediate mold 16 can be supported and guided to the maximum position, and when the three-layer injection mold 10 is clamped, the front ends thereof are accommodation holes 19a, 19b of the fixed mold 12 and the movable mold 14. And has a length that does not protrude from the back side of the fixed mold 12 and the movable mold 14. In order to prevent the intermediate mold 16 from falling off, the guide pins 18a to 18d are respectively released from the injection molding apparatus and released when the molds are divided, such as when performing mold maintenance. At the time of coupling in which injection molding is performed by attaching to the injection molding apparatus in a combined state, a mechanical or electrical stopper (not shown) for preventing mold opening beyond the mold opening limit position is provided. Here, in the three-piece injection mold 10 according to the present embodiment, the guide pins 18a to 18d are provided at two locations on the diagonal line of the fixed mold 12 and the movable mold 14, respectively. For example, various modes such as a mode in which a guide pin is provided at one of the four corners of the fixed mold 12 and the movable mold 14 and a storage hole capable of storing the guide pin is provided at the other four corners are adopted. be able to.

  In the fixed mold 12 and the intermediate mold 16, the molten resin injected from the injection unit 7 flows to the intermediate mold 16, and from the intermediate mold 16 side to the first mold cavity C1 and the second mold cavity C2. Hot runners (not shown) through which molten resin flows are formed. Here, the hot runner refers to one in which a heat retaining mechanism or a heating mechanism is arranged in a resin flow path (runner) in a mold, and the resin is retained and flowed in a constantly molten state. When the resin flow path itself in the mold is formed as a hot runner like the three-piece injection mold 10 according to the present embodiment, a sprue bar or an offset sprue bar that is a separate member is used as the hot runner. Compared to the case, the degree of freedom of arrangement of the resin flow path is high, and a large effective volume that can be used as a mold cavity can be secured. Therefore, molding is performed without restriction even for parts with a large projected area such as a door trim. be able to. In the three-piece injection mold 10 according to the present embodiment, the configuration of each mold for flowing the molten resin is not limited to forming a hot runner in the fixed mold 12 and the intermediate mold 16, for example, a sprue bar or an offset A known configuration such as a sprue bar can be employed. In the three-sheet injection mold 10 according to the present embodiment, the resin flow path in the mold includes the molten resin injected from the injection unit 7 from the intermediate mold 16 side to the first mold cavity C1 and Although it was made to flow in the 2nd metallic mold cavity C2, respectively, it is not limited to this but various modes can be adopted. Further, in the three-piece injection mold 10 according to the present embodiment, a resin shut-off switching valve or the like that can open and close the resin flow path may be provided in the resin flow path in the mold. . In particular, when the resin flow path penetrates the mold dividing surface, it is necessary to provide a resin cutoff opening switching valve or the like at each resin flow path end of the mold dividing surface divided by the mold opening. These switching valves and the like may be either electrical control or mechanical control, but those that are automatically switched to open / close of the molten resin in conjunction with mold opening / closing are preferable. In the injection molding apparatus 1 according to the present embodiment, the molten resin injected from the injection unit 7 is caused to flow into the first mold cavity C1 and the second mold cavity C2, but the present invention is not limited to this. 9 and FIG. 10, another injection unit may be provided, and the molten resin may be injected from the two injection units into the first mold cavity C1 and the second mold cavity C2, respectively.

  As shown in FIGS. 1 to 3, the rack and pinion mechanism 20 includes a pinion 22 provided on the side surface of the intermediate mold 16, an upper rack 24 provided on the side surface of the fixed mold 12, and a movable mold. 14 is provided with a lower rack 26 provided on the side surface of 14 and a pinion moving mechanism 30 that supports the pinion 22 so as to be movable in the mold opening / closing direction and can press the pinion 22 in the mold opening / closing direction. The rack and pinion mechanism 20 is attached to both side surfaces of the fixed mold 12, the movable mold 14 and the intermediate mold 16.

  The upper rack 24 is formed in a long prismatic shape whose longitudinal direction is the mold opening / closing direction, and teeth 25 that can mesh with the pinion 22 are formed continuously on the lower surface thereof in the mold opening / closing direction. The upper end of the upper rack 24 is fixed to the side surface of the fixed mold 12 in a state parallel to the mold opening / closing direction so that the teeth 25 mesh with the upper side of the pinion 22. The lower rack 26 is formed in a long prismatic shape whose longitudinal direction is the mold opening / closing direction, and teeth 27 that can mesh with the pinion 22 are formed continuously on the upper surface thereof in the mold opening / closing direction. . The base of the lower rack 26 is fixed to the side surface of the movable mold 14 in a state parallel to the mold opening / closing direction so that the teeth 27 mesh with the lower side of the pinion 22. The upper rack 24 and the lower rack 26 are guided by rack holders 28 and 29 that are vertically erected on a base portion 32 to be described later of the pinion moving mechanism 30 on the opposite sides of the teeth 25 and 27, respectively. Left and right shaking is prevented. The rack holder 28 that guides the upper rack 24 is formed in a substantially U-shaped cross section that extends in the mold opening / closing direction and opens downward, and guides the upper rack 24 inside the substantially U-shaped cross section. (See FIG. 5). A rack holder 29 that guides the lower rack 26 is formed in a substantially U-shaped cross section that extends in the mold opening and closing direction and opens upward, and the lower rack 26 is installed inside the substantially U-shaped cross section. It is formed so as to guide (see FIG. 5). The pinion 22, the upper rack 24, and the lower rack 26 have the same tooth tip shape, and suitable ones may be used as appropriate depending on the size, load, moving stroke, and the like of the intermediate mold 16 to be moved. it can.

  As shown in FIGS. 3 to 5, the pinion moving mechanism 30 includes a flat base portion 32 attached to the side surface of the intermediate mold 16, a pinion holder 34 that holds the pinion 22, and the pinion holder 34 as a base portion 32. The linear guide 36 is supported so as to be movable in the mold opening / closing direction, and the actuator 38 presses the pinion holder 34 against the base portion 32 in the mold opening / closing direction.

  The base portion 32 is formed in a slightly horizontally long rectangular plate whose longitudinal direction is the mold opening / closing direction, and is on the side surface of the intermediate mold 16 so that one surface is in surface contact with the side surface of the intermediate mold 16. Installed. Hereinafter, one surface of the base portion 32 in surface contact with the side surface of the intermediate mold 16 is referred to as an attachment surface, and the other surface is referred to as a mounting surface.

  The pinion holder 34 is formed in a rectangular tube shape with the upper surface and the lower surface opened and extending slightly in the mold opening / closing direction. When the pinion 22 is disposed inside the pinion holder 34, the upper side of the pinion 22 from the opened upper surface and lower surface And it has a shape that the lower side is exposed. Inside the pinion holder 34, the pinion 22 is rotatably mounted via bearings 35 and 35.

  The linear motion guide 36 includes a linear motion guide rail 36a attached to the mounting surface of the base portion 32, and a pair of linear motion guide blocks 36b and 36b attached to the pinion holder 34 and slidable on the linear motion guide rail 36a. Consists of. The linear motion guide rail 36 a is formed in an I-shaped cross section, extends in the mold opening / closing direction, and stands upright with respect to the mounting surface of the base portion 32. Each of the pair of linear motion guide blocks 36b and 36b is formed in a substantially U-shaped cross section that opens toward the linear motion guide rail 36a, and slidably engages with the linear motion guide rail 36a on the opening side. The surface opposite to the opening is fixed to the back surface of the pinion holder 34.

  The actuator 38 is a reciprocating cylinder (that is, a hydraulic cylinder) driven by hydraulic pressure, and is mounted on the mounting surface of the base portion 32 via an actuator support 40 fixed to the mounting surface of the base portion 32. Yes. The actuator 38 reciprocates the rod 42 in the mold opening / closing direction by a pressure fluid supplied from a pressure source (not shown), thereby pressing the pinion holder 34 in the mold opening / closing direction, thereby causing the pinion 22 attached to the pinion holder 34 to move. The intermediate mold 16 is configured to move in the mold opening / closing direction. The tip of the rod 42 and the pinion holder 34 are connected by a joint 44 that allows (absorbs) some degree of eccentricity and inclination. By connecting the tip of the rod 42 and the pinion holder 34 with the joint 44 in this way, it is possible to suppress an increase in movement resistance and galling of the pinion holder 34 due to manufacturing of related components and assembly tolerances. The pinion holder 34 can be moved smoothly. Here, the actuator 38 is not limited to a hydraulic cylinder, and various actuators such as a reciprocating cylinder driven by pneumatic pressure, an electrically driven reciprocating ball screw mechanism, a spring, a pneumatic damper, or a hydraulic damper may be adopted. it can.

  In the injection molding apparatus 1 according to the present embodiment, the rack and pinion mechanism 20 may be any mode as long as it moves the intermediate mold 16 in the mold opening / closing direction in response to the movement of the movable mold 14 in the mold opening / closing direction. It may be. That is, in the injection molding apparatus 1 according to the present embodiment, the rack and pinion mechanism 20 is attached to both side surfaces of the fixed mold 12, the movable mold 14, and the intermediate mold 16, but the present invention is not limited to this. It is not something. For example, a mode in which the fixed mold 12, the movable mold 14 and the intermediate mold 16 are attached to only one side surface, a mode in which the fixed mold 12, the movable mold 14 and the intermediate mold 16 are mounted on the upper surface and / or the lower surface, etc. Various aspects can be adopted.

  In the injection molding apparatus 1 according to the present embodiment, the upper rack 24 is attached to both side surfaces of the fixed mold 12 and the lower rack 26 is attached to both side surfaces of the movable mold 14. It is not limited to. For example, the vertical arrangement of the racks 24, 26 is reversed (that is, the lower rack 26 is attached to both side surfaces of the fixed mold 12, and the upper rack 24 is attached to both side surfaces of the movable mold 14). Alternatively, the vertical arrangement of the racks 24 and 26 is reversed between one side surface of the molds 12 and 14 and the other side surface (that is, for example, the upper rack 24 on one side surface of the fixed mold 12 and the other side surface Various modes can be employed, such as a mode in which the lower rack 26 is attached and the lower rack 26 is attached to one side of the movable mold 14 and the upper rack 24 is attached to the other side. In this case, the racks 24 and 26 are preferably provided so that the vertical positions of the guide pins 18a to 18d are aligned, so that a large open area on the side surface of the mold when the mold is opened can be secured. The product can be easily taken out.

  Furthermore, in the injection molding apparatus 1 according to the present embodiment, the racks 24 and 26 are provided in the fixed mold 12 and the movable mold 14, but the present invention is not limited to this, and as shown in FIG. , 26 may be provided on the fixed platen 3 and the movable platen 4. In this case, the injection molding apparatus 1 according to the present embodiment is supported between the fixed platen 3 and the movable platen 4 on the fixed platen 3 and movable platen 4 side by a plurality of guide pins and the like in the same manner as the intermediate mold 16. Alternatively, an intermediate plate that is supported by the tie bar 5 or a known guide means so as to be movable in the mold opening / closing direction on the injection molding apparatus side is provided, and an intermediate plate is provided on the surface of the intermediate plate facing the fixed plate 3 and the movable plate 4 respectively. The mold 16 may be attached and the pinion 22 may be attached to the side surface of the intermediate board.

  Furthermore, in the injection molding apparatus 1 according to the present embodiment, the pinion moving mechanism 30 is capable of pressing the pinion 22 to both the fixed mold 12 side and the movable mold 14 side, but is not limited thereto. As long as the pinion 22 can be pressed at least toward the fixed mold 12 (mold opening correction pressing process), or the pinion 22 can be pressed at least toward the movable mold 14 (mold closing correction pressing process). Specifically, the former is a molding method that requires the precision of a minute mold opening amount by which the movable mold 14 and the intermediate mold 16 are slightly opened from the mold closed state by the mold clamping device 6 as in the expanded foam molding method. The latter is suitable for a molding method that requires the precision of a minute mold opening amount for closing the mold from the mold opening state to the minute mold opening state, such as an injection press molding method. Further, as long as the pinion 22 can be pressed to both the fixed mold 12 side and the movable mold 14 side, not only any of these molding methods, but also an injection compression molding method that requires switching of the mold opening / closing operation during the molding process. It is suitable for etc.

  The injection molding apparatus 1 according to the present embodiment is obtained by exchanging the mold used in the general-purpose injection molding apparatus with the three-sheet injection mold 10 according to the present embodiment and minor modifications related thereto. Can be obtained.

  Next, an expanded foam molding method, an injection press molding method, and an injection compression molding method performed using the injection molding apparatus 1 according to the present embodiment will be described with reference to FIGS. FIG. 7 is an explanatory diagram for explaining the process of the expanded foam molding method according to the present embodiment, and FIG. 8 is an explanatory diagram for explaining the operation of the rack and pinion when the mold is opened. These are explanatory drawing for demonstrating the process of the injection press molding method which concerns on this embodiment, and FIG. 10 is explanatory drawing for demonstrating the process of the injection compression molding method which concerns on this embodiment. 7 to 10, each component is schematically shown. In FIGS. 7, 9 and 10, for example, the rack and pinion mechanism 20 and the guide pins 18 a to 18 d are omitted. Yes. Moreover, the shape of each metal mold | die 12,14,16, the aspect of a resin flow path, etc. are not limited to the shape etc. which were illustrated.

  Examples of the thermoplastic resin used in the expanded foam molding method, injection press molding method, and injection compression molding method according to this embodiment include polyethylene (PE), polypropylene (PP), polystyrene (PS), and acrylonitrile butadiene.・ General-purpose resins such as styrene copolymer synthetic resin (ABS) and polyethylene terephthalate (PET), engineering resins such as polyamide (PA), polyacetal (POM), polycarbonate (PC), polybutylene terephthalate (PBT), and polyethersulfone (PES), polyphenylene sulfide (PPS), superether resins such as polyetheretherketone (PEEK), thermoplastic elastomer (TPO), styrene elastomer (SBC), urethane elastomer TPU) elastomer resins, and the like, and these recycled resin can be used. These thermoplastic resins are not only used alone, but can also be used in a mixture of two or more, and if necessary, plasticizers, heat stabilizers, antioxidants, lubricants, electrification It can also be used in the state where various additives such as an inhibitor, a colorant, a flame retardant, and an extender are added. Moreover, it can also be used in the state which added reinforcing agents, such as glass fiber, carbon fiber, and natural fiber, for the intensity | strength and rigidity improvement of a molded article. For example, an inorganic chemical foaming agent mainly composed of sodium bicarbonate or an organic chemical foaming agent mainly composed of an azo compound is mixed with these thermoplastic resins (chemical foaming method), air, carbon dioxide gas, A foamable molten resin obtained by injecting nitrogen gas or the like (physical foam molding method) or obtained by a well-known method can be used not only in the expanded foam molding method but also in the injection press molding method and the injection compression molding method. .

[Expanded foam molding]
The expanded foam molding method according to this embodiment will be described with reference to FIGS. The expanded foam molding method according to the present embodiment includes a first mold cavity C1 formed between the fixed mold 12 and the intermediate mold 16, and a second mold formed between the movable mold 14 and the intermediate mold 16. In the cavity C2, at the same time, a foam molded product is molded by the expanded foam molding method. In this expanded foam molding method, the foamable molten resin injected from the injection unit 7 is caused to flow to the intermediate mold 16, and foamed from the intermediate mold 16 side to the first mold cavity C1 and the second mold cavity C2, respectively. Although the aspect of the resin flow path into which a molten resin flows in is demonstrated, it is not limited to this.

  First, as shown in FIG. 7A, the movable mold 14 and the intermediate mold 16 are moved in the mold closing direction by the mold clamping device 6 and the rack and pinion mechanism 20, and the fixed mold 12, the movable mold 14 and the The intermediate mold 16 is clamped (clamping process). Specifically, the movable platen 4 and the movable mold 14 attached thereto are moved to the mold closing position by the mold clamping device 6, and the movable mold 14 is moved in the mold closing direction by the rack and pinion mechanism 20. In response to this, the intermediate mold 16 is moved to the mold closing position, and all the molds are matched. Then, after all the mold alignment is completed, the fixed mold 12, the movable mold 14, and the intermediate mold 16 are clamped by the mold clamping device 6. As a result, a first mold cavity C1 is formed between the fixed mold 12 and the intermediate mold 16, and a second mold cavity C2 is formed between the movable mold 14 and the intermediate mold 16.

  In this mold clamping process, the pinion 22 is pressed against the movable mold 14 by the pinion moving mechanism 30 with a predetermined pressure 1, and the teeth of the pinion 22 and the movable metal among the plurality of teeth 25 and 27 of the racks 24 and 26 are pressed. The pinion 22 is pressed against the surfaces A and B of the teeth 25 and 27 facing on the mold 14 side (hereinafter referred to as “surface A on the movable mold 14 side” and “surface B on the movable mold 14 side”, respectively) (mold) Closing correction pressing step). The state of the pinion 22 and the racks 24 and 26 at this time is shown in FIG. 8A (in FIG. 8A, the white arrow indicates the pressing direction to the pinion 22 and the black arrow indicates the contact location). . This mold closing correction pressing step is not performed for an original purpose (to make backlash zero) to be described later, but to match the axial position of the pinion 22 orthogonal to the mold opening / closing direction in the mold clamping state. The reason is that, since the pinion 22 is movable in the mold opening / closing direction, the pinion 22 attached to both side surfaces of the intermediate mold 16 does not coincide with the axis position perpendicular to the mold opening / closing direction, that is, the pinion 22 When the respective rotating shafts are eccentric rather than coaxially orthogonal to the mold opening / closing direction, depending on the degree of the eccentricity, pinions on both side surfaces of the intermediate mold 16 are moved by movement of the movable rack 26 in the mold opening / closing direction. This is because the balance of forces in the mold opening / closing direction acting on the intermediate mold 16 via the respective rotation shafts 22 is lost, and an unnecessary load may be applied to the rack and pinion mechanism 20. By this mold closing correction pressing step, among the plurality of teeth 25 and 27 of the pinion 22 and the racks 24 and 26, the surfaces C and D (hereinafter referred to as teeth 25 and 27) facing the teeth of the pinion 22 on the fixed mold 12 side. The backlashes α and β generated between “the surface C on the fixed mold 12 side” and “the surface D on the fixed mold 12 side” are maximized. In the mold clamping process, if the axial position of the pinion 22 that is orthogonal to the mold opening / closing direction is substantially coincident or the degree of eccentricity is small, the mold closing correction pressing process is not necessarily performed. Further, the predetermined pressure 1 of the pinion moving mechanism 30 in this mold closing correction pressing step only needs to be such that the pinion 22 can be moved in the mold opening / closing direction, and is the same as the predetermined pressure 2 in the mold opening correction pressing step described later. May be.

  As shown in FIG. 7B, when the mold closing correction pressing process is performed after the mold clamping process, the mold closing correction pressing process is continued, and when the mold closing correction pressing process is not performed, at a suitable timing as appropriate. Next, the first mold cavity C1 and the second mold cavity C2 are injected and filled with the foamable molten resin from the injection unit 7 through the resin flow path 50 formed in the fixed mold 12 and the intermediate mold 16 ( Foaming resin injection filling process). In this foaming resin injection filling process, until the foaming resin injection filling process is completed, the mold clamping state is maintained, and the volumes of the first mold cavity C1 and the second mold cavity C2 are kept constant and expanded. Whether or not to expand the volume of these mold cavities by starting a foaming mold opening process through a mold clamping release process and a mold opening correction pressing process, which will be described later, before the foamable resin injection filling process is completed, What is necessary is just to select suitably according to the combination with resin to be used, a foaming agent, a product shape, the required quality of a product, etc.

  After the foaming resin injection filling process, the mold clamping force by the mold clamping device 6 is reduced to release the mold clamping state (mold clamping releasing process). By this mold clamping release step, the resin pressure of the foamable molten resin in the first mold cavity C1 and the second mold cavity C2 is reduced, and foaming nuclei that form the base point of the foam cell gap are formed. In this foam nucleation, how much the clamping force is reduced per unit time (decrease rate of clamping force) depends on the combination with the resin and foaming agent used, the product shape and the required quality of the product, etc. What is necessary is just to select suitably. In parallel with this mold clamping release process, the pressing direction of the pinion 22 by the pinion moving mechanism 30 is switched from the movable mold 14 side to the fixed mold 12 side, and the pinion 22 is clamped to the fixed mold 12 side. Pressing with a predetermined pressure 2 weaker than the force (mold opening correction pressing step). The state of the pinion 22 and the racks 24 and 26 at this time is shown in FIG. 8B (in FIG. 8B, the white arrow indicates the pressing direction to the pinion 22 and the black arrow indicates the contact location). . At this stage, since the pressing force (predetermined pressure 2) to the pinion 22 is smaller than the mold clamping force, the pinion 22 does not move to the fixed mold 12 side. Thereafter, the mold clamping force by the mold clamping device 6 gradually decreases, and when the predetermined pressure 2 by the pinion moving mechanism 30 becomes larger than the mold clamping force, the pinion 22 moves backlash α, β to the fixed mold 12 side. The pinion 22 is pressed by a predetermined pressure 2 against the surfaces C and D on the fixed mold 12 side of the teeth 25 and 27 of the racks 24 and 26, and switching from the mold closing correction pressing process to the mold opening correction pressing process. Is completed. The state of the pinion 22 and the racks 24 and 26 at this time is shown in FIG. 8C (in FIG. 8C, the white arrows indicate the pressing direction to the pinion 22 and the moving direction of the lower rack 26, Black arrows indicate contact points). This mold opening correction pressing step is intended to reduce the backlash generated between the pinion 22 and the surfaces C and D on the fixed mold 12 side of the teeth 25 and 27 of the racks 24 and 26, which is the original purpose. It is done. As shown in FIG. 8D, the backlash generated between the pinion 22 and the surfaces C and D on the fixed mold 12 side of the teeth 25 and 27 of the racks 24 and 26 is zero (die opening correction pressing In the step), if the lower rack 26 is moved in the mold opening direction, the same tooth 27 is placed on the lower teeth of the pinion 22 on the surface D of the teeth 27 of the rack 27 on the fixed mold 12 side. The pinion 22 rotates in the clockwise direction. The clockwise rotation of the pinion 22 causes the upper teeth of the pinion 22 to be fixed in the mold opening direction from the teeth 25 of the rack on the surface C on the fixed mold 12 side of the teeth 25 of the upper rack 24 that does not move. Receive reaction force. Due to this reaction force, a force in the mold opening direction acts on the pinion 22, and the intermediate mold 16 having the pinion 22 attached to its side surface via the pinion moving mechanism 30 is moved in the mold opening direction. Since these operations are performed simultaneously, the intermediate mold 16 can be moved in the mold opening direction without delaying the movement of the lower rack 26 in the mold opening direction. Further, as described above, it goes without saying that this mold opening correction pressing step is for matching the axial position of the pinion 22 orthogonal to the mold opening / closing direction. In the mold closing correction pressing step, which will be described later, the pinion 22 is pressed to the movable mold 14 side, and backlash generated between the teeth 25, 27 of the racks 24, 26 and the surfaces A, B on the movable mold 14 side is generated. In the state of zero, the lower rack 26 is moved in the mold closing direction, and the intermediate mold 16 is moved in the mold closing direction. Regarding the movement operation of the intermediate mold 16 in the mold closing direction while the mold closing correction pressing process is continued, the mold opening operation of the intermediate mold 16 during the mold opening correction pressing process described above is reversed. Therefore, the explanation is omitted. Further, this mold opening correction pressing step may be performed after the mold clamping release step is completed, and in this case, the step shown in FIG. 8B is omitted.

  Next, during the mold opening correction pressing process, as shown in FIG. 7C, the movable mold 14 and the intermediate mold 16 are moved by a predetermined amount in the mold opening direction by the mold clamping device 6 and the rack and pinion mechanism 20. Only a is opened by a minute mold (foaming mold opening process). The state of the pinion 22 and the racks 24 and 26 at this time is shown in FIG. 8D (in FIG. 8D, the white arrows indicate the pressing direction to the pinion 22, the moving direction of the lower rack 26, and the pinion 22). The black arrow indicates the contact location). Since the volume of the first mold cavity C1 and the second mold cavity C2 is expanded by this foaming mold opening process, the first mold cavity C1 and the second mold cavity C2 are firstly released in the mold clamping release process. The foam core formed in the foamable molten resin injected and filled therein is expanded (grown) into the foam cell gap, and the foamable molten resin is expanded and expanded, and the foam molded products 52 and 52 are molded. In the expansion (growth) of the foam nuclei into the foam cell gap, how to perform the micro mold opening operation of the foam mold opening process (mold opening speed, mold opening operation divided into multiple times, etc.) is used. What is necessary is just to select suitably according to the combination with resin, a foaming agent, a product shape, the required quality of a product (dispersibility of a foaming cell space | gap), etc. In addition, as in the injection press molding method and injection compression molding method described later, after the foam mold opening process, the volume of these mold cavities expanded by micro mold opening is reduced by a predetermined amount, and the design to the foam molded product is performed. In some cases, it is possible to ensure the final transferability and the molding accuracy.

  It is preferable to continue the mold opening correction pressing process even during and after the foam mold opening process. For example, during the mold opening correction pressing process, at the time of the foaming mold opening process, inadequate arrangement of resin flow paths and setting of inappropriate molding conditions in the first mold cavity C1 or the second mold cavity C2 Due to the sudden rise and fall of the foaming pressure of the foamable molten resin due to the above, there is a possibility that a difference occurs in the foaming pressure of both mold cavities. Therefore, when the foaming pressure of the first mold cavity C1 is higher than the foaming pressure of the second mold cavity C2, the force in the mold opening direction (on the movable mold 14 side) is applied to the intermediate mold 16 by the difference. Works. This force in the mold opening direction acts in a direction opposite to the predetermined pressure 2 that presses the pinion 22 toward the fixed mold 12 (mold closing direction) by the pinion moving mechanism 30 in the continued mold opening correction pressing process. For example, when the force in the mold opening direction is larger than the predetermined pressure 2, the pinion moving mechanism 30 is fixed to the side surface of the intermediate mold 16, so that the intermediate mold 16 includes the pinion 22 and the racks 24, 26. Move to the mold opening direction (movable mold 14 side) by the amount corresponding to the backlash α and β between the teeth 25 and 27 and the surfaces A and B on the movable mold 14 side (FIG. 8C). reference). Therefore, against the force in the mold opening direction acting on the intermediate mold 16, that is, the foaming pressure of the foamable molten resin in the mold cavity, the predetermined pressure 2 is set to the maximum foaming of the assumed foamable molten resin. If the pressure is equal to or higher than the pressure (preferably larger than the maximum foaming pressure), the intermediate mold 16 is held in position on the surfaces C and D of the teeth 25 and 27 of the racks 24 and 26 on the fixed mold 12 side. During the opening process, the rack and pinion mechanism 20 moves in the mold opening direction more than the movement amount in the mold opening direction, and after the foaming mold opening process is completed, it moves in the mold opening direction beyond the set small mold opening amount. Never do. On the contrary, when the foaming pressure of the second mold cavity C2 is higher than the foaming pressure of the first mold cavity C1, a force in the mold closing direction (on the fixed mold 12 side) is applied to the intermediate mold 16 by the difference. ) Acts. This force in the mold closing direction acts in the same direction as the predetermined pressure 2 that presses the pinion 22 toward the fixed mold 12 (mold closing direction) by the pinion moving mechanism 30 in the continued mold opening correction pressing process. For example, when the force in the mold closing direction is larger than the predetermined pressure 2, the pinion 22 is pressed toward the fixed mold 12 by the force in the mold closing direction, and the force in the mold closing direction is smaller than the predetermined pressure 2. In this case, the pinion 22 is pressed toward the fixed mold 12 with a predetermined pressure 2, and the mold opening correction pressing process is maintained in any case. In this case, the predetermined pressure 2 does not need to be equal to or higher than the assumed maximum foaming pressure of the foamable molten resin, but the foaming pressure of the foamable molten resin during foaming expansion is not constant but varies. In order to reliably continue the opening correction pressing step under the control of the apparatus, the predetermined pressure 2 is preferably set to be equal to or higher than the maximum foaming pressure of the assumed foamable molten resin. That is, even when a difference occurs in the foaming pressure between both mold cavities, the predetermined pressure 2 is set to be equal to or higher than the maximum foaming pressure of the foamable molten resin (preferably larger than the maximum foaming pressure), thereby allowing the intermediate metal The mold 16 is held in position on the surfaces C and D of the teeth 25 and 27 of the racks 24 and 26 on the fixed mold 12 side, and in the mold opening direction by the rack and pinion mechanism 20 during the foaming mold opening process. More than this amount of movement, and after completion of the foaming mold opening process, it does not move in the mold opening direction beyond the set minute mold opening amount.

  When the mold opening correction pressing step is performed after a predetermined cooling and solidifying time has elapsed, the mold opening correction pressing step is continued. As shown in FIG. 3, the movable mold 14 and the intermediate mold 16 are moved in the mold opening direction to the product removal position by the mold clamping device 6 and the rack and pinion mechanism 20 (mold opening process). Thereafter, foam molded products 52 and 52 molded between the fixed mold 12 and the intermediate mold 16 (first mold cavity C1) and between the movable mold 14 and the intermediate mold 16 (second mold cavity C2), respectively. Is taken out by a product take-out device (not shown) (product take-out step). During the mold opening process, the foam molded products 52 and 52 may be held by any of the fixed mold 12, the intermediate mold 16, and the movable mold 14. In this way, thereafter, by repeating the molding cycle from the state of FIG. 7A to the state of FIG. 7D, the foam molded articles 52 and 52 are simultaneously and continuously molded.

  In these mold opening process and product taking-out process, since the precision of mold opening is not required, it is not necessary to press the pinion 22 toward the fixed mold 12 by the pinion moving mechanism 30 (mold opening correction pressing process). In order to make the axial position of the pinion 22 orthogonal to the mold opening / closing direction coincide, it is preferable to press the pinion 22 by the pinion moving mechanism 30 until the mold closing operation for the next cycle. The pinion moving mechanism 30 is preferably pressed against the pinion 22 in the direction of the fixed mold 12 (mold opening correction pressing process) when the mold is opened, but in the mold opened state, the movable mold 14 side and Any of the fixed mold 12 side may be sufficient.

  In the expanded foam molding method according to the present embodiment, when the molten resin is a soft resin such as an elastomer, it is preferable to perform a re-clamping process subsequent to the foaming mold opening process or the mold opening process. This re-clamping step is for ensuring the final transferability of the design, molding accuracy, and the like by applying a predetermined clamping force again after the foam layer is formed. In the re-clamping process, the pressing direction of the pinion 22 by the pinion moving mechanism 30 is switched to the movable mold 14 side (mold closing correction pressing process), and the pinion 22 is moved to the movable molds of the teeth 25 and 27 of the racks 24 and 26. It is preferable to carry out in a state where it is pressed against the surfaces A and B on the 14th side. In this way, in the mold closing operation, the pinion 22 is pressed again against the surfaces A and B on the movable mold 14 side of the teeth 25 and 27 of the racks 24 and 26 (mold closing correction pressing process). The influence of backlash can be completely eliminated, thereby improving the accuracy of the clamping amount and clamping speed of the clamping operation, and the re-clamping force can be used for the first mold cavity C1 and the second mold cavity C2. It can be quickly and evenly applied to the foamed molded body. In addition, even during re-clamping, the state in which the pinion 22 is pressed against the surfaces A and B on the movable mold 14 side of the teeth 25 and 27 of the racks 24 and 26 (the mold closing correction pressing process) can be maintained. preferable. In the mold opening process and the product removing process performed after the re-clamping process, it is preferable to press the pinion 22 by the pinion moving mechanism 30 in order to match the axial position of the pinion 22 orthogonal to the mold opening / closing direction. In these mold opening process and product take-out process, the precision of mold opening is not required, so the direction of pressing the pinion 22 by the pinion moving mechanism 30 is either the movable mold 14 side or the fixed mold 12 side. Also good.

  Thus, in the expanded foam molding method according to this embodiment, the pinion 22 is pressed against the teeth 25 and 27 of the racks 24 and 26, that is, the pinion 22 and the teeth 25 and 27 of the racks 24 and 26 are fixed. Influence of backlash because the foaming mold opening process (micro mold opening operation from the mold clamping state) is performed in a state where the backlash generated between the surfaces C and D on the mold 12 side is zero (mold opening correction pressing process). Can be made uniform, and the amount of minute mold opening of the first mold cavity C1 and the second mold cavity C2 can be made uniform during and after the foaming mold opening process, and disturbance such as foaming pressure Even if there is a factor, it is possible to maintain a state in which the backlash is zero, so that the position of the micro mold opening position is maintained and the micro mold opening speed is stabilized in the foam mold opening process. It is possible to obtain a high-quality molded foam.

  The expanded foam molding method according to the present embodiment is particularly suitable for molding foam molded products, for example, symmetrical door trims, in which the molding conditions in the first mold cavity C1 and the second mold cavity C2 need to be the same. Yes. That is, the door trim and the like need to be molded under the same molding conditions in the first mold cavity C1 and the second mold cavity C2, and because the projected area of the product is large, in order to shorten the molding cycle, It is necessary to use a large mold capable of molding both the left and right door trims and to perform expansion foam molding with a large molding apparatus. However, in the case of the injection molding apparatus 1 according to the present embodiment, since a three-piece injection mold 10 is used, a large molding apparatus and a large clamping force are not required, and the rack and pinion mechanism 20 Since the pinion moving mechanism 30 capable of eliminating backlash is provided, the molding conditions including the minute mold opening amount and the minute mold opening speed of the first mold cavity C1 and the second mold cavity C2 are made exactly the same. Can do.

  In the expanded foam molding method according to this embodiment, both the first mold cavity C1 and the second mold cavity C2 have the same molding conditions, and at the same time, the same type of foam molded products 52, 52 by the expanded foam molding method. However, the present invention is not limited to this. That is, in the expanded foam molding method according to the present embodiment, for example, different types of foam molded products may be molded from different molten resins in each of the first mold cavity C1 and the second mold cavity C2. Specifically, a three-sheet injection mold 10 having different cavity shapes is used for the first mold cavity C1 and the second mold cavity C2, and in addition to the injection unit 7, the first mold cavity on the movable mold 14 side is used. Another injection unit capable of injection filling is provided in the two mold cavities C2 (see FIG. 9 and the like), and foamable molten resin is injected from the two injection units into the first mold cavity C1 and the second mold cavity C2, respectively. It can be made to fill. Thus, when molding different foamed molded products in the first mold cavity C1 and the second mold cavity C2, the projected areas of both molded products are different, and the difference in foaming pressure and foaming state becomes significant. According to the expanded foam molding method according to the present embodiment, even when there is a difference in foaming pressure between the mold cavities on both sides of the intermediate mold 16, the intermediate mold 16 when the micro mold is opened is attached to the racks 24 and 26. Since the positions of the teeth 25 and 27 on the surfaces C and D on the fixed mold 12 side are reliably held, a high-quality foam molded product can be molded without any problem.

  Further, the expanded foam molding method according to the present embodiment is an aspect in which a foam molded product is molded by the expanded foam molding method simultaneously in both the first and second mold cavities C1 and C2. However, the present invention is not limited to this, as long as at least one of the first mold cavity C1 and the second mold cavity C2 forms a foam molded product by the expanded foam molding method. That is, for example, a foam molded product is molded by the expanded foam molding method only on one side of the first mold cavity C1 and the second mold cavity C2, and a normal molding method (that is, the mold cavity on the other side is selected) A general injection molding method in which the mold cavity volume is not changed during the molding process), an aspect in which an unfoamed molded article is molded (expanded foam molding-an unfoamed mold aspect), the first mold cavity C1 and the second mold cavity C1 Even in a mode where the foam molded product is molded by the expanded foam molding method only on one side of the mold cavity C2 and nothing is molded in the mold cavity on the other side (expanded foam molding-mode without molding). good. Specifically, in the former expanded-foamed-unfoamed mode, first, foamable melting is performed only on one side of the first mold cavity C1 and the second mold cavity C2, for example, only the first mold cavity C1. Resin is injected and filled and cooled and solidified. As will be described later, when a second injection unit connected to the fixed mold 12 is provided, only the first mold cavity C1 may be injected and filled with non-foamable molten resin. After that, the other side of the first mold cavity C1 and the second mold cavity C2, that is, the second mold cavity C2, is injected and filled with a foamable molten resin and cooled and solidified before the first mold cavity C1 and the second mold cavity C2. The mold cavity C2 is expanded, and only the foamable molten resin in the second mold cavity C2 is expanded and foamed. Thus, in order to expand the volume of both mold cavities after cooling and solidifying the foamable molten resin or non-foamable molten resin initially injected and filled into the first mold cavity C1, the first mold In the cavity C1, not only the non-foamable molten resin but also the foamable molten resin does not expand and expand, and an unfoamed molded product can be molded. In order to separately inject and fill the molten resin into the first mold cavity C1 and the second mold cavity C2, in addition to the injection unit 7, the movable mold 14, the intermediate mold 16, or the fixed mold is used. It is preferable to provide another injection unit connected to 12 or provide a resin cutoff opening switching valve or the like capable of opening and closing the resin flow path in the resin flow path, but it is not limited thereto. In addition, since the latter expansion foam molding-the mode without molding can be easily understood from the conventional expanded foam molding method, description thereof is omitted.

  Furthermore, the expanded foam molding method according to the present embodiment is performed even for a mold having a general structure having a mold dividing surface constituted by only a plane orthogonal to the mold opening / closing direction, not a shear edge structure. be able to. Specifically, the movable part such as a movable core arranged inside the mold can be moved to expand the volume of the mold cavity, or the molten resin does not leak out the minute mold opening amount in the foaming mold opening process The skin layer formed by cooling and solidifying the molten resin at the contact portion between the molten resin injected and filled in the mold cavity and the inner surface of the mold cavity is adjusted by adjusting the temperature of the mold. The foamed molded article may be molded by a known method such as forming the mold thick enough to prevent the molten resin from leaking even if the mold is opened slightly.

[Injection press molding]
Next, the injection press molding method according to the present embodiment will be described with reference to FIG. The injection press molding method according to the present embodiment includes a first mold cavity C1 formed between the fixed mold 12 and the intermediate mold 16, and a second mold formed between the movable mold 14 and the intermediate mold 16. In the cavity C2, an injection press molded product is simultaneously molded by an injection press molding method. The present injection press molding method will be described using the second injection unit 8 provided on the movable mold 14 side in addition to the first injection unit 7 provided on the fixed mold 12 side, but is not limited thereto. Is not to be done. Here, the injection press molding method simply means that the movable mold 14 is held in a micro mold open state with a mold clamping force stronger than the mold opening force by the molten resin pressure to be injected and filled in the mold cavity in advance. By opening the micro mold, molten resin is injected and filled into a mold cavity whose volume is expanded from the time of mold clamping, and the movable mold 14 is clamped with a predetermined mold clamping press force during or after the injection filling. In this method, the volume of the mold cavity is reduced to the time of mold clamping (injection press process) to cool and solidify the molten resin in the mold cavity in a state where a predetermined mold clamping press force is applied. This injection press molding method is particularly suitable for molding molded products that need to suppress distortion and deformation, such as optical disks such as CDs and DVDs, and resin glass products such as automobiles as glass substitutes. In the injection press molding method according to the present embodiment, the operations of the racks 24 and 26 and the pinion 22 can be easily understood from FIG. 8 showing the operations of the racks 24 and 26 and the pinion 22 in the expanded foam molding method. The explanation drawing is omitted.

  First, in the mold open state of the fixed mold 12, the movable mold 14, and the intermediate mold 16 (see FIG. 1), the pressing direction to the pinion 22 by the pinion moving mechanism 30 is changed from the fixed mold 12 side to the movable mold 14 side. In order to make backlash generated between the pinion 22 and the surfaces A and B on the movable mold 14 side of the teeth 25 and 27 of the racks 24 and 26, a mold closing correction pressing step is performed. In this mold closing correction pressing step, the predetermined pressure 1 that presses the pinion 22 toward the movable mold 14 by the pinion moving mechanism 30 is sufficient if it can move the pinion 22 in the mold opening / closing direction.

  Next, in a state where the pinion 22 is pressed against the surfaces A and B on the movable mold 14 side of the teeth 25 and 27 of the racks 24 and 26 (mold closing correction pressing step), as shown in FIG. The movable mold 14 and the intermediate mold 16 are moved in the mold closing direction by the mold clamping device 6 and the rack and pinion mechanism 20 to a position where they cannot be completely aligned, and the movable mold 14 and the intermediate mold 16 are opened in a minute mold state. The position is held with (clamping process). As a result, a first mold cavity C1 ′ is formed between the fixed mold 12 and the intermediate mold 16 and is expanded in the mold opening / closing direction by a predetermined amount b from the time of mold clamping. A second mold cavity C2 ′ is formed between the two molds 16 that is expanded in the mold opening / closing direction by a predetermined amount b from the time of mold clamping.

  After the mold clamping process and during the mold closing correction pressing process, as shown in FIG. 9B, the first mold cavity C1 ′ and the second mold cavity C2 ′ have the fixed mold 12 and the movable mold. The molten resin is injected and filled from the first injection unit 7 and the second injection unit 8 through the resin flow paths 50 ′ and 50 ″ formed in 14 (injection filling step).

  It is preferable to continue the mold closing correction pressing process even during and after the injection filling process. For example, during the mold closing correction pressing process, during the injection filling process, inadequate resin flow paths, inappropriate injection conditions, etc. in the first mold cavity C1 ′ and the second mold cavity C2 ′ Therefore, there is a possibility that a difference occurs in the molten resin pressure between both mold cavities. Therefore, when the molten resin pressure in the first mold cavity C1 ′ is higher than the molten resin pressure in the second mold cavity C2 ′, the intermediate mold 16 has a mold opening direction (movable mold 14) corresponding to the difference. Side) force acts. This force in the mold opening direction acts in the same direction as the predetermined pressure 1 that presses the pinion 22 toward the movable mold 14 (mold opening direction) by the pinion moving mechanism 30 in the continuing mold closing correction pressing process. When the force in the mold opening direction is larger than the predetermined pressure 1, the pinion 22 is pressed toward the movable mold 14 by the force in the mold opening direction, and when the force in the mold opening direction is smaller than the predetermined pressure 1, The pinion 22 is pressed toward the movable mold 14 with a predetermined pressure 1, and in any case, the mold closing correction pressing process is maintained. Therefore, it is only necessary to continue the mold closing correction pressing process (see FIG. 8A) during and after the injection filling process, and the predetermined pressure 1 is applied to the first mold cavity C1 ′ and the second mold. It is not necessary to exceed the molten resin pressure for injection filling the mold cavity C2 ′. Conversely, when the molten resin pressure in the second mold cavity C2 ′ is higher than the molten resin pressure in the first mold cavity C1 ′, the intermediate mold 16 is closed in the mold closing direction (fixed mold) by the difference. 12 side) force acts. This force in the mold closing direction acts in a direction opposite to the predetermined pressure 1 that presses the pinion 22 toward the movable mold 14 (mold opening direction) by the pinion moving mechanism 30 in the continuing mold closing correction process. When the force in the mold closing direction is larger than the predetermined pressure 1, since the pinion moving mechanism 30 is fixed to the side surface of the intermediate mold 16, the intermediate mold 16 is connected to the pinion 22 and the teeth 25 of the racks 24 and 26, Accordingly, it moves in the mold closing direction (fixed mold 12 side) by an amount corresponding to the backlashes α and β between the surfaces C and D on the fixed mold 12 side (see FIG. 8A). Accordingly, a predetermined pressure 1 is applied to the first mold closing correction pressing step against the force in the mold closing direction acting on the intermediate mold 16, that is, the molten resin pressure to be injected and filled into the second mold cavity C2 ′. Or before the injection filling process, if the pressure is equal to or higher than this molten resin pressure (preferably higher than the molten resin pressure), the intermediate mold 16 is moved to the movable mold 14 of the teeth 25, 27 of the racks 24, 26. After completion of the mold clamping process in which the molds are held in the side surfaces A and B and are in the minute mold open state, the injection press process (moving in the mold closing direction), which will be described later, is performed below the set minute mold opening amount. During the operation), the rack and pinion mechanism 20 does not move in the mold closing direction more than the movement amount in the mold closing direction.

  Further, in conjunction with this injection filling process or during the continuation of the mold closing correction pressing process after the injection filling process, as shown in FIG. 9C, the mold clamping device 6 and the rack and pinion mechanism 20 move the movable mold. The mold 14 and the intermediate mold 16 are moved in the mold closing direction, and the fixed mold 12, the movable mold 14 and the intermediate mold 16 are clamped with a predetermined clamping force (injection press process). By this injection press process, a predetermined mold clamping press force is applied to the molten resin in the first mold cavity C1 ′ and the second mold cavity C2 ′, and the injection press molded products 54 and 54 are molded. In the mold clamping state, it is not necessary to press the pinion 22 by the pinion moving mechanism 30 (mold closing correction pressing process), but the pressing is continued in order to match the axial position of the pinion 22 orthogonal to the mold opening / closing direction. It is preferable to do.

  After a predetermined cooling and solidifying time has elapsed, as shown in FIG. 9 (d), by performing the mold opening process and the product removing process as in the expanded foam molding method, the fixed mold 12 and the intermediate mold 16 can be moved and moved. Injection press-molded products 54 and 54 molded between the mold 14 and the intermediate mold 16 are taken out by a product take-out device (not shown). In the mold opening process, the injection press-molded products 54 and 54 may be held in any of the fixed mold 12, the intermediate mold 16, and the movable mold 14. In this way, thereafter, by repeating the molding cycle from the state of FIG. 9 (a) to the state of FIG. 9 (d), the injection press molded products 54 and 54 are simultaneously and continuously molded.

  In these mold opening process and product taking-out process, since the precision of mold opening is not required, it is not necessary to press the pinion 22 toward the fixed mold 12 by the pinion moving mechanism 30 (mold opening correction pressing process). Similarly to the expanded foam molding method, it is preferable to press the pinion 22 by the pinion moving mechanism 30.

  Thus, in the injection press molding method according to the present embodiment, the pinion 22 is pressed against the teeth of the racks 24 and 26, that is, the movable mold 14 of the pinion 22 and the teeth 25 and 27 of the racks 24 and 26. In order to perform an injection filling process and an injection press process (mold closing / clamping operation from a minute mold open state) in a state where the backlash generated between the side surfaces A and B is zero (mold closing correction pressing process) The influence of backlash can be completely eliminated, and the amount of micro mold opening of the first mold cavity C1 ′ and the second mold cavity C2 ′ can be made uniform during and after the injection filling process, Even if there is a disturbance factor such as molten resin pressure, it is possible to maintain the state where the backlash is zero. The fastening speed can be stabilized and a high-quality injection press-molded product can be obtained.

  In the injection press molding method according to this embodiment, both the first mold cavity C1 ′ and the second mold cavity C2 ′ are simultaneously subjected to the same type of injection press molding by the injection press molding method under the same molding conditions. Although the articles 54 and 54 are formed, the present invention is not limited to this. That is, in the injection press molding method according to the present embodiment, for example, different types of injection from different molten resins in each of the first mold cavity C1 ′ and the second mold cavity C2 ′, similarly to the expanded foam molding method. A press-molded product may be molded.

  Further, the injection press molding method according to the present embodiment is an aspect in which an injection press molded product is molded by the injection press molding method simultaneously in both the first and second mold cavities C1 ′ and C2 ′ (injection press molding-injection press). However, the present invention is not limited to this, and an injection press molding-non-injection press molding aspect or an injection press molding-non-molding aspect may be used as in the expanded foam molding method. Specifically, in the former aspect of injection press molding-non-injection press molding, first, only one of the first mold cavity C1 ′ and the second mold cavity C2 ′ in the micro mold open state is melted. The resin is injected and filled, and then the injection press process is performed by the method described above. Thereafter, molten resin is injected and filled into the other side of the first mold cavity C1 ′ and the second mold cavity C2 ′ in the clamped state, and both the first mold cavity C1 ′ and the second mold cavity C2 ′ are filled. The molten resin is cooled and solidified. Thereby, an injection press-molded product can be molded on one side of the first mold cavity C1 ′ and the second mold cavity C2 ′, and a non-injection press-molded product can be molded on the other side. In addition, since the latter aspect of injection press molding-no molding can be easily understood from the conventional injection press molding methods, the description thereof is omitted.

  Further, in the injection press molding method according to the present embodiment, the molten resin is injected and filled into the first mold cavity C1 ′ by the first injection unit 7 provided on the back side of the fixed mold 12, and the movable mold 14 is used. Although the molten resin is injected and filled into the second mold cavity C2 ′ by the second injection unit 8 provided on the side, the present invention is not limited to this. That is, in the injection press molding method according to the present embodiment, for example, similarly to the expanded foam molding method, the second injection unit 8 on the movable mold 14 side is not provided, and the molten resin injected only from the first injection unit 7 is used. May be made to flow to the intermediate mold 16 so that the molten resin flows into the first mold cavity C1 ′ and the second mold cavity C2 ′ from the intermediate mold 16 side (see FIG. 7). In this case, the resin flow path may be provided with a resin shut-off switching valve or the like that can open and close the resin flow path.

[Injection compression molding]
Next, the injection compression molding method according to the present embodiment will be described with reference to FIG. The injection compression molding method according to the present embodiment includes a first mold cavity C1 formed between the fixed mold 12 and the intermediate mold 16, and a second mold formed between the movable mold 14 and the intermediate mold 16. In the cavity C2, an injection compression molding product is simultaneously formed by an injection compression molding method. This injection compression molding method will be described using the second injection unit 8 provided on the movable mold 14 side in addition to the first injection unit 7 provided on the fixed mold 12 side, but is not limited thereto. Is not to be done. Here, the injection compression molding method simply means that the movable mold 14 is clamped in advance with a mold clamping force that is weaker than the mold opening force due to the molten resin pressure that is injected and filled into the mold cavity. The movable mold 14 is slightly opened by the molten resin pressure injected and filled into the mold cavity, and the molten resin is injected and filled into the mold cavity whose volume is expanded from the time of mold clamping by the minute mold opening. In the middle or after completion of injection filling, the movable mold 14 is clamped with a predetermined clamping compression force, and the mold cavity volume is reduced to the clamping time (injection compression process), whereby the molten resin in the mold cavity is predetermined. This is a method of cooling and solidifying in a state where the mold clamping compression force is applied. This injection compression molding method, like the injection press molding method, is a molded product that needs to particularly suppress distortion and deformation, such as optical disks such as CD and DVD, resin glass products such as automobiles as glass substitutes, etc. Particularly suitable for molding. In the injection compression molding method according to the present embodiment, the operations of the racks 24 and 26 and the pinion 22 can be easily understood from FIG. 8 showing the operations of the racks 24 and 26 and the pinion 22 in the expanded foam molding method. The explanation drawing is omitted.

  First, similarly to the injection press molding method described above, the pressing direction to the pinion 22 by the pinion moving mechanism 30 is fixed in the mold open state of the fixed mold 12, the movable mold 14, and the intermediate mold 16 (see FIG. 1). In order to switch from the mold 12 side to the movable mold 14 side, the backlash generated between the pinion 22 and the pinion 22 and the surfaces A and B on the movable mold 14 side of the teeth 25 and 27 of the racks 24 and 26 is made zero. The mold closing correction pressing step is performed. The mold closing correction pressing process is not necessarily performed at this stage, and may be performed from the mold clamping process described later to the start of the injection filling process.

  Next, while the mold closing correction pressing process is continued, the movable mold 14 and the intermediate mold 16 are moved in the mold closing direction by the mold clamping device 6 and the rack and pinion mechanism 20 as shown in FIG. The fixed mold 12, the movable mold 14, and the intermediate mold 16 are clamped (a mold clamping process). As a result, a first mold cavity C 1 ″ is formed between the fixed mold 12 and the intermediate mold 16, and a second mold cavity C 2 ″ is formed between the movable mold 14 and the intermediate mold 16. Here, the mold clamping force of the mold clamping device 6 in the mold closing process is set to be smaller than the molten resin pressure injected and filled into the first mold cavity C1 ″ and the second mold cavity C2 ″. ing.

  After the mold clamping process and during the mold closing correction pressing process, as shown in FIG. 10B, the fixed mold 12 and the movable mold 12 are moved into the first mold cavity C1 ″ and the second mold cavity C2 ″. The molten resin is injected and filled from the first injection unit 7 and the second injection unit 8 through the resin flow paths 51 ′ and 51 ″ formed in the mold 14 (injection filling process).

  In this injection filling process, as shown in FIG. 10 (c), the movable mold 14 and the intermediate mold are pressed by the molten resin pressure injected and filled in the first mold cavity C1 ″ and the second mold cavity C2 ″. The mold 16 is slightly opened by a predetermined amount c in the mold opening direction with respect to the fixed mold 12 (micro mold opening process). Specifically, the mold clamping force of the mold clamping device 6 in the mold clamping process is the molten resin pressure for injecting and filling the first mold cavity C1 ″ and the second mold cavity C2 ″ as described above. Therefore, the movable mold 14 and the intermediate mold 16 have a mold corresponding to the difference between the mold clamping force of the mold clamping device 6 and the force in the mold opening direction due to the molten resin pressure to be injected and filled. The force in the opening direction acts, and the movable mold 14 and the intermediate mold 16 are slightly opened from the fixed mold 12. Here, the movable mold 14 and the intermediate mold 16 are held in advance in a minute mold open state (mold clamping process), and the first mold cavity is expanded in the mold opening / closing direction by a predetermined amount b from the time of mold clamping. Unlike the injection press molding method in which the molten resin is injected and filled into the C1 ′ and the second mold cavity C2 ′, in the injection compression molding method, the first mold cavity C1 ″ and the second metal mold are performed during the injection filling process. Due to the difference in molten resin pressure generated in the mold cavity C2 ″, the mechanism of the micro mold opening operation in each case differs.

  First, the mechanism of the micro mold opening operation when the molten resin pressure in the first mold cavity C1 ″ is higher than the molten resin pressure in the second mold cavity C2 ″ will be described. A force in the mold opening direction acts on the movable mold 14 by the difference between the mold clamping force of the mold clamping device 6 and the force in the mold opening direction due to the pressure of the molten resin injected and filled in the second mold cavity C2 ″. To do. Further, a force in the mold opening direction due to a difference in molten resin pressure injected and filled in the first mold cavity C1 ″ and the second mold cavity C2 ″ acts on the intermediate mold 16, and this mold opening direction. This force is greater than the force in the mold opening direction that acts on the movable mold 14. That is, in this case, the movable mold 14 is slightly opened through the rack and pinion mechanism 20 by the force in the mold opening direction acting on the intermediate mold 16. Specifically, the force in the mold opening direction also acts on the movable mold 14 via the intermediate mold 16 and triggers the movable mold 14 to be slightly opened from the intermediate mold 16. After the movable mold 14 is separated from the intermediate mold 16 in the mold opening direction, the force in the mold opening direction acting on the intermediate mold 16 also acts on the movable mold 14 via the rack and pinion mechanism 20, In conjunction with the micro mold opening operation of the mold 16, the movable mold 14 is micro opened. That is, instead of the mold opening correction pressing process performed in the expansion mold opening process of the expanded foam molding method, the mold closing correction pressing process is reversed, that is, the pinion 22 is a movable mold of the teeth 25 and 27 of the racks 24 and 26. In a state of being pressed against the surfaces A and B on the 14 side, the pinion 22 also moves in the mold opening direction as the intermediate mold 16 moves in the mold opening direction, and the movable mold of the teeth 27 of the lower rack 26 is moved. On the surface B on the 14th side, a force in the mold opening direction is applied to the teeth 27 of the same rack by the lower teeth of the pinion 22. At this time, the pinion 22 receives a counterclockwise reaction force (in the mold closing direction) via the lower teeth, but at the same time, the upper teeth of the pinion 22 are fixed and do not move. Since the surface A on the movable mold 14 side receives a counterclockwise reaction force (mold opening direction), the pinion 22 does not rotate counterclockwise, and the intermediate mold 16 moves in the mold opening direction, While rotating clockwise, the lower rack 26 is moved in the mold opening direction, and the movable mold 14 is moved in the mold opening direction (see FIG. 8A). At this time, the mold clamping device 6 opposes the force in the mold opening direction due to the molten resin pressure acting on the movable mold 14 from the intermediate mold 16 via the rack and pinion mechanism 20, and the minute mold of the movable mold 14. A mold clamping force is applied so as to control the opening amount and the minute mold opening speed, but a force in the mold opening direction is not applied to the movable mold 14. Here, not the mold closing correction pressing process, but the mold opening correction pressing process, that is, the state in which the pinion 22 is pressed against the surfaces C and D on the fixed mold 12 side of the teeth 25 and 27 of the racks 24 and 26 (FIG. 8 (c)), when this micro mold opening process is performed, as described above, in the initial stage of the micro mold opening process in which the movable mold 14 and the intermediate mold 16 are in a mold-matching state, The movable mold 14 is moved together with the intermediate mold in the mold opening direction, but after the movable mold 14 is separated from the intermediate mold 16 in the mold opening direction, only the intermediate mold 16 has teeth of the racks 24 and 26. 25, 27 move to the surfaces A and B on the movable mold 14 side by backlash α and β, and there is a difference in the minute mold opening amounts of the first mold cavity C1 ″ and the second mold cavity C2 ″. It will occur.

  Further, when the molten resin pressure in the first mold cavity C1 ″ is higher than the molten resin pressure in the second mold cavity C2 ″, the force in the mold opening direction (movable mold) acting on the intermediate mold 16 is used. The mold 14 side) acts in the same direction as the predetermined pressure 1 that presses the pinion 22 toward the movable mold 14 side (mold opening direction) by the pinion moving mechanism 30 in the continuing mold closing correction pressing process. When the force in the mold opening direction is larger than the predetermined pressure 1, the pinion 22 is pressed toward the movable mold 14 by the force in the mold opening direction, and when the force in the mold opening direction is smaller than the predetermined pressure 1, the pinion 22 Is pressed to the movable mold 14 side with a predetermined pressure 1, and in any case, the mold closing correction pressing process is maintained. The predetermined pressure 1 does not need to be equal to or higher than the molten resin pressure to be injected and filled into the first mold cavity C1 ″. However, since the molten resin pressure during the injection and filling is not constant and varies, the mold closing correction pressing step In order to reliably continue the operation under the control of the apparatus, it is preferable to set the pressure to be equal to or higher than the molten resin pressure for injecting and filling the first mold cavity C1 ″. Thus, by this mold closing correction pressing process, the intermediate mold 16 is held on the movable mold side surfaces A and B of the teeth 25 and 27 of the racks 24 and 26, and the micro mold opening process is continuing. In this case, the amount of movement in the mold opening direction is larger than the amount of movement in the mold opening direction by the rack and pinion mechanism 20, and after the minute mold opening process is completed, the amount of movement in the mold opening direction is not exceeded. Further, in the injection compression process described later, if the mold closing correction pressing process is continued as it is, the backlash during the movement operation in the mold closing direction from the set minute mold opening position can be made zero.

  On the other hand, even when the molten resin pressure in the second mold cavity C2 ″ is higher than the molten resin pressure in the first mold cavity C1 ″, the movable mold 14 is clamped by the mold clamping device 6. The force in the mold opening direction acts by the difference between the force and the force in the mold opening direction due to the pressure of the molten resin injected and filled in the second mold cavity C2. In addition, a force in the mold closing direction due to a difference in molten resin pressure injected and filled in the first mold cavity C1 ″ and the second mold cavity C2 ″ acts on the intermediate mold 16, and this mold closing direction. This force is smaller than the force in the mold opening direction that acts on the movable mold 14. That is, in this case, the intermediate mold 16 is slightly opened through the rack and pinion mechanism 20 by the force in the mold opening direction acting on the movable mold 14. This is a foam mold opening step of an expanded foam molding method in which the movable platen 4 and the movable mold 14 are moved in the mold opening direction by the mold clamping device 6 and the intermediate mold 16 is moved in the mold opening direction by the rack and pinion mechanism 20. Is the same state. Therefore, not the mold closing correction pressing step in the case where the molten resin pressure in the first mold cavity C1 ″ is higher than the molten resin pressure in the second mold cavity C2 ″ described above, but the mold opening correction. It is preferable to perform a pressing step.

  Also, When the molten resin pressure of the second mold cavity C2 ″ is higher than the molten resin pressure of the first mold cavity C1 ″, The force in the mold closing direction acting on the intermediate mold 16 (on the fixed mold 12 side) is Of the ongoing mold closing correction process, In order to act in a direction opposite to the predetermined pressure 1 for pressing the pinion 22 to the movable mold 14 side (mold opening direction) by the pinion moving mechanism 30, When the force in the mold closing direction is larger than the predetermined pressure 1, The pinion moving mechanism 30 is Because it is fixed to the side of the intermediate mold 16, The intermediate mold 16 includes a pinion 22 and a rack 24. 26 teeth 25, 27, the surface C on the fixed mold 12 side, The amount corresponding to backlash α and β with D, It moves in the mold closing direction (the fixed mold 12 side) (see FIG. 8A). there, Pinion 22, Rack 24, 26 teeth 25, 27, the surface C on the fixed mold 12 side, In order to reduce the backlash between D and zero, By switching the pressing direction to the pinion 22 by the pinion moving mechanism 30, A mold opening correction pressing step (see FIG. 8C) is performed. This The force in the mold closing direction acting on the intermediate mold 16 is Because the pinion moving mechanism 30 acts in the same direction as the predetermined pressure 2 that presses the pinion 22 toward the fixed mold 12 (mold closing direction), When the force in the mold closing direction is larger than the predetermined pressure 2, The pinion 22 is pressed toward the stationary mold 12 by the force in the mold closing direction, When the force in the mold closing direction is smaller than the predetermined pressure 2, The pinion 22 is pressed toward the fixed mold 12 with a predetermined pressure 2, In any case, the mold opening correction pressing step is maintained. This predetermined pressure 2 is It is not necessary to exceed the molten resin pressure to be injected and filled into the second mold cavity C2 ″. Because the molten resin pressure during injection filling is not constant but fluctuates, In order to reliably continue the mold opening correction pressing process under device control, It is preferable that the pressure be equal to or higher than the molten resin pressure for injection filling the second mold cavity C2 ″. in this way, By mold opening correction pressing process, The intermediate mold 16 is Rack 24, 26 teeth 25, 27, the surface C on the fixed mold 12 side, The position is held on the D side, During the micro mold opening process, More than the amount of movement in the mold opening direction by the rack and pinion mechanism, Also, After completion of the micro mold opening process, It does not move in the mold opening direction beyond the set minute mold opening amount. Also, After completion of injection filling process (micro mold opening process), This mold opening correction pressing step again, By switching to the mold closing correction pressing process at an appropriate timing, The backlash during the movement operation in the mold closing direction from the set minute mold opening position can be made zero.

  As described above, the pinion 22 by the pinion moving mechanism 30 may be used according to the difference in the pressure of the molten resin injected and filled into the first mold cavity C1 ″ and the second mold cavity C2 ″ during the injection filling process. By switching the pressing direction and performing an appropriate mold opening / closing correction pressing process, the intermediate mold 16 can be moved to the surfaces A and B of the movable mold 14 of the teeth 25 and 17 of the racks 24 and 26, or The position of the fixed mold 12 is maintained at any appropriate side of the surfaces C and D, and during the micro mold opening process, more than the amount of movement in the mold opening direction by the rack and pinion mechanism 20, After the micro mold opening process is completed, the mold does not move in the mold opening direction beyond the set micro mold opening amount.

  In the injection compression molding method according to the present embodiment, in order to control the micro mold opening amount and micro mold opening speed with high accuracy, the micro mold opening of the movable mold 14 and the intermediate mold 16 is interlocked with the injection filling process. It is preferable to further include a feedback step of monitoring the amount and feedback-controlling the clamping force by the clamping device 6. More specifically, this feedback process is performed by a minute amount of the movable mold 14 and the intermediate mold 16 in a state where the molten resin is injected and filled into the first mold cavity C1 ″ and the second mold cavity C2 ″. The mold opening amount is monitored, and when the minute mold opening amounts of the movable mold 14 and the intermediate mold 16 reach a predetermined amount c, the mold is held so that the positions of the movable mold 14 and the intermediate mold 16 are maintained. This can be performed by mold clamping control for increasing the mold clamping force of the clamping device 6. In the injection compression molding method according to the present embodiment, this feedback step is not necessarily performed. Instead of the feedback step, for example, the minute mold opening amounts of the movable mold 14 and the intermediate mold 16 are a predetermined amount c. Or after that (after the micro mold opening process), it may be transferred to an injection compression process described later.

  After the minute mold opening process, the mold closing correction pressing process is continued, or if the mold opening correction pressing process is continued, after switching to the mold closing correction pressing process, as shown in FIG. The movable mold 14 and the intermediate mold 16 are moved in the mold closing direction by the clamping device 6 and the rack and pinion mechanism 20, and the fixed mold 12, the movable mold 14, and the intermediate mold 16 are compressed with a predetermined clamping force. The mold is clamped (injection compression process). By this injection compression process, the mold compression force is applied to the molten resin in the first mold cavity C1 ″ and the second mold cavity C2 ″, and the injection compression molded products 55 and 55 are molded. This injection compression process may be performed in conjunction with the injection filling process, or may be performed after the injection filling process. In the mold clamping state, it is not necessary to press the pinion 22 by the pinion moving mechanism 30 (mold closing correction pressing process), but the pressing is continued in order to match the axial position of the pinion 22 orthogonal to the mold opening / closing direction. It is preferable to do.

  After a predetermined cooling and solidifying time has elapsed, as shown in FIG. 10 (e), the mold opening process and the product removal process are performed in the same manner as in the expanded foam molding method, so that the fixed mold 12 and the intermediate mold 16 can be moved. Injection compression molded products 55 and 55 respectively molded between the mold 14 and the intermediate mold 16 are taken out by a product take-out device (not shown). In this way, thereafter, by repeating the molding cycle from the state of FIG. 10 (a) to the state of FIG. 10 (e), the injection compression molded products 55, 55 are simultaneously and continuously molded.

  In these mold opening process and product taking-out process, since the precision of mold opening is not required, it is not necessary to press the pinion 22 by the pinion moving mechanism 30 (mold opening correction pressing process). Similar to the press molding method, it is preferable to press the pinion 22 by the pinion moving mechanism 30.

  As described above, according to the injection compression molding method according to the present embodiment, the pinion 22 is pressed against the teeth of the racks 24 and 26, that is, the movable molds of the pinion 22 and the teeth 25 and 27 of the racks 24 and 26. The state in which the backlash generated between the surfaces A and B on the 14 side is zero (mold closing correction pressing step), or the surface C on the fixed mold 12 side of the teeth 25 and 27 of the pinion 22 and the racks 24 and 26, In the state in which the backlash generated between D and D is zero (mold opening correction pressing process), the injection mold process is performed, and the movable mold 14 and the intermediate mold 16 are moved by the molten resin pressure injected and filled in the mold cavity. In a state in which the backlash generated between the pinion 22 and the surfaces A and B on the movable mold 14 side of the teeth 25 and 27 of the racks 24 and 26 is zero (die closing correction pressing process). Since the injection compression process (the mold closing / clamping operation from the minute mold open state) is performed, the influence of the backlash is completely eliminated, and the first mold cavity C1 ″ and the injection mold process are continued and completed. The minute mold opening amount and mold closing amount of the second mold cavity C2 ″ can be made uniform, and even when there is a disturbance factor such as molten resin pressure, the state in which the backlash is zero can be maintained. Therefore, it is possible to stabilize the position of the minute mold opening position, the mold opening speed in the minute mold opening process, and the mold clamping speed in the injection compression process, and obtain a high-quality injection compression molded product.

  In the injection compression molding method according to the present embodiment, both the first mold cavity C1 ″ and the second mold cavity C2 ″ are simultaneously subjected to the same type of single molding process by the injection compression process method under the same molding conditions. It is assumed that the injection compression molded products 55 and 55 of the layer are molded, but the present invention is not limited to this. However, different types of injection compression molded products may be molded from different molten resins.

  In addition, the injection compression molding method according to the present embodiment is a mode in which a single-layer injection compression molding product is molded simultaneously by the injection compression molding method in both the first and second mold cavities C1 ″ and C2 ″ (injection). The embodiment of compression molding-injection compression molding) is not limited to this, but in the same manner as the expansion foam molding method, it is an aspect of injection compression molding-non-injection compression molding, or an aspect of injection compression molding-no molding. Also good.

  Furthermore, in the injection compression molding method according to the present embodiment, the molten resin is injected and filled into the first mold cavity C1 ″ by the first injection unit 7 provided on the back side of the fixed mold 12, and the movable mold is used. 14, the second mold unit C 8 ″ provided on the side surface of the mold 14 is injected and filled with the molten resin into the second mold cavity C 2 ″. However, the present invention is not limited to this. The second injection unit 8 on the 14 side is not provided, and the molten resin injected only from the first injection unit 7 is made to flow to the intermediate mold 16, and the first mold cavity C 1 ″ and the second mold are supplied from the intermediate mold 16 side. A configuration may be adopted in which molten resin flows into the mold cavities C2 ″. In this case, the resin flow path may be provided with a resin shut-off switching valve or the like that can open and close the resin flow path.

  As described above, the three-piece injection mold, the injection molding apparatus, and the injection molding method according to this embodiment are configured so that the pinion 22 is moved in the direction opposite to the mold opening / closing operation by the pinion moving mechanism 30, that is, the movable platen (mold When the mold is opened by the clamping device, the pinion 22 is pressed to the fixed mold 12 side (mold opening correction pressing process) with a predetermined pressure 2, and when the mold is closed, the pinion 22 is moved to the movable mold 14 side (mold closing). At the time of mold opening by the molten resin pressure to be injected and filled into the mold cavity, such as an injection compression molding method or the like, as required by the difference in the molten resin pressure to be injected and filled. By switching the pressing direction of the pinion 22 by the pinion moving mechanism 30 and performing an appropriate mold opening / closing correction pressing step, the mold opening / closing operation of the movable mold 14 and the injection into the mold cavity are performed. Since the influence of the backlash α, β in the rack and pinion mechanism 20 that performs the mold opening / closing operation of the intermediate mold 16 by the molten resin pressure to be filled can be completely eliminated, high-quality foam molded products, injection press molded products In addition, an injection compression molded product can be obtained.

  DESCRIPTION OF SYMBOLS 1 Injection molding apparatus, 3 Fixed board, 4 Movable board, 6 Clamping apparatus, 10 Three-piece structure injection molding mold, 12 Fixed mold, 14 Movable mold, 16 Intermediate mold, 20 Rack and pinion mechanism, 22 Pinion, 24, 26 rack, 25, 27 rack teeth, 30 pinion moving mechanism

Claims (11)

A fixed mold,
A movable mold facing the fixed mold and movable in the mold opening and closing direction;
An intermediate mold provided between the fixed mold and the movable mold so as to be movable in a mold opening and closing direction and capable of forming a mold cavity between the fixed mold and the movable mold; ,
A pinion provided on the intermediate mold, and a rack provided on each of the fixed mold and the movable mold, each having a tooth that can mesh with the pinion, are provided to move the movable mold in the mold opening / closing direction. Correspondingly, a rack and pinion mechanism for moving the intermediate mold in the mold opening and closing direction,
A three-sheet injection mold comprising:
The rack and pinion mechanism further includes a pinion moving mechanism that supports the pinion so as to be movable in the mold opening / closing direction with respect to the intermediate mold, and is capable of pressing the pinion in the mold opening / closing direction ,
The pinion moving mechanism is configured to press the pinion against the fixed mold side, press the pinion against a surface of the rack teeth on the fixed mold side, and press the pinion against the movable mold side. The pinion is configured to be capable of selectively realizing both the state in which the pinion is pressed against the surface of the movable mold side of each rack tooth,
The rack and pinion mechanism corresponds to the movement of the movable mold in the mold opening direction in a state where the pinion is pressed against the surface of the rack teeth on the fixed mold side by the pinion moving mechanism. The mold can be moved in the mold opening direction , and the movable mold can be moved in the mold closing direction when the pinion is pressed against the surface of the rack teeth on the movable mold side by the pinion moving mechanism. The intermediate mold is configured to be movable in the mold closing direction . A three-sheet injection mold. The pinion moving mechanism includes a pinion holder that holds the pinion, a linear guide that supports the pinion holder so as to be movable in the mold opening / closing direction with respect to the intermediate mold, and presses the pinion holder in the mold opening / closing direction. The three-sheet injection mold according to claim 1, further comprising an actuator . An injection molding apparatus comprising the three-sheet injection mold according to claim 1 or 2,
A stationary platen to which the stationary mold can be attached;
A movable plate provided opposite to the fixed plate, movable in a mold opening / closing direction with respect to the fixed plate, and capable of attaching the movable mold;
A mold clamping device for moving the movable plate in the mold opening and closing direction and clamping the mold;
An injection molding apparatus comprising: A fixed part including a fixed mold,
A movable part including a movable mold facing the fixed mold, the movable part being movable in a mold opening / closing direction with respect to the fixed part;
An intermediate mold that can form a mold cavity between the fixed mold and the movable mold, respectively, is provided between the fixed part and the movable part so as to be movable in the mold opening and closing direction. The middle part,
A mold clamping device for moving the movable part in the mold opening and closing direction and clamping the mold;
A pinion provided in the intermediate portion, and a rack provided on each of the fixed portion and the movable portion and having teeth meshable with the pinion, and corresponding to the movement of the movable portion in the mold opening / closing direction A rack and pinion mechanism that moves the middle part in the mold opening and closing direction;
An injection molding apparatus comprising:
The rack and pinion mechanism further includes a pinion moving mechanism that supports the pinion so as to be movable in the mold opening / closing direction with respect to the intermediate portion, and is capable of pressing the pinion in the mold opening / closing direction ,
The pinion moving mechanism is configured to press the pinion toward the fixed part, press the pinion against a surface of the rack teeth against the fixed part, and press the pinion toward the movable part. Is configured to selectively realize both of the state of pressing the teeth of the rack against the surface of the movable part side,
The rack and pinion mechanism is configured to mold the intermediate portion corresponding to the movement of the movable portion in the mold opening direction in a state where the pinion is pressed against the surface of the rack teeth on the fixed portion side by the pinion moving mechanism. The intermediate portion can be moved in the opening direction , and the intermediate portion corresponds to the movement in the mold closing direction of the movable portion in a state where the pinion is pressed against the surface of the rack teeth on the movable portion side by the pinion moving mechanism. An injection molding apparatus characterized by being configured to be movable in the mold closing direction . The fixed portion includes the fixed mold and a fixed plate to which the fixed mold can be attached,
The movable portion includes the movable mold and a movable plate to which the movable mold can be attached,
The injection molding apparatus according to claim 4, wherein the rack is provided on each of the fixed platen and the movable platen.   The pinion moving mechanism includes a pinion holder that holds the pinion, a linear guide that supports the pinion holder so that the pinion holder can move in the mold opening / closing direction, and an actuator that presses the pinion holder in the mold opening / closing direction. With
  An injection molding apparatus according to claim 4 or 5, wherein An injection molding method for performing expanded foam molding using the injection molding apparatus according to any one of claims 3 to 6 ,
Clamping the fixed mold and the intermediate mold to form a first mold cavity and clamping the movable mold and the intermediate mold to form a second mold cavity Process,
A foamable resin injection filling step of injecting and filling foamable molten resin into at least one of the first mold cavity and the second mold cavity after the mold clamping step;
After the foaming resin injection filling step, a mold clamping release step for releasing the mold clamping state,
In parallel with or after the mold-clamping release process, a mold opening correction pressing process for pressing the pinion toward the fixed mold by the pinion moving mechanism,
In a state where the pinion is pressed toward the fixed mold by the mold opening correction pressing step, the movable mold and the intermediate mold are slightly opened in a mold opening / closing direction by a predetermined amount with respect to the fixed mold, An injection molding method comprising: a foaming mold opening step of foaming and expanding the foamable molten resin injected and filled in the foamable resin injection and filling step in the mold cavity. The foamable resin injection filling process, after the mold clamping step, claim 7, characterized in that both of said first mold cavity and said second mold cavity is a step of injecting and filling a foaming molten resin The injection molding method described. An injection molding method for performing injection press molding using the injection molding apparatus according to any one of claims 3 to 6 ,
A mold closing correction pressing step of pressing the pinion toward the movable mold by the pinion moving mechanism;
In a state where the pinion is pressed to the movable mold side by the mold closing correction pressing step, a small amount is formed between the fixed mold and the intermediate mold and between the movable mold and the intermediate mold by a predetermined amount. The fixed mold, the movable mold, and the intermediate mold are closed to the opened position, and a first mold cavity is formed between the fixed mold and the intermediate mold, and the movable mold is formed. A mold closing step of forming a second mold cavity between the mold and the intermediate mold;
An injection filling step of injecting and filling molten resin into at least one of the first mold cavity and the second mold cavity after the mold closing step;
In conjunction with the injection filling process or after the injection filling process, the fixed mold, the movable mold and the intermediate mold are clamped with a predetermined clamping force, and the inside of the first mold cavity and the An injection press step of applying the mold clamping press force to at least one of the molten resins in the second mold cavity. An injection molding method for performing injection compression molding using the injection molding apparatus according to any one of claims 3 to 6 ,
The fixed mold, the movable mold and the intermediate mold are closed, and a first mold cavity is formed between the fixed mold and the intermediate mold, and the movable mold and the intermediate mold are formed. A mold closing step of forming a second mold cavity between
In parallel with or after the mold closing process, a mold closing correction pressing process for pressing the pinion toward the movable mold by the pinion moving mechanism and a mold opening correction pressing process for pressing the pinion toward the fixed mold. Any one of the correction pressing step,
An injection filling step of injecting and filling molten resin into at least one of the first mold cavity and the second mold cavity during one of the mold closing correction pressing step and the mold opening correction pressing step;
A micro mold opening step of micro opening the movable mold and the intermediate mold by a predetermined amount in a mold opening / closing direction with respect to the fixed mold by a molten resin pressure injected and filled in the mold cavity;
After the micro mold opening step, the fixed mold, the movable mold, and the intermediate mold are clamped with a predetermined mold clamping compression force, and at least in the first mold cavity and the second mold cavity. An injection compression step of applying the mold clamping compression force to one of the molten resins. The injection filling process, after the mold closing step, according to claim 9 or 10, characterized in that the step of injecting the molten resin into both the first mold cavity and said second mold cavity Injection molding method.

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