Molding machine and molding method

Abstract

To improve the accuracy of mold clamping in a molding machine that performs molding by a molten resin using a rotating intermediate mold.SOLUTION: The molding machine includes: a mold including a first mold, a second mold opposite the first mold, and an intermediate mold arranged between the first mold and the second mold; a support member for supporting the intermediate mold; and an injection mechanism for injecting a molten resin, wherein the support member has a rotation mechanism, and the intermediate mold is mounted on the rotation mechanism so as to rotate on the same axis as a rotation axis of the rotation mechanism.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a molding apparatus and a molding method.

Background Art

[0002] Conventionally, for joining molded products provided by a molding method typified by injection molding, ultrasonic welding, vibration welding, hot plate welding, and laser welding, which melt and join the welded parts arranged on the molded products, have been used. In these methods, the molded products to be welded are relatively positioned, energy is applied to the welded part while being sufficiently pressed together to melt it, and then, while being pressed together, it is sufficiently cooled to perform normal welding. At this time, if the welded part where stress concentrates is not sufficiently pressed from both sides, it will be locally deformed and cannot be properly welded. Also, if the relative positions of the molded products are displaced or temperature variations occur during the process, there is a possibility that appropriate joining strength cannot be obtained.

[0003] In recent years, in order to improve the reliability and strength of joining and suppress equipment costs, a method using molten resin for joining molded products has been adopted. Specifically, first, a plurality of single parts are molded by an injection molding machine. Then, once the mold is opened, the mold is moved so that the single parts face each other. In that state, the mold is closed again, and by combining the molded single parts, a space for joining is formed. Further, molten resin is poured into the above space to perform joining. By adopting this method, the joining process can be completed within a single injection molding machine. Also, by arranging the formed molded products on the mold and moving the mold to make them face each other, an improvement in positional accuracy such as the relative position and parallelism between the parts can be expected. Furthermore, the clamping force of the injection molding machine can be utilized for pressing the parts together.

[0004] However, in the above method, the process of forming the molded product and the process of flowing the molten resin cannot be performed simultaneously. Therefore, in Patent Document 1 (European Patent No. 2,542,400), a configuration in which a rotatable intermediate mold is provided has been proposed. In this case, first, the molded product is formed between one mold and the first surface of the intermediate mold, and the molded product is left on the intermediate mold. Then, by rotating the intermediate mold by 180°, the molded product is moved between the other mold and the second surface of the intermediate mold, and molding using the molten resin is performed at that position. As a result, since each process can be advanced simultaneously and in parallel on both surfaces, productivity is further improved. Also, by moving the intermediate mold every 90°, it is conceivable to perform various processes on the operating side or the opposite side of the operating side of the molding machine. Examples of various processes include assembling parts on the mold using a supply device, inserting separate parts, and discharging articles.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Patent Document 1 discloses an injection molding apparatus in which an intermediate mold is disposed parallel to each other between a first mold and a second mold, and the intermediate mold is attached to a rotating unit that is rotatably held by a support member. The rotating unit rotates the mold in contact with the gear of the rotating unit by, for example, a motor and a gear.

[0007] Here, basically, high mold clamping accuracy is required for the mold. However, when the rotating unit is driven by a gear as in Patent Document 1, a deviation in the stop position of the intermediate mold occurs due to the play of the gear, which becomes a problem. On the other hand, mold clamping can be performed while correcting the deviation with a tapered guide pin or the like. In this case, however, stress is applied to the mold every time mold clamping is performed, so it is conceivable that the durability will decrease. ​

[0008] The present invention has been made in view of the above problems. The object of the present invention is to improve the accuracy of mold clamping in a molding apparatus that performs molding with a molten resin using a rotating intermediate mold.

Means for Solving the Problems

[0009] The present invention employs the following configuration. That is, a mold including a first mold, a second mold facing the first mold, and an intermediate mold disposed between the first mold and the second mold; a support member that supports the intermediate mold; an injection mechanism that injects molten resin; a molding apparatus comprising: the support member has a rotation mechanism, and the intermediate mold is attached to the rotation mechanism so as to rotate on the same axis as the rotation axis of the rotation mechanism characterized in that it is a molding apparatus.

Effects of the Invention

[0010] According to the present invention, in a molding apparatus that performs molding with a molten resin using a rotating intermediate mold, the accuracy of mold clamping can be improved.

Brief Description of the Drawings

[0011]

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Mode for Carrying Out the Invention

[0012] Hereinafter, with reference to the drawings, preferred embodiments of the present invention will be illustratively described in detail. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment are not intended to limit the scope of the present invention only to these, unless otherwise specified. Also, the materials, shapes, etc. of the members once described in the following description are the same as the initial description in the subsequent description unless otherwise described again. In particular, well-known techniques or publicly known techniques in the relevant technical field can be applied to configurations and processes not specifically illustrated or described. Also, duplicate explanations may be omitted.

[0013] [Embodiment] FIG. 1 is a schematic view of a three-plate mold 101 including a first mold 5, a second mold 6, and an intermediate mold 7. The first mold 5 is attached to the first plate 3 of the molding apparatus 100. The second mold 6 is attached to the second plate 4 of the molding apparatus 100. The intermediate mold 7 is a rotatable member disposed between the first mold 5 and the second mold 6. For example, the intermediate mold 7 rotates about an axis A1 orthogonal to the mold opening and closing direction, performs primary molding of a primary molded product between the first mold 5 and the intermediate mold 7, and performs secondary molding of joining the primary molded products with a resin for joining between the second mold 6 and the intermediate mold 7. is conceivable.

[0014] In this embodiment, as shown in the cross-sectional view of FIG. 2, the intermediate mold 7 is directly attached in a rotatable state without passing through a movable intermediate member and a driving part of the support member 8 (rotated by electric control such as a direct drive motor 10). The intermediate mold 7 is preferably attached so as to rotate on the same axis as the rotation axis of the rotation mechanism of the support member 8. When attaching the intermediate mold 7 to the support member 8 on the molding apparatus 100, a fixing member such as a magnet clamp 11 can be used. This facilitates loading and unloading of the mold 101 without affecting the accuracy during rotation. Also, by using a direct drive motor 10 having a hollow structure, parts can be attached to the mold through the inside of the motor.

[0015] In this embodiment, as shown in the perspective plan view of FIG. 3, by attaching a rotary joint 12 for supplying and discharging fluid from the fixed pipe to the rotating part, water for mold temperature control can be circulated around the intermediate mold 7 in a compact configuration. Also, when discharging the molded product molded by the mold 101, an ejector rod 13 for moving the ejector plate inside the mold can be passed through the hollow part of the direct drive motor 10.

[0016] The perspective schematic view of FIG. 4 shows the configuration for linear movement in the molding apparatus 100. The first LM guide 9 (linear motion guide) to which the support member 8 is attached is a member movable in a linear direction along parallel guide rails 15. Also, the second LM guide 14 to which the second plate 4 is attached is also movable along the same guide rails 15. With this configuration, the second plate 4 and the intermediate mold 7 can move parallel to each other on the same track. Here, by separating the intermediate mold 7 and the tie bar 16 of the molding apparatus 100 independently, the track reproducibility during mold opening and closing can be improved.

[0017] Since the support member 8 supports the moment of the intermediate mold 7 applied during the opening and closing of the mold 101 at a single point, high rigidity is required. The assumed loads on the fixed part include moment loads generated by the rotation of the motor, torsional moments during startup and shutdown, moments generated by the opening and closing of the mold 101, and stress concentration. Therefore, it is necessary to select a direct drive motor 10 that satisfies torque and rigidity while considering the safety factor in view of the acceleration of the opening and closing of the molding apparatus 100 and the weight of the intermediate mold 7. In addition, overall optimization is required including the rotation of the mold and the cycle time of opening and closing. In order to disperse the stress, a configuration in which the intermediate mold 7 is held from above by a peripheral device different from the support member is also conceivable. Note that the holding device from above may be considered as a component of the molding apparatus. However, when using a peripheral holding device, a larger space is required and the investment also increases, so a configuration in which it is supported cantilevered from below is recommended.

[0018] Figs. 5(a) to 5(d) show the mounting procedure of the mold 101. The figures are side views such that the opening and closing direction of the mold along the guide rail is the left - right direction on the paper surface. In this figure, the direction perpendicular to the opening and closing direction of the mold is the rotation axis of the rotation mechanism and the intermediate mold 7.

[0019] When attaching the intermediate mold 7 to the support member 8, first, as shown in Fig. 5(a), with the first mold 5, the second mold 6, and the intermediate mold 7 in the closed state, the mold 101 is placed on the support member 8 by the magnet clamp 11 (arrow D1). Thereby, based on the position of the intermediate mold 7, the positions of the first mold 5 and the second mold 6 are determined, so that the relative positions at the time of mold closing can be aligned. Then, as shown in Fig. 5(b), the support member 8 and the intermediate mold 7 attached to the first LM guide 9 and the second plate 4 attached to the second LM guide 14 are moved in conjunction along the guide rail 15 (arrow D2).

[0020] As a result, as shown in Fig. 5(c), the first mold 5 is on the first plate 3, and the second mold 6 is on the second They each come into contact with the disk 4. Then, the first injection unit 1 injects molten resin to perform molding between the first mold 5 and the intermediate mold 7 (first molding). Subsequently, when the mold is opened, the support member 8 attached to the LM guide 9 of the first and the intermediate mold 7, and the second disk 4 attached to the second LM guide 14 are moved along the guide rail 15 in the direction opposite to mold closing (arrow D3).

[0021] As a result, the mold is opened as shown in FIG. 5(d). Subsequently, the intermediate mold 7 is rotated by driving the direct drive motor 10 (rotation operation), and the process moves to molding between the second mold 6 and the intermediate mold 7. Also at this time, similar to the above, by moving each member along the guide rail 15, mold closing can be performed while maintaining parallelism. Then, the second injection unit 2 injects molten resin to perform molding between the second mold 6 and the intermediate mold 7 (second molding). After that, by opening the mold, the final molded product can be taken out.

[0022] Note that the first injection unit 1 and the second injection unit 2 as injection mechanisms only need to have the function of injecting molten resin between the molds. Also, the injection mechanism does not necessarily have to be divided into two injection units, and it may be one injection unit or three or more injection units. The series of processes following the above mold placement, first molding, rotation operation, second molding, etc. may be executed under the control of a control unit (for example, a processor) provided in the molding apparatus 100 or outside the molding apparatus 100.

[0023] (Effect) As described above, conventionally, in a molding apparatus using a three-plate mold having an intermediate mold type in addition to the first type and the second type, the rotating unit to which the intermediate mold is attached was configured to rotate by driving a gear with a motor. In this case, due to play in the gear, the stop position of the intermediate mold was likely to shift, and there was a limit to improving the positioning accuracy of the intermediate mold. Also, in a configuration in which the intermediate mold is supported through a tie bar, if there is variation in the stop position of the intermediate mold, a load is applied to the tie bar, causing deflection and reducing the accuracy of mold clamping, or in some cases, preventing proper opening and closing.

[0024] Therefore, in the present invention, when manufacturing an article using a mold in which an intermediate mold 7 exists between opposing first mold 5 and second mold 6, the intermediate mold 7 is configured to be attached to a rotating device of a support member 8. That is, a configuration is adopted in which the support member 8 provided with a direct drive motor and the intermediate mold 7 are directly attached. Preferably, the intermediate mold 7 is configured to rotate on the same axis as the rotation axis of the rotating device provided on the support member 8. By doing so, there is no need to interpose components such as gears that lead to a decrease in positioning accuracy in the mechanism related to the rotation of the intermediate mold 7, so the stop position of the intermediate mold 7 is stabilized. As a result, the accuracy in mold clamping can be improved. Furthermore, since the mold clamping accuracy is improved, the load on the mold and the molding machine is reduced, improving durability. In addition, since there is no need to configure an actuator required for gear drive etc. separately from the rotating part, an effect of making the support member compact can also be obtained.

[0025] Also, the support member is attached on the same rail as the guide rail to which the first mold and the second mold are attached, and the intermediate mold is used as a positioning reference. Also, the first mold and the second mold are positioned with reference to the intermediate mold. Thereby, parallelism of the opposing surfaces can be maintained during mold clamping, enabling even higher-precision mold clamping.

[0026] (Application Example) Referring to FIGS. 6 to 9, the case of manufacturing a liquid storage container of an inkjet printer using an injection molding apparatus to which the molding apparatus 100 of the present case is applied will be described. FIG. 6 is a cross-sectional view showing an outline of an inkjet printer 17. The inkjet printer 17 includes an inkjet print head 18 that can discharge a liquid L such as ink stored in a liquid storage container 19. In accordance with an instruction from a control unit such as a computer, the inkjet print head 18 discharges the liquid L onto a recording medium such as paper, thereby recording an image. The inkjet printer 17 is also called a liquid discharge device or a recording device, and the inkjet print head 18 is also called a liquid discharge head or a recording head.

[0027] The inkjet printer 17 has a structure in which a liquid storage container 19 holding a liquid and an inkjet print head 18 communicate with each other via a tube 20 and a hollow needle 21. The molding apparatus 100 of the present invention is useful, for example, when forming a connection portion of the liquid storage container 19.

[0028] FIG. 7(a) is a perspective view of the liquid storage container 19, and FIG. 7(b) is an exploded view of the liquid storage container 19. FIG. 7(c) is a cross-sectional view showing the connection portion F. As shown in FIGS. 7(a) to 7(c), in the connection portion, a first molded product 22, a second molded product 23, and a third molded product 24 are arranged such that a space portion 26 is formed. Further, an elastic member 25 having a cut 28 for inserting the hollow needle 21 is arranged in the combined molded product. With such a configuration, the connection portion F provides the function of a valve for holding and supplying a liquid.

[0029] FIG. 8 is a schematic view showing the process of forming the connection portion F. First, the first molded product 22, the second molded product 23, and the third molded product 24 are formed by injection molding. Next, the elastic member 25 is arranged on the first molded product 22, and finally, the second molded product 23 and the third molded product 24 are assembled thereon and joined.

[0030] FIG. 9 is a cross-sectional view showing the joining process when forming the connecting portion F. After combining the first molded product 22 to the third molded product 24 as shown in FIG. 9(a), it is possible to form an integrally molded product by pouring molten resin into the space portion. For example, in FIG. 9(b), molten resin 27 is being poured into the space between the concave portion of the second molded product 23 and the protruding portion of the third molded product 24. Thereby, a connecting portion F as shown in FIG. 9(c) is formed. At this time, the cut 28 previously provided in the elastic member 25 expands as shown in the figure due to pressure, facilitating the insertion of the hollow needle 21.

[0031] In the injection molding apparatus using this case, as the first step, each molded product is molded with the first mold 5 and the intermediate mold 7. Then, in the second step, the elastic member 25 is supplied to the first molded product 22, and after ejecting the second molded product 23 and the third molded product 24, they are assembled on the elastic member 25.

[0032] After that, in the third step, a joining process is performed on the assembly of each molded product and the elastic member combined in the second step. At this time, using the second mold 6 and the intermediate mold 7, a space portion is formed between the molded products, and molten resin 27 is poured into the space portion. At this time, by appropriately pressing the molded products against each other while compressing the elastic member 25 using the clamping force, it is possible to stably perform the pouring and holding of the molten resin 27 until cooling. In this case, since positioning is performed based on the intermediate mold 7, it is possible to prevent displacement between the molded products during pressing. Finally, in the fourth step, the integrally molded product is ejected to take out the finished product.

[0033] [Configuration 1] A mold including a first mold, a second mold facing the first mold, and an intermediate mold disposed between the first mold and the second mold, A support member for supporting the intermediate mold, An injection mechanism for injecting molten resin, A molding apparatus comprising: The support member has a rotation mechanism, and the intermediate mold is attached to the rotation mechanism so as to rotate on the same axis as the rotation axis of the rotation mechanism A molding apparatus characterized by the following. [Configuration 2] A first molding in which the molten resin is injected between the first mold and the intermediate mold, and after the first molding, the intermediate mold is rotated by the rotation mechanism, and then a second molding in which the molten resin is injected between the second mold and the intermediate mold is performed. The molding apparatus according to Configuration 1, characterized by the above. [Configuration 3] The molding apparatus further includes a guide rail to which the first mold and the second mold are attachably and detachably attached. In the guide rail, between the first mold and the second mold, the support member to which the intermediate mold is attached is attached. When the first mold and the second mold are opened, the intermediate mold is rotatable by the rotation mechanism. The molding apparatus according to Configuration 1 or 2, characterized by the above. [Configuration 4] The intermediate mold rotates about an axis orthogonal to the opening and closing direction of the first mold and the second mold. The molding apparatus according to any one of Configurations 1 to 3, characterized by the above. [Configuration 5] The intermediate mold is movable in the opening and closing direction in conjunction with the first mold and the second mold. The molding apparatus according to Configuration 4, characterized by the above. [Configuration 6] The intermediate mold is supported from below by the support member. The molding apparatus according to any one of Configurations 1 to 5, characterized by the above. [Configuration 7] The intermediate mold is supported from above by a holding mechanism different from the support member. The molding apparatus according to any one of Configurations 1 to 6, characterized by the above. [Configuration 8] The rotation mechanism provided on the support member has a hollow portion, and components can be attached to the intermediate mold through the hollow portion. The molding apparatus according to any one of Configurations 1 to 7, characterized by the above. [Method 1] A molding method using the molding apparatus according to any one of Items 1 to 8, a step of injecting the molten resin between the first mold and the intermediate mold to obtain a first molded product; a step of injecting the molten resin between the second mold and the intermediate mold to obtain a second molded product; a step of assembling the first molded product and the second molded product and joining them with the molten resin; characterized by comprising the above steps. [Method 2] Molding a liquid storage container of an inkjet printer with the molten resin The molding method according to Method 9, characterized by the above step.

Explanation of Reference Numerals

[0034] 1: Injection unit 1, 2: Injection unit 2, 5: First mold, 6: Second mold, 7: Intermediate mold, 8: Support member, 10: Direct drive motor, 27: Molten resin

Claims

1. A mold including a first mold, a second mold facing the first mold, and an intermediate mold disposed between the first mold and the second mold; A support member for supporting the intermediate mold; An injection mechanism for injecting molten resin; A molding apparatus comprising: The support member has a rotation mechanism, and the intermediate mold is attached to the rotation mechanism so as to rotate on the same axis as the rotation axis of the rotation mechanism. A molding apparatus characterized by the above.

2. A first molding in which the molten resin is injected between the first mold and the intermediate mold, and after the first molding, after the intermediate mold is rotated by the rotation mechanism, a second molding in which the molten resin is injected between the second mold and the intermediate mold is performed. The molding apparatus according to claim 1, characterized by the above.

3. Further comprising a guide rail to which the first mold and the second mold are attachably and detachably attached, In the guide rail, between the first mold and the second mold, the support member to which the intermediate mold is attached is attached, When the first mold and the second mold are opened, the intermediate mold is rotatable by the rotation mechanism. The molding apparatus according to claim 1 or 2, characterized by the above.

4. The intermediate mold rotates about an axis orthogonal to the opening and closing direction of the first mold and the second mold. The molding apparatus according to claim 1 or 2, characterized by the above.

5. The intermediate mold is movable in the opening and closing direction in conjunction with the first mold and the second mold. The molding apparatus according to claim 4, characterized by the above.

6. The intermediate mold is supported from below by the support member. The molding apparatus according to claim 1 or 2, characterized by the above.

7. The intermediate mold is supported from above by a holding mechanism different from the support member. The molding apparatus according to claim 1 or 2, characterized by the above.

8. The rotation mechanism provided on the support member has a hollow portion, and components can be attached to the intermediate mold through the hollow portion. The molding apparatus according to claim 1 or 2, characterized by the above.

9. A molding method using the molding apparatus according to claim 1 or 2, A step of injecting the molten resin between the first mold and the intermediate mold to obtain a first molded product; A step of injecting the molten resin between the second mold and the intermediate mold to obtain a second molded product; A step of assembling the first molded product and the second molded product and joining them with the molten resin; A molding method characterized by having [

10. ] The molding method according to claim 9, characterized in that the liquid storage container of an inkjet printer is molded with the molten resin ​

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