Injection molding machine, injection molding system, and method of manufacturing injection molded article

Abstract

To solve the problem in which a conventional injection molding machine is unable to satisfactorily enhance production efficiency.SOLUTION: An injection molding machine according to one embodiment comprises: a first mold platen 10 having a first mold fitting surface 13 and a second mold fitting surface 14; a second mold platen 11 provided with a third mold fitting surface 15; a third mold platen 12 provided with a fourth mold fitting surface 16; a first mold rotation mechanism provided on one surface of the first mold fitting surface 13 and the third mold fitting surface 15 so as to rotate a corresponding mold fitting surface; a second mold rotation mechanism provided on one surface of the second mold fitting surface 14 and the fourth mold fitting surface 16 so as to rotate a corresponding mold fitting surface; a first injection device in which an injection nozzle is brought into contact with a mold fit to the other surface of the first mold fitting surface 13 and the third mold fitting surface 15; and a second injection device in which an injection nozzle is brought into contact with a mold fit to the other surface of the second mold fitting surface 14 and the fourth mold fitting surface 16.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to, for example, an injection molding machine, an injection molding system, and a method for manufacturing an injection molded product. [Background technology]

[0002] Injection molding machines are increasingly required to have the ability to mold a single molded product using multiple resins. For example, there is a demand for a function to perform multi-color molding, in which a single molded product is provided with multiple colored parts using multiple resins of different colors. Patent Document 1 discloses a technology related to an injection molding machine capable of multi-color molding.

[0003] The mold rotation type injection molding machine described in Patent Document 1 is a mold rotation type injection molding machine in which a movable platen is opened and closed horizontally relative to a fixed platen, and a rotary table equipped with a mold is rotatably arranged relative to either the fixed platen or the movable platen, and is characterized in that two or more injection units are arranged only to the sides of the mold clamping unit, and no injection unit is arranged on the side of the fixed platen opposite the mold mounting surface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-30269 A Summary of the Invention [Problem to be solved by the invention]

[0005] In an injection molding machine, the clamping force for clamping the mold is determined approximately proportional to the product of the area of ​​the cavity surface provided between the fixed platen and the movable platen, the number of cavities, and the injection pressure of the molding material injected into the cavities. In other words, as the area of ​​the cavity surface or the number of cavities increases, a larger clamping force is required. For this reason, in the mold rotation type injection molding machine described in Patent Document 1, the area of ​​the cavity surface, the number of cavities, and the injection pressure of the resin injected into the cavities are limited by the upper limit of the clamping force. Such a limitation is problematic because it limits production capacity.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to improve the production efficiency of an injection molding machine or an injection molding system. Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0007] An injection molding machine according to one embodiment includes a first platen having a first mold mounting surface and a second mold mounting surface provided on a rear side of the first mold mounting surface, a second platen having a third mold mounting surface facing the first mold mounting surface, a third platen having a fourth mold mounting surface facing the second mold mounting surface, a mold clamping mechanism that sets one of the first mold platen, the second mold platen, and the third mold platen as a fixed platen and presses two mold platens set as movable platens against the fixed platen while applying pressure in a mold clamping direction, and the first mold rotation mechanism is provided on one of the faces of the first mold mounting surface and the fourth mold mounting surface and rotates the mold mounting surface around an axis in the mold clamping direction; a second mold rotation mechanism is provided on one of the faces of the second mold mounting surface and the fourth mold mounting surface and rotates the mold mounting surface around an axis in the mold clamping direction; a first injection unit whose injection nozzle is abutted against a mold mounted on the other face of the first mold mounting surface and the third mold mounting surface; and a second injection unit whose injection nozzle is abutted against a mold mounted on the other face of the second mold mounting surface and the fourth mold mounting surface.

[0008] An injection molding system according to one embodiment includes a first platen having a first mold mounting surface and a second mold mounting surface provided on a rear side of the first mold mounting surface, a second platen provided with a third mold mounting surface facing the first mold mounting surface, a third platen provided with a fourth mold mounting surface facing the second mold mounting surface, a mold clamping and closing mechanism that presses two mold platens set on a movable platen against the fixed platen while applying pressure in a mold clamping direction, a first mold rotation mechanism that is provided on one of the first mold mounting surface and the third mold mounting surface and rotates the mold mounting surface around an axis in the mold clamping direction, and a second mold rotation mechanism that is provided on one of the second mold mounting surface and the fourth mold mounting surface and rotates the mold mounting surface around an axis in the mold clamping direction. the first injection unit having an injection nozzle abutting against a mold mounted on the other of the first mold mounting surface and the third mold mounting surface; a second injection unit having an injection nozzle abutting against a mold mounted on the other of the second mold mounting surface and the fourth mold mounting surface; and a mold exchange cart that individually replaces each of a first mold set consisting of a mold mounted on the first mold mounting surface and a mold mounted on the third mold mounting surface and a second mold set consisting of a mold mounted on the second mold mounting surface and a mold mounted on the fourth mold mounting surface, with another mold set, and the mold exchange cart moves the mold set horizontally from the side of the first mold platen to the third mold platen to replace the mold set.

[0009] A manufacturing method of an injection molded product according to one embodiment includes a first platen having a first mold mounting surface and a second mold mounting surface provided on a back side of the first mold mounting surface, a second platen having a third mold mounting surface facing the first mold mounting surface, a third platen having a fourth mold mounting surface facing the second mold mounting surface, and a mold clamping mechanism which presses two mold platens set on a movable platen against the fixed platen while applying pressure in a mold clamping closing direction, and a first mold set including a mold pair that forms a plurality of first cavities is attached to the first mold mounting surface and the third mold mounting surface, and a second mold set including a mold pair that forms a plurality of second cavities is attached to the second mold mounting surface and the fourth mold mounting surface, wherein one of the second mold mounting surface and the fourth mold mounting surface is rotatably attached to the mold platen to which the first mold set and the second mold set are attached, a first mold clamping step of clamping a mold set; a first injection step of injecting a molding material into a first primary molding cavity corresponding to a first primary molded product among the plurality of first cavities formed by the first mold set in the mold clamping state and a second primary molding cavity corresponding to a second primary molded product among the plurality of second cavities formed by the second mold set in the mold clamping state; and a first mold opening step of opening the first mold set and the second mold set while the first primary molded product and the second primary molded product are held in the corresponding molds. a mold opening step, a mold rotation step of rotating a mold holding the first primary molded product and a mold holding the second primary molded product to move the first primary molded product and the second primary molded product to a position facing a mold in which cavities corresponding to the first secondary molded product and the second secondary molded product are formed, a second mold clamping step of clamping the first mold set and the second mold set after the mold rotation step, and a first secondary molding cavity corresponding to the first secondary molded product among the multiple first cavities formed by the first mold set in the mold clamping state;The method includes a second injection step of injecting a molding material into a second primary molding cavity corresponding to the second secondary molded product among the plurality of second cavities formed by the second mold set in the mold clamping state, a second mold opening step of opening the first mold set and the second mold set while the first secondary molded product and the second secondary molded product are held in the corresponding molds, and a removal step of removing the first secondary molded product and the second secondary molded product from the molds after the second mold opening step.

[0010] In one embodiment of the injection molding machine, injection molding system, and manufacturing method for injection molded products, there are at least two molding areas arranged consecutively in the horizontal direction, and it is possible to perform a clamping operation in one clamping process for the at least two molding areas. Effect of the Invention

[0011] According to the injection molding machine, the injection molding system, and the method for manufacturing an injection molded product according to one embodiment, it is possible to increase the production efficiency of molded products. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a configuration diagram for explaining an outline of an injection molding system according to a first embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a mold rotation mechanism of the injection molding machine according to the first embodiment. [Diagram 3] FIG. 2 is a configuration diagram of a first example of a lock mechanism of the injection molding machine according to the first embodiment. [Figure 4] FIG. 4 is a configuration diagram of a second example of the lock mechanism of the injection molding machine according to the first embodiment. [Diagram 5] 4 is a flowchart illustrating a flow of a mold changing process of the injection molding system according to the first embodiment. [Figure 6] 4 is a flowchart illustrating an operation during continuous molding operation of the injection molding machine according to the first embodiment. [Figure 7]11 is a flowchart illustrating a first operation example in a continuous molding operation of the injection molding machine according to the second embodiment. [Figure 8] 10 is a flowchart illustrating a first operation example of a continuous molding operation of injection molding according to the second embodiment. [Figure 9] FIG. 11 is a configuration diagram for explaining an outline of an injection molding system which is a first modified example of the injection molding system according to the third embodiment. [Figure 10] FIG. 11 is a configuration diagram for explaining an outline of an injection molding system which is a second modified example of the injection molding system according to the third embodiment. [Figure 11] FIG. 13 is a configuration diagram for explaining an outline of an injection molding system which is a third modified example of the injection molding system according to the third embodiment. [Figure 12] FIG. 13 is a configuration diagram for explaining an outline of an injection molding system which is a fourth modified example of the injection molding system according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In order to clarify the description, the following description and drawings are omitted and simplified as appropriate. In addition, each element shown in the drawings as a functional block performing various processes can be configured in hardware with a CPU (Central Processing Unit), memory, and other circuits, and in software, can be realized by a program loaded into memory. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by hardware alone, software alone, or a combination thereof, and are not limited to any one of them. In addition, the same elements are given the same symbols in each drawing, and duplicated explanations are omitted as necessary.

[0014] Moreover, the above-mentioned program includes a set of instructions (or software code) for making the computer perform one or more functions described in the embodiment when the program is read into the computer. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, the computer-readable medium or the tangible storage medium includes random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disc (DVD), Blu-ray (registered trademark) disk or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may be transmitted on a transitory computer-readable medium or a communication medium. By way of example and not limitation, the transitory computer-readable medium or the communication medium includes electrical, optical, acoustic, or other forms of propagating signals.

[0015] First embodiment 1 shows a configuration diagram for explaining an outline of an injection molding system 1 according to the embodiment 1. Note that the configuration diagram of the injection molding system shown in the following description is a top view of the injection molding system.

[0016] FIG. 1 shows an injection molding machine and a mold exchange mechanism (e.g., a mold exchange carriage 30) among a plurality of devices constituting the injection molding system 1 according to the first embodiment. In addition to the devices shown in FIG. 1, the injection molding system 1 is provided with a mold (mold set), a mold temperature control mechanism, a molded product removal mechanism, a mold temperature control mechanism, a molding material supply mechanism, and the like. The injection molding machine has a mold clamping device CLP and an injection device INJ. In the example shown in FIG. 1, a first mold platen 10, a second mold platen 11, and a third mold platen 12 are shown as the mold clamping device CLP, and main mechanisms used to operate these devices are shown. In the example shown in FIG. 1, injection devices 33a, 33b, 34a, and 34b are shown as the injection device INJ, but the number of injection devices can be arbitrarily set depending on the design of the injection molding system. In the example shown in FIG. 1, injection device carriages 31 and 32 for moving the injection device INJ are shown. In the following description, the mold clamping unit CLP, the injection unit carriages 31 and 32, and the mold exchange carriage 30 will be described in detail.

[0017] 1, an injection molding system 1 according to a first embodiment includes a first platen 10, a second platen 11, and a third platen 12. In the first embodiment, the first platen 10 is set as a fixed platen that is fixed to a bed on which a clamping device CLP is placed. Also, in the first embodiment, the second platen 11 and the third platen 12 are set as movable platens that are provided so as to be displaceable relative to the fixed platen and the bed.

[0018] The first platen 10 has a first mold mounting surface (e.g., mold mounting surface 13) and a second mold mounting surface (e.g., mold mounting surface 14) provided on the back side of the mold mounting surface 13. The second platen 11 is provided with a third mold mounting surface (e.g., mold mounting surface 15) opposite the mold mounting surface 13. The third platen 12 is provided with a fourth mold mounting surface (e.g., mold mounting surface 16) opposite the mold mounting surface 14.

[0019] The mold clamping device CLP of the injection molding machine of the injection molding system 1 according to the first embodiment has mold rotation mechanisms 23 and 24 that rotate the mold attached to the mold mounting surface. More specifically, the injection molding system 1 has a first mold rotation mechanism (e.g., mold rotation mechanism 23) that is provided on one of the mold mounting surfaces 13 and 15 and rotates the corresponding mold mounting surface around a horizontally extending rotation axis 23x, and a second mold rotation mechanism (e.g., mold rotation mechanism 24) that is provided on one of the mold mounting surfaces 14 and the fourth mold mounting surface 16 and rotates the corresponding mold mounting surface around a horizontally extending rotation axis 24x. That is, in this embodiment, the mold rotation mechanism 23 and the mold rotation mechanism 24 that rotate the mold mounting surface around the axis ax in the mold clamping direction are provided. 1, the mold rotation mechanism 23 rotates the molds M32, M31 attached to the mold mounting surface 15, and the mold rotation mechanism 24 rotates the molds M41, M42 attached to the mold mounting surface 16. The mold rotation mechanisms 23, 24 may be configured to transmit the rotational force of a motor via a gear, a belt, or a chain to rotate the mold mounting surface, but there is no limitation on the mechanism by which the mold mounting surface is rotated.

[0020] 1, the platens are arranged in the horizontal direction in the order of second platen 11, first platen 10, and third platen 12. A first molding area (hereinafter referred to as the A-side molding area) is set between the first platen 10 and the second platen 11, and a second molding area (hereinafter referred to as the B-side molding area) is set between the first platen 10 and the third platen 12. Separate mold sets are attached to the mold mounting surfaces that sandwich the A-side molding area and the mold mounting surfaces that sandwich the B-side molding area, respectively.

[0021] In the following description, the term "die set" is used as a name including multiple dies attached to one molding area. Although a cavity is formed by clamping a pair of dies, the term "die" used in the following description refers to one of the pair of dies that forms one cavity. Furthermore, the dies attached to one die mounting surface may be integrally formed corresponding to multiple cavities, or may be provided as separate dies, or multiple dies may be fixed to one die mounting plate. One die set is considered to include dies that constitute two or more cavities. The two or more cavities may be for producing the same molded product, or may be for producing different molded products. In the following description, an example will be described in which one die set constitutes two cavities, one cavity is used to mold a primary molded product, and the other cavity is used to mold a secondary molded product in which a different resin is added to the primary molded product.

[0022] In the example shown in Fig. 1, the first mold set is composed of molds M11 and M12 attached to the mold mounting surface 13, and molds M31 and M32 attached to the mold mounting surface 15. The second mold set is composed of molds M21 and M22 attached to the mold mounting surface 14, and molds M41 and M42 attached to the mold mounting surface 16. In Fig. 1, the molds M11 and M12 each have a main body and a mold mounting plate. The molds M21, M2, M31, M32, M41, and M42 also have a main body and a mold mounting plate, although they are not designated by reference numerals. However, in this embodiment, the cavity surfaces formed in the main bodies of the molds M11 and M12 in the A-side molding region are the same, and the cavity surfaces formed in the main bodies of the molds M31 and M32 are different. Similarly, the cavity surfaces formed in the main bodies of the dies M21 and M22 in the B-side molding region are the same, but the cavity surfaces formed in the main bodies of the dies M41 and M42 are different.

[0023] The mold clamping device CLP according to the first embodiment has a first mold opening and closing mechanism (e.g., mold opening and closing mechanism MMa) and a second mold opening and closing mechanism (e.g., mold opening and closing mechanism MMb). The mold opening and closing mechanism MMa is provided for the second mold platen 11 set on the movable platen. The mold opening and closing mechanism MMa moves the second mold platen 11 forward or backward in the horizontal direction relative to the first mold platen 10, thereby widening or narrowing the width of the A-side molding region. The mold opening and closing mechanism MMb is provided for the third mold platen 12 set on the movable platen. The mold opening and closing mechanism MMb moves the mold mounting surface 13 forward or backward in the horizontal direction relative to the first mold platen 10, thereby widening or narrowing the width of the B-side molding region.

[0024] The clamping device CLP according to the first embodiment also has a clamping mechanism. In FIG. 1, the tie bars 17, the first lock mechanism 18, the second lock mechanism 19, and the clamping force generating mechanism are shown as the clamping mechanism. The tie bars 17 are provided at positions near the four corners of the platen. Each tie bar 17 is provided so as to pass through the first platen 10 and the third platen 12 starting from the second platen 11. The clamping force generating mechanism is provided corresponding to each tie bar 17. The clamping force generating device is provided so as to be fixed to the second platen 11, and moves the corresponding tie bar 17 back and forth in the clamping direction. In the example shown in FIG. 1, a clamping cylinder 20 that operates hydraulically and has the tie bar 17 as a piston rod is shown as the clamping force generating mechanism. It is also possible to use a servo motor or the like as the clamping force generating device.

[0025] The first lock mechanism 18 is provided so as to be fixed to the back surface of the third platen 12 opposite to the fourth mold mounting surface 16. When the clamping cylinder 20 moves the tie bar 17 in a direction in which the third platen 12 approaches the second platen 11, and when the clamping cylinder 20 moves the tie bar 17 in a direction in which the third platen 12 moves away from the second platen 11, the first lock mechanism 18 determines the relative position of the third platen 12 to the tie bar in the clamping direction, and moves the tie bar 17 and the third platen 12 while holding the relative positions of the tie bar 17 and the third platen 12 fixed. Note that the first lock mechanism 18 is in an unlocked state so that the tie bar 17 can be freely displaced relative to the third platen 12 in cases other than the above two cases.

[0026] The second lock mechanism 19 is provided so as to be fixed to the back surface of the first platen 10 opposite to the first mold mounting surface 13. When the clamping cylinder 20 moves the tie bar 17 in a direction in which only the first platen 10 approaches the second platen 11, and when the clamping cylinder 20 moves the tie bar 17 in a direction in which the first platen 10 moves away from the second platen 11, the second lock mechanism 19 defines the relative position of the first platen 10 to the tie bar 17 in the clamping direction, and moves the tie bar 17 while keeping the relative positions of the tie bar 17 and the first platen 10 fixed. In addition, the second lock mechanism 19 is in an unlocked state so that the tie bar 17 can be freely displaced with respect to the first platen 10 in cases other than the above two cases.

[0027] In the injection molding system 1 according to the first embodiment, when a type in which the convex portion of the half nut of the lock mechanism 18 or the like is inserted into the concave portion of the tie bar 17 is used as shown in FIG. 4 described later, a gap occurs between the convex portion and the concave portion when the half nut is inserted, so that the position of the platen relative to the tie bar 17 is not determined when the half nut advances. For this reason, it is also preferable that at least one of the first lock mechanism 18 and the second lock mechanism 19 has a structure that fixes the corresponding platen to the tie bar 17 regardless of the position of the platen relative to the tie bar 17. By adopting such a structure, it is possible to improve the controllability when the first lock mechanism 18 and the second lock mechanism 19 are in a locked state in which the corresponding platen is fixed to the tie bar 17. The structure of the first lock mechanism 18 and the second lock mechanism 19 will be described in detail later.

[0028] In the example shown in FIG. 1, the ejector 21 is provided on the second platen 11, the mold mounting surface 15 of which is attached to the mold rotation mechanism 23 of the mold clamping unit CLP. The rod of the ejector 21 pushes out, for example, an injection molded product from the back surface of the mold on the counter-operation side through a through hole of the turntable 23a of the mold rotation mechanism 23. In addition, the ejector 22 is provided on the third platen 12, the mold mounting surface 16 of which is attached to the mold rotation mechanism 24. The rod of the ejector 22 pushes out, for example, an injection molded product from the back surface of the mold on the counter-operation side through a through hole of the turntable 23a of the mold rotation mechanism 23. Here, in an injection molding machine, a structure corresponding to one operation of the pair is sometimes called the operation side, and a structure corresponding to the other operation is sometimes called the counter-operation side. In the following description, an injection molding machine having two injection processes of molding material will be taken as an example, and the structure used in the process of molding a primary molded product by the first injection of molding material will be referred to as the operation side, and the structure used in the process of molding a secondary molded product by the second injection of molding material will be referred to as the anti-operation side. In Fig. 1, the lower side of the drawing is the operation side, and the upper side of the drawing is the anti-operation side. In addition, the side where the mold exchange cart 30 is not installed is often the operation side because it is easy for an operator to operate it next to the mold clamping device CLP.

[0029] In the injection molding system 1 shown in FIG. 1, an example is shown in which an injection unit corresponding to the operation side among a plurality of injection units included in the injection unit INJ is mounted on an injection unit carriage 31, and an injection unit corresponding to the opposite operation side is mounted on an injection unit carriage 32. The injection unit carriages 31 and 32 are arranged separately on both sides of the mold clamping unit CLP in a direction perpendicular to a mold opening / closing direction in which the second mold platen 11 and the third mold platen 12, which are movable platens of the mold clamping unit CLP, move relative to the first mold platen 10, which is a fixed platen. In the example shown in FIG. 1, the injection unit carriage 31 carrying the injection units 33a and 34a corresponding to the operation side is arranged on the side of the mold clamping unit CLP where the operation side mold is located, and the injection unit carriage 32 carrying the injection units 33a and 34a corresponding to the opposite operation side is arranged on the side of the mold clamping unit CLP where the opposite operation side mold is located. By arranging the entry path of the injection nozzles of the injection units 33a, 33b, 34a, and 34b to be on the side of the mold clamping unit CLP, it becomes possible to easily automate mold exchange by the mold exchange cart 30 described later. In FIG. 1, an example in which the injection units are mounted on each of the injection unit carts 31 and 32 is shown, but the injection unit cart only needs to be able to move the position of the injection nozzle of the injection unit to an appropriate position, and if the injection nozzle is separated from the injection unit main body that extrudes the molding material in a molten state, a configuration in which only the injection nozzle is mounted can be considered. However, in the following description, an example in which the injection unit cart is mounted with an injection unit INJ including an injection nozzle will be described. In addition, in this embodiment, "the injection nozzle is abutted against the mold" includes a case in which the injection nozzle is abutted against the main body of the mold and a case in which it is not abutted against the main body of the mold.

[0030] Here, the first injection molding device and the second injection molding device will be described. The first injection molding device has an injection device 33a mounted on an injection device carriage 31 and an injection device 33b mounted on an injection device carriage 32. The first injection device injects molding material into a cavity with an injection nozzle abutted against a mold attached to the mold attachment surface 13, which is not rotated by the mold rotation mechanism 23, among the mold attachment surface 13 and the mold attachment surface 15. In the example shown in FIG. 1, the injection nozzle of the injection device 33a abuts against the mold M11 on the operation side, which is set on the first mold platen 10 that is a fixed platen and is attached to the mold attachment surface 13 on the non-rotating mold attachment surface by the mold rotation mechanism 23, and the injection nozzle of the injection device 33b abuts against the mold M12 on the opposite operation side. The second injection molding device has an injection device 34a mounted on an injection device carriage 31 and an injection device 34b mounted on an injection device carriage 32. The second injection device injects molding material into a cavity with an injection nozzle abutted against a mold attached to the mold mounting surface 14, which is one of the mold mounting surfaces 14 and the mold mounting surface 16 and is not rotated by the mold rotation mechanism 24. In the example shown in Fig. 1, the injection nozzle of the injection device 34a abuts against the mold M21 on the operation side which is set on a fixed platen and attached to the mold mounting surface 14 on which the mold mounting surface does not rotate by the mold rotation mechanism 24, and the injection nozzle of the injection device 33b abuts against the mold M22 on the opposite operation side.

[0031] With this configuration, the injection nozzles of the injection units 33a, 33b, 34a, and 34b can be kept in contact with the nozzle touch surfaces of the main bodies of the corresponding molds at all times during molding. In other words, in the injection molding machine according to the first embodiment, it is not necessary to move the injection nozzle back and forth during the molding process of the molded product, so that the molding cycle can be shortened. In addition, the problem of stringing (dripping) occurring from the nozzle hole at the tip of the nozzle when the injection nozzle moves back and forth does not occur. In addition, in the injection molding machine according to the first embodiment, the injection nozzle has a nozzle touch hole in the parting surface formed when the mold attached to the first mold mounting surface 13 and the mold attached to the third mold mounting surface 15 are closed, and the nozzle touches the nozzle touch surfaces provided on both molds. The same is true for the mold attached to the second mold mounting surface 14 and the mold attached to the fourth mold mounting surface 16.

[0032] The first injection device and the second injection device are electric injection molding machines that rotate a screw by driving a servo motor for plasticization to plasticize the resin and store the molten resin in front of the screw, and drive an injection servo motor to advance the screw to inject and fill the molten resin into the cavity of the mold. A hopper is connected to the material supply hole of the first injection device and the second injection device, and a material supply mechanism is connected to the hopper. However, the type of the first injection device and the second injection device is not limited, and they may be ones that are partially or entirely driven by a hydraulic cylinder or hydraulic motor, or ones that have no limited driving means and perform injection by a plunger, etc.

[0033] The injection unit carriages 31 and 32 have a nozzle touch mechanism. The nozzle touch mechanism moves the injection nozzle of the injection unit forward relative to the corresponding mold, thereby bringing the injection nozzle into contact with a nozzle touch surface having a nozzle touch hole on the side of the mold. The nozzle touch mechanism also moves the injection nozzle of the injection unit backward relative to the corresponding mold, thereby removing the injection nozzle from the nozzle touch surface of the mold. The nozzle touch mechanism includes an actuator that moves the injection unit forward and backward. Specifically, the actuator of the nozzle touch mechanism is a hydraulic cylinder, and the cylinder part of the hydraulic cylinder is attached to the injection unit carriages 31 and 32, and the rod of the hydraulic cylinder is attached to the injection unit. Also, a guide rail is formed on the upper surface of the injection unit carriages 31 and 32, and the injection unit is moved forward and backward by driving the actuator. Also, the injection unit carriages 31 and 32 hold the injection unit so that it can be moved up and down in the mold opening and closing direction and also in the vertical direction according to the position of the nozzle touch hole of the mold attached to the mold clamping unit CLP. However, since movements in the mold opening / closing direction and the up / down direction are minute movements (position corrections), adjustments are often made without using actuators. Note that movement of the injection unit is synonymous with movement of the injection nozzle. Adjustments to the position of the injection nozzle are often made by moving the entire injection unit and then fine-tuning the direction of the injection unit to adjust the position of the injection nozzle.

[0034] In addition, the example shown in FIG. 1 is an example of molding a two-color molded product, but in multi-color molding, molded products of three or more colors may be molded. When molding products of three or more colors, the same number of cavities and injection devices are usually prepared in the A-side molding area and the B-side molding area corresponding to the number of resin types (colors). That is, three injection devices are prepared for each of the first injection device and the second injection device. However, it is also possible to provide three or more nozzle touch holes in one fixed mold, and the number of molds may be less than the number of resin types (colors). When molding products of three or more colors, the injection nozzle for injecting the second color molding material and the injection nozzle of the injection device for injecting the third color molding material may be stacked vertically on the operation side or the opposite operation side, or may be arranged horizontally. Also, a structure in which the injection nozzle for injecting the third color molding material is inserted from the top of the fixed platen may be used. Therefore, it is sufficient that there are two or more first injection devices and two or more second injection devices.

[0035] Next, the mold exchange cart 30 will be described. In the example shown in Fig. 1, two rails extending in the mold opening / closing direction are laid on the floor on the opposite operation side of the mold clamping unit CLP. Then, the mold exchange cart 30 and the injection unit cart 32 are placed on the rails so as to be movable in the mold opening / closing direction. That is, in the injection molding system 1 shown in Fig. 1, the injection unit cart 32 and the mold exchange cart 30 are moved appropriately along the rails to carry out the injection molding process and the mold exchange process.

[0036] The mold exchange cart 30 individually replaces a first mold set consisting of a mold attached to the mold mounting surface 13 and a mold attached to the mold mounting surface 15, and a second mold set consisting of a mold attached to the mold mounting surface 14 and a mold attached to the mold mounting surface 16, with another mold set. In addition, the mold exchange cart 30 moves the mold set horizontally from the side of the first mold platen 10 to the third mold platen 12 to replace the mold set.

[0037] More specifically, the mold exchange cart 30 is equipped with a driving device such as a driving motor and wheels for movement. A mounting space is provided on the upper surface of the mold exchange cart 30. A different mold set is mounted in each mounting space. A mold loading / unloading drive device consisting of rollers and a driving mechanism (not shown) is provided in each mounting space. The mounting space has a portion for mounting a mold set removed from the mold clamping unit CLP and a portion for mounting a new mold set to be attached to the mold clamping unit CLP. In the example shown in FIG. 1, the mold sets MS1 and MS2 are shown stored in the mounting spaces.

[0038] Between the mold exchange cart 30 and the mold clamping unit CLP, rollers rotating at a fixed position may be provided on the bed on which the mold clamping unit is placed, or a bridge portion provided with a number of rollers may be extended from the mold exchange cart 30. The rollers formed on the mold mounting surface of the fixed platen and the rollers provided on the rotating platen of the movable platen also constitute a part of the mold exchange cart 30. Alternatively, the mold set may be carried in and out by a fork or the like provided on the mold exchange cart 30. In this embodiment, the first mold set has two mold sets fixed by two mold mounting plates. However, two or more mold sets may be placed on the mold exchange cart 30 independently and attached to the first mold mounting surface 13, the third mold mounting surface 15, or the like in the mold exchange process.

[0039] Next, the mold rotation mechanism for rotating the mold mounting surface in the injection molding system 1 according to the first embodiment will be described in detail. In the example shown in FIG. 1, the mold rotation mechanism 23 is provided on the second platen 11, and the mold rotation mechanism 24 is provided on the third platen 12. The mold rotation mechanism 23 rotates the molds M31 and M32 attached to the mold mounting surface 15, and the mold rotation mechanism 24 rotates the molds M41 and M42 attached to the mold mounting surface 16. Here, since the mold rotation mechanisms 23 and 24 are the same, the following describes a configuration example of the mold rotation mechanism by taking the mold rotation mechanism 23 that rotates the mold mounting surface 15 as an example. FIG. 2 shows a diagram for explaining the mold rotation mechanism of the injection molding machine according to the first embodiment.

[0040] As shown in FIG. 2, in the injection molding system 1 according to the first embodiment, tie bars 17 are provided near the four corners of the second platen 11. The mold rotation mechanism 23 includes a rotating platen 23a, a motor 23b, a driving pulley 23c, a belt 23d, and a passive roller 23e. The rotating platen 23a has a rotation axis 23x at the center of the second platen 11. A mold fixing platen having a mold mounting surface 15 is fixed to the rotating platen 23a. The mold M31 and the mold M32 are attached to the mold mounting surface 15. The mold rotation mechanism 23 rotates the driving pulley 23c by the motor 23b. The belt 23d transmits the rotation of the driving pulley 23c to the rotating platen 23a, thereby transmitting the driving force of the motor 23b to the rotating platen 23a. The passive roller 23e is used to adjust the tension of the belt 23d. In addition, in FIG. 2, an example is shown in which the rotating platen 23a is rotated around an axis in the mold clamping direction by the motor 23b, the drive pulley 23c, and the belt 23d. However, the mold rotation mechanism 23 may be one that rotates the rotating platen 23a via gears, or one that directly rotates the rotating platen 23a by a motor incorporated in the second mold platen 11.

[0041] This mold mounting surface 15 is changed from a first state to a second state by the mold rotation mechanism 23. In the example shown in Fig. 2, the mold mounting surface 15 is set to rotate 180 degrees at a time by the mold rotation mechanism 23, and the positions of the mold M31 and the mold M32 are switched between the first state and the second state. In this way, by rotating one of the pair of molds and fixing the other, it becomes possible to form one molded product using two types of cavities.

[0042] Here, the mold rotation mechanism 23 rotates the mold mounting surface 15 about a rotation axis 23x extending in the mold clamping direction (or mold opening / closing direction). With respect to the rotation direction, assuming that the first state is 0 degrees and the second state is 180 degrees, the rotation may alternate between rotating counterclockwise from 0 degrees to 180 degrees and rotating clockwise from 180 degrees to 0 degrees, or the mold mounting surface 15 may always rotate counterclockwise or clockwise. Alternatively, in a mold mounting surface 13, 15 equipped with three mold sets, the turntable 23a may rotate continuously by 120 degrees, or may rotate twice continuously by 120 degrees and then rotate 240 degrees in the reverse direction.

[0043] The rotation axis may be provided in a direction protruding from the center of the second platen 11 toward the center of the mold mounting surface 15. The rotation axis is held by a bearing in a holding portion in the center of the second platen 11. The mechanism for rotating the mold mounting surface 15 is not limited to the rotation axis, and the rotation platen 23a may be held by rollers arranged around the rotation platen 23a and rotated by the rollers. In these mold rotation mechanisms 23, the rotation platen 23a and its mold mounting surface 15 rotate relative to the platen around an axis ax (including a virtual central axis of a rotation platen whose periphery is held by rollers) in the mold clamping direction (or mold opening / closing direction).

[0044] 2, the mold mounting surface is preferably provided with a clamper for fixing the mold, particularly the mold mounting plate, to the mold mounting surface, and rollers for moving the mold horizontally when replacing the mold. A rod hole for inserting the rod of the ejector 21 is formed in the mold opening / closing direction in the mold mounting surface 15, and the ejector rod can move forward and backward within the rod hole by operating the ejector 21.

[0045] Next, the structures of the first locking mechanism 18 and the second locking mechanism 19 will be described in detail. Since the first locking mechanism 18 and the second locking mechanism 19 can have the same structure, the following description will use the first locking mechanism 18 as an example to describe the structure of the locking mechanism. In addition, although various types of locking mechanisms are possible, two examples will be described below.

[0046] FIG. 3 shows a configuration diagram of a first example of the lock mechanism of the injection molding machine according to the first embodiment. The first example of the first lock mechanism 18 shown in FIG. 3 is provided so that the first lock mechanism 18 is fixed to the surface of the third platen 12 opposite to the mold clamping cylinder 20 (here, the second mold mounting surface 14). The first lock mechanism 18 has a cylinder 41 and a brake shoe 42. The cylinder 41 moves the brake shoe 42 so as to approach or move away from the tie bar 17. The first lock mechanism 18 is controlled to either a locked state in which the brake shoe 42 is pressed against the tie bar 17, or an unlocked state in which the brake shoe 42 is separated from the tie bar 17. At least one of the brake shoe 42 and the tie bar 17 is formed so that the surfaces where they come into contact with each other are roughened. By roughening the surfaces where they come into contact with each other in this way, the force with which the first lock mechanism 18 defines and holds the tie bar 17 can be increased. In addition, in the locked state, the first locking mechanism 18 transmits the force from the tie bar 17 to the third platen 12 so that the third platen 12 follows the moving direction of the tie bar 17.

[0047] Fig. 4 shows a configuration diagram of a second example of the lock mechanism of the injection molding machine according to the first embodiment. The second example of the first lock mechanism 18 shown in Fig. 4 is provided so that the first lock mechanism 18 is fixed to the surface of the third platen 12 opposite to the mold clamping cylinder 20 (here, the second mold mounting surface 14). The first lock mechanism 18 has a cylinder 51 and a half nut 52. In the second example of the first lock mechanism 18, the cylinder 51 moves the half nut 52 so as to approach or move away from the tie bar 17.

[0048] 4, the convex portion of the half nut 52 is formed to be narrower than the width of the concave portion of the tie bar 17. As a result, in the example shown in FIG. 4, even if the third platen 12 stops at a position where the convex portion of the half nut 52 is slightly shifted from the center of the concave portion of the tie bar 17, the convex portion of the half nut 52 can be engaged with the concave portion of the tie bar 17. In addition, in a clamping state in which the tie bar 17 is pulled in the clamping direction, the wall of the concave portion of the tie bar 17 presses the convex portion of the half nut 52 toward the third platen 12, thereby pulling the third platen 12 in a direction approaching the second platen 11.

[0049] In this way, the first locking mechanism 18 and the second locking mechanism 19 transmit the force generated in the moving direction of the tie bar 17 to the third platen 12 and the first platen 10. In addition, by controlling the first locking mechanism 18 and the second locking mechanism 19 to an unlocked state, the first platen 10 and the third platen 12 can be freely moved relative to the tie bar 17. In addition, by configuring the first locking mechanism 18 and the second locking mechanism 19 to be able to maintain a locked state regardless of the relative positions of the tie bar 17 and the third platen 12 or the first platen 10, it is possible to improve productivity without the need to adjust the locking mechanism even when a change occurs in the thickness of the mold provided in the molding area due to a mold set replacement. In addition, the first locking mechanism 18 or the second locking mechanism 19 can also fix the half nut to the tie bar 17 by providing two pairs of half nuts as shown in FIG. 4 and moving one half nut toward the axial direction of the tie bar while the half nuts are engaged.

[0050] Next, the operation of the injection molding system 1 according to the first embodiment will be described. The operation of the injection molding system 1 can be considered to be divided into a mold exchange process and a continuous molding process, and therefore, the mold exchange process and the continuous molding process will be described separately below. It is also possible to perform the mold exchange process and the continuous molding process consecutively. The operation described below is realized by a control unit, not shown in FIG. 1, controlling hydraulic mechanisms such as the clamping cylinder 20 and the ejector 21, and mechanisms associated with the clamping device CLP. The control unit also includes a calculation unit capable of executing a program, and various operations of the injection molding system 1 are realized by executing a control program in the calculation unit.

[0051] First, a description will be given of the mold changing process of the injection molding system 1 according to the embodiment 1. FIG.

[0052] As shown in FIG. 5, in the mold exchange process, first, the injection units 33a, 33b, 34a, and 34b are retracted from the mold (step S1). Then, the injection unit cart 32 and the mold exchange cart 30, which are placed on rails laid on the side of the mold clamping unit CLP, are moved (step S2). In this step S2, in particular, the mold exchange cart 30 is moved to a position where the empty mounting space of the mold exchange cart 30 is aligned with the exchange position of the mold attached to the mold clamping unit CLP, and stopped. Then, a mold carrying-out process is performed in which a clamper (not shown) is operated to remove the mold set attached to the mold mounting surface of the mold clamping unit CLP and move it toward the mounting space of the mold exchange cart 30 (step S3). Next, the mold exchange cart 30 is moved so that the mounting space where the mold set to be newly attached to the mold clamping unit CLP is placed is aligned with the mounting target position and stopped (step S4). After that, a new mold set to be used for the next molding is carried from the mold exchange cart 30 to the mold clamping unit CLP side, and the molds are attached to the mold attachment surface of the mold clamping unit CLP (step S5). Next, the mold exchange cart 30 and the injection unit cart 32 are moved again, and the injection nozzles of the injection units 33a, 33b, 34a, and 34b mounted on the injection unit cart 32 are stopped at a position facing the nozzle touch holes formed on the nozzle touch surface on the side of the main body of the mold on the side that is not rotated by the mold rotation mechanism (step S6). Then, the injection units 33a, 33b, 34a, and 34b of the injection unit carts 31 and 32 are each advanced to bring the injection nozzles into contact with the nozzle touch holes of the corresponding molds (step S7). Needless to say, the height direction of the injection nozzles is also adjusted to match the nozzle touch holes at this time.

[0053] Next, the continuous molding process of the injection molding system 1 according to the first embodiment will be described. FIG. 6 shows a flowchart for explaining the operation of the continuous molding operation of the injection molding machine according to the first embodiment. Note that the continuous injection molding starts with both mold sets attached to the two molding regions open before the start of the operation. In addition, in the example shown in FIG. 6, a case will be described in which a continuous molding process is performed in which a primary molded product made of a first color molding material and a secondary molded product made by adding a second color molding material to the primary molded product are continuously molded. In addition, in the example shown in FIG. 6, the continuous molding process is performed simultaneously or with a slight timing difference in both the A-side molding region and the B-side molding region.

[0054] As shown in FIG. 6, in the injection molding system 1 according to the first embodiment, when the continuous molding process is started, first, the second platen 11 and the third platen 12 are moved close to the first platen 10 by the A-side mold opening and closing mechanism MMa and the B-side mold opening and closing mechanism MMb to close both the molds in the A-side molding area and the B-side molding area (step S10). Next, in the injection molding system 1, the first lock mechanism 18 is controlled to be kept in a locked state and the second lock mechanism 19 is controlled to be kept in an unlocked state (step S11). After that, the first mold set in the A-side molding area and the second mold set in the B-side molding area are clamped by the clamping cylinder 20 (step S12). In the clamping of step S12, the clamping cylinder 20 pulls the tie bar 17 toward the second platen 11 to increase the contact pressure of the molds in each molding area. The steps S10 to S12 are referred to as a mold closing step and a mold clamping step, or the step S12 is referred to as a mold clamping step. Moreover, this mold clamping step is a first mold clamping step for the primary molded product, and a second mold clamping step for the secondary molded product.

[0055] Next, an injection process is carried out in which a resin that is a molding material is injected from an injection device into the cavity of the mold set formed in the A-side molding area and the cavity of the mold set formed in the B-side molding area (step S13).

[0056] Here, in the injection molding system 1, a plurality of first cavities (two cavities in the example of FIG. 1) are formed by a mold set attached to the A-side molding region. Among the plurality of first cavities, the cavity on the operation side becomes the first primary molding cavity corresponding to the primary molded product, and the cavity on the opposite operation side becomes the first secondary molding cavity corresponding to the secondary molded product. Also, in the injection molding system 1, a plurality of second cavities (two cavities in the example of FIG. 1) are formed by a mold set attached to the B-side molding region. Among the plurality of second cavities, the cavity on the operation side becomes the second primary molding cavity corresponding to the primary molded product, and the cavity on the opposite operation side becomes the second secondary molding cavity corresponding to the secondary molded product.

[0057] In the injection process of step S13, in the first injection process of the continuous molding, only the first injection process of injecting the molding material from the injection device performing primary molding into the first primary molding cavity and the second primary molding cavity is performed. In the injection process of step S13 from the second injection process onwards of the continuous molding, both the first injection process of injecting the molding material into the first primary molding cavity and the second primary molding cavity and the second injection process of injecting the molding material from the first injection device performing secondary molding into the first secondary molding cavity and the second secondary molding cavity are performed.

[0058] In addition, in the injection process of step S13, the same first injection process and second injection process are performed for the second mold set in the B-side molding area. The first injection process in the B-side molding area and the first injection process in the A-side molding area may be performed simultaneously or slightly differently in time, and the second injection process in the B-side molding area and the second injection process in the A-side molding area may also be performed simultaneously or slightly differently in time.

[0059] In the injection molding system 1 according to the first embodiment, the injection nozzle is basically always in nozzle touch with the mold during the continuous molding process, but it is not impossible to retreat the nozzle except during injection by adopting a shutoff valve or the like in the nozzle of at least one of the first injection device corresponding to the A-side injection region and the second injection device corresponding to the B-side molding region. In addition, the first injection device corresponding to the A-side molding region and the second injection device corresponding to the B-side injection region are assumed to inject simultaneously, but the timing may be slightly shifted. In particular, when the cooling time differs between the molded product molded in the A-side molding region and the molded product molded in the B-side molding region, the time of starting injection may be shifted so that the timing of opening the mold after the completion of cooling is consistent.

[0060] Then, after the injection process of step S13 is completed, a cooling process is performed to cool the molded product in the cavity (step S14). After the cooling process is completed, the injection molding system 1 first forcefully opens the mold set in the B-side molding region by the mold clamping cylinder 20 (step S15). At this time, the primary molded product and the secondary molded product (molded product) in the B-side molding region are held in a mold (for example, a mold attached to a mold mounting surface 16 equipped with a mold rotation mechanism). In step S15, the second lock mechanism in step S11 is maintained in an open state, and the mold opening force generated by the mold clamping cylinder 20 is transmitted to the third mold platen 12 only through the tie bar 17 and the first lock mechanism 18, thereby opening the mold set in the B-side molding region. In addition, at this time, the servo motor of the A-side mold opening / closing mechanism MMa is servo-locked to prevent the mold set in the A-side molding region from being opened first. In this embodiment, it is important to selectively open either the mold set in the A-side molding area or the mold set in the B-side molding area first, but in addition to using a mold opening and closing mechanism, it is also possible to use a locking mechanism on the mold sets or mold mounting surfaces that locks the molds to each other or the mold platens to each other.

[0061] Next, the injection molding system 1 controls the first lock mechanism 18 to be switched from a locked state to an unlocked state, and the second lock mechanism 19 to be switched from an unlocked state to a locked state (step S16). After that, the injection molding system 1 forcefully opens the mold set in the A-side molding region by the mold clamping cylinder 20 (step S17). At this time, the primary molded product and the secondary molded product (molded product) in the A-side molding region are held in the mold (for example, the mold attached to the mold mounting surface 15 equipped with a mold rotation mechanism). Also, in step S17, the mold opening force generated by the mold clamping cylinder 20 is transmitted to the first platen 10 only via the tie bar 17 and the second lock mechanism 19, thereby opening the mold set in the A-side molding region.

[0062] Next, in the injection molding system 1, the second platen 11 and the third platen 12 are separated from the first platen 10 by the A-side mold opening and closing mechanism MMa and the B-side mold opening and closing mechanism MMb to further open the molds in the A-side molding area and the B-side molding area (step S19). Steps S15 to S19 are collectively referred to as a mold opening step. This mold opening step is the first mold opening step for the primary molded product and the second mold opening step for the secondary molded product.

[0063] Next, the injection molding system 1 performs a molded product removal process in which the secondary molded product (molded product) held in the cavity of the mold rotated and moved to the opposite operation side is pushed out by the ejectors 21 and 22 to remove the secondary molded product (step S20). After that, the injection molding system 1 performs a mold rotation process in which the mold holding the first primary molded product and the mold holding the second primary molded product are rotated by the mold rotation mechanisms 23 and 24, respectively, to move the first primary molded product and the second primary molded product to positions facing the mold in which the cavities corresponding to the first secondary molded product and the second secondary molded product are formed (step S21). In the injection molding system 1 according to the first embodiment, the processes of steps S10 to S21 are repeated to continuously produce molded products.

[0064] As described above, the injection molding system 1 according to the first embodiment clamps at least two molding zones arranged adjacent to each other in the horizontal direction with one set of clamping force generating devices (for example, four clamping cylinders). This makes it possible to clamp two molding zones with the same clamping force as that for clamping one molding zone, and with the same clamping pressure as that for clamping one molding zone. In other words, the injection molding system 1 according to the first embodiment can achieve a productivity more than twice that of one molding zone while suppressing power consumption in the clamping process, thereby improving production efficiency.

[0065] In addition, in the injection molding system 1 according to the first embodiment, it is possible to perform multi-color molding using a plurality of cavities in one molding area by the mold rotation mechanisms 23 and 24. In addition, the injection molding system 1 according to the first embodiment is capable of attaching different mold sets to two molding areas, the A-side molding area and the B-side molding area. This can increase the flexibility of production, for example, by producing a first molded product in the A-side molding area and a second molded product in the B-side molding area. In addition, it is also possible to produce different combinations of molded products during one production period, such as producing a first molded product in the A-side molding area and a second molded product in the B-side molding area during a first period, and producing a first molded product in the A-side molding area and a third molded product in the B-side molding area during a second period. In other words, the injection molding system 1 according to the first embodiment can realize flexible production management.

[0066] In addition, in the injection molding system 1 according to the first embodiment, a mold exchange cart 30 is provided movably on the side of the clamping unit CLP, making it easy to exchange the mold set. By facilitating the exchange of the mold set in this way, the time required for mold exchange can be shortened, and production efficiency can be improved.

[0067] In addition, in the injection molding system 1 according to the first embodiment, the injection nozzles of the injection units 33a, 33b, 34a, and 34b are abutted (including pressed) from the side of the clamping unit CLP against the side of the main body of the mold, which is attached to the mold platen set on the fixed platen and attached to the mold mounting surface on the non-rotating side. As a result, in the injection molding system 1 according to the first embodiment, the position of the nozzle touch hole of the mold does not substantially change when the mold is opened and when the mold is clamped, so that the continuous molding process can be performed while the injection nozzle is maintained in the nozzle touch state. This eliminates the need for time to move the injection nozzle back and forth during the continuous molding process. In other words, the injection molding system 1 according to the first embodiment makes it possible to reduce the time to move the injection nozzle back and forth during the continuous molding process, thereby improving production efficiency.

[0068] In addition, in the injection molding system 1 according to the first embodiment, the position of the injection nozzle is set so that the injection nozzle of the injection device touches the side of the mold. Here, for example, there is a vertical injection molding machine that moves the platen in the vertical direction. In such a vertical injection molding machine, the mold is often designed so that the injection nozzle touches the side of the mold from the side. In other words, in the injection molding system 1 according to the first embodiment, since the nozzle touch direction to the mold is the same, the mold used in the vertical injection molding machine can be reused. This makes it unnecessary to remake the mold in response to the replacement of the injection molding machine.

[0069] Embodiment 2 In the second embodiment, a continuous molding process using only either the A-side molding region or the B-side molding region will be described. Fig. 7 shows a flow chart for explaining a first operation example in the continuous molding operation of the injection molding machine according to the second embodiment. The first operation example shown in Fig. 7 explains the flow of the continuous molding process using only the A-side molding region.

[0070] As shown in Fig. 7, in the first operation example according to the second embodiment, the second platen 11 is first moved toward the first platen 10 by the A-side mold opening / closing mechanism MMa to close the mold in the A-side molding region (step S30). In the first operation example according to the second embodiment, the third platen 12 corresponding to the B-side molding region is not moved in this step S30, and the mold in the B-side molding region may be in a closed or open state. Alternatively, the B-side molding region may be molded by attaching a block body without a cavity to the mold mounting surfaces 14, 16 to lock the first lock mechanism and maintain the second lock mechanism in an unlocked state.

[0071] Next, in a first operation example according to the second embodiment, the first lock mechanism 18 is maintained in an unlocked state, and the second lock mechanism 19 is controlled to be in a locked state (step S31). After that, the mold in the A-side molding region is clamped by the mold clamping cylinder 20 (step S32). The processes of steps S30 to S32 are referred to as a mold closing process and a mold clamping process, or the process of step S32 is referred to as a mold clamping process. This mold clamping process is the first mold clamping process for the primary molded product, and the second mold clamping process for the secondary molded product.

[0072] After step S32 is completed, an injection process is performed in which the resin that will be the molding material is injected from each of the first injection devices into the cavity of the mold set formed in the A-side molding region (step S33). In the injection process of step S33, in the first injection process of the continuous molding, only the first injection process of injecting the molding material from the first injection device performing the primary molding into the first primary molding cavity is performed. Then, in the injection process of step S33 from the second or subsequent times of the continuous molding, both the first injection process of injecting the molding material into the first primary molding cavity and the second injection process of injecting the molding material from the first injection device performing the secondary molding into the first secondary molding cavity are performed.

[0073] After the injection process of step S33 is completed, a cooling process is performed to cool the molded product in the cavity (step S34). After the cooling process is completed, in the first operation example according to the second embodiment, the mold in the A-side molding region is forcefully opened by the mold clamping cylinder 20 (step S35). At this time, the primary molded product and the secondary molded product in the A-side molding region are held in a mold (for example, a mold attached to the mold mounting surface 15 rotated by the mold rotation mechanism 23). In step S35, the mold opening force generated by the mold clamping cylinder 20 is transmitted to the first platen 10 via the tie bar 17 and the second lock mechanism 19, thereby opening the mold in the A-side molding region.

[0074] Next, in the first operation example according to the second embodiment, the second lock mechanism 19 is controlled to an unlocked state similarly to the first lock mechanism 18 that was in an unlocked state (step S36). After that, in the first operation example according to the second embodiment, the A-side mold opening / closing mechanism MMa separates the second mold platen 11 from the first mold platen 10 to further open the mold in the A-side molding region (step S37). The processes of steps S35 to S37 are collectively referred to as a mold opening process. This mold opening process is the first mold opening process for the primary molded product, and the second mold opening process for the secondary molded product (molded product).

[0075] Next, in the first operation example according to the second embodiment, a molded product removal step is performed in which the secondary molded product (molded product) held in the cavity of the mold rotated and moved to the opposite operation side is pushed out by the ejector 21 to remove the secondary molded product (step S38). After that, in the first operation example according to the second embodiment, a mold rotation step is performed in which the mold holding the first primary molded product is rotated 180 degrees and the mold mounting surface 15 is rotated so as to move the first primary molded product to a position facing the mold in which the cavity corresponding to the first secondary molded product is formed (step S39). In the first operation example according to the second embodiment, the processes of steps S30 to S39 are repeated to continuously produce molded products using only the A-side molding region.

[0076] Next, a flowchart explaining a second operation example in the continuous molding operation of the injection molding machine according to the embodiment 2 is shown in Fig. 8. The second operation example shown in Fig. 8 explains the flow of the continuous molding process using only the B-side molding region.

[0077] 8, in a second operation example according to the second embodiment, first, one block is attached to the mold attachment surfaces 13, 15 of the A-side molding area to fix the first mold platen 10 and the second mold platen 11 in a fixed relationship. Then, the B-side mold opening / closing mechanism MMa moves the third mold platen 12 close to the first mold platen 10 to close the mold set in the B-side molding area (step S40).

[0078] Next, in a second operation example according to the second embodiment, the first lock mechanism 18 is controlled to be in a locked state, and the second lock mechanism 19 is controlled to be in an unlocked state (step S41). After that, the block body of the A-side molding region and the mold set of the B-side molding region are both clamped by the clamping cylinder 20 (step S42). In step S42, the A-side molding region does not need to be clamped, but the clamping device CLP of the injection molding system 1 is configured so that the A-side molding region is also clamped when clamping the B-side molding region. In addition, in the clamping device CLP of the injection molding system 1, the power required in the clamping process is approximately the same whether one of the two molding regions is clamped or both of the two molding regions are clamped. The processes of steps S40 to S42 are referred to as a mold closing process and a mold clamping process, or the process of step S42 is referred to as a mold clamping process. In addition, this mold clamping process is a first mold clamping process for a primary molded product, and a second mold clamping process for a secondary molded product.

[0079] After step S42 is completed, an injection process is performed in which the second injection device injects the resin that is the molding material into the cavity formed in the B-side molding region (step S43). In the injection process of step S43, in the first injection process of the continuous molding, only the first injection process is performed in which the molding material is injected into the second primary molding cavity from the injection device that performs the primary molding among the second injection device. Then, in the injection process of step S43 from the second injection process onwards of the continuous molding, both the first injection process of injecting the molding material into the second primary molding cavity and the second injection process of injecting the molding material into the second secondary molding cavity from the injection device that performs the secondary molding among the second injection device are performed.

[0080] After the injection process of step S43 is completed, a cooling process is performed to cool the molded product in the cavity (step S44). After the cooling process is completed, in the second operation example according to the second embodiment, the mold in the B-side molding region is forcefully opened by the mold clamping cylinder 20 (step S45). At this time, the primary molded product and the secondary molded product in the B-side molding region are held by the mold (for example, the mold attached to the mold mounting surface 16 rotated by the mold rotation mechanism 24). In addition, in step S45, the mold opening force generated by the mold clamping cylinder 20 is transmitted to the third platen 12 via the tie bar 17 and the first lock mechanism 18, thereby opening the mold set in the B-side molding region.

[0081] Next, in the second operation example according to the second embodiment, the first lock mechanism 18 is controlled to an unlocked state similarly to the second lock mechanism 19 that was in an unlocked state (step S46). After that, in the second operation example according to the second embodiment, the third platen 12 is moved away from the first platen 10 by the B-side mold opening mechanism MMb to further open the mold in the B-side molding area (step S47). The processes of steps S45 to S47 are collectively referred to as a mold opening process. This mold opening process is the first mold opening process for the primary molded product and the second mold opening process for the secondary molded product.

[0082] Next, in the second operation example according to the second embodiment, a molded product removal step is performed in which the secondary molded product (molded product) held in the cavity on the opposite side of the operation is pushed out by the ejector 22 to remove the secondary molded product (step S48). After that, in the second operation example according to the second embodiment, a mold rotation step is performed in which the mold mounting surface 16 is rotated so as to rotate the mold holding the first primary molded product by 180 degrees by differentially rotating the mold rotation mechanism and move the second primary molded product to a position facing the mold in which the cavity corresponding to the second secondary molded product (molded product) is formed (step S49). In the second operation example according to the second embodiment, the processes of steps S40 to S49 are repeated to continuously produce molded products using only the B-side molding region.

[0083] From the above explanation, in the second embodiment, a method for controlling a continuous molding process using only one of the two molding zones of the injection molding system 1 explained in the first embodiment has been explained. By being able to use only one of the molding zones in this way, it becomes possible to perform process management that flexibly responds to differences in the production numbers of molded products to be produced, for example, by producing a first molded product and a second molded product in a first period and producing only the first molded product in a second period.

[0084] Third embodiment In the third embodiment, a modified example will be described in which the combination of the platen mold set on the fixed platen and the mold mounting surface on which the mold rotation mechanism is provided is changed in the injection molding system 1 of the first embodiment. Specifically, in the third embodiment, four modified examples will be described.

[0085] FIG. 9 is a schematic diagram illustrating an injection molding system 2 according to a first modified example of the injection molding system according to the third embodiment. In the injection molding system 2 shown in FIG. 9, the first platen 10 and the third platen 12 are set as movable platens, and the second platen 11 is set as a fixed platen. In the injection molding system 2, mold rotation mechanisms 23 and 24 are provided on the mold mounting surfaces 13 and 14 attached to the first platen 10. The mold mounting surfaces that are fixed without rotating are the mold mounting surface 15 attached to the second platen 11 and the mold mounting surface 16 attached to the third platen 12. Therefore, in the injection molding system 2, the injection nozzles of the injection units 33a, 33b, 34a, and 34b are abutted against the main bodies of the molds M31 and M32 attached to the mold mounting surface 15 and the molds M41 and M42 attached to the mold mounting surface 16.

[0086] In this configuration, the injection units 33a and 33b included in the first injection unit can be fixed in the mold opening / closing direction during continuous molding, but the injection units 34a and 34b included in the second injection unit need to be moved in accordance with the movement of the second mold platen 11 when they are always in nozzle touch. Therefore, in the first modification shown in FIG. 9, the injection units 33a, 33b, 34a, and 34b are separately mounted on the injection unit carriages 31a, 31b, 32a, and 32b, respectively. The injection unit carriages 31a, 31b, 32a, and 32b move the injection units 33a, 33b, 34a, and 34b mounted thereon back and forth relative to the mold clamping unit CLP. The injection unit carriages 32a and 32b carrying the injection units 34a and 34b that inject molding material into the mold attached to the second mold platen 11 are configured to move in accordance with the mold opening / closing direction. Although not shown in Fig. 9, the injection unit carriages 32a, 32b have a drive mechanism for moving the carriages in the mold opening / closing direction. The injection units 34a, 34b do not always have nozzle touch, and may advance toward the nozzle touch holes in the nozzle touch surfaces on the side surfaces of the molds M41, 42 to abut the injection nozzles when the molds M41, 42 are clamped. In this case, the injection unit carriages 32a, 32b of the injection units 34a, 34b do not need to move in the mold opening / closing direction during continuous molding.

[0087] Fig. 10 shows a schematic diagram of an injection molding system 3 which is a second modified example of the injection molding system according to the third embodiment. The injection molding system 3 shown in Fig. 10 is sandwiched between a second platen 11 and a third platen 12 which are set as movable platens, and a clamping bladder 25 is provided on a first platen 10 which is set as a fixed platen. The clamping bladder 25 is a bag (bladder) made of rubber or the like which can be pressurized, and can increase the clamping force by inflating it during clamping or the like. Instead of the clamping bladder 25, a hydraulic cylinder which generates pressure in a direction to separate two mold mounting surfaces may be provided in the first platen 10. It is also preferable that the injection units 33a, 33b, 34a, and 34b are configured so that the injection nozzles are slightly moved in response to the molds M11 and M12 being slightly moved toward the second mold mounting plate 15 during mold clamping and the molds M21 and M22 being slightly moved toward the third mold mounting plate 16. Alternatively, the injection nozzles of the injection units 33a, 33b, 34a, and 34b may be advanced and contacted with the nozzle touch surfaces of the molds M11 and M12 only during mold clamping.

[0088] FIG. 11 shows a schematic diagram of an injection molding system 4 which is a third modified example of the injection molding system according to the third embodiment. The injection molding system 4 shown in FIG. 11 is a modified example in which the platen types set for the fixed platen and the movable platen are changed with respect to the injection molding system 1. In the injection molding system 4, the first platen 10 and the third platen 12 are set as movable platens, and the second platen 11 is set as the fixed platen. Alternatively, the injection molding system 4 shown in FIG. 11 can be said to be a system in which the positions of the platen equipped with the mold rotation mechanism and the corresponding injection unit are changed with respect to the injection molding system 2 shown in FIG. In the injection molding system 3, in order to realize constant nozzle touch during continuous molding, it is necessary to provide the injection unit carts 31 and 32 so that they can move at the same speed as the first platen 10. When nozzle touch is not always performed during continuous molding, the injection units 33a, 33b, 34a, and 34b on the injection unit carts 31 and 32 are stopped in advance at positions corresponding to positions facing the nozzle touch surface on the side surface of the main body of the mold at the mold clamping position of the first platen 10. Then, the nozzles of the injection units 33a, 33b, 34a, and 34b are advanced toward the nozzle touch surface on the side surface of the main body of the mold.

[0089] FIG. 12 is a block diagram for explaining an outline of an injection molding system 5 which is a fourth modified example of the injection molding system according to the third embodiment. In the injection molding system 5 shown in FIG. 12, the arrangement of the injection device having the injection nozzle and the ejector is changed from that of the injection molding system 2 shown in FIG. 9. In the injection molding system 5, the injection nozzles of the injection devices 33a and 33b corresponding to the plurality of first injection devices are configured to nozzle touch the mold from the back side of the second platen 11 (for example, the surface opposite to the surface to which the mold mounting surface 15 is attached). In addition, in the injection molding system 5, the injection nozzles corresponding to the plurality of injection devices 34a and 34b are configured to nozzle touch the mold from the back side of the third platen 12 (for example, the surface opposite to the surface to which the mold mounting surface 16 is attached). In addition, in the injection molding system 5, the ejectors 26 and 27 are provided on the first platen 10. The ejector 26 is provided at a position corresponding to the mold rotated and moved to the opposite operation side of the A-side molding area. The ejector 27 is provided at a position corresponding to the mold that has been rotated and moved to the opposite operation side of the B-side molding area.

[0090] In addition, the injection molding system 5 may be one in which the first platen 10 is a fixed platen, the second platen 11 and the third platen 12 are movable platens as shown in Fig. 1, the first platen 10 is provided with a mold rotation mechanism, and the second platen 11 and the third platen 12 are not provided with a mold rotation mechanism. In these systems, the injection nozzle can directly contact the mold through a nozzle insertion hole formed in the movable platen. Also, in the injection molding systems shown in Figs. 9 to 12, molding can be performed only in the A-side molding region or only in the B-side molding region.

[0091] In this way, various forms are possible regarding which platen the fixed platen and the movable platen are set on, which surface the mold mounting surface rotated by the mold rotation mechanism is set on, and from which direction the injection nozzle touches which mold. In other words, the injection molding system 1 according to the first embodiment can be applied to forms other than those disclosed in FIG. 1 and the like. In addition, the injection molding system of this embodiment does not exclude those in which the first platen, the second platen, and the third platen are arranged vertically to perform molding. Furthermore, the manufacturing method of the injection molded product of the present invention does not exclude those in which a single-color molded product is molded by injecting from one injection device into a cavity of a mold set without rotating the rotating platen in some moldings, or those in which insert molding is performed with a rotating platen.

[0092] The present invention is not limited to the above-described embodiment, and various combinations and modifications can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0093] 1~5 Injection molding system 10 First platen 11 Second platen 12 The third plate 13~16 Mold mounting surface 17 Taiba 18 First locking mechanism 19 Second locking mechanism 20 Clamping cylinder 21, 22, 26, 27 Ejector 23, 24 type rotation mechanism 25 Prada Clamp 30 Mold change trolley 31, 32 Injection device trolley 33a, 33b, 34a, 34b injection device INJ injection device MMa, MMb mold opening and closing mechanism M11, M12, M21, M22, M31, M32, M41, M42 molds

Claims

1. A first platen including a first mold mounting surface and a second mold mounting surface provided on a rear side of the first mold mounting surface; a second platen having a third mold mounting surface opposed to the first mold mounting surface; a third platen having a fourth mold mounting surface opposed to the second mold mounting surface; a clamping mechanism that uses one of the first platen, the second platen, and the third platen as a fixed platen and presses two platens set as movable platens against the fixed platen while applying pressure in a clamping direction; a first mold rotation mechanism provided on one of the first mold mounting surface and the third mold mounting surface and configured to rotate the mold mounting surface around an axis in the mold clamping direction; a second mold rotation mechanism provided on one of the second mold mounting surface and the fourth mold mounting surface and configured to rotate the mold mounting surface around an axis in the mold clamping direction; a first injection device having an injection nozzle that is brought into contact with a mold that is attached to the other surface of the first mold mounting surface and the third mold mounting surface; a second injection device having an injection nozzle abutted against a mold attached to the other of the second mold attachment surface and the fourth mold attachment surface; An injection molding machine having

2. The mold clamping mechanism includes: a tie bar extending from the second die platen through the first die platen and the third die platen; a clamping force generating mechanism that is fixed to the second platen and moves the tie bar back and forth in the clamping direction; a first locking mechanism that determines a position of the third platen in the clamping direction relative to the tie bar when the clamping force generating mechanism moves the tie bar in a direction in which the third platen approaches the second platen and when the clamping force generating mechanism moves the tie bar in a direction in which the third platen moves away from the second platen; a second lock mechanism that determines a position of the first platen in the clamping direction relative to the tie bar when the clamping force generating mechanism moves the tie bar in a direction in which only the first platen approaches the second platen and when the clamping force generating mechanism moves the tie bar in a direction in which the first platen moves away from the second platen; 2. The injection molding machine according to claim 1, further comprising:

3. 3. The injection molding machine according to claim 2, wherein at least one of the first locking mechanism and the second locking mechanism locks the corresponding mold platen to the tie bar regardless of the position of the mold platen relative to the tie bar.

4. 2. The injection molding machine according to claim 1, wherein the first injection unit and the second injection unit have injection nozzles that come into contact with the corresponding molds from the sides.

5. 2. The injection molding machine according to claim 1, wherein the first injection device and the second injection device have injection nozzles abutted against the corresponding molds from behind the second mold mounting surface and the third mold mounting surface on which the molds are mounted.

6. 2. The injection molding machine according to claim 1, wherein a first mold set consisting of molds attached to the first mold mounting surface and the third mold mounting surface, and a second mold set consisting of molds attached to the second mold mounting surface and the fourth mold mounting surface each have two or more cavities.

7. 7. The injection molding machine according to claim 6, wherein the first mold rotation mechanism and the second mold rotation mechanism each change a combination of molds constituting the cavity by rotating the molds.

8. the second platen is a fixed platen; 2. The injection molding machine according to claim 1, wherein the first platen and the third platen are movable platens that move toward and away from the second platen.

9. the first platen is a fixed platen; 2. The injection molding machine according to claim 1, wherein the second platen and the third platen are movable platens that move toward and away from the first platen.

10. A first platen including a first mold mounting surface and a second mold mounting surface provided on a rear side of the first mold mounting surface; a second platen having a third mold mounting surface opposed to the first mold mounting surface; a third platen having a fourth mold mounting surface opposed to the second mold mounting surface; a clamping mechanism that uses one of the first platen, the second platen, and the third platen as a fixed platen and presses two platens set as movable platens against the fixed platen while applying pressure in a clamping direction; a first mold rotation mechanism provided on one of the first mold mounting surface and the third mold mounting surface and configured to rotate the mold mounting surface around an axis in the mold clamping direction; a second mold rotation mechanism provided on one of the second mold mounting surface and the fourth mold mounting surface and configured to rotate the mold mounting surface around an axis in the mold clamping direction; a first injection device having an injection nozzle that is brought into contact with a mold that is attached to the other surface of the first mold mounting surface and the third mold mounting surface; a second injection device having an injection nozzle abutted against a mold attached to the other surface of the second mold mounting surface and the fourth mold mounting surface; a mold exchange carriage for individually exchanging a first mold set consisting of a mold attached to the first mold mounting surface and a mold attached to the third mold mounting surface, and a second mold set consisting of a mold attached to the second mold mounting surface and a mold attached to the fourth mold mounting surface, with another mold set; The mold exchange cart moves the mold set horizontally from the side of the first platen to the third platen to replace the mold set, in an injection molding system.

11. A first platen including a first mold mounting surface and a second mold mounting surface provided on a rear side of the first mold mounting surface; a second platen having a third mold mounting surface opposed to the first mold mounting surface; a third platen having a fourth mold mounting surface opposed to the second mold mounting surface; a clamping mechanism that uses one of the first platen, the second platen, and the third platen as a fixed platen and presses two platens set as movable platens against the fixed platen in a clamping and closing direction while applying pressure thereto, one of the first mold mounting surface and the third mold mounting surface is mounted rotatably relative to a mold platen to which it is attached; A first mold set including a mold pair forming a plurality of first cavities is attached to the first mold mounting surface and the third mold mounting surface; one of the second mold mounting surface and the fourth mold mounting surface is rotatably mounted relative to a mold platen to which it is attached; A method for manufacturing an injection molded product in an injection molding machine in which a second mold set including a mold pair forming a plurality of second cavities is attached to the second mold attachment surface and the fourth mold attachment surface, the method comprising: a first clamping step of clamping the first mold set and the second mold set; a first injection step of injecting a molding material into a first primary molding cavity corresponding to a first primary molded product among the plurality of first cavities formed by the first mold set in the mold clamping state, and into a second primary molding cavity corresponding to a second primary molded product among the plurality of second cavities formed by the second mold set in the mold clamping state; a first mold opening step of opening the first mold set and the second mold set in a mold open state while the first primary molded product and the second primary molded product are held in the corresponding molds; a mold rotation step of rotating a mold holding the first primary molded product and a mold holding the second primary molded product to move the first primary molded product and the second primary molded product to a position facing a mold in which cavities corresponding to the first secondary molded product and the second secondary molded product are formed; a second mold clamping step of clamping the first mold set and the second mold set after the mold rotating step; a second injection step of injecting a molding material into a first secondary molding cavity corresponding to the first secondary molded product among the plurality of first cavities formed by the first mold set in the mold clamping state, and into a second primary molding cavity corresponding to the second secondary molded product among the plurality of second cavities formed by the second mold set in the mold clamping state; a second mold opening step of opening the first mold set and the second mold set in a mold open state while the first secondary molded product and the second secondary molded product are held in the corresponding molds; a removal step of removing the first secondary molded product and the second secondary molded product from the mold after the second mold opening step.

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