Injection molding machine and injection molding process

Abstract

An injection molding machine (1) comprising a three-platen type mold (10) comprising a fixed mold (11), a movable mold (12) movable with respect to the fixed mold (11), and an intermediate mold (13) provided between the fixed mold (11) and the movable mold (12), the injection molding machine filling a molding material into a cavity formed by closing the fixed mold (11), the movable mold (12), and the intermediate mold (13) to mold a molded product (2), the injection molding machine (1) comprising: a first mold connecting element (40, 140, 240) which connects or detaches the fixed mold (11) and the intermediate mold (13) to each other; a second mold connecting element (50, 150, 250) which connects or detaches the movable mold (12) and the intermediate mold (13) to each other; a mold moving device (20) that moves the movable mold (12) with respect to the fixed mold (11); a mold movement control unit (61) which controls the mold movement device (20) so as to bring about one of a mold closing state in which the movable mold (12), the intermediate mold (13) and the fixed mold (11) are connected, a first mold opening state in which the movable mold (12) is separated from the fixed mold (11) together with the intermediate mold (13), and a second mold opening state in which the movable mold (12) is separated from the intermediate mold (13) and the fixed mold (11); and a mold connection control unit (62) which controls the first mold connection element (40, 140, 240) and the second mold connection element (50, 150, 250) such that, in the first mold opening state, the first mold connection element (40, 140, 240) separates the fixed mold (11) and the intermediate mold (13) from each other and the second mold connection element (50, 150, 250) connects the movable mold (12) and the intermediate mold (13) in a state in which the movable mold (12) does not come into contact with the intermediate mold (13), and, in the second mold opening state, the first mold connection element (40, 140, 240) connects the fixed mold (11) and the intermediate mold (13) in a state in which the fixed mold (11) comes into contact with the intermediate mold (13) and the second mold connection element (50, 150, 250) separates the movable mold (12) and the intermediate mold (13) from each other.

Description

BACKGROUND OF THE INVENTIONField of the Invention

[0001] The present invention relates to an injection molding machine and an injection molding method carried out by the injection molding machine. Related technology

[0002] From JP 2013-49229 A, a three-platen type mold (hereinafter also referred to as a "three-platen mold") is known as a mold used for an injection molding machine. It comprises a fixed mold, a movable mold, and an intermediate mold. When the three-platen mold is opened, a clearance is formed between the fixed mold and the intermediate mold, and between the movable mold and the intermediate mold. Therefore, after casting, it is possible to separate a molded product from a sprue and the sprue from a gate simultaneously with the mold opening.

[0003] DE 10 2004 003 962 A1, DE 30 00 798 A1 and DE 36 44 709 A1 each disclose an injection molding tool with several parts that can be opened at their parting planes and thus allow access to the divided molds. SUMMARY OF THE INVENTION

[0004] The molded product and the sprue are removed from the three-platen mold at a position where the intermediate mold is inserted so that the fixed mold and the movable mold are separated from each other. Therefore, in an injection molding machine, a mold with such a mold opening degree that both the molded product and the sprue (hereinafter also referred to as "molded product and the like") can be removed after molding is used. Since a mold included in a large injection molding machine generally has a large mold opening degree, the cost of the machine increases even though it is easy to remove the molded product and the like. On the other hand, since a mold included in a small injection molding machine has a small mold opening degree, it is possible to reduce the cost of the machine even though it is difficult to remove the molded product and the like.Therefore, in molding using a three-platen mold, there is a demand for facilitating removal of a molded product and the like and further reducing the size of an injection molding machine.

[0005] It is an object of the present invention to provide an injection molding machine and an injection molding method capable of easily removing a molded product and the like and further reducing the size of a mold when performing molding using a three-platen mold. This object is achieved by means of the injection molding machine and the injection molding method according to the respective independent claims. Preferred embodiments are specified in the respective dependent claims. (1) An injection molding machine (for example, an injection molding machine 1 to be described later) is disclosed, which comprises: a three-platen type mold (for example, a mold 10 to be described later) comprising a fixed mold (for example, a fixed mold 11 to be described later), a movable mold (for example, a movable mold 12 to be described later) movable with respect to the fixed mold, and an intermediate mold (for example, an intermediate mold 13 to be described later) provided between the fixed mold and the movable mold, wherein the injection molding machine fills a molding material into a cavity formed by closing the fixed mold, the movable mold, and the intermediate mold to mold a molded product, the injection molding machine comprising: a first mold connecting member (for example, a first mold connecting member 40, 140, 240 to be described later),that connects or detaches the fixed mold and the intermediate mold; a second mold connecting member (for example, a second mold connecting member 50, 150, 250 to be described later) that connects or detaches the movable mold and the intermediate mold; a mold moving device (for example, a mold moving device 20 to be described later) that moves the movable mold with respect to the fixed mold; a mold moving control unit (for example, a mold moving control unit 61 to be described later) that controls the mold moving device to bring about one of a mold closing state in which the movable mold, the intermediate mold, and the fixed mold are connected, a first mold opening state in which the movable mold is separated from the fixed mold together with the intermediate mold, and a second mold opening state,in which the movable mold is separated from the intermediate mold and the fixed mold; and a mold connection control unit (for example, a mold connection control unit 62 to be described later) that controls the first mold connection element and the second mold connection element such that, in the first mold opening state, the first mold connection element separates the fixed mold and the intermediate mold from each other and the second mold connection element connects the movable mold and the intermediate mold, and in the second mold opening state, the first mold connection element connects the fixed mold and the intermediate mold and the second mold connection element separates the movable mold and the intermediate mold. (2) In the injection molding machine according to (1), the first mold connecting member (for example, a first mold connecting member 40, 140 to be described later) and the second mold connecting member (for example, a second mold connecting member 50, 150 to be described later) may each include: a movable pin (for example, a movable pin 42, 52, 142, 152 to be described later) provided in one mold; a fixing pin (for example, a fixing pin 43, a holding pin 53, a fixing pin 143, 153 to be described later) provided in the other mold;and a locking rod (for example, a locking rod 41, 51, 141, 151 to be described later) having a holding portion (for example, a holding portion 45, 55, 145, 155 to be described later) fixed to the fixing pin, and a pin engagement portion (for example, a pin engagement portion 44, 54, 144, 154 to be described later) configured to engage with the movable pin, and the movable pin is moved to a position where the movable pin engages with the pin engagement portion of the locking rod so that both molds are brought into a connected state, and the movable pin is moved to a position where the movable pin is disengaged from the pin engagement portion of the locking rod so that both molds are brought into a mutually disengaged state.; (3) In the injection molding machine according to (1), the first mold connecting member (for example, a first mold connecting member 240 to be described later) and the second mold connecting member (for example, a second mold connecting member 250 to be described later) may each include: a movable pin (for example, a movable pin 242, 252 to be described later) provided in one mold; a fixing pin (for example, a fixing pin 243, 253 to be described later) provided in the other mold;and a locking rod (for example, a locking rod 241, 251 to be described later) having a holding portion (for example, a holding portion 245, 255 to be described later) fixed to the movable pin, and a pin engagement portion (for example, a pin engagement portion 244, 254 to be described later) configured to engage with the fixing pin, and the movable pin is rotated and the pin engagement portion of the locking rod engages with the fixing pin so that both molds are brought into a connected state, and the movable pin is rotated in an opposite direction and the pin engagement portion of the locking rod is released from the fixing pin so that both molds are brought into a mutually released state.; (4) Furthermore, there is also disclosed an injection molding method carried out by an injection molding machine comprising: a three-platen type mold including a fixed mold, a movable mold movable with respect to the fixed mold, and an intermediate mold provided between the fixed mold and the movable mold; a first mold connecting member connecting or disconnecting the fixed mold and the intermediate mold; a second mold connecting member connecting or disconnecting the movable mold and the intermediate mold;and a mold moving device that moves the movable mold with respect to the fixed mold, wherein in a first mold opening state in which the movable mold is separated from the fixed mold together with the intermediate mold, the first mold connecting member separates the fixed mold and the intermediate mold from each other and the second mold connecting member connects the movable mold and the intermediate mold to each other, and in a second mold opening state in which the movable mold is separated from the intermediate mold and the fixed mold, the first mold connecting member connects the fixed mold and the intermediate mold to each other and the second mold connecting member separates the movable mold and the intermediate mold from each other.;

[0006] According to the present invention, it is possible to provide an injection molding machine and an injection molding method capable of easily removing a molded product and the like and further reducing the size of a mold when performing molding using a three-plate mold. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a conceptual diagram illustrating an overall configuration of an injection molding machine 1 according to a first embodiment. Fig. 2 is a block diagram illustrating a functional configuration of the injection molding machine 1. Fig. 3A is a schematic diagram showing an internal structure when the mold 10 is in a mold opening state and the fixing plate 14 is on the fixed side. Fig. 3B is a schematic diagram showing an internal structure when the mold 10 is in a mold closing state and the fixing plate 14 is on the fixed side. Fig. 4A is a schematic diagram illustrating a state in which a first mold connecting member 40 and a second mold connecting member 50 are connected. Fig. 4B is a schematic diagram illustrating a state in which the first mold connecting member 40 is released. Fig. Figure 5A is a schematic diagram illustrating a closed mold 10. Fig. Figure 5B is a schematic diagram illustrating an injection step. Fig. Figure 5C is a schematic diagram illustrating a first mold opening step. Fig. Figure 5D is a schematic diagram illustrating a first mold opening step. Fig. Figure 5E is a schematic diagram illustrating a sprue removal step. Fig. Figure 5F is a schematic diagram illustrating a mold closing step. Fig. 5G is a schematic diagram illustrating a second mold opening step and a molded product removing step. Fig. 6 is a flowchart showing a processing procedure of a mold moving and connecting control program executed by a control unit 60 according to the first embodiment. Fig. 7A is a schematic diagram illustrating a state in which a first mold connecting member 140 and a second mold connecting member 150 are connected according to a second embodiment. Fig. 7B is a sectional view taken along a line A - A according to Fig. 7A. Fig. 7C is a sectional view taken along a line A - A according to Fig. 7A. Fig. 7D is a schematic diagram illustrating a state in which the first mold connecting member 140 according to the second embodiment is released. Fig. 8A is a schematic diagram illustrating a state in which a first mold connecting member 240 and a second mold connecting member 250 are connected according to a third embodiment. Fig. 8B is a schematic diagram illustrating a state in which the first mold connecting member 240 and the second mold connecting member 250 are released according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Embodiments of the present invention will be described below. The drawings accompanying this specification are conceptual diagrams or schematic diagrams; and the shapes, scales, dimensional relationships, and the like of respective portions are altered or exaggerated from actuality for a better understanding of the invention. (First embodiment)

[0008] Fig. 1 is a schematic diagram showing an overall configuration of an injection molding machine 1 according to a first embodiment. Fig. Figure 2 is a block diagram illustrating a functional configuration of the injection molding machine 1. The second and third embodiments to be described later share the basic configuration of the injection molding machine 1 according to the first embodiment.

[0009] In the present description and the like, a moving direction of a movable mold 12 to be described later is shown in Fig. 1 is defined as the X direction (X1-X2) and is described in the drawings using arrows. In the X direction, a direction in which the movable mold 12 moves away from a fixed mold 11 is defined as the X1 direction; and a direction in which the movable mold 12 approaches the fixed mold 11 is defined as the X2 direction. On the drawing sheet, a direction perpendicular to the X direction is defined as the Y direction (Y1-Y2). In the Y direction, in a drawing (for example, in Fig. 4A) Arrows are used when the description of this direction is required.

[0010] As in Fig. 1, the injection molding machine 1 includes a mold 10, a mold moving device 20, an injection device 30, a first mold connecting member 40, a second mold connecting member 50, and a control unit 60. The mold 10 includes a fixed mold 11, a movable mold 12, and an intermediate mold 13. The mold 10 according to the first embodiment is designed as a three-plate type mold including the fixed mold 11, the movable mold 12, and the intermediate mold 13.

[0011] The fixed mold 11 is a mold provided on the X2 side of the mold 10 and held by a fixing plate 14 on the fixed side. The fixed mold 11 comprises a channel 11a (see Fig. 3A) serving as a passage for a molding material. The fixed-side fixing plate 14 is a flat member that holds the fixed mold 11; and a surface on the opposite side of the fixed mold 11 is attached to a mold support 15 on the fixed side. The fixed-side mold support 15 is a flat member that holds the fixed-side fixing plate 14 so as to hold the fixed mold 11. The fixed mold 11 includes a first mold connecting member 40 (to be described later). As described later, a portion of the first mold connecting member 40 is provided in the intermediate mold 13. The fixed mold 11 moves together with the intermediate mold 13 so that a very narrow gap (s2) is formed in the X direction in the course of establishing the first and second mold closing and opening states to be described later.

[0012] The movable mold 12 is a mold which has a molding surface 121 on a side facing the intermediate mold 13 (see Fig. 3A) and is configured to be movable in the X direction (X1-X2) by the driving force of the mold moving device 20. In the movable mold 12, an ejector (not shown) is provided on a side opposite to the molding surface 121 (the X1 side). The ejector is a device that ejects a molded product formed by the mold 10 from the movable mold 12. The ejector ejects a molded product from the molding surface 121 of the movable mold 12, for example, by advancing a pin (not shown) of the ejector from a surface of the movable mold 12 on the X1 side to a molding surface on the X2 side. The movable mold 12 includes the second mold connecting member 50 (to be described later). As described later, a portion of the second mold connecting member 50 is provided in the intermediate mold 13.

[0013] The intermediate mold 13 is a mold which has a molding surface 131 (see Fig. 3A) and is provided between the fixed mold 11 and the movable mold 12. The intermediate mold 13 is configured to be movable in the X direction (X1-X2). The intermediate mold 13 is a mold that does not move independently but is moved by being pushed or, in a connected state, tensioned by the movable mold 12 to be described later.

[0014] When the fixed mold 11, the movable mold 12 and the intermediate mold 13 are closed, a cavity CV formed by the molding surface 121 of the movable mold 12 and the molding surface 131 of the intermediate mold 13 (see Fig. 3B) is formed inside the mold 10. By filling a molding material into the cavity CV via the injection device 30, a molded product is formed.

[0015] The mold moving device 20 is a device that moves the movable mold 12 relative to the fixed mold 11 in the X direction (X1-X2). The mold moving device 20 includes a servo motor 21 (see Fig. 2), the rotation direction and rotation amount of which are controlled by the control unit 60. The servo motor 21 is controlled to move the movable mold 12 in the direction of approach to the fixed mold 11 (the X2 direction) by a mold closing start signal sent from a mold movement control unit 61 (the control unit 60) to be described later. Furthermore, the servo motor 21 is controlled to move the movable mold 12 in the direction of distance from the fixed mold 11 (the X1 direction) by a mold opening start signal sent from the mold movement control unit 61 (the control unit 60). The movable mold 12 moves independently, and it moves, as described later, pushing the intermediate mold 13 in the X2 direction and moving in the X1 direction while pulling the intermediate mold 13 connected to it.

[0016] The injection device 30 is a device that fills a molding material (for example, plastic or the like) into the closed mold 10. The injection device 30 has a nozzle at its distal end, which is connected to a gate (not shown) formed in the mold carrier 15 on the fixed side. The injection device 30 includes a servo motor 31 (see Fig. 2), the direction and value of which are controlled by the control unit 60. The servo motor 31 is controlled by an injection control signal sent from the control unit 60 to rotate a screw mechanism provided in a cylinder of the injection device 30 to accordingly fill a predetermined amount of molding material into the mold 10.

[0017] The first mold connecting element 40 is a device that connects or disconnects the fixed mold 11 and the intermediate mold 13. The first mold connecting element 40 includes an electromagnet 46 (see Fig. 2) as a drive unit when changing a connection state. The electromagnet 46 is controlled to connect or release the fixed mold 11 and the intermediate mold 13 with or from each other by a connection signal or release signal sent from a mold connection control unit 62 (the control unit 60) to be described later.

[0018] The second mold connecting member 50 is a device that connects or disconnects the movable mold 12 and the intermediate mold 13. The second mold connecting member 50 includes an electromagnet 56 (see Fig. 2) as a drive unit when changing a connection state. The electromagnet 56 is driven to connect or disconnect the movable mold 12 and the intermediate mold 13 with or from each other by a connection signal or release signal sent from the mold connection control unit 62 (the control unit 60) to be described later. A specific example of the first mold connection element 40 and the second mold connection element 50 will be described later.

[0019] The control unit 60 is a device electrically connected to the mold moving device 20, the ejector device (not shown), the injection device 30, and the like of the injection molding machine 1 to control the operation of these respective devices. Specifically, the control unit 60 controls an operation of the mold moving device 20 that closes and opens the mold 10, an operation of the ejector device that ejects a molded product, an operation of the injection device 30 that injects a molding material, and the like. The control unit 60 executes these basic operations of the injection molding machine 1 as a control of a main part of the control unit. Hereinafter, a portion of the control unit 60 that controls a basic function of the injection molding machine 1 is appropriately referred to as a "main part of the control unit."

[0020] The control unit 60 is designed as a microprocessor unit including a central processing unit (CPU), a memory, and the like. The control unit 60 realizes various functions by reading an application program (for example, a mold movement and connection control program, to be described later) for controlling the injection molding machine 1 from a memory unit 63 and executing the program in cooperation with respective hardware components.

[0021] As in Fig. 2, the control unit 60 comprises the mold movement control unit 61, the mold connection control unit 62 and the storage unit 63. The mold movement control unit 61 moves the movable mold 12 so that either a mold closing state (see, for example, the Fig. 5A), in which the fixed mold 11, the movable mold 12 and the intermediate mold 13 of the mold 10 are connected to each other, or a first mold opening state (see, for example, the later-described Fig. 5D), in which the movable mold 12 and the intermediate mold 13 are separated from the fixed mold 11, or a second mold opening state (see, for example, the later-described Fig. 5G) by separating the movable mold 12 from the intermediate mold 13 and the fixed mold 11. A specific example of the mold closing state, the first mold opening state, and the second mold opening state will be described later.

[0022] In the mold closing state, the mold connection control unit 62 controls the first mold connection member 40 and the second mold connection member 50 such that the first mold connection member 40 connects the fixed mold 11 and the intermediate mold 13, and the second mold connection member 50 connects the movable mold 12 and the intermediate mold 13. In the first mold opening state, the mold connection control unit 62 controls the first mold connection member 40 and the second mold connection member 50 such that the first mold connection member 40 detaches the fixed mold 11 from the intermediate mold 13, and the second mold connection member 50 connects the movable mold 12 and the intermediate mold 13.In the second mold opening state, the mold connection control unit 62 controls the first mold connection member 40 and the second mold connection member 50 so that the first mold connection member 40 connects the fixed mold 11 and the intermediate mold 13 and the second mold connection member 50 detaches the movable mold 12 from the intermediate mold 13.

[0023] The mold connection control unit 62 controls a connection state of each connection element by sending a connection signal or a release signal to the first mold connection element 40 and the second mold connection element 50. The operations of the first mold connection element 40 and the second mold connection element 50 controlled by the mold connection control unit 62 will be described later.

[0024] The storage unit 63 is a storage device in which various programs, data, and the like executed by the injection molding machine 1 are stored. The storage unit 63 is designed, for example, as a semiconductor memory, a hard disk device, and the like. As an application program, for example, a control program for moving and connecting the mold is stored in the storage unit 63.

[0025] Next, an internal structure of the mold 10 and the fixing plate 14 on the fixed side will be described. Fig. 3A and Fig. 3B are schematic diagrams illustrating an internal structure of the mold 10 and the fixing plate 14 on the fixed side. Fig. 3A is a schematic diagram showing an internal structure when the mold 10 is in a mold opening state and the fixing plate 14 is on the fixed side. Fig. Fig. 3B is a schematic diagram showing an internal structure when the mold 10 is in a mold closing state and the fixing plate 14 is on the fixed side. Fig. The mold opening state shown in Fig. 3A illustrates a state in which the respective molds are separated from each other for easier understanding of the structures of the respective portions, and is different from a first mold opening state and a second mold opening state to be described later.

[0026] As in Fig. 3A, the fixed mold 11 has a channel 11a for a molding material provided therein. In addition, the mounting plate 14 on the fixed side has a channel 14a for a molding material provided therein. These channels 11a and 14a communicate with each other when the mold 10 is in a mold-closed state. Although not shown in the drawing, the mold carrier 15 on the fixed side (see Fig. 1) has a gate formed at a position facing the channel 14a of the mounting plate 14 on the fixed side. A nozzle at the distal end of the injection device 30 is connected to the gate.

[0027] As in Fig. 3A, the movable mold 12 has a molding surface 121 on a side facing the intermediate mold 13. As shown in Fig. As shown in Figure 3A, the intermediate mold 13 has a molding surface 131 on a side facing the movable mold 12. The intermediate mold 13 has a channel 13a for a molding material. The channel 13a is connected to the molding surface 131.

[0028] If the Fig. 3A, the mold 10 together with the fixing plate 14 on the fixed side is in a closed state of the mold, as shown in Fig. 3B, a cavity CV formed by the molding surface 121 of the movable mold 12 and the molding surface 131 of the intermediate mold 13 is formed inside the mold 10. The cavity CV communicates with the channel 13a (of the intermediate mold 13), the channel 11a (of the fixed mold 11), and the channel 14a (of the fixed-side mounting plate 14). Therefore, a molding material discharged from the injection device 30 from the gate (not shown) of the fixed-side mold base 15 passes through the respective channels and is filled into the cavity CV. In the mold 10, a molded product remains in the cavity CV after casting, and a sprue remains in the respective channels and the sprue. The molded product and the sprue are contained in the fixed-side mounting plate 14 and the mold 10 after casting. As described later, the molded product and the sprue part are separated when the mold 10 is opened.

[0029] Next, a configuration of the first mold connecting member 40 and the second mold connecting member 50 will be described. Fig. 4A and Fig. 4B are schematic diagrams illustrating the first mold connecting member 40 and the second mold connecting member 50. Fig. 4A is a schematic diagram illustrating a state in which the first mold connecting member 40 and the second mold connecting member 50 are connected. Fig. 4B is a schematic diagram illustrating a state in which the first mold connecting member 40 is released.

[0030] As in Fig. As shown in FIG. 4A, the first mold connecting member 40 includes a locking rod 41, a movable pin 42, and a fixing pin 43. The locking rod 41 is a member that connects or disconnects the fixed mold 11 and the intermediate mold 13. The locking rod 41 includes a pin engaging portion 44 and a holding portion 45. The pin engaging portion 44 is a portion formed approximately in a T-shape. The movable pin 42 engages with the pin engaging portion 44. The holding portion 45 is a portion fixed to the fixing pin 43.

[0031] The movable pin 42 is a member that is movable in the Y direction (Y1-Y2). Two movable pins 42 are formed in the fixed mold 11 along the Y direction. Fig. 4A shows a state in which the movable pin 42 has been moved to a position (hereinafter also referred to as a "connection position") where the movable pin 42 is connected to the locking rod 41. When the movable pin 42 is moved to the connection position, the fixed mold 11 and the intermediate mold 13 are connected because the movable pin 42 is engaged with the pin engagement portion 44 of the locking rod 41.

[0032] Fig. 4B shows a state in which the movable pin 42 has been moved to a position (hereinafter also referred to as a "release position") where the movable pin 42 is disengaged from the lock rod 41. When the movable pin 42 is moved to the release position, the fixed mold 11 and the intermediate mold 13 are disengaged from each other because the movable pin 42 is disengaged from the pin engaging portion 44 of the lock rod 41. The movable pin 42, which has been moved to the release position, does not interfere with the pin engaging portion 44 even when the lock rod 41 is moved in the X direction with the movement of the intermediate mold 13.

[0033] The fixing pin 43 is a member fixed to the intermediate mold 13 and fixes the holding portion 45 of the locking rod 41. The holding portion 45 of the locking rod 41 is fixed by the fixing pin 43 so that it does not rotate. Therefore, the locking rod 41 does not rotate around the fixing pin 43, but remains approximately parallel to the X direction, as shown in Fig. 4B when the intermediate mold 13 moves in the X direction.

[0034] The first mold connecting element 40 according to the first embodiment comprises the electromagnet 46 (see Fig. 2) as a drive unit for moving the movable pin 42 in the Y direction (Y1-Y2). When current is applied to the electromagnet 46 to attract a plunger (not shown), the movable pin 42 can be moved to a release position. When the supply of current to the electromagnet 46 is stopped to push the plunger to an original position, the movable pin 42 can be moved to a connection position. In this case, the current applied to the electromagnet 46 from the mold connection control unit 62 serves as a release signal applied from the mold connection control unit 62 to the first mold connection element 40. A state (for example, a zero-ampere state) in which no current is applied to the electromagnet 46 from the mold connection control unit 62 serves as a connection signal applied from the mold connection control unit 62 to the first mold connection element 40.

[0035] As in Fig. As shown in Figure 4A, the second mold connecting member 50 includes a locking rod 51, a movable pin 52, and a retaining pin 53. The locking rod 51 is a member that connects or releases the movable mold 12 and the intermediate mold 13. The locking rod 51 includes a pin engaging portion 54 and a retaining portion 55. The pin engaging portion 54 is a portion formed approximately in a T-shape. The retaining portion 55 has a narrow and long opening 55a that can engage with the retaining pin 53.

[0036] Since, in the second mold connecting member 50, a configuration by which the movable pin 52 is driven is substantially the same as the configuration by which the movable pin 42 of the first mold connecting member 40 is driven, its description will be omitted. The retaining pin 53 is a member fixed to the intermediate mold 13. The retaining pin 53 engages with the retaining portion 55 (the long opening 55a) of the locking rod 51. As shown in Fig. 4A, the retaining pin 53 has an approximately elliptical shape that is narrow in the X-direction. Therefore, the locking rod 51 does not rotate around the retaining pin 53. As shown in Fig. As shown in Fig. 4A, the locking rod 51 can be moved in the X direction by the same distance as the distance d1 formed between the holding portion 55 and the holding pin 53. As described later, the same gap s1 as the distance d1 is formed between the movable mold 12 and the intermediate mold 13 when the movable mold 12 is moved in the X1 direction.

[0037] As in Fig. As shown in Fig. 4A, a link mechanism 70 is provided between the fixed mold 11 and the fixed-side fixing plate 14. The link mechanism 70 is a mechanism for adjusting a mold opening degree between the fixed mold 11 and the fixed-side fixing plate 14. The link mechanism 70 includes a holding pin 71, a fixing pin 72, and an engaging plate 73. The holding pin 71 is a member fixed to the fixed mold 11. The fixing pin 72 is a member fixed to the fixed-side fixing plate 14. The engaging plate 73 is a flat member and has a narrow and long opening 73a formed therein.

[0038] The long opening 73a of the engagement plate 73 engages with the retaining pin 71. One end of the engagement plate 73 on the X2 side is fixed to the fixing pin 72. Therefore, the fixed die 11 can be moved relative to the fixed-side fixing plate 14 by a distance d2 in the X direction. As described later, when the fixed die 11 moves in the X1 direction, the same gap s2 as the distance d2 is formed between the fixed die 11 and the fixed-side fixing plate 14. A plurality of link mechanisms 70 are formed between the fixed die 11 and the fixed-side fixing plate 14. The link mechanism 70 is not limited to the configuration described above; for example, a loose chain may be stretched between the fixed die 11 and the fixed-side fixing plate 14.

[0039] As in Fig. 4A, the two movable pins 42 are moved to the release positions in the directions Y1 and Y2, respectively, when in a state where the first mold connecting member 40 and the second mold connecting member 50 connect the two corresponding molds, the mold connecting control unit 62 (see Fig. 2) a release signal is sent to the first mold link 40. When the movable mold 12 is moved in the direction X1 in this state, first, the holding portion 55 of the locking rod 51 (the second mold link 50) moves with respect to the holding pin 53 by the same distance as the distance d1 in the direction X1. Therefore, as shown in Fig. 4B, the gap s1, which has the same length as the distance d1, is formed at a mating surface (a parting surface) between the movable mold 12 and the intermediate mold 13. When the gap s1 is formed, the molded product (not shown) formed between the movable mold 12 and the intermediate mold 13 and the sprue formed inside the intermediate mold 13 are separated from the parting surface simultaneously with the mold opening.

[0040] Then, as in Fig. 4B, the intermediate mold 13 moves along with the movable mold 12 in the direction X1. Therefore, a wide gap s3 is formed between the intermediate mold 13 and the fixed mold 11. Since such a wide gap s3 is formed in the mold 10 according to the first embodiment, it is possible to easily remove the sprue part (not shown) formed inside the intermediate mold 13.

[0041] When the intermediate mold 13 moves together with the movable mold 12 in the direction X1, the holding pin 71 of the link mechanism 70 moves with respect to the engagement plate 73 by the distance corresponding to the distance d2 in the direction X1 because the fixed mold 11 moves while being caught on the sprue remaining in the intermediate mold 13 (the details will be described later). Therefore, as shown in Fig. 4B, a gap s2 having the same length as the distance d2 is formed at the mating surface (a parting surface) between the fixed mold 11 and the fixed-side mounting plate 14. When the gap s2 is formed, the sprue formed between the fixed mold 11 and the fixed-side mounting plate 14 is separated from the parting surface simultaneously with the mold opening. A process when only the movable mold 12 moves in the X1 direction will be described later.

[0042] Next, with reference to the Fig. 5A to 5G, a function of the mold 10 in the injection molding machine 1 according to the first embodiment is described. Fig. 5A to 5G are schematic diagrams illustrating a state in which the fixed mold 11, the movable mold 12, and the intermediate mold 13 constituting the mold 10 are moved in a molding cycle. A molding cycle refers to a sequence of steps including a mold 10 closing step, an injection step, a mold opening step, a molded product removal step, and a mold closing step. In the steps to be described later, Fig. 5A to 5G only show the sections required to describe the working processes of the injection molding machine 1.

[0043] Fig. 5A is a schematic diagram illustrating the closed form 10. As in Fig. 5A, the closed mold 10 is in a state where the gap between the fixed mold 11 and the fixing plate 14 on the fixed side, the gap between the fixed mold 11 and the intermediate mold 13, and the gap between the movable mold 12 and the intermediate mold 13 are closed before the start of a cycle. Although not shown in the drawing, the fixed mold 11 and the intermediate mold 13 of the closed mold 10 are connected by the first mold connecting member 40 (see Fig. 4A). In addition, the movable mold 12 and the intermediate mold 13 are connected by the second mold connecting member 50 (see Fig. 4A). With the mold 10 closed, the first mold connecting element 40 and the second mold connecting element 50 can be connected or disconnected as described above.

[0044] Fig. Figure 5B is a schematic diagram illustrating an injection step. As shown in Fig. As shown in Figure 5B, in the injection step, a molding material is filled into the closed mold 10 by the injection device 30. A subsequent first mold opening step is then carried out via compaction, plasticization, cooling, and the like.

[0045] The Fig. 5C and Fig. 5D are schematic diagrams illustrating the first mold opening step. In the first mold opening step, the movable mold 12 is moved in the direction X1 so that the movable mold 12 is separated from the fixed mold 11 together with the intermediate mold 13. In the first mold opening step, a connection state of the first mold connection member 40 is changed (see Fig. 4B), and the intermediate mold 13 and the fixed mold 11 are separated from each other. Since no change in the connection state of the second mold connecting element 50 occurs in this state, the movable mold 12 and the intermediate mold 13 remain in the connected state. When the movable mold 12 begins to move in the direction X1 after performing such a change in the connection state, as shown in Fig. As shown in Figure 5C, the gap s1 is formed at a mating surface P1 between the movable mold 12 and the intermediate mold 13. When the gap s1 is formed, the molded product 2 and the sprue 3 are separated from each other.

[0046] Although not shown in the drawing, a locking mechanism such as a plastic lock, a magnetic lock, or a mechanical lock may be used as a mechanism for controlling the opening procedure of the mold 10. By using these locking mechanisms, it is possible to first separate the mating surface P1 between the movable mold 12 and the intermediate mold 13, and then separate the intermediate mold 13 and the fixed mold 11.

[0047] When the movable mold 12 moves in the direction X1, the sprue 3 is pulled out of the intermediate mold 13. When the sprue 3 is pulled out of the intermediate mold 13, the fixed mold 11 is moved by the distance corresponding to the distance d2 (see Fig. 4A) moves in the direction X1, being stuck to the gate part 3 because of frictional resistance between the fixed mold 11 and the gate part 3. When the fixed mold 11 moves in the direction X1 by the distance d2, the gap s2 is formed at the mating surface P2 between the fixed mold 11 and the fixed-side mounting plate 14. When the gap s2 is formed, the portion of the gate part 3 on the X2 side is separated from the fixed-side mounting plate 14. As shown in Fig. As shown in Figure 5D, the mold 10 enters a first mold opening state when the movable mold 12 moves in the direction X1 to reach a mold opening position. When the movable mold 12 reaches the mold opening position, the wide gap s3 is formed between the intermediate mold 13 and the fixed mold 11.

[0048] Fig. Figure 5E is a schematic diagram illustrating a sprue removal step. As shown in Fig. As shown in Fig. 5E, in the sprue removal step, the sprue 3 is removed from the opened mold 10 by a robot arm 80. Since the wide gap s3 is formed between the fixed mold 11 and the intermediate mold 13 in the sprue removal step, the sprue 3 can be easily removed from the space between the fixed mold 11 and the intermediate mold 13.

[0049] Fig. Figure 5F is a schematic diagram illustrating a mold closing step. In the mold closing step, as shown in Fig. 5F, the movable mold 12 is moved in the direction toward the fixed mold 11 (the direction X2). In the mold closing step, the intermediate mold 13 is moved from the movable mold 12 to a position where the intermediate mold 13 comes into contact with the fixed mold 11. The reason why the intermediate mold 13 is moved to a position where the intermediate mold 13 comes into contact with the fixed mold 11 in the mold closing step is the formation of a wide gap s4 between the movable mold 12 and the intermediate mold 13 in a second mold opening step to be described later. When the intermediate mold 13 is moved to a position where the intermediate mold 13 comes into contact with the fixed mold 11, the fixed mold 11 and the intermediate mold 13 are connected by the first mold connecting member 40 (see Fig. 4A). In addition, the movable mold 12 and the intermediate mold 13 are separated from each other by the second mold connecting member 50 (see Fig. 4A). When the movable mold 12 is released from the intermediate mold 13, the movable mold 12 moves independently in the second mold opening step to be described later.

[0050] In the mold closing step, either the fixed mold 11, the intermediate mold 13, or the movable mold 12 may not be closed. This means that in the second mold opening step to be described later, the fixed mold 11 and the intermediate mold 13 do not need to be connected to each other by the first mold connecting member 40 if the intermediate mold 13 is not pulled by the movable mold 12 moving in the direction X1. If the movable mold 12 and the intermediate mold 13 can be separated from each other by the second mold connecting member 50 when the intermediate mold 13 is moved to a position where the intermediate mold 13 comes into contact with the fixed mold 11 as the movable mold 12 moves, the movable mold 12 does not need to come into contact with the intermediate mold 13.

[0051] Fig. Figure 5G is a schematic diagram illustrating a second mold opening step and a molded product removal step. In the second mold opening step, the movable mold 12 is moved in the direction X1 so that the movable mold 12 is separated from the intermediate mold 13 and the fixed mold 11. As shown in Fig. 5G, the mold 10 enters a second mold opening state when the movable mold 12 moves in the direction X1 to reach the mold opening position. When the movable mold 12 reaches the mold opening position, a wide gap s4 forms between the movable mold 12 and the intermediate mold 13. Since in the second mold opening state, similar to the first mold opening state, the gap s1 and the gap s2 (see Fig. 5C and Fig. 5D) do not form between the molds, the gap s4 is formed, which is wider than the gap s3 in the first mold opening state.

[0052] Subsequently, in the molded product removal step, the molded product 2 is removed from the opened mold 10 by the robot arm 80. Since the wider gap s4 (> s3) is formed between the fixed mold 11 and the intermediate mold 13 in the molded product removal step, the molded product 2 can be easily removed from the inside of the movable mold 12.

[0053] After the molded product removal step is carried out, the clearance between the fixed mold 11 and the fixing plate 14 on the fixed side, the clearance between the fixed mold 11 and the intermediate mold 13 and the clearance between the movable mold 12 and the intermediate mold 13 are closed, and the mold 10 comes into a mold closing state as shown in Fig. 5A. In this way, one casting cycle is completed.

[0054] Next, based on the Fig. 6, the details of the processing of the mold moving and connecting control program executed by the injection molding machine 1 (the control unit 60) according to the first embodiment will be described. Fig. 6 is a flowchart showing a processing procedure of the mold moving and connecting control program executed by the control unit 60 according to the first embodiment.

[0055] In the Fig. In step S101 shown in Figure 6, the main part of the control unit (the control unit 60) determines whether the first mold opening step of the mold 10 has been initiated. The first mold opening step begins, for example, when, after the Fig. 5B, the compression, plasticizing, cooling, and the like are completed. If the control unit main body determines in step S101 that the opening of the mold 10 has started, the flow proceeds to step S102. If the control unit main body determines that the opening of the mold 10 has not started, the flow proceeds to (returns to) step S101.

[0056] In step S102 (step S101: YES), the mold connection control unit 62 (the control unit 60) sends a release signal to the first mold connection member 40 so that the fixed mold 11 and the intermediate mold 13 are released from each other.

[0057] In step S103, the mold movement control unit 61 moves the movable mold 12 in a direction of distance from the fixed mold 11 (the direction X1). In this case, since the intermediate mold 13 is connected to the movable mold 12 by the second mold connecting member 50, the intermediate mold 13 moves together with the movable mold 12. When the movable mold 12 reaches the mold opening position and the mold 10 enters the first mold opening state, the wide gap s3 is formed between the intermediate mold 13 and the fixed mold 11, as shown in FIG. Fig. 5D (first mold opening step).

[0058] In step S104, the main part of the control unit controls the robot arm 80 to remove the sprue part 3 from the space between the fixed mold 11 and the intermediate mold 13, as shown in Fig. 5E (sprue removal step).

[0059] In step S105, the mold movement control unit 61 moves the movable mold 12 in the direction of approach to the fixed mold 11 (the X2 direction). In this case, the intermediate mold 13 moves in the X2 direction while being pressed by the movable mold 12. When the movable mold 12 reaches a mold-closed position, the mold 10 enters a mold-closed state, such as in Fig. 5C (mold closing step).

[0060] In step S106, the mold connection control unit 62 sends a connection signal to the first mold connection element 40 to connect the fixed mold 11 and the intermediate mold 13. In step S107, the mold connection control unit 62 sends a release signal to the second mold connection element 50 to release the movable mold 12 and the intermediate mold 13. The order of the processes in steps S106 and S107 can be reversed, and they can be executed simultaneously.

[0061] In step S108, the mold movement control unit 61 moves the movable mold 12 in the direction of distance from the fixed mold 11 (the direction X1). When the movable mold 12 thus reaches the mold opening position and the mold 10 enters the second mold opening state, the wide gap s4 is formed between the movable mold 12 and the intermediate mold 13, as shown in, for example, Fig. 5G (second mold opening step).

[0062] In step S109, the main part of the control unit controls the robot arm 80, for example, as shown in Fig. 5G to remove the molded product 2 from the space between the movable mold 12 and the intermediate mold 13 (molded product removing step).

[0063] In step S110, the mold movement control unit 61 moves the movable mold 12 in the direction of approach to the fixed mold 11 (the direction X2). In this case, the intermediate mold 13 moves in the direction X2, being pressed by the movable mold 12. When the movable mold 12 reaches the closed position of the mold, the mold 10 enters the position shown in, for example, Fig. 5A. After step S110, the process according to this flowchart ends. After step S110, for example, the mold closing state shown in Fig. 5B shows the injection step.

[0064] The injection molding machine 1 according to the first embodiment achieves, for example, the following advantages. The advantages of the injection molding machine 1 according to the first embodiment are common to the second and third embodiments to be described later. Since, in the injection molding machine 1 according to the first embodiment, the wide gap s3 is formed between the intermediate mold 13 and the fixed mold 11 in the first mold opening state, as shown in Fig. 5D, it becomes easy to remove the sprue part 3. Since in the second mold opening state, as shown in Fig. 5G, the wide gap s4 between the movable mold 12 and the intermediate mold 13 is formed, as in Fig. 5G, it becomes easy to remove the molded product 2. In the injection molding machine 1 according to the first embodiment, when performing molding using the mold 10, which is a three-plate mold, it becomes easy to remove the molded product 2 and the sprue 3.

[0065] In the injection molding machine 1 according to the first embodiment, the intermediate mold 13 is moved alternately in the X1 direction and the X2 direction, whereby the wide gap s3 is formed between the intermediate mold 13 and the fixed mold 11 in the first mold opening state, and the wide gap s4 (>s3) is formed between the movable mold 12 and the intermediate mold 13 in the second mold opening state. Therefore, the mold opening degree of the mold 10 can be reduced compared to a system in which the fixed mold and the movable mold are moved apart with the intermediate mold interposed therebetween, as in the conventional three-platen mold. Therefore, in the injection molding machine 1 according to the first embodiment, it is possible to easily remove the molded product 2 and the sprue 3 and further reduce the size of the mold 10.

[0066] A molding method may be used in which a component is inserted into the mold 10 and then a mold closing operation is performed after the molded product 2 is removed from the movable mold 12. In such a molding method, when the molded product 2 is removed, the robot arm 80 can grip the molded product 2 and the inserted component. In the injection molding machine 1 according to the first embodiment, since the wide gap s4 is formed between the movable mold 12 and the intermediate mold 13 in the second mold opening state for removing the molded product 2, it is possible to ensure sufficient clearance for the robot arm 80 to perform operations without increasing an overall mold opening degree of the mold 10.

[0067] In the injection molding machine 1 according to the present embodiment, the first mold connecting member 40 and the second mold connecting member 50 are controlled by a connection signal or a release signal sent from the mold connection control unit 62. Therefore, it is possible to more quickly switch the connection state of the fixed mold 11 and the intermediate mold 13 and the connection state of the movable mold 12 and the intermediate mold 13. (Second embodiment)

[0068] The Fig. 7A to 7D are schematic diagrams illustrating a first mold connecting member 140 and a second mold connecting member 150 according to the second embodiment. Fig. Fig. 7A is a schematic diagram illustrating a state in which the first mold connecting member 140 and the second mold connecting member 150 are connected according to the second embodiment. Fig. 7B and Fig. 7C are sectional views along a line AA in Fig. 7A. Fig. 7D is a schematic diagram illustrating a state in which the first mold connecting member 140 according to the second embodiment is released. In the description and drawings of the second embodiment, portions that perform the same functions as the constituent elements according to the first embodiment are appropriately denoted by the same reference numerals or the same end digits of the reference numerals (the last two digits), and redundant descriptions thereof will be omitted where appropriate.

[0069] As in Fig. As shown in Figure 7A, the first mold connecting member 140 according to the second embodiment includes a locking rod 141, a movable pin 142, and a fixing pin 143. The locking rod 141 is a member that connects or disconnects the fixed mold 11 and the intermediate mold 13. The locking rod 141 includes a pin engaging portion 144 and a holding portion 145. The pin engaging portion 144 has an opening 144a with which the movable pin 142 can engage. The holding portion 145 is a portion fixed to the fixing pin 143.

[0070] The movable pin 142 is a member that is movable in the Y direction (Y1-Y2) as shown in Fig. 7B. Fig. 7B shows a state in which the movable pin 142 has been moved to a connecting position where the movable pin 142 is connected to the locking rod 141. As in Fig. 7B, the fixed mold 11 and the intermediate mold 13 enter a connected state when the movable pin 142 moves to the connecting position because the movable pin 142 engages with the pin engaging portion 144 of the lock rod 141.

[0071] Fig. 7C shows a state in which the movable pin 142 has been moved to a release position where the movable pin 142 is released from the locking rod 141. As in Fig. 7C, the fixed mold 11 and the intermediate mold 13 enter a release state when the movable pin 142 moves to the release position because the movable pin 142 is disengaged from the pin engaging portion 144 of the lock rod 141.

[0072] The fixing pin 143 is a member fixed to the intermediate mold 13 and fixes the holding portion 145 of the locking rod 141. The holding portion 145 of the locking rod 141 is fixed by the fixing pin 143 so that it does not rotate. Therefore, even when the intermediate mold 13 moves in the X direction, the locking rod 141 does not rotate around the fixing pin 143 and remains approximately parallel to the X direction, as shown in Fig. 7B.

[0073] The first mold connection element 140 according to the second embodiment comprises an electromagnet 146 (see Fig. 7B) as a drive unit for moving the movable pin 142 in the Y direction. When current is applied to the electromagnet 146 to attract a plunger (not shown), the movable pin 142 can be moved to a release position. When the supply of current to the electromagnet 146 to push the plunger to an original position is stopped, the movable pin 142 can be moved to a connection position. In this case, the current applied to the electromagnet 146 by the mold connection control unit 62 serves as a release signal supplied to the first mold connection element 140 from the mold connection control unit 62. A state (for example, a zero-ampere state) in which no current is applied to the electromagnet 146 by the mold connection control unit 62 serves as a connection signal supplied to the first mold connection element 140 from the mold connection control unit 62.

[0074] As in Fig. As shown in Figure 7A, the second mold connecting member 150 according to the second embodiment includes a locking rod 151, a movable pin 152, and a fixing pin 153. The locking rod 151 is a member that connects or disconnects the movable mold 12 and the intermediate mold 13. The locking rod 151 includes a pin engaging portion 154 and a holding portion 155. The pin engaging portion 154 has a narrow and long opening 154a that can engage with the movable pin 152. The holding portion 155 is a portion fixed to the fixing pin 153.

[0075] Since the configuration of the second mold connecting member 150 that drives the movable pin 152 is substantially the same as the configuration (the electromagnet 146) that drives the movable pin 142 of the first mold connecting member 140, its description will be omitted. The movable pin 152 is provided in the movable mold 12. The movable pin 152 engages with the pin engagement portion 154 of the locking rod 151. As shown in Fig. As shown in Figure 7A, the movable pin 152 has a roughly elliptical shape that is narrow in the X direction. When the pin engaging portion 154 of the locking rod 151 engages with the movable pin 152, the locking rod 151 can move the same distance as the distance d1 formed between the pin engaging portion 154 and the movable pin 152. As described later, the same gap s1 as the distance d1 is formed between the movable die 12 and the intermediate die 13 when the movable die 12 moves in the X1 direction.

[0076] The fixing pin 153 is a member fixed to the intermediate mold 13 and fixes the holding portion 155 of the locking rod 151. The holding portion 155 of the locking rod 151 is fixed by the fixing pin 153 so that it does not rotate. Therefore, even when the locking rod 151 is rotated, it does not rotate around the fixing pin 153 and remains approximately parallel to the X direction, as shown in Fig. 7D when the intermediate form 13 moves in the X direction.

[0077] As in Fig. 7A, the movable pin 142 moves in the direction Y2 to the release position when the mold connection control unit 62 (see Fig. 2) in a state where the first mold connecting member 140 and the second mold connecting member 150 connect the two corresponding molds together, a release signal is sent to the first mold connecting member 140. When the movable mold 12 is moved in the direction X1 in this state, as shown in Fig. As shown in Fig. 7D, the intermediate mold 13 connected to the movable mold 12 moves together with the movable mold 12 in the direction X1. Therefore, the wide gap s3 is formed between the intermediate mold 13 and the fixed mold 11.

[0078] When the movable mold 12 moves in the direction X1 as shown in Fig. As shown in Fig. 7D, the movable pin 152 moves with respect to the pin engagement portion 154 of the lock rod 151 (the second mold connecting member 150) by the same distance as the distance d1 in the direction X1. Therefore, the gap s1 has the same length as the distance d1 formed at the fitting surface (a parting surface) between the movable mold 12 and the intermediate mold 13. When the gap s1 is formed, the molded product (not shown) formed between the movable mold 12 and the intermediate mold 13 and the sprue formed inside the intermediate mold 13 can be separated from the parting surface simultaneously with the mold opening. (Third embodiment)

[0079] The Fig. 8A and Fig. 8B are schematic diagrams illustrating a first mold connecting member 240 and a second mold connecting member 250 according to the third embodiment. Fig. 8A is a schematic diagram illustrating a state in which the first mold connecting member 240 and the second mold connecting member 250 are connected according to the third embodiment. Fig. 8B is a schematic diagram illustrating a state in which the first mold connecting member 240 according to the third embodiment is released. In the description and drawings of the third embodiment, portions that perform the same functions as the constituent elements according to the first embodiment are appropriately denoted by the same reference numerals or the same end digits of the reference numerals (the last two digits), and redundant descriptions thereof will be omitted where appropriate.

[0080] As in Fig. As shown in Figure 8A, the first mold connecting member 240 according to the third embodiment includes a locking bar 241, a movable pin 242, and a fixing pin 243. The locking bar 241 is a member that connects or disconnects the fixed mold 11 and the intermediate mold 13. The locking bar 241 includes a pin engagement portion 244 and a holding portion 245.

[0081] The pin engagement portion 244 has a trough-shaped recess 244a formed on a side facing the fixing pin 243. The recess 244a is a portion that engages with the fixing pin 243. The holding portion 245 is a portion fixed to the movable pin 242. The holding portion 245 of the locking rod 241 is rotated by the movable pin 242. Therefore, the locking rod 242 is rotated in the clockwise and counterclockwise directions around the movable pin 242, as shown by arrows in the drawing.

[0082] The movable pin 242 is a member that is rotated in the clockwise and counterclockwise directions. Fig. 8A shows a state in which the movable pin 242 has been rotated to the connecting position. When the movable pin 242 is rotated counterclockwise to the connecting position, the fixed mold 11 and the intermediate mold 13 enter a connected state because the pin engagement portion 244 (the recess 244a) of the locking rod 241 engages with the fixing pin 243. Fig. 8B shows a state in which the movable pin 242 has been rotated to a release position. When the movable pin 242 is rotated clockwise to the release position, the fixed mold 11 and the intermediate mold 13 enter a release state because the pin engagement portion 244 (the recess 244a) of the locking rod 241 is disengaged from the fixing pin 243. The fixing pin 243 is a member fixed to the intermediate mold 13. The fixing pin 243 engages with the pin engagement portion 244 (the recess 244a) of the locking rod 241.

[0083] As a drive unit for rotating the movable pin 242 in the clockwise and counterclockwise directions, a servo motor (not shown), for example, can be used. By applying a normal rotation pulse signal to the servo motor, it is possible to rotate the movable pin 242, for example, in the clockwise direction. By applying a reverse rotation pulse signal to the servo motor, it is possible to rotate the movable pin 242 in the counterclockwise direction. In this case, the normal rotation pulse signal applied from the mold connection control unit 62 to the servo motor serves as the enable signal applied from the mold connection control unit 62 to the first mold connection element 40. The reverse rotation pulse signal applied from the mold connection control unit 62 to the servo motor serves as the connection signal applied from the mold connection control unit 62 to the first mold connection element 40.

[0084] As in Fig. As shown in Figure 8A, the second mold connecting member 250 according to the third embodiment includes a locking rod 251, a movable pin 252, and a fixing pin 253. The locking rod 251 is a member that connects or disconnects the movable mold 12 and the intermediate mold 13. The locking rod 251 includes a pin engaging portion 254 and a holding portion 255. The pin engaging portion 254 is a portion that engages with the fixing pin 253. The pin engaging portion 254 has a narrow and long trough-shaped recess 254a that engages with the fixing pin 253.

[0085] When the pin engagement portion 254 (the recess 254a) of the locking rod 251 engages with the fixing pin 253, the locking rod 251 can move in the X direction by the same distance as the distance d1 formed between the pin engagement portion 254 and the fixing pin 253. When the movable die 12 moves in the X1 direction in a state where the pin engagement portion 254 of the locking rod 251 is engaged with the fixing pin 253, the same gap s1 as the distance d1 is formed between the movable die 12 and the intermediate die 13, as described later.

[0086] The holding portion 255 of the locking rod 251 is a portion fixed to the movable pin 252. Since a configuration for driving the movable pin 252 is the same as the configuration (for example, a servo motor) for driving the movable pin 242 of the first mold connecting member 240, its description will be omitted.

[0087] As in Fig. 8A, the locking rod 241 is rotated in the clockwise direction about the movable pin 242 when the mold connection control unit 62 (see Fig. 2) In a state where the first mold connecting member 240 and the second mold connecting member 250 connect the two corresponding molds, a release signal is sent to the first mold connecting member 240. Therefore, the fixed mold 11 and the intermediate mold 13 enter a release state. When the movable mold 12 is moved in the direction X1 in this state, as shown in Fig. As shown in Fig. 8B, the intermediate mold 13 connected to the movable mold 12 moves along with the movable mold 12 in the direction X1. Therefore, the wide gap s3 is formed between the intermediate mold 13 and the fixed mold 11.

[0088] When the movable mold 12 moves in the X1 direction, the pin engagement portion 254 of the locking rod 251 (the second mold link 250) moves relative to the locating pin 253 by the same distance as the distance d1 in the X1 direction. Therefore, the gap s1 having the same length as the distance d1 is formed at the mating surface (a parting surface) between the movable mold 12 and the intermediate mold 13. When the gap s1 is formed, the molded product (not shown) formed between the movable mold 12 and the intermediate mold 13 and the sprue formed inside the intermediate mold 13 can be separated from the parting surface simultaneously with the mold opening.

[0089] Although the embodiments of the present invention have been described, the present invention is not limited to the above-described embodiments. Various modifications and changes may be made such as the modifications to be described later, and these embodiments are also within the technical scope of the present invention. The advantages described in connection with the embodiments are merely examples of the most preferable results achieved by the present invention, and the advantages of the present invention are not limited to those described in connection with the embodiments. The above-described embodiments and the modifications to be described later may be used in combination as required, and a detailed description thereof will be omitted. (Modification)

[0090] In the first mold connecting element 40 according to the first embodiment (see Fig. 4A and Fig. 4B), the orientation of the locking rod 41 in the X-direction can be reversed so that the movable pin 42 is provided in the intermediate mold 13 and the fixing pin 43 is provided in the fixed mold 11. In the second mold connecting element 50 according to the first embodiment (see Fig. 4A and Fig. 4B), the orientation of the locking rod 51 in the X direction can be reversed so that the movable pin 52 is provided in the intermediate mold 13 and the holding pin 53 is provided in the movable mold 12.

[0091] In the first mold connecting element 140 according to the second embodiment (see Fig. 7A), the orientation of the locking rod 141 in the X-direction can be reversed so that the movable pin 142 is provided in the intermediate mold 13 and the fixing pin 143 is provided in the fixed mold 11. In the second mold connecting element 150 according to the second embodiment (see Fig. 7A), the orientation of the locking rod 151 in the X direction can be reversed so that the movable pin 152 is provided in the intermediate mold 13 and the fixing pin 153 is provided in the movable mold 12.

[0092] In the first mold connecting element 240 according to the third embodiment (see Fig. 8A), the orientation of the locking rod 241 in the X-direction can be reversed so that the movable pin 242 is provided in the intermediate mold 13 and the fixing pin 243 is provided in the fixed mold 11. In the second mold connecting element 250 according to the third embodiment (see Fig. 8A), the orientation of the locking rod 251 in the X direction can be reversed so that the movable pin 252 is provided in the intermediate mold 13 and the fixing pin 253 is provided in the movable mold 12.

[0093] The first and second mold connecting members according to the first to third embodiments can be combined and used together with other connecting mechanisms. The mold connecting member according to the present invention is not limited to the configuration according to the first to third embodiments, but any configuration can be used as long as it is possible to switch the connection state between the fixed mold 11 and the intermediate mold 13 and the connection state between the movable mold 12 and the intermediate mold 13.

[0094] Although in connection with the first to third embodiments, an example has been described in which the sprue part 3 is removed in the first mold opening state and the molded product 2 in the second mold opening state, the molded product 2 may be removed in the first mold opening state and the sprue part 3 in the second mold opening state. More specifically, for the removal of the molded product 2 in the Fig. 5C and Fig.5D, only the movable mold 12 is moved in the direction X1 to form a gap between the movable mold 12 and the intermediate mold 13. Subsequently, the movable mold 12 is moved in the direction of approach to the fixed mold 11 (the direction X2) to connect with the intermediate mold 13. Subsequently, the movable mold 12 is moved together with the intermediate mold 13 in the direction X1 to remove the sprue 3, thereby forming a gap between the intermediate mold 13 and the fixed mold 11.

[0095] Although an example in which the intermediate mold 13 and the movable mold 12 are connected in the first mold-opening state and the intermediate mold 13 and the fixed mold 11 are connected in the second mold-opening state has been described in connection with the first to third embodiments, this is not limited to this. The intermediate mold 13 can be used in a molding cycle in a state in which it is not connected to either the movable mold 12 or the fixed mold 11. EXPLANATION OF REFERENCE SYMBOLS 1 injection molding machine 10 Shape 11 Solid form 12 Movable form 13 Intermediate form 20 Mold moving device 30 Injection device 40, 140, 240 first mold connecting element 50, 150, 250 second mold connecting element 60 control unit 61 Mold motion control unit 62 Mold connection control unit 70 Connection mechanism

Claims

[1] An injection molding machine (1) comprising a three-plate type mold (10) including a fixed mold (11), a movable mold (12) movable with respect to the fixed mold (11), and an intermediate mold (13) provided between the fixed mold (11) and the movable mold (12), the injection molding machine filling a molding material into a cavity formed by closing the fixed mold (11), the movable mold (12), and the intermediate mold (13) to mold a molded product (2), the injection molding machine (1) comprising: a first mold connecting element (40, 140, 240) which connects or detaches the fixed mold (11) and the intermediate mold (13) to each other; a second mold connecting element (50, 150, 250) which connects or detaches the movable mold (12) and the intermediate mold (13) to each other; a mold moving device (20) that moves the movable mold (12) with respect to the fixed mold (11); a mold movement control unit (61) which controls the mold movement device (20) so as to bring about one of a mold closing state in which the movable mold (12), the intermediate mold (13) and the fixed mold (11) are connected, a first mold opening state in which the movable mold (12) is separated from the fixed mold (11) together with the intermediate mold (13), and a second mold opening state in which the movable mold (12) is separated from the intermediate mold (13) and the fixed mold (11); and a mold connection control unit (62) which controls the first mold connection element (40, 140, 240) and the second mold connection element (50, 150, 250) such that, in the first mold opening state, the first mold connection element (40, 140, 240) separates the fixed mold (11) and the intermediate mold (13) from each other and the second mold connection element (50, 150, 250) connects the movable mold (12) and the intermediate mold (13) in a state in which the movable mold (12) does not come into contact with the intermediate mold (13), and, in the second mold opening state, the first mold connection element (40, 140, 240) connects the fixed mold (11) and the intermediate mold (13) in a state in which the fixed mold (11) comes into contact with the intermediate mold (13) and the second mold connection element (50, 150, 250) separates the movable mold (12) and the intermediate mold (13) from each other. [2] Injection molding machine (1) according to claim 1, wherein the first mold connecting element (40, 140) and the second mold connecting element (50, 150) each comprise: a movable pin (42, 52, 142, 152) provided in one mold; a fixing pin (43, 53, 143, 153) provided in the other mold; and a locking rod (41, 51, 141, 151) having a holding portion (45, 55, 145, 155) fixed to the fixing pin (43, 53, 143, 153) and a pin engaging portion (44, 54, 144, 154) configured to engage with the movable pin (42, 52, 142, 152), and the movable pin (42, 52, 142, 152) is moved to a position at which the movable pin engages with the pin engagement portion (44, 54, 144, 154) of the locking rod (41, 51, 141, 151) so that both molds are brought into a connected state, and the movable pin (42, 52, 142, 152) is moved to a position at which the movable pin (42, 52, 142, 152) is released from the pin engagement portion (44, 54, 144, 154) of the locking rod (41, 51, 141, 151) so that both molds are brought into a mutually released state. [3] Injection molding machine (1) according to claim 1, wherein the first mold connecting element (240) and the second mold connecting element (250) each comprise: a movable pin (242, 252) provided in one mold; a fixing pin (243, 253) provided in the other mold; and a locking rod (241, 251) having a holding portion (245, 255) fixed to the movable pin (242, 252) and a pin engaging portion (244, 254) configured to engage with the fixing pin (243, 253), and the movable pin (242, 252) is rotated and the pin engagement portion (244, 254) of the locking rod (241, 251) engages with the fixing pin (243, 253) so that both molds are brought into a connected state, and the movable pin (242, 252) is rotated in an opposite direction and the pin engagement portion (244, 254) of the locking rod (241, 251) is released from the fixing pin (243, 253) so that both molds are brought into a mutually released state. [4] An injection molding method carried out by an injection molding machine (1) comprising: a three-platen type mold (10) including a fixed mold (11), a movable mold (12) movable with respect to the fixed mold (11), and an intermediate mold (13) provided between the fixed mold (11) and the movable mold (12); a first mold connecting member (40, 140, 240) connecting or disconnecting the fixed mold (11) and the intermediate mold (13); a second mold connecting member (50, 150, 250) connecting or disconnecting the movable mold (12) and the intermediate mold (13); and a mold moving device (20) moving the movable mold (12) with respect to the fixed mold (11), wherein in a first mold opening state in which the movable mold (12) is separated from the fixed mold (11) together with the intermediate mold (13), the first mold connecting element (40, 140, 240) separates the fixed mold (11) and the intermediate mold (13) from each other and the second mold connecting element (50, 150, 250) connects the movable mold (12) and the intermediate mold (13) in a state in which the movable mold (12) does not come into contact with the intermediate mold (13), and in a second mold opening state in which the movable mold (12) is separated from the intermediate mold (13) and the fixed mold (11), the first mold connecting member (40, 140, 240) connects the fixed mold (11) and the intermediate mold (13) in a state in which the fixed mold (11) comes into contact with the intermediate mold (13) and the second mold connecting member (50, 150, 250) releases the movable mold (12) and the intermediate mold (13) from each other.

Images