Injection molding machine

Abstract

The present invention provides an injection molding machine capable of suppressing unevenness in the thickness of a molded product by a simple structure. The injection molding machine of the present invention includes a holding member for holding a second mold that forms a molding cavity space together with a first mold; a rotating shaft configured to project toward a side of the holding member opposite to a side holding the second mold so as to transmit a rotational force of the holding member or transmit a rotational force to the holding member; a support member rotatably supporting the holding member via a bearing for embedding the rotating shaft; and a suppression portion installed on the support member and suppressing movement of the rotating shaft toward the side opposite to the holding member.

Description

Technical Field

[0001] This application claims priority based on Japanese Patent Application No. 2024-212013, filed on December 5, 2024. The entire contents of that Japanese application are incorporated herein by reference.

[0002] This invention relates to an injection molding machine. Background Technology

[0003] Conventionally, injection molding machines have been proposed that compress molten resin in a mold cavity during injection molding. For example, Patent Document 1 describes an injection molding machine with the following configuration: a mandrel drive device is provided on a movable mold platen, and a movable mold is mounted on the mandrel drive device. The mandrel drive device includes: an electric motor disposed on the side of the device; a rotating shaft arranged parallel to the mold mounting surface; a pair of bevel gears that convert the rotating shaft to a vertical direction; and a rotating body that rotates due to the electric motor, the rotating shaft, and the bevel gears. This rotating body is stored in an opening at the center of the mold mounting surface of the mandrel drive device, and rotates a predetermined rotating component on the movable mold side. The rotation is converted into linear motion by a ball screw mechanism within the movable mold, thereby driving the compression mandrel for compression molding.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2015-139972

[0005] During injection molding, mold deformation can occur due to pressure from the molding material filling the cavity, potentially leading to uneven thickness in the molded product. Therefore, it is preferable to suppress mold deformation during injection molding.

[0006] The injection molding machine described in Patent Document 1 has room for improvement in terms of its complex structure, such as having a rotating shaft that is parallel to the mold mounting surface and a pair of bevel gears that convert the rotating shaft into a vertical direction. Summary of the Invention

[0007] The purpose of this invention is to provide an injection molding machine that can suppress uneven thickness of molded articles through a simple structure.

[0008] The present invention, which achieves this objective, is an injection molding machine comprising: a retaining member for retaining a second mold that forms a cavity space together with a first mold; a rotating shaft configured to protrude toward a side of the retaining member opposite to the side that holds the second mold, so as to transmit rotational force of the retaining member, or to transmit rotational force to the retaining member; a supporting member for rotatably supporting the retaining member via a bearing for embedding the rotating shaft; and a suppressing portion mounted on the supporting member and suppressing movement of the rotating shaft toward the side opposite to the retaining member.

[0009] Alternatively, the suppressing part may have an inner component that is axially movable along the rotation axis inside the support component and is able to contact the end of the rotation axis opposite to the second mold. By moving the inner component along the axial direction, pressure is applied to the rotation axis, thereby suppressing the movement of the rotation axis.

[0010] Alternatively, it can be as follows: a fitting recess and a communicating hole are formed on the support member, the fitting recess is used to embed the bearing, and the communicating hole is located on the side of the fitting recess opposite to the second mold, allowing the fitting recess to communicate with the outside. The rotating shaft has: a shaft portion for embedding the bearing; and a front end portion, disposed on the side of the shaft portion opposite to the second mold and arranged in the communicating hole. The suppressing portion closes the opening of the communicating hole to prevent the front end portion of the rotating shaft from being exposed from the communicating hole, thereby suppressing the movement of the rotating shaft.

[0011] Furthermore, from other perspectives, the present invention provides an injection molding machine comprising: a holding member for holding a second mold that forms a cavity space together with a first mold; a rotating shaft configured to protrude toward a side of the holding member opposite to the side holding the second mold, so as to transmit rotational force of the holding member, or to transmit rotational force to the holding member; a supporting member for rotatably supporting the holding member via a bearing for embedding the rotating shaft; an inner member disposed inside the holding member and the rotating shaft, and capable of contacting the surface of the second mold opposite to the side of the first mold; and a suppressing portion mounted on the supporting member, and suppressing movement of the inner member toward the side opposite to the second mold.

[0012] Here, the inhibition part may also begin to inhibit movement before filling the cavity space with molding material, and then continue to inhibit movement until the molding of the molded article is completed.

[0013] Alternatively, the inhibiting part may begin to inhibit movement after the molding material is filled into the cavity space, and then continue to inhibit movement until the molding of the molded article is completed.

[0014] Invention Effects

[0015] According to the present invention, uneven thickness of molded articles can be suppressed through a simple structure. Attached Figure Description

[0016] Figure 1 This is a diagram showing an example of the schematic structure of the injection molding machine according to the first embodiment.

[0017] Figure 2 This is a diagram showing an example of a cross-section of a movable pressure plate, a rotary table, etc.

[0018] Figure 3 This is an example of a perspective view of the rotation axis involved in the first embodiment, viewed from the front.

[0019] Figure 4 This is a diagram showing an example of a cross-section of the injection molding machine according to the second embodiment.

[0020] Figure 5 This is a diagram showing an example of a cross-section of the injection molding machine according to the third embodiment.

[0021] In the figure: 1, 2, 3 - Injection molding machine; 81 - Fixed mold (an example of the first mold); 82 - Movable mold (an example of the second mold); 100 - Mold closing device; 110 - Fixed pressure plate; 120 - Movable pressure plate (an example of a support member); 126h - Communicating hole; 127 - Fitting recess; 220, 520 - Rotary table (an example of a holding member); 270, 570 - Rotating shaft; 290 - Inner part; 390 - Restriction part (an example of a suppression part); 400 - Frame; 500 - Control device; 572 - Shaft part; 573 - Front end part; 580 - Bearing; 590 - Pressurizing part (an example of a suppression part); 592 - Shaft (an example of an inner part). Detailed Implementation

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0023] <First Embodiment>

[0024] Figure 1 This is a diagram showing an example of the schematic structure of the injection molding machine 1 according to the first embodiment. In the following description, it will sometimes be referred to as... Figure 1 The anterior side is simply referred to as the "anterior side". Figure 1 The inside side is simply referred to as the "inside side".

[0025] Figure 2 This is a diagram showing an example of a cross-section of the movable pressure plate 120, the rotary table 520, etc.

[0026] The injection molding machine 1 includes a mold assembly 80, a mold clamping assembly 100, a first ejector 201, a second ejector (not shown), a first injection unit 301, and a second injection unit (not shown). Furthermore, the injection molding machine 1 includes: a frame 400; a first moving device 401 for moving the first injection unit 301 relative to the mold assembly 80; a second moving device for moving the second injection unit relative to the mold assembly 80 (not shown); and a control device 500. The first ejector 201, the first injection unit 301, and the first moving device 401 are located near the front, while the second ejector, the second injection unit, and the second moving device are located on the inner side. Figure 1 The positions of the first ejector device 201 and the second ejector device, the positions of the first injection device 301 and the second injection device, and the positions of the first moving device 401 and the second moving device overlap in the vertical direction. Therefore, Figure 1 The second ejection device, the second injection device, and the second moving device are not shown in the figure.

[0027] (Mold device 80)

[0028] The mold assembly 80 includes a fixed mold 81 and a movable mold 82. An example is provided where both the fixed mold 81 and the movable mold 82 are cuboids.

[0029] The fixed mold 81 has a first fixed forming surface 811 and a second fixed forming surface (not shown).

[0030] The movable mold 82 has a first movable forming surface 821 and a second movable forming surface (not shown).

[0031] Figure 1 The image shows the fixed mold 81 and the movable mold 82 in their open states. When the fixed mold 81 and the movable mold 82 are closed, a cavity space is formed between them.

[0032] (Mold closing device 100)

[0033] The mold clamping device 100 includes a fixed pressure plate 110, a movable pressure plate 120, a toggle seat 130, a tie rod 140, a toggle mechanism 150, a mold clamping motor 160, and a ball screw 170. Furthermore, the mold clamping device 100 includes a rotary table 520 rotatably supported on the movable pressure plate 120 relative to the fixed pressure plate 110; and a rotation mechanism 530 for rotating the rotary table 520. The mold clamping device 100 also includes a rotating shaft 570 mounted on the rotary table 520; and a bearing 580 rotatably supporting the rotary table 520 and the rotating shaft 570. Finally, the mold clamping device 100 includes a pressure-applying part 590 that applies pressure to the end of the rotating shaft 570 opposite to the side mounted on the rotary table 520.

[0034] The fixed pressure plate 110 is fixed to the frame 400. On the surface of the fixed pressure plate 110 opposite to the movable pressure plate 120, a fixed mold 81 is installed in such a way that the first fixed forming surface 811 is near the front and the second fixed forming surface is inward.

[0035] The movable pressure plate 120 is configured to be able to move relative to the frame 400 along... Figure 1 The movable platen 120 moves in the left and right directions. A movable mold 82 is mounted on the surface of the movable platen 120 opposite to the fixed platen 110. The movable platen 120 moves relative to the fixed platen 110 along... Figure 1 The mold device 80 is moved left and right to perform mold closing, pressurization, mold clamping, demolding, and mold opening. In the mold clamping device 100, sometimes... Figure 1 The left and right directions are called the "mold opening and closing directions", and the direction of movement of the movable pressure plate 120 when the mold is closed is also called the "mold opening and closing direction". Figure 1 The direction to the right is called "front," and the direction of movement of the movable pressure plate 120 during mold opening is called "front." Figure 1 The left-hand direction is referred to as the "rear". The structure of the movable pressure plate 120 will be described in detail later.

[0036] The toggle seat 130 is configured to move along the mold opening and closing direction on the frame 400.

[0037] The tie rod 140 connects the fixed pressure plate 110 and the toggle seat 130 at a predetermined interval in the mold opening and closing direction. It is possible to provide multiple tie rods 140 (e.g., 4 rods).

[0038] A toggle mechanism 150 is positioned between the movable pressure plate 120 and the toggle seat 130. The toggle mechanism 150 causes the movable pressure plate 120 to move relative to the toggle seat 130 in the mold opening and closing direction. The toggle mechanism 150 has a crosshead 151 and a pair of connecting rods 152. The crosshead 151 has a nut that mates with a ball screw 170. If the ball screw 170 rotates about its axis, the crosshead 151 moves relative to the toggle seat 130 in the mold opening and closing direction. This causes the connecting rods 152 to extend and retract, and the movable pressure plate 120 moves relative to the toggle seat 130 in the mold opening and closing direction.

[0039] The clamping motor 160 and the ball screw 170 are mounted on the toggle seat 130, thereby actuating the toggle mechanism 150. The ball screw 170 is driven by the rotation of the clamping motor 160 to rotate about the axis, and causes the crosshead 151 with the nut to move relative to the toggle seat 130 in the mold opening and closing direction.

[0040] The movable pressure plate 120, the rotary table 520, the rotating mechanism 530, and the rotating shaft 570 are described below.

[0041] (Modible pressure plate 120)

[0042] The movable pressure plate 120 has a front panel 121 located at the frontmost side, a middle block 124, and a gear constraint block 125 located on the outer side of the middle block 124. Furthermore, the movable pressure plate 120 has a rear block 126 located behind the middle block 124, and a toggle rod mounting portion 128 located on the rear end face of the rear block 126.

[0043] For example, the movable pressure plate 120 can be formed by casting iron. In addition, the front panel 121, the middle block 124, the rear block 126 and the toggle rod mounting part 128 can be separate parts, or they can be formed into one piece by casting or other methods.

[0044] A first rod hole 122 is formed on the front panel 121, penetrating the front panel 121 in the mold opening and closing direction. A first ejector rod 211 is disposed in the first rod hole 122, and the first ejector rod 211 is movable in the mold opening and closing direction. Furthermore, a second rod hole (not shown) is formed on the front panel 121, penetrating the front panel 121 in the mold opening and closing direction. A second ejector rod (not shown) is disposed in the second rod hole (not shown), and the second ejector rod is movable in the mold opening and closing direction.

[0045] The intermediate block 124 is disposed inside the cylindrical portion 524 of the rotary table 520, which will be described later. An example is that the intermediate block 124 is cylindrical, with the column direction aligned with the center line. Furthermore, inside the intermediate block 124, spaces are formed for arranging the first ejector 201 and for arranging the second ejector (not shown).

[0046] A front panel 121 is mounted on the front end face of the intermediate block 124. Fitting recesses 127 for embedding the bearing 580 are formed on both the front panel 121 and the intermediate block 124. Sliding plates 610 are respectively provided on the front end face of the front panel 121, on the sides closer to the front than the fitting recesses 127 and the sides further inward than the fitting recesses 127. The sliding plates 610 are, for example, cuboid in shape and are fixed to the front panel 121 using bolts (not shown). It is possible that the material of the sliding plates 610 is softer than the disc portion 523 of the rotary table 520 (described later), for example, a copper alloy such as copper or brass.

[0047] The gear constraint block 125 is positioned in front of the rear block 126 and outside the middle block 124. The gear constraint block 125 constrains the driven gear 535 of the rotating mechanism 530 (described later) to move forward via the sliding plate 620. The gear constraint block 125 prevents the rotary table 520 from tilting.

[0048] The rear block 126 is located behind the intermediate block 124 and is supported by the pressure plate slider 190. For example, the rear block 126 can be a cuboid. Inside the rear block 126, spaces are formed for arranging the first ejector 201 and for arranging the second ejector. The intermediate block 124 is mounted on the front end face of the rear block 126.

[0049] The toggle lever mounting portion 128 is configured to protrude rearward from the rear end face of the rear block 126. The toggle lever mounting portion 128 is respectively provided at the upper and lower ends of the rear block 126. The toggle lever mounting portion 128 has multiple toggle lever mounting plates spaced apart in the horizontal direction, with their thickness direction facing horizontally. The front ends of each of the multiple toggle lever mounting plates have pin holes 129. A pin is inserted into the pin hole 129, and the connecting rod of the toggle mechanism 150 is oscillatingly mounted to the toggle lever mounting portion 128 via the pin.

[0050] (Rotating table 520)

[0051] The rotary table 520 is rotatably supported on the movable pressure plate 120 via the sliding plate 610. The rotation center line CL of the rotary table 520 is in the same direction as the mold opening and closing direction, and the position of the rotation center line CL is between the first movable forming surface 821 and the second movable forming surface (not shown) of the movable mold 82. In the following description, the mold opening and closing direction is sometimes referred to as the "center line direction". Furthermore, the side of the rotary table 520 with the rotation center line CL is sometimes referred to as the "inner side", and the side away from the rotation center line CL is sometimes referred to as the "outer side".

[0052] The rotary table 520 has a mold mounting section 521 for mounting a movable mold 82 and a winding section 522 for winding up the flexible cable chain 510. The rotary table 520 is located inside the multiple (e.g., 4) tie rods 140 to avoid interference with them.

[0053] Examples include the following: the mold mounting part 521 is a plate-shaped part perpendicular to the center line direction, for example, a cuboid shape.

[0054] The winding section 522 has a disc-shaped disc section 523 for fixing the mold mounting section 521, and a cylindrical section 524 extending rearward from the outer periphery of the disc section 523.

[0055] For example, the rotary table 520 can be formed by casting iron. In addition, the mold mounting part 521, the disc part 523 and the cylindrical part 524 can be separate parts, or they can be formed into one piece by casting or other methods.

[0056] The cylindrical portion 524 has a circumferential surface 525. A driven gear 535 of the rotating mechanism 530 (described later) is fixed along the entire circumferential direction of the circumferential surface 525. Furthermore, a flexible cable chain 510 is wound onto the circumferential surface 525.

[0057] One end of the flexible cable chain 510 is fixed to the rotary table 520, and the other end is fixed to the movable pressure plate 120. For example, CABLEVEYOR (registered trademark) can be used as the flexible cable chain 510.

[0058] (Rotating mechanism 530)

[0059] The rotating mechanism 530 includes a rotating motor 531 and a transmission mechanism 532 that transmits the rotational driving force of the rotating motor 531 to the rotating table 520. The transmission mechanism 532 is composed of, for example, a drive gear 533, an intermediate gear 534, and a driven gear 535.

[0060] The rotating mechanism 530 rotates the rotary table 520 between a first rotation angle and a second rotation angle. The first rotation angle is the rotation angle that forms a cavity space between the first movable molding surface 821 of the movable mold 82 and the first fixed molding surface 811 of the fixed mold 81. The first rotation angle is, for example, 0°. The second rotation angle is the rotation angle that forms a cavity space between the second movable molding surface (not shown) of the movable mold 82 and the first fixed molding surface 811 of the fixed mold 81. The second rotation angle is, for example, 180°.

[0061] In this embodiment, the rotating mechanism 530 reverses the direction in which the rotating table 520 rotates from the first rotation angle to the second rotation angle, compared to the direction in which it rotates from the second rotation angle to the first rotation angle. As a result, the wiring and conduit configuration fixed to the rotating table 520 is restored to its original state, making it easier to handle the wiring and conduit.

[0062] The rotating shaft 570 is a cylindrical component. The rotating shaft 570 and the rotary table 520 are connected together by multiple bolts 550 (four in this embodiment). Furthermore, by embedding the rotating shaft 570 into a bearing 580 mounted on the movable pressure plate 120, the rotating shaft 570 and the rotary table 520 can rotate integrally relative to the movable pressure plate 120 via the bearing 580. Detailed descriptions of the rotating shaft 570, the pressure unit 590, etc., will be provided later.

[0063] The mold closing device 100 configured as described above performs the mold closing process, the pressure increasing process, the mold closing process, the pressure releasing process, and the mold opening process under the control of the control device 500.

[0064] During the mold closing process, the mold closing device 100 drives the mold closing motor 160 to rotate the ball screw 170, thereby causing the crosshead 151 to advance to the mold closing end position at a set moving speed. As a result, the movable pressure plate 120 advances and brings the movable mold 82 into contact with the fixed mold 81.

[0065] During the pressurization process, the mold closing device 100 further drives the mold closing motor 160, thereby causing the crosshead 151 to advance further from the mold closing position to the mold closing position. As a result, a mold closing force is generated in the mold 80.

[0066] In the mold closing process, the mold closing device 100 drives the mold closing motor 160, thereby maintaining the position of the crosshead 151 in the mold closing position. Thus, the mold closing force generated in the pressurization process can be maintained during the mold closing process. In the mold closing process, for example, with the rotary table 520 rotated to a first rotation angle, the first injection device 301 fills the cavity space formed between the first movable molding surface 821 of the movable mold 82 and the first fixed molding surface 811 of the fixed mold 81 with liquid first molding material. By solidifying the filled first molding material, a first molded article is obtained. On the other hand, the second injection device fills the cavity space formed between the first molded article formed on the second movable molding surface of the movable mold 82 and the second fixed molding surface of the fixed mold 81 with liquid second molding material. By solidifying the filled second molding material, a second molded article containing the first molded article is obtained.

[0067] In the mold closing process, for example, when the rotary table 520 is rotated to the second rotation angle, the first injection device 301 fills the cavity space between the second movable molding surface of the movable mold 82 and the first fixed molding surface 811 of the fixed mold 81 with liquid first molding material. By solidifying the filled first molding material, a first molded article is obtained. On the other hand, the second injection device fills the cavity space between the first molded article formed on the first movable molding surface 821 of the movable mold 82 and the second fixed molding surface of the fixed mold 81 with liquid second molding material. By solidifying the filled second molding material, a second molded article containing the first molded article is obtained.

[0068] In the depressurization process, the mold closing device 100 drives the mold closing motor 160 to rotate the ball screw 170 in the opposite direction to the mold closing and pressurization processes described above, thereby causing the crosshead 151 to retract from the mold closing position to the mold opening start position. As a result, the movable pressure plate 120 retracts, and the mold closing force decreases. An example is given where the mold opening start position is the same as the mold closing end position described in the mold closing and pressurization processes.

[0069] During the mold opening process, the mold closing device 100 drives the mold closing motor 160 to cause the crosshead 151 to retract from the mold opening start position to the mold opening end position at a set moving speed. As a result, the movable pressure plate 120 retracts, and the movable mold 82 separates from the fixed mold 81.

[0070] (First ejection device 201, etc.)

[0071] The first ejection device 201 performs the ejection process under the control of the control device 500. The second ejection device also has the same structure as the first ejection device 201, and performs the ejection process under the control of the control device 500. The first ejection device 201 and the second ejection device are mounted on the movable pressure plate 120 and move together with the movable pressure plate 120 in the mold opening and closing direction. In the ejection process, the first ejection device 201 actuates the movable part provided on the movable mold 82, thereby ejecting the waste material from the movable mold 82 and separating it. Similarly, the second ejection device actuates the movable part provided on the movable mold 82, thereby ejecting the waste material and the second molded product from the movable mold 82 and separating them.

[0072] (Rotating shaft 570, rotating table 520, pressurizing unit 590, control device 500, etc.)

[0073] Figure 3 This is an example of a perspective view of the rotation axis 570 involved in the first embodiment, viewed from the front.

[0074] Figure 2 This is a diagram showing an example of a cross-section when the movable pressure plate 120, the rotary table 520, and the rotary shaft 570 are cut by a plane that passes through the rotation center line CL and is parallel to the vertical direction.

[0075] The following uses Figure 2 and Figure 3 The rotating shaft 570, the rotating table 520, the pressurizing part 590, and the control device 500 are described.

[0076] The rotating shaft 570 comprises three cylindrical portions of different diameters, each having a base end 571, a shaft portion 572, and a front end 573. The base end 571 is located on the side of the disk portion 523 of the rotary table 520 (in other words, the front side), the front end 573 is located on the side opposite to the disk portion 523 (in other words, the rear side), and the shaft portion 572 is located between the base end 571 and the front end 573. The centerlines of the base end 571, shaft portion 572, and front end 573 are aligned. The outer diameter of the base end 571 is larger than the outer diameter of the shaft portion 572, and the outer diameter of the shaft portion 572 is larger than the outer diameter of the front end 573. Furthermore, the shaft portion 572 of the rotating shaft 570 is embedded inside the inner ring of the bearing 580 of the movable pressure plate 120, and the base end 571 is positioned closer to the disk portion 523 than the inner ring of the bearing 580. Therefore, the centerline of the shaft portion 572 coincides with the aforementioned rotation centerline CL. The front end portion 573 is disposed inside the connecting hole 126h of the movable pressure plate 120, which will be described later.

[0077] An internal thread 574 for fastening the bolt 550 is formed on the front surface 576 of the rotating shaft 570, which is opposite to the disk portion 523. Multiple internal threads 574 are formed at equal intervals around the rotation center line CL (four in this embodiment).

[0078] An insertion recess 527 is formed in the center of the disc portion 523 of the rotary table 520. The insertion recess 527 is recessed from the rear surface 526 of the movable pressure plate 120, which faces the front panel 121, and is inserted into the base end portion 571 of the rotation shaft 570. The insertion recess 527 is cylindrical. The diameter of the insertion recess 527 is greater than or equal to the diameter of the base end portion 571 of the rotation shaft 570. The bottom surface 528 of the insertion recess 527 faces the front surface 576 of the rotation shaft 570.

[0079] Furthermore, a head recess 542 is formed in the center of the mold mounting portion 521 of the rotary table 520. The head recess 542 is recessed from the surface 541 on which the movable mold 82 is mounted and accommodates the head 552 of the bolt 550. An example is that the head recess 542 is cylindrical and its diameter is greater than or equal to the diameter of the insertion recess 527.

[0080] Furthermore, a through hole 543 is formed on the rotary table 520, which connects the insertion recess 527 with the head recess 542 and allows the external thread of the bolt 550 to pass through. Multiple through holes 543 are formed at equal intervals around the rotation center line CL in a manner corresponding to the internal thread 574 of the rotation shaft 570 (four in this embodiment).

[0081] The rotating shaft 570 and the rotating table 520, as described above, are connected together by fastening the external thread of the bolt 550 passing through the through hole 543 to the internal thread 574 of the rotating shaft 570. Furthermore, when the rotating shaft 570 and the rotating table 520 are connected, the front surface 576 of the rotating shaft 570 contacts the bottom surface 528 of the insertion recess 527 of the rotating table 520.

[0082] The rotating shaft 570 is embedded inside the inner ring of the bearing 580.

[0083] The bearing 580 is embedded in the movable pressure plate 120. A fitting recess 127 is formed in the center of the front panel 121 and the intermediate block 124 of the movable pressure plate 120. The fitting recess 127 is used to insert and embed the bearing 580 from the front panel 121 side. The outer ring of the bearing 580 is pressed into the inner circumferential surface of the front panel 121 and the intermediate block 124 where the fitting recess 127 is formed. Examples of bearing 580 being a ball bearing or a roller bearing are possible.

[0084] Furthermore, a connecting hole 126h extending along the centerline is formed in the central portion of the middle block 124 and the rear block 126 of the movable pressure plate 120, allowing the fitting recess 127 to communicate with the outside. An example is provided where the connecting hole 126h is cylindrical, its diameter is less than the inner diameter of the inner ring of the bearing 580, and larger than the diameter of the front end 573 of the rotating shaft 570.

[0085] An example is provided where the pressurizing part 590 has a coil (not shown) or a plunger (not shown) inside the housing 591, and a solenoid with a shaft 592 fixed to the plunger exposed from the housing 591. In the pressurizing part 590, with the shaft 592 disposed in the communication hole 126h of the movable pressure plate 120, the housing 591 is fixed to the rear end face of the movable pressure plate 120.

[0086] The pressure-applying section 590 increases the amount of the shaft 592 protruding from the housing 591 by energizing it, thereby applying pressure to the rear end of the front end 573 of the rotating shaft 570. On the other hand, the pressure-applying section 590 decreases the amount of the shaft 592 protruding from the housing 591 by de-energizing it, thereby stopping the application of pressure to the rear end of the front end 573 of the rotating shaft 570.

[0087] The control unit 500 includes a CPU (Central Processing Unit) (not shown), a ROM (Read Only Memory) (not shown) serving as a storage area for storing programs, and RAM (Random Access Memory) (not shown) serving as an execution area for programs. The control unit 500 implements various functions of the injection molding machine 1 by causing the CPU to execute programs stored in storage devices such as ROM, HDD (Hard Disk Drive), or semiconductor memory.

[0088] The control device 500 controls, for example, the energization of the pressure unit 590. For instance, in the mold closing process described above, before the first injection unit 301 fills the first molding material and the second injection unit fills the second molding material, the control device 500 energizes the pressure unit 590 to apply pressure to the rotating shaft 570 by contacting the shaft 592 with the rear end of the rotating shaft 570. Afterwards, for example, after the mold closing process ends, the control device 500 stops energizing the pressure unit 590 so that the shaft 592 does not apply pressure to the rear end of the rotating shaft 570. For example, in the depressurization process, the control device 500 stops energizing the pressure unit 590 simultaneously with starting to drive the mold closing motor 160.

[0089] As described above, the injection molding machine 1 includes a rotary table 520 (an example of a holding member) for holding a movable mold 82 (an example of a second mold) that forms a cavity space together with a fixed mold 81 (an example of a first mold). The injection molding machine 1 also includes a rotating shaft 570, which is configured to protrude from the side of the rotary table 520 opposite to the side holding the movable mold 82, in order to transmit the rotational force of the rotary table 520. Furthermore, the injection molding machine 1 includes a movable pressure plate 120 (an example of a support member) that rotatably supports the rotary table 520 via a bearing 580 embedded in the rotating shaft 570. Finally, the injection molding machine 1 includes a pressure unit 590 (an example of a suppression unit) mounted on the movable pressure plate 120, which suppresses the rotation shaft 570 from moving to the side opposite to the rotary table 520.

[0090] In the injection molding machine 1 described above, the pressure unit 590 suppresses the rotation shaft 570 from moving to the side opposite to the rotary table 520. This suppresses deformation of the movable mold 82 caused by the pressure of the molding material filling the cavity space. As a result, according to the injection molding machine 1, uneven thickness of the molded article caused by deformation of the movable mold 82 can be suppressed. Furthermore, since the pressure unit 590 applies pressure to the rotation shaft 570, and the pressure-applied rotation shaft 570 applies pressure to the rotary table 520 to prevent deformation of the movable mold 82, deformation suppression of the movable mold 82 can be achieved with a simple structure.

[0091] The pressure unit 590 is configured to move along the axial direction (in other words, the centerline direction) of the rotation shaft 570 inside the movable pressure plate 120, and has a shaft 592 (an example of an inner component) that can contact the end of the rotation shaft 570 opposite to the movable mold 82. By moving the shaft 592 axially, pressure is applied to the rotation shaft 570, thereby suppressing the movement of the rotation shaft 570. Thus, pressure can be applied to the rotation shaft 570 with a simple structure, and mold closing can be performed by the fixed pressure plate 110 and the movable pressure plate 120. Even if the rotary table 520 is under pressure and the rotation shaft 570 is under pressure, the rotary table 520 can be supported by the rotation shaft 570.

[0092] The pressure unit 590 applies pressure to the rotating shaft 570 before filling the cavity space with molding material, and continues to apply pressure to the rotating shaft 570 until the molding of the molded article is completed (for example, until the mold clamping motor 160 is started in the depressurization process). In other words, the pressure unit 590 inhibits the movement of the rotating shaft 570 before filling the cavity space with molding material, and continues to inhibit the movement of the rotating shaft 570 until the molding of the molded article is completed. As a result, deformation of the movable mold 82 caused by the pressure of the molding material filled into the cavity space can be suppressed with high precision.

[0093] Alternatively, the pressure unit 590 can apply pressure to the rotation shaft 570 after the molding material is filled into the cavity space, and continue to apply pressure to the rotation shaft 570 until the molding of the molded article is completed. In other words, after the molding material is filled into the cavity space, the pressure unit 590 begins to reduce (in other words, begins to suppress) the amount of movement of the rotation shaft 570 from its position before the molding material was filled into the cavity space, and then suppresses the movement of the rotation shaft 570 until the molding of the molded article is completed. By compressing the molding material by reducing the volume of the cavity space after the molding material is filled into the cavity space and before the molding material solidifies, the occurrence of shrinkage marks can be suppressed, or the surface properties of the molded article can be improved.

[0094] Alternatively, the pressure section 590 may apply pressure to the rotating shaft 570 when the movable mold 82 is deformed due to the pressure of the molding material filling the cavity space, and not apply pressure to the rotating shaft 570 when the movable mold 82 is not deformed.

[0095] Furthermore, the pressure section 590 may also be a section that suppresses the movement of the rotating wheel 570 when the rotary table 520 moves toward the rotating shaft 570, so as to support the rotary table 520.

[0096] Furthermore, the structure of the pressure unit 590 is not limited to the solenoid described above. For example, the pressure unit 590 may also have a contact member (not shown) that can contact the rear end of the rotating shaft 570, and a moving mechanism (not shown) that moves the contact member along the centerline direction. An example of the moving mechanism is a ball screw motor having a ball screw and a rotary motor that rotates the ball screw. The moving mechanism only needs to fix the rotary motor to the rear end face of the movable pressure plate 120 while the ball screw is positioned within the communication hole 126h of the movable pressure plate 120. An example of the contact member is a cylindrical member with a nut. The contact member only needs to be positioned outside the ball screw within the communication hole 126h of the movable pressure plate 120. Thus, even if the pressure unit 590 is a ball screw mechanism, pressure can be applied to the rotating shaft 570, thereby suppressing deformation of the movable mold 82 with a simple structure.

[0097] Furthermore, the pressure unit 590 can also be a hydraulic actuator, which includes: a cylinder; a piston housed within the cylinder; and a rod with one end fixed to the piston and the other end protruding from the cylinder body. The hydraulic actuator can change the protrusion amount of the rod by supplying oil into the cylinder body. Moreover, the moving mechanism only needs to be configured such that the other end of the rod can contact the rear end of the rotating shaft 570 within the communication hole 126h of the movable pressure plate 120, and the cylinder body can be fixed to the rear end face of the movable pressure plate 120. Thus, even if the pressure unit 590 is a hydraulic actuator, pressure can be applied to the rotating shaft 570, thereby achieving suppression of deformation of the movable mold 82 with a simple structure.

[0098] Furthermore, the pressure-applying part 590 applies pressure to the rear end of the front end portion 573 of the rotating shaft 570, but the position where the pressure is applied to the rotating shaft 570 is not particularly limited. For example, it is also possible to provide a protrusion that protrudes outward from the outer periphery at the center portion (but is not limited to the center portion) in the center line direction of the front end portion 573 of the rotating shaft 570, and the pressure-applying part 590 applies pressure to the protrusion.

[0099] Furthermore, pressure is applied directly to the rotating shaft 570, but this is not a limitation. For example, other components may be connected to the front end 573 of the rotating shaft 570 so that they protrude outward from the outer periphery (e.g., a cylindrical component is pressed in), and the pressure-applying part 590 applies pressure to these other components.

[0100] Furthermore, in the injection molding machine 1 described above, the rotating shaft 570 is connected to the rotary table 520 by bolts 550, thereby transmitting the rotational force of the rotary table 520 to the rotating shaft 570. However, if the rotational force of the rotary table 520 is transmitted to the rotating shaft 570, the rotating shaft 570 and the rotary table 520 may not need to be connected. For example, the rotational force of the rotary table 520 may be transmitted to the rotating shaft 570 via a coupling installed in at least one of the rotary table 520 and the rotating shaft 570.

[0101] Furthermore, in the aforementioned injection molding machine 1, a rotational force is applied to the rotary table 520 via a rotation mechanism 530, and the rotational force of the rotary table 520 is transmitted to the rotation shaft 570, but this method is not particularly limited. For example, it could also be structured such that a rotational force is applied to the rotation shaft 570, for example, via a motor, and the rotary table 520 is rotated by transmitting the rotational force to the rotary table 520 via the rotation shaft 570.

[0102] <Second Implementation>

[0103] Figure 4 This is a diagram showing an example of a cross-section of the injection molding machine 2 according to the second embodiment.

[0104] The injection molding machine 2 according to the second embodiment differs from the injection molding machine 1 according to the first embodiment in that pressure is applied to the movable mold 82. Hereinafter, the differences from the first embodiment will be described. In both the first and second embodiments, the same reference numerals are used for the same parts, and detailed descriptions are omitted.

[0105] The rotating shaft 270 according to the second embodiment differs from the rotating shaft 570 according to the first embodiment in that it does not have a front end portion 573 and a through hole 273 formed in the central portion along the centerline direction. Furthermore, the rotating shaft 270 has a cylindrical bushing 275 at the end of the rotating platform 220 side of the through hole 273. The inner diameter of the bushing 275 is smaller than the diameter of the rear end portion of the through hole 273.

[0106] The rotary table 220 according to the second embodiment differs from the rotary table 520 according to the first embodiment in that a through hole 221 is formed in the central portion, which communicates with the insertion recess 527 and the head recess 542, extending along the center line. The diameter of the through hole 221 is larger than the inner diameter of the bushing 275.

[0107] Furthermore, the injection molding machine 2 is located inside the rotary table 220 and the rotary shaft 270, and has an inner part 290 that can apply pressure to the movable mold 82.

[0108] The inner component 290 has: a front portion 291, which consists of two cylindrical portions with different diameters and is disposed on the side of the movable mold 82 (in other words, the front side); and a rear portion 292, which is disposed on the side opposite to the movable mold 82 relative to the front portion 291 (in other words, the rear side).

[0109] The diameter of the front part 291 is less than the diameter of the bushing 275, and the front part 291 is disposed in the through hole 273 of the rotating shaft 270 and the through hole 221 of the rotating table 220.

[0110] The diameter of the rear part 292 is larger than the diameter of the through hole 273 of the rotating shaft 270, and smaller than the diameter of the connecting hole 126h of the movable pressure plate 120. The rear part 292 is disposed within the connecting hole 126h of the movable pressure plate 120.

[0111] The pressure-applying section 590 increases the amount by which the shaft 592 protrudes from the housing 591 by energizing it, thereby applying pressure to the rear end of the rear portion 292 of the inner component 290. On the other hand, the pressure-applying section 590 decreases the amount by which the shaft 592 protrudes from the housing 591 by de-energizing it, thereby stopping the application of pressure to the rear end of the rear portion 292 of the inner component 290.

[0112] For example, during the mold closing process, before the first injection unit 301 fills the first molding material and the second injection unit fills the second molding material, the control device 500 energizes the pressure unit 590 to apply pressure to the inner component 290 by contacting the shaft 592 with the rear end of the inner component 290. Afterwards, for example, after the mold closing process ends, the control device 500 stops energizing the pressure unit 590 so that the shaft 592 no longer applies pressure to the rear end of the inner component 290. For example, during the depressurization process, the control device 500 stops energizing the pressure unit 590 simultaneously with starting to drive the mold closing motor 160.

[0113] As described above, the injection molding machine 2 includes a rotary table 220 for holding a movable mold 82 that forms a cavity space together with a fixed mold 81. The injection molding machine 2 also includes a rotating shaft 270 configured to protrude from the side of the rotary table 220 opposite to the side holding the movable mold 82, so as to transmit the rotational force of the rotary table 220. Furthermore, the injection molding machine 2 includes a movable pressure plate 120 that rotatably supports the rotary table 220 via a bearing 580 for engaging the rotating shaft 270. Finally, the injection molding machine 2 includes an inner component 290 disposed inside the rotary table 220 and the rotating shaft 270, and capable of contacting the surface of the movable mold 82 opposite to the fixed mold 81. Furthermore, the injection molding machine 2 includes a pressure section 590 (an example of a suppression section), which is mounted on a movable pressure plate 120 and suppresses the inner component 290 from moving to the side opposite to the movable mold 82.

[0114] In the injection molding machine 2 described above, the pressure unit 590 suppresses the inner component 290 from moving to the side opposite to the movable mold 82. This suppresses deformation of the movable mold 82 caused by the pressure of the molding material filling the cavity space. As a result, according to the injection molding machine 2, uneven thickness of the molded article caused by deformation of the movable mold 82 can be suppressed. Furthermore, since the pressure unit 590 applies pressure to the inner component 290, and the pressure-applied inner component 290 applies pressure to the movable mold 82 to prevent deformation, deformation suppression of the movable mold 82 can be achieved with a simple structure.

[0115] <Third Implementation>

[0116] Figure 5 This is a diagram showing an example of a cross-section of the injection molding machine 3 according to the third embodiment.

[0117] The injection molding machine 3 according to the third embodiment differs from the injection molding machine 1 according to the first embodiment in that it has a limiting part 390 instead of a pressure part 590. Hereinafter, the differences from the first embodiment will be described. In both the first and third embodiments, the same reference numerals are used for the same parts, and detailed descriptions are omitted.

[0118] The structure of the limiting part 390 differs from that of the pressurizing part 590 in the first embodiment in that the opening 126e of the communication hole 126h of the movable pressure plate 120 can be closed in order to prevent the rear end of the rotating shaft 570 from protruding from the rear end face of the movable pressure plate 120.

[0119] More specifically, the limiting part 390 includes: a moving member 392 having a flat cover 391; and a driving part 393 that causes the moving member 392 to move in a direction orthogonal to the centerline direction (e.g., in...). Figure 5 Move in orthogonal directions on the paper.

[0120] An example is provided where the drive unit 393 is a solenoid containing a coil (not shown) or a plunger (not shown) within a housing 394, and a shaft (not shown) fixed to the plunger is exposed from the housing 394. Furthermore, the housing 394 is fixed to the rear end face of the movable pressure plate 120, and the shaft is connected to the moving member 392.

[0121] The limiting part 390 increases the amount of the shaft protruding from the housing 394 by energizing the drive part 393, causing the moving member 392 to move in a direction orthogonal to the centerline. Conversely, the limiting part 390 reduces the amount of the shaft protruding by stopping the energization of the drive part 393, causing the moving member 392 to return to its original position. Furthermore, as... Figure 5 As shown, when the drive unit 393 is energized, the limiting unit 390 causes the cover 391 of the moving member 392 to close the opening 126e of the communication hole 126h of the movable pressure plate 120.

[0122] The movable pressure plate 120 has a guide member 126g that guides the moving member 392 around the opening 126e of the connecting hole 126h and further rearward than the opening 126e. The guide member 126g inhibits the moving member 392 from moving along the centerline.

[0123] The control device 500 controls, for example, the energization of the limiting part 390. For instance, during the mold closing process, before the first injection unit 301 fills the first molding material and the second injection unit fills the second molding material, the control device 500 energizes the drive unit 393 to close the opening 126e of the communication hole 126h of the movable pressure plate 120 with the cover 391. Afterwards, for example, after the mold closing process ends, the control device 500 stops energizing the drive unit 393 so that the cover 391 of the moving member 392 does not close the opening 126e of the communication hole 126h of the movable pressure plate 120. For instance, during the depressurization process, the control device 500 stops energizing the drive unit 393 simultaneously with starting to drive the mold closing motor 160.

[0124] In the injection molding machine 3 configured as described above, when the first injection unit 301 and the like fill the molding material, the cover 391 of the moving member 392 closes the opening 126e of the communication hole 126h of the movable pressure plate 120, thus suppressing the rearward movement of the rotating shaft 570. Even if the pressure of the molding material filled into the cavity space causes the rotating shaft 570 to attempt to move rearward, the movement of the rotating shaft 570 is suppressed by the cover 391, and the movement of the cover 391 is also suppressed by the guide member 126g. In other words, the cover 391 of the moving member 392 restricts the movement of the end of the rotating shaft 570 opposite to the side connected to the rotary table 520. Therefore, deformation of the movable mold 82 caused by the pressure of the molding material filled into the cavity space can be suppressed. As a result, according to the injection molding machine 3, uneven thickness of the molded article caused by deformation of the movable mold 82 can be suppressed. Furthermore, the limiting part 390 is a structure that applies pressure to the rotating shaft 570, and the rotating shaft 570, which is subjected to pressure, applies pressure to the rotary table 520 in order to prevent the movable mold 82 from deforming. Therefore, the deformation of the movable mold 82 can be suppressed through a simple structure.

[0125] Furthermore, the magnitude of the centerline direction at the front end portion 573 of the rotating shaft 570 according to the third embodiment is set as follows. That is, assuming that the cover portion 391 does not close the opening 126e of the communication hole 126h of the movable pressure plate 120, it is configured such that the rear end portion of the front end portion 573 protrudes from the opening 126e of the communication hole 126h due to the pressure of the molding material filled into the cavity space. Thus, by closing the opening 126e of the communication hole 126h of the movable pressure plate 120 by the cover portion 391, pressure can be applied to the rear end portion of the rotating shaft 570.

[0126] Furthermore, in the limiting part 390, the movement of the moving part 392 is not limited to the solenoid described above, but may also be the ball screw mechanism or hydraulic actuator described above.

[0127] Furthermore, in the injection molding machine 2 according to the second embodiment, the limiting part 390 can be used instead of the pressure part 590.

Claims

1. An injection molding machine, comprising: A retaining component for retaining the second mold, which together with the first mold forms a cavity space; A rotating shaft is configured to protrude toward the side of the retaining member opposite to the side that holds the second mold, so as to transmit the rotational force of the retaining member, or to transmit the rotational force to the retaining member; A support member that rotatably supports the retaining member via a bearing for embedding in the rotating shaft; and The suppressing part is mounted on the support member and suppresses the movement of the rotation axis to the side opposite to the retaining member.

2. The injection molding machine according to claim 1, wherein, The suppressing part has an inner component that is configured to move axially along the rotation axis inside the support component and to contact the end of the rotation axis opposite to the second mold. By moving the inner component along the axial direction, pressure is applied to the rotation axis, thereby suppressing the movement of the rotation axis.

3. The injection molding machine according to claim 1, wherein, The support member has a fitting recess and a communicating hole. The fitting recess is used to embed the bearing, and the communicating hole, on the side of the fitting recess opposite to the second mold, allows the fitting recess to communicate with the outside. The rotating shaft has: a shaft portion for embedding the bearing; and a front end portion disposed on the side opposite to the second mold relative to the shaft portion and disposed in the communicating hole. The suppressing part closes the opening of the connecting hole to prevent the front end of the rotating shaft from being exposed from the connecting hole, thereby suppressing the movement of the rotating shaft.

4. An injection molding machine, comprising: A retaining component for retaining the second mold, which together with the first mold forms a cavity space; A rotating shaft is configured to protrude toward the side of the retaining member opposite to the side that holds the second mold, so as to transmit the rotational force of the retaining member, or to transmit the rotational force to the retaining member; The support member rotatably supports the retaining member via a bearing for embedding the rotating shaft; An inner component is disposed inside the retaining component and the rotating shaft, and is capable of contacting the surface of the second mold opposite to that of the first mold; and The suppressing part is installed on the supporting member and suppresses the movement of the inner part to the side opposite to the second mold.

5. The injection molding machine according to any one of claims 1 to 4, wherein, The inhibiting part begins to inhibit movement before filling the cavity space with molding material, and then inhibits movement until the molding of the molded article is completed.

6. The injection molding machine according to any one of claims 1 to 4, wherein, The inhibiting part begins to inhibit movement after the molding material is filled into the cavity space, and then inhibits movement until the molding of the molded article is completed.

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