Injection molding machine

Abstract

The mold clamping force can be applied to the mold from the fixed platen side. [Solution] An injection molding machine comprising: a clamping device that applies a first clamping force to the movable mold and the fixed mold from the movable platen side by moving the movable platen that supports the movable mold to the fixed platen side that supports the fixed mold; an injection device that injects material into the gap between the movable mold and the fixed mold; and a pressing device that applies a second clamping force to the movable mold and the fixed mold from the fixed platen side.

Description

Technical Field

[0001] The present invention relates to an injection molding machine.

Background Art

[0002] Patent Document 1 describes a display device for an injection molding machine. This display device displays a setting screen for performing settings related to the control of the torque of an ejector motor by a control device based on the in-mold pressure in the cavity space of a mold device that represents the force opposing the drive of the ejector motor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, the mold clamping force of a mold is generated by reducing the distance between platens by opening and closing a mold clamping device. However, when it is desired to move a part of the mold, such as core compression, it cannot be handled by opening and closing the mold clamping device.

[0005] As a method of applying a mold clamping force to the mold other than the mold clamping device, there is a method of applying the mold clamping force by ejector compression. However, since the ejector generally operates on the movable platen side, with this method, the mold clamping force can only be applied to the mold from the movable platen side.

[0006] An object of the present invention is to enable the application of a mold clamping force to the mold from the fixed platen side.

Means for Solving the Problems

[0007] To this end, the present invention provides an injection molding machine comprising: a clamping device that applies a first clamping force to the movable mold and the fixed mold from the movable platen side by moving the movable platen that supports the movable mold to the fixed platen side that supports the fixed mold; an injection device that injects material into the gap between the movable mold and the fixed mold; and a pressing device that applies a second clamping force to the movable mold and the fixed mold from the fixed platen side.

[0008] The pressing device may be mounted on the injection device. In that case, the pressing device may apply a second clamping force to the movable mold and the fixed mold when the injection device injects material into the gap between the movable mold and the fixed mold.

[0009] The clamping device applies a first clamping force to the first movable mold, the first fixed mold and the second fixed mold from the movable platen side by moving the movable platen supporting the first movable mold to the fixed platen side supporting the first fixed mold and the second fixed mold. The injection device includes a first injection device that injects a first material into the gap between the first movable mold and the first fixed mold, and a second injection device that injects a second material into the gap between the first movable mold and the second fixed mold after the first material has been injected into the gap between the first movable mold and the first fixed mold. The pressing device may apply a second clamping force to the first movable mold and the second fixed mold from the fixed platen side.

[0010] In that case, the pressing device may be mounted on the second injection device. Also in that case, the pressing device may apply a second clamping force to the first movable mold and the second fixed mold when the second injection device injects the second material into the gap between the first movable mold and the second fixed mold. Furthermore, in that case, the pressing device may apply a second clamping force to the first movable mold and the second fixed mold when the second injection device injects the second material onto the first material molded on the surface of the first movable mold. Furthermore, the clamping device may apply a first clamping force of a first magnitude to the first movable mold and the first fixed mold from the movable platen side, and before the second injection device injects the second material into the gap between the first movable mold and the second fixed mold, it may apply a first clamping force of a second magnitude smaller than the first magnitude to the first movable mold and the second fixed mold from the movable platen side, and the pressing device may apply a second clamping force of a second magnitude smaller than the first magnitude and larger than the second magnitude to the first movable mold and the second fixed mold from the fixed platen side when the second injection device injects the second material into the gap between the first movable mold and the second fixed mold.

[0011] The second injection device may inject the second material into the center of the first movable mold, on which the first material has been molded to the surface. [Effects of the Invention]

[0012] According to the present invention, a clamping force can be applied to the mold from the fixed platen side. [Brief explanation of the drawing]

[0013] [Figure 1] This diagram shows the configuration of the injection molding machine in this embodiment. [Figure 2] This diagram shows the configuration of the injection molding machine in this embodiment. [Figure 3] This is a perspective view showing the main parts of the injection molding machine in this embodiment. [Figure 4] This is a perspective view showing the main parts of the injection molding machine in this embodiment. [Figure 5] This is a top view showing the mechanism on the non-operating side of the main part of the injection molding machine in this embodiment. [Figure 6]This diagram illustrates a mechanism that prevents excessive clamping force from being applied to the mold on the non-operating side by the clamping device. [Figure 7] This graph shows the change in the magnitude of the clamping force applied to the mold during one cycle of mold opening and closing. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0015] [Configuration of an injection molding machine] Figures 1 and 2 show the configuration of the injection molding machine 10 in this embodiment. Figure 1 shows the state of the injection molding machine 10 when mold opening is complete. Figure 2 shows the state of the injection molding machine 10 when the mold is clamped. In the injection molding machine 10, the front side in Figures 1 and 2 is the operating side, and the back side in Figures 1 and 2 is the non-operating side. The injection molding machine 10 includes a mold clamping device 100, a first ejector device 201, and a second ejector device 202. However, the first ejector device 201 is located on the operating side, and the second ejector device 202 is located on the non-operating side. Since these positions overlap in the vertical direction in Figures 1 and 2, the second ejector device 202 is not shown in Figures 1 and 2. The injection molding machine 10 also includes a first injection device 301, a second injection device 302, a frame 400, and a control device 500. However, the first injection device 301 is located on the operating side, and the second injection device 302 is located on the opposite side of the operating side. Since these positions overlap in the vertical direction in Figures 1 and 2, the second injection device 302 is not shown in Figures 1 and 2.

[0016] The mold clamping device 100 performs the processes of mold closing, pressure increasing, mold clamping, depressurization, and mold opening of the mold 800. In the description of the mold clamping device 100, the direction of movement of the movable platen 120 during mold closing (to the right in Figures 1 and 2) is considered forward, and the direction of movement of the movable platen 120 during mold opening (to the left in Figures 1 and 2) is considered backward.

[0017] The clamping device 100 has a fixed platen 110, a movable platen 120, a toggle support 130, tie bars 140, a toggle mechanism 150, a clamping motor 160, and a ball screw 170.

[0018] The fixed platen 110 is fixed to the frame 400. On the opposing surface of the fixed platen 110 facing the movable platen 120, the first fixed mold 811 and the second fixed mold 812 are attached as the fixed molds constituting the mold 800. However, the first fixed mold 811 is provided on the operation side, and the second fixed mold 812 is provided on the non-operation side. And since their positions in the vertical direction of FIGS. 1 and 2 overlap, the second fixed mold 812 is not shown in FIGS. 1 and 2.

[0019] The movable platen 120 is provided so as to be movable in the mold opening and closing direction (the left - right direction of FIGS. 1 and 2) with respect to the frame 400. On the opposing surface of the movable platen 120 facing the fixed platen 110, the first movable mold 821 and the second movable mold 822 are attached as the movable molds constituting the mold 800. Also, the movable platen 120 is rotatable about a predetermined rotation axis. The predetermined rotation axis may be perpendicular to the fixed platen 110 and the movable platen 120 and be an axis in the middle of the central axis of the first ejector device 201 and the central axis of the second ejector device 202. The movable platen 120 rotates about this predetermined rotation axis by a first rotation angle and a second rotation angle. The first rotation angle is the rotation angle at which the first fixed mold 811 and the first movable mold 821 are fitted together and the second fixed mold 812 and the second movable mold 822 are fitted together. The first rotation angle is, for example, 0°. On the other hand, the second rotation angle is the rotation angle at which the first fixed mold 811 and the second movable mold 822 are fitted together and the second fixed mold 812 and the first movable mold 821 are fitted together. The second rotation angle is, for example, 180°. FIGS. 1 and 2 show the state where the movable platen 120 rotates by the first rotation angle. In this state, the first movable mold 821 is provided on the operation side, and the second movable mold 822 is provided on the non - operation side. And since their positions in the vertical direction of FIGS. 1 and 2 overlap, the second movable mold 822 is not shown in FIGS. 1 and 2.

[0020] By advancing and retracting the movable platen 120 with respect to the fixed platen 110, mold closing, pressure boosting, mold clamping, pressure release, and mold opening of the mold 800 are performed.

[0021] The toggle support 130 is provided on the frame 400 so as to be movable in the mold opening and closing direction at a distance from the fixed platen 110. The tie bar 140 connects the fixed platen 110 and the toggle support 130 while keeping a distance in the mold opening and closing direction.

[0022] The toggle mechanism 150 is disposed between the movable platen 120 and the toggle support 130. And the toggle mechanism 150 moves the movable platen 120 in the mold opening and closing direction with respect to the toggle support 130 (see the toggle mechanism 150 and the movable platen 120 in FIGS. 1 and 2). The toggle mechanism 150 is composed of a crosshead 150a, a pair of link groups, etc. The crosshead 150a is a nut for the ball screw 170. As will be described later, when the ball screw 170 rotates about its axis, the crosshead 150a advances and retracts with respect to the toggle support 130. Then, the link group flexes and extends, whereby the movable platen 120 advances and retracts with respect to the toggle support 130.

[0023] The mold clamping motor 160 and the ball screw 170 are attached to the toggle support 130 and operate the toggle mechanism 150. The ball screw 170 rotates about its axis under the rotational drive of the mold clamping motor 160 and advances and retracts the crosshead 150a, which is a nut, with respect to the toggle support 130. In other words, the ball screw 170 converts the rotational motion of the mold clamping motor 160 into the linear motion of the crosshead 150a. The position and speed of the crosshead 150a are detected by, for example, an encoder 160a of the mold clamping motor 160. A signal indicating the detection result is sent to the control device 500.

[0024] The mold clamping device 100 performs a mold closing process, a pressure boosting process, a mold clamping process, a pressure release process, a mold opening process, etc. under the control of the control device 500.

[0025] In the mold closing process, the mold clamping device 100 drives the mold clamping motor 160 to rotate the ball screw 170, moving the crosshead 150a forward at a set speed to the mold closing completion position. As a result, the movable platen 120 moves forward, the first movable mold 821 comes into contact with the first fixed mold 811, and the second movable mold 822 comes into contact with the second fixed mold 812.

[0026] Furthermore, when the movable platen 120 is rotated to the second rotation angle, the second movable mold 822 comes into contact with the first fixed mold 811, and the first movable mold 821 comes into contact with the second fixed mold 812.

[0027] In the pressure boosting process, the clamping device 100 further drives the clamping motor 160 to advance the crosshead 150a further from the closed position to the clamping position. This generates a clamping force (first clamping force) in the mold 800.

[0028] In the clamping process, the clamping device 100 drives the clamping motor 160 to maintain the position of the crosshead 150a in the clamping position. This maintains the clamping force generated in the pressurization process during the clamping process. Also in the clamping process, a first cavity space (first void) 831 is formed between the first movable mold 821 and the first fixed mold 811. The first injection device 301 fills this first cavity space 831 with liquid first molding material. A first molded product is obtained when the filled first molding material solidifies. Meanwhile, a second cavity space (second void) 832 (not shown) is formed between the first molded product molded in the second movable mold 822 and the second fixed mold 812. The second injection device 302 fills this second cavity space 832 with liquid second molding material. The filled second molding material solidifies, resulting in a second molded product containing the first molded product.

[0029] Furthermore, when the movable platen 120 is rotated to the second rotation angle, a cavity space (gap) is formed between the second movable mold 822 and the first fixed mold 811. The first injection device 301 fills this cavity space with liquid first molding material. The first molded product is obtained when the filled first molding material solidifies. Meanwhile, a cavity space (gap) is formed between the first molded product molded in the first movable mold 821 and the second fixed mold 812. The second injection device 302 fills this cavity space with liquid second molding material. The second molded product, including the first molded product, is obtained when the filled second molding material solidifies.

[0030] In the depressurization process, the clamping device 100 drives the clamping motor 160 to rotate the ball screw 170 in the opposite direction to that of the mold closing and pressure boosting processes, causing the crosshead 150a to retract from the clamping position to the mold opening start position. This causes the movable platen 120 to retract, reducing the clamping force. The mold opening start position may be the same position as the mold closing completion position described in the mold closing and pressure boosting processes.

[0031] In the mold opening process, the mold clamping device 100 drives the mold clamping motor 160 to retract the crosshead 150a from the mold opening start position to the mold opening completion position at a set movement speed. As a result, the movable platen 120 retracts, and the first movable mold 821 is separated from the first fixed mold 811, and the second movable mold 822 is separated from the second fixed mold 812.

[0032] Furthermore, when the movable platen 120 is rotated to the second rotation angle, the second movable mold 822 is separated from the first fixed mold 811, and the first movable mold 821 is separated from the second fixed mold 812.

[0033] The first ejector device 201 performs the ejection process under the control of the control device 500. The second ejector device 202 has the same configuration as the first ejector device 201 and also performs the ejection process under the control of the control device 500. The first ejector device 201 and the second ejector device 202 are attached to the movable platen 120 and move forward and backward together with the movable platen 120. In the ejection process, the first ejector device 201 operates a movable member provided on the first movable mold 821 to eject and detach the unwanted product from the first movable mold 821. Then, the second ejector device 202 operates a movable member provided on the second movable mold 822 to eject and detach the unwanted product and the second molded product from the second movable mold 822.

[0034] Furthermore, when the movable platen 120 is rotated to the second rotation angle, the first ejector device 201 operates a movable member provided on the second movable mold 822 to eject and detach the unwanted product from the second movable mold 822. Then, the second ejector device 202 operates a movable member provided on the first movable mold 821 to eject and detach the unwanted product and the second molded product from the first movable mold 821.

[0035] The first injection device 301 is mounted on a slide base 411 that can move back and forth relative to the frame 400, and is also able to move back and forth relative to the mold 800. The first injection device 301 touches the mold 800 and fills the mold 800 with the first molding material. In the description of the first injection device 301, unlike the description of the clamping device 100, the direction of movement of the screw 331 during filling (left direction in Figures 1 and 2) is forward, and the direction of movement of the screw 331 during metering (right direction in Figures 1 and 2) is backward.

[0036] The first injection device 301 includes, for example, a cylinder 311, a nozzle 321, a screw 331, a metering motor 340, an injection motor 351, and a pressure detector 360.

[0037] The cylinder 311 heats the first molding material supplied to its interior from the supply port 310a. The supply port 310a is formed at the rear of the cylinder 311. A heating source 310b, such as a heater, and a temperature detector 310c are provided on the outer circumference of the cylinder 311.

[0038] The cylinder 311 is divided into multiple zones along its axial direction (left-right direction in Figures 1 and 2). A heating source 310b and a temperature detector 310c are provided in each zone. For each zone, the control device 500 controls the heating source 310b so that the measured temperature of the temperature detector 310c becomes the set temperature.

[0039] The nozzle 321 is located at the front end of the cylinder 311 and is pressed against the mold 800. A heating source 310b, such as a heater, and a temperature sensor 310c are provided on the outer circumference of the nozzle 321. The control device 500 controls the heating source 310b so that the measured temperature of the nozzle 321 becomes the set temperature.

[0040] The screw 331 is arranged within the cylinder 311 so as to be rotatable and able to move forward and backward.

[0041] The metering motor 340 rotates the screw 331, thereby advancing the first molding material along the helical groove of the screw 331. As the first molding material is advanced, it is gradually melted by the heat from the cylinder 311. As the liquid first molding material is advanced forward by the screw 331 and accumulates at the front of the cylinder 311, the screw 331 is retracted.

[0042] The injection motor 351 moves the screw 331 forward and backward. By advancing the screw 331, the injection motor 351 fills the injection mold 800 from the cylinder 311 with the liquid first molding material accumulated in front of the screw 331. Subsequently, the injection motor 351 pushes the screw 331 forward, applying pressure to the first molding material in the mold 800. This replenishes any insufficient first molding material. Between the injection motor 351 and the screw 331, a motion conversion mechanism is provided that converts the rotational motion of the injection motor 351 into the linear motion of the screw 331. This motion conversion mechanism is composed of, for example, a ball screw mechanism.

[0043] The pressure detector 360 is positioned, for example, between the injection motor 351 and the screw 331, and detects the pressure the screw 331 receives from the first molding material, the back pressure on the screw 331, and the like. The pressure the screw 331 receives from the first molding material corresponds to the pressure acting from the screw 331 on the first molding material. The pressure detector 360 sends a signal indicating its detection result to the control device 500.

[0044] The first injection device 301 performs filling, holding pressure, and metering processes, etc., under the control of the control device 500.

[0045] In the filling process, the first injection device 301 drives the injection motor 351 to advance the screw 331 at a set speed, filling the mold 800 with the liquid first molding material accumulated in front of the screw 331. The position and speed of the screw 331 are detected, for example, by the encoder 351a of the injection motor 351. A signal indicating the detection result is sent to the control device 500. When the position of the screw 331 reaches a predetermined position, a switch from the filling process to the holding pressure process (so-called V / P switching) is performed. The set speed of the screw 331 may be changed according to the position and time of the screw 331.

[0046] In the holding pressure process, the first injection unit 301 drives the injection motor 351 to push the screw 331 forward at a set pressure, applying pressure to the first molding material in the mold 800. This replenishes any insufficient amount of the first molding material. The pressure of the first molding material is detected, for example, by a pressure detector 360. A signal indicating the detection result is sent to the control device 500.

[0047] During the holding pressure process, the first molding material inside the mold 800 is gradually cooled, and upon completion of the holding pressure process, the entrance to the first cavity space 831 is sealed with the solidified first molding material. This state is called a gate seal, and prevents backflow of the first molding material from the first cavity space 831. After the holding pressure process, the cooling process begins. During the cooling process, the first molding material inside the first cavity space 831 is solidified. To shorten the molding cycle, a metering process may be performed during the cooling process.

[0048] In the metering process, the first injection unit 301 drives the metering motor 340 to rotate the screw 331 at a set rotational speed, feeding the first molding material forward along the helical groove of the screw 331. As this occurs, the first molding material is gradually melted. As the liquid first molding material is fed forward by the screw 331 and accumulates at the front of the cylinder 311, the screw 331 is retracted. The rotational speed of the screw 331 is detected, for example, by the encoder 340a of the metering motor 340. A signal indicating the detection result is sent to the control device 500.

[0049] In the metering process, the first injection device 301 may drive the injection motor 351 to apply a set back pressure to the screw 331 in order to limit the rapid retraction of the screw 331. The back pressure on the screw 331 is detected, for example, by a pressure detector 360. A signal indicating the detection result is sent to the control device 500. When the screw 331 has retracted to a predetermined position and a predetermined amount of the first molding material has accumulated in front of the screw 331, the metering process is completed.

[0050] The second injection device 302 is mounted on a slide base 412 (not shown) that can move back and forth relative to the frame 400, and is also able to move back and forth relative to the mold 800. In addition to filling the mold 800 with the second molding material, the second injection device 302 applies clamping force to the mold 800. The configuration of the second injection device 302 will be described later.

[0051] [Configuration of this embodiment] Figures 3 and 4 are perspective views showing the main parts of the injection molding machine 10 shown in Figures 1 and 2. In Figures 3 and 4, the left side corresponds to the operating side, and the right side corresponds to the non-operating side. The main parts of the injection molding machine 10 shown in Figures 3 and 4 include a fixed platen 110, a movable platen 120, a first movable mold 821, and a second movable mold 822. The main parts of this injection molding machine 10 also include a first injection device 301 and a first fixed mold 811 on the operating side. Furthermore, the main parts of this injection molding machine 10 also include a second injection device 302 and a second fixed mold 812 on the non-operating side. The first injection device 301 injects a liquid first molding material (for example, a resin of a first color). The second injection device 302 applies an additional clamping force (second clamping force) to the mold 800. In addition, the second injection device 302 injects a liquid second molding material (for example, a resin of a second color).

[0052] First, as shown in Figure 3, assume that the movable platen 120 is rotated to a first rotation angle. That is, assume that the first fixed mold 811 and the first movable mold 821 face each other on the operating side, and the second fixed mold 812 and the second movable mold 822 face each other on the opposite side. In this case, the first injection device 301 injects the first molding material into the first cavity space 831 between the first fixed mold 811 and the first movable mold 821. Specifically, the injection motor 351 pushes a screw 331 (not shown) inside the cylinder 311 forward, thereby injecting the first molding material from the nozzle 321.

[0053] Subsequently, as shown in Figure 4, assume that the movable platen 120 has rotated to the second rotation angle. That is, assume that the first fixed mold 811 and the second movable mold 822 are facing each other on the operating side, and the second fixed mold 812 and the first movable mold 821 are facing each other on the opposite side. In this case, the second injection device 302 applies additional clamping force to the second fixed mold 812 and the first movable mold 821. Specifically, the injection motor 352 applies additional clamping force by pushing the pressing device 312 forward. In addition, the second injection device 302 injects the second molding material into the cavity space between the second fixed mold 812 and the first movable mold 821. Specifically, the pressing device 312 injects the second molding material from its tip.

[0054] Figure 5 is a top view showing the non-operating mechanism of the main part of the injection molding machine 10 in the state shown in Figure 4. The non-operating mechanism of the main part of the injection molding machine 10 includes a fixed platen 110, a movable platen 120, a second fixed mold 812, a first movable mold 821, and a pressing device 312. As shown in the figure, the pressing device 312 is pressed as indicated by arrow A1, thereby applying additional clamping force to the second fixed mold 812. This applies additional clamping force to the PL surface between the second fixed mold 812 and the first movable mold 821, as indicated by arrow A2. At that time, the pressing device 312 injects the second molding material from a plurality of injection ports 322 provided at its tip, as indicated by arrow A3.

[0055] In other words, the pressing device 312 applies additional clamping force when injecting the second molding material into the cavity space between the first movable mold 821 and the second fixed mold 812. More specifically, the pressing device 312 applies additional clamping force when the second injection device 302 injects the second molding material from above the first molding material molded on the surface of the first movable mold 821. Here, it is assumed that the second molding material fills the surface side (the side facing the second injection device 302) and the sides of the first molding material, but not the back side (the side opposite to the second injection device 302). Under this assumption, "from above" means from the side facing the second injection device 302 (the side where the filled first molding material exists).

[0056] Now, consider the case where the second molding material has an extremely low viscosity compared to the first molding material, for example, a viscosity of 8000 mPa·s or less. In this case, it is necessary to reduce the clamping force applied to the second molding material in the state shown in Figure 4 compared to the clamping force applied to the first molding material in the state shown in Figure 3. Otherwise, when injecting the second molding material into the cavity space between the second fixed mold 812 and the first movable mold 821, air may not escape completely, potentially leading to defects such as short circuits. For this reason, a mechanism to receive the clamping force is provided on the side into which the second molding material is injected. This is based on the premise that almost no force from the clamping device 100 is applied to the cavity space between the second fixed mold 812 and the first movable mold 821. Then, the second injection device 302 applies an additional clamping force when injecting the second molding material into the cavity space between the second fixed mold 812 and the first movable mold 821. In this case, the additional clamping force must be smaller than the clamping force from the clamping device 100. If the additional clamping force is greater than the clamping force from the clamping device 100, there is a risk of damage to the second fixed mold 812 or the first movable mold 821. Therefore, in this embodiment, the second injection device 302 applies an additional clamping force that is smaller than the clamping force from the clamping device 100. This makes it possible to reduce the clamping force applied to the mold 800 filled with the second molding material compared to the mold 800 filled with the first molding material, thereby avoiding defects such as short circuits caused by excessive clamping force. In such cases, it is necessary to prepare a mechanism in the mold 800 or the injection molding machine 10 to prevent a large clamping force from being applied to the mold 800 on the non-operating side from the clamping device 100.

[0057] Figure 6 illustrates this mechanism. Although not shown in Figures 3 and 4, a pair (two) of pillars 191 are provided on the opposing surface of the fixed platen 110 that faces the movable platen 120. Each pillar 191 extends linearly from the fixed platen 110 toward the movable platen 120 and has a set length. The number of pillars 191 is not particularly limited; there may be one or three or more. The pair of pillars 191 are installed at adjacent positions on the non-operating side of the second fixed mold 812.

[0058] Figure 7 is a graph showing the change in the magnitude of the clamping force applied to the mold 800 during one cycle of mold opening and closing. Here, we will explain using the case where the movable platen 120 is rotating to the first rotation angle, as shown in Figure 3.

[0059] The broken line L1 shows the change in the magnitude of the clamping force received by the first fixed mold 811 and the first movable mold 821. In this case, as shown by the broken line L1, the first fixed mold 811 and the first movable mold 821 receive a large clamping force from the clamping device 100. Here, the clamping force received by the first fixed mold 811 and the first movable mold 821 from the clamping device 100 is an example of a clamping force of a first magnitude.

[0060] The broken line L2 shows the change in the magnitude of the clamping force received by the second fixed mold 812 and the second movable mold 822. In this case, before the start of clamping by the second injection device 302, the second fixed mold 812 and the second movable mold 822 receive almost no clamping force from the clamping device 100 due to the mechanism shown in Figure 6. Here, the clamping force received by the second fixed mold 812 and the second movable mold 822 from the clamping device 100 is an example of a second magnitude clamping force that is smaller than the first magnitude. Then, after the start of clamping by the second injection device 302, the second fixed mold 812 and the second movable mold 822 receive an additional clamping force from the second injection device 302. This additional clamping force is smaller than the clamping force from the clamping device 100. Here, the additional clamping force that the second fixed mold 812 and the second movable mold 822 receive from the second injection device 302 is an example of a clamping force that is smaller than the first magnitude and larger than the second magnitude.

[0061] Furthermore, as shown by the broken line L2, the clamping force applied during filling is increased during cooling and metering. This is because applying a large clamping force from the beginning would cause problems with air not being able to escape. Also, if cooling continues with a small clamping force, the clamping force will not be sufficiently transmitted to the molded product.

[0062] Furthermore, in this embodiment, the pressing device 312 of the second injection device 302 may be an assembly. That is, the second injection device 302 may be constructed by replacing the screw 331 assembly of the first injection device 301 with the pressing device 312 assembly.

[0063] This allows the pressing device 312 to be pressed against the mold 800 to generate additional clamping force without altering the performance of a conventional injection molding device.

[0064] Furthermore, it is easy to revert to normal molding by replacing the assembly of the pressing device 312 with the assembly of the screw 331.

[0065] Furthermore, it is possible to apply high clamping forces that cannot be achieved with the nozzle touch force or ejector protrusion of a conventional injection system. Generating high clamping force with nozzle touch force would require modifications such as increasing the size or number of hydraulic cylinders, but such modifications are unnecessary when replacing the assembly.

[0066] [Summary of this embodiment] In this embodiment, an additional clamping force is applied to the mold 800 into which the second molding material is injected, from the fixed platen 110 side. If the additional clamping force were applied from the movable platen 120 side, it would be transmitted through the first molding material, making it difficult to transmit the additional clamping force effectively. In contrast, in this embodiment, surface pressure can be applied directly to the injected second molding material. Therefore, this embodiment is effective in two-component molding machines and insert molding machines.

[0067] Furthermore, in this embodiment, additional clamping force is applied to the mold 800 from the fixed platen 110 side to fill it with molding material. This makes it possible to fill the molding material from the center of the mold 800, unlike the method of injection from the sides or top and bottom. Filling the molding material from the center of the mold 800 in this way allows for even filling of the product with molding material. Now, let's consider the case where additional clamping force is applied to the mold 800 from the movable platen 120 side to fill it with molding material. In this case, since an ejector device is provided on the movable platen 120 side, it is impossible to fill the molding material from the center of the mold 800.

[0068] Furthermore, in this embodiment, additional clamping force is applied from the pressing device of the injection molding machine. This makes it possible to apply additional clamping force from the fixed platen 110 side without using an additional drive source such as an external actuator.

[0069] Furthermore, in this embodiment, by controlling the operation of the pressing device, it is also possible to apply any additional clamping force to the mold 800 from the fixed platen 110 side.

[0070] [Differentiation] In the above, the pressing device 312 is assumed to be mounted on the second injection device 302. With this configuration, there is no need to prepare an external unit or incur operating costs to apply additional clamping force from the fixed platen 110 side. However, this configuration is not limited to this. The pressing device 312 may be provided separately from the second injection device 302.

[0071] Furthermore, in the above description, this embodiment is applied to a so-called two-component molding machine in which the first injection device 301 injects the first molding material and then the second injection device 302 injects the second molding material. However, this embodiment may also be applied to a so-called one-component molding machine in which a single injection device injects a single molding material. In that case, this embodiment can be understood as having a pressing device that pushes the mold 800 mounted on the injection device, separate from the mold clamping device 100 of the injection molding machine 10. Alternatively, this embodiment can be understood as the pressing device moving towards the mold 800 when the injection device performs an injection operation, and pressing the mold 800 from the fixed platen 110 side. Here again, the pressing device is assumed to be mounted on the injection device. However, the configuration is not limited to this. The pressing device may be provided separately from the injection device.

[0072] Furthermore, although the second injection device 302 is described above as the injection device in the injection molding machine 10, it is not limited to this. The second injection device 302 may consist only of a plunger and piston that push out highly viscous material, and may not have a metering motor, injection motor, etc. [Explanation of Symbols]

[0073] 10…Injection molding machine, 100…Clamping device, 110…Fixed platen, 120…Movable platen, 130…Toggle support, 140…Tie bar, 150…Toggle mechanism, 160…Clamping motor, 170…Ball screw, 201…First ejector device, 202…Second ejector device, 301…First injection device, 302…Second injection device, 311…Cylinder, 312…Pressing device, 321…Nozzle, 322…Injection port, 331…Screw, 340…Metering motor, 351, 352…Injection motor, 360…Pressure detector, 400…Frame, 500…Control device, 811…First fixed mold, 812…Second fixed mold, 821…First movable mold, 822…Second movable mold

Claims

1. A clamping device that applies a first clamping force to the movable mold and the fixed mold from the movable platen side by moving the movable platen that supports the movable mold to the fixed platen that supports the fixed mold, An injection device for injecting material into the gap between the movable mold and the fixed mold, A pressing device that applies a second mold clamping force to the movable mold and the fixed mold from the fixed platen side, An injection molding machine equipped with [a specific feature].

2. The injection molding machine according to claim 1, wherein the pressing device is mounted on the injection device.

3. The injection molding machine according to claim 2, wherein the pressing device applies the second clamping force to the movable mold and the fixed mold when the injection device injects the material into the gap between the movable mold and the fixed mold.

4. The clamping device applies the first clamping force to the first movable mold, the first fixed mold, and the second fixed mold from the movable platen side by moving the movable platen that supports the first movable mold towards the fixed platen that supports the first fixed mold and the second fixed mold. The injection apparatus includes a first injection apparatus for injecting a first material into the gap between the first movable mold and the first fixed mold, and a second injection apparatus for injecting a second material into the gap between the first movable mold and the second fixed mold after the first material has been injected into the gap between the first movable mold and the first fixed mold. The injection molding machine according to claim 1, wherein the pressing device applies the second clamping force to the first movable mold and the second fixed mold from the fixed platen side.

5. The injection molding machine according to claim 4, wherein the pressing device is mounted on the second injection device.

6. The injection molding machine according to claim 5, wherein the pressing device applies the second clamping force to the first movable mold and the second fixed mold when the second injection device injects the second material into the gap between the first movable mold and the second fixed mold.

7. The injection molding machine according to claim 6, wherein the pressing device applies the second clamping force to the first movable mold and the second fixed mold when the second injection device injects the second material onto the surface of the first movable mold where the first material has been molded.

8. The clamping device applies a first clamping force of a first magnitude to the first movable mold and the first fixed mold from the movable platen side, and before the second injection device injects the second material into the gap between the first movable mold and the second fixed mold, it applies a first clamping force of a second magnitude smaller than the first magnitude to the first movable mold and the second fixed mold from the movable platen side. The injection molding machine according to claim 6, wherein the pressing device applies a second clamping force, smaller than the first size and larger than the second size, to the first movable mold and the second fixed mold from the fixed platen side when the second injection device injects the second material into the gap between the first movable mold and the second fixed mold.

9. The injection molding machine according to claim 5, wherein the second injection device injects the second material into the central part of the first movable mold on which the first material is formed on the surface.

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