Mold device and injection molding system

Abstract

To provide a technique that can reduce uneven cooling of a mold device in a direction perpendicular to a mold clamping direction and reduce uneven shrinkage of a molded product in the direction perpendicular to the mold clamping direction.SOLUTION: A fixed mold includes: a first mold part that contacts a movable mold when clamped and forms a part of a wall surface of a cavity space; a first cooling part that is temperature-controlled to a temperature lower than the temperature of the first mold part when a molding material is filled; and a first support part that supports one of the first cooling part and the first mold part so that they can move relatively to the other. The first cooling part and the first mold part are relatively movable in both a mold opening direction and a mold closing direction between a position where they are separated from each other and a position where they are in contact with each other.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a mold apparatus and an injection molding system. [Background technology]

[0002] The device described in Patent Document 1 includes a mold consisting of a fixed mold and a movable mold, a temperature control block for heating or cooling the mold, and a pressing mechanism for the temperature control block. A pair of temperature control blocks are provided in a direction perpendicular to the mold clamping direction. The pressing mechanism presses (contacts) the temperature control block against the mold in a direction perpendicular to the mold clamping direction. The temperature of the mold can be controlled by controlling the pressing force (contact force). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-315292 Summary of the Invention [Problem to be solved by the invention]

[0004] The mold assembly includes a fixed mold and a movable mold, and when clamped, a cavity is formed between the fixed mold and the movable mold. The cavity is filled with preheated molding material, which is cooled and solidified within the cavity to produce a molded product.

[0005] If the temperature of the mold device is too low, the fluidity of the molding material during filling is poor, making it difficult to transfer the shape and dimensions of the cavity space to the molded product. Therefore, if the temperature of the mold device is too low, the mold device's transferability is poor. On the other hand, if the temperature of the mold device is too high, it is difficult for the molding material to cool within the cavity space. Therefore, the cooling time until the molding material solidifies enough to be removed from the mold device is too long, resulting in poor production efficiency of molded products.

[0006] It is possible to use the technology described in Patent Document 1 to improve the transferability of the mold device and shorten the cooling time. However, in Patent Document 1, the temperature control block is pressed (contacted) against the mold in a direction perpendicular to the mold clamping direction, which makes it easy for uneven cooling of the mold to occur in the direction perpendicular to the mold clamping direction. As a result, uneven shrinkage of the molded product is easy to occur in the direction perpendicular to the mold clamping direction. Note that the mold clamping direction coincides with the mold opening and closing direction.

[0007] Many molded products have dimensions in the direction perpendicular to the clamping direction that are larger than the dimensions along the clamping direction. For example, lenses, connectors, and container lids have dimensions in the direction perpendicular to the clamping direction that are larger than the dimensions along the clamping direction. Therefore, uneven shrinkage of molded products in the direction perpendicular to the clamping direction leads to a decrease in the dimensional accuracy of the molded products.

[0008] One embodiment of the present invention provides a technology that can reduce uneven cooling of a mold device in a direction perpendicular to the mold clamping direction, and can reduce uneven shrinkage of a molded product in a direction perpendicular to the mold clamping direction. [Means for solving the problem]

[0009] A mold apparatus according to one embodiment of the present invention includes a fixed mold and a movable mold, and forms a cavity between the fixed mold and the movable mold during mold clamping. The cavity is a space into which a preheated molding material is filled. The fixed mold has a first mold part that contacts the movable mold during mold clamping and forms part of the wall of the cavity, a first cooling part whose temperature is adjusted to a temperature lower than that of the first mold part during filling with the molding material, and a first support part that supports one of the first cooling part and the first mold part so that they can move relative to the other. The first cooling part and the first mold part are movable relative to each other in both the mold opening direction and the mold closing direction between a position where they are separated from each other and a position where they are in contact with each other. The movable mold has a second mold part that contacts the fixed mold during mold clamping and forms part of the wall surface of the cavity space, a second cooling part that is temperature-controlled to a temperature lower than the temperature of the second mold part during filling of the molding material, and a second support part that supports one of the second cooling part and the second mold part so that they can move relatively to the other. The second cooling part and the second mold part are relatively movable in both the mold opening direction and the mold closing direction between a position where they are separated from each other and a position where they are in contact with each other. [Effects of the Invention]

[0010] According to one embodiment of the present invention, it is possible to reduce uneven cooling of the mold device in a direction perpendicular to the mold clamping direction, and to reduce uneven shrinkage of the molded product in a direction perpendicular to the mold clamping direction. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing a state when mold opening of an injection molding machine according to one embodiment is completed. [Figure 2] FIG. 2 is a diagram showing a state of the injection molding machine according to one embodiment when clamping the mold. [Figure 3] Figure 3(A) is a cross-sectional view showing the state of a mold device according to one embodiment at the start of filling, Figure 3(B) is a cross-sectional view showing the state of a mold device according to one embodiment at the completion of filling, and Figure 3(C) is a cross-sectional view showing the state of a mold device according to one embodiment during cooling. [Figure 4] Figure 4(A) is a cross-sectional view showing the state of the mold device according to the first modified example at the start of filling, Figure 4(B) is a cross-sectional view showing the state of the mold device according to the first modified example at the completion of filling, and Figure 4(C) is a cross-sectional view showing the state of the mold device according to the first modified example during cooling. [Figure 5] FIG. 5(A) is a cross-sectional view showing the state of the mold device according to the second modified example when filling is completed, and FIG. 5(B) is a cross-sectional view showing the state of the mold device according to the second modified example when cooling. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same reference numerals, and the description thereof may be omitted.

[0013] (injection molding machine) FIG. 1 is a diagram showing a state of an injection molding machine according to an embodiment when mold opening is completed. FIG. 2 is a diagram showing a state of an injection molding machine according to an embodiment when mold clamping is performed. In this specification, the X-axis direction, Y-axis direction, and Z-axis direction are perpendicular to each other. The X-axis direction and Y-axis direction represent horizontal directions, and the Z-axis direction represents vertical directions. When the mold clamping device 100 is of a horizontal type, the X-axis direction is the mold opening / closing direction, and the Y-axis direction is the width direction of the injection molding machine 10. The negative side of the Y-axis direction is called the operating side, and the positive side of the Y-axis direction is called the counter-operating side.

[0014] As shown in FIGS. 1 and 2 , injection molding machine 10 includes a mold clamping unit 100 that opens and closes mold apparatus 800, an ejector unit 200 that ejects a molded product molded by mold apparatus 800, an injection unit 300 that injects molding material into mold apparatus 800, a moving unit 400 that moves injection unit 300 forward and backward relative to mold apparatus 800, a control unit 700 that controls each component of injection molding machine 10, and a frame 900 that supports each component of injection molding machine 10. Frame 900 includes a mold clamping unit frame 910 that supports mold clamping unit 10 and an injection unit frame 920 that supports injection unit 300. Clamping unit frame 910 and injection unit frame 920 are each installed on floor 2 via leveling adjusters 930. Control unit 700 is disposed in the interior space of injection unit frame 920. Each component of injection molding machine 10 will be described below.

[0015] (mold clamping device) In the description of the mold clamping unit 100, the moving direction of the movable platen 120 during mold closing (for example, the positive X-axis direction) is defined as the front, and the moving direction of the movable platen 120 during mold opening (for example, the negative X-axis direction) is defined as the rear.

[0016] The mold clamping device 100 performs mold closing, pressure increase, mold clamping, depressurization, and mold opening of the mold device 800. The mold device 800 includes a fixed mold 810 and a movable mold 820.

[0017] The mold clamping unit 100 is, for example, a horizontal type, and the mold opening and closing direction is horizontal. The mold clamping unit 100 has a fixed platen 110 to which a fixed mold 810 is attached, a movable platen 120 to which a movable mold 820 is attached, and a movement mechanism 102 that moves the movable platen 120 relative to the fixed platen 110 in the mold opening and closing direction.

[0018] The stationary platen 110 is fixed to the mold clamping unit frame 910. A stationary mold 810 is attached to the surface of the stationary platen 110 that faces the movable platen 120.

[0019] The movable platen 120 is disposed so as to be movable in the mold opening / closing direction relative to the mold clamping unit frame 910. A guide 101 for guiding the movable platen 120 is installed on the mold clamping unit frame 910. A movable mold 820 is attached to the surface of the movable platen 120 facing the fixed platen 110.

[0020] The moving mechanism 102 moves the movable platen 120 forward and backward relative to the fixed platen 110, thereby performing mold closing, pressurization, mold clamping, depressurization, and mold opening of the mold apparatus 800. The moving mechanism 102 has a toggle support 130 arranged at a distance from the fixed platen 110, tie bars 140 connecting the fixed platen 110 and the toggle support 130, a toggle mechanism 150 that moves the movable platen 120 in the mold opening / closing direction relative to the toggle support 130, a mold clamping motor 160 that operates the toggle mechanism 150, a motion conversion mechanism 170 that converts the rotational motion of the mold clamping motor 160 into linear motion, and a mold thickness adjustment mechanism 180 that adjusts the distance between the fixed platen 110 and the toggle support 130.

[0021] The toggle support 130 is disposed at a distance from the fixed platen 110 and is placed on the mold clamping unit frame 910 so as to be freely movable in the mold opening and closing direction. The toggle support 130 may be disposed so as to be freely movable along a guide laid on the mold clamping unit frame 910. The guide of the toggle support 130 may be the same as the guide 101 of the movable platen 120.

[0022] In this embodiment, the fixed platen 110 is fixed to the mold clamping unit frame 910, and the toggle support 130 is arranged so as to be freely movable in the mold opening and closing direction relative to the mold clamping unit frame 910, but the toggle support 130 may also be fixed to the mold clamping unit frame 910, and the fixed platen 110 may be arranged so as to be freely movable in the mold opening and closing direction relative to the mold clamping unit frame 910.

[0023] The tie bars 140 connect the fixed platen 110 and the toggle support 130 at an interval L in the mold opening / closing direction. A plurality of tie bars 140 (for example, four) may be used. The plurality of tie bars 140 are arranged parallel to the mold opening / closing direction and extend according to the mold clamping force. At least one tie bar 140 may be provided with a tie bar strain detector 141 that detects strain in the tie bar 140. The tie bar strain detector 141 sends a signal indicating the detection result to the control device 700. The detection result of the tie bar strain detector 141 is used to detect the mold clamping force, etc.

[0024] In this embodiment, the tie bar strain detector 141 is used as the mold clamping force detector that detects the mold clamping force, but the present invention is not limited to this. The mold clamping force detector is not limited to the strain gauge type, and may be a piezoelectric type, a capacitance type, a hydraulic type, an electromagnetic type, or the like, and the attachment position thereof is also not limited to the tie bar 140.

[0025] The toggle mechanism 150 is disposed between the movable platen 120 and the toggle support 130 and moves the movable platen 120 relative to the toggle support 130 in the mold opening / closing direction. The toggle mechanism 150 has a crosshead 151 that moves in the mold opening / closing direction and a pair of link groups that bend and extend with the movement of the crosshead 151. Each of the pair of link groups has a first link 152 and a second link 153 that are connected to bendable and extendable by a pin or the like. The first link 152 is attached to the movable platen 120 by a pin or the like so that it can swing freely. The second link 153 is attached to the toggle support 130 by a pin or the like so that it can swing freely. The second link 153 is attached to the crosshead 151 via a third link 154. When the crosshead 151 advances or retreats relative to the toggle support 130, the first link 152 and the second link 153 bend and extend, and the movable platen 120 advances or retreats relative to the toggle support 130.

[0026] The configuration of the toggle mechanism 150 is not limited to the configuration shown in Figures 1 and 2. For example, although each link group has five nodes in Figures 1 and 2, it may have four nodes, and one end of the third link 154 may be connected to the node between the first link 152 and the second link 153.

[0027] The mold clamping motor 160 is attached to the toggle support 130 and operates the toggle mechanism 150. The mold clamping motor 160 moves the crosshead 151 forward and backward relative to the toggle support 130, thereby bending and extending the first link 152 and the second link 153 and moving the movable platen 120 forward and backward relative to the toggle support 130. The mold clamping motor 160 is directly connected to the motion conversion mechanism 170, but may also be connected to the motion conversion mechanism 170 via a belt, a pulley, or the like.

[0028] The motion conversion mechanism 170 converts the rotational motion of the mold clamping motor 160 into the linear motion of the crosshead 151. The motion conversion mechanism 170 includes a screw shaft and a screw nut that screws onto the screw shaft. A ball or roller may be interposed between the screw shaft and the screw nut.

[0029] The mold clamping unit 100 performs a mold closing process, a pressure increasing process, a mold clamping process, a pressure reducing process, a mold opening process, and the like under the control of the control device 700.

[0030] In the mold closing process, the mold clamping motor 160 is driven to move the crosshead 151 forward at a set movement speed to a mold closing completion position, thereby moving the movable platen 120 forward and bringing the movable mold 820 into contact with the fixed mold 810. The position and movement speed of the crosshead 151 are detected using, for example, a mold clamping motor encoder 161. The mold clamping motor encoder 161 detects the rotation of the mold clamping motor 160 and sends a signal indicating the detection result to the control device 700.

[0031] The crosshead position detector that detects the position of the crosshead 151 and the crosshead movement speed detector that detects the movement speed of the crosshead 151 are not limited to the mold clamping motor encoder 161, and general types can be used. Furthermore, the movable platen position detector that detects the position of the movable platen 120 and the movable platen movement speed detector that detects the movement speed of the movable platen 120 are not limited to the mold clamping motor encoder 161, and general types can be used.

[0032] In the pressure increasing step, the mold clamping motor 160 is further driven to move the crosshead 151 further forward from the mold closing completion position to the mold clamping position, thereby generating a mold clamping force.

[0033] In the mold clamping process, the mold clamping motor 160 is driven to maintain the position of the crosshead 151 at the mold clamping position. In the mold clamping process, the mold clamping force generated in the pressure increase process is maintained. In the mold clamping process, a cavity space 801 (see FIG. 2) is formed between the movable mold 820 and the fixed mold 810, and the injection device 300 fills the cavity space 801 with liquid molding material. The filled molding material is solidified to obtain a molded product.

[0034] The number of cavity spaces 801 may be one or more. In the latter case, multiple molded products are obtained at the same time. An insert material may be placed in a part of the cavity space 801, and another part of the cavity space 801 may be filled with a molding material. A molded product is obtained in which the insert material and the molding material are integrated.

[0035] In the depressurization process, the mold clamping motor 160 is driven to move the crosshead 151 back from the mold clamping position to the mold opening start position, thereby moving the movable platen 120 back and reducing the mold clamping force. The mold opening start position and the mold closing completion position may be the same position.

[0036] In the mold opening process, the mold clamping motor 160 is driven to move the crosshead 151 backward at a set moving speed from the mold opening start position to the mold opening completion position, thereby moving the movable platen 120 backward and separating the movable mold 820 from the fixed mold 810. Thereafter, the ejector unit 200 ejects the molded product from the movable mold 820.

[0037] The setting conditions for the mold closing process, pressure increase process, and mold clamping process are set together as a series of setting conditions. For example, the movement speed and position of the crosshead 151 in the mold closing process and pressure increase process (including the mold closing start position, movement speed switching position, mold closing completion position, and mold clamping position), and the mold clamping force are set together as a series of setting conditions. The mold closing start position, movement speed switching position, mold closing completion position, and mold clamping position are arranged in this order from the rear side to the front, and represent the start and end points of the section for which the movement speed is set. The movement speed is set for each section. There may be one or more movement speed switching positions. The movement speed switching position does not have to be set. Only one of the mold clamping position and the mold clamping force may be set.

[0038] The setting conditions for the depressurization process and mold opening process are also set in a similar manner. For example, the movement speed and position of the crosshead 151 in the depressurization process and mold opening process (mold opening start position, movement speed switching position, and mold opening completion position) are set together as a series of setting conditions. The mold opening start position, movement speed switching position, and mold opening completion position are arranged in this order from the front to the rear, and represent the start and end points of the section for which the movement speed is set. The movement speed is set for each section. There may be one or more movement speed switching positions. The movement speed switching position does not have to be set. The mold opening start position and mold closing completion position may be the same position. Furthermore, the mold opening completion position and mold closing start position may be the same position.

[0039] It should be noted that the moving speed and position of the movable platen 120 may be set instead of the moving speed and position of the crosshead 151. Furthermore, the clamping force may be set instead of the position of the crosshead (e.g., clamping position) or the position of the movable platen.

[0040] The toggle mechanism 150 amplifies the driving force of the mold clamping motor 160 and transmits it to the movable platen 120. The amplification factor is also called the toggle factor. The toggle factor changes depending on the angle θ between the first link 152 and the second link 153 (hereinafter also referred to as the "link angle θ"). The link angle θ is determined from the position of the crosshead 151. When the link angle θ is 180°, the toggle factor is maximum.

[0041] When the thickness of the mold device 800 changes due to replacement of the mold device 800 or a temperature change in the mold device 800, a mold thickness adjustment is performed so that a predetermined clamping force is obtained during mold clamping. In mold thickness adjustment, for example, the distance L between the fixed platen 110 and the toggle support 130 is adjusted so that the link angle θ of the toggle mechanism 150 becomes a predetermined angle at the time of mold touch when the movable mold 820 touches the fixed mold 810.

[0042] The mold clamping unit 100 has a mold thickness adjustment mechanism 180. The mold thickness adjustment mechanism 180 adjusts the mold thickness by adjusting the distance L between the fixed platen 110 and the toggle support 130. The mold thickness adjustment is performed, for example, between the end of a molding cycle and the start of the next molding cycle. The mold thickness adjustment mechanism 180 has, for example, a screw shaft 181 formed at the rear end of the tie bar 140, a screw nut 182 held rotatably and immovably by the toggle support 130, and a mold thickness adjustment motor 183 that rotates the screw nut 182 that is threaded onto the screw shaft 181.

[0043] A screw shaft 181 and a screw nut 182 are provided for each tie bar 140. The rotational driving force of the mold thickness adjustment motor 183 may be transmitted to the plurality of screw nuts 182 via a rotational driving force transmission unit 185. The plurality of screw nuts 182 can be rotated synchronously. Note that by changing the transmission path of the rotational driving force transmission unit 185, the plurality of screw nuts 182 can also be rotated individually.

[0044] The rotational drive force transmission unit 185 is composed of, for example, gears. In this case, a driven gear is formed on the outer periphery of each screw nut 182, a drive gear is attached to the output shaft of the mold thickness adjustment motor 183, and an intermediate gear that meshes with the multiple driven gears and drive gear is rotatably held in the center of the toggle support 130. Note that the rotational drive force transmission unit 185 may be composed of a belt, a pulley, or the like instead of gears.

[0045] The operation of the mold thickness adjustment mechanism 180 is controlled by a control device 700. The control device 700 drives a mold thickness adjustment motor 183 to rotate the screw nut 182. As a result, the position of the toggle support 130 relative to the tie bar 140 is adjusted, and the distance L between the fixed platen 110 and the toggle support 130 is adjusted. Note that a plurality of mold thickness adjustment mechanisms may be used in combination.

[0046] The gap L is detected using a mold thickness adjustment motor encoder 184. The mold thickness adjustment motor encoder 184 detects the amount and direction of rotation of the mold thickness adjustment motor 183, and sends a signal indicating the detection result to the control device 700. The detection result of the mold thickness adjustment motor encoder 184 is used to monitor and control the position of the toggle support 130 and the gap L. Note that the toggle support position detector that detects the position of the toggle support 130 and the gap detector that detects the gap L are not limited to the mold thickness adjustment motor encoder 184, and general detectors can be used.

[0047] The mold clamping unit 100 may have a mold temperature regulator that regulates the temperature of the mold device 800. The mold device 800 has a flow path for a temperature regulation medium inside. The mold temperature regulator regulates the temperature of the mold device 800 by regulating the temperature of the temperature regulation medium supplied to the flow path of the mold device 800.

[0048] The mold clamping unit 100 of this embodiment is a horizontal type in which the mold opening and closing direction is horizontal, but it may also be a vertical type in which the mold opening and closing direction is vertical.

[0049] Although the mold clamping unit 100 of this embodiment has a mold clamping motor 160 as a drive unit, it may have a hydraulic cylinder instead of the mold clamping motor 160. Also, the mold clamping unit 100 may have a linear motor for opening and closing the mold, and an electromagnet for mold clamping.

[0050] (Ejector device) In describing the ejector device 200, similar to the description of the mold clamping device 100, the direction of movement of the movable platen 120 when the mold is closed (e.g., the positive direction of the X-axis) is defined as the front, and the direction of movement of the movable platen 120 when the mold is opened (e.g., the negative direction of the X-axis) is defined as the rear.

[0051] The ejector unit 200 is attached to the movable platen 120 and moves forward and backward together with the movable platen 120. The ejector unit 200 has an ejector rod 210 that ejects a molded product from the mold device 800, and a drive mechanism 220 that moves the ejector rod 210 in the movement direction of the movable platen 120 (X-axis direction).

[0052] The ejector rod 210 is arranged so as to be able to move forward and backward in a through-hole of the movable platen 120. The front end of the ejector rod 210 contacts an ejector plate 826 of the movable mold 820. The front end of the ejector rod 210 may or may not be connected to the ejector plate 826.

[0053] The drive mechanism 220 includes, for example, an ejector motor and a motion conversion mechanism that converts the rotational motion of the ejector motor into linear motion of the ejector rod 210. The motion conversion mechanism includes a screw shaft and a screw nut that screws onto the screw shaft. Balls or rollers may be interposed between the screw shaft and the screw nut.

[0054] The ejector unit 200 performs an ejection process under the control of the control unit 700. In the ejection process, the ejector rod 210 is advanced from the standby position to the ejection position at a set moving speed, thereby advancing the ejector plate 826 and ejecting the molded product. After that, the ejector motor is driven to retract the ejector rod 210 at the set moving speed, and the ejector plate 826 is retracted to the original standby position.

[0055] The position and movement speed of the ejector rod 210 are detected using, for example, an ejector motor encoder. The ejector motor encoder detects the rotation of the ejector motor and sends a signal indicating the detection result to the control device 700. Note that the ejector rod position detector that detects the position of the ejector rod 210 and the ejector rod movement speed detector that detects the movement speed of the ejector rod 210 are not limited to the ejector motor encoder, and general types can be used.

[0056] (injection device) In the description of the injection device 300, unlike the description of the mold clamping device 100 and the description of the ejector device 200, the movement direction of the screw 330 during filling (e.g., the negative X-axis direction) is described as the forward direction, and the movement direction of the screw 330 during metering (e.g., the positive X-axis direction) is described as the rearward direction.

[0057] The injection unit 300 is mounted on a slide base 301, and the slide base 301 is disposed so as to be able to move forward and backward relative to the injection unit frame 920. The injection unit 300 is disposed so as to be able to move forward and backward relative to the mold unit 800. The injection unit 300 touches the mold unit 800 and fills a cavity space 801 in the mold unit 800 with a molding material. The injection unit 300 includes, for example, a cylinder 310 that heats the molding material, a nozzle 320 provided at the front end of the cylinder 310, a screw 330 that is disposed so as to be able to move forward and backward and to be able to rotate within the cylinder 310, a metering motor 340 that rotates the screw 330, an injection motor 350 that moves the screw 330 forward and backward, and a load detector 360 that detects a load transmitted between the injection motor 350 and the screw 330.

[0058] Cylinder 310 heats the molding material supplied to the interior through supply port 311. The molding material includes, for example, resin. The molding material is formed, for example, in the form of pellets and supplied to supply port 311 in a solid state. Supply port 311 is formed at the rear of cylinder 310. A cooler 312, such as a water-cooled cylinder, is provided on the outer periphery of the rear of cylinder 310. A first heater 313, such as a band heater, and a first temperature detector 314 are provided on the outer periphery of cylinder 310, ahead of cooler 312.

[0059] Cylinder 310 is divided into a plurality of zones in the axial direction (e.g., X-axis direction) of cylinder 310. A first heater 313 and a first temperature detector 314 are provided in each of the plurality of zones. A set temperature is set in each of the plurality of zones, and control device 700 controls first heater 313 so that the temperature detected by first temperature detector 314 becomes the set temperature.

[0060] The nozzle 320 is provided at the front end of the cylinder 310 and is pressed against the mold device 800. A second heater 323 and a second temperature detector 324 are provided on the outer periphery of the nozzle 320. The control device 700 controls the second heater 323 so that the detected temperature of the nozzle 320 becomes the set temperature.

[0061] The screw 330 is disposed within the cylinder 310 so as to be rotatable and movable forward and backward. When the screw 330 is rotated, the molding material is sent forward along the spiral groove of the screw 330. As the molding material is sent forward, it is gradually melted by the heat from the cylinder 310. As the liquid molding material is sent forward to the front of the screw 330 and accumulates in the front part of the cylinder 310, the screw 330 is moved backward. Thereafter, when the screw 330 is moved forward, the liquid molding material accumulated in front of the screw 330 is injected from the nozzle 320 and filled into the mold device 800.

[0062] A backflow prevention ring 331 is attached to the front of the screw 330 so as to be movable back and forth as a backflow prevention valve for preventing the molding material from flowing back from the front to the rear of the screw 330 when the screw 330 is pushed forward.

[0063] When the screw 330 is moved forward, the backflow prevention ring 331 is pushed backward by the pressure of the molding material in front of the screw 330, and moves back relative to the screw 330 to a blocking position (see FIG. 2) where it blocks the flow path of the molding material. This prevents the molding material accumulated in front of the screw 330 from flowing backward.

[0064] On the other hand, when the screw 330 is rotated, the backflow prevention ring 331 is pushed forward by the pressure of the molding material sent forward along the spiral groove of the screw 330, and moves forward relative to the screw 330 to the open position (see FIG. 1) where it opens the flow path of the molding material. This causes the molding material to be sent forward of the screw 330.

[0065] The backflow prevention ring 331 may be either a co-rotating type that rotates together with the screw 330 or a non-co-rotating type that does not rotate together with the screw 330.

[0066] The injection device 300 may have a drive source for moving the backflow prevention ring 331 back and forth relative to the screw 330 between the open position and the closed position.

[0067] The metering motor 340 rotates the screw 330. The drive source for rotating the screw 330 is not limited to the metering motor 340, and may be, for example, a hydraulic pump.

[0068] The injection motor 350 advances and retreats the screw 330. A motion conversion mechanism that converts the rotational motion of the injection motor 350 into linear motion of the screw 330 is provided between the injection motor 350 and the screw 330. The motion conversion mechanism has, for example, a screw shaft and a screw nut that screws onto the screw shaft. A ball or roller may be provided between the screw shaft and the screw nut. The drive source that advances and retreats the screw 330 is not limited to the injection motor 350 and may be, for example, a hydraulic cylinder.

[0069] The load detector 360 detects the load transmitted between the injection motor 350 and the screw 330. The detected load is converted into pressure by the control device 700. The load detector 360 is provided on the load transmission path between the injection motor 350 and the screw 330, and detects the load acting on the load detector 360.

[0070] The load detector 360 sends a signal of the detected load to the control device 700. The load detected by the load detector 360 is converted into pressure acting between the screw 330 and the molding material, and is used to control and monitor the pressure that the screw 330 receives from the molding material, the back pressure on the screw 330, the pressure that the screw 330 acts on the molding material, and the like.

[0071] The pressure detector that detects the pressure of the molding material is not limited to the load detector 360, and a general detector can be used. For example, a nozzle pressure sensor or a mold internal pressure sensor may be used. The nozzle pressure sensor is installed in the nozzle 320. The mold internal pressure sensor is installed inside the mold device 800.

[0072] The injection device 300 performs a metering process, a filling process, a pressure holding process, etc. under the control of the control device 700. The filling process and the pressure holding process may be collectively referred to as the injection process.

[0073] In the metering process, the metering motor 340 is driven to rotate the screw 330 at a set rotational speed, and the molding material is sent forward along the spiral groove of the screw 330. As this happens, the molding material gradually melts. As the liquid molding material is sent forward to the screw 330 and accumulates at the front of the cylinder 310, the screw 330 is moved backward. The rotational speed of the screw 330 is detected, for example, using a metering motor encoder 341. The metering motor encoder 341 detects the rotation of the metering motor 340 and sends a signal indicating the detection result to the control device 700. Note that the screw rotational speed detector that detects the rotational speed of the screw 330 is not limited to the metering motor encoder 341, and a general one can be used.

[0074] In the metering process, in order to restrict abrupt retraction of the screw 330, the injection motor 350 may be driven to apply a set back pressure to the screw 330. The back pressure on the screw 330 is detected using, for example, a load detector 360. When the screw 330 retracts to the metering completion position and a predetermined amount of molding material accumulates in front of the screw 330, the metering process is completed.

[0075] The position and rotational speed of the screw 330 in the metering process are set together as a series of setting conditions. For example, a metering start position, a rotational speed switching position, and a metering completion position are set. These positions are arranged in this order from the front to the rear, and represent the start and end points of the section for which the rotational speed is set. The rotational speed is set for each section. There may be one or more rotational speed switching positions. The rotational speed switching position does not have to be set. In addition, a back pressure is set for each section.

[0076] In the filling process, the injection motor 350 is driven to move the screw 330 forward at a set moving speed, and the liquid molding material accumulated in front of the screw 330 is filled into the cavity space 801 in the mold device 800. The position and moving speed of the screw 330 are detected using, for example, an injection motor encoder 351. The injection motor encoder 351 detects the rotation of the injection motor 350 and sends a signal indicating the detection result to the control device 700. When the position of the screw 330 reaches a set position, a switch from the filling process to a pressure holding process (so-called V / P switch) is performed. The position at which the V / P switch is performed is also called the V / P switch position. The set moving speed of the screw 330 may be changed depending on the position of the screw 330, time, etc.

[0077] The position and movement speed of the screw 330 in the filling process are set together as a series of setting conditions. For example, a filling start position (also called an "injection start position"), a movement speed switching position, and a V / P switching position are set. These positions are arranged in this order from rear to front, and represent the start and end points of the section for which the movement speed is set. The movement speed is set for each section. There may be one or more movement speed switching positions. The movement speed switching position does not have to be set.

[0078] An upper limit value for the pressure of the screw 330 is set for each section in which the movement speed of the screw 330 is set. The pressure of the screw 330 is detected by a load detector 360. When the pressure of the screw 330 is equal to or lower than the set pressure, the screw 330 is advanced at the set movement speed. On the other hand, when the pressure of the screw 330 exceeds the set pressure, the screw 330 is advanced at a movement speed slower than the set movement speed so that the pressure of the screw 330 is equal to or lower than the set pressure, in order to protect the mold.

[0079] It should be noted that after the position of the screw 330 reaches the V / P switching position during the filling process, the screw 330 may be temporarily stopped at the V / P switching position, and then V / P switching may be performed. Immediately before V / P switching, instead of stopping the screw 330, the screw 330 may be moved forward or backward at a slow speed. Furthermore, the screw position detector that detects the position of the screw 330 and the screw movement speed detector that detects the movement speed of the screw 330 are not limited to the injection motor encoder 351, and general detectors may be used.

[0080] In the dwelling step, the injection motor 350 is driven to push the screw 330 forward, maintaining the pressure of the molding material at the front end of the screw 330 (hereinafter also referred to as "holding pressure") at a set pressure, and pushing the molding material remaining in the cylinder 310 toward the mold device 800. This can replenish any molding material that is insufficient due to cooling contraction within the mold device 800. The holding pressure is detected, for example, using a load detector 360. The set value of the holding pressure may be changed depending on the elapsed time from the start of the dwelling step, etc. Multiple holding pressures and holding times for maintaining the holding pressure in the dwelling step may be set, or they may be set together as a series of setting conditions.

[0081] In the dwelling step, the molding material in the cavity space 801 in the mold device 800 is gradually cooled, and when the dwelling step is completed, the entrance to the cavity space 801 is blocked by the solidified molding material. This state is called a gate seal, and prevents the molding material from flowing back from the cavity space 801. After the dwelling step, the cooling step begins. In the cooling step, the molding material in the cavity space 801 is solidified. A metering step may be performed during the cooling step in order to shorten the molding cycle time.

[0082] Although the injection device 300 of this embodiment is of an in-line screw type, it may also be of a pre-plasticization type. A pre-plasticization type injection device supplies molding material molten in a plasticization cylinder to an injection cylinder, and injects the molding material from the injection cylinder into a mold device. A screw is disposed in the plasticization cylinder so that it can rotate freely but cannot move back and forth, or the screw is disposed so that it can rotate freely and move back and forth. Meanwhile, a plunger is disposed in the injection cylinder so that it can move back and forth.

[0083] Furthermore, although the injection unit 300 of this embodiment is a horizontal type in which the axial direction of the cylinder 310 is horizontal, it may be a vertical type in which the axial direction of the cylinder 310 is vertical. The mold clamping unit combined with the vertical injection unit 300 may be either a vertical type or a horizontal type. Similarly, the mold clamping unit combined with the horizontal injection unit 300 may be either a horizontal type or a vertical type.

[0084] (Mobile device) In the description of the moving device 400, similar to the description of the injection device 300, the moving direction of the screw 330 during filling (e.g., the negative X-axis direction) is defined as the front, and the moving direction of the screw 330 during metering (e.g., the positive X-axis direction) is defined as the rear.

[0085] The moving device 400 moves the injection device 300 forward and backward relative to the mold device 800. The moving device 400 also presses the nozzle 320 against the mold device 800 to generate nozzle touch pressure. The moving device 400 includes a hydraulic pump 410, a motor 420 as a drive source, a hydraulic cylinder 430 as a hydraulic actuator, and the like.

[0086] The hydraulic pump 410 has a first port 411 and a second port 412. The hydraulic pump 410 is a bidirectional pump, and by switching the rotation direction of the motor 420, it draws in hydraulic fluid (e.g., oil) from one of the first port 411 and the second port 412 and discharges it from the other, thereby generating hydraulic pressure. Note that the hydraulic pump 410 can also draw in hydraulic fluid from a tank and discharge it from either the first port 411 or the second port 412.

[0087] The motor 420 operates the hydraulic pump 410. The motor 420 drives the hydraulic pump 410 in a rotational direction and with a rotational torque according to a control signal from the control device 700. The motor 420 may be an electric motor or an electric servo motor.

[0088] The hydraulic cylinder 430 has a cylinder body 431, a piston 432, and a piston rod 433. The cylinder body 431 is fixed to the injection device 300. The piston 432 divides the interior of the cylinder body 431 into a front chamber 435 as a first chamber and a rear chamber 436 as a second chamber. The piston rod 433 is fixed to the fixed platen 110.

[0089] A front chamber 435 of the hydraulic cylinder 430 is connected to a first port 411 of the hydraulic pump 410 via a first flow path 401. The hydraulic fluid discharged from the first port 411 is supplied to the front chamber 435 via the first flow path 401, thereby pushing the injection unit 300 forward. The injection unit 300 is moved forward, and the nozzle 320 is pressed against the fixed mold 810. The front chamber 435 functions as a pressure chamber that generates nozzle touch pressure of the nozzle 320 by the pressure of the hydraulic fluid supplied from the hydraulic pump 410.

[0090] Meanwhile, the rear chamber 436 of the hydraulic cylinder 430 is connected to the second port 412 of the hydraulic pump 410 via the second flow path 402. The hydraulic fluid discharged from the second port 412 is supplied to the rear chamber 436 of the hydraulic cylinder 430 via the second flow path 402, thereby pushing the injection unit 300 backward. The injection unit 300 is moved backward, and the nozzle 320 is separated from the fixed mold 810.

[0091] In this embodiment, the moving device 400 includes the hydraulic cylinder 430, but the present invention is not limited to this. For example, instead of the hydraulic cylinder 430, an electric motor and a motion conversion mechanism that converts the rotational motion of the electric motor into the linear motion of the injection device 300 may be used.

[0092] (Control device) The control device 700 is configured, for example, by a computer, and as shown in Figures 1 and 2, has a CPU (Central Processing Unit) 701, a storage medium 702 such as a memory, an input interface 703, and an output interface 704. The control device 700 performs various controls by causing the CPU 701 to execute a program stored in the storage medium 702. The control device 700 also receives signals from the outside via the input interface 703 and transmits signals to the outside via the output interface 704.

[0093] The control device 700 repeatedly manufactures molded products by repeating processes such as a metering process, mold closing process, pressure increase process, mold clamping process, filling process, pressure dwell process, cooling process, pressure release process, mold opening process, and ejection process. A series of operations required to obtain a molded product, such as the operations from the start of a metering process to the start of the next metering process, is also called a "shot" or "molding cycle." The time required for one shot is also called the "molding cycle time" or "cycle time."

[0094] One molding cycle includes, for example, a metering process, a mold closing process, a pressurization process, a mold clamping process, a filling process, a pressure holding process, a cooling process, a depressurization process, a mold opening process, and an ejection process, in this order. The order here refers to the order in which each process starts. The filling process, the pressure holding process, and the cooling process are performed during the mold clamping process. The start of the mold clamping process may coincide with the start of the filling process. The completion of the depressurization process coincides with the start of the mold opening process.

[0095] It should be noted that, in order to shorten the molding cycle time, multiple processes may be performed simultaneously. For example, the metering process may be performed during the cooling process of the previous molding cycle, or during the mold clamping process. In this case, the mold closing process may be performed at the beginning of the molding cycle. The filling process may be started during the mold closing process. The ejection process may be started during the mold opening process. If an on-off valve for opening and closing the flow path of the nozzle 320 is provided, the mold opening process may be started during the metering process. This is because, even if the mold opening process is started during the metering process, the molding material will not leak from the nozzle 320 as long as the on-off valve closes the flow path of the nozzle 320.

[0096] One molding cycle may include steps other than the metering step, mold closing step, pressure increase step, mold clamping step, filling step, pressure holding step, cooling step, pressure release step, mold opening step, and ejection step.

[0097] For example, after the dwelling step is completed and before the metering step begins, a pre-metering suck-back step may be performed in which the screw 330 is retracted to a preset metering start position. This can reduce the pressure of the molding material accumulated in front of the screw 330 before the metering step begins, and prevent the screw 330 from retracting suddenly at the start of the metering step.

[0098] Furthermore, after the metering step is completed and before the filling step begins, a post-metering suck-back step may be performed in which the screw 330 is retracted to a preset filling start position (also referred to as the "injection start position"). This can reduce the pressure of the molding material accumulated in front of the screw 330 before the filling step begins, and can prevent the molding material from leaking from the nozzle 320 before the filling step begins.

[0099] The control device 700 is connected to an operation device 750 that accepts input operations by a user and a display device 760 that displays a screen. The operation device 750 and the display device 760 may be integrated, for example, by using a touch panel 770. The touch panel 770 serving as the display device 760 displays a screen under the control of the control device 700. The screen of the touch panel 770 may display information such as settings of the injection molding machine 10 and the current status of the injection molding machine 10. The screen of the touch panel 770 may also display operation units such as buttons and input fields that accept input operations by the user. The touch panel 770 serving as the operation device 750 detects input operations on the screen by the user and outputs signals corresponding to the input operations to the control device 700. This allows, for example, a user to operate the operation units provided on the screen while checking information displayed on the screen to perform settings of the injection molding machine 10 (including input of setting values). The user can also operate the operation units provided on the screen to cause the injection molding machine 10 to perform operations corresponding to the operation units. The operation of the injection molding machine 10 may be, for example, the operation (including stopping) of the clamping device 100, the ejector device 200, the injection device 300, the moving device 400, etc. The operation of the injection molding machine 10 may also be the switching of a screen displayed on the touch panel 770 serving as the display device 760, etc.

[0100] Although the operation device 750 and the display device 760 of this embodiment have been described as being integrated as the touch panel 770, they may be provided independently. Also, a plurality of operation devices 750 may be provided. The operation device 750 and the display device 760 are disposed on the operation side (negative Y-axis direction) of the mold clamping unit 100 (more specifically, the fixed platen 110).

[0101] (Molding equipment) Next, a mold apparatus 800 according to one embodiment will be described with reference to Fig. 3. The mold apparatus 800 includes a fixed mold 810 and a movable mold 820. The fixed mold 810 is attached to a fixed platen 110 of the injection molding machine 10. The movable mold 820 is attached to a movable platen 120 of the injection molding machine 10. The mold apparatus 800 forms a cavity space 801 between the fixed mold 810 and the movable mold 820 when clamped. The cavity space 801 is a space into which a molding material that has been preheated by the cylinder 310 of the injection molding machine 10 is filled. The mold apparatus 800 and the injection molding machine 10 constitute an injection molding system.

[0102] The fixed mold 810 has, for example, a first mold portion 811, a first cooling portion 812, and a first support portion 813. The first mold portion 811 contacts the movable mold 820 during mold clamping and forms part of the wall surface of the cavity space 801. The first mold portion 811 is heated by the heat of the molding material filled into the cavity space 801. The temperature of the first cooling portion 812 is adjusted to a temperature lower than the temperature of the first mold portion 811 during filling with the molding material. The first support portion 813 supports one of the first cooling portion 812 and the first mold portion 811 so that they can move relative to the other. The first support portion 813 functions as a guide. The first cooling portion 812 and the first mold portion 811 can move relatively in both the mold opening direction (e.g., the negative X-axis direction) and the mold closing direction (e.g., the positive X-axis direction) between a position where they are separated from each other and a position where they are in contact with each other.

[0103] The first mold section 811 is fixed to the stationary platen 110, and the first support section 813 supports the first cooling section 812 so that it is movable relative to the stationary platen 110. The first cooling section 812 is disposed in the space between the first mold section 811 and the stationary platen 110. Although not shown, the first cooling section 812 may be fixed to the stationary platen 110, in which case the first support section 813 supports the first mold section 811 so that it is movable relative to the stationary platen 110. The first cooling section 812 and the first mold section 811 only need to be movable relative to each other in both the mold opening direction and the mold closing direction.

[0104] The first mold section 811 and the first cooling section 812 may each be in the form of a plate perpendicular to the mold opening / closing direction. When viewed from the mold opening / closing direction, the first cooling section 812 preferably has a size equal to or larger than that of the first mold section 811 so as to cool the entire first mold section 811. The first support section 813 may be in the form of a rod parallel to the mold opening / closing direction. The first support section 813 is inserted into a through-hole 812a that penetrates the first cooling section 812 in the mold opening / closing direction. A plurality of first support sections 813 may be provided. The first support sections 813 are fixed to the fixed platen 110, and the first cooling section 812 moves along the first support sections 813. The first support sections 813 are compressed in the mold opening / closing direction during mold clamping, transmitting the clamping force. A plurality of first support sections 813 may be provided so that the clamping force is evenly applied to the first mold section 811. The first support portions 813 are provided, for example, at the four corners of the first mold portion 811, respectively.

[0105] As shown in FIGS. 3A and 3B, the first cooling section 812 and the first mold section 811 may be separated during the filling of the molding material. That is, the first cooling section 812 and the first mold section 811 may be separated during the filling process. A space is formed between the first cooling section 812 and the first mold section 811, and this space limits the transfer of heat. Compared to when the first cooling section 812 and the first mold section 811 are in contact with each other, the temperature of the first mold section 811 is higher, and the temperature of the wall surface of the cavity space 801 is also higher. As a result, the fluidity of the molding material during filling is good, and the shape and dimensions of the cavity space 801 are easily transferred to the molded product. Therefore, the transferability of the mold device 800 is good. To improve the transferability of the mold device 800, the first mold section 811 does not need to be heated by a heating device during filling of the molding material. However, the first mold section 811 may be heated by a heating device during filling of the molding material. In either case, the temperature of the first mold section 811 is higher and the temperature of the wall surface of the cavity space 801 is higher than when the first cooling section 812 and the first mold section 811 are in contact with each other.

[0106] It is preferable that the first cooling section 812 and the first mold section 811 are separated from each other at least from the start to the completion of the filling step. It is also more preferable that the first cooling section 812 and the first mold section 811 are separated from each other at least for part (preferably the entirety) of the pressure holding step that follows the filling step. If the temperature of the first mold section 811 is high during the pressure holding step, it is easier to replenish the molding material that is insufficient due to cooling contraction within the cavity space 801.

[0107] As shown in Fig. 3(C), the first cooling section 812 and the first mold section 811 may come into contact with each other when the molding material is cooled. That is, the first cooling section 812 and the first mold section 811 may come into contact with each other during the cooling process. The first cooling section 812 removes heat from the first mold section 811 by coming into contact with the first mold section 811. This allows the first mold section 811 to be cooled, thereby shortening the cooling time required for the molding material to solidify to the extent that it can be removed from the mold device 800. The effect of shortening the cooling time is particularly noticeable when the molded product is a thick product such as a lens.

[0108] For example, when switching from the pressure holding process to the cooling process, the first cooling section 812 and the first mold section 811 are moved relatively from a position where they are separated from each other to a position where they are in contact with each other. Note that the first cooling section 812 and the first mold section 811 may come into contact with each other from the middle of the cooling process. Even if the first cooling section 812 and the first mold section 811 come into contact with each other from the middle of the cooling process, the cooling time can be shortened.

[0109] Incidentally, many molded products have a larger dimension in a direction perpendicular to the mold clamping direction than in the direction along the mold clamping direction. For example, lenses, connectors, container lids, etc. have a larger dimension in a direction perpendicular to the mold clamping direction than in the direction along the mold clamping direction. This is because the cavity space 801 is formed at the parting surface of the mold assembly 800 (the mating surface between the fixed mold 810 and the movable mold 820). In other words, the cavity space 801 expands in the direction perpendicular to the mold clamping direction.

[0110] As described above, the dimensions of many molded products in the direction perpendicular to the mold clamping direction are larger than the dimensions in the direction along the mold clamping direction. Therefore, to improve the dimensional accuracy of the molded product, it is important to suppress uneven cooling of the mold assembly 800 in the direction perpendicular to the mold clamping direction. This is because it can reduce uneven shrinkage of the molded product and reduce distortion of the molded product. In other words, it is possible to accurately transfer the shape and dimensions of the cavity space 801 of the mold assembly 800 to the molded product.

[0111] In this embodiment, the first mold section 811 and the first cooling section 812 are moved relatively in the mold opening / closing direction. Compared to moving the first cooling section 812 in a direction perpendicular to the mold opening / closing direction as in Patent Document 1, this reduces uneven cooling of the first mold section 811 in a direction perpendicular to the mold opening / closing direction (i.e., mold clamping direction). As a result, it is possible to reduce uneven shrinkage of the molded product, reduce distortion of the molded product, and improve the transfer accuracy from the first mold section 811 to the molded product.

[0112] The first cooling section 812 has a flow path 812b therein through which a refrigerant flows. The temperature of the refrigerant is adjusted to a preset temperature by a temperature regulator (not shown). The temperature regulator and the mold device 800 are connected by an outward pipe and a return pipe. The refrigerant is supplied to the flow path 812b via the outward pipe. After flowing through the flow path 812b, the refrigerant is returned to the temperature regulator via the return pipe. The set temperature of the temperature regulator is set lower than the temperature of the first mold section 811 when the molding material is filled. The refrigerant is, for example, water or oil.

[0113] In order to suppress uneven cooling of the first mold part 811 in a direction perpendicular to the mold clamping direction, it is preferable that the flow path 812b is arranged so as to surround the center of the first mold part 811 when viewed from the mold clamping direction. A sprue 802 is formed to penetrate part of the center of the first mold part 811. The sprue 802 is a flow path that allows the molding material to flow from the nozzle 320 of the injection molding machine 10 to the parting surface of the mold device 800.

[0114] In order to suppress uneven cooling of the first mold part 811 in a direction perpendicular to the mold clamping direction, it is preferable that the flow paths 812b be arranged so as to sandwich the center of the first mold part 811 in the Z-axis direction when viewed from the mold clamping direction. Also, in order to suppress uneven cooling of the first mold part 811 in a direction perpendicular to the mold clamping direction, it is preferable that the flow paths 812b be arranged so as to sandwich the center of the first mold part 811 in the Y-axis direction when viewed from the mold clamping direction.

[0115] The fixed mold 810 may have a first cylindrical portion 814. A portion of the sprue 802 passes through the first cylindrical portion 814. The first cylindrical portion 814 is provided in the center of the surface of the first mold part 811 opposite the movable mold 820. The first cylindrical portion 814 is inserted into a through-hole 812c that passes through the first cooling part 812 in the mold opening / closing direction. The first cooling part 812 moves along the first cylindrical portion 814. The first cylindrical portion 814 may function as a guide for the first cooling part 812. Furthermore, the first cylindrical portion 814 may be compressed in the mold opening / closing direction during mold clamping, and transmit the mold clamping force.

[0116] The fixed mold 810 may have a first rear surface portion 815. The first rear surface portion 815 is provided on the opposite side of the movable mold 820 with respect to the first mold portion 811. The first rear surface portion 815 may be in the form of a plate perpendicular to the mold opening / closing direction. The first rear surface portion 815 and the first mold portion 811 are arranged at an interval in the mold opening / closing direction, and a first cooling portion 812 is provided in the space between the first rear surface portion 815 and the first mold portion 811 so as to be movable in both the mold opening direction and the mold closing direction. In addition, a first support portion 813 and a first cylindrical portion 814 are provided in the space between the first rear surface portion 815 and the first mold portion 811. The first rear surface portion 815 is attached to the fixed platen 110.

[0117] The fixed mold 810 may have a first drive unit 819. The first drive unit 819 moves the first cooling unit 812 and the first mold unit 811 relative to each other. The first drive unit 819 is, for example, an air cylinder, a hydraulic cylinder, or an electric motor. The first drive unit 819 does not have to be part of the fixed mold 810, but may be part of the injection molding machine 10. Furthermore, as the first drive unit 819, it is also possible to use an existing device provided in the injection molding machine 10, such as the mold clamping motor 160 of the mold clamping unit 100 or the drive mechanism 220 of the ejector unit 200 shown in FIGS. 1 and 2.

[0118] In this embodiment, the first cooling unit 812 and the first support unit 813 are provided in the fixed mold 810, but they may also be provided in the injection molding machine 10. The first cooling unit 812 and the first support unit 813 may be provided between the fixed mold 810 and the fixed platen 110. It is only necessary that the first cooling unit 812 and the first mold unit 811 are relatively movable in both the mold opening direction and the mold closing direction between a position where they are separated from each other and a position where they are in contact with each other. The first mold unit 811 is provided in the fixed mold 810.

[0119] The movable mold 820 has, for example, a second mold section 821, a second cooling section 822, and a second support section 823. The second mold section 821 contacts the fixed mold 810 during mold clamping and forms part of the wall surface of the cavity space 801. The second mold section 821 is heated by the heat of the molding material filled into the cavity space 801. The temperature of the second cooling section 822 is adjusted to a temperature lower than the temperature of the second mold section 821 during filling with the molding material. The second support section 823 supports one of the second cooling section 822 and the second mold section 821 so that they can move relative to the other. The second support section 823 functions as a guide. The second cooling section 822 and the second mold section 821 can move relatively in both the mold opening direction (e.g., the negative X-axis direction) and the mold closing direction (e.g., the positive X-axis direction) between a position where they are separated from each other and a position where they are in contact with each other.

[0120] The second mold section 821 is fixed to the movable platen 120, and the second support section 823 supports the second cooling section 822 so that it can move relative to the movable platen 120. The second cooling section 822 is disposed in the space between the second mold section 821 and the movable platen 120. As will be described in detail later, the second cooling section 822 may be fixed to the movable platen 120 as shown in FIG. 4, in which case the second support section 823 supports the second mold section 821 so that it can move relative to the movable platen 120. The second cooling section 822 and the second mold section 821 only need to be able to move relatively in both the mold opening direction and the mold closing direction.

[0121] The second mold section 821 and the second cooling section 822 may each be in the form of a plate perpendicular to the mold opening / closing direction. When viewed from the mold opening / closing direction, the second cooling section 822 preferably has a size equal to or larger than that of the second mold section 821 so as to cool the entire second mold section 821. The second support section 823 may be in the form of a rod parallel to the mold opening / closing direction. The second support section 823 is inserted into a through-hole 822a that penetrates the second cooling section 822 in the mold opening / closing direction. A plurality of second support sections 823 may be provided. The second support sections 823 are fixed to the movable platen 120, and the second cooling section 822 moves along the second support sections 823. The second support sections 823 are compressed in the mold opening / closing direction during mold clamping, transmitting the clamping force. A plurality of second support sections 823 may be provided so that the clamping force is evenly applied to the second mold section 821. The second support portions 823 are provided at the four corners of the second mold portion 821, for example.

[0122] As shown in FIGS. 3A and 3B, the second cooling section 822 and the second mold section 821 may be separated during the filling process. That is, the second cooling section 822 and the second mold section 821 may be separated during the filling process. A space is formed between the second cooling section 822 and the second mold section 821, limiting the transfer of heat. Compared to when the second cooling section 822 and the second mold section 821 are in contact with each other, the temperature of the second mold section 821 is higher, and the temperature of the wall surface of the cavity space 801 is also higher. As a result, the fluidity of the molding material during filling is good, and the shape and dimensions of the cavity space 801 are easily transferred to the molded product. This improves the transferability of the mold apparatus 800. To improve the transferability of the mold apparatus 800, the second mold section 821 does not need to be heated by a heating device during filling the molding material. However, the second mold section 821 may be heated by a heating device during filling the molding material. In either case, the temperature of the second mold section 821 is higher and the temperature of the wall surface of the cavity space 801 is higher than when the second cooling section 822 and the second mold section 821 are in contact with each other.

[0123] It is preferable that the second cooling section 822 and the second mold section 821 are separated from each other at least from the start to the completion of the filling step. It is also more preferable that the second cooling section 822 and the second mold section 821 are separated from each other at least for part (preferably the entirety) of the pressure holding step that follows the filling step. If the temperature of the second mold section 821 is high during the pressure holding step, it is easier to replenish the molding material that is insufficient due to cooling contraction within the cavity space 801.

[0124] As shown in Fig. 3(C), the second cooling section 822 and the second mold section 821 may come into contact with each other when the molding material is cooled. That is, the second cooling section 822 and the second mold section 821 may come into contact with each other during the cooling process. The second cooling section 822 removes heat from the second mold section 821 by coming into contact with the second mold section 821. This allows the second mold section 821 to be cooled, thereby shortening the cooling time required for the molding material to solidify to the extent that it can be removed from the mold device 800. This effect of shortening the cooling time is particularly noticeable when the molded product is a thick product such as a lens.

[0125] For example, when switching from the pressure holding process to the cooling process, the second cooling section 822 and the second mold section 821 are moved relatively from a position where they are separated from each other to a position where they are in contact with each other. Note that the second cooling section 822 and the second mold section 821 may come into contact with each other from the middle of the cooling process. Even if the second cooling section 822 and the second mold section 821 come into contact with each other from the middle of the cooling process, the cooling time can be shortened.

[0126] In this embodiment, the second mold section 821 and the second cooling section 822 are moved relatively in the mold opening / closing direction. Compared to moving the second cooling section 822 in a direction perpendicular to the mold opening / closing direction as in Patent Document 1, this reduces uneven cooling of the second mold section 821 in a direction perpendicular to the mold opening / closing direction (i.e., mold clamping direction). As a result, it is possible to reduce uneven shrinkage of the molded product, reduce distortion of the molded product, and improve the transfer accuracy from the second mold section 821 to the molded product.

[0127] The second cooling section 822 has a flow path 822b therein through which a refrigerant flows. The temperature of the refrigerant is adjusted to a preset temperature by a temperature regulator (not shown). The temperature regulator and the mold device 800 are connected by an outward pipe and a return pipe. The refrigerant is supplied to the flow path 822b via the outward pipe. After flowing through the flow path 822b, the refrigerant is returned to the temperature regulator via the return pipe. The set temperature of the temperature regulator is set lower than the temperature of the second mold section 821 when the molding material is filled. The refrigerant is, for example, water or oil.

[0128] In order to suppress uneven cooling of the second mold part 821 in a direction perpendicular to the mold clamping direction, it is preferable that the flow paths 822b are arranged so as to surround the center of the second mold part 821 as viewed from the mold clamping direction. For example, it is preferable that the flow paths 822b are arranged so as to sandwich the center of the second mold part 821 in the Z-axis direction as viewed from the mold clamping direction. It is also preferable that the flow paths 822b are arranged so as to sandwich the center of the second mold part 821 in the Y-axis direction as viewed from the mold clamping direction.

[0129] It is preferable that the first cooling section 812 and the second cooling section 822 be adjusted to the same temperature. This allows the molded product to be cooled evenly from both sides in the mold opening / closing direction, reduces uneven cooling of the molded product, reduces distortion of the molded product, and improves the transfer accuracy from the first mold section 811 and the second mold section 821 to the molded product. However, as long as the transfer accuracy can be improved, the first cooling section 812 and the second cooling section 822 may be adjusted to different temperatures. The control device 700 may acquire information on the shape and dimensions of the molded product, and set, suggest, or adjust the temperatures of the first cooling section 812 and the second cooling section 822 based on the acquired information.

[0130] The movable mold 820 may have a second rear surface portion 825. The second rear surface portion 825 is arranged on the opposite side of the fixed mold 810 with respect to the second mold portion 821. The second rear surface portion 825 may be in the form of a plate perpendicular to the mold opening / closing direction. The second rear surface portion 825 and the second mold portion 821 are arranged at an interval in the mold opening / closing direction, and a second cooling portion 822 is provided in the space between the second rear surface portion 825 and the second mold portion 821 so as to be movable in both the mold opening direction and the mold closing direction. In addition, a second support portion 823 is provided in the space between the second rear surface portion 825 and the second mold portion 821.

[0131] The movable mold 820 may have a second spacer portion 827 and a second mounting portion 828 between the second rear surface portion 825 and the movable platen 120. The second spacer portion 827 is provided in a frame shape on the opposite side of the fixed mold 810 with respect to the second rear surface portion 825, and forms a space between the second rear surface portion 825 and the second mounting portion 828. An ejector plate 826 is provided in this space so as to be movable in both the mold opening direction and the mold closing direction. The second mounting portion 828 is attached to the movable platen 120. The second mounting portion 828 may be in the shape of a plate perpendicular to the mold opening / closing direction.

[0132] The movable mold 820 may have a second drive unit 829. The second drive unit 829 moves the second cooling unit 822 and the second mold unit 821 relative to each other. The second drive unit 829 is, for example, an air cylinder, a hydraulic cylinder, or an electric motor. The second drive unit 829 does not have to be part of the movable mold 820, but may be part of the injection molding machine 10. Furthermore, it is also possible to use, as the first drive unit 819, an existing device provided in the injection molding machine 10, such as the mold clamping motor 160 of the mold clamping unit 100 or the drive mechanism 220 of the ejector unit 200 shown in FIGS. 1 and 2.

[0133] In this embodiment, the second cooling unit 822 and the second support unit 823 are provided in the movable mold 820, but they may also be provided in the injection molding machine 10. The second cooling unit 822 and the second support unit 823 may be provided between the movable mold 820 and the movable platen 120. It is only necessary that the second cooling unit 822 and the second mold unit 821 are relatively movable in both the mold opening direction and the mold closing direction between a position where they are separated from each other and a position where they are in contact with each other. The second mold unit 821 is provided in the movable mold 820.

[0134] Next, a mold apparatus 800 according to a first modified example will be described with reference to FIG. 4. Differences from the above embodiment will be mainly described below. In this modified example, a mold clamping motor 160 of a mold clamping apparatus 100 shown in FIGS. 1 and 2 moves a second cooling section 822 and a second mold section 821 relative to each other. The movable mold 820 of this modified example has a second biasing section 824. The second biasing section 824 biases the second mold section 821 in the mold closing direction (positive direction of the X-axis) relative to the second cooling section 822 during mold clamping. The second biasing section 824 is, for example, a coil spring, which is compressed during mold clamping and biases the second mold section 821 in the mold closing direction (positive direction of the X-axis) relative to the second cooling section 822 by its elastic restoring force.

[0135] The second cooling section 822 is fixed to the movable platen 120, and the second support section 823 supports the second mold section 821 so that it can move relative to the movable platen 120. The second biasing section 824 has, for example, one end fixed to the second support section 823 and the other end fixed to the second mold section 821. The second mold section 821 has a guide hole 821a, and the second support section 823 is inserted into the guide hole 821a. The second biasing section 824 may also have one end fixed to the second cooling section 822 and the other end fixed to the second mold section 821.

[0136] During mold clamping, the mold clamping motor 160 of the mold clamping device 100 advances the movable platen 120 to a desired position against the elastic restoring force of the second biasing portion 824. As shown in FIGS. 4(A) and 4(B), the second cooling portion 822 and the second mold portion 821 may be separated when the molding material is filled. Thereafter, when the mold clamping motor 160 advances the movable platen 120 further, the second cooling portion 822 and the second mold portion 821 come into contact with each other. As shown in FIG. 4(C), the first cooling portion 812 and the first mold portion 811 may come into contact with each other when the molding material is cooled.

[0137] Although not shown, the fixed mold 810 may have a first biasing portion. The first biasing portion biases the first mold section 811 in the mold opening direction (negative direction of the X-axis) relative to the first cooling section 812 during mold clamping. The first cooling section 812 is fixed to the fixed platen 110, and the first support section 813 supports the first mold section 811 movably relative to the fixed platen 110. In this case as well, the mold clamping motor 160 of the mold clamping unit 100 can move the first cooling section 812 and the first mold section 811 relative to each other.

[0138] Next, a mold apparatus 800 according to a second modified example will be described with reference to Fig. 5. Differences from the above embodiment and the first modified example will be mainly described below. In this modified example, as shown in Fig. 5(A), when the first cooling section 812 and the first mold section 811 move apart, the first cooling section 812 and the first cylindrical section 814 move apart, and as shown in Fig. 5(B), when the first cooling section 812 and the first mold section 811 come into contact, the first cooling section 812 and the first cylindrical section 814 come into contact.

[0139] The first cylindrical portion 814 is inserted into a through-hole 812c that penetrates the first cooling portion 812 in the mold opening / closing direction. The through-hole 812c of the first cooling portion 812 has a hole diameter that increases as it moves toward the mold opening direction (negative direction of the X-axis). On the other hand, the first cylindrical portion 814 has an outer diameter that increases as it moves toward the mold opening direction. When the first cooling portion 812 moves in the mold opening direction, the first cooling portion 812 and the first cylindrical portion 814 come into contact. When the first cooling portion 812 moves in the mold closing direction, the first cooling portion 812 and the first cylindrical portion 814 move away from each other.

[0140] As shown in FIG. 5(A), when the molding material is filled, not only are the first cooling section 812 and the first mold section 811 separated from each other, but the first cooling section 812 and the first cylindrical section 814 are also separated from each other. A space is formed between the first cooling section 812 and the first cylindrical section 814, and this space limits the transfer of heat. Compared to when the first cooling section 812 and the first cylindrical section 814 are in contact with each other, the temperature of the first cylindrical section 814 is higher, and the fluidity of the molding material in the sprue 802 is good. Note that when the molding material is filled, a heat insulating material may be provided in the space between the first cooling section 812 and the first cylindrical section 814.

[0141] 5(B), when the molding material is cooled, not only the first cooling section 812 and the first mold section 811 come into contact, but also the first cooling section 812 and the first cylindrical section 814 come into contact. By coming into contact with the first cylindrical section 814, the first cooling section 812 removes heat from the first cylindrical section 814. This allows the first cylindrical section 814 to be cooled, and the cooling time required for the molding material to solidify to the extent that it can be removed from the mold device 800 can be shortened.

[0142] Although the embodiments of the mold apparatus and injection molding system according to the present invention have been described above, the present invention is not limited to the above-described embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These changes also naturally fall within the technical scope of the present invention. [Explanation of symbols]

[0143] 800 mold equipment 801 Cavity Space 810 Fixed mold 811 1st mold section 812 1st cooling section 813 1st support part 820 Movable mold 821 2nd mold section 822 2nd cooling section 823 2nd support part

Claims

1. A mold apparatus comprising a fixed mold and a movable mold, and forming a cavity space between the fixed mold and the movable mold when the mold is clamped, The cavity space is a space to be filled with a preheated molding material. the fixed mold has a first mold portion that contacts the movable mold during mold clamping and forms part of the wall surface of the cavity space, a first cooling portion that is temperature-controlled to a temperature lower than the temperature of the first mold portion during filling of the molding material, and a first support portion that supports one of the first cooling portion and the first mold portion so that they can move relatively to the other, the first cooling section and the first mold section are relatively movable in both a mold opening direction and a mold closing direction between a position where they are spaced apart from each other and a position where they are in contact with each other, the movable mold has a second mold portion that contacts the fixed mold during mold clamping and forms part of a wall surface of the cavity space, a second cooling portion that is temperature-controlled to a temperature lower than the temperature of the second mold portion during filling of the molding material, and a second support portion that supports one of the second cooling portion and the second mold portion so that they can move relatively to the other, A mold device in which the second cooling section and the second mold section are relatively movable in both mold opening and mold closing directions between a position where they are spaced apart from each other and a position where they are in contact with each other.

2. The mold apparatus according to claim 1 , wherein the movable mold has a second drive section that moves the second cooling section and the second mold section relative to each other.

3. The mold apparatus according to claim 1 , wherein the movable mold has a second biasing portion that biases the second mold portion in a mold closing direction relative to the second cooling portion during mold clamping.

4. The mold apparatus according to any one of claims 1 to 3, wherein the first support portion and the second support portion transmit a mold clamping force.

5. the fixed mold has a first cylindrical portion through which a part of a sprue for feeding the molding material into the cavity space passes, A mold device according to any one of claims 1 to 3, wherein the first cooling section and the first cylindrical section are separated when the first cooling section and the first mold section are separated, and the first cooling section and the first cylindrical section are contacted when the first cooling section and the first mold section are contacted.

6. An injection molding system comprising: a mold device having a fixed mold and a movable mold, and forming a cavity space between the fixed mold and the movable mold when the mold is clamped; and an injection molding machine that fills the cavity space of the mold device with a preheated molding material, the fixed mold has a first mold portion that contacts the movable mold during mold clamping and forms a part of a wall surface of the cavity space, the fixed mold or the injection molding machine has a first cooling section whose temperature is adjusted to a temperature lower than the temperature of the first mold section when the molding material is filled, and a first support section that supports one of the first cooling section and the first mold section so that they can move relatively to the other, the first cooling section and the first mold section are relatively movable in both a mold opening direction and a mold closing direction between a position where they contact each other and a position where they are spaced apart from each other, the movable mold has a second mold portion that contacts the fixed mold during mold clamping and forms a part of a wall surface of the cavity space, the fixed mold or the injection molding machine has a second cooling section whose temperature is adjusted to a temperature lower than the temperature of the second mold section when the molding material is filled, and a second support section that supports one of the second cooling section and the second mold section so that they can move relatively to the other, An injection molding system, wherein the second cooling section and the second mold section are relatively movable in both a mold opening direction and a mold closing direction between a position where they are spaced apart from each other and a position where they are in contact with each other.

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