Control device of injection molding machine

Abstract

The present invention addresses the problem of reducing the occurrence of molding defects. A control device for an injection molding machine according to one embodiment of the present invention is a control device for controlling an injection molding machine, the injection molding machine comprising: a mold device having a fixed mold and a movable mold; a mold closing device for opening and closing the fixed mold and the movable mold; and an injection machine that injects a molding material into the mold device, the control device including: an acquisition unit that acquires an allowable amount that is an allowable amount of the size of a gap between the fixed mold and the movable mold in order to suppress discharge of the molding material from the mold device when the molding material is injected into the mold device; acquiring a gap amount indicating the size of a gap provided for discharging gas between the fixed mold and the movable mold; and an adjustment unit that, when the molding material is injected into the mold device that is closed by the mold clamping device, adjusts the mold clamping force of the mold clamping device so as to satisfy a condition based on the allowable amount on the basis of the values of the opening amount and the gap amount between the fixed mold and the movable mold, which are generated by the injection of the molding material.

Description

Technical Field

[0001] This application claims priority based on Japanese Patent Application No. 2023-221886 filed on December 27, 2023. The entire content of the Japanese application is incorporated herein by reference.

[0002] The present invention relates to a control device for an injection molding machine. Background Art

[0003] Conventionally, an injection molding machine includes: a mold device including a fixed mold and a movable mold; a mold clamping device for clamping the mold device; and an injection device for filling a molding material into the mold device. When the injection device fills the molding material into the mold device, the mold clamping device needs to close the mold device with an appropriate clamping force.

[0004] In the clamping force setting method of Patent Document 1, clamping force is generated by two or more different set clamping forces for injection, and the clamping force during the injection is detected. Thereby, a relational expression between the maximum value of the detected clamping force and the set clamping force is obtained, and based on this relational expression, the clamping force that makes the maximum value of the detected clamping force equal to the set clamping force is obtained, and the obtained clamping force is set.

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2012-206499

[0006] As shown in Patent Document 1, a method for setting the clamping force has been proposed in the past. However, it is difficult to derive an appropriate clamping force. For example, when the clamping force is small, the fixed mold and the movable mold are opened due to the pressure of the molding material, and the molding material leaks, resulting in burrs. That is, it is necessary to adjust the clamping force in consideration of the opening amount of the mold device 800. Summary of the Invention

[0007] One aspect of the present invention provides a technique for reducing the occurrence of molding defects.

[0008] A control device for an injection molding machine according to one aspect of the present invention, wherein the injection molding machine includes: a mold device having a fixed mold and a movable mold; a mold clamping device for opening and closing the fixed mold and the movable mold; and an injection machine for injecting a molding material into the mold device, and the control device includes:

[0009] an acquisition unit that, when injecting the molding material into the mold device, acquires an allowable amount that is allowed as the size of the gap between the fixed mold and the movable mold in order to suppress the discharge of the molding material from the mold device, and acquires a gap amount that represents the size of the gap provided for discharging gas between the fixed mold and the movable mold; and

[0010] Adjusting unit: When the molding material is injected into the mold device closed by the mold clamping device, based on the values of the opening amount and the clearance amount between the fixed mold and the movable mold generated by the injection of the molding material, the mold clamping force of the mold clamping device is adjusted in a manner that satisfies the condition based on the allowable amount.

[0011] Advantages of the Invention

[0012] According to one aspect of the present invention, the occurrence of molding defects is reduced by adjusting the mold clamping force of the mold clamping device. Brief Description of the Drawings

[0013] Figure 1 It is a diagram showing the state at the end of mold opening of an injection molding machine according to one embodiment.

[0014] Figure 2 It is a diagram showing the state during mold clamping of an injection molding machine according to one embodiment.

[0015] Figure 3 It is a diagram showing an example of the functional structure of the control device according to the first embodiment.

[0016] Figure 4 It is a diagram showing an example of the process of the molding cycle according to the first embodiment.

[0017] Figure 5 It is a cross-sectional view showing an example of the molding material flowing into the mold device according to the first embodiment.

[0018] Figure 6 It is a cross-sectional view showing the mold device according to the first embodiment.

[0019] Figure 7 It is a cross-sectional view showing the state where the parting surface of the mold device according to the first embodiment is opened.

[0020] Figure 8 It is a diagram showing the table structure of the allowable maximum value storage unit according to the first embodiment.

[0021] Figure 9 It is a cross-sectional view showing an example of the effective length of the connecting rod according to the first embodiment.

[0022] Figure 10 It is a diagram showing an example of the change of the actual value of the mold clamping force over time.

[0023] Figure 11 It is a diagram showing an example of the setting screen output from the output control unit to the display device according to the first embodiment.

[0024] Figure 12It is a flowchart showing the processing steps for adjusting the reference clamping force performed by the control device according to the first embodiment.

[0025] Figure 13 It is a diagram illustrating the log information screen output by the output control unit according to the first embodiment.

[0026] Figure 14 It is a diagram illustrating the clearance amount display screen output by the output control unit according to the first embodiment.

[0027] In the figure: 10 - injection molding machine, 100 - clamping device, 141 - connecting rod strain detector, 700 - control device, 701 - CPU, 711 - clamping control unit, 712 - injection control unit, 713 - acquisition unit, 714 - adjustment unit, 715 - output control unit, 716 - log information processing unit, 702 - storage medium, 721 - allowable maximum value storage unit, 800 - mold device, 803 - vent hole, 810 - fixed mold, 820 - movable mold, 830 - parting surface. Detailed Embodiments

[0028] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. And the embodiments described below are not limiting embodiments of the invention but examples, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention. In addition, in each drawing, the same or corresponding structures may sometimes be labeled with the same or corresponding reference numerals, and the description may be omitted.

[0029] Figure 1 It is a diagram showing the state at the end of mold opening of the injection molding machine according to the first embodiment.

[0030] Figure 2 It is a diagram showing the state during mold clamping of the injection molding machine according to the first embodiment. 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 the horizontal direction, and the Z-axis direction represents the vertical direction. When the clamping device 100 is horizontal, the X-axis direction is the mold opening and 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 operation side, and the positive side of the Y-axis direction is called the opposite side of the operation side.

[0031] As Figures 1 - 2As shown, the injection molding machine 10 has: a mold clamping device 100, a mold opening and closing device 800; an ejection device 200 that ejects the molded product formed by the mold device 800; an injection device 300 that injects a molding material into the mold device 800; a moving device 400 that moves the injection device 300 forward and backward relative to the mold device 800; a control device 700 that controls each component of the injection molding machine 10; and a frame 900 that supports each component of the injection molding machine 10. The frame 900 includes: a mold clamping device frame 910 that supports the mold clamping device 100; and an injection device frame 920 that supports the injection device 300. The mold clamping device frame 910 and the injection device frame 920 are respectively provided on the bottom plate 2 via horizontal adjusting casters 930. The control device 700 is arranged in the internal space of the injection device frame 920. Hereinafter, each component of the injection molding machine 10 will be described.

[0032] (Mold Clamping Device)

[0033] In the description of the mold clamping device 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 for the description.

[0034] The mold clamping device 100 performs mold closing, pressure boosting, mold clamping, pressure release, and mold opening of the mold device 800. The mold device 800 includes a fixed mold 810 and a movable mold 820. The mold clamping device 100 is, for example, horizontal, and the mold opening and closing direction is horizontal. The mold clamping device 100 has a fixed platen 110 for mounting the fixed mold 810, a movable platen 120 for mounting the movable mold 820, and a moving mechanism 102 that moves the movable platen 120 relative to the fixed platen 110 in the mold opening and closing direction.

[0035] The fixed platen 110 is fixed relative to the mold clamping device frame 910. The fixed mold 810 is mounted on the surface of the fixed platen 110 facing the movable platen 120.

[0036] The movable platen 120 is arranged to be movable relative to the mold clamping device frame 910 in the mold opening and closing direction. A guide member 101 for guiding the movable platen 120 is laid on the mold clamping device frame 910. The movable mold 820 is mounted on the surface of the movable platen 120 facing the fixed platen 110.

[0037] The moving mechanism 102 performs mold closing, pressure boosting, mold clamping, pressure release, and mold opening of the mold device 800 by moving the movable platen 120 forward and backward relative to the fixed platen 110. The moving mechanism 102 includes a toggle seat 130 disposed at an interval from the fixed platen 110, a connecting rod 140 connecting the fixed platen 110 and the toggle seat 130, a toggle mechanism 150 that moves the movable platen 120 relative to the toggle seat 130 in the mold opening and closing direction, 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 a linear motion, and a mold thickness adjustment mechanism 180 that adjusts the interval between the fixed platen 110 and the toggle seat 130.

[0038] The toggle seat 130 is disposed at an interval from the fixed platen 110 and is placed on the mold clamping device frame 910 so as to be movable in the mold opening and closing direction. In addition, the toggle seat 130 may be configured to be movable along a guide member laid on the mold clamping device frame 910. The guide member of the toggle seat 130 may be common to the guide member 101 of the movable platen 120.

[0039] In addition, in the present embodiment, the fixed platen 110 is fixed relative to the mold clamping device frame 910, and the toggle seat 130 is configured to be movable relative to the mold clamping device frame 910 in the mold opening and closing direction. However, it may also be that the toggle seat 130 is fixed relative to the mold clamping device frame 910, and the fixed platen 110 is configured to be movable relative to the mold clamping device frame 910 in the mold opening and closing direction.

[0040] The connecting rod 140 connects the fixed platen 110 and the toggle seat 130 at an interval L in the mold opening and closing direction. Multiple (for example, four) connecting rods 140 may be used. The multiple connecting rods 140 are arranged parallel to the mold opening and closing direction and extend according to the mold clamping force. A connecting rod strain detector 141 for detecting the strain of the connecting rod 140 may be provided on at least one connecting rod 140. The connecting rod strain detector 141 sends a signal indicating its detection result to the control device 700. The detection result of the connecting rod strain detector 141 is used for the detection of the mold clamping force and the like.

[0041] In addition, in the present embodiment, the connecting rod strain detector 141 is used as the mold clamping force detector for detecting the mold clamping force. However, the present invention is not limited thereto. The mold clamping force detector is not limited to the strain type, and may also be a piezoelectric type, a capacitive type, a hydraulic type, an electromagnetic type, etc., and its installation position is not limited to the connecting rod 140.

[0042] The toggle mechanism 150 is disposed between the movable platen 120 and the toggle seat 130, and moves the movable platen 120 relative to the toggle seat 130 in the mold opening and closing direction. The toggle mechanism 150 has a crosshead 151 that moves in the mold opening and closing direction and a pair of link groups that flex and extend by 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 by pins or the like so as to be freely flexed and extended. The first link 152 is swingably mounted on the movable platen 120 by a pin or the like. The second link 153 is swingably mounted on the toggle seat 130 by a pin or the like. The second link 153 is mounted on the crosshead 151 via a third link 154. When the crosshead 151 moves forward and backward relative to the toggle seat 130, the first link 152 and the second link 153 flex and extend so that the movable platen 120 moves forward and backward relative to the toggle seat 130.

[0043] In addition, the structure of the toggle mechanism 150 is not limited to Figure 1 and Figure 2 the structure shown. For example, in Figure 1 and Figure 2 the number of nodes of each link group is 5, but it can be 4, or one end of the third link 154 can be joined to the node of the first link 152 and the second link 153.

[0044] The mold clamping motor 160 is mounted on the toggle seat 130 and operates the toggle mechanism 150. The mold clamping motor 160 moves the crosshead 151 forward and backward relative to the toggle seat 130, causing the first link 152 and the second link 153 to flex and extend so that the movable platen 120 moves forward and backward relative to the toggle seat 130. The mold clamping motor 160 is directly connected to the motion conversion mechanism 170, but it can also be connected to the motion conversion mechanism 170 via a belt, a pulley, or the like.

[0045] 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 lead screw shaft and a lead screw nut that engages with the lead screw shaft. A ball or a roller can be interposed between the lead screw shaft and the lead screw nut.

[0046] The mold clamping device 100 performs a mold closing process, a pressure boosting process, a mold clamping process, a pressure releasing process, a mold opening process, etc. under the control of the control device 700.

[0047] In the mold closing process, the crosshead 151 is advanced to the mold closing end position at a set moving speed by driving the mold clamping motor 160, and the movable platen 120 is advanced so that the movable mold 820 contacts the fixed mold 810. For example, a mold clamping motor encoder 161 or the like is used to detect the position and moving speed of the crosshead 151. The mold clamping motor encoder 161 detects the rotation of the mold clamping motor 160 and sends a signal representing the detection result to the control device 700.

[0048] In addition, the crosshead position detector for detecting the position of the crosshead 151 and the crosshead moving speed detector for detecting the moving speed of the crosshead 151 are not limited to the clamping motor encoder 161, and conventional detectors can be used. Also, the movable platen position detector for detecting the position of the movable platen 120 and the movable platen moving speed detector for detecting the moving speed of the movable platen 120 are not limited to the clamping motor encoder 161, and conventional detectors can be used.

[0049] In the boosting process, the clamping motor 160 is further driven to move the crosshead 151 forward from the mold closing end position to the mold clamping position, thereby generating a clamping force.

[0050] In the mold clamping process, the clamping motor 160 is driven to maintain the position of the crosshead 151 at the mold clamping position. In the mold clamping process, the clamping force generated in the boosting process is maintained. In the mold clamping process, a cavity space 801 is formed between the movable mold 820 and the fixed mold 810 (refer to Figure 2 ), and the injection device 300 fills the cavity space 801 with a liquid molding material. The filled molding material is cured, thereby obtaining a molded product.

[0051] The number of the cavity spaces 801 can be one or more. In the latter case, multiple molded products can be obtained simultaneously. Inserts can be arranged in a part of the cavity space 801, and the cavity space 801 can be filled with a molding material in another part. A molded product in which the inserts and the molding material are integrated can be obtained.

[0052] In the pressure release process, the crosshead 151 is retracted from the mold clamping position to the mold opening start position by driving the clamping motor 160, and the movable platen 120 is retracted to reduce the clamping force. The mold opening start position and the mold closing end position can be the same position.

[0053] In the mold opening process, the crosshead 151 is retracted from the mold opening start position to the mold opening end position at a set moving speed by driving the clamping motor 160, and the movable platen 120 is retracted to separate the movable mold 820 from the fixed mold 810. Then, the ejector device 200 ejects the molded product from the movable mold 820.

[0054] The setting conditions in the mold closing process, pressure boosting process, and mold clamping process are set uniformly as a series of setting conditions. For example, the moving speed, position of the crosshead 151 (including the mold closing start position, moving speed switching position, mold closing end position, and mold clamping position) in the mold closing process and pressure boosting process, and the mold clamping force are set uniformly as a series of setting conditions. The mold closing start position, moving speed switching position, mold closing end position, and mold clamping position are arranged in sequence from the rear to the front, and represent the starting point and ending point of the interval where the moving speed is set. The moving speed is set for each interval. The moving speed switching position can be one or more. The moving speed switching position can be not set. Only either the mold clamping position or the mold clamping force can be set.

[0055] The setting conditions in the pressure release process and mold opening process are also set in the same way. For example, the moving speed, position of the crosshead 151 (mold opening start position, moving speed switching position, and mold opening end position) in the pressure release process and mold opening process are set uniformly as a series of setting conditions. The mold opening start position, moving speed switching position, and mold opening end position are arranged in sequence from the front to the rear, and represent the starting point and ending point of the interval where the moving speed is set. The moving speed is set for each interval. The moving speed switching position can be one or more. The moving speed switching position can be not set. The mold opening start position and the mold closing end position can be the same position. Also, the mold opening end position and the mold closing start position can be the same position.

[0056] In addition, instead of the moving speed, position, etc. of the crosshead 151, the moving speed, position, etc. of the movable platen 120 can also be set. Also, instead of the position of the crosshead (such as the mold clamping position) and the position of the movable platen, the mold clamping force can be set.

[0057] However, the toggle mechanism 150 amplifies the driving force of the mold clamping motor 160 and transmits it to the movable platen 120. Its magnification ratio is also called the toggle ratio. The toggle ratio changes according to the angle θ formed by the first link 152 and the second link 153 (hereinafter, also called "link angle θ"). The link angle θ is obtained from the position of the crosshead 151. When the link angle θ is 180°, the toggle ratio becomes the maximum.

[0058] When the thickness of the mold device 800 changes due to replacement of the mold device 800, temperature change of the mold device 800, etc., mold thickness adjustment is performed to obtain a specified mold clamping force during mold clamping. In the mold thickness adjustment, for example, the interval L between the fixed platen 110 and the toggle seat 130 is adjusted so that when the movable mold 820 contacts the fixed mold 810, the link angle θ of the toggle mechanism 150 becomes a specified angle.

[0059] The mold clamping device 100 is provided with a mold thickness adjusting mechanism 180. The mold thickness adjusting mechanism 180 adjusts the interval L between the fixed platen 110 and the toggle seat 130, thereby performing mold thickness adjustment. In addition, regarding the timing of mold thickness adjustment, for example, it is performed during the period from the end of the molding cycle to the start of the next molding cycle. The mold thickness adjusting mechanism 180 has, for example: a lead screw shaft 181 formed at the rear end of the connecting rod 140; a lead screw nut 182 that is rotatably held and non-axially movable in the toggle seat 130; and a mold thickness adjustment motor 183 that rotates the lead screw nut 182 screwed with the lead screw shaft 181.

[0060] The lead screw shaft 181 and the lead screw nut 182 are provided for each connecting rod 140. The rotational driving force of the mold thickness adjustment motor 183 can be transmitted to a plurality of lead screw nuts 182 via a rotational driving force transmission portion 185. The plurality of lead screw nuts 182 can be rotated synchronously. In addition, by changing the transmission path of the rotational driving force transmission portion 185, the plurality of lead screw nuts 182 can also be rotated individually.

[0061] The rotational driving force transmission portion 185 is formed of, for example, gears. At this time, driven gears are formed on the outer periphery of each lead screw nut 182, a driving gear is mounted on the output shaft of the mold thickness adjustment motor 183, and an intermediate gear that meshes with the plurality of driven gears and the driving gear is rotatably held at the center of the toggle seat 130. In addition, instead of gears, the rotational driving force transmission portion 185 can also be formed of a belt, pulleys, etc.

[0062] The operation of the mold thickness adjusting mechanism 180 is controlled by a control device 700. The control device 700 drives the mold thickness adjustment motor 183 to rotate the lead screw nut 182. As a result, the position of the toggle seat 130 relative to the connecting rod 140 is adjusted, and the interval L between the fixed platen 110 and the toggle seat 130 is adjusted. In addition, a plurality of mold thickness adjusting mechanisms can be used in combination.

[0063] The interval L is detected using a mold thickness adjustment motor encoder 184. The mold thickness adjustment motor encoder 184 detects the rotation amount and rotation direction 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 seat 130 and the interval L. In addition, the toggle seat position detector for detecting the position of the toggle seat 130 and the interval detector for detecting the interval L are not limited to the mold thickness adjustment motor encoder 184, and conventional detectors can be used.

[0064] The mold clamping device 100 may be provided with a mold temperature regulator for adjusting the temperature of the mold device 800. The mold device 800 has a flow path for a temperature regulating medium inside it. The mold temperature regulator adjusts the temperature of the temperature regulating medium supplied to the flow path of the mold device 800, thereby adjusting the temperature of the mold device 800.

[0065] In addition, the mold clamping device 100 of the present embodiment is a horizontal type with the mold opening and closing direction being the horizontal direction, but it can also be a vertical type with the mold opening and closing direction being the vertical direction.

[0066] In addition, the mold clamping device 100 of the present embodiment has a mold clamping motor 160 as a drive source, but it can also have a hydraulic cylinder instead of the mold clamping motor 160. Moreover, the mold clamping device 100 has a linear motor for mold opening and closing, and it can also have an electromagnet for mold clamping.

[0067] (Ejector device)

[0068] In the description of the ejector device 200, similar to the description of the mold clamping device 100, the moving direction of the movable platen 120 at the time of mold closing (for example, the positive X-axis direction) is set as the front, and the moving direction of the movable platen 120 at the time of mold opening (for example, the negative X-axis direction) is set as the rear for the description.

[0069] The ejector device 200 is installed on the movable platen 120 and moves forward and backward together with the movable platen 120. The ejector device 200 has: an ejector rod 210 that ejects the molded product from the mold device 800; and a drive mechanism 220 that moves the ejector rod 210 in the moving direction (X-axis direction) of the movable platen 120.

[0070] The ejector rod 210 is configured to be able to move forward and backward in the through hole of the movable platen 120. The front end portion of the ejector rod 210 contacts the ejector plate 826 of the movable mold 820. The front end portion of the ejector rod 210 can be connected to the ejector plate 826 or not connected to it.

[0071] The drive mechanism 220, for example, has an ejector motor and a motion conversion mechanism that converts the rotational motion of the ejector motor into the linear motion of the ejector rod 210. The motion conversion mechanism includes a lead screw shaft and a lead screw nut that is screwed onto the lead screw shaft. A ball or a roller can be interposed between the lead screw shaft and the lead screw nut.

[0072] The ejector device 200 performs an ejection process under the control of the control device 700. In the ejection process, the ejector rod 210 is advanced from the standby position to the ejection position at a set moving speed to advance the ejector plate 826 to eject the molded product. Then, the ejector motor is driven to retract the ejector rod 210 at a set moving speed to retract the ejector plate 826 to the original standby position.

[0073] For example, an ejector motor encoder is used to detect the position and moving speed of the ejector rod 210. The ejector motor encoder detects the rotation of the ejector motor and sends a signal representing the detection result to the control device 700. In addition, the ejector rod position detector for detecting the position of the ejector rod 210 and the ejector rod moving speed detector for detecting the moving speed of the ejector rod 210 are not limited to the ejector motor encoder, and conventional detectors can be used.

[0074] (Injection device)

[0075] In the description of the injection device 300, different from the description of the clamping device 100 and the ejection device 200, the moving direction of the screw 330 during filling (for example, the negative X-axis direction) is set as the front, and the moving direction of the screw 330 during metering (for example, the positive X-axis direction) is set as the rear for the description.

[0076] The injection device 300 is provided on the sliding base 301, and the sliding base 301 is configured to be retractable relative to the injection device frame 920. The injection device 300 is configured to be retractable relative to the mold device 800. The injection device 300 contacts the mold device 800 and fills the cavity space 801 in the mold device 800 with the molding material metered in the cylinder 310. The injection device 300 has, for example, a cylinder 310 for heating the molding material, a nozzle 320 provided at the front end of the cylinder 310, a screw 330 configured to be retractable and rotatable in the cylinder 310, a metering motor 340 for rotating the screw 330, an injection motor 350 for moving the screw 330 forward and backward, and a load detector 360 for detecting the load transmitted between the injection motor 350 and the screw 330.

[0077] The cylinder 310 heats the molding material supplied into the interior from the supply port 311. The molding material includes, for example, resin and the like. The molding material is formed, for example, in a granular shape and is supplied to the supply port 311 in a solid state. The supply port 311 is formed at the rear of the cylinder 310. A cooler 312 such as a water-cooled cylinder is provided on the outer periphery of the rear of the cylinder 310. A heater 313 such as a belt heater and a temperature detector 314 are provided on the outer periphery of the cylinder 310 further forward than the cooler 312.

[0078] The cylinder 310 is divided into a plurality of regions along the axial direction of the cylinder 310 (for example, the X-axis direction). Heaters 313 and temperature detectors 314 are provided in the plurality of regions respectively. Set temperatures are set for the plurality of regions respectively, and the control device 700 controls the heater 313 so that the detected temperature of the temperature detector 314 becomes the set temperature.

[0079] The nozzle 320 is provided at the front end of the cylinder 310 and presses against the mold device 800. A heater 313 and a temperature detector 314 are provided on the outer periphery of the nozzle 320. The control device 700 controls the heater 313 so that the detected temperature of the nozzle 320 becomes the set temperature.

[0080] The screw 330 is configured to be rotatable and axially movable within the cylinder block 310. When the screw 330 rotates, the molding material is conveyed forward along the spiral grooves of the screw 330. While being conveyed forward, the molding material is gradually melted by the heat from the cylinder block 310. As the liquid molding material is conveyed to the front of the screw 330 and accumulates in the front part of the cylinder block 310, the screw 330 is retracted. Then, when the screw 330 is advanced, the liquid molding material accumulated in front of the screw 330 is injected from the nozzle 320 and filled into the mold device 800.

[0081] The check ring 331 is axially movably mounted at the front of the screw 330, and this check ring 331 functions as a check valve to prevent the molding material from flowing backward from the front of the screw 330 to the rear when the screw 330 is pushed forward.

[0082] When the screw 330 is advanced, the check ring 331 is pushed backward by the pressure of the molding material in front of the screw 330 and relatively retracts with respect to the screw 330 to a closed position where the flow path of the molding material is closed (refer to Figure 2 ). Thereby, the molding material accumulated in front of the screw 330 is prevented from flowing backward.

[0083] On the other hand, when the screw 330 rotates, the check ring 331 is pushed forward by the pressure of the molding material conveyed forward along the spiral grooves of the screw 330 and relatively advances with respect to the screw 330 to an open position where the flow path of the molding material is opened (refer to Figure 1 ). Thereby, the molding material is conveyed to the front of the screw 330.

[0084] The check ring 331 can 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.

[0085] In addition, the injection device 300 can have a drive source for moving the check ring 331 forward and backward between the open position and the closed position with respect to the screw 330.

[0086] 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 for example, it can be a hydraulic pump or the like.

[0087] The injection motor 350 moves the screw 330 forward and backward. A motion conversion mechanism or the like for converting the rotational motion of the injection motor 350 into the linear motion of the screw 330 is provided between the injection motor 350 and the screw 330. The motion conversion mechanism, for example, has a lead screw shaft and a lead screw nut that engages with the lead screw shaft. Balls, rollers, etc. can be provided between the lead screw shaft and the lead screw nut. The drive source for moving the screw 330 forward and backward is not limited to the injection motor 350, and for example, it can be a hydraulic cylinder or the like.

[0088] 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 in the load transmission path between the injection motor 350 and the screw 330, and detects the load acting on the load detector 360.

[0089] The load detector 360 sends the signal of the detected load to the control device 700. The load detected by the load detector 360 is converted into the pressure acting between the screw 330 and the molding material, and is used to control and monitor the pressure that the screw 330 bears from the molding material, the back pressure on the screw 330, and the pressure acting on the molding material from the screw 330, etc.

[0090] In addition, the pressure detector for detecting the pressure of the molding material is not limited to the load detector 360, and a conventional detector can be used. For example, a nozzle pressure sensor or an in-mold pressure sensor can be used. The nozzle pressure sensor is provided in the nozzle 320.

[0091] The injection device 300 performs metering process, filling process, holding pressure process, etc. under the control of the control device 700. The filling process and the holding pressure process can be collectively referred to as the injection process.

[0092] In the metering process, the metering motor 340 is driven to rotate the screw 330 at a set speed, and the molding material is conveyed forward along the spiral grooves of the screw 330. Thus, the molding material is gradually melted. As the liquid molding material is conveyed to the front of the screw 330 and accumulates in the front part of the cylinder block 310, the screw 330 retreats. For example, the metering motor encoder 341 is used to detect the rotation speed of the screw 330. The metering motor encoder 341 detects the rotation of the metering motor 340 and sends the signal representing the detection result to the control device 700. In addition, the screw rotation speed detector for detecting the rotation speed of the screw 330 is not limited to the metering motor encoder 341, and a conventional detector can be used.

[0093] In the metering process, in order to limit the sharp retreat of the screw 330, the injection motor 350 can be driven to apply a set back pressure to the screw 330. For example, the load detector 360 is used to detect the back pressure on the screw 330. When the screw 330 retreats to the metering end position and a specified amount of molding material accumulates in front of the screw 330, the metering process ends.

[0094] The position and rotation speed of the screw 330 in the metering process are uniformly set as a series of setting conditions. For example, the metering start position, the rotation speed switching position, and the metering end position are set. These positions are arranged in sequence from the front side to the rear side, and represent the start point and end point of the interval of the set rotation speed. The rotation speed is set for each interval. The rotation speed switching position can be one or more. The rotation speed switching position can be not set. Also, the back pressure is set for each interval.

[0095] In the filling process, the injection motor 350 is driven to make the screw 330 advance 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. For example, the position and moving speed of the screw 330 are detected using the injection motor encoder 351. The injection motor encoder 351 detects the rotation of the injection motor 350 and sends a signal representing the detection result to the control device 700. When the position of the screw 330 reaches the set position, the switching from the filling process to the holding pressure process (so-called V / P switching) is performed. The position where the V / P switching is performed is also called the V / P switching position. The set moving speed of the screw 330 can be changed according to the position, time, etc. of the screw 330.

[0096] The position and moving speed of the screw 330 in the filling process are uniformly set as a series of setting conditions. For example, the filling start position (also called the "injection start position".), the moving speed switching position, and the V / P switching position are set. These positions are arranged in sequence from the rear side to the front side, and represent the start point and end point of the interval of the set moving speed. The moving speed is set for each interval. The moving speed switching position can be one or more. The moving speed switching position can be not set.

[0097] The upper limit value of the pressure of the screw 330 is set for each interval of the set moving speed of the screw 330. The pressure of the screw 330 is detected by the load detector 360. When the pressure of the screw 330 is below the set pressure, the screw 330 advances at the set moving speed. On the other hand, when the pressure of the screw 330 exceeds the set pressure, for the purpose of protecting the mold, the screw 330 advances at a moving speed slower than the set moving speed so that the pressure of the screw 330 becomes below the set pressure.

[0098] In addition, in the filling process, after the position of the screw 330 reaches the V / P switching position, the screw 330 can be paused at the V / P switching position, and then the V / P switching is performed. It is also possible to perform a micro-speed forward or micro-speed backward of the screw 330 instead of the stop of the screw 330 before the V / P switching is about to be performed. Also, the screw position detector for detecting the position of the screw 330 and the screw moving speed detector for detecting the moving speed of the screw 330 are not limited to the injection motor encoder 351, and conventional detectors can be used.

[0099] In the holding pressure process, the driving injection motor 350 pushes the screw 330 forward, maintains 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 pushes the molding material remaining in the cylinder block 310 toward the mold device 800. It is possible to supplement the insufficient amount of molding material in the mold device 800 due to cooling shrinkage. For example, a load detector 360 is used to detect the holding pressure. The set value of the holding pressure can be changed according to the elapsed time since the start of the holding pressure process and the like. The holding pressure and the holding time for maintaining the holding pressure in multiple holding pressure processes can be set separately, or can be set uniformly as a series of set conditions.

[0100] In the holding pressure process, the molding material in the cavity space 801 of the mold device 800 is gradually cooled, and at the end of the holding pressure process, the inlet of the cavity space 801 is closed by the solidified molding material. This state is called gate sealing, which can prevent the reverse flow of the molding material from the cavity space 801. After the holding pressure process, the cooling process starts. In the cooling process, the molding material in the cavity space 801 is solidified. For the purpose of shortening the molding cycle time, the metering process can be carried out in the cooling process.

[0101] In addition, the injection device 300 of the present embodiment is of a coaxial screw type, but it can also be a pre-plasticizing type or the like. The pre-plasticizing type injection device supplies the molding material melted in the plasticizing cylinder to the injection cylinder, and injects the molding material from the injection cylinder into the mold device. In the plasticizing cylinder, the screw is configured to be rotatable and non-retractable, or the screw is configured to be rotatable and retractable. On the other hand, in the injection cylinder, the plunger is configured to be retractable.

[0102] Moreover, the injection device 300 of the present embodiment is a horizontal type with the axial direction of the cylinder block 310 being the horizontal direction, but it can also be a vertical type with the axial direction of the cylinder block 310 being the up and down direction. The mold clamping device combined with the vertical injection device 300 can be vertical or horizontal. Similarly, the mold clamping device combined with the horizontal injection device 300 can be horizontal or vertical.

[0103] (Moving device)

[0104] 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 (for example, the negative X-axis direction) is set as the front, and the moving direction of the screw 330 during metering (for example, the positive X-axis direction) is set as the rear for the description.

[0105] The mobile device 400 moves the injection device 300 forward and backward relative to the mold device 800. Further, the mobile device 400 presses the nozzle 320 against the mold device 800 to generate a nozzle contact pressure. The mobile 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.

[0106] The hydraulic pump 410 has a first port 411 and a second port 412. The hydraulic pump 410 is a bidirectional rotary pump that sucks a working fluid (e.g., oil) from either the first port 411 or the second port 412 and discharges it from the other port by switching the rotation direction of the motor 420 to generate a hydraulic pressure. Further, the hydraulic pump 410 can also suck the working fluid from a tank and discharge the working fluid from either the first port 411 or the second port 412.

[0107] The motor 420 operates the hydraulic pump 410. The motor 420 drives the hydraulic pump 410 with a rotation direction and a rotational torque corresponding to a control signal from the control device 700. The motor 420 may be an electric motor or an electric servo motor.

[0108] The hydraulic cylinder 430 has a cylinder body 431, a piston 432, and a piston rod 433. The cylinder body 431 is fixed relative 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 relative to the fixed platen 110.

[0109] The front chamber 435 of the hydraulic cylinder 430 is connected to the first port 411 of the hydraulic pump 410 via a first flow path 401. The working fluid discharged from the first port 411 is supplied to the front chamber 435 via the first flow path 401, whereby the injection device 300 is pushed forward. The injection device 300 advances and the nozzle 320 is pressed against the fixed mold 810. The front chamber 435 functions as a pressure chamber that generates the nozzle contact pressure of the nozzle 320 by the pressure of the working fluid supplied from the hydraulic pump 410.

[0110] On the other hand, the rear chamber 436 of the hydraulic cylinder 430 is connected to the second port 412 of the hydraulic pump 410 via a second flow path 402. The working 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, whereby the injection device 300 is pushed backward. The injection device 300 retreats and the nozzle 320 separates from the fixed mold 810.

[0111] Further, in the present embodiment, the mobile device 400 includes the hydraulic cylinder 430, but the present invention is not limited thereto. 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 a linear motion of the injection device 300 may be used.

[0112] (Control device)

[0113] The control device 700 is constituted by a computer, for example, as Figures 1 - 2 shown, it has a CPU (Central Processing Unit), a storage medium 702 such as a memory, an input interface 703, an output interface 704, and a communication interface 705. The control device 700 performs various controls by causing the CPU 701 to execute a program stored in the storage medium 702. Also, the control device 700 receives signals from the outside through the input interface 703 and sends signals to the outside through the output interface 704.

[0114] The control device 700 repeatedly produces molded products by repeatedly performing processes such as a metering process, a mold closing process, a pressure boosting process, a mold clamping process, a filling process, a holding pressure process, a cooling process, a pressure releasing process, a mold opening process, and an ejection process. A series of actions for obtaining a molded product, for example, the actions from the metering process to before the start of the next metering process, are also referred to as "injection" or "molding cycle". Also, the time required for one injection is also referred to as "molding cycle time" or "cycle time".

[0115] One molding cycle, for example, sequentially has a metering process, a mold closing process, a pressure boosting process, a mold clamping process, a filling process, a holding pressure process, a cooling process, a pressure releasing process, a mold opening process, and an ejection process. The order here is the order in which each process starts. The filling process, the holding pressure process, and the cooling process are performed during the mold clamping process. It is also possible to make the start of the mold clamping process coincide with the start of the filling process. The end of the pressure releasing process coincides with the start of the mold opening process.

[0116] In addition, for the purpose of shortening the molding cycle time, multiple processes can be performed simultaneously. For example, the metering process can be performed during the cooling process of the previous molding cycle, or it can be performed during the mold clamping process. At this time, it can be set that the mold closing process is performed at the beginning of the molding cycle. Also, the filling process can start during the mold closing process. And the ejection process can start during the mold opening process. When an on-off valve for setting the flow path of the on-off nozzle 320 is provided, the mold opening process can start during the metering process. Because even if the mold opening process starts during the metering process, as long as the on-off valve closes the flow path of the nozzle 320, the molding material will not leak from the nozzle 320.

[0117] In addition, one molding cycle can have processes other than the metering process, the mold closing process, the pressure boosting process, the mold clamping process, the filling process, the holding pressure process, the cooling process, the pressure releasing process, the mold opening process, and the ejection process.

[0118] For example, a pre-metering backflow process of retracting the screw 330 to a preset metering start position can be performed after the pressure holding process is completed and before the metering process starts. The pressure of the molding material accumulated in front of the screw 330 can be reduced before the metering process starts, and the sudden retraction of the screw 330 at the start of the metering process can be prevented.

[0119] Also, a post-metering backflow process of retracting the screw 330 to a preset filling start position (also referred to as the "injection start position") can be performed after the metering process is completed and before the filling process starts. The pressure of the molding material accumulated in front of the screw 330 can be reduced before the filling process starts, and the leakage of the molding material from the nozzle 320 can be prevented before the filling process starts.

[0120] The control device 700 is connected to the operation device 750 that receives the input operations of the user and the display device 760 of the display screen. The operation device 750 and the display device 760 are constituted by a touch panel 770, for example, and can be integrated. The touch panel 770 as the display device 760 displays a screen under the control of the control device 700. Information such as the settings of the injection molding machine 10 and the current state of the injection molding machine 10 can be displayed on the screen of the touch panel 770. The touch panel 770 can accept operations in the displayed screen area. Also, operation parts such as buttons and input fields for receiving the input operations of the user can be displayed in the screen area of the touch panel 770. The touch panel 770 as the operation device 750 detects the input operations of the user on the screen and outputs a signal corresponding to the input operations to the control device 700. Thus, for example, the user can operate the operation parts provided on the screen while confirming the information displayed on the screen, and perform the settings (including the input of set values) of the injection molding machine 10. Also, when the user operates the operation parts provided on the screen, the injection molding machine 10 corresponding to the operation parts can be made to operate. In addition, the operation of the injection molding machine 10 can be, for example, the operation (including stopping) of the mold clamping device 100, the ejection device 200, the injection device 300, the moving device 400, etc. Also, the operation of the injection molding machine 10 can be the switching of the screen displayed on the touch panel 770 as the display device 760.

[0121] In addition, the case where the operation device 750 and the display device 760 of the present embodiment are integrated into the touch panel 770 has been described, but they can also be provided independently. Also, a plurality of operation devices 750 can be provided. The operation device 750 and the display device 760 are arranged on the operation side (negative Y-axis direction) of the mold clamping device 100 (more specifically, the fixed platen 110).

[0122] Figure 3 It is a diagram showing an example of the functional structure of the control device 700 according to the present embodiment. AsFigure 3 As shown Figure 3 in the figure, the components of the control device 700 of the injection molding machine 10 are represented by functional blocks. Figure 3 Each of the functional blocks shown in the figure is a conceptual functional block, and physically, it does not necessarily have to be configured as shown in the figure. All or part of each functional block can be functionally or physically dispersed / integrated in any unit to form. All or any part of each processing function performed in each functional block is implemented by a program executed by the CPU 701. Alternatively, each functional block can be implemented as hardware based on wiring logic. As Figure 3 shown, the CPU 701 of the control device 700 includes, for example, a mold clamping control unit 711, an injection control unit 712, an acquisition unit 713, an adjustment unit 714, an output control unit 715, and a log information processing unit 716. In the storage medium 702 of the control device 700, a maximum allowable value storage unit 721 is provided.

[0123] The mold clamping control unit 711 controls the mold clamping drive source of the mold clamping device 100 and implements Figure 4 the mold closing process, the pressure boosting process, the mold clamping process, the pressure release process, and the mold opening process shown in the figure. The mold clamping drive source is, for example, a mold clamping motor 160, but it can also be a hydraulic cylinder or the like.

[0124] The injection control unit 712 controls the injection drive source of the injection device 300 and implements the injection process. The injection drive source is, for example, an injection motor 350, but it can also be a hydraulic cylinder or the like. The injection process includes a filling process and a holding pressure process. The injection process is performed during the mold clamping process.

[0125] The filling process is a process of controlling the injection drive source so that the actual value of the moving speed of the injection member provided inside the cylinder body 310 becomes the set value. The filling process is a process of filling the liquid molding material accumulated in front of the injection member into the mold device 800 by moving the injection member forward. The injection member is, for example, a screw 330 (refer to Figure 1 and Figure 2 ), but it can also be a plunger.

[0126] The moving speed of the injection member is detected using a speed detector. The speed detector is, for example, an injection motor encoder 351. During the filling process, as the injection member advances, the pressure (hereinafter, also referred to as "filling pressure") acting on the molding material from the injection member increases. The filling process can include a process of pausing the injection member or a process of retracting the injection member before the holding pressure process.

[0127] The holding pressure process is a process of controlling the injection drive source in such a way that the actual value of the filling pressure becomes the set value. The holding pressure process is a process of replenishing the insufficient amount of the molding material caused by cooling shrinkage in the mold device 800 by moving the injection part forward. The filling pressure is detected using a pressure detector such as the load detector 360. As the pressure detector, a nozzle pressure sensor or an in-mold pressure sensor can be used.

[0128] As described above, the injection process is carried out during the mold clamping process. The mold clamping control unit 711, for example, converts the set value of the mold clamping force into the set value of the crosshead position, and controls the mold clamping motor 160 so that the actual value of the crosshead position becomes the set value. The crosshead position is the relative position of the crosshead 151 with respect to the toggle seat 130 (refer to Figure 2 ). The more the crosshead 151 advances, the greater the mold clamping force becomes.

[0129] Next, Figure 5 An example of the molding material M flowing into the inside of the mold device 800 will be described. The molding material M is, for example, resin. The molding material M flows into the cavity space 801 inside the mold device 800. The cavity space 801 is formed on the parting surface 830 between the fixed mold 810 and the movable mold 820. The parting surface 830 is usually referred to as the parting line.

[0130] After the molding material M is injected by the injection device 300, it passes through the sprue (not shown) of the fixed mold 810, etc., and flows into the cavity space 801 formed between the fixed mold 810 and the movable mold 820. Before the flow front of the molding material M reaches the parting surface 830 between the fixed mold 810 and the movable mold 820, even if the mold clamping force F is low, the fixed mold 810 and the movable mold 820 do not open, and thus flash does not occur. Flash is a phenomenon in which the molding material M leaks between the fixed mold 810 and the movable mold 820 and solidifies.

[0131] If the mold clamping force F is large and the mold clamping pressure P2 is greater than the filling pressure P1, then when the molding material M reaches the parting surface 830 between the fixed mold 810 and the movable mold 820, the fixed mold 810 and the movable mold 820 do not open. Therefore, the molding material M does not leak, and thus flash does not occur. In addition, the mold clamping pressure P2 is the value obtained by dividing the mold clamping force F by the area S of the parting surface 830 (P2 = F / S).

[0132] However, if the fixed mold 810 and the movable mold 820 are not opened, it is not easy to discharge the gas from the inside of the mold device 800 to the outside. In the case where the gas cannot be discharged, the gas inside the mold device 800 is compressed and heated, so there is a possibility of gas burning. Gas burning refers to the phenomenon that the molding material M flows into the cavity space 801, and the gas in the cavity space 801 is compressed and heated to carbonize the molding material M. Furthermore, in the case where the gas cannot be discharged, the molding material may not cover the entire cavity space 801 of the mold device 800, and it may also cause short shot of the molded product. Therefore, a gap for discharging gas is usually provided.

[0133] Figure 6 is a cross-sectional view showing the mold device 800 according to the present embodiment. In Figure 6 the example shown, the fixed mold 810 and the movable mold 820 included in the mold device 800 are shown. In Figure 6 the example shown, a sprue 802 is formed on the fixed mold 810. And a runner (not shown) may be provided between the cavity space 801 and the sprue 802.

[0134] In the present embodiment, the injection device 300 injects a liquid molding material, and thus the liquid molding material is filled in the cavity space 801. In the mold device 800, in the case where the molding material is filled into the cavity space 801, vent holes 803 are provided to discharge the air existing in the cavity space 801 before filling and the gas generated from the flow front (flow front end) of the molding material during filling.

[0135] The vent holes 803 provided on the parting surface 830 of the mold device 800 are set to the following depth: discharging air and gas, but not discharging the molding material, that is, not becoming burrs. The depth of the groove of the vent hole 803 is determined according to the type of the molding material. For example, grooves with a depth of several μm to several tens of μm are provided. In Figure 6 the example shown, the depth of the groove of the vent hole 803 is set to 20 μm.

[0136] Moreover, the air existing in the cavity space 801 before filling and the gas generated from the flow front (flow front end) of the molding material during filling are discharged to the outside of the cavity space 801 through the vent holes 803.

[0137] Conventionally, a mold device was usually fastened with a large clamping force without opening the parting surface. However, in this case, since no gap is generated during the filling of the molding material, the only vents for exhausting gas are vent holes. When air and gas accumulate in the vent holes, the velocity of the air and gas passing through the vent holes increases, so the resistance rises when passing through the vent holes. As a result, the air and gas are not easily exhausted, or the gas is cooled when passing through the vent holes, and the components included in the gas precipitate in the vent holes to form mold deposits. Therefore, as a result of repeated injection molding, the vent holes are blocked.

[0138] Therefore, during filling, the parting surface is slightly opened to easily exhaust air and gas. On the other hand, it is preferable to adjust the clamping force so that the molding material is not discharged.

[0139] Figure 7 It is a cross-sectional view showing a state in which the parting surface 830 of the mold device 800 according to the present embodiment is opened. In Figure 7 the example shown, the fixed mold 810 and the movable mold 820 included in the mold device 800 are shown.

[0140] In Figure 7 the example shown, when the molding material M reaches the parting surface 830 between the fixed mold 810 and the movable mold 820, a gap is generated between the fixed mold 810 and the movable mold 820 according to the filling pressure.

[0141] In Figure 7 the example shown, the opening amount of the gap is set to 10 μm. The depth of the groove of the vent hole 803 is set to 20 μm. In Figure 7 the example shown, the sum of the opening amount of 10 μm and the depth of the groove of the vent hole 803 of 20 μm, which is 30 μm, becomes the size of the gap generated in the mold device 800. In the present embodiment, the gap is expressed as a numerical value in the SI unit system, but it is not limited thereto. Furthermore, instead of using the size of the gap itself such as dimensions, a quantity related to the size of the gap or a parameter calculated by substituting a quantity related to the size of the gap into a specified function can be used. Furthermore, a substitute variable related to the size of the gap can be used.

[0142] In the present embodiment, when the molding material is injected into the mold device 800, in order to suppress the injection of the molding material from the mold device 800, the maximum value allowed for the size of the gap between the fixed mold 810 and the movable mold 820, in other words, the maximum value of the size of the gap, is defined as the allowable maximum value (an example of the allowable amount). The allowable maximum value is an example of the allowable amount. Instead of using the maximum value of the size of the gap itself, an allowable amount related to the size of the gap, such as a parameter calculated by substituting a quantity related to the size of the gap into a specified function or a substitute variable related to the size of the gap, may be used. The allowable maximum value varies depending on the type of molding material.

[0143] That is, if the sum of the opening amount of the gap and the depth of the groove of the vent hole 803 is equal to or less than the allowable maximum value corresponding to the type of molding material, the discharge of the molding material is suppressed, and air and gas can be discharged from the gap and the vent hole 803. In Figure 7 the example shown, if the allowable maximum value corresponding to the type of molding material is 30 μm or less, the discharge of the molding material from the mold device 800 is suppressed.

[0144] Therefore, the control device 700 according to the present embodiment adjusts the clamping force so that the sum of the opening amount of the gap and the depth of the groove of the vent hole 803 becomes equal to or less than the allowable maximum value.

[0145] Returning to Figure 3 , the allowable maximum value storage unit 721 of the storage medium 702 stores the allowable maximum value of each molding material used in the injection molding machine 10. Figure 8 is a diagram showing the table structure of the allowable maximum value storage unit 721 according to the present embodiment. As Figure 8 shown, the allowable maximum value storage unit 721 stores the molding material (type) in correspondence with the allowable maximum value. For example, the allowable maximum value of the molding material "ABS" is 0.03 mm (= 30 μm). Therefore, in the case of using the molding material "ABS", in Figure 7 the example shown, if the depth of the groove of the vent hole 803 is 20 μm and the opening amount is 10 μm, the sum of the opening amount of the gap and the depth of the groove of the vent hole 803 becomes 30 μm, so that the discharge of the molding material "ABS" from the cavity space 801 can be suppressed.

[0146] As Figure 8As shown, the allowable maximum values vary depending on the type or characteristics of the molding material. Furthermore, depending on the viscosity of the molding material (which depends on the type and temperature of the resin), the allowable maximum values for which burrs cannot be removed and gas burning does not occur also vary. In the case of a molding material with high viscosity and poor fluidity, the allowable maximum value becomes approximately 100 μm, and in the case of a low-viscosity resin, it becomes approximately 5 μm. The allowable maximum value changes according to the curing speed of the molding material in the cavity space 801 (i.e., the temperature of the mold device 800, the temperature of the molding material (melt viscosity), the melting point of the molding material, the injection speed (shear heat, heat transfer from the resin to the mold), and the speed during holding pressure), and thus is not constant under all conditions. However, in the present embodiment, as approximately consistent content, the value shown in Figure 8 is used.

[0147] Return to Figure 3 , and the acquisition unit 713 acquires the detection results of the sensors provided in the injection molding machine 10 from the injection molding machine 10. Further, the acquisition unit 713 acquires the information input by the user from the operation device 750.

[0148] Specifically, the acquisition unit 713 uses a clamping force detector such as the connecting rod strain detector 141 to acquire the actual value of the clamping force.

[0149] As Figure 9 shown, the connecting rod strain detector 141 detects a change in the effective length La of the connecting rod 140. The effective length La of the connecting rod 140 refers to the length of the portion where the connecting rod 140 extends according to the clamping force F. For example, the effective length La of the connecting rod 140 is the length of the portion between the fixed nut 111 and the adjusting nut 182 of the connecting rod 140.

[0150] The fixed nut 111 is screwed onto the lead screw shaft formed at the front end of the connecting rod 140 and is held so as not to be rotatable or retractable relative to the fixed platen 110. On the other hand, the adjusting nut 182 is screwed onto the lead screw shaft formed at the rear end of the connecting rod 140 and is held so as not to be rotatable or retractable relative to the toggle seat 130. By rotating the adjusting nut 182, the effective length La of the connecting rod 140 can be adjusted.

[0151] The effective length La of the connecting rod 140 changes according to the clamping force F. The connecting rod strain detector 141 detects the actual value of the clamping force by detecting the change in the length La. The acquisition unit 713 acquires the actual value of the clamping force from the connecting rod strain detector 141.

[0152] Next, the change in the clamping force of the injection molding machine 10 will be described. Figure 10 is a diagram showing the change in the clamping force when injecting a molding material in the injection molding machine 10 according to the present embodiment.

[0153] As Figure 10 shown, after the injection process starts, the actual value of the clamping force F stabilizes at the set value until the moment t0 when the molding material M reaches the parting surface 830 between the fixed mold 810 and the movable mold 820. During this period, as Figure 10 shown, the fixed mold 810 and the movable mold 820 are closed. In addition, in the present embodiment, the actual value of the clamping force F stabilizes at the set value, but sometimes the actual value of the clamping force F stabilizes at a value displaced from the set value.

[0154] In the present embodiment, the following clamping force is referred to as the reference clamping force: after the cavity space 801 is closed, until a force is applied in the direction opposite to the clamping force due to the internal pressure generated by the molding material filled in the cavity space 801.

[0155] After the injection process starts until the moment t0, the fixed mold 810 and the movable mold 820 are closed, and the actual value of the clamping force F stabilizes at the set value, in other words, stabilizes at the reference clamping force.

[0156] If at the moment t0 the molding material M reaches the parting surface 830 between the fixed mold 810 and the movable mold 820 and the filling pressure P1 is greater than the clamping pressure P2, then due to the filling pressure P1, the fixed mold 810 and the movable mold 820 open. As a result, as Figure 7 shown, a gap is formed between the fixed mold 810 and the movable mold 820. The effective length La of the connecting rod 140 increases by an amount corresponding to the size of this gap, and the actual value of the clamping force F increases compared to the reference clamping force.

[0157] Therefore, the increase amount ΔF of the actual value of the clamping force F corresponds to the size of the gap formed between the fixed mold 810 and the movable mold 820. That is, the larger the size of the gap becomes, the larger the increase amount ΔF becomes.

[0158] In the present embodiment, the maximum clamping force is referred to as the peak clamping force. In the Figure 10 example shown, at the moment t2, the actual value of the clamping force detected by the connecting rod strain detector 141 becomes the peak clamping force.

[0159] The control device 700 according to the present embodiment adjusts the reference clamping force so that even when the mold device 800 is opened by the peak clamping force, the molding material is not discharged from the mold device 800.

[0160] Therefore, the acquisition unit 713 acquires information on the depth of the groove (an example of a gap) of the vent hole 803 of the mold device 800 installed in the injection molding machine 10 (an example of the gap amount indicating the size of the gap). Information indicating the depth of the groove of the vent hole 803 can be input and accepted by the user, for example. These are examples of the gap amount. Instead of using the size of the gap itself such as dimensions, parameters calculated by substituting a quantity related to the size of the gap into a specified function, surrogate variables related to the size of the gap, etc. can be used.

[0161] In addition, when adjusting the clamping force, the acquisition unit 713 refers to the allowable maximum value storage unit 721 and acquires the allowable maximum value corresponding to the type of molding material used in the injection molding machine 10. Further, the acquisition unit 713 can accept, for example, the type of molding material used in the injection molding machine 10 as an input from the user. Also, the acquisition unit 713 can acquire the allowable maximum value input by the user without referring to the allowable maximum value storage unit 721.

[0162] Moreover, the adjustment unit 714 adjusts the reference clamping force of the clamping device 100 so as to suppress the sum of the opening amount between the fixed mold 810 and the movable mold 820 and the depth of the groove of the vent hole 803 from becoming greater than the allowable maximum value when injecting the molding material into the mold device 800 closed by the clamping device 100. In addition, in the present embodiment, an example of the allowable amount, i.e., the maximum value of the size of the gap, an example of the opening amount, i.e., the opening amount between the fixed mold 810 and the movable mold 820, and an example of the gap amount, i.e., the depth of the groove of the vent hole 803, are all represented by metric values in the SI unit system. Therefore, in the present embodiment, the adjustment unit 714 simply compares the sum of the opening amount between the fixed mold 810 and the movable mold 820 and the depth of the groove of the vent hole 803 with the allowable maximum value, but is not limited to the result of simply comparing the conditions for adjusting the reference clamping force. For example, a coefficient can be used to weight any one or more of the opening amount and the depth of the groove, or a result calculated by substituting any one or more of the opening amount and the depth of the groove into a function, etc. can be used. The values based on the gap amount indicating the size of the gap and the opening amount indicating the size of the gap between the fixed mold 810 and the movable mold 820 can be adjusted so as to satisfy the conditions based on the allowable amount.

[0163] For example, when using ABS resin, as Figure 8 shown, the allowable maximum value becomes 30 μm. When the depth of the groove of the vent hole of the mold device 800 is 20 μm, even if the fixed mold 810 and the movable mold 820 are opened by 10 μm, burrs will not be generated. On the other hand, when the depth of the groove of the vent hole of the mold device 800 is 10 μm, even if it is opened by 20 μm, burrs will not be generated.

[0164] Therefore, specifically, the adjustment unit 714 adjusts the clamping force of the mold clamping device 100 to suppress the sum of the opening amount corresponding to the peak clamping force and the depth of the groove of the vent hole from becoming greater than the allowable maximum value.

[0165] The relationship between the stress σ generated in the connecting rod 140 and the strain amount ε generated in the connecting rod 140 can be expressed by Equation (1). In addition, the Young's modulus of the connecting rod 140 is set to E. The stress σ is the stress at the highest clamping force, that is, the peak clamping force. The opening amount corresponding to the peak clamping force is set to ΔL, and the effective length of the connecting rod 140 is set to La.

[0166] σ = Eε = E·ΔL / La ……(1)

[0167] The stress σ can be expressed as Fd / A. In addition, the force Fd is set to the difference between the peak clamping force and the reference clamping force. The area A is set to the total cross-sectional area of the connecting rod 140 (in the case of 4 connecting rods, it is the cross-sectional area of each connecting rod × 4). Thus, Equation (2) can be derived.

[0168] Fd / A = E·ΔL / La ……(2)

[0169] As shown in Equation (2), the change amount of the clamping force during injection molding of the material, that is, the force Fd which is the difference between the peak clamping force and the reference clamping force, corresponds to the opening amount ΔL of the mold device 800.

[0170] Therefore, the adjustment unit 714 according to the present embodiment adjusts the reference clamping force based on the change amount (the force Fd which is the difference between the peak clamping force and the reference clamping force) of the actual value of the clamping force detected by the connecting rod strain detector 141 during injection molding of the material, so that the clamping force based on the opening amount ΔL can be adjusted.

[0171] From Equation (2), the opening amount ΔL of the mold device 800 can be calculated by "FdLa / AE". Moreover, the adjustment unit 714 according to the present embodiment determines whether the opening amount ΔL of the mold device 800 is an amount that can suppress the discharge of the molding material. Specifically, if the opening amount ΔL becomes less than or equal to L1 - L2, the discharge of the molding material can be suppressed. L1 is set to the allowable maximum value, and L2 is set to the depth of the groove of the vent hole 803 of the mold device 800. From the relationship between Equation (2) and "L1 - L2", Equation (3) can be derived.

[0172] L1 - L2 ≥ ΔL = FdLa / AE ……(3)

[0173] Equation (4) shown below is derived from Equation (3).

[0174] Fd ≤ (L1 - L2)AE / La ……(4)

[0175] When the force Fd of the difference between the peak clamping force and the reference clamping force satisfies Equation (4), the opening amount ΔL becomes an opening amount that can suppress the discharge of the molding material. In other words, as long as the adjustment unit 714 determines whether Equation (4) is satisfied, it can determine whether the opening amount ΔL is an opening amount that suppresses the discharge of the molding material.

[0176] If the reference clamping force is increased, the difference in the force Fd of the difference between the peak clamping force and the reference clamping force will become smaller. If the reference clamping force is decreased, the difference in the force Fd of the difference between the peak clamping force and the reference clamping force will become larger.

[0177] That is, when Equation (4) is not satisfied, the adjustment unit 714 only needs to set the reference clamping force to be increased. In this way, the adjustment unit 714 repeatedly adjusts the reference clamping force to satisfy Equation (4). Thereby, the reference clamping force can be set to suppress the generation of burrs.

[0178] Moreover, the adjustment unit 714 according to the present embodiment also adjusts the reference clamping force so that the force Fd of the difference between the peak clamping force and the reference clamping force approaches (L1 - L2)AE / La.

[0179] That is, by setting the reference clamping force high, the force Fd of the difference between the peak clamping force and the reference clamping force becomes smaller, so Equation (4) can be satisfied. However, when the reference clamping force is high, the mold device 800 is not easily opened. That is, the control device 700 adjusts the reference clamping force to be lower on the basis of satisfying Equation (4), whereby air and gas can be discharged from the gap when the mold device 800 is opened, and the discharge of the molding material from the vent hole 803 of the mold device 800 can be suppressed.

[0180] For example, as Figure 7 shown, as the force Fd of the difference between the peak clamping force and the reference clamping force approaches (L1 - L2)AE / La, the gap between the fixed mold 810 and the movable mold 820 gradually opens, and air and gas are discharged from the gap, but the discharge of the molding material becomes a suppressed state. That is, the leakability of air and gas is improved, and burrs can be suppressed.

[0181] Therefore, the adjustment unit 714 according to the present embodiment adjusts the clamping force of the clamping device 100 so that the sum of the opening amount and the depth of the groove of the vent hole 803 becomes greater than the allowable maximum value and approaches the allowable maximum value.

[0182] Actually, not limited to the determination of conditions such as the comparison between the sum of the opening amount and the depth of the groove of the vent hole 803 and the allowable maximum value as described above, for example, calculations can also be performed using coefficients or the like as in Equation (4). This is because due to flexure or the like caused by the structure of the injection molding machine 10, the actual opening amount is greater than the opening amount ΔL corresponding to the peak clamping force. Therefore, the adjustment unit 714 adjusts the reference clamping force on the basis of considering the allowable error (coefficient) corresponding to the injection molding machine 10, the mold device 800, etc. Regarding the setting of the allowable error (coefficient), for example, it can be input by the user. In the present embodiment, as the setting related to the allowable error (coefficient), the parameter "sensitivity" is used.

[0183] The adjustment unit 714 according to the present embodiment calculates the force Fd of the difference between the peak clamping force and the reference clamping force for each injection from the actual value of the clamping force derived from the connecting rod strain detector 141. Moreover, when the force Fd of the difference between the calculated peak clamping force and the reference clamping force is included within the target range (an example of a specified range), the adjustment of the reference clamping force is ended. In addition, the target range is determined according to (L1 - L2)AE / La and the sensitivity described later. Regarding the specific method for setting the target range, it will be described later.

[0184] If the difference between the peak clamping force and the reference clamping force is not included within the target range, the adjustment unit 714 adjusts the reference clamping force.

[0185] The output control unit 715 outputs information to an external device. For example, the output control unit 715 outputs a display screen to the display device 760.

[0186] The log information processing unit 716 performs processing related to log information. For example, the log information processing unit 716 can determine whether an abnormality has occurred based on the log information.

[0187] Figure 11 is a diagram showing an example of the setting screen output by the output control unit 715 according to the present embodiment to the display device 760. As Figure 11 shown, in the setting screen 2100, a selection column 2101 for the type of molding material, an allowable maximum value display column 2102, a setting column 2103 for the maximum ventilation depth of the mold device, a sensitivity selection column 2104, an adjustment switch selection column 2105, and a display column 2106 for the calculated value of the gap during the most recent molding are displayed.

[0188] The selection column 2101 for the type of molding material is, for example, a drop-down menu, and can display a list of the types of molding materials in a selectable manner. In Figure 11 the example shown, the user accepts the selection of "ABS".

[0189] The allowable maximum value display bar 2102 is allowed to display, through the output control unit 715, the allowable maximum value corresponding to the type of molding material selected in the molding material type selection bar 2101. The allowable maximum value can be derived from the type of molding material selected and the allowable maximum value storage unit 721.

[0190] In addition, when no selection of the molding material is made in the molding material type selection bar 2101, the allowable maximum value display bar 2102 can become a text input bar, enabling the user to directly input the allowable maximum value.

[0191] The maximum venting depth setting bar 2103 of the mold device is a text input bar that can be input by the user, and the user accepts the input of the maximum depth of the groove of the vent hole 803 provided in the mold device 800.

[0192] The sensitivity selection bar 2104 is, for example, a drop-down menu that accepts the selection for setting the sensitivity of the reference clamping force. The sensitivity is a parameter used to derive the allowable error (coefficient) of the mold device 800 installed in the injection molding machine 10. The sensitivity can be selected from, for example, "high", "medium", and "low". The allowable error increases in the order of "high", "medium", and "low". For example, when the mold device 800 has high precision and sufficient thickness (in other words, is not easily deformed), "high" can be set; when the mold device 800 has low precision and is thin (in other words, is easily deformed), "low" can be set.

[0193] Moreover, the adjustment unit 714 sets the target range based on the selected sensitivity and (L1 - L2)AE / La. In addition, the method for setting the target range is not limited to the method shown below, as long as an appropriate target range can be set according to the characteristics of the mold device 800, etc.

[0194] For example, when the selection of "high" is made, the adjustment unit 714 sets the range from "(L1 - L2)AE / La" × 0.8 to "(L1 - L2)AE / La" × 0.95 as the target range.

[0195] For example, when the selection of "medium" is made, the adjustment unit 714 sets the range from "(L1 - L2)AE / La" × 0.6 to "(L1 - L2)AE / La" × 0.90 as the target range.

[0196] For example, when the selection of "low" is made, the adjustment unit 714 sets the range from "(L1 - L2)AE / La" × 0.4 to "(L1 - L2)AE / La" × 0.80 as the target range.

[0197] The adjustment switch selection bar 2105 is, for example, a drop-down menu that accepts a selection of whether to adjust the reference clamping force. For example, either "on" or "off" can be selected. When the selection of "on" is accepted, the control device 700 adjusts the reference clamping force. When the selection of "off" is accepted, the control device 700 suppresses the adjustment of the reference clamping force.

[0198] The display column 2106 for the calculated value of the clearance during recent molding displays the calculated value of the clearance of the mold device 800 calculated based on the actual value of the clamping force detected by the connecting rod strain detector 141 and the maximum depth of the groove of the vent hole 803 during the most recent injection molding.

[0199] For example, each time injection molding is performed, the adjustment unit 714 derives "FdLa / AE + L2" as the calculated value of the clearance of the mold device 800, and the output control unit 715 outputs the calculated value of the clearance of the mold device 800 to the display column 2106 for the calculated value of the clearance during recent molding.

[0200] In addition, Figure 11 An example of the setting screen is shown, but it is not limited to this display item and display method. As a display item, for example, the allowable opening amount obtained by subtracting the maximum depth of the groove of the vent hole 803 from the allowable maximum value can be displayed. The allowable opening amount is calculated by the adjustment unit 714, for example, each time a charge is injected.

[0201] Next, the steps of the process for adjusting the reference clamping force executed by the control device 700 according to the present embodiment will be described. Figure 12 It is a flowchart showing the steps of the process for adjusting the reference clamping force executed by the control device 700 according to the present embodiment.

[0202] First, the output control unit 715 outputs the setting screen to the display device 760 (S2201). As a result, the Figure 11 shown setting screen 2100 is displayed.

[0203] The acquisition unit 713 determines whether a selection of the type of molding material has been accepted from the selection column 2101 for the type of molding material on the setting screen 2100 (S2202). When it is determined that the selection has been accepted (S2202: yes), the acquisition unit 713 refers to the allowable maximum value storage unit 721 to determine the allowable maximum value corresponding to the type of molding material for which the selection has been accepted (S2203). Then, the output control unit 715 displays the specified allowable maximum value in the allowable maximum value display column 2102.

[0204] When it is determined that the selection of the type of molding material on the setting screen has not been accepted (S2202: No), the acquisition unit 713 determines the value entered with respect to the allowable maximum display column 2102 as the allowable maximum value (S2204).

[0205] The acquisition unit 713 receives the selection of sensitivity from the sensitivity selection column 2104 (S2205).

[0206] Based on the allowable maximum value, the maximum depth of the groove of the vent hole of the mold device 800, and the sensitivity, the adjustment unit 714 calculates the target range of the difference between the reference clamping force and the peak clamping force (S2206). Since the calculation method of the target range is as described above, the description is omitted.

[0207] Then, the acquisition unit 713 determines whether the selection of "ON" has been accepted with respect to the adjustment switch selection column 2105 (S2207). In a state where the selection of "ON" has not been accepted, in other words, the selection of "OFF" has been accepted (S2207: No), it waits until the selection of "ON" is accepted.

[0208] When the acquisition unit 713 determines that the selection of "ON" has been accepted with respect to the adjustment switch selection column 2105 (step S2207: "Yes"), the control device 700 performs injection molding using the set reference clamping force (step S2208). In addition, at the first time, an initial value is set as the reference clamping force. In addition, the initial value can be any value corresponding to the embodiment.

[0209] The adjustment unit 714 calculates the differential force Fd between the reference clamping force and the peak clamping force from the actual value of the clamping force detected by the connecting rod strain detector 141 (step S2209). At this time, the adjustment unit 714 also calculates the calculated value of the gap of the mold device 800. Moreover, the output control unit 715 displays the calculated value of the gap of the mold device 800 in the display column 2106 of the gap calculated value at the most recent molding.

[0210] Then, the adjustment unit 714 determines whether the calculated differential force Fd is included in the target range (S2210).

[0211] When it is determined that the calculated differential force Fd is not included in the target range (S2210: No), the adjustment unit 714 determines whether the calculated differential force Fd is less than the lower limit value of the target range (S2210). When it is determined that it is less than the lower limit value of the target range (S2210: Yes), the reference clamping force is reduced by a specified value (for example, 10 kN) (S2211).

[0212] On the other hand, in the case where the calculated differential force Fd is not less than the lower limit value of the target range, that is, not less than the target range and not included in the target range and is determined to be greater than the upper limit value of the target range (S2210: No), the adjustment unit 714 increases the reference clamping force by a specified value (for example, 10 kN) (S2212).

[0213] After the processing of S2211 or S2212, the control device 700 performs injection molding again using the set reference clamping force (S2208). The subsequent processing is as described above, and the processing of S2209 is performed.

[0214] On the other hand, in S2210, in the case where it is determined that the calculated differential force Fd is included in the target range (S2210: Yes), the adjustment unit 714 regards the adjustment of the reference clamping force as completed and ends the processing.

[0215] After the adjustment of the reference clamping force is completed by the above processing, the control device 700 according to the present embodiment performs injection molding using the reference clamping force. At this time, the opening amount of the mold device 800 can be monitored. The setting for monitoring can also be made for the log information screen.

[0216] In the present embodiment, the following case has been described: when the selection of "ON" is accepted with respect to the adjustment switch selection column 2105 in the Figure 11 setting screen 2100, the reference clamping force is adjusted according to whether the differential force Fd between the reference clamping force and the peak clamping force is included in the target range. However, the present embodiment is not limited to the method of adjusting the reference clamping force only when the selection of "ON" is accepted with respect to the adjustment switch selection column 2105. For example, even in the case where there is no adjustment switch selection column 2105, the reference clamping force can be automatically adjusted according to whether the differential force Fd between the reference clamping force and the peak clamping force is included in the target range.

[0217] As a further modification example, when the force Fd which is the difference between the reference clamping force and the peak clamping force is not included in the target range, the output control unit 715 outputs an inquiry screen for whether the reference clamping force can be changed to the display device 760. In the inquiry screen, a "Determine" button and a "Cancel" button are displayed together with the current reference clamping force and an inquiry message on whether the current reference clamping force can be changed. Moreover, when the acquisition unit 713 receives the pressing of the "Determine" button by the user via the operation device 750, the adjustment unit 714 adjusts the reference clamping force. The method for adjusting the reference clamping force is the same as the above method, and thus the description thereof is omitted. On the other hand, when the acquisition unit 713 receives the pressing of the "Cancel" button by the user via the operation device 750, the process for adjusting the reference clamping force based on the adjustment unit 714 ends, and the current reference clamping force is maintained. In this modification example, the reference clamping force is adjusted only when the user has received permission, and thus incorrect adjustment of the reference clamping force can be suppressed, and improvement in the quality of the molded product can be achieved.

[0218] Returning to the embodiment, Figure 13 FIG. is an example of a log information screen output by the output control unit 715 according to the present embodiment. In Figure 13 the log information screen shown displays log information related to injection molding. Moreover, in the log information screen, the log information processing unit 716 can perform settings for storing log information.

[0219] In Figure 13 the log information screen 2300 shown, a total number 2311, a qualified product quantity 2312, a non-conforming quantity 2313, a scrap quantity 2314, a record button 2315, a monitoring setting button 2316, a save button 2317, an update button 2318, a statistical overview 2320, and an actual overview 2330 are shown.

[0220] The statistical overview 2320 displays statistical information (e.g., average, range, maximum, minimum, standard deviation) for each setting column 2321 to 2327. The content displayed in the setting columns 2321 to 2327 can be set by the user. In the present embodiment, with respect to the items displayed in the setting columns 2321 to 2327, display, monitoring, and saving of log information can be performed. In addition, the monitoring in the present embodiment determines whether it is a qualified product based on a specified criterion.

[0221] The statistical information is information calculated based on actual values (an example of parameters) obtained each time a molded product is manufactured by injection molding in the injection molding machine 10. For example, in the statistical overview 2320, it includes the average, range, maximum, minimum, and standard deviation calculated for each setting column 2321 to 2327. In addition, this embodiment shows an example of statistical information, and it can also be statistical information other than the average, range, maximum, minimum, and standard deviation, such as an integral value, etc. Moreover, the items that are the objects of calculating the statistical information are not limited to the items set in the setting columns 2321 to 2327, and other items can also be used.

[0222] The output control unit 715 calculates statistical information based on actual values (an example of parameters) obtained by various sensors through injection molding within the range shown in the actual overview 2330. Moreover, the output control unit 715 displays the calculated statistical information on the statistical list 2320.

[0223] The "monitoring", "monitoring value", and "range" in the statistical overview 2320 are set as information for determining whether the molded product in this setting column is non-conforming.

[0224] It is shown as follows: When the monitoring in the statistical overview 2320 is "off", the control device 700 does not perform monitoring. When the monitoring in the statistical overview 2320 is "on", the control device 700 performs monitoring. In the case of "on", the control device 700 determines whether the measured actual value in the item shown in this setting column satisfies the criteria shown in the "monitoring value" and "range" (for example, whether the "monitoring value" is included within the "range" as the median). As another example, the control device 700 can use the set monitoring value as the central value and determine whether it satisfies the criteria based on the set positive tolerance and negative tolerance or whether it satisfies the criteria of the set upper limit value and lower limit value. In addition, any method can be used for the monitoring method of the actual value, without being limited to the above method. The switching of this monitoring is performed through the monitoring setting button 2316.

[0225] The "non-conforming" in the statistical overview 2320 indicates the number of molded products that do not satisfy the criteria shown in the "monitoring value" and "range".

[0226] The "cycle time" in the setting column 2321, the "fill time" in the setting column 2322, and the "metering time" in the setting column 2323 are items set for monitoring the time required for the cycle, filling, and metering.

[0227] The "V-P switching position" in the setting column 2324 is an item set for monitoring the position (V / P switching position) of the screw 330 when switching from the filling process to the holding pressure process.

[0228] The "maximum clearance" in the setting column 2325 is an item set to monitor the maximum clearance of the die device 800 (the sum of the maximum depth of the groove of the vent hole 803 of the die device 800 and the opening amount corresponding to the peak clamping force).

[0229] For example, the output control unit 715 displays the value of "FdLa / AE + L2" calculated by the adjustment unit 714 as a value representing the sum of the maximum depth of the groove of the vent hole 803 and the opening amount corresponding to the peak clamping force in the setting column 2325. In addition, "FdLa / AE + L2" is based on the above formula (3).

[0230] The "filling peak pressure" in the setting column 2326 is an item set to monitor the peak value of the pressure when the molding material is filled.

[0231] The "opening amount" in the setting column 2327 is an item set to monitor the opening amount corresponding to the peak clamping force.

[0232] For example, the output control unit 715 displays the value of "FaLa / AE" calculated by the adjustment unit 714 as a value representing the opening amount corresponding to the peak clamping force in the setting column 2327. In addition, "FaLa / AE" is based on the above formula (3).

[0233] In addition, the setting columns 2321 to 2327 can be changed to items that the user wishes to monitor. The description of the change method is omitted.

[0234] For example, in the "maximum clearance" of the setting column 2325, the monitoring is set to "on", so the log information processing unit 716 monitors whether an abnormality occurs. In Figure 13 In the example shown, the monitoring value "30.00" is set as the allowable maximum value. Moreover, the log information processing unit (an example of a processing unit) 716 monitors whether the "maximum clearance" (the sum of the opening amount and the maximum depth of the groove of the vent hole 803) is greater than the monitoring value "30.00" (an example of the allowable amount). For example, the log information processing unit 716 determines that an abnormality has occurred when the "maximum clearance" is greater than the monitoring value "30.00". Moreover, when the "maximum clearance" calculated in each injection is greater than the monitoring value "30.00", the log information processing unit 716 regards it as a possible burr generation and counts it as a defective product.

[0235] As another example, in the "opening amount" of the setting column 2327, the monitoring is set to "on", so the log information processing unit 716 determines whether an abnormality has occurred. In Figure 13In the example shown, the monitoring value "20.00" is set as the maximum opening amount of the mold device 800. For example, the log information processing unit 716 monitors whether the "opening amount" is greater than the monitoring value "20.00". For example, the log information processing unit 716 determines that it is abnormal when the "opening amount" is greater than the monitoring value "20.00". Moreover, when the "opening amount" calculated in each injection is greater than the monitoring value "20.00", the log information processing unit 716 regards it as a possible burr generation and counts it as a defective product.

[0236] In Figure 13 for illustration, an example is shown in which the "maximum clearance" and the "opening amount" are set in the setting column, but it is not limited to the method of setting the "maximum clearance" and the "opening amount", and only either the "maximum clearance" or the "opening amount" can be set.

[0237] The actual list 2330 shows a list of the setting information (for example, set values) in the items set in the setting columns 2321 to 2327 at each injection or the actual values measured by various sensors. The items set in the setting columns 2321 to 2327 are set to "CH1" to "CH7". And at each injection, as information indicating the injection, the "injection number", the "time" of injection molding, and the "discrimination" of injection molding are associated.

[0238] The record button 2315 is a button for accepting the selection of whether to save the actual values shown in the actual list 2330 as log information. When the record button 2315 (displayed as "Data recording on") is pressed, the log information processing unit 716 saves the information shown in the actual list 2330 (for example, the actual values based on various sensors) as log information in the storage medium 702.

[0239] That is, in the present embodiment, the maximum value of the clearance of the mold device 800 at each injection (the sum of the maximum depth of the groove of the vent hole 803 of the mold device 800 and the opening amount corresponding to the peak clamping force) and the opening amount corresponding to the peak clamping force, etc. can be saved as log information in the storage medium 702.

[0240] The monitoring setting button 2316 is a button for accepting whether to monitor according to the monitored items in the statistical list 2320. When the monitoring setting button 2316 (displayed as "Monitoring on") is pressed, it monitors whether it is a defective product at each injection and includes the monitoring result in the log information. When the monitoring setting button 2316 is pressed, the monitoring of each of the setting columns 2321 to 2327 in the statistical list 2320 can be switched between "off" and "on".

[0241] The save button 2317 is a button for accepting whether to save the statistical values (such as average, range, maximum, minimum, standard deviation, etc.) of each setting column 2321 - 2327. When the save 2317 is pressed, the log information processing unit 716 saves the statistical value of each of the setting columns 2321 - 2327 and the actual values shown in the actual list 2330 as log information in the storage medium 702. In the present embodiment, an example of saving statistical values and actual values is described, but it is not limited to saving statistical values and actual values. For example, when a setting is displayed in the actual list 2330, the log information processing unit 716 may also save the set value together. Further, even if the set value is not shown in the actual list 2330, the log information processing unit 716 may save the set value in association with the actual values shown in the actual list 2330.

[0242] The update button 2318 is a button for accepting whether to update the statistical list 2320 and the actual list 2330 each time the injection molding of the injection molding machine 10 is completed. When the update button 2318 (displaying "always") is pressed, the statistical list 2320 and the actual list 2330 are updated each time the injection molding of the injection molding machine 10 is completed.

[0243] The total number 2311 represents the number of molded products molded in the injection molding machine 10. The number of qualified products 2312 represents the number of molded products determined to be qualified according to "monitoring", "monitoring value", and "range". The number of unqualified products 2313 represents the number of molded products determined to be unqualified according to "monitoring", "monitoring value", and "range". The number of scrap products 2314 represents the number of molded products set as scrap.

[0244] As described above, when the output control unit 715 of the control device 700 produces a molded product from a molding material by the injection molding machine 10, the actual values (an example of the detection result) detected by various sensors in the process of producing the molded product are displayed in the actual list 2330 of the display device 760 for each such molded product.

[0245] For example, in the actual list 2330, "CH5" corresponds to "maximum clearance". That is, in the "CH5" column 2331 of the actual list 2330, the maximum value of the clearance of the mold device 800 (the sum of the maximum depth of the groove of the vent hole 803 of the mold device 800 and the opening amount corresponding to the peak clamping force) is displayed as the actual value for each injection of the material.

[0246] As another example, "CH7" in the actual list 2330 corresponds to "opening amount". That is, in the "CH7" column 2332 of the actual list 2330, the opening amount of the mold device 800 when the peak clamping force is detected is displayed as the actual value for each injection of the material.

[0247] Furthermore, when the record button 2315 is pressed, the log information processing unit 716 stores the information shown in the actual list 2330 (for example, actual values ​​based on various sensors) as log information in the storage medium 702, so that the maximum value of the gap of the mold device 800 and the opening amount of the mold device 800 when the peak mold clamping force is detected are stored as log information in the storage medium 702. Therefore, the opening amount of the mold device 800 can be managed for each molded product.

[0248] exist Figure 13 In the log information screen 2300 shown, the "maximum gap value" and the "opening amount" are displayed for each shot, so that the user can visually recognize whether there is a possibility of burrs being generated in the molded product.

[0249] The screen used by the output control unit 715 for monitoring is not limited to Figure 13 The log information screen is shown.

[0250] Figure 14 2 is a diagram illustrating an example of a gap amount display screen output by the output control unit 715 according to the present embodiment. Figure 14 The gap amount display screen shown shows the gap amount per shot represented by line 2401. The gap amount per shot is the sum of the maximum depth of the groove of the vent hole 803 of the mold device 800 and the opening amount corresponding to the peak clamping force.

[0251] Furthermore, in the gap amount display screen, a threshold value 2402 serving as a reference for the molding material to be discharged from the mold device 800 can be set. Figure 14 In the example shown, "30.00" is set as the threshold value.

[0252] Then, the user can refer to the gap amount display screen to check in chronological order whether the waveform indicating the gap amount for each shot exceeds the threshold value 2402. That is, the user can recognize whether a defective product may be generated due to burrs at a certain timing.

[0253] In addition, the present embodiment describes an example in which the amount of change in the mold clamping force detected by the connecting rod strain detector 141 is calculated as an amount corresponding to the amount of opening between the fixed mold 810 and the movable mold 820 caused by the injection of the molding material. However, the present embodiment is not limited to the method of calculating the amount of opening between the fixed mold 810 and the movable mold 820 caused by the injection of the molding material as an amount corresponding to the amount of change in the mold clamping force detected by the connecting rod strain detector 141, and the detection result of other sensors (for example, a distance sensor capable of detecting the amount of opening) may also be used.

[0254] (Second embodiment)

[0255] In the above-described embodiment, an example in which the control device 700 of the injection molding machine 10 adjusts the clamping force of the mold device 800 has been described. However, the above-described embodiment is not limited to the method in which the control device 700 of the injection molding machine 10 adjusts the clamping force of the mold device 800. The second embodiment is an example managed by a group management device (an example of a control device) that controls a plurality of injection molding machines 10.

[0256] For example, in the case where the same-shaped mold devices 800 are used in a plurality of injection molding machines 10 and the same type of molding material is used, the group management device collectively adjusts the reference clamping force for each of the plurality of injection molding machines 10. For example, the group management device uses any one of the plurality of injection molding machines 10 to perform the same control as in the above-described embodiment.

[0257] In the present embodiment, since the group management device collectively adjusts the reference clamping force for each of the plurality of injection molding machines 10, the work load can be reduced.

[0258] <Function>

[0259] The control device 700 according to the present embodiment performs the above-described processing. Therefore, by the user selecting the type of molding material or inputting the allowable maximum value and inputting the maximum depth of the groove of the vent hole of the mold device 800, even without confirming whether there are burrs in the molded product, the control device 700 can adjust to a reference clamping force at which air and gas are discharged and no burrs are generated. Therefore, the user does not need to confirm whether burrs are generated in the molded product and manually adjust the clamping force, so that the operation burden can be reduced.

[0260] Conventionally, it has been difficult for non-experts to adjust the reference clamping force. However, in the present embodiment, by the control device 700 performing the above-described processing, the quality of the molded product can be made the same regardless of whether the user is an expert. Therefore, it is possible to improve the quality of the molded product.

[0261] The control device 700 according to the present embodiment can adjust the amount of clearance generated on the parting surface 830 of the mold device 800 during filling to a level at which air and gas can be discharged but the molding material cannot be discharged by adjusting the reference clamping force to be within a target range. Therefore, air and gas are easily discharged from the clearance generated on the parting surface 830, so that it is possible to suppress the concentration of air and gas discharge in the vent hole 803. Therefore, it is possible to reduce the generation of mold deposits in the vent hole 803, so that the time for closing the vent hole 803 can be extended. Therefore, the interval for cleaning the mold device 800 can be extended. Therefore, the work efficiency can be improved and the cleaning burden can be reduced.

[0262] As a method for detecting the opening amount of a mold device, there is a method of providing a sensor that can detect the clearance amount of the parting surface between the movable mold and the fixed mold of the mold device. Further, a method can be considered in which the control device adjusts the clearance amount of the mold device based on the detection result of the sensor. In the case of using this method, it is necessary to provide the same number of sensors as the number of mold devices. In addition, when replacing the sensor of the mold device, it is necessary to adjust the sensor, so there is a burden and time required for adjustment. Further, since the injection molding machine vibrates due to injection molding or opening / closing of the mold device, positional deviation between the mold device and the sensor, that is, deviation of the detection result, may occur.

[0263] In contrast, in the above-described embodiment, since the link strain detector 141 is provided on the link 140, there is no need to re-set and re-adjust the sensor when replacing the mold device 800. Further, since the strain amount of the link 140 is detected, the influence of deviation caused by vibration can be reduced. Therefore, the work burden on the user can be reduced, and errors during vibration can be suppressed. Therefore, the detection accuracy can be improved, and thus defective molding can be suppressed.

[0264] Further, a method of calculating the opening amount of the parting surface of the mold device based on the filling pressure of the mold device can also be considered. When calculating the opening amount of the parting surface of the mold device using the filling pressure, there are many factors that determine the magnitude of the filling pressure, and generally there is no direct relationship with the opening amount of the mold device. As factors that determine the magnitude of the filling pressure, there are the average temperature of the molding material, the magnitude of temperature unevenness of the molding material, the density of the molding material, the temperature of the cavity / runner portion of the mold device, the closed state during screw filling, the amount of drooling before injection, and the like. Due to these factors, the viscosity of the filled resin or the pressure loss easily changes, and as a result, the filling pressure changes. Further, a factor that adds the rigidity of the clamping device and the rigidity of the mold device becomes the clearance amount of the parting surface of the mold device. When these factors change, a difference occurs between the force applied to the cavity space and the filling pressure. Therefore, when calculating the opening amount based on the filling pressure, it can be considered that the error becomes large.

[0265] In contrast, the control device 700 according to the above-described embodiment calculates the clearance amount of the parting surface 830 of the mold device 800 based on the strain amount of the link 140. In this method, compared with the filling pressure, there are fewer factors and less deviation is likely to occur, so that it is possible to improve the accuracy of adjusting the reference clamping force.

[0266] In addition, a method of setting a pressure sensor in the cavity space and adjusting the reference clamping force based on the detection result of the pressure sensor can also be considered. However, depending on the molding material, the temperature in the cavity space can approach 200°C, so there are fewer types of sensors that can be used. Furthermore, since it repeatedly becomes a high-pressure state during injection molding, the risk of abnormalities in the pressure sensor increases in such a high-load environment. When the pressure sensor fails, in order to remove the pressure sensor and install a new one, the mold device needs to be disassembled. Therefore, there is a need for workload and working time. Also, since a pressure sensor needs to be provided for each mold device, the cost of the mold device becomes high.

[0267] In contrast, the control device 700 according to the present embodiment uses the detection result of the link strain detector 141. Therefore, even when there are multiple mold devices 800, it can be measured by one link strain detector 141 installed in the injection molding machine 10, so the cost can be reduced. Also, since the link strain detector 141 is installed on the link 140, the load of temperature and pressure can be reduced compared to the case of using a pressure sensor, so the risk of abnormalities can be reduced and replacement can be easily performed. Therefore, since abnormalities can be suppressed and the detection accuracy can be improved, molding defects can be suppressed from occurring. Also, since replacement can be easily performed, the workload can be reduced.

[0268] The control device 700 according to the present embodiment calculates the amount of clearance generated on the parting surface 830 in consideration of the maximum depth of the groove of the vent hole 803. Since the maximum depth of the groove of the vent hole 803 and the amount of clearance are in the unit of the same distance, there is no need for conversion or calculation, and errors caused by conversion or calculation can be suppressed, so an improvement in accuracy can be achieved. That is, it is possible to improve the accuracy when adjusting the reference clamping force that can suppress the discharge of the molding material and can discharge air and gas in consideration of the depth of the groove of the vent hole 803. That is, the control device 700 according to the present embodiment can adjust the reference clamping force, for example, in either the case where the mold device 800 is not provided with the vent hole 803 or the case where the mold device 800 is provided with a vent hole 803 having a depth close to the upper limit of the allowable maximum value.

[0269] As described above, the embodiments of the control device of the injection molding machine according to the present invention have been described, but the present invention is not limited to the above embodiments and the like. Various changes, corrections, replacements, additions, deletions, and combinations can be made within the scope described in the technical solution. Of course, these also fall within the technical scope of the present invention.

Claims

1. A control device for controlling an injection molding machine, wherein: The injection molding machine comprises: a mold device having a fixed mold and a movable mold; a mold clamping device for opening and closing the fixed mold and the movable mold; and an injection machine for injecting a molding material into the mold device, wherein the control device comprises: an acquisition unit that acquires an allowable amount that is allowed as the size of the gap between the fixed mold and the movable mold in order to suppress discharge of the molding material from the mold device when the molding material is injected into the mold device, and acquires a gap amount that indicates the size of the gap provided for discharging gas between the fixed mold and the movable mold; and An adjustment unit adjusts the clamping force of the clamping device in a manner that satisfies the condition based on the allowable amount based on an opening amount indicating the size of a gap between the fixed mold and the movable mold generated by the injection of the molding material and a value of the gap amount when the molding material is injected into the mold device that is closed by the clamping device.

2. The control device for an injection molding machine according to claim 1, wherein: The adjustment unit adjusts the mold clamping force of the mold clamping device on the mold device based on the values ​​of the opening amount and the gap amount so as to satisfy a condition based on the allowable amount and approach the allowable amount.

3. The control device for an injection molding machine according to claim 1 or 2, wherein: The acquisition unit acquires the mold clamping force from a detection result of a detection device provided on a connecting rod extended according to the mold clamping force, The adjustment unit adjusts the mold clamping force of the mold clamping device according to a change amount of the mold clamping force when the molding material is injected into the mold device.

4. The control device for an injection molding machine according to claim 1 or 2, wherein: The acquisition unit acquires the gap amount input from an operation device.

5. The control device for an injection molding machine according to claim 1 or 2, wherein: The acquisition unit acquires the allowable amount corresponding to the type of the molding material whose input is received.

6. The control device for an injection molding machine according to claim 1 or 2, further comprising: The output control unit outputs one or more of the allowable amount, the opening amount, and a value based on the opening amount and the gap amount to a display device.

7. The control device for an injection molding machine according to claim 1 or 2, further comprising: The processing unit monitors whether or not the value based on the opening amount and the gap amount satisfies the condition of the allowable amount every time the molding material is injected into the mold device closed by the mold clamping device.

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