Measuring device for injection molding machine, and injection molding machine

Abstract

To properly recognize an injection amount of a molding material.SOLUTION: A measuring device for an injection molding machine according to an embodiment of the present invention comprises: a measuring mechanism having a filling port capable of filling a molding material injected from an injection device of an injection molding machine, a discharge port capable of discharging the molding material, and a space connecting the filling port and the discharge port; and a control unit configured to calculate an amount of the molding material discharged from the discharge port, to calculate an amount of the molding material remaining in the space, and to calculate an amount of the molding material injected from the injection device to the filling port in an n-th injection (n is a natural number equal to or greater than 2) based on an amount of the molding material discharged from the discharge port by the n-th injection, an amount of the molding material remaining in the space after the n-th injection, and an amount of the molding material remaining in the space after an (n-1)-th injection.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This invention relates to a measuring device for an injection molding machine and to an injection molding machine. [Background technology]

[0002] Conventionally, to measure the amount of molding material filled into an injection molding machine, a common technique is to weigh the molded product, which is formed after the molding material has cooled and solidified in the mold device where it is filled, using a balance or similar device. However, this technique requires waiting for the material to cool and solidify, and weighing it using a balance or similar device is time-consuming.

[0003] In recent years, techniques have been proposed for injection molding machines to measure the amount of molding material (for example, the filling weight filled into the mold) before it cools and solidifies (for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 02-265724 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, Patent Document 1 is a technique for calculating the filling weight of the molding material filled into a mold device, and not a technique for calculating the amount of molding material injected from an injection device.

[0006] One aspect of the present invention provides a mechanism for calculating the amount of molding material injected from the injection device of an injection molding machine. [Means for solving the problem]

[0007] A measuring device for an injection molding machine according to one aspect of the present invention comprises: a measuring mechanism having a filling port into which molding material injected from the injection device of the injection molding machine can be filled; an outlet into which molding material can be discharged; and a space connecting the filling port and the outlet; and a control unit configured to calculate the amount of molding material discharged from the outlet, the amount of molding material remaining in the space, and to calculate the amount of molding material injected from the injection device into the filling port in the nth injection based on the amount of molding material discharged from the outlet in the nth injection, the amount of molding material remaining in the space after the nth injection, and the amount of molding material remaining in the space after the (n-1)th injection. [Effects of the Invention]

[0008] According to one aspect of the present invention, a technology is provided that can recognize variations in the amount of injection-molded material. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 shows the state of an injection molding machine upon completion of mold opening according to one embodiment. [Figure 2] Figure 2 shows the state of an injection molding machine during mold clamping according to one embodiment. [Figure 3] Figure 3 is an example of a measuring device for an injection molding machine according to the first embodiment. [Figure 4] Figure 4 is an enlarged view of the first region of Figure 3, showing the measurement mechanism according to the first embodiment. [Figure 5] Figure 5 is an enlarged view of the second region in Figure 3 of the measurement mechanism according to the first embodiment. [Figure 6] Figure 6 is a diagram showing the components of the information processing device according to the first embodiment in terms of functional blocks. [Figure 7] Figure 7 shows the changes in the measurement mechanism due to the filling of molding material by the injection device according to the first embodiment. [Figure 8] Figure 8 shows the PVT properties of the molding material according to the first embodiment. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings. Furthermore, the embodiments described below are illustrative and not limiting to the invention, and not all features or combinations thereof described in the embodiments are necessarily essential to the invention. In addition, identical or corresponding components in each drawing are denoted by the same or corresponding reference numerals, and their descriptions may be omitted.

[0011] Figure 1 shows the state of the injection molding machine when the mold opening is complete according to the first embodiment. Figure 2 shows the state of the injection molding machine when the mold is clamped 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 mold 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 in the Y-axis direction is called the operating side, and the positive side in the Y-axis direction is called the non-operating side.

[0012] As shown in Figures 1 and 2, the injection molding machine 10 includes a clamping device 100 for opening and closing the mold device 800, an ejector device 200 for ejecting the molded product formed in the mold device 800, an injection device 300 for injecting molding material into the mold device 800, a moving device 400 for moving the injection device 300 forward and backward relative to the mold device 800, a control device 700 for controlling each component of the injection molding machine 10, and a frame 900 for supporting each component of the injection molding machine 10. The frame 900 includes a clamping device frame 910 for supporting the clamping device 100 and an injection device frame 920 for supporting the injection device 300. The clamping device frame 910 and the injection device frame 920 are each installed on the floor 2 via leveling adjusters 930. The control device 700 is located in the internal space of the injection device frame 920. The components of the injection molding machine 10 will be described below.

[0013] (mold clamping device) In describing the mold clamping device 100, the direction of movement of the movable platen 120 when the mold is closed (for example, the positive X-axis direction) is described as forward, and the direction of movement of the movable platen 120 when the mold is open (for example, the negative X-axis direction) is described as backward.

[0014] The mold clamping device 100 performs mold closing, pressure increasing, mold clamping, pressure decreasing, and mold opening of the mold apparatus 800. The mold apparatus 800 includes a fixed mold 810 and a movable mold 820. The mold clamping device 100 is, for example, a horizontal type, and the mold opening and closing direction is horizontal. The mold clamping device 100 has a fixed platen 110 to which the fixed mold 810 is attached, a movable platen 120 to which the movable mold 820 is attached, and a moving mechanism 102 that moves the movable platen 120 relative to the fixed platen 110 in the mold opening and closing direction.

[0015] The fixed platen 110 is fixed to the clamping device frame 910. The fixed mold 810 is attached to the surface of the fixed platen 110 facing the movable platen 120.

[0016] The movable platen 120 is positioned to move freely in the mold opening and closing direction relative to the mold clamping device frame 910. Guides 101 are laid on the mold clamping device frame 910 to guide the movable platen 120. A movable mold 820 is attached to the surface of the movable platen 120 facing the fixed platen 110.

[0017] The moving mechanism 102 performs mold closing, pressure increasing, mold clamping, depressurization, 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 support 130 positioned at a distance from the fixed platen 110, a tie bar 140 connecting the fixed platen 110 and the toggle support 130, a toggle mechanism 150 that moves the movable platen 120 in the mold opening and closing direction relative to the toggle support 130, a mold clamping motor 160 that operates the toggle mechanism 150, a motion conversion mechanism 170 that converts the rotational motion of the mold clamping motor 160 into linear motion, and a mold thickness adjustment mechanism 180 that adjusts the distance between the fixed platen 110 and the toggle support 130.

[0018] The toggle support 130 is positioned at a distance from the fixed platen 110 and is mounted on the mold clamping device frame 910 so as to be movable in the mold opening and closing direction. The toggle support 130 may also be positioned so as to be movable along a guide laid on the mold clamping device frame 910. The guide for the toggle support 130 may be the same as the guide 101 for the movable platen 120.

[0019] In this embodiment, the fixed platen 110 is fixed to the clamping device frame 910, and the toggle support 130 is arranged to be movable relative to the clamping device frame 910 in the mold opening and closing direction. However, the toggle support 130 may be fixed to the clamping device frame 910, and the fixed platen 110 may be arranged to be movable relative to the clamping device frame 910 in the mold opening and closing direction.

[0020] The tie bars 140 connect the fixed platen 110 and the toggle support 130 at a distance L in the mold opening and closing direction. Multiple tie bars 140 (for example, four) may be used. Multiple tie bars 140 are arranged parallel to the mold opening and closing direction and stretch in accordance with the clamping force. At least one tie bar 140 may be provided with a tie bar strain detector 141 that detects the strain of the tie bar 140. The tie bar strain detector 141 sends a signal indicating its detection result to the control device 700. The detection result of the tie bar strain detector 141 is used for detecting the clamping force, etc.

[0021] In this embodiment, a tie bar strain detector 141 is used as a clamping force detector to detect the clamping force, but the present invention is not limited to this. The clamping force detector is not limited to strain gauge type, but may be piezoelectric, capacitive, hydraulic, electromagnetic, etc., and its mounting position is not limited to the tie bar 140.

[0022] The toggle mechanism 150 is positioned between the movable platen 120 and the toggle support 130, and moves the movable platen 120 in the mold opening and closing direction relative to the toggle support 130. The toggle mechanism 150 has a crosshead 151 that moves in the mold opening and closing direction, and a pair of link groups that bend and extend as the crosshead 151 moves. Each of the link groups has a first link 152 and a second link 153 that are bendable and extendable connected by a pin or the like. The first link 152 is pivotably attached to the movable platen 120 by a pin or the like. The second link 153 is pivotably attached to the toggle support 130 by a pin or the like. The second link 153 is attached to the crosshead 151 via a third link 154. When the crosshead 151 moves forward and backward relative to the toggle support 130, the first link 152 and the second link 153 bend and extend, and the movable platen 120 moves forward and backward relative to the toggle support 130.

[0023] Note that the configuration of the toggle mechanism 150 is not limited to the configuration shown in Figures 1 and 2. For example, in Figures 1 and 2, each link group has five nodes, but it may also have four, and one end of the third link 154 may be connected to the node between the first link 152 and the second link 153.

[0024] The clamping motor 160 is attached to the toggle support 130 and operates the toggle mechanism 150. The clamping motor 160 moves the crosshead 151 forward and backward relative to the toggle support 130, thereby bending and extending the first link 152 and the second link 153, and moving the movable platen 120 forward and backward relative to the toggle support 130. The clamping motor 160 is directly connected to the motion conversion mechanism 170, but it may also be connected to the motion conversion mechanism 170 via a belt, pulley, or the like.

[0025] The motion conversion mechanism 170 converts the rotational motion of the clamping motor 160 into the linear motion of the crosshead 151. The motion conversion mechanism 170 includes a screw shaft and a screw nut that screws onto the screw shaft. A ball or roller may be interposed between the screw shaft and the screw nut.

[0026] The mold clamping device 100 performs processes such as mold closing, pressure boosting, mold clamping, depressurization, and mold opening under the control of the control device 700.

[0027] In the mold closing process, the clamping motor 160 is driven to advance the crosshead 151 to the mold closing completion position at a set movement speed, thereby advancing the movable platen 120 and bringing the movable mold 820 into contact with the fixed mold 810. The position and movement speed of the crosshead 151 are detected using, for example, a clamping motor encoder 161. The clamping motor encoder 161 detects the rotation of the clamping motor 160 and sends a signal indicating the detection result to the control device 700.

[0028] Furthermore, the crosshead position detector for detecting the position of the crosshead 151 and the crosshead speed detector for detecting the movement speed of the crosshead 151 are not limited to the clamping motor encoder 161, and general-purpose devices can be used. Similarly, the movable platen position detector for detecting the position of the movable platen 120 and the movable platen speed detector for detecting the movement speed of the movable platen 120 are not limited to the clamping motor encoder 161, and general-purpose devices can be used.

[0029] In the boosting process, the clamping motor 160 is further driven to advance the crosshead 151 from the closed position to the clamping position, thereby generating clamping force.

[0030] In the clamping process, the clamping motor 160 is driven to maintain the position of the crosshead 151 in the clamping position. In the clamping process, the clamping force generated in the pressurization process is maintained. In the clamping process, a cavity space 801 (see Figure 2) is formed between the movable mold 820 and the fixed mold 810, and the injection unit 300 fills the cavity space 801 with liquid molding material. A molded product is obtained when the filled molding material solidifies.

[0031] The number of cavity spaces 801 may be one or more. In the latter case, multiple molded products can be obtained simultaneously. An insert material may be placed in part of the cavity space 801, and the molding material may be filled in the other part of the cavity space 801. A molded product in which the insert material and the molding material are integrated is obtained.

[0032] In the depressurization process, the clamping motor 160 is driven to retract the crosshead 151 from the clamping position to the mold opening start position, thereby retracting the movable platen 120 and reducing the clamping force. The mold opening start position and the mold closing completion position may be the same position.

[0033] In the mold opening process, the clamping motor 160 is driven to retract the crosshead 151 from the mold opening start position to the mold opening completion position at a set movement speed, thereby retracting the movable platen 120 and separating the movable mold 820 from the fixed mold 810. Subsequently, the ejector device 200 ejects the molded product from the movable mold 820.

[0034] The setting conditions for the mold closing process, the pressure boosting process, and the mold clamping process are set together as a series of setting conditions. For example, the movement speed and position of the crosshead 151 (including the mold closing start position, movement speed switching position, mold closing completion position, and mold clamping position), and the mold clamping force in the mold closing process and the pressure boosting process are set together as a series of setting conditions. The mold closing start position, movement speed switching position, mold closing completion position, and mold clamping position are arranged in this order from rear to front and represent the start and end points of the section in which the movement speed is set. The movement speed is set for each section. There may be one or more movement speed switching positions. There may be no movement speed switching positions. The mold clamping position and the mold clamping force may be set individually or individually.

[0035] The setting conditions for the depressurization process and the mold opening process are set similarly. For example, the movement speed and position of the crosshead 151 in the depressurization process and the mold opening process (mold opening start position, movement speed switching position, and mold opening completion position) are set together as a series of setting conditions. The mold opening start position, movement speed switching position, and mold opening completion position are arranged in this order from front to back and represent the start and end points of the sections in which the movement speed is set. The movement speed is set for each section. There may be one or more movement speed switching positions. There may be no movement speed switching positions. The mold opening start position and the mold closing completion position may be the same position. Also, the mold opening completion position and the mold closing start position may be the same position.

[0036] Alternatively, the movement speed and position of the movable platen 120 may be set instead of the movement speed and position of the crosshead 151. Furthermore, the clamping force may be set instead of the position of the crosshead (e.g., the clamping position) or the position of the movable platen.

[0037] Incidentally, the toggle mechanism 150 amplifies the driving force of the clamping motor 160 and transmits it to the movable platen 120. This amplification ratio is also called the toggle ratio. The toggle ratio changes depending on the angle θ between the first link 152 and the second link 153 (hereinafter also referred to as the "link angle θ"). The link angle θ can be determined from the position of the crosshead 151. The toggle ratio is maximized when the link angle θ is 180°.

[0038] If the thickness of the mold device 800 changes due to replacement of the mold device 800 or a change in the temperature of the mold device 800, the mold thickness is adjusted so that a predetermined clamping force is obtained during mold clamping. In mold thickness adjustment, for example, the distance L between the fixed platen 110 and the toggle support 130 is adjusted so that the link angle θ of the toggle mechanism 150 becomes a predetermined angle at the time of mold touch when the movable mold 820 touches the fixed mold 810.

[0039] The mold clamping device 100 has a mold thickness adjustment mechanism 180. The mold thickness adjustment mechanism 180 adjusts the mold thickness by adjusting the distance L between the fixed platen 110 and the toggle support 130. The timing of the mold thickness adjustment is, for example, between the end of one molding cycle and the start of the next molding cycle. The mold thickness adjustment mechanism 180 includes, for example, a screw shaft 181 formed at the rear end of the tie bar 140, a screw nut 182 that is rotatably and immovably held by the toggle support 130, and a mold thickness adjustment motor 183 that rotates the screw nut 182 that is screwed onto the screw shaft 181.

[0040] A screw shaft 181 and screw nut 182 are provided for each tie bar 140. The rotational driving force of the mold thickness adjustment motor 183 may be transmitted to multiple screw nuts 182 via a rotational driving force transmission unit 185. Multiple screw nuts 182 can be rotated synchronously. It is also possible to rotate multiple screw nuts 182 individually by changing the transmission path of the rotational driving force transmission unit 185.

[0041] The rotational drive force transmission unit 185 is composed of, for example, gears. In this case, driven gears are formed on the outer circumference of each screw nut 182, a drive gear is attached to the output shaft of the mold thickness adjustment motor 183, and an intermediate gear that meshes with the multiple driven gears and the drive gear is rotatably held in the center of the toggle support 130. Note that the rotational drive force transmission unit 185 may be composed of a belt or pulley instead of gears.

[0042] The operation of the mold thickness adjustment mechanism 180 is controlled by the control device 700. The control device 700 drives the mold thickness adjustment motor 183 to rotate the screw nut 182. As a result, the position of the toggle support 130 relative to the tie bar 140 is adjusted, and the distance L between the fixed platen 110 and the toggle support 130 is adjusted. Multiple mold thickness adjustment mechanisms may be used in combination.

[0043] The interval L is detected using the mold thickness adjustment motor encoder 184. The mold thickness adjustment motor encoder 184 detects the amount and direction of rotation of the mold thickness adjustment motor 183 and sends a signal indicating the detection result to the control device 700. The detection result of the mold thickness adjustment motor encoder 184 is used to monitor and control the position and interval L of the toggle support 130. Note that the toggle support position detector for detecting the position of the toggle support 130 and the interval detector for detecting the interval L are not limited to the mold thickness adjustment motor encoder 184, but general-purpose devices can be used.

[0044] The clamping device 100 may have a mold temperature controller that adjusts the temperature of the mold device 800. The mold device 800 has a flow path for a temperature-controlled medium inside it. The mold temperature controller adjusts the temperature of the mold device 800 by adjusting the temperature of the temperature-controlled medium supplied to the flow path of the mold device 800.

[0045] In this embodiment, the mold clamping device 100 is a horizontal type in which the mold opening and closing direction is horizontal, but it may also be a vertical type in which the mold opening and closing direction is vertical.

[0046] In this embodiment, the clamping device 100 has a clamping motor 160 as a drive source, but a hydraulic cylinder may be used instead of the clamping motor 160. Furthermore, the clamping device 100 may have a linear motor for opening and closing the mold, and an electromagnet for clamping the mold.

[0047] (Ejector device) In describing the ejector device 200, similar to the description of the clamping device 100, the direction of movement of the movable platen 120 when the mold is closed (for example, the positive X-axis direction) is described as forward, and the direction of movement of the movable platen 120 when the mold is open (for example, the negative X-axis direction) is described as backward.

[0048] The ejector device 200 is attached to the movable platen 120 and moves back and forth together with the movable platen 120. The ejector device 200 includes 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 direction of movement of the movable platen 120 (in the X-axis direction).

[0049] The ejector rod 210 is positioned to move back and forth within a through-hole in the movable platen 120. The front end of the ejector rod 210 contacts the ejector plate 826 of the movable mold 820. The front end of the ejector rod 210 may or may not be connected to the ejector plate 826.

[0050] The drive mechanism 220 includes, for example, an ejector motor and a motion conversion mechanism that converts the rotational motion of the ejector motor into the linear motion of the ejector rod 210. The motion conversion mechanism includes a screw shaft and a screw nut that screws onto the screw shaft. A ball or roller may be interposed between the screw shaft and the screw nut.

[0051] The ejector device 200 performs the 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 travel speed, thereby advancing the ejector plate 826 and ejecting the molded product. Subsequently, the ejector motor is driven to retract the ejector rod 210 at a set travel speed, retracting the ejector plate 826 back to its original standby position.

[0052] The position and speed of the ejector rod 210 are detected, for example, using an ejector motor encoder. The ejector motor encoder detects the rotation of the ejector motor and sends a signal indicating the detection result to the control device 700. Note that the ejector rod position detector, which detects the position of the ejector rod 210, and the ejector rod speed detector, which detects the speed of the ejector rod 210, are not limited to ejector motor encoders, but general-purpose devices can be used.

[0053] (injection device) In the description of the injection device 300, unlike the descriptions of the clamping device 100 and the ejector device 200, the direction of movement of the screw 330 during filling (for example, the negative X-axis direction) is described as forward, and the direction of movement of the screw 330 during metering (for example, the positive X-axis direction) is described as backward.

[0054] The injection device 300 is mounted on a slide base 301, which is positioned to move back and forth relative to the injection device frame 920. The injection device 300 is positioned to move back and forth relative to the mold device 800. The injection device 300 touches 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 includes, 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 positioned within the cylinder 310 to move back and forth and to rotate, a metering motor 340 for rotating the screw 330, an injection motor 350 for moving the screw 330 back and forth, and a load detector 360 for detecting the load transmitted between the injection motor 350 and the screw 330.

[0055] The cylinder 310 heats the molding material supplied to its interior from the supply port 311. The molding material includes, for example, resin. The molding material is formed, for example, into pellets and 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 circumference of the rear of the cylinder 310. In front of the cooler 312, a heater 313, such as a band heater, and a temperature detector 314 are provided on the outer circumference of the cylinder 310.

[0056] The cylinder 310 is divided into multiple zones along its axial direction (for example, the X-axis direction). A heater 313 and a temperature detector 314 are provided in each of the multiple zones. A set temperature is set for each of the multiple zones, and the control device 700 controls the heater 313 so that the temperature detected by the temperature detector 314 becomes the set temperature.

[0057] The nozzle 320 is located at the front end of the cylinder 310 and is pressed against the mold device 800. A heater 313 and a temperature detector 314 are provided on the outer circumference of the nozzle 320. The control device 700 controls the heater 313 so that the detected temperature of the nozzle 320 reaches a set temperature.

[0058] The screw 330 is rotatably and reciprocally positioned within the cylinder 310. When the screw 330 is rotated, the molding material is fed forward along the helical groove of the screw 330. As the molding material is fed forward, it is gradually melted by the heat from the cylinder 310. As the liquid molding material is fed forward to the screw 330 and accumulates at the front of the cylinder 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.

[0059] A backflow prevention ring 331 is mounted on the front of the screw 330 so as to be able to move back and forth, acting as a backflow prevention valve to prevent backflow of the molding material from the front to the rear of the screw 330 when the screw 330 is pushed forward.

[0060] When the screw 330 is advanced, the backflow prevention ring 331 is pushed backward by the pressure of the molding material in front of the screw 330, and retracts relative to the screw 330 to a closed position (see Figure 2) that blocks the flow path of the molding material. This prevents the molding material accumulated in front of the screw 330 from flowing backward.

[0061] On the other hand, when the screw 330 is rotated, the backflow prevention ring 331 is pushed forward by the pressure of the molding material being sent forward along the helical groove of the screw 330, and moves relative to the screw 330 to an open position (see Figure 1) that opens the flow path of the molding material. As a result, the molding material is sent forward of the screw 330.

[0062] The backflow prevention ring 331 may be either a co-rotating type that rotates together with the screw 330, or a non-co-rotating type that does not rotate together with the screw 330.

[0063] The injection device 300 may also have a drive source that moves the backflow prevention ring 331 back and forth between an open position and a closed position relative to the screw 330.

[0064] The metering motor 340 rotates the screw 330. The drive source for rotating the screw 330 is not limited to the metering motor 340; for example, a hydraulic pump or the like may also be used.

[0065] The injection motor 350 moves the screw 330 forward and backward. Between the injection motor 350 and the screw 330, there is a motion conversion mechanism that converts the rotational motion of the injection motor 350 into the linear motion of the screw 330. The motion conversion mechanism has, for example, a screw shaft and a screw nut that screws onto the screw shaft. Balls or rollers may be provided between the screw shaft and the screw nut. The drive source for moving the screw 330 forward and backward is not limited to the injection motor 350, but may also be, for example, a hydraulic cylinder.

[0066] 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 installed in the load transmission path between the injection motor 350 and the screw 330 and detects the load acting on the load detector 360.

[0067] The load detector 360 sends a signal of the detected load to the control device 700. The load detected by the load detector 360 is converted into pressure acting between the screw 330 and the molding material, and is used for controlling and monitoring the pressure the screw 330 receives from the molding material, the back pressure on the screw 330, and the pressure acting from the screw 330 on the molding material.

[0068] The pressure detector used to detect the pressure of the molding material is not limited to the load detector 360, but can be any general-purpose pressure detector. For example, a nozzle pressure sensor or a mold pressure sensor may be used. The nozzle pressure sensor is installed in the nozzle 320. The mold pressure sensor is installed inside the mold device 800.

[0069] The injection device 300 performs processes such as metering, filling, and holding pressure under the control of the control device 700. The filling and holding pressure processes may be collectively referred to as the injection process.

[0070] In the weighing process, the weighing motor 340 is driven to rotate the screw 330 at a set rotational speed, and the molding material is fed forward along the helical groove of the screw 330. As this occurs, the molding material is gradually melted. As the liquid molding material is fed forward to the screw 330 and accumulates at the front of the cylinder 310, the screw 330 is retracted. The rotational speed of the screw 330 is detected, for example, using a weighing motor encoder 341. The weighing motor encoder 341 detects the rotation of the weighing motor 340 and sends a signal indicating the detection result to the control device 700. Note that the screw rotational speed detector for detecting the rotational speed of the screw 330 is not limited to the weighing motor encoder 341, and a general type can be used.

[0071] In the weighing process, the injection motor 350 may be driven to apply a set back pressure to the screw 330 in order to limit the rapid retraction of the screw 330. The back pressure on the screw 330 is detected, for example, using a load detector 360. The weighing process is completed when the screw 330 has retracted to the weighing completion position and a predetermined amount of molding material has accumulated in front of the screw 330.

[0072] The position and rotational speed of the screw 330 in the metering process are set together as a series of setting conditions. For example, the metering start position, rotational speed switching position, and metering completion position are set. These positions are arranged in this order from front to back and represent the start and end points of the sections in which the rotational speed is set. The rotational speed is set for each section. There may be one or more rotational speed switching positions. The rotational speed switching positions may not be set. In addition, back pressure is set for each section.

[0073] In the filling process, the injection motor 350 is driven to advance the screw 330 at a set speed, filling the cavity space 801 in the mold device 800 with the liquid molding material accumulated in front of the screw 330. The position and speed of the screw 330 are detected, for example, using an injection motor encoder 351. The injection motor encoder 351 detects the rotation of the injection motor 350 and sends a signal indicating the detection result to the control device 700. When the position of the screw 330 reaches the set position, a switchover from the filling process to the holding pressure process (so-called V / P switching) occurs. The position at which the V / P switching occurs is also called the V / P switching position. The set speed of the screw 330 may be changed depending on the position and time of the screw 330.

[0074] The position and movement speed of the screw 330 during the filling process are set together as a series of setting conditions. For example, the filling start position (also called the "injection start position"), the movement speed switching position, and the V / P switching position are set. These positions are arranged in this order from rear to front and represent the start and end points of the sections in which the movement speed is set. The movement speed is set for each section. There may be one or more movement speed switching positions. The movement speed switching positions may not be set at all.

[0075] For each section in which the movement speed of the screw 330 is set, an upper limit is set for the pressure of the screw 330. The pressure of the screw 330 is detected by the load sensor 360. If the pressure of the screw 330 is below the set pressure, the screw 330 moves forward at the set movement speed. On the other hand, if the pressure of the screw 330 exceeds the set pressure, for the purpose of protecting the mold, the screw 330 moves forward at a slower movement speed than the set movement speed so that the pressure of the screw 330 becomes below the set pressure.

[0076] Furthermore, during the filling process, after the screw 330 reaches the V / P switching position, the screw 330 may be temporarily stopped at the V / P switching position, and then the V / P switching may be performed. Immediately before the V / P switching, instead of stopping the screw 330, the screw 330 may be moved forward or backward at a slow speed. In addition, the screw position detector that detects the position of the screw 330 and the screw movement speed detector that detects the movement speed of the screw 330 are not limited to the injection motor encoder 351, but general-purpose ones can be used.

[0077] In the holding pressure process, the injection motor 350 is driven to push the screw 330 forward, maintaining the pressure of the molding material at the front end of the screw 330 (hereinafter also referred to as "holding pressure") at a set pressure, and pushing the molding material remaining in the cylinder 310 toward the mold device 800. This allows for the replenishment of molding material lost due to cooling shrinkage within the mold device 800. The holding pressure is detected, for example, using a load detector 360. The set value of the holding pressure may be changed according to the elapsed time from the start of the holding pressure process. Multiple holding pressures and holding times for maintaining the holding pressure in the holding pressure process may be set, and may be set together as a series of setting conditions.

[0078] During the holding pressure process, the molding material in the cavity space 801 within the mold device 800 is gradually cooled, and upon completion of the holding pressure process, the entrance to the cavity space 801 is sealed with solidified molding material. This state is called a gate seal, and prevents backflow of molding material from the cavity space 801. After the holding pressure process, the cooling process begins. During the cooling process, the molding material in the cavity space 801 is solidified. To shorten the molding cycle time, a metering process may be performed during the cooling process.

[0079] In this embodiment, the injection device 300 is an in-line screw type, but a pre-plasticization type or the like may also be used. In a pre-plasticization injection device, the molding material molten in a plasticizing cylinder is supplied to the injection cylinder, and the molding material is injected from the injection cylinder into the mold device. In the plasticizing cylinder, a screw is arranged to be rotatable but unable to move back and forth, or a screw is arranged to be rotatable and able to move back and forth. On the other hand, a plunger is arranged to be able to move back and forth in the injection cylinder.

[0080] Furthermore, although the injection device 300 in this embodiment is a horizontal type with the axial direction of the cylinder 310 being horizontal, it may also be a vertical type with the axial direction of the cylinder 310 being vertical. The clamping device combined with the vertical injection device 300 may be vertical or horizontal. Similarly, the clamping device combined with the horizontal injection device 300 may be horizontal or vertical.

[0081] (Mobile device) In describing the moving device 400, similar to the description of the injection device 300, the direction of movement of the screw 330 during filling (for example, the negative X-axis direction) is described as forward, and the direction of movement of the screw 330 during metering (for example, the positive X-axis direction) is described as backward.

[0082] The moving device 400 moves the injection device 300 forward and backward relative to the mold device 800. The moving device 400 also presses the nozzle 320 against the mold device 800, generating nozzle touch pressure. The moving device 400 includes a hydraulic pump 410, a motor 420 as a drive source, a hydraulic cylinder 430 as a hydraulic actuator, and the like.

[0083] The hydraulic pump 410 has a first port 411 and a second port 412. The hydraulic pump 410 is a bidirectional rotatable pump, and by switching the rotation direction of the motor 420, it can draw in working fluid (e.g., oil) from either the first port 411 or the second port 412 and discharge it from the other to generate hydraulic pressure. The hydraulic pump 410 can also draw working fluid from a tank and discharge it from either the first port 411 or the second port 412.

[0084] Motor 420 operates the hydraulic pump 410. Motor 420 drives the hydraulic pump 410 with a rotational direction and rotational torque corresponding to the control signal from the control device 700. Motor 420 may be an electric motor or an electric servo motor.

[0085] The hydraulic cylinder 430 comprises a cylinder body 431, a piston 432, and a piston rod 433. The cylinder body 431 is fixed to the injection device 300. The piston 432 divides the inside of the cylinder body 431 into a front chamber 435 as a first chamber and a rear chamber 436 as a second chamber. The piston rod 433 is fixed to the fixed platen 110.

[0086] The front chamber 435 of the hydraulic cylinder 430 is connected to the first port 411 of the hydraulic pump 410 via a first passage 401. The hydraulic fluid discharged from the first port 411 is supplied to the front chamber 435 via the first passage 401, pushing the injection device 300 forward. As the injection device 300 moves forward, the nozzle 320 is pressed against the fixed mold 810. The front chamber 435 functions as a pressure chamber that generates nozzle touch pressure on the nozzle 320 by the pressure of the hydraulic fluid supplied from the hydraulic pump 410.

[0087] Meanwhile, the rear chamber 436 of the hydraulic cylinder 430 is connected to the second port 412 of the hydraulic pump 410 via the second passage 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 passage 402, pushing the injection device 300 backward. As the injection device 300 is retracted, the nozzle 320 is separated from the fixed mold 810.

[0088] In this embodiment, the moving device 400 includes a 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 the linear motion of the injection device 300 may be used.

[0089] (Control device) The control device 700 is, for example, a computer and, as shown in Figures 1 and 2, has a CPU (Central Processing Unit) 701, a storage medium 702 such as memory, an input interface 703, an output interface 704, and a communication interface 705. The control device 700 performs various controls by having the CPU 701 execute a program stored in the storage medium 702. The control device 700 also receives signals from the outside through the input interface 703 and transmits signals to the outside through the output interface 704. Furthermore, the control device 700 transmits information to an external device through the communication interface 705.

[0090] The control device 700 repeatedly produces molded products by repeatedly performing processes such as metering, mold closing, pressure increasing, mold clamping, filling, holding pressure, cooling, depressurization, mold opening, and ejection. A series of operations to obtain a molded product, such as the operations from the start of one metering process to the start of the next metering process, is also called a "shot" or "molding cycle." The time required for one shot is also called the "molding cycle time" or "cycle time."

[0091] A single molding cycle includes, for example, a weighing process, a mold closing process, a pressurizing process, a clamping process, a filling process, a holding pressure process, a cooling process, a depressurizing process, a mold opening process, and an ejection process, in this order. The order here refers to the order in which each process begins. The filling, holding pressure, and cooling processes take place during the clamping process. The start of the clamping process may coincide with the start of the filling process. The completion of the depressurizing process coincides with the start of the mold opening process.

[0092] Furthermore, multiple processes may be performed simultaneously to shorten the molding cycle time. For example, the metering process may be performed during the cooling process of the previous molding cycle, or during the mold clamping process. In this case, the mold closing process may be performed at the beginning of the molding cycle. The filling process may also be started during the mold closing process. The ejection process may also be started during the mold opening process. If an on-off valve is provided to open and close the flow path of the nozzle 320, the mold opening process may be started during the metering process. This is because even if the mold opening process is started during the metering process, if the on-off valve closes the flow path of the nozzle 320, the molding material will not leak from the nozzle 320.

[0093] Furthermore, a single molding cycle may include steps other than the weighing step, mold closing step, pressurization step, mold clamping step, filling step, holding pressure step, cooling step, depressurization step, mold opening step, and ejection step.

[0094] For example, after the holding pressure process is completed and before the metering process begins, a pre-metering suck-back process may be performed in which the screw 330 is retracted to a preset metering start position. This reduces the pressure of the molding material accumulated in front of the screw 330 before the metering process begins and prevents the screw 330 from retracting too quickly at the start of the metering process.

[0095] Furthermore, after the metering process is completed and before the filling process begins, a post-metering suck-back process may be performed in which the screw 330 is retracted to a preset filling start position (also called the "injection start position"). This reduces the pressure of the molding material accumulated in front of the screw 330 before the filling process begins and prevents leakage of the molding material from the nozzle 320 before the filling process begins.

[0096] The control device 700 is connected to an operating device 750 that accepts user input operations and a display device 760 that displays a screen. The operating device 750 and the display device 760 may be integrated, for example, by a touch panel 770. The touch panel 770, as the display device 760, displays a screen under the control of the control device 700. The screen of the touch panel 770 may display information such as the settings of the injection molding machine 10 and the current status of the injection molding machine 10. The touch panel 770 accepts operations in the displayed screen area. The screen area of ​​the touch panel 770 may also display operation parts such as buttons and input fields that accept user input operations. The touch panel 770, as the operating device 750, detects user input operations on the screen and outputs a signal corresponding to the input operation to the control device 700. This allows, for example, the user to operate the operation parts provided on the screen while confirming the information displayed on the screen to configure the injection molding machine 10 (including inputting setting values), etc. Furthermore, the user can operate the injection molding machine 10 corresponding to the operation unit by operating the operation unit provided on the screen. The operation of the injection molding machine 10 may include, for example, the operation (including stopping) of the clamping device 100, ejector device 200, injection device 300, moving device 400, etc. Alternatively, the operation of the injection molding machine 10 may include switching the screen displayed on the touch panel 770, which serves as the display device 760.

[0097] Although the operating device 750 and display device 760 in this embodiment have been described as being integrated as a touch panel 770, they may be provided independently. Furthermore, multiple operating devices 750 may be provided. The operating device 750 and display device 760 are positioned on the operating side (negative Y-axis direction) of the clamping device 100 (more specifically, the fixed platen 110).

[0098] (First embodiment) In this embodiment, a measuring device is used to calculate the amount of molding material injected from the injection device 300 of the injection molding machine 10 (in this embodiment, weight as an example). In this embodiment, weight is shown as an example of the amount of molding material, but the amount of molding material may be other than weight.

[0099] Figure 3 is a diagram illustrating the measuring device of the injection molding machine 10 according to this embodiment.

[0100] The measuring device 1200 consists of a measuring mechanism 1000 and an information processing device 1100.

[0101] In this embodiment, a measuring mechanism 1000 is attached to the injection molding machine 10 in order to calculate the weight of the molding material injected from the injection device 300. In this embodiment, in order to attach the measuring mechanism 1000, the mold device 800 attached to the injection molding machine 10 is removed. Then, by attaching the measuring mechanism 1000 in the position where the mold device 800 is located, the molding material is injected into the measuring mechanism 1000 instead of the mold device 800.

[0102] Thus, the measurement mechanism 1000 can be installed on the injection molding machine 10 by replacing the mold device 800 provided on the injection molding machine 10.

[0103] Then, based on the detection results from various sensors installed in the measurement mechanism 1000, the information processing device 1100 calculates the weight of the injected molding material.

[0104] The measuring mechanism 1000 shown in Figure 3 is fixed to the fixed platen 110 of the injection molding machine 10. Any fixing method is acceptable; for example, the measuring mechanism 1000 may be fixed to the fixed platen 110 with bolts. The movable platen 120 may be located anywhere as long as it is not near the end of the measuring mechanism 1000 on the -X axis side.

[0105] As shown in Figure 3, the measuring mechanism 1000 has a nozzle storage space 1006 formed on the fixed platen 110 side (+X axis side) for positioning the nozzle 320 of the injection device 300.

[0106] Furthermore, a filling port 1021 is provided at the end of the nozzle storage space 1006 on the X-axis side, into which the molding material injected from the injection device 300 of the injection molding machine 10 can be filled. The measuring mechanism 1000 is filled with the molding material from this filling port 1021.

[0107] Furthermore, an outlet 1022 for discharging molding material is provided at the end of the measuring mechanism 1000 on the X-axis side. Molding material is discharged from the outlet 1022 depending on the situation. The situation in which molding material is discharged will be described later.

[0108] The measuring mechanism 1000 has a space connecting the filling port 1021 and the discharge port 1022. In this embodiment, the internal space of the measuring mechanism 1000 is made to be closer to the inside of the mold device 800, and includes at least a sprue section 1001, a runner section 1002, and a cavity section 1004. For example, the sprue section 1001, the runner section 1002, and the cavity section 1004 are flow paths connecting each part and may have a cylindrical shape. The internal configuration of the measuring mechanism 1000 is shown as an example and is not limited to this configuration.

[0109] The sprue portion 1001 is a space composed of a diameter D1 and a length L1. The length L1 and diameter D1 are determined according to the embodiment.

[0110] The runner portion 1002 is a space with a diameter D2 and a length L2. The length L2 and diameter D2 are determined according to the embodiment. In this embodiment, the diameter D2 of the runner portion 1002 is smaller than the diameter D1 of the sprue portion 1001. This embodiment describes an example in which the runner portion 1002 is provided, but an embodiment without the runner portion 1002 is also possible. In the embodiment without the runner portion 1002, for example, the sprue portion 1001 may be directly connected to the gate 1003. Even in this embodiment, it is possible to calculate the amount of molding material.

[0111] The cavity portion 1004 is a space with a diameter D4 and a length L4. The length L4 and diameter D4 are determined according to the embodiment. In this embodiment, the diameter D4 of the cavity portion 1004 is formed to be larger than the diameter D2 of the runner portion 1002. This embodiment is shown as an example, and for example, the diameter D4 of the cavity portion 1004 may be formed to be smaller than the diameter D2 of the runner portion 1002.

[0112] The lengths L1, L2, and L4 may be determined according to the embodiment, and are preferably tens of millimeters or less. For example, length L2 may be shorter than lengths L1 and L4. The diameters D1, D2, and D4 may be determined according to the embodiment, and are preferably tens of millimeters or less.

[0113] Furthermore, a gate (an example of a constriction) 1003 is provided between the runner section 1002 and the cavity section 1004 to suppress the movement of the molding material.

[0114] Figure 4 is an enlarged view of the first region 1050A in Figure 3, which is part of the measurement mechanism according to the first embodiment. As shown in Figure 4, the measurement mechanism 1000 is provided with a gate 1003 (an example of a throttling) in the flow path of the molding material connecting the filling port 1021 and the discharge port 1022, the gate 1003 (an example of a throttling) having a narrower opening area compared to the sprue portion 1001, runner portion 1002, and cavity portion 1004 (another region) present in the flow path. The gate (an example of a throttling) 1003 may have a cylindrical shape.

[0115] The gate 1003 is a throttling mechanism to suppress the movement of the molding material. For example, it is preferable to set the diameter D3 of the gate 1003 such that the molding material flows when injection pressure is applied for injection from the injection device 300, but resistance is created to suppress the flow of the molding material when pressure other than injection (e.g., back pressure) is applied.

[0116] For example, if the viscosity of the molding material is 2 to 20 (Pa·S), the diameter D3 of the gate 1003 should be 0.2 to 0.5 (mm). The length L3 of the gate 1003 may be shorter than the length L4 of the cavity portion 1004 and the length L2 of the runner portion 1002, and is preferably 0.5 to 1 (mm).

[0117] Furthermore, the discharge port 1022 is provided with a throttling section to suppress drooling.

[0118] Figure 5 is an enlarged view of the second region 1050B in Figure 3, which is part of the measurement mechanism according to the first embodiment. As shown in Figure 5, a throttling portion 1005 is provided between the outlet 1022 and the cavity portion 1004. The throttling portion 1005 may have a cylindrical shape.

[0119] The discharge port 1022 is used to discharge molding material when it is being injected from the injection device 300, but drooling (molding material leakage) may occur under other circumstances as well.

[0120] Therefore, in this embodiment, a constricted portion 1005 is provided to suppress drooling of the molding material. The diameter D5 of the constricted portion 1005 is made smaller than at least the diameter D4 of the cavity portion 1004. In other words, in this embodiment, by making the diameter D5 of the constricted portion 1005 smaller than the diameter D4 of the cavity portion 1004, resistance to the movement of the molding material is present, thereby suppressing the flow of the molding material.

[0121] For example, if the viscosity of the molding material is 2 to 20 (Pa·S), the diameter D5 of the constricted portion 1005 should be 0.5 to 3 (mm). The length L5 of the constricted portion 1005 can be determined according to the embodiment.

[0122] In this embodiment, the molding material injected from the injection device 300 is, for example, resin. In this embodiment, the molten molding material is filled from the injection device 300 through the filling port 1021.

[0123] The measurement mechanism 1000 according to this embodiment is provided with a heater 1051. The heater (an example of a heating element) 1051 is, for example, a band heater. The heater 1051 heats the measurement mechanism 1000 from the surroundings, thereby maintaining the molten state of the molding material injected into the measurement mechanism 1000.

[0124] Therefore, in this embodiment, the sprue portion 1001, runner portion 1002, gate 1003, cavity portion 1004, and throttling portion 1005 are filled with molten molding material discharged from the nozzle 320, and the molten state of the molding material is maintained thereafter.

[0125] Furthermore, the measuring mechanism 1000 is equipped with a sensor for measuring the molding material. In this embodiment, a gate 1003 is provided to suppress the movement of the molding material. In other words, the condition of the molding material (e.g., pressure and temperature) changes through the gate 1003. Therefore, in this embodiment, a sensor 1011 is provided in the sprue section 1001 before the molding material passes through the gate, and a sensor 1012 is provided in the cavity section 1004 after the molding material has passed through the gate.

[0126] Sensor 1011 is used to detect the state of the molding material present in the sprue portion 1001. Sensor 1011 includes a pressure sensor and a temperature sensor. While it would suffice to detect the state of the molding material (e.g., clay), a pressure sensor and a temperature sensor are preferred considering factors such as cost, size, and the impact on layout due to ease of routing.

[0127] For example, the pressure sensor 1011 detects the pressure of the molding material inside the sprue portion 1001, which is adjacent to the sensor 1011.

[0128] The temperature sensor 1011 detects the temperature of the molding material inside the sprue portion 1001, which is adjacent to the sensor 1011.

[0129] Sensor 1012 is a sensor for detecting the state of the molding material present in the cavity portion 1004. Sensor 1012 includes at least a pressure sensor and a temperature sensor.

[0130] For example, the pressure sensor 1012 detects the pressure of the molding material inside the cavity 1004 adjacent to the sensor 1012.

[0131] The temperature sensor 1012 detects the temperature of the molding material inside the cavity 1004, which is adjacent to the sensor 1012.

[0132] The sensors 1011 and 1012 according to this embodiment constantly measure the state of the molding material.

[0133] Furthermore, in this embodiment, the detection result of the molding material by the sensor 1011 is applied to the molding material present in the sprue section 1001 and the runner section 1002. In other words, assuming that there is no change in the pressure and temperature of the molding material before passing through the gate 1003, the detection result of the molding material by the sensor 1011 is applied not only to the sprue section 1001 but also to the runner section 1002.

[0134] This embodiment shows just one example of how the sensors can be installed; sensors may also be installed in the sprue section 1001 and the runner section 1002.

[0135] In this embodiment, a sensor 1013 is also provided. The sensor 1013 detects the temperature near the outer circumference of the measurement mechanism 1000 and outputs the detection result to the information processing device 1100. The information processing device 1100 then controls the temperature of the heater 1051 so that the molding material inside the measurement mechanism 1000 remains in a molten state.

[0136] Next, we will describe an information processing device 1100 that uses the detection results of sensors 1011 and 1012 to measure the weight of the molding material injected from the injection device 300. In this embodiment, the number of times the material is injected from the injection device 300 is counted as the number of shots. This embodiment describes an example in which the weight of the injected molding material is measured. Note that this embodiment shows weight as an example of the injection amount, and does not limit the injection amount to weight.

[0137] Figure 6 is a diagram showing the components of the information processing device 1100 according to the first embodiment in functional blocks. The information processing device 1100 is composed of, for example, a computer and has a CPU (Central Processing Unit) 1101 and a storage medium 1102. The information processing device 1100 performs various controls by causing the CPU 1101 to execute a program stored in the storage medium 1102.

[0138] Each functional block shown in Figure 6 is conceptual and does not necessarily need to be physically configured as shown. All or part of each functional block can be configured by functionally or physically distributing and integrating them in any unit. All or any part of the processing functions performed in each functional block are realized by a program executed by the CPU 1101. Alternatively, each functional block may be realized as wired logic hardware. As shown in Figure 6, the CPU 1101 includes an acquisition unit 1111, an emission calculation unit 1112, a residual amount calculation unit 1113, an injection amount calculation unit 1114, and a write control unit 1115. The control device 700 also includes a log information storage unit 1121 on the storage medium 1102.

[0139] The log information storage unit 1121 stores log information relating to the amount of molding material injected from the injection device 300 into the filling port 1021. The log information includes, for example, information relating to the weight of the molding material injected each time an injection is performed.

[0140] In this embodiment, the information processing device 1100 calculates the amount of molding material injected, taking into account the movement of the molding material within the measuring mechanism 1000. Therefore, the relationship between the movement of the molding material within the measuring mechanism 1000 and the injection of the molding material into the measuring mechanism 1000 in this embodiment will be explained.

[0141] Figure 7 shows the change in the measurement mechanism 1000 due to the injection of molding material by the injection device 300 according to this embodiment.

[0142] Situation 1701 in Figure 7 shows the completion of holding pressure for the (n-1)th shot (example of the (n-1)th injection). In situation 1701, after injection up to the (n-1)th shot, molten molding material remains in the space within the measuring mechanism 1000 (sprew section 1001, runner section 1002, gate 1003, cavity section 1004, and throttling section 1005). In this embodiment, the amount of molding material (e.g., weight) in the space within the measuring mechanism 1000 at the completion of holding pressure for the (n-1)th shot is defined as the amount of molding material remaining after the (n-1)th shot. Note that n is a natural number of 2 or greater.

[0143] Situation 1702 in Figure 7 shows the injection of the nth shot (example of the nth time). In situation 1702, the liquid molding material accumulated in front of the screw 330 is injected from the nozzle 320 into the measuring mechanism 1000 by the injection of the nth shot. As the molding material is injected into the measuring mechanism 1000, the molding material is discharged from the discharge port 1022 as indicated by arrow 1721. In this embodiment, the amount (e.g., weight) of molding material injected from the injection device 300 into the filling port 1021 of the measuring mechanism 1000 at the time of the nth shot is defined as the injection amount of molding material for the nth shot. In this embodiment, the amount (e.g., weight) of molding material discharged from the discharge port 1022 of the measuring mechanism 1000 at the time of the nth shot is defined as the discharge amount of molding material for the nth shot.

[0144] Situation 1703 in Figure 7 shows the completion of holding pressure for the nth shot (example of the nth time). In situation 1703, after injection up to the nth shot, molten molding material is injected into the space within the measuring mechanism 1000 (sprew section 1001, runner section 1002, gate 1003, cavity section 1004, and throttling section 1005). In this embodiment, the amount of molding material (e.g., weight) in the space within the measuring mechanism 1000 at the completion of holding pressure for the nth shot is defined as the residual amount of molding material for the nth shot.

[0145] The difference between the weight of the molding material injected from nozzle 320 in the nth shot and the weight of the molding material discharged from outlet 1022 in the nth shot is the difference in the weight of the molding material remaining in the measuring mechanism 1000 after the holding pressure is completed between the (n-1)th shot and the nth shot. In other words, "Amount of molding material injected in the nth shot - Amount of molding material discharged in the nth shot = Amount of molding material remaining after the nth shot - Amount of molding material remaining after the 'n-1'th shot" holds true. Therefore, the amount of molding material injected in the nth shot can be calculated using the following formula (1). Note that (injection amount) n Let be the weight of the molding material injected in the nth shot, and (ejection amount) n (The weight of the molding material discharged in the nth shot is the weight of the (residual amount) n-1 This is the weight of the molding material remaining after the (n-1) shot, (residual amount) n This is calculated as the weight of the molding material remaining after the nth shot.

[0146]

number

[0147] Therefore, the information processing device 1100 according to this embodiment calculates the amount (e.g., weight) of the molding material injected in the nth shot based on the above-described equation (1).

[0148] The acquisition unit 1111 acquires detection results from various sensors. For example, the acquisition unit 1111 acquires detection results from sensors 1011 and 1012. Specifically, the acquisition unit 1111 acquires the temperature and pressure of the molding material remaining in the sprue section 1001 from sensor (an example of a detection unit) 1011. The acquisition unit 1111 acquires the temperature and pressure of the molding material remaining in the cavity section 1004 from sensor (an example of a detection unit) 1012.

[0149] The residual amount calculation unit 1113 calculates the residual amount of molding material remaining in the space within the measuring mechanism 1000 (sprue section 1001, runner section 1002, gate section 1003, cavity section 1004, and drawing section 1005).

[0150] The residual amount calculation unit 1113 according to this embodiment calculates the (residual amount) indicating the weight of the molding material remaining in the measuring mechanism 1000 after the (n - 1)-th shot, which is represented by Equation (1). n-1 and the (residual amount) indicating the weight of the molding material remaining in the measuring mechanism 1000 after the n-th shot n and calculates them. (Residual amount) n is calculated using the following Equation (2). ρ nキャビティ ρ is the density of the molding material remaining in the cavity portion 1004 after the n-th shot. nスプル ρ is the density of the molding material remaining in the sprue portion 1001 after the n-th shot. V<00********0>V is the volume of the cavity portion 1004. 絞り V is the volume of the throttle portion 1005. スプル V is the volume of the sprue portion 1001. ランナ V is the volume of the runner portion 1002. ゲート V is the volume of the gate 1003.

[0151] Note that the pressure and temperature of the molding material in the runner portion 1002 and the gate 1003 are regarded as the same as those in the sprue portion 1001, and the pressure and temperature of the molding material in the throttle portion 1005 are regarded as the same as those in the cavity portion 1004. This is because even if there are errors in pressure and temperature, the volumes V ランナ V ゲート、 V 絞り are considered to have little influence on the calculation result because they are small compared to the volumes V[[ID=******]] スプル V キャビティ . If the length L2 and diameter D2 of the runner portion 1002 are not smaller than any one or more of the length L4 and diameter D4 of the cavity portion 1004 and the length L1 and diameter D1 of the sprue portion 1001, a sensor for detecting the temperature, pressure, etc. of the molding material in the runner portion 1002 may be provided. <0********9>

Equation

[0153] As shown in equation (2), density ρ nキャビティ is ρ(P nキャビティ ,T nキャビティ ρ(P nキャビティ ,T nキャビティ ) is pressure P nキャビティ and temperature T nキャビティ Based on this, density ρ nキャビティ This shows the calculation method for calculating pressure P. nキャビティ This indicates the pressure of the molding material remaining in the cavity 1004 after the nth shot, and the temperature T nキャビティ This indicates the temperature of the molding material remaining in the cavity 1004 after the nth shot.

[0154] Next, the PVT properties of the molding material will be described. Figure 8 shows the PVT properties of the molding material according to this embodiment. As shown in Figure 8, the vertical axis represents the specific volume (cm³). 3 The horizontal axis shows the volume (cm³) per unit pressure, and the horizontal axis shows the temperature (°C). Each line shown in Figure 8 represents the volume (cm³) per unit pressure. 3 This shows the correspondence between pressure (in g) and temperature (in °C). The pressures shown on each line are P1 < P2 < P3 < P4 < P5 < P6 (MPa).

[0155] As shown in Figure 8, the specific volume (cm³) of the molding material can be calculated from the pressure and temperature of the molding material. 3 The specific volume (cm³) can be determined. 3 ρ(P) is the reciprocal of density. That is, ρ(P) nキャビティ ,T nキャビティ As shown in ), pressure P nキャビティ and temperature T nキャビティ Based on this, the density ρ of the molding material nキャビティ The pressure P of the molding material in the cavity section 1004 can be calculated. nキャビティ and temperature T nキャビティ This can be obtained from sensor 1012. Therefore, the residual amount calculation unit 1113 calculates the pressure P of the cavity section 1004. nキャビティ and temperature T nキャビティ Based on this, the density ρ of the molding material nキャビティ The density ρ of cavity section 1004 is calculated. nキャビティThe specific calculation method may be based on table information showing correspondence relationships, such as the PVT diagram shown in Figure 8, or it may be calculated using a predetermined function, with pressure P nキャビティ and temperature T nキャビティ You can also calculate it by substituting the values.

[0156] Furthermore, as shown in equation (2), density ρ nスプル is ρ(P nスプル ,T nスプル ρ(P nスプル ,T nスプル ) is pressure P nスプル and temperature T nスプル Based on this, density ρ nスプル This shows the calculation method for calculating pressure P. nスプル This indicates the pressure of the molding material remaining in the sprue portion 1001 after the nth shot, and the temperature T nスプル This indicates the temperature of the molding material remaining in the sprue portion 1001 after the nth shot. The pressure P of the molding material in the sprue portion 1001. nスプル and temperature T nスプル This can be obtained from sensor 1011. Therefore, the residual amount calculation unit 1113 calculates the pressure P of the molding material of the sprue section 1001. nスプル and temperature T nスプル Based on this, the density ρ of the molding material of the sprue portion 1001 nスプル The density ρ of the sprue section 1001 is calculated. nスプル The specific calculation method may be based on table information showing correspondence relationships, such as the PVT diagram shown in Figure 8, or it may be calculated using a predetermined function, with pressure P nスプル and temperature T nスプル You can also calculate it by substituting the values.

[0157] V キャビティ , V 絞り , V スプル , V ランナ , V ゲートThis can be calculated from the various dimensions of the measuring mechanism 1000. For example, the sprue section 1001, runner section 1002, gate 1003, cavity section 1004, and throttling section 1005 are flow paths connecting each section, as described above, and may have a cylindrical shape. In this case, the volume V can be calculated from the diameter and length of each of the runner section 1002, gate 1003, cavity section 1004, and throttling section 1005. スプル , V ランナ , V ゲート , V キャビティ、 V 絞り We can derive this. Thus, volume V スプル , V ランナ , V ゲート , V キャビティ、 V 絞り This is a constant.

[0158] Therefore, the residual amount calculation unit 1113 substitutes the pressure and temperature obtained from sensor 1012 after the nth shot, and the pressure and temperature obtained from sensor 1011 after the nth shot, into equation (2) to determine the residual weight of the molding material after the nth shot (residual amount). n It can be calculated.

[0159] Similarly, the residual amount calculation unit 1113 substitutes the pressure and temperature obtained from sensor 1012 after the (n-1)th shot, and the pressure and temperature obtained from sensor 1011 after the (n-1)th shot, into equation (2) to determine the residual weight of the molding material after the (n-1)th shot (residual amount). n-1 It can be calculated.

[0160] In other words, the residual amount calculation unit 1113 can calculate the weight of the molding material remaining in the space based on the volume of the space within the measuring mechanism 1000, the pressure of the molding material remaining in the space, and the temperature of the molding material remaining in the space, using the above-described formula (2). The molding material is kept in a molten state by the heating of the measuring mechanism 1000 by the heater 1051. Therefore, the residual amount calculation unit 1113 can calculate the weight of the molding material in the molten state.

[0161] The discharge calculation unit 1112 calculates the amount of molding material discharged from the discharge port 1022.

[0162] The discharge amount calculation unit 1112 according to this embodiment calculates the weight of the molding material discharged from the discharge port 1022 at the n-th shot, which is shown by the formula (1) (discharge amount). n It calculates (discharge amount). n It is calculated using the following formula (3).

[0163]

Equation

[0164] ρ(P nキャビティ ,T nキャビティ ) is the density of the molding material in the cavity part 1004 as described above. Q(P nキャビティ ,T nキャビティ ) indicates the flow rate of the molding material per unit time. In order to calculate the weight of the molding material discharged at the n-th shot, the integration of formula (3) is performed from the start of filling to the completion of pressure holding. In this embodiment, from the start of filling to the completion of pressure holding, for each unit time when the sensor 1012 performs detection, the temperature and pressure of the molding material detected by the sensor 1012 are used.

[0165] Q(P nキャビティ ,T nキャビティ ) can be calculated by using the Hagen-Poiseuille equation. The pressure P nキャビティ , the temperature T nキャビティ are detected by the sensor 1012. In this embodiment, in order to calculate the flow rate of the molding material discharged from the discharge port 1022, the length of the flow path from the sensor 1012 to the discharge port 1022, the diameter D5 of the throttle part 1005, and the diameter D4 of the cavity part 1004 are used. The length of the flow path from the sensor 1012 to the discharge port 1022 includes the length L from the sensor 1012 to the throttle part 1005 41 and the length L5 of the throttle part 1005. By considering these variables, formula (4) can be derived. Let η(T nキャビティ ) be the viscosity of the molding material remaining in the cavity part 1004 shown in formula (4). Also, the pressure P 大気圧Let the pressure outside the discharge port 1022, that is, the atmospheric pressure, be the reference. Any method for detecting the atmospheric pressure may be used. In the example shown by Equation (4), it is assumed that the shapes of the cavity portion 1004 and the throttle portion 1005 are cylindrical, and the side surface of the cylinder serves as the inner wall for guiding the molding material to the discharge port 1022.

[0166]

Number

[0167] The viscosity η(T nキャビティ ) can be calculated using the exponential function shown in the following Equation (5). As shown in Equation (5), the variables B and η0 are constants specific to the molding material, and R is the gas constant.

[0168]

Number

[0169] Therefore, the discharge amount calculation unit 1112 according to the present embodiment can calculate the flow rate Q of the molding material. Also, the following Equation (6) can be calculated from Equations (3) and (4). The temperature T nキャビティ and the pressure P nキャビティ are the temperature and pressure of the molding material detected by the sensor 1012 during the period from the start of filling to the completion of pressure holding in the n-th shot. Therefore, the discharge amount calculation unit 1112 applies the temperature T nキャビティ and the pressure P nキャビティ of the molding material in the cavity portion 1004 measured by the sensor 1012 every unit time to Equation (6) to calculate (the discharge amount) n .

[0170]

Number

[0171] Therefore, the discharge calculation unit 1112 can calculate the weight of the molded material discharged from the discharge port 1022 by the nth injection, based on the pressure and temperature of the molded material obtained from sensors 1011 and 1012 (an example of a detection unit) while the injection device 300 is injecting the molding material into the filling port 1021. The molded material is kept in a molten state by heating with the heating device 1051 of the measuring mechanism 1000. Therefore, the discharge calculation unit 1112 can calculate the weight of the molded material in the molten state.

[0172] The injection volume calculation unit 1114 calculates the weight of the molding material injected from the injection device 300 into the filling port 1021 during the nth injection, based on the weight of the molding material discharged from the discharge port 1022 during the nth injection, the weight of the molding material remaining in the space within the measuring mechanism 1000 after the nth injection, and the weight of the molding material remaining in the space after the (n-1)th injection.

[0173] The injection volume calculation unit 1114 calculates the residual volume (residual volume) using the residual volume calculation unit 1113. n , (residual amount) n-1 And the emissions calculated by the emissions calculation unit 1112 (emissions) n By substituting and into equation (1), we get (injection amount) n This allows us to calculate the weight of the molding material injected from the injection device 300 in the nth shot.

[0174] By the way, the (residual amount) calculated from equation (2) is given by equation (1). n , (residual amount) n-1 and (emissions) calculated from formula (6) n By substituting the values, we can derive equation (7) shown below.

[0175]

number

[0176] Therefore, the injection volume calculation unit 1114 may apply the pressure and temperature of the molding material obtained from sensors 1011 and 1012 (an example of a detection unit) to equation (7) to calculate the weight of the molding material injected from the injection device 300 in the nth shot.

[0177] The write control unit 1115 registers and updates log information stored in the log information storage unit 1121. For example, the write control unit 1115 registers the weight of the molding material injected from the injection device 300 in the nth shot, calculated by the injection amount calculation unit 1114, in the log information stored in the log information storage unit 1121, in association with the injection conditions, etc.

[0178] The information processing device 1100 according to this embodiment can calculate the weight of the molding material injected from the injection device 300 for each shot by the control described above. The calculated weight of the molding material is then registered as log information in the log information storage unit 1121. Therefore, the user can recognize the variation in the weight of the injected molding material (an example of the amount of molding material injected) by referring to the log information.

[0179] In the embodiments described above, the internal structure of the measuring mechanism 1000 is shown as an example and is not limited to that structure. In this embodiment, an example in which the measuring mechanism 1000 has a sprue section 1001, a runner section 1002, a gate 1003, a cavity section 1004, and a constricted section 1005 inside is described, but is not limited to this structure. In other words, any structure that can calculate the weight of the molding material remaining in the measuring mechanism 1000 is acceptable.

[0180] In this embodiment, an example is described in which a gate 1003 is provided to suppress the discharge of molding material from the discharge port 1022 at times other than injection. However, the method is not limited to providing a gate 1003, and other mechanisms that suppress the discharge of molding material from the discharge port 1022 at times other than injection may be provided instead of the gate 1003.

[0181] In this embodiment, an example has been described in which a heater 1051 is provided to maintain the molten state of the molding material in the measurement mechanism 1000. However, the method is not limited to providing a heater 1051, and the molten state of the molding material may be maintained using other mechanisms or other methods. Furthermore, in this embodiment, if the temperature and pressure of the molding material can be appropriately detected by sensors 1011 and 1012, it is not necessarily required to use a method to maintain the molten state of the molding material.

[0182] In this embodiment, a method for calculating the weight of the molding material was described based on the detected pressure and temperature of the molding material. However, this embodiment is not limited to a method for calculating the weight of the molding material based on the detected pressure and temperature of the molding material; other methods may be used to calculate the weight of the remaining molding material and the weight of the discharged molding material.

[0183] <effect> In the above-described embodiment, by having the above-described configuration, the weight of the molding material injected from the injection device 300 by the nth injection can be calculated each time injection is performed from the injection device 300, based on the pressure and temperature of the molding material obtained from sensors 1011 and 1012 (an example of a detection unit). Therefore, the weight of the molding material injected into the measuring mechanism 1000 can be calculated on a shot-by-shot basis of the injection molding machine. Since there is no need to wait for the molded product to cool and solidify as in the conventional method, the time until weight measurement is performed each time injection is performed can be shortened.

[0184] In this embodiment, using the measurement mechanism 1000, the weight of the molding material injected from the injection device 300 by the nth injection can be calculated based on the pressure and temperature of the molding material obtained from sensors 1011 and 1012 (an example of a detection unit). Therefore, the weight of the molding material injected from the injection device 300 to the measurement mechanism 1000 can be calculated without being limited by the capacity of the mold device 800. In this way, the measurement device 1200 can appropriately recognize the amount of molding material injected from the injection device 300.

[0185] Furthermore, by performing injection multiple times, the measuring device 1200 can recognize variations in the weight of the injected molding material according to the injection conditions. This weight variation can be measured for each condition set in the injection molding machine 10. Therefore, the measuring device 1200 according to this embodiment can recognize variations in the weight of the injected molding material according to the injection conditions. As a result, by referring to the log information recorded in the above-described embodiment, injection conditions that can suppress variations can be derived, thereby improving the stability during injection.

[0186] Furthermore, in this embodiment, the measuring device 1200 can calculate the weight of the molded material after it has been injected from the injection device 300. In other words, instead of estimating the weight of the injected molded material based on the detection results of the condition of the molded material inside the cylinder 310 of the injection device 300, the measuring device calculates the actual weight of the molded material after it has been injected. Therefore, since the actual weight of the injected molded material is calculated, the accuracy of the weight calculation can be improved compared to the case where the weight of the injected molded material is estimated from the detection results of the condition inside the cylinder 310.

[0187] Furthermore, in the above-described embodiment, the heater 1051 heats the area around the measuring mechanism 1000, so the molten state of the molding material inside the measuring mechanism 1000 can be maintained. Therefore, when using the mold device 800, cooling and solidification of the molding material inside the mold device 800 can be suppressed. In other words, cooling and solidification of the molding material near the walls of sensors 1011 and 1012 can be suppressed. Therefore, it is possible to prevent a situation where the temperature and pressure of the molten molding material cannot be measured due to the generation of cooled and solidified molding material near sensors 1011 and 1012. In other words, in the above-described embodiment, the temperature and pressure of the molten molding material can be detected, so a decrease in the accuracy of calculating the weight of the actually injected molding material can be suppressed.

[0188] The above describes embodiments of the measuring device for an injection molding machine and the injection molding machine according to the present invention, but the present invention is not limited to the above embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope described in the claims. These also naturally fall within the technical scope of the present invention. [Explanation of Symbols]

[0189] 10 injection molding machine 300 Injection device 310 Cylinder 320 nozzles 1200 Measuring device 1000 Measuring Mechanism 1001 Sprue section 1002 Runners 1003 Gate 1004 Cavity section 1005 Aperture section 1006 Nozzle storage space 1011, 1012 sensors 1021 Filling port 1022 Outlet 1051 Heater 1100 Information Processing Device 1101 CPU 1111 Acquisition Department 1112 Emissions Calculation Department 1113 Residual amount calculation section 1114 Injection amount calculation section 1115 Writing Control Unit 1102 Storage medium 1121 Log Information Storage Unit

Claims

1. A measuring mechanism having a filling port into which molding material injected from the injection device of an injection molding machine can be filled, an outlet into which the molding material can be discharged, and a space connecting the filling port and the outlet, The amount of the molding material discharged from the discharge port is calculated, The amount of the molding material remaining in the space is calculated, A control unit configured to calculate the amount of molding material injected from the injection device into the filling port during the nth injection, based on the amount of molding material discharged from the discharge port during the nth injection, the amount of molding material remaining in the space after the nth injection, and the amount of molding material remaining in the space after the (n-1)th injection. A measuring device for an injection molding machine equipped with [specific features / features].

2. The control unit, The pressure and temperature of the molding material remaining in the space are obtained from the detection unit. Based on the volume of the space, the pressure, and the temperature, the amount of molding material remaining in the space is calculated. While the injection device is injecting the molding material into the filling port, the amount of the molding material discharged from the discharge port by the nth injection is calculated based on the pressure and temperature of the molding material obtained from the detection unit. A measuring device for an injection molding machine according to claim 1.

3. The measurement mechanism further comprises a heating section for heating the aforementioned measuring mechanism. The control unit, Based on the volume of the space, the pressure, and the temperature, the amount of the molding material that has been melted by heating in the heating section is calculated. The injection device is configured to calculate the amount of the molding material that has been melted by heating by the heating unit and discharged from the discharge port, based on the pressure and temperature obtained from the detection unit while the injection device is injecting the molding material into the filling port. A measuring device for an injection molding machine according to claim 2.

4. The measurement mechanism is provided with a constriction in the flow path of the molding material connecting the filling port and the discharge port within the space, such that the opening area is narrower compared to other areas of the flow path. The control unit is configured to acquire the temperature and pressure of the molding material before it passes through the choke, and to acquire the temperature and pressure of the molding material after it passes through the choke. A measuring device for an injection molding machine according to claim 2 or 3.

5. The measurement mechanism can be installed on the injection molding machine, replacing the mold device provided on the injection molding machine. A measuring device for an injection molding machine according to any one of claims 1 to 3.

6. An injection molding machine equipped with the measuring device according to any one of claims 1 to 3.

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