Injection molding machine

Abstract

To provide a technique for improving convenience of a user of an injection molding machine.SOLUTION: An injection molding machine includes: a control device for controlling a moving mechanism on the basis of a result value of a clamp force detected at a predetermined acquisition timing during a molding cycle; and a display device for displaying a setting screen to which the acquisition timing is inputted. The control device acquires the result value of the clamp force detected at the acquisition timing inputted in the setting screen. The setting screen includes waveform data indicating the transition of the clamp force, and a pointer indicating the acquisition timing on the waveform data. The control device acquires the result value of the clamp force detected at the acquisition timing designated at a position indicated by the pointer. The control device controls the display device to display a candidate of the acquisition timing on the setting screen simultaneously with the waveform data and the pointer for proposal to a user.SELECTED DRAWING: Figure 11

Description

[Technical Field]

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

[0002] The injection molding machine of Patent Document 1 has a fixed platen on which a fixed mold is attached, a movable platen on which a movable mold is attached, a toggle support arranged at an interval from the fixed platen, tie bars connecting the fixed platen and the toggle support, and a toggle mechanism that moves the movable platen in the mold opening / closing direction relative to the toggle support. The fixed mold and movable mold constitute a mold device.

[0003] The thickness of the mold unit may change due to temperature changes in the mold unit. Since the temperature of the mold unit tends to rise over time, the thickness of the mold unit tends to increase over time. However, the thickness of the mold unit may also decrease. If the thickness of the mold unit changes, the actual clamping force value will also change.

[0004] Therefore, the injection molding machine of Patent Document 1 has a mold thickness adjustment mechanism that adjusts the distance between the fixed platen and the toggle support. The mold thickness adjustment mechanism includes a screw shaft formed on the tie bar, a screw nut rotatably attached to the toggle support, and a mold thickness adjustment motor that rotates the screw nut screwed onto the screw shaft. The mold thickness adjustment mechanism adjusts the mold thickness by adjusting the position of the toggle support. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2017 / 164420 Summary of the Invention [Problem to be solved by the invention]

[0006] The control device controls the movement mechanism based on the actual value of the mold clamping force detected at a predetermined acquisition timing during the molding cycle. The movement mechanism moves the movable platen in the mold opening / closing direction relative to the fixed platen. The detected value at the acquisition timing is the actual value of the mold clamping force used to control the movement mechanism.

[0007] The movement mechanism is controlled based on the actual value of the mold clamping force, and for example, mold thickness adjustment is performed. The actual value of the mold clamping force is used for mold thickness adjustment. When the deviation between the actual value of the mold clamping force and the set value is outside the allowable range, mold thickness adjustment is performed. On the other hand, when the deviation is within the allowable range, mold thickness adjustment is not performed.

[0008] Conventionally, the timing for acquiring the actual value of the mold clamping force was stored in advance in a storage medium of a control device and could not be changed. This resulted in poor user convenience. For example, if the actual value of the mold clamping force fluctuates during the mold clamping process, restrictions such as prohibiting mold thickness adjustment were imposed, resulting in poor user convenience. Mold thickness adjustment is prohibited because, if the actual value of the mold clamping force fluctuates during the mold clamping process, poor timing for acquiring the actual value of the mold clamping force will result in a large error in the actual value of the mold clamping force.

[0009] One aspect of the present invention provides a technique for improving convenience for users of injection molding machines. [Means for solving the problem]

[0010] According to one aspect of the present invention The injection molding machine includes a movement mechanism that moves a movable platen relative to a fixed platen in a mold opening / closing direction, a clamping force detector that detects an actual value of the clamping force, a control device that controls the movement mechanism based on the actual value of the clamping force detected at a predetermined acquisition timing during a molding cycle, and a display device that displays a setting screen into which the acquisition timing is input. The control device acquires the actual value of the clamping force detected at the acquisition timing input to the setting screen. The setting screen includes a designation unit that designates the acquisition timing. The control device acquires the actual value of the clamping force detected at the acquisition timing designated by the designation unit. The control device determines whether the acquisition timing designated by the designation unit is appropriate, and if the acquisition timing designated by the designation unit is not appropriate, controls the display device to display candidates for appropriate acquisition timing on the setting screen. [Effects of the Invention]

[0011] According to one aspect of the present invention, the timing for acquiring the actual value of the mold clamping force can be changed, thereby improving convenience for users of injection molding machines. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing a state when mold opening of an injection molding machine according to one embodiment is completed. [Figure 2] FIG. 2 is a diagram showing a state of the injection molding machine according to one embodiment when clamping the mold. [Figure 3] FIG. 3 is a diagram showing an example of the operation of the mold clamping device, and is a diagram showing the mold device at time t0 in FIG. [Figure 4] FIG. 4 is a diagram showing an example of the operation of the mold clamping device following FIG. 3, and is a diagram showing the mold device at time t1 in FIG. [Figure 5] FIG. 5 is a diagram showing an example of the operation of the mold clamping device following FIG. 4, and is a diagram showing the mold device at time t2 in FIG. [Figure 6] FIG. 6 is a diagram showing an example of the operation of the mold clamping device following FIG. 5, and is a diagram showing the mold device at time t3 in FIG. [Figure 7] FIG. 7 is a diagram showing an example of the operation of the mold clamping device following FIG. 6, and is a diagram showing the mold device at time t4 in FIG. [Figure 8] FIG. 8 is a diagram showing an example of a setting screen for mold clamping compression. [Figure 9] FIG. 9 is a diagram showing an example of the transition of the mold clamping force controlled in accordance with the setting screen of FIG. [Figure 10] FIG. 10 is a functional block diagram illustrating an example of components of the control device. [Figure 11] FIG. 11 is a diagram showing an example of a setting screen for inputting the timing for acquiring the actual value of the mold clamping force. [Figure 12] FIG. 12 is a diagram showing another example of the setting screen on which the timing for acquiring the actual value of the mold clamping force is input. DETAILED DESCRIPTION OF THE INVENTION

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0047] The mold clamping unit 100 may have a tie bar temperature regulator 190 that regulates the temperature of the tie bars 140. The tie bar temperature regulator 190 includes a heater, for example. The heater heats the tie bars 140. The tie bar temperature regulator 190 may also include a cooler, such as a water-cooled jacket. The cooler cools the tie bars 140. The tie bar temperature regulator 190 may include both a heater and a cooler.

[0048] The tie bar temperature regulator 190 adjusts the temperature of the tie bar 140 and adjusts the length of the tie bar 140. The higher the temperature of the tie bar 140, the greater the thermal expansion of the tie bar 140, and the longer the length of the tie bar 140. When the length of the tie bar 140 changes, the distribution of the surface pressure generated at the parting surface (so-called parting surface) between the fixed mold 810 and the movable mold 820 during mold clamping changes. The temperature of the tie bar 140 is adjusted so that the distribution becomes the desired distribution.

[0049] The control device 700 detects the distribution of surface pressure generated on the parting surfaces of the fixed mold 810 and the movable mold 820 during mold clamping using a plurality of tie bar strain detectors 141 attached to the plurality of tie bars 140. The control device 700 then controls the temperature of the tie bars 140 so that the distribution of surface pressure becomes the desired distribution. The tie bar temperature regulator 190 is attached to one or more tie bars 140 and regulates the temperature of the one or more tie bars 140.

[0050] The mold clamping unit 100 of this embodiment is a horizontal type in which the mold opening and closing direction is horizontal, but it may also be a vertical type in which the mold opening and closing direction is vertical.

[0051] Although the mold clamping unit 100 of this embodiment has a mold clamping motor 160 as a drive source, it may have a hydraulic cylinder instead of the mold clamping motor 160. Also, the mold clamping unit 100 may have a linear motor for opening and closing the mold, and an electromagnet for mold clamping.

[0052] (Ejector device) In describing the ejector device 200, similar to the description of the mold clamping device 100, the direction of movement of the movable platen 120 when the mold is closed (e.g., the positive direction of the X-axis) is defined as the front, and the direction of movement of the movable platen 120 when the mold is opened (e.g., the negative direction of the X-axis) is defined as the rear.

[0053] The ejector unit 200 is attached to the movable platen 120 and moves forward and backward together with the movable platen 120. The ejector unit 200 has an ejector rod 210 that ejects a molded product from the mold device 800, and a drive mechanism 220 that moves the ejector rod 210 in the movement direction of the movable platen 120 (X-axis direction).

[0054] The ejector rod 210 is arranged so as to be able to move forward and backward in a through-hole of the movable platen 120. The front end of the ejector rod 210 contacts an ejector plate 826 of the movable mold 820. The front end of the ejector rod 210 may or may not be connected to the ejector plate 826.

[0055] The drive mechanism 220 includes, for example, an ejector motor and a motion conversion mechanism that converts the rotational motion of the ejector motor into linear motion of the ejector rod 210. The motion conversion mechanism includes a screw shaft and a screw nut that screws onto the screw shaft. Balls or rollers may be interposed between the screw shaft and the screw nut.

[0056] The ejector unit 200 performs an ejection process under the control of the control unit 700. In the ejection process, the ejector rod 210 is advanced from the standby position to the ejection position at a set moving speed, thereby advancing the ejector plate 826 and ejecting the molded product. After that, the ejector motor is driven to retract the ejector rod 210 at the set moving speed, and the ejector plate 826 is retracted to the original standby position.

[0057] The position and movement speed of the ejector rod 210 are detected using, for example, an ejector motor encoder. The ejector motor encoder detects the rotation of the ejector motor and sends a signal indicating the detection result to the control device 700. Note that the ejector rod position detector that detects the position of the ejector rod 210 and the ejector rod movement speed detector that detects the movement speed of the ejector rod 210 are not limited to the ejector motor encoder, and general types can be used.

[0058] (injection device) In the description of the injection device 300, unlike the description of the mold clamping device 100 and the description of the ejector device 200, the movement direction of the screw 330 during filling (e.g., the negative X-axis direction) is described as the forward direction, and the movement direction of the screw 330 during metering (e.g., the positive X-axis direction) is described as the rearward direction.

[0059] The injection unit 300 is mounted on a slide base 301, and the slide base 301 is disposed so as to be able to move forward and backward relative to the injection unit frame 920. The injection unit 300 is disposed so as to be able to move forward and backward relative to the mold unit 800. The injection unit 300 touches the mold unit 800 and fills a cavity space 801 in the mold unit 800 with a molding material. The injection unit 300 includes, for example, a cylinder 310 that heats the molding material, a nozzle 320 provided at the front end of the cylinder 310, a screw 330 that is disposed so as to be able to move forward and backward and to be able to rotate within the cylinder 310, a metering motor 340 that rotates the screw 330, an injection motor 350 that moves the screw 330 forward and backward, and a load detector 360 that detects a load transmitted between the injection motor 350 and the screw 330.

[0060] Cylinder 310 heats the molding material supplied to the interior through supply port 311. The molding material includes, for example, resin. The molding material is formed, for example, in the form of pellets, and is supplied to supply port 311 in a solid state. Supply port 311 is formed at the rear of cylinder 310. A cooler 312, such as a water-cooled cylinder, is provided on the outer periphery of the rear of cylinder 310. A heater 313, such as a band heater, and a temperature detector 314 are provided on the outer periphery of cylinder 310, ahead of cooler 312.

[0061] Cylinder 310 is divided into a plurality of zones in the axial direction (e.g., X-axis direction) of cylinder 310. Each of the plurality of zones is provided with a heater 313 and a temperature detector 314. A set temperature is set for each of the plurality of zones, and control device 700 controls heater 313 so that the temperature detected by temperature detector 314 becomes the set temperature.

[0062] The nozzle 320 is provided 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 periphery of the nozzle 320. The control device 700 controls the heater 313 so that the detected temperature of the nozzle 320 becomes the set temperature.

[0063] The screw 330 is disposed within the cylinder 310 so as to be rotatable and movable forward and backward. When the screw 330 is rotated, the molding material is sent forward along the spiral groove of the screw 330. As the molding material is sent forward, it is gradually melted by the heat from the cylinder 310. As the liquid molding material is sent forward to the front of the screw 330 and accumulates in the front part of the cylinder 310, the screw 330 is moved backward. Thereafter, when the screw 330 is moved forward, the liquid molding material accumulated in front of the screw 330 is injected from the nozzle 320 and filled into the mold device 800.

[0064] A backflow prevention ring 331 is attached to the front of the screw 330 so as to be movable back and forth as a backflow prevention valve for preventing the molding material from flowing back from the front to the rear of the screw 330 when the screw 330 is pushed forward.

[0065] When the screw 330 is moved forward, the backflow prevention ring 331 is pushed backward by the pressure of the molding material in front of the screw 330, and moves back relative to the screw 330 to a blocking position (see FIG. 2) where it blocks the flow path of the molding material. This prevents the molding material accumulated in front of the screw 330 from flowing backward.

[0066] On the other hand, when the screw 330 is rotated, the backflow prevention ring 331 is pushed forward by the pressure of the molding material sent forward along the spiral groove of the screw 330, and moves forward relative to the screw 330 to the open position (see FIG. 1) where it opens the flow path of the molding material. This causes the molding material to be sent forward of the screw 330.

[0067] 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.

[0068] The injection device 300 may have a drive source for moving the backflow prevention ring 331 back and forth relative to the screw 330 between the open position and the closed position.

[0069] The metering motor 340 rotates the screw 330. The drive source for rotating the screw 330 is not limited to the metering motor 340, and may be, for example, a hydraulic pump.

[0070] The injection motor 350 advances and retreats the screw 330. A motion conversion mechanism that converts the rotational motion of the injection motor 350 into linear motion of the screw 330 is provided between the injection motor 350 and the screw 330. The motion conversion mechanism has, for example, a screw shaft and a screw nut that screws onto the screw shaft. A ball or roller may be provided between the screw shaft and the screw nut. The drive source that advances and retreats the screw 330 is not limited to the injection motor 350 and may be, for example, a hydraulic cylinder.

[0071] The load detector 360 detects the load transmitted between the injection motor 350 and the screw 330. The detected load is converted into pressure by the control device 700. The load detector 360 is provided on the load transmission path between the injection motor 350 and the screw 330, and detects the load acting on the load detector 360.

[0072] The load detector 360 sends a signal of the detected load to the control device 700. The load detected by the load detector 360 is converted into pressure acting between the screw 330 and the molding material, and is used to control and monitor the pressure that the screw 330 receives from the molding material, the back pressure on the screw 330, the pressure that the screw 330 acts on the molding material, and the like.

[0073] The pressure detector that detects the pressure of the molding material is not limited to the load detector 360, and a general detector can be used. For example, a nozzle pressure sensor or a mold internal pressure sensor may be used. The nozzle pressure sensor is installed in the nozzle 320. The mold internal pressure sensor is installed inside the mold device 800.

[0074] The injection device 300 performs a metering process, a filling process, a pressure holding process, etc. under the control of the control device 700. The filling process and the pressure holding process may be collectively referred to as the injection process.

[0075] In the metering process, the metering motor 340 is driven to rotate the screw 330 at a set rotational speed, and the molding material is sent forward along the spiral groove of the screw 330. As this happens, the molding material gradually melts. As the liquid molding material is sent forward to the screw 330 and accumulates at the front of the cylinder 310, the screw 330 is moved backward. The rotational speed of the screw 330 is detected, for example, using a metering motor encoder 341. The metering motor encoder 341 detects the rotation of the metering motor 340 and sends a signal indicating the detection result to the control device 700. Note that the screw rotational speed detector that detects the rotational speed of the screw 330 is not limited to the metering motor encoder 341, and a general one can be used.

[0076] In the metering process, in order to restrict abrupt retraction of the screw 330, the injection motor 350 may be driven to apply a set back pressure to the screw 330. The back pressure on the screw 330 is detected using, for example, a load detector 360. When the screw 330 retracts to the metering completion position and a predetermined amount of molding material accumulates in front of the screw 330, the metering process is completed.

[0077] The position and rotational speed of the screw 330 in the metering process are set together as a series of setting conditions. For example, a metering start position, a rotational speed switching position, and a metering completion position are set. These positions are arranged in this order from the front to the rear, and represent the start and end points of the section for which the rotational speed is set. The rotational speed is set for each section. There may be one or more rotational speed switching positions. The rotational speed switching position does not have to be set. In addition, a back pressure is set for each section.

[0078] In the filling process, the injection motor 350 is driven to move the screw 330 forward at a set moving speed, and the liquid molding material accumulated in front of the screw 330 is filled into the cavity space 801 in the mold device 800. The position and moving speed of the screw 330 are detected using, for example, an injection motor encoder 351. The injection motor encoder 351 detects the rotation of the injection motor 350 and sends a signal indicating the detection result to the control device 700. When the position of the screw 330 reaches a set position, a switch from the filling process to a pressure holding process (so-called V / P switch) is performed. The position at which the V / P switch is performed is also called the V / P switch position. The set moving speed of the screw 330 may be changed depending on the position of the screw 330, time, etc.

[0079] The position and movement speed of the screw 330 in the filling process are set together as a series of setting conditions. For example, a filling start position (also called an "injection start position"), a movement speed switching position, and a V / P switching position are set. These positions are arranged in this order from rear to front, and represent the start and end points of the section for which the movement speed is set. The movement speed is set for each section. There may be one or more movement speed switching positions. The movement speed switching position does not have to be set.

[0080] An upper limit value for the pressure of the screw 330 is set for each section in which the movement speed of the screw 330 is set. The pressure of the screw 330 is detected by a load detector 360. When the pressure of the screw 330 is equal to or lower than the set pressure, the screw 330 is advanced at the set movement speed. On the other hand, when the pressure of the screw 330 exceeds the set pressure, the screw 330 is advanced at a movement speed slower than the set movement speed so that the pressure of the screw 330 is equal to or lower than the set pressure, in order to protect the mold.

[0081] It should be noted that after the position of the screw 330 reaches the V / P switching position during the filling process, the screw 330 may be temporarily stopped at the V / P switching position, and then V / P switching may be performed. Immediately before V / P switching, instead of stopping the screw 330, the screw 330 may be moved forward or backward at a slow speed. Furthermore, the screw position detector that detects the position of the screw 330 and the screw movement speed detector that detects the movement speed of the screw 330 are not limited to the injection motor encoder 351, and general detectors may be used.

[0082] In the dwelling step, the injection motor 350 is driven to push the screw 330 forward, maintaining the pressure of the molding material at the front end of the screw 330 (hereinafter also referred to as "holding pressure") at a set pressure, and pushing the molding material remaining in the cylinder 310 toward the mold device 800. This can replenish any molding material that is insufficient due to cooling contraction within the mold device 800. The holding pressure is detected, for example, using a load detector 360. The set value of the holding pressure may be changed depending on the elapsed time from the start of the dwelling step, etc. Multiple holding pressures and holding times for maintaining the holding pressure in the dwelling step may be set, or they may be set together as a series of setting conditions.

[0083] In the dwelling step, the molding material in the cavity space 801 in the mold device 800 is gradually cooled, and when the dwelling step is completed, the entrance to the cavity space 801 is blocked by the solidified molding material. This state is called a gate seal, and prevents the molding material from flowing back from the cavity space 801. After the dwelling step, the cooling step begins. In the cooling step, the molding material in the cavity space 801 is solidified. A metering step may be performed during the cooling step in order to shorten the molding cycle time.

[0084] Although the injection device 300 of this embodiment is of an in-line screw type, it may also be of a pre-plasticization type. A pre-plasticization type injection device supplies molding material molten in a plasticization cylinder to an injection cylinder, and injects the molding material from the injection cylinder into a mold device. A screw is disposed in the plasticization cylinder so that it can rotate freely but cannot move back and forth, or the screw is disposed so that it can rotate freely and move back and forth. Meanwhile, a plunger is disposed in the injection cylinder so that it can move back and forth.

[0085] Furthermore, although the injection unit 300 of this embodiment is a horizontal type in which the axial direction of the cylinder 310 is horizontal, it may be a vertical type in which the axial direction of the cylinder 310 is vertical. The mold clamping unit combined with the vertical injection unit 300 may be either a vertical type or a horizontal type. Similarly, the mold clamping unit combined with the horizontal injection unit 300 may be either a horizontal type or a vertical type.

[0086] (Mobile device) In the description of the moving device 400, similar to the description of the injection device 300, the moving direction of the screw 330 during filling (e.g., the negative X-axis direction) is defined as the front, and the moving direction of the screw 330 during metering (e.g., the positive X-axis direction) is defined as the rear.

[0087] The moving device 400 moves the injection device 300 forward and backward relative to the mold device 800. The moving device 400 also presses the nozzle 320 against the mold device 800 to generate nozzle touch pressure. The moving device 400 includes a hydraulic pump 410, a motor 420 as a drive source, a hydraulic cylinder 430 as a hydraulic actuator, and the like.

[0088] The hydraulic pump 410 has a first port 411 and a second port 412. The hydraulic pump 410 is a bidirectional pump, and by switching the rotation direction of the motor 420, it draws in hydraulic fluid (e.g., oil) from one of the first port 411 and the second port 412 and discharges it from the other, thereby generating hydraulic pressure. Note that the hydraulic pump 410 can also draw in hydraulic fluid from a tank and discharge it from either the first port 411 or the second port 412.

[0089] The motor 420 operates the hydraulic pump 410. The motor 420 drives the hydraulic pump 410 in a rotational direction and with a rotational torque according to a control signal from the control device 700. The motor 420 may be an electric motor or an electric servo motor.

[0090] The hydraulic cylinder 430 has a cylinder body 431, a piston 432, and a piston rod 433. The cylinder body 431 is fixed to the injection device 300. The piston 432 divides the interior of the cylinder body 431 into a front chamber 435 as a first chamber and a rear chamber 436 as a second chamber. The piston rod 433 is fixed to the fixed platen 110.

[0091] A front chamber 435 of the hydraulic cylinder 430 is connected to a first port 411 of the hydraulic pump 410 via a first flow path 401. The hydraulic fluid discharged from the first port 411 is supplied to the front chamber 435 via the first flow path 401, thereby pushing the injection unit 300 forward. The injection unit 300 is moved forward, and the nozzle 320 is pressed against the fixed mold 810. The front chamber 435 functions as a pressure chamber that generates nozzle touch pressure of the nozzle 320 by the pressure of the hydraulic fluid supplied from the hydraulic pump 410.

[0092] Meanwhile, the rear chamber 436 of the hydraulic cylinder 430 is connected to the second port 412 of the hydraulic pump 410 via the second flow path 402. The hydraulic fluid discharged from the second port 412 is supplied to the rear chamber 436 of the hydraulic cylinder 430 via the second flow path 402, thereby pushing the injection unit 300 backward. The injection unit 300 is moved backward, and the nozzle 320 is separated from the fixed mold 810.

[0093] In this embodiment, the moving device 400 includes the hydraulic cylinder 430, but the present invention is not limited to this. For example, instead of the hydraulic cylinder 430, an electric motor and a motion conversion mechanism that converts the rotational motion of the electric motor into the linear motion of the injection device 300 may be used.

[0094] (Control device) The control device 700 is configured, for example, by a computer, and as shown in Figures 1 and 2, has a CPU (Central Processing Unit) 701, a storage medium 702 such as a memory, an input interface 703, and an output interface 704. The control device 700 performs various controls by causing the CPU 701 to execute a program stored in the storage medium 702. The control device 700 also receives signals from the outside via the input interface 703 and transmits signals to the outside via the output interface 704.

[0095] The control device 700 repeatedly manufactures molded products by repeating processes such as a metering process, mold closing process, pressure increase process, mold clamping process, filling process, pressure dwell process, cooling process, pressure release process, mold opening process, and ejection process. A series of operations required to obtain a molded product, such as the operations from the start of a metering process to the start of the next metering process, is also called a "shot" or "molding cycle." The time required for one shot is also called the "molding cycle time" or "cycle time."

[0096] One molding cycle includes, for example, a metering process, a mold closing process, a pressurization process, a mold clamping process, a filling process, a pressure holding process, a cooling process, a depressurization process, a mold opening process, and an ejection process, in this order. The order here refers to the order in which each process starts. The filling process, the pressure holding process, and the cooling process are performed during the mold clamping process. The start of the mold clamping process may coincide with the start of the filling process. The completion of the depressurization process coincides with the start of the mold opening process.

[0097] It should be noted that, in order to shorten the molding cycle time, multiple processes may be performed simultaneously. For example, the metering process may be performed during the cooling process of the previous molding cycle, or during the mold clamping process. In this case, the mold closing process may be performed at the beginning of the molding cycle. The filling process may be started during the mold closing process. The ejection process may be started during the mold opening process. If an on-off valve for opening and closing the flow path of the nozzle 320 is provided, the mold opening process may be started during the metering process. This is because, even if the mold opening process is started during the metering process, the molding material will not leak from the nozzle 320 as long as the on-off valve closes the flow path of the nozzle 320.

[0098] One molding cycle may include steps other than the metering step, mold closing step, pressure increase step, mold clamping step, filling step, pressure holding step, cooling step, pressure release step, mold opening step, and ejection step.

[0099] For example, after the dwelling step is completed and before the metering step begins, a pre-metering suck-back step may be performed in which the screw 330 is retracted to a preset metering start position. This can reduce the pressure of the molding material accumulated in front of the screw 330 before the metering step begins, and prevent the screw 330 from retracting suddenly at the start of the metering step.

[0100] Furthermore, after the metering step is completed and before the filling step begins, a post-metering suck-back step may be performed in which the screw 330 is retracted to a preset filling start position (also referred to as the "injection start position"). This can reduce the pressure of the molding material accumulated in front of the screw 330 before the filling step begins, and can prevent the molding material from leaking from the nozzle 320 before the filling step begins.

[0101] The control device 700 is connected to an operation device 750 that accepts input operations by a user and a display device 760 that displays a screen. The operation device 750 and the display device 760 may be integrated, for example, by using a touch panel 770. The touch panel 770 serving as the display device 760 displays a screen under the control of the control device 700. The screen of the touch panel 770 may display information such as settings of the injection molding machine 10 and the current status of the injection molding machine 10. The screen of the touch panel 770 may also display operation units such as buttons and input fields that accept input operations by the user. The touch panel 770 serving as the operation device 750 detects input operations on the screen by the user and outputs signals corresponding to the input operations to the control device 700. This allows, for example, a user to operate the operation units provided on the screen while checking information displayed on the screen to perform settings of the injection molding machine 10 (including input of setting values). The user can also operate the operation units provided on the screen to cause the injection molding machine 10 to perform operations corresponding to the operation units. The operation of the injection molding machine 10 may be, for example, the operation (including stopping) of the clamping device 100, the ejector device 200, the injection device 300, the moving device 400, etc. The operation of the injection molding machine 10 may also be the switching of a screen displayed on the touch panel 770 serving as the display device 760, etc.

[0102] Although the operation device 750 and the display device 760 of this embodiment have been described as being integrated as the touch panel 770, they may be provided independently. Also, a plurality of operation devices 750 may be provided. The operation device 750 and the display device 760 are disposed on the operation side (negative Y-axis direction) of the mold clamping unit 100 (more specifically, the fixed platen 110).

[0103] (mold clamping compression) The movement mechanism 102 of the mold clamping unit 100 advances the movable platen 120 as shown in FIGS. 3 to 7 under the control of the control device 700, compressing the molding material filled in the cavity space 801. Compressing the molding material by the operation of the mold clamping unit 100 is called "mold clamping compression." Mold clamping compression is performed under the control of the control device 700. FIG. 3 is a diagram showing an example of the operation of the mold clamping unit, and is a diagram showing the mold unit at time t0 in FIG. 9. FIG. 4 is a diagram showing an example of the operation of the mold clamping unit subsequent to FIG. 3, and is a diagram showing the mold unit at time t1 in FIG. 9. FIG. 5 is a diagram showing an example of the operation of the mold clamping unit subsequent to FIG. 4, and is a diagram showing the mold unit at time t2 in FIG. 9. FIG. 6 is a diagram showing an example of the operation of the mold clamping unit subsequent to FIG. 5, and is a diagram showing the mold unit at time t3 in FIG. 9. FIG. 7 is a diagram showing an example of the operation of the mold unit subsequent to FIG. 6, and is a diagram showing the mold unit at time t4 in FIG. 9.

[0104] The mold apparatus 800 includes a fixed mold 810 and a movable mold 820. The fixed mold 810 has, for example, a fixed mounting plate 811 attached to the fixed platen 110, a fixed mold plate 812 that forms a cavity space 801 when the mold is clamped, and a sprue bushing 813 against which the nozzle 320 of the injection apparatus 300 is pressed. The sprue bushing 813 includes a bushing that is inserted into a through hole in the fixed mold plate 812 and a flange that is inserted into a through hole in the fixed mounting plate 811. A sprue 802 is formed to pass through the sprue bushing 813. The sprue 802 is a flow path for the molding material. The nozzle 320 of the injection apparatus 300 is pressed against the sprue bushing 813 to inject the molding material into the sprue 802.

[0105] The movable mold 820 has a movable mounting plate 821 attached to the movable platen 120, a movable mold plate 822 that forms a cavity space 801 when the mold is clamped, a movable receiving plate 823 that supports the movable mold plate 822 from the rear, and a spacer block 824 that is arranged between the movable receiving plate 823 and the movable mounting plate 821. The spacer block 824 forms a space in which an ejector plate 826 moves in the mold opening and closing direction. From the rear side to the front side, the movable mounting plate 821, the spacer block 824, the movable receiving plate 823, and the movable mold plate 822 are stacked in this order.

[0106] The movable mold 820 has ejector pins 825 that eject the molded product, and an ejector plate 826 to which the ejector pins 825 are attached. The ejector pins 825 are inserted into through holes that penetrate the movable mold plate 822 and the movable receiving plate 823. The ejector plate 826 includes two plates 826a and 826b that sandwich and press the flanges of the ejector pins 825.

[0107] The movable mold 820 further includes a movable core 827 that is guided in the mold opening / closing direction by the movable mold plate 822, and a spring 828 that urges the movable core 827 in the mold closing direction. A cylinder (not shown) that moves the movable core 827 in the mold opening / closing direction may be provided instead of the spring 828. The movable core 827 comes into contact with the fixed mold plate 812 during mold clamping.

[0108] 5, the movable core 827 forms a runner 803 when the mold is clamped. The runner 803 is a flow path for the molding material that continues to the sprue 802 and is connected to the cavity space 801 via a gate 804. The molding material passes through the sprue 802, the runner 803, and the gate 804 and is filled into the cavity space 801.

[0109] The movable mold 820 has a core pin 829 that ejects unwanted parts solidified in the runner 803. The core pin 829 is inserted into a through hole that penetrates the movable core 827 and the movable receiving plate 823. Like the ejector pin 825, the core pin 829 is attached to the ejector plate 826 and moves forward and backward together with the ejector plate 826.

[0110] The mold device 800 includes a gap detector 831 that detects the gap G between the movable mold plate 822 and the fixed mold plate 812 during mold clamping. The gap detector 831 includes, for example, a displacement sensor 831a attached to the movable receiving plate 823 and a target 831b attached to the movable core 827.

[0111] Displacement sensor 831a detects the displacement of target 831b and, by extension, movable core 827, thereby detecting gap G (see FIGS. 4 to 7) between movable mold plate 822 and fixed mold plate 812. Target 831b may be attached to fixed mold plate 812 instead of movable core 827. Also, the positions of displacement sensor 831a and target 831b may be reversed.

[0112] The movement mechanism 102 of the mold clamping unit 100, under the control of the control device 700, moves the movable platen 120 forward as shown in Figures 3 to 7, thereby compressing the molding material filled in the cavity space 801. First, as shown in Figure 3, at the start of the mold closing process, the movable mold 820 and the fixed mold 810 are separated. Next, when the movement mechanism 102 moves the movable platen 120 forward, the movable core 827 comes into contact with the fixed mold plate 812 as shown in Figure 4, and the mold closing process is completed.

[0113] Next, when the movement mechanism 102 moves the movable platen 120 forward, the spring 828 contracts as shown in FIG. 5. The elastic restoring force of the spring 828 and the mold clamping force are balanced. When the mold clamping force reaches a preset Frst (see FIG. 9), the advancement of the movable platen 120 is stopped, and the pressure increase process is completed. At the completion of the pressure increase process, the gap G detected by the gap detector 831 is reset to zero. A negative gap G means that the gap G is narrowing, and a positive gap G means that the gap G is widening.

[0114] Next, the movement mechanism 102 moves the movable platen 120 backward or forward until the gap G reaches a preset G0 (see FIG. 8) or until the mold clamping force reaches a preset F0 (see FIG. 9). G0 and F0 correspond one-to-one, and the smaller G0 is, the larger F0 is.

[0115] Next, when the gap G is G0 or the mold clamping force is F0, the nozzle 320 of the injection unit 300 injects the molding material into the mold unit 800, as shown in Fig. 6. The molding material passes through the sprue 802, the runner 803, and the gate 804, and fills the cavity space 801.

[0116] 7, the moving mechanism 102 advances the movable platen 120, compressing the molding material filled in the cavity space 801. By compressing the molding material, the molding material can be spread throughout the entire cavity space 801. This allows a thin molded product to be molded with high precision. Furthermore, because filling of the molding material begins with the gap G widened, the filling pressure can be reduced.

[0117] The molding material filled in the cavity space 801 is compressed, cooled, and solidified. As a result, a molded product is obtained. After the mold is opened, the molded product is ejected from the movable mold 820 by the ejector pin 825. Specifically, the ejector rod 210 advances and pushes the ejector plate 826, which in turn advances the ejector pin 825 and ejects the molded product. At the same time, the core pin 829 also advances and ejects the unwanted part. The ejector rod 210 is then retracted to its original position.

[0118] Fig. 8 is a diagram showing an example of a setting screen for mold clamping compression. Setting screen 780 shown in Fig. 8 is displayed by display device 760. Setting screen 780 includes input fields 781A to 781E, 782A to 782E, 783A to 783D, and 784B to 784E for inputting settings for mold clamping compression for each stage of mold clamping compression. In Fig. 8, an initial stage, a first stage, a second stage, a third stage, and a fourth stage are provided as the stages of mold clamping compression.

[0119] The control method for each stage is input in input fields 781A to 781E. Either position or clamping force is selected as the control method. When position is selected as the control method, feedback control of the movement mechanism 102 of the clamping unit 100 is performed so that the detected value of the gap G becomes the set value. On the other hand, when clamping force is selected as the control method, feedback control of the movement mechanism 102 of the clamping unit 100 is performed so that the detected value of the clamping force becomes the set value. In FIG. 8, position is input as the control method for the initial stage, and clamping force is input as the control method for the first to fourth stages.

[0120] In input fields 782A to 782E, the set values ​​of the physical quantities selected as the control method are input. When position is selected as the control method, the set value of gap G is input. On the other hand, when clamping force is selected as the control method, the set value of clamping force is input. In FIG. 8, G0 is input as the set value of the initial stage position, F1 is input as the set value of the first stage clamping force, F2 is input as the set value of the second stage clamping force, F3 is input as the set value of the third stage clamping force, and F4 is input as the set value of the fourth stage clamping force.

[0121] The time length of each stage is input in input fields 783A to 783D. In Fig. 8, Th0 is input as the time length of the initial stage, Th1 is input as the time length of the first stage, Th2 is input as the time length of the second stage, and Th3 is input as the time length of the third stage. Note that the time length of the fourth stage is not input because it is automatically determined by the time length of the cooling process.

[0122] In input fields 784B to 784E, the length of time over which the set value of the physical quantity selected as the control method is changed from the value at the completion of the previous stage to the value input in input fields 782B to 782E is input for each stage except the initial stage. In Fig. 8, Tm1 is input as the length of time over which the clamping force set value is changed from F0 to F1 in the first stage, Tm2 is input as the length of time over which the clamping force set value is changed from F1 to F2 in the second stage, Tm3 is input as the length of time over which the clamping force set value is changed from F2 to F3 in the third stage, and Tm4 is input as the length of time over which the clamping force set value is changed from F3 to F4 in the fourth stage.

[0123] Fig. 9 is a diagram showing an example of the transition of mold clamping force controlled in accordance with the setting screen of Fig. 8. Fig. 9 shows the transition of the screw position in addition to the transition of the mold clamping force. In the filling process, the screw 330 is advanced from the filling start position to the V / P switching position, and the screw position value decreases. In the pressure holding process, the screw 330 is advanced or retreated (advanced in Fig. 9) so that the pressure of the molding material reaches the set value. In the cooling process, a metering process is performed, and the screw 330 is retreated to the metering completion position. The metering completion position and the filling start position may be the same position.

[0124] 9, the movement mechanism 102 of the mold clamping unit 100 starts to advance the movable platen 120, thereby starting the mold closing process. Thereafter, at time t1, the mold closing process is completed. Next, the pressure increase process is started, and the movement mechanism 102 advances the movable platen 120 until the mold clamping force reaches a preset Frst. When the mold clamping force reaches Frst, the pressure increase process is completed, and the gap G detected by the gap detector 831 is reset to zero.

[0125] Next, the initial stage of mold clamping compression begins, and the movement mechanism 102 moves the movable platen 120 backward or forward (backward in FIG. 9) until the gap G reaches a preset G0. There is a one-to-one correspondence between the gap G and the mold clamping force, and when the gap G reaches G0, the mold clamping force becomes F0. Once a preset time has elapsed since the gap G reached G0 and the gap G has stabilized, the filling process begins. The filling process begins in the middle of the initial stage.

[0126] When the elapsed time from the start of the initial stage reaches Th0, the first stage begins, and the set value of the mold clamping force is changed continuously or stepwise from F0 to F1. The time required for this change is Tm1. The time for which the set value of the mold clamping force is held at F1 is equal to the difference between Th1 (Th1>Tm1) and Tm1.

[0127] When the elapsed time from the start of the first stage reaches Th1, the second stage begins, and the set value of the mold clamping force is changed continuously or stepwise from F1 to F2. The time required for this change is Tm2. The time for which the set value of the mold clamping force is held at F2 is equal to the difference between Th2 (Th2>Tm2) and Tm2.

[0128] When the elapsed time from the start of the second stage reaches Th2, the third stage begins, and the set value of the mold clamping force is changed continuously or in steps from F2 to F3. The time required for this change is Tm3. The time for which the set value of the mold clamping force is held at F3 is equal to the difference between Th3 (Th3>Tm3) and Tm3.

[0129] When the elapsed time from the start of the third stage reaches Th3, the fourth stage begins, and the set value of the mold clamping force is changed continuously or stepwise from F3 to F4. The time required for this change is Tm4. After that, when the cooling process is completed, the depressurization process begins, followed by the mold opening process.

[0130] (Timing for obtaining actual clamping force values) The thickness of the mold device 800 may change due to temperature changes in the mold device 800, etc. Since the temperature of the mold device 800 tends to rise over time, the thickness of the mold device 800 tends to increase over time. However, the thickness of the mold device 800 may also decrease. If the thickness of the mold device 800 changes, the actual value of the mold clamping force will also change. The actual value of the mold clamping force is detected by a mold clamping force detector such as a tie bar strain detector 141.

[0131] Therefore, the movement mechanism 102 of the injection molding machine 10 has a mold thickness adjustment mechanism 180 that adjusts the distance L between the fixed platen 110 and the toggle support 130. The mold thickness adjustment mechanism 180 includes a screw shaft 181 formed on the tie bar 140, a screw nut 182 rotatably attached to the toggle support 130, and a mold thickness adjustment motor 183 that rotates the screw nut 182 that is threaded onto the screw shaft 181. The mold thickness adjustment mechanism 180 adjusts the mold thickness by adjusting the position of the toggle support 130.

[0132] The control device 700 controls the moving mechanism 102 based on the actual value of the mold clamping force detected at a predetermined acquisition timing during the molding cycle. The detected value at the acquisition timing is the actual value of the mold clamping force used to control the moving mechanism 102. Based on the actual value of the mold clamping force, the moving mechanism 102 is controlled, and for example, mold thickness adjustment is performed. The actual value of the mold clamping force is used for mold thickness adjustment. If the deviation between the actual value of the mold clamping force and the set value is outside the allowable range, mold thickness adjustment is performed. On the other hand, if the deviation is within the allowable range, mold thickness adjustment is not performed.

[0133] Conventionally, the timing for acquiring the actual value of the mold clamping force was stored in advance in the storage medium 702 of the control device 700 and could not be changed. This resulted in poor user convenience. For example, if the actual value of the mold clamping force fluctuates during the mold clamping process, restrictions such as prohibiting mold thickness adjustment were imposed, resulting in poor user convenience. Mold thickness adjustment is prohibited because, if the actual value of the mold clamping force fluctuates during the mold clamping process, poor timing for acquiring the actual value of the mold clamping force will result in a large error in the actual value of the mold clamping force.

[0134] Therefore, the control device 700 of this embodiment has various functions to improve user convenience. FIG. 10 is a diagram showing an example of components of the control device in the form of functional blocks. Each functional block shown in FIG. 10 is conceptual and does not necessarily have to be physically configured as shown. All or part of each functional block can be configured by functionally or physically distributing or integrating it in any unit. All or any part of the processing functions performed by each functional block can be realized by a program executed by a CPU, or can be realized as hardware using wired logic.

[0135] 10, the control device 700 has, for example, a setting screen display unit 711 that displays a setting screen on a display device 760, into which the timing for acquiring the actual value of the mold clamping force is input, an input data receiving unit 712 that receives data input into the setting screen, an acquisition timing setting unit 713 that sets the acquisition timing in accordance with the received data, and an actual value acquiring unit 714 that acquires the actual value of the mold clamping force detected at the set acquisition timing. Since the timing for acquiring the actual value of the mold clamping force can be changed on the setting screen, convenience for the user of the injection molding machine can be improved.

[0136] 11 is a diagram showing an example of a setting screen in which the timing for acquiring the actual value of mold clamping force is input. The setting screen 790 includes, for example, a first input field 791 in which the reference timing is input, and a second input field 792 in which the delay time from the reference timing to the acquisition timing is input. The acquisition timing can be specified by inputting the reference timing and the delay time. Note that an advance time may be input in place of the delay time in the second input field 792.

[0137] A plurality of options are prepared in advance as the reference timing, and one option from the plurality of options is input into the first input field 791. The options are not particularly limited, but for example, the start of the filling process, the start of the dwelling process, the completion of the dwelling process, the start of the first stage of mold clamping compression, the completion of the pressurization process, and the start of the mold closing process are prepared. In FIG. 11, "start of filling," which is the start of the filling process, is input as the reference timing. The acquisition timing is not limited to during the mold clamping process, and may be any timing during one molding cycle, such as during the mold closing process, pressurization process, depressurization process, or mold opening process.

[0138] The setting screen 790 may also include waveform data 793 showing the transition of the mold clamping force, and a pointer 794 used to input the acquisition timing on the waveform data 793. The waveform data 793 may be an actual value or a set value. The pointer 794 is movable along the time axis of the waveform data 793, and the acquisition timing is specified by the position where the pointer 794 stops.

[0139] The user inputs the acquisition timing by moving the pointer 794 using the operation device 750. Data indicating the acquisition timing designated by the pointer 794 may be automatically input into the first input field 791 and the second input field 792. The user can input the acquisition timing while viewing the waveform data 793.

[0140] Note that the setting screen 790 may include the first input field 791 and the second input field 792, but may not include the waveform data 793 and the pointer 794. Also, the setting screen 790 may include the waveform data 793 and the pointer 794, but may not include the first input field 791 and the second input field 792. In any case, the timing for acquiring the actual value of the mold clamping force can be changed on the setting screen, thereby improving convenience for the user of the injection molding machine.

[0141] The setting screen 790 may further include an input confirmation button 795 for confirming the input data. When the input confirmation button 795 is operated, the data input to the setting screen 790 is sent to the input data receiving unit 712. Note that the input confirmation button 795 may not be provided, in which case the data is automatically sent to the input data receiving unit 712 when it is input.

[0142] The control device 700 may further include an appropriateness determination unit 715 that determines whether the acquisition timing input to the setting screen 790 is appropriate. The appropriateness determination unit 715 determines that the acquisition timing is appropriate when the acquisition timing is within time zones Z1, Z3, Z5, Z7, Z9, and Z11 where the mold clamping force is stable, for example.

[0143] Whether the mold clamping force is stable or not is determined based on (A) whether the amount of change in the actual value of the mold clamping force per unit time is equal to or less than a threshold value, (B) whether the amount of fluctuation in the actual value of the mold clamping force between shots is equal to or less than a threshold value, or (C) whether the deviation between the actual value of the mold clamping force and the set value is equal to or less than a threshold value. A plurality of determination criteria selected from (A) to (C) may be used.

[0144] By determining whether the acquisition timing entered into the setting screen 790 is appropriate using the suitability determination unit 715, the actual values ​​of the mold clamping force can be obtained in time zones Z1, Z3, Z5, Z7, Z9, and Z11 where the mold clamping force is stable, thereby reducing errors in the actual values ​​of the mold clamping force.

[0145] The control device 700 may further include a setting reservation unit 716 that reserves the setting of the acquisition timing by the acquisition timing setting unit 713 until the acquisition timing is determined to be appropriate by the suitability determination unit 715. When the suitability determination unit 715 determines that the acquisition timing is appropriate, the acquisition timing setting unit 713 sets the acquisition timing.

[0146] By using the setting reservation unit 716 to reserve the setting of the acquisition timing, the user can be given an opportunity to correct the acquisition timing, and the actual value of the mold clamping force can be acquired at an appropriate acquisition timing.

[0147] The control device 700 may further include an acquisition timing proposing unit 717 that controls the display device 760 and displays appropriate candidates for the acquisition timing on the setting screen 790. When the acquisition timing input by the user is in time zones Z2, Z4, Z6, Z8, and Z10 where the mold clamping force is unstable, the acquisition timing proposing unit 717 displays appropriate candidates for the acquisition timing on the setting screen 790.

[0148] The acquisition timing proposing unit 717, for example, displays appropriate candidates for the acquisition timing in a first input field 791 and a second input field 792, or displays them with a pointer 794 on waveform data 793. The candidates displayed by the acquisition timing proposing unit 717 and the data input by the user may be displayed on the setting screen 790 at the same time.

[0149] The time zone closest to the acquisition time input by the user and having a stable clamping force is used as the appropriate candidate for the acquisition time. Alternatively, the time zone with the highest clamping force among the time zones having a stable clamping force may be used as the appropriate candidate for the acquisition time, regardless of the acquisition time input by the user.

[0150] The acquisition timing suggestion unit 717 may display multiple time zones with stable mold clamping force as acquisition timing candidates on the setting screen so that the user can select the acquisition timing from the multiple candidates. In this case, the acquisition timing setting unit 713 sets the time zone selected by the user as the acquisition timing.

[0151] By displaying appropriate candidates for the acquisition timing on the setting screen 790 by the acquisition timing suggestion unit 717, it is possible to present to the user a policy for correcting the acquisition timing, thereby further improving user convenience.

[0152] The control device 700 may have a mold thickness adjustment execution unit 718 that executes mold thickness adjustment using the actual value of the mold clamping force acquired by the actual value acquisition unit 714. When mold clamping compression is performed, 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 when the mold clamping force is at its highest. In this case, it is preferable to acquire the actual value of the mold clamping force when the mold clamping force is at its highest in order to adjust the link angle θ to a predetermined angle when the mold clamping force is at its highest.

[0153] The control device 700 may have a mold thickness adjustment tie bar temperature adjustment execution unit 719 that adjusts the temperature of the tie bars 140 using the actual value of the mold clamping force acquired by the actual value acquisition unit 714. When mold clamping compression is performed, for example, the temperature of the tie bars 140 is adjusted so that the distribution of the surface pressure generated on the parting surfaces of the fixed mold 810 and the movable mold 820 becomes a desired distribution when the mold clamping force is at its highest. In this case, it is preferable to acquire the actual value of the mold clamping force when the mold clamping force is at its highest in order to adjust the distribution of the surface pressure to a desired distribution when the mold clamping force is at its highest.

[0154] The actual clamping force value has various uses, and therefore, a setting screen 790 may be prepared for each use.

[0155] The setting screen 790 may not be present. In that case, the acquisition timing setting unit 713 may automatically set the acquisition timing. For example, the acquisition timing setting unit 713 sets the acquisition timing during a time zone in which the mold clamping force is stable. Preferably, the acquisition timing setting unit 713 sets the acquisition timing during the time zone in which the mold clamping force is the highest among the time zones in which the mold clamping force is stable. Whether the mold clamping force is stable can be determined from the set conditions for the mold closing process, the pressure increase process, and the mold clamping process, for example, from the movement speed or position of the crosshead 151 or the mold clamping force setting. For example, the acquisition timing setting unit 713 acquires data indicating the transition of the mold clamping force, selects a time zone in which the mold clamping force is stable from the acquired data, and sets the selected time zone as the acquisition timing. The data indicating the transition of the mold clamping force may be an actual value or a set value.

[0156] Although the present embodiment has been described with reference to a case where clamping compression is performed, the present invention is also applicable to a case where clamping compression is not performed, that is, a case where the position of the movable platen 120 or the clamping force is controlled to be constant from the start to the end of the clamping process. Below, a case where the position of the movable platen 120 is controlled to be constant from the start to the end of the clamping process will be described with reference to FIG.

[0157] Fig. 12 is a diagram showing another example of a setting screen on which the timing for acquiring the actual value of the mold clamping force is input. In addition to the transition of the actual value of the mold clamping force, Fig. 12 also shows the transition of the actual value of the screw position and the transition of the actual value of the filling pressure of the molding material. In the filling process, the screw 330 is advanced from the filling start position to the V / P switch position, and the filling pressure increases.

[0158] If the clamping force is small and the surface pressure generated on the parting surfaces of the fixed mold 810 and the movable mold 820 during clamping is small, an increase in filling pressure may cause the fixed mold 810 and the movable mold 820 to open. The tie bars 140 extend by the amount of this opening, and the clamping force detected by the tie bar strain detector 141 may increase.

[0159] The mold clamping force causes the fixed mold 810 and the movable mold 820 to open due to an increase in filling pressure, allowing the gas inside the cavity space 801 to escape to the outside. As a result, it becomes easier to fill the molding material into the cavity space 801. In addition, adiabatic compression of the gas can be suppressed, and heat generation can be suppressed, thereby suppressing carbonization of the molding material.

[0160] As described above, even when the position of the movable platen 120 is controlled to be constant from the start to the end of the mold clamping process, the actual value of the mold clamping force may fluctuate due to fluctuations in the filling pressure of the molding material.

[0161] 11, the setting screen 790 shown in Fig. 12 also includes a first input field 791, a second input field 792, waveform data 793, a pointer 794, and an input confirmation button 795. Therefore, the timing for acquiring the actual value of the mold clamping force can be changed on the setting screen 790.

[0162] When the actual value of the mold clamping force is used for mold thickness adjustment or tie bar temperature control, that is, when the actual value of the mold clamping force detected at the acquisition timing is used to control the movement mechanism 102, the acquisition timing of the actual value of the mold clamping force is preferably time zone Z1 where the mold clamping force is stable. However, there are various uses for the actual value of the mold clamping force, and depending on the use, the acquisition timing may be preferably time zone Z2 where the mold clamping force is not stable.

[0163] For example, the actual clamping force value detected at the acquisition timing can be used not only to control the movement mechanism, but also to control the quality of molded products. If the actual clamping force value is used for quality control of molded products, it is preferable to acquire the actual clamping force value in time zone Z2 when the clamping force is unstable. This is because differences in filling pressure between shots are likely to appear in the actual clamping force value, and differences in the quality of molded products between shots are likely to appear in the actual clamping force value.

[0164] While the embodiments of the injection molding machine according to the present invention have been described above, the present invention is not limited to the above-described embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These changes also naturally fall within the technical scope of the present invention.

[0165] The control device 700 may record and / or display the actual value of the mold clamping force detected at the acquisition timing. The control device 700 stores the actual value of the mold clamping force detected at the acquisition timing in the storage medium 702. The control device 700 also displays the actual value of the mold clamping force detected at the acquisition timing on the display device 760. [Explanation of symbols]

[0166] 10 injection molding machine 102 Moving mechanism 110 Fixed Platen 120 Movable Platen 141 Tie bar strain detector (mold clamping force detector) 700 control device 760 Display device

Claims

1. a movement mechanism that moves the movable platen relative to the fixed platen in a mold opening / closing direction; a mold clamping force detector that detects an actual value of the mold clamping force; a control device that controls the movement mechanism based on the actual value of the mold clamping force detected at a predetermined acquisition timing during a molding cycle; a display device that displays a setting screen for inputting the acquisition timing; the control device acquires the actual value of the mold clamping force detected at the acquisition timing input on the setting screen, the setting screen includes a designation section for designating the acquisition timing, the control device acquires the actual value of the mold clamping force detected at the acquisition timing designated by the designation unit, The control device determines whether the acquisition timing specified by the designation unit is appropriate, and if the acquisition timing specified by the designation unit is not appropriate, controls the display device to display candidates for appropriate acquisition timing on the setting screen.

2. 2. The injection molding machine according to claim 1, wherein the control device determines whether the acquisition timing specified by the specification unit is appropriate based on at least one of: (A) an amount of change in the actual value of the clamping force per unit time; (B) an amount of fluctuation in the actual value of the clamping force between shots; and (C) a deviation between the actual value of the clamping force and a set value.

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