Injection molding machine and control device
The injection molding machine's mold clamping device with controlled movable parts ensures a smooth transition from depressurization to mold opening, improving process efficiency and precision.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- SUMITOMO HEAVY IND LTD
- Filing Date
- 2024-12-18
- Publication Date
- 2026-06-30
Smart Images
Figure 2026106548000001_ABST
Abstract
Description
Technical Field
[0006] , ,
[0005] , , ,
[0001] The present disclosure relates to an injection molding machine and a control device.
Background Art
[0002] Conventionally, an injection molding machine having a mold clamping device that opens and closes a mold device, and a control device that controls each component of the injection molding machine are known (see Patent Document 1 below).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] The present disclosure provides an injection molding machine and a control device capable of smoothly transitioning from decompression to mold opening.
Means for Solving the Problems
[0005] An embodiment of the present disclosure includes a mold clamping device having a movable part that opens and closes a mold device, a decompression that controls the position of the movable part in the mold opening / closing direction of the mold device to move the movable part from a decompression start position to a mold opening start position, and a mold opening that moves the movable part in the mold opening direction when the movable part reaches the mold opening start position, and provides an injection molding machine including a control device that performs the above.
[0006] Another embodiment of the present disclosure controls the position of a movable part in the mold opening / closing direction of a mold device of an injection molding machine including a mold clamping device having a movable part that opens and closes the mold device, and performs a decompression that moves the movable part from a decompression start position to a mold opening start position, and a mold opening that moves the movable part in the mold opening direction when the movable part reaches the mold opening start position, and provides a control device.
Effects of the Invention
[0007] According to embodiments of this disclosure, it is possible to provide an injection molding machine and control device that can smoothly transition from depressurization to mold opening. [Brief explanation of the drawing]
[0008] [Figure 1] This diagram shows the state of the injection molding machine when the mold opening is complete. [Figure 2] This diagram shows the state of the injection molding machine during mold clamping. [Figure 3] This is a time chart showing an example of a molding cycle for an injection molding machine. [Figure 4] This graph shows the change in position of the movable parts that make up the clamping mechanism of an injection molding machine. [Figure 5] This graph shows the change in position of the movable parts that make up the clamping mechanism of an injection molding machine. [Figure 6] This graph shows the change in position of the movable parts that make up the clamping mechanism of an injection molding machine. [Modes for carrying out the invention]
[0009] Embodiments of the injection molding machine and control device according to this disclosure will be described below with reference to the drawings. The embodiments described below are illustrative and do not limit the invention. Not all features and combinations thereof in the embodiments of this disclosure are necessarily essential to the invention. In addition, the same or corresponding components in each drawing are denoted by the same or corresponding reference numerals, and redundant descriptions may be omitted.
[0010] (injection molding machine) Figure 1 shows the state of an injection molding machine when the mold opening is complete according to one embodiment of this disclosure. Figure 2 shows the state of the injection molding machine when the mold is clamped according to the embodiment of Figure 1. 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.
[0011] 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, and an injection device 300 for injecting molding material into the mold device 800. The injection molding machine 10 also includes 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 that supports the clamping device 100 and an injection device frame 920 that supports 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.
[0012] (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.
[0013] The mold clamping device 100 performs mold closing, pressure increasing, mold clamping, pressure release, and mold opening of the mold apparatus 800. The mold apparatus 800 includes a fixed mold 810 and a movable mold 820.
[0014] The mold clamping device 100 is, for example, horizontal, and the mold opening / closing direction is horizontal. The mold clamping device 100 includes 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 moving mechanism 102 that moves the movable platen 120 in the mold opening / closing direction with respect to the fixed platen 110.
[0015] The fixed platen 110 is fixed to the mold clamping device frame 910. The fixed mold 810 is attached to the opposing surface of the fixed platen 110 facing the movable platen 120.
[0016] The movable platen 120 is disposed movably in the mold opening / closing direction with respect to the mold clamping device frame 910. A guide 101 for guiding the movable platen 120 is laid on the mold clamping device frame 910. The movable mold 820 is attached to the opposing surface of the movable platen 120 facing the fixed platen 110.
[0017] The moving mechanism 102 performs mold closing, pressure boosting, mold clamping, pressure release, and mold opening of the mold device 800 by advancing and retreating the movable platen 120 with respect to the fixed platen 110. The moving mechanism 102 includes a toggle support 130 disposed at an interval from the fixed platen 110, a tie bar 140 connecting the fixed platen 110 and the toggle support 130, and a toggle mechanism 150 that moves the movable platen 120 in the mold opening / closing direction with respect to the toggle support 130. Further, the moving mechanism 102 includes a mold clamping motor 160 that operates the toggle mechanism 150, a motion conversion mechanism 170 that converts the rotational motion of the mold clamping motor 160 into a linear motion, and a mold thickness adjustment mechanism 180 that adjusts the interval between the fixed platen 110 and the toggle support 130.
[0018] The toggle support 130 is disposed at an interval from the fixed platen 110 and is placed movably in the mold opening / closing direction on the mold clamping device frame 910. Incidentally, the toggle support 130 may be disposed movably along a guide laid on the mold clamping device frame 910. The guide of the toggle support 130 may be common with the guide 101 of the movable platen 120.
[0019] In this embodiment, the fixed platen 110 is fixed to the mold clamping device frame 910, and the toggle support 130 is arranged movably in the mold opening and closing direction with respect to the mold clamping device frame 910. Incidentally, the toggle support 130 may be fixed to the mold clamping device frame 910, and the fixed platen 110 may be arranged movably in the mold opening and closing direction with respect to the mold clamping device frame 910.
[0020] The tie bars 140 connect the fixed platen 110 and the toggle support 130 with a gap L in the mold opening and closing direction. A plurality of (for example, four) tie bars 140 may be used. The plurality of tie bars 140 are arranged in parallel in the mold opening and closing direction and extend according to the clamping force. At least one tie bar 140 may be provided with a tie bar strain detector 141 for detecting 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 and the like.
[0021] Incidentally, in this embodiment, the tie bar strain detector 141 is used as the clamping force detector for detecting the clamping force, but the present invention is not limited to this. The clamping force detector is not limited to the strain gauge type, and may be a piezoelectric type, a capacitive type, a hydraulic type, an electromagnetic type, 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 pair of 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] Furthermore, 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 a portion of the cavity space 801, and the molding material may be filled in the other portion of the cavity space 801. This results in a molded product in which the insert material and the molding material are integrated.
[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] In this embodiment, the crosshead 151 is a movable part that moves in the mold opening / closing direction of the mold apparatus 800 to open and close the mold apparatus 800 by controlling the rotation of the clamping motor 160 by the control device 700. The control device 700 controls the position of the crosshead 151 in the mold opening / closing direction of the mold apparatus 800 to perform depressurization and mold opening. For example, the control device 700 controls the position of the crosshead 151 based on the detection result of the clamping motor encoder 161, which acts as a position detector that detects the position of the crosshead 151 as a movable part.
[0035] Furthermore, the movable part of the clamping device 100 that opens and closes the mold device 800 is not limited to the crosshead 151. For example, if the clamping device 100 has a hydraulic cylinder for clamping instead of a toggle mechanism 150, the movable part of the clamping device 100 may be the piston rod of the hydraulic cylinder that opens and closes the mold device 800. Alternatively, a movable platen 120 that is moved in the mold opening and closing direction by the toggle mechanism 150 or a hydraulic cylinder to open and close the mold device 800 may also be used as the movable part of the clamping device 100.
[0036] The setting conditions for the mold closing process, the pressurization process, and the mold clamping process are set together as a series of setting conditions. For example, the movement speed and position of movable parts such as the crosshead 151 in the mold closing process and the pressurization 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 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. There may be no movement speed switching positions. The mold clamping position and the mold clamping force may be set individually or individually.
[0037] The setting conditions for the depressurization process and the mold opening process are set similarly. For example, the movement speed and position of movable parts such as 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 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 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.
[0038] Furthermore, instead of the movement speed and position of the crosshead 151, the movement speed and position of the movable platen 120, which is a movable part that opens and closes the mold device 800, may be set. Also, instead of the position of the crosshead (e.g., the clamping position) or the position of the movable platen, the clamping force may be set.
[0039] 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 according to 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°.
[0040] 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.
[0041] 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.
[0042] 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.
[0043] 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, and a drive gear is attached to the output shaft of the mold thickness adjustment motor 183. In addition, an intermediate gear that meshes with multiple driven gears and a 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 belts, pulleys, or the like instead of gears.
[0044] 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.
[0045] 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.
[0046] 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.
[0047] 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.
[0048] Furthermore, although the clamping device 100 of this embodiment has a clamping motor 160 as a drive unit, it may have a hydraulic cylinder instead of the clamping motor 160. Also, the clamping device 100 may have a linear motor for opening and closing the mold and an electromagnet for clamping the mold.
[0049] (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.
[0050] 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).
[0051] 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.
[0052] 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.
[0053] 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.
[0054] 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.
[0055] (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.
[0056] 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 within the mold device 800 with molding material. 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, and a screw 330 positioned within the cylinder 310 to move back and forth and to rotate. The injection device 300 also includes 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.
[0057] 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 cylinder 310. A cooler 312, such as a water-cooled cylinder, is provided on the outer circumference of the rear of cylinder 310. In front of the cooler 312, a first heater 313, such as a band heater, and a first temperature detector 314 are provided on the outer circumference of cylinder 310.
[0058] The cylinder 310 is divided into multiple zones along its axial direction (for example, the X-axis direction). A first heater 313 and a first 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 first heater 313 so that the temperature detected by the first temperature detector 314 becomes the set temperature.
[0059] The nozzle 320 is located at the front end of the cylinder 310 and is pressed against the mold device 800. A second heater 323 and a second temperature detector 324 are provided on the outer circumference of the nozzle 320. The control device 700 controls the second heater 323 so that the temperature detected by the second temperature detector 324 becomes the set temperature.
[0060] 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.
[0061] A backflow prevention ring 331 is mounted on the front of the screw 330 so as to be movable 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.
[0062] 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.
[0063] 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.
[0064] 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.
[0065] Furthermore, the injection device 300 may 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.
[0066] 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.
[0067] 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.
[0068] 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.
[0069] 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.
[0070] Furthermore, the pressure detector used to detect the pressure of the molding material is not limited to the load detector 360, but a general-purpose one can be used. For example, a nozzle pressure sensor or an in-mold pressure sensor may be used. The nozzle pressure sensor is installed in the nozzle 320. The in-mold pressure sensor is installed inside the mold device 800.
[0071] 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.
[0072] 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 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 by 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 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 for detecting the rotational speed of the screw 330 is not limited to the metering motor encoder 341, and a general-purpose one can be used.
[0073] 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.
[0074] 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.
[0075] 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.
[0076] 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.
[0077] 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.
[0078] 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.
[0079] 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.
[0080] 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.
[0081] 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.
[0082] 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.
[0083] (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.
[0084] 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.
[0085] 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.
[0086] 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.
[0087] 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.
[0088] 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.
[0089] 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. The injection device 300 is retracted, and the nozzle 320 is separated from the fixed mold 810.
[0090] 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.
[0091] (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, and an output interface 704. 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.
[0092] The control device 700 includes electronic circuits such as a CPU, FPGA (Field Programmable Gate Array), or ASIC (Application Specific Integrated Circuit), and performs various control operations described in this specification by executing instruction codes stored in memory or by designing the circuit for special applications.
[0093] The control device 700 repeatedly manufactures 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."
[0094] Figure 3 is a time chart showing an example of a molding cycle for injection molding machine 10. One molding cycle includes, for example, a metering 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 process, the holding pressure process, and the cooling process are performed 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.
[0095] Furthermore, multiple processes may be performed simultaneously in order 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.
[0096] Furthermore, a single molding cycle may include steps other than the weighing process, mold closing process, pressurization process, mold clamping process, filling process, holding pressure process, cooling process, depressurization process, mold opening process, and ejection process.
[0097] 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 abruptly at the start of the metering process.
[0098] 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.
[0099] 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 screen 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 set the injection molding machine 10 (including inputting setting values). Furthermore, by operating the operation parts provided on the screen, the user can make the injection molding machine 10 operate in accordance with the operation part. Furthermore, the operation of the injection molding machine 10 may also include the operation (including stopping) of, for example, the clamping device 100, the ejector device 200, the injection device 300, the moving device 400, etc. Alternatively, the operation of the injection molding machine 10 may also include switching the screen displayed on the touch panel 770, which serves as the display device 760.
[0100] Although the operating device 750 and display device 760 of 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).
[0101] Figures 4 to 6 are graphs showing the change in position P of the crosshead 151, which is a movable part of the mold clamping device 100 of the injection molding machine 10. In the graphs of Figures 4 to 6, the vertical axis represents the position P of the crosshead 151 and the horizontal axis represents time T, showing the change in position P of the crosshead 151 over time T as it transitions from depressurization to mold opening.
[0102] The injection molding machine 10 and control device 700 of this embodiment are characterized by the following configuration. As described above, the injection molding machine 10 includes a mold clamping device 100 and a control device 700. The mold clamping device 100 has a crosshead 151 as a movable part that opens and closes the mold device 800. The control device 700 controls the position of the crosshead 151 in the mold opening and closing direction of the mold device 800 to perform depressurization and mold opening. The control device 700 moves the crosshead 151 as a movable part from the depressurization start position P1 to the mold opening start position P2 to perform depressurization, and when the crosshead 151 reaches the mold opening start position P2, it moves the crosshead 151 in the mold opening direction to perform mold opening.
[0103] The thin dashed lines in Figures 4 to 6 represent the change in position P of the movable part of the clamping device that opens and closes the mold device in an injection molding machine of a comparative example, which is different from the injection molding machine 10 of this embodiment, with respect to time T. Also, in Figures 4 and 5, the thick solid lines represent the change in position P of the crosshead 151, which is a movable part of the injection molding machine 10 of this embodiment, with respect to time T. Also, in Figure 6, the thick dashed and double-dotted lines represent the change in position P of the crosshead 151, which is a movable part of the injection molding machine 10 of this embodiment, with respect to time T.
[0104] As shown by the thin dashed line in Figure 4, the comparative injection molding machine starts moving the movable part from the depressurization start position P1 to the mold opening start position P2 at the depressurization start time T1, and brings the movable part to the mold opening start position P2 at a time T2a, before the mold opening start time T2. Subsequently, the comparative injection molding machine holds the movable part at the mold opening start position P2 until the mold opening start time T2, and then starts moving the movable part from the mold opening start position P2 to the mold opening end position at the mold opening start time T2.
[0105] The depressurization start position P1 of the movable part is the end position of the cooling process in which clamping force is acting on the mold device. In an injection molding machine, depressurization, which moves the movable part from the depressurization start position P1 to the mold opening start position P2, includes a first stage and a second stage. In the first stage of depressurization, the movable part is moved from the depressurization start position P1 to the mold opening start position P2 by not only operating the clamping motor but also utilizing the restoring force of the tie bar, which has been elastically stretched to apply the clamping force. In the second stage of depressurization, the clamping motor is operated to move the movable part to the mold opening start position P2.
[0106] In the comparative example injection molding machine, the duration of the cooling process and the mold opening start time T2 are defined, and the time from the start to the end of depressurization is set so that it can be reliably completed in time for the mold opening start time T2 after the end of the cooling process. Therefore, the comparative example injection molding machine will allow a margin of safety by having the movable part reach the mold opening start position P2 at a time T2a earlier than the mold opening start time T2. As a result, a waiting time occurs between the time T2a when the movable part reaches the mold opening start position P2 and the mold opening start time T2, resulting in cycle loss.
[0107] In contrast, the control device 700 of the injection molding machine 10 in this embodiment controls the position of the crosshead 151, which is a movable part of the mold clamping device 100, in the mold opening and closing direction of the mold device 800. Then, as shown by the thick solid line in Figure 4, the control device 700 moves the crosshead 151 from the depressurization start position P1 to the mold opening start position P2 at the depressurization start time T1 to perform depressurization. Furthermore, at the time T2a when the crosshead 151 has reached the mold opening start position P2, the control device 700 moves the crosshead 151 in the mold opening direction to perform mold opening.
[0108] Furthermore, the control device 700 reduces the movement speed of the crosshead 151, which is a movable part, at the mold opening start position P2, for example, as shown by the thick solid line in Figure 4. In this case, the movement speed of the crosshead 151 at the mold opening start position P2 may be zero or it may not be zero. In other words, the control device 700 may start mold opening after stopping the crosshead 151 at the mold opening start position P2 at the end of depressurization, or it may start mold opening without stopping the crosshead 151 at the mold opening start position P2 at the end of depressurization.
[0109] Furthermore, the control device 700 may maintain the movement speed of the crosshead 151 as a movable part before and after the mold opening start position P2, for example, as shown by the thick solid line in Figure 5. Alternatively, the control device 700 may delay the depressurization start time T1 to times T1a and T1b, for example, as shown by the thick dashed and double dashed lines in Figure 6, so that the crosshead 151 reaches the mold opening start position P2 at the same time as the mold opening start time T2, thereby extending the cooling process.
[0110] The operation of the injection molding machine 10 and the control device 700 of this embodiment will be described below.
[0111] As described above, the injection molding machine 10 of this embodiment includes a mold clamping device 100 and a control device 700. The mold clamping device 100 has a crosshead 151 as a movable part that opens and closes the mold device 800. The control device 700 controls the position of the crosshead 151 in the mold opening and closing direction of the mold device 800 to perform depressurization and mold opening. The control device 700 moves the crosshead 151 from the depressurization start position P1 to the mold opening start position P2 to perform depressurization, and when the crosshead 151 reaches the mold opening start position P2, it moves the crosshead 151 in the mold opening direction to perform mold opening.
[0112] This configuration allows the crosshead 151, which acts as a movable part for opening and closing the mold device 800, to reach the mold opening start position P2 at the end of depressurization and simultaneously begin mold opening. Therefore, the injection molding machine 10 of this embodiment allows for a smooth transition from depressurization to mold opening. This links the depressurization operation and mold opening operation of the clamping device 100, eliminating wasted movement of the clamping device 100 from depressurization to mold opening completion and making the operation of the clamping device 100 smoother. In addition, the time during which the crosshead 151 waits at the mold opening start position P2 can be eliminated, making it possible to shorten the molding cycle.
[0113] Furthermore, in the injection molding machine 10 of this embodiment, the control device 700 reduces the movement speed of the crosshead 151, which is a movable part, at the mold opening start position P2.
[0114] This configuration reduces noise caused by vacuum rupture in the cavity space 801 of the mold device 800 during the transition from depressurization to mold opening. Furthermore, as shown by the thick dashed line in Figure 6, by bringing the crosshead 151 to the mold opening start position P2 at the same time as the mold opening start time T2, the cooling process time can be extended, thereby suppressing sink marks in the molded product.
[0115] Furthermore, in the injection molding machine 10 of this embodiment, the control device 700 maintains the movement speed of the crosshead 151, which is a movable part, before and after the mold opening start position P2.
[0116] With this configuration, as shown in Figures 4 and 5, the crosshead 151, whose movement speed has been reduced at the mold opening start position P2, can reach the mold opening start position P2 at a time T2b earlier than the time T2a at which it reaches the mold opening start position P2. As a result, the time of the depressurization process can be shortened compared to the case where the movement speed of the crosshead 151 is reduced at the mold opening start position P2 during the transition from depressurization to mold opening, and the molding cycle can be shortened further. Therefore, according to the injection molding machine 10 of this embodiment, high-cycle molding can be achieved. In addition, as shown by the thick dashed line in Figure 6, by having the crosshead 151 reach the mold opening start position P2 at the same time as the mold opening start time T2, the time of the cooling process can be further extended, and sink marks on the molded product can be suppressed more reliably.
[0117] Furthermore, the injection molding machine 10 of this embodiment is further equipped with a clamping motor encoder 161 as a position detector for detecting the position of the crosshead 151 as a movable part. The control device 700 controls the position of the crosshead 151 as a movable part based on the detection result of the clamping motor encoder 161 as a position detector.
[0118] With this configuration, the position of the crosshead 151, which acts as a movable part, can be controlled by the control device 700 using the detection result of the clamping motor encoder 161 provided in the injection molding machine 10.
[0119] Furthermore, in the injection molding machine 10 of this embodiment, the clamping device 100 includes a fixed platen 110, a movable platen 120, and a moving mechanism 102. The fixed platen 110 is to which the fixed mold 810 of the mold device 800 is attached. The movable platen 120 is to which the movable mold 820 of the mold device 800 is attached. The moving mechanism 102 moves the movable platen 120 relative to the fixed platen 110 in the mold opening and closing direction of the mold device 800. The moving mechanism 102 includes a toggle support 130, a tie bar 140, a toggle mechanism 150, a clamping motor 160, and a motion conversion mechanism 170. The toggle support 130 is positioned at a distance from the fixed platen 110. The tie bar 140 connects the fixed platen 110 and the toggle support 130. The toggle mechanism 150 moves the movable platen 120 in the mold opening and closing direction relative to the toggle support 130. The clamping motor 160 actsuates the toggle mechanism 150. The motion conversion mechanism 170 converts the rotational motion of the clamping motor 160 into linear motion. The toggle mechanism 150 has a crosshead 151 as a movable part and a pair of link groups including a first link 152, a second link 153, and a third link 154. The crosshead 151 moves in the mold opening and closing direction by converting the rotational motion of the clamping motor 160 into linear motion by the motion conversion mechanism 170. The pair of link groups are pivotably connected to the fixed platen 110 and the toggle support 130 and flex and extend as the crosshead 151 moves in the mold opening and closing direction.
[0120] With this configuration, the control device 700 can control the clamping motor 160 to move the crosshead 151, which is a movable part, from the depressurization start position P1, through the mold opening start position P2, to the mold opening end position at the depressurization start times T1, T1a, and T1b. In addition, the control device 700 can control the speed of the crosshead 151, which is a movable part, in the mold opening and closing direction by controlling the clamping motor 160 during the depressurization process.
[0121] Furthermore, the control device 700 of this embodiment controls the injection molding machine 10. The injection molding machine 10 includes a mold clamping device 100 having a crosshead 151 as a movable part that opens and closes the mold device 800. The control device 700 controls the position of the crosshead 151 in the mold opening and closing direction of the mold device 800 to perform depressurization and mold opening. The control device 700 moves the crosshead 151 from the depressurization start position P1 to the mold opening start position P2 to perform depressurization, and when the crosshead 151 reaches the mold opening start position P2, it moves the crosshead 151 in the mold opening direction to perform mold opening.
[0122] This configuration allows the crosshead 151, which acts as a movable part for opening and closing the mold device 800, to reach the mold opening start position P2 at the end of depressurization and simultaneously begin mold opening. Therefore, the control device 700 of this embodiment makes the transition from depressurization to mold opening of the injection molding machine 10 smooth. This links the depressurization operation and mold opening operation of the clamping device 100, eliminating wasted movement of the clamping device 100 from depressurization to completion of mold opening, and enabling smooth operation of the clamping device 100 from depressurization to completion of mold opening. In addition, the time during which the crosshead 151 waits at the mold opening start position P2 can be eliminated, making it possible to shorten the molding cycle.
[0123] As described above, according to the embodiments of this disclosure, an injection molding machine 10 and control device 700 that can smoothly transition from depressurization to mold opening can be provided.
[0124] Preferred embodiments of the present disclosure have been described above. However, the inventions of the present disclosure are not limited to the embodiments described above. Various modifications, substitutions, etc., can be applied to the embodiments described above without departing from the scope of the inventions of the present disclosure. Furthermore, each of the features described with reference to the embodiments described above may be combined as appropriate, as long as they do not contradict each other technically. [Explanation of Symbols]
[0125] 10 injection molding machine 100 Mold clamping device 102 Moving mechanism 110 Fixed Platen 120 Movable Platen 130 Toggle Support 140 Tie Bar 150 Toggle Mechanism 151 Crosshead (movable part) 152. First Link (Link Group) 153 Second Link (Link Group) 154 Third Link (Link Group) 160-type clamping motor 161 Type Clamping Motor Encoder (Position Detector) 170 Motion conversion mechanism 700 Control Unit 800 mold equipment 810 Fixed mold 820 movable mold P1 Depressurization start position P2 mold opening start position
Claims
1. A mold clamping device having a movable part for opening and closing the mold device, A control device that controls the position of the movable part in the mold opening and closing direction of the mold apparatus to perform depressurization, which moves the movable part from the depressurization start position to the mold opening start position, and mold opening, which moves the movable part in the mold opening direction when the movable part reaches the mold opening start position. An injection molding machine equipped with [a specific feature].
2. The control device reduces the movement speed of the movable part at the mold opening start position. The injection molding machine according to claim 1.
3. The control device maintains the movement speed of the movable part before and after the mold opening start position. The injection molding machine according to claim 1.
4. The system further includes a position detector for detecting the position of the movable part, The control device controls the position of the movable part based on the detection result of the position detector. The injection molding machine according to claim 1.
5. The mold clamping device comprises a fixed platen to which the fixed mold of the mold apparatus is attached, a movable platen to which the movable mold of the mold apparatus is attached, and a moving mechanism for moving the movable platen relative to the fixed platen in the mold opening and closing direction. The moving mechanism comprises a toggle support positioned at a distance from the fixed platen, a tie bar connecting the fixed platen and the toggle support, a toggle mechanism for moving the movable platen in the mold opening and closing direction relative to the toggle support, a mold clamping motor for operating the toggle mechanism, and a motion conversion mechanism for converting the rotational motion of the mold clamping motor into linear motion. The toggle mechanism comprises a crosshead, which is a movable part that moves in the mold opening and closing direction by converting the rotational motion of the mold clamping motor into linear motion by the motion conversion mechanism, and a pair of link groups that are pivotably connected to the movable platen and the toggle support and flex and extend as the crosshead moves in the mold opening and closing direction. The injection molding machine according to claim 1.
6. A control device for an injection molding machine equipped with a clamping device having a movable part for opening and closing a mold device, which controls the position of the movable part in the mold opening and closing direction of the mold device to perform depressurization, which moves the movable part from a depressurization start position to a mold opening start position, and mold opening, which moves the movable part in the mold opening direction when the movable part reaches the mold opening start position.