JP2018165033A - Injection molding machine and evaluation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection molding machine capable of accurately detecting unmelted resin.SOLUTION: An injection molding machine 1 comprises an injection device 300, a control device 700 that controls action of the injection device 300 and discharges a purge resin 805 from the injection device 300, a high speed camera 801 that photographs the purge resin 805 discharged from the injection device 300, an image acquiring unit 811 for acquiring an image of the purge resin 805 photographed by the high speed camera 801, and an evaluation device 804 that has a melting determination unit 813 for determining whether or not the resin in the injection device 300 is an unmelted state based on the image.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an injection molding machine and an evaluation system for determining a molten state of a resin of the injection molding machine.

  In injection molding, molding of PET bottle caps and the like requires high production capacity, so it is important to shorten the molding cycle. One way to shorten the cycle is to shorten the metering time by turning the screw of the injection device at a high rotational speed to increase the plasticizing ability (melting ability). Is transported to the front of the screw without receiving sufficient heat from the cylinder, and the resin to be injected may contain unmelted resin. When the unmelted resin is injected, defects such as poor appearance and insufficient strength of the molded product occur. Therefore, the injected resin needs to have a level at which there is no unmelted resin or the unmelted resin does not become a problem.

  As described above, since the presence or absence of unmelted resin affects the quality of the molded product, the evaluation of unmelted resin is important. As a method for determining unmelted resin, for example, in Patent Document 1, an infrared temperature sensor is provided in a resin flow path from a cylinder head of an injection molding machine to a nozzle, and the output of this sensor is compared with a set temperature every predetermined time. A technique is disclosed.

JP-A-4-59324

  However, since the temperature in the resin cannot be measured by the method described in Patent Document 1, there is a possibility that the presence or absence of the unmelted resin cannot be accurately evaluated when the unmelted resin is formed inside.

  The present invention has been made in view of the above, and an object thereof is to provide an injection molding machine and an evaluation system that can detect unmelted resin with high accuracy.

  In order to solve the above problems, an injection molding machine according to an aspect of the present invention includes an injection device, a control device that controls the operation of the injection device and discharges purge resin from the injection device, and discharges from the injection device. A camera that captures the purge resin, an image acquisition unit that acquires an image of the purge resin captured by the camera, and whether or not the resin in the injection apparatus is in an unmelted state based on the image An evaluation apparatus having a melting determination unit for determining.

  Similarly, an evaluation system according to an aspect of the present invention is an evaluation system for evaluating a molten state of a resin in an injection device of an injection molding machine, and a camera that photographs a purge resin discharged from the injection device; An image acquisition unit that acquires an image of the purge resin imaged by the camera, and an evaluation device that includes a melting determination unit that determines whether or not the resin in the injection apparatus is in an unmelted state based on the image; .

  According to one aspect of the present invention, it is possible to provide an injection molding machine and an evaluation system that can accurately detect unmelted resin.

It is a figure which shows the state at the time of mold opening completion of the injection molding machine by one Embodiment. It is a figure which shows the state at the time of the mold clamping of the injection molding machine by one Embodiment. FIG. 6 is a view showing a state in which the valve body is moved from the open position shown in FIG. 5 to the closed position by swinging the swing lever shown in FIG. 5 in a first direction (for example, clockwise). FIG. 4 is a diagram illustrating a state in which the swing lever illustrated in FIG. 3 is swung in a second direction (for example, counterclockwise). It is a figure which shows the state which moved the valve body shown in FIG. 4 from the obstruction | occlusion position to the open position with the pressure of the molding material. It is a figure which shows schematic structure of the evaluation system of the resin molten state which concerns on this embodiment. It is a figure which shows schematic structure when the evaluation system shown in FIG. 6 is seen from the Y-axis positive direction side. It is a flowchart of the injection molding process incorporating the evaluation process of the resin molten state in this embodiment. It is a flowchart of the subroutine process of the fusion evaluation step in FIG. It is a figure explaining an example of the image process for extracting unmelted resin from the picked-up image of purge resin.

  Hereinafter, embodiments will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

  1 to 6, the X direction, the Y direction, and the Z direction are directions perpendicular to each other. The X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction. The X direction is the same as the moving direction and mold opening / closing direction of the movable platen 120 and the injection apparatus 300 of the injection molding machine 1 according to this embodiment, and the Y direction is the width direction of the injection molding machine 1.

  First, with reference to FIG.1 and FIG.2, the schematic structure of the whole injection molding machine 1 which concerns on this embodiment is demonstrated.

(Injection molding machine)
Drawing 1 is a figure showing the state at the time of mold opening completion of injection molding machine 1 by one embodiment. FIG. 2 is a diagram illustrating a state at the time of mold clamping of the injection molding machine 1 according to the embodiment. As shown in FIGS. 1 to 2, the injection molding machine 1 includes a mold clamping device 100, an ejector device 200, an injection device 300, a moving device 400, and a control device 700. Hereinafter, each component of the injection molding machine 1 will be described.

(Clamping device)
In the description of the mold clamping device 100, the moving direction of the movable platen 120 when the mold is closed (right direction in FIGS. 1 and 2) is the front, and the moving direction of the movable platen 120 when the mold is opened (left in FIGS. 1 and 2). (Direction) will be described as the rear.

  The mold clamping apparatus 100 performs mold closing, mold clamping, and mold opening of the mold apparatus 10. The mold clamping device 100 is, for example, a horizontal mold, and the mold opening / closing direction is the horizontal direction. The mold clamping device 100 includes a fixed platen 110, a movable platen 120, a toggle support 130, a tie bar 140, a toggle mechanism 150, a mold clamping motor 160, a motion converting mechanism 170, and a mold thickness adjusting mechanism 180.

  The fixed platen 110 is fixed to the frame Fr. The fixed mold 11 is attached to the surface of the fixed platen 110 facing the movable platen 120.

  The movable platen 120 is movable in the mold opening / closing direction with respect to the frame Fr. A guide 101 for guiding the movable platen 120 is laid on the frame Fr. The movable mold 12 is attached to the surface of the movable platen 120 that faces the fixed platen 110.

  By moving the movable platen 120 forward and backward with respect to the fixed platen 110, mold closing, mold clamping, and mold opening are performed. The fixed mold 11 and the movable mold 12 constitute a mold apparatus 10.

  The toggle support 130 is connected to the fixed platen 110 at an interval, and is placed on the frame Fr so as to be movable in the mold opening / closing direction. The toggle support 130 may be movable along a guide laid on the frame Fr. The guide of the toggle support 130 may be the same as the guide 101 of the movable platen 120.

  In this embodiment, the fixed platen 110 is fixed to the frame Fr, and the toggle support 130 is movable in the mold opening / closing direction with respect to the frame Fr. However, the toggle support 130 is fixed to the frame Fr and fixed to the fixed platen. 110 may be movable in the mold opening / closing direction with respect to the frame Fr.

  The tie bar 140 connects the fixed platen 110 and the toggle support 130 with an interval L in the mold opening / closing direction. A plurality (for example, four) of tie bars 140 may be used. Each tie bar 140 is parallel to the mold opening / closing direction and extends according to the mold clamping force. At least one tie bar 140 is provided with a tie bar distortion detector 141 that detects distortion of the tie bar 140. The tie bar distortion detector 141 sends a signal indicating the detection result to the control device 700. The detection result of the tie bar distortion detector 141 is used for detecting the clamping force.

  In this embodiment, the tie bar strain detector 141 is used as a mold clamping force detector for detecting 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 capacitive type, a hydraulic type, an electromagnetic type, and the like, and the mounting position thereof is not limited to the tie bar 140.

  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 includes a cross head 151, a pair of links, and the like. Each link group includes a first link 152 and a second link 153 that are connected to each other by a pin or the like. The first link 152 is swingably attached to the movable platen 120 with a pin or the like, and the second link 153 is swingably attached to the toggle support 130 with a pin or the like. The second link 153 is attached to the crosshead 151 via the third link 154. When the crosshead 151 is moved back and forth with respect to the toggle support 130, the first link 152 and the second link 153 are bent and extended, and the movable platen 120 is moved back and forth relative to the toggle support 130.

  Note that the configuration of the toggle mechanism 150 is not limited to the configuration shown in FIGS. 1 and 2. For example, in FIGS. 1 and 2, the number of nodes in each link group is five, but four may be used, and one end of the third link 154 is coupled to the node between the first link 152 and the second link 153. May be.

  The mold clamping motor 160 is attached to the toggle support 130 and operates the toggle mechanism 150. The mold clamping motor 160 causes the first link 152 and the second link 153 to bend and extend by advancing and retracting the cross head 151 relative to the toggle support 130, and advances and retracts the movable platen 120 relative to the toggle support 130. The mold clamping motor 160 is directly connected to the motion conversion mechanism 170, but may be connected to the motion conversion mechanism 170 via a belt, a pulley, or the like.

  The motion conversion mechanism 170 converts the rotational motion of the mold clamping motor 160 into the linear motion of the cross head 151. The motion conversion mechanism 170 includes a screw shaft 171 and a screw nut 172 that is screwed onto the screw shaft 171. A ball or a roller may be interposed between the screw shaft 171 and the screw nut 172.

  The mold clamping device 100 performs a mold closing process, a mold clamping process, a mold opening process, and the like under the control of the control device 700.

  In the mold closing process, the mold clamping motor 160 is driven to advance the cross head 151 to a mold closing completion position at a set speed, thereby moving the movable platen 120 forward and touching the movable mold 12 to the fixed mold 11. The position and speed of the cross head 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.

  In the mold clamping process, a mold clamping force is generated by further driving the mold clamping motor 160 to further advance the cross head 151 from the mold closing completion position to the mold clamping position. A cavity space 14 is formed between the movable mold 12 and the fixed mold 11 during mold clamping, and the injection device 300 fills the cavity space 14 with a liquid molding material. A molded product is obtained by solidifying the filled molding material. A plurality of cavity spaces 14 may be provided, and in this case, a plurality of molded products can be obtained simultaneously.

  In the mold opening process, the mold clamping motor 160 is driven to retract the cross head 151 to the mold opening completion position at a set speed, thereby retracting the movable platen 120 and separating the movable mold 12 from the fixed mold 11. Thereafter, the ejector device 200 ejects the molded product from the movable mold 12.

  Setting conditions in the mold closing process and the mold clamping process are collectively set as a series of setting conditions. For example, the speed and position (including the speed switching position, the mold closing completion position, and the mold clamping position) of the cross head 151 in the mold closing process and the mold clamping process are collectively set as a series of setting conditions. Instead of the speed and position of the cross head 151, the speed and position of the movable platen 120 may be set. Further, a mold clamping force may be set instead of the position of the cross head (for example, the mold clamping position) or the position of the movable platen.

  By the way, the toggle mechanism 150 amplifies the driving force of the mold clamping motor 160 and transmits it to the movable platen 120. The amplification magnification is also called toggle magnification. The toggle magnification changes in accordance with an angle θ formed by the first link 152 and the second link 153 (hereinafter also referred to as “link angle θ”). The link angle θ is obtained from the position of the crosshead 151. When the link angle θ is 180 °, the toggle magnification is maximized.

  When the thickness of the mold apparatus 10 changes due to replacement of the mold apparatus 10 or temperature change of the mold apparatus 10, the mold thickness adjustment is performed so that a predetermined mold clamping force can be obtained at the time of mold clamping. In the mold thickness adjustment, for example, the distance L between the fixed platen 110 and the toggle support 130 is set so that the link angle θ of the toggle mechanism 150 becomes a predetermined angle when the movable mold 12 touches the fixed mold 11. Adjust.

  The mold clamping apparatus 100 includes a mold thickness adjusting mechanism 180 that performs mold thickness adjustment by adjusting the distance L between the fixed platen 110 and the toggle support 130. The mold thickness adjusting mechanism 180 rotates a screw shaft 181 formed at the rear end portion of the tie bar 140, a screw nut 182 that is rotatably held by the toggle support 130, and a screw nut 182 that is screwed onto the screw shaft 181. And a mold thickness adjusting motor 183.

  The screw shaft 181 and the screw nut 182 are provided for each tie bar 140. The rotation of the mold thickness adjusting motor 183 may be transmitted to the plurality of screw nuts 182 via the rotation transmitting unit 185. A plurality of screw nuts 182 can be rotated synchronously. In addition, it is also possible to rotate the several screw nut 182 separately by changing the transmission path | route of the rotation transmission part 185. FIG.

  The rotation transmission unit 185 is configured with a gear, for example. In this case, a passive 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 adjusting motor 183, and a plurality of passive gears and an intermediate gear that meshes with the drive gear are in the central portion of the toggle support 130. It is held rotatably. In addition, the rotation transmission part 185 may be comprised with a belt, a pulley, etc. instead of a gearwheel.

  The operation of the mold thickness adjusting mechanism 180 is controlled by the control device 700. The control device 700 drives the mold thickness adjusting motor 183 to rotate the screw nut 182, thereby adjusting the position of the toggle support 130 that rotatably holds the screw nut 182 with respect to the fixed platen 110. The interval L with the toggle support 130 is adjusted.

  In this embodiment, the screw nut 182 is rotatably held with respect to the toggle support 130, and the tie bar 140 on which the screw shaft 181 is formed is fixed with respect to the fixed platen 110. However, the present invention is not limited to this.

  For example, the screw nut 182 may be rotatably held with respect to the fixed platen 110 and the tie bar 140 may be fixed with respect to the toggle support 130. In this case, the interval L can be adjusted by rotating the screw nut 182.

  Further, the screw nut 182 may be fixed to the toggle support 130, and the tie bar 140 may be held rotatably with respect to the fixed platen 110. In this case, the interval L can be adjusted by rotating the tie bar 140.

  Furthermore, the screw nut 182 may be fixed to the fixed platen 110, and the tie bar 140 may be held rotatably with respect to the toggle support 130. In this case, the interval L can be adjusted by rotating the tie bar 140.

  The interval L is detected using a mold thickness adjusting 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 adjusting motor encoder 184 is used for monitoring and controlling the position and interval L of the toggle support 130.

  The mold thickness adjusting mechanism 180 adjusts the interval L by rotating one of the screw shaft 181 and the screw nut 182 that are screwed together. A plurality of mold thickness adjusting mechanisms 180 may be used, and a plurality of mold thickness adjusting motors 183 may be used.

  The mold thickness adjusting mechanism 180 of this embodiment has a screw shaft 181 formed on the tie bar 140 and a screw nut 182 screwed to the screw shaft 181 in order to adjust the interval L. It is not limited to.

  For example, the mold thickness adjusting mechanism 180 may include a tie bar temperature controller that adjusts the temperature of the tie bar 140. The tie bar temperature controller is attached to each tie bar 140 and adjusts the temperature of the plurality of tie bars 140 in cooperation with each other. As the temperature of the tie bar 140 increases, the tie bar 140 becomes longer due to thermal expansion, and the interval L increases. The temperature of the plurality of tie bars 140 can be adjusted independently.

  The tie bar temperature controller includes a heater such as a heater, and adjusts the temperature of the tie bar 140 by heating. The tie bar temperature controller may include a cooler such as a water cooling jacket, and the temperature of the tie bar 140 may be adjusted by cooling. The tie bar temperature controller may include both a heater and a cooler.

  The mold clamping device 100 of the present embodiment is a horizontal mold in which the mold opening / closing direction is the horizontal direction, but may be a vertical mold in which the mold opening / closing direction is the vertical direction. The vertical mold clamping apparatus includes a lower platen, an upper platen, a toggle support, a tie bar, a toggle mechanism, and a mold clamping motor. One of the lower platen and the upper platen is used as a fixed platen, and the other is used as a movable platen. A lower mold is attached to the lower platen, and an upper mold is attached to the upper platen. The lower die and the upper die constitute a mold apparatus. The lower mold may be attached to the lower platen via a rotary table. The toggle support is disposed below the lower platen and connected to the upper platen via a tie bar. The tie bar connects the upper platen and the toggle support at intervals in the mold opening / closing direction. The toggle mechanism is disposed between the toggle support and the lower platen, and moves the movable platen up and down. The mold clamping motor operates a toggle mechanism. When the mold clamping device is a saddle type, the number of tie bars is usually three. The number of tie bars is not particularly limited.

  The mold clamping device 100 according to the present embodiment includes the mold clamping motor 160 as a drive source, but may include a hydraulic cylinder instead of the mold clamping motor 160. The mold clamping device 100 may include a linear motor for opening and closing the mold and an electromagnet for mold clamping.

(Ejector device)
In the description of the ejector device 200, as in the description of the mold clamping device 100, the movement direction (right direction in FIGS. 1 and 2) of the movable platen 120 when the mold is closed is the front, and the movement of the movable platen 120 when the mold is opened. The direction (left direction in FIGS. 1 and 2) will be described as the rear.

  The ejector device 200 projects a molded product from the mold device 10. The ejector device 200 includes an ejector motor 210, a motion conversion mechanism 220, an ejector rod 230, and the like.

  The ejector motor 210 is attached to the movable platen 120. The ejector motor 210 is directly connected to the motion conversion mechanism 220, but may be connected to the motion conversion mechanism 220 via a belt, a pulley, or the like.

  The motion conversion mechanism 220 converts the rotational motion of the ejector motor 210 into the linear motion of the ejector rod 230. The motion conversion mechanism 220 includes a screw shaft and a screw nut that is screwed onto the screw shaft. A ball or a roller may be interposed between the screw shaft and the screw nut.

  The ejector rod 230 can be moved forward and backward in the through hole of the movable platen 120. The front end portion of the ejector rod 230 is in contact with the movable member 15 which is disposed inside the movable mold 12 so as to be able to advance and retract. The front end portion of the ejector rod 230 may or may not be connected to the movable member 15.

  The ejector device 200 performs the ejection process under the control of the control device 700.

  In the ejecting process, the ejector motor 210 is driven to advance the ejector rod 230 from the standby position to the ejecting position at a set speed, thereby moving the movable member 15 forward and ejecting the molded product. Thereafter, the ejector motor 210 is driven to retract the ejector rod 230 at a set speed, and the movable member 15 is retracted to the original standby position. The position and speed of the ejector rod 230 are detected using the ejector motor encoder 211, for example. The ejector motor encoder 211 detects the rotation of the ejector motor 210 and sends a signal indicating the detection result to the control device 700.

(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 moving direction of the screw 330 during filling (the left direction in FIGS. 1 and 2) is the front, and the screw 330 during weighing is used. The moving direction (right direction in FIGS. 1 and 2) will be described as the rear.

  The injection device 300 is installed on a slide base 301 that can move forward and backward with respect to the frame Fr, and can move forward and backward with respect to the mold device 10. The injection apparatus 300 touches the mold apparatus 10 and fills the cavity space 14 in the mold apparatus 10 with a molding material. The injection device 300 includes, for example, a cylinder 310, a nozzle 320, a screw 330, a metering motor 340, an injection motor 350, a pressure detector 360, and the like.

  The cylinder 310 heats the molding material supplied to the inside from the supply port 311. The supply port 311 is formed at the rear part of the cylinder 310. A cooler 312 such as a water-cooled cylinder is provided on the outer periphery of the rear portion of the cylinder 310. In front of the cooler 312, a heater 313 such as a band heater and a temperature detector 314 are provided on the outer periphery of the cylinder 310.

  The cylinder 310 is divided into a plurality of zones in the axial direction of the cylinder 310 (the left-right direction in FIGS. 1 and 2). A heater 313 and a temperature detector 314 are provided in each zone. For each zone, the control device 700 controls the heater 313 so that the temperature detected by the temperature detector 314 becomes a set temperature.

  The nozzle 320 is provided at the front end of the cylinder 310 and is pressed against the mold apparatus 10. 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.

  The screw 330 is disposed in the cylinder 310 so as to be rotatable and movable back and forth. When the screw 330 is rotated, the molding material is fed forward along the spiral groove of the screw 330. The molding material is gradually melted by the heat from the cylinder 310 while being fed forward. As the liquid molding material is fed forward of the screw 330 and accumulated in the front of the cylinder 310, the screw 330 is retracted. Thereafter, 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 in the mold apparatus 10.

  A backflow prevention ring 331 is attached to the front portion of the screw 330 as a backflow prevention valve that prevents a backflow of the molding material from the front to the back of the screw 330 when the screw 330 is pushed forward.

  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 is relatively relative to the screw 330 to a closed position (see FIG. 2) that closes the flow path of the molding material. fall back. This prevents the molding material accumulated in front of the screw 330 from flowing backward.

  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 to open the flow path of the molding material. It moves forward relative to the screw 330 up to (see FIG. 1). Thereby, a molding material is sent ahead of the screw 330.

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

  The injection device 300 may have a drive source that causes the backflow prevention ring 331 to advance and retreat between the open position and the closed position with respect to the screw 330.

  The weighing 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 a hydraulic pump, for example.

  The injection motor 350 moves the screw 330 back and forth. Between the injection motor 350 and the screw 330, a motion conversion mechanism for converting the rotational motion of the injection motor 350 into the linear motion of the screw 330 is provided. The motion conversion mechanism includes, for example, a screw shaft and a screw nut that is screwed onto the screw shaft. A ball, a roller, or the like may be provided between the screw shaft and the screw nut. The drive source for moving the screw 330 back and forth is not limited to the injection motor 350, and may be a hydraulic cylinder, for example.

  The pressure detector 360 detects the pressure transmitted between the injection motor 350 and the screw 330. The pressure detector 360 is provided in a force transmission path between the injection motor 350 and the screw 330 and detects the pressure acting on the pressure detector 360.

  The pressure detector 360 sends a signal indicating the detection result to the control device 700. The detection result of the pressure detector 360 is used for control and monitoring of the pressure received by the screw 330 from the molding material, the back pressure against the screw 330, the pressure acting on the molding material from the screw 330, and the like.

  The injection device 300 performs a filling process, a pressure holding process, a weighing process, and the like under the control of the control device 700.

  In the filling step, the injection motor 350 is driven to advance the screw 330 at a set speed, and the liquid molding material accumulated in front of the screw 330 is filled into the cavity space 14 in the mold apparatus 10. The position and speed of the screw 330 are detected using, for example, the 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, switching from the filling process to the pressure holding process (so-called V / P switching) is performed. A position where the V / P switching is performed is also referred to as a V / P switching position. The set speed of the screw 330 may be changed according to the position and time of the screw 330.

  In addition, after the position of the screw 330 reaches the set position in the filling process, the screw 330 may be temporarily stopped at the set position, and then 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 the pressure holding process, the injection motor 350 is driven to push the screw 330 forward, and the pressure of the molding material at the front end portion of the screw 330 (hereinafter also referred to as “holding pressure”) is maintained at a set pressure, The remaining molding material is pushed toward the mold apparatus 10. Insufficient molding material due to cooling shrinkage in the mold apparatus 10 can be replenished. The holding pressure is detected using a pressure detector 360, for example. The pressure detector 360 sends a signal indicating the detection result to the control device 700. The set value of the holding pressure may be changed according to the elapsed time from the start of the pressure holding process.

  In the pressure holding process, the molding material in the cavity space 14 in the mold apparatus 10 is gradually cooled, and when the pressure holding process is completed, the inlet of the cavity space 14 is closed with the solidified molding material. This state is called a gate seal, and the backflow of the molding material from the cavity space 14 is prevented. After the pressure holding process, the cooling process is started. In the cooling process, the molding material in the cavity space 14 is solidified. In order to shorten the molding cycle time, a metering step may be performed during the cooling step.

  In the metering step, 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 spiral groove of the screw 330. Along with this, the molding material is gradually melted. As the liquid molding material is fed forward of the screw 330 and accumulated in the front of the cylinder 310, the screw 330 is retracted. The number of rotations of the screw 330 is detected by using, for example, a weighing motor encoder 341. The weighing motor encoder 341 detects the rotation of the weighing motor 340 and sends a signal indicating the detection result to the control device 700.

  In the metering step, the set back pressure may be applied to the screw 330 by driving the injection motor 350 in order to limit the rapid retreat of the screw 330. The back pressure with respect to the screw 330 is detected using, for example, a pressure detector 360. The pressure detector 360 sends a signal indicating the detection result to the control device 700. When the screw 330 is retracted to the measurement completion position and a predetermined amount of molding material is accumulated in front of the screw 330, the measurement process is completed.

  In addition, although the injection apparatus 300 of this embodiment is an inline screw system, a pre-plastic system etc. may be sufficient. A pre-plastic injection device supplies a molding material melted in a plasticizing cylinder to the injection cylinder, and injects the molding material from the injection cylinder into a mold device. In the plasticizing cylinder, a screw is rotatably or rotatably and reciprocally disposed, and in the injection cylinder, a plunger is reciprocally disposed.

  In addition, the injection device 300 of the present embodiment is a horizontal type in which the axial direction of the cylinder 310 is the horizontal direction, but may be a vertical type in which the axial direction of the cylinder 310 is the vertical direction. The clamping device combined with the vertical injection device 300 may be vertical or horizontal. Similarly, the mold clamping device combined with the horizontal injection device 300 may be a horizontal type or a saddle type.

(Moving device)
In the description of the moving device 400, similarly to the description of the injection device 300, the moving direction of the screw 330 during filling (the left direction in FIGS. 1 and 2) is the front, and the moving direction of the screw 330 during weighing (see FIGS. 1 and 2). In the following description, the right direction in FIG.

  The moving device 400 moves the injection device 300 forward and backward with respect to the mold device 10. Further, the moving device 400 presses the nozzle 320 against the mold device 10 to generate a 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.

  The hydraulic pump 410 has a first port 411 and a second port 412. The hydraulic pump 410 is a bi-directionally rotatable pump, and by switching the rotation direction of the motor 420, hydraulic fluid (for example, oil) is sucked from one of the first port 411 and the second port 412 and discharged from the other. Then, hydraulic pressure is generated. The hydraulic pump 410 can also suck the working fluid from the tank and discharge the working fluid from either the first port 411 or the second port 412.

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

  The hydraulic cylinder 430 includes a cylinder body 431, a piston 432, and a piston rod 433. The cylinder body 431 is fixed with respect 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.

  The front chamber 435 of the hydraulic cylinder 430 is connected to the first port 411 of the hydraulic pump 410 via the 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, whereby the injection device 300 is pushed forward. The injection device 300 is advanced, and the nozzle 320 is pressed against the fixed mold 11. The front chamber 435 functions as a pressure chamber that generates the nozzle touch pressure of the nozzle 320 by the pressure of the hydraulic fluid supplied from the hydraulic pump 410.

  On the other hand, the rear chamber 436 of the hydraulic cylinder 430 is connected to the second port 412 of the hydraulic pump 410 via 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 through the second flow path 402, whereby the injection device 300 is pushed backward. The injection device 300 is retracted, and the nozzle 320 is separated from the fixed mold 11.

  In the present 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 a linear motion of the injection device 300 may be used.

(Control device)
The control device 700 includes a CPU (Central Processing Unit) 701, a storage medium 702 such as a memory, an input interface 703, and an output interface 704 as shown in FIGS. The control device 700 performs various controls by causing the CPU 701 to execute a program stored in the storage medium 702. In addition, the control device 700 receives a signal from the outside through the input interface 703 and transmits a signal to the outside through the output interface 704.

  The control device 700 repeatedly manufactures a molded product by repeatedly performing a mold closing process, a mold clamping process, a mold opening process, and the like. In addition, the control device 700 performs a weighing process, a filling process, a pressure holding process, and the like during the mold clamping process. A series of operations for obtaining a molded product, for example, operations from the start of the weighing process to the start of the next weighing process are also referred to as “shot” or “molding cycle”. The time required for one shot is also referred to as “molding cycle time”.

  The control device 700 is connected to the operation device 750 and the display device 760. The operation device 750 receives an input operation by a user and outputs a signal corresponding to the input operation to the control device 700. The display device 760 displays an operation screen corresponding to an input operation on the operation device 750 under the control of the control device 700.

  The operation screen is used for setting the injection molding machine 1 and the like. A plurality of operation screens are prepared and displayed by switching or overlapping. The user performs settings of the injection molding machine 1 (including input of set values) by operating the operation device 750 while viewing the operation screen displayed on the display device 760.

  The operation device 750 and the display device 760 may be configured with a touch panel, for example, and may be integrated. In addition, although the operating device 750 and the display device 760 of this embodiment are integrated, you may provide independently. In addition, a plurality of operation devices 750 may be provided.

(Opening and closing of nozzle of injection device)
FIG. 3 is a view showing a state in which the valve body is moved from the open position shown in FIG. 5 to the closed position by swinging the swing lever shown in FIG. 5 in the first direction (for example, clockwise). FIG. 4 is a view showing a state in which the swing lever shown in FIG. 3 is swung in a second direction (for example, counterclockwise). FIG. 5 is a view showing a state where the valve body shown in FIG. 4 is moved from the closed position to the open position by the pressure of the molding material.

  The injection device 300 has a valve body 322 that is moved between an open position (see FIG. 5) for opening the flow path 321 of the molding material in the nozzle 320 and a closed position (see FIGS. 3 and 4) for closing the flow path 321. Have. When the valve body 322 is in the closed position, a wedge-shaped gap 323 that is tapered forward may be formed between the valve body 322 and the wall surface of the flow path 321. When the pressure of the molding material in the wedge-shaped gap 323 becomes sufficiently large, the valve body 322 overcomes the adhesive force of the molding material and is moved from the closed position to the open position.

  The moving direction of the valve body 322 may be a direction orthogonal to the axial direction of the nozzle 320 or the radial direction of the flow path 321 of the nozzle 320. Since the valve body 322 moves from the closed position to the open position, the diameter of the flow path 321 is widened, so that the molding material easily passes through the nozzle 320. Therefore, the flow resistance of the molding material at the nozzle 320 in the filling step can be reduced, and the heat generation of the molding material can be suppressed. Therefore, the cooling process time can be shortened and the molding cycle can be shortened.

  The moving direction of the valve body 322 is a direction orthogonal to the axial direction of the nozzle 320 in the present embodiment, but may be the axial direction of the nozzle 320 as in the prior art.

  The injection device 300 includes a moving mechanism 324 that moves the valve body 322 between an open position and a closed position. The moving mechanism 324 includes, for example, a swing lever 325 that is swingably attached to the nozzle 320, and a fluid that moves the valve body 322 from the open position to the closed position by swinging the swing lever 325 in the first direction. Pressure cylinder 326.

  The swing lever 325 is swingable about a swing shaft 371 fixed to the nozzle 320, and is swung by expansion and contraction of the fluid pressure cylinder 326. The swing lever 325 contacts the valve body 322 but is not connected to the valve body 322.

  The fluid pressure cylinder 326 includes a cylinder body 327 and a piston rod 328 that moves by the pressure of the fluid supplied to the inside of the cylinder body 327. A proximal end portion of the piston rod 328 is connected to a piston that slides inside the cylinder body 327. The piston divides the inside of the cylinder body 327 into two chambers. By supplying pressure to one of the chambers, the piston is moved, and the piston rod 328 is moved.

  The cylinder body 327 is swingable about a swing shaft 372 fixed to the nozzle 320. On the other hand, the piston rod 328 is swingably connected to the swing lever 325 by a pin 373. The arrangement of the cylinder body 327 and the piston rod 328 may be reversed. That is, the cylinder body 327 may be connected to the swing lever 325 by the pin 373, and the piston rod 328 may be swingable about the swing shaft 372.

  As shown in FIG. 5, when the fluid pressure cylinder 326 is extended with the valve body 322 in the open position, the swing lever 325 is swung in the first direction (for example, clockwise). As a result, the valve body 322 is pushed by the swing lever 325 and moved to the closed position as shown in FIG.

  On the other hand, when the fluid pressure cylinder 326 is contracted with the valve body 322 in the closed position as shown in FIG. 3, the swing lever 325 swings in a second direction (for example, counterclockwise) opposite to the first direction. Be moved. As a result, the swing lever 325 returns to the original position as shown in FIG. 4 and does not hinder the movement of the valve body 322 from the closed position to the open position.

  As a result, the valve body 322 is moved from the closed position shown in FIG. 4 to the open position shown in FIG. 5 by the pressure of the molding material in the wedge-shaped gap 323. The movement of the valve body 322 from the closed position to the open position may be performed simultaneously with the swing of the swing lever 325 in the second direction or after the swing of the swing lever 325 in the second direction. It may be broken.

  In this embodiment, since the swing lever 325 is swung in the second direction and returned to the original position, the driving force of the fluid pressure cylinder 326 is used, but the pressure of the molding material generated in the filling process is used. Is also possible. In this case, instead of supplying pressure to the fluid pressure cylinder 326, the control device 700 releases pressure from the fluid pressure cylinder 326 and allows fluid to enter and exit from the two chambers defined by the piston and the outside. For example, when the fluid pressure cylinder 326 is a pneumatic cylinder, two rooms defined by the pistons are opened to the atmosphere. This allows the piston to move freely in both directions. Therefore, the pressure of the molding material generated in the filling process is used to move the valve body 322 from the closed position to the open position, and the valve body 322 pushes the swing lever 325 to swing the swing lever 325 in the second direction. Can be made. When the pressure of the molding material generated in the filling process is used to return the swing lever 325 to the original position, the swing lever 325 and the valve body 322 may be connected by a pin or the like. The valve body 322 may be moved from the closed position to the open position using the pressure of the molding material generated in the measuring step.

  The control device 700 reciprocates the valve body 322 between the open position and the closed position during one shot (for example, from the start of the measurement process to the start of the next measurement process). The position of the valve body 322 is, for example, an open position in the filling process and the pressure holding process, and a closed position in the measurement process. When the measurement process is performed in the mold open state, the molding material can be prevented from leaking from the nozzle 320.

  In the following description, the structure that closes the nozzle 320 by the operation of the valve body 322 described with reference to FIGS. 3 to 5 is referred to as a “shutoff mechanism 370”. The injection molding machine 1 of the present embodiment includes the shut-off mechanism 370 so that back pressure is applied in the same manner as in actual molding even when the nozzle 320 of the injection device 300 does not touch the mold device 10. Can be measured, and the cycle time can be shortened, which is particularly advantageous for application to high cycle molding.

(Evaluation system for resin melt state)
With reference to FIG.6 and FIG.7, the evaluation system 800 of the resin molten state which concerns on this embodiment is demonstrated. The injection molding machine 1 according to the present embodiment includes an evaluation system 800 for evaluating the molten state of the resin (molding material) in the injection apparatus 300.

  FIG. 6 is a diagram showing a schematic configuration of a resin molten state evaluation system 800 according to the present embodiment. FIG. 7 is a diagram showing a schematic configuration when the evaluation system 800 shown in FIG. 6 is viewed from the Y axis positive direction side. As shown in FIGS. 6 and 7, the evaluation system 800 uses the purge resin 805 discharged from the injection apparatus 300 to determine whether or not the resin in the injection apparatus 300 is in an unmelted state. In the present embodiment, the “unmelted state” means a state in which the resin in the injection apparatus 300 includes a predetermined amount or more of unmelted resin. The threshold for determining the unmelted state is calculated in advance by, for example, the ratio (area, number, etc.) of unmelted resin to the purge resin in the photographed image when purging is performed under the molding conditions under which a normal molded product can be manufactured. This ratio can be used as a threshold value. “Unmelted resin” means a resin having a viscosity that is not less than a predetermined value and relatively hard with respect to the molten resin.

  The evaluation system 800 includes a high speed camera 801, a light 802, a dark curtain 803, and an evaluation device 804.

  The high speed camera 801 captures the purge resin 805 discharged from the nozzle 320 of the injection apparatus 300 and outputs the captured image data to the evaluation apparatus 804. The high-speed camera 801 is installed at a position where the purge resin 805 purged (discharged) from the nozzle 320 can be photographed when the injection molding machine 1 is not touching the nozzle. For example, as shown in FIG. 6, the high-speed camera 801 is arranged on one side in the width direction of the injection apparatus 300 (Y-axis positive direction side). As long as the purge resin 805 can be photographed, a photographing means (camera) other than the high-speed camera 801 such as a shutter camera may be used. Further, the image pickup means may take a plurality of continuous images or may take a single image.

  The light 802 and the dark curtain 803 are installed in order to clear the shooting of unmelted resin with the high-speed camera 801. The light 802 is installed at a position where the purge resin 805 in the photographing range of the high-speed camera 801 is illuminated with light. For example, as shown in FIG. 6, the light 802 is on the same side as the high-speed camera 801 in the width direction of the injection apparatus 300 (Y-axis (Positive direction side) The black curtain 803 is installed behind the purge resin 805 when viewed from the high speed camera 801. For example, as shown in FIG. 6, the dark curtain 803 is opposite to the high speed camera 801 in the width direction of the injection apparatus 300 (on the Y axis negative direction side). Is arranged.

  Note that the evaluation system 800 does not necessarily include the light 802 and the dark curtain 803. In FIG. 7, for the convenience of illustration, the arrangement of the high-speed camera 801 and the light 802 is different from the above description, but in this embodiment, the arrangement of FIG. 6 is the correct arrangement.

  The evaluation device 804 determines whether or not the molten state of the resin in the injection device 300 is an unmelted state including a predetermined amount or more of the unmelted resin based on the image data of the purge resin 805 photographed by the high speed camera 801. To do. The evaluation device 804 includes an image acquisition unit 811, an image processing unit 812, and a melting determination unit 813.

  The image acquisition unit 811 acquires image data of the purge resin 805 photographed by the high speed camera 801.

  The image processing unit 812 performs image processing (see FIG. 10) on the portion of the purge resin 805 in the camera image acquired by the image acquisition unit 811.

  The melting determination unit 813 detects the presence or absence of unmelted resin using the image that has been subjected to image processing by the image processing unit 812, and the resin in the injection apparatus 300 is unmelted when a predetermined amount or more of unmelted resin is detected. It is determined that it is in a state.

  The evaluation device 804 is electrically connected to the high speed camera 801, the light 802, and the control device 700, and controls the operation of the high speed camera 801 and the light 802 and emits in cooperation with the control device 700. The operation of the apparatus 300 is controlled.

  The evaluation device 804 is physically a computer device having a CPU, a memory, an input interface, an output interface, and the like. The evaluation device 804 may be implemented as a part of the control device 700 described above, or may be implemented as an arithmetic device different from the control device 700.

  In FIG. 6, the constituent elements of the evaluation device 804 are shown as functional blocks, but each functional block is conceptual and does not necessarily need to be physically configured as illustrated. All or a part of each functional block can be configured to be functionally or physically distributed and integrated in arbitrary units. Each processing function performed in each functional block may be realized entirely or arbitrarily by a program executed by the CPU, or may be realized as hardware by wired logic.

  Next, with reference to FIG.8 and FIG.9, the evaluation process of the resin molten state in this embodiment is demonstrated. FIG. 8 is a flowchart of an injection molding process incorporating a resin melt state evaluation process in the present embodiment. FIG. 9 is a flowchart of the subroutine processing of the melting evaluation step in FIG. As shown in the flowchart of FIG. 8, in this embodiment, the evaluation of the resin melt state is performed immediately before the injection apparatus 300 touches the mold apparatus 10 with a nozzle.

  In step S101, various molding conditions are set by the control device 700 so as to satisfy the metering time and injection volume that can achieve the cycle time required for molding, based on input information from the user via the operation device 750. The The molding conditions are, for example, screw rotation speed, measuring stroke, and the like. When the process of step S101 is completed, the process proceeds to step S102.

  In step S102, the control device 700 performs the purge operation of the injection device 300. Any known method can be applied as the purge operation. For example, in a state where the shut-off mechanism 370 is released, the molding material is fed forward and discharged from the nozzle 320 by rotating the screw 330 while fixing the position of the screw 330. Alternatively, as the molding material is accumulated in the front portion of the cylinder 310 by the rotation of the screw 330, the screw 330 is retracted, and then the screw 330 is pushed forward to discharge the resin in the cylinder 310 from the nozzle 320. When the process of step S102 is completed, the process proceeds to step S103.

  In step S103, the control device 700 determines whether or not the number of repetitions of the purge operation has reached a predetermined number of stable purges. As the number of stable purges, for example, the number of repetitions of the purge operation required until the molten state of the molding material in the cylinder 310 is stabilized can be set. If the purge operation has not reached the number of stable purges, the process returns to step S102, and the purge operation is repeated until the molten state of the molding material is stabilized.

  If the result of determination in step S103 is that the purge operation has reached the number of safe purges, it is determined that the molten state of the molding material in the cylinder 310 has stabilized, and the molten state evaluation process is executed in step S104. In the molten state evaluation process, each process of a subroutine of steps S201 to S208 shown in FIG. 9 is performed. The molten state evaluation process is performed by the evaluation device 804.

  First, the evaluation device 804 controls the operation of the injection device 300 in cooperation with the control device 700, the shut-off mechanism 370 is closed (step S201), and the weighing of the injection device 300 is performed under the molding conditions set in step S101. A process is performed (step S202). Further, in the evaluation system 800, the light 802 is turned on under the control of the evaluation device 804, and preparation for photographing by the high speed camera 801 is performed (step S203).

  Next, when the shut-off mechanism 370 is released (step S204) and the purge resin 805 starts to be discharged from the nozzle 320, photographing of the purge resin 805 by the high speed camera 801 is started (step S205). The high speed camera 801 captures the number of shots necessary for the molten state evaluation, and outputs the captured image data to the image acquisition unit 811 of the evaluation device 804. The image acquisition unit 811 outputs the acquired image data to the image processing unit 812.

  The image processing unit 812 of the evaluation device 804 performs image processing on the image data of the purge resin 805 photographed by the high speed camera 801 in step S205, and extracts an unmelted portion of the purge resin 805 from the image data. (Step S206).

  Here, with reference to FIG. 10, an example of image processing performed in the image processing unit 812 of the evaluation apparatus 804 for extracting an unmelted portion from the captured image of the purge resin 805 will be described. As shown in FIG. 6, since the dark curtain 803 is installed behind the purge resin 805, the background of the raw image A taken by the high speed camera 801 is black as shown in FIG. The flow of the purge resin 805 irradiated by the light 802 is photographed so as to be conspicuous. This is because the light is reflected by the purge resin 805 while the light is absorbed by the dark curtain 803 of the background.

  First, as shown in FIG. 10B, this raw image A is binarized to create a contour image B in which the contour of the purge resin portion is extracted. The contour image B is, for example, converted from the raw image A into a gray scale that expresses the gray level between white where the light is the strongest to the weakest black, and the gray scale value is larger than a predetermined threshold (FIG. 10). The white portion in (b) can be created by a technique such as recording pixel coordinates as a portion where the resin exists. In addition, said threshold value can be set based on sensory evaluation etc. previously, for example.

  Next, as shown in FIG. 10C, the contour image B is applied to the raw image A, the purge resin area is cut out from the raw image A, and a processed image C is created by processing the edge of the purge resin area darkly. To do. At the end portion of the purge resin 805, more light from the light 802 is reflected, and the luminance is high due to this reflection. For this reason, the process of lowering the brightness is performed according to the distance from the contour of the purge resin region. For example, the lowering of the brightness is increased for pixels closer to the contour.

  Next, as shown in FIG. 10D, the processed image C is binarized to create an extracted image D from which unmelted portions are extracted. For example, a portion higher than a predetermined threshold value of the processed image C (a white portion in FIG. 10D) is extracted as an unmelted portion. This is because the white portion in the processed image C is a portion having a higher luminance than the black portion, and the unmelted portion has a higher density than the molten portion and is easily reflected by light. As a result, it is possible to determine how much unmelted portion is included in the range of the purge resin region of the photographed raw image A.

  Returning to FIG. 9, in step S207, the melting determination unit 813 of the evaluation device 804 determines whether or not the area of the unmelted portion extracted in step S206 is smaller than a predetermined allowable value. For example, the permissible value may be set as a permissible value by calculating in advance the area of the unmelted portion in the photographed image when purged under molding conditions under which a normal molded product can be manufactured.

  As a result of the determination in step S207, if the area of the unmelted portion is greater than or equal to the allowable value, the melting determination unit 813 determines that the unmelted resin is in an unmelted state with an amount greater than the allowable amount, and in step S208, the control device 700 Thus, the molding conditions are adjusted. For example, if the screw rotation speed is lowered among the molding conditions, the unmelted resin is easily melted when the molding material is fed forward along the spiral groove of the screw 330. Further, when the cylinder set temperature is raised among the molding conditions, the unmelted resin inside the cylinder 310 is easily melted. Further, when the back pressure with respect to the screw 330 is increased, the shear stress received by the molding material sent forward by the screw 330 is increased, and the amount of heat generated by the molding material due to the shear stress is increased, so that the unmelted resin is easily melted. Thus, the parameters of the molding conditions of the injection apparatus 300 are adjusted so that the unmelted resin can be easily melted and the resin is changed from the unmelted state to the molten state. After the molding conditions are adjusted, the process returns to step S201, and the molten state evaluation is performed again using the adjusted molding conditions.

  On the other hand, if the result of determination in step S207 is that the area of the unmelted portion is less than the allowable value, the melting determination unit 813 determines that the unmelted resin is less than the allowable amount and is not in the unmelted state, and the melting evaluation process To return to the main flow.

  Returning to FIG. 8, the injection device 300 is nozzle-touched to the mold device 10 by the control device 700 (step S105), and the resin (molding material) in a molten state from the injection device 300 to the cavity space 14 in the mold device 10 is obtained. Is filled and molding with a mold is performed (step S106). When the process of step S106 is completed, the control flow ends.

  In the melt state evaluation process in step S104, for example, the unmelted state may be evaluated using images from the beginning to the end of the injected purge resin 805, or the purge resin 805 in which the unmelted resin is easily formed. Evaluation may be performed using only the last image. Further, as a method for determining whether or not an unmelted state exists, in addition to the evaluation based on the area of the unmelted portion as described above, for example, the number of unmelted resin portions in the extracted image D in FIG. 10 is compared with an allowable value. And may be evaluated. Further, the allowable value used for determining the unmelted state may be a state in which there is no unmelted resin.

  Next, effects of the injection molding machine 1 according to this embodiment will be described. The injection molding machine 1 according to the present embodiment includes an injection device 300, a control device 700 that controls the operation of the injection device 300 and discharges the purge resin 805 from the injection device 300, and the purge resin 805 discharged from the injection device 300. A high-speed camera 801 that captures the image, an image acquisition unit 811 that acquires an image of the purge resin 805 captured by the high-speed camera 801, and the resin in the injection apparatus 300 based on this image exceeds a predetermined amount of unmelted resin. And an evaluation device 804 having a melting determination unit 813 that determines whether or not it is in an unmelted state.

  Similarly, an evaluation system 800 that evaluates the molten state of the resin in the injection device 300 of the injection molding machine 1 according to the present embodiment includes a high-speed camera 801 that photographs the purge resin 805 discharged from the injection device 300, and this An image acquisition unit 811 that acquires an image of the purge resin 805 photographed by the high-speed camera 801, and whether or not the resin in the injection apparatus 300 is in an unmelted state that includes at least a predetermined amount of unmelted resin based on the image. An evaluation device 804 having a melting determination unit 813 for determining.

  As described above, as a conventional method for determining unmelted resin, there is a method in which an infrared temperature sensor is provided in the resin flow path inside the injection apparatus 300, and the surface temperature of the resin measured by the infrared temperature sensor is compared with the installation temperature. there were. However, in this method, since the temperature inside the resin cannot be measured, there is a possibility that the presence or absence of the unmelted resin cannot be accurately evaluated when the unmelted resin is formed inside.

  In contrast, in the present embodiment, since the image of the purge resin 805 discharged from the injection device 300 is used as described above, not only the surface of the purge resin 805 flow but also the internal unmelted state can be determined. Molten resin can be detected with high accuracy. In addition, since the molten state of the resin can be determined at the purge stage before actually performing the molding with the mold, the molding defect due to the unmelted resin can be eliminated.

  In addition, the injection molding machine 1 of this embodiment includes a shut-off mechanism 370 that is provided in the injection apparatus 300 and closes the nozzle 320 to prevent the resin from leaking from the nozzle 320. The evaluation device 804 determines the unmelted state based on the image of the purge resin 805 obtained by closing the nozzle 320 by the shut-off mechanism 370 by the control device 700 and measuring the resin in the injection device 300 in the same state as at the time of molding. To do.

  With this configuration, the purge resin 805 generated under the same conditions as in actual molding can be used for evaluation using the shut-off mechanism 370, so that it is close to the resin that is actually supplied to the mold apparatus 10. The unmelted state can be determined from the resin in the state, and the detection accuracy of the unmelted resin can be increased.

  Further, in the injection molding machine 1 of the present embodiment, when the melting determination unit 813 of the evaluation device 804 determines that the resin is in an unmelted state, the control device 700 causes the injection device to change the resin from the unmelted state to the molten state. 300 molding conditions are adjusted.

  With this configuration, initially (step S101 in FIG. 8) roughly sets the molding conditions, and if appropriate adjustments can be made according to the determination result of the unmelted state, the molding conditions can be easily set. It is possible to reduce the time required for setting the conditions.

  Further, in the injection molding machine 1 according to the present embodiment, the evaluation device 804 includes an image processing unit 812 that performs image processing on the portion of the purge resin 805 in the image photographed by the high speed camera 801. The melting determination unit 813 of the evaluation device 804 detects the presence or absence of unmelted resin using the image that has been subjected to image processing by the image processing unit 812, and determines that it is in an unmelted state when it detects a predetermined amount or more of unmelted resin. To do.

  With this configuration, since the unmelted state is determined after processing the purge resin image so that the unmelted resin can be easily extracted, the detection accuracy of the unmelted resin can be increased.

  The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Those in which those skilled in the art appropriately modify the design of these specific examples are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Each element included in each of the specific examples described above and their arrangement, conditions, shape, and the like are not limited to those illustrated, and can be changed as appropriate. Each element included in each of the specific examples described above can be appropriately combined as long as no technical contradiction occurs.

  In the above-described embodiment, when the evaluation device 804 acquires an image of the purge resin 805 used for determining the unmelted state, the nozzle 320 is closed by the shut-off mechanism 370, so that the injection device 300 is in a state similar to that at the time of molding. Although the configuration in which the resin inside is measured has been illustrated, a configuration in which the resin is measured under the same conditions as those at the time of molding by another method may be used. For example, the injection device 300 can be measured in a state similar to that at the time of molding by using a method in which the nozzle 320 is kept open without using the shut-off mechanism 370 and the injection device 300 is in a nozzle touch state with the mold device 10. The resin inside can be measured. In the case of this method, the nozzle resin is returned after the measurement and the purge resin 805 is discharged.

  In the above-described embodiment, the purge operation for purging the purge resin 805 from the injection apparatus 300 after the nozzle 320 is closed by the shut-off mechanism 370 is illustrated as the purge operation when acquiring an image used for evaluation of the unmelted state. The purge operation may be performed without using the shutoff mechanism 370. In this case, steps S201, S202, and S204 are not executed in the flowchart of FIG. In step S205, the molding material delivered to the front portion of the cylinder 310 by the rotation of the screw 330 is purged as it is and photographed. Alternatively, in step S205, the purge resin purged from the injection apparatus 300 in the final purge operation in step S102 in the flowchart of FIG. 8 may be photographed.

DESCRIPTION OF SYMBOLS 1 Injection molding machine 300 Injection apparatus 370 Shutoff mechanism 700 Control apparatus 800 Evaluation system 801 High speed camera (camera)
804 Evaluation device 805 Purge resin 811 Image acquisition unit 812 Image processing unit 813 Melting determination unit

Claims (7)

An injection device;
A control device for controlling the operation of the injection device and discharging the purge resin from the injection device;
A camera for photographing the purge resin discharged from the injection device;
An image acquisition unit that acquires an image of the purge resin imaged by the camera, and an evaluation device that includes a melting determination unit that determines whether or not the resin in the injection apparatus is in an unmelted state based on the image; ,
Injection molding machine. The unmelted state is a state containing a predetermined amount of unmelted resin,
The injection molding machine according to claim 1. The evaluation device determines an unmelted state based on an image of a purge resin obtained by weighing the resin in the injection device in the same state as at the time of molding.
The injection molding machine according to claim 1 or 2. Provided in the injection device, comprising a shut-off mechanism for closing the nozzle and preventing the resin from leaking from the nozzle,
The evaluation device uses the control device to close the nozzle by the shut-off mechanism, and determines an unmelted state based on an image of a purge resin obtained by measuring the resin in the injection device in the same state as at the time of molding. ,
The injection molding machine according to claim 3. When the melting determination unit of the evaluation device determines that it is in an unmelted state,
The control device adjusts the molding conditions of the injection device so that the resin is in a molten state from an unmelted state,
The injection molding machine according to any one of claims 1 to 4. The evaluation apparatus includes an image processing unit that performs image processing on a portion of the purge resin in an image photographed by the camera,
The melting determination unit detects the presence or absence of unmelted resin using an image subjected to image processing by the image processing unit, and determines an unmelted state when detecting a predetermined amount or more of unmelted resin.
The injection molding machine according to any one of claims 1 to 5. An evaluation system for evaluating a molten state of a resin in an injection device of an injection molding machine,
A camera for photographing the purge resin discharged from the injection device;
An image acquisition unit that acquires an image of the purge resin imaged by the camera, and an evaluation device that includes a melting determination unit that determines whether or not the resin in the injection apparatus is in an unmelted state based on the image; ,
An evaluation system comprising: