JP2018167453A - Injection molding machine - Google Patents

Abstract

To provide an injection molding machine capable of suppressing accumulation of errors of detected values of rotational angles of a mold.SOLUTION: The injection molding machine includes: a mold rotating motor for rotating a mold; a rotation angle detector for detecting a rotation angle of the mold; a positioning mechanism for stopping the mold at a predetermined rotation angle; and a control device for controlling the mold rotating motor and the positioning mechanism. The control device includes: a servo control unit that rotates the mold so that a detection value detected by the rotation angle detector becomes the predetermined rotation angle; a rotation prevention processing unit that executes and releases rotation prevention of the mold by the positioning mechanism; and a detection value correcting unit that corrects a detection value detected by the rotation angle detector in a state where the rotation of the mold is prevented.SELECTED DRAWING: Figure 9

Description

  The present invention relates to an injection molding machine.

  The injection blow molding machine described in Patent Literature 1 includes a fixed platen to which a fixed mold is attached, a movable platen to which a movable mold is attached, and a support frame provided between the fixed platen and the movable platen. An intermediate mold is pivotally supported on the support frame by a rotating device such as a hydraulic motor. A plurality of first core molds protrude from one of the front and rear surfaces of the intermediate mold, and a plurality of second core molds protrude from the other of the front and rear surfaces of the intermediate mold. . In the mold-clamped state, the first core mold and the fixed mold are filled with resin, and the preform is injection-molded. When the resin is cooled to a predetermined temperature, the mold is opened and the intermediate mold is rotated 180 °. The mold is clamped again, the first core mold fitted with the preform is inserted into the movable mold for blowing, and air is blown to perform blow molding. At this time, the resin is filled in the space between the second core mold and the fixed mold, and the injection molding of the preform is performed. Blow molding and injection molding are performed simultaneously.

JP 2003-136571 A

  An injection molding machine includes: a mold rotation motor that rotates a mold; a rotation angle detector that detects a rotation angle of the mold; a positioning mechanism that stops the mold from rotating at a predetermined rotation angle; a mold rotation motor; And a control device for controlling the positioning mechanism. The control device releases the rotation prevention by the positioning mechanism, rotates the mold until the detection value detected by the rotation angle detector reaches a predetermined rotation angle, and repeatedly performs the control for preventing the rotation of the mold by the positioning mechanism. . The mold rotation motor rotates the mold repeatedly in one direction. The positioning mechanism has a positioning pin that is inserted into the positioning hole of the mold. When the detected value of the rotation angle of the mold is 0 ° and 180 °, the positioning pin is inserted into the positioning hole, and the mold is prevented from rotating.

  FIG. 12 is a diagram illustrating a relationship between a detection value of a conventional rotation angle and a true value of the rotation angle. Since the detected value includes an error, a deviation may occur between the detected value and the true value. FIG. 12 illustrates a case where the true value change amount is smaller than the detected value change amount. FIG. 12A is a diagram illustrating a state where the detected value of the rotation angle is 0 ° and the true value of the rotation angle is 0 °. FIG. 12B is a diagram showing a state where the detected value of the rotation angle is 180 ° and the true value of the rotation angle is 180 ° −Δθ1. FIG. 12C is a diagram illustrating a state in which the detected value of the rotation angle is 180 ° + Δθ1 and the true value of the rotation angle is 180 °. FIG. 12D is a diagram illustrating a state in which the detected value of the rotation angle is 0 ° and the true value of the rotation angle is 0 ° −Δθ1−Δθ2.

  When the mold 21B is rotated from the state where the rotation angle detection value is 0 ° as shown in FIG. 12A to the state where the rotation angle detection value is 180 ° as shown in FIG. The true value of the angle may be 180 ° −Δθ1.

  Subsequently, as shown in FIG. 12C, when the positioning pin 613B is inserted into the positioning hole 25B, the true value of the rotation angle becomes 180 °, while the detected value of the rotation angle becomes 180 ° + Δθ1. Thereafter, the positioning pin 613B is extracted from the positioning hole 25B.

  Next, as shown in FIG. 12D, when the mold 21B is rotated until the detected value of the rotation angle is 0 °, the detected value of the rotation angle is changed by 180 ° −Δθ1. The change amount of the true value is smaller than the change amount of the detected value.

  Therefore, in FIG. 12D, the true value of the rotation angle is 0 ° −Δθ1−Δθ2. As described above, when the deviation between the detected value and the true value is accumulated, the positioning pin 613B cannot be finally inserted into the positioning hole 25B, and the die 21B cannot be prevented from rotating.

  Although the case where the true value change amount is smaller than the detected value change amount has been described with reference to FIG. 12, the true value change amount may naturally be larger than the detected value change amount. Also in this case, if the deviation between the detected value and the true value accumulates, the positioning pin 613B cannot be finally inserted into the positioning hole 25B, and the die 21B cannot be prevented from rotating.

  This invention is made | formed in view of the said subject, Comprising: It aims at provision of the injection molding machine which can suppress that the difference | error of the detected value of the rotation angle of a metal mold | die is piled up.

In order to solve the above problems, according to one aspect of the present invention,
A mold rotation motor that rotates the mold; and
A rotation angle detector for detecting a rotation angle of the mold;
A positioning mechanism for preventing the mold from rotating at a predetermined rotation angle;
A control device for controlling the mold rotation motor and the positioning mechanism,
The control device includes:
A servo control unit that rotates the mold so that a detection value detected by the rotation angle detector becomes the predetermined rotation angle;
An anti-rotation processing unit for executing and releasing the anti-rotation of the mold by the positioning mechanism;
An injection molding machine is provided that includes a detection value correction unit that corrects a detection value detected by the rotation angle detector while the rotation prevention of the mold is being performed.

  According to one aspect of the present invention, there is provided an injection molding machine capable of suppressing the accumulation of errors in the detected value of the rotation angle of the mold.

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. It is a figure which shows the state at the time of the completion | finish of mold opening of the mold clamping apparatus by one Embodiment. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. It is a figure which shows the state at the time of the mold clamping of the mold clamping apparatus by one Embodiment. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. It is a figure which shows the positioning mechanism by one Embodiment, Comprising: It is a figure which fractures | ruptures and shows a part of intermediate mold support frame. It is a figure which shows the component of the control apparatus by one Embodiment with a functional block. It is a flowchart which shows the process of the control apparatus by one Embodiment. It is a figure which shows the relationship between the detected value of a rotation angle by one Embodiment, and the true value of a rotation angle. It is a figure which shows the state at the time of the mold clamping of the metal mold | die apparatus by other one Embodiment. It is a figure which shows the relationship between the detection value of the conventional rotation angle, and the true value of a rotation angle.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In each of the drawings, the same or corresponding components are denoted by the same or corresponding reference numerals, and description thereof will be omitted.

(Injection molding machine)
FIG. 1 is a diagram illustrating a state when mold opening of an injection molding machine according to an embodiment is completed. FIG. 2 is a diagram illustrating a state during mold clamping of the injection molding machine according to the embodiment. 1 and 2, the X direction, the Y direction, and the Z direction are directions perpendicular to each other. The mold opening / closing direction is the X direction. When the mold clamping device is a horizontal mold, the X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction. 1 and 2, the illustration of the intermediate mold support frame and the intermediate mold shown in FIGS. As shown in FIGS. 1 to 2, the injection molding machine includes a mold clamping device 100, an injection device 300, a moving device 400, and a control device 700. Hereinafter, each component of the injection molding machine 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 movable platen 120 is advanced by driving the mold clamping motor 160 and advancing the cross head 151 to the mold closing completion position at a set speed. 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 is formed inside the mold apparatus 10 during mold clamping, and the injection apparatus 300 fills the cavity space with a liquid molding material. A molded product is obtained by solidifying the filled molding material. A plurality of cavity spaces may be provided, and in this case, a plurality of molded products can be obtained simultaneously.

  In the mold opening process, the movable platen 120 is retracted by driving the mold clamping motor 160 and retracting the cross head 151 to the mold opening completion position at a set speed. Thereafter, the molded product is taken out from the mold apparatus 10.

  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 interval L between the fixed platen 110 and the toggle support 130 is adjusted so that the link angle θ of the toggle mechanism 150 becomes a predetermined angle when the mold closing is completed.

  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.

(Injection device)
In the description of the injection device 300, unlike the description of the mold clamping device 100, 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 (FIG. 1). In the following description, the right direction in FIG.

  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 in the mold apparatus 10 with the 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 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 in the mold apparatus 10 is gradually cooled, and when the pressure holding process is completed, the inlet of the cavity space 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 is prevented. After the pressure holding process, the cooling process is started. In the cooling step, the molding material in the cavity space 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. A plurality of operation screens are prepared and displayed by switching or overlapping. The user performs settings of the injection molding machine (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.

(Injection blow molding)
FIG. 3 is a diagram illustrating a state when the mold opening of the mold clamping device according to the embodiment is completed. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a diagram illustrating a state during mold clamping of the mold clamping device according to the embodiment. 6 is a cross-sectional view taken along line VI-VI in FIG.

  For example, the mold clamping device 100 moves the intermediate mold support frame 510 between the fixed platen 110 and the movable platen 120, and moves the intermediate mold support frame 510 relative to the fixed platen 110, thereby An intermediate mold moving device 520 that moves the intermediate mold 21 supported by the mold support frame 510. The mold clamping apparatus 100 also includes a mold rotation motor 570 that rotates the intermediate mold 21 supported by the intermediate mold support frame 510. Furthermore, the mold clamping device 100 includes a split mold opening / closing device 580 that opens and closes the first split mold 16 and the second split mold 17 constituting the movable mold 12.

  The fixed platen 110 may be fixed to the frame Fr. The fixed mold 11 is mounted on the mold mounting surface of the fixed platen 110. As shown in FIG. 6, the fixed mold 11 has a plurality of concave mold portions 31 that form a cavity space for injection molding in cooperation with the intermediate mold 21. Six concave mold portions 31 for injection molding are arranged in the Z direction to form a row, and two rows are provided at intervals in the Y direction. In addition, the number of the recessed mold parts 31 for injection molding is not particularly limited.

  The movable platen 120 can be moved forward and backward along the guide 101 laid on the frame Fr. The movable mold 12 is attached to the mold attachment surface of the movable platen 120. The movable mold 12 includes, for example, a first split mold 16 and a second split mold 17. As shown in FIG. 6, the first split mold 16 and the second split mold 17 have a plurality of concave mold portions 32 that form a cavity space for blow molding in cooperation with the intermediate mold 21 as shown in FIG. 6. Have. A row is formed by arranging six concave mold portions 32 for blow molding in the Z direction, and the row is formed by a pair of first split mold 16 and second split mold 17. Two sets of the second split mold 17 are provided at intervals in the Y direction. In addition, the number of the recessed mold parts 32 for blow molding is not particularly limited.

  The intermediate mold support frame 510 is disposed between the fixed platen 110 and the movable platen 120, and can move forward and backward along the guide 101 independently of the movable platen 120. The intermediate mold support frame 510 rotatably supports the intermediate mold 21.

  The intermediate mold support frame 510 is formed in a square frame shape when viewed in the mold opening / closing direction. Through holes that penetrate the intermediate mold support frame 510 in the X direction are formed at the four corners of the intermediate mold support frame 510, and the tie bars 140 are inserted through the through holes. The intermediate mold support frame 510 can be moved forward and backward along the tie bar 140.

  The intermediate mold support frame 510 has a pair of column portions 511 each extending in the Z direction, and a pair of beam portions 512 (see FIG. 7) that connect both ends of the pair of column portions 511 in the Z direction. The pair of column portions 511 hold bearings 514 that rotatably support the rotation shaft 513 at the center in each Z direction. The axial direction of the rotating shaft 513 is the Y direction, and the intermediate mold 21 is fixed to the rotating shaft 513, and the intermediate mold 21 rotates together with the rotating shaft 513.

  The intermediate mold 21 includes a plate-like portion 22 formed in a plate shape when viewed in the axial direction (viewed in the Y direction) of the rotation shaft 513, and a first convex portion 23 provided on one main surface of the plate-like portion 22. And the second convex part 24 provided on the remaining main surface of the plate-like part 22. The first convex part 23 and the second convex part 24 are arranged symmetrically with the plate-like part 22 in between. The first convex mold part 23 is provided in the same number as the concave mold part 31 for injection molding and the concave mold part 32 for blow molding. Similarly, the same number of the second convex mold parts 24 as the concave mold parts 31 for injection molding and the concave mold parts 32 for blow molding are provided.

  When the first convex part 23 faces the concave mold part 31 for injection molding, the second convex part 24 faces the concave mold part 32 for blow molding. When the first convex part 23 faces the blow molding concave part 32, the second convex part 24 faces the injection molding concave part 31. Each time the intermediate mold 21 is rotated 180 °, the combination of facing molds changes.

  In the present embodiment, the convex mold part is provided in the intermediate mold 21 and the concave mold part is provided in the fixed mold 11 and the movable mold 12. However, the arrangement of the convex mold part and the concave mold part may be reversed. That is, the convex mold part may be provided in the fixed mold 11 and the movable mold 12, and the concave mold part may be provided in the intermediate mold 21.

  The intermediate mold moving device 520 moves the intermediate mold 21 in the X direction by moving the intermediate mold support frame 510 in the X direction. As shown in FIGS. 4 and 6, the intermediate mold moving device 520 includes an intermediate mold moving pump 530, an intermediate mold moving motor 540, an intermediate mold moving cylinder 550, and the like. Two sets of the intermediate mold moving pump 530, the intermediate mold moving motor 540, and the intermediate mold moving cylinder 550 are provided. The intermediate mold moving pump 530 and the intermediate mold moving motor 540 may be common to the two intermediate mold moving cylinders 550, or may be provided one by one.

  The intermediate mold transfer pump 530 has a first port 531 and a second port 532. The intermediate mold moving pump 530 is a pump that can rotate in both directions. By switching the rotation direction of the intermediate mold moving motor 540, hydraulic fluid (for example, oil) is output from one of the first port 531 and the second port 532. Is sucked in and discharged from the other to generate hydraulic pressure. The intermediate mold moving pump 530 can also suck the working fluid from the tank and discharge the working fluid from either the first port 531 or the second port 532.

  The intermediate mold moving motor 540 operates the intermediate mold moving pump 530. The intermediate mold movement motor 540 drives the intermediate mold movement pump 530 with a rotation direction and a rotation torque according to a control signal from the control device 700. The intermediate mold moving motor 540 may be an electric motor or an electric servo motor.

  The intermediate mold moving cylinder 550 has a cylinder body 551, a piston 552, and a piston rod 553. The piston rod 553 extends from the cylinder body 551 in the X direction, and is fixed to the center portion in the Z direction of the column portion 511 of the intermediate mold support frame 510 at the tip portion. The cylinder body 551 is fixed to the fixed platen 110. The piston 552 divides the interior of the cylinder body 551 into a front chamber 555 as a first chamber and a rear chamber 556 as a second chamber.

  The front chamber 555 of the intermediate mold moving cylinder 550 is connected to the first port 531 of the intermediate mold moving pump 530 via the first flow path 521. The hydraulic fluid discharged from the first port 531 is supplied to the front chamber 555 via the first flow path 521, whereby the intermediate mold support frame 510 is pushed backward. As a result, the intermediate mold support frame 510 moves backward and the intermediate mold 21 is separated from the fixed mold 11.

  On the other hand, the rear chamber 556 of the intermediate mold moving cylinder 550 is connected to the second port 532 of the intermediate mold moving pump 530 via the second flow path 522. The hydraulic fluid discharged from the second port 532 is supplied to the rear chamber 556 of the intermediate mold moving cylinder 550 via the second flow path 522, whereby the intermediate mold support frame 510 is pushed forward. As a result, the intermediate mold support frame 510 moves forward, and the intermediate mold 21 is pressed against the fixed mold 11.

  The position of the intermediate mold 21 in the X direction with respect to the fixed mold 11 is detected by, for example, a linear encoder 560 (see FIGS. 3 and 5). The linear encoder 560 includes a linear scale 561 extending in the X direction and a linear head 562 that detects a displacement amount with respect to the linear scale 561. The linear scale 561 is fixed to the fixed platen 110 at the front end, and the linear head 562 is fixed to the intermediate mold support frame 510. The arrangement of the linear scale 561 and the linear head 562 may be reversed. The linear scale 561 may be fixed to the intermediate mold support frame 510 at the rear end, and the linear head 562 may be fixed to the fixed platen 110. The linear head 562 sends a signal indicating the detection result to the control device 700.

  In this embodiment, the intermediate mold moving device 520 includes the intermediate mold moving cylinder 550, but the present invention is not limited to this. For example, instead of the intermediate mold moving cylinder 550, an electric motor and a motion conversion mechanism that converts the rotational motion of the electric motor into a linear motion of the intermediate mold support frame 510 may be used.

  The mold rotation motor 570 rotates the intermediate mold 21 supported by the intermediate mold support frame 510. The mold rotation motor 570 is provided, for example, on the column portion 511 of the intermediate mold support frame 510. A drive gear 571 provided on the output shaft of the mold rotation motor 570 and a passive gear 572 provided on the rotation shaft 513 are engaged with each other. The drive gear 571 and the passive gear 572 constitute a speed reducer 573. The rotational movement of the mold rotating motor 570 is transmitted to the rotating shaft 513 through the speed reducer 573. In addition, the structure of the reduction gear 573 is not specifically limited. The rotational movement of the mold rotation motor 570 may be transmitted to the rotation shaft 513 through a belt or a pulley.

  The mold rotation motor encoder 574 functions as a rotation angle detector that detects the rotation angle of the intermediate mold 21. The mold rotation motor encoder 574 detects the rotation of the output shaft of the mold rotation motor 570 and sends a signal indicating the detection result to the control device 700. The control device 700 performs servo control of the mold rotation motor 570 so that the detected value of the rotation angle of the intermediate mold 21 becomes a predetermined rotation angle (for example, 0 ° or 180 °). When the intermediate mold 21 is rotated by 180 °, the output shaft of the mold rotating motor 570 may rotate more than 180 °. The rotation angle of the intermediate mold 21 is obtained from the rotation angle of the output shaft of the mold rotation motor 570 and the reduction ratio.

  The split mold opening / closing device 580 opens and closes the first split mold 16 and the second split mold 17 constituting the movable mold 12. The split mold opening / closing device 580 includes a pair of hydraulic cylinders 590 provided on the movable platen 120, for example. The pair of hydraulic cylinders 590 are symmetrically disposed at the center in the Z direction of the movable platen 120 with an interval in the Y direction. The pair of hydraulic cylinders 590 are provided so as to face each other.

  Each hydraulic cylinder 590 has a cylinder body 591 fixed to the movable platen 120 and a piston rod 593 extending from the cylinder body 591 in the Y direction. The tip of one piston rod 593 is fixed to one of the plurality of first split molds 16 connected by the first connecting member 594. The tip of the other piston rod 593 is fixed to one of the plurality of second split molds 17 connected by the second connecting member 595. When each hydraulic cylinder 590 is operated, the first split mold 16 and the second split mold 17 are opened and closed.

  Next, the operation of the mold clamping apparatus 100 having the above configuration will be described. The mold clamping device 100 performs a mold closing process, a mold clamping process, a mold opening process, a split mold opening / closing process, an intermediate mold rotating 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 the mold closing completion position at a set speed, thereby moving the movable platen 120 forward and causing the movable mold 12 to approach the fixed mold 11. . At this time, the intermediate mold moving device 520 moves the intermediate mold support frame 510 forward so that the intermediate mold 21 approaches the fixed mold 11. The movable mold 12 is in contact with the intermediate mold 21, and the intermediate mold 21 is in contact with the fixed mold 11.

  Subsequently, 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. In FIG. 6, a cavity space for injection molding is formed between the concave mold part 31 of the fixed mold 11 and the first convex mold part 23 of the intermediate mold 21. In FIG. 6, a blow molding cavity space is formed between the concave mold part 32 of the movable mold 12 and the second convex mold part 24 of the intermediate mold 21.

  In the cavity space for injection molding, the molding material is filled and the preform 2 is injection molded. On the other hand, in the blow molding cavity space, the preform 2 that has been injection molded in advance in the injection molding cavity space is expanded by the pressure of the compressed air, and the molded product 4 is blow molded. Since the compressed air for inflating the preform 2 is injected from the intermediate mold 21, the blow-molded molded article 4 is separated from the intermediate mold 21. The injection molding of the preform 2 and the blow molding of the molded product 4 are performed simultaneously.

  Subsequently, 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 moving the movable mold 12 relative to the fixed mold 11. Separate. At this time, the intermediate mold moving device 520 moves the intermediate mold support frame 510 backward to separate the intermediate mold 21 from the fixed mold 11. The movable mold 12 is separated from the intermediate mold 21, and the intermediate mold 21 is separated from the fixed mold 11. Meanwhile, the intermediate mold 21 holds the preform 2 before blow molding.

  Subsequently, in the split mold opening / closing process, the split mold opening / closing device 580 opens the first split mold 16 and the second split mold 17. Thereafter, when the molded product 4 is taken out from the movable mold 12, the split mold opening / closing device 580 closes the first split mold 16 and the second split mold 17.

  Subsequently, in the intermediate mold rotating step, the mold rotating motor 570 is driven to rotate the intermediate mold 21 by 180 °. Thereby, the combination of the first convex mold part 23 and the second convex mold part 24 facing the concave mold part 31 for injection molding and the concave mold part 32 for blow molding changes. While the intermediate mold 21 is rotated 180 °, the intermediate mold 21 holds the preform 2 before blow molding.

  The intermediate mold rotation process may be performed simultaneously with the split mold opening / closing process, or may be performed before the split mold opening / closing process. The intermediate mold rotation process may be performed after the completion of the mold opening process and before the start of the next mold closing process.

  Thereafter, the control device 700 repeatedly performs a mold closing process, a mold clamping process, a mold opening process, a split mold opening / closing process, an intermediate mold rotating process, and the like.

  FIG. 7 is a view showing a positioning mechanism according to an embodiment, and is a view showing a part of an intermediate mold support frame in a broken state. The positioning mechanism 600 prevents the intermediate mold 21 from rotating at a predetermined rotation angle (for example, 0 ° and 180 °).

  The positioning mechanism 600 includes, for example, a telescopic cylinder 610 provided in the beam portion 512 of the intermediate mold support frame 510. The telescopic cylinder 610 is configured by a pneumatic cylinder or a hydraulic cylinder. The telescopic cylinder 610 includes a cylinder main body 611 fixed to the beam portion 512 and a positioning pin 613 configured by a piston rod extending from the cylinder main body 611 in the Z direction.

  When the telescopic cylinder 610 is operated, the positioning pin 613 moves in the Z direction. By inserting the positioning pin 613 into the positioning hole 25 formed in the end face of the intermediate mold 21, the intermediate mold 21 is prevented from rotating. Further, by pulling out the positioning pin 613 from the positioning hole 25 of the intermediate mold 21, the detent of the intermediate mold 21 is released.

  The positioning hole 25 has a tapered hole portion 26 formed in the opening portion and a straight hole portion 27 extending from the deepest portion of the tapered hole portion 26. The tapered hole portion 26 is formed such that the diameter decreases as the depth from the surface increases. The straight hole 27 has a slightly larger diameter than the positioning pin 613. The positioning pin 613 passes through the tapered hole portion 26 and is inserted into the straight hole portion 27.

  The positioning mechanism 600 is provided on the intermediate mold support frame 510 in this embodiment, but may be provided on the intermediate mold 21. In this case, the cylinder body 611 is fixed to the intermediate mold 21, and the positioning hole 25 into which the positioning pin 613 is inserted is formed on the inner peripheral surface of the intermediate mold support frame 510.

  The positioning mechanism 600 includes a fluid pressure cylinder such as a pneumatic cylinder or a hydraulic cylinder in the present embodiment, but the present invention is not limited to this. For example, instead of the fluid pressure cylinder, an electric motor and a motion conversion mechanism that converts the rotational motion of the electric motor into a linear motion of the positioning pin 613 may be used.

  FIG. 8 is a diagram illustrating functional elements of the control device according to the embodiment. Each functional block illustrated in FIG. 8 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.

  The control device 700 includes, for example, a servo control unit 711 that rotates the intermediate mold 21 so that a detected value of the rotation angle of the intermediate mold 21 becomes a predetermined rotation angle (for example, 0 ° or 180 °), and a positioning mechanism 600. And an anti-rotation processing unit 712 for executing and releasing the anti-rotation of the intermediate mold 21. The control device 700 further includes a detection value correction unit 713 that corrects the detection value of the rotation angle of the intermediate mold 21 in a state where the rotation of the intermediate mold 21 is being executed. The servo control unit 711 rotates the intermediate mold 21 so that the detection value of the rotation angle of the intermediate mold 21 becomes a predetermined rotation angle based on the correction of the detection value of the detection value correction unit 713.

  As a rotation angle detector that detects the rotation angle of the intermediate mold 21, for example, a mold rotation motor encoder 574 is used. The mold rotation motor encoder 574 detects the rotation of the output shaft of the mold rotation motor 570 and sends a signal indicating the detection result to the control device 700. The rotation angle of the intermediate mold 21 is obtained from the rotation angle of the output shaft of the mold rotation motor 570 and the reduction ratio.

  FIG. 9 is a flowchart illustrating processing of the control device according to the embodiment. The process after step S101 shown in FIG. 9 is started when the start condition of the intermediate mold rotating process is satisfied. The start condition of the intermediate mold rotating process includes, for example, that the cross head 151 has returned to the mold opening completion position.

  In step S <b> 101, the anti-rotation processing unit 712 pulls out the positioning pin 613 from the positioning hole 25 and releases the anti-rotation of the intermediate mold 21.

  Subsequently, in step S102, the servo control unit 711 drives the mold rotation motor 570 to rotate the intermediate mold 21.

  Subsequently, in step S103, the servo control unit 711 determines whether or not the detected value of the rotation angle of the intermediate mold 21 is a predetermined rotation angle (for example, 0 ° or 180 °).

  When the detected value of the rotation angle of the intermediate mold 21 does not reach the predetermined rotation angle in Step S103 (No in Step S103), the process returns to Step S102 and the processing after Step S102 is continued.

  On the other hand, when the detected value of the rotation angle of the intermediate mold 21 has reached the predetermined rotation angle in step S103 (step S103, Yes), the process proceeds to step S104, and the servo control unit 711 stops the rotation of the intermediate mold 21. Let

  Subsequently, in step S105, the processing of the servo control unit 711 is canceled, and the output shaft of the mold rotation motor 570 is freely rotatable.

  Subsequently, in step S <b> 106, the anti-rotation processing unit 712 inserts the positioning pin 613 into the positioning hole 25 of the intermediate mold 21. When the positions of the positioning hole 25 and the positioning pin 613 of the intermediate mold 21 are slightly shifted, the positioning mold 613 presses the tapered surface of the tapered hole portion 26, whereby the intermediate mold 21 rotates. Since the output shaft of the mold rotation motor 570 is rotatable in advance in step S105, the mold rotation motor 570 can be prevented from interfering with the rotation of the intermediate mold 21 in step S106. The positioning pin 613 passes through the tapered hole portion 26 and is inserted into the straight hole portion 27.

  Subsequently, in step S107, the process waits for a predetermined time from the completion of the insertion of the positioning pin 613. The elapsed time from the completion of insertion of the positioning pin 613 is measured by a timer of the control device 700 or the like. The predetermined time used for the determination is determined based on a measurement result obtained by previously measuring, for example, a time during which the rotational vibration of the intermediate mold 21 caused by the insertion of the positioning pin 613 is attenuated.

  Subsequently, in step S108, the detection value correction unit 713 corrects the detection value of the rotation angle of the intermediate mold 21. For example, the detection value correction unit 713 corrects the detection value of the rotation angle of the intermediate mold 21 to the closest rotation angle among predetermined rotation angles (for example, 0 ° and 180). In step S107, a predetermined time is waited for after completion of insertion of the positioning pin 613. Therefore, after the rotational vibration of the intermediate mold 21 due to insertion of the positioning pin 613 is attenuated, the rotation angle of the intermediate mold 21 is determined in step S108. The detected value can be corrected and the detected value of the rotation angle can be accurately adjusted to the true value of the rotation angle.

  Thereafter, the control device 700 ends the current process and waits until the start condition of the intermediate mold rotating process is satisfied again. In the subsequent processing, the servo control unit 711 rotates the intermediate mold 21 so that the detected value of the rotation angle of the intermediate mold 21 becomes a predetermined rotation angle based on the correction of the detection value of the detection value correction unit 713. . Therefore, it is possible to absorb the deviation between the detected value of the rotation angle and the true value of the rotation angle, and to suppress the accumulation of errors in the detected value of the rotation angle. If errors in the detected value of the rotation angle are accumulated, the positioning pin 613 cannot be finally inserted into the positioning hole 25, and the intermediate mold 21 cannot be prevented from rotating.

  In the present embodiment, step S108 for correcting the detected value of the rotation angle of the intermediate mold 21 is performed after step S106 for inserting the positioning pin 613, but before step S101 for pulling out the positioning pin 613. May be.

  In the present embodiment, the detection value of the rotation angle of the intermediate mold 21 is corrected every time the intermediate mold rotation process is performed, but the present invention is not limited to this. For example, the detection value of the rotation angle of the intermediate mold 21 may be corrected every time the intermediate mold rotation process is performed a plurality of times.

  FIG. 10 is a diagram illustrating a relationship between a detected value of the rotation angle and a true value of the rotation angle according to an embodiment. Since the detected value includes an error, a deviation may occur between the detected value and the true value. FIG. 10 illustrates a case where the change amount of the true value is smaller than the change amount of the detection value. FIG. 10A is a diagram illustrating a state in which the detected value of the rotation angle is 0 ° and the true value of the rotation angle is 0 °. FIG. 10B is a diagram showing a state where the detected value of the rotation angle is 180 ° and the true value of the rotation angle is 180 ° −Δθ1. FIG. 10C is a diagram showing a state when the true value of the rotation angle is 180 ° and the detection value of the rotation angle is corrected from 180 ° + Δθ1 to 180 °. FIG. 10D is a diagram illustrating a state where the detected value of the rotation angle is 0 ° and the true value of the rotation angle is 0 ° −Δθ1.

  When the intermediate mold 21 is rotated from the state where the detected value of the rotation angle is 0 ° as shown in FIG. 10 (a) to the state where the detected value of the rotation angle is 180 ° as shown in FIG. 10 (b), The true value of the rotation angle may be 180 ° −Δθ1.

  Subsequently, when the positioning pin 613 is inserted into the positioning hole 25 as shown in FIG. 10C, the true value of the rotation angle becomes 180 °, while the detected value of the rotation angle becomes 180 ° + Δθ1. In the present embodiment, when the true value of the rotation angle is 180 °, the detected value of the rotation angle is corrected from 180 ° + Δθ1 to 180 °. Thereafter, the positioning pin 613 is extracted from the positioning hole 25.

  Next, as shown in FIG. 10D, when the intermediate mold 21 is rotated until the detected value of the rotation angle is 0 °, the detected value of the rotation angle is changed by 180 °. The change amount of the true value is smaller by Δθ1 than the change amount of the detected value.

  Therefore, in FIG. 10D, the true value of the rotation angle is 0 ° −Δθ1. When the positioning pin 613 is inserted into the positioning hole 25 from the state shown in FIG. 10D, the true value of the rotation angle becomes 0 °, while the detected value of the rotation angle becomes 0 ° + Δθ1. In the present embodiment, when the true value of the rotation angle is 0 °, the detected value of the rotation angle is corrected from 0 ° + Δθ1 to 0 °. Thereafter, the positioning pin 613 is extracted from the positioning hole 25.

  Although the case where the true value change amount is smaller than the detected value change amount has been described with reference to FIG. 10, the true value change amount may naturally be larger than the detected value change amount. Also in this case, when the positioning pin 613 is inserted into the positioning hole 25, the rotation angle detection value may be corrected.

  As described above, the detection value correction unit 713 corrects the detection value of the rotation angle of the intermediate mold 21 while the rotation of the intermediate mold 21 is being stopped. Therefore, it is possible to absorb the deviation between the detected value of the rotation angle and the true value of the rotation angle, and to suppress the accumulation of errors in the detected value of the rotation angle. If errors in the detected value of the rotation angle are accumulated, the positioning pin 613 cannot be finally inserted into the positioning hole 25, and the intermediate mold 21 cannot be prevented from rotating.

  The detection value correction unit 713 cancels the processing of the servo control unit 711 so that the output shaft of the mold rotation motor 570 is rotatable and the intermediate mold 21 is stopped. The detected value of the rotation angle 21 is corrected. Generation of a load due to rotation of the intermediate mold 21 by the servo control unit 711 and rotation prevention of the intermediate mold 21 by the positioning mechanism 600 can be suppressed, and damage to the mold rotation motor 570, the intermediate mold 21, and the positioning mechanism 600 is suppressed. it can.

  Further, the detection value correction unit 713 cancels the processing of the servo control unit 711 so that the output shaft of the mold rotation motor 570 can rotate and the intermediate mold 21 is prevented from rotating, and after a predetermined time has elapsed, The detected value of the rotation angle of the intermediate mold 21 is corrected. Therefore, after the rotational vibration of the intermediate mold 21 due to the insertion of the positioning pin 613 is attenuated, the detection value of the rotation angle of the intermediate mold 21 can be corrected, and the detection value of the rotation angle is accurately set to the true value of the rotation angle. Can be adapted to

  Furthermore, when the detected value of the rotation angle of the intermediate mold 21 reaches a predetermined rotation angle, the processing of the servo control unit 711 is canceled, the output shaft of the mold rotation motor 570 is made rotatable, and the rotation is prevented. The processing unit 712 prevents the intermediate mold 21 from rotating. When the positions of the positioning hole 25 of the intermediate mold 21 and the positioning pin 613 are slightly shifted, the intermediate mold 21 is rotated by the insertion of the positioning pin 613. For example, when the positioning pin 613 presses the tapered surface of the tapered hole portion 26, the intermediate mold 21 rotates. Since the output shaft of the mold rotation motor 570 is rotatable in advance, it is possible to prevent the mold rotation motor 570 from interfering with the rotation of the intermediate mold 21.

(Deformation and improvement)
The embodiments of the injection molding machine have been described above, but the present invention is not limited to the above embodiments and the like, and various modifications are possible within the scope of the gist of the present invention described in the claims. Improvements are possible.

  The axial direction of the rotation shaft 513 of the intermediate mold 21 is the Y direction in the above embodiment, but may be the Z direction, and is not particularly limited.

  The intermediate mold 21 is disposed between the fixed mold 11 and the movable mold 12 in the above embodiment, but may be disposed between the two movable molds, and is not particularly limited.

  The rotation angle of the intermediate mold 21 that prevents the rotation of the intermediate mold 21 is 0 ° and 180 ° in the above embodiment, but may be 0 °, 90 °, 180 °, and 270 °. The number and value of the rotation angle of the intermediate mold 21 that prevents the rotation of the intermediate mold 21 are not particularly limited.

  FIG. 11 is a diagram illustrating a state when the mold apparatus according to another embodiment is clamped. In FIG. 11, an alternate long and short dash line indicates a state when the mold opening is completed. A mold apparatus 10A shown in FIG. 11 includes an intermediate mold 21A, and a first movable mold 11A and a second movable mold 12A provided so as to sandwich the intermediate mold 21A.

  The intermediate mold 21A is supported so as to be unmovable and rotatable with respect to the frame Fr shown in FIG. The intermediate mold 21A rotates together with the rotation shaft 513A. The axial direction of the rotation shaft 513A is the Z direction.

  The intermediate mold 21A includes a block portion 22A that is formed in a square shape when viewed from the axial direction of the rotation shaft 513A, and a convex mold portion 23A that is provided on four surfaces of the block portion 22A. The convex part 23A is provided in rotational symmetry, and the rotational symmetry is four-fold symmetry. The plurality of convex portions 23A may be arranged in a row by arranging them in the Z direction. The number of columns is one in FIG. 11, but may be more than one.

  The first movable mold 11A and the second movable mold 12A are provided so as to sandwich the intermediate mold 21A in the X direction. The mold is closed and clamped by bringing the first movable mold 11A and the second movable mold 12A closer to the intermediate mold 21A. Further, mold opening is performed by separating the first movable mold 11A and the second movable mold 12A from the intermediate mold 21A.

  The first movable mold 11A has a concave mold portion 31A that forms a first cavity space in cooperation with the intermediate mold 21A. The recessed mold portions 31 </ b> A may be arranged in a row by arranging them in the Z direction. A plurality of the columns may be provided at intervals in the Y direction.

  Similarly, the second movable mold 12A has a concave mold portion 32A that forms a second cavity space in cooperation with the intermediate mold 21A. A plurality of the recessed portions 32A may be arranged in a row in the Z direction. A plurality of the columns may be provided at intervals in the Y direction. The first cavity space and the second cavity space may have the same shape and the same dimensions.

  A mold apparatus 10A is configured by the intermediate mold 21A, the first movable mold 11A, and the second movable mold 12A. Hereinafter, a mold closing process, a mold clamping process, a mold closing process, and an intermediate mold rotating process of the mold apparatus 10A will be described.

  In the mold closing step, the first movable mold 11A and the second movable mold 12A are brought closer to the intermediate mold 21A, and the first movable mold 11A and the second movable mold 12A are brought into contact with the intermediate mold 21A. .

  Subsequently, in the mold clamping process, the intermediate mold 21A is clamped by the first movable mold 11A and the second movable mold 12A to generate a mold clamping force. A first cavity space is formed between the first movable mold 11A and the intermediate mold 21A, and a second cavity space is formed between the second movable mold 12A and the intermediate mold 21A. The injection device 300 simultaneously fills both the first cavity space and the second cavity space with a molding material via a sprue or runner formed in the intermediate mold 21A, and molds a molded product.

  Subsequently, in the mold opening process, the first movable mold 11A and the second movable mold 12A are separated from the intermediate mold 21A. At this time, the molded product is held in the intermediate mold 21A.

  Subsequently, in the intermediate mold rotating step, the intermediate mold 21A is rotated by 90 °, and the molded product held in the intermediate mold 21A is opposed to the unloader 900A. The unloader 900A is provided at an interval in the Y direction so as to sandwich the intermediate mold 21A.

  Thereafter, the mold closing process and the mold clamping process are performed again, and a molded product is molded in both the first cavity space and the second cavity space. During this time, the take-out machine 900A receives the molded product held in the intermediate mold 21A and takes it out of the injection molding machine. In this way, the molding cycle time can be shortened by simultaneously molding the molded product and taking out the molded product.

  By the way, the intermediate mold 21A is stopped by the positioning mechanism 600 every time it is rotated by 90 °. The positioning mechanism 600 prevents the intermediate mold 21 from rotating at a predetermined rotation angle (0 °, 90 °, 180 °, and 270 °).

  Therefore, the detection value correction unit 713 corrects the detection value of the rotation angle of the intermediate mold 21A while the rotation of the intermediate mold 21A is being stopped. Therefore, it is possible to absorb the deviation between the detected value of the rotation angle and the true value of the rotation angle, and to suppress the accumulation of errors in the detected value of the rotation angle.

  The detection value correction unit 713 cancels the processing of the servo control unit 711 so that the output shaft of the mold rotation motor 570 is rotatable and the intermediate mold 21A is stopped. The detected value of the rotation angle of 21A is corrected. Generation of a load due to rotation of the intermediate mold 21A by the servo control unit 711 and rotation prevention of the intermediate mold 21A by the positioning mechanism 600 can be suppressed, and damage to the mold rotating motor 570, the intermediate mold 21A, and the positioning mechanism 600 can be suppressed. it can.

  Further, the detection value correction unit 713 cancels the processing of the servo control unit 711 so that the output shaft of the mold rotation motor 570 can rotate and the intermediate mold 21A is prevented from rotating, and after a predetermined time has elapsed, The detected value of the rotation angle of the intermediate mold 21A is corrected. Therefore, after the rotational vibration of the intermediate mold 21A due to the insertion of the positioning pin 613 is attenuated, the detection value of the rotation angle of the intermediate mold 21A can be corrected, and the detection value of the rotation angle is accurately set to the true value of the rotation angle. Can be adapted to

  Furthermore, when the detected value of the rotation angle of the intermediate mold 21A reaches a predetermined rotation angle, the processing of the servo control unit 711 is canceled, the output shaft of the mold rotation motor 570 is made rotatable, and the rotation is prevented. The processing unit 712 stops the rotation of the intermediate mold 21A. When the positions of the positioning hole 25 and the positioning pin 613 of the intermediate mold 21A are slightly shifted, the intermediate mold 21A is rotated by the insertion of the positioning pin 613. For example, when the positioning pin 613 presses the tapered surface of the tapered hole portion 26, the intermediate mold 21A rotates. Since the output shaft of the mold rotation motor 570 is rotatable in advance, it is possible to prevent the mold rotation motor 570 from interfering with the rotation of the intermediate mold 21A.

  In FIG. 11, the first cavity space and the second cavity space have the same shape and the same dimensions, and the same molded product is molded in the first cavity space and the second cavity space, but the present invention is limited to this. Not. For example, the second cavity space is larger than the first cavity space, and a primary molded product is formed in the first cavity space, and the second cavity space is formed on the primary molded product previously molded in the first cavity space. The next molded product may be molded. A finished product composed of the primary molded product and the secondary molded product is taken out by the take-out machine 900A. In this case, the molding of the primary molded product, the molding of the secondary molded product, and the removal of the finished product can be performed simultaneously, and the molding cycle time can be shortened. In this case, the unloader 900A may be provided only on one side in the Y direction of the intermediate mold 21A.

  In FIG. 11, the convex mold part is provided in the intermediate mold 21A and the concave mold part is provided in the first movable mold 11A and the second movable mold 12A. However, the arrangement of the convex mold part and the concave mold part may be reversed. Good. That is, the convex mold part may be provided in the first movable mold 11A and the second movable mold 12A, and the concave mold part may be provided in the intermediate mold 21A.

  In FIG. 11, the intermediate mold 21A is a fixed mold incapable of moving in the mold opening / closing direction, and the first movable mold 11A and the second movable mold 12A are provided so as to sandwich the intermediate mold 21A. However, the present invention is not limited to this. For example, the intermediate mold 21A may be a movable mold that moves in the mold opening / closing direction. In this case, one of the first movable mold 11A and the second movable mold 12A cannot move in the mold opening / closing direction. It may be a fixed mold.

  The intermediate mold 21 and the intermediate mold 21A are repeatedly rotated in one direction and prevented from rotating at a predetermined rotation angle. However, the rotation direction may be reversed before and after the rotation prevention. The intermediate mold 21 and the intermediate mold 21A may be a reversing mold whose rotating direction is reversed. In the inversion type, for example, the rotation direction may be reversed every time it is rotated 180 °.

DESCRIPTION OF SYMBOLS 10 Mold apparatus 11 Fixed mold 12 Movable mold 21 Intermediate mold 100 Clamping apparatus 110 Fixed platen 120 Movable platen 510 Intermediate mold support frame 570 Mold rotation motor 574 Mold rotation motor encoder (rotation angle detector)
600 Positioning Mechanism 700 Control Device 711 Servo Control Unit 712 Anti-rotation Processing Unit 713 Detection Value Correction Unit

Claims (4)

A mold rotation motor that rotates the mold; and
A rotation angle detector for detecting a rotation angle of the mold;
A positioning mechanism for preventing the mold from rotating at a predetermined rotation angle;
A control device for controlling the mold rotation motor and the positioning mechanism,
The control device includes:
A servo control unit that rotates the mold so that a detection value detected by the rotation angle detector becomes the predetermined rotation angle;
An anti-rotation processing unit for executing and releasing the anti-rotation of the mold by the positioning mechanism;
An injection molding machine comprising: a detection value correction unit that corrects a detection value detected by the rotation angle detector in a state where the rotation prevention of the mold is executed.   The detection value correction unit cancels the processing of the servo control unit, makes the output shaft of the mold rotation motor freely rotatable, and executes the rotation prevention of the mold. The injection molding machine according to claim 1, wherein the detection value detected at step S is corrected.   The detection value correction unit cancels the processing of the servo control unit to make the output shaft of the mold rotation motor rotatable and performs the rotation prevention of the mold after a predetermined time has elapsed. The injection molding machine according to claim 1 or 2, wherein the detection value detected by the angle detector is corrected.   When the detection value detected by the rotation angle detector reaches the predetermined rotation angle, the processing of the servo control unit is canceled, and the output shaft of the mold rotation motor is made rotatable, and the rotation stopper The injection molding machine according to any one of claims 1 to 3, wherein a processing unit executes the rotation prevention of the mold.

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