JP6054215B2 - Injection molding machine and setting support device for injection molding machine - Google Patents

Description

  The present invention relates to an injection molding machine and a setting support device for an injection molding machine.

  The injection molding machine includes a cylinder, a material supply unit that supplies a molding material into the cylinder, and a screw that is rotatably and reciprocally disposed within the cylinder. The molding material supplied in the spiral groove formed in the screw is fed forward as the screw rotates. A plurality of band heaters are provided on the outer periphery of the cylinder, and heat from the plurality of band heaters is transferred to the cylinder to gradually melt the molding material that advances in the cylinder. As the molten molding material is fed to the front of the screw and accumulated in the front of the cylinder, the screw is retracted. Thereafter, when the screw is advanced, the molding material accumulated in front of the screw is injected from the nozzle formed at the tip of the cylinder and filled into the cavity space of the mold apparatus. A molded product is obtained by solidifying the filled molding material (see, for example, Patent Document 1).

JP 2004-351661 A

  Conventionally, the molding conditions are set by trial and error depending on the experience and intuition of the user, and it may take time to determine the conditions.

  The present invention has been made in view of the above problems, and an object thereof is to provide an injection molding machine capable of supporting the setting of molding conditions.

In order to solve the above problems, according to one aspect of the present invention,
A cylinder,
A material supply unit for supplying a molding material into the cylinder;
A screw disposed rotatably in the cylinder and capable of moving back and forth in the axial direction;
A setting support device that supports the setting of molding conditions;
The material supply unit supplies the molding material into the cylinder at a supply speed according to a command value in synchronization with the rotation of the screw.
The setting support device is based on one of a rotational speed of the screw and a supply speed among a plurality of molding conditions for determining a pressure rising position in the screw of the molding material to be sent along a groove formed in the screw. An injection molding machine is provided that calculates the other of the rotational speed and the supply speed at which the pressure increase position becomes a target position.

  According to one aspect of the present invention, an injection molding machine that can support setting of molding conditions is obtained.

It is a figure which shows the injection molding machine of one Embodiment of this invention. It is a figure which shows the drive device of FIG. It is a figure which shows an example of the pressure distribution of the molding material sent along the helical groove | channel formed in the screw of FIG. It is a figure which shows an example of a process of the setting assistance apparatus by one Embodiment of this invention. It is a figure which shows an example of the relationship between the injection pressure measured by the setting assistance apparatus, and an injection speed. It is a figure which shows an example of the viscosity characteristic (relationship between a shear stress and a shear rate) of the molding material measured by the setting assistance apparatus. It is a figure which shows another example of a process of the setting assistance apparatus by one Embodiment of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same or corresponding reference numerals, and description thereof is omitted. Hereinafter, the screw moving direction in the filling step is assumed to be the front, and the screw moving direction in the weighing step is assumed to be the rear.

  The injection molding machine has a mold closing process for closing a mold apparatus composed of a fixed mold and a movable mold, a mold clamping process for closing the mold apparatus, a filling process for pouring molten molding material into the mold apparatus, and a casting process. Pressure holding process for applying pressure to the molding material, cooling process for solidifying the molding material in the mold apparatus after the pressure holding process, weighing process for measuring the molding material for the next molded product, mold opening process for opening the mold apparatus And the extrusion process which protrudes a molded article from the die apparatus after mold opening is made into 1 cycle, and a molded article is repeatedly manufactured. In order to shorten the molding cycle, the metering step may be performed during the cooling step.

  FIG. 1 is a view showing an injection molding machine according to an embodiment of the present invention. The injection molding machine 2 has a mold clamping device and an injection device 10. The mold clamping device includes a fixed platen to which a fixed mold is attached and a movable platen to which a movable mold is attached. The mold is closed by advancing and retreating the movable platen and bringing the movable mold into and out of contact with the fixed mold. And mold opening. The mold clamping device may be any of a toggle type using an electric motor and a toggle mechanism, a direct pressure type using a fluid pressure cylinder, and an electromagnetic type using a linear motor and an electromagnet, and the method is not particularly limited.

  The injection device 10 includes a cylinder 11, a material supply unit 81 that supplies a molding material (for example, resin pellets) into the cylinder 11, and a screw 20 that is disposed in the cylinder 11 so as to be rotatable and movable in the axial direction. Is provided.

  The screw 20 includes a screw main body 21 and an injection portion 22 disposed in front of the screw main body 21, and is connected to the driving device 60 via a shaft portion 51 at the rear end. The screw main body 21 includes a flight part 23 and a pressure part 24 disposed at the front end of the flight part 23.

  The flight part 23 includes a rod-like main body part 23a and a spiral flight 23b formed so as to protrude from the outer peripheral surface of the main body part 23a, and a spiral groove 26 is formed along the flight 23b. From the rear end to the front end of the flight part 23, the depth of the groove 26 may be constant, and the screw compression ratio may be constant.

  The pressure part 24 may be composed of a cylindrical part having an outer diameter larger than that of the rod-shaped main body part 23a. Between the main body portion 23a and the cylindrical portion, a truncated cone-shaped inclined portion (not shown) whose outer diameter gradually increases from the main body portion 23a to the cylindrical portion may be provided. May be configured.

  In addition, you may form a flight part over the whole screw main body 21, without arrange | positioning the pressure part 24. FIG. The screw main body 21 is distinguished from the rear end to the front end as a supply portion to which the molding material is supplied, a compression portion for melting the supplied molding material while compressing, and a measuring portion for measuring the molten molding material by a certain amount. Also good. In this case, the depth of the spiral groove is deeper in the supply unit, shallower in the measuring unit, and shallower toward the front in the compression unit.

  The injection part 22 includes a head part 31 having a conical portion at the tip, a rod part 32 formed adjacent to the rear of the head part 31, and a check ring 33 disposed around the rod part 32. , And a seal ring (check ring) 34 attached to the front end of the pressure portion 24.

  When the screw 20 is retracted during the measuring step, the check ring 33 is moved forward with respect to the rod portion 32, and when released from the seal ring 34, the molding material is sent forward from the rear of the injection portion 22. . Further, when the check ring 33 is moved rearward with respect to the rod portion 32 and brought into contact with the seal ring 34 as the screw 20 moves forward during the injection process, backflow of the molding material is prevented.

  The material supply unit 81 supplies the molding material into the cylinder 11 at a supply speed corresponding to the command value from the controller 40. A molding material supply port 14 is formed at the rear portion of the cylinder 11.

  The material supply unit 81 includes a hopper 82 that accommodates a molding material (for example, resin pellets), a feed cylinder 83 that extends in the horizontal direction from the lower end of the hopper 82, and a cylindrical guide portion that extends downward from the front end of the feed cylinder 83. 84, a feed screw 85 rotatably arranged in the feed cylinder 83, a feed motor 86 for rotating the feed screw 85, and the like. Note that the feed cylinder 83 does not necessarily extend in the horizontal direction, and may, for example, extend obliquely with respect to the horizontal direction, and the outlet side may be higher than the inlet side.

  The molding material supplied from the hopper 82 into the feed cylinder 83 is advanced along a spiral groove formed in the feed screw 85 as the feed screw 85 rotates. The molding material sent into the guide portion 84 from the front end of the feed screw 85 falls in the guide portion 84 and is supplied into the cylinder 11. The molding material supplied into the feed cylinder 83 may be heated (preheated) by a heater (not shown). At this time, the molding material may be preheated to a temperature at which it does not melt, for example, a predetermined temperature below the glass transition point.

  FIG. 2 is a diagram showing the driving device of FIG. The driving device 60 includes a measuring motor 61 that rotates the screw 20 in the cylinder 11. The weighing motor 61 may be a servo motor. The metering motor 61 includes a stator 62 fixed to the support frame Fr, and a cylindrical rotor 63 disposed inside the stator 62. A spline nut 64 fixed to the rear end of the rotor 63 is splined to the rotating member 65. That is, the rotation member 65 is rotatable together with the spline nut 64 and can advance and retreat with respect to the spline nut 64. The rotating member 65 includes a connecting body 66 connected to the rear end of the shaft portion 51 of the screw 20 via a coupling 52, and a support body 67 fixed to the connecting body 66 with a bolt or the like. A spline groove 68 for coupling to the spline nut 64 is formed on the outer periphery of the support 67. The rotation of the metering motor 61 is transmitted to the shaft portion 51 via the rotating member 65, and the screw 20 is rotated. If it does so, the flight 23b of the flight part 23 will move and the molding material supplied in the groove | channel 26 of the flight part 23 will be sent ahead.

  The drive device 60 includes an injection motor 71 that moves the screw 20 in the axial direction within the cylinder 11. The injection motor 71 may be a servo motor. The injection motor 71 has a cylindrical output shaft (not shown), and a ball screw shaft 72 is splined to the output shaft. That is, the ball screw shaft 72 is rotatable together with the output shaft of the injection motor 71 and can be advanced and retracted relative to the output shaft of the injection motor 71. A ball screw nut 73 screwed with the ball screw shaft 72 is fixed to the support frame Fr via the load cell 74. The load cell 74 is disposed between the support frame Fr and the injection motor 71 and detects the back pressure of the screw 20 (pressure that pushes the screw 20 forward). A shaft 75 extending coaxially from the front end of the ball screw shaft 72 is supported so as to be rotatable with respect to the rotating member 65 via bearings Br1 and Br2 and so as not to advance and retract. When the injection motor 71 is driven, the ball screw shaft 72 is advanced and retracted while rotating, and the rotating member 65 and the screw 20 are advanced and retracted. When the screw 20 is advanced in the filling process, the metering motor 61 may be driven to stop the rotation of the rotating member 65 so that the screw 20 does not rotate. The metering motor 61 may be a motor with a brake, and the rotation of the rotating member 65 may be stopped by the braking force of the brake in the filling process.

  The drive device 60 only needs to be able to rotate or advance and retract the screw 20 in the cylinder 11, and the configuration is not limited to the configuration in FIG. For example, when the injection motor 71 is driven and the screw 20 is advanced and retracted, the metering motor 61 may be advanced and retracted together with the screw 20 and the rotating member 65. In this case, the rotating member 65 may be integrated with the rotor 63 of the metering motor 61.

  Next, the operation of the injection molding machine 2 will be described with reference to FIGS. 1 and 2 again. The operation of the injection molding machine 2 (for example, the operation of the injection device 10 and the operation of the material supply unit 81) is controlled by the controller 40. The controller 40 includes a CPU 41, a ROM 42 for storing control programs, a readable / writable RAM 43 for storing calculation results, a storage unit 44 such as a hard disk, an input interface, an output interface, a timer, and a counter. The controller 40 implements various functions by causing the CPU 41 to execute programs stored in the ROM 42 or the storage unit 44.

  In the weighing process, the weighing motor 61 is driven, and the screw 20 is rotated at the set rotational speed. At this time, the feed motor 86 may be driven to rotate the feed screw 85 at a set rotational speed, and the rotation of the screw 20 and the rotation of the feed screw 85 may be started simultaneously. The set rotation speed of the screw 20 and the set rotation speed of the feed screw 85 are set independently, and may be changed according to the position of the screw 20 or the elapsed time from the start of measurement.

  The molding material supplied from the hopper 82 into the feed cylinder 83 is advanced along a spiral groove formed in the feed screw 85 as the feed screw 85 rotates. The molding material sent into the guide portion 84 from the front end of the feed screw 85 falls in the guide portion 84 and is supplied into the cylinder 11.

  The molding material supplied into the cylinder 11 may be immediately sent forward by the screw 20 without staying at the molding material supply port 14. Therefore, the molding material is not densely filled in the groove 26 of the screw 20, and the molding material in the groove 26 is in a sparse state (starvation state). Therefore, as the molding material supply speed by the material supply unit 81 increases, the amount of the molding material fed forward by the screw 20 per unit time increases.

  The molding material supplied into the cylinder 11 is advanced along a spiral groove 26 formed in the screw 20 as the screw 20 rotates. A plurality of band heaters h11 to h13 are provided on the outer periphery of the cylinder 11, and the heat of the plurality of band heaters h11 to h13 is transmitted to the cylinder 11 to gradually melt the molding material that advances in the cylinder 11. As the molten molding material is fed to the front of the screw 20 and accumulated in the front part of the cylinder, the screw 20 is retracted.

  In the measuring step, the injection motor 71 may be driven so as to apply a predetermined back pressure to the screw 20 in order to limit the rapid retreat of the screw 20. When the screw 20 is retracted to a predetermined position and a predetermined amount of molding material is accumulated in front of the screw 20, the driving of the metering motor 61 and the injection motor 71 is stopped. The rotation of the screw 20 and the rotation of the feed screw 85 may be stopped simultaneously.

  Thus, the rotation of the screw 20 and the rotation of the feed screw 85 may be started at the same time and stopped simultaneously. That is, the screw 20 and the feed screw 85 may be rotated in synchronization.

  In the filling process, the injection motor 71 is driven, the screw 20 is advanced at a set speed, and the molding material accumulated in front of the screw 20 is discharged from the nozzle 12 disposed at the front end of the cylinder and contacts the nozzle 12. The cavity space in the mold apparatus is filled. When the screw 20 moves forward to a predetermined position (so-called V / P switching position), the pressure holding process is started. Note that when the elapsed time from the start of the filling process reaches a predetermined time, the pressure holding process may be started. The set speed of the screw 20 may be constant or may be changed according to the screw position or the elapsed time.

  In the pressure-holding step, the injection motor 71 is driven to push the screw 20 forward at a set pressure to replenish the molding material for the volume contraction due to the cooling of the molding material in the cavity space. After the entrance (so-called gate) of the cavity space is sealed with the solidified molding material and the backflow of the molding material from the cavity space is prevented, the cooling process is started. During the cooling step, a metering step for weighing the molding material for the next molded part may be performed. The set pressure of the screw 20 may be constant or may be changed according to the elapsed time.

  FIG. 3 is a diagram illustrating an example of a pressure distribution of a molding material that is sent along a spiral groove formed in a screw in a measuring step. In FIG. 3, S0 is the front end position of the pressure part 24, S1 is the rear end position of the pressure part 24 (that is, the boundary position between the pressure part 24 and the flight part 23), and S2 is the pressure rise position of the molding material in the flight part 23. Represent.

  At the front end position S0 of the pressure portion 24 and in front thereof, the same pressure P0 as the back pressure of the screw 20 acts on the molding material. As shown in FIG. 3, the pressure acting on the molding material gradually increases from the front end position S0 of the pressure part 24 to the rear end position S1 of the pressure part 24, and reaches the maximum pressure P1 at the rear end position S1 of the pressure part 24. . As shown in FIG. 3, the pressure acting on the molding material gradually decreases from the rear end position S1 of the pressure portion 24 toward the rear, and becomes substantially zero at the pressure rise position S2 of the molding material in the flight portion 23.

  The pressure increase position S2 mainly includes (1) the supply speed of the material supply unit 81 (the rotational speed of the feed screw 85), (2) the feed speed of the molding material by the screw rotation (the rotational speed of the screw 20), (3) Dimensions of screw 20, (4) Back pressure P0 of screw 20, (5) One shot capacity (amount of molding material used in one shot), (6) Viscosity characteristics of molding material (relationship between shear stress and shear rate) ), (7) dimensions of the cylinder 11, and (8) temperature of the cylinder 11. The position of the pressure increase position S2 with respect to the cylinder 11 changes, but the position with respect to the screw 20 hardly changes. Therefore, the pressure rise position with respect to the screw 20 hardly changes during the weighing process.

  (1) The supply speed of the material supply unit 81 is proportional to the rotational speed of the feed screw 85. The higher the rotation speed of the feed screw 85, the faster the supply speed of the material supply unit 81. The faster the supply speed, the higher the maximum pressure P1 of the molding material, the gentler the pressure gradient in the flight part 23, and the pressure rise position S2 shifts backward.

  (2) The feeding speed of the molding material by screw rotation is proportional to the rotational speed of the screw 20. The higher the rotational speed of the screw 20, the faster the feed rate of the molding material by screw rotation. The faster the molding material feed rate, the steeper the pressure gradient in the flight part 23, and the pressure increase position S2 shifts forward.

  When the pressure increase position S2 is within a predetermined range behind the rear end position S1 of the pressure portion 24, a molded product with good quality can be stably obtained.

  Therefore, the controller 40 has a function as a setting support device that supports the setting of the molding condition in which the pressure increase position S2 is the target position. The setting support device may be provided separately from the controller 40 that controls the operation of the injection device 10 and the material supply unit 81, or may be provided separately from the injection molding machine 2 and connected to the injection molding machine 2. .

  The controller 40 calculates the remaining molding conditions in which the pressure increase position S2 becomes the target position, based on some molding conditions among the plurality of molding conditions that determine the pressure increase position S2. The plurality of molding conditions for determining the pressure increase position S2 are, for example, the above (1) to (8). The molding conditions used for the calculation and the target position of the pressure increase position S2 may be stored in advance in the ROM 42 or the storage unit 44, or may be received by the input unit 45. At least one of the molding conditions used for the calculation is prepared by an input operation of the input unit 45 by the user.

  For example, the controller 40 stores the relationship between the pressure increase position S2 and a plurality of molding conditions that determine the pressure increase position S2 in the form of an equation, and performs calculation using the stored equation. The formula used for the calculation is read out and stored in advance in a recording medium such as the storage unit 44.

  The controller 40 may display the calculation result on the display unit 46. In this embodiment, the input unit 45 and the display unit 46 are provided separately. However, the input unit 45 and the display unit 46 may be integrated, and may be configured by a touch panel, for example.

  Next, with reference to FIG. 4, an example of a condition setting process by the controller 40 will be described. FIG. 4 is a diagram illustrating an example of processing of a controller as a setting support apparatus according to an embodiment of the present invention.

  First, the controller 40 prepares (2) other molding conditions excluding the rotational speed of the screw 20 among a plurality of molding conditions that determine the pressure increase position S2 (step S102). Other molding conditions include (1) the supply speed of the material supply unit 81 (the rotational speed of the feed screw 85). You may prepare the supply speed of the material supply part 81 by input operation of the input part 45 by a user.

  Subsequently, the controller 40 calculates the rotation speed of the screw 20 at which the pressure increase position S2 is the target position (step S104). Therefore, the molding conditions are determined in a short time without depending on the user's experience and intuition.

  Subsequently, the controller 40 measures the viscosity characteristic of the molding material under the condition including the calculation result of the rotational speed of the screw 20 (step S106). (6) The validity of the viscosity characteristics of the molding material prepared in step S102 can be confirmed. The viscosity characteristic of the molding material is obtained, for example, from the relationship between the injection pressure and the injection speed.

  FIG. 5 is a diagram illustrating an example of the relationship between the injection pressure and the injection speed measured by the setting support device. The relationship between the injection pressure and the injection speed is determined by measuring the injection pressure when the molding material accumulated in front of the screw 20 is injected at the predetermined injection speed at the rotation speed calculated in step S104. It is measured by repeating. From the relationship between injection pressure and injection speed, the relationship between shear stress and shear rate can be measured. Shear stress is proportional to injection pressure and shear rate is proportional to injection rate.

  FIG. 6 is a diagram illustrating an example of a viscosity characteristic of the molding material (relationship between shear stress and shear rate) measured by the setting support device. The relationship between the shear stress and the shear rate shows the same tendency as the relationship between the injection pressure and the injection rate.

  Subsequently, the controller 40 prepares molding conditions including the viscosity characteristics of the molding material measured in step S106 (step S108), and again calculates the rotational speed of the screw 20 at which the pressure increase position S2 is the target position (step S108). S110). Since the rotational speed of the screw 20 is calculated based on the viscosity characteristic measured under the same conditions as in actual injection molding, the reliability is high.

  Subsequently, the controller 40 checks whether or not the calculation result of the rotational speed of the screw 20 has converged (step S112). Whether or not the calculation result has converged can be determined by whether or not the difference between the previous calculation result and the current calculation result is within an allowable range.

  If the calculation result has not converged in step S112 (step S112, NO), the viscosity characteristics of the molding material are measured again under the conditions including the current calculation result (step S114), as in step S106. Thereafter, the controller 40 returns to step S108, prepares the molding conditions including the viscosity characteristic measured in step S114, executes the processing after step S110 again, and calculates the rotational speed of the screw 20 again. By performing the convergence determination, the reliability is further increased.

  On the other hand, when the calculation result has converged in step S112 (step S112, YES), the controller 40 proceeds to step S116.

  The controller 40 checks whether or not the calculation result of the rotational speed of the screw 20 is appropriate as an actual molding condition (step S116). For example, if the rotational speed of the screw 20 exceeds the threshold value, the controller 40 is inappropriate because the capacity of the metering motor 61 is exceeded, and appropriate if the rotational speed of the screw 20 is less than the threshold value. Then, the controller 40 determines whether the molding conditions used for the calculation are appropriate based on the check result.

  When the calculation result is inappropriate as the actual molding condition in step S116 (step S116, NO), the controller 40 determines that the molding condition used for the calculation is inappropriate (step S118), and the measurement time is within the cooling time. It resets (step S120). With the resetting of the measurement time, the controller 40 resets (1) the supply speed of the material supply unit 81 (the number of rotations of the feed screw 85). The supply speed of the material supply unit 81 is calculated by (5) dividing one shot capacity by the measurement time. Thereafter, the controller 40 returns to step S102, prepares the molding conditions including the supply speed of the material supply unit 81 reset in step S120, and continues the processing after step S104. Practical molding conditions can be calculated.

  On the other hand, when the calculation result is appropriate as the actual molding condition in step S116 (step S116, YES), the controller 40 determines that the molding condition used for the calculation is appropriate (step S122), and proceeds to step S124.

  The controller 40 estimates the temperature of the molding material at the pressure increase position based on the calculation result of the rotational speed of the screw 20 (step S124). The temperature of the molding material depends on heat transfer from the cylinder 11, heat generation due to shearing, and the like. The higher the number of rotations of the screw 20 and the higher the feeding speed of the molding material by rotating the screw, the lower the heat transfer from the cylinder 11 and the lower the temperature of the molding material. Moreover, the temperature of a molding material is so high that the rotation speed of the screw 20 is large and there is much heat_generation | fever by shearing.

  Subsequently, the controller 40 determines whether or not the estimated temperature of the molding material at the pressure increase position is within an appropriate temperature range (step S126). For example, when the temperature of the molding material at the pressure increase position S2 is lower than the lower limit temperature of an appropriate temperature range, the molding material is too hard to knead the molding material, or the molding material has high shear stress. In addition, the molding material may be burnt due to the shear heat generation. The upper limit temperature may be set in the appropriate temperature range, or may not be set. The appropriate temperature range is read and used in advance stored in the ROM 42 or the storage unit 44 of the controller 40.

  If it is determined in step S126 that the estimated temperature is not within the appropriate temperature range (NO in step S126), (8) the temperature of the cylinder 11 is reset (step 8) in order to solve problems such as insufficient kneading and burning. S128). Thereafter, the controller 40 returns to step S102, prepares the molding conditions including the temperature of the cylinder 11 reset in step S128, and continues the processing after step S104. Molding conditions can be obtained in which the molding material can be sufficiently kneaded and burning can be suppressed.

  When it is determined in step S126 that the estimated temperature is not within the appropriate temperature range, (1) the supply speed of the material supply unit 81 (the rotational speed of the feed screw 85), (4) the back pressure P0 of the screw 20, (8) An arbitrary condition selected from the temperature of the cylinder 11 may be reset. At this time, a plurality of conditions may be reset, and the combination is not particularly limited.

  On the other hand, if it is determined in step S126 that the estimated temperature is within the appropriate temperature range (step S126, YES), a high-quality molded product can be stably obtained under the calculated molding conditions, and the controller 40 ends the process. To do.

  In the process shown in FIG. 4, the order of each step can be changed. For example, step S116 for checking whether the calculation result of the rotational speed of the screw 20 is appropriate as the actual molding condition precedes step S112 for checking whether the calculation result of the rotational speed of the screw 20 has converged. May be done.

  Next, with reference to FIG. 7, another example of the forming condition processing by the controller 40 will be described. FIG. 7 is a diagram illustrating another example of processing of the controller as the setting support apparatus according to the embodiment of the present invention.

  First, the controller 40 prepares (1) other molding conditions excluding the supply speed of the material supply unit 81 among a plurality of molding conditions that determine the pressure increase position S2 (step S202). Other molding conditions include (2) the rotational speed of the screw 20. You may prepare the rotation speed of the screw 20 by input operation of the input part 45 by a user.

  Subsequently, the controller 40 calculates the supply speed of the material supply unit 81 (the rotation speed of the feed screw 85) at which the pressure increase position S2 is the target position (step S204). Therefore, the molding conditions are determined in a short time without depending on the user's experience and intuition.

  Subsequently, the controller 40 measures the viscosity characteristics of the molding material under conditions including the calculation result of the supply rate of the material supply unit 81 (step S206). (6) The validity of the viscosity characteristic of the molding material prepared in step S202 can be confirmed. The viscosity characteristic of the molding material is obtained, for example, from the relationship between the injection pressure and the injection speed. Regarding the relationship between the injection pressure and the injection speed, the injection pressure when the molding material in the cylinder supplied at the supply speed calculated in step S204 is injected at a predetermined injection speed is repeatedly measured while changing the injection speed. Is measured.

  Subsequently, the controller 40 prepares molding conditions including the measured viscosity characteristics of the molding material (step S208), and again the supply speed of the material supply unit 81 at which the pressure increase position S2 is the target position (rotation of the feed screw 85). Number) is calculated (step S210). Since the supply speed of the material supply unit 81 is calculated based on the viscosity characteristics measured under the same conditions as in actual injection molding, the reliability is high.

  Subsequently, the controller 40 checks whether or not the calculation result of the supply rate of the material supply unit 81 has converged (step S212). Whether or not the calculation result has converged can be determined by whether or not the difference between the previous calculation result and the current calculation result is within an allowable range.

  If the calculation result has not converged in step S212 (NO in step S212), the viscosity characteristics of the molding material are measured again under the conditions including the current calculation result (step S214), as in step S206. Thereafter, the controller 40 returns to step S208, prepares the molding conditions including the viscosity characteristics measured in step S214, executes the processing after step S210 again, and calculates the supply speed of the material supply unit 81 again. By performing the convergence determination, the reliability is further increased.

  On the other hand, when the calculation result has converged in step S212 (step S212, YES), the controller 40 proceeds to step S216.

  The controller 40 checks whether or not the calculation result of the supply rate of the material supply unit 81 is appropriate as the actual molding condition (step S216). For example, if the supply speed of the material supply unit 81 exceeds a threshold value, the controller 40 determines that the measurement time exceeds the cooling time and the measurement process does not end during the cooling process, so that the supply speed of the material supply unit 81 is not appropriate. Appropriate when below threshold. Then, the controller 40 determines whether the molding conditions used for the calculation are appropriate based on the check result.

  If the calculation result is inappropriate as the actual molding condition in step S216 (step S216, NO), the controller 40 determines that the molding condition used for the calculation is inappropriate (step S218) and allows the rotational speed of the screw 20 to be allowed. Reset within the range (step S220). Thereafter, the controller 40 returns to step S202, prepares molding conditions including the number of rotations of the screw 20 reset in step S220, and continues the processing from step S204. Practical molding conditions can be calculated.

  On the other hand, when the calculation result is appropriate as the actual molding condition in step S216 (step S216, YES), the controller 40 determines that the molding condition used for the calculation is appropriate (step S222), and proceeds to step S224.

  The controller 40 estimates the temperature of the molding material at the pressure increase position based on the calculation result of the supply speed of the material supply unit 81 (step S224). The temperature of the molding material depends on heat transfer from the cylinder 11, heat generation due to shearing, and the like.

  Subsequently, the controller 40 determines whether or not the estimated temperature of the molding material at the pressure increase position is within an appropriate temperature range (step S226). For example, when the temperature of the molding material at the pressure increase position S2 is lower than the lower limit temperature of the appropriate temperature range, the molding material is too hard to knead the molding material, or a high shear stress is applied to the molding material and shearing is performed. The molding material may be burned due to heat generation. The upper limit temperature may be set in the appropriate temperature range, or may not be set. The appropriate temperature range is read and used in advance stored in the ROM 42 or the storage unit 44 of the controller 40.

  If it is determined in step S226 that the estimated temperature is not within the appropriate temperature range (NO in step S226), (8) the temperature of the cylinder 11 is reset (step 8) in order to solve problems such as insufficient kneading and burning. S228). Thereafter, the controller 40 returns to step S202, prepares the molding conditions including the temperature of the cylinder 11 reset at step S228, and continues the processing after step S204. Molding conditions can be obtained in which the molding material can be sufficiently kneaded and burning can be suppressed.

  If it is determined in step S226 that the estimated temperature is not within the appropriate temperature range, (1) the supply speed of the material supply unit 81 (the rotational speed of the feed screw 85), (4) the back pressure P0 of the screw 20, (8) An arbitrary condition selected from the temperature of the cylinder 11 may be reset. At this time, a plurality of conditions may be reset, and the combination is not particularly limited.

  On the other hand, if it is determined in step S226 that the estimated temperature is within the appropriate temperature range (step S226, YES), a good quality molded product can be stably obtained under the calculated molding conditions, so the controller 40 ends the process. To do.

  In the process shown in FIG. 7, the order of each step can be changed. For example, step S216 for checking whether or not the calculation result of the supply rate of the material supply unit 81 is appropriate as an actual molding condition is a step of checking whether or not the calculation result of the supply rate of the material supply unit 81 has converged. It may be performed prior to S212.

  As mentioned above, although embodiment of the injection molding machine was described, this invention is not restrict | limited to the said embodiment, A various deformation | transformation and improvement are possible within the range described in the claim.

  For example, although the material supply part of the said embodiment contains a feed screw, it may also contain a vacuum loader and the structure is not specifically limited. Further, the material supply unit may be one that does not control the supply speed, and may be configured by a hopper connected to the molding material supply port 14.

  Moreover, although the injection apparatus of the said embodiment rotates the screw 20 and the feed screw 85 synchronizing, you may rotate separately. For example, the feed screw 85 may be rotated only in a part of the weighing process (for example, the first half). That is, in the said embodiment, although the supply time of the material supply part 81 and the measurement time are the same, you may differ.

  Moreover, although the injection device of the said embodiment is a thing of a screw in-line system, a screw pre-pull system may be used. In the screw / prepa system, the molding material melted in the plasticizing cylinder is supplied to the injection cylinder, and the molding material is injected from the injection cylinder into the mold apparatus. In the screw / prepa system, a screw is disposed in a plasticizing cylinder.

2 Injection molding machine 10 Injection device 11 Cylinder 20 Screw 21 Screw body 22 Injection unit 23 Flight unit 24 Pressure unit 26 Thread groove 40 Controller (setting support device)
45 Input unit 46 Display unit 60 Drive device 61 Weighing motor 71 Injection motor 81 Material supply unit 83 Feed cylinder 85 Feed screw 86 Feed motor

Claims (10)

A cylinder,
A material supply unit for supplying a molding material into the cylinder;
A screw disposed rotatably in the cylinder and capable of moving back and forth in the axial direction;
A setting support device that supports the setting of molding conditions;
The material supply unit supplies the molding material into the cylinder at a supply speed according to a command value in synchronization with the rotation of the screw.
The setting support device is based on one of a rotational speed of the screw and a supply speed among a plurality of molding conditions for determining a pressure rising position in the screw of the molding material to be sent along a groove formed in the screw. An injection molding machine that calculates the other of the rotation speed and the supply speed , at which the pressure increase position becomes a target position. Prior Symbol setting support device, based on the feed rate of the material supply unit, calculates a rotation speed of the screw the pressure increase position is the target position, an injection molding machine according to claim 1. Prior Symbol setting support device, based on the rotational speed of the screw, the pressure increase position is calculated feed rate of the material supply unit as a target position, an injection molding machine according to claim 1. The injection molding machine according to any one of claims 1 to 3, wherein the setting support device checks whether the other calculation result of the rotation speed and the supply speed is appropriate as an actual molding condition. 5. The injection according to claim 4, wherein the setting support device determines whether the one of the rotation speed and the supply speed used in the other calculation of the rotation speed and the supply speed is appropriate based on a check result. Molding machine. The setting support device recalculates the other calculation of the rotation speed and the supply speed based on the viscosity characteristic of the molding material measured under the condition including the other calculation result of the rotation speed and the supply speed. The injection molding machine according to any one of claims 1 to 5. The injection molding machine according to claim 6, wherein the setting support device determines whether or not the other calculation result of the rotation speed and the supply speed has converged within a predetermined allowable range. The said setting assistance apparatus estimates the temperature of the said molding material in the said pressure rise position of the target based on the said other calculation result of the said rotation speed and the said supply speed , In any one of Claims 1-7 The injection molding machine described.   The injection molding machine according to claim 8, wherein the setting support device checks whether or not the estimated temperature of the molding material at the target pressure increase position is within a predetermined appropriate temperature range. A cylinder, a material supply part for supplying a molding material into the cylinder, and a screw disposed in the cylinder so as to be rotatable and movable back and forth in the axial direction, the material supply part being configured to rotate the screw. A setting support device that supports the setting of an injection molding machine that supplies a molding material into the cylinder at a supply speed according to a command value in synchronization ,
Based on one of the number of rotations of the screw and the supply speed among a plurality of molding conditions for determining the pressure increase position in the screw of the molding material sent along the groove formed in the screw, the pressure increase position is A setting support device for an injection molding machine that calculates the other of the rotation speed and the supply speed as a target position.

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