JP2009119654A - Injection molding machine - Google Patents

Abstract

An object of the present invention is to automatically set a set temperature of a hopper lower part B to a suitable temperature.
In an in-line screw type injection molding machine having a screw disposed in a heating cylinder so as to be able to rotate and move forward and backward, a base portion of the heating cylinder is incorporated and held, and a raw material resin is placed in the heating cylinder on the upper part. The set temperature of the lower part of the hopper (lower part of the hopper) in the headstock where the hopper to be supplied is set depends on the set temperature of the partial area of the heating cylinder heated by the band heater closest to the headstock (lower part of the hopper) Set automatically.
[Selection] Figure 1

Description

  The present invention relates to an in-line screw type injection molding machine, and in particular, a lower portion of a hopper in a headstock that incorporates and holds a base portion of a heating cylinder (a portion of a headstock that wraps the base portion of the heating cylinder under the hopper) ) Related to temperature control technology.

  In an in-line screw type injection molding machine, a plurality of band heaters are wound around a heating cylinder and a band heater is wound around a nozzle, and the temperature of each part around which the band heaters are wound is determined by an operator (operator). Each band heater is driven by temperature feedback control by PID (proportional / integral / derivative) control by a heater driver so that becomes a preset temperature.

  In addition, the lower part of the hopper in the headstock in which the base of the heating cylinder is built-in and held and the hopper is installed on the upper part (the part of the headstock that wraps the base of the heating cylinder below the hopper; The set temperature of the lower part is also set in advance by the operator. The lower part of the hopper is heated by heat conduction from a heating cylinder heated by a band heater, and is cooled by circulating temperature-controlled water (cooling medium). When the measured temperature of the portion exceeds the set temperature, control is performed such that cooling water is circulated to the lower portion of the hopper to lower the temperature of the lower portion of the hopper.

  FIG. 3 is a diagram showing a configuration around a heating cylinder in a general in-line screw type injection molding machine. In FIG. 3, reference numeral 31 denotes a head stock (heating cylinder holding block), 32 denotes a heating cylinder in which the base portion is built and held (fixed) in the head stock 31, and 33 denotes a nozzle attached to the front end side of the heating cylinder 32. , 34 are arranged in the heating cylinder 32 so as to be able to rotate and move forward and backward (in FIG. 3, the screw 34 is a linear motion block (not shown) (a member that is driven forward and backward by an injection motor not shown)). , 35 is a resin supply hole which is disposed on the top of the headstock 31 and is made by drilling a raw material resin into the headstock 31. A hopper for dropping and supplying into the heating cylinder 31 through a resin supply hole 31 (not shown) formed in the heating cylinder 32 and 31a.

  Further, 36 is a band heater “1” wound around the nozzle 33, 37 is a band heater “2” wound around the front of the heating cylinder 32 outside the head stock 31, and 38 is a head stock. The band heaters “3” and 39 wound around the intermediate part of the heating cylinder 32 outside the head 31 are the band heaters “4” wound around the rear part of the heating cylinder 32 outside the headstock 31; In the example shown in FIG. 3, a four-channel band heater is used, but the number of band heaters can be arbitrarily changed.

  The four portions (four regions) around which the band heaters “1” to “4” 36 to 39 are wound are individually controlled in temperature, and the four portions are individually targeted. Is set by an operator. In FIG. 3, the set temperature of the lower part of the hopper indicated by B is also set by the operator.

  By the way, regarding the region where the heating is controlled by the multi-channel band heater, the operator tries to set the optimum temperature in consideration of the temperature gradient, but the temperature setting of the lower part B of the hopper is very important. In the present situation, the recognition (insight) of the optimum temperature of the lower hopper B differs depending on the worker. In other words, the concept (approach) for the optimum setting (preferable setting) of the temperature of the hopper lower part B varies depending on the worker, and depending on the worker, the temperature of the hopper lower part B is not dependent on the type of the raw resin. Sometimes, a constant temperature is always set.

  As described above, conventionally, even when the same type of raw material resin is used, the set temperature of the hopper lower part B differs depending on the operator. Therefore, the set temperature of the hopper lower part B is higher than the preferred temperature. If it is too low, for example, the temperature of the raw material resin dried at about 120 ° C. and preheated in this heating process will decrease in the resin supply hole corresponding to the lower part B of the hopper and the inside of the heating cylinder 32. Thus, there is a problem that the achievement of good plasticization of the resin is hindered. If the set temperature of the hopper lower part B is too higher than the preferred temperature, the raw material resin is heated too early in the resin supply hole corresponding to the hopper lower part B and inside the heating cylinder 32. It is said that the raw material resins (resin pellets) are prematurely bonded to each other due to partial melting of the resin too early, and the bite into the raw material resin becomes worse in the feed zone of the screw, and the performance of feeding the resin forward is inhibited. There's a problem.

  The present invention has been made in view of the above points, and an object thereof is to enable the set temperature of the lower hopper portion B to be automatically set to a suitable temperature.

  In order to achieve the above-described object, the present invention provides an in-line screw type injection molding machine having a screw disposed in a heating cylinder so as to be able to rotate and move forward and backward. The set temperature of the lower part of the hopper (lower part of the hopper) in the headstock where the hopper for supplying the raw material resin is installed in the heating cylinder is adjusted by the band heater closest to the headstock (lower part of the hopper). A controller that automatically sets the temperature according to the set temperature of the partial area is provided.

  In the present invention, the set temperature of the lower part of the hopper is automatically set according to the set temperature of the partial region of the heating cylinder heated by the band heater closest to the lower part of the hopper, so that the type of raw material resin used for molding Accordingly, the set temperature of the lower part of the hopper can be automatically set to the preferred temperature in accordance with the set temperature of the heating control region by the band heater that is suitably set by the operator. Therefore, the set temperature of the lower part of the hopper can be automatically set to a suitable temperature corresponding to the temperature gradient of the region controlled to be heated by the multi-channel band heater, and a good weighing operation can be performed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 relate to an inline screw type injection molding machine according to an embodiment of the present invention (hereinafter referred to as the present embodiment), and FIG. 1 illustrates a control system of the injection molding machine (machine) of the present embodiment. It is a block diagram which simplifies and shows the structure. The injection molding machine of this embodiment has a configuration around the heating cylinder equivalent to the configuration around the heating cylinder shown in FIG. 3, and the configuration around the heating cylinder of the injection molding machine of this embodiment. For the explanation of FIG. 3, FIG. 3 and the above description are used.

  In FIG. 1, 1 is a system controller that controls the entire machine (injection molding machine), 2 is an input device for an operator to perform various input operations, and 3 is an image of various display modes for the operator. 4 is a sensor group including a number of sensors (position sensor, speed sensor, pressure sensor, rotation amount detection sensor, temperature sensor, etc.) disposed in each part of the machine. This is a driver group consisting of a large number of drivers (motor drivers, heater drivers, etc.) for driving and controlling actuators such as motors and heaters arranged in the respective sections. The driver group 5 includes a heater driver 5a that drives and controls the band heater “1” 36 described above with reference to FIG. 3, a heater driver 5b that controls and drives the band heater “2” 37 described above with reference to FIG. The heater driver 5c for driving and controlling the band heater “3” 38 described above with reference to FIG. 3, the heater driver 5d for driving and controlling the band heater “4” 39 described with reference to FIG. And a valve driver 5e for driving and controlling (open / close control) the temperature-controlled water circulation control valve 6 for circulating / stopping the temperature-controlled water with respect to the hopper lower part B. The valve driver 5e is provided in a temperature-controlled water circulation control device (not shown) that performs temperature control of temperature-controlled water (cooling medium) and temperature-controlled water supply / return control.

  In the system controller 1, 11 is an operation condition setting storage unit, 12 is a measured value storage unit, 13 is a hopper lower part set temperature determination unit, 14 is an operation process control unit, and 15 is a display processing unit.

  The operation condition setting storage unit 11 includes operation control conditions for each process (mold closing (clamping), injection, weighing, mold opening, eject forward, eject reverse) of the molding cycle input in advance, and a band heater. The temperature control condition of each part such as the temperature control condition of each region of the nozzle 33 or the heating cylinder 32 controlled by “1” to “4” 36 to 39 and the temperature control condition of the lower part B of the hopper is stored in a rewritable manner. Has been.

  The measurement value storage unit 12 stores measurement information (position information, speed information, pressure information, rotation angle information, rotation speed (number of rotations per unit time) information, temperature information, etc.) of each part of the machine by the sensor group 4 or the like. Captured and stored in real time. The measurement information taken in and stored in the measurement value storage unit 12 includes measured temperature data of the nozzle 33 controlled by the band heater “1” 36 and band heaters “2” to “4” 37 to 39, respectively. Measured temperature data of the three regions of the heating cylinder 32 to be heated, measured temperature data of the hopper lower part B controlled by circulation of temperature-controlled water, units of each band heater “1” to “4” 36 to 39 Measured data on the power supply rate per hour is included.

  The hopper lower part set temperature determination unit 13 uses the appropriate temperature setting image displayed on the display device 3 by the operator to input the head stock 31 (hopper lower part B) described above with reference to FIG. 3 is a partial region of the heating cylinder 32 controlled by a band heater (here, the band heater “4” 39) (hereinafter referred to as a hopper lower and near cylinder region A), and reference numeral A in FIG. Is set), the set temperature data of the near-hopper lower cylinder area A set in the operating condition setting storage unit 11 is referred to, and the set temperature of the lower hopper portion B is A suitable value corresponding to the set temperature of the near cylinder region A is determined, and the determined set temperature of the lower hopper B is set and held in the operating condition setting storage unit 11.

  That is, the hopper lower part set temperature determining unit 13 holds reference table data for determining the set temperature of the hopper lower part B from the set temperature of the near hopper lower cylinder area A, which is obtained in advance through a case study. The hopper lower part set temperature determining unit 13 refers to this control table data and determines and sets the set temperature of the hopper lower part B to a suitable temperature according to the set temperature of the hopper lower close cylinder area A. It is like that.

An example of the control table data for determining the set temperature of the hopper lower part B from the set temperature of the hopper lower and near cylinder area A is as follows.
(1) A set temperature less than 220 ° C → B set temperature 40 ° C
(2) A set temperature 220 ° C. to less than 260 ° C. → B set temperature 50 ° C.
(3) A set temperature 260 ° C to less than 300 ° C → B set temperature 60 ° C
(4) A set temperature 300 ° C or higher → B set temperature 70 ° C
In the case of (1), it is suitable for use in PP (polypropylene), PS (polystyrene), etc. In the case of (2), it is suitable for use in ABS (acrylonitrile butadiene styrene), etc. (3 ) Is suitable for use in PC (polycarbonate), PMMA (polymethyl methacrylate), and the like.

  Thus, in the present embodiment, the hopper lower part set temperature determining unit 13 automatically determines the set temperature of the hopper lower part B to a suitable value in accordance with the set temperature of the hopper lower close proximity cylinder region A, Since this is set and held in the operating condition setting storage unit 11, the set temperature of the hopper lower part B can always be automatically set to a suitable value, and the operator can set the set temperature of the hopper lower part B to what extent. There is no need to consider what to do. Therefore, the set temperature of the lower part B of the hopper is set to a suitable temperature corresponding to the temperature gradient in the region controlled by the multi-channel band heater (here, the 4-channel band heaters “1” to “4” 36 to 39). Can be set automatically, and a good weighing operation can be performed.

  In addition, the hopper lower part set temperature determining unit 13 automatically sets the set temperature of the hopper lower part B according to the set temperature of the near hopper lower cylinder region A, and then in an appropriate temperature setting image displayed on the display device 3. When the operator performs an operation for changing the set temperature of the lower part B of the hopper, it is checked whether or not the change width is within the allowable range, and if it is within the allowable range, the operation condition setting is stored. The set temperature of the hopper lower part B of the part 11 is updated to the changed value. When the change range of the set temperature of the hopper lower part B performed by the operator is outside the allowable range, the hopper lower part set temperature determination unit 13 sets the change range to the display device 3 through the display processing unit 15. A message indicating that the change is out of the allowable range is displayed, and the operator is prompted to make corrections so that the change width is within the allowable range. Thus, after the set temperature of the hopper lower part B is automatically set, the set temperature can be changed by the worker so that the temperature can be set at the discretion of the worker. Subtle adjustment of the set temperature of B is also possible.

  Furthermore, the hopper lower part set temperature determining unit 13 determines the energization rate per unit time of the band heater “4” 39 in the near hopper lower cylinder region A captured in the measured value storage unit 12 during the automatic molding operation. When the energization rate exceeds the upper limit predetermined value, a process for raising the set temperature of the lower part B of the hopper in the operation condition setting storage unit 11 by a predetermined temperature (for example, about 1 ° C. to 3 ° C.) is performed. When the rate falls below the lower limit predetermined value, a process of lowering the set temperature of the hopper lower part B in the operating condition setting storage unit 11 by a predetermined temperature (for example, about 1 ° C. to 3 ° C.) is performed. In this way, the set temperature of the lower hopper B can be adaptively automatically adjusted to a suitable value in accordance with the situation during the automatic molding operation.

  The operation process control unit 14 measures the measurement information in the measurement value storage unit 12 based on the operation control program for each process prepared in advance and the set value of the operation condition for each step stored in the operation condition setting storage unit 11. In addition, the driver group 5 is driven and controlled while referring to the state confirmation information from each part and its own timing information, and the operation of each process is executed. In addition, the operation process control unit 14 includes a heater energization control program prepared in advance, an operation control program of a temperature control water circulation control device (not shown), and each temperature control target part (each temperature stored in the operation condition setting storage unit 11). The heater drivers 5a to 5d in the driver group 5 are driven and controlled while referring to the measured temperatures of the temperature control target portions in the measured value storage unit 12 based on the set temperature values in the control target region). The temperature control by “1” to “4” 36 to 39 is executed, and the valve driver 5e in the driver group 5 is driven and controlled by the temperature control water circulation control valve 6 (by ON / OFF of the temperature control water circulation). The temperature control of part B is executed.

  Based on various display processing programs prepared in advance and fixed display data, the display processing unit 15 refers to the contents of the operating condition setting storage unit 11 and the measured value storage unit 12 as necessary, and performs various processes. A display mode image is generated and displayed on the display device 3.

  FIG. 2 shows an example of the temperature setting image displayed on the display screen of the display device 3 by the operator appropriately operating the input device 2. In FIG. 2, reference numeral 21 denotes a temperature setting field of the nozzle 33 around which the band heater “1” 36 is wound, and 22 denotes a heating cylinder 32 outside the head stock 31 around which the band heater “2” 37 is wound. The temperature setting column in the front region, 23 is the temperature setting column in the intermediate region in the heating cylinder 32 outside the headstock 31 around which the band heater “3” 38 is wound, and 24 is the band heater “4” 39 A temperature setting field 25 in the rear region of the heating cylinder 32 outside the wound head stock 31 is a temperature setting field in the lower part B of the hopper.

  In this embodiment, when a numerical value is input to the temperature setting field 24 and the temperature of the region corresponding to the band heater “4” 39 is set, the numerical value is automatically displayed in the temperature setting field 25 in the lower part B of the hopper. The set temperature displayed in the temperature setting field 25 is automatically set as the set temperature of the lower part B of the hopper. Further, when a numerical value is changed in the temperature setting field 25 in a state where the set temperature is displayed in the temperature setting field 25, if the change range is within the allowable range as described above, The set temperature of the part B is set as a new set temperature. In addition, after changing the set temperature of the hopper lower part B in the temperature setting field 25, when returning to the automatically set temperature, the temperature setting field 24 is once cleared to 0 (zero) and the temperature setting field 24 is cleared. Enter the same numerical value as before.

It is a block diagram which simplifies and shows the structure of the control system in the injection molding machine which concerns on one Embodiment of this invention. It is explanatory drawing which shows the example of the temperature setting image displayed on the display apparatus in the injection molding machine which concerns on one Embodiment of this invention. It is explanatory drawing which simplifies and shows the structure around a heating cylinder in a general in-line screw type injection molding machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 System controller 2 Input device 3 Display device 4 Sensor group 5 Driver group 5a, 5b, 5c, 5d Heater driver 5e Valve driver 6 Temperature control water circulation control valve 11 Operating condition setting storage part 12 Measured value storage part 13 Hopper lower part set temperature Determination unit 14 Operation process control unit 15 Display processing unit 21, 22, 23, 24, 25 Temperature setting column 31 Headstock 31a Resin supply hole 32 Heating cylinder 33 Nozzle 34 Screw 35 Hopper 36 Band heater “1”
37 Band Heater “2”
38 Band heater "3"
39 Band heater "4"
A Lower cylinder area near hopper B Lower hopper

Claims (4)

In an in-line screw type injection molding machine having a screw arranged in a heating cylinder so as to be able to rotate and move forward and backward,
A band heater closest to the headstock is set temperature of the lower part of the hopper in the headstock in which the base of the heating cylinder is built-in and held and a hopper for supplying the raw material resin into the heating cylinder is installed above the base. An injection molding machine comprising a controller that automatically sets the temperature according to a set temperature of a partial region of the heating cylinder that is heated by The injection molding machine according to claim 1,
The injection molding machine according to claim 1, wherein a set temperature of a lower portion of the hopper in the headstock can be changed by an operator after the controller automatically sets. The injection molding machine according to claim 1,
The controller monitors the energization rate per unit time of the band heater closest to the headstock during the automatic molding operation, and when the energization rate exceeds an upper limit predetermined value, setting of the lower part of the hopper in the headstock An injection molding machine characterized in that when the temperature is increased by a predetermined temperature and the energization rate falls below a lower limit predetermined value, the set temperature of the lower portion of the hopper in the headstock is decreased by a predetermined temperature. In the injection molding machine according to any one of claims 1 to 3,
An injection molding machine, wherein a lower portion of the hopper in the headstock is heated by heat transfer from the heating cylinder and cooled by a flow of a cooling medium.

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