JP4515399B2 - Control method of injection molding machine - Google Patents

Description

  The present invention relates to a control method for an injection molding machine suitable for use in starting up an operation after material replacement or operation interruption.

  Generally, in an injection molding machine, a purge process (a purging process) is performed when starting up an operation after material change or operation interruption. The purge process is a process for discharging the residual resin in the heating cylinder used in the previous production prior to the next production, and the material change is a switch to a different type, for example, a different color material. It is discharged so that the materials used in the next production will not be mixed. Further, when the operation is interrupted due to trouble or the like, the resin left unattended due to the interruption is deteriorated, so that old residual resin is discharged before the operation is restarted from the viewpoint of ensuring the quality of the product.

  As described above, since the purge process aims at discharging unnecessary resin, usually, the purge process conditions (purge speed, screw rotation speed, back pressure, etc.) for performing the purge process are set as quickly as possible. In addition, the operation is controlled so that the discharge can be performed efficiently.

Conventionally, as this type of purge processing, for example, a method for changing the purge of an injection molding machine disclosed in Japanese Patent No. 2941043 and a resin change / color change in an injection molding machine disclosed in Japanese Patent Laid-Open No. 11-28753 The method is known. In the former mold change purge method, at the time of mold change, the operation mode of the injection molding machine is the mold change mode, the mold change purge switch is turned on, and the injection device is in the retreat limit position with respect to the mold. As a result, the weighing operation and the injection operation of the injection device are repeated with a certain interval. In the latter resin change / color change method, the old resin in the injection cylinder is discharged into the mold after the tip of the injection cylinder is in contact with the resin inlet of the mold, and then the new resin is injected into the injection cylinder. While the plastic is supplied and plasticized, the injection cylinder is retracted and new resin is stored at the tip of the injection screw. Repeated multiple injection cycles with a new resin after repeating the resin replacement molding cycle, injecting a new resin into the mold several times until reaching the limit position, taking out the molded product from the mold and taking out the molded product. It is to be transferred.
Patent No. 2941043 JP-A-11-28753

  By the way, in the purge process in an injection molding machine, the following problems generally occur. That is, when the purge process is completed and the next production is actually performed, a good product cannot be obtained from the beginning, and a considerable number of defective products are generated. FIG. 10 shows data obtained by measuring a peak injection pressure Ppr when a general purge process such as that disclosed in Patent Document 1 is repeated without interruption, and then production is started. As is apparent from the figure, the injection pressure increases from the beginning up to about 10 shots, and defective products occur in the molded product. The reason is considered that the molten resin does not have a normal viscosity due to an unstable temperature state. In FIG. 10, PBT (polybutylene terephthalate) is used as a material. However, depending on the type of material, initial defective products can reach several tens of shots or more. In addition, since the production of non-defective products cannot be started immediately after the purge process is completed, this period is a so-called run-off operation, and the interval time until the next production is started becomes longer. After all, it is not possible to realize a quick and efficient production start-up.

  On the other hand, from the viewpoint of avoiding an unstable temperature state, as disclosed in Patent Document 2 described above, it is considered effective to proceed with replacement of the material while performing actual molding. Therefore, although it can be expected to be effective to some extent from the viewpoint of reducing the burden on workers, eliminating mistakes in work, and saving labor, the effectiveness from the viewpoint of realizing a quick and efficient purge process is not I can't hope.

  An object of the present invention is to provide a method for controlling an injection molding machine that solves the problems existing in the background art.

  An injection molding machine control method according to the present invention is a control method for starting up an operation through at least a material change or an operation interruption in the injection molding machine M in order to solve the above-described problem. When setting the operation condition Cd corresponding to the molding conditions related to the molding, and setting the cycle time Tc for at least one shot when molding according to the molding conditions as the operation condition Cd, and starting the operation, A start-up purge process step is performed in which a purge operation for discharging the resin R in the heating cylinder 2 to the outside in accordance with the operation condition Cd is performed for a predetermined number of shots.

  In this case, according to a preferred aspect of the invention, the start-up purge process step can be performed in combination with the purge process step for discharging the resin R remaining in the heating cylinder 2 to the outside, or set exclusively for the purge process. It can also be performed after the normal purge processing step in which the metering operation and the injection operation are performed without interruption according to the purge processing conditions. Further, the cycle time Tc is determined by providing a mold opening / closing operation time Tm related to the mold opening / closing operation by providing the mold 3 with a mold opening / closing operation mode in which the resin R is not filled, and using the mold opening / closing operation time Tm. Can do. On the other hand, the operation condition Cd can be set by the operation condition setting unit 5 provided on the setting screen Vp for setting the purge process condition related to the normal purge process process, and the purge process condition related to the normal purge process process is set. It can also be set by a dedicated operation condition setting unit 6 provided separately for the setting screen Vp. Further, in the start-up purge process, the nozzle opening / closing mechanism 8 attached to the injection nozzle 7 can be used for measurement by closing the nozzle passage 7r of the injection nozzle 7.

  According to the control method of the injection molding machine according to the present invention by such a method, the following remarkable effects can be obtained.

  (1) An operating condition Cd corresponding to the molding condition related to molding after the start-up of the operation is set, and as this operating condition Cd, a cycle time Tc for at least one shot when molding is performed according to the molding condition is set. When the operation is started, the start-up purge process step for performing the purge operation for discharging the resin R in the heating cylinder 2 to the outside by the operating condition Cd is performed for a predetermined number of shots. Both of the advantages (high-speed resin discharge) and the advantages of running-in for molding after the start-up of operation (early start-up) can be enjoyed. As a result, a non-defective product can be produced immediately after the start-up purge process step is completed, and the occurrence of defective products that have conventionally occurred at the start-up of the operation can be eliminated.

  (2) Since the cycle time Tc for at least one shot when molding is performed according to molding conditions is set as the operation condition Cd, the operation can be performed with the same tact as the actual molding cycle performed next time. Accordingly, the resin R staying state in the heating cylinder 2 during the start-up purge process, that is, the temperature state (viscosity state) can be made substantially the same as in the normal molding, so that the generation of defective products is more reliably generated. Can be eliminated.

  (3) If the start-up purge process step is performed in combination with the purge process step for discharging the resin R remaining in the heating cylinder 2 to the outside according to a preferred embodiment, the normal purge process is performed. Can be performed at the same time, so the interval time until the next production starts can be shortened, and a quick and efficient production start-up can be realized.

  (4) If the start-up purge process step is performed after the normal purge process step in which the metering operation and the injection operation are performed without interruption in accordance with the purge process condition set exclusively for the purge process according to a preferred embodiment, the normal purge process is performed. Both the process and the leveling operation for molding after start-up of the operation can be appropriately combined, and optimum conditions can be set according to the type of the resin R, the production status, and the like.

  (5) According to a preferred embodiment, the cycle time Tc is determined, and the mold opening / closing operation time Tm related to the mold opening / closing operation is obtained by providing the mold 3 with a mold opening / closing operation mode in which the resin R is not filled. If it is set by using it, even if the cycle time for the next production is completely unknown, a guideline for setting the cycle time Tc can be obtained, and an accurate cycle time Tc is set. be able to. In addition, various operations adjustments (such as mold opening / closing operation adjustment, low-pressure mold clamping adjustment, confirmation of interlocking with peripheral automatic machines, etc.) can be performed in parallel during the startup purge process. Shorten up time, speed up start-up work, and increase efficiency.

  (6) If the operation condition Cd is set by the operation condition setting unit 5 provided on the setting screen Vp for setting the purge process condition related to the normal purge process step according to a preferred embodiment, the normal purge process condition is set. It is possible to efficiently set the operating condition Cd while referring to the setting screen Vp to be set.

  (7) If the operation condition Cd is set by the dedicated operation condition setting unit 6 separately provided for the setting screen Vp for setting the purge process condition related to the normal purge process step according to a preferred embodiment, the operation condition Cd is set. A screen configuration specialized for setting Cd can contribute to simplification and ease of setting.

  (8) According to a preferred embodiment, if the start-up purge process is performed by closing the nozzle passage 7r of the injection nozzle 7 by the nozzle opening / closing mechanism 8 attached to the injection nozzle 7, the resin R is applied to the mold 3. Even if it is a startup purge process that does not fill with water, it can be brought closer to the same state as actual production by realizing a weighing process with back pressure applied. Occurrence can be more reliably eliminated.

  Next, the best embodiment according to the present invention will be given and described in detail with reference to the drawings.

  First, the configuration of an injection molding machine M that can implement the control method according to the present embodiment will be described with reference to FIGS.

  In FIG. 2, M indicated by an imaginary line is an injection molding machine, which includes a machine base Mb, an injection device Mi and a mold clamping device Mc installed on the machine base Mb. The injection device Mi includes a heating cylinder 2, an injection nozzle 7 (see FIG. 6) at the front end of the heating cylinder 2, and a hopper 22 that supplies material at the rear of the heating cylinder 2. On the other hand, the mold clamping device Mc includes a mold 3 composed of a movable mold and a fixed mold. Further, a side panel 24 is erected on the machine base Mb, and a display 25 using a color liquid crystal display or the like is disposed on the side panel 24. As shown in FIG. 3, the display 25 is provided with a touch panel 25t, and the display 25 including the touch panel 25t is connected to a controller main body 30m built in the machine base Mb.

  FIG. 3 is a block diagram of the molding machine controller 30. The molding machine controller 30 has a computer function for controlling the entire injection molding machine M. Reference numeral 31 denotes a CPU, and a chip set 33 is connected to the CPU 31 via an internal bus 32. Further, a bus line 34 using a local bus such as a PCI bus is connected to the chip set 33 to constitute an HMI (Human Machine Interface) control system. For this reason, the bus line 34 is connected with an internal memory 35 that collects various memories such as RAM and ROM. Further, the display unit 36 and the touch panel 25t are connected to the bus line 34 through a display interface 36, and a drive unit 39 that reads and writes data from and to a storage medium 38 such as a memory card through an input / output interface 37. Connecting.

  On the other hand, a bus line 40 similar to the bus line 34 is connected to the chip set 33 to constitute a PLC (programmable logic controller) control system. Therefore, the bus line 40 is provided with switching data Dd... Obtained from the switch group 41 including various switches and relays, etc., to the CPU 31 and an input / output interface for giving control command data Do... Obtained from the CPU 31 to the corresponding actuator. 42, a detection signal Sd... Obtained from a sensor group 43 including various sensors is converted from analog to digital and applied to the CPU 31, and control command data obtained from the CPU 31 is converted from digital to analog. An input / output interface 44 for applying So to the corresponding actuator is connected. Thus, a predetermined feedback control system and an open loop control system are configured.

  Therefore, the internal memory 35 stores the PLC program and the HMI program and various processing programs. The PLC program is software for realizing sequence operations of various processes in the injection molding machine M, monitoring of the injection molding machine M, etc., and the HMI program sets and displays operation parameters of the injection molding machine M, and injection. This is software for realizing display of operation monitoring data of the molding machine M and the like. These software are constructed as a unique architecture of the injection molding machine M on which the molding machine controller 30 is mounted, and in particular, can execute processing related to the control method according to the present embodiment.

  2 and 4 show an injection / metering screen Vx used in the control method according to the present embodiment displayed on the display 25. Various molding conditions relating to the injection process and the measurement process can be set on the injection / metering screen Vx. Further, the injection / metering screen Vx has an automatic purge setting key 51, and when the automatic purge setting key 51 is selected (ON), the setting screen Vp shown in FIG. 4 is displayed in the injection / metering screen Vx. A window is displayed.

  In the setting screen Vp, 52 indicates a purge start key, and 53 indicates a “close” key. Reference numeral 54 denotes a mode selection key, and the types of modes that can be selected are shown in FIG. By operating the mode selection key 54, three basic modes of “startup purge” mode A1, “normal purge + startup purge” mode A2 or “normal purge” mode A3 can be selected. In this case, the “start-up purge” mode A1 is a mode according to the basic mode implemented by the control method according to the present embodiment, and is also used as a purge process step for discharging the resin R remaining in the heating cylinder 2 to the outside. Can be done. That is, the basic operation is a normal purge process, but the specific operation is performed according to the operation condition Cd set by the control method according to the present embodiment. In addition, the “normal purge + startup purge” mode A2 is performed by the control method according to the present embodiment after the normal purge process step in which the metering operation and the injection operation are performed without interruption according to the purge process condition set exclusively for the purge process. In this mode, the “up purge” mode A1 is performed. Further, in the “normal purge” mode A3, the conventional general purge process that does not include the control method according to the present embodiment, that is, the measurement operation and the injection operation are performed without interruption according to the purge process conditions set exclusively for the purge process. It becomes a mode.

  On the other hand, 55 is a condition setting unit. The condition setting unit 55 is connected to the normal purge condition setting unit 56 for setting the purge process condition when performing the purge process in the conventional normal purge process step, that is, the “normal purge” mode A3. Thus, an operation condition setting unit 5 for setting an operation condition Cd for performing the start-up purge process is added. In FIG. 4, the range indicated by the phantom line is the added operation condition setting unit 5.

  In this case, the normal purge condition setting unit 56 includes an injection mode setting unit 57 that sets a purge speed and a purge pressure during injection, a measurement mode setting unit 58 that sets a measurement rotation speed and a measurement stop position during measurement, and a back pressure application. Back pressure mode setting unit 59 for setting back pressure and retreating speed at the time, purge number setting unit 60n for setting the number of purges Nn in the normal purge process, and out of material for setting the monitoring time Tn for monitoring the material outage in the normal purge process It has a monitoring setting unit 61n. This monitoring time Tn is a time for monitoring that the screw 71 (refer to FIG. 6) does not move backward during weighing as the material (residual resin R) is discharged from the heating cylinder 2, and therefore the monitoring time Tn is monitored. . Therefore, if the screw 71 does not move backward even after the monitoring time Tn has elapsed, it is considered that the material has been discharged, and the purge process is terminated even if the set number of purges Nn remains. In this normal purge condition setting unit 56, it is desirable to set conditions (high-speed metering, high-speed injection) for discharging the resin R as quickly and efficiently as possible.

  The operation condition setting unit 5 sets an operation condition Cd corresponding to a molding condition related to molding after the start-up of the operation, and a molding cycle time (cycle time) when molding is performed according to the molding condition. ) A purge cycle setting unit 62 for setting Tc, a purge number setting unit 60s for setting the number of purges Ns in the start-up purge process, and a material-out monitoring setting unit 61s for setting a monitoring time Ts for monitoring material outage in the start-up purge process Have Therefore, the cycle time Tc, the number of purges Ns, and the monitoring time Ts are the operation conditions Cd for performing the start-up purge process.

  In the control method according to the present embodiment, the setting of the cycle time Tc is important. By setting the cycle time Tc, the cycle time Tc can be operated with the same tact as the molding cycle related to molding after the start-up of the operation. Therefore, the leveling operation is performed simultaneously with the purge process, and the staying state of the resin R in the heating cylinder 2 during the start-up purge process, that is, the temperature state (viscosity state) is almost the same as that in the normal molding. Therefore, the generation of defective products can be surely eliminated.

  A plurality of screen switching keys K1, K2, K3... Provided for each screen item for switching various screens are displayed on the upper and lower sections of the display screen of the display 25. The screen switching keys K1... Are ranked in consideration of the frequency of use. In the upper part, the mold opening / closing screen switching key K1, the ejector screen switching key K2, the injection / weighing screen switching key K3, and the temperature screen switching key K4. The first group Ga related to the setting of the operating conditions of the molding machine having the monitor screen switching key K5, the main condition screen switching key K6, and the condition switching screen switching key K7 is arranged in a horizontal row, and in the lower row, the others A second group Gb having a setup screen switching key K8, a process monitoring screen switching key K9, a production information screen switching key K10, a waveform screen switching key K11, a statistical screen switching key K12, and a trend screen switching key K13 Arranged. The second group Gb is in a state where the first layer is displayed, but can be switched to the screen switching key in the second layer by touching the layer screen switching key Kc at the right end of the screen.

  Next, the control method of the basic form according to the present embodiment will be described according to the flowchart shown in FIG. 1 with reference to FIGS.

  Now, in the injection molding machine M, it is assumed that the operation is interrupted due to a trouble or the like, and the operation is started after the operation is interrupted. In this case, since the resin R left undisturbed due to the interruption, the old residual resin R is discharged from the heating cylinder 2 to the outside before restarting the operation from the viewpoint of ensuring the quality of the product, and a new resin (material) Need to be replaced. For this reason, the start-up purge process is performed by the control method according to the present embodiment. In the startup purge process, the injection device Mi is set apart from the mold 3 so that the resin R remaining in the heating cylinder 2 can be discharged to the outside. Moreover, the molding conditions during molding can be basically used as detailed conditions during injection and weighing.

  First, as shown in FIG. 4, the automatic purge setting key 51 is selected (ON) on the injection / metering screen Vx (step S1). Thereby, the setting screen Vp is displayed in a window in the injection / metering screen Vx (step S2). Next, on the setting screen Vp, the mode selection key 54 is operated to select the mode. In this case, the “startup purge” mode A1 (FIG. 5) is selected (step S3). When another “normal purge + startup purge” mode A2 or “normal purge” mode A3 is selected, the corresponding purge process is performed (step S4). The case where the “normal purge + startup purge” mode A2 is selected will be described in a modified embodiment to be described later.

  By selecting the “start-up purge” mode A1, the operation condition setting unit 5 in the range indicated by the phantom line shown in FIG. 4 becomes valid, so that the operation condition setting unit 5 operates the operation condition Cd for performing the start-up purge process. Is set (step S5). First, the purge cycle setting unit 62 sets the cycle time Tc (step S51). This cycle time Tc is a cycle time Tc for one shot corresponding to the molding conditions related to molding after the start-up of operation. In the case of the example, since the startup is performed after the operation is interrupted, the operator basically sets a cycle time Tc for one shot based on the molding conditions during molding. Further, the purge number setting unit 60s sets the purge number Ns in the startup purge process (step S52). Further, the material shortage monitoring setting unit 61s sets a monitoring time Ts for performing material shortage monitoring in the startup purge process (step S53).

  When the setting is completed, the purge start key 52 is selected (ON) (steps S6 and S7). Thereby, the purge process in the “start-up purge” mode A1 is automatically executed (step S8). In this case, in one start-up purge process, an injection operation by the advancement of the screw 71 and a metering operation by the rotation of the screw 71 are performed, and the resin R is discharged from the heating cylinder 2. However, since the mold 3 is not used, a mold closing process, a mold clamping process, a cooling process, a mold opening process, an ejector process, and the like, which are normal molding processes, are not performed. Therefore, after the weighing operation, the next injection operation is not performed until the set cycle time Tc has elapsed (step S9). When the cycle time Tc has elapsed, the cycle time Tc is reset, and the same cycle (shot) is repeated until the purge end condition is satisfied (steps S10 and S11). As a result, when the set number of purges Ns ends or the monitoring time Ts based on the material shortage monitoring has elapsed, the start-up purge process ends (step S11). The setting screen Vp can be closed by selecting (ON) the “close” key 53.

  Therefore, according to such a control method according to the present embodiment, the operation condition Cd corresponding to the molding condition related to the molding after the start-up of the operation is set, and when the operation is started, the heating cylinder is set according to the operation condition Cd. Since the purge operation for discharging the residual resin R in 2 to the outside is performed for a predetermined number of shots, so to speak, the advantage of the normal purge process (high-speed resin discharge) and the molding after the start-up of the operation You can enjoy both the benefits (early start-up) of running-in. FIG. 9 shows data obtained by measuring the injection peak pressure Pp when the startup purge process is performed and then the production is started up. As is clear from the data, a non-defective product can be produced from the first shot immediately after the start-up purge process step is completed, and the occurrence of defective products that have conventionally occurred at the start-up of the operation can be eliminated. In addition, FIG. 9 uses PBT as a material similarly to FIG.

  Further, according to the control method according to the basic mode described above, the startup purge process step is performed in combination with the purge process step for discharging the resin R remaining in the heating cylinder 2 to the outside. The purge process and the running-in operation can be performed simultaneously. Accordingly, it is possible to shorten the interval time until the next production is started, and to realize a quick and efficient production start-up.

  Next, various modified embodiments of the control method according to the present invention will be described with reference to FIGS.

  FIG. 1 shows the control method in the “start-up purge” mode A1, but as shown in FIG. 5, the purge process can be selected from three basic modes. The “normal purge + startup purge” mode A2 is a purge process in which the startup purge process and the normal purge process are combined. Since the normal purge process aims at high-speed metering and high-speed injection that have been conventionally performed, first, the normal purge process step is quickly and efficiently performed according to the purge process conditions set exclusively for the purge process. It is possible to perform a leveling operation based on molding conditions related to molding after the startup of the operation by the startup purge process. In particular, in the normal purge process, since the resin R is discharged quickly, the total number of purges can be made smaller than the number of purges Ns in the “start-up purge” mode A1. For example, when the number of purges Ns in the “start-up purge” mode A1 is set to 20 times, the number of purges Nn in the normal purge process is started up 8 times by selecting the “normal purge + start-up purge” mode A2. The total number of purges can be reduced, for example, by setting the number of purges Ns to eight.

  A control method when the “normal purge + startup purge” mode A2 is selected will be described with reference to the flowchart shown in FIG. As described above, when the automatic purge setting key 51 is selected (ON) on the injection / metering screen Vx, the setting screen Vp is displayed in a window in the injection / metering screen Vx. The selection key 54 is operated to select the “normal purge + startup purge” mode A2 (steps S21, S22, S23). Step S24 shows a purge process when another “start-up purge” mode A1 or “normal purge” mode A3 is selected.

  By selecting the “normal purge + startup purge” mode A2, the entire condition setting unit 55 shown in FIG. 4 becomes effective. First, the normal purge condition setting unit 56 sets the purge conditions for the first normal purge process to be performed. Set (step S25). Specifically, the setting of the purge speed and the purge pressure at the time of injection by the injection mode setting unit 57, the setting of the measurement rotation speed and the measurement stop position at the time of measurement by the measurement mode setting unit 58, and the back pressure by the back pressure mode setting unit 59 Set the back pressure and reverse speed when applying. The purge number setting unit 60n sets the purge number Nn in the normal purge process. In the “normal purge + startup purge” mode A2, the setting of the monitoring time Tn by the material shortage monitoring setting unit 61n is ignored because the next startup purge process is taken over before the purge process is completed. Further, the operation condition setting unit 5 sets the operation condition Cd for performing the start-up purge process in the same manner as step S5 in FIG. 1 described above (step S26).

  When the setting is completed, the purge start key 52 is selected (ON) (steps S27 and S28). Thereby, first, the normal purge process is automatically performed (step S29). This normal purge process is repeated until the purge end condition, that is, the set purge count Nn is reached (steps S29 and S30). When the set number of purge times Nn is reached, the normal purge process is terminated, and the startup purge process is continued (steps S30 and S31). The operation of the start-up purge process is the same as that in the basic embodiment shown in FIG. 1, and the start-up purge process is automatically performed. Thereafter, the start-up purge process is repeated until the purge end condition is satisfied (steps S31 and S32). As a result, when the set number of purge times Ns ends or when the monitoring time Ts by the material shortage monitoring has elapsed, the start-up purge process ends (step S32).

  Therefore, by selecting such “normal purge + startup purge” mode A2, the resin R is discharged mainly by the normal purge process, and in the startup purge process, mainly after the startup of the operation. The leveling operation is performed based on the cycle time Tc related to the molding. Therefore, both the normal purge processing step and the next leveling operation can be appropriately combined, and optimum conditions can be set according to the type of the resin R, the production status, and the like.

  The “normal purge” mode A3 is a conventional purge process for the purpose of high-speed metering and high-speed injection that has been conventionally performed, that is, as described above, the metering operation is performed according to the purge process condition set exclusively for the purge process. In addition, a normal purge process is performed in which the injection operation is performed without interruption. Therefore, in the case of the resin R that hardly deteriorates even if it remains, the “normal purge” mode A3 may be selected (ON).

  Further, as shown in FIG. 5, in the “startup purge” mode A1 and the “normal purge + startup purge” mode A2, depending on necessity (option), the “mold opening / closing operation” mode A4 or “mold opening / closing operation release” is performed. The mode A5 can be selected, and the “nozzle opening / closing mechanism used” mode A6 or the “nozzle opening / closing mechanism not used” mode A7 can be selected.

  By selecting the “mold opening / closing operation” mode A 4, the mold opening / closing operation of the mold 3 can be performed in a state where the mold 3 and the injection device Mi are separated from each other. The “die opening / closing operation” mode A4 is particularly effective when performing material change including mold change. In this case, even when the cycle time Tc related to the next production is completely unknown, the actual mold opening / closing operation time Tm is measured by setting the cycle time Tc by executing the mold opening / closing operation in a pseudo manner. The cycle time Tc can be set accurately. In addition, during the startup purge process for executing mold opening / closing operations, various operation adjustments (mold opening / closing operation adjustment, low-pressure mold clamping adjustment, interlocking confirmation with peripheral automatic machines, etc.) can be performed in parallel. Furthermore, it is possible to further shorten the startup time, speed up the startup work, and increase the efficiency. The “mold opening / closing operation” mode A4 can be canceled by selecting the “mold opening / closing operation cancellation” mode A5.

  On the other hand, in the “use of nozzle opening / closing mechanism” mode A6, when performing the start-up purge processing step, the nozzle passage 7r of the injection nozzle 7 is closed by the nozzle opening / closing mechanism 8 attached to the injection nozzle 7, as shown in FIG. It can be done. The nozzle opening / closing mechanism 8 is configured by incorporating a shutoff valve 72 using a cylindrical rotary valve in the nozzle passage 7 r of the injection nozzle 7. The shut-off valve 72 has a through hole 73 in the radial direction, and the nozzle passage 7r can be closed by rotating the shut-off valve 72 to the closed position Xc indicated by the solid line by the drive cylinder 74 and the link mechanism 75. In addition, the nozzle passage 7r can be opened by rotating the shut-off valve 72 to the open position Xo indicated by the phantom line.

  By using such a nozzle opening / closing mechanism 8, even in the start-up purge process in which the mold 3 is not filled with the resin R, the measurement process with the back pressure applied can be realized to achieve the same state as the actual production. Accordingly, it is possible to more reliably eliminate the occurrence of defective products while preventing so-called dripping. The “nozzle opening / closing mechanism used” mode A6 can be canceled by selecting the “nozzle opening / closing mechanism not used” mode A7.

  On the other hand, in FIG. 8, when performing the start-up purge process, the operation condition Cd is set by the dedicated operation condition setting unit 6 separately provided for the setting screen Vp for setting the purge process condition related to the normal purge process. Is. For this reason, a startup purge setting key 51 s is provided in the injection / metering screen Vx separately from the automatic purge setting key 51. Accordingly, the dedicated operation condition setting unit 6 can be displayed by selecting (ON) the startup purge setting key 51s. In the embodiment shown in FIG. 4, the operation condition Cd is set by the operation condition setting unit 5 provided on the setting screen Vp for setting the purge process condition related to the normal purge process step, so that the normal purge process condition is set. Although there is an advantage that the operation condition Cd can be efficiently set with reference to the screen Vp, the modified embodiment shown in FIG. There is an advantage that it is possible to contribute to simplification and facilitation of the setting by the screen configuration specialized for the setting of Cd. In addition, in the other structure in FIG. 8, the same code | symbol is attached | subjected to the same part as FIG. 4, and the structure was clarified.

  Although the best embodiment has been described in detail above, the present invention is not limited to such an embodiment, and the detailed configuration, method, and the like can be arbitrarily set within the scope of the present invention. Can be changed, added or deleted.

  For example, as a mode of starting up the operation in the injection molding machine M, not only a mode of starting up after operation interruption, but also a mode of starting up after changing materials, a mode of starting up after changing molds, etc. The present invention can be applied to various modes that require discharge. In addition, the operating condition Cd corresponding to the molding condition may directly use the molding condition or includes various operating conditions related to the molding condition. Therefore, although the case where the cycle time Tc when performing molding according to molding conditions is set as the operating condition Cd has been shown, other various operating conditions Cd that can promote the same effect or effect can be added. Further, an alarm may be issued at predetermined intervals to clear the resin R discharged by the purge process, or a purge receiver for receiving the discharged resin R may be provided as necessary.

The flowchart which shows the process sequence of the control method of the injection molding machine which concerns on the best embodiment of this invention, Overview of the injection molding machine, Block diagram of a molding machine controller provided in the injection molding machine, A display form diagram of a setting screen used for the control method of the injection molding machine, Mode explanatory diagram used for the control method of the injection molding machine, Configuration diagram of a nozzle opening and closing mechanism that can be used in the control method of the injection molding machine, A flowchart showing a processing procedure of a control method according to a modified embodiment of the injection molding machine, A display configuration diagram of a setting screen according to a modified embodiment used in the control method of the same injection molding machine, Change characteristic diagram of injection heak pressure with respect to the number of shots after start-up when the control method of the injection molding machine is implemented, Change characteristic diagram of injection heak pressure with respect to the number of shots after start-up when performing the conventional purge process,

Explanation of symbols

  2: heating cylinder, 3: mold, 5: operation condition setting unit, 6: dedicated operation condition setting unit, 7: injection nozzle, 7r: nozzle passage, 8: nozzle opening / closing mechanism, R: resin, Tc: one molding cycle Time (cycle time), M: injection molding machine, R: resin, Vp: setting screen

Claims (7)

  In the injection molding machine control method when starting up the operation after at least material replacement or operation interruption in the injection molding machine, the operation conditions corresponding to the molding conditions related to the molding after the start-up of the operation are set, and this operation As a condition, a cycle time for at least one shot when performing molding according to the molding conditions is set, and when starting up the operation, a purge operation for discharging the resin in the heating cylinder to the outside according to the operating conditions is performed in a predetermined manner. A control method for an injection molding machine, characterized in that a start-up purge process step is performed for the number of shots.   2. The method of controlling an injection molding machine according to claim 1, wherein the startup purge processing step is performed in combination with a purge processing step of discharging the resin remaining in the heating cylinder to the outside.   2. The method of controlling an injection molding machine according to claim 1, wherein the startup purge processing step is performed after a normal purge processing step in which a metering operation and an injection operation are performed without interruption under a purge processing condition set exclusively for the purge processing. .   The cycle time is determined by setting a mold opening / closing operation time related to the mold opening / closing operation by providing a mold opening / closing operation mode in which a mold is not filled with resin, and using the mold opening / closing operation time. 2. A method for controlling an injection molding machine according to 1.   4. The injection molding machine according to claim 2, wherein the operation condition is set by a dedicated operation condition setting unit separately provided for a setting screen for setting a purge process condition related to the normal purge process. 5. Control method.   4. The method of controlling an injection molding machine according to claim 3, wherein the operation condition is set by an operation condition setting unit provided on a setting screen for setting a purge process condition related to the normal purge process.   4. The method of controlling an injection molding machine according to claim 1, wherein the start-up purge process step performs measurement by closing a nozzle passage of the injection nozzle by a nozzle opening / closing mechanism attached to the injection nozzle.

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