JP3881613B2 - Waveform display method of injection molding machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a waveform display method for an injection molding machine suitable for use in displaying a waveform of a target value for a predetermined control item related to operation control.
[0002]
[Prior art]
Conventionally, in an injection molding machine, in addition to displaying a waveform of actual measurement values related to actual operation on the display screen, the target value corresponding to the actual measurement value is displayed in an overlapping manner, and the actual operation state (measurement value) with respect to the target value is displayed. ) Can be easily monitored. In this case, for example, in the waveform display of the target value with respect to the injection speed, normally, since the multistage setting in which the speed changes stepwise with respect to time is performed, the displayed waveform becomes a waveform that changes stepwise (for example, (See Japanese Patent Publication No. 8-25216 and Japanese Patent Laid-Open No. 61-249730).
[Patent Document 1]
Japanese Patent Publication No. 8-25216 [Patent Document 2]
Japanese Patent Laid-Open No. 61-249730
[Problems to be solved by the invention]
By the way, when controlling the servo motor, even if the target value for the injection speed is set as it is as the command value, it is difficult to instantaneously raise the target value to the injection speed, and overshoot also occurs in actual control. The control becomes unstable. Therefore, the acceleration (or negative acceleration) is set as a command value so that the target value can be stably reached, and control is performed so as to reach the target value after a predetermined acceleration time (or deceleration time). For this reason, the target value and the command value do not necessarily match.
[0004]
In addition, in the case of injection speed, the command value is set by acceleration (or negative acceleration), so the unit of the horizontal axis is time when displaying the waveform, whereas the horizontal axis related to the waveform display of the actual measurement value. Since the unit is displayed at the screw position, it is difficult to superimpose the actual measurement value and the command value. For these reasons, there has been a difficulty in that accurate and accurate observation (evaluation) of measured values cannot be performed quickly and easily.
[0005]
The present invention solves such a problem in the prior art, and provides a waveform display method for an injection molding machine capable of quickly and easily performing accurate and accurate observation (evaluation) on measured values. With the goal.
[0006]
[Means for Solving the Problems and Embodiments]
In the waveform display method for an injection molding machine according to the present invention, when the target value Vs for a predetermined control item related to operation control is displayed on the screen Wa of the display 2, the horizontal axis display unit for displaying the target value Vs is displayed. In addition, the measured value is converted so as to coincide with the display unit of the horizontal axis for waveform display, and the waveform is displayed, and the change value Vcs of the command value Cc for the operation control changed by the conversion process is included in the target value Vs. It is characterized in that the waveform is displayed.
[0007]
In this case, according to a preferred embodiment, the injection speed can be applied to the control item, and the conversion process at this time is performed by converting the time T, which is a unit of the horizontal axis related to the command value Vcs, to the actual measurement value. The position can be converted into a position (screw position) S which is a unit of the horizontal axis to be displayed. Further, the conversion process can use a calculation by a conversion function or a preset data table.
[0008]
【Example】
Next, preferred embodiments according to the present invention will be given and described in detail with reference to the drawings.
[0009]
First, the configuration of an injection molding machine M that can implement the waveform display method according to the present embodiment will be described with reference to FIGS. 2 and 3.
[0010]
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 10, an injection nozzle that does not appear in the drawing at the front end of the heating cylinder 10, and a hopper 11 that supplies material to the rear of the heating cylinder 10. On the other hand, the mold clamping device Mc includes a mold 12 composed of a movable mold and a fixed mold. Further, a side panel 13 is erected on the machine base Mb, and a display unit 15 is disposed on the side panel 13. The display unit 15 includes a display 2 such as a color liquid crystal display provided with a touch panel 2t. The display unit 15 is connected to a controller 20 (FIG. 3) built in the machine base Mb.
[0011]
FIG. 3 shows a block system diagram of the controller 20. Reference numeral 21 denotes a CPU, and a chip set 23 is connected to the CPU 21 via an internal bus 22. Further, a bus line 24 using a local bus such as a PCI bus is connected to the chip set 23 to constitute an HMI (Human Machine Interface) control system. For this reason, the bus line 24 is connected to an internal memory 25 that collects various memories such as RAM and ROM. Further, the display unit 15 described above is connected to the bus line 24 via a display interface 26, and a drive unit that reads and writes data to a storage medium 28 (external memory) such as a memory card via an input / output interface 27. 29 is connected.
[0012]
On the other hand, a bus line 30 similar to the bus line 24 is connected to the chip set 23 to constitute a PLC (programmable logic controller) control system. For this reason, the bus line 30 is connected with an input / output interface 31 for giving switching data Di such as a switch to the CPU 21 and giving control command data Do obtained from the CPU 21 to the corresponding actuator, and detection signals of various sensors An input / output interface 32 is connected to apply Si to the CPU 21 after analog-to-digital conversion and to apply to the corresponding actuator a control signal So obtained by digital-to-analog conversion of control command data obtained from the CPU 21. Thus, a predetermined feedback control system and an open loop control system are configured.
[0013]
Therefore, the internal memory 25 stores the PLC program and the HMI program and various processing programs. The PLC program is software for realizing the sequence operation of various processes in the injection molding machine M, the monitoring of the injection molding machine M, and the HMI program is the setting and display of operation parameters of the injection molding machine M, 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 controller 20 is mounted, and in particular, can execute the processing of the waveform display method according to the present embodiment.
[0014]
Next, the waveform display method according to the present embodiment will be specifically described with reference to FIGS.
[0015]
First, an injection / metering screen for displaying a waveform by the waveform display method according to the present embodiment will be described with reference to FIG. FIG. 1 shows an injection / weighing screen Wa displayed on the display 2. On the injection / weighing screen Wa, a plurality of screen switching keys K1, K2, K3... Provided for each screen item for switching the various screens Wa. 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 part, A second group Gb having a switch & option screen switching key K8, a history screen switching key K9, a program screen switching key K10, a signal recorder screen switching key K11, a diagnostic screen switching key K12, and a support screen switching key K13 is arranged in a horizontal row. Arrange. The second group Gb displayed in FIG. 1 is a state in which the second hierarchy is displayed. By touching the hierarchy screen switching key Kc at the right end of the screen, the process monitoring screen switching key in the first hierarchy, The production information screen switching key, waveform screen switching key, statistical screen switching key, and trend screen switching key are displayed in the same manner in such a manner that they are replaced with the screen switching keys K8 to K13 of the second layer.
[0016]
The screen switching keys K1, K2,... Are displayed in the same manner even when the injection / metering screen Wa is switched to another screen. For example, FIG. 2 shows an outline of the process monitoring screen Wb when the first-layer process monitoring screen switching key in the second group Gb is selected. The screen switching keys K1, K2,... Are shown in FIG. The same shape is displayed at the same position as the injection / weighing screen Wa. Further, the controller 20 is provided with an array change function for arbitrarily changing the array of the screen switching keys K1... On the user side and an array storage function for storing the changed array. Accordingly, the user himself / herself can arbitrarily change the arrangement (order) of the screen switching keys K1. With such a layout display, even when the name display displayed on each screen switching key K1... Is changed, it can be easily handled by software, man-hours and costs can be reduced due to the change, and each screen switching key K1. Visibility and operability for ... can be improved.
[0017]
The main part of the injection / metering screen Wa is displayed between the upper screen switching key K1... And the lower screen switching key K8. The injection / weighing screen Wa is a setting screen for setting various molding conditions such as the injection process and the injection speed related to the weighing process, and a waveform according to the present embodiment is included in a part of the injection / metering screen Wa. It has a waveform display unit 51 that displays a waveform by a display method. The illustrated waveform display section 51 shows a state in which target values Vs of injection speeds set in six stages are displayed by the waveform display method according to the present embodiment. Therefore, the target value Vs includes a change amount Vcs of a command value Cc described later. The horizontal axis of the waveform display unit 51 is set to the screw position S, and the vertical axis is set to the injection speed V. In addition, in addition to the target value Vs, the waveform related to the actual measurement value is displayed on the waveform display unit 51, but this is omitted in FIG.
[0018]
Next, the processing procedure of the waveform display method according to this embodiment will be described according to the flowchart shown in FIG. 4 with reference to FIGS.
[0019]
Now, the target value for the second speed in FIG. 6 is set to Va, the target value for the third speed is set to Vb, and the acceleration (command value Cc) in the acceleration time Tc from the second speed to the third speed is set to Vt. A case is assumed (step S1). In this case, the acceleration Vt at the acceleration time Tc has a unit of the horizontal axis as the time T. Therefore, when the waveform is displayed, it changes linearly (proportional change) as shown by a two-dot chain line in FIG.
[0020]
On the other hand, when the target values Va and Vb and the acceleration Vt (command value Cc) are set, the conversion processing is performed so that the waveform can be displayed at the position (screw position) S on the horizontal axis. This conversion process is performed as follows. FIG. 5 shows the injection speed V [mm / s] in which the unit of the horizontal axis is set to time T [s], Va is the second speed target value, Vb is the third speed target value, and Vt is the acceleration ( Command value Cc). First, the acceleration time Tc in which acceleration control is performed is divided into minute times Td1, Td2,..., And the injection speed Vd1 at the time when the first minute time Td1 has elapsed is converted into a conversion equation (conversion function).
Vd1 = {(Vb−Va) · Td1 / Tc} + Va
It is obtained by a calculation process using (step S2). Further, the movement distance Sd1 of the minute time Td1 is converted into a conversion formula (conversion function)
Sd1 = Sd1p + Sd1t
= (Va · Td1) + {(Vd1−Va) · Td1 · 1/2}
It is obtained by calculation processing using (step S3). Then, the obtained moving distance Sd1 and injection speed Vd1 are stored as display data (step S4). Similarly, the injection speed Vd2 and the movement distance Sd2 at the elapse of the next minute time Td2 are obtained and stored (steps S5, S6, S7). Thereafter, the same calculation process is executed for all sections of the acceleration time Tc (step S8).
[0021]
Therefore, the obtained display data can be waveform-displayed with the unit of the horizontal axis as the position S and the unit of the vertical axis as the speed V. By combining the change Vcs due to the command value Cc (acceleration Vt) and the target values Va and Vb, a waveform of the target value Vs indicated by a solid line in FIG. 6 is obtained, and the target value Vs including the change Vcs and Become. The waveform of the target value Vs has a shape that swells upward when compared with the waveform of the acceleration Vt in which the unit of the horizontal axis is time T.
[0022]
In the above, between 2nd speed and 3rd speed was explained, but since the same processing can be performed in other acceleration sections, such as between 3rd speed and 4th speed, the entire process in the injection process The process is executed in the same manner (step S9). Then, when the processing of all the steps is completed, it is displayed on the waveform display unit 51 shown in FIG. 6 (FIG. 1) (step S10). Thereby, the target value Vs processed by the waveform display method according to the present embodiment is displayed on the waveform display unit 51. In FIG. 6, a dotted line Vr indicates a display mode according to a conventional method in which only the target values Va and Vb are displayed in a step shape.
[0023]
According to such a waveform display method according to the present embodiment, when the target value Vs for the injection speed is displayed as a waveform, the change Vcs due to the command value Cc (acceleration or negative acceleration) for the operation control is included in the target value Vs. In addition to displaying the waveform, the time T, which is the display unit of the target value Vs including the change Vcs of the command value Cc, is converted into a position (screw position) S, which is a display unit for displaying the actual measurement value, and the waveform is displayed. As a result, the displayed target value Vs includes the change amount Vcs of the command value Cc that substantially matches the actual measurement value, so that accurate and accurate observation (evaluation) with respect to the actual measurement value of the injection speed Vs can be performed. It can be done quickly and easily.
[0024]
Although the embodiments have been described in detail above, the present invention is not limited to such embodiments, and the detailed configuration, arrangement, quantity, method, and the like can be arbitrarily set within the scope of the present invention. Can be changed, added or deleted. For example, although the injection speed is exemplified as the predetermined control item related to the operation control, it can be similarly applied to other control items such as the injection pressure. Moreover, although the case where the conversion process is performed by a calculation process using a conversion function has been shown, the conversion process can also be performed using a preset data table.
[0025]
【The invention's effect】
As described above, when the waveform display method according to the present invention displays the target value for the predetermined control item related to the operation control on the display screen, the display unit of the horizontal axis for displaying the target value is used as the measured value. Since the waveform is displayed after being converted to match the display unit of the horizontal axis to display the waveform, the change in the command value for the operation control that changes due to the conversion processing is included in the target value, and the waveform is displayed. The displayed target value includes a change in the command value that substantially matches the actual measurement value, so that accurate and accurate observation (evaluation) on the actual measurement value can be performed quickly and easily. There is an effect.
[Brief description of the drawings]
FIG. 1 is an injection / metering screen diagram for performing waveform display by a waveform display method according to a preferred embodiment of the present invention;
FIG. 2 is a schematic diagram of an injection molding machine that can implement the waveform display method;
FIG. 3 is a functional block diagram of a controller provided in the injection molding machine,
FIG. 4 is a flowchart showing a processing procedure of the waveform display method;
FIG. 5 is an auxiliary diagram for explaining conversion processing in the waveform display method;
FIG. 6 is a waveform diagram displayed by the waveform display method;
[Explanation of symbols]
2 Display Wa screen (Injection / Weighing screen)
Vs Target value including change due to command value T Time S Position (screw position)

Claims (4)

  In a waveform display method of an injection molding machine for displaying a target value for a predetermined control item related to operation control on a display screen, the horizontal axis for displaying the target value is displayed in the horizontal axis for displaying the target value. The injection molding is characterized in that the waveform is displayed after being converted so as to match the display unit, and the change in the command value for the operation control that is changed by the conversion is included in the target value. Waveform display method.   2. The waveform display method for an injection molding machine according to claim 1, wherein the control item is an injection speed.   2. The waveform of the injection molding machine according to claim 1, wherein the conversion process converts time, which is a unit of a horizontal axis related to the command value, into a position which is a unit of the horizontal axis for displaying the actual measurement value. Display method.   4. The waveform display method for an injection molding machine according to claim 1, wherein the conversion processing uses a calculation by a conversion function or uses a preset data table.

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