JPH0260726A - Injection monitor system of injection molding machine - Google Patents

Abstract

PURPOSE:To obtain the optimum data in the monitoring of injection and pressure holding by displaying injection pressure as a function of a screw position by a graph during an injection process from the starting time of injection to the change-over time of pressure holding and displaying the injection pressure during the pressure holding process after the change-over of pressure holding as a function of a time. CONSTITUTION:Injection pressure and a screw position are synchronously detected at every predetermined cycle to be stored in a memory means. As a result, the injection pressure and the screw position are stored in the memory means as a function of a time. Since the injection pressure and the screw position are synchronously detected, the injection pressure can be calculated as a function of the screw position. Then, the time from injection start to the change-over of pressure holding and the injection pressure and screw position detected at the same cycle to be stored in the memory device are read and the injection pressure is displayed on a display means as the function of the screw position by a graph. During pressure holding on and after the change-over of pressure holding, the injection pressure at every cycle stored in the memory device is read to be displayed on the display means as a function of a time by a graph. The graph displays during injection and pressure holding are performed by changing display colors.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to injection pressure (including holding pressure) in an injection molding machine.
Regarding the method of monitoring.

BACKGROUND ART A method of detecting pressure during injection and pressure holding and displaying the detected pressure on a CRT display is already known. That is, during injection and pressure holding, the injection pressure is detected at predetermined intervals, and the pressure detected in the predetermined layer wJFJ is displayed on the screen of the display device, with the horizontal axis representing time and the vertical axis representing pressure, as shown in FIG. The injection pressure (holding pressure) was displayed as a function of time. Additionally, as shown in Japanese Patent Application Laid-open No. 106219/1983,
The pressure and screw position during injection and holding pressure are detected in synchronization, and as shown in Figure 6, the relationship between the detected pressure and screw position is displayed graphically, with the horizontal axis representing the screw position and the vertical axis representing pressure. The method is known. That is, a monitoring method is also known in which the injection pressure (including holding pressure) is displayed as a function of the screw position.

Problems to be Solved by the Invention In injection molding machines, a method is generally adopted in which the speed is controlled by the screw position during injection from the start of injection to switching to holding pressure. During the subsequent pressure holding period, it is common to control the pressure according to time.

As a result, in the method of graphically displaying pressure as a function of time as shown in Fig. 7, the pressure holding time and pressure (
It is possible to monitor the relationship between the injection pressure and the holding pressure, but during injection, only the relationship between time and injection pressure can be monitored, and since the speed is controlled by the screw position during injection, there is no point in monitoring it.

Furthermore, as shown in Figure 6, when the relationship between screw position and pressure is displayed graphically and monitored, it is possible to monitor the screw position and pressure during injection, which also makes it possible to control the speed of the screw position. However, when the pressure is held, the holding time that is to be controlled cannot be monitored.

Therefore, an object of the present invention is to improve rI during injection as a function of screw position and during holding pressure! The object of the present invention is to provide a monitoring system that graphically displays injection pressure (including holding pressure) as a function of f171.

Means for Solving the Problems The present invention provides an injection molding machine that synchronizes injection pressure and screw position, detects them at predetermined intervals, stores them in a storage means, and displays the stored injection pressure and screw position in a graph on a display means. In the monitor method, the time between injection start and holding pressure switching is measured to detect when injection is in progress. The above problem was solved by changing the color during pressure holding and displaying a graph on the display means based on the data stored in the storage means.

Every predetermined operation 1111, the injection pressure and screw position are detected synchronously and stored in the storage means. As a result, the injection pressure and screw position stored in the storage means are stored as functions of time.

Furthermore, since the injection pressure and the screw position are detected synchronously, the relationship between the screw position and the injection pressure in the same period, that is, the injection pressure can be determined as a function of the screw position. Therefore, the time from the start of injection to the switching of holding pressure, that is, (g) Yamanaka, is determined by reading out the injection pressure and screw position detected at each same period and stored in the storage means, and calculating the injection pressure as a function of the screw position. Display the graph on the display means. Further, during pressure holding after switching to pressure holding, the injection pressure (=holding pressure) for each cycle stored in the storage means is read out and displayed as a graph on the display means as a function of time. Note that the graphs are displayed in different colors during injection and during pressure holding.

Example An embodiment of the present invention will be described below.

FIG. 3 is a diagram showing an electric injection molding machine employing an embodiment of the present invention and the main parts of the control system of the injection molding machine. 5 is a heating cylinder.

In addition, a valve coder 3 is attached to the 1-novo motor 2 for injection to detect the current position of the screw 1-1, and the resin pressure is detected by the reaction force acting on the screw 1 in the axial direction of the screw. Injection pressure sensor 4
is provided. Further, an in-mold pressure sensor 7 is provided inside the mold 6, and these injection pressure sensors 4. The driving vJ current of the in-mold pressure sensor 7 and the small motor 2 is transferred to the A/D converter 1 in the numerical control device 100 via the changeover switch 8.
01 is input.

Reference numeral 100 denotes a numerical control device (hereinafter referred to as an NC device) that controls the injection molding machine, and the NC device 100 t,i N
It has a microprocessor+1 (hereinafter referred to as CF) 112 for C and a CPU 114 for a progelin stimulant controller (hereinafter referred to as PMC).
The C CPU 114 has a ROM 1 that stores sequence programs etc. that control sequence operations of the injection molding machine.
7 and PMC RAMll0 are connected. N.C.
The servo interface 111 includes a ROM 115 that stores a management program for overall control of the injection molding machine, and a servo circuit 103 that drives and controls the servo motors of each axis for injection, clamping, screw rotation, ejector, etc. connected via. In FIG. 1, only the injection servo motor 2 and the servo circuit 103 of the servo motor 2 are shown. In addition, 105 is a non-volatile shared RAM composed of bubble memory or CMOS memory, and includes a memory section that stores NC programs etc. that control each operation of the injection molding machine, various setting values, parameters, etc.
It has a setting memory section that stores macro variables.

113 is a bus arbiter controller (hereinafter referred to as BAC), and the BAC 113 includes a CPU 112 for NC and a P
MC CPU114. Shared RAM 105, input circuit 10
6. Each bus of the output circuit 107 is connected, and the BAC 11
3 controls the bus to be used.

Further, 119 is a tilting data input device with a CRT display device (hereinafter referred to as CRT/MDi) connected to the BAC 113 via the operator panel controller 116, and displays various setting screens and work menus on the CRT display screen. By operating various operation keys (soft keys, numeric keys, etc.), you can input various setting data and select setting screens. In addition, 104 is NC
The RAM is connected to the CPU 112 via a bus and is used for temporary storage of data. The above servo circuit 10
3 is connected to the injection servo motor 2, and the pulse coder 3
The output is input to the servo circuit 103.

Further, a torque limit value for controlling the output torque of the injection servo motor 2 is outputted from the output circuit 107 to the servo circuit 103. Further, an address generator 118 is connected to the output circuit 107, and the output of the address generator 118 is input to RAM108 and 109 connected to the PMC CPU114 by bus.
The same address of 08°109 is specified. The RAM 108 is provided with an A/C converter that converts the output signal of the in-mold pressure sensor 7 or the injection pressure sensor 4 or the drive current of the injection servo motor into a digital signal via the changeover switch 8. A D converter is connected, and the signal from the pulse coder 3 is input to the RAM 109.
A counter 102 that counts by 1 and detects the screw position is connected, and when a monitor start command is output from the output circuit 107, an address generator 118 generates a predetermined address (address O in this embodiment as described later). RAMIO3,109
The output of the A/D converter 101,
The output of the counter 102 is stored at a designated address. Furthermore, when a monitor start command is output from the output circuit 107, the counter 102 is cleared by this command.

The mold pressure sensor 7 selected by the changeover switch 8 detects the injection pressure inside the mold, and the injection pressure horn sensor 4 detects the resin pressure by the reaction force acting on the screw 7. Since the driving current of the servo motor 2 represents the output torque of the servo motor 2, the injection pressure can also be represented by this driving current value, and the signals from these mold pressure sensors 7 , the signal from the injection pressure sensor 4, and the drive vJ current as the injection pressure by the selector switch 8. The data is stored in the RAM 108 via the A/D converter 101.

In the above configuration, the NC device 100 has a shared R
While the PMC CPU 114 performs sequence control based on the NC program stored in the AM 105, the various molding conditions described above, and the sequence program stored in the ROM 117, the NCff1 CPU 112 connects the servo interface to the servo circuit 103 of each axis of the injection molding machine. Pulse distribution via the Ace 111 and control of the injection molding machine are the same as in the conventional method.

In connection with the present invention, the operator
When inputting the injection stone command from I119, PM
The C CPU 114 executes the processing shown in FIGS. 1 and 2 at predetermined synchronization intervals.

First, it is determined whether or not the injection flag F1 provided in the RAM 110 indicating that injection is in progress is set (step S1).
, if not set, it is determined whether or not injection is in progress (step 32). This determination is made based on whether automatic operation is in progress and whether the injection pressure holding process flag, which is set in the shared RAM 105 when the injection pressure holding process starts, has already been set. If the injection is not in progress, this process for the current cycle ends, and if it is determined that the injection is in progress,
Timer T1. Start T2 (steps 83 and 84)
>, a monitor start command is output from the output circuit 107 via the BACl 13, the counter 102 is reset, and the address generator 118 is driven.
Addresses are generated sequentially from address 18 to address 120 at a predetermined period τ, and addresses of RAMs 108 and 109 are specified. As a result, the value of the counter 102, that is, the screw position, is sequentially stored in the RAM 109, and the A
The value of the drive current of the in-mold pressure sensor 7, the injection pressure sensor 4, or the ejecting revo motor, that is, the injection pressure, which is converted into a digital signal by the /D converter 101, is stored in order. FIG. 4 shows the injection pressures stored in the RAMs 108 and 109.

In the explanatory diagram of the screw position, when address O of RAM 108, 109 is selected by the address generator 118, the injection pressure at time ○ is stored at address O of RAM 108.
Further, the screw position at time O is stored at address O of RAM9, and the screw position at address 1 (i=o to n) is stored in RAM10.
The injection pressure and screw position at time iτ are stored in 8 and 109, respectively.

In this way, the address generator 118 is driven, and the injection B force,
After starting to import the screw position into the RAM 108, 109, the PMC CPtJ 114 sets the flag F1 to "1".
” and end this cycle. Then, in the next cycle, it is detected in step S1 that the flag F1 is set, so the process moves from step S1 to step S2, and it is determined whether or not the flag F2 indicating pressure holding is being set, and the flag F1 is set. If F2 is set, shared RA
It is determined whether or not the holding pressure switching flag is set during M105, and if the holding pressure switching is not performed and the flag is not set, the processing for the cycle is immediately terminated.Hereinafter, each cycle is The processes of steps 81, 87, and 88 are repeated every time, and when it is determined in step S8 that the injection process is shifted to the pressure holding process, and that the holding pressure switching has been performed, the timer T1 is stopped and the flag F2 is set. rlJ (step 39.3IO).This means that the time from the start of injection to switching to holding pressure is stored in Tie-T1.

From the next cycle, flag F1. Since F2 is set, the process moves to steps 81, 87, and 811, and in step 811 it is determined whether or not the holding pressure end flag F3 is set, and if it is not set, the holding pressure end flag F3 is set in the shared RAM 104. It is determined whether or not the flag indicating the end of pressure has been set (step 312); if not, the process for the cycle is ended. From the next cycle, step S1. S7.811. The process of Sl 2 is repeated, and when the end of holding pressure is detected in step 812, timer T2 is activated.
address generator 1 by outputting a monitor stop command.
18 is stopped, writing of injection pressure and screw position to RAM 108, 109 is stopped, and flag F3 is stopped.
is set to 11” (steps S13, 314, 51
5). As a result, the timer T2 stores the time from the start of injection to the end of holding pressure.

In the next cycle, flag F1. F2. Since F3 is set, the process of step S16 is performed via step Sl, 87.811, that is, the counter A as an index is set to 10.
” and the RAM 10 indicated by the value of counter A.
8. Detect the injection pressure and screw position entered in the address of 109, and set the screw position as the horizontal axis and the injection pressure as the vertical axis.
Display the graph in color a on the screen (Step 317), then add "1" to the counter △ (Step 818), so that the value of the counter A changes from the value of the timer T1 to the address generator 11.
Step 519) In other words, it is determined whether the address indicated by the value of counter A exceeds the address for storing the injection pressure and screw position of the injection process. However, if the pressure is not exceeded, the processes of steps S17-818 and S19 are repeated to display the injection pressure with respect to the screw position on the CRr screen as shown in FIG. Then, in step 819, A〉TI/τ
When it is determined that the value of counter A is
When the state indicates address 9, the injection pressure (holding pressure) is read from the address of RAMIO3 with the value indicated by counter A, and the horizontal axis is time and the vertical axis is injection pressure (holding pressure).
The pressure is displayed as a function of time on the CRT screen (step 520). Then, “1” is added to counter A.
In addition, step 521) determines whether the value of counter A is greater than the value obtained by dividing timer T2 by the period τ of address generator 118, that is, whether the value of counter A is greater than the address value that stores the injection pressure until the end of holding pressure. It is determined whether the value has become larger (step 522), and if it is not, step 82)
0. The processes of S21 and S22 are repeated, and the injection pressure (holding pressure) is displayed as a color graph on the CRT screen as a function of time, as shown in FIG.

A RAM 108 stores the injection pressure at the end of holding pressure.
When the value of counter A exceeds the address of flag F1. F2. Reset F3 (step 523),
Finish the process.

As described above, the above processing is performed every time an injection monitor command is input, and the CRT screen displays the following information as shown in FIG.
During the injection process, the injection pressure against the screw position is displayed graphically, and during the pressure holding process, as the holding pressure time elapses,
The injection pressure (holding pressure) at that time is displayed graphically.

Since the color a of the graph display of the injection process and the color A of the graph display of the pressure holding process are different, the distinction between the injection process and the pressure holding process is also clear.

Effects of the Invention The present invention graphically displays the injection pressure as a function of the screw position during the injection process from the start of injection to the time of pressure holding switch,
The holding pressure process after switching the holding pressure displays the injection pressure (holding pressure) as a function of time, so we can obtain data based on the screw position that is suitable for controlling the injection process in which the injection speed and injection pressure are controlled by the screw position. In addition, data based on time suitable for controlling injection pressure (holding pressure) using holding pressure time can be obtained, and data suitable for monitoring injection and holding pressure can be obtained.

[Brief explanation of the drawing]

Figures 1 and 2 are flowcharts of an injection monitor system according to an embodiment of the present invention, Figure 3 is a block diagram of main parts of an electric injection molding machine in the same embodiment, and Figure 4 is a diagram showing injection pressure and screw position. FIG. 5 is a diagram showing an example of a graph display according to the embodiment;
FIG. 6 is a graph showing the injection pressure with respect to the conventional screw position, and FIG. 7 is a graph showing the injection pressure with respect to the conventional injection and pressure holding time. 1...Screw, 4...Injection pressure sensor, 7...
・In-mold pressure sensor, 8... Selector switch, 100...
・Numerical control device.

Claims (1)

[Claims] In the injection monitoring system of an injection molding machine, which synchronizes the injection pressure and screw position, detects them at predetermined intervals, stores them in the storage means, and displays the stored injection pressure and screw position in a graph on the display means, from the start of injection to the holding pressure switch. The time during injection is detected and the injection pressure is expressed as a function of the screw position during injection, the injection pressure is expressed as a function of time during pressure retention, and the colors are changed during injection and pressure retention to record the above-mentioned storage means. An injection monitoring method for an injection molding machine that displays a graph on a display means based on data stored in the machine.