JPH02198817A - Sequence input signal monitoring apparatus - Google Patents

Abstract

PURPOSE:To prevent mechanical damage by monitoring a sequence input signal continuously and emitting an alarm when abnormality is detected to stop the operation of an injection molding machine. CONSTITUTION:A comparator 6 judges whether inputted ON/OFF timing is normal and compares the ON/OFF timing signal 2c of the sequence input signal transmitted from an input monitor circuit 2 with the normal value 4' corresponding to the sequence input signal stored in a memory circuit 4. When the ON/ OFF timing signal 2c coincides with the normal value 4', ON/OFF timing is judged to be normal and, when said signal 2c does not coincide with the normal value 4', the ON/OFF timing signal 2c is compared with the tolerance range 5' set by a tolerance range setting device 5. When the ON/OFF timing signal 2c is within the tolerance range 5', ON/OFF timing is judged to be normal and, when said signal 2c is out of the tolerance range 5', timing is judged to be abnormal to show an abnormal signal state 6' judging whether this timing abnormality is ON-timing or OFF-timing to start an alarm output circuit 7. The alarm output circuit 7 outputs an alarm signal 7' and emits an alarm showing sequence abnormality to stop the operation of an injection molding machine.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sequence input signal monitoring device for an injection molding machine.

[Prior Art] In a conventional injection molding machine, the sequence input signal input to the sequencer is monitored by visual monitoring using an LED display provided in the input circuit of the sequencer, or by intermittent monitoring using a recorder or tester. It was surveillance.

[Problems to be Solved by the Invention] In the conventional sequence input signal monitoring described above, since the monitoring is performed intermittently to visually determine whether the sequence is abnormal or normal, it is not possible to immediately respond to sequence abnormalities that occur, and furthermore, sequence abnormalities cannot be immediately dealt with. Since the sequence input state at the time cannot be determined, it is difficult to investigate the cause.

The present invention has been made in view of the above-described shortcomings of the conventional technology, and an object of the present invention is to provide a sequence input signal monitoring device that continuously monitors sequence input signals and is capable of determining an abnormal sequence.

[Means for Solving the Problems] The sequence input signal monitoring device of the present invention is such that, in the sequence control device of an injection molding machine, the sequencer to which the sequence input signal is input outputs a cycle start signal, and the injection molding machine is operated normally. a storage start switch that outputs a storage instruction signal instructing storage of on/off timing of the sequence input signal during an operation cycle; a cycle start signal is output from the sequencer; and a storage instruction signal is output from the storage start switch. A storage circuit that stores the on/off timing of the sequence input signal when the sequence input signal is output, and a tolerance setting device that sets a timing error tolerance range for the on/off timing stored in the storage circuit. , when the on or off timing of the sequence input signal input during operation of the injection molding machine is outside the tolerance range set by the tolerance range setting device, an alarm is issued and sequence signal information indicating the sequence input signal; An alarm output circuit outputs the abnormal signal state to stop the operation of the injection molding machine, and the memory circuit stores the on/off timing of the sequence input signal input during operation of the injection molding machine. If the on/off timing of the input sequence input signal does not match the normal on/off timing, then the on/off timing of the input sequence input signal is compared with the on/off timing of the input sequence input signal.
The off timing is compared with the tolerance range set by the tolerance range setting device, and if the on and off timings are outside the tolerance range, an abnormal signal state indicating an abnormality in the on or off timing is notified and the alarm output circuit is activated. and a comparison circuit that constantly monitors the sequence input signal input during operation of the injection molding machine, and transfers the on/off timing of the input sequence input signal to the comparison circuit and to the storage circuit. , and an input monitoring circuit that transfers sequence signal information indicating the sequence input signal to the alarm output circuit.

[Function] It memorizes the on/off timing of the sequence input signal during the normal operation cycle of the injection molding machine, sets the tolerance range for the timing error, and constantly monitors the sequence input signal input during the operation of the injection molding machine. Then, the on/off timing of the input sequence input signal is compared with the on/off timing during normal operation described above. As a result of this comparison, if the on/off timing of the input sequence input signal matches the normal timing or is within the set tolerance range, the injection molding machine continues to operate, but the input sequence input The on/off timing of the signal does not match the normal timing, and
If it is outside the set tolerance range, it is determined that there is a sequence abnormality in the operation cycle and an alarm is generated, and sequence signal information indicating the abnormal sequence is outputted to stop the operation of the injection molding machine.

[Example] Next, an example of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the sequence input signal monitoring device 1 includes an input monitoring circuit 2, a memory start switch 3, a memory circuit 4, a tolerance setter 5, a comparator 6, an alarm output circuit 7, and an AND circuit 8. has been done.

The input monitoring circuit 2 constantly monitors the sequence input signals 1 to n input to the sequencer 9 during operation of the injection molding machine (not shown), and monitors the on/off timing signals 2a of the sequence input signals input to the sequencer 9. , 2C are transferred to the storage circuit 4 and the comparator 6, respectively, and further, the input signal address 2b, which is sequence signal information indicating the sequence input signal, is transferred to the alarm output circuit 7.

The memory circuit 4 stores sequence input signals 1 to 1 regarding a series of sequences during the normal operation cycle of the injection molding machine.
The on and off timings of n are stored as their normal values. This storage circuit 4 outputs a cycle start signal 9 when the AND circuit 8 receives the storage instruction signal 3° from the storage start switch 3 and the cycle start signal 9° from the sequencer 9 and outputs an AND signal 8'. It starts with ゛!
The on/off timings of a series of sequence input signals 1 to n transferred from the input monitoring circuit 2 during a cycle are stored.

The tolerance range setter 5 sets the on/off timing signals 2a of each sequence input signal stored in the storage circuit 4.
Set the allowable range of timing error for each.

The comparator 6 judges whether the input on/off timing is normal or not, and the on/off timing signal 2C of the sequence input signal input during operation of the injection molding machine transferred from the input monitoring circuit 2 is used. First, the memory circuit 4
It is compared with the normal value 4, which is the normal on/off timing corresponding to the sequence input signal, which is stored in the memory. By this comparison, if the on/off timing signal 2C of the input sequence input signal and the normal value 4' match, the on/off timing of the sequence input signal is determined to be normal, and if they do not match, the on/off timing of the sequence input signal is determined to be normal. , the on/off timing signal 2C is compared with the tolerance range 5' set by the tolerance range setting device 5.
If it is within the range of , the on/off timing of the sequence input signal is judged to be normal, but if it is outside the tolerance range of 5 degrees, it is judged to be a timing abnormality, and it is determined whether this timing abnormality is the on timing or the off timing. The alarm output circuit 7 is activated by indicating an abnormal signal state 6'.

The alarm output circuit 7 outputs an alarm signal 7' when activated by the comparator 6, issues an alarm indicating an abnormality in the sequence, stops operation of the injection molding machine, and outputs a sequence transferred from the input monitoring circuit 2. The input signal address 2b of the input signal and the abnormal signal state 6° indicated by the comparator 6 are output to a printer (not shown).

Next, the operation of this embodiment will be explained with reference to FIGS. 1 and 2.

When the injection molding machine is operating normally, the memory start switch 3 is set and the memory instruction signal 3° is output to the AND circuit 8.
Furthermore, when the cycle start signal 9' is input from the sequencer 9 to the AND circuit 8, the AND circuit 8 outputs an AND signal 8° to the memory circuit 4. When the memory circuit 4 receives the AND signal 8°, it starts with the cycle start signal 9°! The on/off timings of sequence input signals 1 to n transferred from the input monitoring circuit 2 within a cycle are sequentially stored as their normal values. Also, at this time, the allowable range setter 5 sets an allowable range of timing error, as shown by diagonal lines in FIG. 2, for the on/off timings stored in the storage circuit 4. In this way, the storage of on/off timings and the setting of allowable ranges for sequence input signals 1 to n in one cycle during normal operation of the injection molding machine are completed.

When the next cycle begins, the on/off timings of sequence input signals 1 to n in this cycle are compared with their normal values and allowable ranges to determine the normality of the timings.

In Figure 2, first, considering sequence input signal 1, this on-timing matches the normal value on-timing, and the off-timing does not match the normal value off-timing, but is within the allowable range. Therefore, sequence input signal 1 is determined to be normal.

Next, consider sequence input signal 2. Although the on-timing of the sequence input signal 2 does not match the normal on-timing, it is within the allowable range, so the on-timing is normal.

However, looking at the off timing, the sequence input signal 2 is determined to be abnormal because it does not turn off within the allowable range of normal values and remains on. In this case, the alarm output circuit 7 is activated by the comparator 6 and outputs an alarm signal 7'. At this time, an alarm indicating an abnormality in the sequence is issued and the operation of the injection molding machine is stopped, and the input signal address indicating the abnormal sequence input signal 2 and the signal state indicating the abnormal off timing are transferred to the printer. Output to.

[Effects of the Invention] As explained above, the present invention continuously monitors sequence input signals, and when an abnormality is detected, issues an alarm and stops operation of the injection molding machine, thereby preventing machine damage. It can be prevented. Furthermore, when an abnormality is detected, signal information and signal status indicating the abnormality sequence are output.
The occurrence of an abnormality can be dealt with immediately, and the cause can be easily investigated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the sequence input signal monitoring device of the present invention, and FIG. 2 is a timing chart showing the operation of the sequence input signal monitoring device of FIG. DESCRIPTION OF SYMBOLS 1... Sequence input signal monitoring device, 2... Input monitoring circuit, 3... Memory start switch, 4... Memory circuit, 5... Tolerance range setter, 6... Comparator,
7... Alarm output circuit, 8-A N D circuit, 9... Sequencer, 2a, 2cm on, off timing signal, 2b... Input signal address, 3'
---memory instruction signal, 4'--normal value, 5'-
-Tolerance range, 6°--abnormal signal state, 7'--alarm signal, 8°-AND signal, 9'--cycle start signal.

Claims (1)

[Claims] 1. In a sequence control device for an injection molding machine, a sequencer (9) to which a sequence input signal is input outputs a cycle start signal (9'), and during a normal operation cycle of the injection molding machine, the sequencer (9) receives the sequence input signal. a memory start switch (3) that outputs a memory instruction signal (3') that instructs to memorize on and off timings of sequence input signals; a cycle start signal (9') is output from the sequencer (9), and a memory circuit (4) for storing on/off timing of the sequence input signal when the memory instruction signal (3') is output from the memory start switch (3); A tolerance range setter (5) is provided for setting an allowable range of timing error for on and off timings, and the on or off timing of the sequence input signal input during operation of the injection molding machine is determined by the tolerance range setter (5). (
5) is outside the set tolerance range, an alarm output circuit (7) issues an alarm and outputs sequence signal information indicating the sequence input signal and its abnormal signal state to stop operation of the injection molding machine; , Compare the on/off timing of the sequence input signal input during operation of the injection molding machine with the normal on/off timing stored in the memory circuit (4), and determine the on/off timing of the input sequence input signal. , if the off timing does not match the normal on and off timing, further,
The on and off timings of the input sequence input signal are compared with the tolerance range set by the tolerance range setting device (5), and if the on and off timings are outside the tolerance range, an error indicating an abnormality in the on or off timing is detected. a comparison circuit (6) that notifies the signal state and activates the alarm output circuit (7);
The sequence input signal inputted during operation of the injection molding machine is constantly monitored, and the on/off timing of the inputted sequence input signal is transferred to the comparison circuit (6) and the storage circuit (4). and an input monitoring circuit (2) that transfers sequence signal information indicating the sequence input signal to the alarm output circuit (7).