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.
YAMAMOTO SHIGEYUKI
MONTSUZUMI KUNIKATSU
KIYOGAMI TACHIKI
| JPS5430255A | 1979-03-06 |