| 摘要 |
PROBLEM TO BE SOLVED: To provide a key operation method capable of improving security by inhibiting illegitimate change of setting of a duplicate key while maintaining convenience of allowing a number of persons to carry the duplicate key for operation of machines.SOLUTION: A key operation method includes: a distribution stage for changing a lock-unlock device of a machine to a second state by using a distribution change key B when a distributor hands the machine to an operation entity; a key change state for setting a key pattern Y of an operation unlock key C possessed by the operation entity to the lock-unlock device to establish a first state by inserting the operation unlock key C into a key insertion part of the lock-unlock device being in the second state before the operation entity, being handed the machine, starts operation of the machine; an operation stage for unlocking the machine by inserting the operation unlock key C into the key insertion part of the lock-unlock device being in the first state, when the operation entity starts operation of the machine; and a re-distribution stage for changing the lock-unlock device of the machine to the second state by using an operation change key D when the operation entity hands the machine to a distributor. |
