Synchronous control method and device of the same

A synchronous control method of a web rotary printing press having a first and second motors, and in which rotation phases of the first and second motors are synchronized, and having first braking means for braking a rotation of a first motor, and second braking means for braking a rotation of a second motor, the method comprising:

• operating the first braking means and the second braking means, in response to a stop instruction to the first motor;
• detecting rotation phases of the first and second motors at a time of restart;
• comparing the rotation phase of the second motor with the rotation phase of the first motor;
• and
• based on a result of the comparison, performing a home position alignment of the first and second motors at a start time of a subsequent operation by driving the first and second motors simultaneously in the same direction at a low speed so as to synchronize the rotation phases with each other.

A synchronous control device for controlling a web rotary printing press, comprising:

• a motor;
• a central control unit generating a synchronous reference signal, and with which the motor is controlled to rotate synchronously with the synchronous reference signal supplied from the central control unit;
• braking means for braking a rotation of the motor;
• motor rotation phase detecting means for detecting a rotation phase of the motor;
• and
• controlling means for performing control in such a manner that the braking means is activated in response to a stop instruction supplied from the central control unit;
• a required rotation phase of the motor is stored;
• at a time of restart the required rotation phase of the motor is compared with the detected rotation phase thereof detected by the motor rotation phase detecting means;
• and a home position alignment of the motor is performed at a stan time of a subsequent operation by driving the motor at a low speed in a direction indicated by a synchronous reference signal supplied from, the central control unit, depending on a result of the comparison, such that the detected rotation phase of the motor synchronizes with the synchronous reference signal.

A synchronous control device for controlling a web rotary printing press, comprising:

• a first and second motors, and with which rotation phases of the first and second motors are synchronized;
• first braking means for braking a rotation of the first motor;
• second braking means for braking a rotation of the second motor;
• first motor rotation phase detecting means for detecting a rotation phase thereof;
• second motor rotation phase detecting means for detecting a rotation phase thereof;
• and
• controlling means for performing control in such a manner that the first and second braking means are activated in response to a stop instruction supplied to the first motor;
• at a time of restart the detected rotation phase of the first motor detected by the first motor rotation phase detecting means is compared with the rotation phase of the second motor detected by the second motor rotation phase detecting means;
• and a home position alignment of the second motor is performed at a start time of a subsequent operation by driving the first and second motors simultaneously in the same direction at a low speed depending on a result of the comparison so as to synchronize the rotation phases with each other.