Prin ung machine

A printing machine comprising:

• a printing plate;
• an ink transfer roll rotatable to transfer ink to the printing plate;
• a pair of machine frames arranged in spaced-apart relation in a rotational axis direction of the ink transfer roll, wherein the ink transfer roll is disposed in an interspace region between the machine frames;
• an ink reservoir formed along the ink transfer roll so as to apply the ink onto the ink transfer roll;
• an ink supply pipe for supplying the ink from an ink container to the ink reservoir;
• an ink recovery pipe for recovering the ink from the ink reservoir, or from an ink pool for temporarily pooling the ink received from the ink reservoir, in an ink recovery direction directed toward the ink container;
• a cleaning water supply unit for supplying cleaning water to the ink reservoir;
• and
• a drain pipe for draining the cleaning water in the ink reservoir;
• wherein the printing machine is configured to sequentially carry out a printing step of supplying the ink to the ink reservoir to perform printing, an ink recovery step of, after completion of the printing step, recovering the ink from the ink reservoir or from the ink reservoir and the ink pool, and a cleaning step of cleaning the ink reservoir by supplying the cleaning water to the ink reservoir and draining the cleaning water via the drain pipe;
• wherein the printing machine further comprises:
• a first restriction device for restricting a fluid communication state of the ink recovery pipe;
• a first coupling part for coupling a high-pressure air generation part for generating high-pressure air, with the ink recovery pipe;
• and
• a first high-pressure air control device for controlling supply of the high-pressure air to the ink recovery pipe through the first coupling part, and stop of the supply;
• wherein:
• the ink recovery pipe comprises:
• an inflow port for allowing the ink from the ink reservoir or the ink pool to flow in the ink recovery pipe therethrough, the inflow port disposed at a position closer to one of the pair of machine frames than a roll middle position in the rotational axis direction of the ink transfer roll;
• and an outflow port for allowing the ink in the ink recovery pipe to flow out toward the ink container therethrough, the outflow port being disposed at a position closer to the other of the pair of machine frames than the roll middle position in the rotational axis direction of the ink transfer roll;
• the first restriction device is disposed at a disposition position of the inflow port of the ink recovery pipe, or a position downstream of the inflow port in the ink recovery direction;
• the first coupling part is coupled to the ink recovery pipe at a position downstream of the first restriction device in the ink recovery direction;
• and
• the first high-pressure air control device is configured to, in the printing step, stop the supply of the high-pressure air to the ink recovery pipe through the first coupling part, and, while at least the cleaning step is carried out after completion of the printing step, supply the high-pressure air to the ink recovery pipe through the first coupling part, so as to recover the ink in the ink recovery pipe.

A printing machine comprising:

• a printing plate;
• an ink transfer roll rotatable to transfer ink to the printing plate;
• a pair of machine frames arranged in spaced-apart relation in a rotational axis direction of the ink transfer roll, wherein the ink transfer roll is disposed in an interspace region between the machine frames;
• an ink reservoir formed along the ink transfer roll so as to apply the ink onto the ink transfer roll;
• an ink supply pipe for supplying the ink from an ink container to the ink reservoir;
• an ink recovery pipe for recovering the ink from the ink reservoir, or from an ink pool for temporarily pooling the ink received from the ink reservoir, in an ink recovery direction directed toward the ink container;
• a cleaning water supply unit for supplying cleaning water to the ink reservoir;
• and
• a drain pipe for draining the cleaning water in the ink reservoir;
• wherein the printing machine is configured to sequentially carry out a printing step of supplying the ink to the ink reservoir to perform printing, an ink recovery step of, after completion of the printing step, recovering the ink from the ink reservoir or from the ink reservoir and the ink pool, a first cleaning step of cleaning the ink reservoir by supplying the cleaning water to the ink reservoir and draining the cleaning water from the ink reservoir via the drain pipe, and a second cleaning step of cleaning the ink supply pipe and the ink recovery pipe by supplying the cleaning water to the ink supply pipe and the ink recovery pipe and draining the cleaning water from the ink supply pipe and the ink recovery pipe;
• wherein the printing machine further comprises:
• a first restriction device for restricting a fluid communication state of the ink recovery pipe;
• a first coupling part for coupling a high-pressure air generation part for generating high-pressure air, with the ink recovery pipe;
• and
• a first high-pressure air control device for controlling supply of the high-pressure air to the ink recovery pipe through the first coupling part, and stop of the supply;
• wherein:
• the ink recovery pipe comprises:
• an inflow port for allowing the ink from the ink reservoir or the ink pool to flow in the ink recovery pipe therethrough, the inflow port disposed at a position closer to one of the pair of machine frames than a roll middle position in the rotational axis direction of the ink transfer roll;
• and an outflow port for allowing the ink in the ink recovery pipe to flow out toward the ink container therethrough, the outflow port being disposed at a position closer to the other of the pair of machine frames than the roll middle position in the rotational axis direction of the ink transfer roll;
• the first restriction device is disposed at a disposition position of the inflow port of the ink recovery pipe, or a position downstream of the inflow port in the ink recovery direction;
• the first coupling part is coupled to the ink recovery pipe at a position downstream of the first restriction device in the ink recovery direction;
• and
• the first high-pressure air control device is configured to, in the printing step, stop the supply of the high-pressure air to the ink recovery pipe through the first coupling part, and, while at least the first cleaning step and the second cleaning step are carried out in a process from completion of the printing step to completion of the second cleaning step, supply the high-pressure air to the ink recovery pipe through the first coupling part, so as to recover the ink in the ink recovery pipe and drain the cleaning water in the ink recovery pipe.