Negative pressure ink supply device and protection method thereof

Abstract

A negative pressure ink supply device comprises a negative pressure gas path and an ink supply path, wherein, the negative pressure gas path comprises a vacuum pump, a negative pressure box and a two-level ink box, which are connected by a negative pressure pipeline, and the ink supply path comprises an ink supply pump and an ink supply pump controller. A first liquid level sensor is arranged inside the two-level ink box and is used for detecting whether the ink is full, and a second liquid level sensor is arranged inside the negative pressure box and is used for detecting whether the ink exceeds a first preset liquid level. The ink supply pump controller comprises a first control unit and a second control unit, wherein, the first control unit is used for controlling the ink supply pump to stop supplying ink when the first liquid level sensor detects that the two-level ink box is full, and the second control unit is used for controlling the ink supply pump to stop supplying ink when the second liquid level sensor detects that the ink exceeds the first preset liquid level. The embodiment of the invention also provides a corresponding protection method. The reliability and safety ofprotection of the negative pressure ink supply device is enhanced and the protection quality is improved through two-level detection and control.

Description

technical field [0001] The invention relates to the technical field of negative pressure ink supply, in particular to a negative pressure ink supply device and a protection method thereof. Background technique [0002] The negative pressure ink supply device includes a negative pressure air circuit and an ink supply circuit. In the negative pressure air circuit, the vacuum pump usually pumps air to the atmosphere to generate negative pressure, and the negative pressure passes through the negative pressure pipeline, buffered by the negative pressure box, and then connected to the secondary ink cartridge. In the ink supply path, the ink supply pump draws ink from the ink tank to the secondary ink tank, and the secondary ink tank supplies ink to the nozzle. There is a liquid level sensor (such as a float switch) in the secondary ink cartridge to detect whether the ink is full. When it detects that the ink is not full, the ink supply pump controller turns on the ink supply pump...

AI Technical Summary

Problems solved by technology

[0003] During the research and practice of the prior art, the inventors of the present invention have found that whether to turn off the ink supply pump is determined by detecting whether the ink in the secondary ink tank is full. When a fault occurs, it will be detected that the ink is not full (actually the ink in the secondary ink tank is full), the ink supply pump will always supply ink, and the excess ink in the secondary ink tank will be sucked to the negative pressure due to the negative pressure. Press the box, continue to supply ink, the ink will flow from the negative pressure box to the vacuum pump through the negative pressure pipeline, and then be discharged through the exhaust port, which will cause the ink to corrode the vacuum pump and cause the vacuum pump to be damaged

Therefore, the above-mentioned negative pressure ink supply device is less safe, and the ink supply pump may supply ink all the time, which may cause ink overflow to damage equipment and pollute machines and products.

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