Positive and negative pressure circulation ink supply device and ink-jet printing equipment

Abstract

The utility model relates to the technical field of ink-jet printing equipment, and discloses a positive and negative pressure circulation ink supply device and ink-jet printing equipment, a main ink barrel is divided into a positive pressure cavity and a negative pressure cavity, the positive pressure cavity is connected with an ink supply end of a printing spray head through an ink supply pump circulation pump, and the negative pressure cavity is directly connected with an ink outlet end of the printing spray head. A closed-loop working end is formed, the negative pressure needed by normal work of the printing spray head is set through the negative pressure sensor connected to the negative pressure cavity, and the negative pressure pump can automatically adjust the rotating speed according to the value set by the negative pressure sensor so that the negative pressure needed by normal work of the whole system can be generated in the negative pressure cavity. Therefore, the ink supply stability of the whole ink supply circulation system can be ensured by only one negative pressure sensor, the structure is simpler, and the required set working parameters are fewer. Meanwhile, the negative pressure cavity is directly connected with the ink outlet end of the printing nozzle, and no pump equipment is arranged in the middle, so that the ink quantity fluctuation of the printing nozzle is smaller, and the printing quality is more stable.

Description

Technical Field

[0001] This utility model relates to the field of inkjet printing equipment technology, and in particular to a positive and negative pressure circulating ink supply device and an inkjet printing device. Background Technology

[0002] A circulating ink supply system is an ink supply system used in inkjet printers. In existing technologies, the printheads of inkjet printers may be affected by fluctuations in ink volume within the circulating ink supply system, leading to inconsistent print quality. Therefore, how to make the circulating ink supply system more stable has been a long-term research and continuous improvement issue in the ink supply industry.

[0003] For example, a Chinese utility model patent with publication number CN210970365U discloses a circulating ink supply device. Its main ink tank is equipped with an ink supply port and an ink return port. The ink supply port is connected in sequence via a pipe to a circulating ink supply pump, an ink supply buffer box, a first differential pressure sensor, and the ink inlet of the printer head. The ink return port is connected in sequence to a circulating ink return pump, an ink return buffer box, a second differential pressure sensor, and the ink outlet of the printer head. The ink inlet of the printer head is connected to the ink outlet of the printer head, thus forming a circulating ink supply. Its control components are electrically connected to the circulating ink supply pump, the circulating ink return pump, the first differential pressure sensor, and the second differential pressure sensor, respectively.

[0004] Although the above-mentioned utility model can improve the ink supply stability of the circulating ink supply system, it requires the use of more components and structures to achieve stable ink supply capability. This not only increases the system's energy consumption and cost, but also requires setting more operating parameters. Utility Model Content

[0005] The purpose of this utility model is to provide a positive and negative pressure circulating ink supply device and an inkjet printing equipment, so as to solve one or more technical problems existing in the prior art and at least provide a beneficial option or create conditions.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] A positive and negative pressure circulating ink supply device includes a main ink tank, a negative pressure pump, a negative pressure sensor, an ink supply circulation pump, and a control component. The main ink tank has a positive pressure chamber and a negative pressure chamber. The negative pressure pump is connected between the positive pressure chamber and the negative pressure chamber through a negative pressure pipeline to generate the negative pressure required for normal operation in the negative pressure chamber. The negative pressure sensor is used to detect the negative pressure value of the negative pressure chamber. An ink supply port is provided on the positive pressure chamber. The ink supply circulation pump is connected between the ink supply port and the ink supply end of the print head through an ink supply pipeline. An ink return port is provided on the negative pressure chamber. The ink outlet end of the print head is directly connected to the ink return port through an ink return pipeline. The control component is electrically connected to the negative pressure pump, the negative pressure sensor, and the ink supply circulation pump.

[0008] More preferably, a certain volume space is left on the highest liquid level surface of the positive pressure chamber and the negative pressure chamber, and the liquid level surface of the negative pressure chamber is lower than that of the positive pressure chamber.

[0009] More preferably, a buffer filter is provided on the negative pressure pipeline, and the buffer filter is connected to the outlet end of the negative pressure pump.

[0010] More preferably, an on / off valve electrically connected to the control component is provided on the ink supply pipeline. The on / off valve is connected to the outlet end of the ink supply circulation pump and is used to maintain the negative pressure of the printhead when it is not in operation.

[0011] More preferably, a positive pressure shunt pipe is provided on the ink supply line, and a negative pressure shunt pipe is provided on the ink return line.

[0012] More preferably, the positive pressure chamber is provided with an ink overflow port, the ink overflow port is connected to the ink tank through an ink overflow pipe, and an ink overflow pump electrically connected to the control component is provided on the ink overflow pipe.

[0013] More preferably, the positive pressure chamber is provided with an ink replenishment port, which is connected to the ink tank through an ink replenishment pipe, and an ink replenishment pump is provided on the ink replenishment pipe; a liquid level sensor is provided in the positive pressure chamber; the ink replenishment pump and the liquid level sensor are electrically connected to the control component.

[0014] More preferably, a temperature sensor and a heater are provided on the positive pressure chamber, and the temperature sensor and the heater are electrically connected to the control component.

[0015] More preferably, the print head is provided with a print head heater and a print head temperature sensor, and the print head heater and the print head temperature sensor are electrically connected to the control component.

[0016] On the other hand, this utility model also provides an inkjet printing device having a positive and negative pressure circulating ink supply device as described above.

[0017] The technical solution provided by this utility model has at least the following technical effects or advantages.

[0018] I. The positive and negative pressure circulating ink supply device provided by this utility model divides the main ink tank into a positive pressure chamber and a negative pressure chamber. The positive pressure chamber is connected to the ink supply end of the print head via an ink supply pump, while the negative pressure chamber is directly connected to the ink outlet end of the print head, forming a closed-loop working end. The negative pressure required for the normal operation of the print head is set by a negative pressure sensor connected to the negative pressure chamber. The negative pressure pump automatically adjusts its speed according to the value set by the negative pressure sensor, thereby generating the negative pressure required for the normal operation of the entire system within the negative pressure chamber. In this way, only one negative pressure sensor is needed to ensure the ink supply stability of the entire ink supply circulation system, resulting in a simpler structure and fewer required operating parameters. Furthermore, since the negative pressure chamber is directly connected to the ink outlet end of the print head, without any intermediate pump devices, the ink volume fluctuation of the print head is smaller, resulting in more stable print quality.

[0019] Other beneficial effects of this invention will become more apparent in the following description or may be learned through practice. Attached Figure Description

[0020] Figure 1 The diagram shown is a structural schematic of the positive and negative pressure circulating ink supply device provided by this utility model.

[0021] Figure 2 The diagram shown is another structural schematic of the positive and negative pressure circulating ink supply device provided by this utility model.

[0022] Explanation of the reference numerals in the attached figures.

[0023] 1: Main ink tank, 2: Negative pressure pump, 3: Negative pressure sensor, 4: Ink supply circulation pump, 5: Print head, 6: Buffer filter, 7: On / off valve, 8: Positive pressure diverter pipe, 9: Negative pressure diverter pipe, 10: Ink tank, 11: Overflow pump, 12: Refill pump.

[0024] 1-1: Positive pressure chamber, 1-2: Negative pressure chamber, 1-3: Ink overflow port, 1-4: Ink replenishment port. Detailed Implementation

[0025] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings, making the technical solution and beneficial effects of this utility model clearer and more explicit. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0026] Additional aspects and advantages of this invention will become apparent in the following description or may be learned by practice of this invention.

[0027] Reference Figure 1As shown, a positive and negative pressure circulating ink supply device includes a main ink tank 1, a negative pressure pump 2, a negative pressure sensor 3, an ink supply circulation pump 4, and a control component. The main ink tank 1 is provided with a positive pressure chamber 1-1 and a negative pressure chamber 1-2. The negative pressure pump 2 is connected between the positive pressure chamber 1-1 and the negative pressure chamber 1-2 through a negative pressure pipeline to generate the negative pressure required for normal operation in the negative pressure chamber 1-2. The negative pressure sensor 3 is used to detect the negative pressure value of the negative pressure chamber 1-2. An ink supply port is provided on the positive pressure chamber 1-1. The ink supply circulation pump 4 is connected between the ink supply port and the ink supply end of the print head 5 through an ink supply pipeline. An ink return port is provided on the negative pressure chamber 1-2. The ink outlet end of the print head 5 is directly connected to the ink return port through an ink return pipeline. The control component is electrically connected to the negative pressure pump 2, the negative pressure sensor 3, and the ink supply circulation pump 4.

[0028] In this invention, the main ink tank 1 is divided into a positive pressure chamber 1-1 and a negative pressure chamber 1-2. Both the positive pressure chamber 1-1 and the negative pressure chamber 1-2 have a certain volume space on their highest liquid level surfaces, and the liquid level surface of the negative pressure chamber 1-2 is lower than that of the positive pressure chamber 1-1. This allows for a larger volume space and makes the entire ink path more stable.

[0029] In this embodiment, a buffer filter 6 is preferably provided on the negative pressure pipeline, and the buffer filter 6 is connected to the outlet end of the negative pressure pump 2. By setting the buffer filter 6, air bubbles can be reduced when the negative pressure pump 2 draws ink from the negative pressure chamber 1-2 to the positive pressure chamber 1-1 during normal operation. This also eliminates the need to use an anti-foaming filter at the ink supply end of the print head 5, saving equipment costs.

[0030] In this embodiment, a shut-off valve 7 electrically connected to the control component is preferably provided on the ink supply pipeline. The shut-off valve 7 is preferably a two-way solenoid valve, connected to the outlet end of the ink supply circulation pump 4, used to maintain the negative pressure of the printhead when it is not in operation. For example, when the machine needs maintenance or there is an abnormal power outage, the two-way solenoid valve will close, and the negative pressure chamber 1-2 of the main ink tank 1 and the positive and negative pressure ends of the printhead 5 will form a sealed closed loop. This allows the entire ink system to maintain the working negative pressure of the printhead 5 for 24 hours in the event of a power outage, reducing the cost caused by printhead damage and ink loss due to sudden power outages.

[0031] In this embodiment, a positive pressure diversion pipe 8 is preferably provided on the ink supply line, and a negative pressure diversion pipe 9 is provided on the ink return line. By setting the positive pressure diversion pipe 8 and the negative pressure diversion pipe 9, not only can the ink be diverted to meet different printing needs, but it can also play a certain buffering role, further improving the stability of the ink supply.

[0032] Reference Figure 2As shown, an ink overflow port 1-3 is provided on the positive pressure chamber 1-1. The ink overflow port 1-3 is connected to the ink tank 10 through an ink overflow pipe. An ink overflow pump 11, which is electrically connected to the control component, is provided on the ink overflow pipe. By setting the ink overflow port 1-3 and the ink overflow pump 11, excess ink that overflows can be returned to the ink tank 10, ensuring that the negative pressure value meets the set requirements.

[0033] In this embodiment, an ink replenishment port 1-4 is provided on the positive pressure chamber 1-1. The ink replenishment port 1-4 is connected to the ink tank 10 through an ink replenishment pipe, and an ink replenishment pump 12 is provided on the ink replenishment pipe. A liquid level sensor is provided in the positive pressure chamber. The ink replenishment pump and the liquid level sensor are electrically connected to the control component. The liquid level sensor can monitor the ink level in the positive pressure chamber 1-1 in real time, and the ink replenishment pump 12 automatically adds ink to the main ink tank 1 to achieve automatic ink replenishment when ink is insufficient.

[0034] In one embodiment, a temperature sensor and a heater are further provided on the positive pressure chamber 1-1, and the temperature sensor and the heater are electrically connected to the control component.

[0035] In one embodiment, the printhead is provided with a printhead heater and a printhead temperature sensor, and the printhead heater and the printhead temperature sensor are electrically connected to the control component.

[0036] By setting temperature sensors and heaters, the ink in the ink path can be kept constant at the operating temperature set by the control components, ensuring printing quality.

[0037] On the other hand, this utility model also provides an inkjet printing device having a positive and negative pressure circulating ink supply device as described above.

[0038] It should also be noted that in the description of this utility model, directional terms such as "center", "horizontal", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this utility model.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Thus, the use of "first" and "second" to define a feature may explicitly or implicitly include one or more of that feature, and in this description of the utility model, "at least" means one or more, unless otherwise explicitly specified.

[0040] In this utility model, unless otherwise explicitly specified and limited, the terms "assembly," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can also refer to a mechanical connection; they can refer to a direct connection or a connection through an intermediate medium; or they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0041] In this utility model, unless otherwise specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "below," and "over" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Above," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0042] Based on the above description of the structure and principle, those skilled in the art should understand that this utility model is not limited to the specific embodiments described above. Improvements and substitutions made using techniques known in the art based on this utility model all fall within the protection scope of this utility model, which should be defined by the claims and their equivalents. Parts not described in the specific embodiments are all prior art or common knowledge.

Claims

1. A positive and negative pressure circulation ink supply device characterized by, The ink supply device comprises a main ink tank, a negative pressure pump, a negative pressure sensor, an ink supply circulating pump and a control assembly, the main ink tank is provided with a positive pressure chamber and a negative pressure chamber, the negative pressure pump is connected between the positive pressure chamber and the negative pressure chamber through a negative pressure pipeline to generate a negative pressure required for normal operation in the negative pressure chamber, the negative pressure sensor is used to detect the negative pressure value of the negative pressure chamber, an ink supply port is arranged on the positive pressure chamber, the ink supply circulating pump is connected between the ink supply port and an ink supply end of a print head through an ink supply pipeline, an ink return port is arranged on the negative pressure chamber, and an ink return end of the print head is directly connected to the ink return port through an ink return pipeline, and the control assembly is electrically connected with the negative pressure pump, the negative pressure sensor and the ink supply circulating pump.

2. The positive and negative pressure circulating ink supply device according to claim 1, characterized in that, A certain volume of space is left above the highest liquid level of the positive pressure chamber and the negative pressure chamber, and the liquid level of the negative pressure chamber is lower than that of the positive pressure chamber.

3. The positive and negative pressure circulating ink supply device according to claim 1, characterized in that, A buffer filter is arranged on the negative pressure pipeline and connected to the outlet end of the negative pressure pump.

4. The positive and negative pressure circulating ink supply device according to claim 1, characterized in that, An on-off valve electrically connected with the control assembly is arranged on the ink supply pipeline and connected to the outlet end of the ink supply circulating pump to maintain the negative pressure of the print head when not working.

5. The positive and negative pressure circulating ink supply device according to claim 1, wherein, A positive pressure shunt pipe is arranged on the ink supply pipeline, and a negative pressure shunt pipe is arranged on the ink return pipeline.

6. The positive and negative pressure circulating ink supply device according to claim 1, wherein, An ink overflow port is arranged on the positive pressure chamber and connected to the ink tank through an ink overflow pipeline, and an ink overflow pump electrically connected with the control assembly is arranged on the ink overflow pipeline.

7. The positive and negative pressure circulating ink supply device according to claim 1, wherein, An ink replenishment port is arranged on the positive pressure chamber and connected to the ink tank through an ink replenishment pipeline, and an ink replenishment pump is arranged on the ink replenishment pipeline; a liquid level sensor is arranged on the positive pressure chamber; and the ink replenishment pump and the liquid level sensor are electrically connected with the control assembly.

8. The positive and negative pressure circulating ink supply device according to claim 1, wherein, A temperature sensor and a heater are arranged on the positive pressure chamber and electrically connected with the control assembly.

9. The positive and negative pressure circulating ink supply device according to claim 1, wherein, A print head heater and a print head temperature sensor are arranged on the print head and electrically connected with the control assembly.

10. An inkjet printing apparatus, characterized by comprising: The ink supply device has the positive and negative pressure circulating ink supply device as claimed in any one of claims 1-9.

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