Circulating ink path device of ink jet printer

Abstract

The utility model provides a circulating ink path device of a printing ink jet machine. The circulating ink path device comprises an ink storage unit; the ink jet unit comprises a spray head and at least one circulating ink bin, and the spray head is connected with the circulating ink bin; the circulating pipeline comprises an ink supply pipe and an ink return pipe, and the ink supply pipe and the ink return pipe are arranged on the ink storage unit and connected with the circulating ink bin; the feedback unit comprises a sensor and an ink pump which are electrically connected, the sensor is arranged on the circulating ink bin to monitor the internal pressure value, and the ink pump is arranged on the circulating ink path to adjust the rotating speed according to the pressure value. The utility model provides a circulating ink path device of a printing ink jet machine, which can realize closed-loop control of a circulating ink path, maintain ink supply pressure and ink return pressure of the circulating ink path, and enable ink in the ink path to keep a circulating state.

Description

Technical Field

[0001] The utility model relates to the technical field of digital inkjet printing, in particular to an ink circulation device for an inkjet printer. Background Art

[0002] Inkjet printers convert colored liquid ink into fine particles through a nozzle and spray them onto a substrate. Drop-on-demand inkjet printers typically utilize micro-piezoelectric printheads. As the inkjet industry continues to demand stable, long-term printing and high-volume printing, many printhead manufacturers have introduced high-flow printheads that require a recirculating ink circuit. Furthermore, many industries require larger pigment particle sizes to meet process and color development requirements.

[0003] Therefore, a precisely controlled circulating ink system is urgently needed to support the printing of circulating nozzles. Utility Model Content

[0004] In view of the deficiencies in the prior art, the present invention proposes an ink circulation device for an inkjet printer, which can realize closed-loop control of the ink circulation circuit and maintain the ink supply pressure and ink return pressure of the ink circulation circuit.

[0005] The technical solution of the present utility model is achieved as follows:

[0006] An ink circulation device for an inkjet printer, comprising:

[0007] ink storage unit;

[0008] An inkjet unit, comprising a plurality of nozzles and at least one internally hollow circulating ink tank, wherein the nozzles are connected to the circulating ink tank;

[0009] A circulation pipeline, comprising an ink supply pipe and an ink return pipe, wherein the ink supply pipe and the ink return pipe are arranged on the ink storage unit and connected to the circulating ink tank;

[0010] The feedback unit includes an electrically connected sensor and an ink pump, wherein the sensor is arranged on the circulating ink tank to monitor the internal pressure value, and the ink pump is arranged on the circulating ink path to adjust the rotation speed according to the pressure value.

[0011] A further technical solution of this embodiment is that the number of the circulating ink tanks is configured to be two, the two circulating ink tanks are arranged opposite to each other, and the nozzle is mounted between the circulating ink tanks and connected to the circulating ink tanks.

[0012] A further technical solution of this embodiment is that several of the nozzles are arranged in parallel.

[0013] A further technical solution of this embodiment is that the number of the sensors is configured to be two, the sensors are respectively arranged on the two circulating ink tanks, and the detection ends extend into the interior of the circulating ink tanks.

[0014] A further technical solution of this embodiment is that the ink pump includes a first pump body and a second pump body, the first pump body is arranged on the ink supply tube, and the second pump body is arranged on the ink return tube.

[0015] A further technical solution of this embodiment is that the circulating ink tank includes a first ink port and a second ink port having the same number as the nozzles, and the second ink ports are arranged in the same direction.

[0016] A further technical solution of this embodiment is that a liquid level detector is provided in the ink storage unit.

[0017] A further technical solution of this embodiment is that a stirring component is provided in the ink storage unit.

[0018] A further technical solution of this embodiment is that one or more of a filter and a defoamer are further provided on the circulating ink path.

[0019] A further technical solution of this embodiment is that it also includes a cleaning branch connected to the circulating ink tank.

[0020] Compared with the prior art, the utility model has the following advantages:

[0021] This embodiment realizes monitoring and control of ink supply and return in the circulating ink circuit by arranging sensors on the ink pump, thereby ensuring that the ink in the circulating ink circuit is always in motion and avoiding ink precipitation. By detecting the ink tank through sensors, the use of additional positive pressure and negative pressure air circuit control systems is avoided, thereby reducing the complexity of the system and the probability of equipment problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the implementation methods or the description of the prior art. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 The utility model is a schematic structural diagram of an ink circulation device of an inkjet printer.

[0024] Figure identification: 1-ink storage unit; 21-nozzle; 22-circulating ink tank; 31-sensor; 32-ink pump; 41-ink supply pipe; 42-ink return pipe; 51-filter; 52-defoamer; 53-solenoid valve; 54-stirring assembly; 55-cleaning branch; 56-liquid level detector. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," "third," and "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0028] Example 1

[0029] like Figure 1 As shown, the embodiment of the utility model discloses an ink circulation device for an inkjet printer, comprising an ink storage unit 1, an inkjet unit, a circulation pipeline and a feedback unit;

[0030] The ink storage unit 1 is an ink barrel for storing ink. The ink in the circulating ink system is constantly in a state of supply and return, thereby providing a stable ink supply to the printhead 21. To avoid the problem of inconsistent ink circulation speeds between the supply and return, which could lead to ink shortages in the printhead 21, the main ink barrel is used to increase the ink reserve and improve the stability of the circulating ink circuit. A stirring assembly 54 is provided at the axis of the main ink barrel to stir the ink within the barrel, preventing ink from settling and flowing into the pipeline, which could cause blockage in the printhead 21. Several liquid level sensors 56 are also provided inside the main ink barrel to detect the ink level within the barrel and ensure an adequate ink supply in the circulating ink circuit at all times.

[0031] The inkjet unit includes several nozzles 21 and at least one hollow internal circulating ink tank 22. The nozzles 21 are connected to the circulating ink tank 22. After the ink enters the circulating ink tank 22, it passes through the nozzles 21 to form the desired image on the pattern carrier. At the same time, the ink continuously flows from the circulating ink tank 22 through the pipeline back to the main ink tank, completing the circulation. The circulating ink tank 22 is a cylindrical cavity, which ensures smoother ink flow and prevents sedimentation in the ink tank.

[0032] In this embodiment, the circulating ink reservoir 22 has a first ink port, and second ink ports spaced at intervals and oriented in the same direction. The number of second ink ports is determined by the number of nozzles 21 to be circulated. Multiple nozzles 21 can be connected to the second ink ports, with the nozzles 21 arranged parallel to each other and facing the substrate, thereby accurately printing a pattern on the substrate.

[0033] Furthermore, a cleaning branch 55 is connected to the circulating ink tank 22. A controllable solenoid valve 53 is provided on the cleaning branch 55. When the circulating ink tank 22 needs to be cleaned, the ink inside is drawn out through the cleaning branch 55, and cleaning liquid is injected through the cleaning branch 55 to backwash the circulating ink circuit.

[0034] The circulation line includes an ink supply line 41 and an ink return line 42, which are installed on the ink storage unit 1 and connected to the circulating ink reservoir 22. Both the ink supply line 41 and the ink return line 42 are made of Super Tom fluorine hose, which combines excellent corrosion resistance, flexibility, and low flow resistance. Optionally, the circulation line is equipped with a filter 51 for filtering impurities in the ink and a defoamer 52 for removing air from the ink to enhance the stability of the circulating ink line.

[0035] The feedback unit includes an electrically connected sensor 31 and an ink pump 32. The sensor 31 is located on the circulating ink reservoir 22 to monitor internal pressure, and the ink pump 32 is located on the circulating ink path to adjust the speed based on the pressure. The sensor 31 is configured as a pressure sensor with a monitoring accuracy of 0.01 kPa. Since the piezoelectric printhead 21 operates within a ±1 kPa range for ink pressure, the ink path control achieves a circulating ink pressure variation accuracy of ±0.1 kPa. The sensor 31 is directly installed on the circulating ink tank 22 and monitors the ink pressure value inside the circulating ink tank 22. Since the circulating ink tank 22 is both the end point of ink supply and the starting point of ink return, the sensor 31 can simultaneously detect the ink supply and ink return conditions, thereby grasping the overall pressure value of the circulating ink path and outputting it to the ink pump 32, and further used to adjust the speed power of the ink pump 32 to reduce or increase the ink pressure value in the ink supply tube 41 and the ink return tube 42, pumping the ink from the main ink barrel to the circulating ink tank 22, and then pumping it back to the main ink barrel from the circulating ink tank 22, finally realizing the circulation of the ink in the system. At the same time, it is monitored by the sensor 31, and the ink flow rate at various points in the circulating pipeline is adjusted at all times to maintain the circulation of the ink path.

[0036] The ink circulation path in this embodiment is:

[0037] Ink storage unit—ink pump X—circulating ink tank—printer head—ink pump Y—ink storage unit;

[0038] The entire system is filled with ink throughout the entire ink circuit. The ink is essentially isolated from air and other media, eliminating the risk of contamination. The ink is fully circulated throughout the entire ink circuit. No air pressure control is required. The pressure sensor 31 directly monitors the ink pressure in the circulating ink reservoir 22, providing intuitive ink pressure data without the need to derive the ink pressure from air pressure measurements.

[0039] The ink pump 32 in this embodiment includes a pump X for ink supply and a pump Y for ink return, which are respectively arranged on the ink supply pipe 41 and the ink return pipe 42. After the circulating ink circuit is started, the pump 32 is in a continuous working state, continuously supplying and returning ink, avoiding the impact problem caused by stopping and restarting the pump, and maintaining the stability of the entire ink circuit system.

[0040] Example 2

[0041] As a more optimal technical solution, this embodiment includes at least two circulating ink tanks in the inkjet unit, namely circulating ink tank X and circulating ink tank Y. The two circulating ink tanks are arranged opposite each other, and the nozzle is mounted between the circulating ink tanks and connected to the circulating ink tanks. The ink is simultaneously sprayed onto the carrier from the nozzle during the process of being transported from circulating ink tank X to circulating ink tank Y. The number of sensors is configured to be two, namely sensor X and sensor Y. The sensors are respectively installed on the two circulating ink tanks, and the detection ends extend into the interior of the circulating ink tanks; pressure sensor X monitors the ink pressure value in circulating ink tank X, and pressure sensor X controls the operation of pump X. Pressure sensor Y monitors the ink pressure value in circulating ink tank Y, and pressure sensor Y controls the operation of pump Y. By providing two circulating ink tanks, the ink supply part and the ink return part can be further separated, making the feedback control of the ink path more precise. At the same time, the circulating ink tanks can further provide redundant space for the circulation of ink.

[0042] Specifically, the ink supply tube and the ink return tube are respectively provided with a solenoid valve A and a solenoid valve B, 1.5 solenoid valve X, solenoid valve A, and pump X constitute the ink supply part, and the solenoid valve Y, solenoid valve B, and pump Y constitute the ink return part.

[0043] The working principle of this embodiment is as follows:

[0044] Pressure sensor X monitors the pressure of the ink in circulating ink tank X and compares it with the set pressure value. The speed of pump X is set based on the difference between the set value and the detected value through a proportional relationship. The program uses the PID algorithm to achieve full closed-loop control of the ink flow rate pressure value of circulating ink tank X and pump X.

[0045] Pressure sensor Y monitors the pressure value of the ink in the circulating ink tank Y and compares it with the set pressure value. The speed of pump Y is set through the difference between the set value and the detected value through the proportional relationship. The program uses the PID algorithm to achieve full closed-loop control of the ink flow rate pressure value of the circulating ink tank Y and pump Y.

[0046] When controlling the operation of pump X, the operation of solenoid valve X and solenoid valve A is controlled; when controlling the operation of pump Y, the operation of solenoid valve Y and solenoid valve B is controlled.

[0047] The pressure sensor monitors the pressure value signal and sends it to the controller PLC. The PLC outputs a signal to control the speed of the pump through the internal program. At the same time, the PLC controls the operation of the solenoid valve by outputting a contact signal.

[0048] The control program flow of this embodiment is as follows:

[0049] The ink circuit is activated, and the main ink tank liquid level is tested for normality. If abnormal, an alarm is triggered. If normal, pumps X and Y are activated to circulate the ink. The pressure values ​​of circulating ink reservoirs X and Y are monitored. The difference between the detected pressure value and the set pressure value is used to implement a PID closed-loop control of the speeds of pumps X and Y to bring the ink pressure in the ink circuit to the set value. If positive pressure cleaning is required during the process, positive pressure cleaning is performed. After completion, the pressure values ​​of circulating ink reservoirs X and Y are monitored again to control the speeds of pumps X and Y.

[0050] The benefits of this embodiment are:

[0051] 1. The circulating ink system supports the piezoelectric print heads that require circulating ink supply launched by print head manufacturers.

[0052] 2. More precise ink circulation control, fully closed-loop active adjustment of ink supply and ink return, maintaining stable flow rate in the ink path inside the printhead.

[0053] 3. The ink in the entire ink path system moves fully, reducing the problem of ink sedimentation in the ink path.

[0054] 4. The ink stick circulation ink path system has a simple architecture and the ink stick design has low installation space requirements. It is particularly suitable for multi-nozzle, single-pass printing module equipment, which can give more space to other spare parts such as nozzle boards.

[0055] 5. The ink strip circulation ink path system does not require additional positive and negative pressure air path control systems, reducing the complexity of the system and reducing the problem points of the system.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A circulating ink path device for an inkjet printer, characterized in that: include: Ink storage unit (1); An inkjet unit, comprising a plurality of nozzles (21) and at least one internally hollow circulating ink tank (22), wherein the nozzles (21) are connected to the circulating ink tank (22); A circulation pipeline, the circulation pipeline comprising an ink supply pipe (41) and an ink return pipe (42), the ink supply pipe (41) and the ink return pipe (42) being arranged on the ink storage unit (1) and connected to the circulation ink tank (22); A feedback unit comprises an electrically connected sensor (31) and an ink pump (32), wherein the sensor (31) is arranged on a circulating ink tank (22) to monitor an internal pressure value, and the ink pump (32) is arranged on the circulating ink path to adjust a rotation speed according to the pressure value.

2. The ink circulation device for an inkjet printer according to claim 1, characterized in that: The number of the circulating ink tanks (22) is configured to be two, the two circulating ink tanks (22) are arranged opposite to each other, and the nozzle (21) is mounted between the circulating ink tanks (22) and connected to the circulating ink tanks (22).

3. The ink circulation device of the inkjet printer according to claim 2, characterized in that: Several of the nozzles (21) are arranged in parallel.

4. The ink circulation device for an inkjet printer according to claim 2, characterized in that: The number of the sensors (31) is two, and the sensors (31) are respectively arranged on the two circulating ink bins (22), with the detection ends extending into the interior of the circulating ink bins (22).

5. The ink circulation device for an inkjet printer according to claim 1, characterized in that: The ink pump (32) comprises a first pump body and a second pump body, wherein the first pump body is arranged on the ink supply tube (41), and the second pump body is arranged on the ink return tube (42).

6. The ink circulation device for an inkjet printer according to claim 1, characterized in that: The circulating ink tank (22) comprises a first ink port and a second ink port having the same number as the nozzles (21), and the second ink ports are arranged in the same direction.

7. The ink circulation device for an inkjet printer according to claim 1, characterized in that: A liquid level detector (56) is provided in the ink storage unit (1).

8. The ink circulation device for an inkjet printer according to claim 1, characterized in that: A stirring component (54) is provided in the ink storage unit (1).

9. The ink circulation device for an inkjet printer according to claim 1, characterized in that: The circulating ink path is further provided with one or more of a filter (51) and a defoamer (52).

10. The ink circulation device for an inkjet printer according to claim 1, characterized in that: It also includes a cleaning branch (55) connected to the circulating ink tank (22).

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