A constant temperature ink supply method for inkjet printer

Abstract

The present invention relates to the field of inkjet printing technology, and specifically discloses a constant temperature ink supply method for an inkjet printer, which is at least equipped with an ink storage bottle, an inkjet terminal, an ink constant temperature device, and a circulation pipeline, wherein the inkjet terminal has an ink inlet end and a circulation ink outlet end; the ink in the ink storage bottle is continuously or intermittently transported to the inkjet terminal after heat exchange through the ink constant temperature device, and the ink of the inkjet terminal flows out from the circulation ink outlet end continuously or intermittently, so that the ink of the inkjet terminal is kept at a preset temperature through dynamic circulation. The above-mentioned constant temperature ink supply method reduces the temperature change of the longer ink delivery pipeline from the ink constant temperature device to the part close to the inkjet print head, so that the ink close to the inkjet print head reaches a relatively constant temperature after a certain pre-delivery time and pre-delivery flow rate, thereby better meeting the constant temperature control requirements when the ink of the inkjet print head part with different instantaneous flow rates enters the print head during subsequent work.

Description

Technical Field

[0001] The invention relates to the technical field of inkjet printing, and in particular to a constant temperature ink supply method for an inkjet printer. Background Art

[0002] As the main equipment of digital printing, inkjet printing equipment is more and more widely used. As the mainstream of printing equipment, inkjet printing can realize printing on various media, such as various papers, polymer film media and films, various cloths, etc., and is playing an increasingly important role. The current working principles of inkjet print heads are thermal foaming and piezoelectric. The two principles each use different methods to form micro-droplets of ink and spray the ink droplets from the nozzle onto the substrate. In this process, the physical and chemical properties of the ink, including changes in surface tension and viscosity, will affect the integrity, size, flight path, etc. of the ink droplets ejected from the print head nozzle, thereby affecting the color consistency of the printed product and the stability of the ink droplet landing point. The viscosity of the liquid is highly sensitive to temperature. Changes in the ink temperature in the working area of ​​the print head will directly lead to changes in the size of the ink droplets and the formation of the complete ink droplet shape, resulting in changes in the color and accuracy of the printed product.

[0003] The temperature of the ink in the working area of ​​the print head may be affected by two main factors: (1) The temperature of the ink itself changes due to factors such as the air temperature environment; (2) The working heat or temperature fluctuation of the print head itself causes the ink flowing through the print head to change in temperature due to heat conduction. For the piezoelectric nozzles that are widely used in the market, such as the micro-piezoelectric nozzles represented by Japan's Epson, the heat generated by the nozzle itself is relatively small due to the integration and miniaturization of the process, so the heat conduction of the nozzle itself to the flowing ink is relatively small. For piezoelectric nozzles with higher power, the heating of the nozzle can also be controlled by external cooling measures near the nozzle. In addition, some heat itself is also very easy to be carried away by the flowing ink in the working state. Therefore, the temperature change of the ink itself due to environmental changes becomes the main factor in controlling the temperature stability of the ink in the nozzle of the print head.

[0004] When the ambient temperature and ink temperature rise, the ink viscosity will decrease rapidly. Too low viscosity will cause the ink droplets ejected from the print head to be scattered, fragmented, slanted or cut off, and will also cause the inkjet print head to overheat and work abnormally or stop working. When the ambient temperature and ink temperature are low, due to the increase in ink viscosity, the ink droplets ejected from the print head will become larger, and it will often cause serious ink jetting abnormalities or ink cuts during printing.

[0005] Therefore, heating the ink under low ambient temperature conditions and cooling the ink under high ambient temperature conditions to achieve constant control of the temperature of the jetted ink near the print head is one of the important factors in improving the stability of printing quality.

[0006] The ink of a printer is often composed of multiple colors, and the flow of each color ink is determined by the image to be printed and the printing mode setting of the printer. It is a kind of instantaneous activation and instantaneous stop working nature. The time and amount of each color to be ejected are highly sudden. At the same time, most of the printing equipment with scanning nozzle movement has a long distance of plastic ink delivery hose from the ink storage bottle (or ink cartridge) to the print head. Therefore, most of the direct heating and cooling methods of the ink in the ink storage bottle cannot meet the requirements of both instantaneous change and continuous constant temperature of the ink with different flow rates at the same time. Secondly, after passing through a long pipeline, the temperature at the end of the inkjet print head changes greatly, and the effect is poor. Other methods of wrapping and heating the outside of the long ink pipeline (often made of plastic materials that are easy to bend) also cannot achieve a good temperature control effect of instantaneous inkjet. Moreover, the outer wall of the plastic ink tube is not suitable for long-term heating.

[0007] In summary, the ink temperature control products currently on the market can only achieve extensive changes, have poor reliability, and have extremely large temperature fluctuations. Summary of the invention

[0008] The technical problem to be solved by the present invention is to solve the technical defects of poor reliability and large temperature fluctuation of the ink temperature control method of the inkjet printer in the prior art.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions: A constant temperature ink supply method for an inkjet printer, at least configured with:

[0010] Ink storage bottle;

[0011] An inkjet terminal, the inkjet terminal having an ink inlet end and an ink circulation outlet end;

[0012] An ink thermostat, wherein the ink inlet end of the ink thermostat is connected to the ink storage bottle, and the ink outlet end of the ink thermostat is connected to the ink inlet end of the inkjet terminal;

[0013] A circulation pipeline, through which the circulation ink outlet of the inkjet terminal is connected to the ink inlet of the ink storage bottle or the ink thermostat;

[0014] Among them, the ink in the ink storage bottle is continuously or intermittently transported to the inkjet terminal after heat exchange through the ink constant temperature device, and the ink of the inkjet terminal continuously or intermittently flows back to the ink storage bottle from the circulating ink outlet end or is transported to the inkjet terminal again after heat exchange through the ink constant temperature device, so that the ink of the inkjet terminal is maintained at a preset temperature through dynamic circulation.

[0015] In a preferred embodiment, the inkjet terminal includes an inkjet print head with a circulation function, the ink inlet end of the inkjet print head is connected to the ink constant temperature device, and the circulating ink outlet end of the inkjet print head is connected to the ink inlet end of the ink storage bottle or the ink constant temperature device through a circulation pipeline.

[0016] In a preferred embodiment, the inkjet terminal includes a secondary ink bottle A and an inkjet print head, wherein the inkjet print head is an inkjet print head without a circulation function or an inkjet print head with a circulation function but the circulation function is not enabled, and the secondary ink bottle A includes an ink outlet end connected to the inkjet print head, an ink inlet end connected to the ink outlet end of an ink constant temperature device, and a circulating ink outlet end connected to the ink inlet end of the ink constant temperature device or the ink storage bottle through a circulation pipeline.

[0017] In a preferred embodiment, the inkjet terminal comprises a secondary ink bottle A, an inkjet print head and a secondary ink bottle B. The inkjet print head is an inkjet print head with a circulation function. The secondary ink bottle A comprises an ink outlet end connected to the inkjet print head, an ink inlet end connected to the ink outlet end of the ink thermostat, and a circulating ink outlet end connected to the ink inlet end of the ink thermostat through a circulation pipeline. The pressure in the secondary ink bottle A is P H , the pressure in the secondary ink bottle B is P L , where P H >P L The circulating ink outlet of the inkjet print head is connected to the ink inlet of the secondary ink bottle B, and the ink outlet of the secondary ink bottle B is connected to the ink inlet of the secondary ink bottle A, the ink constant temperature device or the ink storage bottle.

[0018] A preferred embodiment further comprises a circulation pump arranged on the circulation pipeline, and the circulation pipeline is unidirectional.

[0019] A preferred embodiment further comprises a temperature sensor and a circulation control system disposed in the secondary ink bottle A, wherein the circulation control system controls the start and stop of the circulation pump based on a feedback signal from the temperature sensor.

[0020] A preferred embodiment further includes an ink supply pump arranged between the ink storage bottle and the ink constant temperature device, and a liquid level sensor and a liquid replenishment control system arranged in the secondary ink bottle A, and the liquid replenishment control system controls the start and stop of the ink supply pump based on the signal feedback of the liquid level sensor.

[0021] Compared with the prior art, the constant temperature ink supply method of the inkjet printer of this embodiment has the following beneficial effects:

[0022] The ink in the ink storage bottle is continuously or intermittently transported to the inkjet terminal after heat exchange through the ink thermostat, and the ink in the inkjet terminal continuously or intermittently flows back to the ink storage bottle from the circulating ink outlet or is transported to the inkjet terminal again after heat exchange through the ink thermostat. The continuous transport or cyclic transport design allows the ink in the inkjet terminal to be maintained at a preset temperature through dynamic circulation, regardless of whether the inkjet print head is working or stopped at this time, thereby gradually reducing the temperature change of the longer ink transport pipeline from the ink thermostat to the part close to the inkjet print head, so that the ink close to the inkjet print head reaches a relatively constant temperature after a certain pre-transport time and pre-transport flow rate, thereby better meeting the constant temperature control requirement when the ink at the inkjet print head part with different flow rates instantly enters the print head during subsequent work. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A system schematic diagram of a first implementation of the constant temperature ink supply method for an inkjet printer of this embodiment;

[0024] Figure 2 This is one of the system schematic diagrams of the second implementation method of the constant temperature ink supply method of the inkjet printer of this embodiment;

[0025] Figure 3 This is a second system schematic diagram of a second implementation method of the constant temperature ink supply method of the inkjet printer of this embodiment;

[0026] Figure 4 A system schematic diagram of a third implementation of the constant temperature ink supply method for an inkjet printer of this embodiment;

[0027] Figure 5 This is a schematic diagram of the layout of heat pipes in the first implementation manner of the ink constant temperature device in this embodiment;

[0028] Figure 6 Schematic diagram of the layout of heat pipes in the second implementation mode of the ink constant temperature device in this embodiment;

[0029] Figure 7 Schematic diagram of the layout of heat pipes in the third implementation mode of the ink constant temperature device in this embodiment;

[0030] Figure 8 This is a schematic diagram of the constant temperature control of the first implementation mode of the ink constant temperature device in this embodiment;

[0031] Fig. 9 This is a schematic diagram of the constant temperature control of the second implementation mode of the ink constant temperature device in this embodiment. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0033] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] In the description of the present invention, it should be noted that the terms "connected", "connected" and the like described in the present invention refer to a connection relationship in a broad sense, especially the relationship of ink flowing through, and do not necessarily mean that this must be directly connected physically. Based on the needs of actual applications, some connector components are often used in the middle, or some functional components such as filters, one-way valves, degassing lung joints and other parts are inserted. As long as there is a relationship of ink flowing through, it does not affect the relationship of "connected", "connected" and the like referred to in the present invention.

[0035] Embodiment 1

[0036] A constant temperature ink supply method for an inkjet printer of this embodiment, such as Figure 1 As shown, an ink storage bottle 30, an ink thermostat 20, an inkjet print head 40 as an inkjet terminal, and a circulation pipeline 60 are configured. The ink storage bottle 30 is connected to the ink inlet end of the ink thermostat 20, and an ink supply pump 31 and a liquid replenishment control system 32 are arranged between the ink storage bottle and the ink thermostat to control the ink in the ink storage bottle to be transported to the ink thermostat.

[0037] In this embodiment, the inkjet print head 40 has a circulation function, and the ink inlet end of the inkjet print head 40 is connected to the ink outlet end of the ink thermostat 20, and the circulating ink outlet end of the inkjet print head 40 is connected to the ink inlet end of the ink storage bottle 30 or the ink thermostat 20 through the circulation pipeline 60. Since the circulation pipeline 60 can circulate back to the ink storage bottle 30, it can also flow back to the ink thermostat 20, Figure 1 In the figure, a dotted frame 70 is used to represent the above connection method.

[0038] In this embodiment, the ink in the ink storage bottle 30 is continuously transported to the inkjet print head 40 after heat exchange through the ink constant temperature device 20, and the ink of the inkjet print head 40 continuously flows back to the ink storage bottle from the circulating ink outlet end or is transported to the inkjet print head 40 again after heat exchange through the ink constant temperature device, so that the ink of the inkjet print head 40 is maintained at a preset temperature through dynamic circulation, thereby achieving the technical purpose of constant temperature ink supply.

[0039] In this embodiment, a preferred ink constant temperature device 20 is as follows: Figure 5-9 As shown, it includes a tank body 21, a heating device 26, a cooling device 25, a control system 24 and a heat pipe 10. The tank body 21 is used to hold a heat-conducting liquid 22, the heating device 26 is used to heat the heat-conducting liquid 21, the cooling device 25 is used to cool the heat-conducting liquid 21, and the control system 24 controls the heating device and the cooling device based on the real-time feedback of the temperature sensor 23 in the heat-conducting liquid 21 to keep the heat-conducting liquid in a constant temperature state.

[0040] It should be noted that the above-mentioned constant temperature control method of the heat-conducting liquid 22 belongs to the existing conventional technology. Figure 8 A constant temperature control method for indirect heating and cooling is provided. As is common knowledge, cooling can be achieved by using a combination of a compressor and an evaporator. Fig. 9 A heat exchange method is provided by directly attaching a semiconductor cooling sheet or a heating sheet to the outer wall of the tank body. Of course, as an existing conventional technology, the cooling and heating methods are not limited to the above examples.

[0041] It should be noted that, according to the temperature of the actual working environment and the requirements of inkjet printing, the ink thermostat can be heating or cooling, or have both heating and cooling. For example, in winter when the ambient temperature is low, only using an ink thermostat with a heating function can make the ink in the initial low temperature state warm up, and when it circulates to the inkjet terminal, it reaches and remains constant in the temperature range required by the user; in summer when the ambient temperature is high, only using an ink thermostat with a cooling function can make the ink in the initial high temperature state cool down, and when it circulates to the inkjet terminal, it reaches and remains constant in the temperature range required by the user; and when the ambient temperature fluctuates above and below the temperature target required by the user, an ink thermostat with both heating and cooling functions can be used, so that the ink is controlled and remains constant in the temperature range required by the user when it circulates to the inkjet terminal.

[0042] As a special feature of this embodiment, the heat pipe 10 is provided with an ink inlet end 11 and an ink outlet end 12. Most or all of the heat pipe 10 is immersed in the heat-conducting liquid 21. When the ink flows through the heat pipe, heat is exchanged with the heat-conducting liquid 21, so that the temperature of the ink when flowing out from the ink outlet end 12 is the same as or close to the temperature of the heat-conducting liquid 21.

[0043] In this embodiment, as a preference, in order to achieve a better heat exchange constant temperature effect in a limited volume, it is generally necessary to use a material with good thermal conductivity and easy to bend to make the heat pipe 10. Commonly used materials include but are not limited to copper, copper alloy, aluminum alloy, and alloy steel.

[0044] At the same time, it is necessary to design a longer heat pipe 10 in the heat transfer liquid 21 to ensure that the water flowing through the heat pipe 10 can obtain sufficient heat exchange and achieve a constant temperature effect close to the temperature of the heat transfer liquid 21 outside the heat pipe. Figure 5 The multiple looping method shown, where, Figure 5 The view a is a sectional view, and the view b is a top view. Figure 6 The spiral design similar to the Tai Chi diagram shown in the figure, Figure 6 In the figure, view a is a cross-sectional view, and view b is a top view. In summary, in order to achieve the effect of a longer heat pipe and lower flow resistance, the heat pipe is bent and extended in the heat transfer liquid, and the bending form is not limited.

[0045] In particular, in the present embodiment, the bent extension portion bends and extends in the horizontal direction, so that the flow resistance of the ink in the heat-conducting tube is small and the kinetic energy loss is small.

[0046] As a preference, Figure 7 A schematic diagram of the stacking arrangement of multiple heat pipes in the tank is given, where: Figure 7 View a is a sectional view and view b is a top view.

[0047] In this embodiment, the ink enters the heat pipe of the high thermal conductivity material to be controlled by the liquid bath constant temperature. The heat transfer liquid of the controlled temperature in the tank body performs heat transfer exchange with the ink in the heat pipe. Combined with the appropriate ink flow rate in the heat pipe, the cross-sectional size and bending shape of the liquid-immersed part of the heat pipe, and the length of the heat pipe, the ink reaching the ink outlet of the heat pipe has undergone relatively sufficient heat transfer exchange under various flow requirements, and the ink temperature at the outlet is basically constant within the temperature range required by the user; and then the heat pipe is continuously conveyed or circulated to the inkjet print head, regardless of whether the inkjet print head is working or stopped at this time, thereby gradually reducing the temperature change of the longer ink conveying pipeline from the heat pipe outlet to the part close to the inkjet print head, so that the ink close to the inkjet print head reaches a relatively constant temperature after a certain pre-conveying time and pre-conveying flow rate, thereby better meeting the constant temperature control requirement when the ink at the inkjet print head part with different flow rates enters the print head in the subsequent work.

[0048] Embodiment 2

[0049] A constant temperature ink supply method for an inkjet printer of this embodiment, such as Figure 2 and Figure 3 As shown, an ink storage bottle 30, an ink constant temperature device 20, an inkjet print head 40, a secondary ink bottle A50 and a circulation pipeline 60 are configured, wherein the inkjet print head 30 and the secondary ink bottle A50 constitute the inkjet terminal of this embodiment.

[0050] In this embodiment, the ink inlet end of the ink thermostat 20 is connected to the ink storage bottle 30, and an ink supply pump 31 is provided between the ink thermostat 20 and the ink storage bottle 30 to deliver the ink in the ink storage bottle 30 to the ink thermostat 20. It should be noted that the ink storage bottle 30 and the ink thermostat 20 are unidirectionally connected, and the implementation method of the unidirectional connection is not limited. For example, the ink supply pump 31 adopts a peristaltic pump with a check function, and a diaphragm pump without a check function can also be used to cooperate with a one-way valve 33 to achieve unidirectional connection.

[0051] In this embodiment, the ink outlet end of the ink constant temperature device 20 is connected to the ink inlet end of the secondary ink bottle A50, and the ink after constant temperature heat exchange is transported to the secondary ink bottle A50 for temporary storage.

[0052] In this embodiment, the inkjet print head 40 is an inkjet print head without a circulation function, or an inkjet print head with a circulation function but the circulation function is not enabled. It can usually be connected to the secondary ink bottle A50 in two ways. One of them is as follows Figure 2 As shown, the secondary ink bottle A50 is connected to the inkjet print head 40 through an ink bag 41 with an automatic switch valve. At this time, the pressure PA in the secondary ink bottle A50 can be atmospheric pressure or a small negative pressure. Another method is to directly connect the secondary ink bottle A50 to the inkjet print head 40, such as Figure 3 As shown, in order to prevent ink from dripping from the print head, an appropriate negative pressure must be maintained in the secondary ink bottle A50.

[0053] In this embodiment, the circulation pipeline is arranged between the circulation ink outlet end of the secondary ink bottle A50 and the ink inlet end of the ink thermostat 20. Accordingly, a temperature sensor 64 is arranged in the secondary ink bottle A50, and a circulation pump 61 is arranged on the circulation pipeline 60. Both the temperature sensor 64 and the circulation pump 61 are connected to the circulation control system 63. When it is detected that the temperature in the secondary ink bottle A50 deviates from the set temperature, the circulation pump 61 is started to transport the secondary ink bottle A50 to the ink thermostat 20 for heat exchange again, thereby ensuring that the ink in the secondary ink bottle A50 is at a desired temperature state.

[0054] Of course, as another variation of the present embodiment, the circulation pipeline can also be arranged between the circulation ink outlet end of the secondary ink bottle A50 and the ink storage bottle, that is, the ink flows back from the secondary ink bottle A50 to the ink storage bottle, and then is re-transported from the ink storage bottle to the ink constant temperature device 20 for heat exchange again before entering the secondary ink bottle A50, so as to ensure that the ink in the secondary ink bottle A50 is in the desired temperature state.

[0055] In this embodiment, the circulation pipeline 60 is unidirectional. The implementation method of the unidirectional conduction is not limited. For example, the circulation pump 61 adopts a peristaltic pump with a check function, or a diaphragm pump without a check function can be used in conjunction with a one-way valve 62 to achieve unidirectional conduction.

[0056] In this embodiment, after the inkjet print head 40 sprays ink, the ink in the secondary ink bottle A50 will decrease. A liquid level sensor 51 is provided in the secondary ink bottle A50. The liquid replenishment control system 32 collects information from the liquid level sensor to control the operation of the ink supply pump 31, and timely pumps the ink in the ink storage bottle 30 into the heat conducting tube 10. After the heat (cold) bath of the heat conducting tube 10, the ink at a suitable temperature is replenished into the secondary ink bottle A50 to maintain a proper water level. At the same time, since the ink flowing into the secondary ink bottle A20 is the ink that has been thermostatically controlled, the temperature control effect in the secondary ink bottle A is not destroyed.

[0057] In this embodiment, by intermittently delivering the ink that has undergone heat conduction to the secondary ink bottle A50 and intermittently circulating the ink in the secondary ink bottle A50 to the ink constant temperature device, the ink in the secondary ink bottle A50 is maintained at a preset temperature through dynamic circulation, thereby achieving the technical purpose of constant temperature ink supply.

[0058] Embodiment 3

[0059] A constant temperature ink supply method for an inkjet printer of this embodiment, such as Figure 4 As shown, the difference from the second embodiment is that the inkjet terminal includes a secondary ink bottle A50, an inkjet print head 40 and a secondary ink bottle B52, and the inkjet print head 40 is an inkjet print head with a circulation function. In this embodiment, the secondary ink bottle A50 directly supplies ink to the inkjet print head 40 generally adopts a relatively high pressure P H The ink from the circulating ink outlet of the inkjet print head 40 flows back into the secondary ink bottle B52, which generally adopts a relatively low pressure P L , where P H >P L .

[0060] In this embodiment, the ink in the secondary ink bottle B52 can flow directly back to the ink storage bottle 30. Generally, the ink storage bottle 30 is at standard atmospheric pressure P0. In addition, according to control requirements, the ink in the secondary ink bottle B52 can also be pumped back to the secondary ink bottle A50; or it can be pumped to flow through the heat conduction pipe and then flow into the secondary ink bottle A50. Usually, the pressure P at the front end of the print head is H Greater than the back-end P L , forming a certain pressure difference to produce a certain flow rate.

[0061] In short, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A constant temperature ink supply method for an inkjet printer, characterized in that: At least the following configurations are required: Ink storage bottle; An inkjet terminal, the inkjet terminal comprising a secondary ink bottle A and an inkjet print head, the inkjet print head being an inkjet print head without a circulation function or an inkjet print head with a circulation function but the circulation function is not enabled, the secondary ink bottle A comprising an ink outlet end connected to the inkjet print head, an ink inlet end connected to the ink outlet end of an ink thermostat, and a circulating ink outlet end connected to the ink inlet end of the ink thermostat via a circulation pipeline; An ink thermostat, wherein the ink inlet end of the ink thermostat is connected to the ink storage bottle, and the ink outlet end of the ink thermostat is connected to the ink inlet end of the secondary ink bottle A; A circulation pipeline, through which the circulation ink outlet of the secondary ink bottle A is connected to the ink inlet of the ink thermostat; Among them, the ink in the ink storage bottle is continuously or intermittently transported to the secondary ink bottle A after heat exchange through the ink constant temperature device, and the ink in the secondary ink bottle A is continuously or intermittently transported to the secondary ink bottle A again after heat exchange through the ink constant temperature device from the circulating ink outlet end, so that the ink in the secondary ink bottle A is maintained at a preset temperature through dynamic circulation.

2. A constant temperature ink supply method for an inkjet printer, characterized in that: At least the following configurations are required: Ink storage bottle; The inkjet terminal comprises a secondary ink bottle A, an inkjet print head and a secondary ink bottle B. The inkjet print head is an inkjet print head with a circulation function. The secondary ink bottle A comprises an ink outlet end connected to the inkjet print head, an ink inlet end connected to the ink outlet end of the ink thermostat, and a circulating ink outlet end connected to the ink inlet end of the ink thermostat through a circulation pipeline. The pressure in the secondary ink bottle A is P H , the pressure in the secondary ink bottle B is P L , where P H >P L The circulating ink outlet of the inkjet print head is connected to the ink inlet of the secondary ink bottle B, and the ink outlet of the secondary ink bottle B is connected to the ink inlet of the secondary ink bottle A or the ink thermostat; An ink thermostat, wherein the ink inlet end of the ink thermostat is connected to the ink storage bottle, and the ink outlet end of the ink thermostat is connected to the ink inlet end of the secondary ink bottle A; A circulation pipeline, through which the circulation ink outlet of the secondary ink bottle A is connected to the ink inlet of the ink thermostat; Among them, the ink in the ink storage bottle is continuously or intermittently transported to the secondary ink bottle A after heat exchange through the ink constant temperature device, and the ink in the secondary ink bottle A is continuously or intermittently transported to the secondary ink bottle A again after heat exchange through the ink constant temperature device from the circulating ink outlet end, so that the ink in the secondary ink bottle A is maintained at a preset temperature through dynamic circulation.

3. The constant temperature ink supply method according to claim 1 or 2, characterized in that: The invention also comprises a circulation pump arranged on the circulation pipeline, and the circulation pipeline is unidirectional.

4. The constant temperature ink supply method according to claim 3, characterized in that: It also includes a temperature sensor and a circulation control system arranged in the secondary ink bottle A. The circulation control system controls the start and stop of the circulation pump based on the feedback signal of the temperature sensor.

5. The constant temperature ink supply method according to claim 1, 2 or 4, characterized in that: It also includes an ink supply pump arranged between the ink storage bottle and the ink constant temperature device, and a liquid level sensor and a liquid replenishment control system arranged in the secondary ink bottle A. The liquid replenishment control system controls the start and stop of the ink supply pump based on the signal feedback of the liquid level sensor.

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