JP2016179654A - Liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid discharge device including an ink supply system which enables heat exchange with an ink at a stable temperature regardless of a flow rate of hot water circulated therein.SOLUTION: A liquid discharge device includes: a head unit 70 which discharges an ink; an ink circulation passage 81 for circulating the ink and supplying the ink to the head unit 70; a hot water circulation passage 82 for circulating hot water; a hot water tank 90 configured to store the hot water in the hot water circulation passage 82 and including an inflow port 91 into which the hot water flows from the hot water circulation passage 82 and an outflow port 92 from which the hot water flows to the hot water circulation passage 82; a heat plate 93 which heats the hot water in the hot water tank 90; a heat exchange part 83 which conducts heat exchange between the ink circulation passage 81 and the hot water circulation passage 82; a flow rate regulation part 88 which regulates a flow rate of the hot water flowing into the heat exchange part 83; and a hot water return passage 89 for returning at least part of the hot water flowing out from the outflow port 92 to the inflow port 91.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a liquid ejection apparatus.

In an ink jet printer as a liquid ejecting apparatus that ejects ink droplets from a nozzle to form an image on a printing medium, in order to further stabilize printing quality, the temperature or Techniques for maintaining the composition within a certain range are known.
For example, Patent Document 1 is provided with a plurality of supply paths that supply ink to each of a plurality of ink discharge heads, and the ink that flows through the supply paths and the liquid temperature adjustment device are adjusted to a predetermined temperature and supplied. The heat exchange means for exchanging heat with the liquid medium, and the heat exchange means provided corresponding to these heat exchange means, respectively, adjust the flow rate of the liquid medium circulated and supplied to the respective heat exchange means (changes individually) A liquid supply device comprising a flow rate adjusting means and a control means thereof is described. According to this liquid supply apparatus, the temperature of the ink supplied to each ink ejection head can be adjusted for each type of ink simply by changing the supply amount of the liquid medium supplied to each heat exchange unit. The cost can be reduced.

JP 2011-73190 A

  However, in the liquid supply device described in Patent Document 1, the temperature of the liquid medium supplied to the heat exchange unit becomes unstable depending on the supply amount of the liquid medium circulated and supplied to each heat exchange unit. There is a problem that it may be difficult to stably maintain the temperature within a predetermined temperature range. Specifically, for example, when it is necessary to control the total amount of the liquid medium flowing out from the liquid temperature adjusting device (for example, when performing control to reduce the overall heat exchange efficiency), the liquid temperature adjusting device Depending on the configuration, as a result of the restriction of the internal flow of the liquid medium accommodated in the liquid temperature adjusting device, the temperature variation in the liquid temperature adjusting device increases, and the liquid supplied from the liquid temperature adjusting device to the heat exchange unit There was a problem that the temperature of the medium became unstable.

  The present invention has been made to solve the above-described problems, and can be implemented as the following application examples or forms.

  Application Example 1 A liquid discharge apparatus according to this application example includes a discharge unit that discharges a first liquid, a first circulation passage that circulates the first liquid and supplies the first liquid to the discharge unit, and a second A second circulation channel that circulates the liquid, an inflow port that accommodates the second liquid and into which the second liquid flows from the second circulation channel, and the second circulation channel; A storage section having an outlet through which the second liquid flows out into the two circulation channels; a heating section for heating the second liquid inside the storage section; the first circulation channel and the first A heat exchanging part for exchanging heat with the circulation path, a flow rate adjusting part for adjusting the flow rate of the second liquid flowing to the heat exchanging part, and the second liquid flowing out from the outlet A reflux flow path capable of returning at least a part to the inflow port.

Since the storage unit includes a heating unit that heats the second liquid therein, the temperature of the second liquid inside the storage unit depends on the movement state (flow rate) of the second liquid inside the storage unit. Distribution may be different.
According to this application example, since the at least part of the second liquid flowing out from the outlet of the storage unit is provided with the return flow path capable of returning to the inlet of the storage unit, the flow flows to the heat exchange unit. Even when the flow rate of the second liquid is changed, the flow rate inside the housing portion can be maintained within a predetermined range. As a result, it is possible to suppress the temperature of the second liquid circulated from the storage unit to the heat exchange unit from becoming unstable.

  Application Example 2 In the liquid ejection device according to the application example described above, the liquid ejection apparatus includes a detection unit that detects the temperature of the ejection unit or the temperature of the first liquid, and the flow rate adjustment unit has a temperature detected by the detection unit. Based on this, the ratio of the flow rate flowing to the heat exchange section and the flow rate flowing to the reflux flow path is adjusted.

The efficiency of heat exchange performed between the first circulation channel and the second circulation channel can be adjusted by adjusting the ratio between the flow rate flowing to the heat exchange unit and the flow rate flowing to the reflux channel.
According to this application example, in order to adjust the flow rate of the second liquid flowing to the heat exchange unit based on the temperature of the discharge unit or the temperature of the first liquid detected by the detection unit, the temperature of the discharge unit or the first liquid It becomes possible to control the temperature of the liquid.

  Application Example 3 In the liquid ejection device according to the application example described above, the flow rate adjustment unit includes a first pump that sends the second liquid and a control unit that controls the first pump. It is characterized by.

  According to this application example, it is possible to control the temperature of the first liquid by controlling the first pump.

  Application Example 4 In the liquid ejection apparatus according to the application example, the flow rate adjustment unit includes a valve provided in the second circulation channel and a control unit that controls the valve. To do.

  According to this application example, it is possible to control the temperature of the first liquid by controlling the valve provided in the second circulation channel.

  Application Example 5 In the liquid ejection device according to the application example, the reflux flow path includes a second pump that feeds the second liquid flowing through the reflux flow path. .

  According to this application example, at least a part of the second liquid flowing out from the outlet of the storage unit can be returned to the inlet of the storage unit by the second pump.

  Application Example 6 In the liquid ejection device according to the application example, a second ejection unit that ejects a third liquid, a third circulation channel that circulates the third liquid and supplies the third liquid to the ejection unit, And a second heat exchanging part that exchanges heat between the third circulation channel and the second circulation channel.

  According to this application example, since the plurality of liquids (the first liquid and the third liquid) are heat-exchanged by the second liquid sent out from one storage unit, the temperatures of the plurality of liquids can be more efficiently performed. Can be stabilized.

  Application Example 7 In the liquid ejection apparatus according to the application example, the main component of the second liquid is a main solvent of the first liquid.

  According to this application example, in the heat exchange unit, even if a situation occurs in which the second liquid adjacent to the first liquid is mixed into the first liquid, the first circulation channel is damaged. Such chemical changes (for example, generation of foreign matter) are less likely to occur.

1 is a front view of a liquid ejection apparatus according to Embodiment 1. FIG. Schematic diagram showing the configuration of the ink supply unit Perspective view showing the configuration of the hot water tank Example of a control table that controls the flow rate of hot water based on the detection result of the temperature sensor FIG. 6 is a schematic diagram illustrating a configuration of an ink supply unit included in a liquid ejection apparatus according to Embodiment 2.

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention. In the following drawings, the scale may be different from the actual scale for easy understanding.

(Embodiment 1)
FIG. 1 is a front view of a printer 100 as a liquid ejection apparatus according to the first embodiment.
The printer 100 is an ink jet printer that performs printing by ejecting ink as a “first liquid” (hereinafter simply referred to as ink) to the print medium 10. The printer 100 includes a transport unit 20 that transports the print medium 10, a head unit 70 as an “ejection unit” that ejects ink, a supply unit 50 that supplies the print medium 10 before printing, and a winding that winds up the print medium after printing. A take-up unit 51, a controller 60 as a “control unit” that controls the entire printer 100, an ink supply unit 80 that supplies ink to the head unit 70, and the like are provided.

  The transport unit 20 includes a supply roller 21, a transport motor 22, a transport roller 23, a rotating drum 26, a discharge roller 25, and the like, and the print medium 10 passes from the supply unit 50 through a print area below the head unit 70 and is taken up. A transport path for transporting to 51 is configured. The rotating drum 26 supports the printing medium 10 during printing.

The rotary drum 26 is a cylindrical drum that is rotatably supported by a support mechanism (not shown). The rotating drum 26 supports the print medium 10 on the outer peripheral surface thereof from the back side of the print medium 10, that is, the side opposite to the head unit 70. When the print medium 10 is fed along the outer peripheral surface of the rotary drum 26, the rotary drum 26 is driven to rotate by the frictional force between the outer peripheral surface and the print medium 10.
The head unit 70 discharges ink onto the print medium 10 in a path where the print medium 10 is supported on the outer peripheral surface of the rotary drum 26 in the transport path from the supply roller 21 to the discharge roller 25.

The head unit 70 includes a first head unit 70a, a second head unit 70b, a third head unit 70c, a fourth head unit 70d, and a fifth head unit 70e in order from the upstream side in the transport direction of the print medium 10. The head units 70a to 70e are arranged radially around the rotary drum 26.
Each of the head units 70a to 70e includes an inkjet head 71 (71a to 71e) having a plurality of nozzles that eject ink as ink droplets by an inkjet method. The nozzles are arranged corresponding to the width of the rotating drum 26. That is, each head unit 70a-70e comprises the line type head.

The head units 70a to 70e sequentially eject white, black, yellow, cyan, and magenta inks. For example, when the print medium 10 is made of a transparent film material, the first head unit 70a discharges white ink over the entire surface to form a white background, and the first background is formed on the formed background. Each color ink is ejected from the two head units 70b to the fifth head unit 70e to form a color image.
In addition, the color of the ink which each head unit 70a-70e discharges is not specifically limited. Further, the number of head units 70, that is, the number of colors of ink to be ejected is not particularly limited.

  The controller 60 controls each of the transport unit 20, the head unit 70, the supply unit 50, the winding unit 51, and the ink supply unit 80 based on print data received from an external connection device (for example, a personal computer), and prints. An image is printed (image formation) on the medium 10. The received print data is converted, for example, so that general RGB digital image information obtained by a digital camera or the like can be printed by the printer 100 by software such as an image processing application or a printer driver provided in an external device. This is data for image formation, and includes commands for controlling the printer 100.

FIG. 2 is a schematic diagram illustrating the configuration of the ink supply unit 80.
The ink supply unit 80 is a supply system that supplies temperature-controlled ink to the head unit 70 while circulating it. The ink supply unit 80 includes an ink circulation channel 81 as a “first circulation channel”, a hot water circulation channel 82 as a “second circulation channel”, a heat exchange unit 83, and a hot water tank 90 as an “accommodating unit”. , A flow rate adjusting unit 88, a hot water recirculation path 89 as a “reflux flow path”, and the like.

  The ink circulation channel 81 is configured as ink circulation channels 81a to 81e that supply ink independently to each of the head units 70a to 70e. That is, the ink circulation flow path 81 includes a plurality of inks including the “first circulation flow path” and the “third circulation flow path” in the description of the application example described above (the “first liquid” and the “third liquid”). A plurality of inks including ink as “liquid”. The ink circulation channels 81a to 81e communicate with the inkjet heads 71a to 71e, respectively, and supply the respective inks to the inkjet heads 71a to 71e.

Each of the ink circulation channels 81a to 81e includes an ink tank 85 (85a to 85e) that stores ink, an ink pump 86 (86a to 86e) that circulates ink in the channel, and a heat exchange unit 83. (83a to 83e).
In FIG. 2, only three of the ink circulation channels 81a to 81e are illustrated.

  The hot water circulation channel 82 is a channel that circulates and supplies the hot water as the “second liquid” to the heat exchange unit 83 (83a to 83e), and the hot water tank 90 and the hot water tank 90 are provided in the channel. , A hot water pump 87 as a “first pump” that circulates the hot water to the heat exchanging parts 83a to 83e is provided. The hot water circulation channel 82 is configured to branch into the heat exchange units 83 a to 83 e in the channel downstream from the hot water pump 87, merge after passing through the heat exchange units 83 a to 83 e, and return to the hot water tank 90. Yes.

  The heat exchanging unit 83 performs heat exchange between the ink circulated by the ink circulation channel 81 (ink circulation channels 81a to 81e) and the supplied hot water, and controls the ink to a predetermined temperature. Although the heat exchange part 83 is comprised using the multi-tube type shell and tube type heat exchanger as a suitable example, it is not limited to this.

FIG. 3 is a perspective view showing an example of the configuration of the hot water tank 90.
In the hot water tank 90, hot water flows from the hot water circulation channel 82 (that is, warm water after heat exchange recirculates), and the hot water flows out to the hot water circulation channel 82 (that is, in the direction of the hot water pump 87). And an outlet 92 through which hot water flows out. The hot water tank 90 includes a heat plate 93 as a “heating unit” for heating the hot water (water) inside the hot water, and an inlet 91 and a heat plate 93 inside the hot water tank 90. A partition plate 94 is provided that is separated into one region and a second region including the outflow port 92.

As shown in FIG. 3, the hot water tank 90 is a rectangular parallelepiped storage tank that can store hot water (water) inside, and as a preferred example, the hot water tank 90 is configured using a SUS (Stainless Used Steel) material. .
Hereinafter, in order to make the explanation easy to understand, as shown in FIG. 3, four side surfaces among the six surfaces constituting the rectangular parallelepiped shape are side surfaces A to D, and the respective side surfaces are viewed from above the hot water tank 90. However, it is assumed that the side surface A, the side surface B, the side surface C, the side surface D, and the side surface A are successively connected clockwise. In addition, the bottom surface of the hot water tank 90 is hereinafter simply referred to as a bottom surface.

The inflow port 91 is a communication port that communicates the hot water circulation channel 82 formed in a region close to the bottom surface of the side surface A and the side surface B with the hot water tank 90.
The outflow port 92 is a communication port that connects the hot water circulation channel 82 formed in the region near the bottom surface of the side surface D and the side surface A and the hot water tank 90.
The warm water flows into the warm water tank 90 from the warm water circulation channel 82 through the inlet 91 and flows out to the warm water circulation channel 82 through the outlet 92 by the action of the warm water pump 87.

The partition plate 94 is a rectangular plate in which a notch 94 a is formed at one corner, and its three sides are in contact with the bottom surface, the side surface A, and the side surface D of the hot water tank 90. The remaining one side has a gap with the top.
A triangular prism-shaped region surrounded by the partition plate 94 and the bottom surface, the side surface A, and the side surface D constitutes a second region that communicates with the hot water circulation channel 82 through the outlet 92. The second region does not include the inflow port 91.
The notch 94a is formed as a rectangular notch at a corner where a side where the partition plate 94 and the side surface D contact and a side having a gap between the top and the top intersects.
Although the partition plate 94 is configured using a SUS material as a preferred example, it is not limited to this.

Of the internal region of the hot water tank 90, the region other than the second region constitutes a first region including the inlet 91 and the heat plate 93. The volume of the first region is larger than the volume of the second region, and the heat plate 93 is disposed at the bottom of the first region having a large volume.
Further, the height of the partition plate 94 is sufficiently high so that the notch 94 a is disposed at a position higher than the inlet 91, the outlet 92, and the heat plate 93 in the vertical direction. That is, the notch 94a constitutes a communication hole that connects the first region and the second region at a position higher than the inlet 91 and the heat plate 93 in the vertical direction.

  The heat plate 93 is a heater in which a heating wire such as a nichrome wire is enclosed, and the temperature of the hot water detected by a temperature sensor (not shown) disposed in the hot water circulation channel 82 near the outlet 92. Based on the above, the controller 60 controls the heating temperature.

  The hot water tank 90 having such a configuration is filled with water having a water level exceeding the height of the partition plate 94, heated by the heat plate 93 so as to become hot water of a predetermined temperature, and this hot water is circulated by the hot water pump 87. Circulate through the channel 82.

In the first region, the movement of the water (warm water) in the warm water tank 90 is such that the positive pressure of the water (warm water) flowing in from the inlet 91, the convection of the water (warm water) heated by the heat plate 93, the partition 94 Due to the negative pressure of the water (warm water) flowing out from the notch 94a (and the portion exceeding the height of the partition plate 94) to the outlet 92, convection is generated as shown in FIG.
Further, the movement of the water (warm water) in the warm water tank 90 is caused by the positive pressure of the water (warm water) flowing from the notch 94a (and the portion exceeding the height of the partition plate 94) of the partition plate 94 in the second region. As a result of the negative pressure of the water (warm water) flowing out from the outlet 92 by the hot water pump 87, a convection spiraling as shown in FIG.

Thus, in order to maintain the temperature of the ink at a predetermined temperature, the temperature of the hot water for heat exchange is maintained at the predetermined temperature. For example, when the temperature of the ink decreases due to a change in the environment in which the printer 100 is used. Depending on the degree, the ink temperature may not be maintained (that is, the temperature falls below a predetermined temperature range) if the flow rate of the hot water supplied from the hot water tank 90 remains constant. Conversely, if the temperature of the ink is excessively high, it takes time for the temperature of the hot water to drop even if the heat plate 93 is turned off, and the ink may exceed a predetermined temperature.
Therefore, in this embodiment, a method of controlling the heat exchange efficiency of the heat exchange unit 83 by controlling the flow rate of hot water is taken. Since the flow rate control of the hot water can change the heat exchange efficiency relatively quickly, the ink temperature can be changed earlier than the control of the heat plate 93.

However, as described above, since the temperature of the hot water from the hot water tank 90 is stabilized by sufficient agitation by convection inside the hot water tank 90, the change in the flow rate affects the degree of stability. There is. For example, when the ink temperature is about to exceed a predetermined temperature due to some factor, control is performed to reduce the flow rate in order to reduce the heat exchange efficiency between the hot water and the ink in the heat exchange unit 83. As a result, the stirring in the hot water tank 90 may be insufficient.
Therefore, in the present embodiment, the hot water circulation passage 82 is added to the hot water circulation passage 82 so that the stirring in the hot water tank 90 can be maintained.

Returning to FIG. 2, the flow rate adjusting unit 88 and the warm water reflux path 89 that characterize the present embodiment will be specifically described.
The flow rate adjusting unit 88 is a part that adjusts the flow rate of the hot water flowing to the heat exchanging unit 83, and is configured by the hot water pump 87, the three-way valve 99, the controller 60, and the like in this embodiment. That is, the flow rate of the warm water flowing to the heat exchange unit 83 is controlled by the controller 60 by controlling the output of the warm water pump 87 and the opening / closing amount of the three-way valve 99. The controller 60 controls the output of the hot water pump 87 and the opening / closing amount of the three-way valve 99 based on the temperature of the ink.

The head unit 70 includes a temperature sensor (not shown) as a “detection unit” that detects the temperature of the ink. Specifically, a temperature sensor is provided in each of the head units 70a to 70e. The controller 60 adjusts the flow rate of the hot water flowing to the heat exchanging unit 83 based on the ink temperature detected by the temperature sensor.
Note that the temperature of the ink to be detected does not have to be the actual temperature of the ink, and may be, for example, the temperature at a predetermined position of the head unit 70 as an alternative characteristic of the ink temperature.

  In this embodiment, the temperature of the ink is controlled by heat exchange between the hot water supplied by one hot water tank 90 and one flow rate adjusting unit 88 and the ink. That is, it is not the structure which controls the temperature of each ink separately. Therefore, the average temperature of the temperature sensor provided in each of the head units 70a to 70e is used as the temperature of the ink for adjusting the flow rate of the hot water. The controller 60 acquires the detection value of the temperature sensor provided in each of the head units 70a to 70e, calculates an average value when each temperature is within a normal predetermined temperature range, and based on the result, The flow rate of the hot water flowing to the exchange unit 83 is adjusted. By adjusting the flow rate of the hot water, the heat exchange efficiency of the heat exchange unit 83 can be changed, and the ink temperature can be controlled.

  The three-way valve 99 is provided between the hot water pump 87 and the heat exchange unit 83 in the hot water circulation passage 82, and warm water flowing from the hot water pump 87 into the inlet 99 a of the three-way valve 99 is supplied to the heat exchange unit 83. Are divided into an outlet 99b communicating with the outlet 99c and an outlet 99c communicating with the hot water reflux path 89. The outlet 99 c of the three-way valve 99 communicates with the inlet 91 of the hot water tank 90 through the hot water reflux path 89. That is, the hot water recirculation path 89 is a bypass flow path that can recirculate at least part of the hot water flowing out from the outlet 92 of the hot water tank 90 to the inlet 91 of the hot water tank 90. Therefore, it is configured as a flow path for returning the hot water divided by the three-way valve 99 from the outlet 99c of the three-way valve 99 to the inlet 91 of the hot water tank 90 without passing through the heat exchange unit 83.

  The ink circulation channel 81, the hot water circulation channel 82, and the hot water reflux channel 89 are each configured by a pipe. The material of these pipes is not particularly limited, but is preferably one that is hardly deteriorated by circulation of the liquid and that is covered with a heat insulating material that is not easily affected by the temperature of the surrounding environment.

FIG. 4 is an example of a control table for controlling the flow rate of hot water based on the detection result of the temperature sensor.
When the average temperature of the plurality of head units 70 is t ° C., and the center value of the predetermined temperature to be maintained by the ink is K ° C., the three-way valve 99 for every 1 ° C. in the range from K−3 ° C. to K + 2 ° C. It is set so that the open / close ratio of is changed. Moreover, in each temperature range for every 1 degreeC, it sets so that the output of the hot water pump 87 may change in the range of 10 to 20% according to temperature.

For example, when the temperature t is K-3 <t ≦ K−2 ° C., it is necessary to further heat the ink by heat exchange with hot water, so the flow rate to the heat exchange unit 83 is 80%, and the water is returned to the hot water tank 90. The open / close control of the three-way valve 99 is performed so that the flow rate to the warm water recirculation path 89 is 20%, and the output p of the warm water pump 87 is set to control in the range of 80 ≦ p <100%.
Further, for example, when the temperature t is K-1 <t ≦ K ° C., it is not necessary to warm the ink so much, so the flow rate to the heat exchanging unit 83 is 40%, and the hot water recirculation path 89 that recirculates to the hot water tank 90. The opening / closing control of the three-way valve 99 is performed so that the flow rate to the valve becomes 60%, and the output p of the hot water pump 87 is set to control in the range of 60> p ≧ 40%.
Further, for example, when the temperature t is K + 1 <t ≦ K + 2 ° C., the ink must not be warmed. Therefore, the flow rate to the heat exchange unit 83 is 0%, and the flow rate to the hot water return path 89 that returns to the hot water tank 90. Is controlled to open and close the three-way valve 99 so that the output p of the hot water pump 87 is controlled in the range of 20> p ≧ 10%. Even in this case, that is, even when the hot water is not circulated to the heat exchanging unit 83, the output p of the hot water pump 87 is set to 100 in the range of 20> p ≧ 10% via the hot water return path 89 to the hot water tank 90. % Reflux.

As described above, according to the liquid ejection apparatus according to the present embodiment, the following effects can be obtained.
Since a hot water return path 89 is provided that can return at least a part of the hot water flowing out from the outlet 92 of the hot water tank 90 to the inlet 91 of the hot water tank 90, the flow rate of the hot water flowing to the heat exchange unit 83 is reduced. Even if it is changed, the flow rate inside the hot water tank 90 can be maintained within a predetermined range. As a result, it is possible to suppress the temperature of the hot water circulated from the hot water tank 90 to the heat exchange unit 83 from becoming unstable.

  Further, since the flow rate of the hot water flowing to the heat exchange unit 83 is adjusted based on the temperature of the head unit 70 or the temperature of the ink detected by the temperature sensor, the temperature of the head unit 70 or the temperature of the ink can be controlled. .

  Further, the temperature of the ink can be controlled by controlling the hot water pump 87.

  Further, the temperature of the ink can be controlled by controlling the three-way valve 99 provided in the hot water circulation passage 82.

(Embodiment 2)
Next, a liquid ejection apparatus according to the second embodiment will be described. In the description, the same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.
FIG. 5 is a schematic diagram illustrating a configuration of an ink supply unit 80a included in the liquid ejection apparatus (printer 100) according to the second embodiment.
The ink supply unit 80 a includes an ink circulation channel 81, a hot water circulation channel 82 a as a “second circulation channel”, a heat exchange unit 83, a hot water tank 90, a flow rate adjustment unit 88 a, and hot water reflux as a “reflux channel”. A path 89a is formed.

  In the first embodiment, as illustrated in FIG. 2, the flow rate adjusting unit 88 is described as being configured by the hot water pump 87, the three-way valve 99, the controller 60, and the like, but is not limited thereto. Like the flow rate adjustment unit 88a of the present embodiment, it may be configured by a hot water pump 87a as a “first pump”, a hot water pump 87b as a “second pump”, a controller 60, and the like. That is, instead of the three-way valve 99, two pumps (a hot water pump 87a and a hot water pump 87b) may be used to divert to the heat exchange unit 83 and the inlet 91 of the hot water tank 90.

  The warm water pump 87a and the warm water pump 87b are provided on the downstream side of the warm water tank 90 in the warm water circulation passage 82a. The hot water pump 87a sends hot water to the heat exchanging unit 83 (83a to 83e), and the hot water pump 87b sends hot water to the hot water tank 90 (inlet 91). That is, the warm water reflux path 89a includes the warm water pump 87b.

The controller 60 calculates the average value from the detection values of the temperature sensors provided in each of the head units 70a to 70e, and controls the outputs of the hot water pump 87a and the hot water pump 87b based on the result, and the heat exchange unit 83 and the flow rate of the hot water flowing to the hot water tank 90 is adjusted.
In order to control the temperature of the ink, for example, even when the flow rate of hot water flowing through the heat exchanging unit 83 is decreased, the flow rate of hot water flowing through the hot water return path 89a by the hot water pump 87b is maintained inside the hot water tank 90. A predetermined amount that ensures sufficient agitation by convection is ensured.
As described above, also in the liquid ejection device according to the present embodiment, the same effect as in the case of the first embodiment can be obtained.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be added to the above-described embodiment. A modification will be described below. Here, the same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.

(Modification 1)
Although Embodiment 1 and Embodiment 2 demonstrated using warm water (water) as a "2nd liquid", it is not limited to this. For example, the main component of the “second liquid” may be a liquid composed of the main solvent of the ink.
Specifically, for example, in the case of a non-aqueous ink in which the main solvent of the ink is an organic solvent, the same organic solvent is used as the “second liquid”.
Specific examples of the organic solvent include γ-lactones such as γ-butyrolactone, γ-valerolactone, γ-caprolactone, γ-caprolactone and γ-laurolactone, and δ- such as δ-valerolactone. Examples include lactones and lactones such as ε-lactones such as ε-caprolactone. Moreover, for example, polyhydric alcohols such as ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, glycerin, and polyglycerin, and lower alcohols such as methanol, ethanol, normal propanol, and isopropanol can be used. Moreover, for example, esters such as ethyl acetate, propyl acetate, butyl acetate, and methyl 2-methoxypropionate, and ketones such as methyl isobutyl ketone and cyclohexanone are included. Also, for example, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, etc. And monohydric alcohol derivatives.

  As in the present modification, as the “second liquid”, a liquid whose main component is composed of the main solvent of the ink is used, so that the heat exchange unit 83 is close to the ink in order to perform heat exchange. Even when the “second liquid” is mixed into the ink, a chemical change (for example, generation of foreign matter) that damages the ink circulation channel 81 is less likely to occur.

  DESCRIPTION OF SYMBOLS 10 ... Print medium, 20 ... Conveyance unit, 21 ... Supply roller, 22 ... Conveyance motor, 23 ... Conveyance roller, 25 ... Discharge roller, 26 ... Rotating drum, 50 ... Supply part, 51 ... Winding part, 60 ... Controller, DESCRIPTION OF SYMBOLS 70 ... Head unit, 71 ... Inkjet head, 80 ... Ink supply part, 81 ... Ink circulation channel, 82 ... Hot water circulation channel, 83 ... Heat exchange part, 85 ... Ink tank, 86 ... Ink pump, 87 ... Hot water pump DESCRIPTION OF SYMBOLS 88 ... Flow control part 89 ... Warm water return path, 90 ... Warm water tank, 91 ... Inlet, 92 ... Outlet, 93 ... Heat plate, 94 ... Partition plate, 99 ... Three-way valve, 100 ... Printer.

Claims (7)

A discharge section for discharging the first liquid;
A first circulation channel for circulating the first liquid and supplying the first liquid to the discharge unit;
A second circulation flow path for circulating the second liquid;
In the second circulation channel, the second liquid is accommodated, the inlet into which the second liquid flows from the second circulation channel, and the second liquid flows into the second circulation channel. An outlet having an outlet,
A heating unit for heating the second liquid inside the housing unit;
A heat exchanging section for exchanging heat between the first circulation channel and the second circulation channel;
A flow rate adjusting unit for adjusting the flow rate of the second liquid flowing to the heat exchange unit;
A liquid ejection device comprising: a reflux channel capable of refluxing at least part of the second liquid flowing out from the outlet to the inlet. A detection unit for detecting the temperature of the discharge unit or the temperature of the first liquid;
2. The liquid ejection according to claim 1, wherein the flow rate adjusting unit adjusts a ratio of a flow rate flowing to the heat exchange unit and a flow rate flowing to the reflux flow path based on a temperature detected by the detection unit. apparatus.   3. The liquid according to claim 1, wherein the flow rate adjustment unit includes a first pump that sends the second liquid and a control unit that controls the first pump. 4. Discharge device.   The said flow volume adjustment part is comprised including the control part which controls the valve provided in the said 2nd circulation flow path, and the said valve, It is any one of Claims 1-3 characterized by the above-mentioned. Liquid discharge device.   5. The reflux channel according to claim 1, wherein the reflux channel includes a second pump for feeding the second liquid flowing through the reflux channel. 6. Liquid ejection device. A second ejection part for ejecting a third liquid;
A third circulation flow path for circulating the third liquid and supplying the third liquid to the discharge unit;
6. A second heat exchanging unit that exchanges heat between the third circulation channel and the second circulation channel, 6. Liquid discharge device.   The liquid ejecting apparatus according to claim 1, wherein a main component of the second liquid is a main solvent of the first liquid.

Images