LIQUID JET HEAD, LIQUID JET RECORDING DEVICE, AND METHOD OF ASSEMBLING LIQUID JET HEAD

Information

  • Patent Application
  • 20240100829
  • Publication Number
    20240100829
  • Date Filed
    September 20, 2023
    8 months ago
  • Date Published
    March 28, 2024
    2 months ago
Abstract
A flow rate distribution of flow paths is controlled. An inkjet head jets ink. The inkjet head is provided with a head main body having a jet flow path through which the ink passes, a cooling pipe having a cooling flow path through which the ink passes as a cooling medium for cooling a drive circuit, and a throttle member for controlling a flow path resistance of the cooling flow path.
Description
RELATED APPLICATIONS

This application claims priority to Japanese Patent application No. JP2022-153668, filed on Sep. 27, 2022, the entire content of which is incorporated herein by reference.


BACKGROUND OF THE INVENTION
1. Field of the Invention

The present disclosure relates to a liquid jet head, a liquid jet recording device, and a method of assembling a liquid jet head.


2. Description of the Related Art

In JP2015-171806A (Document 1), there is disclosed a liquid jet head provided with a head unit having a supply flow path for circulating a liquid supplied from an outside, and a cooling section including a cooling flow path. In Document 1, a part of the liquid supplied from the outside is circulated through the supply flow path of the head unit, and another part of the liquid is circulated through the cooling flow path of the cooler.


In JP2019-84704A (Document 2), there is disclosed a liquid jet head provided with a liquid jet head chip for jetting a liquid, and a cooling section including a cooling medium flow path through which a cooling medium passes. In Document 2, there is a mode in which ink is used not only as a raw material for printing but also as the cooling medium for cooling the control circuit and so on.


For example, depending on the design specification and so on, a wide variety of types of ink different in viscosity and thermal conductivity are used in some cases using systems the same in specification, or using heads the same in specification. Depending on differences in ink type (viscosity or thermal conductivity), ejection condition, and so on, an optimum distribution of amounts of the ink to be made to flow through the respective flow paths varies. However, when the flow path resistance is constant in the flow paths, it is difficult to control the flow rate distribution of the flow paths.


The present disclosure is made in view of the problem described above, and has an object of controlling the flow rate distribution of the flow paths.


SUMMARY OF THE INVENTION

(1) A liquid jet head according to an aspect of the present disclosure is a liquid jet head configure to jet liquid, and including a jet unit having a jet flow path configured to jet the liquid, a cooling pipe having a cooling flow path through which the liquid passes as a cooling medium configured to cool a heat source, and a throttle member configured to control a flow path resistance of at least one of the jet flow path and the cooling flow path.


According to the liquid jet head related to the present aspect, by providing the throttle member for controlling the flow path resistance of at least one of the jet flow path and the cooling flow path, it is possible to make the flow path resistance different between the flow paths, namely the jet flow path and the cooling flow path. Therefore, it is possible to control the flow rate distribution of the flow paths.


(2) In the liquid jet head according to the aspect (1), the throttle member can be made replaceable with another throttle member different in flow path resistance from the throttle member.


According to this configuration, by replacing the throttle member, it is possible to control the flow rate distribution of the flow paths in accordance with the design specification and so on.


(3) In the liquid jet head according to the aspect (2), the throttle member can include a cylindrical part extending along the cooling flow path, and a flared part flared from the cylindrical part to an outside of an end portion of the cooling pipe.


According to this configuration, by supporting the flared part, it is possible to perform the attachment and the detachment of the throttle member.


(4) In the liquid jet head according to the aspect (3), the flared part can include an elastically deforming part which extends from the flared part along an outer circumferential surface of the cooling pipe, and which is elastically deformable.


According to this configuration, it is possible to support the throttle member on the outer circumferential surface of the cooling pipe with the elastically deforming part. Therefore, the attachment and the detachment of the throttle member can more efficiently be performed.


(5) In the liquid jet head according to the aspect (4), the throttle member can include a ring-like groove in which an end portion of the cooling pipe is inserted, and a radial groove radially extending from the ring-like groove so as to zone the elastically deforming part in a circumferential direction of the cylindrical part.


According to this configuration, it is possible to absorb the elastic deformation of the elastically deforming parts in the radial groove. Therefore, the attachment and the detachment of the throttle member can more efficiently be performed.


(6) In the liquid jet head according to any one of the aspects (1) to (5), the throttle member can include a throttle entrance in which the liquid inflows, and a throttle exit from which the liquid outflows, and an aperture area of the throttle exit can be smaller than an aperture area of the throttle entrance.


According to this configuration, since a flow velocity of the liquid becomes higher in the throttle exit than in the throttle entrance, it is possible to prevent the bubbles from being retained in the flow path.


(7) In the liquid jet head according to any one of the aspects (1) to (6), there can further be included a flow path member provided with a jet-side branch path branching from a liquid flow path in which the liquid inflows from an outside of the liquid jet head, or from which the liquid outflows, to be communicated with the jet flow path, and a cooling-side branch path branching from the liquid flow path to be communicated with the cooling flow path, wherein the flow path member can have a housing recess configured to house at least a part of the throttle member.


According to this configuration, it is possible to enhance sealability (airtightness and liquid-tightness) of the portion housed in the housing recess in the throttle member.


(8) In the liquid jet head according to any one of the aspects (1) to (7), there can further be included a cooling member which has a heat source arrangement surface on which the heat source is arranged, and in which at least a part of the cooling pipe is embedded, wherein the throttle member can be disposed in a portion other than a portion overlapping the heat source arrangement surface in the cooling pipe.


According to this configuration, it is possible to make the heat difficult to be transferred from the heat source to the throttle member compared to when the throttle member is disposed in a portion overlapping the heat source arrangement surface in the cooling pipe. Therefore, it is possible to prevent the throttle member from being deformed or deteriorated by the heat from the heat source.


(9) A liquid jet recording device according to an aspect of the present disclosure includes the liquid jet head according to any one of the aspects (1) to (8), and a carriage to which the liquid jet head is attached.


According to the liquid jet recording device related to the present aspect, it is possible to obtain the liquid jet recording device capable of controlling the flow rate distribution of the flow paths.


(10) A method of assembling a liquid jet head according to an aspect of the present disclosure is a method of assembling a liquid jet head configured to jet liquid, and including a jet unit having a jet flow path through which the liquid passes, a cooling pipe having a cooling flow path through which the liquid passes as a cooling medium configured to cool a heat source, and a throttle member configured to control a flow path resistance of at least one of the jet flow path and the cooling flow path, the method including a throttle member installation step of installing the throttle member to the cooling pipe, wherein in the throttle member installation step, one having a predetermined flow path resistance is selected from a plurality of throttle members having respective flow path resistances different from each other, and is installed.


According to the method of assembling the liquid jet head related to the present aspect, in the throttle member installation step, by selecting one having the predetermined flow path resistance from the plurality of throttle members having the respective flow path resistances different from each other, and then installing the throttle member thus selected, it is possible to make the flow path resistance different between the flow paths, namely the jet flow path and the cooling flow path. Therefore, it is possible to control the flow rate distribution of the flow paths.





BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 is a schematic configuration diagram of a printer according to an embodiment.



FIG. 2 is a schematic configuration diagram of an inkjet head and an ink circulation mechanism according to the embodiment.



FIG. 3 is a front view of the inkjet head according to the embodiment.



FIG. 4 is a cross-sectional view for explaining a flow of ink related to the embodiment.



FIG. 5 is a perspective cross-sectional view along an arrow V-V shown in FIG. 3.



FIG. 6 is a perspective view of a cooling unit related to the embodiment.



FIG. 7 is an explanatory diagram showing an installation place of a throttle member related to the embodiment.



FIG. 8 is a perspective view of the throttle member related to the embodiment.



FIG. 9 is a cross-sectional view for explaining an arrangement structure of the throttle member related to the embodiment.



FIG. 10 is a graph showing a relationship between differential pressure and a flow rate corresponding to a throttle dimension when using the ink having the viscosity of 5 cp.



FIG. 11 is a graph showing a relationship between differential pressure and a flow rate corresponding to a throttle dimension when using the ink having the viscosity of 10 cp.



FIG. 12 is a cross-sectional view for explaining a first modified example of the throttle member related to the embodiment.



FIG. 13 is a cross-sectional view for explaining a second modified example of the throttle member related to the embodiment.





DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment according to the present disclosure will hereinafter be described with reference to the drawings.


In the embodiment and modified examples described hereinafter, constituents corresponding to each other are denoted by the same reference symbols, and the description thereof will be omitted in some cases. Further, in the following description, expressions representing relative or absolute arrangement such as “parallel,” “perpendicular,” “center,” and “coaxial” not only represent strictly such arrangements, but also represent the state of being relatively displaced with a tolerance, or an angle or a distance to the extent that the same function can be obtained.


[Printer 1]


FIG. 1 is a schematic configuration diagram of a printer 1 according to the embodiment.


As shown in FIG. 1, the printer 1 (a liquid jet recording device) according to the present embodiment is provided with a pair of conveying mechanisms 2, 3, ink tanks 4, inkjet heads 5 (liquid jet heads), ink circulation mechanisms 6, and a scanning mechanism 7.


In the following explanation, the description is presented using an orthogonal coordinate system of X, Y, and Z as needed. An X direction is a conveying direction (a sub-scanning direction) of a recording target medium P (e.g., paper). A Y direction is a scanning direction (a main-scanning direction) of the scanning mechanism 7. A Z direction is a height direction (a gravitational direction) perpendicular to the X direction and the Y direction.


Further, in the following explanation, the description will be presented defining an arrow side as a positive (+) side, and an opposite side to the arrow as a negative (−) side in the drawings in each of the X direction, the Y direction, and the Z direction. In the present embodiment, the +Z side corresponds to an upper side in the gravitational direction, and the −Z side corresponds to a lower side in the gravitational direction.


The conveying mechanisms 2, 3 convey the recording target medium P toward the +X side. The conveying mechanisms 2, 3 each include a pair of rollers 11, 12 extending in, for example, the Y direction. There is disposed a plurality of ink tanks 4 which respectively contain ink of four colors such as yellow, magenta, cyan, and black.


There is disposed a plurality of inkjet heads 5 which are configured so as to be able to respectively eject the four colors of ink, namely the yellow ink, the magenta ink, the cyan ink, and the black ink in accordance with the ink tanks 4 coupled thereto.



FIG. 2 is a schematic configuration diagram of the inkjet head 5 and the ink circulation mechanism 6 related to the embodiment.


As shown in FIG. 1 and FIG. 2, the ink circulation mechanism 6 circulates the ink between the ink tank 4 and the inkjet head 5. Specifically, the ink circulation mechanism 6 is provided with a circulation flow path 23 having an ink supply tube 21 and an ink discharge tube 22, a pressure pump 24 coupled to the ink supply tube 21, and a suction pump 25 coupled to the ink discharge tube 22.


The pressure pump 24 pressurizes an inside of the ink supply tube 21 to deliver the ink to the inkjet head 5 through the ink supply tube 21. Thus, the ink supply tube 21 is provided with positive pressure with respect to the inkjet head 5.


The suction pump 25 depressurizes the inside of the ink discharge tube 22 to suction the ink from the inkjet head 5 through the ink discharge tube 22. Thus, the ink discharge tube 22 is provided with negative pressure with respect to the inkjet head 5. The ink circulates between the inkjet head 5 and the ink tank 4 through the circulation flow path 23 due to drive of the pressure pump 24 and the suction pump 25.


As shown in FIG. 1, the scanning mechanism 7 reciprocates the inkjet heads 5 in the Y direction. The scanning mechanism 7 is provided with a guide rail 28 extending in the Y direction, a carriage 29 movably supported by the guide rail 28, and a drive device for moving the carriage 29. The drive device is constituted by, for example, a motor, a pulley, and a belt.


<Inkjet Heads 5>

The inkjet heads 5 are mounted on the carriage 29. The inkjet heads 5 according to the present embodiment are each an inkjet head of an electromechanical transduction system in which ink is ejected from a head chip including an actuator plate formed of a piezoelectric element made of PZT (lead zirconate titanate) or the like.


In this inkjet head 5, in order to eject the ink, a voltage is applied between electrodes on drive walls of an ejection path provided to the actuator plate to cause the drive wall to make a thickness-shear deformation. Thus, due to a change in volume of the ejection path, the ink in the ejection path is ejected through a nozzle hole. It should be noted that an ejection system of the liquid is not limited to the electromechanical transduction system described above, and it is possible to adopt a charge control system, a pressure vibration system, an electrothermal transduction system, an electrostatic suction system, and so on.


The charge control system is for providing a charge to a material with a charge electrode to eject the material from a nozzle while controlling a flight direction of the material with a deflection electrode. Further, the pressure vibration system is for applying super high pressure to a material to eject the material toward a nozzle tip, and when a control voltage is not applied, the material goes straight to be ejected from the nozzle, and when the control voltage is applied, an electrostatic repelling force is generated between the materials, and the material flies in all directions to be prevented from being ejected from the nozzle.


Further, the electrothermal transduction system is for rapidly vaporizing a material with a heater provided in a space retaining the material to generate a bubble, to eject the material located in the space with the pressure of the bubble. The electrostatic suction system is for applying minute pressure to a space retaining a material to form a meniscus of the material in the nozzle, applying an electrostatic attractive force in this state, and then pulling the material out. Further, besides the above, it is possible to adopt technologies such as a system using a viscosity alteration of a fluid due to an electric field, or a system of flying a material with a discharge spark.



FIG. 3 is a front view of the inkjet head 5 according to the embodiment. FIG. 4 is a cross-sectional view for explaining a flow of the ink related to the embodiment. FIG. 5 is a perspective cross-sectional view along an arrow V-V shown in FIG. 3. FIG. 6 is a perspective view of a cooling unit 40 related to the embodiment.


As shown in these drawings, the inkjet heads 5 each jet the ink (liquid). The inkjet heads 5 are each provided with a head main body 30 (a jet unit), a cooling pipe 41, a cooling member 50, throttle members 100, flow path members 80, 90, wherein the head main body 30 has a jet flow path 32 through which the ink passes, the cooling pipe 41 has a cooling flow path 42 through which the ink (a cooling medium) for cooling drive circuits 35 (heat sources) passes, at least a part of the cooling pipe 41 is embedded in the cooling member 50, the throttle members 100 each control a flow path resistance of the cooling flow path 42, the flow path members 80, 90 are provided with a jet-side branch path and a cooling-side branch path, the jet-side branch path branches from an ink flow path 20 (a liquid flow path) into which the ink inflows from the outside of the inkjet head 5, or from which the ink outflows to the outside of the inkjet head 5, the jet-side branch path is communicated with the jet flow path 32, and the cooling-side branch path branches from the ink flow path 20, and is communicated with the cooling flow path 42.


[Head Main Body 30]

The head main body 30 has a rectangular box-like shape. On a lower surface of the head main body 30, there is disposed a nozzle array not shown for jetting the ink. The head main body 30 is supported by a base member 31 to be installed in the carriage 29. The base member 31 is formed so as to be longer in the X direction than the head main body 30. On a lower surface of the base member 31, there is formed an elongated hole not shown for exposing the nozzle array of the head main body 30.


[Drive Circuits 35]

The drive circuits 35 are each a driver IC for controlling, for example, an operation of the head main body 30 and an operation of the circulation mechanism. The drive circuits 35 have thermal contact with the cooling member 50. In the example shown in the drawings, the drive circuits 35 have indirect contact with the cooling member 50 via an insulating member 36. The insulating member 36 is a sheet-like member formed of an insulating material such as silicon. It should be noted that the heat sources are not limited to the drive circuits 35 such as driver ICs. The heat sources are only required to be what generates heat when performing driving, and can be other electronic components.


[Board Unit 60]

The inkjet head 5 is provided with a board unit 60 on which the drive circuits 35 are mounted. The board unit 60 is provided with a board main body 61 on which a plurality of electric circuits are mounted, and a flexible board 62 for electrically coupling the board main body 61 and drive electrodes (electrodes on the drive walls) of the actuator plate described above.


The board main body 61 is, for example, a rigid board. The board main body 61 is coupled to the cooling member 50 and so on via a coupling member not shown. In an upper part of the board main body 61, there are disposed connectors 65. The board main body 61 is electrically coupled to a main controller, a power supply, and so on located outside via the connectors 65.


It should be noted that the board main body 61 can be a flexible board. In this case, it is possible to extend a part of the board main body 61 to the outside of the inkjet head 5 to directly be coupled to the printer 1 without providing the connectors 65 to the board main body 61.


The flexible board 62 extends obliquely downward so as to get away in the Y direction from the board main body 61. The part extending obliquely downward in the flexible board 62 is coupled to the drive electrodes of the actuator plate described above.


On the flexible board 62, there are mounted a plurality of the drive circuits 35 in a straight line at intervals in the X direction. The drive circuits 35 are each the driver IC, and are high in amount of heat generation. Therefore, there are disposed support members 70 for receiving heat from the drive circuits 35. In FIG. 3, the support members 70 are represented by dashed-two dotted lines.


[Support Members 70]

The support members 70 are formed of a material excellent in thermal conductivity and radiation performance such as aluminum. The support members 70 are disposed as a pair of members in the Y direction via the cooling member 50 and so on. The support members 70 are each provided with a main body portion 71 extending in the X direction, end side fixation portions 72 disposed in both end portions in the X direction of the main body portion 71, and a lower middle fixation portion 73 disposed at a lower side of a central portion in the X direction of the main body portion 71.


The main body portion 71 is formed to have a plate-like shape. The main body portion 71 is opposed to the drive circuits 35 in the Y direction via the flexible board 62. The main body portion 71 has thermal contact with the drive circuits 35.


The end side fixation portions 72 extend toward both sides in the Z direction from the both end portions of the main body portion 71. The pair of support members 70 are screwed in the respective end side fixation portions 72 via through holes 57 of the cooling member 50.


The lower middle fixation portion 73 extends toward the −Z side from a lower side of the central portion in the X direction of the main body portion 71. The pair of support members 70 are screwed in the respective lower middle fixation portions 73 via a lower middle recessed part 58 of the cooling member 50.


[Flow Path Members 80, 90]

The inkjet head 5 is provided with the entrance-side flow path member 80 and the exit-side flow path member 90. The flow path members 80, 90 are each formed of a resin material such as polyethylene, polycarbonate, polypropylene, polyethylene terephthalate, or polyphenylene sulfide. Each of the flow path members 80, 90 is formed to have an L shape.


The entrance-side flow path member 80 is disposed at one side (the +X side) in the X direction of the inkjet head 5. The entrance-side flow path member 80 is provided with an entrance port 81 to which the ink supply tube 21 described above is coupled. The entrance-side flow path member 80 is attached to one side (the +X side) in the X direction of the head main body 30 via a fastener member such as a bolt.


The entrance-side flow path member 80 has a first inflow branch path 82 (the jet-side branch path) and a second inflow branch path 83 (the cooling-side branch path) branching from an inflow path (the liquid flow path) into which the ink inflows from the entrance port 81. The first inflow branch path 82 is a path for guiding the ink from the inflow path of the entrance port 81 into the head main body 30 (the jet flow path 32). The second inflow branch path 83 is a path for guiding the ink from the inflow path of the entrance port 81 into the cooling pipe 41 (the cooling flow path 42).


The exit-side flow path member 90 is disposed at the other side (the −X side) in the X direction of the inkjet head 5. The exit-side flow path member 90 is provided with an exit port 91 to which the ink discharge tube 22 described above is coupled. The exit-side flow path member 90 is attached to the other side (the −X side) in the X direction of the head main body 30 via a fastener member such as a bolt.


The exit-side flow path member 90 has a first outflow branch path 92 (the jet-side branch path) and a second outflow branch path 93 (the cooling-side branch path) branching from an outflow path (the liquid flow path) from which the ink outflows to the exit port 91. The first outflow branch path 92 is a path for guiding the ink from the inside of the head main body 30 (the jet flow path 32) to the outflow path of the exit port 91. The second outflow branch path 93 is a path for guiding the ink from the inside of the cooling pipe 41 (the cooling flow path 42) to the outflow path of the exit port 91.


[Cooling Pipe 41]

The cooling pipe 41 has a corrosion resistance to the ink. Here, the corrosion resistance means a rate at which the corrosion progresses when dipped into the ink. The cooling pipe 41 is higher in corrosion resistance compared to the cooling member 50. Here, the fact that the corrosion resistance is high means that the corrosion with respect to the ink progresses slowly. The cooling pipe 41 is formed of, for example, stainless steel.


It should be noted that the cooling pipe 41 can be formed of copper alloy, titanium alloy, nickel alloy, chromium alloy, or the like. It is preferable for the cooling pipe 41 to be formed of a material higher in corrosion resistance to the ink compared to the cooling member 50. For example, it is possible to change the constituent material of the cooling pipe 41 in accordance with a design specification.


The cooling pipe 41 branches from a flow path (the liquid flow path) of the entrance port 81 through which the ink passes. The cooling pipe 41 has the cooling flow path 42 through which the ink passes as the cooling medium. The cooling flow path 42 communicates with the second inflow branch path 83 of the entrance-side flow path member 80, and the second outflow branch path 93 of the exit-side flow path member 90.


For example, when activating the pressure pump 24 and the suction pump 25, the ink located in the ink tank 4 is transmitted to the head main body 30 and the cooling pipe 41 passing through the entrance port 81, the first inflow branch path 82 and the second inflow branch path 83 of the entrance-side flow path member 80 in this order. Subsequently, the ink is returned to the inside of the ink tank 4 passing through the first outflow branch path 92 and the second outflow branch path 93 of the exit-side flow path member 90, and the exit port 91 in this order.


The cooling pipe 41 is formed by insert molding with respect to the cooling member 50. Here, the insert molding means inserting a material around a component set in a mold and molding the component and the material as a single component. The cooling pipe 41 in the present embodiment is molded as a single component with the material of the cooling member 50 being inserted around the cooling pipe 41 set in a mold. The component obtained by integrating the cooling pipe 41 and the cooling member 50 with each other is hereinafter referred to as the “cooling unit 40.”


The cooling pipe 41 has a straight-pipe shape. The cooling pipe 41 extends linearly along the X direction. The cooling pipe 41 has a cylindrical shape extending along the X direction.


End portions of the cooling pipe 41 are arranged outside an outer shape of the cooling member 50. One (a +X-side end portion) of the end portions of the cooling pipe 41 is arranged outside (at the +X side of) one side surface (the +X-side surface) of the cooling member 50. The other (a −X-side end portion) of the end portions of the cooling pipe 41 is arranged outside (at the −X side of) the other side surface (the −X-side surface) of the cooling member 50. A part (a part at a middle side in the X direction) other than the both end portions in the X direction in the cooling member 50 is embedded in the cooling member 50.


There is disposed the single cooling pipe 41 in the example shown in the drawings, but this is not a limitation. For example, there can be disposed a plurality of the cooling pipes 41. For example, it is possible to change the number of the cooling pipes 41 installed therein in accordance with the design specification.


The cross-sectional shape of the cooling pipe 41 (the shape of the cooling pipe 41 cut along the Y-Z plane) is the ring-like shape in the example shown in the drawings, but this is not a limitation. For example, the cross-sectional shape of the cooling pipe 41 can be a rectangular frame shape. For example, it is possible to change the cross-sectional shape of the cooling pipe 41 in accordance with the design specification.


[Cooling Member 50]

The cooling member 50 has higher thermal conductivity than that of the cooling pipe 41. The cooling member 50 is formed to have a rectangular solid shape having a longitudinal direction in the X direction. The cooling member 50 is formed of, for example, aluminum simple body or aluminum alloy.


It should be noted that the cooling member 50 can also be formed of zinc alloy. It is preferable for the cooling member 50 to be formed of a material having higher thermal conductivity compared to that of the cooling pipe 41. For example, it is possible to change the constituent material of the cooling member 50 in accordance with the design specification.


The cooling member 50 has a first surface 51 (a −Y-side surface) and a second surface 52 (a +Y-side surface) arranged at respective sides opposite to each other across the cooling pipe 41. The first surface 51 is a surface along the X-Z plane at the −Y side of the cooling pipe 41. The second surface 52 is a surface along the X-Z plane at the +Y side of the cooling pipe 41.


The cooling member 50 has recessed parts 53A, 53B in at least a part of a portion surrounding the cooling pipe 41. The recessed parts 53A, 53B open toward four directions crossing the central axis of the cooling pipe 41. The four directions are a direction at the +Z side and the −Y side, a direction at the −Z side and the −Y side, a direction at the +Z side and the +Y side, and a direction at the −Z side and the +Y side with respect to the central axis of the cooling pipe 41 when viewed from the X direction.


In the example shown in the drawings, there are shown the first upside recessed part 53A formed at an upper side (the +Z side) of the first surface 51 of the cooling member 50, and the first downside recessed part 53B formed at a lower side (the −Z side) of the first surface 51 of the cooling member 50 are shown out of the recessed parts 53A, 53B opening in the four directions. The illustration of a second upside recessed part formed at the upper side of the second surface 52 of the cooling member 50 and a second downside recessed part formed at the lower side of the second surface 52 of the cooling member 50 is omitted.


The cooling member 50 has heat source arrangement surfaces 56 on which the drive circuits 35 are respectively arranged. In the example shown in the drawings, the heat source arrangement surfaces 56 are represented by dashed-dotted lines. The heat source arrangement surfaces 56 are disposed in other portions than the recessed parts 53A, 53B in the cooling member 50.


In the example shown in the drawings, the recessed parts 53A, 53B are each formed to have a rectangular shape having round corners when viewed from the Y direction. In the example shown in the drawings, six pairs of recessed parts arranged side by side in the Z direction (the first upside recessed parts 53A and the first downside recessed parts 53B) are arranged at intervals in the X direction. In the X direction, the recessed parts 53A, 53B and the heat source arrangement surfaces 56 are alternately disposed. It should be noted that the shapes, the arrangement number, the arrangement places, and so on of the recessed parts 53A, 53B are not limited to the above, and can be changed in accordance with the design specification.


The heat source arrangement surfaces 56 are each a plane. The heat source arrangement surfaces 56 are disposed along the X-Z plane. The heat source arrangement surfaces 56 overlap the cooling pipe 41 when viewed from the Y direction. For example, it is preferable for the heat source arrangement surface 56 to have a larger outer shape than the outer shape of the drive circuit 35 when viewed from the Y direction. For example, when the drive circuit 35 has a rectangular shape when viewed from the Y direction, it is preferable for the heat source arrangement surface 56 to have a rectangular shape larger than the outer shape of the drive circuit 35. In the example shown in the drawings, the heat source arrangement surfaces 56 are arranged at five places at intervals in the X direction in a portion other than the pairs of recessed parts 53A, 53B each arranged side by side in the Z direction in the cooling member 50.


The heat source arrangement surfaces 56 are disposed in each of the first surface 51 and the second surface 52 of the cooling member 50. For example, the heat source arrangement surfaces 56 are arranged at five places (totally ten places in both of the first surface 51 and the second surface 52) at intervals in the X direction in other portion than the pairs of recessed parts 53A, 53B each arranged side by side in the Z direction on each of the first surface 51 and the second surface 52 of the cooling member 50. It should be noted that the shapes, the arrangement number, the arrangement places, and so on of the heat source arrangement surfaces 56 are not limited to the above, and can be changed in accordance with the design specification.


At an X-direction end portion side of the cooling member 50, there are formed the pair of through holes 57 which are arranged vertically, and which open in the Y direction. At a lower middle side in the X direction of the cooling member 50, there is formed the lower middle recessed part 58 recessed toward the +Z side from the lower surface of the cooling member 50. The through holes 57 and the lower middle recessed part 58 are portions through which the screws for fixing the pair of support members 70 pass. In the example shown in the drawings, the cooling member 50 is fixed to the pair of support members 70 via the screws at two places arranged vertically at each of the both ends in the X direction, and a single place at lower middle side in the X-direction, totally five places.


[Throttle Member 100]


FIG. 7 is an explanatory diagram showing an installation place of the throttle member 100 related to the embodiment. FIG. 8 is a perspective view of the throttle member 100 related to the embodiment. FIG. 9 is a cross-sectional view for explaining an arrangement structure of the throttle member 100 related to the embodiment.


First, a pump system (an ink system located outside the inkjet head 5) for supplying the inkjet head 5 with the ink will be described. The pump system corresponds to a system including the ink circulation mechanism 6 (see FIG. 2) described above.


In the pump system, supply pressure (pump pressure) from the pressure pump 24 is raised in some cases so that the necessary amount of ink flows through the head main body 30 (the jet flow path 32) and the cooling pipe 41 (the cooling flow path 42). A total flow rate Qin of the ink supplied by the pump system at specific supply pressure is determined by a pipe line resistance in the inkjet head 5.


In the following formula (1), Qa denotes a flow rate to the jet flow path 32 in the total flow rate Qin of the ink, Qb denotes a flow rate to the cooling flow path 42 in the total flow rate Qin of the ink, Ra denotes a flow path resistance of the jet flow path 32, and Rb denotes a flow path resistance of the cooling flow path 42, respectively.






Qa/Qb=Rb/Ra  (1)


As expressed in the formula (1), a ratio between the flow rate Qa to the jet flow path 32 and the flow rate Qb to the cooling flow path 42 in the total flow rate Qin of the ink becomes a reciprocal ratio between the flow path resistances Ra, Rb in the respective flow paths, namely the jet flow path 32 and the cooling flow path 42.


For example, depending on the design specification and so on, a wide variety of types of ink different in viscosity and thermal conductivity are used in some cases using systems the same in specification, or using heads the same in specification. Depending on a difference in an ink type (the viscosity and the thermal conductivity), a change in viscosity of the ink with the temperature, ejection conditions (an ejection amount and a drive frequency), and an amount of heat generated by the driver IC, the optimum distribution (proportion) of the amounts of the ink which is made to flow into the respective flow paths changes. However, when the flow path resistance is constant in the flow paths, it is difficult to control the flow rate distribution of the flow paths.


For example, when increasing the pump pressure so that minimum required amount of the ink flows through one of the jet flow path 32 and the cooling flow path 42, the pump system increases in cost. However, when increasing the pump pressure in order to flow the necessary amount through one of the flow paths, it results in that the flow rate in the other of the flow paths also rises in proportion.


In contrast, in the present embodiment, there is provided the throttle member 100 for controlling the flow path resistance in at least one of the jet flow path 32 and the cooling flow path 42. In the example shown in FIG. 7, the throttle member 100 is disposed at an entrance side of the cooling flow path 42. Thus, it is possible to change a ratio of the pipe line resistance in accordance with the type of the ink to be used, an ejection condition, and so on. Therefore, it is possible to minimize the flow rate at the ejection side (the flow rate to the jet flow path 32) and the driver IC cooling side (the flow rate to the cooling flow path 42) necessary for each of the inkjet heads 5.


The pipe line resistance increases in proportion to the length of the flow path, and at the same time, in inverse proportion to the diameter of the flow path. Therefore, it is preferable to prepare a plurality of types of throttle members 100 different in inner diameter or length from each other, and then select suitable one in accordance with the ink type, the ejection condition, and so on. For example, it is possible to select the throttle member 100 by measuring a total amount of the ink flowing through the inkjet head 5 and an amount of ejection.


In the example shown in FIG. 4, the throttle member 100 is disposed at each of an entrance side and an exit side of the cooling flow path 42. For example, the throttle member 100 disposed at the entrance side of the cooling flow path 42 has the same shape as the shape of the throttle member 100 disposed at the exit side of the cooling flow path 42. The description will hereinafter be presented citing the throttle member 100 disposed at the entrance side of the cooling flow path 42. The throttle member 100 disposed at the exit side of the cooling flow path 42 has substantially the same configuration as that of the throttle member 100 disposed at the entrance side of the cooling flow path 42 except the installation direction and so on, and therefore, the detailed description of the throttle member 100 disposed at the exit side of the cooling flow path 42 will be omitted.


The throttle member 100 is formed of a resin material such as polyethylene, polycarbonate, polypropylene, polyethylene terephthalate, or polyphenylene sulfide. For example, the throttle member 100 can be formed of the same material as that of the flow path members 80, 90.


The throttle member 100 is made to detachably be attached to the cooling pipe 41. The throttle member 100 is made to be able to be replaced with other throttle members different in flow path resistance from the throttle member 100 described above. As shown in FIG. 8 and FIG. 9, the throttle member 100 is provided with a cylindrical part 101 extending along the cooling flow path 42, and a flared part 102 flared outward to the outside of the end portion of the cooling pipe 41 from the cylindrical part 101.


The cylindrical part 101 has a straight-pipe shape smaller than the cooling pipe 41. The cylindrical part 101 extends linearly along the X direction. The cylindrical part 101 has a cylindrical shape extending along the X direction. The inner diameter of the cylindrical part 101 is smaller than the inner diameter of the cooling pipe 41. The outer diameter of the cylindrical part 101 has a size no larger than the inner diameter of the cooling pipe 41. For example, the outer diameter of the cylindrical part 101 can be substantially the same as the inner diameter of the cooling pipe 41. For example, when the throttle member 100 is attached to or detached from the cooling pipe 41, the outer circumferential surface of the cylindrical part 101 can have slidable contact with an inner circumferential surface of the cooling pipe 41.


The flared part 102 is provided with elastically deforming parts 103 which extend from the flared part 102 along the outer circumferential surface of the cooling pipe 41, and which is elastically deformable. The throttle member 100 has a ring-like groove 105 to which the end portion of the cooling pipe 41 is inserted, and radial grooves 106 radially extending from the ring-like groove 105 so as to zone the elastically deforming parts 103 in a circumferential direction of the cylindrical part 101. The ring-like groove 105 is formed to have a ring-like shape along the end portion of the cooling pipe. The radial grooves 106 are formed so as to extend from the ring-like groove 105 in four directions crossing the central axis of the cylindrical part 101.


The throttle member 100 has a throttle entrance 108 to which the ink (the liquid) inflows, and a throttle exit 109 from which the ink outflows. The aperture area of the throttle exit 109 is the same as the aperture area of the throttle entrance 108. The aperture area of the throttle member 100 has a uniform size throughout the whole length in the X direction.


In FIG. 9, a reference symbol d represents the inner diameter of the throttle member 100, and a reference symbol L represents the length of the throttle member 100. The inner diameter d of the throttle member 100 corresponds to the inner diameter of the cylindrical part 101. The length L of the throttle member 100 corresponds to the length of an area between the tip (the −X-side end) of the cylindrical part 101 and one end (the +X-side end) of the flared part 102.


The flow path member 80 has a housing recess 110 for housing at least a part of the throttle member 100. The housing recess 110 has a cylindrical shape extending along the X direction. The housing recess 110 houses the flared part 102 of the throttle member 100. The housing recess 110 opens toward the one side surface (the +X-side surface) of the cooling member 50. A gap 112 is disposed between a bottom surface 111 (a −X-side surface) of the housing recess 110 and the one side surface (the +X-side surface) of the flared part 102.


There can be disposed a spacer 120 and a sealing member 130 between the one side surface (the +X-side surface) of the cooling member 50 and the other side surface (the −X-side surface) of the flared part 102.


The spacer 120 is made to detachably be attached to the cooling pipe 41. The spacer 120 is formed to have a cylindrical shape extending along an outer circumferential surface of the cooling pipe 41. The spacer 120 is provided with a first intervening part 121 housed in the housing recess 110, and a second intervening part 122 arranged between the one side surface (the +X-side surface) of the cooling member 50 and the first intervening part 121.


An outer diameter of the first intervening part 121 is a size no larger than an inner diameter of the housing recess 110. For example, the outer diameter of the first intervening part 121 can be substantially the same as the inner diameter of the housing recess 110. For example, when the flow path member 80 is attached to or detached from the spacer 120, an outer circumferential surface of the first intervening part 121 can have slidable contact with an inner circumferential surface of the housing recess 110.


An outer diameter of the second intervening part 122 is larger than the inner diameter of the housing recess 110. The outer circumferential part of the second intervening part 122 is sandwiched between the one side surface (the +X-side surface) of the cooling member 50 and the one side surface (the −X-side surface) of the flow path member 80. The one side surface (the +X-side surface) of the second intervening part 122 has direct contact with the one side surface (the −X-side surface) of the flow path member 80. The other side surface (the −X-side surface) of the second intervening part 122 has direct contact with the one side surface (the +X-side surface) of the cooling member 50.


The sealing member 130 is, for example, an O-ring. The sealing member 130 is made to detachably be attached to the cooling pipe 41. For example, the sealing member 130 is formed of an elastic material. The sealing member 130 has a ring-like shape along the outer circumference of the cooling pipe 41. The sealing member 130 is disposed between the first intervening part 121 of the spacer 120 and the flared part 102 of the throttle member 100.


For example, the sealing member 130 has a circular cross-sectional surface uniform throughout the whole length in the circumferential direction of the sealing member 130 in a state (an initial state before an elastic deformation) in which the sealing member 130 is not installed in the inkjet head 5. In contrast, in a state (the state shown in FIG. 9) in which the sealing member 130 has been installed in the inkjet head 5, the sealing member 130 is elastically squeezed by members adjacent to each other. In the example shown in FIG. 9, a part of the sealing member 130 is squeezed by parts of the members (the outer circumferential surface of the cooling pipe 41, the flared part 102 of the throttle member 100, the inner circumferential surface of the housing recess 110, and the first intervening part 121 of the spacer 120) adjacent to each other.


The throttle member 100 is disposed in a portion other than the portion overlapping the heat source arrangement surface 56 in the cooling pipe 41. The throttle member 100 is disposed in a portion other than the portion overlapping the heat source arrangement surface 56 when viewed from the Y direction. The tip (the −X-side end) of the cylindrical part 101 in the throttle member 100 is arranged at the outer side (the +X direction side) of an outer end in the X direction (the +X-side end of the heat source arrangement surface 56 located at the extreme +X-direction side) of the heat source arrangement surface 56.


[Method of Manufacturing Inkjet Head 5]

A method of manufacturing the inkjet head 5 according to the present embodiment is a method of manufacturing the inkjet head 5 provided with the head main body 30 for jetting the ink, the cooling pipe 41 which has the corrosion resistance to the ink, and through which the ink for cooling the drive circuits 35 passes, and the cooling member 50 having higher thermal conductivity than that of the cooling pipe 41, wherein molding is performed in the state of supporting the cooling pipe 41 in the step of manufacturing the cooling member 50.


The method of manufacturing the inkjet head includes a head main body preparation step of preparing the head main body 30, a cooling unit manufacturing step (a step of manufacturing the cooling member 50) of manufacturing the cooling unit 40, and a unit coupling step of coupling the head main body 30 and the cooling unit 40 to each other.


In the head main body preparation step, there is prepared the head main body 30 including the actuator plate, the nozzle plate, and so on described above. After the head main body preparation step, there is made the transition to the cooling unit manufacturing step.


In the cooling unit manufacturing step, there are prepared a pair of metal molds (not shown) constituting the mold for manufacturing the cooling unit 40, and the cooling pipe 41 constituting the cooling unit 40. For example, the pair of metal molds are a first metal mold corresponding to a −Y-side portion of the cooling unit 40, and a second metal mold corresponding to a +Y-side portion of the cooling unit 40.


Then, one of the pair of metal molds is made to support the cooling pipe 41. Then, the pair of metal molds are combined with each other. For example, the matching surface of the first metal mold and the matching surface of the second metal mold are made to have contact with each other.


Then, molten aluminum (about 680° C.) is poured into the mold. For example, in the state in which the pair of metal molds are combined with each other, the molten metal described above is poured into an internal space (around the cooling pipe 41) through a hole not shown. In the cooling unit manufacturing step, the molding is performed in the state of supporting the cooling pipe 41. After the molding, the mold is separated. Thus, the cooling unit 40 having the cooling pipe 41 and the cooling member 50 integrated with each other is obtained. After the cooling unit manufacturing step, there is made the transition to the unit coupling step.


In the unit coupling step, the board unit 60, the support member 70, the flow path members 80, 90, and so on described above are coupled to the head main body 30 and the cooling unit 40 with coupling members, fastening members, or the like not shown. Due to the steps described hereinabove, the inkjet head 5 is obtained.


[Method of Assembling Inkjet Head 5]

A method of assembling the inkjet head 5 according to the present embodiment is a method of assembling the inkjet head for jetting the ink which is provided with the head main body 30 having the jet flow path 32 through which the ink passes, the cooling pipe 41 having the cooling flow path 42 through which the ink passes as the cooling medium for cooling the drive circuits 35, and the throttle member 100 for controlling the flow path resistance of the cooling flow path 42, and includes a throttle member installation step of installing the throttle member 100 to the cooling pipe 41, and in the throttle member installation step, one throttle member 100 having a predetermined throttle dimension (the flow path resistance) is selected from a plurality of the throttle members 100 having the respective throttle dimensions (the flow path resistances) different from each other, and is then installed.


For example, the throttle member installation step is performed between the cooling unit manufacturing step and the unit coupling step described above. For example, in the throttle member installation step, the throttle member 100 thus selected is installed in the portion (the portion arranged at the outer side of the outer shape of the cooling member 50) in which the cooling pipe 41 protrudes in the cooling unit 40.


In the throttle member installation step, the spacer 120 and the sealing member 130 described above are installed in the portion in which the cooling pipe 41 protrudes in the cooling unit 40, and then the throttle member 100 thus selected is installed. Thus, the throttle member 100 and so on are integrated with the cooling unit 40. In the unit coupling step, the flow path members 80, 90 described above and so on are coupled to the cooling unit 40 with which the throttle member 100 and so on are integrated. Due to the steps described hereinabove, it is possible to assemble the inkjet head 5.


[Relationship Between Differential Pressure and Flow Rate Corresponding to Throttle Dimension]


FIG. 10 is a graph showing a relationship between differential pressure and a flow rate corresponding to a throttle dimension when using the ink having the viscosity of 5 cp. FIG. 11 is a graph showing a relationship between differential pressure and a flow rate corresponding to a throttle dimension when using the ink having the viscosity of 10 cp. The throttle dimension corresponds to the inner diameter d (see FIG. 9) of the throttle member 100. In each of the drawings, differential pressure in the horizontal axis corresponds to an absolute value of a difference between applied pressure (positive pressure at the ink supply tube 21 side shown in FIG. 2) by the pressure pump 24 and reduced pressure (negative pressure at the ink discharge tube 22 side shown in FIG. 2) by the suction pump 25. A flow rate in the vertical axis corresponds to the flow rate of the ink flowing through the cooling pipe 41 (the cooling flow path 42).


In the drawings, the graph G1 corresponds to when plugging the cooling flow path 42 (when the throttle member 100 with the throttle dimension of 0 mm is disposed in the cooling flow path 42), the graph G2 corresponds to when plugging the jet flow path 32 (when the throttle member 100 with the throttle dimension of 0 mm is disposed in the jet flow path 32), the graph G3 corresponds to when the throttle member 100 with the throttle dimension of 0.5 mm is disposed in the cooling flow path 42, the graph G4 corresponds to when the throttle member 100 with the throttle dimension of 0.5 mm is disposed in the jet flow path 32, the graph G5 corresponds to when the throttle member 100 with the throttle dimension of 1.0 mm is disposed in the cooling flow path 42, the graph G6 corresponds to when the throttle member 100 with the throttle dimension of 1.0 mm is disposed in the jet flow path 32, the graph G7 corresponds to when the throttle member 100 is not disposed in the cooling flow path 42 (when opening the cooling flow path 42 with the diameter of 2.0 mm), and the graph G8 corresponds to when the throttle member 100 is not disposed in the jet flow path 32 (when opening the jet flow path 32 with the diameter of 2.0 mm).


As shown in the drawings, there is a tendency that the flow rate rises when the differential pressure increases. When the ink with the viscosity of 5 cp is used, a degree of rise in flow rate is higher than when the ink with the viscosity of 10 cp is used. Depending on the relationship between the differential pressure and the flow rate corresponding to the throttle dimension, a magnitude relationship between the flow rates is reversed in some cases. For example, when focusing attention on the graphs G3, G8, when the differential pressure is lower than a predetermined value, the flow rate in the graph G3 is higher than the flow rate in the graph G8. It is understood that when the differential pressure exceeds the predetermined value on the other hand, the flow rate in the graph G3 becomes lower than the flow rate in the graph G8 to reverse the magnitude relationship between the flow rates.


Further, depending on the difference in viscosity of the ink, the magnitude relationship between the flow rates is reversed in some cases. For example, when focusing attention on the graphs G5, G6, when the ink with the viscosity of 5 cp is used, the flow rate in the graph G6 is higher than the flow rate in the graph G5 as a whole (see FIG. 10). In contrast, when the ink with the viscosity of 10 cp is used, the flow rate in the graph G6 is lower than the flow rate in the graph G5 as a whole (see FIG. 11).


Since the control in which the magnitude relationship between the flow rates is reversed in such a manner becomes possible, it is possible to increase the design freedom of the inkjet head.


[Functions and Advantages]

The inkjet heads 5 according to the present embodiment jet the ink. The inkjet heads 5 are each provided with the head main body 30 having the jet flow path 32 through which the ink passes, the cooling pipe 41 having the cooling flow path 42 through which the ink passes as the cooling medium for cooling the drive circuits 35, and the throttle members 100 for controlling the flow path resistance of the cooling flow path 42.


According to this configuration, since the throttle members 100 for controlling the flow path resistance of the cooling flow path 42 are provided, it is possible to make the flow path resistance different between the flow paths, namely the jet flow path 32 and the cooling flow path 42. Therefore, it is possible to control the flow rate distribution of the flow paths.


In addition, it is possible to change a ratio of the pipe line resistance in accordance with the type of the ink to be used, the ejection condition, and so on. Therefore, it is possible to minimize the flow rate at the ejection side (the flow rate to the jet flow path 32) and the driver IC cooling side (the flow rate to the cooling flow path 42) necessary for each of the inkjet heads 5.


In the inkjet heads 5 according to the present embodiment, the throttle member 100 is made to be able to be replaced with other throttle members different in flow path resistance from the throttle member 100 described above.


According to this configuration, by replacing the throttle member 100, it is possible to control the flow rate distribution of the flow paths in accordance with the design specification and so on.


In the inkjet heats 5 according to the present embodiment, the throttle member 100 is provided with the cylindrical part 101 extending along the cooling flow path 42, and the flared part 102 flared outward to the outside of the end portion of the cooling pipe 41 from the cylindrical part 101.


According to this configuration, by supporting the flared part 102, it is possible to perform the attachment and the detachment of the throttle member 100.


In the inkjet heads 5 according to the present embodiment, the flared part 102 is provided with the elastically deforming parts 103 which extend from the flared part 102 along the outer circumferential surface of the cooling pipe 41, and which is elastically deformable.


According to this configuration, it is possible to support the throttle member 100 on the outer circumferential surface of the cooling pipe 41 with the elastically deforming parts 103. Therefore, the attachment and the detachment of the throttle member 100 can more efficiently be performed.


In the inkjet heads 5 according to the present embodiment, the throttle member 100 has the ring-like groove 105 to which the end portion of the cooling pipe 41 is inserted, and the radial grooves 106 radially extending from the ring-like groove 105 so as to zone the elastically deforming parts 103 in the circumferential direction of the cylindrical part 101.


According to this configuration, it is possible to absorb the elastic deformation of the elastically deforming parts 103 in the radial grooves 106. Therefore, the attachment and the detachment of the throttle member 100 can more efficiently be performed.


The inkjet heads 5 according to the present embodiment are each further provided with the flow path member 80 provided with the jet-side branch path 82 branching from the ink flow path 20 in which the ink inflows from the outside of the inkjet head 5, or from which the ink outflows, and being communicated with the jet flow path 32, and the cooling-side branch path 83 branching from the ink flow path 20 and communicated with the cooling flow path 42. The flow path member 80 has the housing recess 110 for housing at least a part of the throttle member 100.


According to this configuration, it is possible to enhance sealability (airtightness and liquid-tightness) of the portion housed in the housing recess 110 in the throttle member 100.


The inkjet heads 5 according to the present embodiment are each further provided with the cooling member 50 which has the heat source arrangement surfaces 56 on which the drive circuits 35 are respectively arranged, and in which at least a part of the cooling pipe 41 is embedded. The throttle member 100 is disposed in a portion other than the portion overlapping the heat source arrangement surface 56 in the cooling pipe 41.


According to this configuration, it is possible to make the heat difficult to be transferred from the drive circuits 35 to the throttle member 100 compared to when the throttle member 100 is disposed in a portion overlapping the heat source arrangement surfaces 56 in the cooling pipe 41. Therefore, it is possible to prevent the throttle member 100 from being deformed or deteriorated by the heat from the drive circuits 35.


The printer 1 according to the present embodiment is provided with the inkjet heads 5 described above, and the carriage 29 to which the inkjet heads 5 are attached.


According to this configuration, it is possible to obtain the printer 1 capable of controlling the flow rate distribution of the flow paths.


The method of assembling the inkjet head 5 according to the present embodiment is a method of assembling an inkjet head for jetting the ink. The inkjet heads 5 are each provided with the head main body 30 having the jet flow path 32 through which the ink passes, the cooling pipe 41 having the cooling flow path 42 through which the ink passes as the cooling medium for cooling the drive circuits 35, and the throttle members 100 for controlling the flow path resistance of the cooling flow path 42. The method of assembling the inkjet head 5 includes the throttle member installation step of installing the throttle member 100 to the cooling pipe 41. In the throttle member installation step, one having the predetermined throttle dimension is selected from the plurality of throttle members having the respective throttle dimensions different from each other, and is then installed.


According to this method, in the throttle member installation step, by selecting one having the predetermined throttle dimension from the plurality of throttle members having the respective throttle dimensions different from each other, and then installing the throttle member thus selected, it is possible to make the flow path resistance different between the flow paths, namely the jet flow path 32 and the cooling flow path 42. Therefore, it is possible to control the flow rate distribution of the flow paths.


Although the preferred embodiment of the present disclosure is hereinabove described, it should be understood that this is an illustrative description of the present disclosure, and should not be considered as a limitation. Modification such as addition, omission, and displacement can be implemented within the scope or the spirit of the present disclosure. Therefore, the present disclosure should not be assumed to be limited by the above description, but is limited by the appended claims.


Modified Examples

For example, in the embodiment described above, there is illustrated the configuration provided with the throttle members for controlling the flow path resistance of the cooling flow path, but this configuration is not a limitation. For example, the inkjet head can be provided with a throttle member for controlling the flow path resistance of the jet flow path. For example, it is sufficient for the inkjet head to be provided with a throttle member for controlling the flow path resistance of at least one of the jet flow path and the cooling flow path. For example, it is possible to change the installation aspect of the throttle members in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which the throttle member can be replaced with other throttle members different in flow path resistance from the throttle member described above, but this configuration is not a limitation.



FIG. 12 is a cross-sectional view for explaining a first modified example of the throttle member related to the embodiment. In FIG. 12, the same constituents as those of the embodiment described above are denoted by the same reference symbols, and the detailed description thereof will be omitted.


For example, as shown in FIG. 12, it is possible to dispose a variable throttle structure 200 for controlling the flow path resistance of the cooling flow path 42. For example, the variable throttle structure 200 can be provided with a throttle member 210 having a external thread part 211 and a head part 212, a flow path member 220 having an internal thread part 221 with which the external thread part 211 engages, and a sealing member 230. For example, the head part 212 of the throttle member 210 can be disposed outside the flow path member 220. For example, it is possible for the throttle member 210 to move in a direction of the arrow M (a direction of decreasing the flow path area) by rotating the head part 212 of the throttle member 210 in one direction around the axis of the external thread part 211. For example, it is possible for the throttle member 210 to move in an opposite direction to the arrow M (a direction of increasing the flow path area) by rotating the head part 212 of the throttle member 210 in the other direction around the axis of the external thread part 211. For example, it is possible to change the flow path area of the cooling flow path 42 by the movement of the throttle member 210 in the direction of the arrow M (or the opposite direction to the arrow M). According to this configuration, since the variable throttle structure 200 for controlling the flow path resistance of the cooling flow path 42 is disposed, it is not required to replace the throttle member 210. Therefore, it is possible to control the flow rate distribution of the flow paths without replacing the component. For example, it is possible to change the configuration aspect of the variable throttle structure in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which the throttle members are each provided with the cylindrical part extending along the cooling flow path, and the flared part flared from the cylindrical part to the outer side of the end portions of the cooling pipe, but this configuration is not a limitation. For example, it is possible for the throttle member to be formed to have a cylindrical shape extending along the cooling flow path. For example, the throttle member is not required to be provided with the flared part. For example, it is possible to perform the attachment and the detachment of the throttle member by supporting the end portion of the throttle member. For example, it is possible to change the configuration aspect of the throttle members in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which the flared part is provided with the elastically deforming parts which extend from the flared part along the outer circumferential surface of the cooling pipe, and which is elastically deformable, but this configuration is not a limitation. For example, it is possible for the flared part to be formed to have a ring-like shape along the outer circumference of the cooling pipe. For example, the flared part is not required to be provided with the elastically deforming parts. For example, it is possible to change the configuration aspect of the flared part in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which the throttle member has the ring-like groove in which the end portion of the cooling pipe is inserted, and the radial grooves radially extending from the ring-like groove so as to zone the elastically deforming parts in the circumferential direction of the cylindrical part, but this configuration is not a limitation. For example, it is possible for the throttle member to have a groove extending in a single direction from the ring-like groove, or grooves extending in a plurality of directions from the ring-like groove. For example, it is possible to change the aspect of the grooves provided to the throttle member in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which the throttle member has the throttle entrance in which the ink inflows and the throttle exit from which the ink outflows, and the aperture area of the throttle exit is the same as the aperture area of the throttle entrance, but this configuration is not a limitation.



FIG. 13 is a cross-sectional view for explaining a second modified example of the throttle member related to the embodiment. In FIG. 13, the same constituents as those of the embodiment described above are denoted by the same reference symbols, and the detailed description thereof will be omitted.


For example, as shown in FIG. 13, in a throttle member 300, the aperture area of a throttle exit 309 can be smaller than the aperture area of a throttle entrance 308. For example, it is possible for the flow path area of the throttle member 300 to gradually decrease toward a direction from the throttle entrance 308 toward the throttle exit 309. For example, it is possible for a cylindrical part 301 to have a cylindrical shape like an inverse tapered shape gradually decreasing in inner diameter toward the direction from the throttle entrance 308 toward the throttle exit 309 (toward the −X direction). According to this configuration, since the aperture area of the throttle exit 309 is smaller than the aperture area of the throttle entrance 308, the flow rate of the ink becomes higher in the throttle exit 309 than in the throttle entrance 308, and therefore, it is possible to prevent bubbles from being retained in the flow path. For example, it is possible to change the aspect of the flow path area of the throttle member in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which there is further provided the flow path member provided with the jet-side branch path and the cooling-side branch path, the jet-side branch path branches from the ink flow path in which the ink inflows from the outside of the inkjet head, and from which the ink outflows, to be communicated with the jet flow path, the cooling-side branch path branches from the ink flow path to be communicated with the cooling flow path, and the flow path member has the housing recess for housing at least a part of the throttle member, but this configuration is not a limitation. For example, the whole of the throttle member can be disposed outside the flow path member. For example, the flow path member is not required to have the housing recess. For example, it is possible to change the configuration aspect of the flow path member in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which there is further provided the cooling member having the heat source arrangement surfaces on which the drive circuits are arranged, and having at least a part of the cooling pipe embedded therein, and the throttle member is disposed in other portion than the portion overlapping the heat source arrangement surfaces in the cooling pipe, but this configuration is not a limitation. For example, it is possible for the throttle member to be disposed in the portion overlapping the heat source arrangement surfaces in the cooling pipe. For example, it is possible to change the installation aspect of the throttle members in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the case when selecting one having the predetermined throttle dimension from the plurality of throttle members having the respective throttle dimensions different from each other and then installing the throttle member thus selected in the throttle member installation step in the method of assembling the inkjet head, but this example is not a limitation. For example, in the throttle member installation step, it is possible to select one having a predetermined length of the cylindrical part (the length L of the throttle member) from the plurality of throttle members having respective lengths of the cylindrical part different from each other, and then install the throttle member thus selected. For example, the flow path resistance of the throttle member can be changed not only by the throttle dimension (the inner diameter d of the throttle member) but also by the length of the cylindrical part, and therefore, can be determined by a combination of the throttle dimension and the length of the cylindrical part. For example, in the throttle member installation step, it is sufficient to select one having a predetermined flow path resistance from the plurality of throttle members having the respective flow path resistances different from each other, and then install the throttle member thus selected. For example, it is possible to change the aspect of the throttle member installation step in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the case when the throttle member installation step is performed between the cooling unit manufacturing step and the unit coupling step in the method of assembling the inkjet head, but this example is not a limitation. For example, it is possible to perform the throttle member installation step when reassembling the inkjet head which has once been manufactured and then disassembled. For example, when changing the type of the ink to be ejected, it is possible to replace the throttle member in accordance with the physical property values such as the viscosity or the thermal conductivity of the ink thus changed in the throttle member installation step. For example, it is possible to perform the throttle member installation step when maintaining the inkjet head. For example, it is possible to change the timing of performing the throttle member installation step in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which the recessed parts open toward the four directions crossing the central axis of the cooling pipe, but this configuration is not a limitation. For example, the recessed parts can open toward three or less, or five or more directions crossing the central axis of the cooling pipe. For example, it is possible to change the directions in which the recessed parts open in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which the cooling member has the heat source arrangement surfaces on which the drive circuits are arranged, and the heat source arrangement surfaces are disposed in the portion other than the recessed parts in the cooling member, but this configuration is not a limitation. For example, the heat source arrangement surfaces can be disposed in the recessed parts of the cooling member. For example, it is possible to change the installation aspect of the heat source arrangement surfaces in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which the heat source arrangement surfaces are each a plane, but this configuration is not a limitation. For example, the heat source arrangement surfaces can each include a curved surface. For example, the heat source arrangement surfaces can each have a shape along one of the surfaces of the drive circuit. For example, it is possible to change the configuration aspect of the heat source arrangement surfaces in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which the cooling member has the first surface and the second surface arranged at respective sides opposite to each other across the cooling pipe, and the heat source arrangement surfaces are disposed on each of the first surface and the second surface, but this configuration is not a limitation. For example, the heat source arrangement surfaces can be disposed on either one of the first surface and the second surface (a single side). For example, it is possible to change the installation aspect of the heat source arrangement surfaces in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which the end portions of the cooling pipe are arranged outside the outer shape of the cooling member, but this configuration is not a limitation. For example, the end portions of the cooling pipe can be arranged inside or coplanar with the outer shape of the cooling member. For example, it is possible to change the arrangement aspect of the end portions of the cooling pipe in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which the cooling pipe has the straight-pipe shape, but this configuration is not a limitation. For example, the cooling pipe can have a curved shape. For example, the cooling pipe can include a straight part and a curved part. For example, it is possible to change the shape of the cooling pipe in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which the cooling pipe is formed of stainless steel, and the cooling member is formed of aluminum simple body or aluminum alloy, but this configuration is not a limitation. For example, the cooling pipe can be formed of copper alloy, titanium alloy, nickel alloy, chromium alloy, or the like, and the cooling member can be formed of zinc alloy or the like. For example, it is possible to change the constituent materials of the cooling pipe and the cooling member in accordance with the design specification.


For example, in the embodiment described above, there is illustrated the configuration in which the cooling member has the recessed parts in at least a part of the portion surrounding the cooling pipe, but this configuration is not a limitation. For example, the cooling member is not required to have the recessed parts. For example, it is sufficient to embed at least a part of the cooling pipe in the cooling member using the insert molding or the like. For example, it is possible to change the installation aspect of the recessed parts in accordance with the design specification.


Further, for example, in the embodiment described above, the description is presented citing the inkjet printer as an example of the liquid jet recording device, but the liquid jet recording device is not limited to the printer. For example, a facsimile machine, an on-demand printing machine, and so on can also be adopted.


In the embodiment described above, the description is presented citing the configuration (a so-called shuttle machine) in which the inkjet head moves with respect to the recording target medium when performing printing as an example, but this configuration is not a limitation. The configuration related to the present disclosure can be adopted as the configuration (a so-called stationary head machine) in which the recording target medium is moved with respect to the inkjet head in the state in which the inkjet head is fixed.


In the embodiment described above, there is described the case when the recording target medium P is paper, but this configuration is not a limitation. The recording target medium P is not limited to paper, but can also be a metal material or a resin material, and can also be food or the like.


In the embodiment described above, there is described the configuration in which the liquid jet head is installed in the liquid jet recording device, but this configuration is not a limitation. Specifically, the liquid to be jetted from the liquid jet head is not limited to what is landed on the recording target medium, but can also be, for example, a medical solution to be blended during a dispensing process, a food additive such as seasoning or a spice to be added to food, or fragrance to be sprayed in the air.


In the embodiment described above, there is described the configuration in which the Z direction coincides with the gravitational direction, but this configuration is not a limitation, and it is also possible to set the Z direction to a direction along the horizontal direction.

Claims
  • 1. A liquid jet head configured to jet liquid comprising: a jet unit having a jet flow path through which the liquid passes;a cooling pipe having a cooling flow path through which the liquid passes as a cooling medium configured to cool a heat source; anda throttle member configured to control a flow path resistance of at least one of the jet flow path and the cooling flow path.
  • 2. The liquid jet head according to claim 1, wherein the throttle member is made replaceable with another throttle member different in flow path resistance from the throttle member.
  • 3. The liquid jet head according to claim 2, wherein the throttle member includes a cylindrical part extending along the cooling flow path, anda flared part flared from the cylindrical part to an outside of an end portion of the cooling pipe.
  • 4. The liquid jet head according to claim 3, wherein the flared part includes an elastically deforming part which extends from the flared part along an outer circumferential surface of the cooling pipe, and which is elastically deformable.
  • 5. The liquid jet head according to claim 4, wherein the throttle member includes: a ring-like groove in which an end portion of the cooling pipe is inserted, anda radial groove radially extending from the ring-like groove so as to zone the elastically deforming part in a circumferential direction of the cylindrical part.
  • 6. The liquid jet head according to claim 1, wherein the throttle member includes: a throttle entrance in which the liquid inflows, anda throttle exit from which the liquid outflows, andan aperture area of the throttle exit is smaller than an aperture area of the throttle entrance.
  • 7. The liquid jet head according to claim 1, further comprising a flow path member provided with a jet-side branch path branching from a liquid flow path in which the liquid inflows from an outside of the liquid jet head, or from which the liquid outflows to the outside of the liquid jet head, to be communicated with the jet flow path, and a cooling-side branch path branching from the liquid flow path to be communicated with the cooling flow path, wherein the flow path member has a housing recess configured to house at least a part of the throttle member.
  • 8. The liquid jet head according to claim 1, further comprising a cooling member which has a heat source arrangement surface on which the heat source is arranged, and in which at least a part of the cooling pipe is embedded, wherein the throttle member is disposed in a portion other than a portion overlapping the heat source arrangement surface in the cooling pipe.
  • 9. A liquid jet recording device comprising: the liquid jet head according to claim 1; anda carriage to which the liquid jet head is attached.
  • 10. A method of assembling a liquid jet head configured to jet liquid, the liquid jet head including: a jet unit having a jet flow path through which the liquid passes,a cooling pipe having a cooling flow path through which the liquid passes as a cooling medium configured to cool a heat source, anda throttle member configured to control a flow path resistance of at least one of the jet flow path and the cooling flow path, the method comprising: a throttle member installation step of installing the throttle member to the cooling pipe, whereinin the throttle member installation step, one having a predetermined flow path resistance is selected from a plurality of throttle members having respective flow path resistances different from each other, and is installed.
Priority Claims (1)
Number Date Country Kind
2022-153668 Sep 2022 JP national