EP1077331A2 - Sprühapparat für Flüssigkeitstropfen - Google Patents

Sprühapparat für Flüssigkeitstropfen Download PDF

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Publication number
EP1077331A2
EP1077331A2 EP00307094A EP00307094A EP1077331A2 EP 1077331 A2 EP1077331 A2 EP 1077331A2 EP 00307094 A EP00307094 A EP 00307094A EP 00307094 A EP00307094 A EP 00307094A EP 1077331 A2 EP1077331 A2 EP 1077331A2
Authority
EP
European Patent Office
Prior art keywords
flow path
introducing hole
liquid
spraying apparatus
pressure chambers
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP00307094A
Other languages
English (en)
French (fr)
Other versions
EP1077331A3 (de
Inventor
Toshikazu Hirota
Takao Ohnishi
Motoo Noritake
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NGK Insulators Ltd
Original Assignee
NGK Insulators Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NGK Insulators Ltd filed Critical NGK Insulators Ltd
Publication of EP1077331A2 publication Critical patent/EP1077331A2/de
Publication of EP1077331A3 publication Critical patent/EP1077331A3/de
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B43/00—Machines, pumps, or pumping installations having flexible working members
    • F04B43/02—Machines, pumps, or pumping installations having flexible working members having plate-like flexible members, e.g. diaphragms
    • F04B43/04—Pumps having electric drive
    • F04B43/043—Micropumps
    • F04B43/046—Micropumps with piezoelectric drive
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/14—Structure thereof only for on-demand ink jet heads
    • B41J2/14201—Structure of print heads with piezoelectric elements
    • B41J2/14233—Structure of print heads with piezoelectric elements of film type, deformed by bending and disposed on a diaphragm
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/14—Structure thereof only for on-demand ink jet heads
    • B41J2/14201—Structure of print heads with piezoelectric elements
    • B41J2002/14306—Flow passage between manifold and chamber
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/14—Structure thereof only for on-demand ink jet heads
    • B41J2002/14419—Manifold

Definitions

  • the present invention relates to a liquid drop spraying or ejecting apparatus for example a raw material fuel discharge device for a variety of uses, the discharge device treating liquid or operating by discharging a liquid raw material or fuel.
  • a plurality of pressure chambers are connected to an identical flow path via an introducing hole provided at each of the pressure chambers, and liquid drops are discharged from a discharge opening with a volume change of the pressure chamber, thereby performing spraying.
  • the liquid supplied to a plurality of pressure chambers connected to one flow path is stored through the introducing hole formed at each pressure chamber. Liquid drops are discharged from a nozzle hole connected with the other side of each pressure chamber with a volume change of the pressure chamber, and the entirety is sprayed.
  • a liquid drop spraying apparatus in which a piezoelectric / electrostrictive element is formed at a part of the wall of the pressure chamber, and a pressure change is produced at the element by means of a voltage signal applied to the element has been superior in a liquid drops spraying state.
  • the number of pressure chambers in which a plurality of liquid drops spraying apparatuses are mounted is increased, and the discharge period is decreased.
  • liquid to be discharge is not flowed to the inside smoothly in the case where liquid is supplied from an introducing hole immediately after discharge because a large amount of back flow caused by the liquid pressurized by a piezoelectric / electrostrictive element for the purpose of spraying is supplied from the introducing hole to the flow path.
  • a piezoelectric / electrostrictive element for the purpose of spraying is supplied from the introducing hole to the flow path.
  • the pressure reducing speed of the pressure chamber becomes slow in order to prevent air bubble entry, and setting must be changed such that the discharge period is lengthened, and therefore, the discharge quantity cannot be increased.
  • the present invention provides a liquid drops spraying apparatus comprising a number of pressure chambers in which liquid pressurized by a piezoelectric / electrostrictive element for the purpose of spraying reduces a back flow generated from an introducing hole to a flow path.
  • a liquid drops spraying apparatus a plurality of pressure chambers being connected to an identical flow path via an introducing hole provided in each of these pressure chambers, liquid drops being discharged from a discharge opening with a volume change of the pressure chamber, thereby performing spraying, wherein the depth of the flow path is formed to be selectively shallower than any other portion at a portion provided immediately underneath the introducing hole.
  • the depth of the flow path indicates a distance from an introducing hole to a face opposite to a face of the flow path in which the introducing hole is formed.
  • a portion provided immediately underneath the introducing hole indicates a portion at which an extension line passing the center of the introducing hole crosses an opposite face.
  • interference from the other pressure chamber or interference to its own pressure chamber due to the reflection waves can be reduced, liquid can be supplied smoothly, and spraying is stabilized.
  • a portion provided immediately underneath the introducing hole is formed selectively more shallowly than any other portion. In this manner, when liquid is charged in the entire flow path at the start of spraying, the flow velocity at a shallow portion is increased, and air bubble can be discharged from the pressure chambers through the introducing hole without accumulation.
  • a liquid drops spraying apparatus in which a protrusion having the width of the flow path narrower than any other portion is formed at the flow path.
  • pressure chambers connected to the same flow path are divided into two or more groups by a portion at which the protrusion is formed so as to selectively narrow the width of the flow path, the shock wave due to back flow generated in the pressure chambers of one group collides with, and is absorbed and dispersed by a portion at which the protrusion is formed so as to selectively narrow the width of the flow path.
  • the width of the flow path denotes a distance between faces mutually opposed orthogonal to the fluid flow direction, and a diameter if the flow cross section is circular or oval.
  • a portion at which a protrusion is formed so as to selectively narrow the width of the flow path denotes a portion at which a pressure chamber is not coupled via the introducing hole.
  • a fine liquid drops spraying apparatus is often manufactured by means of a laminate layer such as green sheets.
  • a protrusion portion is formed in the planar direction of at least one laminate body forming the flow path.
  • a width rate between the flow path width provided at the laminate body and the protrusion is preferably 1 : 0.5 to 1 : 0.8.
  • the width of the protrusion is 0.5 or less relevant to the width of the flow path, the absorption rate of the shock wave is lowered, and an effect of back flow reduction is reduced.
  • the above width is 0.8 or more, the flow of fluid in the flow path is prevented, and smooth liquid supply to the pressure chambers is inhibited irrespective of the presence or absence of shock wave.
  • a shock wave may reach the other path over an inlet opening for supplying liquid from a liquid reservoir to the flow path.
  • a shock wave may reach the other path over an inlet opening for supplying liquid from a liquid reservoir to the flow path.
  • Such arrangement is preferably adopted in the case where one flow path diverges into two or more flow paths. That is, a multiply layered protrusion shaped portion is formed at a diverging portion in thickness direction, and an original one flow path serves as an inlet opening relevant to two or more diverging flow paths. In this manner, the shock wave generated at these two or more diverging flow paths is prevented from interfering with any other flow path.
  • a liquid drops spraying apparatus wherein a diameter of an introducing hole and/or an discharge opening positioned most distantly from an inlet opening for injecting liquid into the flow path is formed to be greater than a diameter of any other introducing hole and/or a discharge opening, and/or an exhaust hole is formed on the discharge opening forming face positioned most distantly from an inlet opening for injecting liquid into the flow path.
  • the discharge opening forming face is pressure reduced and suctioned when spraying is started, whereby liquid is charged from the inlet opening into the flow path and pressure chamber. In that case, air bubbles may remain at the tip end of the flow path.
  • air bubbles may remain at the tip end of the flow path.
  • air bubbles or the like can be discharged from the flow path without being air bubble retained, and a spraying failure does not occur.
  • the size of the diameter of the introducing hole and discharge opening is 1.1 times or more than that of any other introducing hole and discharge opening, air bubbles are well removed.
  • the size is twice or less, liquid leakage never occurs, which is preferable.
  • the exhaust hole in the case of an exhaust hole, unlike an introducing hole and/or discharge opening with a pressure chamber interposed on its way, the exhaust hole directly diverges into an ejection face.
  • the size of the diameter of the exhaust hole is 0.5 times or more than that of any other discharge opening on the formed face, air bubbles are well removed.
  • the size of the exhaust hole is preferably twice or less than any other discharge opening associated with spraying.
  • a liquid drops spraying apparatus wherein the depth of a portion at which fluid flows in a direction different from a direction in which the fluid of the introducing hole flows is formed to be selectively shallower than that of any other portion of the flow path in the middle of a first introducing hole communicating with the pressure chambers, and a second introducing hole communicating with the flow path is formed at a portion other than the extension line of the first introducing hole of the portion.
  • the depth denotes a distance from each introducing hole to a portion at which the introducing hole is formed, and a face opposed to the face of the flow path. In this manner, the pressure of the shock wave due to back flow is absorbed and reduced by the portion, and is not propagated into the flow path.
  • a liquid drops spraying apparatus wherein the periphery of the selectively shallowly formed portion is formed deeply in stepwise manner.
  • the shock wave that does not collide with the shock wave absorption face and is not absorbed thereby is diminished stepwise, the number of shallow portions is not increased, and the space of the flow path can be prevented from being reduced.
  • a fine liquid drops spraying apparatus is often manufactured by means of a laminate layer.
  • stepwise formation is easy, and in a stepwise structure having a stepped portion corresponding to the thickness of the laminate layer, a peripheral portion close to an inclined face can be formed by increasing the number of laminating steps.
  • the selectively shallowly formed portion be equal to or greater than and 5 times or less of the diameter of the introducing hole in depth from the lower end of the introducing hole. This is because, when the depth is more than 5 times, the efficiency of absorption due to collusion with the bottom face drops, or alternatively, when the depth is less than the diameter, the resistance of the flow path during fluid introduction is increased, and the fluid cannot be introduced smoothly.
  • a liquid drops spraying apparatus wherein the surface roughness of the selectively shallowly formed portion is larger than that of any other flow path interior face.
  • Methods for roughening the surface roughness of the flow path interior wall includes: forming an uneven shape by physical techniques such as lamination or cutting. Even if such shape is not formed, the surface may be formed by chemical techniques such as changing material quality or the like of the shallow portion, for example, laminating another material or another grain material; or irradiating such shallowly formed portion with another substance or reacting with another substance.
  • a liquid drops spraying apparatus wherein the flow path is formed of ZrO 2 ceramics, and at least part of the flow path is changed in its shape with the pressure change in the flow path.
  • the pressure change is absorbed by at least part of the flow path formed of ZrO 2 ceramics.
  • FIG. 1 is a longitudinal cross section of the liquid drops spraying apparatus.
  • a discharge opening 11 having an outwardly opening nozzle hole 11a is provided downwardly at one end; an introducing hole 12 is provided at the other end at which the discharge opening 11 is provided; and the pressure chamber is connected to a flow path 20 via the introducing hole 12.
  • a piezoelectric / electrostrictive element 13 is provided at a part of the upper wall thereof, and each piezoelectric / electrostrictive element 13 laminates an upper electrode, a piezoelectric / electrostrictive layer, and a lower electrode.
  • a predetermined voltage signal is applied to the piezoelectric / electrostrictive element 13, whereby the piezoelectric / electrostrictive layer is deformed by an electric field generated between the upper electrode and the lower electrode.
  • the liquid supplied to the pressure chamber 10n is discharged as liquid drops from the discharge opening 11, and liquid drops are sprayed in an atomizing manner by means of a number of discharge openings.
  • the introducing hole 12 is provided in orthogonal direction relevant to the lower face of the pressure chamber 10n, and is vertically connected to the upper face of the flow path 20.
  • a shock absorption face 21 with its depth D that is twice or more of the diameter L of the introducing hole 12 is formed so as to be protruded from the lower face of the flow path 20.
  • the shock absorption face 21 is wider than the diameter circle of the introducing hole 12, and its periphery is vertically cut off, and the stepped portion 22 is formed.
  • dotted lines 21s, 22s, and 20s each indicate a laminate face during manufacture, and the thickness of the stepped portion corresponds to that of the laminate layer.
  • FIG. 2 is an illustrative sectional view illustrating another embodiment taken along line A-A that omits the upper wall face shown in FIG. 1.
  • An introducing hole 12 connected to each pressure chamber 10n is provided at a flow path 20 common to a plurality of pressure chambers 10a, 10b, ... 10n, and a discharge opening 11 for outwardly discharging liquid is punched at the other end.
  • a piezoelectric / electrostrictive element 13 is provided at a part of the upper wall of the pressure chamber 10n.
  • Flow paths 20 can be provided in one or more arrays relevant to a liquid supply source.
  • the flow paths 20 are formed so that its face width narrows as they are distant from the liquid supply source.
  • a shock absorption face 21 may be formed so that the face width of the shallow portion narrows as the face is distant from the liquid supply source relevant to the flow paths 20, as shown in FIG. 3. In this manner, a flow path resistance from the fluid supply source to each introducing hole is equal to another, the spraying distortion between the pressure chambers is reduced, and stable spraying is performed.
  • a side connection of the flow path 20 to the introducing hole 12 is formed in planar and protrusive shape, and is connected to the introducing hole 12 in the vicinity of its apex at its protrusion.
  • the depth of the protrusion is formed more shallowly than any other portion of the flow path 20 as shown in the end face (B) taken along line A-A shown in FIG. 4A, and may be arranged so that the bottom face is employed as a shock absorption face 21.
  • FIG. 4C shows an end face of the introducing hole 12 taken along line B-B orthogonal to line A-A.
  • the introducing hole 12 is disposed at the apex position of the protrusion in the laminated face direction, thereby smoothening the flow of air bubbles.
  • the shock absorption face 21 is formed in stepwise manner, thereby making it possible to form the introducing hole 12 at the shallowest position (C) and utilize the hole.
  • FIG. 5 is an illustrative view illustrating another embodiment in which green sheets are laminated, as shown in FIG. 1.
  • a liquid drops spraying apparatus is formed by laminating seven green sheets (hereinafter, referred to as a laminate body) S1 to S7.
  • FIG. 6 to FIG. 8 each shows a plan view of a second laminate body to a seventh laminate body with the exception of a first laminate body at which only an inlet opening 25 is provided.
  • a pressure chamber 10n in which the first laminate body S1 is employed as a cover portion is formed by the second laminate body.
  • the downward oriented discharge opening 11 at one end is coupled with the third to sixth laminate bodies while their diameters are reduced.
  • An outward opening nozzle hole 11a is formed at the seventh laminate body S7.
  • an introducing hole 12 is provided at the other end of a face at which a discharge opening 11 is provided, and a flow path 20 connected via the introducing hole 12 is formed by the third, fourth, and fifth laminate bodies.
  • the first laminate body S1 being the upper wall of the pressure chamber 10n is provided with a piezoelectric / electrostrictive element 13 which laminates an upper electrode, a piezoelectric / electrostrictive layer, and a lower electrode.
  • a predetermined voltage signal is applied to the piezoelectric / electrostrictive element 13, whereby a piezoelectric / electrostrictive layer is deformed by an electric field generated between the upper electrode and the lower electrode, and the upper wall being fixed with pressure chamber 10n is deformed by distance L as indicated by short two dots and long one line.
  • the liquid supplied to the pressure chamber 10n is discharged as liquid drops from the discharge opening 11, and the ejection is repeated at a high speed, whereby liquid drops are ejected in sprayed manner by a number of discharge openings 11 provided on a flat face.
  • Reference numeral 11b denotes a liquid repellent member mounted to the discharge opening 11 so as not to ensure that the liquid drops remain. Even if the liquid drops that have not been scattered adhere to the liquid repellent member 11b, they drop and disappear without rapid growth.
  • a shock absorption face 21 of 0.12 mm in depth that is 3.5 times relevant to L0.034 mm in diameter of the introducing hole 12 is formed to be protruded from the lower face of the flow path 20 by the fifth laminate body S5.
  • the size of the shock absorption face 21 is formed in width of 0.25 mm wider than L0.034 mm in diameter of the introducing hole 12, and a stepped portion 22 of its periphery is 0.38 mm in the layer thickness of the fifth laminate body S5.
  • the back flow pressure generated by the pressurization of the pressure chamber 10n and propagating the introducing hole 12 collides with the shock absorption face 21 immediately after the introducing hole 12 has been passed.
  • the back flow pressure reduces its energy, and is conveyed to the entirety of the flow path 20.
  • FIG. 6 is a plan view showing the second laminate body S2 and the third laminate body S3, and an inlet opening 25 proceeding from the first laminate body S1 is punched downward of these respective bodies.
  • a block in which fourteen elongated pressure chambers 10n each having one planar shape formed in arc shape at both ends are made adjacent to each other is arranged in two longitudinal arrays and four horizontal arrays, and a total of 112 pressure chambers 10n are formed.
  • 112 discharge opening 11 of 0.25 mm in diameter and 112 introducing holes 12 of 0.034 mm in diameter are punched corresponding to its pressure chambers 10n.
  • FIG. 7 is a plan view showing the fourth laminate body S4 and the fifth laminate body S5. Downward of a respective one of these laminate bodies, the flow paths 20 at one end operating at the inlet opening 25 proceeding from the upper layer are disposed at the left and right according to a diverging portion 25a, and each flow path 20 further diverges at the other end.
  • the flow paths 20 diverging into four sections are coupled with the respective twenty eight introducing holes 12 formed in third laminate bodies S3.
  • the shock absorption face 21 is provided at the fifth laminate body S5 immediately underneath the introducing hole 12 of the third laminate body S3.
  • a discharge opening 11 of 0.15 mm in diameter and a discharge opening of 0.1 mm in diameter are punched at a fourth laminate body S4 and a fifth laminate body S5, respectively, relevant to the discharge opening 11 of the third laminate body S3.
  • the flow path 20 is formed so that the face width of the flow path 20 to which the introducing holes 12 are connected narrows as the flow path is distant from the inlet opening 25 of the liquid supply source. In this manner, when liquid is initially charged in the flow path, the liquid can be charged smoothly by utilizing the capillary action. In addition, even if the flow path is distant from the fluid supply source, the flow rate of the fluid in the flow path is not slow. Thus, there is provided an advantageous effect that air bubbles or the like hardly remains on the wall face.
  • the diameter of the introducing hole and/or discharge opening positioned most distantly relevant to the inlet opening for injecting liquid into the flow path may be formed to be larger than the diameter of any other introducing hole and/or discharge opening, and an exhaust hole may be formed on the ejection forming face at the tip end of the flow path 20 positioned most distantly relevant to the inlet opening 25 for injecting liquid into the flow path 20.
  • an exhaust hole may be formed on the ejection forming face at the tip end of the flow path 20 positioned most distantly relevant to the inlet opening 25 for injecting liquid into the flow path 20.
  • FIG. 8 is a plan view showing a sixth laminate body S6 and a seventh laminate body S7.
  • the sixth laminate body S6 can be employed as a bottom face of the flow path 20.
  • a discharge opening 11 of 0.05 mm in diameter and a discharge opening 11 of 0.031 mm in diameter are punched at a sixth laminate body S6 and a seventh laminate body S7, respectively, relevant to the discharge opening 11 of the fifth laminate body S5.
  • FIG. 9 is a sectional view when laminate bodies S1 to S7 are formed in laminated manner, and are cut taken along line B-B shown in FIG. 6 to FIG. 8.
  • a diverging portion 25a is formed in the flow path 20 at a portion provided immediately underneath the inlet opening 25, and is selectively shallower than any other portion of the flow path 20 by remaining the fourth laminate body S4 and the fifth laminate body S5.
  • a face 20d on which the diverging portion 25a is orthogonal to the flow direction of the flow path 20 absorbs the shock wave conveyed to the flow path 20, thereby preventing interference with the other flow path.
  • the width of the diverging portion 25a is narrow relevant to the liquid supplied from the inlet opening 25, and thus, the supply resistance is eliminated.
  • a frequency of a drive signal is merely adjusted while the displacement quantity of the piezoelectric / electrostrictive element is kept constant, whereby the spray quantity can be changed, and a large amount of spray is made possible.
  • FIG. 10 shows another embodiment of the fourth laminate body S4 and fifth laminate body S5 shown in FIG. 7.
  • a respective one of the flow paths 20 diverged into four sections in its destination is coupled with twenty eight introducing holes 12 of the third laminate body S3 respectively.
  • a protrusion 20e in which the flow width is selectively narrower than that of any other portion is formed in planer direction in the middle of the portion to be coupled with.
  • an array of introducing holes 12 are divided into two sections by 14 pieces.
  • pressure chambers connected to the same flow path are divided into two groups by the protrusion 20e.
  • the shock wave due to the back flow generated in the pressure chambers of one group collides with the protrusion 20e, and is dispersed there.
  • the back flow to the pressure chambers that are in the other group can be reduced, the liquid is supplied smoothly, and spraying is stabilized.
  • FIG. 11 is an illustrative view showing another embodiment in the same manner as that shown in FIG. 1.
  • a pressure reducing chamber 14 for changing the fluid flow direction is formed in a first introducing hole 12a formed in vertical direction on the lower face of the pressure chamber of the liquid drops spraying apparatus. Then, the depth of the pressure reducing chamber 14 is equal to or larger than the diameter of the first introducing hole 12a or is 5 times or less, whereby the shock force of the back flow is absorbed by the bottom face of the pressure reducing chamber.
  • a second introducing hole 12b communicating with the flow path 20 is formed on a bottom face other than the portion provided immediately underneath the first introducing hole 12a.
  • a direction in which the flow of the fluid is changed is not limited to a direction orthogonal to the extension line passing through the center immediately after the fluid has entered the introducing hole. This direction can be properly adjusted in consideration of the fluid properties, flow rate, flow velocity or the like.
  • FIG. 12 and FIG. 13 are illustrative views each illustrating another embodiment in the same manner as that shown in FIG. 1.
  • a liquid drops spraying apparatus wherein a flow path 20 of the liquid drops spraying apparatus is formed of ZrO 2 ceramics, and at least part of the flow path 20 is changed in its shape due to the pressure change in the flow path.
  • the pressure change is absorbed by changing its shape of at least part of the flow path having its wall face formed of ZrO 2 ceramic.
  • liquid supply can be started speedily.
  • part of the lower face of the flow path 20 is formed at the thin portion 20a, in FIG.
  • a hollow portion 20b is formed upward of the flow path 20, and a thin portion 20c is formed between the flow path 20 and the hollow portion 20b. If a back flow is generated at the flow path 20, the thin portions 20a and 20c are deformed as indicated by dotted line, thereby absorbing the back flow.
  • the depth of a flow path of a liquid drops spraying apparatus is selectively formed more shallowly than any other portion at least at a portion provided immediately underneath the introducing hole.
  • the shock wave due to the back flow propagated from the pressure chamber to the introducing hole for the purpose of spraying first collides with the bottom face of the shallowly formed flow path, and is absorbed thereby. Thereafter, the shock wave is diverged into another flow path.
  • interference from any other pressure chamber or interference to its own pressure chamber with reflection wave can be reduced, liquid is supplied smoothly, and spraying is stabilized without any intermittence.
  • a protrusion at which the width of the flow path is selectively narrower than any other portion is formed at a flow path of the liquid drops spraying apparatus.
  • the back flow to any other portion can be reduced, liquid is supplied smoothly, and spraying is stabilized.
  • two or more flow paths of the liquid drops spraying apparatus are connected to each other at an inlet opening, and at least a portion provided immediately underneath the inlet opening is formed to be selectively shallower than any other portion.
  • the shock wave generated at one of the two or more flow paths collides with such selectively shallowly formed portion, and is dispersed.
  • the diameter of the introducing hole and/or discharge opening positioned most distantly from an inlet opening for injecting liquid into a flow path of the liquid drops spraying apparatus is formed to be larger than that of any other introducing hole and/or discharge opening; and/or an exhaust path is formed at the discharge opening forming face at the tip end of the flow path positioned most distantly from the inlet opening for injecting liquid into the flow path.
  • a liquid drops spraying apparatus wherein a pressure reducing chamber for changing the fluid flow direction is formed in a first introducing hole communicating with the pressure chamber, and a second introducing hole communicating with the flow path is formed at a portion other than a portion provided immediately underneath the first introducing hole of the pressure reducing chamber.
  • a liquid drops spraying apparatus wherein the periphery of the selectively shallowly formed portion is formed deeply in stepwise manner.
  • the shock wave that has not collided with the shock wave absorption face and has not been absorbed thereby is eliminated in stepwise direction, the number of such shallow portions is not increased, and the capacity of the entire pressure chamber can be prevented from being reduced.
  • a fine liquid drops spraying apparatus is often manufactured by a laminate layer.
  • the number of laminating steps is increased, whereby a peripheral portion close to an inclined face can be formed.
  • the selectively shallowly formed portion is equal to or greater than the diameter of the introducing hole or 5 times or less in depth from the lower end of the introducing hole. In this manner, the back flow pressure in the extension direction of the introducing hole collides with a portion shallowly formed prior to scattering in horizontal direction, and decreases.
  • a liquid drops spraying apparatus wherein the surface roughness of the selectively shallowly formed portion is rougher than that of any other portion of the interior wall of the flow path. In this manner, the efficiency of which the shock wave is absorbed is improved.
  • a liquid drops spraying apparatus wherein the flow path is formed of ZrO 2 ceramics, and at least part of the flow path is changed in its shape due to the pressure change in the flow path.
  • the pressure change is absorbed by at least part of the flow path formed of ZrO 2 .

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Particle Formation And Scattering Control In Inkjet Printers (AREA)
  • Special Spraying Apparatus (AREA)
  • Ink Jet (AREA)
  • Nozzles (AREA)
EP00307094A 1999-08-19 2000-08-18 Sprühapparat für Flüssigkeitstropfen Withdrawn EP1077331A3 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP23327799 1999-08-19
JP23327799 1999-08-19
JP2000225953A JP2001121693A (ja) 1999-08-19 2000-07-26 液滴噴霧装置
JP2000225953 2000-07-26

Publications (2)

Publication Number Publication Date
EP1077331A2 true EP1077331A2 (de) 2001-02-21
EP1077331A3 EP1077331A3 (de) 2002-09-25

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EP00307094A Withdrawn EP1077331A3 (de) 1999-08-19 2000-08-18 Sprühapparat für Flüssigkeitstropfen

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EP (1) EP1077331A3 (de)
JP (1) JP2001121693A (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003046381A1 (en) * 2001-11-26 2003-06-05 Motorola, Inc. Ceramic micropump with ball check valve
EP1356939A3 (de) * 2002-04-25 2004-04-28 Brother Kogyo Kabushiki Kaisha Tintenstrahlkopf und Tintenstrahldrucker
EP1493576A1 (de) * 2003-06-30 2005-01-05 Brother Kogyo Kabushiki Kaisha Tintenstrahldruckkopf
EP1780018A1 (de) * 2005-10-26 2007-05-02 Brother Kogyo Kabushiki Kaisha Tröpfchenausstossgerät mit Tintenverteiler, der das Übersprechen vermindert
EP1832424A1 (de) * 2006-03-06 2007-09-12 Brother Kogyo Kabushiki Kaisha Vorrichtung zum Sprühen flüssiger Tröpfchen
US8646878B2 (en) 2011-01-14 2014-02-11 Panasonic Corporation Ink-jet head

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JP4666822B2 (ja) * 2000-07-10 2011-04-06 キヤノン株式会社 液体吐出記録ヘッド
JP4639002B2 (ja) * 2001-06-13 2011-02-23 株式会社リコー インク供給装置と記録ヘッド及びインクジェット記録装置
JP4292841B2 (ja) * 2003-03-24 2009-07-08 富士ゼロックス株式会社 インクジェット記録ヘッド及びインクジェット記録装置
JP4274085B2 (ja) * 2004-08-27 2009-06-03 ブラザー工業株式会社 インクジェットヘッド
JP4274084B2 (ja) * 2004-08-27 2009-06-03 ブラザー工業株式会社 インクジェットヘッド
JP4735144B2 (ja) * 2005-09-13 2011-07-27 ブラザー工業株式会社 インクジェット式記録装置
JP2007090638A (ja) * 2005-09-28 2007-04-12 Brother Ind Ltd 記録ヘッド、およびインクジェット記録装置
JP4941038B2 (ja) * 2007-03-23 2012-05-30 ブラザー工業株式会社 液滴吐出装置
KR101101623B1 (ko) * 2009-10-29 2012-01-02 삼성전기주식회사 잉크젯 프린트 헤드
JP5364084B2 (ja) * 2010-03-16 2013-12-11 パナソニック株式会社 インクジェット装置
JP5223934B2 (ja) 2010-03-29 2013-06-26 パナソニック株式会社 インクジェット装置
JP6439357B2 (ja) * 2014-09-29 2018-12-19 ブラザー工業株式会社 液体噴射装置
JP6786909B2 (ja) * 2016-06-29 2020-11-18 セイコーエプソン株式会社 液体噴射ヘッド及び液体噴射装置
JP6857807B2 (ja) 2017-02-08 2021-04-14 パナソニックＩｐマネジメント株式会社 インクジェット印刷方法
CN108394197B (zh) 2017-02-08 2021-07-27 松下知识产权经营株式会社 喷墨印刷方法

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WO2003046381A1 (en) * 2001-11-26 2003-06-05 Motorola, Inc. Ceramic micropump with ball check valve
US6620273B2 (en) 2001-11-26 2003-09-16 Motorola, Inc. Micropump including ball check valve utilizing ceramic technology and method of fabrication
EP1356939A3 (de) * 2002-04-25 2004-04-28 Brother Kogyo Kabushiki Kaisha Tintenstrahlkopf und Tintenstrahldrucker
US6926382B2 (en) 2002-04-25 2005-08-09 Brother Kogyo Kabushiki Kaisha Ink-jet head and ink-jet printer
EP1493576A1 (de) * 2003-06-30 2005-01-05 Brother Kogyo Kabushiki Kaisha Tintenstrahldruckkopf
US7246889B2 (en) 2003-06-30 2007-07-24 Brother Kogyo Kabushiki Kaisha Inkjet printing head
CN100372687C (zh) * 2003-06-30 2008-03-05 兄弟工业株式会社 喷墨打印头
EP1780018A1 (de) * 2005-10-26 2007-05-02 Brother Kogyo Kabushiki Kaisha Tröpfchenausstossgerät mit Tintenverteiler, der das Übersprechen vermindert
US7625074B2 (en) 2005-10-26 2009-12-01 Brother Kogyo Kabushiki Kaisha Liquid droplet-jetting apparatus and ink-jet printer
EP1832424A1 (de) * 2006-03-06 2007-09-12 Brother Kogyo Kabushiki Kaisha Vorrichtung zum Sprühen flüssiger Tröpfchen
US7661802B2 (en) 2006-03-06 2010-02-16 Brother Kogyo Kabushiki Kaisha Liquid droplet spraying apparatus
US8646878B2 (en) 2011-01-14 2014-02-11 Panasonic Corporation Ink-jet head

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