JP2013163044A - Fluid jet device and surgical scalpel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid jet device to/from which a nozzle unit and a piezoelectric element unit are attachable/detachable.SOLUTION: A fluid jet device 10, which reduces the volume of a fluid chamber 120 by a diaphragm 70 and jets a liquid from a nozzle 95 like a pulse, includes: a nozzle unit 11 that has the fluid chamber 120, an entrance channel 83 for supplying the liquid to the fluid chamber 120, an exit channel 88 for discharging the liquid from fluid chamber 120, and the nozzle 95 that leads to the exit channel 88; and a piezoelectric element unit 12 that has a piezoelectric element 40 for displacing the diaphragm 70. The nozzle unit 11 and the piezoelectric element unit 12 are mounted detachably.

Description

  The present invention relates to a piezoelectric element unit that generates pulsation in a fluid, a nozzle unit that ejects fluid, and a fluid ejecting apparatus that ejects fluid in pulses.

  Surgery with the ejected fluid allows the incision of the organ parenchyma while preserving the vasculature such as blood vessels, and the incidental damage to living tissue other than the incision is minimal, resulting in a burden on the patient. In addition, since the bleeding is small and bleeding does not interfere with the field of view of the operative field, rapid surgery is possible.

  As a fluid ejection device for incising or excising a living tissue, one end is connected to a pulsation generating mechanism that performs a fluid discharge operation by reducing the volume of a fluid chamber, and the other end of the pulsation generating mechanism There is known a fluid ejecting apparatus having a connection channel pipe provided with a nozzle whose portion is smaller than the diameter of the outlet channel (see, for example, Patent Document 1).

JP 2005-152127 A

  When the fluid ejecting apparatus according to Patent Document 1 described above is used for surgery, it is considered that blood, body fluid, or the like adheres to the fluid ejecting apparatus. Therefore, when this fluid ejecting apparatus is repeatedly used, it is required to sterilize using means such as cleaning and autoclave including not only the outer peripheral part but also the part where the fluid flows inside.

  However, it is difficult to sterilize at the site of use, and it has been more preferable to make the fluid ejection device disposable for each operation.

  However, disposing a conventional fluid ejecting apparatus that is difficult for the user to disassemble and reassemble leads to an increase in running cost, reducing the cost of the fluid ejecting apparatus, and in particular repetitive use of high cost elements. It is desirable to reduce the cost of components that are considered to be in direct contact with blood, bodily fluids and fluids and to make them disposable.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A fluid ejecting apparatus according to this application example is a fluid ejecting apparatus that ejects fluid from a nozzle in a pulsed manner by reducing the volume of a fluid chamber with a diaphragm. The fluid ejecting apparatus includes: A nozzle unit having an inlet channel for supplying fluid, an outlet channel for discharging fluid from the fluid chamber, and a nozzle communicating with the outlet channel, and a piezoelectric element unit having a piezoelectric element for displacing the diaphragm And the nozzle unit and the piezoelectric element unit are detachably mounted.

  In the fluid ejecting apparatus according to this application example, the piezoelectric element is an overwhelmingly high cost element compared to other components. Therefore, the nozzle unit and the piezoelectric element unit are configured to be detachable. This enables the disposable use of a nozzle unit including an inlet channel, a diaphragm, a fluid chamber, an outlet channel, and a nozzle that are considered to be in direct contact with fluid, body fluid, and blood. This nozzle unit is low in cost with respect to the piezoelectric element and is suitable for disposable use. In addition, the piezoelectric element unit, which is not costly contacted with fluids, body fluids, and blood, and can be used repeatedly, can be used repeatedly, and safety can be improved and running cost can be reduced.

  As the piezoelectric element, a laminated piezoelectric element in which a piezoelectric material and a plurality of interlayer electrodes are alternately stacked is employed in order to enhance piezoelectric characteristics, and a lead-containing material may be used as the piezoelectric material. Is Ag or an alloy of Ag and Pd.

Therefore, when discarding the fluid ejecting apparatus, it is possible to reduce the environmental load by separating and discarding the piezoelectric element containing lead from the piezoelectric element unit having few components.
Further, there is an effect that expensive Ag or an alloy of Ag and Pd can be easily separated and recovered.

  Application Example 2 The fluid ejection device according to the application example described above includes an auxiliary member that is fixed to one end surface in the expansion / contraction direction of the piezoelectric element and is in close contact with the diaphragm, and is fixed to the other end surface and the housing of the nozzle unit. And a lid member fixed to the body.

  According to such a configuration, the piezoelectric element unit is composed of the piezoelectric element, the auxiliary member, and the lid member, and has a simple configuration, so that the assemblability is improved and the unit alone is easy to handle. .

  Application Example 3 In the fluid ejecting apparatus according to the application example, a connection lead for inputting a driving signal is connected to the piezoelectric element, and covers a surface of the piezoelectric element including a connection portion between the connection lead and the piezoelectric element. It is preferable that a resin layer is provided.

  With such a configuration, by covering the periphery of the piezoelectric element with resin, it is possible to prevent a short circuit between the electrodes due to moisture adhering to the piezoelectric element, and further prevent deterioration of the piezoelectric characteristics.

  Further, the connection portion can be reinforced by covering the connection portion between the connection lead and the piezoelectric element with a resin layer.

  Application Example 4 In the fluid ejecting apparatus according to the application example described above, it is preferable that an opening for inserting the connection lead is provided in the lid member.

  In the configuration of this application example, a connection lead for inputting a drive signal is connected to the piezoelectric element. Therefore, by providing an opening for inserting the connection lead in the lid member, the piezoelectric element unit can be attached to the nozzle unit with the connection lead connected, and handling can be facilitated.

Application Example 5 In the fluid ejecting apparatus according to the application example, it is preferable that the auxiliary member is formed of a material having a Young's modulus smaller than that of the diaphragm and the piezoelectric element.
Here, as a material of the auxiliary member, for example, Al or Al alloy, Cu or Cu alloy, or the like can be adopted.

  By doing so, it is possible to increase the affinity between the piezoelectric element and the auxiliary member, and to prevent the contact surface with the auxiliary member of the piezoelectric element having brittleness or the chipping of the corner portion.

  Application Example 6 In the fluid ejecting apparatus according to the application example described above, it is preferable that the diaphragm includes an elastic element that biases the piezoelectric element.

  As described above, the fluid ejecting apparatus according to this application example has a configuration in which the nozzle unit and the piezoelectric element unit are detachable. The separation boundary portion of these units is a diaphragm, and it is necessary to bring the diaphragm and the piezoelectric element (with an auxiliary member interposed) into close contact with each other.

  These units have dimensional variations in manufacturing, and it is conceivable that the diaphragm and the piezoelectric element do not come into close contact with each other in the mounted state. Therefore, by providing an elastic element in the diaphragm and always energizing the piezoelectric element, the diaphragm and the piezoelectric element can be kept in close contact, and the diaphragm can follow the expansion and contraction of the piezoelectric element.

  Application Example 7 In the fluid ejecting apparatus according to the application example described above, in the state where the auxiliary member and the diaphragm are in close contact with each other, a joint portion between the end surface of the housing in which the piezoelectric element is disposed and the lid member It is desirable that a gap is provided in the gap and the gap is filled with a joining member.

According to such a configuration, the dimensional variation in the manufacturing of the nozzle unit and the piezoelectric element unit is absorbed and joined by the gap between the end surface of the casing on the nozzle unit side and the lid member on the piezoelectric element unit side. The piezoelectric element and the diaphragm can be brought into close contact with each other.
In addition, as a joining member, it is more preferable to use a low melting metal and an adhesive agent.

  Application Example 8 In the fluid ejection device according to the application example described above, it is preferable that the diaphragm and the piezoelectric element are bonded with a low-melting-point bonding material.

  In this way, the diaphragm and the piezoelectric element (with the auxiliary member interposed) can be tightly bonded. Further, since the low melting point bonding material is used for bonding, the diaphragm and the piezoelectric element (that is, by heating) The nozzle unit and the piezoelectric element unit) can be separated.

  Application Example 9 In the fluid ejecting apparatus according to the application example described above, the nozzle unit includes the diaphragm, the piezoelectric element unit stores a housing that stores the piezoelectric element, and an opening in the diaphragm direction of the housing. A thin plate member that seals one end surface of the piezoelectric element and a lid member that seals the opening of the housing in a direction opposite to the diaphragm and is fixed to the other end surface of the piezoelectric element. When the piezoelectric element unit and the nozzle unit are mounted, it is preferable that the diaphragm and the thin plate member are in close contact with each other.

  In this way, the nozzle unit and the piezoelectric element unit can be separated between the diaphragm and the thin plate member, and the diaphragm is made to follow the expansion and contraction of the piezoelectric element because it is displaced almost the same as the diaphragm. be able to.

  Application Example 10 In the fluid ejection device according to the application example described above, it is preferable that a fluid thin film is provided at an interface between the diaphragm and the thin plate member.

  Thus, by providing a thin film having fluidity between the diaphragm and the thin plate member, the diaphragm and the thin plate member can be brought into close contact with each other and can be easily separated.

  Further, the air layer between the diaphragm and the thin plate member can be eliminated by the fluid thin film. The presence of an air layer between the diaphragm and the thin plate member eliminates the problem that the pressure in the fluid chamber cannot be sufficiently increased due to the air layer acting as a damper when the diaphragm is displaced in the direction of reducing the volume of the fluid chamber. be able to.

  Application Example 11 In the fluid ejection device according to the application example described above, it is preferable that the internal space of the piezoelectric element unit is filled with resin.

  According to such a configuration, short-circuiting between electrodes due to moisture adhering to the piezoelectric element can be prevented by covering the periphery of the piezoelectric element with the resin. In addition, it is possible to prevent deterioration of piezoelectric characteristics due to moisture adhering to the piezoelectric element. Therefore, it is desirable that the resin to be filled has a small water absorption.

  Application Example 12 A nozzle unit according to this application example discharges fluid from the fluid chamber, a diaphragm that reduces the volume of the fluid chamber, an inlet channel that supplies fluid to the fluid chamber, and the fluid chamber. An outlet channel and a nozzle communicating with the outlet channel are provided.

  According to such a configuration, the elements that are in direct contact with the flowing fluid are concentrated in the nozzle unit, and the components can be processed by the machining means, so that the cost can be reduced.

  Application Example 13 A piezoelectric element unit according to this application example includes a piezoelectric element, an auxiliary member that is fixed to one end surface in the expansion / contraction direction of the piezoelectric element and is in close contact with the diaphragm, and a lid member that is fixed to the other end surface. And is provided.

  As the piezoelectric element, a laminated piezoelectric element in which a piezoelectric material and a plurality of interlayer electrodes are alternately stacked is employed in order to enhance piezoelectric characteristics. A lead-containing material may be used for the piezoelectric material, and Ag may be used for the interlayer electrode. Alternatively, Ag and Pd alloy are used.

  Therefore, when a lead-containing piezoelectric material is used, it is possible to reduce the environmental load by separating and discarding the piezoelectric element containing lead from the piezoelectric element unit having few constituent elements. Further, there is an effect that expensive Ag or an alloy of Ag and Pd can be easily separated and recovered.

  Application Example 14 In the piezoelectric element unit according to the application example described above, it is preferable that a resin layer covering at least the surface of the piezoelectric element is provided.

  In this way, by covering the periphery of the piezoelectric element with resin in the state of the piezoelectric element unit, it is possible to prevent a short circuit between electrodes due to moisture adhering to the piezoelectric element and to prevent deterioration of the piezoelectric characteristics. . Accordingly, it is desirable that the resin to be coated has a low water absorption.

  [Application Example 15] The piezoelectric element unit according to the application example is fixed to seal a cylindrical casing that houses the piezoelectric element and an opening of the casing on the diaphragm side, and the auxiliary unit. And a thin plate member fixed to the member, and the lid member is preferably fixed so as to seal the opening of the housing facing the opening on the diaphragm side.

  According to such a configuration, since the piezoelectric element unit is integrated with the piezoelectric element stored inside the housing, it can be stored alone or attached to the nozzle unit without touching the piezoelectric element. It is possible and easy to handle.

  Application Example 16 In the piezoelectric element unit according to the application example described above, it is preferable that the inside of the space formed by the casing, the lid member, and the thin plate member is filled with resin.

According to such a configuration, by filling the inside of the piezoelectric element unit with the resin, it is possible to prevent a short circuit between the electrodes due to moisture adhering to the piezoelectric element. In addition, it is possible to prevent deterioration of piezoelectric characteristics due to moisture adhering to the piezoelectric element.
Therefore, it is desirable that the resin to be filled has a small water absorption.

  Furthermore, if a resin containing a material having a high thermal conductivity is used, heat generated when the piezoelectric element is driven is dissipated to the outside through the housing, thereby preventing deterioration of characteristics due to the high temperature of the piezoelectric element. be able to.

Explanatory drawing which shows schematic structure of a fluid injection system. FIG. 3 is a cross-sectional view illustrating the main configuration of the fluid ejecting apparatus according to Embodiment 1 cut along a liquid flow path direction. The side view which illustrated the fluid injection apparatus of FIG. 2 from the right side. The side view which illustrated the fluid injection apparatus of FIG. 2 from the left side. FIG. 3 is a cross-sectional view illustrating details of a joint portion between the nozzle unit and the piezoelectric element unit according to the first embodiment. The top view which shows the state which visually recognized the 1st machine casing which concerns on Embodiment 1 from the piezoelectric element side. FIG. 3 is an enlarged cross-sectional view illustrating an inflow port according to the first embodiment. Sectional drawing which shows the joining structure of the nozzle which concerns on Embodiment 1, and a connection flow-path pipe. FIG. 9 is a partial cross-sectional view illustrating Example 1 of the fluid ejecting apparatus according to the second embodiment. FIG. 9 is a partial cross-sectional view illustrating Example 2 of the fluid ejecting apparatus according to the second embodiment. FIG. 9 is a partial cross-sectional view illustrating a fluid ejection device according to a third embodiment. FIG. 9 is a partial cross-sectional view illustrating a fluid ejection device according to a fifth embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 shows a fluid ejection system, FIGS. 2 to 8 show a fluid ejection apparatus according to Embodiment 1, FIGS. 9 and 10 show Embodiment 2, FIG. 11 shows Embodiment 3, and FIG. 12 shows Embodiment 5. FIG.
Note that the drawings referred to in the following description are schematic views in which the vertical and horizontal scales of members or portions are different from actual ones for convenience of illustration.

In addition, the fluid ejection system and the fluid ejection device according to the present invention can be used in various ways such as drawing using ink, cleaning fine objects and structures, scalpels, and the like in the embodiments described below. A fluid ejecting apparatus suitable for incising or excising a living tissue will be described as an example. Therefore, the fluid used in the embodiment is a liquid such as water or physiological saline, and the fluid may be expressed as a liquid.
(Fluid injection system)

  FIG. 1 is an explanatory diagram showing a schematic configuration of a fluid ejection system. In FIG. 1, a fluid ejection system 1 includes a control device 20 including a liquid container that stores liquid as a basic configuration and a pump (not shown) as a pressure generation unit, and fluid that pulsates and ejects liquid supplied from the pump. It is comprised from the injection apparatus 10, and the connection tube 25 which connects the fluid injection apparatus 10 and a pump.

  The fluid ejecting apparatus 10 includes a pulsation generating mechanism 30 that pulsates and discharges the supplied liquid at a high pressure and a high frequency, and a connection flow channel pipe 90 connected to the pulsation generation mechanism. A nozzle 95 having a fluid ejection opening 97 having a reduced cross-sectional area of the flow path is inserted into the nozzle 95.

  Next, the flow of liquid in the fluid ejection system 1 will be described. The liquid stored in the liquid container provided in the control device 20 is supplied to the pulsation generating mechanism 30 through the connection tube 25 at a constant pressure by a pump.

  The pulsation generating mechanism 30 includes a fluid chamber 120 and a diaphragm 70 and a piezoelectric element 40 (both see FIG. 2) as means for changing the volume of the fluid chamber 120, and drives the volume changing means to generate pulsation. Then, the liquid is ejected from the fluid ejection opening 97 in a pulse shape at a high speed.

  The pressure generating unit is not limited to a pump, and an infusion bag as a liquid container may be held at a position higher than the pulsation generating mechanism 30 by a stand or the like. Accordingly, there is an advantage that a pump is not required, the configuration can be simplified, and the liquid channel can be easily sterilized.

  The discharge pressure of the pump is generally set to 3 atm (0.3 MPa) or less. Moreover, when using an infusion bag, the altitude difference between the pulsation generating mechanism 30 and the top surface of the infusion bag is a pressure, and is about 0.1 to 0.15 atm (0.01 to 0.015 MPa). It is desirable to set the altitude difference.

  When performing an operation using the fluid ejection system 1, the main part that the operator holds is the pulsation generating mechanism 30. Therefore, it is preferable that the connection tube 25 connected to the pulsation generating mechanism 30 is as flexible as possible. For that purpose, it is preferable to use a flexible and thin tube and to reduce the pressure within a range in which the liquid can be fed to the pulsation generating mechanism 30.

In particular, as in the case of brain surgery, when there is a possibility that a failure of the fluid ejection system 1 may cause a serious accident, it is inevitable that high-pressure fluid is ejected when the connection tube 25 is disconnected. In view of this, it is required to keep the pressure low.
(Embodiment 1)

Next, the structure of the fluid ejection device according to the first embodiment will be described.
2 is a cross-sectional view showing the main configuration of the fluid ejecting apparatus according to Embodiment 1 cut along the liquid flow path direction, FIG. 3 is a side view illustrating the fluid ejecting apparatus of FIG. 2 from the right side, and FIG. It is the side view illustrated from the left side.

  First, a schematic configuration of the fluid ejecting apparatus will be described with reference to FIGS. The fluid ejecting apparatus 10 is configured in a state where a nozzle unit 11 and a piezoelectric element unit 12 are mounted.

  The nozzle unit 11 includes a fluid chamber 120 provided on one end surface of the first machine casing 80, an inlet channel 83 that supplies liquid to the fluid chamber 120, an outlet channel 88 that discharges liquid from the fluid chamber 120, The connecting channel pipe 90 communicates with the outlet channel 88, and the nozzle 95 press-fitted into the connecting channel pipe 90.

  In the present embodiment, since the connection channel tube 90 is detachably screwed to the first machine casing 80, the portion excluding the connection channel tube 90 may be the nozzle unit 11.

  On the wall surface 82 of the first machine frame 80, a ring-shaped spacer 60 and a peripheral edge of a diaphragm 70 made of a disk-shaped metal thin plate are overlapped and fixed firmly. The fluid chamber 120 is formed by a space surrounded by the wall surface 82, the inner peripheral wall 61 of the spacer 60, and the diaphragm 70.

  A tube connection pipe 81 projects from the outer side surface of the first machine casing 80, and an inflow connection flow path 84 is opened in the tube connection pipe 81. The inflow connection channel 84 is provided with a connection channel 85 that communicates with an inlet channel 83 formed in the wall surface 82. The inlet channel 83 will be described in detail with reference to FIGS.

  The tube connection pipe 81 is fitted with the connection tube 25, and the connection tube 25 is connected to a pump provided inside the control device 20 (see FIG. 1), and the fluid chamber 120 is connected via the inlet channel 83. The liquid is supplied to the inside.

  Further, the first machine casing 80 is provided with an outlet channel 88 communicating with the fluid chamber 120 substantially perpendicularly to the wall surface 82 at the approximate center of the wall surface 82. The outlet channel 88 is continuous with the outlet connection channel 89 having a diameter (cross-sectional area) larger than that of the outlet channel 88. In addition, the connection part with the fluid chamber 120 of the exit flow path 88 is rounded smoothly.

  A connection flow channel tube insertion portion 80a projects from the end surface of the first machine frame 80 facing the diaphragm 70, and the connection flow channel tube 90 is inserted into the connection flow channel tube insertion portion 80a. A female screw 80d is formed in a range from the distal end portion of the connection flow channel insertion portion 80a to the outlet connection flow channel 89.

  A connection flow channel 92 is opened in the connection flow channel tube 90, and a male screw 90a is formed on the outer periphery of the tip portion. The connection channel tube 90 is fixed to the first machine frame 80 by screwing these screw portions. Therefore, the connection channel tube 90 is detachable from the first machine casing 80.

  The connection channel tube 90 is fixed by being screwed in until the tip of the male screw 90a is in close contact with the bottom of the female screw 80d.

  A cut portion 90b is formed on the outer peripheral portion in the longitudinal direction of the connection flow channel tube 90. The cut portion 90b is formed by cutting the outer peripheral portion of the connection flow channel tube 90 with planes facing each other. The cut portion 90b can be grasped and rotated by a jig or the like, and the connection channel tube 90 and the first machine casing 80 can be attached and detached.

  Therefore, according to such a configuration, in the unlikely event that the nozzle 95 is clogged, the connection flow channel tube 90 can be removed and cleaned and disinfected, and the connection flow channel tube 90 can be easily replaced. Can do.

  In addition, a plurality of types of the connection channel tube 90 can be prepared, and the shape of the connection channel tube 90 can be arbitrarily selected and used depending on the object of use.

  The connection channel tube 90 is provided with a connection channel 92 that communicates with the outlet connection channel 89, and a nozzle 95 is inserted into the end opposite to the outlet channel 88. The nozzle 95 has a nozzle channel 96 communicating with the connection channel 92 and a fluid ejection opening 97.

  Here, the connection channel 92, the nozzle channel 96, and the outlet connection channel 89 have the same cross-sectional area, and this cross-sectional area is larger than the cross-sectional area of the outlet channel 88.

  Further, the cross-sectional area of the fluid ejection opening 97 is reduced more than the cross-sectional area of the outlet channel 88. By doing so, it is possible to eject a pulsed droplet having a higher excision ability at a higher speed.

  In addition, the said cross-sectional area represents the cross-sectional area of a flow path when cut | disconnecting perpendicularly | vertically with respect to the flow direction of a liquid.

  The first machine casing 80 is equipped with a second machine casing 50 that is a cylindrical member having an outer flange 56 and a cylinder 51. As shown in FIG. 3, the outer shape of the outer flange portion 56 and the cylindrical portion 51 is a quadrangle. And the cylindrical hole 51a which penetrates the 2nd machine casing 50 is opened.

  The first machine frame 80 and the second machine frame 50 are screwed and fixed at the four corners with the fixing screws 161 with the peripheral edge of the diaphragm 70 and the spacer 60 sandwiched therebetween (see also FIG. 4), and are in close contact with each other. Let Therefore, in the present embodiment, the nozzle unit 11 is configured including the second machine casing 50.

  The piezoelectric element unit 12 is configured such that an upper plate 110 as an auxiliary member is fixed to one end portion of the piezoelectric element 40 in the expansion / contraction direction, and a lower plate 100 as a lid member is fixed to the other end portion.

  The upper plate 110 is made of a material having a Young's modulus (or hardness) smaller than that of the diaphragm 70 and the piezoelectric element 40 such as Al or Al alloy, Cu or Cu alloy.

  The piezoelectric element 40 employs a laminated piezoelectric element in which a piezoelectric material and a plurality of interlayer electrodes (not shown) are alternately stacked in order to improve piezoelectric characteristics, and Ag or an alloy of Ag and Pd is used as the interlayer electrode. A material having good conductivity is used.

  Driving electrodes (not shown) connected to the interlayer electrodes are provided on the opposite side surfaces of the piezoelectric element 40, and connection leads 151 and 152 are connected to these driving electrodes. Each of the connection leads 151 and 152 is inserted into lead insertion holes 101 and 102 serving as openings provided in the lower plate 100 and led to the outside, and a drive circuit unit (not shown) of the control device 20 (see FIG. 1). Connected).

  Further, a resin layer 140 is provided on the entire surface of the piezoelectric element 40 so as to cover the surface including the connection portions with the connection leads 151 and 152 and the insides of the lead insertion holes 101 and 102. Since the resin layer 140 covers the periphery of the piezoelectric element 40, the resin layer 140 is flexible enough to prevent the piezoelectric element 40 from being driven. The resin layer 140 is more preferably a material with low water absorption.

  The material of the resin layer 140 can be selected from, for example, a polyethylene resin, a polyimide resin, a polysulfone resin, a silicon resin, an epoxy resin, or a rubber resin. Each of these resins also has grades with different water absorption (water absorption rate), and among them, it is desirable to select a resin with low water absorption. The water absorption is more preferably 0.5% or less.

  The piezoelectric element unit 12 configured as described above is inserted into the hole 51a of the second machine frame 50 so that the upper plate 110 is in close contact with the diaphragm 70, and the lower plate 100 is inserted into the second machine frame 50. It fixes to the opening part end surface using the fixing screw 160 (refer FIG. 3). Therefore, the second machine casing 50 is a housing for the piezoelectric element unit 12.

  Note that the second machine casing 50 and the lower plate 100 are fixed after adjusting the dimensions so that the diaphragm 70 is not deformed while the piezoelectric element unit 12 is attached to the nozzle unit 11, and in close contact with each other.

Next, the joint between the nozzle unit 11 and the piezoelectric element unit 12 will be described in more detail with reference to FIG.
FIG. 5 is a cross-sectional view illustrating details of a joint portion between the nozzle unit and the piezoelectric element unit according to the first embodiment. Therefore, the same reference numerals as those in FIG.

  The first machine casing 80 is formed with a ring-shaped recess 86 around the outside of the wall surface 82, and the second machine casing 50 is formed with a ring-shaped protrusion 53 facing the ring-shaped recess 86. By inserting the ring-shaped convex portion 53 into the ring-shaped concave portion 86, accurate position regulation of the first machine frame 80 and the second machine frame 50 is performed.

  At this time, the diaphragm 70 and the spacer 60 are interposed between the wall surface 82 at the center of the first machine casing 80 and the inner peripheral flange 52 protruding from the inner side of the ring-shaped protrusion 53 of the second machine casing 50. Pressed.

  The diameters of the inner peripheral side wall 61 of the spacer 60 and the inner peripheral flange portion 52 of the second machine casing 50 are set to be substantially equal, and the support position for the displacement of the diaphragm 70 is the same.

  A packing 130 as a sealing material is interposed between the bottom of the ring-shaped concave portion 86 of the first machine casing 80 and the tip of the ring-shaped convex section 53 of the second machine casing 50. The packing 130 is pressed in a state where the diaphragm 70 and the spacer 60 are pressed, and the movement of the liquid between the outside and the fluid chamber 120 is restricted.

Next, the inlet channel 83 will be described with reference to FIGS.
FIG. 6 is a plan view showing a state in which the first machine casing is viewed from the piezoelectric element side. The inlet channel 83 is formed as a groove in the wall surface 82 of the first machine casing 80, has an end that is connected to the connection channel 85, and has a substantially arc shape extending to the inlet 83 a communicating with the fluid chamber 120. Has been extended.

  This groove is a concentric circle centering on the outlet channel 88 and extends counterclockwise from the connection with the connection channel 85 to the position indicated by the symbol A in the figure. It extends in the tangential direction of the peripheral side wall 61 (that is, the tangential direction of the side wall of the fluid chamber 120). Further, the range from C to D extends along the inner peripheral wall 61 of the spacer 60.

  Further, the range from A to B is connected by a small arc that smoothly changes the flow direction of the liquid.

  Most of the openings (upper part in the figure) of the grooves formed in this way are sealed by a ring-shaped spacer 60 to form an inlet channel 83, and the inlet part 83 a communicates with the fluid chamber 120. .

  By forming the inlet channel 83 in this way, the liquid that flows in from the connection tube 25 at a constant pressure becomes a swirl flow along the inner peripheral side wall 61 of the spacer 60.

  In this way, by making the liquid swirl in the fluid chamber 120, the liquid is drawn toward the outside of the fluid chamber 120 by centrifugal force, and the bubbles contained in the liquid gather in the center, and from the outlet channel 88. It can be discharged to the outside as the liquid is discharged. Therefore, it is possible to suppress bubbles from staying in the fluid chamber 120 and sufficiently increase the pressure inside the fluid chamber 120, so that reliable pulsation discharge can be performed.

The inlet 83a of the inlet channel 83 to the fluid chamber 120 is continuous with a slope 83d from the bottom surface to the wall surface 82.
FIG. 7 is an enlarged cross-sectional view of the inlet portion. The inflow port portion 83a is continued from the bottom surface 83b of the groove to the wall surface 82 by an inclined surface in the range from the code C to the code D of the inlet channel 83 shown in FIG.

  By doing so, the fluid resistance at the connection portion between the inflow port portion 83a and the wall surface 82 is reduced, and the turbulence caused by the vortex generated by the sudden change of the flow path is prevented from being disturbed by the swirling flow and the generation of bubbles. Can be suppressed.

Next, the joint structure between the nozzle and the connection channel pipe in the present embodiment will be described with reference to the drawings.
FIG. 8 is a cross-sectional view showing a joint structure between a nozzle and a connection flow channel tube. The nozzle 95 is composed of a tip flange portion 98 and an insertion portion 99, and a nozzle channel 96 and a fluid ejection opening 97 that communicate with the connection channel 92 of the connection channel tube 90 are opened. On the outer peripheral surface of the insertion portion 99, a groove 99a is formed in the middle in the longitudinal direction, and a thin tube portion 99b having a reduced outer diameter is formed at the insertion-side distal end portion.

  A nozzle insertion hole 90f is formed at the end of the connection flow channel tube 90. The nozzle 95 is press-fitted into the nozzle insertion hole 90f. At this time, the end surface 99c of the nozzle 95 is brought into close contact with the bottom surface 94 of the nozzle insertion hole 90f.

  The nozzle 95 is press-fitted into the connection flow channel tube 90 after an adhesive is applied to the outer peripheral side surface of the insertion portion 99 for reinforcing press-fitting strength. During the press-fitting, the adhesive accumulates in the groove 99a. Therefore, the groove 99a in the present embodiment is an adhesive reservoir, and has a function of increasing the adhesive strength and a function of preventing liquid leakage and air intrusion at the joint portion between the nozzle 95 and the connection flow channel tube 90.

  The narrow tube portion 99b prevents the adhesive from stopping in the range of the narrow tube portion 99b and entering the inside of the connection flow channel 92 or the nozzle flow channel 96.

  Next, the operation of the fluid ejection device 10 in the present embodiment will be described with reference to FIGS. The liquid discharge of the present embodiment is performed by the difference between the inertance L1 on the inlet flow channel side (sometimes referred to as the synthetic inertance L1) and the inertance L2 on the outlet flow channel side (sometimes referred to as the synthetic inertance L2).

First, inertance will be described.
The inertance L is expressed by L = ρ × h / S where the density ρ of the liquid, the cross-sectional area S of the flow path, and the length h of the flow path are set. If the pressure difference ΔP in the flow path, the flow rate Q of the liquid flowing in the flow path, and the time t are used, the equation of motion in the flow path is transformed using the inertance L, and the relationship ΔP = L × dQ / dt is derived. .

  That is, the inertance L indicates the degree of influence on the time change of the flow rate. The larger the inertance L, the less the time change of the flow rate, and the smaller the inertance L, the greater the time change of the flow rate.

  The synthetic inertance L1 is set so that the cross-sectional area of the inflow connecting flow path 84 and the connecting flow path 85 is sufficiently larger than the cross-sectional area of the inlet flow path 83. Is calculated in At this time, since the connection tube 25 has flexibility, it may be deleted from the calculation of the synthetic inertance L1.

  The synthetic inertance L2 can be considered as the sum of the outlet flow path 88 and the outlet connection flow path 89 because the connection flow path tube 90 has sufficient rigidity for the propagation of the pressure wave of the liquid.

  In this embodiment, the flow path length and cross-sectional area of the inlet flow path 83 and the flow path length and cross-sectional area of the outlet flow path 88 and the outlet connection flow path 89 are set so that the synthetic inertance L1 is larger than the synthetic inertance L2. Set.

Next, the liquid ejection operation will be described with reference to FIG.
The liquid is always supplied to the inlet channel 83 by a pump at a constant hydraulic pressure. As a result, when the piezoelectric element 40 does not operate, the liquid flows into the fluid chamber 120 due to the difference between the discharge pressure of the pump and the fluid resistance value of the entire inlet channel.

  Here, if a drive signal is input to the piezoelectric element 40 and the piezoelectric element 40 expands suddenly, the pressure in the fluid chamber 120 is such that the combined inertances L1 and L2 on the inlet channel side and the outlet channel side are sufficiently large. If it has, it will rise rapidly and reach several tens of atmospheres. Since this pressure is much larger than the pressure by the pump applied to the inlet channel 83, the inflow of liquid from the inlet channel 83 into the fluid chamber 120 is reduced by the pressure, and the outflow from the outlet channel 88. Will increase.

  However, since the synthetic inertance L1 on the inlet flow path side is larger than the synthetic inertance L2 on the outlet flow path side, the liquid is discharged from the outlet flow path 88 more than the decrease in the flow rate of the liquid flowing into the fluid chamber 120 from the inlet flow path 83. The increased amount of liquid is larger. As a result, a pulsed fluid discharge, that is, a pulsating flow is generated in the outlet channel 88.

  The pressure fluctuation at the time of discharge propagates through the connection flow channel tube 90, and the liquid is ejected from the fluid ejection opening 97 (see FIG. 2) of the nozzle 95 at the tip. Since the diameter of the fluid ejection opening 97 is reduced more than the diameter of the outlet channel 88, the liquid is ejected as a high-pressure, high-speed pulsed droplet.

  On the other hand, the inside of the fluid chamber 120 is in a vacuum state immediately after the pressure increase due to the interaction between the decrease in the amount of liquid inflow from the inlet channel 83 and the increase in the outflow of liquid from the outlet channel 88. As a result, the liquid flowing in the inlet channel 83 returns to the fluid chamber 120 at a speed similar to that before the operation of the piezoelectric element 40 after a predetermined time has elapsed due to both the pressure of the pump and the vacuum state in the fluid chamber 120. To do. If the piezoelectric element 40 is expanded after the flow of the liquid in the inlet channel 83 is restored, the liquid can be continuously ejected from the nozzle 95 in a pulse shape.

  Therefore, according to the present embodiment, the piezoelectric element 40 is overwhelmingly expensive as compared with other components. Therefore, the piezoelectric element unit 12 includes an inlet channel 83, a diaphragm 70, a fluid chamber 120, an outlet channel 88, a connection channel tube 90, and a nozzle 95 that are considered to be in direct contact with a flowing liquid, body fluid, or blood. By using the low-cost nozzle unit 11 as a single-use for the (piezoelectric element 40) and repeatedly using the high-cost piezoelectric element unit 12 without being in direct contact with the flowing liquid, body fluid, or blood, safety is achieved. And the running cost can be reduced.

  In addition, as the piezoelectric element 40, a laminated piezoelectric element in which a piezoelectric material and a plurality of interlayer electrodes are alternately laminated is employed in order to enhance piezoelectric characteristics. The piezoelectric material may be a lead-containing material, and the interlayer electrode is made of Ag or an alloy of Ag and Pd.

Therefore, when the piezoelectric element 40 contains lead, the environmental load can be reduced by separating and discarding the piezoelectric element 40 from the piezoelectric element unit 12 having few components.
Further, there is an effect that expensive Ag or an alloy of Ag and Pd can be easily separated and recovered.

  Further, since the piezoelectric element unit 12 is composed of the piezoelectric element 40, the upper plate 110, and the lower plate 100 and has a simple configuration, the handling becomes easy and the assembling property is improved.

  Further, by covering the surface of the piezoelectric element 40 including the connection portion between the connection leads 151, 152 and the piezoelectric element 40 with the resin layer 140 having low water absorption, short circuit between interlayer electrodes caused by moisture adhering to the piezoelectric element 40 is prevented. It is possible to prevent the deterioration of the piezoelectric characteristics.

  In addition, the connection leads 151 and 152 can be reinforced by filling the resin layers 140 in the lead insertion holes 101 and 102 through which the connection leads 151 and 152 are inserted.

  Furthermore, when the piezoelectric element unit 12 is handled alone, since the piezoelectric element 40 is covered with the resin layer 140, the piezoelectric element 40 is not damaged or chipped, so that the handling is facilitated.

  The piezoelectric element unit 12 according to the present embodiment includes a piezoelectric element 40, an upper plate 110, and a lower plate 100. At this time, the lead insertion holes 101 and 102 are provided in the lower plate 100 and the connection leads 151 and 152 are inserted, and the piezoelectric element unit 12 can be attached to the nozzle unit 11 with the connection leads 151 and 152 connected. Handling can be facilitated.

Further, the upper plate 110 is made of a material having a Young's modulus smaller than that of the diaphragm 70 and the piezoelectric element 40 such as Al or Al alloy, Cu or Cu alloy. As a result, the affinity between the piezoelectric element 40 and the upper plate 110 can be increased, and chipping of the contact surface or corner portion with the auxiliary member of the piezoelectric element generally having brittleness can be prevented.
(Embodiment 2)

  Next, the fluid ejecting apparatus according to the second embodiment will be described with reference to the drawings. The second embodiment is characterized in that the diaphragm 70 includes an elastic element that biases the piezoelectric element 40. Two specific examples will be exemplified and described with a focus on differences from the first embodiment. Note that the shape of the diaphragm 70 is exaggerated.

First, Example 1 will be described.
FIG. 9 is a partial cross-sectional view illustrating Example 1 of the fluid ejecting apparatus according to the second embodiment. The diaphragm 70 is press-fitted and fixed with a spacer 60 interposed between the first machine casing 80 and the second machine casing 50 at the periphery. Here, the central portion of the diaphragm 70 is formed in a convex shape in the direction of the piezoelectric element 40 and is in contact with the upper plate 110.

  In this state, the piezoelectric element unit 12 is in the process of being attached to the nozzle unit 11, and the end surface 57 on the opening side of the second machine casing 50 and the peripheral end surface 103 of the lower plate 100 have a slight gap. doing.

  From this state, the piezoelectric element unit 12 is pushed into the nozzle unit 11 until the end face 57 on the opening side of the second machine casing 50 and the peripheral edge face 103 of the lower plate 100 come into close contact with each other. Then, the diaphragm 70 is displaced by the piezoelectric element unit 12 to a position illustrated by a diaphragm 70 ′ (represented by a two-dot chain line).

  The diaphragm 70 ′ forms a fluid chamber 120 having substantially the same volume as that of the first embodiment (see FIG. 5). As a result, the piezoelectric element 40 is urged by an elastic force corresponding to the displacement amount of the diaphragm 70. Therefore, the upper plate 110 (that is, the piezoelectric element 40) and the diaphragm 70 are brought into close contact with each other.

  As described above, in the fluid ejecting apparatus 10, the boundary portion between the nozzle unit 11 and the piezoelectric element unit 12 is the diaphragm 70, and the diaphragm 70 and the piezoelectric element 40 need to be in close contact with both units attached. .

  These units have manufacturing dimensional variations, and it is conceivable that the diaphragm 70 and the piezoelectric element 40 do not come into close contact with each other in the mounted state. Therefore, the diaphragm 70 is provided with an elastic element, and the piezoelectric element 40 is always urged in the expansion / contraction direction to form a close state between the diaphragm 70 and the piezoelectric element 40, thereby causing the diaphragm 70 to follow the expansion / contraction movement of the piezoelectric element 40. be able to.

Next, Example 2 will be described.
FIG. 10 is a partial cross-sectional view illustrating Example 2 of the fluid ejecting apparatus according to the second embodiment. The diaphragm 70 is press-fitted and fixed with a spacer 60 interposed between the first machine casing 80 and the second machine casing 50 at the periphery. Here, FIG. 10 shows a state in which the piezoelectric element unit 12 is attached to the nozzle unit 11 (the end surface 57 on the opening side of the second machine casing 50 and the peripheral end surface 103 of the lower plate 100 are in close contact). .

  Before the piezoelectric element unit 12 is mounted, the diaphragm 70 is not deformed (substantially flat state shown by a two-dot chain line), and when the piezoelectric element unit 12 is mounted, the diaphragm 70 ′ is placed inside the fluid chamber 120. Is displaced to the position shown in FIG.

  As a result, the piezoelectric element 40 is urged in the expansion / contraction direction of the piezoelectric element 40 by an elastic force corresponding to the displacement amount of the diaphragm 70. Therefore, the upper plate 110 (that is, the piezoelectric element 40) and the diaphragm 70 are brought into close contact with each other.

  It should be noted that the dimensions should be corrected so that the volume of the fluid chamber 120 becomes a predetermined volume in the state where the piezoelectric element unit 12 is mounted. Specifically, it can be easily performed by adjusting the thickness of the spacer 60.

Even in such a configuration, the diaphragm 70 is provided with an elastic element, and the piezoelectric element 40 is always urged in the expansion / contraction direction, thereby forming a close state between the diaphragm 70 and the piezoelectric element 40, and against the expansion / contraction movement of the piezoelectric element 40. The diaphragm 70 can be made to follow.
(Embodiment 3)

  Subsequently, a fluid ejecting apparatus according to Embodiment 3 will be described with reference to the drawings. In the third embodiment, a gap is provided at the joint between the end surface of the second machine frame on the nozzle unit side and the lower plate on the piezoelectric element unit side, and the piezoelectric element and the diaphragm are adjusted to be in close contact with each other by this gap. It has the characteristics. Therefore, the description will focus on differences from the first embodiment (see FIG. 5).

  FIG. 11 is a partial cross-sectional view illustrating the fluid ejection device according to the third embodiment. The diaphragm 70 is press-fitted and fixed with a spacer 60 interposed between the first machine casing 80 and the second machine casing 50 at the periphery. The piezoelectric element 40 is in close contact with the diaphragm 70 with the upper plate 110 interposed therebetween.

  In this state, the dimension is set in advance so that the end surface 57 on the opening side of the second machine casing 50 and the peripheral end surface 103 of the lower plate 100 have a slight gap.

  The position where the diaphragm 70 and the upper plate 110 abut can be detected by detecting the position of the diaphragm 70 or the displacement position from the outlet channel 88 using a light detection device. Alternatively, it is also possible to detect an electrical connection between the diaphragm 70 and the upper plate 110 and a contact resistance value.

  Thus, when it is detected that the upper plate 110 is in contact with the diaphragm 70, the joining member 141 is placed in the gap between the end surface 57 on the opening side of the second machine casing 50 and the peripheral end surface 103 of the lower plate 100. Fill and solidify.

  As the joining member 141, it is possible to use a low melting point metal or a thermoplastic adhesive, which has a sufficient joining strength (rigidity) at room temperature, and is heated between the second machine casing 50 and the lower plate 100. Separate the junction. That is, the nozzle unit 11 and the piezoelectric element unit 12 are separated.

  When the piezoelectric element unit 12 is reused, the residue of the joining member 141 may be washed away and attached to the nozzle unit 11 by the method described above.

According to such a configuration, the dimensional variation in manufacturing of the nozzle unit 11 and the piezoelectric element unit 12 is absorbed and joined by the gap between the end surface 57 of the second machine casing 50 as the housing and the end surface of the lower plate 100. Thus, the piezoelectric element 40 and the diaphragm 70 can be brought into close contact with each other.
(Embodiment 4)

  Subsequently, a fluid ejecting apparatus according to the fourth embodiment will be described. The fourth embodiment is characterized in that the diaphragm and the piezoelectric element are bonded with a low melting point bonding material. Description will be made with reference to FIGS. 2 and 5 focusing on the differences from the first embodiment.

  As in the first embodiment, the piezoelectric element unit 12 is configured by fixing the piezoelectric element 40, the upper plate 110, and the lower plate 100 to each other with an adhesive or the like. In the present embodiment, the piezoelectric element unit 12 has the piezoelectric element 40 bonded to the diaphragm 70 with a low melting point bonding material with the upper plate 110 interposed therebetween, and the lower plate 100 is fixed to the second machine frame 50 using the fixing screw 160. Fix it.

  As the low melting point bonding material, a low melting point metal or a thermoplastic adhesive can be used, and has a sufficient bonding strength (rigidity) at room temperature. An adhesive that can be dissolved by a solvent can also be used.

  The nozzle unit 11 and the piezoelectric element unit 12 are separated from each other by separating the joint between the diaphragm 70 and the upper plate 110 by heating after removing the fixing screw 160. That is, the nozzle unit 11 and the piezoelectric element unit 12 can be separated.

  In this way, since the diaphragm 70 and the piezoelectric element 40 can be tightly bonded, the displacement of the diaphragm 70 can follow the expansion and contraction of the piezoelectric element 40.

Furthermore, since the low melting point bonding material is used for bonding, the nozzle unit 11 and the piezoelectric element unit 12 can be easily separated by heating.
(Embodiment 5)

  Next, a fluid ejecting apparatus according to the fifth embodiment will be described with reference to the drawings. The fifth embodiment is characterized in that the piezoelectric element unit includes a thin plate member that is in close contact with the diaphragm. Therefore, the description will focus on differences from the first embodiment (see FIG. 5).

  FIG. 12 is a partial cross-sectional view illustrating the fluid ejection device according to the fifth embodiment. A spacer 60 and a diaphragm 70 are stacked and fixed on the wall surface 82 on the piezoelectric element 40 side of the first machine frame 80 to form a fluid chamber 120.

  On the other hand, the piezoelectric element unit 12 has a cylindrical second machine casing 50 as a housing and a separation plate 75 as a thin plate member fixed to the end face of the second machine casing 50 facing the diaphragm 70.

  The separation plate 75 is formed of a disk-like member having an outer diameter that is substantially the same as that of the diaphragm 70 and a thickness that is the same as that of the diaphragm 70.

  The piezoelectric element 40 is inserted into the second machine frame 50 with the upper plate 110 and the lower plate 100 fixed to both end faces, the upper plate 110 is fixed to the separation plate 75, and the lower plate 100 is attached to the second plate 50. The two machine frames 50 are fixed to the end face of the opening by fixing screws 160 (see FIG. 2).

  Accordingly, the piezoelectric element unit 12 is configured as a unit in which the piezoelectric element 40 is housed in an internal space where both end faces of the opening of the second machine casing 50 are sealed with the separation plate 75 and the lower plate 100.

  Note that connection leads 151 and 152 are connected to the piezoelectric element 40, and the connection leads 151 and 152 are led out through the lead insertion holes 101 and 102 formed in the lower plate 100.

  The nozzle unit 11 and the piezoelectric element unit 12 are fixed by a fixing screw 161 (see FIG. 2) as in the first embodiment. Therefore, it is a detachable structure.

  In the present embodiment, the inside of the piezoelectric element unit 12 and the lead insertion holes 101 and 102 are filled with a resin 142 having a low water absorption. As the material of the resin 142, the same material as the resin layer 140 (see FIG. 2) described in the first embodiment can be selected.

  The resin 142 is more preferably a material having high thermal conductivity. As a material having a high thermal conductivity, a material in which a material having a high thermal conductivity such as an inorganic ceramic powder or a carbon powder is mixed into the base resin can be considered.

  Note that the resin 142 is more preferably a material that satisfies both conditions of low absorbency and high thermal conductivity.

  A liquid thin film (not shown) is provided at the interface between the diaphragm 70 and the separation plate 75. As the thin film having fluidity, for example, silicon oil or the like can be used, and a material having an appropriate viscosity is selected so as to spread uniformly at the interface as a thin thin film.

  Therefore, the nozzle unit 11 and the piezoelectric element unit 12 can be separated between the diaphragm 70 and the separation plate 75, and the separation plate 75 has almost the same displacement form as the diaphragm 70. The diaphragm 70 can be made to follow the movement of expansion / contraction.

  Further, by providing a fluid thin film between the diaphragm 70 and the separation plate 75, the diaphragm 70, the separation plate 75, and the fluid thin film can be brought into close contact with each other, and separation can be easily performed.

  Furthermore, the air layer between the diaphragm 70 and the separation plate 75 can be eliminated by the fluid thin film. If an air layer exists between the diaphragm 70 and the separation plate 75, the air layer becomes a damper when the diaphragm 70 is displaced in a direction to reduce the volume of the fluid chamber 120 by the piezoelectric element 40, thereby causing the inside of the fluid chamber 120. The problem that the pressure cannot be sufficiently increased can be eliminated.

  Further, by filling the inside of the piezoelectric element unit 12 with the resin 142 having a small water absorption, it is possible to prevent a short circuit of the interlayer electrode due to moisture adhering to the piezoelectric element 40. In addition, it is possible to prevent deterioration of piezoelectric characteristics due to moisture adhering to the piezoelectric element 40. Furthermore, the connection leads 151 and 152 can be reinforced, and the reliability can be improved.

  When the fluid ejection device 10 is continuously driven for a long time, the piezoelectric element 40 generates heat. Therefore, by filling the space between the piezoelectric element 40 and the second machine frame 50 with a resin having high thermal conductivity, the generated heat is dissipated to the outside through the second machine frame 50, so that the piezoelectric element 40 is There is an effect that deterioration of characteristics due to high temperature can be prevented.

  DESCRIPTION OF SYMBOLS 10 ... Fluid injection apparatus, 11 ... Nozzle unit, 12 ... Piezoelectric element unit, 40 ... Piezoelectric element, 70 ... Diaphragm, 83 ... Inlet flow path, 88 ... Outlet flow path, 95 ... Nozzle, 120 ... Fluid chamber.

Claims (16)

A fluid ejecting apparatus that ejects fluid from a nozzle in a pulsed manner by reducing the volume of a fluid chamber with a diaphragm,
A nozzle unit comprising: the fluid chamber; an inlet channel that supplies fluid to the fluid chamber; an outlet channel that discharges fluid from the fluid chamber; and a nozzle that communicates with the outlet channel;
A piezoelectric element unit having a piezoelectric element for displacing the diaphragm,
The fluid ejecting apparatus, wherein the nozzle unit and the piezoelectric element unit are detachably mounted. The fluid ejection device according to claim 1,
An auxiliary member that is fixed to one end surface of the piezoelectric element in the expansion / contraction direction and is in close contact with the diaphragm; and a lid member that is fixed to the other end surface and is fixed to the casing of the nozzle unit. A fluid ejecting apparatus. The fluid ejection device according to claim 1 or 2,
A fluid ejecting apparatus, wherein a connection lead for inputting a driving signal is connected to the piezoelectric element, and a resin layer covering a surface of the piezoelectric element including a connection portion between the connection lead and the piezoelectric element is provided. . In the fluid ejection device according to claim 2 or 3,
An opening for inserting the connection lead is provided in the lid member. In the fluid ejection device according to claim 2 or 3,
The fluid ejecting apparatus, wherein the auxiliary member is made of a material having a Young's modulus smaller than that of the diaphragm and the piezoelectric element. The fluid ejection device according to claim 1,
The fluid ejection device, wherein the diaphragm includes an elastic element that biases the piezoelectric element. The fluid ejection device according to claim 1 or 2,
In a state where the auxiliary member and the diaphragm are in close contact with each other, a gap is provided in a joint portion between the end surface of the casing in which the piezoelectric element is disposed and the lid member, and the gap is filled with the joint member. A fluid ejecting apparatus. The fluid ejection device according to claim 1,
The fluid ejecting apparatus, wherein the diaphragm and the piezoelectric element are joined with a low melting point joining material. The fluid ejection device according to claim 1,
The nozzle unit includes the diaphragm;
The piezoelectric element unit includes a housing that houses the piezoelectric element, a thin plate member that seals the opening in the diaphragm direction of the housing, and one end face of the piezoelectric element is fixed, and the housing A lid member that seals an opening in a direction opposite to the diaphragm and is fixed to the other end face of the piezoelectric element;
The fluid ejecting apparatus according to claim 1, wherein when the piezoelectric element unit and the nozzle unit are mounted, the diaphragm and the thin plate member are in close contact with each other. The fluid ejection device according to claim 9, wherein
A fluid ejecting apparatus, wherein a fluid thin film is provided at an interface between the diaphragm and the thin plate member. The fluid ejection device according to claim 9, wherein
A fluid ejecting apparatus, wherein an internal space of the piezoelectric element unit is filled with a resin.   A fluid chamber; a diaphragm for reducing the volume of the fluid chamber; an inlet channel for supplying fluid to the fluid chamber; an outlet channel for discharging fluid from the fluid chamber; and a nozzle communicating with the outlet channel. A nozzle unit comprising: It is detachable from the nozzle unit according to claim 12,
A piezoelectric element unit comprising: a piezoelectric element; an auxiliary member fixed to one end face of the piezoelectric element in an expansion / contraction direction and in close contact with the diaphragm; and a lid member fixed to the other end face . The piezoelectric element unit according to claim 13,
A piezoelectric element unit comprising a resin layer covering at least the surface of the piezoelectric element. The piezoelectric element unit according to claim 13,
A cylindrical housing for storing the piezoelectric element;
A thin plate member fixed to the auxiliary member and fixed to seal the diaphragm side opening of the housing; and
The piezoelectric element unit, wherein the lid member is fixed so as to seal an opening of the housing facing the opening on the diaphragm side. The piezoelectric element unit according to claim 15,
A piezoelectric element unit, wherein a space formed by the casing, the lid member, and the thin plate member is filled with resin.

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