JP2018202312A - Dispenser - Google Patents

Abstract

To provide a dispenser which can suppress liquid leakage caused by thermal expansion of a piezoelectric element and positional deviation of a valve due to creep.SOLUTION: A dispenser 100 includes a liquid discharge member 200, a valve 300 which discharges and closes off a liquid from the liquid discharge member 200, and a piezoelectric actuator 400 for driving the valve 300. The piezoelectric actuator 400 includes first and second piezoelectric elements 2, 3 arranged in parallel, and a displacement magnifying mechanism 10 which magnifies and outputs displacement of them. The displacement magnifying mechanism 10 includes a fixing member 11 for fixing one ends of the piezoelectric elements 2, 3, a first arm 16 which is connected to the other end of the first piezoelectric element 2 so as to swing to the fixing part 11, and a second arm 19 which is connected to the other end of the second piezoelectric element so as to swing to the fixing part 11. Voltages are applied on the piezoelectric elements 2, 3 so as to displace by a predetermined amount in directions opposite to each other, and the first arm 16 and the second arm 19 are displaced by an approximately same amount in a same direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a dispenser that discharges liquid.

  As a dispenser (droplet discharge device) that discharges liquid droplets, a device that supplies liquid from a liquid flow path to a liquid chamber and opens and closes a discharge port provided in the liquid chamber by a valve (needle) is known. As a mechanism for driving the valve, a combination of a piezoelectric element and a displacement enlarging mechanism has been proposed (Patent Document 1).

  The dispenser (droplet discharge device) of Patent Document 1 has an even number of drive devices made of piezoelectric elements symmetrically arranged, and these displacements are enlarged by a displacement enlargement mechanism to act on a valve (needle) to discharge. Open and close the exit.

Japanese Patent Laying-Open No. 2015-51399

  In the dispenser described in Patent Document 1, a plurality of piezoelectric elements are expanded and contracted in the same direction. In this case, when the ambient temperature has changed or when the piezoelectric element is driven at a high frequency and the temperature rises due to self-heating from the piezoelectric element itself, the initial position of the valve is caused by the thermal expansion of the piezoelectric element. May change.

  In addition, a phenomenon called creep occurs in which, after applying a stepped voltage, a constant voltage, or the like to the piezoelectric element, the amount of elongation changes without stability over time. Creep can be corrected in closed loop control, but not in open loop control.

  Thus, if the position of the valve is shifted due to thermal expansion or creep of the piezoelectric element, liquid leakage may occur.

  Therefore, an object of the present invention is to provide a dispenser capable of suppressing liquid leakage accompanying valve position shift due to thermal expansion or creep of a piezoelectric element.

  In order to solve the above problems, the present invention provides the following (1) to (11).

(1) A dispenser that includes a liquid ejection member that introduces liquid and ejects the introduced liquid, a valve that ejects and shuts off the liquid from the liquid ejection member, and a piezoelectric actuator that drives the valve. ,
The piezoelectric actuator is
A first piezoelectric element and a second piezoelectric element, which are arranged in parallel so as to expand and contract in the same direction, and each have a first end and a second end at corresponding positions;
A displacement enlarging mechanism for enlarging the displacement of the first piezoelectric element and the second piezoelectric element and outputting the expanded displacement;
A drive unit that applies a voltage to the first piezoelectric element and the second piezoelectric element to drive the first piezoelectric element and the second piezoelectric element to extend and contract,
The displacement enlarging mechanism is
A U-shape having a recess in the center, and a fixing member for fixing the first end of the first piezoelectric element and the second piezoelectric element to the bottom thereof;
The expansion and contraction of the first piezoelectric element is perpendicular to the expansion and contraction direction of the first piezoelectric element on one side and the second end of the first piezoelectric element across the concave portion of the fixing member. A first arm connected to be swingable in a direction to
The expansion side of the second piezoelectric element is perpendicular to the expansion / contraction direction of the second piezoelectric element on the other side of the fixing member across the recess and the second end of the second piezoelectric element. A second arm that is swingably connected in the direction of
The distal ends of the first arm and the second arm function as an output unit to displace the valve,
The driving unit applies a voltage to the first piezoelectric element and the second piezoelectric element so that the first piezoelectric element and the second piezoelectric element are displaced by a predetermined amount in directions opposite to each other, As a result, the first arm and the second arm are given substantially the same amount of displacement in the same direction, and the valve is displaced together with the first arm and the second arm. A dispenser for discharging and blocking liquid from a discharge member.

  (2) The liquid discharge member includes a main body portion, a liquid chamber formed in the main body portion through which the valve is inserted, a liquid introduction portion for introducing liquid into the liquid chamber, and a bottom portion of the liquid chamber. (1) The dispenser according to (1), further comprising a liquid discharge port that communicates with a valve seat that is provided at a bottom portion of the liquid chamber and on which a tip of the valve is seated.

  (3) It further has an output member connected to the tip of the first arm and the second arm, and the valve is displaced by the output member (1) or (2) The dispenser described in 1.

  (4) The dispenser according to (3), wherein the liquid discharge member and the valve constitute a unit, and the unit is detachable.

(5) The liquid discharge member includes a main body portion, a liquid chamber formed in the main body portion, a liquid introduction portion that introduces liquid into the liquid chamber, a liquid discharge port that communicates with a bottom portion of the liquid chamber, A valve seat provided at the bottom of the liquid chamber;
The valve is provided between a valve main body inserted into the liquid chamber, a flange provided at an upper end of the valve main body, the flange and the main body portion of the liquid discharge member, and the valve main body is directed upward. The dispenser according to (4), further comprising an urging means for urging.

  (6) The drive unit of the piezoelectric actuator applies a voltage to the first piezoelectric element and the second piezoelectric element so that one of them is displaced in a direction in which one extends and the other in a direction in which the other contracts. The dispenser according to any one of (1) to (5), characterized in that

  (7) The drive unit of the piezoelectric actuator applies the output voltage of the drive unit to the first terminals of the first piezoelectric element and the second piezoelectric element, and (1) to (6) including a drive circuit that applies a minimum voltage of the drive unit to the second terminal and applies a maximum voltage of the drive unit to the second terminal of the second piezoelectric element. The dispenser according to any one of the above.

  (8) In the piezoelectric actuator, the first arm is respectively connected to the one side portion of the fixing member and the second end portion of the first piezoelectric element via a flexible hinge. The second arm is connected to the other side of the fixing member and the second end of the second piezoelectric element via a flexible hinge. The dispenser according to any one of (1) to (7).

  (9) The piezoelectric actuator further includes a first pressurizing mechanism and a second pressurizing mechanism that apply a compressive force to the first piezoelectric element and the second piezoelectric element in the expansion and contraction directions, respectively. The dispenser according to any one of (1) to (8), characterized in that:

(10) In the piezoelectric actuator, a first cap member is attached to the second end portion of the first piezoelectric element, and the first arm is formed by the first cap member and the hinge. Concatenated,
A second cap member is attached to the second end of the second piezoelectric element, and the second arm is connected to the second cap member by the hinge. The dispenser according to any one of (1) to (9).

  (11) The dispenser according to (10), wherein the first cap member and the second cap member are connected to each other by a connecting member via a flexible hinge.

  According to the present invention, a voltage is applied to the first piezoelectric element and the second piezoelectric element of the piezoelectric actuator so as to be displaced by a predetermined amount in opposite directions, and the first arm and the second arm are moved. Since the first piezoelectric element and the second piezoelectric element are displaced by substantially the same amount in the same direction orthogonal to the expansion / contraction direction of the first and second piezoelectric elements, the valve is displaced thereby to discharge and block the liquid from the liquid discharge member. The initial position of the valve due to expansion and the position shift of the valve due to creep of the piezoelectric element can be suppressed to suppress liquid leakage.

It is a partial section front view showing the dispenser concerning a 1st embodiment of the present invention. It is a perspective view which shows the dispenser of FIG. It is sectional drawing which shows the discharge member of the dispenser of FIG. 1, and is a figure which shows the state by which the liquid discharge port was obstruct | occluded with the valve. It is sectional drawing which shows the discharge member of the dispenser of FIG. 1, and is a figure which shows the state by which the liquid discharge port was opened by the valve. It is a figure which shows the state which applied the voltage to the piezoelectric actuator and moved the valve upward. It is a figure which shows the state which cancelled | released the voltage application of the piezoelectric actuator and returned the valve. It is a figure which shows the suitable example of a drive circuit. It is a figure for demonstrating the creep phenomenon of a piezoelectric element. It is a fragmentary sectional front view which shows the dispenser which concerns on the 2nd Embodiment of this invention. FIG. 10 is a partial cross-sectional front view showing a state where a valve / discharge member unit is removed from the dispenser of FIG. 9. It is sectional drawing which shows the valve and discharge member unit of the dispenser which concerns on the 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail.
<First Embodiment>
First, the first embodiment will be described.
FIG. 1 is a partial sectional front view showing a dispenser according to the first embodiment of the present invention, FIG. 2 is a perspective view thereof, and FIGS. 3 and 4 are sectional views showing a liquid discharge member.
As shown in FIG. 1, the dispenser 100 is driven by a liquid discharge member 200 that introduces liquid and discharges the introduced liquid, a valve 300 that discharges and shuts off the liquid from the liquid discharge member 200, and the valve 300. And a piezoelectric actuator 400.

  As shown in FIG. 3, the liquid ejection member 200 includes a main body portion 201, a liquid chamber 202 through which the valve 300 formed in the main body portion 201 is inserted, and a liquid introduction portion 203 that introduces liquid into the liquid chamber 202. The liquid discharge port 204 communicates with the bottom of the liquid chamber 202, and the valve seat 205 provided at the bottom of the liquid chamber 202, on which the tip of the valve 300 is seated.

  The valve 300 has a spherical rod shape at the tip and extends in the Y direction in the drawing, which is the vertical direction, and the liquid chamber 202 has a cylindrical shape corresponding to the shape of the valve 300. As shown in FIG. 3, the valve 300 normally has a tip seated on a valve seat 205 and the liquid discharge port 204 is closed. In this state, no liquid is ejected.

  The valve 300 is driven up and down in the Y direction by the piezoelectric actuator 400. From the state of FIG. 3, by driving the piezoelectric actuator 400 to raise the valve 300, the liquid discharge port 204 is opened as shown in FIG. 4, and liquid is discharged from the liquid discharge port 204.

  The piezoelectric actuator 400 includes a first piezoelectric element 2 and a second piezoelectric element 3, a displacement enlarging mechanism 10 that expands these displacements, and a drive unit 30 that drives the first piezoelectric element 2 and the second piezoelectric element. And have.

  The displacement enlarging mechanism 10 includes a fixing member 11 that fixes one end of the first piezoelectric element 2 and the second piezoelectric element 3. The fixing member 11 has a U-shape with a recess 24 formed in the center. Both sides of the recess 24 are a first side 11a and a second side 11b, and the bottom of the recess 24 is a bottom 11c. ing. The first piezoelectric element 2 and the second piezoelectric element 3 are arranged in parallel in the recess 24 in a state in which a compressive force is applied in advance by the first pressurizing mechanism 4 and the second pressurizing mechanism 5, respectively. Base end portions (first end portions) of the first piezoelectric element 2 and the second piezoelectric element 3 are fixed to the bottom portion 11 c of the fixing member 11. The first piezoelectric element 2 and the second piezoelectric element 3 are adapted to expand and contract in the X direction of FIG. 1, which is their longitudinal direction. The fixing member 11 is attached to a base material (not shown) by bolts, and a plurality of attachment holes 25 penetrating in the thickness direction are provided. The contraction operation of the expansion / contraction displacement includes returning to the original length after the piezoelectric element is extended.

  Further, the displacement magnifying mechanism 10 further includes a first cap member 12 and a second cap member provided at the distal end portions (second end portions) of the first piezoelectric element 2 and the second piezoelectric element 3, respectively. 13, the first cap member 12 and the first arm 16 connected to the tip of the first side portion 11a of the fixing member 11 via the first hinge 14 and the second hinge 15, respectively, A second arm 19 connected via a third hinge 17 and a fourth hinge 18 to the distal end portions of the cap member 13 and the second side portion 11b of the fixing member 11, respectively, the first cap member 12 and the second cap member 13. And a connecting member 23 that connects the cap member 13 via a fifth hinge 21 and a sixth hinge 22. The first arm 16 and the second arm 19 extend along the longitudinal direction of the first piezoelectric element 2 and the second piezoelectric element 3 and have the same length.

  The first arm 16 has a proximal end portion 16a to which the first hinge 14 and the second hinge 15 are connected, and a long distal end portion 16b that is detachably attached to the proximal end portion 16a. Similarly, the second arm 19 has a base end 19a connected to the third hinge 17 and the fourth hinge 18, and a long tip 19b detachably attached to the base end 19a. . As the tip portions 16b and 19b, those of various lengths can be used according to the required displacement.

  In addition, the 1st-6th hinges 14, 15, 17, 18, 21, and 22 are formed with the material which has flexibility.

  The first arm 16 can swing in the Y direction, that is, the vertical direction by the expansion and contraction of the first piezoelectric element 2. That is, in the first arm 16, when the first piezoelectric element 2 is extended, the second hinge 15 is a fulcrum, the first hinge 14 is a power point, and the tip of the first arm 16 is an action point. At the tip of the first arm 16, a displacement expanded upward along the Y direction perpendicular to the X direction, which is the displacement direction of the first piezoelectric element 2, appears by the lever principle. Further, when the first piezoelectric element 2 is degenerated, a downwardly expanded displacement appears at the distal end portion of the first arm 16 based on the same principle.

  On the other hand, the second arm 19 can swing in the Y direction, that is, the A direction and the B direction by the expansion and contraction of the second piezoelectric element 3. That is, when the second piezoelectric element 3 is extended, the second arm 19 has the fourth hinge 18 as a fulcrum, the third hinge 17 as a power point, and the tip of the second arm 19 as an action point. At the tip of the second arm 19, a displacement expanded downward in the direction orthogonal to the displacement direction of the second piezoelectric element 3 appears due to the lever principle. Further, when the second piezoelectric element 3 is degenerated, an upwardly expanded displacement appears at the tip of the second arm 19 based on the same principle.

  At this time, the first arm 16 and the second arm 19 are displaced by substantially the same amount in the same direction as the first piezoelectric element 2 and the second piezoelectric element 3 are displaced by a predetermined amount in directions opposite to each other. It swings with.

  An output member 60 extending in the Y direction is mounted on the distal end portion of the first arm 16 and the distal end portion of the second arm 19 by mounting members 61 and 62. The valve 300 described above is attached to the lower end of the output member 60. Note that the valve 300 may be directly mounted on the first arm 16 and the second arm 19 without using the output member 60.

  The fixing member 11, the first cap member 12 and the second cap member 13, the hinges 14, 15, 17, 18, 21 and 22, the first arm 16, the second arm 19, and the connecting member 23 are included. The displacement magnifying mechanism 10 can be produced by an integral machining means such as wire cut electric discharge machining. Examples of the material constituting the displacement magnifying mechanism 10 include materials having a small thermal expansion and a relatively good thermal conductivity, such as an Invar alloy, a super Invar alloy, and stainless steel.

  By applying a voltage to the first piezoelectric element 2 and the second piezoelectric element so as to be displaced by a predetermined amount in opposite directions, the first arm 16 and the second arm 19 of the displacement enlarging mechanism 10 are moved in the A direction. Alternatively, it is possible to displace approximately the same amount in the same direction of the B direction, and to transmit the displacement in the Y direction enlarged several times to several tens of times to the output member 60 and drive the valve 300.

The first piezoelectric element 2 and the second piezoelectric element 3 are made of the same material and have the same size. These are configured as a rectangular parallelepiped (for example, a length of 40 mm) as a whole by laminating a plurality of plate-shaped (for example, 10 mm × 10 mm) piezoelectric bodies with electrodes interposed therebetween. The first piezoelectric element 2 and the second piezoelectric element 3 have electrical terminals (not shown) for applying a voltage to the side surfaces, and expand and contract when a voltage is applied between the electrical terminals. It is configured as follows. As the piezoelectric material constituting the piezoelectric body, a ceramic material having a piezoelectric effect is used. As such a material, typically, lead zirconate titanate (Pb (Zr, Ti) O ₃ ; PZT) is cited. Can do. The shape of the piezoelectric elements 2 and 3 is not limited to a rectangular parallelepiped, and may be a polygonal cylinder such as a triangular prism or a hexagonal cylinder, or a cylinder.

  The first pressurizing mechanism 4 and the second pressurizing mechanism 5 are configured such that a compressive force is applied in advance in the expansion and contraction directions of the first piezoelectric element 2 and the second piezoelectric element 3. The piezoelectric element is made of a ceramic material which is a brittle material, and is weak against tensile force. Therefore, it is important to apply a compressive force in advance.

  The first pressurizing mechanism 4 is, for example, spanned between a pair of head pieces 40a and 40b fixed to one end surface and the other end surface of the first piezoelectric element 2, and a pair of head pieces 40a and 40b. And a compressive force applying member 41 provided. The second pressurizing mechanism 5 is spanned between a pair of head pieces 50a and 50b fixed to one end surface and the other end surface of the second piezoelectric element 3, and the pair of head pieces 50a and 50b, for example. And a compressive force applying member 51 provided as described above. The first and second pressurizing mechanisms 4 and 5 apply a compressive force of about 1/5 to 1/2 with respect to the force generated from the first and second piezoelectric elements 2 and 3. There are two compression force applying members 41 and 51, for example.

  Materials constituting the first and second pressurizing mechanisms 4 and 5 have a rigidity capable of imparting a compressive force, a relatively high strength, excellent weather resistance and corrosion resistance, and a small thermal expansion coefficient. preferable. Examples of such materials include invar alloys, super invar alloys, carbon fibers, and stainless steel.

  In addition, you may give the function as a pressurization mechanism to a displacement expansion mechanism, without providing a pressurization mechanism.

  The drive unit 30 applies a predetermined voltage to the first piezoelectric element 2 and the second piezoelectric element 3 to charge and discharge them, thereby extending and contracting the driver 31, and the driver 31 includes the first piezoelectric element 2 and And a control unit 32 that gives a command for expanding and contracting the second piezoelectric element 3. The driver 31 has a power supply and a drive circuit. The drive unit 30 can apply a voltage to the first piezoelectric element 2 and the second piezoelectric element 3 so that one of them is displaced in the direction in which one extends and the other in the direction in which the other contracts.

  A support member 80 is provided below the second side portion 11 b of the fixing member 11. The support member 80 supports the fixing member 11 of the piezoelectric actuator 400 and supports the liquid ejection member 200.

  In the dispenser 100 configured as described above, in a state where no voltage is applied to the first piezoelectric element 2 and the second piezoelectric element 3, the tip of the valve 300 is liquid ejected as shown in FIG. The member 200 is seated on the valve seat 205, the liquid discharge port 204 is closed, and no liquid is discharged.

  From this state, the driver 31 applies a predetermined voltage to the first piezoelectric element 2 and the second piezoelectric element 3 on the basis of a command from the control unit 32 of the driving unit 30 of the piezoelectric actuator 400, whereby the first piezoelectric element As the second and second piezoelectric elements 3 are displaced in the X direction, the displacement enlarged mechanism 10 outputs an enlarged displacement to the output member 60.

  At this time, the drive unit 30 applies a voltage to the first piezoelectric element 2 and the second piezoelectric element 3 so as to be displaced by a predetermined amount in directions opposite to each other. Specifically, as shown in FIG. 5, the first and second arms 16 and 2 are displaced by elongating and displacing the first piezoelectric element 2 by a predetermined amount and degenerating and displacing the second piezoelectric element 3 by a predetermined amount. The tip of 19 is displaced upward by a displacement amount several to several tens of times the displacement amount of the piezoelectric element. As a result, as shown in FIG. 4, the valve 300 is driven to rise in the Y direction, the liquid discharge port 204 is opened, and liquid is discharged from the liquid discharge port 204.

  By canceling the voltage application of the first piezoelectric element 2 and the second piezoelectric element 3 from this state, the first piezoelectric element 2 and the second piezoelectric element 3 are displaced in the opposite directions as shown in FIG. Then, the distal ends of the first arm 16 and the second arm 19 are lowered by substantially the same amount, and the output member 60 returns to the original position. As shown in FIG. Sits on the valve seat 205 of the liquid discharge member 200, closes the liquid discharge port 204, and stops the discharge of the liquid.

  The above is a case where the liquid discharge port 204 is normally closed. However, when no voltage is applied, the valve 300 is in a state where the liquid discharge port 204 is open, and when the voltage is applied, the first piezoelectric element. 2 is retracted, the second piezoelectric element 3 is extended and displaced, the valve 300 is lowered together with the output member 60 via the first arm 16 and the second arm 19, and the liquid discharge port 204 is closed. It may be.

  As described above, in the piezoelectric actuator 400, the first arm 16 and the second piezoelectric element 3 are applied by applying a voltage to the first piezoelectric element 2 and the second piezoelectric element 3 so as to be displaced by a predetermined amount in directions opposite to each other. The two arms 19 can be displaced by substantially the same amount, thereby giving the output member 60 an enlarged displacement in the vertical direction, and the valve 300 can be raised and lowered.

  At this time, voltage application to the first piezoelectric element 2 and the second piezoelectric element 3 is controlled such that liquid (droplet) is ejected at a predetermined timing based on a command from the control unit 32.

  As a drive circuit that can always apply a voltage that causes the first piezoelectric element 2 and the second piezoelectric element 3 to be displaced by a predetermined amount in opposite directions, a drive circuit as shown in FIG. 7 is preferably used. it can.

The drive circuit in FIG. 7 includes an amplifier 70. The amplifier 70 has an input terminal 71, and a voltage of 0 to 10 V, for example, is input to the input terminal 71 (V _in ). In this example, the amplifier 70 amplifies the input voltage by 20 times, and the amplified voltage is output from the output terminal 72 (V _out ). The voltage connected to the output terminal 72 is applied to the first terminals of the first piezoelectric element 2 and the second piezoelectric element 3 via the wiring 74. The second terminal of the first piezoelectric element 2 has a minimum voltage (ground potential (0 V)), and the other terminal of the second piezoelectric element 3 always has a maximum voltage from the maximum voltage output terminal 73 of the amplifier 70. A voltage of 200 V, which is a voltage, is applied. In this way, the reference voltage is set to 100 V, and a reverse voltage is always applied to the first piezoelectric element 2 and the second piezoelectric element 3, so that the first piezoelectric element 2 and the second piezoelectric element are It can be displaced by a predetermined amount in the opposite direction.

  By the way, in the dispenser 100, when the piezoelectric actuator 400 is operated, when there is a change in the ambient temperature, or when the piezoelectric element is driven at a high frequency and the temperature rises due to self-heating from the piezoelectric element itself, The length of the piezoelectric element changes due to the expansion. At that time, in the conventional dispenser (droplet discharge device) as shown in Patent Document 1, the initial position of the output portion of the displacement magnifying mechanism changes due to the change in the length of the piezoelectric element. ) May change, and liquid leakage may occur when no liquid discharge command is issued.

  In contrast, in the dispenser 100 of the present embodiment, even if the lengths of the first piezoelectric element 2 and the second piezoelectric element 3 of the piezoelectric actuator 400 change due to thermal expansion, the first arm 16 and the second arm respectively. The displacement expanded through the arm 19 becomes the same amount in the opposite direction, and the fluctuation is cancelled. Therefore, the change in the initial position of the output member 60 can be made substantially zero, and accordingly, the change in the initial position of the valve 300 can also be made almost zero, so that liquid leakage occurs when the valve 300 is closed. Can be suppressed almost completely.

  In addition, as shown in FIG. 8, the piezoelectric element has a phenomenon called creep in which the amount of elongation changes with time after applying a stepped voltage, a constant voltage, or the like. Creep speed decreases logarithmically over time. The creep phenomenon can be corrected in the closed loop control but cannot be corrected in the open loop control. Therefore, in the technique of the above-mentioned Patent Document 1, it is necessary to control the piezoelectric element to be feedback control in order to suppress the liquid leakage due to the change in elongation due to the creep phenomenon of the piezoelectric element, but the control becomes complicated.

  On the other hand, in the dispenser 100 of the present embodiment, even if creep occurs in the first piezoelectric element 2 and the second piezoelectric element 3 of the piezoelectric actuator 400, they are displaced in directions opposite to each other. The change is canceled out, and the displacement due to the creep phenomenon can be reduced. For this reason, liquid leakage can be suppressed almost completely without performing closed loop control.

<Second Embodiment>
Next, a second embodiment will be described.
9 is a partial cross-sectional front view showing the dispenser according to the first embodiment of the present invention, FIG. 10 is a partial cross-sectional front view showing a state in which the valve / discharge member unit is removed from the dispenser of FIG. 9, and FIG. It is sectional drawing which shows a discharge member unit.

  In this embodiment, an example is shown in which a valve and a liquid discharge member are unitized to form a valve / discharge member unit, and the valve / discharge member unit is detachable. Since other configurations are the same as those of the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  The liquid ejection member 200 ′ is configured in the same manner as the liquid ejection member 200, but can be removed by moving outward along the guide member 81 as shown in FIG. The guide member 81 is notched so as not to hinder the movement of the protrusion corresponding to the liquid discharge port 204 of the liquid discharge member 200 ′. On the other hand, the valve 300 ′ is configured to be able to contact and separate from the output member 60 of the piezoelectric actuator 400, and is integrated with the liquid discharge member 200 ′. As described above, the liquid discharge member 200 ′ and the valve 300 ′ are integrated to form the valve / discharge member unit 500, and the entire unit is detachable.

  As shown in FIG. 11, the valve 300 ′ includes a valve main body 301, a flange 302 provided at the upper end of the valve main body 301, and a coil provided between the flange 302 and the main body portion 201 of the liquid discharge member 200 ′. And a spring 303. The valve body 301 has a spherical rod shape at the tip, extends in the Y direction, and the tip is inserted into the liquid chamber 202 of the liquid discharge member 200 ′. The valve main body 301 is urged upward by a coil spring 303. When the valve / discharge member unit 500 is removed, the valve main body 301 is lifted by the urging force of the coil spring 303. When the main body 301 is pressed by the output member 60 of the piezoelectric actuator 400, the liquid discharge port 204 of the liquid discharge member 200 'can be closed to stop the liquid discharge. Instead of the coil spring 303, other biasing means such as a leaf spring may be used.

  As described above, even if the output member 60 of the piezoelectric actuator 400 and the valve 300 ′ are separated and detachably provided, the valve main body 303 is pressed by the output member 60 by the action of the coil spring 303. Similar operations are possible.

In addition, since the liquid discharge member 200 ′ and the valve 300 ′ are integrated to form the valve / discharge member unit 500, and the entire unit can be attached and detached, the maintainability can be remarkably improved.
<Other applications>
Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be variously modified. For example, in the above-described embodiment, the example in which the compression force is applied to the piezoelectric element in advance by the pressurizing mechanism is shown, but the pressurizing mechanism is not essential.

  Further, the displacement enlarging mechanism is not limited to the above-described embodiment, and any mechanism that can expand and contract the expansion / contraction displacement of two piezoelectric elements arranged in parallel and output the displacement in a direction orthogonal to the displacement direction. For example, you may have an arm extended to a bottom part along the side surface of the fixing member which fixes a piezoelectric element.

  Further, the configuration of the liquid discharge member and the valve is not limited to the above embodiment, and an appropriate configuration can be adopted according to the device design.

2; 1st piezoelectric element 3; 2nd piezoelectric element 10; Displacement magnification mechanism 11; Fixing member 11a; 1st side part 11b; 2nd side part 11c; Bottom part 12, 13; 17, 18, 21, 22; hinge 16; first arm 19; second arm 23; connecting member 24; recess 30; drive unit 60; output member 100; dispenser 200, 200 ′; '; Valve 400; Piezoelectric actuator 500; Valve / discharge member unit

Claims (11)

A dispenser comprising a liquid ejection member that introduces liquid and ejects the introduced liquid, a valve that ejects and shuts off the liquid from the liquid ejection member, and a piezoelectric actuator that drives the valve,
The piezoelectric actuator is
A first piezoelectric element and a second piezoelectric element, which are arranged in parallel so as to expand and contract in the same direction, and each have a first end and a second end at corresponding positions;
A displacement enlarging mechanism for enlarging the displacement of the first piezoelectric element and the second piezoelectric element and outputting the expanded displacement;
A drive unit that applies a voltage to the first piezoelectric element and the second piezoelectric element to drive the first piezoelectric element and the second piezoelectric element to extend and contract,
The displacement enlarging mechanism is
A U-shape having a recess in the center, and a fixing member for fixing the first end of the first piezoelectric element and the second piezoelectric element to the bottom thereof;
The expansion and contraction of the first piezoelectric element is perpendicular to the expansion and contraction direction of the first piezoelectric element on one side and the second end of the first piezoelectric element across the concave portion of the fixing member. A first arm connected to be swingable in a direction to
The expansion side of the second piezoelectric element is perpendicular to the expansion / contraction direction of the second piezoelectric element on the other side of the fixing member across the recess and the second end of the second piezoelectric element. A second arm that is swingably connected in the direction of
The distal ends of the first arm and the second arm function as an output unit to displace the valve,
The driving unit applies a voltage to the first piezoelectric element and the second piezoelectric element so that the first piezoelectric element and the second piezoelectric element are displaced by a predetermined amount in directions opposite to each other, As a result, the first arm and the second arm are given substantially the same amount of displacement in the same direction, and the valve is displaced together with the first arm and the second arm. A dispenser for discharging and blocking liquid from a discharge member.   The liquid discharge member includes a main body, a liquid chamber formed in the main body through which the valve is inserted, a liquid introduction section for introducing a liquid into the liquid chamber, and a liquid communicating with the bottom of the liquid chamber. The dispenser according to claim 1, further comprising a discharge port and a valve seat provided at a bottom portion of the liquid chamber and on which a tip of the valve is seated.   3. The output device according to claim 1, further comprising an output member connected to tip portions of the first arm and the second arm, wherein the valve is displaced by the output member. Dispenser.   The dispenser according to claim 3, wherein the liquid discharge member and the valve constitute a unit, and the unit is detachable. The liquid discharge member includes a main body, a liquid chamber formed in the main body, a liquid introduction section for introducing a liquid into the liquid chamber, a liquid discharge port communicating with the bottom of the liquid chamber, and the liquid chamber And a valve seat provided at the bottom of the
The valve is provided between a valve main body inserted into the liquid chamber, a flange provided at an upper end of the valve main body, the flange and the main body portion of the liquid discharge member, and the valve main body is directed upward. The dispenser according to claim 4, further comprising an urging unit that urges the dispenser.   The drive unit of the piezoelectric actuator applies a voltage to the first piezoelectric element and the second piezoelectric element so that one of them is displaced in a direction in which one extends and the other in a direction in which the other contracts. The dispenser according to any one of claims 1 to 5.   The drive unit of the piezoelectric actuator applies an output voltage of the drive unit to first terminals of the first piezoelectric element and the second piezoelectric element, and a second terminal of the first piezoelectric element. 7. A driving circuit for applying a minimum voltage of the driving unit to the second terminal of the second piezoelectric element and applying a maximum voltage of the driving unit to the second terminal of the second piezoelectric element. A dispenser according to claim 1.   In the piezoelectric actuator, the first arm is connected to the one side portion of the fixing member and the second end portion of the first piezoelectric element via flexible hinges, respectively. Each of the second arms is connected to the other side portion of the fixing member and the second end portion of the second piezoelectric element via a flexible hinge. The dispenser according to any one of claims 1 to 7.   The piezoelectric actuator further includes a first pressurizing mechanism and a second pressurizing mechanism that apply a compressive force to the first piezoelectric element and the second piezoelectric element in the expansion and contraction directions, respectively. The dispenser according to any one of claims 1 to 8. In the piezoelectric actuator, a first cap member is attached to the second end portion of the first piezoelectric element, and the first arm is connected to the first cap member by the hinge,
A second cap member is attached to the second end of the second piezoelectric element, and the second arm is connected to the second cap member by the hinge. The dispenser according to any one of claims 1 to 9.   The dispenser according to claim 10, wherein the first cap member and the second cap member are connected by a connecting member via a flexible hinge.

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