TW202003271A - Liquid agent applying device - Google Patents

Abstract

To provide a liquid agent applying device with which it is possible to prevent damage to a piezoelectric element and to improve the durability of the piezoelectric element. A liquid agent applying device 100 is provided with a pressure chamber plate 8, a diaphragm 7, and a pressurization drive unit 2. The pressure chamber plate 8 includes a pressure chamber 82 for storing a liquid agent. The diaphragm 7 is disposed on the pressure chamber plate 8. The pressurization drive unit 2 applies pressurizing vibrations to the diaphragm 7. The pressurization drive unit 2 includes a weight member 5 disposed on the diaphragm 7, an intermediate member 4 disposed on the weight member 5, and a piezoelectric element 3 disposed on the intermediate member 4. The intermediate member 4 is in point contact with the weight member 5 and in surface contact with the piezoelectric element 3.

Description

Liquid agent coating device

The invention relates to a liquid agent coating device.

The piezoelectric element that performs energy conversion from electrical energy to mechanical energy by the piezoelectric effect is excellent in responsiveness. Therefore, it is used to eject a liquid agent toward the surface of an object in a wide range of fields such as semiconductors, printing, and chemicals. Liquid agent coating device.

Patent Document 1 discloses a liquid agent coating device, which includes: a head module, a pressure chamber having a liquid agent stored therein, and a nozzle connected to the pressure chamber; and a piezoelectric element, which The wall surface is deformed and the liquid agent is ejected from the nozzle. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Open Gazette: Japanese Patent Laid-Open No. 2016-187892

[Problems to be Solved by the Invention] However, in the liquid coating device described in Patent Document 1, compressive stress is concentratedly applied to the piezoelectric element, which may damage the piezoelectric element, or the durability of the piezoelectric element The risk of decline.

An object of the present invention is to provide a liquid agent coating device that can prevent damage to a piezoelectric element and improve the durability of the piezoelectric element. [Means to solve the problem]

The liquid agent coating device of one aspect of the present invention includes a pressure chamber plate, a diaphragm, and a driving unit for pressurization. The pressure chamber plate has a pressure chamber for storing liquid agent. The diaphragm is arranged on the pressure chamber plate. The pressure driving unit applies pressure vibration to the diaphragm. The driving unit for pressing has a piezoelectric element and an intermediate member. The intermediate member makes surface contact with the piezoelectric element, and makes point contact with a point-contact object located on the opposite side of the piezoelectric element. [Effect of invention]

According to one aspect of the present invention, it is possible to provide a liquid agent coating device that can prevent breakage of a piezoelectric element and improve the durability of the piezoelectric element.

Hereinafter, the liquid agent coating device according to an embodiment of the present invention will be described with reference to the drawings. However, the scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention. In the following drawings, in order to easily understand each structure, the scale and number of each structure may be different from the scale and number of actual structures.

In this manual, "connection" and "contact" are different concepts. The so-called "connection" refers to two components fixed or connected to each other. The so-called "contact" means that the two members are in direct contact, but the two members are not fixed or connected to each other.

In this specification, the term "parallel" refers to a concept that includes not only a case that is physically strict but also a case that is substantially parallel. The term "substantially parallel" refers to a case of being inclined within a range of 15° or less. In addition, the term "vertical" refers to a concept that includes not only a case that is physically strictly vertical but also a case that is substantially vertical. The term substantially vertical refers to a case where it is inclined within a range of 15° or less.

(Liquid agent applying device 100) The structure of the liquid agent applying device 100 of the present embodiment will be described with reference to the drawings. FIG. 1 is a perspective view of a liquid agent coating device 100. FIG. 2 is an exploded perspective view of the liquid agent coating device 100. FIG. 3 is a cross-sectional view of the liquid agent coating device 100. In FIG. 2, only the outline is shown so that the inside of the upper plate 6 can be seen.

The liquid agent coating device 100 includes a drive assembly 200 and a flow path assembly 300. The drive assembly 200 is a unit that generates pressure for ejecting liquid agent. The flow path assembly 300 is a unit for supplying a liquid agent.

(Drive unit 200) The drive unit 200 has a base plate 1 and a driving unit 2 for pressing. The driving unit 2 for pressing includes a piezoelectric element 3, an intermediate member 4, and a weight member 5.

[Bottom plate 1] The bottom plate 1 is disposed on the flow path assembly 300. The base plate 1 is a member for fixing the position of the piezoelectric element 3 relative to the flow path assembly 300. The bottom plate 1 has a first column portion 11, a second column portion 12, a beam portion 13, and a storage recess 14.

The first column portion 11 and the second column portion 12 are each formed in a column shape. The beam portion 13 connects the upper ends of the first column portion 11 and the second column portion 12. The first column portion 11 and the second column portion 12 are respectively connected to the upper plate 6 described later. With this, the base plate 1 is positioned relative to the flow path assembly 300.

The storage recess 14 is a gap surrounded by the first column portion 11, the second column portion 12, and the beam portion 13. The piezoelectric element 3 is accommodated in the accommodating recess 14.

In addition, the shape of the base plate 1 is not particularly limited as long as it can fix the position of the piezoelectric element 3 relative to the flow path assembly 300.

[Piezoelectric element 3] The piezoelectric element 3 is accommodated in the accommodating recess 14. The piezoelectric element 3 is arranged between the beam portion 13 and the intermediate member 4. One end of the piezoelectric element 3 is connected to the beam portion 13, and the other end of the piezoelectric element 3 is connected to the intermediate member 4. For example, an adhesive such as epoxy resin may be used to connect the piezoelectric element 3 to the beam portion 13 and the intermediate member 4 respectively.

The piezoelectric element 3 is displaced (stretched) in the z-axis direction in response to a drive pulse applied from a control unit (not shown). The displacement of the piezoelectric element 3 is transmitted to the diaphragm 7 described later via the intermediate member 4 and the weight member 5. The piezoelectric element 3 includes at least one piezoelectric body and a pair of electrodes. The piezoelectric element 3 may also have a so-called partial electrode structure. As the piezoelectric element 3, various well-known piezoelectric elements can be used. The piezoelectric element 3 of this actual form is formed in a square column shape, but it may have another shape.

[Intermediate Member 4] The intermediate member 4 is accommodated in the accommodating recess 14. The intermediate member 4 is arranged between the piezoelectric element 3 and the hammer member 5. The intermediate member 4 is a member for suppressing the concentration of stress on a part of the piezoelectric element 3 when the piezoelectric element 3 is displaced.

The intermediate member 4 is connected to the piezoelectric element 3. For example, an adhesive such as epoxy resin may be used to connect the intermediate member 4 to the piezoelectric element 3. The intermediate member 4 is in surface contact with the piezoelectric element 3. The intermediate member 4 makes point contact with the hammer member 5. The intermediate member 4 can be separated/connected with the hammer member 5. The detailed structure of the intermediate member 4 will be described later.

[Hammer member 5] The hammer member 5 is an example of a "point contact object" that makes point contact with the intermediate member 4, and is an example of a "bearing member" that receives a load from the intermediate member 4. The hammer member 5 is arranged between the intermediate member 4 and the diaphragm 7. The hammer member 5 is disposed in the through hole 6c of the upper plate 6. The hammer member 5 is in contact with the intermediate member 4. The hammer member 5 can be separated/connected with the intermediate member 4. The hammer member 5 is connected to the diaphragm 7. For example, an adhesive such as epoxy resin may be used, or the hammer member 5 and the diaphragm 7 may be connected by welding.

The displacement of the piezoelectric element 3 is transmitted to the hammer member 5 via the intermediate member 4. When the displacement of the piezoelectric element 3 is transmitted to the hammer member 5, the hammer member 5 functions as a hammer and imparts an inertial force to the diaphragm 7. As a result, the diaphragm 7 can be displaced relatively large compared to the slight displacement of the piezoelectric element 3.

The hammer member 5 has an abutment surface 51c that abuts on the diaphragm 7. The contact surface 51c is connected to the diaphragm 7. In this embodiment, the outer edge shape of the contact surface 51c is circular.

The hammer member 5 of the present embodiment is formed in a cylindrical shape extending in the z-axis direction, but the hammer member 5 only needs to function as a hammer, and its shape and size are not limited.

(Flow path assembly 300) The flow path assembly 300 has an upper plate 6, a diaphragm 7, a pressure chamber plate 8, and a seal 9.

[Upper plate 6] The upper plate 6 is arranged on the diaphragm 7. The upper plate 6 is in contact with the diaphragm 7 at the diaphragm side surface 6S. The diaphragm-side surface 6S of this embodiment is flat.

The upper plate 6 has a through hole 6c, a liquid supply channel 6d, a liquid discharge channel 6e, and a diaphragm side surface 6S.

The liquid supply passage 6d guides the liquid agent supplied from the storage tank (not shown) via the cylindrical joint 61 to the inflow passage 81 of the pressure chamber plate 8 described later. A cylindrical joint 61 for connecting a liquid supply pipe (not shown) extending from the storage tank is attached to the inlet of the liquid supply channel 6d. The liquid discharge channel 6e guides the liquid discharged from the outflow channel 84 of the pressure chamber plate 8 described later to the outside. A drain connector 62 for connecting a drain pipe (not shown) extending outward is attached to the outlet of the drain channel 6e.

[Separator 7] The separator 7 is formed in a plate shape extending in the x-axis direction and the y-axis direction. The x-axis direction is a direction perpendicular to the y-axis direction and the z-axis direction. The y-axis direction is a direction perpendicular to the x-axis direction and the z-axis direction.

The diaphragm 7 is arranged on the pressure chamber plate 8. The diaphragm 7 is sandwiched between the upper plate 6 and the pressure chamber plate 8. The diaphragm 7 is in contact with the upper plate 6 on the upper plate side surface 7S. The diaphragm 7 is in contact with the pressure chamber plate 8 at the pressure chamber plate side surface 7T.

4 is a plan view of the diaphragm 7 viewed from the upper plate side surface 7S. The diaphragm 7 has a liquid supply hole 7e, a liquid discharge hole 7f, and a flexible region 7g.

The liquid supply hole 7e is connected to the liquid supply passage 6d of the upper plate 6 and the inflow passage 81 of the pressure chamber plate 8 described later. The drain hole 7f is connected to the drain channel 6e of the upper plate 6 and the outflow channel 84 of the pressure chamber plate 8 described later.

The flexible region 7g is a part of the diaphragm 7. The flexible region 7g is a region of the diaphragm 7 that does not contact the upper plate 6 and the pressure chamber plate 8. On the flexible region 7g, the driving unit 2 for pressure is arranged. The abutting surface 51c of the hammer member 5 is connected to the flexible region 7g. The shape of the outer edge of the flexible region 7g in plan view is the same circular shape as the contact surface 51c of the hammer member 5.

The flexible region 7g covers the pressure chamber 82 of the pressure chamber plate 8 described later. The displacement of the piezoelectric element 3 is transmitted to the flexible region 7g via the intermediate member 4 and the hammer member 5, whereby the flexible region 7g elastically vibrates in the z-axis direction. In this way, it is only the flexible region 7g that functions as the diaphragm in the diaphragm 7 substantially.

[Pressure chamber plate 8] The pressure chamber plate 8 is formed in a plate shape extending in the x-axis direction and the y-axis direction. The diaphragm 7 is arranged on the pressure chamber plate 8. The pressure chamber plate 8 is arranged parallel to the diaphragm 7. The pressure chamber plate 8 is in contact with the diaphragm 7 at the contact surface 8S. In this embodiment, the size of the pressure chamber plate 8 is equal to the size of the diaphragm 7.

FIG. 5 is a plan view of the pressure chamber plate 8 viewed from the contact surface 8S. 6 is a perspective view of the pressure chamber plate 8 viewed from the contact surface 8S. FIG. 7 is a cross-sectional view of the diaphragm 7, the pressure chamber plate 8, and the seal 9 taken along line A-A in FIG. 5. 7 is a cross section perpendicular to the contact surface 8S.

The pressure chamber plate 8 has an inflow passage 81, a pressure chamber 82, a nozzle 83, an outflow passage 84, and a sealing groove 85.

The inflow channel 81 includes a first recess C1 formed in the contact surface 8S. The inflow channel 81 is formed by the first concave portion C1 being blocked by the diaphragm 7. The inflow channel 81 extends along the contact surface 8S. The inflow channel 81 of this embodiment extends parallel to the x-axis direction. In this way, the through hole is not formed inside the pressure chamber plate 8, and the inflow passage 81 is formed by closing the concave portion formed on the surface of the pressure chamber plate 8 with the diaphragm 7. Therefore, the pressure chamber plate 8 can be made thinner, so that the liquid agent coating device 100 can be reduced in size.

As shown in FIG. 7, the inflow channel 81 has a rectangular cross section. The width W1 of the inflow channel 81 in the y-axis direction (an example of the plane direction) parallel to the contact surface 8S is larger than the height H1 of the inflow channel 81 in the z-axis direction (an example of the thickness direction) perpendicular to the contact surface 8S. That is, the ratio of the height H1 of the inflow channel 81 to the width W1 is less than 1. Therefore, by making the inflow passage 81 flat, the pressure chamber plate 8 can be further thinned, and thus the volume of the pressure chamber 82 can be reduced, thereby changing the volume of the pressure chamber 82 corresponding to the vibration amount of the diaphragm 7 The rate becomes larger. As a result, even if the pressure of the diaphragm 7 is small, the liquid agent in the pressure chamber 82 can be greatly pressurized, and the pressure can be efficiently transmitted, so that the viscosity can be ejected from the nozzle 83 with lower power consumption. High liquid.

One end of the inflow channel 81 is connected to the liquid supply hole 7e of the diaphragm 7. The liquid agent is supplied to the inflow channel 81 via the liquid supply hole 7e of the diaphragm 7 and the liquid supply channel 6d of the upper plate 6. The other end of the inflow channel 81 is connected to the pressure chamber 82. The liquid agent that has been supplied to the inflow channel 81 flows into the pressure chamber 82. The detailed structure of the inflow channel 81 will be described later.

The pressure chamber 82 includes a second recess C2 formed in the contact surface 8S. The pressure chamber 82 is formed by closing the diaphragm 7 by the second recess C2. Therefore, the pressure chamber plate 8 can be made thinner, so that the volume of the pressure chamber 82 can be reduced, thereby increasing the volume change rate of the pressure chamber 82 corresponding to the vibration amount of the diaphragm 7. The shape of the outer edge of the second concave portion C2 (that is, the pressure chamber 82) is the same circular shape as the contact surface 51 c of the hammer member 5 and the flexible region 7 g of the diaphragm 7. The range of the flexible region 7g of the diaphragm 7 is defined by the outer edge of the second recess C2.

The pressure chamber 82 stores the liquid agent flowing in from the inflow channel 81. The liquid agent that has been stored in the pressure chamber 82 is ejected from the nozzle 83. In addition, in order to remove air bubbles that have mixed into the pressure chamber 82, the liquid agent that has been stored in the pressure chamber 82 may be discharged from the outflow channel 84. The detailed structure of the pressure chamber 82 will be described later.

The nozzle 83 is connected to the pressure chamber 82. The nozzle 83 is a hole penetrating the pressure chamber plate 8. The nozzle 83 opens on the outer surface 8T of the pressure chamber plate 8. The nozzle 83 faces the diaphragm 7 in the z-axis direction. In the plan view of the contact surface 8S, the nozzle 83 is arranged inside the pressure chamber 82. In the plan view of the contact surface 8S, the nozzle 83 is arranged in the center of the pressure chamber 82. The outer edge shape of the nozzle 83 is the same circular shape as the pressure chamber 82. The liquid agent that has been stored in the pressure chamber 82 is ejected from the nozzle 83 to the outside. The detailed structure of the nozzle 83 will be described later.

The outflow channel 84 includes a third recess C3 formed in the contact surface 8S. The outflow channel 84 is formed by the diaphragm 7 being blocked by the third recess C3. Therefore, the pressure chamber plate 8 can be made thinner, so that the volume of the pressure chamber 82 can be reduced, thereby increasing the volume change rate of the pressure chamber 82 corresponding to the vibration amount of the diaphragm 7. The outflow channel 84 extends along the contact surface 8S. The outflow channel 84 of this embodiment extends parallel to the x-axis direction. One end of the outflow channel 84 is connected to the pressure chamber 82. The other end of the inflow channel 81 is connected to the drain hole 7f of the diaphragm 7. When the air bubbles that have been mixed into the pressure chamber 82 are removed, the liquid agent is discharged from the outflow channel 84 to the outside through the liquid discharge hole 7f of the diaphragm 7 and the liquid discharge channel 6e of the upper plate 6.

The sealing groove 85 is formed on the contact surface 8S. In the plan view of the contact surface 8S, the sealing groove 85 is provided around the first recess C1 to the third recess C3. The sealing groove 85 is provided along the outer edges of the first concave portion C1 to the third concave portion C3. The sealing groove 85 surrounds the entirety of the first recess C1 to the third recess C3. The sealing groove 85 is formed in a ring shape.

[Seal 9] As shown in FIG. 7, the seal 9 is sandwiched between the diaphragm 7 and the pressure chamber plate 8. The seal 9 is arranged in the seal groove 85 of the pressure chamber plate 8. The seal 9 surrounds the inflow passage 81, the pressure chamber 82, and the outflow passage 84 of the pressure chamber plate 8. The seal 9 is pressed against the diaphragm 7 in a state where it has been arranged in the seal groove 85. This ensures the liquid-tightness and air-tightness of the inflow passage 81, the pressure chamber 82, and the outflow passage 84. The seal 9 may include an elastic member such as rubber, for example.

(Flow resistance of the inflow passage 81 and the nozzle 83) In this embodiment, the ratio of the flow resistance of the nozzle 83 to the flow resistance of the inflow passage 81 is 1 or more. That is, the flow path resistance of the nozzle 83 is the same as or larger than the flow path resistance of the inflow channel 81. Therefore, when the liquid agent is continuously discharged from the nozzle 83, the liquid agent can be smoothly replenished from the inflow passage 81 toward the pressure chamber 82.

The comparison of the flow path resistance of the nozzle 83 to the flow path resistance of the inflow channel 81 is preferably 2 or less. That is, the flow path resistance of the nozzle 83 is preferably equal to or less than twice the flow path resistance of the inflow channel 81. Thereby, when the self-pressurization driving unit 2 applies pressurization vibration to the diaphragm 7 (specifically, the flexible region 7g), the volume of the pressure chamber 82 has become small, and the liquid agent can be suppressed from the pressure chamber 82 toward the inflow passage 81 Backflow. As a result, the liquid agent can be smoothly discharged from the nozzle 83 in response to the pressurized vibration of the diaphragm 7.

The flow path resistance of the inflow channel 81 is calculated by performing cross-sectional analysis across the entire length of the inflow channel 81. Similarly, the flow path resistance of the nozzle 83 is calculated by cross-sectional analysis across the entire length of the nozzle 83. In the profile analysis, the flow path resistance can be calculated based on the following general formula (1) for calculating the pressure loss.

p1-p2=U×(8×μ×L)/(π×r ⁴ )... (1) Furthermore, in formula (1), p1-p2 is the pressure loss, and p1 is the pressure on the inflow side ( Unit: Pa), p2 is the pressure on the outflow side (unit: Pa). In addition, in formula (1), μ is the viscosity coefficient (unit: N·sec/m ² ), L is the flow path length (unit: m), r is the flow path radius (unit: m), and U is the flow rate (Unit: m ³ /sec).

(Shapes of the pressure chamber 82 and the nozzle 83) FIG. 8 is a cross-sectional view of the liquid agent coating device 100 cut along the line B-B in FIG. 5. FIG. 8 is a cross section perpendicular to the contact surface 8S of the pressure chamber plate 8.

The pressure chamber 82 (second recess C2) is formed in a tapered shape toward the nozzle 83 as a whole. The pressure chamber 82 has a shape tapered toward the tip of the nozzle 83. Therefore, the width W2 of the pressure chamber 82 in the x-axis direction (an example of the plane direction) parallel to the contact surface 8S becomes narrower as the diaphragm 7 approaches the nozzle 83.

With this, the volume of the pressure chamber 82 can be reduced, and therefore the volume change rate of the pressure chamber 82 corresponding to the vibration amount of the diaphragm 7 (specifically, the flexible region 7g) can be increased. As a result, even if the pressure of the diaphragm 7 is small, the liquid agent in the pressure chamber 82 can be greatly pressurized, and the pressure can be efficiently transmitted, so that the viscosity can be ejected from the nozzle 83 with lower power consumption. High liquid. In particular, in the present embodiment, the inflow channel 81 is formed by the first recess C1, whereby the pressure chamber plate 8 can be made thinner, and the volume of the pressure chamber 82 can be easily further reduced, so that the efficiency can be more effectively reduced. The pressure is transferred to the liquid agent. In addition, compared with the case where the pressure chamber 82 is formed into a cylindrical shape, the thickness of the pressure chamber plate 8 around the nozzle 83 can be made thicker, so even if the total length of the nozzle 83 is shortened and the flow path resistance is reduced, the pressure can be ensured The rigidity of the chamber plate 8.

In addition, the total width W2max of the pressure chamber 82 in the x-axis direction is larger than the total height H2max of the pressure chamber 82 in the z-axis direction (an example of the thickness direction). In this manner, by forming the pressure chamber 82 flat, the pressure chamber plate 8 can be thinned, and thus the liquid agent coating device 100 can be miniaturized. Furthermore, the total height H2max of the pressure chamber 82 is the distance between the diaphragm 7 and the nozzle 83 in the z-axis direction.

The comparison of the full width W2max of the pressure chamber 82 to the full height H2max is preferably 10 or more. That is, the full width W2max of the pressure chamber 82 is preferably 10 times or more the full height H2max. With this, the pressure from the diaphragm 7 can be transmitted to the liquid agent more efficiently, and the liquid agent coating device 100 can be further miniaturized.

In this embodiment, the cross section of the pressure chamber 82 has a truncated cone shape. Specifically, the pressure chamber 82 has a cross-sectional shape in which the apex portion has been removed from the cone having the flexible region 7g of the diaphragm 7 as the bottom surface. Therefore, the inner side surface 82S of the pressure chamber 82 becomes a part of the conical surface whose apex portion has been removed. However, the pressure chamber 82 may be formed in a tapered shape toward the nozzle 83, and its cross section is not limited to the shape of a truncated cone.

The nozzle 83 is formed into a tapered shape as a whole toward the outer surface 8T. The nozzle 83 has a shape tapering toward the front end of the outer surface 8T. Therefore, the width W3 of the nozzle 83 in the x-axis direction parallel to the contact surface 8S becomes narrower as it moves away from the pressure chamber 82.

In this embodiment, the nozzle 83 has a truncated cone shape in cross section. In detail, the nozzle 83 has a cross-sectional shape in which the vertex portion of the cone having the pressure chamber 82 as the bottom surface has been removed. Therefore, the inner side surface 83S of the nozzle 83 becomes a part of the conical surface whose apex portion has been removed. However, the nozzle 83 only needs to be formed in a tapered shape toward the outer surface 8T, and its cross section is not limited to the shape of a truncated cone.

Here, the inner side surface 83S of the nozzle 83 has a larger inclination with respect to the contact surface 8S than the inner side surface 82S of the pressure chamber 82. That is, the inner surface 83S of the nozzle 83 is inclined with respect to the x-y plane more than the inner surface 82S of the pressure chamber 82. Therefore, the wall thickness of the pressure chamber plate 8 around the nozzle 83 can be increased, so that the rigidity around the nozzle 83 can be ensured.

In addition, as shown in FIG. 8, the central axis 83A of the nozzle 83 coincides with the central axis 82A of the pressure chamber 82. Therefore, the pressurizing force can be efficiently transmitted from the pressure chamber 82 to the nozzle 83, so that the liquid agent can be ejected from the nozzle 83 more smoothly.

Furthermore, the central axis 2A of the pressurizing drive unit 2 coincides with the central axis 82A of the pressure chamber 82 and the central axis 83A of the nozzle 83, respectively. Therefore, the pressurizing force can be efficiently transmitted from the pressurizing drive unit 2 to the pressure chamber 82, so that the liquid agent can be ejected from the nozzle 83 more smoothly.

(Structure of the intermediate member 4) FIG. 9 is a perspective view of the intermediate member 4.

The intermediate member 4 is connected to the front end of the piezoelectric element 3. The intermediate member 4 has a flat surface 4S connected to the piezoelectric element 3. The flat surface 4S is formed in a flat shape.

The intermediate member 4 has a curved surface 4T provided on the opposite side of the plane 4S. The curved surface 4T makes point contact with the hammer member 5 (see FIG. 8 ). The curved surface 4T may be a part of a spherical surface or a curved surface. By bringing the curved surface 4T into point contact with the hammer member 5, the durability of the piezoelectric element 3 can be improved.

In addition, the intermediate member 4 of the present embodiment is formed in a hemispherical shape, but as long as it has a flat surface 4S and a curved surface 4T, its shape and size are not particularly limited.

The intermediate member 4 preferably contains a material having a hardness greater than that of the hammer member 5. In addition, the intermediate member 4 preferably contains a material having higher wear resistance than the hammer member 5. As such a material, for example, it is possible to use Mata loose iron-based stainless steel (for example, SUS440, etc.), ceramic-based material (for example, alumina, etc.), and ruby. This can reduce the number of times that the intermediate member 4 that is usually connected to the piezoelectric element 3 by an adhesive is worn or deformed to replace the intermediate member 4 together with the piezoelectric element 3, thereby reducing maintenance time and maintenance cost.

(Features) The pressurizing drive unit 2 of the present embodiment includes the weight member 5 disposed on the diaphragm 7, the intermediate member 4 disposed on the weight member 5, and the piezoelectric element 3 disposed on the intermediate member 4. The intermediate member 4 makes point contact with the hammer member 5 and makes surface contact with the piezoelectric element 3. Therefore, the force applied to the piezoelectric element 3 from the hammer member 5 can be transmitted equally through the intermediate member 4. As a result, the generation of concentrated compressive stress inside the piezoelectric element 3 can be suppressed, so that the breakage of the piezoelectric element 3 can be prevented, and the durability can be improved. In addition, the piezoelectric element 3 is in point contact with the hammer member 5 disposed on the diaphragm 7, so that the assembly position of the piezoelectric element 3 relative to the diaphragm 7, especially the tolerance of the assembly angle, can be relaxed. The cost reduction of manufacturing parts caused by the relaxation and the simplification of assembly steps.

(Modification of Embodiment) Although the present invention is described by the above-mentioned embodiment, the description and drawings constituting a part of the present disclosure should not be construed as limiting the present inventor. For those skilled in the art, various alternative embodiments, examples, and application techniques will become clear from the present disclosure.

[Modification 1] In the pressure chamber plate 8 of the above embodiment, the inflow passage 81, the pressure chamber 82, and the outflow passage 84 are formed on the contact surface 8S, but they may be formed inside the pressure chamber plate 8, respectively. In this case, the liquid agent coating device 100 may not include the sealing member 9.

[Modification 2] The pressure chamber plate 8 of the above embodiment has the outflow channel 84, but it may not have the outflow channel 84.

[Modification 3] The width W2 of the pressure chamber 82 of the above-described embodiment is narrower as it approaches the nozzle 83, but it is not limited thereto.

[Modification 4] The width W3 of the nozzle 83 of the above-mentioned embodiment narrows as the distance from the pressure chamber 82 decreases, but it is not limited thereto.

[Modification 5] The size of the diaphragm 7 of the above-mentioned embodiment is equal to the size of the pressure chamber plate 8, but the diaphragm 7 may have a size that can cover the inflow passage 81, the pressure chamber 82, and the outflow passage 84.

[Modification 6] In the above embodiment, the first column portion 11 and the second column portion 12 are connected to the upper plate 6 to thereby position the bottom plate 1 relative to the flow path assembly 300, but the positioning method of the bottom plate 1 It can be changed appropriately.

[Modification 7] In the above embodiment, the diaphragm 7, the pressure chamber plate 8, and the upper plate 6 are connected to each other, but, for example, they may be connected to each other by screws.

[Modification 8] In the above-described embodiment, the driving unit 2 for pressurization includes the piezoelectric element 3, the intermediate member 4, and the weight member 5, but the weight member 5 may not be provided. In this case, the intermediate member 4 directly makes point contact with the diaphragm 7, so the diaphragm 7 becomes a “point contact object”.

[Modification 9] Although not specifically mentioned in the above embodiment, the members (upper plate 6, diaphragm 7, and pressure chamber plate 8) in contact with the liquid agent in the flow path assembly 300 preferably include Corrosion-resistant material of liquid agent. However, if the surfaces in contact with the liquid agent among these members are covered with a corrosion-resistant film or the like, various constituent materials can be used.

1‧‧‧Bottom plate 2‧‧‧Pressure drive unit 2A, 82A, 83A‧‧‧Central axis 3‧‧‧Piezo element 4‧‧‧Intermediate member 4S‧‧‧Flat surface 4T‧‧‧Curved surface 5‧‧ ‧Hammer member 6‧‧‧Upper plate 6c ‧‧‧Through hole 6d ‧‧‧ Liquid supply channel 6e ‧‧‧ Discharge channel 6S ‧‧‧ Diaphragm side surface 7 ‧‧Drain hole 7g‧‧‧Flexible area 7S‧‧‧Upper plate side surface 7T‧‧‧Pressure chamber plate side surface 8‧‧‧Pressure chamber plate 8S‧‧‧Contact surface 8T‧‧‧Outer surface 9‧ ‧‧Seal 11‧‧‧First column part 12‧‧‧Second column part 13‧‧‧Beam part 14‧‧‧Receiving recess 51c‧‧‧Abutment surface 61‧‧‧Cylinder joint 62‧‧‧ Discharge connector 81‧‧‧channel 82‧‧‧ pressure chamber 82S, 83S‧‧‧inner side 83‧‧‧nozzle 84‧‧‧outflow channel 85‧‧‧sealing tank 100‧‧‧liquid agent coating device 200‧‧ ‧Drive assembly 300‧‧‧Flow path assembly C1‧‧‧The first concave part C2‧‧‧Second concave part C3‧‧‧‧The third concave part H1‧‧‧Height H2max W2max‧‧‧full width

FIG. 1 is a perspective view of a liquid agent application device. Fig. 2 is an exploded perspective view of a liquid agent coating device. 3 is a cross-sectional view of a liquid agent coating device. 4 is a plan view of the diaphragm. Fig. 5 is a plan view of the pressure chamber plate. 6 is a perspective view of a pressure chamber plate. 7 is a cross-sectional view of a diaphragm, a pressure chamber plate, and a seal. FIG. 8 is a cross-sectional view of the liquid agent coating device 100. 9 is a perspective view of an intermediate member.

3‧‧‧ Piezoelectric element

4‧‧‧Intermediate component

4S‧‧‧Plane

4T‧‧‧Surface

Claims (9)

A liquid agent coating device, comprising: a pressure chamber plate having a pressure chamber for storing liquid agent; a diaphragm arranged on the pressure chamber plate; and a driving unit for pressurization, which applies pressure vibration to the diaphragm; The driving unit for pressing has a piezoelectric element and an intermediate member that makes surface contact with the piezoelectric element and makes point contact with a point-contact object located on the opposite side of the piezoelectric element. The liquid agent coating device according to item 1 of the patent application range, wherein the point contact object is a receiving member disposed between the diaphragm and the intermediate member. The liquid agent coating device according to item 1 of the patent application range, wherein the point contact object is the diaphragm. The liquid agent coating device according to item 1 of the patent application range, wherein the intermediate member contains a material having a hardness greater than that of the point-contact object. The liquid agent coating device according to item 1 of the patent application range, wherein the intermediate member contains a material having higher wear resistance than the point contact object. The liquid agent coating device according to item 1 of the patent application range, wherein the pressure chamber plate has a contact surface that contacts the diaphragm, and the pressure chamber includes a concave portion formed on the contact surface. The liquid agent coating device according to item 4 of the patent application range, wherein the point contact object is a receiving member disposed between the diaphragm and the intermediate member, and the receiving member has a contact with the diaphragm And the outer edge shape of the contact surface is the same as the outer edge shape of the concave portion of the contact surface. The liquid agent coating device according to item 1 of the patent application range, wherein the intermediate member has a curved surface that makes point contact with the point contact object. The liquid agent coating device according to item 1 of the patent application range, wherein the intermediate member is connected to the piezoelectric element and can be separated/connected to the point-contact object.

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