CN101658439A - Pulsation generating mechanism, connecting flow channel tube, and fluid ejecting apparatus - Google Patents

Abstract

The invention provides a fluid injection device (10) for jetting fluid in a pulse shape, which has a pulsation generating mechanism (30) and a connecting flow pipe (90) inserted in the pulsation generating mechanism (30), and the pulsation generating mechanism (30) ) has: a fluid chamber (120), a diaphragm (70), a wall (82) opposite to the diaphragm (70), and an annular shape between the diaphragm (70) and the wall (82). The inner peripheral side wall (61) of the spacer (60) is formed; the inlet flow path (83) is formed by a groove penetrating in a substantially circular arc shape along the wall surface (82), so that the base end is connected to the supply liquid. The flow path (85) is communicated, and the front end is communicated with the fluid chamber (120); and the piezoelectric element (40) displaces the diaphragm (70), and the connecting flow path pipe (90) has a nozzle (95), and the nozzle ( 95) communicates with the outlet flow path (88) opened to communicate with the fluid chamber (120), and uses the diaphragm (70) to reduce the volume of the fluid chamber (120) to spray liquid in pulse form from the nozzle (95).

Description

Pulsation generating mechanism, connecting flow pipe, fluid injection device

technical field

The invention relates to a pulsation generating mechanism for pulsatingly discharging fluid, a connecting flow pipe inserted in the pulsation generating mechanism, and a fluid injection device with the pulsation generating mechanism and the connecting flow pipe, which ejects fluid in a pulse shape.

Background technique

The operation using jet fluid can cut the actual organs while preserving the vascular structure such as blood vessels, and the collateral damage to the living tissue other than the incision is slight, so the burden on the patient is small, and the bleeding is less. Bleeding does not interfere with the surgical field of view, so the operation can be performed quickly, and it is mostly used in clinical applications such as liver resection, which is difficult to deal with bleeding from small blood vessels.

As a fluid ejection device for incising or resecting living tissue, there is known a fluid ejecting device having: a pulsation generating mechanism that reduces the volume of a fluid chamber to discharge fluid; and a connecting channel tube that One end is connected to the outlet channel of the pulsation generating mechanism, and the other end is provided with a nozzle whose diameter is smaller than that of the outlet channel (for example, refer to Patent Document 1).

[Patent Document 1] Japanese Patent Laid-Open No. 2005-152127

According to such a fluid ejection device of Patent Document 1, since the fluid ejection device itself performs a pumping operation, it is necessary to fill water in the pump chamber and remove air bubbles at startup due to its drive characteristics.

Also, there will always be a small amount of gas (air) in the fluid (liquid). In the presence of gas in a liquid, the gas gradually gathers into bubbles and stays there. If air bubbles remain in the fluid chamber, there is a high possibility that when the volume is reduced, the internal pressure does not rise sufficiently and pulse discharge cannot be performed.

Contents of the invention

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 ejection device according to this application example, the fluid ejection device has a fluid chamber, an inlet flow path, and a nozzle, and the volume of the fluid chamber is changed to supply the fluid from the inlet flow path to the fluid chamber. The fluid is ejected in a pulse form from the nozzle, and it is characterized in that the fluid ejection device has: a diaphragm; a wall, which is arranged to be opposite to the diaphragm; a spacer, which is arranged between the diaphragm and the wall between, and has a cylindrical through-hole; a piezoelectric element, which displaces the diaphragm; and a connection flow pipe, which communicates with the fluid chamber, and the nozzle is arranged on the connection flow pipe. The end portion opposite to the fluid chamber, the fluid chamber is formed by the diaphragm, the wall surface, and the inner surface of the through hole of the spacer, and the inlet flow path is provided in a groove on the wall surface formed with the spacer and in communication with the fluid chamber.

According to the configuration of this application example, the inlet flow path forms an arc-shaped inlet flow path on the wall surface constituting a part of the fluid chamber. Therefore, the inertia of the inlet flow path side of the fluid chamber can be made smaller than that of the inlet flow path in view of the fact that the flow path length of the inlet flow path is set long and the cross-sectional area perpendicular to the flow direction of the fluid can be made small. The inertia of the outlet channel side of the fluid chamber is sufficiently large. Therefore, a simple structure without providing a check valve can be realized.

As a result, it is possible to realize an operation in which fluid is supplied from the inlet channel at a constant pressure to the fluid chamber, and the volume of the fluid chamber is changed by the diaphragm to convert it into strong pulsation. Therefore, the water injection operation is unnecessary, and the inflow of the fluid continues even if air bubbles are generated, so that the fluid can be discharged within a certain period of time and return to the normal operation.

[Application example 2] In the fluid ejection device according to the above application example, preferably, the groove on the wall surface has a first end portion, and the first end portion is provided with a hole for supplying the fluid to the groove on the wall surface. The groove of the wall surface is formed to extend in an arc shape from the first end along the wall surface, and the groove of the wall surface is formed from the side opposite to the first end portion of the portion formed in the arc shape. The inner surface of the spacer is formed to extend in the tangential direction of the inner surface of the spacer, and the groove of the wall surface is formed from the part extending in the tangential direction and the arc-shaped The opposite side of the portion is formed along the edge of the inner side of the spacer.

According to this configuration, the fluid can flow along the inner surface of the through-hole of the spacer (that is, the inner peripheral side of the fluid chamber), and swirling flow can be generated in the fluid chamber.

By turning the fluid into a swirling flow, the fluid is deflected to the outside of the fluid chamber by the centrifugal force, and the air bubbles are concentrated at the center, and can be discharged to the outside through the connecting flow pipe along with the discharge of the fluid. Therefore, stagnation of air bubbles in the fluid chamber can be suppressed, the pressure inside the fluid chamber can be sufficiently increased, and reliable pulsating discharge can be performed.

[Application example 3] In the fluid ejection device according to the above application example, it is desirable that, in the groove of the wall surface, the end portion of the portion formed along the edge of the inner surface of the spacer is formed from The bottom surface of the groove of the wall surface of the inlet channel is continuous toward the slope of the wall surface.

In this way, since the bottom surface of the groove constituting the inlet flow path continues to the wall surface on the inclined surface to communicate with the fluid chamber, the fluid resistance in the connection portion between the inlet flow path and the wall surface can be reduced, and the flow path caused by sudden changes can be suppressed. The turbulence of the swirling flow and the generation of bubbles caused by the generated vortex.

[Application Example 4] In the fluid ejection device according to the above application example, it is desirable that a coating layer is provided on the inner wall surface of the fluid chamber.

Here, as the covering layer, for example, a film layer using plating can be used.

The gas contained in the liquid is generated from the fluid under the pressure reduction in the fluid chamber. These air bubbles are concentrated in the center of the fluid chamber due to the swirling flow, and it is expected that when there are minute gaps or corners of components, the air bubbles will adhere to these parts and cannot be discharged.

Therefore, by forming a continuous coating layer inside the fluid chamber to cover minute gaps or joint corners to form a continuous surface, generation of air bubbles can be suppressed.

[Application Example 5] In the fluid ejection device according to the above application example, it is preferable that the fluid ejection device has a holding portion that holds the peripheral edge portion of the diaphragm, and the holding portion is provided with the In the piezoelectric element, a space between the piezoelectric element and the holding portion is filled with resin.

According to this structure, 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. Therefore, it is desirable that the filled resin is a resin with low water absorption.

[Application Example 6] In the fluid ejection device according to the above application example, it is desirable that the resin has thermal conductivity.

When the fluid ejection device of this application example is continuously driven for a long time, heat is generated from the piezoelectric element. Therefore, by filling the space between the piezoelectric element and the holding portion with a resin that itself is a material with high thermal conductivity or mixed with a material with high thermal conductivity, the generated heat is dissipated to the outside via the holding portion, thereby having the potential The effect of preventing the characteristic degradation caused by the temperature increase of the piezoelectric element.

[Application Example 7] In the fluid ejection device according to the above application example, it is desirable that the connection portion between the inner wall of the connection channel pipe and the inner wall of the fluid chamber is connected in a substantially arc shape.

In this way, the fluid resistance of the communication portion between the fluid chamber and the connecting flow pipe can be reduced, and the generation of eddy currents in the joint portion can be suppressed, and the pressure wave generated when the volume of the fluid chamber is reduced can be transmitted to the nozzle without attenuation. .

[Application example 8] In the fluid ejection device related to the above application example, preferably, the nozzle is inserted into the connection flow pipe, and a groove.

Press-fit the nozzle and the connection channel tube, reinforce the joint with adhesive, and seal the joint. In this case, it is difficult to uniformly apply the adhesive to the entire joint. Therefore, by forming grooves on the bonding surface of the nozzle to serve as adhesive reservoirs, reinforcement and airtightness can be ensured.

[Application example 9] In the fluid ejection device according to the application example above, it is preferable that the connection channel tube is detachable.

Here, as a detachable structure, for example, a screwing structure can be adopted.

According to this configuration, in case of clogging of the nozzle, etc., the connection flow pipe can be removed for cleaning, and the connection flow pipe can be easily replaced.

In addition, various shapes of connection flow tubes are prepared, and there is an effect that the shape of connection flow tubes can be arbitrarily selected, replaced, and used according to the object of use.

[Application example 10] A pulsation generating mechanism according to this application example, the pulsation generating mechanism has a fluid chamber and an inlet flow path, the volume of the fluid chamber is changed, and the fluid supplied from the inlet flow path to the fluid chamber is changed from The flow channel connected with the fluid chamber is pulsatingly discharged, and the pulsation generating mechanism has: a diaphragm; a wall, which is arranged to be opposite to the diaphragm; a spacer, which is arranged between the diaphragm and the diaphragm; and a piezoelectric element that displaces the diaphragm, the fluid chamber is composed of the diaphragm, the wall, and the through hole of the spacer. The inner surface is formed, and the inlet flow path is formed by the groove provided on the wall surface and the spacer, and communicates with the fluid chamber.

According to this application example, the flow path length of the inlet flow path can be set long, and the cross-sectional area perpendicular to the flow direction of the fluid can be formed small, and the inlet flow path side of the fluid chamber can be made smaller. The inertia is sufficiently larger than that of the outlet channel side of the fluid chamber. Therefore, pulsating flow can be performed. Therefore, a pulsation generating mechanism of a simple structure without providing a check valve can be realized.

[Application example 11] The connection flow pipe related to this application example, the connection flow pipe can be detached from the pulsation generating mechanism, the pulsation generating mechanism changes the volume of the fluid chamber, and the fluid is connected to the fluid chamber. The outlet flow path pulsating discharge is characterized in that the connection flow pipe is configured to be able to communicate with the outlet flow path, and has a fluid ejection opening at the end opposite to the side communicating with the outlet flow path, and the fluid A cross-sectional area of the injection opening in a direction perpendicular to the flow direction of the fluid is smaller than a cross-sectional area of the outlet flow path.

In this way, the fluid pulsated and discharged from the pulsation generating mechanism can be ejected at a higher speed as pulsed droplets having a high cutting ability so that the fluid can be ejected from the fluid ejection opening whose cross-sectional area is smaller than that of the outlet flow path.

In addition, various shapes of the connection flow tube are prepared, and there is an effect that the shape of the connection flow tube can be arbitrarily selected and used according to the object of use. In addition, the flow tube can be detachably connected to the pulsation generating mechanism, so that convenience can be further improved.

Description of drawings

FIG. 1 is an explanatory diagram showing a schematic configuration of a fluid ejection system.

2 is a cross-sectional view of the main structure of the pulsation generating mechanism according to Embodiment 1 cut along the flow path direction of the liquid.

Fig. 3 is a side view illustrating the pulsation generating mechanism from the right side.

Fig. 4 is a side view illustrating the pulsation generating mechanism from the left side.

5 is a cross-sectional view showing details of a junction between a first machine frame and a second machine frame according to Embodiment 1. FIG.

6 is a plan view showing a state in which the first housing according to Embodiment 1 is viewed from the side of the piezoelectric element.

FIG. 7 is an enlarged cross-sectional view showing an inlet portion according to Embodiment 1. FIG.

8 is a cross-sectional view showing a joint structure of the nozzle and the connection channel tube according to the first embodiment.

FIG. 9 is a cross-sectional view showing a part of the fluid ejection device according to Embodiment 2. FIG.

Fig. 10 shows a fluid ejection device according to Embodiment 3, Fig. 10(a) is a cross-sectional view showing a part of the fluid ejection device, and Fig. 10(b) is a cross-section showing the E-E cross section of Fig. 10(a) picture.

Label description

10: fluid injection device; 40: piezoelectric element; 50: second frame; 60: spacer; 61: inner peripheral side wall; 70: diaphragm; 80: first frame; 82: wall; 83: inlet Flow path; 85: connecting flow path; 90: connecting flow path pipe; 91: outlet flow path; 95: nozzle; 120: fluid chamber.

Detailed ways

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a fluid ejection system, FIGS. 2 to 8 show a fluid ejection device according to the first embodiment, FIG. 9 shows the second embodiment, and FIG. 10 shows the third embodiment.

In addition, for convenience of illustration, the drawings referred to in the following description are schematic diagrams in which the vertical and horizontal scales of components or parts are different from actual components or parts.

Furthermore, the fluid ejection system and the fluid ejection device of the present invention can be used in various applications such as drawing using ink, washing of delicate objects and structures, surgical scalpels, etc. However, in the embodiments described below, Fluid ejection devices suitable for cutting or excision of living tissue are described. Therefore, the fluid used in the embodiment is a liquid such as water or physiological saline, and the fluid is sometimes 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 , the fluid injection system 1 is composed of the following as a basic structure: a control device 20 including a liquid container containing a liquid and a pump (not shown) as a pressure generating part; a supplied liquid; and a connecting tube 25 which communicates the fluid ejection device 10 with the pump.

The fluid ejection device 10 has: a pulsation generating mechanism 30, which pulsates at high pressure and high frequency to discharge the supplied liquid; There is a nozzle 95 having a fluid ejection opening 97 in which the cross-sectional area of the flow path is reduced.

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

A fluid chamber 120 (see FIG. 2 ) and a volume changing unit of the fluid chamber 120 are provided in the pulsation generating mechanism 30 . The volume changing unit is driven to generate pulsation, and the liquid is ejected from the fluid ejection opening 97 in pulse form at high speed. The detailed description of the pulsation generating mechanism 30 will be described later with reference to FIGS. 2 to 7 .

In addition, the pressure generating unit is not limited to the pump, and an infusion bag serving as a liquid container may be held at a position higher than the pulsation generating mechanism 30 by a stand or the like. Therefore, there are advantages in that a pump is unnecessary, the structure can be simplified, and the liquid flow path can be easily sterilized.

The discharge pressure of the pump is set to approximately 3 atmospheres (0.3 MPa) or less. In addition, when an infusion bag is used, the height difference between the pulsation generating mechanism 30 and the liquid upper surface of the infusion bag becomes the pressure, and it is desirable to set the height difference to about 0.1 to 0.15 atmospheres (0.01 to 0.015 MPa). .

In addition, 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 this reason, it is preferable to use a flexible and thin tube so that the liquid is at a low pressure within the range that can be sent to the pulsation generating mechanism 30 .

In addition, especially in brain surgery, when a failure of the fluid ejection system 1 is likely to cause a serious accident, it is necessary to avoid ejection of high-pressure fluid when the connecting pipe 25 is cut off, so low pressure is also required.

(Embodiment 1)

Next, the configuration of the fluid ejection device 10 according to Embodiment 1 will be described.

2 is a sectional view showing the main structure of the pulsation generating mechanism according to Embodiment 1 cut along the flow path direction of the liquid, FIG. 3 is a side view showing the pulsation generating mechanism from the right side, and FIG. A side view showing the left side of the pulsation generating mechanism.

First, a schematic configuration of the fluid ejection device 10 will be described with reference to FIGS. 2 to 4 . The fluid ejection device 10 is composed of: a pulsation generating mechanism 30 including a pulsation generating unit that generates pulsation of liquid; and a connection channel pipe 90 having an outlet connection channel 92 and a nozzle 95 for discharging liquid.

The pulsation generating mechanism 30 has a fluid chamber 120, and the fluid chamber 120 is configured such that the periphery of the ring-shaped spacer 60 and the disc-shaped diaphragm 70 made of a thin metal plate are tightly sandwiched between the first frame 80 and as a mechanism. The opposing surfaces of the second machine frame 50 of the frame are surrounded by the wall surface 82 on the second machine frame 50 side of the first machine frame 80 , the diaphragm 70 , and the inner peripheral wall surface of the spacer 60 .

A pipe connection pipe 81 is protruded from the outer side of the first machine frame 80 , and an inflow connection flow path 84 is opened in the pipe connection pipe 81 . The inflow connection flow path 84 is connected with a connection flow path 85 communicating with the fluid chamber 120 , and the connection flow path 85 communicates with the inlet flow path 83 pierced on the wall surface 82 . The inlet channel 83 will be described in detail with reference to FIGS. 5 and 6 .

The connection pipe 25 is fitted in the pipe connection pipe 81 . The connection pipe 25 is configured to be connected to a pump provided inside the control device 20 (see FIG. 1 ) and to supply liquid into the fluid chamber 120 through the inlet channel 83 .

In addition, in the first machine frame 80 , a connection channel pipe 90 is inserted substantially perpendicular to the diaphragm 70 (that is, the wall surface 82 ) at approximately the center of the wall surface 82 . The connecting channel tube 90 has an outlet channel 91 communicating with the fluid chamber 120 and an outlet connecting channel 92 communicating with the outlet channel 91 , and a nozzle 95 is inserted at the end opposite to the outlet channel 91 .

The nozzle 95 has a nozzle flow path 96 communicating with the outlet connection flow path 92 and a fluid ejection opening 97 .

Here, the outlet connection flow path 92 and the nozzle flow path 96 have the same cross-sectional area, which is larger than the cross-sectional area of the outlet flow path 91 . Furthermore, the cross-sectional area of the fluid ejection opening 97 is smaller than the cross-sectional area of the outlet connection channel 92 .

In addition, the above cross-sectional area represents the cross-sectional area of the flow path when cut perpendicular to the flow direction of the liquid.

On the other hand, the second machine frame 50 is a cylindrical member having an outer flange portion 56 and a cylindrical portion 51 , and the external shapes of the outer flange portion 56 and the cylindrical portion 51 are square. Then, a cylindrical hole 51a penetrating through the second machine frame 50 is opened.

The opening of the hole 51 a in the direction opposite to the first machine frame 80 is sealed by the lower plate 100 . A piezoelectric element 40 as a driving source is disposed inside the hole 51 a. The piezoelectric element 40 is a laminated piezoelectric element and constitutes a columnar actuator.

One end of the piezoelectric element 40 is fixed to the diaphragm 70 via the upper plate 110 , and the other end is fixed to the inner surface of the lower plate 100 .

Drive electrodes (not shown) are respectively provided on opposite side surfaces of the piezoelectric element 40 , and connection leads 151 and 152 covered with insulation are connected to these drive electrodes. The connecting lead wires 151, 152 are drawn to the outside through the lead wire insertion holes 54, 55 provided on the side surface of the cylindrical portion 51 of the second machine frame 50, and connected to the drive circuit portion ( not shown) connection.

The first machine frame 80 and the second machine frame 50 fasten and fix the four corners with fixing screws 161 in a state of sandwiching the peripheral edge portion of the diaphragm 70 and the spacer 60 to make close contact with each other (see FIG. 4 ).

On the other hand, the dimensions of the second machine frame 50 and the lower plate 100 are adjusted so that the piezoelectric element 40 does not deform the diaphragm 70 in the assembled state, and then the four corners are fastened and fixed with the fixing screws 160 .

With the first machine frame 80 , the second machine frame 50 , and the lower plate 100 fixed in this way, the resin 140 is filled in the space formed by the cylindrical portion 51 of the second machine frame 50 and the piezoelectric element 40 . The filling range also includes the inside of the lead wire insertion holes 54 and 55 through which the connecting lead wires 151 and 152 are inserted.

In addition, it is preferable to use a material with little water absorption (or a material with water repellency) for the filled resin 140 . In addition, resin itself is a material with high thermal conductivity or a resin mixed with a material with high thermal conductivity is preferable. As the material to be mixed, inorganic ceramic powder and carbon powder with high thermal conductivity can be considered. The material is more preferable as long as it satisfies the two conditions of low water absorption and thermal conductivity.

Furthermore, the resin has flexibility to the extent that it does not interfere with the driving of the piezoelectric element 40 in order to fill and cover the periphery of the piezoelectric element 40 .

Next, the joining portion between the first machine frame 80 and the second machine frame 50 will be described with reference to FIG. 5 .

Fig. 5 is a cross-sectional view showing details of a junction between a first machine frame and a second machine frame. Therefore, the same reference numerals as those in FIG. 2 will be assigned and described.

In the first machine frame 80 , an annular concave portion 86 is formed around the wall surface 82 , and in the second machine frame 50 , an annular convex portion 53 is formed to face the annular concave portion 86 . By inserting the annular convex portion 53 into the annular concave portion 86 , accurate positioning 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 pressed between the central wall surface 82 of the first machine frame 80 and the inner peripheral flange portion 52 protruding inside the annular protrusion 53 of the second machine frame 50 .

In addition, the diameters of the inner peripheral side wall 61 of the spacer 60 and the inner peripheral flange portion 52 of the second machine frame 50 are set to be substantially the same, so that the support positions for the displacement of the diaphragm 70 are the same.

A packing 130 as a sealing material is provided between the bottom of the annular concave portion 86 of the first machine frame 80 and the front end portion of the annular convex portion 53 of the second machine frame 50 . In a state where the diaphragm 70 and the spacer 60 are pressed together, the packing 130 is pressed and deformed to restrict the movement of liquid between the outside and the fluid chamber 120 .

Furthermore, the connection channel pipe 90 is press-fitted in the first machine frame 80 until the end reaches the fluid chamber 120 , and the outlet channel 91 communicates with the fluid chamber 120 . In addition, the end surface of the connecting channel tube 90 is processed to be the same plane as the surface of the wall surface 82 in the fluid chamber 120 . Furthermore, the connection portion (communication portion) of the outlet channel 91 with the fluid chamber 120 is smoothly connected in a substantially arc shape.

Such processing can be achieved by pressing the connection flow pipe 90 into the fluid chamber 120 slightly protruding from the wall surface 82, and then grinding according to the surface of the wall surface 82, and then correcting the inner corner of the outlet flow path 91. Grinding is performed.

The inlet channel 83 is composed of a groove formed in the wall surface 82 of the first machine frame 80 and a spacer 60 that seals the opening of the groove.

Next, the inlet channel 83 will be described with reference to FIGS. 6 and 7 .

Fig. 6 is a plan view showing a state in which the first frame is viewed from the side of the piezoelectric element. The inlet flow path 83 is formed as a groove on the wall surface 82 of the first machine frame 80, and the connection portion with the connection flow path 85 is used as a base end portion, and extends in a substantially arc shape until the front end portion communicating with the fluid chamber 120 reaches Inflow port 83a.

The groove extends from the connection portion with the connecting flow path 85 to the position shown in A in a concentric circle centered on the outlet flow path 91 , and the range from the shown B to the shown C is on the inner peripheral side wall 61 of the spacer 60 . The tangential direction of (ie, the tangential direction of the sidewall of the fluid chamber 120 ) extends. Also, the range from illustration C to illustration D extends along the inner peripheral side wall 61 of the spacer 60 .

In addition, the range from A in the illustration to B in the illustration is connected by a small circular arc that only smoothly changes the flow direction of the liquid.

Most of the openings (upper side in the drawing) of the groove formed in this way are sealed by the ring-shaped spacer 60 to form the inlet channel 83 , and the inflow port 83 a communicates with the fluid chamber 120 .

By forming the inlet channel 83 in this way, the liquid flowing in from the connecting pipe 25 at a constant pressure becomes a swirling flow along the inner peripheral side wall 61 of the spacer 60 .

In addition, the inlet portion 83a of the inlet channel 83 leading to the fluid chamber 120 is continuous on the slope 83d from the bottom surface to the wall surface 82 .

Fig. 7 is a sectional view showing an enlarged inflow port. The inflow port 83a extends from the bottom surface 83b of the groove to the wall surface 82 through the slope 83d within the range of the inlet channel 83 from C to D in the drawing (see also FIG. 6 ).

Next, the joining structure of the nozzle and the connecting channel tube in this embodiment will be described with reference to the drawings.

Fig. 8 is a cross-sectional view showing a joint structure of a nozzle and a connecting channel tube. The nozzle 95 is composed of a front end flange portion 98 and an insertion portion 99 , and has a nozzle flow path 96 and a fluid ejection opening 97 communicating with the outlet connection flow path 92 of the connection flow path pipe 90 . On the outer peripheral surface of the insertion portion 99, a groove 99a is formed halfway in the longitudinal direction, and a thin tube portion 99b having a reduced outer diameter is formed at the insertion-side tip.

In addition, a nozzle insertion hole 90 f is formed at an end portion of the connection flow pipe 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 in close contact with the bottom surface 94 of the nozzle insertion hole 90f.

In addition, the nozzle 95 is press-fitted into the connection channel tube 90 after the adhesive is applied to the outer peripheral side of the insertion portion 99 to increase the press-fitting strength. During this press-fitting, the adhesive is accumulated in the groove 99a. Therefore, the groove 99 a in the present embodiment is an adhesive reservoir, and has a function of improving the adhesive strength, and a function of preventing liquid leakage and air intrusion at the junction between the nozzle 95 and the connection channel tube 90 .

In addition, the narrow tube portion 99 b prevents the adhesive from staying within the range of the narrow tube portion 99 b and entering into the outlet connection flow path 92 or the nozzle flow path 96 .

Next, the operation of the fluid ejection device 10 in this embodiment will be described with reference to FIGS. 5 and 6 . The liquid discharge from the pulsation generating mechanism 30 of this embodiment is performed based on the difference between the inertia L1 on the inlet channel side (sometimes referred to as combined inertia L1 ) and the outlet channel side inertia L2 (sometimes called combined inertia L2 ).

First, inertia will be explained.

When the density of the liquid is ρ, the cross-sectional area of the flow path is S, and the length of the flow path is h, the inertia L is represented by L=ρ×h/S. Assuming that the pressure difference of the flow path is ΔP, the flow rate of the liquid flowing through the flow path is Q, and the time is t, use the inertia L to transform the equation of motion in the flow path, and derive the formula of ΔP=L×dQ/dt relation.

That is, the inertia L represents the degree of influence on the temporal change of the flow rate. The larger the inertia L, the smaller the temporal change of the flow rate, and the smaller the inertia L, the larger the temporal change of the flow rate.

In addition, since the cross-sectional areas of the inflow connecting flow path 84 and the connecting flow path 85 are set sufficiently larger than the cross-sectional area of the inlet flow path 83 , the combined inertia L1 is calculated within the range of the inlet flow path 83 . In this case, since the connecting pipe 25 has flexibility, it can be omitted from the calculation of the combined inertia L1.

In addition, since the connection channel pipe 90 has sufficient rigidity for the pressure wave propagation of the liquid, the resultant inertia L2 can be considered as the sum of the outlet channel 91 and the outlet connection channel 92 .

Then, 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 91 and the outlet connection flow path 92 are set so that the combined inertia L1 is greater than the combined inertia L2. .

Next, the operation of the pulsation generating mechanism 30 will be described.

The liquid is always supplied to the inlet flow path 83 by the pump at a certain pressure. As a result, when the piezoelectric element 40 is not operating, the liquid flows into the fluid chamber 120 according to the difference between the discharge pressure of the pump and the fluid resistance value of the entire inlet channel side.

Here, assuming that a drive signal is input to the piezoelectric element 40 and the piezoelectric element 40 expands rapidly, when the combined inertia L1, L2 on the side of the inlet flow path and the side of the outlet flow path has a sufficient magnitude, the fluid chamber 120 The pressure rises sharply and reaches tens of atmospheres. Since this pressure is much higher than the pump pressure applied to inlet flow path 83 , the inflow of liquid from inlet flow path 83 into fluid chamber 120 decreases and the outflow of liquid from outlet flow path 91 increases according to this pressure.

However, since the resultant inertia L1 on the side of the inlet flow path is greater than the resultant inertia L2 on the side of the outlet flow path, the amount of liquid discharged from the outlet flow path 91 is reduced compared to the decrease in the flow rate of the liquid flowing from the inlet flow path 83 into the fluid chamber 120. The increase is larger. Therefore, a pulsed fluid discharge, that is, a pulsating flow, occurs in the outlet channel 91 .

The pressure fluctuation at the time of discharge propagates in the connection channel pipe 90, and the liquid is ejected from the fluid ejection opening 97 (both refer to FIG. 2 ) of the nozzle 95 at the tip. Since the diameter of the fluid ejection opening 97 is smaller than the diameter of the outlet channel 91 , the liquid is further ejected as high-pressure, high-speed pulsed droplets.

On the other hand, in the fluid chamber 120 , due to the interaction between the decrease of the inflow of liquid from the inlet channel 83 and the increase of the outflow of liquid from the outlet channel 91 , it is in a vacuum state immediately after the pressure rises. As a result, due to both the pressure of the pump and the vacuum state in the fluid chamber 120 , the liquid in the inlet channel 83 resumes flowing into the fluid chamber 120 at the same speed as before the operation of the piezoelectric element 40 after a certain period of time. After the flow of the liquid in the inlet flow path 83 is restored, the liquid can be continuously ejected from the nozzle 95 in a pulsed manner while the piezoelectric element 40 is stretched.

In the present embodiment, the inlet channel 83 is formed as a groove in the wall surface 82 of the first machine frame 80 , and the opening is sealed with the spacer 60 . Therefore, from the perspective of setting the flow path length of the inlet flow path 83 long and making the cross-sectional area in the direction perpendicular to the flow direction of the liquid small, the resultant inertia L on the inlet flow path side can be made smaller than that of the outlet flow path. The resultant inertia L2 on the flow path side is sufficiently large. Therefore, a simple structure without providing a check valve can be realized.

As a result, an operation can be realized in which the liquid is supplied from the inlet flow path 83 into the fluid chamber 120 at a constant pressure, and converted into strong pulsation by the pulsation generating mechanism 30 . Therefore, the water injection operation is unnecessary, and the inflow of the liquid continues even if air bubbles are generated, so that the liquid can be discharged within a certain period of time and return to the normal operation.

In addition, the inlet flow path 83 is along the arc portion extending from the connection portion (base end portion) with the connection flow path 85 , from the arc portion along the tangential direction of the inner peripheral side wall 93 of the spacer 60 , and further along the The inner peripheral side wall 93 extends and communicates with the fluid chamber 120 from the inlet portion 83a. Accordingly, a swirling flow is generated within the fluid chamber 120 .

When the swirl flow is generated, the liquid is deflected to the outside of the fluid chamber 120 by the centrifugal force, the air bubbles gather at the center, and are discharged from the outlet channel 91 to the outside along with the discharge of the liquid. Therefore, stagnation of air bubbles in the fluid chamber 120 can be suppressed, the pressure inside the fluid chamber 120 can be sufficiently increased, and high-pressure pulse discharge can be performed.

In addition, in the inlet portion 83a where the inlet flow path 83 is connected to the fluid chamber 120, the bottom surface 83b of the groove forming the inlet flow path 83 continues to the wall surface 82 on the slope 83d, so that the number of inlet portions 83a and the fluid chamber 120 can be reduced. Fluid resistance in the connection part of the flow path can be suppressed, and the turbulence of the swirling flow caused by the eddy flow generated by the sudden change of the flow path can be suppressed.

Furthermore, the space of the cylindrical portion 51 of the second machine frame 50 where the piezoelectric element 40 is arranged is filled with the resin 140 . The resin 140 has a low water absorption property, and thus prevents moisture from infiltrating into the space, and prevents a short circuit between electrodes caused by moisture adhering to the piezoelectric element 40 .

In addition, the resin 140 is also filled in the lead wire insertion holes 54, 55 (see FIG. 2 ) through which the connecting lead wires 151, 152 are inserted, so that the connection portion with the piezoelectric element 40 and the connection in the second machine frame 50 can be strengthened. The leads 151, 152 are connected.

Moreover, by using a material with high thermal conductivity for the resin 140, the heat generated from the piezoelectric element 40 due to continuous driving for a long time can be dissipated to the outside through the second machine frame 50, thereby preventing the temperature of the piezoelectric element 40 from increasing. Effect of characteristic degradation due to heightening.

In addition, since the joint portion of the outlet flow path 91 and the wall surface 82 is connected in a substantially arc shape and smoothly rounded, the fluid resistance in the joint portion of the fluid chamber 120 and the outlet flow path 91 can be reduced, and the flow resistance can be suppressed. The generation of the vortex in this joint portion allows the pressure wave generated when the volume of the fluid chamber 120 is reduced to be transmitted to the nozzle 95 without attenuation.

In addition, a groove 99 a serving as an adhesive reservoir is formed on the joint surface between the nozzle 95 and the connection channel pipe 90 . The nozzle 95 and the connection flow pipe 90 are press-fitted, and the joint is reinforced with an adhesive, and by providing an adhesive reservoir, strength enhancement and airtightness can be ensured.

(Embodiment 2)

Next, Embodiment 2 will be described with reference to the drawings. Embodiment 2 has a feature that, compared to Embodiment 1, an outlet flow path is provided in the first frame, and an outlet connection flow path provided in a connection flow pipe is communicated with the outlet flow path. Therefore, the description will focus on differences from Embodiment 1. FIG.

FIG. 9 is a cross-sectional view showing a part of the fluid ejection device according to Embodiment 2. FIG. In Fig. 9, an outlet flow path 88 communicating with the fluid chamber 120 is opened in the first machine frame 80, and a connecting flow path pipe insertion portion 80a protrudes from the opposite side of the fluid chamber 120, and a connecting flow path pipe insertion portion 80a is protruded on the central portion thereof. An insertion hole 80c is pierced therethrough.

Then, the connecting channel tube 90 is inserted into the connecting channel tube insertion portion 80a. An outlet connection flow path 92 is opened in the connection flow path pipe 90 so that the outlet flow path 88 and the outlet connection flow path 92 communicate.

In addition, the channel length and cross-sectional area (diameter) of the outlet channel 88 and the outlet connecting channel 92 are set to be the same as those in the first embodiment.

Furthermore, the connecting channel tube 90 is pressed until the front end portion 90g thereof comes into close contact with the bottom portion 80b of the insertion hole 80c.

In addition, a groove portion 90d is provided in the middle of the joint range of the connection channel tube 90 with the insertion hole 80c, and a thin tube portion 90e having a reduced outer diameter is provided at the front end.

After the adhesive is applied to the outer peripheral surface of the connection channel tube 90 to increase the press-fit strength, it is press-fitted into the insertion hole 80c. When the connection channel tube 90 is press-fitted, the adhesive is accumulated in the groove portion 90d. Therefore, the groove portion 90d in the present embodiment is an adhesive reservoir, has a function of improving the adhesive strength, and prevents liquid leakage and air intrusion at the joint portion connecting the flow pipe 90 and the first machine frame 80. Function.

Furthermore, the narrow tube portion 90 e prevents the adhesive from staying within the range of the narrow tube portion 90 e and entering into the outlet flow path 88 or the outlet connection flow path 92 .

In addition, in this structure, the outlet flow path 88 is opened in the first machine frame 80 . Therefore, the outlet flow path 88 is continuous on the same surface as the wall surface 82 constituting a part of the fluid chamber 120, so that a junction connecting the flow path tube 90 and the wall surface 82 is not formed in the fluid chamber 120, so that it is possible to suppress damage due to the presence of the junction surface. Bubbles are produced.

(Embodiment 3)

Next, a fluid ejection device according to Embodiment 3 will be described with reference to the drawings. In Embodiment 1 and Embodiment 2, the connection flow pipe 90 is press-fitted and fixed in the pulsation generating mechanism 30 (the first machine frame 80 ), while the feature of Embodiment 3 is that the connection flow pipe 90 can be mounted on the pulsation generating mechanism 30 To disassemble. Therefore, the description will focus on differences from the first and second embodiments described above.

Fig. 10 shows a fluid ejection device according to Embodiment 3, Fig. 10(a) is a cross-sectional view showing a part of the fluid ejection device, and Fig. 10(b) is a cross-section showing the E-E cross section of Fig. 10(a) picture. In FIG. 10 , the fluid ejection device 10 is configured such that in the pulsation generating mechanism 30 , the connection channel pipes 90 are screwed and fixed to the threaded portions of each other.

Specifically, in the first machine frame 80 constituting the pulsation generating mechanism 30, a connection channel tube insertion portion 80a is projected on the opposite side to the fluid chamber 120, and a connection channel tube insertion portion 80a is opened in the connection channel tube insertion portion 80a. There is an outlet flow path 88 and a connection flow path 89 communicating with the fluid chamber 120 . Furthermore, a female thread 80 d is formed in a range from the front end portion of the connection flow-path tube insertion portion 80 a to the connection flow path 89 .

An outlet connection flow path 92 is opened in the connection flow path pipe 90, and an external thread 90a is formed on the outer periphery of the front end thereof. By tightening these threaded portions, the connection channel tube 90 is fixed to the pulsation generating mechanism 30 . Therefore, the connecting channel pipe 90 has a structure that can be attached to and detached from the pulsation generating mechanism 30 (that is, the first machine frame 80 ).

In addition, the connection channel pipe 90 is fixed by screwing the front end portion 90g until it comes into close contact with the bottom portion 80b of the internal thread 80d.

In addition, the diameters of the connecting flow path 89 and the outlet connecting flow path 92 are the same, and the flow path length and cross-sectional area (diameter) of the outlet flow path 88, the connecting flow path 89, and the outlet connecting flow path 92, that is, the combined inertia of the outlet flow path side L2 is set to be the same as in the first embodiment.

In addition, a cut portion 90 b is formed on the outer peripheral portion of the connecting channel tube 90 midway in the longitudinal direction. As shown in FIG. 10( b ), the cutting portion 90 b is formed by cutting the outer peripheral portion of the connecting channel tube 90 on planes facing each other. Rotating the cutting portion 90 b with a jig or the like can be used for attaching and detaching the connection channel tube 90 to the pulsation generating mechanism 30 .

Therefore, according to this configuration, in case of clogging of the nozzle 95, etc., the connection flow pipe 90 can be removed for cleaning and disinfection, and the connection flow pipe 90 can be easily replaced.

In addition, various shapes of the connection channel tube 90 are prepared, and there is an effect that the shape of the connection channel tube 90 can be arbitrarily selected according to the object of use, installed and used.

Next, Embodiment 4 will be described. Embodiment 4 is characterized in that a covering layer is formed on the inner wall surface of the fluid chamber. Illustration is omitted, and description will be made with reference to FIG. 5 .

The fluid chamber 120 is constituted by a space surrounded by the wall surface 82 of the first machine frame 80 , the inner peripheral side wall 61 of the spacer 60 , and the diaphragm 70 . At this time, the junction and corner of the first machine frame 80 and the wall surface 82, the junction and corner of the inner peripheral side wall 61 of the spacer 60 and the diaphragm 70, and the junction of the flow pipe 90 and the wall surface 82 are formed. junction.

It is considered that a slight gap in processing is formed on these junctions, and the inner angle of the corner is 90 degrees.

A covering layer is formed on the entire circumference of the inner wall surface of such a fluid chamber 120 . As an example of the coating layer, a metal plating layer can be used. The material of the plating layer is not particularly limited, but a material resistant to the liquid used is selected.

In addition, the formation of the plating layer can be carried out by inserting the connecting flow pipe 90 into the pulsation generating mechanism 30 and then immersing it in the plating solution. In the case of forced flow in the connection flow path 92, the plating layer can be formed in the entire flow path as the plating solution circulates to the details of each flow path.

In addition, the coating layer is also formed at the corner formed between the bottom and the side wall of the groove of the inlet flow path 83 and the corner of the junction with the spacer 60 that seals the groove. In addition, a covering layer is also formed at the joint between the nozzle 95 and the connection channel tube 90 .

Therefore, a continuous thin coating layer is formed over the entire liquid flow path.

As described above, the gas contained in the flowing liquid gradually collects in the minute gaps and corners of the joints of the components to generate air bubbles. When air bubbles exist in the fluid chamber 120 , it is considered that the internal pressure does not rise sufficiently when the volume of the fluid chamber 120 is reduced by the diaphragm 70 .

Therefore, by forming a continuous thin coating layer in the entire liquid flow path including the fluid chamber 120, filling the minute gaps in the joint parts of each component, and using the rounded corners of the coating layer, it is possible to suppress the occurrence of small Bubbles are generated by closing gaps and corners, and the internal pressure of the fluid chamber 120 can be increased to a predetermined level.

In addition, although this Embodiment demonstrated the said Embodiment 1 as an example, it is applicable also to the structure of the said Embodiment 2 and Embodiment 3.

Claims (11)

1. fluid ejection apparatus, this fluid ejection apparatus has fluid chamber, inlet stream and nozzle, changes the volume of described fluid chamber, will be pulse type from described nozzle from the fluid that described inlet stream offers described fluid chamber and spray, it is characterized in that this fluid ejection apparatus has:

Diaphragm;

Wall, it is arranged to described diaphragm opposed;

Distance piece, it is located between described diaphragm and the described wall, and has columnar through hole;

Piezoelectric element, it makes described diaphragm displacement; And

Connect flow channel tube, it is communicated with described fluid chamber,

Described nozzle is located at the end opposite with described fluid chamber of described connection flow channel tube,

Described fluid chamber is formed by the medial surface of the through hole of described diaphragm, described wall and described distance piece,

Described inlet stream is formed by the groove and the described distance piece that are located on the described wall, and is communicated with described fluid chamber.

2. fluid ejection apparatus according to claim 1 is characterized in that,

The groove of described wall has the 1st end, and the groove that the 1st end is provided with to described wall provides described fluidic hole,

The groove of described wall is circular-arc extension along described wall from described the 1st end and forms,

Part and opposition side described 1st end the described medial surface to described distance piece of the groove of described wall from being described circular-arc formation extends in the tangential direction of the medial surface of described distance piece and to form,

The groove of described wall is from extend the part that forms in described tangential direction and opposition side described circular-arc part, forms along the edge of the described medial surface of described distance piece.

3. fluid ejection apparatus according to claim 2, it is characterized in that, in the groove of described wall, along the edge of the described medial surface of described distance piece and the terminal part of the part that forms, be successive towards the inclined-plane of described wall in bottom surface from the groove of the described wall that forms described inlet stream.

4. fluid ejection apparatus according to claim 1 is characterized in that, is provided with cover layer at the internal face of described fluid chamber.

5. fluid ejection apparatus according to claim 1 is characterized in that,

Described fluid ejection apparatus has maintaining part, and this maintaining part keeps described diaphragm-operated circumference,

Be equipped with described piezoelectric element in the inside of described maintaining part, be filled with resin in the space between described piezoelectric element and described maintaining part.

6. fluid ejection apparatus according to claim 5 is characterized in that described resin has heat conductivity.

7. fluid ejection apparatus according to claim 1 is characterized in that, the inwall of described connection flow channel tube is roughly with connecting portion between the inwall of described fluid chamber that circular shape is connected.

8. fluid ejection apparatus according to claim 1 is characterized in that, described nozzle is inserted in the described connection flow channel tube, is provided with groove along described nozzle with the described composition surface that is connected flow channel tube.

9. fluid ejection apparatus according to claim 1 is characterized in that, described connection flow channel tube is can dismounting.

10. pulsation generating mechanism, this pulsation generating mechanism has fluid chamber and inlet stream, changes the volume of described fluid chamber, will offer the stream pulsation discharge of fluid from being communicated with described fluid chamber of described fluid chamber from described inlet stream, it is characterized in that this pulsation generating mechanism has:

Diaphragm;

Wall, it is arranged to described diaphragm opposed;

Distance piece, it is located between described diaphragm and the described wall, and has columnar through hole; And

Piezoelectric element, it makes described diaphragm displacement,

Described fluid chamber is formed by the medial surface of the through hole of described diaphragm, described wall and described distance piece,

Described inlet stream is formed by the groove and the described distance piece that are located on the described wall, and is communicated with described fluid chamber.

11. one kind connects flow channel tube, this connection flow channel tube can carry out dismounting on pulsation generating mechanism, and the volume of this pulsation generating mechanism change fluid chamber is discharged fluid from the outlet stream pulsation that is communicated with described fluid chamber, it is characterized in that,

Described connection flow channel tube constitutes and can be communicated with described outlet stream,

The end opposite in a side that is communicated with described outlet stream has the fluid jet peristome, this fluid jet peristome and the sectional area of sectional area fluidic flow direction vertical direction less than described outlet stream.

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