JP5870565B2 - Liquid ejector - Google Patents

Description

  The present invention relates to a liquid ejecting apparatus.

  There has been developed a liquid ejecting apparatus that incises or excises a biological tissue by pressurizing a liquid such as water or physiological saline and ejecting the liquid toward a living tissue from a nozzle having a narrow cross-sectional area. In surgery using such a liquid ejecting apparatus, it is possible to selectively incision or excision only of tissues such as organs without damaging nerves and blood vessels, etc., and there is little damage to surrounding tissues. Can be reduced.

  Further, there has been proposed a liquid ejecting apparatus that enables incision or excision of a living tissue with a small amount of ejection by ejecting liquid in a pulse form instead of simply ejecting liquid continuously from a nozzle (for example, , See Patent Document 1). This liquid ejecting apparatus rapidly increases the pressure in the liquid chamber by rapidly decreasing the volume of the liquid chamber while the liquid chamber is filled with the liquid, and the pressure causes a pulse from the nozzle connected to the liquid chamber. The liquid is jetted in the shape of Subsequently, the volume of the liquid chamber is returned to the original, and the liquid is filled again. By repeating these operations, a pulsed jet can be generated periodically.

JP 2008-082202 A

  However, in such a liquid ejecting apparatus that ejects liquid in a pulsed manner, bubbles that are generated in the liquid chamber due to bubbles that exist in the liquid or gas that has been dissolved in the liquid are retained in the liquid chamber. As a result, there was a problem that the ability of incision and excision deteriorated. That is, as described above, the pulsed jet is generated by reducing the volume of the liquid chamber and pressurizing the liquid in the liquid chamber. Therefore, if there are bubbles in the liquid chamber, the volume of the liquid chamber is decreased. Even if it makes it, it cannot fully pressurize the liquid by the bubble being compressed. For this reason, it has become a problem that the liquid cannot be ejected in a pulse form from the nozzle, and the ability to cut and excise is reduced.

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

  Application Example 1 In the liquid ejecting apparatus according to this application example, a cross-sectional area is provided between an inlet channel to which a liquid is supplied, an outlet channel communicating with a nozzle, and the inlet channel and the outlet channel. A liquid chamber having a substantially constant spiral flow path and having a given volume, and a volume changing section for deforming the liquid chamber in a direction to reduce the volume of the liquid chamber from the given volume. And an ejection control means for ejecting the liquid in a pulse form from the nozzle by driving the volume changing section in a state where the liquid is filled in the liquid chamber. .

  According to this application example, the liquid chamber having the spiral channel is formed between the inlet channel and the outlet channel, and when the volume changing unit is driven, the liquid chamber is pressed by the volume changing unit, and the liquid The chamber volume is reduced. As a result, the liquid in the liquid chamber is rapidly pressurized, and the pressurized liquid can be ejected from the nozzle communicating with the outlet channel of the liquid chamber at a high speed.

  In the liquid ejecting apparatus, when the liquid chamber is filled with the liquid, the liquid supplied from the inlet channel flows along the spiral channel to the outlet channel, so that it is difficult for bubbles to stay in the liquid chamber. .

  For example, if the flow of liquid in the liquid chamber is irregular and there are places where the flow is fast and places where the flow is slow, bubbles tend to stay in the places where the flow is slow, and the presence of such bubbles prevents the liquid from being fully pressurized, The liquid cannot be ejected properly. Therefore, if a spiral channel having a substantially constant cross-sectional area is formed between the inlet channel and the outlet channel, the flow of the liquid in the liquid chamber is regulated to a substantially constant flow velocity along the spiral channel. Therefore, it is possible to suppress the bubbles from staying at a place where the flow is slow, and the bubbles in the liquid chamber can be easily discharged from the outlet channel. As a result, the pressure in the liquid chamber can be sufficiently increased without being affected by bubbles, and stable liquid ejection can be maintained.

Application Example 2 In the liquid ejecting apparatus according to the application example, the volume changing unit includes a piezoelectric element, the volume of the liquid chamber is decreased by extending the piezoelectric element, and the piezoelectric element is It is preferable that the liquid chamber is disposed so as to press in a state where the piezoelectric element is not extended.
Here, the piezoelectric element expands when a drive voltage waveform is applied from the ejection control means, reduces the volume of the liquid chamber, contracts when the drive voltage waveform is removed, and returns the volume of the liquid chamber to a given volume. Let

  As described above, the piezoelectric element that reduces the volume of the liquid chamber by extending has a characteristic that it is strong against the compressive force from the outside but weak against the tensile force. If force is applied, it may cause damage. Therefore, even when the piezoelectric element is not extended, if the piezoelectric element is provided in a state of pressing the liquid chamber, a force in the compression direction can be applied to the piezoelectric element in advance as a reaction force of the pressing. it can. Thereby, when a force in the tensile direction is applied to the piezoelectric element, the force in the tensile direction is reduced, so that the occurrence of breakage of the piezoelectric element due to the action of the tensile force can be reduced.

  Further, if the piezoelectric element is provided so as to press the liquid chamber even when the piezoelectric element is not expanded, the pressing of the liquid chamber starts immediately when the piezoelectric element starts to expand. Therefore, there is no stroke loss between the expansion of the piezoelectric element and the volume reduction of the liquid chamber, and there is an effect that the liquid can be efficiently ejected.

  Application Example 3 In the liquid ejecting apparatus according to the application example described above, it is preferable that a cross-sectional area of the inlet channel is smaller than a cross-sectional area of the outlet channel, and the inlet channel has a capillary shape.

  When the volume of the liquid chamber is reduced, the liquid tends to flow out from both the outlet channel and the inlet channel. However, since the cross-sectional area of the inlet channel is smaller than the cross-sectional area of the outlet channel and has a capillary shape, the back flow from the inlet channel is suppressed and the pressure in the liquid chamber is increased. Can be easily discharged. In this way, backflow can be suppressed without providing a check valve or the like on the inlet channel side. Although the capillary shape will be described later in the embodiment, the capillary shape is a narrow tube having a channel diameter of about 0.3 mm.

  Application Example 4 In the liquid ejecting apparatus according to the application example, when a unit including the inlet channel and the outlet channel, the liquid chamber, and the nozzle is an ejection unit, and the volume changing unit is a volume changing unit. The injection unit and the volume changing unit are preferably detachable.

The ejection unit is an element for flowing a liquid such as water, saline, or a chemical solution. For example, when the liquid ejection device is used as a surgical instrument, the ejection unit may come into contact with blood, body fluid, or the like. Therefore, safety can be improved by removing the ejection unit from the volume changing unit and making it disposable.
Further, the volume changing unit that does not come into contact with the liquid can be used repeatedly, and the running cost can be reduced if the volume changing unit, which is more expensive than the injection unit, is used repeatedly.

Application Example 5 In the liquid ejecting apparatus according to the application example, the liquid chamber is a flexible tube wound in a spiral shape.
It is preferable that the tube has an inflow port communicating with the inlet flow channel and an outflow port communicating with the outlet flow channel.

In the configuration in which the liquid chamber is formed of a tube having an inlet and an outlet, the arrangement of the inlet channel and the outlet channel and the winding shape of the tube are not particularly limited. Therefore, the degree of freedom in designing the liquid chamber is increased, and the structure of the liquid ejecting apparatus can be simplified and downsized.
Further, by using the tube, the cross-sectional area of the spiral flow path can be easily regulated to be almost constant.

Application Example 6 In the liquid ejecting apparatus according to the application example described above, it is preferable that the tube is provided with a gap between adjacent tubes for each winding.
Here, each winding means, for example, the first roll and the second roll, or the second roll and the third roll.

  The volume of the tube is changed by being pressed by the volume changing unit. At this time, by providing a gap for deformation, it is possible to eliminate an increase in load due to the adjacent tubes pressing against each other, and to secure a pressing amount necessary for liquid ejection.

  Application Example 7 In the liquid ejecting apparatus according to the application example, the inflow port is disposed at an outer peripheral end of the tube wound in a spiral shape, and the outlet port is wound in a spiral shape. It is preferable that it is arranged at the center side end of the tube.

  In the liquid ejecting apparatus having such a configuration, the pressing force near the center of the liquid chamber tends to be stronger than the pressing force at the outer peripheral portion. Accordingly, since the pressure toward the outlet channel increases, the liquid can be pushed out strongly.

  Moreover, in such a structure, the inlet flow path which an inflow port communicates is arrange | positioned in an outer peripheral side edge part, and the exit flow path which an outflow port communicates is arrange | positioned in a center side edge part. Therefore, when the liquid ejecting apparatus is operated by hand, the nozzle located on the extension of the outlet channel can be arranged at substantially the center of the liquid ejecting apparatus, so that there is an advantage that it is easy to operate.

  Application Example 8 In the liquid ejecting apparatus according to the application example described above, the inflow port is disposed at a center side end portion of the tube wound in the spiral shape, and the outlet port is wound in the spiral shape. It is preferable that it is arranged at the outer peripheral side end of the tube.

  As described above, when the tube is pressed by the piezoelectric element, the pressing amount at the center portion tends to be larger than the pressing amount at the outer peripheral portion. Therefore, if the inlet is arranged in the center, the pressure near the inlet is increased. At this time, if the cross-sectional area of the inlet (inlet channel) is smaller than the outlet (outlet channel), backflow from the liquid chamber to the inlet is suppressed, and the pressure in the liquid chamber can be increased. Strong liquid jet can be obtained.

  Application Example 9 In the liquid ejecting apparatus according to the application example described above, the liquid chamber has a spiral flow whose cross-sectional area is substantially constant by a deformable partition wall between the inlet channel and the outlet channel. It is preferable that the road is partitioned.

  When the volume changing section is driven in a state where the liquid supplied from the inlet channel is filled in the liquid chamber, the partition wall is deformed to reduce the volume of the liquid chamber, and the liquid pressurized in the liquid chamber is spiral-shaped. Along the flow path of the gas, guided to the outlet flow path, and ejected from the nozzle through the outlet flow path. Therefore, even in the configuration of this application example, since the liquid flows at a sufficient flow velocity along the spiral flow path, it is possible to suppress the bubbles from staying at a slow flow point and to discharge the bubbles in the liquid chamber. It can be quickly discharged from the flow path. As a result, the pressure in the liquid chamber can be sufficiently increased without being affected by bubbles, and stable liquid ejection is possible.

  Further, when the volume of the liquid chamber is reduced by driving the volume changing unit, the partition wall is deformed so as to contract the flow path toward the outlet flow path, so that the pressurized liquid in the liquid chamber is discharged from the outlet. The liquid can be strongly ejected by moving toward the flow path.

  Application Example 10 In the liquid ejecting apparatus according to the application example, the partition wall constitutes the liquid chamber and the surface on the first direction side that reduces the volume of the liquid chamber from the given volume, or the Standing from any one of the surfaces in the second direction facing the surface in the first direction, and on the tip of the partition wall facing the surface in the second direction, or on the first direction It is preferable that the leading end portion is provided in an unfixed state.

  According to such a configuration, when the volume of the liquid chamber is reduced by driving the volume changing unit, the front end of the partition wall that is not fixed can be deformed so as to fall down toward the outlet channel. It is possible to generate a flow of liquid over the partition wall toward the outlet channel. Thus, since the liquid is collected from the periphery to the outlet channel even from the flow crossing the spiral channel, the liquid can be strongly ejected.

  Application Example 11 In the liquid ejecting apparatus according to the application example described above, the partition wall constitutes the liquid chamber and the surface on the first direction side that reduces the volume of the liquid chamber from the given volume, or the A partition wall other than the outermost partition wall is erected from any one surface of the second direction side facing the first direction side surface, and the tip end portion facing the first direction side surface It is preferable that the front end portion directed toward the second direction is provided in an unfixed state.

  The partition wall having such a configuration can be considered as a fixed wall on the outermost peripheral side and a movable wall on the inner peripheral side. When the volume of the liquid chamber is reduced by driving the volume changing unit, the inner wall, which is a movable wall, is deformed so as to move toward the outlet channel, and the liquid in the liquid chamber also moves from the inlet channel of the liquid chamber. It can be moved towards the outlet channel.

  Application Example 12 In the liquid ejecting apparatus according to the application example described above, the inlet flow channel is communicated with an outer peripheral side end of the spiral flow channel of the liquid chamber, and the outlet flow channel is a spiral of the liquid chamber. It is preferable that it is connected with the center side edge part of a flow path.

In this way, when the liquid chamber is formed in a spiral shape by the partition wall, in the configuration in which the tip of the partition wall is fixed, the pressure is directed from the outer periphery toward the center portion, so that the outlet channel is in the center direction. The central part in the cross-sectional direction of the partition wall is deformed.
In the configuration in which the tip of the partition wall is not fixed, the direction of the tip of the partition wall is deformed and the liquid flows over the partition wall from the outer peripheral direction to the center direction. The liquid can be jetted strongly.
Further, when the inner peripheral partition wall is a movable wall, the partition wall can be deformed so as to move to the central part as if the mainspring is wound up, and the liquid can be collected in the central part.

  Application Example 13 In the liquid ejecting apparatus according to the application example described above, the inlet channel is communicated with a central side end portion of the spiral channel of the liquid chamber, and the outlet channel is a spiral of the liquid chamber. It is preferable that it communicates with the outer peripheral side end of the flow path.

In this way, when the liquid chamber is formed in a spiral shape by the partition wall, in the configuration in which the tip of the partition wall is fixed, the pressure is directed from the central portion where the inlet flow path is disposed to the outer peripheral direction. The central portion in the cross-sectional direction of the partition wall is deformed in the outer peripheral direction where the flow path exists. Further, in the configuration in which the tip end portion of the partition wall is not fixed, the tip end portion of the partition wall is deformed in the outer peripheral direction, and the partition wall extends from the central direction in which the inlet flow channel is arranged to the outer peripheral direction in which the outlet flow channel is arranged Since the flow of the liquid over the above is generated, the liquid can be collected from the periphery into the outlet channel, and the liquid can be strongly ejected.
Further, when the inner peripheral partition wall is a movable wall, the partition wall is deformed so as to move in the outer peripheral direction so as to open the spring, and the liquid can be collected in the outlet channel.
Further, as described above, since the liquid is pumped from the central portion to the outlet channel in the outer peripheral portion, the bubble elimination can be further improved.

Explanatory drawing which showed the main structures of the liquid ejecting apparatus. The assembly exploded view which shows the pulsation generating part which concerns on 1st Example. Explanatory drawing which shows the structure of the liquid chamber which concerns on 1st Example. It is explanatory drawing showing the state which does not apply a drive voltage waveform to a piezoelectric element, (a) is a fragmentary sectional view of a pulsation generation | occurrence | production part, (b) is a top view of a liquid chamber. It is explanatory drawing showing the state which applied the drive voltage waveform to the piezoelectric element, (a) is a fragmentary sectional view of a pulsation generation | occurrence | production part, (b) is a top view of a liquid chamber. The assembly exploded view which shows a part of pulsation generation | occurrence | production part which concerns on 2nd Example. Explanatory drawing which shows the structure of the liquid chamber which concerns on 2nd Example. The fragmentary sectional view which shows the state which drives the piezoelectric element which concerns on 2nd Example, and is pressing the liquid chamber. Explanatory drawing which shows the shape of the liquid chamber which concerns on a modification. The assembly exploded view showing the pulsation generation part concerning the 3rd example. The top view which shows the shape of the flow-path formation member which concerns on 3rd Example. In the third embodiment, a driving voltage waveform is not applied to the piezoelectric element, (a) is a partial sectional view, and (b) is a plan view of a liquid chamber. In the third embodiment, a driving voltage waveform is applied to a piezoelectric element, (a) is a partial cross-sectional view, and (b) is a plan view of a liquid chamber. It is a fragmentary sectional view which shows the internal structure of the pulsation generation part which concerns on 4th Example, (a) is the state which does not apply a drive voltage waveform to a piezoelectric element, (b) is the state which applied and extended the drive voltage waveform to the piezoelectric element. . It is a fragmentary sectional view showing an internal structure of a pulsation generating part concerning a 5th example, (a) is a state where a drive voltage waveform is not applied to a piezoelectric element, and (b) is a state where a drive voltage waveform is applied and extended to a piezoelectric element. . The assembly exploded view showing the pulsation generating part concerning the 6th example. Explanatory drawing which showed the shape of the flow-path formation member based on 6th Example. In the sixth embodiment, a driving voltage waveform is applied to a piezoelectric element, (a) is a partial cross-sectional view, and (b) is a plan view showing the shape of a flow path forming member. A part of internal structure of the pulsation generating part according to the seventh embodiment is shown, (a) is a state in which the drive voltage waveform is not applied to the piezoelectric element, (b) is a state in which the drive voltage waveform is applied to the piezoelectric element and extended. . A part of internal structure of the pulsation generating part concerning the 8th example is shown, (a) is a state where a drive voltage waveform is not applied to a piezoelectric element, and (b) is a state where a drive voltage waveform is applied to a piezoelectric element.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The drawings referred to in the following description are schematic views in which the vertical and horizontal scales of each member or part are different from actual ones in order to make each member a recognizable size.
(Liquid ejecting device)

First, the configuration of the liquid ejecting apparatus 10 will be described.
FIG. 1 is an explanatory diagram showing the main configuration of the liquid ejecting apparatus 10. The liquid ejecting apparatus 10 includes a pulsation generating unit 100 that ejects a liquid such as water or physiological saline in a pulsed manner, a liquid supply unit 300 that supplies the liquid to the pulsating generating unit 100, and a liquid container 306 that stores the ejected liquid. And a control unit 200 serving as an ejection control unit that controls operations of the pulsation generating unit 100 and the liquid supply unit 300.

  The pulsation generating unit 100 has a structure in which the second case 106 and the first case 108 are overlapped and fixed so as to be detachable by screwing or the like. The pulsation generating unit 100 is on the opposite side of the surface of the second case 106 that mates with the first case 108. A circular pipe-shaped liquid jet pipe 104 is connected to the surface, and a nozzle 105 is provided at the tip of the liquid jet pipe 104.

  A liquid chamber 110 filled with a liquid is provided on the mating surface of the second case 106 and the first case 108, and the liquid chamber 110 is connected to the nozzle 105 via the liquid ejection pipe 104. . In addition, a multilayer piezoelectric element 112 is provided inside the first case 108, and the volume of the liquid chamber 110 is increased by applying a drive voltage waveform from the control unit 200 to drive the piezoelectric element 112 to expand and contract. It is possible to eject the liquid in the liquid chamber 110 from the nozzle 105 in a pulsed manner by varying it. The detailed configuration of the pulsation generator 100 will be described later with reference to FIG.

  The liquid supply means 300 is connected to the liquid container 306 via the first connection tube 302, and supplies the liquid sucked from the liquid container 306 to the liquid chamber 110 of the pulsation generator 100 via the second connection tube 304. To do. Although not shown, the liquid supply means 300 of the present embodiment has a configuration in which two pistons slide in the cylinder, and the pulsation generator 100 is controlled by appropriately controlling the moving speeds of both pistons. It is possible to stably pump the liquid toward.

  The control unit 200 controls the operation of the piezoelectric element 112 built in the pulsation generating unit 100 and the operation of the liquid supply means 300. In the liquid ejecting apparatus 10 of the present embodiment, the flow rate of the liquid supplied from the liquid supply unit 300, the waveform of the drive voltage applied to the piezoelectric element 112, the maximum voltage value, and the frequency are changed to change the amount of liquid from the nozzle 105. It is possible to change the injection mode.

Subsequently, the configuration of the pulsation generator 100 will be described with reference to a typical example.
(First embodiment)

  FIG. 2 is an exploded view showing the pulsation generator 100 according to the first embodiment. The pulsation generator 100 is fixed by screwing together the second case 106 and the first case 108. Therefore, the second case 106 and the first case 108 are detachable. The first case 108 is formed with a through hole 108 h having a circular cross section that penetrates the first case 108 at the center position of the surface that meets the second case 106. The piezoelectric element 112 is accommodated in the through hole 108 h, and the opening of the through hole 108 h opposite to the surface where the second case 106 is joined is closed by the third case 118. The piezoelectric element 112 is configured by a stacked piezoelectric element in which a large number of piezoelectric bodies are stacked to form a columnar shape, and one end of the piezoelectric element 112 is fixed to the third case 118. A circular reinforcing plate 116 made of a metal plate or the like is fixed to the other end of the piezoelectric element 112. Note that the piezoelectric element 112 and the reinforcing plate 116 of this embodiment that reduce the volume of the liquid chamber 110 correspond to a “volume changing portion”.

  In the second case 106, a circular shallow recess 106c is formed on the surface where it meets the first case 108. An inlet channel 106 a that communicates with the second connection tube 304 connected to the second case 106 is opened at the peripheral edge of the recess 106 c. An outlet channel 106b communicating with the liquid jet pipe 104 is opened at a substantially central position of the recess 106c.

  In the recess 106c of the second case 106, a liquid chamber 110 formed of a tube 120 having a circular cross section is disposed. In the pulsation generator 100 of the present embodiment, the liquid chamber 110 is formed of a metal tube, but the material of the tube 120 is not limited to metal as long as it has flexibility, and is made of resin. It may be a tube. Further, the cross-sectional shape of the tube 120 is not limited to a circle, but may be a square or an ellipse.

Next, the configuration of the liquid chamber 110 will be described with reference to FIG.
FIG. 3 is an explanatory diagram illustrating the configuration of the liquid chamber 110 according to the first embodiment. 3 shows a state in which the liquid chamber 110 is viewed from the first case 108 side. As shown in the figure, the liquid chamber 110 is formed in a substantially circular shape by winding the tube 120 into a spiral shape, and a predetermined gap is provided between the multiple turns of the tube 120. ing.

  The diameter of the outermost periphery of the spiral tube 120 is set smaller than the outer diameter of the circular reinforcing plate 116. Furthermore, the outer peripheral side end and the central side end of the tube 120 are bent toward the second case 106 (see FIG. 2). In the present embodiment, the opening at the outer peripheral end of the spiral tube 120 forming the liquid chamber 110 is referred to as “inlet 110a”, and the opening at the central end is referred to as “outlet 110b”.

  As shown in FIG. 2, the liquid chamber 110 configured in this manner has a concave portion of the second case 106 with the inlet 110 a connected to the inlet channel 106 a and the outlet 110 b connected to the outlet channel 106 b. 106c. When the second case 106 and the first case 108 are screwed together, one side surface of the tube 120 is in contact with the concave bottom surface 106d of the second case 106, and the other side surface of the tube 120 is in contact with the reinforcing plate 116, thereby forming the concave portion. The tube 120 is sandwiched between the bottom surface 106d and the reinforcing plate 116.

  As described above, one side of the tube 120 is in contact with the concave bottom surface 106 d of the second case 106, and the other side is in contact with the reinforcing plate 116. As will be described in detail later, in the pulsation generating unit 100 of the present embodiment, the piezoelectric element 112 moves the side surface of the tube 120 through the reinforcing plate 116 even when the piezoelectric element 112 is not expanded without applying a drive voltage waveform. The thickness or the like of the reinforcing plate 116 is set so that the pressed state is obtained. However, this pressing amount may be smaller than the pressing amount when the drive voltage waveform is applied and the piezoelectric element 112 is expanded, and may be in a state of “0” where the reinforcing plate 116 contacts the tube 120.

  As shown in FIG. 2, a liquid ejection pipe 104 is connected to the surface of the second case 106 opposite to the face that mates with the first case 108, and the inner diameter of the liquid ejection pipe 104 has an outlet channel. It is set larger than the inner diameter of 106b. In addition, a nozzle 105 having a liquid ejection opening having an inner diameter smaller than that of the outlet channel 106 b is inserted at the tip of the liquid ejection pipe 104. Accordingly, the flow path until the pressurized liquid is ejected in the liquid chamber 110 has a larger cross-sectional area when it reaches the liquid ejection pipe 104 through the outlet flow path 106b. The cross-sectional area becomes narrow again at the nozzle 105 portion.

Here, a configuration in which the first case 108, the third case 118, the piezoelectric element 112, and the reinforcing plate 116 are fixed to each other is referred to as a volume changing unit 101. A configuration in which the second case 106, the liquid jet pipe 104 including the nozzle 105, and the tube 120 are fixed or inserted is referred to as the jet unit 102.
The volume changing unit 101 and the injection unit 102 are configured to be detachable by fixing screws on the mating surfaces of the first case 108 and the second case 106.

  In the pulsation generator 100 configured as described above, it is possible to eject liquid from the nozzle 105 in a pulsed manner by applying a driving voltage waveform to the piezoelectric element 112 so as to expand and contract. Below, the operation | movement which the pulsation generation | occurrence | production part 100 injects a liquid is demonstrated.

4 and 5 are explanatory diagrams schematically showing the operation of the pulsation generator 100 in the first embodiment for ejecting liquid. FIG. 4 shows a state in which the drive voltage waveform is not applied to the piezoelectric element 112. FIG. 5 shows a state in which the drive voltage waveform is applied to the piezoelectric element 112.
First, a state where the piezoelectric element 112 is not driven will be described with reference to FIG. 4A is a partial cross-sectional view of the pulsation generator 100, and FIG. 4B is a plan view of the liquid chamber 110. FIG. In this state, as shown in FIG. 4A, the liquid supplied from the liquid supply means 300 to the pulsation generator 100 via the second connection tube 304 flows into the liquid chamber 110 through the inlet channel 106a. Then, the liquid chamber 110 is filled with the liquid. In addition, the arrow of the broken line shown to Fig.4 (a) represents the flow of the liquid.

  As shown in FIG. 4B, in the liquid chamber 110, a spiral flow path is formed by winding the tube 120 in a spiral shape, and from the peripheral inflow port 110a connected to the inlet flow path 106a. The inflowing liquid is guided to the central outlet 110b connected to the outlet channel 106b while swirling along the tube 120. In addition, the arrow of the broken line shown in FIG.4 (b) represents the flow of the liquid. Since the cross-sectional area of the spiral flow path of the tube 120 is substantially constant, the liquid flow in the liquid chamber 110 can flow from the inlet 110a to the outlet 110b at a substantially uniform flow rate.

  As described above, since the liquid is supplied from the liquid supply means 300 at a substantially constant and stable pressure, when the liquid chamber 110 is filled with the liquid, the liquid chamber 110 is not driven even if the piezoelectric element 112 is not driven. The liquid inside is pushed out toward the nozzle 105 from the outlet 110b through the outlet channel 106b.

Next, a state where the piezoelectric element 112 is driven will be described with reference to FIG. 5A is a partial cross-sectional view of the pulsation generator 100, and FIG. 5B is a plan view of the liquid chamber 110. FIG.
When a drive voltage waveform is applied to the piezoelectric element 112 in a state where the liquid chamber 110 is filled with the liquid, as shown in FIG. 5A, the piezoelectric element 112 expands due to the increase of the drive voltage, and the reinforcing plate 116. Then, the side surface of the tube 120 is pressed toward the concave bottom surface 106d of the second case 106. For this reason, the cross section of the tube 120 is deformed from a circle to an ellipse, and the volume of the liquid chamber 110 is reduced. As a result, the liquid in the liquid chamber 110 is pressurized.

  In addition, since the diameter of the outermost periphery of the tube 120 forming the liquid chamber 110 is set smaller than the outer diameter of the reinforcing plate 116, the entire spiral flow path of the liquid chamber 110 is pressed. The tube 120 is wound with a predetermined gap for each winding, but when pressed and deformed, the tube 120 is brought into close contact with each other or the gap is reduced. The liquid thus pressurized in the liquid chamber 110 passes through the outlet channel 106b connected to the outlet 110b and the liquid jet pipe 104, as indicated by the dashed arrows in FIG. Injected from the nozzle 105.

  The liquid chamber 110 is connected to two flow paths: an inlet flow path 106a connected to the flow inlet 110a and an outlet flow path 106b connected to the flow outlet 110b. Therefore, it is considered that the liquid pressurized in the liquid chamber 110 tends to flow out not only to the outlet channel 106b but also to the inlet channel 106a. However, the ease of liquid flow in the flow path is determined by the cross-sectional area of the flow path, the length of the flow path, and the like. For example, if the diameter of the outlet 110b is about 1 mm and the diameter of the channel of the inlet 110a is about 0.3 mm, the change in flow rate per unit time is proportional to the cross-sectional area and inversely proportional to the length. Most of the liquid can flow out to the outlet channel 106b.

  Furthermore, since the liquid pressure-fed from the liquid supply means 300 tends to flow into the liquid chamber 110 into the inlet channel 106 a, the reverse flow of the liquid in the liquid chamber 110 is prevented. In the outlet channel 106b, there are few elements that serve as resistance and increase the inertia that prevent the liquid in the liquid chamber 110 from flowing out. Therefore, the liquid pressurized in the liquid chamber 110 flows out exclusively to the outlet channel 106 b and is ejected from the nozzle 105 at the tip through the liquid ejection pipe 104.

  As shown in FIG. 5B, the spiral flow path of the liquid chamber 110 is formed by winding the tube 120 into a spiral shape, and the liquid pressurized in the liquid chamber 110 is the spiral-shaped tube 120. To the central outlet 110b. At this time, in the tube 120 wound in multiple layers, in the outermost peripheral part away from the central outlet 110b, the amount of liquid that moves is slight, but the flow rate increases as it approaches the outlet 110b. In a portion close to the outlet 110b, the liquid corresponding to the volume decrease of the liquid chamber 110 moves at a stretch and is pushed out from the outlet 110b. As a result, the liquid is ejected at high speed from the nozzle 105 via the outlet channel 106 b and the liquid ejection pipe 104.

  Subsequently, when the drive voltage is decreased, the piezoelectric element 112 contracts and returns to the original length. Then, since the tube 120 forming the liquid chamber 110 is less pressed by the piezoelectric element 112, the restoring force of the tube 120 returns the cross section from an ellipse to a circle, and the volume of the liquid chamber 110 is restored to the original volume. As a result, the liquid supplied from the liquid supply means 300 flows along the tube 120 and fills the liquid chamber 110, whereby the state before the piezoelectric element 112 shown in FIG. 4 is driven is restored.

  Thereafter, when the piezoelectric element 112 expands again due to the increase of the driving voltage, the liquid pressurized in the liquid chamber 110 is ejected from the nozzle 105 as shown in FIG. By repeating such an operation, the pulsation generator 100 in the first embodiment can periodically generate a pulsed jet.

  As described above, the pulsation generator 100 is configured to press the side surface of the tube 120 forming the liquid chamber 110 even when the drive voltage waveform is not applied and the piezoelectric element 112 is not expanded. It is preferable. This is due to the following reason.

  The piezoelectric element 112 composed of a laminated piezoelectric element has a characteristic that it is strong against an external compressive force but weak against a tensile force. When the piezoelectric element 112 contracts, a force in the tensile direction is easily applied to the piezoelectric element 112 due to an inertial force caused by the mass of the element itself, so that the piezoelectric element 112 may be damaged such as delamination. is there. Therefore, even when the piezoelectric element 112 is contracted, if the pressure is applied to the side surface of the liquid chamber 110 formed by the tube 120, the piezoelectric element 112 is compressed in the compression direction by the restoring force of the tube 120 as a reaction force. Therefore, the tensile force applied to the piezoelectric element 112 can be reduced. As a result, the occurrence of breakage of the piezoelectric element 112 due to the action of the tensile force can be reduced.

  According to the first embodiment described above, if the spiral liquid chamber 110 having a substantially constant cross-sectional area is formed between the inlet channel 106a and the outlet channel 106b, the liquid in the liquid chamber 110 Is regulated to a substantially constant flow velocity along the spiral flow path, so that bubbles are prevented from staying at a slow flow point, and the bubbles in the liquid chamber can be easily discharged from the outlet flow path 106b. As a result, the pressure in the liquid chamber 110 can be sufficiently increased without being affected by bubbles, and stable liquid ejection can be maintained.

  Even when the piezoelectric element 112 is not extended, if the liquid chamber 110 is pressed, a force in the compression direction can be applied to the piezoelectric element 112 in advance as a reaction force of the pressing. . Thereby, when a force in the tensile direction is applied to the piezoelectric element 112, the force in the tensile direction is reduced, so that the occurrence of breakage of the piezoelectric element 112 due to the action of the tensile force can be reduced.

  Further, even when the piezoelectric element 112 is not expanded, if the liquid chamber 110 is pressed, the volume of the liquid chamber 110 is immediately reduced when the piezoelectric element 112 starts to expand. Therefore, there is no stroke loss between the expansion of the piezoelectric element 112 and the volume reduction of the liquid chamber 110, and there is an effect that the liquid can be efficiently ejected.

  Further, by setting the cross-sectional area of the inlet channel 106a to be smaller than the cross-sectional area of the outlet channel 106b, the back flow to the inlet channel 106a is suppressed to increase the pressure in the liquid chamber 110, and the outlet 110b having a large cross-sectional area. It is possible to make it easy to flow out of. In this way, backflow can be suppressed without providing a check valve or the like in the inlet channel 106a.

Further, the ejection unit 102 and the volume changing unit 101 are configured to be detachable. The ejection unit 102 is a unit for flowing a liquid such as water, saline, or a chemical solution. For example, when the liquid ejection device 10 is used as a surgical instrument, it may come into contact with blood, body fluid, or the like. Therefore, safety can be improved by removing the ejection unit 102 from the volume changing unit 101 and making it disposable.
In addition, the volume changing unit 101 that does not come into contact with the liquid can be used repeatedly and is more expensive than the ejection unit 102. Therefore, by repeatedly using the volume changing unit 101, the running cost can be reduced. it can.

The liquid chamber 110 has a spiral flow path formed by a flexible tube 120 wound in a spiral shape. Thus, in the configuration in which the liquid chamber 110 is formed by the tube 120, the arrangement of the inlet channel 106a and the outlet channel 106b and the winding shape of the tube 120 are not limited by the manufacturing method or the like. Therefore, the degree of freedom in designing the liquid chamber 110 is increased, and the structure of the liquid ejecting apparatus 10 can be simplified and downsized.
Further, by using the tube 120 for the liquid chamber 110, the cross-sectional area of the spiral flow path can be easily regulated to be almost constant.

  Further, the tube 120 is provided with a gap between the adjacent flow paths every winding. The tube 120 is pressed and deformed by the piezoelectric element 112. At this time, by providing a gap for each winding, it is possible to eliminate an increase in load due to the adjacent tubes 120 pressing against each other, and to secure a pressing amount necessary for liquid ejection.

Moreover, the inflow port 110a is arrange | positioned at the outer peripheral side edge part of the tube 120 wound by the spiral shape, and the outflow port 110b is arrange | positioned at the center side edge part of the tube 120 wound by the spiral shape. In the liquid ejecting apparatus 10 configured as described above, the pressing force near the center of the liquid chamber 110 tends to be stronger than the pressing force at the outer peripheral portion. Therefore, since the pressure increases toward the outlet 110b, the liquid can be pushed out strongly.
In addition, an inlet channel 106a that communicates with the inlet 110a is disposed at the outer peripheral side end of the liquid chamber 110, and an outlet channel 106b that communicates with the outlet 110b is disposed at the central end. Therefore, when the liquid ejecting apparatus 10 is operated by hand, the nozzle 105 located on the extension of the outlet channel 106b can be disposed almost at the center of the liquid ejecting apparatus 10. Therefore, there is an advantage that the operation is easy.
(Second embodiment)

  Next, a second embodiment will be described with reference to the drawings. In the first example described above, the inflow port 110a is arranged at the outer peripheral side end portion of the tube 120, and the outflow port 110b is arranged at the central side end portion of the tube 120. The arrangement of the inflow port 110a and the outflow port 110b is different. Therefore, the same functional elements as those of the first embodiment will be described by assigning the same reference numerals to the differences from the first embodiment.

FIG. 6 is an exploded view showing a part of the pulsation generator 100 according to the second embodiment. The configurations of the first case 108, the piezoelectric element 112, and the reinforcing plate 116 in the second embodiment are the same as those in the first embodiment.
On the other hand, an inlet channel 106a communicating with the second connection tube 304 connected to the second case 106 is opened at the center position of the recess 106c of the second case 106, and the inlet 110a of the liquid chamber 110 is connected. Has been. In addition, an outlet channel 106b communicating with the liquid jet pipe 104 is opened at the peripheral position of the concave portion 106c, and the outlet 110b is connected.

  A liquid chamber 110 formed by a tube 120 having a circular cross section is disposed in the recess 106c. In the second embodiment, although the arrangement positions of the liquid ejecting pipe 104 and the nozzle 105 are the same as those in the first embodiment, detailed description thereof is omitted.

Next, the configuration of the liquid chamber 110 according to the second embodiment will be described.
FIG. 7 is an explanatory diagram illustrating the configuration of the liquid chamber 110 according to the second embodiment. FIG. 7 shows a state in which the liquid chamber 110 is viewed from the first case 108 side. As shown in the figure, the liquid chamber 110 is formed in a substantially circular shape by winding the tube 120 in a spiral shape, and there is a predetermined gap between each other of the tubes 120 wound in multiple layers. Is provided.

  The diameter of the outermost periphery of the spiral tube 120 is set smaller than the outer diameter of the circular reinforcing plate 116. Furthermore, the outer periphery side edge part and center side edge part of the tube 120 are bent toward the 2nd case 106 (refer FIG. 6). The inlet 110a at the center side end of the spiral tube 120 forming the liquid chamber 110 is connected to the inlet channel 106a, and the outlet 110b at the outer end is connected to the outlet channel 106b.

  Thus, the liquid chamber 110 constituted by the tube 120 is installed in the recess 106 c of the second case 106. 6, when the second case 106 and the first case 108 are screwed together, one side surface of the tube 120 comes into contact with the concave bottom surface 106d of the second case 106, and the other side surface of the tube 120. Comes into contact with the reinforcing plate 116, and the tube 120 is sandwiched between the bottom surface 106 d of the recess and the reinforcing plate 116.

  FIG. 7 is a plan view of the liquid chamber 110 according to the second embodiment. In the state shown in the figure, the liquid supplied from the liquid supply means 300 to the pulsation generator 100 via the second connection tube 304 flows into the liquid chamber 110 through the inlet channel 106a, and the liquid chamber 110 is liquid. Indicates a state that is satisfied. In addition, the broken-line arrow shown in FIG. 7 represents the flow of the liquid.

  In the liquid chamber 110, a spiral flow path is formed by winding the tube 120 in a spiral shape, and the liquid flowing in from the central inflow port 110 a connected to the inlet flow path 106 a flows along the tube 120. Then, it is guided to the outlet 110b at the peripheral edge connected to the outlet channel 106b. Since the cross-sectional area of the spiral flow path of the tube 120 is substantially constant, the liquid flow in the liquid chamber 110 can flow from the inlet 110a to the outlet 110b at a substantially uniform flow rate.

  As described above, since the liquid is supplied from the liquid supply means 300 at a substantially constant and stable pressure, when the liquid chamber 110 is filled with the liquid, the liquid chamber 110 is not driven even if the piezoelectric element 112 is not driven. The liquid inside is pushed out from the outlet 110b toward the liquid jet pipe 104 through the outlet channel 106b.

FIG. 8 is a partial cross-sectional view illustrating a state where the piezoelectric element 112 according to the second embodiment is driven to press the liquid chamber 110. FIG. 8 shows the deformation of the reinforcing plate 116 in an enlarged manner for easy understanding.
When a drive voltage waveform is applied to the piezoelectric element 112 in a state where the liquid chamber 110 is filled with liquid, the piezoelectric element 112 expands due to the increase of the drive voltage and presses the tube 120 as in the first embodiment. . The reinforcing plate 116 has an outer diameter equal to or larger than the outer peripheral diameter of the tube 120 wound, and the piezoelectric element 112 is smaller than the outer diameter of the reinforcing plate 116.

  When the tube 120, the reinforcing plate 116, and the piezoelectric element 112 are in such a relationship, when the tube 120 is pressed, as shown in FIG. 8, the reinforcing plate 116 is centered on the central portion where the inflow port 110a is disposed. Since the outer peripheral edge of the liquid chamber 110 is warped, the pressing amount of the liquid chamber 110 is large near the center, and the change in volume is large. In the outer circumferential direction, the pressing amount is small and the change in volume is small. That is, it is considered that the pressure in the liquid chamber 110 is high in the central portion and low in the outer peripheral portion. Therefore, the liquid in the liquid chamber 110 is strongly pushed out from the central portion to the outer peripheral portion.

  Thus, the pressure in the vicinity of the inlet 110a in the center increases, and the return pressure of the liquid in the vicinity of the inlet 110a increases. However, since the inlet 110a has a capillary shape with a diameter of about 0.3 mm, the back flow from the liquid chamber 110 to the inlet 110a is suppressed, the pressure of the liquid chamber 110 can be increased, and a strong liquid jet can be obtained. Can do.

  The spiral flow path of the liquid chamber 110 is formed by winding the tube 120 in a spiral shape, and the liquid pressurized in the liquid chamber 110 flows out along the spiral tube 120 at the outer peripheral end portion. Move to 110b. At this time, the flow rate increases as it approaches the outflow port 110b, and in a portion close to the outflow port 110b, the liquid corresponding to the volume decrease of the liquid chamber 110 moves all at once and is pushed out from the outflow port 110b. As a result, the liquid is ejected at high speed from the nozzle 105 via the outlet channel 106 b and the liquid ejection pipe 104.

  Subsequently, when the drive voltage is decreased, the piezoelectric element 112 contracts and returns to the original length. Then, since the pressing force by the piezoelectric element 112 is weakened, the cross section returns from an ellipse to a circle by the restoring force of the tube 120, and the volume of the liquid chamber 110 is restored to the original volume. Thereafter, when the piezoelectric element 112 expands again due to an increase in driving voltage, the liquid pressurized in the liquid chamber 110 is ejected from the nozzle 105. By repeating these operations, the pulsation generator 100 of the second embodiment can periodically generate a pulsed jet.

  In the configuration according to the second embodiment, when the tube 120 is pressed by the piezoelectric element 112, the pressing amount at the central portion tends to be larger than the pressing amount at the outer peripheral portion. Therefore, if the inflow port 110a is arranged at the center, the pressure near the inflow port is increased. At this time, if the cross-sectional areas of the inlet 110a and the inlet channel 106a are made to have a capillary shape of about 0.3 mm smaller than the outlet 110b and the outlet channel 106b, the back flow from the liquid chamber 110 to the inlet 110a is suppressed, The pressure in the liquid chamber can be increased, and a strong liquid jet can be obtained.

Furthermore, as described above, since the liquid is pumped from the central portion of the liquid chamber 110 to the outlet channel 106b at the outer peripheral side end portion, it is easy for the bubbles to move, and as a result, the bubbles can be removed more efficiently. be able to.
(Modification)

  In the first and second embodiments described above, the liquid chamber 110 is formed in a substantially circular shape by winding the tube 120 in a spiral shape. However, the shape of the liquid chamber 110 formed by the tube 120 is not limited to this as long as the entire tube 120 can be pressed by the extension of the piezoelectric element 112. Below, the modification which employ | adopted the liquid chamber 110 of a shape different from the Example mentioned above is demonstrated. In the description of the modification, the same components as those of the first embodiment described above are denoted by the same reference numerals as those of the first embodiment described above, and detailed description thereof is omitted.

  FIG. 9 is an explanatory diagram showing the shape of the liquid chamber 110 according to a modification. As shown in the drawing, the liquid chamber 110 of the modified example is formed into a substantially quadrangular shape in which a circular cross-section tube 120 having a substantially constant cross-sectional area is folded in layers and formed into a substantially quadrangular shape. It is bent while maintaining the cross-sectional area without closing. Moreover, the inflow port 110a and the outflow port 110b which comprise the both ends of the tube 120 folded in quadrilateral are each located in the square diagonal.

  Corresponding to the shape of the liquid chamber 110, the reinforcing plate 116 is formed in a quadrangular shape, and the size of the reinforcing plate 116 is set larger than the outer edge of the tube 120 folded in the quadrangular shape. The entire chamber 110 can be pressed. Although not shown in the drawings, the second case 106 of the modification has a shallow shallow concave portion 106c formed on the surface mating with the first case 108, and an inlet channel 106a is opened at one corner of the concave portion 106c. And the outlet flow path 106b is opened in the diagonal.

  Also in the liquid ejecting apparatus 10 of such a modification, as in the above-described embodiment, when the piezoelectric element 112 extends, the side surface of the tube 120 forming the liquid chamber 110 is pressed through the reinforcing plate 116. At this time, the volume of the liquid chamber 110 decreases because the cross-sectional shape of the tube 120 is deformed. As a result, the liquid pressurized in the liquid chamber 110 can be ejected from the nozzle 105 in pulses. In addition, since the liquid that has flowed into the liquid chamber 110 from the inlet 110a flows to the outlet 110b along the folded tube 120, the flow of the liquid in the liquid chamber 110 is restricted to a constant flow. For this reason, bubbles do not stay in a place where the flow is slow, and the bubbles in the liquid chamber 110 can be quickly discharged.

  Further, as is clear from the above, the shape of the tube 120 forming the liquid chamber 110 is not particularly limited as long as it can be pressed by the extension of the piezoelectric element 112, and the arrangement of the inlet 110a and the outlet 110b is also It is possible to set according to the inlet channel 106a and the outlet channel 106b provided in the second case 106. As described above, since the degree of freedom of the arrangement of the inlet 110a and the outlet 110b, and hence the inlet channel 106a and the outlet channel 106b is increased, the structure of the pulsation generator 100 can be simplified and downsized.

  The liquid ejecting apparatus 10 of the present invention has been described with reference to the first embodiment, the second embodiment, and the modified examples. However, the present invention is not limited to these embodiments and does not depart from the spirit of the present invention. It can be implemented in various ways.

  For example, by combining the first embodiment or the second embodiment described above and the modification, a portion where the tube 120 is wound and a portion where the tube 120 is folded are formed between the inlet 110a and the outlet 110b. Also good. Also in this case, the same effects as those of the above-described embodiments and modifications can be obtained.

  Further, in the first embodiment, the second embodiment, and the modification described above, the inlet 110a and the outlet 110b of the liquid chamber 110 formed by the tube 120 are opened to the recess 106c of the second case 106. The channel 106a and the outlet channel 106b were connected to each other. However, the end of the liquid chamber 110 on the inflow port 110a side may be formed integrally with the inlet channel 106a and the tube 120.

Further, the end of the tube 120 on the outlet 110b side is extended to integrally form the outlet channel 106b and the liquid jet pipe 104, and further, the tip of the liquid jet pipe 104 is narrowed to form the nozzle 105. May be. In this way, the tube from the inlet channel 106a to the nozzle 105 can be formed integrally with the tube 120, so that liquid leakage in the pulsation generator 100 can be prevented. In such a configuration, the tube 120 is preferably made of metal.
(Third embodiment)

Next, a third embodiment will be described with reference to the drawings. In the first and second embodiments described above, the liquid chamber 110 is formed by the tube 120 wound in a spiral shape, whereas in the third embodiment, the liquid chamber 110 has a partition wall 130w. It is formed by the path forming member 130. In addition, about a common part with 1st Example, the same code | symbol as 1st Example is attached | subjected and demonstrated.
FIG. 10 is an exploded view showing the pulsation generator 100 according to the third embodiment, and FIG. 11 is a plan view showing the shape of the flow path forming member 130. The first case 108 is formed with a circular shallow recess 108c substantially at the center of the surface mating with the second case 106. A circular cross-sectional through-hole penetrating the first case 108 is formed at the center of the recess 108c. 108h is formed. A circular diaphragm 114 formed of a thin metal plate or the like is fixed to the bottom surface of the recess 108c so as to close the through hole 108h.

  The piezoelectric element 112 is housed in the through hole 108 h closed by the diaphragm 114, and the opening of the through hole 108 h is closed by the third case 118. A circular reinforcing plate 116 is inserted between the piezoelectric element 112 and the diaphragm 114. When the piezoelectric element 112 is housed in the through hole 108h of the first case 108 and the through hole 108h is closed by the third case 118, the diaphragm 114 and the reinforcing plate 116, the reinforcing plate 116 and the piezoelectric element 112, the piezoelectric element The thickness of the reinforcing plate 116 is set so that 112 and the third case 118 just contact each other. One end of the piezoelectric element 112 is fixed to the third case 118, and the other end of the piezoelectric element 112 is fixed to the reinforcing plate 116. The surface of the reinforcing plate 116 opposite to the piezoelectric element 112 is fixed to the diaphragm 114.

  On the surface of the diaphragm 114 facing the second case 106, a flow path forming member 130 is fitted in the recess 108c so that the support plate 130b is overlapped with the diaphragm 114. In the flow path forming member 130, the partition wall 130 w is erected on the one side of the support plate 130 b on the first direction side toward the second case 106. The surface of the support plate 130b opposite to the surface on which the partition wall 130w is erected is fixed to the diaphragm 114. Further, the thickness of the support plate 130b and the diaphragm 114 is the same as the depth of the recess 108c. It is formed to become. The flow path forming member 130 is formed of a flexible material so as to be deformable. The shape of the partition wall 130w of the flow path forming member 130 will be described later with reference to FIG.

  On the other hand, in the second case 106, a circular shallow recess 106c is formed on the surface where it is combined with the first case 108. The inner diameter of the recess 106c is smaller than the outer diameter of the support plate 130b of the flow path forming member 130 fitted in the first case 108, and is large enough to enclose the partition wall 130w erected on the support plate 130b. Is set. The depth of the recess 106c is set to be substantially the same as the height of the partition wall 130w.

  When the second case 106 and the first case 108 are screwed together, the liquid is formed by the recess 106c of the second case 106 and the support plate 130b of the flow path forming member 130 fitted on the first case 108 side. A chamber 110 is formed. Furthermore, the end of the partition wall 130w of the flow path forming member 130 in the first direction facing the second case 106 is fixed to the recess bottom surface 106d of the recess 106c, and the interior of the liquid chamber 110 is partitioned by the partition wall 130w. A spiral-shaped flow path is formed.

  However, on the contrary, the support plate 130b of the flow path forming member 130 is fixed to the concave bottom surface 106d of the second case 106, and the second case 106 and the first case 108 are combined and screwed together. An end of the partition wall 130 w of the flow path forming member 130 on the second direction side facing the first case 108 may be fixed to a diaphragm 114 provided in the first case 108.

  In the second case 106, an inlet channel 106a that guides the liquid supplied from the second connection tube 304 connected to the second case 106 to the liquid chamber 110, and a liquid pressurized in the liquid chamber 110 are ejected to the liquid. An outlet channel 106b leading to the tube 104 is opened. Among these, the inlet channel 106a is opened at the peripheral edge of the recess 106c, and the outlet channel 106b is opened at the center of the recess 106c.

  The inner diameter of the liquid jet pipe 104 connected to the front surface of the second case 106 is set larger than the inner diameter of the outlet channel 106b. In addition, a nozzle 105 having a liquid ejection opening having an inner diameter smaller than that of the outlet channel 106 b is inserted at the tip of the liquid ejection pipe 104. Therefore, the flow path through which the liquid flowing out of the liquid chamber 110 travels increases in cross-sectional area when it reaches the liquid ejection pipe 104 through the outlet flow path 106b, and the cross-sectional area again at the nozzle 105 portion at the tip of the liquid ejection pipe 104 Is becoming narrower.

  The outlet 110 b may be directly connected to the liquid chamber 110 by making the inner diameter of the outlet channel 106 b the same as the inner diameter of the liquid jet pipe 104.

Here, a configuration in which the first case 108, the third case 118, the piezoelectric element 112, the reinforcing plate 116, and the diaphragm 114 are fixed to each other is referred to as a volume changing unit 101. A configuration in which the second case 106, the liquid jet pipe 104 including the nozzle 105, and the flow path forming member 130 are fixed or inserted is referred to as the jet unit 102.
The volume changing unit 101 and the injection unit 102 are configured to be detachable by using screw fixing on the mating surfaces of the first case 108 and the second case 106.

  Next, the configuration of the flow path forming member 130 will be described with reference to FIG. FIG. 11 shows a state where the flow path forming member 130 is viewed from the side of the first case 108 facing the second case 106. The support plate 130b of the flow path forming member 130 is formed in the same circular shape as the diaphragm 114, and rotates while being wound toward the center of the support plate 130b on the surface of the support plate 130b facing the second case 106. A spiral partition wall 130w is erected.

  The spiral-shaped partition wall 130w is formed so that the outer peripheral surface of the outermost wall is in contact with the inner peripheral surface of the recess 106c, and the radial spacing of the multiple-folded partition walls 130w is substantially constant. Is set. As described above, when the second case 106 and the first case 108 are screwed together, the partition wall 130w forms a spiral flow path toward the center while turning from the peripheral portion inside the liquid chamber 110. The

  An inlet channel 106a and an outlet channel 106b are connected to the recess 106c of the second case 106, and when the second case 106 and the first case 108 are aligned and screwed together at an appropriate position, An outlet channel 106b is opened at the central portion of the spiral channel formed inside, and an inlet channel 106a is opened at the abutting portion on the peripheral side of the spiral channel.

  In the pulsation generator 100 configured as described above, it is possible to eject liquid from the nozzle 105 in a pulsed manner by applying a drive voltage waveform to the piezoelectric element 112 and driving the piezoelectric element 112 to expand and contract. Yes. Below, the operation | movement which the pulsation generation | occurrence | production part 100 injects a liquid is demonstrated.

12 and 13 are explanatory views schematically showing the operation of the pulsation generating unit 100 injecting the liquid. FIG. 12 shows a state in which the drive voltage waveform is not applied to the piezoelectric element 112, and FIG. 13 shows the drive voltage. A state where a waveform is applied to the piezoelectric element 112 is shown.
First, a state where the piezoelectric element 112 is not driven will be described with reference to FIG. 12A is a partial cross-sectional view, and FIG. 12B is a plan view of the liquid chamber 110. In this state, as shown in FIG. 12A, the liquid supplied from the liquid supply means 300 via the second connection tube 304 flows into the liquid chamber 110 through the inlet channel 106a, and the liquid chamber 110 The inside is filled with liquid. In addition, the arrow of the broken line shown to Fig.12 (a) represents the flow of the liquid.

  In the liquid chamber 110, a spiral flow path is formed by forming the partition wall 130w in a spiral shape, and the liquid flowing in from the inlet flow path 106a is separated as shown by the broken arrow in FIG. While turning along the wall 130w, it is guided to the outlet channel 106b. Since the cross-sectional area of the spiral flow path of the liquid chamber 110 formed by the partition wall 130w is substantially constant, the liquid flow in the liquid chamber 110 is at a substantially uniform flow rate from the inlet flow path 106a to the outlet flow path 106b. It can be made to flow.

  Since the liquid is supplied from the liquid supply means 300 at a substantially constant and stable pressure, when the liquid chamber 110 is filled with the liquid, the liquid in the liquid chamber 110 is discharged even if the piezoelectric element 112 is not driven. The liquid jet tube 104 is pushed out through the flow path 106b.

  Next, a state where the piezoelectric element 112 is driven will be described with reference to FIG. 13A is a partial cross-sectional view, and FIG. 13B is a plan view of the liquid chamber 110. When a driving voltage waveform is applied to the piezoelectric element 112 in a state where the liquid chamber 110 is filled with liquid, the piezoelectric element 112 expands due to an increase in driving voltage as shown in FIG. The diaphragm 114 and the support plate 130b of the flow path forming member 130 are pressed toward the liquid chamber 110 via As a result, the volume of the liquid chamber 110 is reduced. As a result, the liquid in the liquid chamber 110 is pressurized. The liquid pressurized in the liquid chamber 110 is ejected in a pulse form from the nozzle 105 through the outlet channel 106b and the liquid ejection pipe 104, as indicated by the dashed arrows in FIG. .

  Note that the liquid chamber 110 communicates with two channels, an inlet channel 106a and an outlet channel 106b. Therefore, it is considered that the liquid pressurized in the liquid chamber 110 flows out not only from the outlet channel 106b but also from the inlet channel 106a. However, since the ease of liquid flow in the flow path is determined by the cross-sectional area of the flow path, the length of the flow path, and the like, the cross-sectional areas and lengths of the inlet flow path 106a and the outlet flow path 106b should be set appropriately. For example, it is possible to make it easier for the liquid to flow out of the outlet channel 106b than the inlet channel 106a. For example, in this embodiment, the outlet channel 106b has a capillary shape with a diameter of about 1 mm and the inlet channel 106a has a diameter of about 0.3 mm. Therefore, the backflow from the inlet channel 106a is suppressed.

  In the inlet channel 106a, there is a flow in which the liquid pressure-fed from the liquid supply means 300 attempts to flow into the liquid chamber 110, which prevents the liquid from flowing out in the liquid chamber 110, whereas in the outlet channel 106b There are few factors that increase the resistance and fluid inertia that hinder the outflow of the liquid in the liquid chamber 110. Therefore, the liquid pressurized in the liquid chamber 110 flows out from the outlet channel 106 b exclusively and is ejected from the nozzle 105 at the tip through the liquid ejection pipe 104.

  The interior of the liquid chamber 110 of the third embodiment is partitioned in a spiral shape by the partition wall 130 w of the flow path forming member 130. However, when the volume of the liquid chamber 110 decreases due to the extension of the piezoelectric element 112, not only the liquid flows along the spiral partition wall 130w, but the partition wall 130w is deformed toward the outlet channel 106b. Thus, the liquid in the liquid chamber 110 moves toward the center of the liquid chamber 110. This point will be supplementarily described.

  Considering as an example the partition wall 130w that forms the innermost wall of the spiral-shaped partition wall 130w that is wound in multiple layers, the outlet channel 106b is located at the center of the liquid chamber 110 inside the innermost partition wall 130w. Since the liquid chamber 110 is open, when the volume of the liquid chamber 110 decreases, an increase in pressure is suppressed by the liquid flowing out from the outlet channel 106b.

  On the other hand, outside the partition wall 130w, the inlet channel 106a has a capillary shape, and the pressure rises compared to the inside of the partition wall 130w in order to suppress the outflow of liquid. Since the partition wall 130w is formed of a flexible material so as to be deformable, the partition wall 130w is pushed and deformed from the high pressure outside toward the low pressure inside, so that the pressure difference between the inside and the outside is increased. Try to decrease. Since the partition wall 130w of the third embodiment is erected from the support plate 130b and the tip is fixed to the concave bottom surface 106d of the second case 106, as shown in FIG. The central portion of the partition wall 130w is pushed from the outside and deformed so as to bend inward.

  The pressure difference between the inner side and the outer side of the partition wall 130w is not only the innermost partition wall 130w but also the innermost partition wall 130w that is deformed inward to reduce the outer pressure. It also occurs in the heavy partition wall 130w and similarly propagates to the triple partition wall 130w. Therefore, the spiral partition wall 130w is deformed so as to contract the spiral flow path toward the center of the liquid chamber 110 as a whole. As shown in FIG. 13A, the displacement of the partition wall 130w is largest in the innermost partition wall 130w having a small inner diameter.

  As described above, when the volume of the liquid chamber 110 decreases due to the extension of the piezoelectric element 112, the central portion of the spiral partition wall 130 w is deformed so as to bend toward the center of the liquid chamber 110. This liquid tends to move toward the outlet channel 106b in the center of the liquid chamber 110 in the direction of the broken arrow shown in FIG.

  When the volume of the liquid chamber 110 is reduced due to the extension of the piezoelectric element 112, an approximately equal amount of the liquid is collected in the outlet channel 106 b and pushed out, and the liquid is ejected from the nozzle 105 at the tip of the liquid ejection pipe 104. At this time, it is considered that the spiral partition wall 130w in the liquid chamber 110 is an obstacle, and a sufficient amount of liquid cannot be collected from the surroundings in the central outlet channel 106b. However, in the pulsation generator 100 of the third embodiment, the amount of displacement due to the expansion of the piezoelectric element 112 is small, and the amount of liquid ejected in one pulse is 1/100 of the volume of the liquid chamber 110. Therefore, the partition wall 130w is slightly deformed toward the center of the liquid chamber 110, and a sufficient amount of liquid is collected from the surroundings in the outlet channel 106b.

For example, when the injection amount V is 1/100 of the volume of the liquid chamber 110, the inner radius of the liquid chamber 110 is R, and the thickness of the liquid chamber 110, that is, the depth of the recess 106c is H.
V = πR ² H / 100 Formula (1)
It can be expressed as.

The innermost inner radius of the spiral partition wall 130w is r, and the innermost partition wall 130w is displaced by the distance s toward the center of the liquid chamber 110, and is collected in the outlet channel 106b. Assuming that the pushed amount of liquid is ejected from the nozzle 105, the ejection amount V is the difference between the volume V1 inside the innermost contour before deformation and the volume V2 inside the innermost contour after deformation. From that
V1 = πr ² H
V2 = π (rs) ² H
V = V1−V2 = πH {r ² − (r ² −2rs + s ² )}
= ΠH (2rs−s ² )
It can be expressed as.

Here, if the distance s is a slight displacement, s ² is a very small value. Therefore,
V≈2πrsH Formula (2)
And can be approximated.

For example, when the inner radius r of the innermost partition wall 130w is set to half (1/2) of the inner radius R of the liquid chamber 110, the above equations (1) and (2) From the two equations
2π (R / 2) sH = πR ² H / 100 (3)
s = R / 100 Formula (4)
It becomes. Accordingly, the innermost partition wall 130w is slightly displaced on the scale of 1/100 of the inner radius of the liquid chamber 110 toward the center of the liquid chamber 110, so that the liquid corresponding to the ejection amount is discharged to the outlet channel 106b. To be collected. Therefore, the spiral partition wall 130w in the liquid chamber 110 is not hindered when the liquid is ejected.

  After the liquid is ejected, the piezoelectric element 112 contracts and returns to its original length due to a decrease in the driving voltage. Accordingly, the volume of the liquid chamber 110 is restored to the original volume. Further, the liquid supplied from the liquid supply means 300 to the liquid chamber 110 flows along the partition wall 130w to fill the liquid chamber 110, and the partition wall 130w in the liquid chamber 110 is also restored to the original upright state. As a result, the state before the piezoelectric element 112 shown in FIG.

  When the piezoelectric element 112 expands again due to the increase of the driving voltage, the liquid pressurized in the liquid chamber 110 is ejected from the nozzle 105 as shown in FIG. By repeating these operations, the pulsation generator 100 of the third embodiment can eject liquid from the nozzle 105 in pulses.

  According to the third embodiment described above, the liquid chamber 110 is partitioned into a spiral channel having a substantially constant cross-sectional area between the inlet channel 106a and the outlet channel 106b by the deformable partition wall 130w. Has been. Then, when the piezoelectric element 112 is driven in a state where the liquid supplied from the inlet channel 106 a is filled in the liquid chamber 110, the partition wall 130 w is deformed and the volume of the liquid chamber 110 is reduced. The pressurized liquid flows along the spiral channel, is guided to the outlet channel 106b, and is ejected from the nozzle 105 through the outlet channel 106b. Accordingly, since the liquid flows along the spiral flow path at a sufficiently high flow velocity, it is possible to suppress the bubbles from staying at a slow flow point and quickly discharge the bubbles in the liquid chamber 110 from the outlet flow path 106b. can do. As a result, the pressure in the liquid chamber 110 can be sufficiently increased without being affected by bubbles, and stable liquid ejection is possible.

In addition, since the partition wall 130w forming the spiral flow path inside the liquid chamber 110 can be deformed by a flexible material, when the piezoelectric element 112 extends and the volume of the liquid chamber 110 decreases. The central part of the spiral partition wall 130 w is deformed so as to bend toward the center of the liquid chamber 110. As a result, the pressurized liquid in the liquid chamber 110 can move toward the center of the liquid chamber 110. Therefore, a liquid flow toward the outlet channel 106b opening in the center is generated inside the innermost wall of the spiral partition wall 130w, and the liquid is collected from the surroundings in the outlet channel 106b. As described above, in the liquid ejecting apparatus 10 according to the present embodiment, the partition wall 130w is provided in the liquid chamber 110. However, the partition wall 130w is not hindered when ejecting the liquid, and the liquid is ejected strongly. be able to.
(Fourth embodiment)

  In addition to the pulsation generator 100 according to the third embodiment described above, an embodiment in which the technical idea of the third embodiment is developed can be realized. Hereinafter, these other embodiments will be described. In the description of the embodiment, the same components as those of the third embodiment are denoted by the same reference numerals as those of the third embodiment, and the detailed description of common portions is omitted.

  FIG. 14 is an explanatory diagram showing the internal structure of the pulsation generating unit 100 of the fourth embodiment. FIG. 14A shows a state in which the drive voltage waveform is not applied to the piezoelectric element 112, and FIG. A driving voltage waveform is applied to the piezoelectric element 112 and expanded. In the third embodiment described above, the partition wall 130w of the flow path forming member 130 is erected from the support plate 130b, and the tip is fixed to the concave bottom surface 106d of the second case 106. However, in the fourth embodiment, the tip of the partition wall 130w is not fixed to the concave bottom surface 106d of the second case 106.

  As shown in FIG. 14A, the flow path forming member 130 is provided with a spiral partition wall 130w on a support plate 130b. In the liquid chamber 110, a spiral flow path partitioned by a partition wall 130w is formed. However, in the fourth embodiment, unlike the third embodiment described above, the line end portion on the first direction side facing the second case 106 of the partition wall 130w is not fixed to the concave bottom surface 106d of the second case 106. A slight gap is provided between the tip of the partition wall 130w and the bottom surface 106d of the recess.

  Also in the pulsation generating section 100 of the fourth embodiment as described above, the liquid flowing in from the inlet channel 106a opening at the peripheral edge of the liquid chamber 110 flows along the partition wall 130w as in the third embodiment. The liquid chamber 110 is filled with the liquid by flowing to the central outlet channel 106b while turning. Since the gap between the front end of the partition wall 130w and the bottom surface 106d of the recess is very small, the liquid that has flowed into the liquid chamber 110 flows exclusively along the spiral flow path.

  When the piezoelectric element 112 is expanded by applying the drive voltage waveform in a state where the liquid chamber 110 is filled with the liquid in this manner, the volume of the liquid chamber 110 is reduced and the liquid in the liquid chamber 110 is pressurized. At this time, since a pressure difference is generated between the inside and the outside of the partition wall 130w, the partition wall 130w is pushed and deformed from the high pressure outside to the low pressure inside. In the pulsation generating portion 100 of the fourth embodiment, the tip of the partition wall 130w is not fixed to the concave bottom surface 106d of the second case 106, so that the tip side of the partition wall 130w is the liquid chamber as shown in FIG. It is deformed so as to fall toward the center of 110.

  When the leading end side of the partition wall 130w falls toward the center of the liquid chamber 110 in this way, the liquid outside the partition wall 130w flows over the partition wall 130w and flows into the inside, so that a spiral flow is generated inside the liquid chamber 110. A liquid flow is generated across the path toward the central outlet channel 106b.

  As described above, in the pulsation generating portion 100 of the fourth embodiment, the tip of the partition wall 130w is not fixed to the concave bottom surface 106d of the second case 106, but when the liquid chamber 110 is filled with liquid. As in the third embodiment described above, the flow of the liquid in the liquid chamber 110 can be restricted to a constant flow velocity along the spiral flow path formed by the partition wall 130w. Therefore, the bubbles do not stay in a place where the flow is slow, and the bubbles in the liquid chamber 110 can be quickly discharged.

Further, when the piezoelectric element 112 expands and the volume of the liquid chamber 110 decreases, the tip of the partition wall 130 w that is not fixed to the concave bottom surface 106 d of the second case 106 falls toward the center of the liquid chamber 110. As a result, a liquid flow is generated inside the liquid chamber 110 and travels over the partition wall 130w toward the central outlet channel 106b. As described above, since the liquid crossing the spiral flow path is also added and the liquid is collected from the periphery to the central outlet flow path 106b, the liquid can be appropriately ejected.
(5th Example)

  Next, the pulsation generator 100 according to the fifth embodiment will be described. In the third and fourth embodiments described above, the partition wall 130w of the flow path forming member 130 is erected from the support plate 130b. The fifth embodiment is characterized in that the spiral inner partition wall 130w is not erected on the support plate 130b.

  FIG. 15 is an explanatory diagram showing the internal structure of the pulsation generator 100 according to the fifth embodiment. (A) shows a state where the drive voltage waveform is not applied to the piezoelectric element 112, and (b) shows a state where the drive voltage waveform is applied to the piezoelectric element 112 and extended. Also in the pulsation generator 100 of the fifth embodiment, a spiral flow path partitioned by a spiral partition wall 130w is formed inside the liquid chamber 110, as in the third and fourth embodiments described above. Has been.

  The partition wall 130w is not fixed to the concave bottom surface 106d of the second case 106, and a slight gap is provided between the partition wall 130w and the concave bottom surface 106d. In addition, the entire partition wall 130w is not erected from the support plate 130b, but only the outermost part of the spirally-shaped partition wall 130w wound in multiple layers is erected on the support plate 130b. The remaining portion is a series of spiral shapes but is not erected from the support plate 130b and has a slight gap.

  Also in the pulsation generator 100 of the fifth embodiment configured as described above, when the liquid chamber 110 is filled with the liquid, as in the third and fourth embodiments described above, Since the liquid flow is regulated at a constant flow velocity along the spiral flow path formed by the partition wall 130w, the bubbles in the liquid chamber 110 can be quickly discharged on the flow.

  On the other hand, as shown in FIG. 15B, when the volume of the liquid chamber 110 decreases due to the extension of the piezoelectric element 112 and a pressure difference occurs between the inside and the outside of the partition wall 130w, the pressure is increased from the outside where the pressure is high. The partition wall 130w is pushed toward the lower inside. At this time, the portion of the spiral partition wall 130w that is not fixed to the support plate 130b moves toward the center of the liquid chamber 110 so that the mainspring is just wound up. The liquid moves toward the center of the liquid chamber 110. In addition, since the liquid flows toward the central outlet channel 106b so as to cross the spiral channel and cross the partition wall 130w, the liquid is collected from the surroundings into the outlet channel 106b, so that the liquid is strongly ejected. be able to.

In the third embodiment, the fourth embodiment, and the fifth embodiment described above, in order to efficiently guide the liquid supplied to the liquid chamber 110 to the outlet channel 106b, the outlet channel 106b is provided with a liquid. It was set as the structure opened to the center position of the recessed part 106c which comprises the chamber 110. FIG. However, the position where the outlet channel 106b is opened is not limited to the central position of the recess 106c, but at least the outlet channel 106b is positioned closer to the center of the recess 106c than the inlet channel 106a. It only has to be.
(Sixth embodiment)

  Next, the pulsation generator 100 according to the sixth embodiment will be described. In the third embodiment, the fourth embodiment, and the fifth embodiment described above, the outlet channel 106b is in the center of the liquid chamber 110 formed in a spiral shape, and the inlet channel 106a is the outer peripheral edge of the liquid chamber 110. The part is open. In contrast, the sixth embodiment is characterized in that the outlet channel 106b is opened at the outer peripheral edge of the liquid chamber 110 formed in a spiral shape, and the inlet channel 106a is opened at the center of the liquid chamber 110. To do. Therefore, in the description of the sixth embodiment, the same components as those of the third embodiment described above are denoted by the same reference numerals as those of the third embodiment described above, and detailed description thereof is omitted.

  FIG. 16 is an exploded view showing the pulsation generator 100 according to the sixth embodiment. The pulsation generator 100 is formed with a circular shallow recess 108c in the approximate center of the surface where the first case 108 and the second case 106 are combined, and the bottom surface of the recess 108c closes the through hole 108h. A circular diaphragm 114 formed of a thin metal plate or the like is fixed.

  The piezoelectric element 112 is accommodated in the through hole 108 h closed by the diaphragm 114. A circular reinforcing plate 116 is inserted between the piezoelectric element 112 and the diaphragm 114. The thickness of the reinforcing plate 116 is set so that the diaphragm 114 and the reinforcing plate 116, and the piezoelectric element 112 and the third case 118 are just in contact with each other. One end of the piezoelectric element 112 is fixed to a third case 118 (not shown), and the other end of the piezoelectric element 112 is fixed to a reinforcing plate 116. Further, the surface of the reinforcing plate 116 opposite to the piezoelectric element 112 is fixed to the diaphragm 114.

  On the side of the diaphragm 114 facing the second case 106, a flow path forming member 130 having a partition wall 130 w standing on one side of a circular support plate 130 b is formed in the recess 108 c so that the support plate 130 b is overlapped with the diaphragm 114. It is inserted. The support plate 130b is fixed to the diaphragm 114 on the surface opposite to the surface on which the partition wall 130w is erected. The thickness including the support plate 130b and the diaphragm 114 is formed to be the same as the depth of the recess 108c. The flow path forming member 130 is formed of a flexible material so as to be deformable. The shape of the partition wall 130w will be described later with reference to FIG.

  On the other hand, in the second case 106, a circular shallow recess 106c is formed on the surface where it is combined with the first case 108. When the second case 106 and the first case 108 are screwed together, the liquid chamber 110 is formed by the recess 106c of the second case 106 and the flow path forming member 130 provided on the first case 108 side. Is done. Furthermore, the tip of the partition wall 130w of the flow path forming member 130 on the side facing the second case 106 is fixed to the concave bottom surface 106d of the second case 106, and the liquid chamber 110 is partitioned by the partition wall 130w. A spiral flow path is formed.

  However, on the contrary, the support plate 130b of the flow path forming member 130 is fixed to the concave bottom surface 106d of the second case 106, and the second case 106 and the first case 108 are combined and screwed together. The tip of the partition wall 130 w of the flow path forming member 130 on the side facing the diaphragm 114 may be fixed to the diaphragm 114.

  An inlet channel 106a communicates with the central portion of the spiral liquid chamber 110, and an outlet channel 106b communicates with the outer peripheral edge. A second connection tube 304 is connected to the inlet channel 106a, and a liquid ejection pipe 104 is connected to the outlet channel 106b.

Next, the configuration of the flow path forming member 130 according to the sixth embodiment will be described with reference to FIG.
FIG. 17 is an explanatory view showing the shape of the flow path forming member 130. FIG. 17 shows a state in which the flow path forming member 130 is viewed from the diaphragm 114 side. As shown in the figure, the support plate 130b of the flow path forming member 130 is formed in the same circular shape as the diaphragm 114, toward the center of the support plate 130b on the surface of the support plate 130b facing the second case 106. A partition wall 130w is erected in a spiral shape that swirls while being wound.

  The spiral-shaped partition wall 130w is formed so that a part of the outer peripheral surface of the outermost wall is in contact with the inner peripheral surface of the recess 106c, and the spiral flow path between the inlet channel 106a and the outlet channel 106b is interrupted. The area is almost constant. When the second case 106 and the first case 108 are screwed together, a spiral flow path is formed in the liquid chamber 110 toward the outer peripheral edge while turning from the center by the partition wall 130w.

  Further, as shown in FIG. 16, an inlet channel 106a and an outlet channel 106b are communicated with the recess 106c of the second case 106, and the second case 106 and the first case 108 are aligned at an appropriate position. When screwed, the inlet channel 106a opens at the center of the spiral channel formed inside the liquid chamber 110, and the outlet channel 106b opens at the outer periphery of the spiral channel. It has become.

  Also in the pulsation generating unit 100 configured as described above, it is possible to eject liquid from the nozzle 105 in a pulsed manner by applying a drive voltage waveform to the piezoelectric element 112 and driving the piezoelectric element 112 to expand and contract. .

  Next, the liquid ejecting operation performed by the pulsation generator 100 according to the sixth embodiment will be described. In a state where the piezoelectric element 112 is not driven (a state where no driving voltage waveform is applied), as shown in FIGS. 16 and 17, the liquid passes from the liquid supply means 300 through the inlet channel 106 a via the second connection tube 304. By flowing into the liquid chamber 110, the liquid chamber 110 is filled with the liquid.

  The liquid chamber 110 is partitioned by the partition wall 130w of the flow path forming member 130 to form a spiral flow path having a substantially constant cross-sectional area. The liquid flowing in from the inlet channel 106a that opens to the center of the liquid chamber 110 opens at the outer peripheral edge of the liquid chamber 110 while swirling along the partition wall 130w, as indicated by the dashed arrows in FIG. It is guided to the outlet channel 106b. By restricting the flow of the liquid along the partition wall 130w in this way, a portion where the flow is fast and a portion where the flow is slow does not occur in the liquid chamber 110, and the liquid flowing in from the inlet channel 106a is allowed to flow out to the outlet channel 106b. Can flow at a substantially uniform flow rate.

  In addition, since the liquid is supplied from the liquid supply means 300 at a substantially constant pressure without interruption, when the liquid chamber 110 is filled with the liquid, even if the piezoelectric element 112 is not driven, The liquid is pushed out toward the liquid jet pipe 104 through the outlet channel 106b.

  18A and 18B show a state in which the drive voltage waveform is applied to the piezoelectric element 112 in the sixth embodiment. FIG. 18A is a partial cross-sectional view of the pulsation generator 100, and FIG. FIG. When a driving voltage waveform is applied to the piezoelectric element 112 in a state where the liquid chamber 110 is filled with liquid, the piezoelectric element 112 expands due to an increase in driving voltage as shown in FIG. The diaphragm 114 and the support plate 130b of the flow path forming member 130 are pressed toward the liquid chamber 110 via As a result, the volume of the liquid chamber 110 is reduced, and the liquid in the liquid chamber 110 is pressurized. The liquid pressurized in the liquid chamber 110 is ejected in a pulse form from the nozzle 105 through the outlet channel 106b and the liquid ejection pipe 104, as indicated by the dashed arrows in FIG. .

  Note that the liquid chamber 110 is connected to two channels, an inlet channel 106a and an outlet channel 106b. Therefore, it is considered that the liquid pressurized in the liquid chamber 110 flows out not only from the outlet channel 106b but also from the inlet channel 106a. However, since the ease of liquid flow in the flow path is determined by the cross-sectional area of the flow path, the length of the flow path, and the like, the cross-sectional areas and lengths of the inlet flow path 106a and the outlet flow path 106b should be set appropriately. For example, it is possible to make it easier for the liquid to flow out of the outlet channel 106b than the inlet channel 106a. For example, in the fifth embodiment, the outlet channel 106b has a capillary shape with a diameter of about 1 mm and the inlet channel 106a has a diameter of about 0.3 mm. Therefore, the backflow from the inlet channel 106a is suppressed.

  In the inlet channel 106a, there is a flow in which the liquid pressure-fed from the liquid supply means 300 attempts to flow into the liquid chamber 110, which prevents the liquid from flowing out in the liquid chamber 110, whereas in the outlet channel 106b There are few factors that increase the resistance and fluid inertia that hinder the outflow of the liquid in the liquid chamber 110. Therefore, the liquid pressurized in the liquid chamber 110 flows out from the outlet channel 106 b exclusively and is ejected from the nozzle 105 at the tip through the liquid ejection pipe 104.

  The interior of the liquid chamber 110 of the sixth embodiment is partitioned in a spiral shape by the partition wall 130 w of the flow path forming member 130. However, when the volume of the liquid chamber 110 decreases due to the extension of the piezoelectric element 112, not only the liquid flows along the spiral partition wall 130w, but the partition wall 130w is located on the outer peripheral edge of the outlet channel 106b. The liquid in the liquid chamber 110 moves toward the outer peripheral side of the liquid chamber 110 by being deformed toward the surface. This point will be supplementarily described.

  First, considering as an example the partition wall 130w that forms the innermost wall of the spiral-shaped partition wall 130w that is wound in multiple layers, the inlet channel 106a is located at the center of the liquid chamber 110 inside the innermost partition wall 130w. Therefore, when the volume of the liquid chamber 110 decreases, the increase in pressure is suppressed by the liquid flowing out from the outlet channel 106b.

  On the other hand, the inlet channel 106a has a capillary shape inside the partition wall 130w, and the pressure rises compared to the outside of the partition wall 130w in order to suppress the outflow of liquid. Since the partition wall 130w is made of a flexible material so as to be deformable, the partition wall 130w is pushed and deformed from the high pressure inside to the low pressure outside, so that the pressure difference between the inside and the outside is increased. Try to decrease. Since the partition wall 130w of the sixth embodiment is erected from the support plate 130b and the tip is fixed to the concave bottom surface 106d of the second case 106, as shown in FIG. The central portion of the partition wall 130w is deformed so that it is pushed from the inside and bent outward.

  The pressure difference between the inner side and the outer side of the partition wall 130w is not limited to the innermost partition wall 130w, but the innermost partition wall 130w is deformed to the outside and the inner pressure is reduced. It also occurs in the partition wall 130w and similarly propagates to the third partition wall 130w. Accordingly, the spiral partition wall 130w is deformed so as to expand the spiral toward the outer peripheral side of the liquid chamber 110 as a whole.

  When the volume of the liquid chamber 110 decreases due to the extension of the piezoelectric element 112, the central portion of the spiral partition wall 130w is deformed so as to bend toward the outside of the liquid chamber 110. As shown by the broken line arrow in FIG. 18B, the liquid chamber 110 tends to move from the central portion toward the outlet channel 106b at the outer peripheral edge.

  When the volume of the liquid chamber 110 decreases due to the extension of the piezoelectric element 112, a corresponding amount of liquid is collected in the outlet channel 106 b and pushed out, so that the liquid is ejected from the nozzle 105 at the tip of the liquid ejection pipe 104. . At this time, it is considered that the spiral partition wall 130w in the liquid chamber 110 becomes an obstacle, and a sufficient amount of liquid cannot be collected from the surroundings to the outlet channel 106b at the outer peripheral edge. However, in the pulsation generator 100 of the sixth embodiment, the amount of displacement due to the expansion of the piezoelectric element 112 is small, and the amount of liquid ejected in one pulse (ejection amount) is relative to the volume of the liquid chamber 110. Since the partition wall 130w is slightly deformed toward the center of the liquid chamber 110, a sufficient amount of liquid is collected from the center portion in the outlet channel 106b. This can be supported by the equations (1) to (4) described in the third embodiment.

  As shown in FIG. 18A, the peripheral edge of the support plate 130b is fixed so as to be sandwiched between the first case 108 and the second case 106, and the outer diameter of the reinforcing plate 116 is the support plate 130b. Further, the cross-sectional dimension of the piezoelectric element 112 is smaller than the outer diameter of the reinforcing plate 116. Accordingly, when the liquid chamber 110 is pressed by the piezoelectric element 112, the outer peripheral edge is warped around the central portion where the inlet channel 106a is disposed. Therefore, the pressing amount of the liquid chamber 110 is large near the central portion, and the volume changes. Is big. Further, the pressing amount is small on the outer peripheral side, and the change in volume is small. That is, it is considered that the pressure in the liquid chamber 110 is high in the central portion and low in the outer peripheral portion. Therefore, the liquid in the liquid chamber 110 is strongly pushed out from the central portion to the outer peripheral portion including that the liquid is fed from the liquid supply means 300 to the inlet channel 106a at a substantially constant pressure.

  Therefore, the pressure in the vicinity of the inlet channel 1106a at the center increases, and the return pressure of the liquid at the inlet 110a increases. However, since the diameter of the inlet 110a is a capillary shape, the backflow from the liquid chamber 110 to the inlet channel 106a is suppressed, so that the pressure of the liquid chamber 110 can be increased and a strong liquid jet can be obtained. Can do.

In the sixth embodiment, a spiral flow path is formed using the flow path forming member 130, and the outlet flow path 106 b is formed in a spiral shape on the outer peripheral edge of the liquid chamber 110 and the inlet flow path 106 a is disposed on the liquid chamber 110. The configuration communicated with the central portion has been described. Even with such a configuration, the concept of the fourth embodiment or the fifth embodiment described above can be applied.
(Seventh embodiment)

  The seventh embodiment is different from the fourth embodiment described above in the arrangement of the inlet channel 106a and the outlet channel 106b, and the other configuration can be applied to the fourth embodiment. Therefore, the same components as those in the fourth embodiment described above are denoted by the same reference numerals as those in the fourth embodiment, and detailed descriptions of common portions are omitted.

  FIG. 19 shows a part of the internal structure of the pulsation generator 100 according to the seventh embodiment, and FIG. 19A shows a state in which the drive voltage waveform is not applied to the piezoelectric element 112, and FIG. ) Shows a state in which a drive voltage waveform is applied to the piezoelectric element 112.

  As shown in FIG. 19A, the flow path forming member 130 is provided with a spiral partition wall 130w on a support plate 130b. In the liquid chamber 110, a spiral flow path partitioned by a partition wall 130w is formed. In the seventh embodiment, the tip of the partition wall 130w facing the second case 106 is not fixed to the recess bottom surface 106d of the second case 106, and between the tip of the partition wall 130w and the recess bottom surface 106d, A slight gap is provided. The outlet channel 106 b is opened at the outer peripheral edge of the liquid chamber 110 formed in a spiral shape, and the inlet channel 106 a is opened at the center of the liquid chamber 110.

  In the seventh embodiment having such a configuration, as in the fifth embodiment described above, the liquid flowing in from the inlet channel 106a opening in the center of the liquid chamber 110 is swung along the partition wall 130w. By flowing to the central outlet channel 106b, the liquid chamber 110 is filled with the liquid. Since the gap between the front end of the partition wall 130w and the bottom surface 106d of the recess is very small, the liquid that has flowed into the liquid chamber 110 flows exclusively along the spiral flow path.

  When the piezoelectric element 112 is expanded by applying the drive voltage waveform in a state where the liquid chamber 110 is filled with the liquid in this manner, the volume of the liquid chamber 110 is reduced and the liquid in the liquid chamber 110 is pressurized. At this time, since a pressure difference is generated between the inside and the outside of the partition wall 130w, the partition wall 130w is pushed and deformed from the high pressure inside to the low pressure outside. In the seventh embodiment, the leading end of the partition wall 130w is not fixed to the concave bottom surface 106d of the second case 106, so that the leading end side of the partition wall 130w is on the outer peripheral side of the liquid chamber 110 as shown in FIG. Deforms to fall down.

  Thus, when the tip side of the partition wall 130w falls toward the outer peripheral side of the liquid chamber 110, the liquid inside the partition wall 130w flows over the partition wall 130w and flows into the outer peripheral side. A liquid flow is generated across the spiral flow path toward the outlet flow path 106b on the outer peripheral side.

  As described above, in the pulsation generating unit 100 of the seventh embodiment, the leading end of the partition wall 130w is not fixed to the concave bottom surface 106d of the second case 106, but when the liquid chamber 110 is filled with liquid. As in the fifth embodiment described above, the flow of the liquid in the liquid chamber 110 can be restricted to a constant flow velocity along the spiral flow path formed by the partition wall 130w. Therefore, the bubbles do not stay in a place where the flow is slow, and the bubbles in the liquid chamber 110 can be quickly discharged.

Further, when the piezoelectric element 112 expands and the volume of the liquid chamber 110 decreases, the tip of the partition wall 130 w that is not fixed to the concave bottom surface 106 d of the second case 106 falls down in the outer peripheral direction of the liquid chamber 110. In the liquid chamber 110, a liquid flow is generated which goes over the partition wall 130 w and goes to the central outlet channel 106 b. As described above, since the liquid crossing the spiral flow path is also added and the liquid is collected from the periphery to the central outlet flow path 106b, the liquid can be appropriately ejected.
(Eighth embodiment)

Next, the configuration of the pulsation generator 100 according to the eighth embodiment will be described.
The eighth embodiment is different from the fifth embodiment described above in the arrangement of the inlet channel 106a and the outlet channel 106b, and the other configuration can be applied to the fifth example. Accordingly, the same components as those of the fifth embodiment described above are denoted by the same reference numerals as those of the fifth embodiment, and detailed descriptions of common portions are omitted.

  FIG. 20 is an explanatory diagram showing the internal structure of the pulsation generator 100 according to the eighth embodiment. FIG. 20A shows a state in which the drive voltage waveform is not applied to the piezoelectric element 112, and FIG. b) shows a state in which the drive voltage waveform is applied to the piezoelectric element 112 and extended. As shown in FIG. 20 (a), in the pulsation generator 100 of the eighth embodiment as well, the liquid chamber 110 is partitioned by a spiral partition wall 130w in the same manner as the fifth embodiment described above. A spiral flow path is formed.

  The partition wall 130w is not fixed to the concave bottom surface 106d of the second case 106, and a slight gap is provided between the partition wall 130w and the concave bottom surface 106d. In addition, the entire partition wall 130w is not erected from the support plate 130b, but only the outermost part of the spirally-shaped partition wall 130w wound in multiple layers is erected on the support plate 130b. The remaining inner peripheral portion is a series of spiral shapes, but is not erected from the support plate 130b and has a slight gap.

  In the eighth embodiment having such a configuration, the liquid flowing in from the inlet channel 106a that opens to the center of the liquid chamber 110 turns toward the outlet channel 106b at the outer peripheral edge while turning along the partition wall 130w. The liquid chamber 110 is filled with the liquid. In addition, since the clearance gap between the front-end | tip of the partition wall 130w and the recessed part bottom face 106d and the support plate 130b is slight, the liquid which flowed into the liquid chamber 110 flows exclusively along a spiral flow path.

  Also in the pulsation generator 100 of the eighth embodiment having such a configuration, when the liquid chamber 110 is filled with the liquid, the flow of the liquid in the liquid chamber 110 is a spiral flow path formed by the partition wall 130w. Therefore, it is possible to quickly discharge the bubbles in the liquid chamber 110 on the flow.

  On the other hand, as shown in FIG. 20B, when the volume of the liquid chamber 110 decreases due to the extension of the piezoelectric element 112 and a pressure difference is generated between the inside and the outside of the partition wall 130w, the pressure is increased from the high pressure inside. The partition wall 130w is pushed toward the lower outside. At this time, the portion of the inner peripheral partition wall 130w that is not fixed to the concave bottom surface 106d and the support plate 130b moves toward the outer peripheral direction so that the mainspring is just opened. The pressurized liquid moves toward the outer periphery of the liquid chamber 110. In addition, since the liquid flows toward the outlet channel 106b in the outer peripheral direction so as to cross over the spiral channel over the partition wall 130w, the liquid is collected from the surroundings in the outlet channel 106b. Can be injected.

  In the sixth to eighth embodiments described above, the inlet channel 106 a is disposed at the center of the liquid chamber 110, and the outlet channel 106 b is disposed at the outer periphery of the liquid chamber 110. If the inlet channel 106a and the outlet channel 106b are arranged in this way, the liquid is pumped from the central portion to the outlet channel in the outer peripheral portion, so that it is possible to further improve the bubble elimination.

  In the third to seventh embodiments described above, a spiral flow path is formed in the liquid chamber 110 by the partition wall 130w. However, the flow path formed in the liquid chamber 110 is not particularly limited as long as it has a shape turning from the inlet flow path 106a toward the outlet flow path 106b. For example, a deformation such as a zigzag folded shape may be added.

  The liquid ejecting apparatus 10 described above is a surgical instrument for incising or excising a living tissue by spraying a liquid such as water or physiological saline toward the living tissue, or applying a chemical solution to a wound or washing. In addition to medical use, the present invention can be utilized as a device that uses a small amount of liquid to be ejected at high speed, such as drawing using ink as a liquid, cleaning of precision parts, and a cooling device for electronic equipment.

  DESCRIPTION OF SYMBOLS 10 ... Liquid injection apparatus, 102 ... Nozzle, 110 ... Liquid chamber, 110a ... Inlet, 110b ... Outlet, 112 ... Piezoelectric element, 120 ... Tube, 200 ... Control part.

Claims (7)

An inlet channel through which liquid is supplied;
An outlet channel communicating with the nozzle;
A spiral chamber having a substantially constant cross-sectional area is formed between the inlet channel and the outlet channel, and a liquid chamber having a given volume;
A volume changing unit that deforms the liquid chamber in a direction to reduce the volume of the liquid chamber from the given volume;
An ejection control means for ejecting the liquid in a pulse form from the nozzle by driving the volume changing unit in a state where the liquid is filled in the liquid chamber ;
The liquid chamber is partitioned into a spiral channel between the inlet channel and the outlet channel by a deformable partition wall;
The partition wall is a surface on the first direction side that forms the liquid chamber and reduces the volume of the liquid chamber below the given volume, or a surface on the second direction side that faces the surface on the first direction side. Standing up from any one of the surfaces, the tip of the partition wall facing the second direction surface or the tip of the partition wall facing the first direction is provided in an unfixed state. ,
A liquid ejecting apparatus. An inlet channel through which liquid is supplied;
An outlet channel communicating with the nozzle;
A spiral chamber having a substantially constant cross-sectional area is formed between the inlet channel and the outlet channel, and a liquid chamber having a given volume;
A volume changing unit that deforms the liquid chamber in a direction to reduce the volume of the liquid chamber from the given volume;
An ejection control means for ejecting the liquid in a pulse form from the nozzle by driving the volume changing unit in a state where the liquid is filled in the liquid chamber;
The liquid chamber is partitioned into a spiral channel between the inlet channel and the outlet channel by a deformable partition wall;
The partition wall is a surface on the first direction side that forms the liquid chamber and reduces the volume of the liquid chamber below the given volume, or a surface on the second direction side that faces the surface on the first direction side. A partition wall other than the outermost partition wall is erected from any one of the surfaces, and has a distal end portion that faces the surface on the first direction side and a distal end portion that faces the second direction side. That it is provided without
A liquid ejecting apparatus. The volume changing unit has a piezoelectric element,
Reducing the volume of the liquid chamber by extending the piezoelectric element;
The piezoelectric element is disposed so as to press the liquid chamber in a state where the piezoelectric element is not extended.
The liquid ejecting apparatus according to claim 1 or 2, characterized in. The cross-sectional area of the inlet channel is smaller than the cross-sectional area of the outlet channel, and wherein it inlet passage is a capillary shape, liquid jet according to any one of claims 1 to 3, wherein apparatus. A unit including the inlet channel, the outlet channel, the liquid chamber, and the nozzle is an ejection unit,
When the volume changing unit is a volume changing unit,
The injection unit and the volume changing unit are detachable,
Liquid ejecting apparatus as claimed in any one of claims 1 to 4, characterized in. The inlet channel is in communication with the outer peripheral side end of the spiral channel of the liquid chamber;
The outlet channel is in communication with a central side end of the spiral channel of the liquid chamber;
The liquid ejecting apparatus according to claim 1 , wherein the liquid ejecting apparatus is a liquid ejecting apparatus. The inlet channel is in communication with a central side end of the spiral channel of the liquid chamber;
The outlet channel is in communication with the outer peripheral end of the spiral channel of the liquid chamber;
The liquid ejecting apparatus according to claim 1 , wherein the liquid ejecting apparatus is a liquid ejecting apparatus.

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