JP2009107265A - Droplet discharge head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a droplet discharge head capable of easily and appropriately sealing a joint portion between a flow path unit and a support frame by injecting a liquid sealing agent.
A droplet discharge head (6) includes a flow path unit (10), a piezoelectric unit (11), and a support frame (5) having an opening (5a), and an outer periphery (11a) of the piezoelectric unit (11) and an opening (5a) of the support frame (5). A gap path 60 is formed between the inner peripheral portion 5b and the liquid sealant 66 is urged to be introduced into and held in the vicinity of the inner peripheral portion 5b of the support frame 5 in the gap path 60. The introduction groove 65 is provided along the gap path 60.
[Selection] Figure 5

Description

  The present invention relates to a droplet discharge head including an inkjet printer head that discharges ink onto a medium such as paper.

  As an example of a liquid droplet ejection apparatus using an ink jet printer apparatus, a flow path unit having a liquid flow path to a nozzle hole for ejecting liquid droplets inside, and a nozzle by applying a discharge pressure to the liquid in the liquid flow path Some include a droplet discharge head having a piezoelectric unit for discharging a liquid from a hole and a support frame that forms a frame shape surrounding the piezoelectric unit and is bonded and fixed to the upper surface periphery of the flow path unit ( For example, see Patent Document 1).

  More specifically, as disclosed in Patent Document 1, in this type of droplet discharge head, a piezoelectric element having an outer dimension smaller than that of the channel unit is formed on the upper surface of the channel unit having a rectangular shape in plan view. Units are laminated and bonded. A frame-like support frame, which is larger than the outer shape of the flow path unit and surrounds the outer periphery of the piezoelectric unit and has an opening at the center, is further bonded to the periphery of the upper surface of the flow path unit. The opening of the support frame is formed to be larger than the outer dimensions of the piezoelectric unit. Between the inner periphery (opening) of the support frame and the outer periphery of the piezoelectric unit, the opening is along the inner periphery of the support frame. A void path that circulates around is formed. Further, one end of the wiring unit is joined to the upper surface of the piezoelectric unit, and the piezoelectric unit is driven by a voltage supplied through the wiring unit.

  By the way, although the flow path unit and the support frame are bonded to each other by a sheet adhesive or the like, some foreign matter is sandwiched between the two at the time of bonding, or the bonded state as designed cannot be secured for other reasons. In some cases, a minute gap is generated between the two. Further, the flow path unit has an ink inlet for supplying ink from the ink outlet of the ink tank, which is an ink reservoir, to the flow path unit through the ink connection port of the support frame. Ink leakage from each connection portion between the ink outlet, the ink connecting port, and the ink inlet, or ink ejected from the nozzle hole enters the slight gap between the flow path unit and the support frame. There is a possibility of reaching the piezoelectric unit. Thus, when the ink reaches the piezoelectric unit, an electrical connection failure occurs between the piezoelectric unit and the wiring unit, which may cause a malfunction of the piezoelectric unit.

For this reason, a good sealing property is required between the support frame and the flow path unit. Therefore, in the droplet discharge head disclosed in Patent Document 1, a liquid sealant is separately injected after bonding the two together. Work is being performed (see FIG. 3 of Patent Document 1). More specifically, as described above, a void path having the upper surface of the flow path unit as the bottom surface is formed between the inner peripheral portion of the support frame and the outer peripheral portion of the piezoelectric unit, and liquid sealing is performed along the void path. Stopper is being injected. As a result, even if a gap is generated at the connection point between the flow path unit and the support frame, the opening on the gap path side in this gap can be closed, and liquid can reach the piezoelectric unit by preventing liquid from entering through this gap. To prevent it from happening.
JP 2006-44196 A (refer to FIG. 3 in particular)

    By the way, injection of such a liquid sealing agent is performed by handling and is not easy due to the narrowness of the gap. Furthermore, the wiring unit connected to the piezoelectric unit has a configuration in which one end is connected to the piezoelectric unit and the other end is pulled out from the opening of the support frame across a part of the gap. Therefore, it is necessary to inject the liquid sealing agent after the wiring unit is lifted up to expose the gap path in the portion of the gap path that is located below and straddling the wiring unit. Not only is it difficult to inject properly, but the wiring unit may be peeled off from the piezoelectric unit by this work. In addition, even when it is desired to reduce the size of the droplet discharge head, if the width dimension of the gap passage becomes smaller, it becomes more difficult to inject the liquid sealant by handling, so the width dimension of the gap passage is reduced. This is a cause of hindering the realization of the above-mentioned demand.

  Furthermore, the general liquid sealant is deformed by reducing the volume due to the vaporization of the solvent in the drying step after injection, so even if the joint between the flow path unit and the support frame can be sealed at the time of injection, After drying, the joint location may be exposed and may not be finally sealed. Further, in the operation by handling, the injection amount of the liquid sealant varies. Conventionally, in order to cope with such a situation, after injecting and drying a liquid sealant, the trouble of visually confirming a sealing failure portion and injecting the liquid sealing agent again into the portion and drying it. Has been forced to work.

  Accordingly, an object of the present invention is to provide a liquid droplet ejection head that can easily and appropriately seal a joint portion between a flow path unit and a support frame by injecting a liquid sealing agent.

  The present invention has been made in view of the above-described circumstances, and a droplet discharge head according to the present invention includes a flow path unit having a liquid flow path up to a nozzle hole for discharging a liquid, and the flow path. A piezoelectric unit that is stacked on the unit, has an outer dimension smaller than that of the flow path unit, and applies a discharge pressure to the liquid for discharging droplets from the nozzle hole, and has a frame shape surrounding the piezoelectric unit; A support frame that is bonded and fixed to the flow path unit and supports the flow path unit, and extends between the outer peripheral portion of the piezoelectric unit and the inner peripheral portion of the support frame along the inner peripheral portion of the support frame. An air passage is formed in which the liquid sealant is filled, and an introduction groove for encouraging the introduction of the liquid sealant and holding the liquid sealant is provided near the inner periphery of the support frame in the air passage. Is the gap It is provided along the.

  By adopting such a configuration, an introduction groove having a passage cross section smaller than the gap passage is formed in the vicinity of the inner peripheral portion of the support frame, and the introduction of the liquid sealant into the introduction groove is promoted by capillary action. Since the liquid sealing agent diffuses along the introduction groove, the liquid sealing agent can be easily injected. In addition, since the injected liquid sealant is introduced and maintained in the narrow introduction groove, the shape change during drying is suppressed, and there is no need to repeat the injection and drying steps. In addition, since a narrow introduction groove is formed at the bottom of the air gap, the liquid sealant is appropriately injected into the joint between the flow path unit located at the deepest part of the air gap and the support frame without difficulty. be able to. In addition, since the liquid sealant can be introduced along the introduction groove using the capillary phenomenon, the width of the gap path can be reduced, and the droplet discharge head can be downsized. is there.

  Further, on the upper surface of the flow path unit, a portion that forms the bottom surface of the gap path is provided with a ridge extending along the gap path, and the ridge and the inner peripheral portion of the support frame are provided. The introduction groove may be formed by being sandwiched. By setting it as such a structure, an introduction groove | channel can be formed with a protrusion part and the inner peripheral part of a support frame.

  Moreover, the height dimension which protrudes from the upper surface of the said flow path unit in the said protrusion part may be smaller than each thickness direction dimension of the said piezoelectric unit and the said support frame. With such a configuration, it is possible to positively introduce the liquid sealing agent into the introduction groove, hold at least the liquid sealing agent in the introduction groove, and to increase the liquid sealing more than the volume of the introduction groove. By injecting the agent, the portion overflowing from the introduction groove is received by the gap channel, and the gap channel is filled with the liquid sealant so as to bury the introduction groove. A joint location will be sealed more reliably.

  Moreover, the said protrusion part may be formed so that a part of upper surface member of the said flow path unit may be extended upwards. By adopting such a configuration, it is possible to form a protrusion at the time of manufacturing the flow channel unit, so that the introduction groove can be easily formed simply by adhering such a flow channel unit to the support frame. it can.

  Further, a linear member forming the protrusion is disposed along the gap in the gap, and the introduction groove is sandwiched between the linear member and an inner peripheral portion of the support frame. May be formed. By adopting such a configuration, the introduction groove can be formed simply by disposing the linear member in the gap after the piezoelectric unit and the support frame are bonded and fixed to the flow path unit. Therefore, the conventional flow path unit, piezoelectric unit, and support frame can be used as they are.

  In addition, a notch portion that extends along the gap path and opens to the inner peripheral side of the support frame is formed at a position of the support frame facing the flow path unit. The introduction groove may be formed by the upper surface of the substrate and the cutout portion. With such a configuration, the introduction groove can be formed simply by bonding the flow path unit and the support frame. In addition, since the introduction groove can be formed in the immediate vicinity of the joint portion between the flow path unit and the support frame, appropriate sealing can be realized by the liquid sealant injected into the introduction groove.

  The piezoelectric unit further includes a strip-shaped wiring unit that supplies a driving voltage to the piezoelectric unit so as to generate the discharge pressure. The wiring unit has one end laminated on the piezoelectric unit and the other end. The portion is drawn outward through an opening formed by the inner peripheral portion of the support frame and across a part of the gap path, and the introduction groove is provided at least in a part of the gap path across the wiring unit. It may be done. By adopting such a configuration, the liquid sealant can be appropriately injected into the portion of the air gap that spans the wiring unit without raising the wiring unit as in the prior art, and the wiring unit is a piezoelectric unit. Can be prevented from being peeled off, and workability can be improved.

  According to the droplet discharge head according to the present invention, the joint between the flow path unit and the support frame can be easily and appropriately sealed by injecting the liquid sealant.

  Hereinafter, a droplet discharge head according to an embodiment of the present invention will be specifically described with reference to the drawings.

  FIGS. 1A and 1B are cross-sectional views of a carriage including a droplet discharge head according to the present embodiment using an inkjet printer head as an example. 1A shows a cross-sectional view of the droplet discharge head as viewed from one side, and FIG. 1B shows the droplet discharge head along the line AA in FIG. 1A. A sectional view when cut is shown. As shown in FIG. 1, the carriage 1 includes, for example, an ink tank 3 that supplies liquids (inks, etc.) of each color such as cyan, magenta, yellow, and black independently to a flow path unit 10 described later. A holder case 4 that accommodates and holds the ink tank 3, and a droplet discharge head 6 that is bonded to the lower portion of the holder case 4 with an adhesive 4 a via a support frame 5.

  In addition, the droplet discharge head 6 has a plurality of plates laminated and bonded to each other, and a flow path unit 10 having an ink flow path 10a (see FIG. 2) inside, and a top surface of the flow path unit 10 stacked and bonded. The piezoelectric unit 11 includes a wiring unit (chip-on-film) 12 connected to the upper surface of the piezoelectric unit 11. A driver IC 51, which is a drive circuit, is connected to the wiring unit 12, and the driver IC 51 outputs a drive signal for selectively driving the piezoelectric unit based on print data from the main body side. The carriage 1 having such a droplet discharge head 6 is configured to be movable (X direction) in parallel with the paper surface of the recording paper, similarly to a known inkjet printer device, and from the droplet discharge head 6 while moving. By ejecting the liquid droplets, the recording paper moves in a direction (Y direction) perpendicular to the movement direction of the carriage 1, whereby an image can be formed on the paper surface.

  FIG. 2 is an enlarged cross-sectional view of the droplet discharge head 6 provided in the carriage 1 shown in FIG. 1, and FIG. 3 shows the droplet discharge head 6 as a flow path unit 10, a piezoelectric unit 11, a wiring unit 12, and a support frame. FIG.

  As shown in FIG. 2, the flow path unit 10 of the droplet discharge head 6 includes a pressure chamber plate 20, a first spacer plate 21, a throttle plate 22, a second spacer plate 23, a first manifold plate 24, and a second manifold. The plate 25, the damper plate 26, the cover plate 27, and the nozzle plate 28 are arranged from above in this order and are laminated and bonded.

  Among these, the nozzle plate 28 is a resin sheet such as polyimide, and the other plates 21 to 27 are metal plates such as 42% nickel alloy steel plate (42 alloy), and each has a rectangular shape in plan view. , Each has a thickness of about 50 to 150 μm. Each of the plates 20 to 27 is formed with an opening or a recess constituting the ink flow path (channel) 10a by electrolytic etching, laser processing, plasma jet processing, or the like.

  The lowermost nozzle plate 28 of the flow path unit 10 is provided with a large number of nozzle holes 28a for discharging ink droplets having a minute diameter at minute intervals. The nozzle holes 28a are arranged in the long side direction of the nozzle plate 28. It is arranged in a row extending along (Y direction in FIG. 3), and five rows are provided in the short side direction (X direction in FIG. 3). The pressure chamber plate 20 located in the uppermost layer of the flow path unit 10 is formed with a number of pressure chamber holes 20a serving as the pressure chambers 31 so as to penetrate the pressure chamber plate 20 in the thickness direction, and the nozzle holes 28a. 5 rows in the X direction are provided in a row along the Y direction. The pressure chamber holes 20 a have an elongated shape in plan view along the short side of the pressure chamber plate 20, and are arranged in parallel so that the longitudinal direction (X direction) is along the long side of the pressure chamber plate 20. The plurality of pressure chamber holes 20a are stacked with the piezoelectric actuators 11 from above and the first spacer plate 21 from below to form a plurality of pressure chambers 31 having an internal space.

  Each of the first spacer plate 21 to the cover plate 27 is formed with a through-opening that serves as a nozzle communication channel 36 that communicates with one end of each pressure chamber 31 and communicates with each nozzle hole 28a. The spacer plate 21, the diaphragm plate 22, and the second spacer plate 23 have communication holes 21 a and 23 a serving as connection channels 33 that communicate the common ink chamber 35 and the other end of the pressure chamber 31, and a long hole shape. A throttle hole 22a is formed.

  Further, the first and second manifold plates 24 and 25 located below the second spacer plate 23 are arranged at the lower position corresponding to the position where the pressure chambers 31 are arranged in the row direction (Y direction). Divided manifold holes 24a, 25a that extend along the thickness of the manifold plates 24, 25a are formed through the manifold plates 24, 25 in the thickness direction, and are provided in five rows in the X direction. In addition, a damper wall 26 a having a concave surface formed opposite to the surface facing the common liquid chamber 35 in the damper plate 26 and having a thin wall thickness corresponds to the shape of the common liquid chamber 35. The second spacer plate 23, the two manifold plates 24 and 25, the damper plate 26, and the cover plate 27 are stacked in this order to form a common liquid chamber 35 and a damper space 26b. Is done. Further, a nozzle plate 28 having a plurality of nozzle holes 28a is laminated and bonded to the cover plate 27 from below.

  With the above configuration, the ink supplied from the ink tank 3 into the flow path unit 10 is guided to the nozzle 28a through the common ink chamber 35, the connection flow path 33, the pressure chamber 31, and the nozzle communication flow path 36 in order. .

  The plates 20 to 25 from the pressure chamber plate 20 to the manifold plates 24 and 25 correspond to four color inks by corresponding the upper and lower positions to one end portion in the longitudinal direction (Y direction). Four color ink supply ports 34 are formed (see FIG. 3). The four colors of ink from the ink tank 3 are independently supplied to the ink supply port 34. In addition, the ink supply port 34 into which frequently used black ink flows is formed in a larger size than the others, and communicates with one end of the two common liquid chambers 35 in the Y direction. It is connected. The other ink supply ports 34 communicate with one end portion in the Y direction of one common liquid chamber 35 independent of each other, and are connected to each ink flow path 10a. Thus, the flow path unit 10 has five ink flow paths 10a, and the inkjet head 6 is configured to be able to eject four types of inks independently of each other.

As shown in FIG. 1, the ink supply port 34 has an ink color of the ink tank 3 mounted on the holder case 4 when the droplet discharge head 6 is attached to the holder case 4 via the support plate 5. Each ink outlet 3a and each ink connection port 5c of the support plate 5 are connected in communication. (See FIG. 1 (b) and FIG. 3)
On the other hand, as shown in FIG. 2, the piezoelectric unit 11 has a rectangular shape that is long in the Y direction in a plan view, and a large number of rectangular piezoelectric sheets 40 to 45 that are long in the Y direction and an insulating top sheet 46 are laminated. Has been configured. The piezoelectric sheets 40 to 45 are made of a lead zirconate titanate (PZT) ceramic material having a thickness of about 30 μm.

Among the piezoelectric sheets 40 to 45, a large number of piezoelectric sheets 41 and 43 that are counted upward from the lowermost piezoelectric sheet 40 are arranged on the upper surface so as to individually correspond to the positions of the pressure chambers 31. The individual electrodes 47 are printed and formed in five rows so as to correspond to the respective rows formed by the pressure chambers 31. In addition, on the upper surface of the odd-numbered piezoelectric sheets 40, 42, 44 counted upward from the lowermost piezoelectric sheet 40, the common electrode 47 is arranged so as to cover all the individual electrodes 47 for each row when viewed in plan. 48 is printed. The individual electrode 47 and the common electrode 48 are external electrodes provided on the top surface of the top sheet 46 via relay wires (not shown) provided on the side end surfaces of the piezoelectric sheets 40 to 45 and the top sheet 46 or through holes (not shown). 49 (see also FIG. 3). The common electrode 48 is grounded. The drive electrode 49 will be described in detail later. The electrodes 47 and 48 and the drive electrode 49 are screen-printed with an Ag—Pd-based conductive material.
The piezoelectric unit 11 has a smaller outer shape than the flow path unit 10 and is disposed so as to expose the ink supply port 34 at one end of the flow path unit 10 in the Y direction. 47 and the pressure chamber 31 of the flow path unit 10 are laminated and joined so as to face each other in a plan view.

  One end of the wiring unit 12 is joined to the upper surface of the piezoelectric unit 11. The wiring unit 12 is a flexible strip-shaped wiring member, and has a plurality of power supply electrodes 50 corresponding to the external electrodes 49 on the upper surface of the piezoelectric unit 11, and the power supply electrodes 50 are connected to the other end of the wiring unit 12. It is electrically connected to a provided IC chip 51 (see FIG. 3) by a lead wire (not shown). The wiring unit 12 is laminated on the upper surface of the piezoelectric unit 11, and the power supply electrode 50 and the external electrode 49 are electrically connected by solder.

  The droplet discharge head 6 having such a configuration operates as follows and discharges ink droplets from the nozzle holes 28a. Ink is supplied from the ink outlet 3 a of the ink tank 3 to the ink connection hole 5 c and the ink supply port 34 of the support plate 5. A filter (not shown) is attached to the ink supply port 34. The ink supplied from the ink supply port 34 into the flow path unit 10 is filled in the ink flow path 10 a including the common liquid chamber 35, the throttle passage 33, the pressure chamber 31, and the nozzle passage 36. In this state, when the driver IC 51 selectively applies a driving potential from the wiring unit 12 to the piezoelectric unit 11 according to the print data and selectively sets the plurality of individual electrodes 47 to a predetermined potential, the driver IC 51 is common to the individual electrodes 47 to which the potential is applied. A potential difference is generated between the electrode 48 and an electric field acts on the active portions of the piezoelectric sheets 41 to 44 to cause distortion in the stacking direction. Here, the active portion refers to a portion sandwiched between the individual electrode 47 and the common electrode 48 in each of the piezoelectric sheets 41 to 44, and substantially refers to a portion where distortion deformation in the stacking direction as described above occurs. When the active portion is deformed in this manner, the piezoelectric sheet protrudes into the corresponding pressure chamber 31, so that the internal pressure of the pressure chamber 31 rises and the internal liquid is discharged from the nozzle hole 28 a to the outside through the nozzle passage 36. The

By the way, such a droplet discharge head 6 is supported on the holder case 4 (see FIG. 1) by a support frame 5 having a rectangular frame shape as shown in FIG. More specifically, as shown in FIG. 3, the support frame 5 is a metal plate member having a rectangular shape in plan view, and the outer shape thereof is larger than the outer shape of the flow path unit 10. It has a frame shape in which an opening 5a having a rectangular shape in plan view is formed to penetrate therethrough. Further, four ink connection ports 5c are formed through one end portion in the longitudinal direction (Y direction) of the support frame 5 along the Y direction, and the ink outlet 3a and the ink supply port 34 are communicated with each other. The opening 5a has an opening area that is slightly larger than the outer dimensions of the piezoelectric unit 11 in plan view, and the support frame 5 has the piezoelectric unit 11 to which one end of the wiring unit 12 is connected in the opening 5a, and the wiring unit. The other end of 12 is bonded and fixed to the upper surface 10a of the flow path unit 10 so as to be drawn out from the opening 5a. (See also Fig. 1 (b))
At this time, a gap path 60 is formed between the inner peripheral part 5 b forming the opening 5 a in the support frame 5 and the outer peripheral part 11 a of the piezoelectric unit 11.

  The support frame 5 is attached to the bottom of the holder case 4 with the adhesive 4a in a state where the support frame 5 is bonded and fixed to the flow path unit 10 in this way (see FIG. 1A). This adhesive 4a is applied over the entire circumference of the outer peripheral portion of the support frame 5, and the outside of the support frame 5 from the lower surface of the nozzle plate 28 of the flow path unit 10 (the surface on the side where the nozzle holes 28a open outward). A path that passes through the piezoelectric unit 11 through the adhesive 4a is closed by the adhesive 4a.

Example 1
4 is a plan view of the droplet discharge head 6, and FIG. 5 is a partial cross-sectional view showing a configuration when the droplet discharge head 6 shown in FIG. The configuration in the vicinity thereof is shown enlarged. 4 and 5, the piezoelectric unit 11 is laminated and bonded to the upper surface 10b of the flow path unit 10, and the support frame 5 having the opening 5a is connected to the outer peripheral part 11a of the piezoelectric unit 11. The support frame 5 is disposed so that the inner peripheral portion 5b of the opening 5a is located with a gap therebetween. Bonded and fixed.

  As a result, a gap path 60 having a substantially rectangular cross section is formed by being surrounded by the upper surface 10 b of the flow path unit 10, the outer peripheral portion 11 a of the piezoelectric unit 11, and the inner peripheral portion 5 b of the support frame 5. The air gap path 60 makes a round around the piezoelectric unit 11 along the inner peripheral portion 5b of the support frame 5, and is formed in a groove shape having substantially the same width over the entire circumference. Further, one end of the wiring unit 12 is connected to the upper surface of the piezoelectric unit 11, and a portion 60a of the gap 60 is straddled by the wiring unit 12 extending from the piezoelectric unit 11 (FIG. 4). reference). The cross sectional dimension H in the X-axis direction of the gap path 60 (the dimension width of the gap path in the left-right direction in FIG. 4) is a narrow dimension including a positional deviation between the flow path unit having the piezoelectric unit 11 and the support frame. And about 0.6 mm to 0.9 mm. The cross-sectional dimension of the air gap path 60 may not be substantially the same width over the entire circumference.

As shown in FIG. 5, a protrusion 62 is provided on the bottom surface portion 10 b of the gap 60. As shown in FIG. 4, the protrusion 62 extends along the entire gap 60 along the entire circumference. Is provided. The protrusion 62 in the first embodiment has a portion between the outer shape of the piezoelectric unit 11 and the inner peripheral wall of the support frame 5 on the upper surface of the pressure chamber plate 20 (see FIG. 2) of the flow path unit 10. The pressure chamber plate 20 is formed integrally with the pressure chamber plate 20 by extending upward. As shown in FIG. 5, the inner peripheral portion of the support frame 5 rather than the outer peripheral portion 11 a of the piezoelectric unit 11 in the cross section of the gap path 60. It is formed so as to be close to 5b. Further, the height dimension (protrusion dimension projecting upward from the upper surface 10 b of the flow path unit 10) H ₁ of the protrusion 62 is equal to the height dimension H ₂ in the thickness direction of the piezoelectric unit 11 and the thickness direction of the support frame 5. It is configured to be smaller than any of the height dimension H ₃ . An introduction groove 65 having a smaller gap (smaller cross-sectional width dimension) than the gap path 60 is formed between the protruding portion 62 and the inner peripheral portion 5 b of the support frame 5, and the introduction groove 65. A liquid sealant 66 is injected into the liquid.

  According to the droplet discharge head 6 described above, since the introduction groove 65 having a small width dimension is formed at a position near the support frame 5 at the bottom of the gap path 60, the liquid injected into the gap path 60 is formed. The sealing agent 66 is positively introduced in the extending direction (entire circumference) along the introduction groove 65 by capillary action, and the liquid sealing agent 66 is held in the narrow introduction groove 65. Accordingly, the liquid sealing agent 66 can be easily injected, and the joint between the flow path unit 10 and the support frame 5 is appropriately sealed by the liquid sealing agent 66 injected and held in the introduction groove 65. be able to. In addition, since it is actively introduced into the introduction groove 65, it is not necessary to apply the coating twice, and the number of man-hours can be reduced.

  Here, the capillary phenomenon is a phenomenon in which the liquid moves along the wall surface due to the wettability and surface tension of the liquid as is well known, and as the wettability and surface tension of the liquid sealant 66 increase, Moreover, this phenomenon appears more noticeably as the cross section of the introduction groove 65 is smaller. Therefore, with regard to the introduction groove 65, it is preferable to form the cross-sectional area as small as possible within a practical range where the liquid sealing agent 66 can be injected.

  Note that the liquid sealant 66 is attached to the vicinity of the upper opening of the air gap 60 and the flow path unit 10 located at the deepest part of the air gap 60 and the support frame as compared with the case where the air gap 60 itself is narrowly formed. However, in the present invention, the liquid sealing agent 66 can be appropriately injected without such difficulty.

  Further, since the protrusion 62 is formed when the flow path unit 10 is manufactured, the protrusion 62 and the inner peripheral portion 5b of the support frame 5 can be obtained simply by bonding the flow path unit 10 and the support frame 5. An introduction groove 65 can be formed.

  In addition, for the portion 60 a straddling the wiring unit 12 in the gap 60, when the liquid sealing agent 66 is injected in the vicinity of one end of the portion 60 a, the liquid sealing agent 66 passes under the wiring unit 12. Thus, it is easily introduced toward the other end of the portion 60a. Therefore, it is not necessary to lift up the wiring unit 12 and inject the liquid sealing agent 66, and the injection operation is facilitated, and the wiring unit 12 can be prevented from being peeled off from the piezoelectric unit 11 during the injection operation.

  5 shows a state where the liquid sealing agent 66 is introduced and held in the introduction groove 65 in FIG. 5, but is injected and held in the introduction groove 65, and further the liquid overflowing from the introduction groove 65. The sealing agent 66 is sufficiently injected so that the gap 60 is filled, and ink is applied to the bonding surface between the flow path unit 10 and the piezoelectric unit 11 and the bonding surface between the piezoelectric unit 11 and the wiring unit 12. It is preferable to enhance the sealing effect so as not to enter (see FIG. 1). Further, even if the injection amount of the liquid sealing agent 66 varies, it is possible to prevent the liquid from entering the piezoelectric unit 11 through the joint portion between the flow path unit 10 and the support frame 5. FIG. 6 is a cross-sectional view for explaining the configuration for preventing the liquid from entering the piezoelectric unit 11 in the droplet discharge head 6 according to the amount of liquid sealing agent 66 injected.

FIG. 6A shows a case where the injection amount of the liquid sealing agent 66 is not so large as to sufficiently fill the space 60. Since the height H ₁ of the protrusions 62 is smaller than either of the height H ₃ of height H ₂ and the supporting frame 5 of the piezoelectric unit 11 (see FIG. 5), positively introduced into the introducing groove 65 The liquid sealing agent 66 is sufficiently held in the introduction groove 65, and the liquid sealing agent 66 overflowing from the groove 65 is filled into the gap 60. As a result, at least the ink that enters between the adhesive sheet 61 and the support frame 5 is sealed, and the overflowing liquid sealing agent 66 is cured so as to cover the introduction groove 65, so that a further sealing effect is achieved. Will be demonstrated.

  As shown in FIG. 6B and FIG. 6C, when the injection amount of the liquid sealant 66 is relatively small, the ridge 65a on the support frame 5 side at the bottom of the introduction groove 65, or the ridge. The liquid sealant 66 adheres to the ridge 65b on the 62 side. This is due to a phenomenon in which surface tension acts on the exposed liquid surface and attempts to reduce the exposed area. And when the liquid sealing agent 66 adheres to the ridge part 65a by the side of the support frame 5 like FIG.6 (b), the junction location of the flow-path unit 10 and the support frame 5 can be sealed favorably. it can. In addition, as shown in FIG. 6C, the liquid sealing agent 66 is attached to the ridge 65 b on the ridge 62 side, and the introduction groove 65 is temporarily provided through the joint portion between the flow path unit 10 and the support frame 5. Even if liquid enters, the protrusion 62 serves as a breakwater, so that liquid can be prevented from entering the piezoelectric unit 11.

Further, since the protrusion 62 is provided, the liquid sealing agent 66 can be easily introduced into at least the introduction groove 65 with respect to the narrow gap 60, and the liquid droplet ejection head When 6 is downsized, the liquid sealing agent 66 can be injected even when the width dimension of the gap path 60 is narrowed.
In addition, the width dimension Ha (width dimension Ha on the right side in the X direction in FIG. 4) of the gap path 60 on the side straddling the other end side of the wiring unit 12 is the width dimension of the other side gap path. It is desirable that it is slightly larger than Hb (width dimension Hb on the left side in the X direction in FIG. 4) (for example, Ha = 0.9 mm, Hb = 0.6 mm). Since the gap path 60 on the side crossed by the other end side of the wiring unit 12 is a boundary of solder joint on one end side of the piezoelectric unit 11 and the wiring unit 12, a liquid sealing agent is used to increase the reliability of the sealing effect. Preferably, 66 is introduced more into the wide gap path 60.

  Further, in the above-described embodiment, the configuration in which the protruding portion 62 is formed over the entire circumference of the gap path 60 has been described, but the present invention is not limited to this. For example, the protrusions 62 may be formed only in the lower part 60 a of the wiring unit 12 that is considered to be most difficult to perform the injection operation in the gap path 60, or may be formed in other parts of the gap path 60. Furthermore, the protrusions 62 may be intermittently formed at a plurality of locations along the gap path 60.

(Example 2)
FIG. 7 is a partial cross-sectional view of the droplet discharge head 6, and shows another form of the protrusion 62 that the droplet discharge head 6 has. As shown in FIG. 7, a linear member 70 having a circular shape in cross section, which forms a protrusion 62, is disposed in the gap path 60 of the droplet discharge head 6. The linear member 70 is formed, for example, by bending a metal wire or the like into a rectangular frame shape, and extends over the entire circumference along the gap 60 similarly to the protruding portion 62 shown in FIG. Has been. An introduction groove 65 is formed between the linear member 70 and the inner peripheral portion 5 b of the support frame 5. Since other configurations are the same as those already described, the corresponding components are denoted by the same reference numerals, and the description thereof is omitted.

  According to such a droplet discharge head 6, after the piezoelectric unit 11 and the support frame 5 are bonded to the flow path unit 10, the introduction groove 65 is formed simply by placing the linear member 70 in the gap path 60. be able to. Therefore, it is not necessary to change the design of the flow path unit 10, the piezoelectric unit 11, and the support frame 5 from the conventional ones, and only the linear member 70 is added.

  Further, since the surface of the linear member 70 having a circular shape in cross section is a curved surface (circular in a cross sectional view), when the liquid sealing agent 65 is introduced into the introduction groove 65, the linear member 70 and the bottom surface are arranged. Since a capillary force as shown by an arrow in FIG. 7 acts in a narrow space (ridge portion 65b) with the portion 11b, it can be expected that introduction into the introduction groove 65 and the ridge portion 65b is performed smoothly. Therefore, even when the injection amount of the liquid sealing agent 66 is relatively small, when a small amount of the liquid sealing agent 66 adheres to the ridge 65a on the support frame 5 side, it is the same as the case shown in FIG. Moreover, the support frame 5 and the flow path unit 10 can be well sealed. On the other hand, when adhering to the ridge 65b on the ridge 62 side (that is, the linear member 70 side), the lower part of the linear member 70 and the upper surface 10b of the flow path unit 10 are joined so as not to generate a gap. . Accordingly, the linear member 70 plays the role of a breakwater like the protruding portion 62 shown in FIG. 6C, and the liquid is retained in the introduction groove 65 to prevent the penetration to the piezoelectric unit 11 side. be able to.

  The linear member 70 does not need to be disposed over the entire circumference of the gap path 60, and may be disposed only below the wiring unit 12, for example, and corresponds to the four straight portions of the gap path 60. Then, the linear member 70 divided into four parts may be arranged at various places. In addition to the metal wire, a synthetic resin wire may be used as the linear member 70, and the cross-sectional shape is not limited to a circle, and may be a polygon such as a rectangle or an ellipse. Further, the linear member 70 may be a single-winding, multi-winding, or coiled. Further, the liquid sealing agent 66 is shown in a state where it is introduced and held in the introduction groove 65 in FIG. 7. However, the liquid sealant 66 is injected and held in the introduction groove 65, and further, the liquid overflowing from the introduction groove 65. The sealing agent 66 is sufficiently injected so that the gap 60 is filled, and ink is applied to the bonding surface between the flow path unit 10 and the piezoelectric unit 11 and the bonding surface between the piezoelectric unit 11 and the wiring unit 12. The sealing effect is strengthened so as not to enter.

(Example 3)
FIG. 8 is a partial cross-sectional view of the droplet discharge head 6 and shows another form of the introduction groove 65 of the droplet discharge head 6. As shown in FIG. 8, the support frame 5 extends along the gap 60 at the ridge portion 5 d of the lower surface 5 c facing the flow path unit 10 and opens toward the inner peripheral portion 5 b of the support frame 5. A notch 71 is formed. The notch 71 and the upper surface 10 b of the flow path unit 10 form an introduction groove 65 having a smaller cross-sectional dimension than the gap path 60. Since other configurations are the same as those already described, the corresponding components are denoted by the same reference numerals, and the description thereof is omitted.

  According to such a droplet discharge head 6, the introduction groove 65 can be formed simply by bonding the flow path unit 10 and the support frame 5. In addition, the introduction groove 65 is adjacent to a joint portion between the flow path unit 10 and the support frame 5, and a sealing effect can be more effectively exhibited by injecting the liquid sealing agent 66.

  Note that the notch 71 does not need to be formed over the entire circumference of the gap 60, and the cross-sectional shape of the notch 71 is not particularly limited. Further, it may be formed only below the wiring unit 12, or may be formed partially along the gap path 60 or intermittently along the gap path 60. Further, the configuration of the gap path 60 may be appropriately adapted depending on the viscosity and type of the liquid sealant 66 to be used. Further, although the liquid sealing agent 66 is shown in a state of being introduced and held in the introduction groove 65 in FIG. 8, the liquid sealant 66 is injected and held in the introduction groove 65 and further the liquid overflowing from the introduction groove 65. The sealing agent 66 is sufficiently injected so that the gap 60 is filled, and ink is applied to the bonding surface between the flow path unit 10 and the piezoelectric unit 11 and the bonding surface between the piezoelectric unit 11 and the wiring unit 12. The sealing effect is strengthened so as not to enter.

  As described above, the support frame 5 is disposed in the gap 60 so that unexpected ink does not enter through a slight gap between the lower surface of the support frame 5 and the adhesive sheet 61 on the upper surface of the flow path unit 10. Since the introduction groove 65 is provided on the inner peripheral wall side, and the liquid sealing agent 66 is configured to actively enter the introduction groove 65 by capillary force, at least the connection between the support frame 5 and the flow path unit 10 is achieved. Infiltration of ink from the surface can be prevented. Further, since the liquid sealing agent 66 overflowing from the introduction groove 65 is filled in the gap 60 in a state where the liquid sealing agent 66 is introduced and held in the introduction groove 65, a sealing effect is further exhibited. be able to. In addition, since the introduction groove 65 is provided in a portion of the gap path 60 where the wiring unit 12 is drawn and straddles the gap path 60, the liquid sealing agent 66 is introduced without lifting the wiring unit 12 by handling. Since it can be injected into the groove 65, the wiring unit 12 can be prevented from peeling off from the piezoelectric unit 11. Furthermore, when the liquid sealant 66 is introduced, it is easily and smoothly introduced into the introduction groove 65, so that it is not necessary to apply the coating twice and the number of steps can be reduced. In addition, since the liquid sealing agent 66 can be easily introduced into the narrow gap 60 by the introduction groove 65, even if the gap 60 is further narrowed with respect to the downsizing of the droplet discharge head 6. This can be handled in a sufficiently sealable state.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a droplet discharge head that can easily and appropriately seal a joint portion between a flow path unit and a support frame by injecting a liquid sealant.

FIG. 2 is a cross-sectional view of a carriage including a droplet discharge head according to the present embodiment, taking an inkjet printer head as an example, and (a) shows a cross-sectional view when the droplet discharge head is viewed from one side; (B) is a cross-sectional view of the droplet discharge head taken along the line AA in (a). FIG. 2 is an enlarged cross-sectional view of a droplet discharge head provided in the carriage shown in FIG. It is a perspective view when a droplet discharge head is disassembled into a flow path unit, a piezoelectric unit, a wiring unit, and a support frame. It is a top view of a droplet discharge head. FIG. 5 is a partial cross-sectional view illustrating a configuration when the droplet discharge head illustrated in FIG. 4 is cut along a VV line, and illustrates an enlarged configuration of a gap path and its vicinity. FIG. 6 is a cross-sectional view for explaining a configuration for preventing liquid from entering the piezoelectric unit in the droplet discharge head according to the amount of liquid sealing agent injected, and FIG. In this case, (b) shows an example when the injection amount is relatively small, and (c) shows another example when the injection amount is relatively small. It is a fragmentary sectional view of a droplet discharge head, and shows other forms of a projection part which this droplet discharge head has. It is a fragmentary sectional view of a droplet discharge head, Comprising: The other form of the introduction groove | channel which this droplet discharge head has is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 Support frame 6 Droplet discharge head 10 Flow path unit 10a Liquid flow path 11 Piezoelectric unit 12 Wiring unit 60 Cavity path 62 Projection part 65 Introduction groove 66 Liquid sealing agent 70 Linear member 71 Notch part

Claims (7)

A flow path unit having a liquid flow path up to a nozzle hole for discharging a droplet;
A piezoelectric unit that is stacked on the flow path unit, has an outer dimension smaller than that of the flow path unit, and applies a discharge pressure to the liquid to discharge a droplet from the nozzle hole;
A frame surrounding the piezoelectric unit, and a support frame that supports the channel unit by adhering and fixing to the flow path unit;
Between the outer peripheral part of the piezoelectric unit and the inner peripheral part of the support frame, a gap path extending along the inner peripheral part of the support frame and filled with a liquid sealant is formed,
An introduction groove for urging and holding the liquid sealant is provided along the gap path in the vicinity of the inner periphery of the support frame in the gap path. Droplet discharge head.   A portion of the upper surface of the flow path unit that forms the bottom surface of the air gap is provided with a protrusion extending along the air gap, and is sandwiched between the protrusion and the inner peripheral portion of the support frame. The droplet discharge head according to claim 1, wherein the introduction groove is formed.   3. The liquid droplet ejection according to claim 2, wherein a height dimension of the protruding portion protruding from the upper surface of the flow path unit is smaller than dimensions in the thickness direction of the piezoelectric unit and the support frame. head.   4. The droplet discharge head according to claim 2, wherein the protrusion is formed such that a part of an upper surface member of the flow path unit extends upward. 5.   A linear member forming the protrusion is disposed along the gap in the gap, and the introduction groove is formed between the linear member and the inner periphery of the support frame. The droplet discharge head according to claim 2, wherein the droplet discharge head is formed.   A notch portion that extends along the gap and opens to the inner peripheral side of the support frame is formed at a portion of the support frame facing the flow channel unit, and an upper surface of the flow channel unit. The droplet discharge head according to claim 1, wherein the introduction groove is formed by the cutout portion and the cutout portion. In order to generate the discharge pressure in the piezoelectric unit, further comprising a strip-shaped wiring unit for supplying a driving voltage to the piezoelectric unit,
One end of the wiring unit is stacked on the piezoelectric unit, and the other end is drawn outwardly through an opening formed by the inner periphery of the support frame and across a part of the gap path,
7. The droplet discharge head according to claim 1, wherein the introduction groove is provided at least in a portion where the wiring unit straddles the gap path.

Images