JP2017144664A - Inkjet head and inkjet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet head which enables a plate-like member provided with a nozzle to be properly adhered to a structure forming a passage, and to provide an inkjet device.SOLUTION: An inkjet head includes: a pressure chamber which is filled with an ink; an actuator which changes a pressure of the ink filling the pressure chamber; a lower member (a plate-like member) 40b provided with a nozzle 41 for discharging the ink; a communication passage 54 which connects the pressure chamber with the nozzle 41; an upper member 40a provided with the communication passage and to which the lower member (the plate-like member) 40b is adhered; and a recessed part 42 which is provided on a nozzle 41 side surface of the upper member 40a so as to enclose the communication passage 54.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an inkjet head that ejects ink onto a printing surface and an inkjet apparatus that uses the inkjet head.

  An inkjet apparatus is an apparatus that performs printing or drawing on a printing surface by ejecting ink from an inkjet head. An ink jet head mounted on an ink jet apparatus applies pressure to a pressure chamber for filling ink, a flow path for guiding ink to the pressure chamber, a nozzle connected to the pressure chamber, and ink filled in the pressure chamber. Actuator. By driving the actuator to increase the pressure in the pressure chamber, ink filled in the pressure chamber is ejected from the nozzle.

JP 2005-244174 A

  In the ink jet head having the above-described configuration, each pressure chamber and each nozzle are connected by mounting a plate-like member having a large number of nozzles on a structure constituting the flow path. Here, the plate-like member is attached to the structure using an adhesive. In this case, if the amount of the applied adhesive is large, the adhesive may flow into the nozzle during the bonding, and the discharge performance of the nozzle may decrease. On the other hand, if the amount of adhesive applied is small, adjacent nozzles cannot be reliably partitioned by the adhesive layer, and air leakage may occur between these nozzles. Even when air leaks occur in this way, the ink ejection accuracy decreases. Such a problem becomes conspicuous particularly in a configuration in which the interval between the nozzles is reduced to increase the ink density.

  In view of such a problem, an object of the present invention is to provide an ink jet head and an ink jet apparatus capable of appropriately bonding a plate-like member on which a nozzle is formed to a structure constituting a flow path.

  A first aspect of the present invention relates to an inkjet head. An ink jet head according to a first aspect includes a pressure chamber filled with ink, an actuator that changes the pressure of the ink filled in the pressure chamber, and a plate-like member on which a nozzle for ejecting ink is formed. A communication channel connecting the pressure chamber and the nozzle, a structure in which the communication channel is formed and the plate-like member is bonded, and the nozzle side of the structure so as to surround the communication channel And a concave portion provided on the surface.

  According to the ink jet head according to this aspect, even if the adhesive is applied in many ways, the excess adhesive is prevented from collecting in the recess and flowing into the nozzle. Therefore, there is no need to worry about the flow into the nozzle when the plate member is bonded, and a sufficient amount of adhesive can be used. Thereby, the problem of the air leak between nozzles can also be solved.

  A second aspect of the present invention relates to an inkjet head. An ink jet head according to a second aspect includes a pressure chamber filled with ink, an actuator that changes the pressure of the ink filled in the pressure chamber, and a plate-like member on which nozzles for ejecting ink are formed. A communication channel connecting the pressure chamber and the nozzle, a structure in which the communication channel is formed and the plate-like member is bonded, and the nozzle side of the structure so as to surround the communication channel And a protrusion provided on the surface.

  According to the ink jet head according to this aspect, even if the adhesive is applied in many ways, the excess adhesive is blocked by the protrusions and is prevented from flowing into the nozzle. Therefore, there is no need to worry about the flow into the nozzle when the plate member is bonded, and a sufficient amount of adhesive can be used. Thereby, the problem of the air leak between nozzles can also be solved.

  A third aspect of the present invention relates to an ink jet apparatus. An ink jet apparatus according to a third aspect includes the ink jet head according to the first aspect or the second aspect, and an ink supply unit that supplies ink to the ink jet head.

  According to the ink jet device according to the third aspect, since the ink jet head according to the first aspect or the second aspect is used, the plate-like member on which the nozzle is formed can be appropriately adhered to the structure as described above. For this reason, the performance of an inkjet apparatus can be improved.

  As described above, according to the ink jet head and the ink jet device of the present invention, the plate-like member on which the nozzle is formed can be appropriately bonded to the lower surface of the structure constituting the flow path.

  The effects and significance of the present invention will become more apparent from the following description of embodiments. However, the embodiment described below is merely an example when the present invention is implemented, and the present invention is not limited to what is described in the following embodiment.

FIG. 1A is a diagram illustrating a configuration of the inkjet head according to the first embodiment, and FIG. 1B is a diagram schematically illustrating a configuration in which the actuator according to the first embodiment and the structure are combined. 2A is an enlarged view of a part of the actuator and the structure according to the first embodiment, and FIG. 2B is a diagram schematically illustrating the main flow path and the pressure chamber according to the first embodiment. It is. FIG. 2C is a diagram schematically illustrating an arrangement of nozzles in the structure according to the first embodiment. FIG. 3 is a partial perspective view illustrating a configuration in the vicinity of the pressure chamber according to the first embodiment. 4A is a cross-sectional view schematically showing the structure around the nozzle before bonding the lower member and the upper member according to the first embodiment, and FIG. 4B is a lower view according to the first embodiment. It is sectional drawing which shows typically the structure of the nozzle periphery after adhere | attaching a member and an upper member. FIG. 5 is a plan view illustrating a configuration around a nozzle of the lower member according to the first embodiment. FIG. 6 is a plan view showing a configuration around the communication channel of the upper member according to the first embodiment. 7A and 7B are cross-sectional views schematically showing the flow of the adhesive in the bonding process according to the comparative example. 7C and 7D are cross-sectional views schematically showing the flow of the adhesive in the bonding process according to the first embodiment. FIG. 8 is a block diagram illustrating a configuration of the ink jet apparatus according to the first embodiment. 9A is a cross-sectional view schematically showing a structure around the nozzle before bonding the lower member and the upper member according to the second embodiment, and FIG. 9B is a lower view according to the second embodiment. It is sectional drawing which shows typically the structure of the nozzle periphery after adhere | attaching a member and an upper member. FIGS. 10A and 10B are cross-sectional views schematically showing the flow of the adhesive in the bonding process according to the comparative example. FIGS. 10C and 10D are cross-sectional views schematically showing the flow of the adhesive in the bonding process according to the second embodiment. Fig.11 (a) is sectional drawing which shows typically the structure of the periphery of the nozzle which concerns on the example of a change, and the flow of the adhesive agent in an adhesion process. FIG. 11B is a cross-sectional view schematically showing the configuration of the periphery of the nozzle according to another modification and the flow of the adhesive in the bonding step.

<Embodiment 1>
Embodiment 1 of the present invention will be described below with reference to the drawings. For convenience, the X, Y, and Z axes that are orthogonal to each other are appended to each drawing. The Z-axis direction is the height direction of the inkjet head 1, and the positive Z-axis direction is the downward direction. Further, the X-axis direction is the thickness direction of the inkjet head 1, and the Y-axis direction is the width direction of the inkjet head 1. The inkjet head 1 ejects ink in the positive Z-axis direction (downward).

  FIG. 1A is a diagram illustrating a configuration of the inkjet head 1 according to the first embodiment, and FIG. 1B schematically illustrates a configuration in which the actuator 30 according to the first embodiment and the structure 40 are combined. FIG.

  As shown in FIG. 1A, the inkjet head 1 includes a storage box 10 and a head base 20. The storage box 10 is detachable from the head base 20.

  The storage box 10 is a rectangular box whose bottom surface is open. A cutout 10a connected to the inside is provided on the upper surface of the storage box 10, and the circuit board 11 is stored in the storage box 10 through the cutout 10a. A drive circuit for driving the actuator 30 is mounted on the circuit board 11. Circular holes 10b are respectively provided on the Y axis positive side and the Y axis negative side of the notch 10a. The hole 10 b is for guiding an ink supply tube (not shown) to the inside of the storage box 10.

  The head base 20 is composed of a frame having a rectangular opening 20a penetrating vertically. The actuator 30 and the structure 40 shown in FIG. 1B are installed at the lower end of the opening 20a. The actuator 30 is electrically connected to the circuit board 11 by FPC (Flexible Printed Circuits) in the opening 20a.

  As shown in FIG.1 (b), the actuator 30 consists of a plate body which has a rectangular outline. The actuator 30 is overlaid on the upper surface of the structure 40. The structure 40 is a plate having a rectangular outline. In the structure 40, four main flow paths 51 arranged in the X-axis direction are formed.

  Four ink supply ports 30a are formed side by side in the X-axis direction at the Y-axis positive end and the Y-axis negative end of the actuator 30, respectively. Each of the two ink supply ports 30a arranged in the Y-axis direction is connected to one independent main channel 51.

  Fig.2 (a) is the figure which expanded the edge part by the side of the Y-axis positive side of the structure of FIG.1 (b).

  A groove is formed on the back surface of the actuator 30. By overlapping the actuator 30 on the structure 40, a pressure chamber 52 is formed between the groove on the back surface of the actuator 30 and the upper surface of the structure 40. The pressure chamber 52 is connected to the main flow path 51 via a communication flow path 53 (see FIG. 2B) formed in the structure 40.

  Note that a terminal group (not shown) for connecting the FPC of the circuit board 11 is provided on each of the X-axis negative side end and the X-axis positive side end of the upper surface of the actuator 30. This terminal group is for applying a voltage (drive signal) to the piezoelectric layer 34 (see FIG. 2B) of the actuator 30.

  As described above, the end of the main channel 51 is connected to the ink supply port 30a. A large number of pressure chambers 52 are arranged along the main flow path 51, and each pressure chamber 52 is connected to the main flow path 51 by each communication flow path 53 (see FIG. 2B).

  Referring back to FIG. 1B, tubes (not shown) are individually fitted into the eight ink supply ports 30a, and ink is supplied to the tubes from ink supply tubes (not shown). . The tube is supported by a support member disposed in the opening 20a, and a tube for supplying ink to the tube is drawn out through the hole 10b. Ink is supplied to the ink supply port 30a through the ink supply tube and the tube. As a result, ink is supplied to the pressure chamber 52 through the main channel 51 and the communication channel 53.

  The same color ink is supplied to the two ink supply ports 30a arranged in the Y-axis direction, and different color inks are supplied to the four ink supply ports 30a arranged in the X-axis direction. Therefore, in the configuration shown in FIG. 1B, four colors of ink are supplied to the actuator 30. As a result, the pressure chambers 52 arranged in the Y-axis direction are filled with the same color ink, and the pressure chambers 52 arranged in the X-axis direction are filled with inks of different colors. A combination of the actuator 30 and the structure 40 is installed at the lower end of the opening 20 a of the head base 20. Therefore, four colors of ink are ejected from the lower surface of the head base 20.

  Note that the same color ink may be supplied to the four main flow paths 51. Alternatively, the same color ink is supplied to the two main flow paths on the X axis positive side, and the two main flow paths on the X axis negative side are different in color from the two main flow paths on the X axis positive side, Ink of the same color may be supplied.

  2B, the pressure chamber 52 in the vicinity of the X-axis positive side (right side) of FIG. 2A is cut along a plane parallel to the XZ plane at the center position in the Y-axis direction of the pressure chamber 52. It is sectional drawing which shows a cross section typically.

  The ink 60 that has flowed into the main channel 51 passes through the communication channel 53 and fills the pressure chamber 52. The structure 40 includes an upper member 40 a having a main channel 51 and communication channels 53 and 54 and a lower member 40 b having a nozzle 41. In the lower member 40b, a substantially circular hole serving as the nozzle 41 is formed in a portion of the communication channel 54 extending from the pressure chamber 52 in the positive Z-axis direction. The nozzle 41 gradually decreases in diameter toward the positive direction of the Z axis, and the diameter is uniform in the vicinity of the outlet.

  The lower member 40b is a thin plate-shaped plate member made of metal. Further, a recess 42 is formed on the surface of the upper member 40a on the nozzle 41 side so as to surround the communication channel 54. The configuration of the nozzle 41 and the recess 42 will be described later with reference to FIGS. 4 (a) and 4 (b), FIG. 5 and FIG. The lower member 40b corresponds to the “plate member” described in the claims, and the upper member 40a corresponds to the “structure” described in the claims.

  The actuator 30 is configured by laminating a diaphragm layer 32, an insulating layer 33, a piezoelectric layer 34, and an electrode layer 35 on the pressure chamber layer 31. The diaphragm layer 32, the insulating layer 33, the piezoelectric layer 34, and the electrode layer 35 are formed by a vacuum film forming technique such as sputtering. These layers may be formed by other film forming techniques such as coating. The pressure chamber layer 31 is formed by a thick film forming technique such as a plating method or a metal plate etching method. By attaching the upper member 40 a to the lower surface of the pressure chamber layer 31, the pressure chamber 52 is formed. The diaphragm layer 32 is made of a conductive metal material and also serves as a lower electrode (common electrode) of the piezoelectric layer 34. The insulating layer 33 insulates the diaphragm layer 32 from the piezoelectric layer 34. That is, the insulating layer 33 shields voltage application to the piezoelectric layer 34 other than the piezoelectric functional region R1.

  The piezoelectric layer 34 is made of, for example, lead zirconate titanate (PZT). The film thickness of the piezoelectric layer 34 is about several μm. The electrode layer 35 is formed of a conductive material. The electrode layer 35 is formed from titanium containing a noble metal, for example. The film thickness of the electrode layer 35 is about 0.2 μm.

  When a voltage is applied to the electrode layer 35, the piezoelectric layer 34 is deformed in the Z-axis direction in the piezoelectric functional region R1, and accordingly, the diaphragm layer 32 is deformed. When the diaphragm layer 32 is deformed downward in the piezoelectric function region R1, the volume of the pressure chamber 52 is reduced, and the pressure of the ink 60 filled in the pressure chamber 52 is increased. Thereby, the droplet 61 of the ink 60 is ejected from the nozzle 41.

  Each of the pressure chamber layer 31, the diaphragm layer 32, the insulating layer 33, the piezoelectric layer 34, and the electrode layer 35 is not necessarily a single layer, and may be formed of a plurality of layers. Further, another layer may be disposed between the layers.

  FIG. 2C is a diagram schematically showing the arrangement of the nozzles 41 in the structure 40.

  As shown in FIG. 2C, the structure body 40 has a plurality of nozzles 41 arranged in one direction. In the structure 40, rows L1 to L4 of four nozzles 41 are arranged. For example, 200 nozzles 41 are provided at regular intervals in each of the rows L1 to L4. The number of nozzles 41 in each row is not limited to this.

  In the first embodiment, as will be described later, the group of nozzles 41 respectively arranged in the rows L1 to L4 are not arranged in a straight line microscopically but meander in the X-axis direction with a constant swing width. (See FIG. 5). Thereby, the density of these nozzles 41 can be increased while shrinking the arrangement region of the group of nozzles 41 in the Y-axis direction.

  FIG. 3 is a partial perspective view showing a cross section of the configuration in the vicinity of the pressure chamber 52. FIG. 3 shows a cross section in which the actuator 30 and the structure 40 are cut so as to pass through the center of the nozzle 41 in a plane parallel to the XZ plane.

  As shown in FIG. 3, the upper member 40 a of the structure 40 is configured by stacking plate-like bodies 411 and 412, seven plate-like bodies 413, and a plate-like body 414. Each of the plate-like bodies 411 to 414 has a predetermined thickness, and has the same contour as that of the structure body 40 in plan view. The seven plate-like bodies 413 have the same structure. A thin damper 415 is sandwiched between the first and second plate-like bodies 413 from the bottom. The damper 415 is for absorbing a pressure wave applied from the communication channel 53 to the main channel 51 when the actuator 30 is driven and the diaphragm layer 32 is displaced downward (Z-axis positive direction). is there.

  In the plate-like bodies 411 and 412, long holes 411 a and 412 a for forming the communication channel 54 are formed, respectively. In the long holes 411a and 412a, the X-axis direction is the longitudinal direction. In plan view, each of the long holes 411a and 412a has an oval outline that is long in the X-axis direction. More specifically, the long hole 411a has an outline in which the ends of two semicircular arcs facing each other are connected by a straight line. The long hole 412a has an outline in which two semicircular arcs similar to the long hole 411a are connected by a straight line shorter than the long hole 411a.

  The seven plate-like bodies 413 are formed with holes 413 a for forming the communication channel 54. The hole 413a is substantially circular. The plate-like body 414 and the damper 415 are also formed with holes 414a and 415a for forming the communication channel 54, respectively. The diameters of the holes 414a and 415a are substantially the same as the diameter of the hole 413a. The seven holes 413a have the same center. The centers of the holes 414a and 415a coincide with the center of the hole 413a. The center of the nozzle 41 coincides with the center of the holes 413a, 414a, 415a.

  The center of the long hole 412a coincides with the center of the hole 413a in the Y-axis direction, and deviates in the X-axis negative direction from the center of the hole 413a in the X-axis direction. Further, the center of the long hole 411a coincides with the center of the long hole 412a in the Y-axis direction, and is shifted from the center of the long hole 412a in the X-axis negative direction in the X-axis direction. In plan view, the X-axis positive side edge of each of the long holes 411a and 412a coincides with the X-axis positive side edge of the hole 413a.

  In the plate-like bodies 412, 413, openings 412b, 413b are formed in regions corresponding to the main flow paths 51, respectively. The opening 412b is narrower in the X-axis direction than the opening 413b. In plan view, the edge on the X axis positive side of the opening 412b coincides with the edge on the X axis positive side of the opening 413b. The main flow path 51 is partitioned by a damper 415.

  The plate-like body 411 has an opening 411 b in a region corresponding to the communication channel 53. A filter 411 c is formed at the bottom of the opening 411 b, that is, at the inlet of the communication channel 53. The filter 411c is provided with a large number of holes H1 having a diameter of about several μm. The diameter of the hole H1 provided in the filter 411c is slightly smaller than the diameter of the outlet of the nozzle 41. For example, the diameter of the outlet of the nozzle 41 is 20 μm, and the diameter of the hole H1 of the filter 411c is 15 μm. In plan view, the opening 411b has a hexagonal outline that is long in the X-axis direction. In addition, the opening 411b may have an oval outline that is long in the X-axis direction, for example, an outline in which the ends of two semicircular arcs facing each other are connected by a straight line.

  The long hole 411a, the hole 412a, and the opening 411b described above may have a large circular shape. However, the pitch of the nozzles 41 cannot be reduced and hinders high-density printing. It is preferable to do.

  The opening 411b is arranged so as to be shifted from the pressure chamber 52 in the X-axis direction so that the X-axis positive side overlaps the pressure chamber 52 and the X-axis negative side does not overlap the pressure chamber 52. Further, the filter 411 c is disposed in the entire area of the inlet of the communication channel 53. As a result, a gap is formed between the X-axis negative side portion of the filter 411c and the lower surface of the pressure chamber layer 31, and this gap is also an ink flow path.

  On the X-axis negative side of the opening 411b, the ink that has passed through the filter 411c from the main channel 51 passes through the gap between the filter 411c and the lower surface of the pressure chamber layer 31, and then the pressure chamber from the X-axis positive side of the opening 411b. Enter 52. When the actuator 30 is driven to increase the pressure in the pressure chamber 52, the ink filled in the pressure chamber 52 passes through the communication channel 54 constituted by the long holes 411a, 412a and the holes 413a, 414a, 415a, and the nozzle 41 It is discharged from.

  As shown in FIG. 3, in the first embodiment, the upper member 40a of the structure 40 is configured by stacking a plurality of plate-like bodies 411, 412, 413, 414, and the lower member 40b is bonded to the lower surface of the upper member 40a. It is joined using an agent. Further, the upper member 40 a is bonded to the lower surface of the pressure chamber layer 31, and the structure 40 including the upper member 40 a and the lower member 40 b is attached to the actuator 30. That is, the pressure chamber 52 and the communication channel 54 are connected by bonding the structure 40 having the communication channel 54 to the actuator 30. At the same time, the pressure chamber 52 and the communication channel 53 are connected.

  By the way, as mentioned above, joining of the lower member 40b with respect to the upper member 40a is performed using an adhesive agent. In this case, if the amount of the applied adhesive is large, excess adhesive is pushed out from the gap between the upper member 40a and the lower member 40b, and the pushed-out adhesive flows into the nozzle 41. Can happen. In this case, the flow of ink is hindered by the adhesive flowing into the nozzle 41, and the ejection performance of the nozzle 41 is degraded. On the other hand, if the amount of adhesive applied is small, the adjacent nozzles 41 may not be reliably partitioned by the adhesive layer, and air leakage may occur between these nozzles. When an air leak occurs in this way, a part of the ink to be ejected from one nozzle 41 flows into the nozzle 41 adjacent to the nozzle 41, and as a result, the ink ejection accuracy at both nozzles 41 decreases.

  On the other hand, in the first embodiment, as described above, the recess 42 is formed on the surface of the upper member 40a on the nozzle 41 side so as to surround the communication channel 54. For this reason, even if the adhesive is applied multiple times, the excess adhesive is prevented from collecting in the recess 42 and flowing into the nozzle 41. Therefore, there is no need to worry about the adhesive flowing into the nozzle 41 when the lower member 40b is bonded to the upper member 40a, and the bonding can be performed using a sufficient amount of the adhesive. Thereby, joining of the lower member 40b with respect to the upper member 40a can be strengthened, and the problem of air leakage between the adjacent nozzles 41 can be solved.

  Hereinafter, the detailed structure of the recessed part 42 and the effect by it are demonstrated.

  4A is a cross-sectional view schematically showing the structure around the nozzle 41 before bonding the lower member 40b and the upper member 40a, and FIG. 4B shows bonding of the lower member 40b and the upper member 40a. It is sectional drawing which shows typically the structure of the nozzle 41 periphery after having performed. Unlike FIGS. 3A and 3B, FIGS. 4A and 4B show cross sections in which the upper member 40a and the lower member 40b are cut so as to pass through the center of the nozzle 41 in a plane parallel to the YZ plane. ing.

  As shown in FIG. 4A, a recess 42 is formed on the lower surface (the surface on the Z-axis positive side) of the upper member 40a so as to surround the communication channel 54. The nozzle 41 includes a cylindrical hole 41a and a conical inclined surface 41b. The recess 42 is formed at a position spaced outward by a predetermined distance from the nozzle 41 side outlet of the communication channel 54. The recess 42 has a ring shape in plan view, and is formed so as to surround the outlet on the nozzle 41 side of the communication channel 54 over the entire circumference. The width of the recess 42 in the radial direction is constant, and the depth is also constant.

  As shown in FIG. 4B, when the lower member 40b is joined to the upper member 40a, the concave portion 42 overlaps the upper surface of the lower member 40b at a position outside the communication channel 54. The communication channel 54 has a larger diameter than the inlet of the nozzle 41 on the communication channel 54 side. For this reason, there is a space of a predetermined distance between the recess 42 and the inlet of the nozzle 41.

  FIG. 5 is a plan view showing a configuration around the nozzle 41 of the lower member 40b. FIG. 5 shows a part of the group of nozzles 41 arranged in any one of the rows L1 to L4 shown in FIG. For convenience, in FIG. 5, the outlet of the communication channel 54 (the hole 414a of the lowermost plate 414) and the recess 42 are indicated by broken lines.

  In FIG. 5, the pitch D3 of the nozzles 41 in the Y-axis direction is, for example, about 300 μm. Further, the diameter D1 of the inlet of the nozzle 41 is, for example, about 100 μm, and the diameter D2 of the hole 41a is, for example, about 20 μm.

  FIG. 6 is a plan view showing a configuration around the communication channel 54 of the upper member 40a. For convenience, the nozzle 41 is shown in broken lines in FIG. In FIG. 6, the lower surface of the upper member 40a and the recessed part 42 are shown by different hatching.

  As shown in FIG. 6, the communication channel 54 is disposed so as to be coaxial with the nozzle 41. The diameter of the outlet of the communication channel 54 is about 150 μm. A recess 42 is formed at a position away from the outlet of the communication channel 54 by, for example, 10 μm to several tens of μm. The width D5 of the concave portion 42 in the radial direction is, for example, about 10 μm to several tens of μm. The depth of the recess 42 is, for example, about 10 μm to several tens of μm.

  The nozzle 41 and the recess 42 are formed by, for example, laser processing. In the processing, the laser beam is irradiated to the lower member 40b or the upper member 40a while being swung around an axis parallel to the Z axis and passing through the center position of the hole 41a. A plurality of nozzles 41 are simultaneously formed on the lower member 40b by a plurality of laser beams. In addition, a plurality of recesses 42 are simultaneously formed in the upper member 40a by a plurality of laser beams.

  As shown in FIG. 5, at the time of joining, an adhesive 70 is applied to the upper surface (the Z-axis negative side surface) of the lower member 40b. In the first embodiment, a thermosetting adhesive is used as the adhesive 70. The adhesive 70 is applied to a region excluding the region R2 having a diameter slightly larger than the diameter of the communication channel 54. In this state, as shown in FIGS. 4A and 4B, the upper member 40a is overlaid on the upper surface of the lower member 40b, and heat treatment is performed. As a result, the adhesive 70 is cured, and the upper member 40a and the lower member 40b are joined. An adhesive other than thermosetting may be used as the adhesive 70.

  FIGS. 7A and 7B are cross-sectional views schematically showing the flow of the adhesive 70 in the bonding process according to the comparative example. In the comparative example, the recess 42 is not formed around the outlet of the communication channel 54.

  As shown in FIG. 7A, the adhesive 70 includes particles 71 having a predetermined particle diameter. The particles 71 have such a strength that they are not crushed even when the upper member 40a is pressed against the lower member 40b with a predetermined pressure during the joining. The particle diameter of the particles 71 is, for example, about 5 μm.

  At the time of joining, the upper member 40a is pressed against the lower member 40b with a predetermined pressure in a state where the adhesive 70 is applied to the upper surface of the lower member 40b as shown in FIG. 7A. Thereby, as shown in FIG.7 (b), the upper member 40a overlaps with the lower member 40b. At this time, if the amount of the applied adhesive 70 is large, excess adhesive 70 may protrude from the gap between the upper member 40 a and the lower member 40 b, and the protruded adhesive 70 may flow into the nozzle 41. Alternatively, a phenomenon in which the nozzle 41 is clogged with the adhesive 70 occurs. In this case, the flow of ink is hindered by the adhesive 70 that has flowed into the nozzle 41, and the ejection performance from the nozzle 41 is reduced.

  In the first embodiment, as shown in FIGS. 7A and 7B, the particles 70 are included in the adhesive 70, and therefore the upper member 40 a and the lower member are used by the particles 71 during bonding. A gap having the same size as the particle diameter of the particles 71 is ensured between them and 40b. That is, even when a predetermined pressure is applied to the upper member 40 a during joining, the gap between the upper member 40 a and the lower member 40 b does not become smaller than the particle size of the particles 71. Thereby, it can suppress that the adhesive agent 70 is extruded from the clearance gap between the upper member 40a and the lower member 40b without limitation.

  However, in order to avoid the problem of air leakage between the nozzles 41 described above, a large amount of adhesive 70 tends to be applied to the upper surface of the lower member 40b. For this reason, even by the action of the particles 71 as described above, it is possible that the excess adhesive 70 is pushed out from the gap between the upper member 40 a and the lower member 40 b and flows into the nozzle 41.

  In the first embodiment, this problem is solved by the recess 42.

  7C and 7D are cross-sectional views schematically showing the flow of the adhesive 70 in the bonding process according to the first embodiment.

  When joining, if the upper member 40a is pressed against the lower member 40b with a predetermined pressure in a state where the adhesive 70 is applied to the upper surface of the lower member 40b as shown in FIG. Then, it is pushed out from the gap between the upper member 40a and the lower member 40b. At this time, even if a slightly larger amount of adhesive 70 is applied to the upper surface of the lower member 40b, as shown in FIG. 7B, the adhesive 70 toward the nozzle 41 accumulates in the recess 42, and the nozzle No flow into 41. Thereby, it is avoided that the adhesive 70 is cured on the inclined surface 41b and the hole 41a of the nozzle 41. Thus, the ink flow is prevented from being hindered by the adhesive 70, and the ejection accuracy of the nozzle 41 is maintained high.

  FIG. 8 is a block diagram illustrating a configuration of the ink jet apparatus according to the embodiment.

  The ink jet apparatus includes an ink supply unit 2, a controller 3, and an interface 4 in addition to the ink jet head 1 having the above configuration.

  The ink supply unit 2 includes the above-described tube for supplying ink to the inkjet head 1, an ink tank connected to the tube, and a pump for supplying ink from the ink tank to the tube. The controller 3 includes a CPU and a memory, and controls the inkjet head 1 and the ink supply unit 2 in accordance with a program held in the memory. The interface 4 receives input of drawing information such as characters and graphics to be printed and outputs the drawing information to the controller 3.

  The controller 3 controls the inkjet head 1 according to the input drawing information, and performs printing or drawing on the printing surface. In this way, ink is ejected from the nozzle 41 corresponding to the print image onto the printing surface, and printing or drawing is performed on the printing surface.

<Effect of Embodiment 1>
As mentioned above, according to Embodiment 1, the following effects are produced.

  As described with reference to FIGS. 7C and 7D, even if the adhesive 70 is applied to the upper surface of the lower member 40b, the excess adhesive 70 accumulates in the recesses 42 and becomes a nozzle. Inflow to 41 is suppressed. Therefore, when the lower member 40b is bonded, there is no need to worry about the flow into the nozzle 41, and a sufficient amount of the adhesive 70 can be applied to the upper surface of the lower member 40b. Thereby, the problem of the air leak between the nozzles 41 can also be solved. As the pitch D3 and the swing width D4 shown in FIG. 5 are reduced and the density of the nozzles 41 is increased, air leaks easily occur between the nozzles 41. As described above, in Embodiment 1, since a sufficient amount of the adhesive 70 can be applied to the upper surface of the lower member 40b, the pitch D3 and the swing width D4 shown in FIG. In addition, the problem of air leakage between the nozzles 41 can be avoided more reliably.

  As shown in FIGS. 4A and 4B, the communication channel 54 is larger in diameter than the inlet of the nozzle 41 on the communication channel 54 side. For this reason, there is a space of a predetermined distance between the recess 42 and the inlet of the nozzle 41. As a result, as shown in FIG. 7D, even if excess adhesive 70 is extruded from the gap between the upper member 40a and the lower member 40b, the extruded adhesive 70 immediately flows into the nozzle 41. There is no. Therefore, it is possible to more reliably prevent the adhesive 70 from flowing into the nozzle 41.

  As shown in FIGS. 4A and 4B, the recess 42 is formed at a position spaced outward by a predetermined distance from the outlet of the connecting channel 54 on the nozzle 41 side. For this reason, compared with the case where the recess 42 is connected to the inner side surface of the communication channel 54, the excess adhesive 70 is accumulated in the recess 42 and is less likely to flow out to the communication channel 54. Therefore, it is possible to more reliably prevent the adhesive 70 from flowing into the nozzle 41.

  As shown in FIGS. 7C and 7D, the adhesive 70 includes particles 71 for keeping the distance between the lower member 40b and the upper member 40a at a predetermined distance. For this reason, even if a predetermined pressure is applied to the upper member 40 a during joining, the gap between the upper member 40 a and the lower member 40 b does not become smaller than the particle size of the particles 71. Thereby, it is suppressed that the adhesive 70 is extruded from the clearance gap between the upper member 40a and the lower member 40b without limitation.

<Embodiment 2>
In the first embodiment, the recess 42 is formed around the outlet of the communication channel 54, but in the second embodiment, a protrusion is formed around the outlet of the communication channel 54.

  9A is a cross-sectional view schematically showing the structure around the nozzle 41 before bonding the lower member 40b and the upper member 40a, and FIG. 9B shows the bonding of the lower member 40b and the upper member 40a. It is sectional drawing which shows typically the structure of the nozzle 41 periphery after having performed.

  As shown in FIG. 9A, a protrusion 43 is formed on the lower surface (the surface on the Z-axis positive side) of the upper member 40 a so as to surround the communication channel 54. The protrusion 43 is formed at a position spaced outward from the outlet of the communication channel 54 by a predetermined distance. The protrusion 43 has a ring shape in a plan view and is formed so as to surround the outlet of the communication channel 54 over the entire circumference. The width of the protrusion 43 in the radial direction is constant, and the height is also constant. The protrusion 43 is formed on the lower surface of the plate-like body 414 (lower member 40b) by, for example, electroforming. In this case, the plate-like body 414 is made of a conductive material.

  As shown in FIG. 9B, when the lower member 40b is joined to the upper member 40a, the protrusion 43 overlaps the upper surface of the lower member 40b at a position outside the connecting flow path 54. The communication channel 54 has a larger diameter than the inlet of the nozzle 41 on the communication channel 54 side. For this reason, there is a space of a predetermined distance between the protrusion 43 and the inlet of the nozzle 41.

  The arrangement of the nozzles 41 in the lower member 40b is the same as in FIG. In the second embodiment, the recess 42 in FIGS. 5 and 6 is replaced with a protrusion 43.

  10C and 10D are cross-sectional views schematically showing the flow of the adhesive 70 in the bonding process according to the second embodiment. Note that the flow of the adhesive 70 in the comparative example is shown in FIGS. 10A and 10B as objects to be compared. Since the comparative example of FIGS. 10A and 10B has the same configuration as the comparative example of FIGS. 7A and 7B, description thereof is omitted here.

  When the upper member 40a is pressed against the lower member 40b with a predetermined pressure in a state where the adhesive 70 is applied to the upper surface of the lower member 40b as shown in FIG. 10C, the excess adhesive 70 is removed from the upper member 40b. It is pushed out from the gap between 40a and lower member 40b. At this time, even if a slightly larger amount of adhesive 70 is applied to the upper surface of the lower member 40b, the adhesive 70 is blocked by the protrusion 43 and flows into the nozzle 41 as shown in FIG. There is nothing. Thereby, it is avoided that the adhesive 70 is cured on the inclined surface 41b and the hole 41a of the nozzle 41. Thus, the ink flow is prevented from being hindered by the adhesive 70, and the ejection accuracy of the nozzle 41 is maintained high.

<Effect of Embodiment 2>
As mentioned above, according to Embodiment 2, the following effects are produced.

  As described with reference to FIGS. 10C and 10D, even if the adhesive 70 is applied to the upper surface of the lower member 40 b, the excess adhesive 70 is blocked by the protrusions 43. The flow into the nozzle 41 is suppressed. Therefore, when the lower member 40b is bonded, there is no need to worry about the flow into the nozzle 41, and a sufficient amount of the adhesive 70 can be applied to the upper surface of the lower member 40b. Thereby, the problem of the air leak between the nozzles 41 can also be solved.

  As shown in FIGS. 9A and 9B, the communication channel 54 is larger in diameter than the inlet of the nozzle 41 on the communication channel 54 side. For this reason, there is a space of a predetermined distance between the protrusion 43 and the inlet of the nozzle 41. As a result, as shown in FIG. 10 (d), even if excess adhesive 70 is pushed out from the gap between the upper member 40a and the lower member 40b, the pushed adhesive 70 immediately flows into the nozzle 41. There is no. Therefore, it is possible to more reliably prevent the adhesive 70 from flowing into the nozzle 41.

  As shown in FIGS. 9A and 9B, the protrusion 43 is formed at a position spaced outward by a predetermined distance from the outlet of the communication channel 54 on the nozzle 41 side. For this reason, compared with the case where the protrusion 43 is formed in the boundary of the communication flow path 54, the space between the protrusion 43 and the inlet_port | entrance of the nozzle 41 can be expanded. Thereby, the excessive adhesive 70 pushed out from the gap between the upper member 40a and the lower member 40b becomes even more difficult to reach the nozzle 41. Therefore, it is possible to more reliably prevent the adhesive 70 from flowing into the nozzle 41.

  As shown in FIG. 10 (d), since the lower surface of the protrusion 43 contacts the upper surface of the lower member 40b, even if a downward pressure is applied to the upper member 40a during joining, the upper member 40a and the lower member The gap between the projections 40b does not become smaller than the height of the protrusion 43. Therefore, in the configuration of the second embodiment, it is not always necessary to contain the particles 71 in the adhesive 70, and the protrusions 43 are prevented from being pushed out from the gap between the upper member 40a and the lower member 40b by the protrusion 43 without limitation. Can be done.

<Example of change>
The first and second embodiments of the present invention have been described above, but the present invention is not limited to these first and second embodiments.

  For example, in the second embodiment, the protrusion 43 is formed at a position outside by a predetermined distance from the outlet of the communication channel 54. However, as shown in FIGS. , It may be formed along the boundary of the outlet of the communication channel 54. In this case, an area that overlaps the lower surface of the upper member 40a and the upper surface of the lower member 40b that is bonded by the adhesive 70 is widened, so that the upper member 40a and the lower member 40b can be bonded more firmly.

  Moreover, in the said Embodiment 1, only the recessed part 42 was formed in the upper member 40a, and in the said Embodiment 2, although only the protrusion 43 was formed in the upper member 40a, it shows to FIG.11 (c), (d). As described above, both the recess 42 and the protrusion 43 may be formed on the upper member 40a. In this way, since the excess adhesive 70 can be blocked by the protrusion 43 while accumulating in the recess 42, it is possible to more reliably prevent ink from flowing into the nozzle 41.

  In the first and second embodiments, the recess 42 or the protrusion 43 is formed only once around the outlet of the communication channel 54, but the recess 42 or the protrusion 43 is formed at the outlet of the communication channel 54. Two or more circumferences may be formed around the circumference. Moreover, the recessed part 42 or the protrusion 43 does not necessarily need to be continuously connected over one round, and may be separated by a slight gap in the middle of one round.

  Furthermore, the shape of the recess 42 or the protrusion 43 in a plan view is not necessarily a ring shape, and may be another shape such as a square. Moreover, the cross-sectional shape of the recessed part 42 or the protrusion 43 does not necessarily need to be a rectangle, and other shapes, such as a triangle, a trapezoid, and a semicircle, may be sufficient as it.

  Moreover, in the said embodiment, although the upper member 40a of the structure 40 was comprised by overlapping the some plate-shaped body 411, 412, 413, 414, the structure method of the structure 40 is limited to this. It is not something. For example, the upper six plate-like bodies 413 of the seven plate-like bodies 413 shown in FIG. 3 may be integrally formed by one member.

  In addition, the configurations of the inkjet head 1 and the actuator 30, and the shapes and configurations of the main flow path 51, the pressure chamber 52, and the communication flow paths 53 and 54 are not limited to those in the above embodiment. In the above embodiment, ink is supplied from two ink supply ports 30a arranged in the Y-axis direction with respect to one main flow path, but one ink supply port 30a is provided for one main flow path. It may be provided.

  The embodiments of the present invention can be appropriately modified in various ways within the scope of the technical idea shown in the claims.

DESCRIPTION OF SYMBOLS 1 ... Inkjet head 2 ... Ink supply part 30 ... Actuator 40a ... Upper member (structure)
40b ... Lower member (plate member)
DESCRIPTION OF SYMBOLS 41 ... Nozzle 42 ... Recess 43 ... Projection 54 ... Communication flow path 70 ... Adhesive 71 ... Particle

Claims (9)

A pressure chamber filled with ink;
An actuator for changing the pressure of the ink filled in the pressure chamber;
A plate-like member on which nozzles for discharging ink are formed;
A communication channel connecting the pressure chamber and the nozzle;
A structure in which the communication channel is formed and the plate-like member is bonded;
A recess provided on the nozzle side surface of the structure so as to surround the communication channel,
An inkjet head characterized by that. The inkjet head according to claim 1,
The communication channel is wider than the inlet of the nozzle on the communication channel side.
An inkjet head characterized by that. The inkjet head according to claim 1 or 2,
The recess is formed at a position spaced outward by a predetermined distance from the nozzle-side outlet of the communication channel.
An inkjet head characterized by that. A pressure chamber filled with ink;
An actuator for changing the pressure of the ink filled in the pressure chamber;
A plate-like member on which nozzles for discharging ink are formed;
A communication channel connecting the pressure chamber and the nozzle;
A structure in which the communication channel is formed and the plate-like member is bonded;
A protrusion provided on the nozzle side surface of the structure so as to surround the communication channel,
An inkjet head characterized by that. The inkjet head according to claim 4,
The communication channel is wider than the inlet of the nozzle on the communication channel side.
An inkjet head characterized by that. The inkjet head according to claim 4 or 5,
The protrusion is formed at a position spaced outward by a predetermined distance from the nozzle side outlet of the communication channel,
An inkjet head characterized by that. In the ink jet head according to any one of claims 4 to 6,
The protrusion is formed along the boundary of the outlet on the nozzle side of the communication channel,
An inkjet head characterized by that. In the ink jet head according to any one of claims 1 to 7,
The adhesive for bonding the plate-like member to the structure includes particles for keeping a distance between the plate-like member and the structure at a predetermined distance.
An inkjet head characterized by that. An ink jet head according to any one of claims 1 to 6;
An ink jet apparatus comprising: an ink supply unit that supplies ink to the ink jet head.

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