JP6769042B2 - Inkjet head and inkjet device - Google Patents

Description

The present invention relates to an inkjet head that ejects ink onto a surface to be printed and an inkjet device that uses the inkjet head.

An inkjet device is a device that prints or draws on a surface to be printed by ejecting ink from an inkjet head. An inkjet head mounted on an inkjet device 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. It is equipped with an actuator. By driving the actuator to increase the pressure in the pressure chamber, the ink filled in the pressure chamber is ejected from the nozzle.

Japanese Unexamined Patent Publication No. 2005-244174

In the inkjet head having the above configuration, each pressure chamber and each nozzle are connected by mounting a plate-shaped member having a large number of nozzles formed on the structure constituting the flow path. Here, the plate-shaped member is attached to the structure by using an adhesive. In this case, if the amount of the adhesive to be applied is large, the adhesive may flow into the nozzle at the time of adhesion, and the ejection performance of the nozzle may deteriorate. On the other hand, if the amount of adhesive applied is small, adjacent nozzles cannot be reliably separated by an adhesive layer, and air leaks may occur between these nozzles. Even if an air leak occurs in this way, the ink ejection accuracy is lowered. Such a problem becomes remarkable especially in a configuration in which the distance between nozzles is shortened to increase the density of ink.

In view of such a problem, an object of the present invention is to provide an inkjet head and an inkjet device capable of appropriately adhering a plate-shaped member on which a nozzle is formed to a structure constituting a flow path.

The first aspect of the present invention relates to an inkjet head. The inkjet head according to the first aspect includes a pressure chamber filled with ink, an actuator for changing the pressure of the ink filled in the pressure chamber, and a plate-shaped member having a nozzle for ejecting ink. , The communication flow path connecting the pressure chamber and the nozzle, the structure in which the communication flow path is formed and the plate-shaped member is adhered, and the communication of the plate-shaped member so as to surround the periphery of the nozzle. and a recess and protrusion provided on the surface of the flow path side, one side of one side surface and the projection of the recess surface Ri one der, the communication passage is the communication flow path side of the nozzle It is wider than the inlet, and the recess and the protrusion are formed in a region outside the inlet of the nozzle and overlapping the connecting flow path.

According to the ink jet head of the present embodiment, even if the adhesive is applied to versatile, excess adhesive Ri balls into the recess, blocked further protrusion is suppressed that the flow into the nozzle .. Therefore, when the plate-shaped member is bonded, it is not necessary to worry about the flow into the nozzle, and a sufficient amount of adhesive can be used. This also solves the problem of air leaks between nozzles.

A second aspect of the present invention relates to an inkjet device. Ink jet apparatus according to the second embodiment includes an inkjet head according to the first state-like, and an ink supply portion for supplying ink to said ink jet head.

According inkjet device according to the second aspect, since the ink jet head of the first state-like are used, as described above, can be properly bonded to the structure of the nozzle is formed plate-like member. Therefore, the performance of the inkjet device can be improved.

As described above, according to the inkjet head and the inkjet device according to the present invention, the plate-shaped member in which the nozzle is formed can be appropriately adhered to the lower surface of the structure constituting the flow path.

The effects or significance of the present invention will be further clarified by the description of the embodiments shown below. However, the embodiments shown below are merely examples when the present invention is put into practice, and the present invention is not limited to those described in the following embodiments.

FIG. 1A is a diagram showing a configuration of an inkjet head according to the first embodiment, and FIG. 1B is a diagram schematically showing a configuration in which an actuator and a structure according to the first embodiment are combined. FIG. 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 showing a part of the main flow path and the pressure chamber according to the first embodiment. Is. FIG. 2C is a diagram schematically showing an arrangement of nozzles in the structure according to the first embodiment. FIG. 3 is a partial perspective view showing a configuration in the vicinity of the pressure chamber according to the first embodiment. FIG. 4 (a) 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. 4 (b) is the lower view according to the first embodiment. It is sectional drawing which shows typically the structure around the nozzle after adhering a member and an upper member. FIG. 5 is a plan view showing the configuration around the nozzle of the lower member according to the first embodiment. 6 (a) and 6 (b) are cross-sectional views schematically showing the flow of the adhesive in the bonding step according to the comparative example, respectively. 6 (c) and 6 (d) are cross-sectional views schematically showing the flow of the adhesive in the bonding step according to the first embodiment, respectively. FIG. 7 is a block diagram showing a configuration of an inkjet device according to the first embodiment. FIG. 8 (a) is a cross-sectional view schematically showing the structure around the nozzle before bonding the lower member and the upper member according to the second embodiment, and FIG. 8 (b) is the lower view according to the second embodiment. It is sectional drawing which shows typically the structure around the nozzle after adhering a member and an upper member. 9 (a) and 9 (b) are cross-sectional views schematically showing the flow of the adhesive in the bonding step according to the comparative example, respectively. 9 (c) and 9 (d) are cross-sectional views schematically showing the flow of the adhesive in the bonding step according to the second embodiment, respectively. 10 (a) and 10 (b) are cross-sectional views schematically showing the configuration around the nozzle and the flow of the adhesive in the bonding step according to the modified example. 10 (c) and 10 (d) are cross-sectional views schematically showing the configuration around the nozzle and the flow of the adhesive in the bonding step according to another modified example. 11 (a) and 11 (b) are cross-sectional views schematically showing the structure around the nozzle and the flow of the adhesive in the bonding step according to still another modification.

<Embodiment 1>
Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. For convenience, the X, Y, and Z axes that are orthogonal to each other are added to each figure. The Z-axis direction is the height direction of the inkjet head 1, and the Z-axis positive 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 direction (downward) of the Z axis.

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

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

The storage box 10 is formed of a rectangular box having an open lower surface. A notch 10a connected to the inside is provided on the upper surface of the storage box 10, and the circuit board 11 is housed in the storage box 10 through the notch 10a. A drive circuit for driving the actuator 30 is mounted on the circuit board 11. Circular holes 10b are provided on the Y-axis positive side and the Y-axis negative side of the notch 10a, respectively. The hole 10b 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 in the center. 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 in the opening 20a by FPCs (Flexible Printed Circuits).

As shown in FIG. 1 (b), the actuator 30 is made of a plate having a rectangular contour. The actuator 30 is superposed on the upper surface of the structure 40. The structure 40 is made of a plate having a rectangular outline. Further, the structure 40 is formed with four main flow paths 51 arranged in the X-axis direction.

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

FIG. 2A is an enlarged view of the end on the positive side of the Y-axis of the configuration of FIG. 1B.

A groove is formed on the back surface of the actuator 30. By stacking 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.

Terminal groups (not shown) for connecting the FPC of the circuit board 11 are provided at the end on the negative side of the X-axis and the end on the positive side of the X-axis on the upper surface of the actuator 30, respectively. 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 flow path 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).

Returning to FIG. 1 (b), tubes (not shown) are individually fitted into the eight ink supply ports 30a, and ink is supplied to each tube from an ink supply tube (not shown). .. The tube is supported by a support member arranged in the opening 20a, and the tube that supplies ink to the tube is pulled out through the hole 10b. Ink is supplied to the ink supply port 30a via the ink supply tube and the tube. As a result, ink is supplied to the pressure chamber 52 through the main flow path 51 and the connecting flow path 53.

Ink of the same color is supplied to the two ink supply ports 30a arranged in the Y-axis direction, and inks of different colors are supplied to the four ink supply ports 30a arranged in the X-axis direction. Therefore, in the configuration of 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 inks of the same color, 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 20a of the head base 20. Therefore, the four color inks are ejected from the lower surface of the head base 20.

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

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

The ink 60 that has flowed into the main flow path 51 is filled in the pressure chamber 52 through the connecting flow path 53. The structure 40 includes an upper member 40a having a main flow path 51 and connecting flow paths 53 and 54, and a lower member 40b having a nozzle 41. The lower member 40b is formed with a substantially circular hole serving as a nozzle 41 in a portion of a connecting flow path 54 extending in the positive direction of the Z axis from the pressure chamber 52. The diameter of the nozzle 41 gradually decreases toward the positive direction of the Z axis, and the diameter becomes uniform near the outlet.

The lower member 40b is a thin plate-shaped member made of metal. A recess 42 is formed on the surface of the lower member 40b on the connecting flow path 54 side so as to surround the periphery of the nozzle 41. The configurations of the nozzle 41 and the recess 42 will be described later with reference to FIGS. 4 (a), 4 (b) and 5. The lower member 40b corresponds to the "plate-shaped 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 upper part of 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 a sputtering method. 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 an etching method of a metal plate. The pressure chamber 52 is formed by mounting the upper member 40a on the lower surface of the pressure chamber layer 31. 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 the application of voltage to the piezoelectric layer 34 other than the piezoelectric functional region R1.

The piezoelectric layer 34 is formed 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 of, for example, titanium containing a noble metal. 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 the diaphragm layer 32 is deformed accordingly. When the diaphragm layer 32 is deformed downward in the piezoelectric function region R1, the volume of the pressure chamber 52 decreases, and the pressure of the ink 60 filled in the pressure chamber 52 increases. As a result, the droplet 61 of the ink 60 is ejected from the nozzle 41.

The pressure chamber layer 31, the diaphragm layer 32, the insulating layer 33, the piezoelectric layer 34, and the electrode layer 35 do not necessarily have to be a single layer, but may be formed by a plurality of layers. Further, another layer may be arranged between the layers.

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

As shown in FIG. 2C, a plurality of nozzles 41 are arranged in one direction in the structure 40. Rows L1 to L4 of four nozzles 41 are arranged in the structure 40. For example, 200 nozzles 41 are provided at regular intervals in rows L1 to L4, respectively. 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 arranged in the rows L1 to L4 are not microscopically aligned and meander in the X-axis direction with a constant swing width. They are lined up like this (see Fig. 5). As a result, the density of these nozzles 41 can be increased while reducing the arrangement area 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 near the pressure chamber 52. FIG. 3 shows a cross section of the actuator 30 and the structure 40 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 40a of the structure 40 is formed by stacking plate-shaped bodies 411 and 412, seven plate-shaped bodies 413, and plate-shaped bodies 414. Each of the plate-shaped bodies 411 to 414 has a predetermined thickness and has the same contour as the structure 40 in a plan view. The seven plate-shaped bodies 413 have the same structure. A thin damper 415 is sandwiched between the first and second plate-shaped bodies 413 from the bottom. The damper 415 is for absorbing the pressure wave applied from the connecting flow path 53 to the main flow path 51 when the actuator 30 is driven and the diaphragm layer 32 is displaced downward (Z-axis positive direction). is there.

The plate-shaped bodies 411 and 412 are formed with elongated holes 411a and 412a for forming the connecting flow path 54, respectively. The elongated holes 411a and 412a have a longitudinal direction in the X-axis direction. In plan view, the elongated holes 411a and 412a each have an oval contour that is long in the X-axis direction. More specifically, the elongated hole 411a has a contour in which the ends of two semicircles facing each other are connected by a straight line. The elongated hole 412a has a contour in which two semicircles similar to the elongated hole 411a are connected by a straight line shorter than the elongated hole 411a.

Holes 413a for forming the connecting flow path 54 are formed in the seven plate-shaped bodies 413. The hole 413a is substantially circular. Holes 414a and 415a for forming the connecting flow path 54 are also formed in the plate-shaped body 414 and the damper 415, respectively. The diameter of the holes 414a and 415a is substantially the same as the diameter of the holes 413a. The seven holes 413a are centered on each other. Further, the center of the holes 414a and 415a coincides with the center of the hole 413a. The center of the nozzle 41 coincides with the center of the holes 413a, 414a, and 415a.

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

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

The plate-shaped body 411 is formed with an opening 411b in a region corresponding to the connecting flow path 53. A filter 411c is formed at the bottom of the opening 411b, that is, at the inlet of the connecting flow path 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 contour that is long in the X-axis direction. In addition, the opening 411b may have an oval contour long in the X-axis direction, for example, a contour in which the ends of two semicircular arcs facing each other are connected by a straight line.

The elongated holes 411a, holes 412a, and openings 411b described above may have a large circular shape, but the pitch of the nozzles 41 cannot be narrowed, which hinders high-density printing. Therefore, the elongated holes are formed as described above. It is preferable to do so.

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

On the negative side of the X-axis of the opening 411b, the ink that has passed through the filter 411c from the main flow path 51 passes through the gap between the filter 411c and the lower surface of the pressure chamber layer 31 and passes through the gap between the positive side of the X-axis of the opening 411b and the pressure chamber. 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 flow path 54 composed of the elongated holes 411a, 421a and the holes 413a, 414a, 415a, and the nozzle 41. Is discharged from.

As shown in FIG. 3, in the first embodiment, the upper member 40a of the structure 40 is formed by stacking a plurality of plate-shaped bodies 411, 412, 413, 414, and the lower member 40b is adhered to the lower surface of the upper member 40a. Joined with an agent. Further, the upper member 40a is adhered to the lower surface of the pressure chamber layer 31, and the structure 40 composed of the upper member 40a and the lower member 40b is attached to the actuator 30. That is, the pressure chamber 52 and the connecting flow path 54 are connected by adhering the structure 40 having the connecting flow path 54 to the actuator 30. At the same time, the pressure chamber 52 and the communication flow path 53 are connected.

By the way, as described above, the lower member 40b is joined to the upper member 40a by using an adhesive. In this case, if the amount of the adhesive to be applied is large, the excess adhesive is extruded from the gap between the upper member 40a and the lower member 40b at the time of adhesion, and the extruded adhesive flows into the nozzle 41. Can happen. In this case, the adhesive flowing into the nozzle 41 obstructs the flow of ink, and the ejection performance of the nozzle 41 deteriorates. On the other hand, if the amount of the adhesive to be applied is small, the adjacent nozzles 41 may not be reliably separated by the adhesive layer, and an air leak 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 nozzles 41 adjacent to the nozzle 41, and as a result, the ink ejection accuracy in both nozzles 41 is lowered.

On the other hand, in the first embodiment, as described above, the recess 42 is formed on the surface of the lower member 40b on the connecting flow path 54 side so as to surround the periphery of the nozzle 41. Therefore, even if the adhesive is applied in a large amount, the excess adhesive is prevented from accumulating in the recess 42 and flowing into the nozzle 41. Therefore, when the lower member 40b is bonded to the upper member 40a, there is no need to worry about the adhesive flowing into the nozzle 41, and the bonding can be performed using a sufficient amount of the adhesive. As a result, the bonding of the lower member 40b to the upper member 40a can be strengthened, and the problem of air leakage between adjacent nozzles 41 can be solved.

Hereinafter, the detailed structure of the recess 42 and the action and effect thereof will be described.

FIG. 4A is a cross-sectional view schematically showing the structure around the nozzle 41 before the lower member 40b and the upper member 40a are bonded, and FIG. 4B shows the lower member 40b and the upper member 40a bonded together. It is sectional drawing which shows typically the structure around the nozzle 41 after that. In addition, unlike FIG. 3, FIGS. 4A and 4B show cross sections of the upper member 40a and the lower member 40b cut so as to pass through the center of the nozzle 41 in a plane parallel to the YY plane. ing.

As shown in FIG. 4A, a recess 42 is formed on the upper surface (Z-axis negative side surface) of the lower member 40b so as to surround the periphery of the nozzle 41. The nozzle 41 includes a columnar hole 41a and a conical inclined surface 41b. The recess 42 is formed at a position separated outward by a predetermined distance from the inlet of the nozzle 41 on the communication flow path 54 side. The recess 42 has a ring shape in a plan view, and is formed so as to surround the inlet of the nozzle 41 on the connecting flow path 54 side over the entire circumference. The radial width of the recess 42 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 recess 42 is positioned inside the connecting flow path 54. The diameter of the connecting flow path 54 is larger than that of the inlet of the nozzle 41 on the connecting flow path 54 side. The recess 42 is formed in a region outside the inlet of the nozzle 41 and overlapping the connecting flow path 54.

FIG. 5 is a plan view showing the configuration around the nozzle 41 of the lower member 40b. FIG. 5 shows a part of a group of nozzles 41 arranged in any one of the rows L1 to L4 shown in FIG. 2C. For convenience, FIG. 5 shows the outlet of the connecting flow path 54 (the hole 414a of the lowermost plate-shaped body 414) with a broken line.

In FIG. 5, the pitch D3 of the nozzle 41 in the Y-axis direction is, for example, about 300 μm. 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. A recess 42 is formed at a position separated from the inlet of the nozzle 41 to the outside by, for example, 10 μm to several tens of μm. The width D5 of the recess 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 lower member 40b is irradiated with laser light from the upper surface side of the lower member 40b. The laser beam is swirled around an axis that is parallel to the Z axis and penetrates the center of the hole 41a. At the time of processing, the recess 42 is first formed, and then the inclined surface 41b and the hole 41a of the nozzle 41 are formed. A set of a plurality of nozzles 41 and a recess 42 is formed at the same time by a plurality of laser beams.

At the time of joining, the adhesive 70 is applied to the upper surface (the surface on the negative side of the Z axis) 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 other than the region R2 having a diameter slightly larger than the diameter of the connecting flow path 54. In this state, as shown in FIGS. 4A and 4B, the upper member 40a is superposed 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.

6 (a) and 6 (b) are cross-sectional views schematically showing the flow of the adhesive 70 in the bonding step according to the comparative example, respectively. In the comparative example, the recess 42 is not formed around the inlet of the nozzle 41.

As shown in FIG. 6A, the adhesive 70 contains particles 71 having a predetermined particle size. The particles 71 have a strength that does not collapse even if the upper member 40a is pressed against the lower member 40b at a predetermined pressure at the time of joining. The particle size 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 while the adhesive 70 is applied to the upper surface of the lower member 40b as shown in FIG. 6A. As a result, as shown in FIG. 6B, the upper member 40a overlaps the lower member 40b. At this time, if the amount of the applied adhesive 70 is large, the excess adhesive 70 may protrude from the gap between the upper member 40a and the lower member 40b, and the protruding adhesive 70 may flow into the nozzle 41. Alternatively, a phenomenon occurs in which the nozzle 41 is clogged with the adhesive 70. In this case, the adhesive 70 that has flowed into the nozzle 41 obstructs the flow of ink, and the ejection performance from the nozzle 41 deteriorates.

In the first embodiment, as shown in FIGS. 6A and 6B, since the adhesive 70 contains the particles 71, the particles 71 are used to form the upper member 40a and the lower member at the time of joining. A gap having the same size as the particle size of the particle 71 is secured between the particle 71 and the particle 71. That is, even if a predetermined pressure is applied to the upper member 40a at the time of joining, the gap between the upper member 40a and the lower member 40b does not become smaller than the particle size of the particles 71. As a result, it is possible to prevent the adhesive 70 from being pushed out from the gap between the upper member 40a and the lower member 40b indefinitely.

However, in order to avoid the problem of air leakage between the nozzles 41 described above, the adhesive 70 tends to be applied in a large amount on the upper surface of the lower member 40b. Therefore, due to the action of the particles 71 as described above, the excess adhesive 70 may also be pushed out from the gap between the upper member 40a and the lower member 40b and flow into the nozzle 41.

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

6 (c) and 6 (d) are cross-sectional views schematically showing the flow of the adhesive 70 in the bonding step according to the first embodiment, respectively.

At the time of joining, when the upper member 40a is pressed against the lower member 40b with a predetermined pressure while the adhesive 70 is applied to the upper surface of the lower member 40b as shown in FIG. 6A, the excess adhesive 70 is released. , It is pushed out from the gap between the upper member 40a and the lower member 40b. At this time, even if the adhesive 70 is applied to the upper surface of the lower member 40b in a slightly large amount, as shown in FIG. 6B, the extruded adhesive 70 accumulates in the recess 42 and reaches the nozzle 41. It does not flow. As a result, the adhesive 70 is prevented from being cured on the inclined surface 41b and the hole 41a of the nozzle 41. In this way, the adhesive 70 is prevented from obstructing the flow of ink, and the ejection accuracy of the nozzle 41 is maintained high.

FIG. 7 is a block diagram showing a configuration of an inkjet device according to an embodiment.

In addition to the inkjet head 1 having the above configuration, the inkjet device includes an ink supply unit 2, a controller 3, and an interface 4.

The ink supply unit 2 includes the above-mentioned 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 according to a program held in the memory. The interface 4 receives input of drawing information such as characters and figures 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 prints or draws on the surface to be printed. In this way, ink is ejected from the nozzle 41 corresponding to the printed image to the surface to be printed, and printing or drawing is performed on the surface to be printed.

<Effect of Embodiment 1>
As described above, according to the first embodiment, the following effects are achieved.

As described with reference to FIGS. 6 (c) and 6 (d), even if a large amount of the adhesive 70 is applied to the upper surface of the lower member 40b, the excess adhesive 70 accumulates in the recess 42 and the nozzle The flow to 41 is suppressed. Therefore, when the lower member 40b is adhered, it is not necessary 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. As a result, the problem of air leakage between the nozzles 41 can be solved. The smaller the pitch D3 and the swing width D4 shown in FIG. 5 and the higher the density of the nozzles 41, the more likely it is that air leaks will occur between the nozzles 41. As described above, in the first embodiment, 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. 5 are reduced to increase the density of the nozzle 41. In addition, the problem of air leakage between the nozzles 41 can be avoided more reliably.

As shown in FIGS. 4A and 4B, the connecting flow path 54 has a larger diameter than the inlet of the nozzle 41 on the connecting flow path 54 side, and the recess 42 is outside the inlet of the nozzle 41. , Is formed in a region overlapping the connecting flow path 54. As a result, the adhesive 70 can be widely permeated into substantially the entire area of the surfaces of the upper member 40a and the lower member 40b facing each other, and the joint strength between the upper member 40a and the lower member 40b can be increased.

As shown in FIGS. 4A and 4B, the recess 42 is formed at a position separated outward by a predetermined distance from the inlet of the nozzle 41 on the communication flow path 54 side. Therefore, as shown in FIG. 6D, even if the excess adhesive 70 slightly overflows from the recess 42, it is possible to prevent the overflowing adhesive 70 from immediately flowing into the nozzle 41.

As shown in FIGS. 6C and 6D, the adhesive 70 contains particles 71 for keeping the distance between the lower member 40b and the upper member 40a at a predetermined distance. Therefore, even if a predetermined pressure is applied to the upper member 40a at the time of joining, the gap between the upper member 40a and the lower member 40b does not become smaller than the particle size of the particles 71. As a result, the adhesive 70 is prevented from being pushed out from the gap between the upper member 40a and the lower member 40b indefinitely.

<Embodiment 2>
In the first embodiment, the recess 42 is formed around the inlet of the nozzle 41, but in the second embodiment, the protrusion is formed around the inlet of the nozzle 41.

FIG. 8A 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. 8B shows the lower member 40b and the upper member 40a bonded together. It is sectional drawing which shows typically the structure around the nozzle 41 after that.

As shown in FIG. 8A, a protrusion 43 is formed on the upper surface (the surface on the negative side of the Z axis) of the lower member 40b so as to surround the periphery of the nozzle 41. The protrusion 43 is formed at a position separated outward by a predetermined distance from the inlet of the nozzle 41 on the communication flow path 54 side. The protrusion 43 has a ring shape in a plan view, and is formed so as to surround the inlet of the nozzle 41 on the connecting flow path 54 side over the entire circumference. The radial width of the protrusion 43 is constant, and the height is also constant. The protrusion 43 is formed on the upper surface of the lower member 40b by, for example, an electroforming method.

As shown in FIG. 8B, when the lower member 40b is joined to the upper member 40a, the protrusion 43 is positioned inside the connecting flow path 54. The diameter of the connecting flow path 54 is larger than that of the inlet of the nozzle 41 on the connecting flow path 54 side. The protrusion 43 is formed in a region outside the inlet of the nozzle 41 and overlapping the connecting flow path 54.

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 FIG. 5 is replaced with the protrusion 43.

9 (c) and 9 (d) are cross-sectional views schematically showing the flow of the adhesive 70 in the bonding step according to the second embodiment, respectively. The flow of the adhesive 70 in the comparative example is shown in FIGS. 9A and 9B as objects to be compared. Since the comparative examples of FIGS. 9 (a) and 9 (b) have the same configuration as the comparative examples of FIGS. 6 (a) and 6 (b), the description thereof is omitted here.

As shown in FIG. 9C, when the upper member 40a is pressed against the lower member 40b with a predetermined pressure while the adhesive 70 is applied to the upper surface of the lower member 40b, the excess adhesive 70 is released from the upper member. It is extruded from the gap between the 40a and the lower member 40b. At this time, even if the upper surface of the lower member 40b is coated with a slightly large amount of the adhesive 70, as shown in FIG. 9D, the extruded adhesive 70 is blocked by the protrusion 43 and the nozzle 41 Does not flow into. As a result, the adhesive 70 is prevented from being cured on the inclined surface 41b and the hole 41a of the nozzle 41. In this way, the adhesive 70 is prevented from obstructing the flow of ink, and the ejection accuracy of the nozzle 41 is maintained high.

<Effect of Embodiment 2>
As described above, according to the second embodiment, the following effects are achieved.

As described with reference to FIGS. 9 (c) and 9 (d), even if the adhesive 70 is applied to the upper surface of the lower member 40b in a large amount, the excess adhesive 70 is blocked by the protrusion 43. , The flow into the nozzle 41 is suppressed. Therefore, when the lower member 40b is adhered, it is not necessary 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. As a result, the problem of air leakage between the nozzles 41 can be solved.

As shown in FIGS. 8A and 8B, the connecting flow path 54 has a larger diameter than the inlet of the nozzle 41 on the connecting flow path 54 side, and the protrusion 43 is outside the inlet of the nozzle 41. Is formed in a region overlapping the connecting flow path 54. As a result, the adhesive 70 can be widely permeated into substantially the entire area of the surfaces of the upper member 40a and the lower member 40b facing each other, and the joint strength between the upper member 40a and the lower member 40b can be increased.

As shown in FIGS. 8A and 8B, the protrusion 43 is formed at a position separated outward by a predetermined distance from the inlet of the nozzle 41 on the communication flow path 54 side. Therefore, even if the excess adhesive 70 gets over the protrusion 43 from the state shown in FIG. 9D, it is possible to prevent the adhesive 70 that has passed over the protrusion 43 from immediately flowing into the nozzle 41.

As shown in FIGS. 9C and 9D, the adhesive 70 contains particles 71 for keeping the distance between the lower member 40b and the upper member 40a at a predetermined distance. Therefore, as in the first embodiment, the adhesive 70 is prevented from being pushed out from the gap between the upper member 40a and the lower member 40b indefinitely.

<Change example>
Although the first and second embodiments of the present invention have been described above, the present invention is not limited to the first and second embodiments.

For example, in the first embodiment, the recess 42 is formed in a region outside the inlet of the nozzle 41 that overlaps the connecting flow path 54, but as shown in FIGS. 10A and 10B, the recess 42 is formed. , It may be formed in a region outside the inlet of the nozzle 41 on the connecting flow path 54 side and not overlapping the connecting flow path 54. By doing so, the amount of the adhesive 70 protruding from the gap between the upper member 40a and the lower member 40b can be reduced by adjusting the amount of the adhesive 70. As a result, the flow of ink from the connecting flow path 54 to the nozzle 41 can be further stabilized.

Further, in the second embodiment, the protrusion 43 is formed in a region outside the inlet of the nozzle 41 and overlapping the connecting flow path 54, but as shown in FIGS. 10C and 10D, the protrusion 43 is formed. The 43 may be formed in a region outside the inlet of the nozzle 41 on the connecting flow path 54 side and not overlapping the connecting flow path 54. By doing so, as in the cases of FIGS. 10C and 10D, by adjusting the amount of the adhesive 70, the amount of the adhesive 70 protruding from the gap between the upper member 40a and the lower member 40b can be reduced, and the contact can be made. The flow of ink from the flow path 54 to the nozzle 41 can be more stabilized.

In the modified examples of FIGS. 10 (c) and 10 (d), the upper surface of the protrusion 43 abuts on the lower surface of the upper member 40a, so that even if a downward pressure is applied to the upper member 40a at the time of joining, the upper member 40a may be subjected to downward pressure. The gap between the upper member 40a and the lower member 40b is not smaller than the height of the protrusion 43. Therefore, in this modification, it is not always necessary to include the particles 71 in the adhesive 70, and the protrusion 43 can prevent the adhesive 70 from being pushed out from the gap between the upper member 40a and the lower member 40b indefinitely. ..

Further, in the first embodiment, only the recess 42 is formed in the lower member 40b, and in the second embodiment, only the protrusion 43 is formed in the lower member 40b, which are shown in FIGS. 11A and 11B. As described above, both the recess 42 and the protrusion 43 may be formed in the lower member 40b. By doing so, the excess adhesive 70 can be blocked by the protrusion 43 while being accumulated in the recess 42, so that the inflow of ink to the nozzle 41 can be more reliably suppressed.

Further, in the first and second embodiments, the recess 42 or the protrusion 43 is formed only once around the inlet of the nozzle 41, but the recess 42 or the protrusion 43 is formed around two circumferences around the inlet of the nozzle 41. The above may be formed. Further, the recess 42 or the protrusion 43 does not necessarily have to be continuously connected over one round, and may be separated by a slight gap in the middle of one round.

Further, the shape of the recess 42 or the protrusion 43 in a plan view does not necessarily have to be a ring shape, and may be another shape such as a square. Further, the cross-sectional shape of the recess 42 or the protrusion 43 does not necessarily have to be rectangular, and may be another shape such as a triangle, a trapezoid, or a semicircle.

Further, in the above embodiment, the upper member 40a of the structure 40 is constructed by stacking a plurality of plate-shaped bodies 411, 412, 413, 414, but the method of constructing the structure 40 is limited to this. It's not something. For example, of the seven plate-shaped bodies 413 shown in FIG. 3, the upper six plate-shaped bodies 413 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 connecting flow paths 53 and 54 are not limited to those of the above embodiment. Further, in the above embodiment, ink is supplied from two ink supply ports 30a arranged in the Y-axis direction to one main flow path, but one ink supply port 30a is supplied to 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.

1 ... Ink head 2 ... Ink supply unit 30 ... Actuator 40a ... Upper member (structure)
40b ... Lower member (plate-shaped member)
41 ... Nozzle 42 ... Recess 43 ... Protrusion 54 ... Communication flow path 70 ... Adhesive 71 ... Particles

Claims (6)

A pressure chamber filled with ink and
An actuator that changes the pressure of the ink filled in the pressure chamber,
A plate-shaped member on which a nozzle for ejecting ink is formed,
A communication flow path connecting the pressure chamber and the nozzle,
A structure in which the connecting flow path is formed and the plate-shaped member is adhered to the structure.
A recess and a protrusion provided on the surface of the plate-shaped member on the connecting flow path side so as to surround the periphery of the nozzle are provided.
One aspect of one side surface and the projection of the recess Ri flush der,
The connecting flow path is wider than the inlet of the nozzle on the connecting flow path side.
The recess and the protrusion are formed in a region outside the inlet of the nozzle and overlapping the connecting flow path.
An inkjet head that features that. In the inkjet head according to claim 1 ,
The recess is formed at a position separated outward by a predetermined distance from the inlet of the nozzle on the connecting flow path side.
An inkjet head that features that. In the inkjet head according to claim 1 or 2 .
The protrusion is formed at a position closer to the inlet side of the nozzle than the recess.
An inkjet head that features that. In the inkjet head according to any one of claims 1 to 3 .
The protrusion is formed at a position separated outward by a predetermined distance from the inlet of the nozzle on the connecting flow path side.
An inkjet head that features that. In the inkjet head according to any one of claims 1 to 4 .
The adhesive for adhering the plate-shaped member to the structure contains particles for keeping the distance between the plate-shaped member and the structure at a predetermined distance.
An inkjet head that features that. The inkjet head according to any one of claims 1 to 5 .
An inkjet device including an ink supply unit that supplies ink to the inkjet head.

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