JP6241369B2 - Inkjet head - Google Patents

Description

  The present invention relates to an ink jet head, and more particularly, to an ink jet head capable of suppressing deformation of a head chip due to a difference in coefficient of thermal expansion between a manifold member and a surrounding member covering the periphery of the manifold member.

  Some inkjet heads supply ink to a pressure chamber of a head chip by a manifold member. The manifold member is provided on the ink inlet side of the pressure chamber. The inside of the manifold member serves as an ink reservoir, and communicates with a plurality of pressure chambers via ink inlets, thereby forming a common ink chamber that supplies ink to each pressure chamber in common (Patent Document 1). ).

  Ink jet heads are also provided with a housing that covers the periphery of the head chip and the manifold member, and the head chip and the manifold member are housed inside (Patent Document 2). This casing is made of aluminum and has two through holes through which the two ink tubes projecting from the manifold member pass. The manifold member is attached such that its side surface and the ink tube are in close contact with the through hole so as not to wobble with respect to the housing.

JP 2007-83705 A JP 2009-285901 A

  The ink jet head generates a lot of heat when driven. In particular, an inkjet head that ejects ink to be used with a reduced viscosity until it becomes ejectable by heating, such as UV ink and wax ink, is always exposed to high-temperature ink. Therefore, during the driving of the ink jet head, the manifold member and the casing covering the manifold member are affected by heat.

  As a result of confirmation by the present inventor, it has been found that an ink jet head provided with a housing as in Patent Document 2 may be warped in the head chip due to heat generated during such use.

  Here, the manifold member is generally formed of a material having a thermal expansion coefficient that is the same as or close to that of the head chip, so that the influence of thermal expansion on the head chip can be suppressed. However, the housing material is made of aluminum, which houses and protects the head chip and the manifold member, and has a higher coefficient of thermal expansion than the manifold member because it needs to be positioned and attached to the carriage with high accuracy. Therefore, it is difficult to make the coefficient of thermal expansion uniform with the manifold member or the like. The inventor has found that there is a possibility that the head chip may be warped due to the difference in thermal expansion coefficient between the manifold member and the housing.

  That is, when the ink jet head is affected by heat, the housing is relatively stretched more than the manifold member, and the two ink tubes are separated from each other through the through-hole through which the ink tube is inserted. . As a result, the manifold member receives a stress that deforms so that the side on which the ink tube is provided is convex. As a result, the head chip fixed to the manifold member is likely to warp. Further, when the casing is in contact with the side surface of the manifold member, the deformation stress acting on the manifold member is further increased.

  Although the deformation due to the difference in the thermal expansion coefficient is extremely small in reality, in order to maintain and improve the performance of the ink jet head, the above-described manifold member and a casing that covers the periphery of the manifold member, etc. It is desirable to have an ink jet head structure that can cope with deformation caused by a difference in thermal expansion coefficient with the surrounding members.

  Accordingly, an object of the present invention is to provide an ink jet head that can suppress deformation of a head chip due to a difference in thermal expansion coefficient between a manifold member and a surrounding member covering the periphery of the manifold member.

  Other problems of the present invention will become apparent from the following description.

  The above problems are solved by the following inventions.

1. A head chip having a pressure chamber;
A manifold member having at least two ink tubes serving as ink flow paths and disposed on the ink inlet side of the pressure chamber;
A through hole having an inner diameter larger than the outer diameter of the ink tube for each ink tube, and a surrounding member that houses the manifold member in a state in which the ink tube is inserted into the through hole;
The inkjet head characterized in that the peripheral member has a thermal expansion coefficient larger than that of the manifold member, and is bonded to the ink pipe by an adhesive having a smaller elastic modulus than the peripheral member inside the through hole. .

  2. 2. The inkjet head according to claim 1, wherein the peripheral member is provided in a non-contact state with a gap between at least a side surface of the manifold member.

  3. The ink jet according to claim 1 or 2, wherein the ink tube protrudes from a surface of the manifold member opposite to the head chip side and is arranged along a longitudinal direction of the head chip. head.

4). A plurality of the pressure chambers are arranged on the head chip,
4. The ink jet head according to claim 3, wherein the ink tube protrudes from the surface of the manifold member outside the pressure chambers located at both ends in the arrangement direction of the pressure chambers.

  5. 5. The ink jet head according to any one of 1 to 4, wherein a gap between the through hole and the ink tube is larger on an inner end side than on an outer end side of the through hole.

6). The outer diameter of the portion of the ink tube passing through the through hole is constant over the entire length of the through hole,
6. The ink jet head according to 5, wherein an inner diameter on the inner end side of the through hole is larger than an inner diameter on the outer end side of the through hole.

7). The inner diameter of the through hole is constant over the entire length,
6. The ink jet head according to 5, wherein an outer diameter of the ink tube located on the inner end side of the through hole is smaller than an outer diameter of the ink tube located on the outer end side of the through hole.

  8). Between the through hole and the ink tube, a first sealing portion located on the inner end side of the through hole and a second seal located on the outer end side of the through hole are formed by the adhesive. That at least two sealing portions of the portion are formed, and a space portion where no adhesive is present is formed between the first sealing portion and the second sealing portion. 5. The ink jet head according to any one of 1 to 4 above.

  9. The ink tube is divided into a first tube portion protruding from the manifold member and a second tube portion connected to the first tube portion, and the first tube portion 9. The ink jet head according to 8, wherein a boundary portion formed on the outer peripheral surface by connection with the second tube portion is located in the space portion.

  10. 10. The ink jet head according to 9, wherein a gap between the through hole and the first tube portion is larger than a gap between the through hole and the second tube portion.

11. The inner diameter of the through hole is constant over the entire length,
11. The ink jet head according to 10, wherein an outer diameter of the first tube portion is smaller than an outer diameter of the second tube portion.

  ADVANTAGE OF THE INVENTION According to this invention, the inkjet head which can suppress the deformation | transformation of the head chip resulting from the difference of the thermal expansion coefficient of the manifold member and the surrounding member which covers the circumference | surroundings can be provided.

The side view which shows an example of 1st Embodiment of the structure of the inkjet head which concerns on this invention The exploded perspective view which looked at parts other than the surrounding member in the inkjet head shown in FIG. 1 from the nozzle plate side Perspective view of surrounding members The enlarged view which shows only the site | part of the insertion structure of the through-hole and inflow tube in 2nd Embodiment of the structure of the inkjet head which concerns on this invention. The enlarged view which shows only the site | part of the penetration structure of the through-hole and inflow tube in 3rd Embodiment of the structure of the inkjet head which concerns on this invention. The enlarged view which shows only the site | part of the insertion structure of the through-hole and inflow tube in 4th Embodiment of the structure of the inkjet head which concerns on this invention. The enlarged view which shows only the site | part of the insertion structure of the through-hole and inflow tube in 5th Embodiment of the structure of the inkjet head which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a side view showing an example of the structure of an ink jet head according to the present invention, and shows only a peripheral member in section. 2 is an exploded perspective view of a portion other than the peripheral member in the inkjet head shown in FIG. 1 as viewed from the nozzle plate side, and FIG. 3 is a perspective view of the peripheral member.

  The inkjet head 1 has a nozzle plate 11, a head chip 12, a wiring substrate 13, and a manifold member 14, and these are covered with a peripheral member 15 so as to be housed therein.

  The head chip 12 has a hexahedral shape, and a plurality of channels 121 and drive walls 122 which are pressure chambers in the present invention are alternately arranged. Each channel 121 is formed so as to penetrate the head chip 12 on the surface on the nozzle plate 11 side and the surface on the wiring board 13 side so as to penetrate in a straight shape with almost no change in size and shape. The opening on the nozzle plate 11 side of the channel 121 is an ink outlet, and the opening on the opposite side of the wiring board 13 is an ink inlet.

  The nozzle plate 11 is formed with a nozzle 111 serving as an ink discharge port so as to correspond to the ink inlet of the channel 121, and is adhered to the surface of the head chip 12 where the ink inlet of the channel 121 is open. Yes.

  The drive wall 122 is at least partially formed of a piezoelectric element such as PZT that has been subjected to polarization treatment, and a drive electrode (not shown) is formed on the surface of the drive wall 122 facing the channel 121. The drive wall 122 is shear-deformed by applying a drive signal of a predetermined voltage to the drive electrodes on both sides thereof, and the volume of the channel 121 sandwiched between the pair of drive walls 122 and 122 is expanded and contracted. As a result, a pressure for ejection is applied to the ink supplied into the channel 121.

  The wiring substrate 13 is a flat thin plate having a size protruding from the periphery of the head chip 12 and is bonded to the surface of the channel 121 opposite to the nozzle plate 11 of the head chip 12 where the ink inlet is open. ing. On the surface of the wiring substrate 13 on the head chip 12 side, wiring 131 that is electrically connected to each drive electrode of the head chip 12 is formed. The region of the wiring board 13 protruding from the head chip 12 functions as a connection portion of a flexible substrate (not shown) that electrically connects this wiring and a drive circuit (not shown).

  An opening 132 is formed at the center of the wiring board 13. The opening 132 has a rectangular shape that is long along the arrangement direction of the channels 121 of the head chip 12, and is formed to have a size that can surround the ink inlet side of all the channels 121 that open to the head chip 12. Yes. Therefore, the ink inlet of each channel 121 of the head chip 12 is exposed toward the manifold member 14 through the opening 132.

  The manifold member 14 is formed in a box shape whose one surface is open, and is bonded to the outer edge portion of the surface of the wiring board 13 opposite to the head chip 12 so as to close the opening. As a result, a common ink chamber 141 that supplies ink in common to all the channels 121 that eject ink is formed inside the manifold member 14.

  Examples of the material of the manifold member 14 include resins such as acrylic, polyamide, polyether amide, polyimide, polyether imide, polyethylene terephthalate, polyphenylene sulfide, polysulfone, polyether ether ketone, polyphenylene ether, polyethylene naphthalate, and liquid crystal polymer. And polycarbonate. A metal may be used, and examples thereof include aluminum, stainless steel, and titanium.

  On the upper surface 14 a, which is the surface opposite to the head chip 12 side, of the outer surface of the manifold member 14, the ink is discharged from the common ink chamber 141 and the inflow pipe 142 that allows the ink to flow into the common ink chamber 141. Two ink pipes of the outflow pipe 143 to be carried out project. The inflow pipe 142 and the outflow pipe 143 protrude from the upper surface 14a of the manifold member 14 in the direction opposite to the head chip 12 side, and are connected to an ink tube (not shown) at the tip.

  The peripheral member 15 is formed in a box shape having a size that can sufficiently cover the periphery of the nozzle plate 11, the head chip 12, the wiring substrate 13, and the manifold member 14 so as to accommodate the integrated member. Yes. The peripheral member 15 has an opening on one side, a peripheral member main body 151 that accommodates most of the integrated body of the nozzle plate 11, the head chip 12, the wiring board 13, and the manifold member 14, and an opening of the peripheral member main body 151. And a top plate 152 to be closed.

  Here, the peripheral member main body 151 and the top plate 152 are formed of a material having a higher coefficient of thermal expansion than the manifold member 14. Specific examples of the material include aluminum, stainless steel, and titanium. A metal material having good thermal conductivity is also preferable for heat radiation from the head that generates heat by driving to the head printer.

  Through holes 153 and 154 are formed on the upper surface of the peripheral member main body 151 at positions corresponding to the inflow pipe 142 and the outflow pipe 143 protruding from the manifold member 14, respectively. The inner diameters of the through holes 153 and 154 shown in the present embodiment are constant over the entire length, and are slightly larger than the outer diameters of the corresponding inflow pipe 142 and outflow pipe 143, respectively. The peripheral member main body 151 accommodates the integrated body of the nozzle plate 11, the head chip 12, the wiring board 13, and the manifold member 14 with the inflow pipe 142 and the outflow pipe 143 inserted into the through holes 153 and 154. . The leading end sides of the inflow pipe 142 and the outflow pipe 143 protrude to the outside from the through holes 153 and 154.

  The top plate 152 is attached so as to close the opening of the peripheral member main body 151 in a state in which the nozzle plate 11, the head chip 12, the wiring board 13 and the manifold member 14 are integrated. An opening 155 having a size that can surround the periphery of the head chip 12 is formed in the central portion of the top plate 152. When the ceiling member 152 is attached so as to close the opening of the surrounding member main body 151, this opening The nozzle surface of the nozzle plate 11 is exposed from the portion 155 to the outside. The top plate 152 is in contact with the integral part of the nozzle plate 11, the head chip 12, the wiring board 13, and the manifold member 14 anywhere other than the part that is adhered to the periphery of the head chip 12 by an adhesive described later. It is preferable that they are not attached and not fixed.

  Note that reference numeral 156 in FIG. 3 denotes a board insertion opening formed on the upper surface of the peripheral member main body 151 through which the flexible board connected to the wiring board 13 is inserted and taken out to the outside.

  The peripheral member 15 is bonded to the integrated body of the nozzle plate 11, the head chip 12, the wiring board 13, and the manifold member 14 through the adhesive holes G <b> 1 and G <b> 2 through the through holes 153 and 154. At 155, it is bonded via an adhesive G3. The adhesives G1 and G2 in the present embodiment are filled so as to fill the entire inside of the through holes 153 and 154.

  Here, among these adhesives G1 to G3, an adhesive having an elastic modulus smaller than that of the peripheral member 15 is used for at least the adhesives G1 and G2. The elastic modulus is a ratio representing difficulty of deformation and is defined by force / strain. That is, the adhesives G1 and G2 are more easily elastically deformed than the surrounding member main body 151 that is in direct contact.

  Such an adhesive is appropriately determined depending on the relationship with the material of the surrounding member 15, and examples thereof include an epoxy adhesive and a silicone adhesive. Among these, an adhesive mainly composed of a polymer having a fluorinated polyether skeleton in the main chain is preferable in that it has both elasticity and ink resistance.

  Next, a case where deformation stress resulting from the difference in thermal expansion coefficient between the manifold member 14 and the surrounding member 15 acts on the inkjet head 1 will be described.

  When heat is applied to the manifold member 14 and the peripheral member 15, the peripheral member 15 has a larger coefficient of thermal expansion than the manifold member 14, so that the longitudinal direction (the arrangement direction of the channels 121, FIG. It extends greatly in the left and right direction), and exerts a stress that attempts to separate the distance between the inflow pipe 142 and the outflow pipe 143 through the through holes 153 and 154. However, since the adhesives G1 and G2 are more easily elastically deformed than the surrounding member main body 151, this stress is absorbed by the elastic deformation of the adhesives G1 and G2 themselves. This prevents the head chip 12 from being deformed and warped via the manifold member 14.

  Therefore, according to the inkjet head 1, it is possible to suppress the deformation of the head chip 1 due to the difference in thermal expansion coefficient between the manifold member 14 and the surrounding member 15 covering the periphery thereof.

  The peripheral member main body 151 in the present embodiment exemplifies a preferable aspect in which the inner dimension is sufficiently larger than the outer dimension of the manifold member 14 so as to be separated from the outer surface of the manifold member 14 at a predetermined interval. ing. Accordingly, the peripheral member 15 is provided in a non-contact state with the manifold member 14 via the gap S between the upper surface 14a and the side surface 14b of the manifold member 14 at a portion other than the portion bonded by the adhesives G1 and G2. It has been.

  For this reason, the deformation of the peripheral member 15 is not directly transmitted to the manifold member 14, and the deformation of the head chip 12 via the manifold member 14 is suppressed in combination with the elastic deformation action of the adhesives G1 and G2. The effect can be further improved.

  The illustrated gap S is formed between the upper surface 14a and the side surface 14b of the manifold member 14 and the peripheral member main body 151, but is formed at least between the side surface 14b of the manifold member 14 and the peripheral member main body 151. It only has to be.

  In the manifold member 14 shown in the present embodiment, an inflow pipe 142 and an outflow pipe 143 are arranged along the longitudinal direction of the manifold member 14. In such a configuration, the manifold member 14 is easily deformed through the inflow pipe 142 and the outflow pipe 143 due to the expansion of the surrounding member main body 151, and thus the effect of the application of the present invention is remarkably obtained.

  In addition, as shown in FIG. 1, the inflow pipe 142 and the outflow pipe 143 shown in the present embodiment are formed on the manifold member 14 corresponding to the outside of the two channels 121 and 121 located at both ends in the arrangement direction of the channels 121. It protrudes from the upper surface 14a. In such a configuration, the expansion of the peripheral member main body 151 makes the manifold member 14 more easily deformed via the inflow pipe 142 and the outflow pipe 143, and thus the effect of the application of the present invention becomes more remarkable.

(Second Embodiment)
Next, an embodiment in which the gaps between the through holes 153 and 154 and the inflow pipe 142 and the outflow pipe 143 are made larger on the inner end side than on the outer end side of the through holes 153 and 154 will be described below.

  FIG. 4 is an enlarged view showing only the insertion portion between the through hole 153 and the inflow pipe 142 of the ink jet head in the second embodiment. Since the insertion part of the other through-hole 154 and the outflow pipe 143 has the same configuration, the following description is used for this insertion part, and illustration and description thereof are omitted here.

  The outer diameter of the portion of the inflow pipe 142 passing through the through hole 153 is constant over the entire length of the through hole 153. The through-hole 153 has a large-diameter portion 153a having a large inner diameter on the inner end side (inside the surrounding member main body 151) and a small-diameter portion 153b having a small inner diameter on the outer end side (outside the surrounding member main body 151). Has been. For this reason, as for the space | interval of the inner surface of the through-hole 153, and the outer surface of the inflow tube 142, the large diameter part 153a is formed more widely than the small diameter part 153b. The adhesive G1 is filled so as to fill the entire inside of the through hole 153.

  Here, when a stress is applied to the distance between the inflow pipe 142 and the outflow pipe 143 due to the extension of the surrounding member main body 151, the leading ends of the inflow pipe 142 and the outflow pipe 143 are inclined in a direction away from each other. On the other hand, the root side can hardly move. For this reason, with respect to the inflow pipe 142, the force acting on the large diameter portion 153a of the through hole 153 is greater than the force acting on the small diameter portion 153b. At this time, the larger diameter portion 153a of the through-hole 153 is larger in distance from the outer surface of the inflow pipe 142, so that the thickness of the adhesive G1 becomes thicker. Therefore, a large deformation stress acting on the large diameter portion 153a is sufficiently generated. Can be absorbed. Therefore, it is possible to further improve the effect of suppressing the deformation of the head chip 1 due to the difference in thermal expansion coefficient between the manifold member 14 and the peripheral member 15.

  In the present embodiment, the inner surface of the through hole 153 may be formed in a tapered shape that gradually decreases in diameter from the inner end side toward the outer end side, in addition to being formed in a step shape as shown in the figure.

(Third embodiment)
Next, another embodiment in which the gaps between the through holes 153 and 154 and the inflow pipe 142 and the outflow pipe 143 are made larger on the inner end side than on the outer end side of the through holes 153 and 154 will be described below.

  FIG. 5 is an enlarged view showing only the insertion portion between the through hole 153 and the inflow pipe 142 of the ink jet head in the third embodiment. Since the insertion part of the other through-hole 154 and the outflow pipe 143 has the same configuration, the following description is used for this insertion part, and illustration and description thereof are omitted here.

  The inner diameter of the through hole 153 is constant over the entire length. The outer diameter of the inflow pipe 142 located on the inner end side of the through hole 153 is smaller than the outer diameter of the inflow pipe 142 located on the outer end side of the through hole 153. That is, the inflow pipe 142 has a small-diameter pipe part 142 a located on the inner end side of the through hole 153 and a large-diameter pipe part 142 b located on the outer end side of the through hole 153. For this reason, as for the space | interval of the inner surface of the through-hole 153, and the outer surface of the inflow pipe 142, the direction of the small diameter pipe part 142a of the inflow pipe 142 is formed wider than the large diameter pipe part 142b. The adhesive G1 is filled so as to fill the entire inside of the through hole 153.

  Also in this embodiment, the small-diameter pipe portion 142a of the inflow pipe 142 located on the inner end side of the through-hole 153 has a larger distance from the inner surface of the through-hole 153, so that the same as in the second embodiment. Since the thickness of the adhesive G1 is increased, the large deformation stress acting on the small-diameter pipe portion 142a of the inflow pipe 142 can be sufficiently absorbed, resulting from the difference in thermal expansion coefficient between the manifold member 14 and the surrounding member 15. The effect of suppressing the deformation of the head chip 1 can be further improved.

  The small-diameter pipe part 142a and the large-diameter pipe part 142b of the inflow pipe 142 can be formed by a single pipe, but can also be formed by divided pipe parts. When formed by the divided pipe parts, the small diameter pipe part 142a is a first pipe part protruding from the upper surface 14a of the manifold member 14, and the large diameter pipe part 142b is connected to the first pipe part. It is the 2nd pipe part made. Thus, the small-diameter pipe part 142a and the large-diameter pipe part 142b are configured by configuring the small-diameter pipe part 142a and the large-diameter pipe part 142b of the inflow pipe 142 by the divided first pipe part and second pipe part. Can be easily formed.

  Further, when the small-diameter pipe part 142a and the large-diameter pipe part 142b are formed by divided pipe parts, it is preferable that the small-diameter pipe part 142a and the large-diameter pipe part 142b are not in direct contact with each other. For example, the adhesive G1 is applied in a state where the inner diameter of the large-diameter pipe part 142b is formed larger than the outer diameter of the small-diameter pipe part 142a and the tip part of the small-diameter pipe part 142a is placed over the large-diameter pipe part 142b. By injecting and curing, a structure in which the small-diameter pipe portion 142a and the large-diameter pipe portion 142b are not in direct contact with each other can be obtained. A gap is formed between the small-diameter tube portion 142a and the large-diameter tube portion 142b, but since the periphery is surrounded by the adhesive G1, there is no fear that ink leaks to the outside.

  Thus, by forming the small-diameter pipe part 142a and the large-diameter pipe part 142b by the divided pipe parts and having a structure in which they are not in direct contact with each other, the expansion of the peripheral member 15 due to the influence of thermal expansion is caused by When acting on the outflow pipe 143, the small-diameter pipe part 142a and the large-diameter pipe part 142b are displaced from each other, so that stress can be absorbed. For this reason, the influence of the thermal expansion of the peripheral member 15 on the head chip 1 and the manifold 14 can be further mitigated in combination with the stress absorption effect by the adhesive G1.

  In the present embodiment, the outer surface of the inflow pipe 142 is formed in a stepped shape by a small diameter pipe part 142a and a large diameter pipe part 142b as shown in the figure, and gradually from the inner end side to the outer end side of the through hole 153. You may form in the taper shape which expands in diameter.

  Furthermore, in this embodiment, as shown in FIG. 4, the inner surface of the through hole 153 may be formed in a step shape having a large diameter portion 153a and a small diameter portion 153b, or from the inner end side to the outer end side. You may form in the taper shape which diameters reduce gradually.

(Fourth embodiment)
Next, still another embodiment of the bonding configuration between the through holes 153 and 154 and the inflow pipe 142 and the outflow pipe 143 will be described below.

  FIG. 6 is an enlarged view showing only the insertion site between the through hole 153 and the inflow pipe 142 of the inkjet head in the fourth embodiment. Since the insertion part of the other through-hole 154 and the outflow pipe 143 has the same configuration, the following description is used for this insertion part, and illustration and description thereof are omitted here.

  The inner diameter of the through hole 153 is constant over the entire length. Further, the outer diameter of the portion passing through the through hole 153 of the inflow pipe 142 is also constant. The adhesive between the inner surface of the through hole 153 and the outer surface of the inflow pipe 142 is positioned on the first sealing portion G1a located on the inner end side of the through hole 153 and on the outer end side of the through hole 153. Two sealing portions of the second sealing portion G1b are formed, and a space portion 153c where no adhesive is present between the first sealing portion G1a and the second sealing portion G1b. Is formed.

  Thereby, the adhesion area between the through-hole 153 and the inflow pipe 142 can be reduced, and the sealing portions G1a and G2b can be easily elastically deformed due to the presence of the space portion 153c. Therefore, it is possible to further improve the effect of suppressing the deformation stress applied to the manifold member 14 by the extension of the peripheral member 15.

  Examples of a method for forming the first sealing portion G1a and the second sealing portion G1b include the following methods.

  When the viscosity of the adhesive is sufficiently high, a thin needle-like adhesive injection pipe is inserted between the through hole 153 and the inflow pipe 142, and the adhesive is first injected into the inner end side of the through hole 153. After forming one sealing portion G1a, an adhesive is injected into the outer end side of the through-hole 153 at a distance from the first sealing portion G1a to form the second sealing portion G1b. be able to.

  When the viscosity of the adhesive is low, the adhesive adheres to the inner surface of the through hole 153 corresponding to the space portion 153c and the outer surface of the inflow tube 142 so that the adhesive does not enter the entire through hole 153 by capillary action. A liquid repellent film for avoiding this may be formed in advance, and then the first sealing portion G1a and the second sealing portion G1b may be formed in this order using an adhesive injection tube in the same manner as described above. .

  Here, two sealing portions are provided, ie, the first sealing portion G1a and the second sealing portion G1b. However, three or more sealing portions may be formed. In this case, a space portion is formed between each sealing portion. Since the number of sealing portions increases, the adhesive strength can be improved while improving the elastic deformation of the sealing portions.

  In the present embodiment, the inner surface of the through hole 153 may be formed in a step shape having a large diameter portion 153a and a small diameter portion 153b, as shown in FIG. In this case, the first sealing portion G1a is disposed on the large diameter portion 153a, and the second sealing portion G1b is disposed on the small diameter portion 153b, so that the deformation stress that the expansion of the peripheral member 15 gives to the manifold member 14 is increased. The suppressing effect can be further improved.

Further, the inner surface of the through hole 153 may be formed in a tapered shape that gradually decreases in diameter from the inner end side toward the outer end side.
(Fifth embodiment)
Next, still another embodiment of the bonding configuration between the through holes 153 and 154 and the inflow pipe 142 and the outflow pipe 143 will be described below.

  FIG. 7 is an enlarged view showing only the insertion site between the through hole 153 and the inflow pipe 142 of the inkjet head in the fifth embodiment. Since the insertion part of the other through-hole 154 and the outflow pipe 143 has the same configuration, the following description is used for this insertion part, and illustration and description thereof are omitted here.

  The inner diameter of the through hole 153 is constant over the entire length. Then, the adhesive between the inner surface of the through hole 153 and the outer surface of the inflow pipe 142 is similar to FIG. 6 in that the first sealing portion G1a located on the inner end side of the through hole 153 and the through hole 153 Two sealing portions of the second sealing portion G1b located on the outer end side are formed, and an adhesive is provided between the first sealing portion G1a and the second sealing portion G1b. A space portion 153c in which no is present is formed.

  The inflow pipe 142 has a small-diameter pipe part 142a that is a first pipe part protruding from the upper surface 14a of the manifold member 14, and a large-diameter that is a second pipe part connected to the first pipe part. The pipe part 142b is divided into two pipe parts and connected to each other. The inflow pipe 142 has a boundary part 142c formed on the outer peripheral surface by the connection between the small diameter pipe part 142a and the large diameter pipe part 142b, and the first sealing part G1a and the second sealing part G1b. It is located in the space part 153c.

  The boundary portion 142c is formed on the outer peripheral surface of the connection boundary portions formed on the inner peripheral surface and the outer peripheral surface of the inflow tube 142 by connecting the small-diameter pipe portion 142a and the large-diameter pipe portion 142b. It is a connection boundary part. Since the boundary 142c is located in the space 153c, even if ink leaks from the boundary 142c, the boundary 142c stays in the space 153c and does not leak to the outside.

  Of course, the first sealing portion G1a and the second sealing portion G1b can reduce the bonding area between the through hole 153 and the inflow pipe 142, and the space portion 153c allows the sealing portions G1a and G2b to be reduced. Since each can be easily elastically deformed, the deformation stress applied to the manifold member 14 due to the extension of the surrounding member 15 can be suppressed and improved.

  Also in this embodiment, the small-diameter pipe part 142a and the large-diameter pipe part 142b formed by the divided pipe parts may have a structure that is not in direct contact as described in the third embodiment. Similarly to FIG. 4, the through hole 153 is formed in a step shape having a large diameter portion 153a and a small diameter portion 153b, or is formed in a tapered shape that gradually decreases in diameter from the inner end side toward the outer end side. As a result, the effect of suppressing the deformation stress applied to the manifold member 14 can be further improved.

(Other embodiments)
In the ink jet head 1 described above, when the ink is used with its viscosity lowered until it can be ejected by heating, heating means such as a heater is provided in the common ink chamber 141 or on the outer surface of the manifold member 14. You may do it.

  Further, the number of ink tubes provided in the inkjet head 1 is not limited to two, that is, the inflow tube 142 and the outflow tube 143 described above, and may be three or more by providing additional inflow tubes or outflow tubes.

  Further, the peripheral member 15 may integrally have an attachment portion for positioning and attaching the inkjet head 1 to a carriage or the like.

  In the inkjet head 1 described above, the head chip 12 is exemplified as a shear mode type head chip in which the channels 121 and the drive walls 122 are alternately arranged in parallel, but the invention is not limited thereto. For example, the ink in the pressure chamber is ejected from the nozzle by the bursting action of bubbles generated when the ink in the pressure chamber is heated, or one wall surface of the pressure chamber is a vibration plate, and the ink in the pressure chamber is driven by the vibration action of the vibration plate. May be ejected from the nozzle.

1: Inkjet head 11: Nozzle plate 111:
12: Head chip 121: Channel (pressure chamber)
122: drive wall 13: wiring board 131: wiring 132: opening 14: manifold member 14a: upper surface 14b: side surface 141: common ink chamber 142: inflow pipe (ink pipe)
142a: Small diameter pipe part 142b: Large diameter pipe part 142c: Boundary part 143: Outflow pipe (ink pipe)
15: Peripheral member 151: Peripheral member body 152: Top plate 153, 154: Through hole 153a: Large diameter portion 153b: Small diameter portion 153c: Space portion 155: Opening portion 156: Opening portion for board insertion G1-G3: Adhesive G1a : First sealing part G1b: second sealing part S: gap

Claims (11)

A head chip having a pressure chamber;
A manifold member having at least two ink tubes serving as ink flow paths and disposed on the ink inlet side of the pressure chamber;
A through hole having an inner diameter larger than the outer diameter of the ink tube for each ink tube, and a surrounding member that houses the manifold member in a state in which the ink tube is inserted into the through hole;
The inkjet head characterized in that the peripheral member has a thermal expansion coefficient larger than that of the manifold member, and is bonded to the ink pipe by an adhesive having a smaller elastic modulus than the peripheral member inside the through hole. .   The inkjet head according to claim 1, wherein the peripheral member is provided in a non-contact state with a gap between at least a side surface of the manifold member.   3. The ink tube according to claim 1, wherein the ink tube protrudes from a surface of the manifold member opposite to the head chip side and is arranged along a longitudinal direction of the head chip. Inkjet head. A plurality of the pressure chambers are arranged on the head chip,
4. The ink jet head according to claim 3, wherein the ink tube protrudes from the surface of the manifold member outside the pressure chambers located at both ends in the arrangement direction of the pressure chambers.   The inkjet head according to claim 1, wherein a gap between the through hole and the ink tube is larger on an inner end side than on an outer end side of the through hole. The outer diameter of the portion of the ink tube passing through the through hole is constant over the entire length of the through hole,
6. The ink jet head according to claim 5, wherein an inner diameter on the inner end side of the through hole is larger than an inner diameter on the outer end side of the through hole. The inner diameter of the through hole is constant over the entire length,
6. The ink jet head according to claim 5, wherein an outer diameter of the ink tube located on the inner end side of the through hole is smaller than an outer diameter of the ink tube located on the outer end side of the through hole.   Between the through hole and the ink tube, a first sealing portion located on the inner end side of the through hole and a second seal located on the outer end side of the through hole are formed by the adhesive. That at least two sealing portions of the portion are formed, and a space portion where no adhesive is present is formed between the first sealing portion and the second sealing portion. The inkjet head according to any one of claims 1 to 4, wherein   The ink tube is divided into a first tube portion protruding from the manifold member and a second tube portion connected to the first tube portion, and the first tube portion 9. The ink jet head according to claim 8, wherein a boundary portion formed on the outer peripheral surface by connection with the second pipe portion is located in the space portion.   The inkjet head according to claim 9, wherein a gap between the through hole and the first tube portion is larger than a gap between the through hole and the second tube portion. The inner diameter of the through hole is constant over the entire length,
The inkjet head according to claim 10, wherein an outer diameter of the first tube portion is smaller than an outer diameter of the second tube portion.

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