Inkjet head

Abstract

The inkjet head includes: a flow path portion having at least a nozzle and a flow path for supplying ink to the nozzle; a pressure variation unit that varies the pressure of the ink; and a support body that supports the pressure fluctuation part, the support body being connected to the flow path part, and the support body having a vibration conversion part that converts vibration in the first direction generated by the pressure fluctuation part into vibration in a second direction perpendicular to the first direction.

Description

Technical Field

[0001] The present invention relates to an ink jet head for an ink jet device. Background Art

[0002] In recent years, a method of manufacturing a device using an inkjet device has attracted attention. The inkjet device ejects ink droplets from a plurality of nozzles provided in an inkjet head while controlling the positional relationship between the printing object and the printing object, thereby applying ink to the printing object.

[0003] As the demand for high-definition printing increases, inkjet heads need to have narrower nozzle pitches and higher droplet ejection frequencies. In addition, the ejected ink needs to be ejected with greater force in order to increase the viscosity of the ejected ink.

[0004] In an inkjet head that realizes the ejection of such narrow-pitch nozzles, high ejection frequency, and high-viscosity ink, when ink is ejected from multiple nozzles at the same time, driving components such as PZT elements and ink flow path components vibrate slightly in the ejection direction of the ink. As a result, so-called structural crosstalk occurs in which the ejection nozzles affect each other, and this structural crosstalk becomes a problem.

[0005] As a method of suppressing the structural crosstalk, it is considered to increase at least one of the rigidity and weight of at least one of the drive member and the flow path member to suppress the vibration. Patent document 1 discloses a method of joining the drive member and the flow path member to a heavy base member to dampen the vibration.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent No. 6557863 Summary of the invention

[0009] One embodiment of the inkjet head of the present invention has:

[0010] a flow path portion including at least a nozzle and a flow path for supplying ink to the nozzle;

[0011] a pressure varying section that varies the pressure of the ink; and

[0012] a support body that supports the pressure changing portion,

[0013] The support body is connected to the flow path portion, and includes a vibration conversion portion that converts vibration in a first direction generated by the pressure changing portion into vibration in a second direction perpendicular to the first direction.

[0014] One embodiment of the inkjet head of the present invention has:

[0015] a flow path portion including at least a nozzle and a flow path for supplying ink to the nozzle;

[0016] a pressure varying section that varies the pressure of the ink; and

[0017] a support body that supports the pressure changing portion,

[0018] The support body has:

[0019] a beam portion extending in a longitudinal direction and supporting the pressure changing portion at a central portion in the longitudinal direction; and

[0020] The first connecting portion and the second connecting portion are respectively disposed at the first end portion and the second end portion of the beam portion and connected to the flow path portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is an exploded perspective view showing the overall structure of the inkjet head according to the embodiment.

[0022] Figure 2 This is a cross-sectional view of the vicinity of one nozzle that ejects ink in the inkjet head.

[0023] Figure 3 It is a simplified line cross-sectional view for simply showing the relationship among the base portion, the pressure changing portion, and the flow path portion.

[0024] Figure 4 It is a cross-sectional view showing the base part.

[0025] Figure 5 This is a simplified line cross-sectional view for explaining the vibration conversion operation using the base portion.

[0026] Figure 6 It is a cross-sectional view of a base showing the structure of another embodiment.

[0027] Figure 7 It is a cross-sectional view of a base showing the structure of another embodiment.

[0028] Figure 8 It is a cross-sectional view of a base showing the structure of another embodiment. DETAILED DESCRIPTION

[0029] In the method described in Patent Document 1, the weight of the base unit needs to be increased in order to suppress vibration, which has the problem of trade-off with miniaturization. Especially recently, with the demand for high-precision printing accuracy, there is a demand for further suppression of structural crosstalk. When the structural crosstalk is to be fully suppressed using the previous method, the weight of the base unit needs to be made quite heavy. As a result, the capacity of the base unit increases, which leads to the enlargement of the inkjet head.

[0030] The present invention has been made in consideration of the above points, and provides an inkjet head capable of effectively suppressing structural crosstalk while suppressing an increase in the capacity of a base portion.

[0031] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0032] <1> Overall structure of inkjet head

[0033] Figure 1 : is an exploded perspective view showing the overall structure of the inkjet head 1 according to the embodiment. In the embodiment, the description is made using an orthogonal coordinate system (X, Y, Z). Figure 1 In the figure, the -Z direction is the ejection direction of ink from the inkjet head 1, the Y direction is the length direction of the inkjet head 1 (also referred to as the arrangement direction of the nozzles), and the X direction is the width direction of the inkjet head 1. In addition, the Z direction can also be referred to as the stacking direction of the plates as the components of the inkjet head 1.

[0034] The inkjet head 1 includes a housing 10 , a vibration plate 20 , a flow channel plate 30 , a nozzle plate 40 , a pressure changing unit 50 , and a base 60 .

[0035] The pressure changing portion 50 is formed at the lower end portion of the base portion 60. The upper portion of the housing portion 10 is opened, and the pressure changing portion 50 and the base portion 60 are housed in the housing portion 10 through the opening.

[0036] The flow path portion 70 is provided on the lower surface side of the housing portion 10 via the vibration plate 20. The flow path portion 70 includes the flow path plate 30 and the nozzle plate 40. The vibration plate 20, the flow path plate 30, and the nozzle plate 40 are fixedly laminated in this order.

[0037] The nozzle plate 40 and the flow path plate 30, the flow path plate 30 and the vibration plate 20, the vibration plate 20 and the housing 10, the vibration plate 20 and the pressure change part 50, the base part 60 and the vibration plate 20, and the base part 60 and the pressure change part 50 are fixed by means of adhesives or the like. As the adhesive, for example, an epoxy adhesive having a thermosetting property is used. It should be noted that as the adhesive for joining the various components, the same adhesive may be used, or different adhesives may be used. For example, a rubber adhesive and an epoxy adhesive may be used in combination.

[0038] Figure 2 It is a cross-sectional view of the vicinity of one nozzle that ejects ink in the inkjet head 1 .

[0039] The nozzle plate 40 is formed by, for example, molding a stainless steel plate having a thickness of 100 μm by etching or pressing. A plurality of nozzles 41 are provided through the nozzle plate 40 in the Y direction.

[0040] The flow path plate 30 is formed in a rectangular parallelepiped shape. The flow path plate 30 is formed by stacking, for example, stainless steel plate members having a thickness of 10 to 100 μm formed by etching or stamping. The number of stacked layers is, for example, 3 to 10. The flow path plate 30 is formed with a plurality of pressure chambers 33 connected one-to-one with the plurality of nozzles 4, and a silo portion 36 connecting the pressure chambers 33 with the nozzles 41.

[0041] The pressure chamber 33 is formed in a rectangular parallelepiped shape extending along the X direction of the flow path plate 30, and the upper wall forming the upper side (+Z direction) surface is composed of the vibration plate 20. It should be noted that the pressure chamber 33 may not be a rectangular parallelepiped but may have a plurality of steps inside. The silo part 36 connects the pressure chamber 33 with the nozzle 41 and stores ink. The silo part 36 is formed along the Z direction.

[0042] In addition, the flow path plate 30 is provided with upstream side individual flow path portions 32 which are connected one-to-one with the pressure chamber 33 on the upstream side, an upstream side common flow path portion 31 which is connected with multiple upstream side individual flow path portions 32, downstream side individual flow path portions 34 which are connected one-to-one with the pressure chamber 33 on the downstream side, and a downstream side common flow path portion 35 which is connected with multiple downstream side individual flow path portions 34.

[0043] The vibration plate 20 is a thin film having a thickness of 5 to 50 μm, for example, and is formed of Ni, for example. The vibration plate 20 has an upstream opening 21 disposed just above the upstream common flow path 31 (in the +Z direction) and a downstream opening 22 disposed just above the downstream common flow path 35 (in the +Z direction).

[0044] The housing 10 is formed in a rectangular parallelepiped shape. The housing 10 is formed by cutting alloy steel such as stainless steel. The thickness of the housing 10 in the Z direction is, for example, about 1 cm.

[0045] The housing 10 includes an upstream common flow path 12 disposed just above the upstream opening 21 (in the +Z direction) and a downstream common flow path 14 disposed just above the downstream opening 22 (in the +Z direction). The upstream common flow path 12 of the housing 10, the upstream common flow path portion 31 of the flow path plate 30, and the upstream opening 21 of the vibration plate 20 form the upstream common flow path L1. The downstream common flow path 14 of the housing 10, the downstream common flow path portion 35 of the flow path plate 30, and the downstream opening 22 of the vibration plate 20 form the downstream common flow path L.

[0046] In addition, an ink introduction path (not shown) for introducing ink from the outside and an ink discharge path (not shown) for discharging ink to the outside are formed in the housing portion 10. The ink introduced into the upstream common flow path L1 via the ink introduction path is discharged from the ink discharge path via the upstream common flow path L1, the upstream individual flow path portion 32, the pressure chamber 33, the downstream individual flow path portion 34, and the downstream common flow path L2 in the following order.

[0047] The pressure changing unit 50 is disposed inside the housing, and applies pressure changes to the ink in the pressure chamber 33. The pressure changes propagate toward the nozzles 41, and the ink is ejected from the nozzles 41.

[0048] The vibration plate 20 is provided with a convex portion 24 protruding in the +Z direction, and the fluctuation of the pressure varying portion 50 is input by the convex portion 24. A plurality of convex portions 24 are formed in parallel in the Y direction at positions corresponding to the nozzles 41.

[0049] The pressure changing part 50 is composed of a piezoelectric element. Specifically, the pressure changing part 50 is composed of a piezoelectric element. Specifically, the pressure changing part 50 has a driving part (not shown) that inserts an electrode into the piezoelectric element and applies an electrical signal to the electrode to drive it. The driving part is separated into a plurality of channels corresponding to the nozzle 41 one-to-one by the slit 50a. The pressure changing part 50 is supported by the base part 60. In other words, the base part 60 can also be said to be a supporting body that supports the pressure changing part 50. It should be noted that a control substrate 51 for controlling the piezoelectric element of the pressure changing part 50 is installed on the base part 60. The control substrate 51 is electrically connected to the pressure changing part 50. It should be noted that in Figure 2 , an example is shown in which the control substrate 51 is mounted on the base portion 60 , but the control substrate 51 may be mounted on a portion other than the base portion 60 .

[0050] The pressure changing part 50 is arranged to contact the convex part 24 of the vibration plate 20 constituting the upper side wall (+Z direction side wall) of the pressure chamber 33. The piezoelectric element deforms so as to expand and contract in the Z direction when a voltage is applied. Specifically, the piezoelectric element is a D33 mode stacked piezoelectric actuator.

[0051] The piezoelectric element is deformed so as to extend in the Z direction, and the convex portion 24 is pressed downward (in the -Z direction). As a result, the upper side wall (+Z direction side wall) of the pressure chamber 33 is deformed, and the pressure change of the ink in the pressure chamber 33 is generated. The pressure change is transmitted toward the nozzle 41 through the silo portion 36, and the ink is ejected from the nozzle 41 to the outside. In this way, the piezoelectric element of the pressure change portion 50 is operated, thereby controlling the ejection of the ink.

[0052] <2> Structure and Operation of the Base Unit 60

[0053] The present invention is characterized by the structure of the base portion 60 , and therefore the base portion 60 will be described in detail here.

[0054] Figure 3 2 is a simplified cross-sectional view showing the relationship among the base portion 60, the pressure changing portion 50 and the flow path portion 70. Figure 3 In the figure, the vibration plate 20 is omitted. The pressure change portion 50 is bonded to the lower surface of the base portion 60 at the bonding surface A by using an adhesive. The pressure change portion 50 and the flow path portion 70 are bonded to the bonding surface B by using an adhesive. In fact, the pressure change portion 50 is connected to the flow path portion 70 via the vibration plate 20 ( Figure 1 , Figure 2 ) and connected to the flow path portion 70.

[0055] Both ends of the base portion 60 in the Y direction are bonded to the upper surface of the flow path portion 70 by adhesive at bonding surfaces C and D. The pressure changing portion 50 is divided into a plurality of channels in the Y direction by the slits 50a.

[0056] An example of the manufacturing steps is described. First, the base portion 60 is joined to the pressure changing portion 50. Next, the pressure changing portion 50 is processed. Specifically, a plurality of slits 50a are formed in the piezoelectric element so as to be divided into a plurality of driving channels by cutting. Next, both ends of the base portion 60 are joined to the upper surface of the flow path portion 70 (more specifically, the vibration plate 20) by bonding.

[0057] Figure 4 2 is a cross-sectional view showing a single body of the base portion 60. The base portion 60 includes a weight body 61, a beam portion 62, and connection portions 63 (first and second connection portions).

[0058] The beam portion 62 extends in the Y direction, which is the length direction of the base portion 60, and supports the pressure changing portion 50 at the center portion in the length direction. Figure 3 As shown, the pressure varying portion 50 is joined to the lower surface of the center portion in the longitudinal direction of the beam portion 62. In addition, a weight body 61 is provided on the upper surface of the center portion in the longitudinal direction of the beam portion 62.

[0059] It should be noted that the beam portion 62 may be referred to as a connecting portion that connects the two connecting portions 63. In addition, the weight body 61 may be referred to as a weight increasing portion that increases the weight of the base portion 60.

[0060] The two connection parts 63 are formed so as to protrude downward (in the −Z direction) from both ends of the beam part 62. The lower surface of the connection part 63 is connected to the flow path part 70 via the vibration plate 20. In the present embodiment, the lower surface of the connection part 63 is connected to the upper surface of the flow path part 70 via the vibration plate 20 using an adhesive.

[0061] In practice, the base portion 60 can be manufactured by cutting out from the same material. Figure 4 In order to easily illustrate the weight body 61, the beam portion 62, and the connection portion 63, a boundary line is described between them for convenience, but these portions are not actually separated as components.

[0062] Here, the relationship among the weight body 61 , the beam portion 62 , and the connection portion 63 will be further described.

[0063] The weight body 61 is arranged at a substantially central position in the Y direction of the beam portion 62, and the total length in the Y direction of the weight body 61 is shorter than the total length in the Y direction of the beam portion 62. Therefore, there are regions where the weight body 61 does not exist in the upper direction (+Z direction) of both ends of the beam portion 62 and in the upper direction (+Z direction) of the connecting portion 63. In addition, the height in the Z direction of the beam portion 62 is lower than the height in the Z direction of the weight body 61.

[0064] As a result, if Figure 5 As shown in FIG. 1 , when a force in the Z direction is applied to the beam portion 62, the beam portion 62 is deformed in such a manner that it bends in the Z direction with the thin-walled portion 62a as a starting point. Figure 5 In order to easily understand the action of the beam 62, the beam 62 is also bent near the center of the beam 62, but in fact, the beam 62 does not bend greatly near the center of the beam 62 because of the presence of the weight body 61. However, the beam 62 is bent at least at the thin-walled portion 62a where the weight body 61 is not present.

[0065] Next, the operation of this embodiment will be described.

[0066] The inkjet head 1 drives the piezoelectric element of the pressure change section 50 when the ink is ejected. At this time, the piezoelectric element is deformed in a manner of extending in the Z direction, causing the pressure of the ink in the pressure chamber 33 of the flow path plate 30 to change, resulting in the ink being ejected from the nozzle 41 to the outside. The pressure change section 50 and the flow path section 70 are vibrated integrally by the reaction force caused by the pressure propagation of the ink. In particular, when the channels of the pressure change section 50 are expanded and contracted at the same time, the value of the propagated pressure increases, so vibration is easily generated. When such vibration occurs, the ink ejection stability is deteriorated.

[0067] In this embodiment, the base portion 60 suppresses the vibration. Specifically, the base portion 60 is bent by the beam portion 62 to Figure 5 The direction of the force is converted by the input of the force generated by the vibration as shown by the arrow 100. Specifically, the force caused by the vibration in the Z direction shown by the arrow 100 is converted into a force including a Y direction component at the bonding surface C of the connecting portion 63 as shown by the arrow 200.

[0068] That is, the base portion 60 of the present embodiment functions as a vibration converter that converts the direction of the force of the vibration generated by the pressure changing portion 50 into a force in the surface direction (Y direction) of the flow path portion 70 .

[0069] On the other hand, the connection portion 63 is bonded to the flow path portion 70 at the bonding surface C via the vibration plate 20 .

[0070] Since the flow path portion 70 has a thickness of about 0.1 to 0.5 mm, it is easy to deform in the vibration direction (in other words, it can be called the thickness direction or the Z direction), but it is almost not deformed in the direction perpendicular to the vibration direction (in other words, it can be called the surface direction or the Y direction). In other words, the flow path portion 70 has almost no force to restrict the movement in the vibration direction, but has sufficient strength for the direction perpendicular to the vibration direction and has a large restrictive force for the movement in this direction. Therefore, the base portion 60 joined to the flow path portion 70 is restricted by the flow path portion 70 in the displacement in the direction perpendicular to the vibration direction.

[0071] That is, the vibration force given to the beam 62 in the Z direction due to the pressure fluctuation is converted by the beam 62 and the connection portion 63 into a force including a direction perpendicular to the vibration direction, but the rigidity of the flow path portion 70 in the direction perpendicular to the vibration direction is very high, so as a result, the beam 62 and the connection portion 63 hardly fluctuate, and the fluctuation of the vibration direction of the beam 62 is limited. Therefore, the vibration of the pressure fluctuation portion 50 and the flow path portion 70 in the Z direction (vibration direction) can be suppressed.

[0072] As described above, according to the structure of this embodiment, the vibration in the Z direction can be suppressed even without increasing the weight of the weight body 61 to suppress the vibration in the Z direction, so the trade-off between vibration suppression and miniaturization of the inkjet head 1 can be improved.

[0073] Here, in recent years, there has been a growing demand for high-precision ink coating performance brought about by inkjet devices, for example, a requirement for an ink ejection amount of 1-5pL, a requirement for an ejection accuracy of 1-10μm, etc. In addition, a requirement for ejecting high-viscosity inks such as 5-50cp. In order to achieve such performance, it is necessary to suppress the vibration of the pressure change portion 50 and the flow path portion 70 in the Z direction to a very small level. In the structure of this embodiment, the vibration in the Z direction can be suppressed to a very small level without increasing the weight of the weight body 61, so that an inkjet head 1 that can take into account both miniaturization and improved printing accuracy can be realized.

[0074] <3> Effects of implementation

[0075] As described above, the inkjet head 1 of the present embodiment comprises: a flow path portion 70, which has at least a nozzle 41 and a flow path for supplying ink to the nozzle 41; a pressure change portion 50, which causes the pressure of the ink to change; and a support body (base portion 60), which supports the pressure change portion 50, the support body (base portion 60) is connected to the flow path portion 70, and the support body (base portion 60) has a vibration conversion portion that converts a vibration in a first direction generated by the pressure change portion 50 into a vibration in a second direction perpendicular to the first direction.

[0076] Thus, it is possible to realize an inkjet head 1 that can achieve both miniaturization and improved printing accuracy by effectively suppressing structural crosstalk while suppressing an increase in the capacity of the support body (base portion 60). More specifically, in the present invention, even if the base portion 60 is not enlarged, the force conversion effect brought about by the base portion 60 having a beam structure and the effect that the force in the surface direction brought about by the flow path portion 70 is strong are used to effectively suppress the vibration generated by the pressure changing portion 50.

[0077] In addition, according to the present embodiment, the support body (base portion 60) includes: a beam portion 62 extending in the longitudinal direction and supporting the pressure changing portion 50 in the central portion in the longitudinal direction; and first and second connecting portions 63 respectively disposed at the first and second ends of the beam portion 62 and connected to the flow path portion 70.

[0078] Furthermore, according to the present embodiment, the support body (base portion 60 ) includes the thin-walled portion 62 a whose thickness in the first direction is thinner than the center of the support body.

[0079] Thus, the support body (base portion 60) can be made to function as a vibration conversion portion that converts the direction of the vibration force generated by the pressure changing portion 50 into the surface direction of the flow path portion 70 (in other words, a direction perpendicular to the original vibration direction) using a simple structure.

[0080] <4> Other implementation methods

[0081] The above-mentioned embodiment is only an example of the embodiment of the present invention, and the technical scope of the present invention should not be interpreted in a limiting manner. That is, the present invention can be implemented in various forms within the scope of its gist or its main features.

[0082] In the above-mentioned embodiment, if using Figure 4 as well as Figure 5 As described above, by making the total length of the weight body 61 in the Y direction shorter than the total length of the beam portion 62 in the Y direction, a thin-walled portion 62a is formed, and the thin-walled portion 62a is used to realize the function of a vibration conversion portion that converts the direction of the force of the vibration generated by the pressure change portion 50 into a direction perpendicular to the direction. The present invention is not limited to this, and for example, Figure 6 , Figure 7 as well as Figure 8 The structure enables the base parts 60a, 60b, and 60c to function as vibration conversion parts.

[0083] To Figure 4 The corresponding parts are marked with the same reference numerals. Figure 6 The base portion 60a has a notch portion 61a1. The notch portion 61a1 is obtained by cutting off a part of the weight body 61a in a manner that forms a space above the two ends of the beam portion 62 and above the connecting portion 63. According to this structure, as in the above-mentioned embodiment, a thin-walled portion 62a that is thin and easy to bend can be formed near the two ends of the beam portion 62. Therefore, the beam portion 62 bends along with the vibration generated by the pressure change portion 50, so that it can function as a vibration conversion portion. In addition, according to this structure, only the notch portion 61a1 is formed, so compared with the embodiment, the vibration conversion portion can be realized by simpler processing.

[0084] To Figure 4 The corresponding parts are marked with the same reference numerals. Figure 7 The base portion 60b has a notch portion 61b1. The notch portion 61b1 is formed near both ends of the beam portion 62 in a manner that penetrates the thickness of the weight body 61b in the Z direction. According to this structure, a thin-walled portion 62a that is thinner and easier to bend can be formed near the lower portion of the notch portion 61b1. The thin-walled portion 62a is connected to the two end portions 61b2 of the weight body 61b (in other words, the portion of the weight body 61b that is closer to the outside than the notch portion 61b1). Therefore, along with the vibration generated by the pressure change portion 50, the beam portion 62 can bend with the thin-walled portion 62a as the starting point, and become one with the two end portions 61b2 of the weight body 61b to play the function of a vibration conversion portion. In addition, according to this structure, only the notch portion 61b1 is required, so compared with the embodiment, the vibration conversion portion can be realized by simpler processing.

[0085] To Figure 4 The corresponding parts are marked with the same reference numerals. Figure 8 The two shoulders 61c1 of the weight body 61c of the base part 60c are cut off obliquely. According to this structure, the two ends of the weight body 61c are less rigid than when the two shoulders of the weight body 61c are not cut off obliquely, and the base 60c is easy to bend due to the vibration in the Z direction. In other words, it is easy to realize the function as a vibration conversion part. Moreover, the two ends of the two shoulders 61c in the length direction are located at a position closer to the inside than the connecting part 63. Therefore, in Figure 8 In the structure, the vicinity of both ends of the beam portion 62 has the same effect as the thin-walled portion 62a, and the vibration conversion function can be further exerted by utilizing the notches of the two shoulders.

[0086] exist Figure 4 , Figure 6 - Figure 8 In the structure shown, a thin-walled portion 62a thinner than the center in the vibration direction is formed on the base portion 60, 60a, 60b, and 60c, and the beam portion 62 is bent along with the vibration in the Z direction, thereby realizing the vibration conversion portion. This is described, but it is not limited to this. In order to realize the vibration conversion portion, a portion that is bent along with the vibration in the Z direction can be formed on the beam portion 62 of the base portion (in other words, the support body), and a low-rigidity portion with lower rigidity than other portions can be formed instead of the thin-walled portion 62a. In short, a portion that is easy to bend in the Z direction is provided on the support body of the support pressure change portion 50, and the direction of the vibration force can be converted into a direction perpendicular to the vibration direction by using this deflection.

[0087] In addition to the structure of the above-mentioned embodiment, it is also possible to improve the bonding structure of the base portion 60 and the flow path portion 70, thereby further suppressing the vibration generated by the pressure change portion 50. This is explained. The base portion 60 and the flow path portion 70 are preferably bonded using an adhesive containing beads having a diameter of 2 μm or more and 6 μm or less. The thickness of the adhesive is determined according to the diameter of the beads, so the thickness of the adhesive can be adjusted to a desired thickness. For example, when the thickness of the adhesive is greater than 20 μm, the adhesive itself can deform in the shear direction, so the vibration suppression effect caused by the restriction based on the surface direction of the flow path portion 70 is weakened. On the other hand, when the thickness of the adhesive is too thin, gaps in the adhesive are generated, resulting in problems such as reduced adhesive force and ink leakage.

[0088] Considering this, the adhesive bonding the base 60 and the flow path 70 preferably includes beads with a diameter of about 2-6 μm. This can suppress deformation of the adhesive in the shear direction and generation of cracks in the adhesive, and can effectively suppress vibration of the pressure fluctuation unit 50 by the flow path 70.

[0089] In addition, the base portion 60 and the flow path portion 70 are preferably bonded via a thermosetting adhesive because room temperature curing adhesives often have insufficient performance in terms of bonding strength and solvent resistance.

[0090] In addition, when a thermosetting adhesive is used, the thermal expansion coefficient of the base portion 60 is preferably smaller than that of the flow path portion 70. The reason is described. When the thermal expansion coefficient of the base portion 60 is large, the adhesive is cured in a state where the base portion 60 is stretched more than the flow path portion 70, and the two parts are joined. Therefore, when the adhesive is heated and cured and returns to room temperature, the contraction amount of the base portion 60 is larger than the contraction amount of the flow path portion 70, so the base portion 60 generates a force that pulls the flow path portion 70 in the inner direction (the center direction in the Y direction). The flow path portion 70 is weaker in rigidity than the base portion 60, so it sometimes buckles under the action of the pulling force and generates tiny wrinkles. When a force is applied to the surface direction of the flow path portion 70 by the connecting portion 63 in a state where wrinkles are generated in the flow path portion 70, the restricting force of the connecting portion 63 brought by the flow path portion 70 becomes weak, and the vibration suppression effect generated by the pressure change portion 50 is reduced.

[0091] On the other hand, when the thermal expansion coefficient of the base portion 60 is smaller than that of the flow path portion 70, the adhesive is cured and the two parts are joined in a state where the flow path portion 70 is stretched more than the base portion 60. Therefore, when the adhesive finishes heating and curing and returns to room temperature, the contraction amount of the flow path portion 70 is greater than the contraction amount of the base portion 60, so the base portion 60 generates a force that pulls the flow path portion 70 outward (the end direction in the Y direction). If the force is pulled outward, the flow path portion 70 will not be buckled, and no tiny wrinkles will be generated. Therefore, when the connection portion 63 is used to apply a force to the surface direction of the flow path portion 70, the displacement of the connection portion 63 in the surface direction caused by the flow path portion 70 can be reliably limited, and the vibration generated by the pressure change portion 50 can be reliably suppressed.

[0092] According to the present invention, it is possible to realize an inkjet head capable of efficiently suppressing structural crosstalk while suppressing an increase in the capacity of the base portion.

[0093] Industrial Applicability

[0094] The technology of the present invention is suitable for an inkjet head having a pressure variation unit that applies pressure variation to ink.

[0095] Description of Reference Numerals

[0096] 1 Inkjet head

[0097] 10 Housing

[0098] 20 Vibration Plate

[0099] 30 Manifold board

[0100] 40 Nozzle Plate

[0101] 41 Nozzle

[0102] 50 Pressure change part

[0103] 60, 60a, 60b, 60c Base

[0104] 61, 61a, 61b, 61c Weight body

[0105] 62 beam

[0106] 62a Thin wall part

[0107] 63 Connection

[0108] 70 Flow path section

[0109] A, B, C, D bonding surfaces.

Claims

1. An inkjet head, wherein: The inkjet head has: a flow path portion including at least a nozzle and a flow path for supplying ink to the nozzle; a pressure varying unit for varying the pressure of the ink; as well as a support body that supports the pressure changing portion, The support body is connected to the flow path portion, and includes a vibration conversion portion that converts vibration in a first direction generated by the pressure changing portion into vibration in a second direction perpendicular to the first direction.

2. An inkjet head, wherein: The inkjet head has: a flow path portion including at least a nozzle and a flow path for supplying ink to the nozzle; a pressure varying section that varies the pressure of the ink; and a support body that supports the pressure changing portion, The support body has: a beam portion extending in a longitudinal direction and supporting the pressure changing portion at a central portion in the longitudinal direction; and The first connecting portion and the second connecting portion are respectively disposed at the first end portion and the second end portion of the beam portion and connected to the flow path portion.

3. The inkjet head according to claim 1 or 2, wherein: The support body has a thin-walled portion whose thickness in the first direction is thinner than that in the center of the support body.

4. The inkjet head according to claim 2, wherein: The support body further includes a weight body that is shorter than the beam portion and is disposed at the central portion. The first end portion and the second end portion each have a region where the weight body does not exist.

5. The inkjet head according to claim 2, wherein: The vibration generated by the pressure changing portion is a vibration having a direction perpendicular to the surface of the flow path portion as a main component. The beam portion converts the vibration in the first direction into the vibration in the second direction by deflection of the beam portion.

6. The inkjet head according to claim 2, wherein: The first connection portion and the second connection portion are connected to the flow path portion using an adhesive including beads having a diameter of 2 μm or more and 6 μm or less.

7. The inkjet head according to claim 1 or 2, wherein: The support body is connected to the flow path portion using a thermosetting adhesive. The support body has a thermal expansion coefficient smaller than a thermal expansion coefficient of the flow path portion.

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