JP2016068382A - Ink jet head and ink jet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet head capable of smoothly supplying ink flowing in the ink jet head to a nozzle.SOLUTION: An ink jet head 31 includes a first member 40, a second member 47, a third member 51, and a fourth member 59. The first member includes a nozzle 41. The second member includes a first flow channel 48. The third member includes a pressure chamber 52 and a first inflow part. The first inflow part 53 supplies ink flowing through the first flow channel to the pressure chamber. A driving element 61 is provided in the fourth member. The first member, the second member, the third member, and the fourth member are bonded together by a first adhesive layer 63, a second adhesive layer 64, and a third adhesive layer 65. The first inflow part includes a first inner peripheral surface 54, a second inner peripheral surface 55, and a first step surface 56. The first inner peripheral surface is connected to the first flow channel, and a flow channel diameter is set to a first value. The second inner peripheral surface is connected to the pressure chamber, and a flow path channel is set to a second value. The first step surface is generated at a boundary between the first inner peripheral surface and the second inner peripheral surface in a first direction.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an inkjet head and an inkjet recording apparatus.

  A technique related to an inkjet head of an inkjet recording apparatus has been proposed. For example, Patent Document 1 discloses an inkjet head. In this ink jet head, the flow path plate and the drive plate are joined by an adhesive. The channel plate is provided with a nozzle groove and a relief groove. When the drive plates are joined, the adhesive flows into the escape groove.

  Patent Document 2 discloses an ink jet recording head. In this ink jet recording head, a nozzle plate, a pool plate, a supply hole plate, a pressure chamber plate, and a vibration plate are sequentially stacked, and an actuator is attached. Each plate is bonded together by a plurality of adhesive layers. The thickness of each adhesive layer is adjusted according to the thinner one of the two substrates to be bonded together. The thickness of the adhesive layer used for laminating thin substrates is made thinner than the thickness of the adhesive layer used for laminating substrates thicker than this substrate.

  Patent Document 3 discloses an ink jet print head as a liquid ejecting apparatus. The ink jet print head includes a liquid flow path member. The liquid flow path member is formed by stacking an ejection hole plate, a pool plate, a supply hole plate, a sealing plate, a pressure chamber plate, and a vibration plate. Inside the liquid flow path member, a liquid flow path from the liquid pool to the supply hole, the supply communication path, the pressure chamber, the communication hole, and the liquid ejection hole is formed by a through hole formed in each plate. The liquid flow path member is obtained by laminating and bonding each plate via an adhesive layer. In the liquid flow path member, an adhesive shielding protrusion for improving the sealing property between the plates is formed in a partition shape around the through hole on the surface of one of the opposing plates. The protrusion comes into contact with the surface of the opposite plate.

  Patent Document 4 discloses a droplet discharge head. In this droplet discharge head, the element substrate and the support substrate are bonded via an adhesive. The element substrate is obtained by bonding a first substrate, a second substrate, and a third substrate. When an adhesive application abnormality occurs, surplus adhesive in the middle of curing starts to penetrate into the common ink supply port of the first substrate and the inner wall of the ink supply port of the support substrate. The adhesive that protrudes remains in the step provided on the support substrate.

JP-A-5-330067 Japanese Patent No. 3166671 Japanese Patent No. 4620955 JP 2009-143014 A

  An inkjet head may be formed by laminating a plurality of members. Inside the ink jet head formed by laminating a plurality of members, a flow path is formed for flowing ink supplied from the ink tank to the nozzle. This flow path is formed by connecting and continuously forming holes and / or grooves formed in advance in each member to be laminated. Each member forming the ink jet head is bonded by an adhesive layer in a stacked state. The adhesive layer is formed by an adhesive. Therefore, when assembling the ink jet head, the adhesive applied to the end face of each member may flow into the above-described holes and / or grooves, which are the flow paths inside the ink jet head. Due to the adhesive flowing into the holes and / or grooves, the flow path inside the ink jet head may become narrow or clogged. In such a case, the flow of ink inside the ink jet head is hindered. As a result, ink ejection failure from the nozzles may occur, and high-definition images may not be recorded.

  An object of the present invention is to provide an ink jet head and an ink jet recording apparatus that can smoothly supply ink flowing inside the ink jet head to nozzles.

  One aspect of the present invention is a second member including a first member including a nozzle that ejects ink, a first flow path through which the ink supplied from an ink tank flows, and a second flow path connected to the nozzle. A pressure chamber that stores the ink, a first inflow portion that connects the first flow path and the pressure chamber, and flows the ink flowing through the first flow path to the pressure chamber; the pressure chamber; A third member including an outflow portion connected to the second flow path and flowing the ink stored in the pressure chamber to the second flow path; and acting on the ink stored in the pressure chamber And a fourth member provided with a drive element that generates energy for ejecting the ink from the nozzle, the first member, and the second member stacked on the first member. And a first adhesive layer for joining, and an adhesive Formed by a second adhesive layer that joins the second member and the third member stacked on the second member, and an adhesive, and the third member and the third member A third adhesive layer that joins the fourth member to be laminated, and the first inflow portion is connected to the first flow path, and the flow path diameter is set to a first value. And a second inner peripheral surface connected to the pressure chamber and having a flow path diameter set to a second value smaller than the first value, and the ink flows along the first inner peripheral surface through the first inflow portion. In the first direction, the ink jet head includes a first step surface generated at a boundary between the first inner peripheral surface and the second inner peripheral surface.

  According to this, it is suppressed that the 1st inflow part becomes narrow or clogged with the adhesive which forms the 2nd adhesion layer in the part (2nd part) of the 1st inflow part corresponding to the 2nd inner peripheral surface. can do. When joining the member corresponding to the second member and the member corresponding to the third member, the adhesive forming the adhesive layer corresponding to the second adhesive layer protrudes from between each end face of each member, It is conceivable to flow into the inflow portion connecting the flow path corresponding to the first flow path and the space corresponding to the pressure chamber. In this case, the inflow portion is assumed to be narrowed or clogged by the flowing adhesive. When the inflow portion is in the state described above, the ink flow is inhibited, and the ink flow from the flow path corresponding to the first flow path to the space corresponding to the pressure chamber is not smoothly performed. The ink flow may stop. As a result, the stability of ink ejection from the nozzles decreases. In the ink jet head described above, even if the adhesive forming the second adhesive layer protrudes from between the end surfaces of the second member and the third member, the corners of the first inner peripheral surface and the first step surface In the first step surface, the adhesive that flows along the first inner peripheral surface and proceeds toward the second portion can be stopped. As a result, it is possible to prevent the adhesive from reaching the second portion. Clogging of the first inflow portion in the second portion can be suppressed, and ink can flow from the first flow path to the pressure chamber. It is possible to prevent the stability of ink ejection from the nozzles from being lowered.

  In the inkjet head, the first step surface may be a surface along a second direction orthogonal to the first direction. According to this, the shape of the corner | angular part of a 1st internal peripheral surface and a 1st level | step difference surface can be made into a right angle. The adhesive flowing along the first inner peripheral surface can be stopped at this corner. For example, the performance of stopping the progress of the adhesive can be improved as compared with a configuration in which the angle formed by the first inner peripheral surface and the first step surface is wider than 90 °.

  In the inkjet head, the dimension corresponding to the first direction is set to a third value on the second inner peripheral surface, and the dimension corresponding to the first direction is set to the third value on the first inner peripheral surface. A large fourth value may be set. According to this, the tolerance | permissible_quantity with respect to the adhesive agent which protruded from between each end surface of a 2nd member and a 3rd member can be increased. When joining the second member and the third member, it is possible to apply an appropriate amount of adhesive to the end surfaces to be joined. The joint strength between the second member and the third member by the second adhesive layer can be improved. For example, it is possible to prevent a situation in which ink leaks from between the second member and the third member during image recording.

  In the ink jet head, the first inflow portion has a flow area of the first portion of the first inflow portion corresponding to the first inner peripheral surface. The flow path is set narrower than the area, and the area of the first step surface is set to be wider than the flow path area of the second portion of the first inflow portion corresponding to the second inner peripheral surface. Also good. According to this, ink can be smoothly flowed from the first flow path to the pressure chamber. The adhesive that proceeds toward the second portion can be stopped on the first step surface.

  In the ink jet head, the first member includes a second inflow portion that connects the second flow path and the nozzle and flows the ink flowing through the second flow path to the nozzle, and the second inflow The third inner peripheral surface having a flow path diameter set to a fifth value larger than the diameter of the nozzle at the boundary with the second inflow portion; and In a third direction flowing along the surface, a second step surface generated at the boundary between the third inner peripheral surface and the nozzle may be included. According to this, it can suppress that a nozzle becomes narrow or clogged with the adhesive agent which forms a 1st contact bonding layer. When joining the member corresponding to the first member and the member corresponding to the second member, the adhesive forming the adhesive layer corresponding to the first adhesive layer protrudes from between each end face of each member, It is possible to flow into the nozzle. In this case, it is assumed that the nozzle becomes narrow or clogged by the flowing adhesive. When the nozzle is in the above-described state, ink ejection is hindered or ink ejection is not performed. That is, the stability is lowered with respect to the ejection of ink from the nozzles. In the ink jet head described above, even if the adhesive forming the first adhesive layer protrudes from between the end faces of the first member and the second member, the corners of the third inner peripheral surface and the second step surface In the second step surface, the adhesive that flows along the third inner peripheral surface and proceeds to the nozzle side can be stopped. As a result, the adhesive can be prevented from reaching the nozzle. The clogging of the nozzle due to the adhesive can be suppressed, and the ink can flow from the second flow path to the nozzle. It is possible to prevent the stability of ink ejection from the nozzles from being lowered. In the above, the third direction may be a direction along the first direction. That is, the third direction may be the same as the first direction or the opposite direction to the first direction.

  Another aspect of the present invention is an inkjet recording apparatus including the inkjet head described above. According to this, an ink jet recording apparatus in which the above-described function is realized can be obtained.

  According to the present invention, an ink jet head and an ink jet recording apparatus that can smoothly supply ink flowing inside the ink jet head to nozzles can be obtained.

1 is a perspective view illustrating a schematic configuration of an ink jet recording apparatus. It is a perspective view which shows schematic structure of an inkjet head. It is the PQRS line sectional view shown in FIG. An example of the internal flow path of an inkjet head is shown.

  Embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to the configurations described below, and various configurations can be employed in the same technical idea. For example, some of the configurations shown below may be omitted or replaced with other configurations. Other configurations may be included.

<Inkjet recording apparatus>
The ink jet recording apparatus 10 will be described with reference to FIG. In the inkjet recording apparatus 10, the recording medium 15 is conveyed, and an image is recorded on the recording surface 16 of the recording medium 15. In the ink jet recording apparatus 10, images are recorded on various recording media 15. As the recording medium 15, for example, a fabric or a building material is used. In the embodiment, a case where the recording medium 15 is a long fabric will be described as an example. The ink colors used for image recording are four colors of black, magenta, yellow and cyan. The ink color may be a color other than these. The number of ink colors may be 3 colors or less or 5 colors or more. The halftone dot pattern attached to the portion of the recording medium 15 illustrated on the downstream side in the conveyance direction in FIG. 1 corresponds to the image recorded on the recording medium 15.

  As shown in FIG. 1, the ink jet recording apparatus 10 includes a transport unit 20, a recording unit 30, a moving unit 70, main tanks 80K, 80M, 80Y, and 80C, and supply channels 81K, 81M, 81Y, and 81C. Prepare. The transport unit 20 transports the recording medium 15 along the longitudinal direction of the recording medium 15. The recording medium 15 transported by the transport unit 20 passes through the recording unit 30. In the embodiment, a direction in which the recording medium 15 is transported by the transport unit 20 is referred to as a “transport direction”. A direction perpendicular to the longitudinal direction and the transport direction of the recording medium 15 is referred to as a “main scanning direction”. The main scanning direction coincides with the short direction of the recording medium 15. The short side direction of the recording medium 15 is the width direction of the recording medium 15. A direction that coincides with the longitudinal direction of the recording medium 15 and is orthogonal to the short side direction and the main scanning direction of the recording medium 15 is referred to as a “sub-scanning direction”.

  The recording unit 30 includes inkjet heads 31K, 31M, 31Y, 31C and a carriage 35. The inkjet head 31K is an inkjet head that discharges black ink and records an image with the black ink. A plurality of nozzles 41 (see FIG. 3) for discharging black ink are formed in the inkjet head 31K. The inkjet head 31M is an inkjet head that discharges magenta ink and records an image with the magenta ink. A plurality of nozzles 41 that eject magenta ink are formed in the inkjet head 31M. The inkjet head 31Y is an inkjet head that discharges yellow ink and records an image with the yellow ink. A plurality of nozzles 41 for discharging yellow ink are formed on the inkjet head 31Y. The ink jet head 31C is an ink jet head that discharges cyan ink and records an image with the cyan ink. A plurality of nozzles 41 that discharge cyan ink are formed in the inkjet head 31C.

  The inkjet heads 31K, 31M, 31Y, and 31C are mounted on the carriage 35 in a state where they are positioned at predetermined positions. As shown in FIG. 1, the inkjet heads 31K, 31M, 31Y, and 31C are mounted on the carriage 35 in a state of being adjacent to each other in the main scanning direction. The arrangement order of the inkjet heads 31K, 31M, 31Y, and 31C may be different from that shown in FIG. These arrangement orders are appropriately determined in consideration of various conditions. The other description regarding the inkjet heads 31K, 31M, 31Y, and 31C will be described later.

  The moving unit 70 reciprocates the recording unit 30 in the main scanning direction. As shown in FIG. 1, the moving unit 70 includes two pulleys 71 and 72, a timing belt 73, and a motor 74. The two pulleys 71 and 72 are respectively provided on both sides in the main scanning direction with the transport unit 20 as a reference. A motor 74 is connected to the pulley 71. The pulley 72 is rotatably supported. The pulley 71 rotates as the motor 74 rotates. The timing belt 73 is stretched over pulleys 71 and 72 in a state where tension is applied. The recording unit 30 is attached to the timing belt 73 via a support unit 76 fixed to the carriage 35.

  The main tank 80K stores black ink. The supply flow path 81K connects the main tank 80K and the inkjet head 31K. The black ink flows out of the main tank 80K, flows through the supply flow path 81K, and is supplied to the inkjet head 31K. The main tank 80M stores magenta ink. The supply flow path 81M connects the main tank 80M and the inkjet head 31M. The magenta ink flows out from the main tank 80M, flows through the supply flow path 81M, and is supplied to the inkjet head 31M. The main tank 80Y stores yellow ink. The supply flow path 81Y connects the main tank 80Y and the inkjet head 31Y. The yellow ink flows out from the main tank 80Y, flows through the supply channel 81Y, and is supplied to the inkjet head 31Y. The main tank 80C stores cyan ink. The supply flow path 81C connects the main tank 80C and the inkjet head 31C. The cyan ink flows out of the main tank 80C, flows through the supply channel 81C, and is supplied to the inkjet head 31C.

  In FIG. 1, the supply flow paths 81K, 81M, 81Y, and 81C are illustrated in a simplified state. The supply channels 81K, 81M, 81Y, and 81C are provided in a state that can accommodate the reciprocating movement of the recording unit 30 in the main scanning direction. The ink jet recording apparatus 10 includes a pump (not shown) in addition to the above-described units. Four pumps are provided corresponding to the number of ink colors. Four pumps are provided in the supply flow paths 81K, 81M, 81Y, 81C, respectively. The inks of the respective colors stored in the main tanks 80K, 80M, 80Y, 80C are sent to the ink jet heads 31K, 31M, 31Y, 31C by the pumps for the respective colors.

  The inkjet heads 31K, 31M, 31Y, and 31C have the same configuration. The main tanks 80K, 80M, 80Y, 80C have the same configuration. Supply flow paths 81K, 81M, 81Y, 81C have the same configuration. In the embodiment, the inkjet heads 31K, 31M, 31Y, and 31C are referred to as “inkjet head 31” when they are not distinguished or are collectively referred to. When the main tanks 80K, 80M, 80Y, and 80C are not distinguished from each other or are collectively referred to as “main tank 80”. The supply flow paths 81K, 81M, 81Y, 81C are referred to as “supply flow path 81” when they are not distinguished or are collectively referred to.

  Image recording by the inkjet recording apparatus 10 is started when an image recording start command is input to the control device. In FIG. 1, illustration of the control device is omitted. The control device is communicably connected to the inkjet recording apparatus 10 and controls the inkjet recording apparatus 10. With the input of the start command to the control device, the moving unit 70 and the transport unit 20 operate as follows. That is, in the moving unit 70, the motor 74 connected to the pulley 71 reciprocally rotates in the clockwise and counterclockwise directions. As the motor 74 rotates, the pulley 71 rotates back and forth on both the left and right sides. An “arc-shaped arrow” shown inside the pulley 71 in FIG. 1 indicates the rotation direction of the pulley 71. When the pulley 71 rotates counterclockwise as the motor 74 rotates in a predetermined direction, the timing belt 73 also rotates counterclockwise. The pulley 72 rotates following the timing belt 73 that rotates counterclockwise. Accordingly, the recording unit 30 moves from the second side in the main scanning direction to the first side. When the recording unit 30 reaches the first moving end in the main scanning direction, the rotation direction of the motor 74 is reversed, and the pulley 71 rotates to the right. When the pulley 71 rotates to the right, the timing belt 73 also rotates to the right. The pulley 72 rotates following the timing belt 73 that rotates clockwise. Accordingly, the recording unit 30 moves from the first side in the main scanning direction to the second side. When the recording unit 30 reaches the second moving end in the main scanning direction, the rotation direction of the motor 74 is reversed again, and the pulley 71 rotates counterclockwise again.

  The transport unit 20 transports the recording medium 15 in the transport direction in response to the reciprocation of the recording unit 30 in the main scanning direction. That is, the conveyance of the recording medium 15 by the conveyance unit 20 is intermittently performed according to the reciprocating movement of the recording unit 30 in the main scanning direction. The inks of the respective colors are ejected toward the recording medium 15 from the nozzles 41 respectively formed on the inkjet heads 31K, 31M, 31Y, and 31C at a predetermined timing when the recording unit 30 moves in the main scanning direction. The inks of the respective colors ejected from the nozzles 41 of the inkjet heads 31K, 31M, 31Y, and 31C land on the recording surface 16 of the recording medium 15. An image is recorded on the recording surface 16 of the recording medium 15 by the landed ink of each color. The recording surface 16 of the recording medium 15 is a surface facing the ejection surface 42 (see FIG. 3) of the ink jet head 31 for each color when the recording medium 15 passes through the recording unit 30. The ejection surface 42 is a surface on which the nozzles 41 are formed by the inkjet heads 31 for each color.

  The moving unit 70 operates until image recording is completed. Therefore, the reciprocating movement of the recording unit 30 in the main scanning direction is repeated until the image recording is completed. For example, the conveyance unit 20 stops at a predetermined timing after the image recording is completed. As the transport unit 20 stops, transport of the recording medium 15 in the transport direction also ends.

<Inkjet head>
The inkjet head 31 will be described with reference to FIGS. As described above, the inkjet heads 31K, 31M, 31Y, and 31C have the same configuration. Accordingly, the following description will be made without distinguishing ink colors.

  Half of the plurality of nozzles 41 formed in the inkjet head 31 are arranged in the sub-scanning direction to form one nozzle row, and the nozzle rows are arranged in a state where two nozzle rows are provided in the main scanning direction. In this case, the two nozzle rows are provided adjacent to each other in the main scanning direction while being shifted by a predetermined amount in the sub scanning direction. That is, the plurality of nozzles 41 are arranged in a staggered manner. The arrangement of the plurality of nozzles 41 is an example. Therefore, the arrangement of the plurality of nozzles 41 may be different from such an arrangement. In the embodiment, the nozzle 41 has a tapered shape in which the diameter φF of the nozzle 41 on the ejection surface 42 is smaller than the diameter φG of the nozzle 41 at the boundary with the second inflow portion 43 described later. The shape of the nozzle 41 may be different from this. For example, the nozzle 41 may have a straight shape with the same diameters φF and φG.

  The inkjet head 31 includes an internal flow path 32. The internal flow path 32 is a flow path formed inside the inkjet head 31. The internal flow path 32 causes the ink supplied to the inkjet head 31 through the supply port 33 (see FIG. 2) to flow to the nozzle 41. The supply port 33 is connected to the end of the supply flow path 81 that is opposite to the end of the supply flow path 81 connected to the main tank 80. Each of the supply port 33 and the plurality of nozzles 41 is connected by an internal flow path 32 (see FIG. 1). The ink supplied from the main tank 80 flows into the inkjet head 31 from the supply port 33 and flows through the internal flow path 32. The ink flowing through the internal flow path 32 reaches each of the plurality of nozzles 41 and is ejected from each nozzle 41.

  As shown in FIG. 3, the inkjet head 31 includes a first member 40, a second member 47, a third member 51, a fourth member 59, a first adhesive layer 63, a second adhesive layer 64, A third adhesive layer 65 is provided. The first member 40 includes a plurality of nozzles 41. That is, in the inkjet head 31, the plurality of nozzles 41 are formed on the first member 40. In addition, the first member 40 includes a second inflow portion 43. The second inflow portion 43 will be described later. The second member 47 includes a first flow path 48 and a second flow path 49. The first flow path 48 is a flow path through which ink supplied from the main tank 80 flows. The second flow path 49 is a flow path connected to the nozzle 41.

  The third member 51 includes a pressure chamber 52, a first inflow portion 53, and an outflow portion 57. The pressure chamber 52 stores ink. The first inflow portion 53 connects the first flow path 48 and the pressure chamber 52. The first inflow portion 53 is a flow path for flowing ink flowing through the first flow path 48 to the pressure chamber 52. The ink stored in the pressure chamber 52 passes through the first inflow portion 53 from the first flow path 48 and flows into the pressure chamber 52. The shape of the first inflow portion 53 will be described later. The outflow part 57 connects the pressure chamber 52 and the second flow path 49. The outflow part 57 is a flow path for flowing the ink stored in the pressure chamber 52 to the second flow path 49. The ink stored in the pressure chamber 52 flows from the pressure chamber 52 to the second flow path 49 through the outflow portion 57.

  The fourth member 59 is provided with a drive element 61. In the embodiment, the drive element 61 is joined to the upper end surface of the fourth member 59 in the vertical direction. The drive element 61 faces the pressure chamber 52 with the fourth member 59 interposed therebetween. An adhesive is used for joining the drive element 61. As an adhesive agent, the adhesive agent similar to the adhesive agent which forms the 1st contact bonding layer 63, the 2nd contact bonding layer 64, and the 3rd contact bonding layer 65 mentioned later is used, for example. The drive element 61 generates energy for ejecting ink from the nozzles 41. An example of the driving element 61 is a piezo element. When the driving element 61 is a piezo element, the energy for ejecting ink from the nozzle 41 is generated by the deformation of the piezo element. The piezo element is deformed in response to application of a voltage. The energy generated by the drive element 61 acts on the ink stored in the pressure chamber 52. That is, the pressure associated with the deformation of the piezo element acts on the ink stored in the pressure chamber 52. The ink stored in the pressure chamber 52 flows into the second flow path 49 from the pressure chamber 52 through the outflow portion 57 due to the pressure acting on the ink. Along with this, ink is ejected from the nozzle 41. As the driving element 61, a heater can be adopted as in the known ink jet head. When the drive element 61 is a heater, the energy for ejecting ink from the nozzle 41 is the thermal energy generated by the heater.

  The second inflow portion 43 of the first member 40 connects the nozzle 41 and the second flow path 49. The second inflow portion 43 is a flow path for flowing ink flowing through the second flow path 49 to the nozzle 41. The ink flowing through the second flow path 49 reaches the nozzle 41 from the second flow path 49 through the second inflow portion 43. The shape of the second inflow portion 43 will be described later.

  The first member 40, the second member 47, the third member 51, and the fourth member 59 are laminated in the state described below, and are joined by the first adhesive layer 63, the second adhesive layer 64, and the third adhesive layer 65, respectively. Is done. The first adhesive layer 63, the second adhesive layer 64, and the third adhesive layer 65 are adhesive layers in which the adhesive is cured. As the adhesive, for example, an epoxy or acrylic adhesive is used. In the embodiment, the direction in which the first member 40, the second member 47, the third member 51, and the fourth member 59 are stacked is the vertical direction.

  The second member 47 is stacked on the first member 40. The first adhesive layer 63 joins the first member 40 and the second member 47. That is, the first member 40 and the second member 47 are laminated such that the upper end surface in the vertical direction of the first member 40 and the lower end surface in the vertical direction of the second member 47 face each other, and the first adhesive layer 63 is joined. The end surface on the upper side in the vertical direction of the first member 40 is an end surface on the opposite side to the discharge surface 42 in the vertical direction. The ejection surface 42 in the inkjet head 31 is formed by the lower end surface of the first member 40 in the vertical direction. The adhesive forming the first adhesive layer 63 is applied to one or both of the upper end surface in the vertical direction of the first member 40 and the lower end surface in the vertical direction of the second member 47. For example, the adhesive is applied to the lower end surface of the second member 47 in the vertical direction.

  The third member 51 is stacked on the second member 47. The second adhesive layer 64 joins the second member 47 and the third member 51. In other words, the second member 47 and the third member 51 are laminated such that the upper end surface in the vertical direction of the second member 47 and the lower end surface in the vertical direction of the third member 51 face each other, and the second adhesive layer 64 is joined. The adhesive forming the second adhesive layer 64 is applied to one or both of the upper end surface in the vertical direction of the second member 47 and the lower end surface in the vertical direction of the third member 51. For example, the adhesive is applied to the upper end surface of the second member 47 in the vertical direction.

  The fourth member 59 is stacked on the third member 51. The third adhesive layer 65 joins the third member 51 and the fourth member 59. That is, the third member 51 and the fourth member 59 are laminated in a state where the upper end surface in the vertical direction of the third member 51 and the lower end surface in the vertical direction of the fourth member 59 face each other, and the third adhesive layer Joined by 65. The adhesive forming the third adhesive layer 65 is applied to one or both of the upper end face in the vertical direction of the third member 51 and the lower end face in the vertical direction of the fourth member 59. For example, the adhesive is applied to the upper end surface of the third member 51 in the vertical direction. As described above, the drive element 61 is joined to the upper end surface of the fourth member 59 in the vertical direction.

  The first member 40, the second member 47, the third member 51, and the fourth member 59 are joined by the first adhesive layer 63, the second adhesive layer 64, and the third adhesive layer 65, respectively. Are assembled together. In this case, the first flow path 48, the first inflow part 53, the pressure chamber 52, the outflow part 57, the second flow path 49, and the second inflow part 43 are connected to form a continuous flow path. This flow path is included in the internal flow path 32 of the inkjet head 31. That is, the first flow path 48, the first inflow part 53, the pressure chamber 52, the outflow part 57, the second flow path 49, and the second inflow part 43 form at least a portion of the internal flow path 32 that becomes a branch flow path. To do. The branch flow path of the internal flow path 32 is a portion branched from the main flow portion 34 of the internal flow path 32 having the supply port 33 as an end to the nozzle 41 side. The main flow part 34 is provided in a state extending in the sub-scanning direction. In FIG. 3, the portion of the branch channel of the internal channel 32 is mainly illustrated. In FIG. 3, illustration of a form that can be seen behind the cut surface in the line-of-sight direction (see “PQRS line” shown in FIG. 2) is omitted as appropriate, except for the main flow part 34.

<First inflow section>
The shape of the first inflow portion 53 will be described with reference to FIG. The first inflow portion 53 includes a first inner peripheral surface 54, a second inner peripheral surface 55, and a first step surface 56. The first inner peripheral surface 54 is a portion of the inner peripheral surface that forms the first portion in the first direction of the first inflow portion 53 connected to the first flow path 48 out of the entire inner peripheral surface of the first inflow portion 53. . The second inner peripheral surface 55 is a portion of the inner peripheral surface forming the second portion in the first direction of the first inflow portion 53 connected to the pressure chamber 52 out of the entire inner peripheral surface of the first inflow portion 53. . The first direction is a direction in which ink flowing from the first flow path 48 to the pressure chamber 52 flows through the first inflow portion 53. That is, the first direction is a direction along the first inner peripheral surface 54 and the second inner peripheral surface 55. In the embodiment, the first direction is from the lower side to the upper side in the vertical direction.

  The first inner peripheral surface 54 has a channel diameter set to a diameter φA. The second inner peripheral surface 55 has a flow path diameter set to a diameter φB. The diameter φB is set to a value smaller than the diameter φA (diameter φB <diameter φA). Therefore, in the first inflow portion 53, a first step surface 56 is generated at the boundary between the first inner peripheral surface 54 and the second inner peripheral surface 55 in the first direction. That is, the first step surface 56 is an annular step surface generated at the above-described boundary. The first step surface 56 is a surface along the second direction. The second direction is a direction orthogonal to the first direction. In the embodiment, the second direction is the horizontal direction.

Here, in the first channel 48, the channel diameter at the boundary with the first inflow portion 53 is set to the diameter φD. The diameter φA is set to a value smaller than the diameter φD (diameter φA <diameter φD). Further, regarding the diameters φA and φB set to “diameter φB <diameter φA”, the diameters φA and φB are respectively set to values satisfying the following relationship. That is, the diameter .phi.A, [phi] B is "([pi × diameter ^{φA 2/4) - (π} × diameter φB ^2/4)> π × diameter [phi] B ^2/4" is set to the value to be satisfied. Here, "[pi × diameter .phi.A ^2/4" is a flow path area of the first portion of the first inlet portion 53 corresponding to the first inner peripheral surface 54. "[Pi × diameter [phi] B ^2/4" is a flow path area of the second portion of the first inlet portion 53 corresponding to the second inner peripheral surface 55. Therefore, "([pi × diameter ^{φA 2/4) - (π} × diameter φB ^2/4)" is the area of the first stepped surface 56. Accordingly, in the first inflow portion 53, the flow area of the first portion of the first inflow portion 53 corresponding to the first inner peripheral surface 54 is larger than the flow area of the first flow path 48 at the boundary with the first inflow portion 53. The flow path is set narrower and the area of the first step surface 56 is set wider than the flow area of the second portion of the first inflow portion 53 corresponding to the second inner peripheral surface 55.

  On the first inner peripheral surface 54, the dimension corresponding to the first direction is set to the dimension HK. On the second inner peripheral surface 55, the dimension corresponding to the first direction is set to the dimension HL. The dimension HK is set to a value larger than the dimension HL (dimension HK> dimension HL). Therefore, in the first inflow portion 53, the first portion dimension HK of the first inflow portion 53 corresponding to the first inner peripheral surface 54 corresponds to the second inner peripheral surface 55 in the first direction (vertical direction). The flow path is also set longer than the dimension HL of the second portion of the one inflow portion 53.

<Second inflow part>
The shape of the second inflow portion 43 will be described with reference to FIG. The second inflow portion 43 includes a third inner peripheral surface 44 and a second step surface 45. The third inner peripheral surface 44 is an inner peripheral surface of the second inflow portion 43. The third inner peripheral surface 44 has a channel diameter set to a diameter φE. In the embodiment, the diameter φE can also be referred to as the flow path diameter of the second inflow portion 43. The diameter φE is set to a value larger than the diameter φG of the nozzle 41 at the boundary with the second inflow portion 43 (diameter φE> diameter φG). Therefore, the second inflow portion 43 has a second step surface 45 at the boundary between the third inner peripheral surface 44 and the nozzle 41 in the third direction. That is, the second step surface 45 is an annular step surface generated at the boundary described above. The third direction is a direction in which the ink flowing from the second flow path 49 to the nozzle 41 flows through the second inflow portion 43. That is, the third direction is a direction along the third inner peripheral surface 44. In the embodiment, the third direction is from the upper side to the lower side in the vertical direction. The second step surface 45 is a surface along the second direction. Accordingly, the second step surface 45 is a surface parallel to the first step surface 56.

<Effect of embodiment>
According to the embodiment, the following effects can be obtained.

  (1) In the inkjet head 31, the first member 40, the second member 47, the third member 51, and the fourth member 59 are joined by the first adhesive layer 63, the second adhesive layer 64, and the third adhesive layer 65, respectively. (See FIGS. 2 and 3). The third member 51 is provided with a pressure chamber 52, a first inflow portion 53, and an outflow portion 57 (see FIG. 3). The first inflow portion 53 connects the first flow path 48 provided in the second member 47 and the pressure chamber 52, and causes the ink flowing through the first flow path 48 to flow to the pressure chamber 52. In the first inflow portion 53, a first step is formed at the boundary between the first inner peripheral surface 54 and the second inner peripheral surface 55 in the first direction in which the ink flows through the first inflow portion 53 (from the lower side to the upper side in the vertical direction). A surface 56 is provided (see FIG. 3).

  Therefore, the first inflow portion 53 is suppressed from being narrowed or clogged by the adhesive forming the second adhesive layer 64 at the second portion of the first inflow portion 53 corresponding to the second inner peripheral surface 55. Can do. When the member corresponding to the second member 47 and the member corresponding to the third member 51 are joined, the adhesive forming the adhesive layer corresponding to the second adhesive layer 64 is eaten from between the end surfaces of the respective members. It is conceivable that the liquid flows out toward the inflow portion connecting the flow path corresponding to the first flow path 48 and the space corresponding to the pressure chamber 52. In this case, the inflow portion is assumed to be narrowed or clogged by the flowing adhesive. When the inflow portion is in the above-described state, the ink flow is inhibited, and the ink flow from the flow path corresponding to the first flow path 48 to the space corresponding to the pressure chamber 52 is not smoothly performed. The ink flow may stop. As a result, the stability of ink ejection from the nozzles decreases. In the ink jet head 31, even if the adhesive forming the second adhesive layer 64 protrudes from between the end surfaces of the second member 47 and the third member 51, the first inner peripheral surface 54 and the first step surface At the corners 56 and the first step surface 56, the adhesive that flows along the first inner peripheral surface 54 and proceeds toward the second portion can be stopped. As a result, it is possible to prevent the adhesive from reaching the second portion. The clogging of the first inflow portion 53 in the second portion can be suppressed, and the ink can flow from the first flow path 48 to the pressure chamber 52. It is possible to prevent the ink ejection stability from the nozzle 41 from being lowered. In the inkjet head 31, the ink can be smoothly supplied to the nozzle 41.

  (2) In the 1st inflow part 53, the 1st level | step difference surface 56 was made into the surface along the 2nd direction orthogonal to a 1st direction (refer FIG. 3). Therefore, the shape of the corners of the first inner peripheral surface 54 and the first step surface 56 can be made a right angle. The adhesive flowing along the first inner peripheral surface 54 can be stopped at this corner. For example, the performance of stopping the progress of the adhesive can be improved as compared with a configuration in which the angle formed by the first inner peripheral surface and the first step surface is wider than 90 °. By the way, a 1st level | step difference surface can also be made into the surface from which the angle | corner with a 1st internal peripheral surface becomes less than 90 degrees. However, when the angle formed between the first inner peripheral surface and the first step surface is less than 90 °, ink accumulation tends to occur in the corner region between the first inner peripheral surface and the first step surface. There may be a case where a measure for realizing a smooth ink flow in this portion is required. By making the first step surface 56 a surface along the second direction, it is possible to eliminate the occurrence of ink accumulation. A smooth ink flow in this portion is possible without taking special measures.

  (3) In the first inflow portion 53, the dimension HK in the first direction (vertical direction) is set longer than the dimension HL (see FIG. 3). The dimension HK is the dimension of the first portion of the first inflow portion 53 corresponding to the first inner peripheral surface 54. The dimension HL is a dimension of the second portion of the first inflow portion 53 corresponding to the second inner peripheral surface 55. Therefore, it is possible to increase the allowable amount for the adhesive protruding from between the end surfaces of the second member 47 and the third member 51. When joining the 2nd member 47 and the 3rd member 51, it becomes possible to apply | coat the adhesive agent of a quantity suitable for joining to the end surface of joining object. The bonding strength between the second member 47 and the third member 51 by the second adhesive layer 64 can be improved. For example, it is possible to prevent a situation in which ink leaks from between the second member 47 and the third member 51 during image recording.

  (4) In the first inflow portion 53, the flow area of the first portion of the first inflow portion 53 corresponding to the first inner peripheral surface 54 is the flow area of the first flow passage 48 at the boundary with the first inflow portion 53. Set narrower. In the first inflow portion 53, the area of the first step surface 56 is set wider than the flow path area of the second portion of the first inflow portion 53 corresponding to the second inner peripheral surface 55. Therefore, the ink can flow smoothly from the first flow path 48 to the pressure chamber 52. The adhesive traveling toward the second portion can be stopped on the first step surface 56. Even if air bubbles exist with the ink in the internal flow path 32, the air bubbles can be discharged by a smooth ink flow.

  (5) The 1st member 40 containing the nozzle 41 is provided with the 2nd inflow part 43 (refer FIG. 3). The second inflow portion 43 connects the nozzle 41 and the second flow path 49 provided in the second member 47, and causes ink flowing through the second flow path 49 to flow to the nozzle 41. In the second inflow portion 43, in the third direction (from the upper side to the lower side in the vertical direction) through which the ink flows through the second inflow portion 43, Two step surfaces 45 are provided. Therefore, the nozzle 41 can be prevented from becoming narrow or clogged by the adhesive that forms the first adhesive layer 63. When the member corresponding to the first member 40 and the member corresponding to the second member 47 are joined, the adhesive forming the adhesive layer corresponding to the first adhesive layer 63 is eaten from between the end faces of the respective members. It can be considered that it overflows and flows into the nozzle. In this case, it is assumed that the nozzle becomes narrow or clogged by the flowing adhesive. When the nozzle is in the above-described state, ink ejection is hindered or ink ejection is not performed. That is, the stability is lowered with respect to the ejection of ink from the nozzles. In the inkjet head 31, even if the adhesive forming the first adhesive layer 63 protrudes from between the end surfaces of the first member 40 and the second member 47, the third inner peripheral surface 44 and the second step surface At the corner portion 45 and the second step surface 45, the adhesive flowing into the nozzle 41 side along the third inner peripheral surface 44 can be stopped. As a result, it is possible to prevent the adhesive from reaching the nozzle 41. The clogging of the nozzle 41 by the adhesive can be suppressed, and the ink can flow from the second flow path 49 to the nozzle 41. It is possible to prevent the ink ejection stability from the nozzle 41 from being lowered.

<Modification>
The embodiment can also be performed as follows. Some configurations of the modifications shown below can be appropriately combined and employed. Hereinafter, points different from the above will be described, and description of similar points will be omitted as appropriate.

  (1) In the above, the case where the inkjet recording apparatus 10 is a serial type has been described as an example (see FIG. 1). The structure of the inkjet head 31 can also be adopted for a line-type inkjet head. In the line-type inkjet head, the plurality of nozzles are arranged in the main scanning direction that coincides with the short direction of the recording medium 15. The range in the main scanning direction in which the nozzles are arranged is, for example, not less than the width W of the recording medium 15 (see FIG. 1). The number of nozzle rows may be a plurality of rows as described above.

  (2) In the above description, the inkjet recording apparatus 10 in which the main tank 80 and the inkjet head 31 are directly connected via the supply flow path 81 has been described as an example (see FIG. 1). The ink jet recording apparatus 10 may include a sub tank in addition to the above-described units. A sub tank is provided corresponding to each ink jet head 31 for each color. The sub tank for each color is provided in the middle of the supply flow path 81 for each color. The sub tank stores the ink supplied from the main tank 80 via the first portion of the supply flow path 81. The ink stored in the sub tank flows out of the sub tank, flows through the second portion of the supply channel 81, and is supplied to the inkjet head 31. The first portion of the supply flow path 81 is a portion of the supply flow path 81 that connects the main tank 80 and the sub tank. The second part of the supply channel 81 is a part of the supply channel 81 that connects the sub tank and the inkjet head 31. Of the both ends of the second portion of the supply channel 81, the end on the ink jet head 31 side is connected to the supply port 33.

  (3) In the above description, the first member 40 including the second inflow portion 43 has been described as an example (see FIG. 3). In the first member, the second inflow portion 43 may be omitted. In this case, the first member includes a third inflow portion having the following shape as an inflow portion that connects the nozzle and the second flow path 49 and flows the ink flowing through the second flow path 49 to the nozzle. For example, the third inflow portion has a straight shape having the same diameter as the nozzle. In the embodiment, the nozzle 41 has a taper shape in which the diameter φF of the nozzle 41 on the discharge surface 42 is smaller than the diameter φG of the nozzle 41 at the boundary with the second inflow portion 43 (see FIG. 3). In such a case, the inner diameter of the third inflow portion is the same as the diameter of the nozzle on the second flow path 49 side (see “diameter φG” shown in FIG. 3). In addition, the third inflow portion may have a shape in which the inner peripheral surface is a tapered surface (conical truncated conical surface) having the same or different angle as the inner peripheral surface of the nozzle.

(4) Although the description is omitted above, the shape of the second inflow portion 43 may be as follows. That is, the diameter φE is set to a value smaller than the diameter φJ (diameter φE <diameter φJ see FIG. 3). The diameter φE is the flow path diameter of the third inner peripheral surface 44 as described above. The diameter φJ is a channel diameter of the second channel 49 at the boundary with the second inflow portion 43 (see FIG. 3). Furthermore, regarding the diameter φE set to “diameter φE> diameter φG”, the diameter φE may be set to a value satisfying the following relationship. That is, the diameter .phi.E is "([pi × diameter ^{φE 2/4) - (π} × diameter φG ^2/4)> π × diameter [phi] G ^2/4" is set to the value to be satisfied. Here, "[pi × diameter .phi.E ^2/4" is a flow path area of the second inlet 43. "[Pi × diameter [phi] G ^2/4" is a flow path area of the nozzle 41 at the boundary between the second inlet 43 (opening area). Therefore, "([pi × diameter ^{φE 2/4) - (π} × diameter [phi] G ^2/4)" is the area of the second stepped surface 45. In this case, the second inflow portion 43 is set so that the flow passage area is narrower than the flow passage area of the second flow passage 49 at the boundary with the second inflow portion 43, and the area of the second step surface 45 is the second inflow portion. The flow path is set wider than the flow area of the nozzle 41 at the boundary with the portion 43.

  A dimension corresponding to the third direction in the second inflow portion 43 (third inner peripheral surface 44) is defined as a dimension HM. A dimension (nozzle length) corresponding to the third direction in the nozzle 41 is defined as a dimension HN. The dimension HM may be set to a value larger than the dimension HN (dimension HM> dimension HN). In this case, the second inflow portion 43 is a flow path in which the dimension HM of the third inner peripheral surface 44 is set longer than the dimension HN of the nozzle 41 in the third direction (vertical direction).

  (5) In the above description, the first direction in which the ink flows through the first inflow portion 53 is described as an example from the lower side to the upper side in the vertical direction (see FIG. 3). The internal flow path in the inkjet head may be in a state where the first direction is the horizontal direction. For example, an internal flow path in a state where ink flows through the first inflow portion in the main scanning direction may be used. In this case, the second direction orthogonal to the first direction is the vertical direction.

  In the inkjet head 31, the internal flow path 32 in which the first direction and the third direction are both vertical directions has been described as an example (see FIG. 3). For example, an internal flow path in which the first direction is the horizontal direction and the third direction is the vertical direction may be used. In this case, the first inflow portion and the second inflow portion are respectively provided at predetermined positions of the internal flow path so that the first step surface and the second step surface are orthogonal to each other. That is, each arrangement of the first flow path 48, the first inflow portion 53, the pressure chamber 52, the outflow portion 57, the second flow path 49, and the second inflow portion 43 in the embodiment is an example. The first flow path, the first inflow part, the pressure chamber, the outflow part, the second flow path, and the second inflow part are appropriately set in the vertical direction or the horizontal direction, or in a direction inclined with respect to both directions in consideration of various conditions. Provided.

DESCRIPTION OF SYMBOLS 10 Inkjet recording device, 15 Recording medium, 16 Recording surface, 20 Conveying part 30 Recording part, 31, 31K, 31M, 31Y, 31C Inkjet head 32 Internal flow path, 33 Supply port, 34 Main stream part, 35 Carriage 40 First member , 41 nozzle, 42 discharge surface, 43 second inflow portion 44 third inner peripheral surface, 45 second step surface, 47 second member, 48 first flow channel 49 second flow channel, 51 third member, 52 pressure chamber, 53 First inflow portion 54 First inner peripheral surface, 55 Second inner peripheral surface, 56 First step surface, 57 Outflow portion 59 Fourth member, 61 Drive element, 63 First adhesive layer, 64 Second adhesive layer 65 First Three adhesive layers, 70 moving part, 71, 72 pulley 73 timing belt, 74 motor, 76 support part 80, 80K, 80M, 80Y, 80C main tank 81, 81K, 8 M, 81Y, 81C supply channel φA, φB, φD, φE, φF, φG, φJ diameter HK, HL, HM, HN dimension, W width

Claims (6)

A first member including a nozzle for discharging ink;
A second member including a first flow path through which the ink supplied from the ink tank flows, and a second flow path connected to the nozzle;
A pressure chamber that stores the ink; a first inflow portion that connects the first flow path and the pressure chamber; and that causes the ink flowing through the first flow path to flow into the pressure chamber; the pressure chamber; A third member including an outflow portion that connects two flow paths and flows the ink stored in the pressure chamber to the second flow path;
A fourth member provided with a drive element that acts on the ink stored in the pressure chamber and generates energy for discharging the ink from the nozzle;
A first adhesive layer formed by an adhesive and joining the first member and the second member stacked on the first member;
A second adhesive layer formed by an adhesive and joining the second member and the third member laminated on the second member;
A third adhesive layer formed by an adhesive and joining the third member and the fourth member laminated on the third member;
The first inflow portion is
A first inner peripheral surface connected to the first flow path, the flow path diameter being set to a first value;
A second inner peripheral surface connected to the pressure chamber and having a channel diameter set to a second value smaller than the first value;
A first step surface formed at a boundary between the first inner peripheral surface and the second inner peripheral surface in a first direction in which the ink flows through the first inflow portion along the first inner peripheral surface. , Inkjet head.   The inkjet head according to claim 1, wherein the first step surface is a surface along a second direction orthogonal to the first direction. In the second inner peripheral surface, the dimension corresponding to the first direction is set to a third value,
The inkjet head according to claim 1 or 2, wherein a dimension corresponding to the first direction is set to a fourth value larger than the third value on the first inner peripheral surface.   In the first inflow portion, the flow area of the first portion of the first inflow portion corresponding to the first inner peripheral surface is set to be narrower than the flow area of the first flow channel at the boundary with the first inflow portion. The area of the first step surface is a channel set wider than the channel area of the second portion of the first inflow portion corresponding to the second inner peripheral surface. The inkjet head of any one of these. The first member includes a second inflow portion that connects the second flow path and the nozzle and flows the ink flowing through the second flow path to the nozzle,
The second inflow portion is
A third inner peripheral surface having a flow path diameter set to a fifth value larger than the diameter of the nozzle at the boundary with the second inflow portion;
2. A second step surface generated at a boundary between the third inner peripheral surface and the nozzle in a third direction in which the ink flows through the second inflow portion along the third inner peripheral surface. The inkjet head according to any one of claims 1 to 4.   An ink jet recording apparatus comprising the ink jet head according to any one of claims 1 to 5.

Images