JP2010030230A - Liquid jetting head, its manufacturing method and liquid jetting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jetting head and a liquid jetting apparatus which can improve a printing quality by highly accurately positioning and fixing a head body to a frame. <P>SOLUTION: The liquid jetting head includes the frame 20 to which the head body 10 for jetting liquid droplets from a nozzle is attached via a mounting plate 15, mounting screws 30 which fix the mounting plate 15 to the frame 20, and a plurality of washers 32a and 32b arranged between the mounting plate 15 and the mounting screw 30. A friction coefficient between the washers 32a and 32b is made lower than a friction coefficient between one washer 32a and the mounting plate and a friction coefficient between the other washer 32b and the mounting screw 30. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid ejecting head in which a head main body that discharges droplets from nozzles is attached to a frame via an attachment plate, a manufacturing method thereof, and a liquid ejecting apparatus.

  A liquid ejecting apparatus typified by an ink jet recording apparatus such as an ink jet printer or a plotter includes a liquid ejecting head capable of ejecting a liquid such as a stored ink such as a cartridge or a tank as droplets.

  In the liquid ejecting head used in such a liquid ejecting apparatus, increasing the density and length of the nozzles with a single head body lowers the yield of the head body and increases the manufacturing cost. This is difficult. For this reason, there has been proposed a liquid ejecting head in which a plurality of head bodies are fixed to a frame which is a common plate to form a module (composite component) (see, for example, Patent Document 1).

  In such a liquid ejecting head, the head main body is fixed to the frame by fixing the mounting plate to the head main body and screwing the mounting plate to the frame.

International Publication No. 2004/022344 (Page 6, Figures 4 and 5)

  However, after positioning the head body with respect to the frame with high precision, if the head body is to be fastened to the frame with screws, the mounting plate rotates with the rotation of the screws, and the position of the head positioned with high precision. There is a problem that shifts.

  Note that such a problem is not limited to an ink jet recording head that ejects ink, and similarly exists in liquid ejecting heads that eject other liquids.

  SUMMARY An advantage of some aspects of the invention is that it provides a liquid ejecting head, a manufacturing method thereof, and a liquid ejecting apparatus capable of improving printing quality by positioning and fixing a head main body to a frame with high accuracy. .

An aspect of the present invention that solves the above problems includes a frame in which a head body that ejects liquid droplets from a nozzle is attached via a mounting plate, a mounting screw that fixes the mounting plate to the frame, the mounting plate, A plurality of washers arranged between the mounting screws, and the friction coefficient between the washers is based on the friction coefficient between one washer and the mounting plate and the friction coefficient between the other washer and the mounting screw. The liquid ejecting head is characterized by being lowered.
In this aspect, since the force in the rotational direction at the time of fastening of the mounting screw is difficult to be transmitted to the mounting plate by the plurality of washers, the rotation of the mounting plate by the force in the rotational direction by fastening of the mounting screw can be reduced. Thereby, the position shift of the head main body with respect to the frame can be reduced.

  Here, it is preferable that the mounting plate is fixed to the frame with the mounting screw, and the mounting plate is fixed to the frame with a fixing screw. According to this, since the mounting plate and the frame are fixed by the fixing screw, even if the mounting screw is loosened by a plurality of washers, the fixing between the frame and the mounting plate (head body) is not released. . Further, by fixing the mounting plate to the frame with a fixing screw, the head main body can be easily detached from the frame simply by loosening the mounting screw and the fixing screw.

According to another aspect of the invention, there is provided a liquid ejecting apparatus including the liquid ejecting head according to the above aspect.
According to this aspect, it is possible to realize a liquid ejecting apparatus that can perform high-quality printing by highly accurate positioning of the head body.

Furthermore, another aspect of the present invention is a method for manufacturing a liquid ejecting head in which a head main body for ejecting liquid from a nozzle is attached to a frame via a mounting plate, and fastening a mounting screw with a plurality of washers interposed Then, after fixing the mounting plate to the frame, the mounting plate is fixed to the frame by fastening a fixing screw.
In this aspect, the head main body can be fixed in a state of being positioned with high accuracy on the frame.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
FIG. 1 is a schematic perspective view of an ink jet recording head that is an example of a liquid jet head according to Embodiment 1 of the present invention, FIG. 2 is a plan view of a nozzle side of the ink jet recording head, and FIG. FIG. 2 is a plan view of a main part opposite to a nozzle of an ink jet recording head, and a sectional view taken along the lines AA ′ and BB ′.

  As shown in the figure, the ink jet recording head I includes a plurality of head main bodies 10 and a frame 20 attached in a state where the plurality of head main bodies 10 are aligned. In the present embodiment, a plurality of head main bodies 10 are arranged in a staggered manner and attached to the frame 20.

  As shown in FIG. 2, the head body 10 of the present embodiment includes a nozzle row 12 in which nozzles 11 are linearly arranged on one end surface. The number of nozzle rows 12 is not particularly limited, and may be, for example, one row or a plurality of rows of two or more. In the present embodiment, the nozzle row 12 is configured by arranging the nozzles 11 in a straight line with an arrangement density of 180 dpi, and the head body 10 is provided with eight nozzle rows 12. Each head body 10 is configured such that black ink, a plurality of color inks, and the like are ejected from each nozzle row 12. The number of nozzle rows 12 is not particularly limited, and may be determined as appropriate according to the number of ink colors to be ejected.

  Here, in the present embodiment, a direction in which the nozzles 11 are arranged in the nozzle row 12 is a first direction, and a direction intersecting the first direction is a second direction. Therefore, the eight nozzle rows 12 are juxtaposed in the second direction.

  Although not shown, the head main body 10 discharges ink from the pressure generation chamber that forms part of the flow path communicating with the nozzle 11 and a pressure change in the pressure generation chamber. Pressure generating means. The pressure generating means is not particularly limited. For example, the pressure generating means uses a piezoelectric element in which a piezoelectric material exhibiting an electromechanical conversion function is sandwiched between two electrodes, or a heating element is disposed in the pressure generating chamber to generate heat from the heating element. A device that discharges liquid droplets from the nozzle 11 using bubbles generated in the above, or a device that generates static electricity between the vibration plate and the electrode and deforms the vibration plate by electrostatic force to discharge liquid droplets from the nozzle is used. be able to. In addition, as a piezoelectric element, a bending vibration type piezoelectric element in which a lower electrode, a piezoelectric material, and an upper electrode are stacked from the pressure generating chamber side to bend and deform, or a piezoelectric material and an electrode forming material are alternately stacked in an axial direction. For example, a longitudinal vibration type piezoelectric element that expands and contracts can be used.

  A flow path for supplying ink from the outside into the head body 10 or discharging the ink from the head body 10 to the outside is connected to the surface of the head body 10 opposite to the nozzle 11.

  Further, flange portions 13 projecting outward are provided on both side surfaces of the outer peripheral portion of the head body 10 in the first direction.

  An attachment plate 15 is fixed to the flange portions 13 provided on both side surfaces of the head body 10. In the present embodiment, the attachment plate 15 is fixed to each of the flange portions 13 provided so as to protrude on both sides in the first direction. That is, two mounting plates 15 are provided in one head body 10. The number of attachment plates 15 is not particularly limited to this, and for example, a single attachment plate in which two attachment plates are continuous may be used. That is, a single mounting plate having a through-hole through which the head body 10 can be inserted may be fixed to the flange portion 13. Of course, you may make it provide two or more attachment plates in each flange part.

  Moreover, the fixing method of the attachment plate 15 and the head main body 10 is not specifically limited, The method using an adhesive agent, a screw, a rivet, etc. is mentioned.

  Since the mounting plate 15 is used for fixing the head body 10 to the frame 20, it is preferable to use a material having rigidity, for example, resin or metal.

  Such a head body 10 is fixed to a common frame 20 via a mounting plate 15. Here, the frame 20 will be described.

  As shown in FIG. 3, the frame 20 is made of a plate-like member such as metal or resin provided with a holding hole 21 into which the nozzle 11 side of each head body 10 is inserted. The holding hole 21 of the frame 20 is provided with an opening that is slightly larger than the outer periphery of the head body 10 on the nozzle 11 side and smaller than the mounting plate 15. With the 11 side being inserted into the holding hole 21, the attachment plate 15 is fixed around the holding hole 21, so that it is held by the frame 20. The head main body 10 is provided so as to be slightly movable in the first direction and the second direction with respect to the frame 20 by the gap between the head main body 10 and the holding hole 21. The nozzle rows 12 are held by the frame 20 in a state of being positioned with respect to each other.

  The head main body 10 is temporarily fixed to the frame 20 with the mounting plate 15 fixed to the head main body 10 by the mounting screws 30 and is fixed to the frame 20 by the fixing screws 31.

  The attachment screw 30 is a male screw, and one is provided at the center of the pressing plate 15 in the first direction. The attachment screw 30 is inserted into the first through hole 16 provided in the holding plate 15, and the tip end side thereof is screwed into the frame 20.

  Further, between the head of the mounting screw 30 and the mounting plate 15, two washers 32a and 32b made of low friction washers are arranged. The mounting plate 15 is attached by the mounting screw 30 and the washers 32a and 32b. It is concluded.

  Here, the low friction washer means that the friction coefficient between the two washers 32a and 32b is larger than the friction coefficient between the one washer 32a and the mounting plate 15 and the friction coefficient between the other washer 32b and the mounting screw 30. Say low. In order to make the friction coefficient between the two washers 32a and 32b lower than the friction coefficient between the one washer 32a and the mounting plate 15 and the friction coefficient between the other washer 32b and the mounting screw 30, for example, As in the embodiment, two low friction washers made of a material having a relatively low friction coefficient may be used.

  In addition, for example, only one washer 32a may be a low friction washer made of a material having a relatively low coefficient of friction. In this case, for example, the friction coefficient between one washer 32a formed of a material having a low friction coefficient and the other washer 32b is lower than the friction coefficient between the washer 32a and the mounting plate 15, and the washer 32b. It only needs to be lower than the coefficient of friction with the mounting screw 30.

  Further, for example, by adjusting the smoothness of the surfaces of the washers 32 a and 32 b, the friction coefficient between the two washers 32 a and 32 b is determined from the friction coefficient between the washers 32 a and 32 b, the attachment plate 15, and the attachment screw 30. May be lowered. That is, for example, by smoothing only the surfaces of the washers 32a and 32b that are in contact with each other, the friction coefficient between the two washers 32a and 32b is changed to the friction coefficient between the one washer 32a and the mounting plate 15 and the other washer. It can be made lower than the friction coefficient between 32b and the mounting screw 30. Of course, only the smoothness of one washer 32a or 32b may be increased, and only one of the washers may be a low friction washer.

  In this way, when the attachment plate 15 is attached to the frame 20 with the two washers 32a and 32b having a low coefficient of friction between the washers 32a and 32b, the attachment screw 30 is rotated and fastened. Since the rotational force of 30 is buffered by the rotation between the two washers 32a and 32b, the rotation of the mounting plate 15 by the rotation of the mounting screw 30 can be reduced. Accordingly, it is possible to further reduce the positional deviation of the head main body 10 positioned with high accuracy with respect to the frame 20.

  In such a configuration, since the coefficient of friction between the two washers 32a and 32b is low, the mounting screw 30 may loosen due to vibration or the like over time. For this reason, in this embodiment, the attachment plate 15 is permanently fixed to the frame 20 by the fixing screw 31.

  In the present embodiment, the two washers 32a and 32b are arranged between the attachment plate 15 and the attachment screw 30, but the number of washers is not particularly limited to this, and the attachment plate Three or more washers may be arranged between 15 and the mounting screw 30. In this case, any one of the three or more overlapping washers has a friction coefficient between the one washer in contact with the attachment plate 15 and the attachment plate 15 and the other washer in contact with the attachment screw 30 and the attachment screw 30. It is sufficient that the friction coefficient is lower than the friction coefficient.

  The fixing screw 31 is a male screw and is provided on both sides of the mounting screw 30 in the first direction. That is, two fixing screws 31 are provided on one mounting plate 15. The fixing screw 31 is inserted into the second through hole 17 provided in the holding plate 15, and the tip end side is screwed into the frame 20.

  In the present embodiment, one normal washer that is not a low friction washer is disposed between the head of the fixing screw 31 and the mounting plate 15. As a result, the mounting plate 15 can be securely fastened (fixed) to the frame 20 by the fixing screw 31.

  Here, a method for manufacturing the ink jet recording head of the present embodiment in which the head body 10 is fixed to the frame 20 will be described. FIG. 4 is a cross-sectional view of the main part showing the method for manufacturing the ink jet recording head of this embodiment.

  First, as shown in FIG. 4A, the mounting plate 15 of the head main body 10 positioned with high accuracy on the frame 20 is temporarily fixed to the frame 20 with mounting screws 30.

  At this time, since the mounting screw 30 is fastened through the two washers 32a and 32b, the force in the rotation direction of the mounting screw 30 is buffered by the rotation between the two washers 32a and 32b. Rotation of the mounting plate 15 can be reduced. That is, the force in the rotational direction when the mounting screw 30 is screwed to the frame 20 and fastened works in the direction in which the mounting plate 15 is rotated, but the friction coefficient between the two washers 32a and 32b is low. The force in the rotation direction of the mounting screw 30 is buffered when the two washers 32a and 32b idle. Accordingly, the position of the head main body 10 positioned with high accuracy with respect to the frame 20 is reduced by reducing the displacement of the mounting plate 15 as compared with the case where the mounting plate 15 is fixed to the frame 20 only by the fixing screw 31. Deviation can be reduced.

  Next, as shown in FIG. 4B, the mounting plate 15 temporarily fixed to the frame 20 with the mounting screw 30 is permanently fixed to the frame 20 with the fixing screw 31.

  When fastening the fixing screw 31, as described above, as shown in FIG. 4A, the mounting plate 15 is pressed to the frame 20 side by the mounting screw 30. Even if the frictional resistance between the plate 15 and the frame 20 is large and the force in the rotation direction of the fixing screw 31 is transmitted to the mounting plate 15, it is possible to prevent the mounting plate 15 from rotating and causing displacement. That is, when the mounting plate 15 is fixed to the frame 20 by the fixing screw 31 in a state where it is not pressed by the mounting screw 30, when the force in the rotational direction of the fixing screw 31 is transmitted to the mounting plate 15, its own weight. Since the force in the rotational direction is suppressed only by the frictional resistance with the frame 20 due to the above, there is a high possibility that the mounting plate 15 rotates. As described above, the mounting plate 15 is temporarily fixed to the frame 20 by the mounting screw 30. Thus, the frictional resistance between the attachment plate 15 and the frame 20 can be increased, and the displacement of the attachment plate 15 due to the force caused by the rotation of the fixing screw 31 can be reduced.

  As described above, the head main body 10 is temporarily fixed to the frame 20 by using the mounting screw 30 and the two washers 32 a and 32 b, and then the head main body 10 is permanently fixed to the frame 20 by the fixing screw 31. The positional deviation of the head body 10 when the head body 10 is fixed to the head can be reduced.

  In addition, since the friction coefficient between the two washers 32a and 32b is low, the attachment screw 30 may loosen due to vibration or the like over time, but the attachment plate 15 is attached to the frame 20 by the fixing screw 31. By fixing the main body 10, it is possible to reliably prevent the positional deviation of the head body 10 due to the passage of time or vibration.

  Further, since the mounting plate 15 (head main body 10) is fixed to the frame 20 by the mounting screws 30 and the fixing screws 31, the mounting screws 30 and the fixing screws 31 are loosened when the head main body 10 is repaired or replaced. Only the head main body 10 can be removed from the frame 20. Therefore, replacement and repair of the head body 10 can be easily performed.

  In the present embodiment, five head bodies 10 arranged in parallel in the first direction, which is the direction in which the nozzles 11 are arranged in the nozzle array 12 of the head body 10, and 5 arranged in parallel in the first direction. A row of the head main bodies 10 is arranged in the second direction. That is, ten head main bodies 10 are fixed to the frame 20 as described above.

  In the head main body 10, the nozzles 11 form a nozzle row 12 in the first direction, and the plurality of head main bodies 10 are staggered along the first direction so that the nozzle rows 12 are continuous in the first direction. Is arranged. As a result, a total of ten head bodies 10 can form nozzle rows 12 that are 10 times longer than the nozzle rows 12 of one head body 10 and that are continuous in the first direction. Thereby, compared with the case where it prints with the nozzle row | line | column 12 of one head main body 10, a wide range printing can be performed at high speed.

  The nozzle row 12 of the head body 10 is continuous in the first direction. In the head bodies 10 adjacent to each other in the second direction, the nozzles 11 at the end of the nozzle row 12 of one head body 10; It means that the nozzles 11 at the end of the nozzle row 12 of the other head body 10 are arranged so as to be in the same position in the first direction.

(Other embodiments)
As mentioned above, although one Embodiment of this invention was described, the basic composition of this invention is not limited to what was mentioned above. For example, in the first embodiment described above, the ink jet recording head I in which the plurality of head main bodies 10 are fixed to the frame 20 is illustrated, but the number and arrangement of the head main bodies 10 are not limited to those described above. For example, an ink jet recording head I in which one head body 10 is fixed to the frame 20 may be used.

  In the first embodiment described above, the mounting plates 15 are provided on both side surfaces of the head body 10 in the second direction. However, the present invention is not limited to this, and the mounting plate 15 is mounted in the first direction of the head body 10. It may be provided on both side surfaces. However, in the first embodiment described above, the arrangement of the head main bodies 10 adjacent to each other in the first direction is defined by the length of the nozzle row 12, and therefore, between the head main bodies 10 adjacent to each other in the first direction. The area may be narrow. Therefore, the mounting plates 15 are provided on both side surfaces in the second direction so that the mounting plates 15 do not affect the position of the head body 10.

  Furthermore, in the first embodiment described above, each mounting plate 15 is fixed to the frame 20 with one mounting screw 30 and two fixing screws 31, but the numbers and positions of the mounting screws 30 and the fixing screws 31 are different. The invention is not particularly limited to this.

  In the first embodiment described above, the two washers 32a and 32b including the low friction washers are arranged between the attachment plate 15 and the attachment screw 30, but the number of washers is particularly limited to this. For example, a washer other than the low friction washer may be further arranged.

  Further, in the first embodiment described above, the mounting plate 15 is permanently fixed to the frame 20 with the fixing screw 31. However, the present invention is not particularly limited thereto. For example, the mounting screw 30 is not provided without the fixing screw 31. You may make it fix to the flame | frame 20 or the attachment board 15 with a screwing agent or an adhesive agent.

  The ink jet recording head I described above is mounted on an ink jet recording apparatus. FIG. 5 is a schematic view showing an example of the ink jet recording apparatus.

  As shown in FIG. 5, the ink jet recording apparatus 1 is a so-called line recording apparatus that performs printing by transporting a recording paper S such as paper with the ink jet recording head I fixed. Specifically, the ink jet recording apparatus 1 includes an apparatus main body 2, an ink jet recording head I fixed to the apparatus main body 2, a transport unit 4 for transporting the recording paper S, and a cap member 5.

  The ink jet recording head I is fixed to the apparatus main body 2 so that the transport direction of the recording paper S is the second direction.

  Although not shown, the ink jet recording head I is connected to an ink storage means such as an ink tank or an ink cartridge in which ink is stored so that the ink can be supplied. For example, the ink storage unit may be held above the ink jet recording head I or may be held at a position different from the ink jet recording head I in the apparatus main body 2.

  The transport unit 4 includes a first transport unit 7 and a second transport unit 8 provided on both sides of the inkjet recording head I in the transport direction of the recording paper S.

  The first conveying means 7 includes a driving roller 7a, a driven roller 7b, and a conveying belt 7c wound around the driving roller 7a and the driven roller 7b. Similarly to the first transport unit 7, the second transport unit 8 includes a driving roller 8a, a driven roller 8b, and a transport belt 8c.

  Driving means such as a driving motor (not shown) are connected to the respective driving rollers 7a and 8a of the first conveying means 7 and the second conveying means 8, and the conveying belt 7c, The recording paper S is conveyed on the upstream side and the downstream side of the ink jet recording head I by the rotational drive of the 8c.

  In the present embodiment, the first conveying means 7 and the second conveying means 8 constituted by the driving rollers 7a and 8a, the driven rollers 7b and 8b, and the conveying belts 7c and 8c are exemplified. You may further provide the holding means hold | maintained on the conveyance belts 7c and 8c. As the holding means, for example, a charging means for charging the outer peripheral surface of the recording paper S may be provided, and the recording paper S charged by the charging means may be attracted onto the transport belts 7c and 8c by the action of dielectric polarization. . Further, as a holding unit, a pressing roller may be provided on the conveying belts 7c and 8c, and the recording paper may be sandwiched between the pressing roller and the conveying belts 7c and 8c.

  The cap member 5 is provided between the first conveying means 7 and the second conveying means 8 so as to face the ink jet recording head I. Such a cap member 5 receives ink when the ink jet recording head I performs a preliminary ejection operation. For example, the cap member 5 is provided so as to be movable so as to contact a liquid ejection surface (in this embodiment, a surface of a nozzle plate described later) in which the nozzle openings of the ink jet recording head I are opened, and the cap member 5. A suction device such as a vacuum pump is connected to the suction device, and the cap member 5 is sucked by the suction device in a state where the cap member 5 is in contact with the ejection surface where the nozzle 11 is opened. You may make it function as a suction means to do.

  Although FIG. 5 illustrates a line type recording apparatus, the ink jet recording apparatus 1 of the present invention is an ink jet that performs printing by moving the ink jet recording head I in a direction that intersects the conveyance direction of the recording paper S. The present invention can also be applied to a type recording apparatus.

  Furthermore, the present invention is intended for a wide range of liquid jet heads in general, for example, for manufacturing recording heads such as various ink jet recording heads used in image recording apparatuses such as printers, and color filters such as liquid crystal displays. The present invention can also be applied to a coloring material ejecting head, an organic EL display, an electrode material ejecting head used for forming an electrode such as an FED (field emission display), a bioorganic matter ejecting head used for biochip production, and the like.

1 is a schematic perspective view of a recording head according to Embodiment 1 of the invention. FIG. 3 is a plan view of the recording head according to the first embodiment of the invention. 2A and 2B are a plan view and a cross-sectional view of main parts of a recording head according to Embodiment 1 of the invention. FIG. 4 is a cross-sectional view of a main part showing the recording head manufacturing method according to Embodiment 1 of the invention. 1 is a diagram illustrating a schematic configuration of a recording apparatus according to an embodiment of the present invention.

Explanation of symbols

  I ink jet recording head (liquid ejecting head), 1 ink jet recording apparatus (liquid ejecting apparatus), 10 head body, 15 mounting plate, 20 frame, 30 mounting screw, 31 fixing screw, 32a, 32b washer

Claims (4)

A frame on which a head body for ejecting liquid droplets from a nozzle is attached via a mounting plate;
A mounting screw for fixing the mounting plate to the frame;
A plurality of washers disposed between the mounting plate and the mounting screw;
The liquid ejecting head, wherein a friction coefficient between the washers is lower than a friction coefficient between one washer and the mounting plate and a friction coefficient between the other washer and the mounting screw.   The liquid ejecting head according to claim 1, wherein the mounting plate is fixed to the frame with the mounting screw, and the mounting plate is fixed to the frame with a fixing screw.   A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1. A method of manufacturing a liquid ejecting head in which a head main body for ejecting liquid from a nozzle is attached to a frame via a mounting plate,
The liquid jet is characterized in that the mounting plate is fixed to the frame by fastening a fixing screw after the mounting plate is fixed to the frame by fastening a mounting screw with a plurality of washers interposed therebetween. Manufacturing method of the head.

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