JP4158149B2 - Ink jet head, ink jet recording apparatus, and housing forming method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a housing forming method for an ink jet head that realizes a high-density nozzle, an ink jet including the housing formed by the housing forming method, and an ink jet recording apparatus.
[0002]
[Prior art]
An example of a conventional inkjet head is shown in FIG. This ink jet head is configured to apply pressure to the ink in the pressure chamber 200 and eject ink droplets from the orifice 202 by driving a vibrator 225 such as a piezoelectric element to vibrate the foot 224 in the direction of the arrow. ing. This type of head is capable of low-voltage driving and high-density nozzles up to a certain level, and has excellent ejection characteristics. However, since the through holes 206a of the housing 206 into which the individual feet 224 are inserted are formed by machining, it is difficult to further increase the density (for example, Reference 1).
[0003]
In order to solve this problem, a method of forming an inkjet head by forming a single long hole instead of forming a plurality of through holes for a vibrator has been proposed (for example, Reference 2). In this case, since it is not necessary to drill small holes individually by machining, the nozzle can be further densified.
[0004]
[Reference 1]
JP 58-119872 A [Reference 2]
Japanese Patent No. 3185372
[Problems to be solved by the invention]
However, in the configuration in which the inkjet head is formed by forming one elongated hole, the side wall that partitions the pressurizing chamber and the pressurizing chamber is not bonded to the housing, so that the pressurizing chamber is deformed by driving the vibrator. Interference occurs between the nozzles, and there has been a problem of deterioration in ejection characteristics due to speed variation and the like.
[0006]
SUMMARY An advantage of some aspects of the invention is that it provides an ink jet head, a recording apparatus, and a method for manufacturing a housing that increase the rigidity of a pressurization chamber that is mounted at a high density to prevent a decrease in ink ejection characteristics.
[0007]
[Means for Solving the Problems]
To solve the above problems, the present onset Ming, a chamber plate formed in rows a plurality of pressurizing chamber in a first direction to store ink, and the vibration plate bonded to the chamber plate, the first A surface is bonded to the diaphragm, and a housing having a plurality of through holes formed at positions facing the pressurizing chamber across the diaphragm, is housed in the through holes, and one end is bonded to the diaphragm. And a plurality of first grooves extending in a second direction perpendicular to the first direction on the first surface of the housing at positions corresponding to the plurality of pressurizing chambers. A second groove extending in the first direction is formed at a position corresponding to the plurality of pressurizing chambers on the second surface facing the first surface. in the grooves and the ink jet head wherein a through hole is formed in a portion where the second grooves intersecting, said through The first groove except with unfilled resin, said first surface and said resin is characterized by forming the same plane. According to such a configuration, not only the side wall located between adjacent through holes, but also the entire periphery of the through hole is bonded to the diaphragm, so that the rigidity of the pressurizing chamber is maximized. The first groove is preferably formed by a dicer or a wire saw. According to such a configuration, a high-density through hole is easily formed.
[0008]
The invention according to claim 2 is formed with a plurality of pressurizing chambers arranged in the longitudinal direction,
Forming a first groove extending in the longitudinal direction on a first surface; and a plurality of second grooves extending in a width direction perpendicular to the longitudinal direction at positions corresponding to the plurality of pressurizing chambers. Forming a plurality of through holes in a portion where the first groove and the second groove intersect by forming on the second surface opposite to the first surface,
The method further comprises the step of embedding a resin in the second groove excluding the portion of the through hole, and the step of polishing the first surface to form the same plane with the first surface by the resin. According to such a configuration, not only both sides of the through hole but also the entire periphery of the through hole is bonded to the diaphragm, so that the rigidity of the pressurizing chamber is maximized.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
An ink jet recording apparatus using the ink jet head according to the first embodiment of the present invention will be described.
[0017]
As shown in FIG. 1, the ink jet recording apparatus 100 includes a housing 30 and a head base 31. Although not shown, a roll paper transport device and a control device are accommodated in the housing 30, and a roll paper supply device is disposed on the back side of the housing 30. The roll paper transport device transports the roll paper 33 supplied from the roll paper supply device in the direction of the arrow.
[0018]
Left and right frames 39, 40 are formed on the upper portion of the housing 30, and rods 37, 38 are provided between the frames 39, 40. Support members 35 and 36 are slidably supported on the rods 37 and 38. The head base 31 is attached to the supports 35 and 36. In addition, four head units 32 are mounted on the head base 31. With this configuration, the head unit 32 can be moved to the position of the head cleaning mechanism 40 by sliding the supports 35 and 36 in the width direction of the roll paper 33.
[0019]
The four head units 32 are supplied with cyan, magenta, yellow, and black ink from an ink tank (not shown) through four ink supply pipes 34. Each head unit 32 includes a plurality (for example, 20) of inkjet heads 32 </ b> A shown in FIG. 2 arranged in the width direction of the roll paper 33.
[0020]
As shown in FIG. 2, each inkjet head 32A includes an orifice plate 13, a pressurizing chamber plate 12, a restrictor plate 11, a diaphragm 3, a support plate 14, and a filter that are laminated in order from the bottom. It has a plate 16 and a housing 15. A plurality (only one is shown in FIG. 2) of orifices 1 is formed in the orifice plate 13. A plurality of pressurizing chambers 2 having an orifice 1 as an opening end are formed on the pressurizing plate 12, and a plurality of restrictors 7 are formed on the restrictor plate 11. The filter plate 16 forms the filter 9. A piezoelectric element 4 as a vibrator is inserted into the opening 17 of the housing 15. One end of the piezoelectric element 4 is connected to the diaphragm 3 by an elastic adhesive 10 such as a silicon adhesive, and the other end of the piezoelectric element 4 is fixed to the piezoelectric element fixing plate 6. A pair of signal input terminals 5a and 5b are provided from the side surface of the piezoelectric element fixing plate 6 to the side surface of the piezoelectric element 4, and when a potential difference is applied between the signal input terminals 5a and 5b, the piezoelectric element 4 expands and contracts. When there is no potential difference between the signal input terminals 5a and 5b, the signal input terminals 5a and 5b are configured to return to the form before expansion and contraction. A common ink flow path 20 is further formed in the housing 15, and an ink supply pipe 8 is provided in the housing 15 so that ink does not leak from the common ink flow path 20 to the outside. The support plate 14 reinforces the diaphragm 3.
[0021]
Among these components, the nozzle 50 is constituted by the orifice 1, the pressurizing chamber 2, the restrictor 7, the piezoelectric element 4, and the like, and a total of 128 nozzles 50 are formed in each ink jet head 32A in the present embodiment. Has been. These 128 nozzles 50 are arranged in the longitudinal direction L (FIG. 3) of the housing 15, that is, in a direction perpendicular to the paper surface of FIG.
[0022]
The diaphragm 3, the restrictor plate 11, the pressurizing chamber plate 12, and the support plate 14 are made of, for example, stainless steel, and the orifice plate 13 is made of nickel or stainless steel. The piezoelectric element fixing plate 6 is made of an insulator such as ceramics or polyimide. The housing 15 is made of stainless steel (SUS).
[0023]
In such a configuration, ink is supplied from an ink tank (not shown) to the common ink flow path 20 and is distributed to each restrictor 7 via the filter 9. The restrictor 7 supplies ink to the pressurizing chamber 2 and the orifice 1 while controlling the inflow of ink. When a potential difference is applied between the signal input terminals 5a and 5b, the piezoelectric element 4 expands and contracts, whereby pressure is applied to the ink in the pressurizing chamber 2 and ink droplets are ejected from the orifice 1. The ejected ink droplets land on the roll paper 33 to form an image.
[0024]
FIG. 3 is a perspective view of the housing 15. Grooves 17 extending in the longitudinal direction L are formed on the upper surface 15 b of the housing 15, and a plurality of grooves 18 extending in the width direction W are provided on the lower surface 15 a bonded to the diaphragm 3 at positions facing the pressurizing chamber 2. Is formed. A through hole 19 for inserting the piezoelectric element 4 is formed at a portion where the groove 17 and the groove 18 intersect. A common ink flow path 20 that penetrates the housing 15 in the thickness direction T is formed in parallel with the groove 17.
[0025]
Next, the manufacturing process of the housing 15 will be described with reference to FIG. First, as shown in FIG. 4A, a master disk made of stainless steel (SUS) having a thickness of 10 mm is prepared, a through hole is formed as the common ink channel 20, and a width of 2 mm and a depth are formed on the upper surface 15b. A 7 mm groove 17 is formed. Next, as shown in FIG. 4B, 128 grooves 18 having a depth of 3.5 mm are formed at a position corresponding to the pressurizing chamber 2 on the lower surface 15a at a pitch of 0.338 mm. The groove 18 is formed by a dicer or a wire saw using a blade having a width of 0.2 mm. By forming the groove 17 and the groove 18 on both surfaces 15b and 15a of the housing 15 in this manner, a width of 0.25 mm penetrating the housing 15 in the thickness direction T is formed at a portion where the groove 17 and the groove 18 intersect, A through hole 19 having a length of 2 mm is formed.
[0026]
Next, as shown in FIG. 4C, the lower surface 15a is polished so that the thickness of the surrounding thin portion (side wall) 21 forming the through hole 19 is 1 mm and the flatness is 5 microns. The thickness of the thin portion 21 may not be 1 mm as long as it is thinner than the length of the vibrator 4. The flatness is preferably 10 microns or less because it affects the gap between the vibrator 4 and the diaphragm 3.
[0027]
The housing 15 is manufactured in this way, and an adhesive is applied to the lower surface 15a bonded to the diaphragm 3 of the housing 15 by a general method such as spraying or transferring, thereby, as shown in FIG. 11 is bonded to the thin wall portion 21 which is a part of the housing 15 through the diaphragm 3, the rigidity of the pressure chamber 2 is increased, and interference between nozzles is suppressed. be able to. The present inventors conducted an experiment for examining the influence of the number of simultaneously driven nozzles of the inkjet head 32A having the above-described configuration on the ink ejection speed. The experimental results are shown in FIG.
[0028]
As can be seen from FIG. 5, even when the number of nozzles 50 that discharge simultaneously increases, the ink discharge speed varies little and good ink discharge characteristics can be obtained. This is because, as described above, the side wall of the pressurizing chamber 2 is bonded to the thin wall portion 21 via the diaphragm 3, so that the rigidity of the pressurizing chamber 2 is increased and interference between nozzles is suppressed. .
[0029]
Next, an inkjet head according to a second embodiment of the present invention will be described. The ink jet head according to the present embodiment differs from that in the first embodiment in that it includes a housing 115 shown in FIG. The housing 115 is similar to the housing 15 described above, but differs in that a resin 22 is filled in the groove 18 except for the through hole 19 portion of the housing 115. With this configuration, all four sides of the through hole 19 are bonded to the diaphragm 3, so that the rigidity of the pressurizing chamber 2 is further increased and the speed variation due to interference between the nozzles 50 is further reduced. be able to. Further, since the edge portion of the common ink passage 20 is coplanar and bonded to the diaphragm 3, sufficient rigidity can be obtained without providing the ink supply pipe 8.
[0030]
Next, the manufacturing process of the housing 115 will be described with reference to FIG. First, as shown in FIGS. 7A and 7B, a master disk made of stainless steel (SUS) having a thickness of 10 mm is prepared by the same method as the housing 15, and a through hole as a common ink flow path 20 is prepared. In addition, a groove 17 is formed on the upper surface 15b, and a plurality of grooves 18 are formed on the lower surface 15a. Next, as shown in FIG. 7C, a resin 22 such as an epoxy resin is packed in the groove 18 except for the through-hole 19 portion, and is heated to 150 ° C. to perform thermosetting. Then, as shown in FIG. 7D, the lower surface 15a is polished so that the thickness of the thin portion 21 around the through-hole 19 is 1 mm, and the housing 115 and the resin 22 are flush with each other. As the resin 22, an epoxy resin such as Araldite Standard (manufactured by Ciba Geigy) can be used, but the material is not limited to this. Further, a curing method suitable for the type of material is selected as the resin curing method.
[0031]
Next, an ink jet head according to a third embodiment of the present invention will be described. The ink jet head according to the present embodiment is different from that in the first embodiment in that it includes a housing 215 shown in FIG. A groove 17 and a common ink flow path 20 are formed in the housing 215 as in the case of the housing 15 described above, but the through hole 19 of the housing 215 is formed by a punch 60 as shown in FIG. More specifically, as shown in FIGS. 10A and 10A ′, first, a master disk made of stainless steel (SUS) having a thickness of 10 mm is prepared, and a through hole as a common ink channel 20 is formed. At the same time, the thin portion 21 is formed by forming a groove 17 having a depth of 7 mm on the upper surface 15b. Next, the housing 15 is disposed in a lower mold 61 in which a plurality of grooves 62 are previously formed at a predetermined pitch, with the lower surface 15 a facing upward, and the through hole 19 is formed in the thin portion 21 by the punch 60. After the predetermined number of through holes 19 are formed, the housing 215 is completed as shown in FIGS. 10C and 10C by removing it from the lower mold 61 and performing finishing such as polishing. Thus, by using the punch 60 and the lower mold 61, the housing 215 can be formed more easily.
[0032]
A plurality of holes may be simultaneously formed by punching. More specifically, as shown in FIGS. 11 (a) and 11 (b), stainless steel (SUS) in which the thin portion 21 is formed by the above-described method is installed in the lower mold 61, and a plurality of punches The odd-numbered through holes 19 are formed using 61. Next, as shown in FIG. 11C, the even-numbered through holes 19 are formed by shifting the punch 61. Thereafter, finishing such as polishing is performed to complete the housing 215 as shown in FIG. By forming a plurality of through holes 19 at a time in this way, the processing time can be shortened, and the dimensional deviation due to stress at the time of forming the through holes 19 can be suppressed, thereby improving the dimensional accuracy. .
[0033]
The ink jet recording apparatus of the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made within the scope described in the claims. For example, the present invention can be applied to a dispenser such as a general-purpose small-sized inkjet recording apparatus or an industrial display manufacturing apparatus in addition to the above-described inkjet recording apparatus. Further, the thickness of the housing, the depth of the groove, and the like are not limited to the specific dimensions.
[0034]
【The invention's effect】
According to the first aspect of the present invention, since the fine through-hole is easily formed with high accuracy at a position corresponding to the pressurizing chamber, a printer head having high-density nozzles can be easily manufactured. Further, since the rigidity of the pressurizing chamber is increased by adhering the side wall located between the adjacent through holes to the vibration plate, it is possible to prevent interference between the nozzles, the ink discharge speed caused by such interference, and the like. It is possible to prevent image deterioration due to decrease in image quality. Further, by forming the first groove and the second groove, it is possible to form a plurality of through holes without individually drilling holes, so that it is possible to easily realize high density nozzles.
[0035]
According to the invention described in claim 2, since the rigidity of the pressurizing chamber is maximized by adhering the entire periphery of the through-hole to the diaphragm, interference between nozzles can be further effectively prevented. Therefore, it is possible to prevent the image from being lowered and to execute good image formation. If the first groove is formed by a dicer or a wire saw, a high-density through hole can be easily and inexpensively formed.
[0036]
According to the invention described in claim 5, since the ink jet head according to claims 1 to 4 is provided, an ink jet recording apparatus having the above-described effects can be provided.
[0037]
According to the invention described in claim 6, since the fine through-hole can be easily formed with high accuracy, the manufacturing process of the housing can be simplified. Moreover, since the rigidity of the pressurizing chamber can be increased, it is possible to prevent interference between the nozzles, and to prevent a decrease in the image due to a decrease in the ink discharge speed and the like due to the interference, and an ink jet head capable of forming a good image In addition, an ink jet recording apparatus can be provided.
[0038]
According to the seventh aspect of the invention, since not only both sides of the through hole but also the entire periphery of the through hole is bonded to the diaphragm, the rigidity of the pressurizing chamber is maximized, and the interference between the nozzles is further effective. Therefore, it is possible to provide an ink jet head and an ink jet recording apparatus capable of preventing image formation and forming a good image. Further, by forming the first groove and the second groove, it is possible to form a plurality of through holes without individually drilling holes, so that it is possible to easily realize high density nozzles.
[0039]
According to the housing forming method of the eighth aspect, since the fine through hole can be easily formed with high accuracy, the manufacturing process of the housing can be simplified. Moreover, since the rigidity of the pressurizing chamber can be increased, it is possible to prevent interference between the nozzles, and to prevent a decrease in the image due to a decrease in the ink discharge speed and the like due to the interference, and an ink jet head capable of forming a good image In addition, an ink jet recording apparatus can be provided. Moreover, according to the structure of Claim 9, a through-hole can be easily formed by using the metal mold | die and punch with which several holes were formed with the predetermined pitch.
[0040]
According to the tenth aspect of the present invention, since the housing includes the housing formed by the housing forming method according to the eighth or ninth aspect, the same effect as that of the eighth or ninth aspect can be obtained.
[Brief description of the drawings]
FIG. 1 is an external view showing an ink jet recording apparatus according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing an ink jet head according to an embodiment of the present invention.
FIG. 3 is a perspective view showing a housing according to the first embodiment of the present invention.
FIG. 4 is an explanatory view showing a manufacturing process of the housing according to the first embodiment of the present invention.
FIG. 5 is a graph showing the relationship between the droplet velocity of the inkjet head of the present invention and the number of drive nozzles.
FIG. 6 is a perspective view showing a housing according to a second embodiment of the present invention.
FIG. 7 is an explanatory view showing a manufacturing process of the housing according to the second embodiment of the present invention.
FIG. 8 is a perspective view showing a housing according to a third embodiment of the present invention.
FIG. 9 is a perspective view showing a punch used for manufacturing a housing according to a third embodiment of the present invention.
FIG. 10 is an explanatory view showing a manufacturing process of a housing according to a third embodiment of the present invention, in which (a) is a cross-sectional view showing a state in which a common ink flow path and a groove are formed; Is a bottom view of the housing shown in (a), (b) is a cross-sectional view showing a process of forming a through hole by a punch, (b ′) is a bottom view of the housing shown in (b), and (c) is a completed housing. Sectional drawing, (c ') is a bottom view of the housing shown in (c).
FIGS. 11A and 11B are explanatory views showing a modified example of the manufacturing process of the housing according to the third embodiment of the present invention, in which FIG. 11A shows a state in which a common ink flow path and a groove are formed, and FIG. The state in which the odd-numbered through hole was formed by the punch is shown, (c) shows the process of forming the odd-numbered through hole by the punch, and (d) is a cross-sectional view showing the completed housing.
FIG. 12 is a cross-sectional view showing a conventional inkjet head.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Orifice 2 Pressurizing chamber 3 Diaphragm 4 Piezoelectric element 5a, 5b Signal input terminal 6 Piezoelectric element fixed board 7 Restrictor 8 Common ink supply path 9 Filter 10 Adhesive 11 Restrictor plate 12 Pressurizing chamber plate 13 Orifice plate 14 Support Plate 15, 115, 215 Housing 15a Lower surface 15b Upper surface 16 Filter plate 17, 18 Groove 19 Through hole 20 Common ink flow path 21 Thin portion 22 Resin 60 Punch 61 Lower mold

Claims (2)

A chamber plate in which a plurality of pressurizing chambers for storing ink are formed in a row in the first direction;
A diaphragm bonded to the chamber plate;
A housing in which a first surface is bonded to the diaphragm, and a plurality of through holes are formed at positions facing the pressurizing chamber across the diaphragm;
A plurality of vibrators housed in the through-hole and bonded at one end to the diaphragm;
A plurality of first grooves extending in a second direction perpendicular to the first direction are formed on the first surface of the housing at positions corresponding to the plurality of pressurizing chambers,
A second groove extending in the first direction is formed on the second surface facing the first surface at a position corresponding to the plurality of pressurizing chambers. The first groove and the second groove In the inkjet head in which the through hole is formed in a portion where the grooves intersect ,
An ink jet head, wherein the first groove excluding the through hole is filled with a resin, and the first surface and the resin form the same plane. Forming a plurality of pressurizing chambers arranged in a longitudinal direction and forming a first groove extending in the longitudinal direction on a first surface;
By forming a plurality of second grooves extending in a width direction perpendicular to the longitudinal direction at positions corresponding to the plurality of pressurizing chambers on a second surface opposite to the first surface, The groove and the second groove intersect
Forming a plurality of through holes in a portion to be formed, and embedding a resin in a second groove excluding the through hole portion, and polishing the first surface to form the first surface. housing forming method comprising further comprising Rukoto and forming a flush by the resin.

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