JP6546058B2 - Ink jet printer - Google Patents

Description

  The present invention relates to an inkjet printing apparatus that ejects ink from an inkjet head to print.

  There is known an inkjet printing apparatus having a plurality of inkjet heads arranged along the main scanning direction and printing by discharging ink from the inkjet head while conveying a sheet in the sub scanning direction.

  In an inkjet printing apparatus including this type of apparatus, when the inkjet head is driven, the drive circuit and the like generate heat. The temperature rise due to heat generation causes the failure of the ink jet head and the like. For this reason, it is necessary to cool the inkjet head.

  On the other hand, Patent Document 1 discloses an inkjet printing apparatus in which two fans are disposed with a plurality of inkjet heads disposed along the main scanning direction. In this inkjet printing apparatus, one fan blows air on the inkjet head and the other sucks air. The ink jet head is cooled by the cooling air generated thereby.

JP, 2010-264752, A

  However, in the technology of cooling the inkjet head with the fan as described above, the cooling air may be blown off by the inkjet head and the cooling efficiency may be reduced.

  The present invention has been made in view of the above, and it is an object of the present invention to provide an inkjet printing apparatus capable of improving the cooling efficiency of the inkjet head.

  In order to achieve the above object, the first feature of the ink jet printing apparatus according to the present invention is to form a plurality of head rows extending in the head arrangement direction and to shift the position in the head arrangement direction between the adjacent head rows. A plurality of ink jet heads arranged in a staggered pattern, a spray unit for blowing air from one side of the head arrangement direction to the head row, and a suction unit for drawing air on the other side of the head arrangement direction with respect to the head row And a plurality of plate-shaped adjusting ribs which are disposed on the one side of the head arrangement direction of each ink jet head and which are parallel to the head arrangement direction and which are perpendicular to the horizontal plane and parallel to the head arrangement direction.

  A second feature of the ink jet printing apparatus according to the present invention is a plurality of inclined members disposed above each head row, and having inclined surfaces formed such that the other side in the head arrangement direction is lower than the one side. To further provide

  In a third aspect of the inkjet printing apparatus according to the present invention, the suction unit includes a plurality of suction ports respectively disposed on extensions of the head rows on the other side of the head arrangement direction with respect to the plurality of head rows. And a plurality of cylindrical ducts extending from the suction port to the head row side.

  According to the first feature of the ink jet printing apparatus in accordance with the present invention, divergence of the cooling air can be suppressed and loss of the cooling air can be reduced by the wind adjusting ribs respectively disposed on one side of the head arrangement direction of each ink jet head. . Thereby, the cooling efficiency of the inkjet head can be improved.

  According to a second feature of the inkjet printing apparatus according to the present invention, the plurality of inclined members disposed above the head row and having inclined surfaces formed so that the other side in the head arrangement direction is lower than one side The cooling air passing above the head row is guided to the head row. Thereby, the cooling efficiency of the inkjet head can be further improved.

  According to the third aspect of the inkjet printing apparatus of the present invention, the suction unit has a cylindrical duct extending from the suction port to the head row side. For this reason, since the suction unit sucks the air through the duct, it is possible to concentrate the cooling air toward the duct and to increase the wind speed. As a result, it is possible to suppress the decrease in the cooling performance of the downstream inkjet head. As a result, the cooling efficiency of the inkjet head can be further improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the inkjet printing apparatus which concerns on 1st Embodiment. It is a perspective view of the printing part of the inkjet printing apparatus shown in FIG. It is a top view of the printing part shown in FIG. It is sectional drawing along the AA of FIG. It is a figure which shows the air flow in the head holder seen from the upper direction of the printing part shown in FIG. It is a figure which shows the air flow in the head holder seen from the side of the printing part shown in FIG. It is a perspective view of the printing part in 2nd Embodiment. It is a top view of the printing part shown in FIG. It is sectional drawing along the BB line of FIG. It is a figure which shows the air flow in the head holder seen from the upper direction of the printing part shown in FIG. It is a perspective view of the printing part in 3rd Embodiment. It is a top view of the printing part shown in FIG. It is sectional drawing along the C-C line of FIG. It is a figure which shows the air flow in the head holder seen from the side of the printing part shown in FIG. It is a perspective view of the printing part in 4th Embodiment. It is a top view of the printing part shown in FIG. It is sectional drawing along the DD line of FIG. It is a figure which shows the air flow in the head holder seen from the upper direction of the printing part shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or equivalent parts or components are denoted by the same or equivalent reference numerals throughout the drawings.

  The embodiment shown below exemplifies an apparatus etc. for embodying the technical idea of this invention, and the technical idea of this invention is the material, shape, structure, arrangement etc. of each component. Does not specify the following. Various changes can be added to the technical idea of the present invention within the scope of the claims.

First Embodiment
FIG. 1 is a schematic block diagram of an ink jet printing apparatus according to a first embodiment of the present invention. FIG. 2 is a perspective view of a printing unit of the inkjet printing apparatus shown in FIG. FIG. 3 is a plan view of the printing unit shown in FIG. FIG. 4 is a cross-sectional view taken along the line AA of FIG. In the following description, the direction orthogonal to the paper surface of FIG. 1 is taken as the front-rear direction, and the paper surface front direction is taken as the front. Further, the top, bottom, left, and right of the paper surface in FIG.

  As shown in FIG. 1, the inkjet printing apparatus 1 according to the first embodiment includes a transport unit 2 and a printing unit 3.

  The transport unit 2 transports the sheet P. The conveyance unit 2 includes a conveyance belt 11, a drive roller 12, driven rollers 13, 14 and 15, and a sheet suction fan 16.

  The conveyance belt 11 adsorbs and holds the sheet P and conveys it. The conveyance belt 11 is an annular belt which is wound around the driving roller 12 and the driven rollers 13 to 15. The transport belt 11 is formed with a plurality of belt holes (not shown). The conveyance belt 11 adsorbs and holds the sheet P on the upper surface by the adsorption force generated in the belt hole by the driving of the sheet adsorption fan 16. The transport belt 11 transports the suctioned and held sheet P in the right direction by rotating in the clockwise direction in FIG.

  The driving roller 12 rotates the conveyance belt 11 in the clockwise direction in FIG. The drive roller 12 is rotationally driven by a motor (not shown).

  The driven rollers 13 to 15 support the transport belt 11 together with the drive roller 12. The driven rollers 13 to 15 are driven to rotate by the drive roller 12 via the transport belt 11. The driven roller 13 is disposed at the same height as the drive roller 12 and to the left of the drive roller 12. The driven rollers 14 and 15 are disposed at the same height below the drive roller 12 and the driven roller 13 so as to be separated in the left-right direction.

  The sheet suction fan 16 generates an air flow downward. As a result, the sheet suction fan 16 sucks air through the belt holes of the conveyance belt 11 to generate a negative pressure in the belt holes, and suctions the sheet P onto the conveyance belt 11. The sheet suction fan 16 is disposed in an area surrounded by the annular conveyance belt 11.

  The printing unit 3 prints an image on the sheet P conveyed by the conveyance unit 2. The printing unit 3 is disposed above the conveyance unit 2. As shown in FIGS. 1 to 4, the printing unit 3 includes a plurality of inkjet heads 21, a head holder 22, and a head cooling unit 23.

  The inkjet head 21 discharges the ink onto the sheet P to print an image. The inkjet head 21 is arranged by forming a plurality of head rows extending in the front-rear direction (main scanning direction) which is the head arranging direction. In the present embodiment, as shown in FIG. 2 and FIG. 3, twelve inkjet heads 21 form four head rows LA to LD arranged in parallel in the left-right direction (sub scanning direction).

  The head rows LA to LD each have three inkjet heads 21 arranged at equal intervals along the front-rear direction. The inkjet heads 21 of the head rows LA to LD are arranged such that the positions in the front and rear direction between adjacent head rows are shifted by a half pitch. Thus, the twelve inkjet heads 21 are arranged in a staggered manner.

  The inkjet head 21 has a plurality of nozzles (not shown), a piezo element (not shown) for discharging ink from the nozzles, a drive circuit (not shown) for driving the piezo element, and a heat radiating portion 26. . The heat radiating portion 26 releases the heat generated by the drive of the drive circuit to the outside of the ink jet head 21. The heat radiating portion 26 is disposed on the left side surface of the ink jet head 21.

  The head holder 22 holds the inkjet head 21. The head holder 22 is formed in a hollow substantially rectangular shape. The head holder 22 is provided with a lid (not shown) that covers the top. The bottom surface of the head holder 22 is formed with a plurality of openings to which the ink jet heads 21 are attached. The head holder 22 holds the ink jet head 21 by causing the lower end of the ink jet head 21 to project downward from the opening.

  The head cooling unit 23 cools the inkjet head 21 by the cooling air. The head cooling unit 23 includes a blowing unit 31 and a suction unit 32.

  The spray unit 31 sprays air to the inkjet head 21. The spray unit 31 is disposed on the front side of the head holder 22. The spray unit 31 includes a spray chamber 36 and a spray fan 37.

  The spray chamber 36 distributes the wind from the spray fan 37 to the head rows LA to LD. The spray chamber 36 is formed in a hollow shape that is elongated in the left-right direction. In the spray chamber 36, four spray ports 36a to 36d are formed.

  The spray ports 36 a to 36 d are outlets of air from the spray chamber 36. The spray ports 36 a to 36 d are open in the head holder 22. The spray ports 36a to 36d are disposed on the front sides of the head rows LA to LD, respectively, on the extension of the head rows LA to LD.

  The spray fan 37 blows air into the spray chamber 36. Thus, air is sprayed from the front side to the head rows LA to LD through the spray ports 36 a to 36 d of the spray chamber 36.

  The suction unit 32 sucks air from the head holder 22. The suction unit 32 is disposed on the rear side of the head holder 22. The suction unit 32 includes a suction chamber 38, a suction fan 39, and ducts 40A to 40D.

  The suction chamber 38 forms an air flow path between the head holder 22 and the suction fan 39. The suction chamber 38 is formed in a hollow shape that is elongated in the left-right direction. Four suction ports 38 a to 38 d are formed in the suction chamber 38.

  The suction ports 38 a to 38 d are air inlets to the suction chamber 38. The suction ports 38 a to 38 d are opened in the head holder 22. The suction ports 38a to 38d are disposed on the extension lines of the head rows LA to LD on the rear side of the head rows LA to LD. That is, the suction ports 38a to 38d are disposed to face the spray ports 36a to 36d, respectively, with the head rows LA to LD interposed therebetween.

  The suction fan 39 sucks air from one end of the suction chamber 38. Thus, air is sucked from the head holder 22 through the suction ports 38 a to 38 d of the suction chamber 38.

  The ducts 40A to 40D suppress the divergence of the cooling air directed from the blowing ports 36a to 36d to the suction ports 38a to 38d, and improve the straightness. The ducts 40A to 40D are attached to the suction ports 38a to 38d, respectively. The ducts 40A to 40D are formed in a tubular shape extending from the suction ports 38a to 38d to the head rows LA to LD (front side). The ducts 40A to 40D extend close to the rearmost inkjet heads 21 of the corresponding head rows LA to LD. The ducts 40A to 40D have a partial conical shape in which the outer diameter increases toward the front side. The ducts 40A to 40D are arranged such that the opening at the front end (upstream end) overlaps with at least a part of the heat dissipation portion 26 of the ink jet head 21 in the opening surface view.

  Next, the operation of the inkjet printing apparatus 1 will be described.

  When printing is performed by the inkjet printing apparatus 1, the driving roller 12 and the sheet suction fan 16 start driving. By the drive of the drive roller 12, the transport belt 11 rotates in the clockwise direction in FIG. By driving the sheet suction fan 16, air is sucked through the belt hole of the conveyance belt 11, and suction force is generated in the belt hole.

  Also, the blowing fan 37 and the suction fan 39 start driving. By driving the blowing fan 37, air is blown to the head rows LA to LD through the blowing ports 36a to 36d of the blowing chamber 36. In addition, air is sucked from the head holder 22 through the ducts 40A to 40D and the suction ports 38a to 38d by driving the suction fan 39. As a result, as shown in FIGS. 5 and 6, the cooling air W flowing from the front side to the rear side is generated in the head holder 22.

  When the sheet P is fed from the sheet feeding unit (not shown) to the conveyance unit 2, the sheet P is conveyed while being held by suction by the conveyance belt 11 by the suction force at the belt hole. The inkjet head 21 discharges the ink onto the sheet P to be conveyed to print an image. When the designated number of printed sheets is a plurality of sheets, the ink jet head 21 discharges the ink onto each sheet P which is sequentially fed and transported on the transport belt 11 to print an image.

  When the inkjet head 21 is driven, the inkjet head 21 generates heat. On the other hand, in the inkjet printing apparatus 1, the inkjet head 21 is cooled by the cooling air W.

  Here, the cooling air W diverges when it strikes the inkjet head 21. For this reason, unlike the present embodiment, when the ducts 40A to 40D are not provided, the cooling air W hitting the ink jet head 21 becomes weaker toward the downstream side (rear side). Further, since the cooling air W is warmed by the heat radiation of the ink jet head 21, the temperature of the cooling air W becomes higher toward the downstream side. Therefore, when the ducts 40A to 40D are not provided, the cooling performance is lower as the downstream inkjet head 21 is, and the temperature is likely to rise.

  On the other hand, in the inkjet printing apparatus 1 of the present embodiment, the suction unit 32 sucks the air via the ducts 40A to 40D, whereby the divergence of the cooling air W is suppressed and the straightness improves. Thus, the cooling air W is concentrated toward the ducts 40A to 40D, and the wind speed is increased. For this reason, it is suppressed that a cooling property falls to the downstream inkjet head 21 side.

  Further, the ducts 40A to 40D are disposed so that the opening at the front end (upstream end) overlaps with at least a part of the heat radiating portion 26 of the ink jet head 21 in the opening surface view. The wind speed of the wind W can be raised. For this reason, the inkjet head 21 is cooled efficiently.

  When the printed sheet P leaves the conveyance unit 2, the sheet P is conveyed to a discharge unit (not shown) and discharged. When the last sheet P is discharged, the drive roller 12, the sheet suction fan 16, the blowing fan 37, and the suction fan 39 stop. Thus, the printing operation is completed.

  As described above, in the inkjet printing apparatus 1, the suction unit 32 includes cylindrical ducts 40A to 40D extending from the suction ports 38a to 38d toward the head rows LA to LD. For this reason, since suction part 32 sucks air via ducts 40A-40D, cooling wind W can be concentrated toward ducts 40A-40D, and a wind speed can be raised. As a result, it is possible to suppress the decrease in the cooling performance of the inkjet head 21 on the downstream side. As a result, the cooling efficiency of the inkjet head 21 can be improved.

Second Embodiment
A second embodiment in which the printing unit of the above-described embodiment is changed will be described. FIG. 7 is a perspective view of the printing unit in the second embodiment. FIG. 8 is a plan view of the printing unit shown in FIG. FIG. 9 is a cross-sectional view taken along the line B-B of FIG.

  As shown in FIGS. 7 to 9, the printing unit 3A according to the second embodiment has a configuration in which the ducts 40A to 40D are omitted from the printing unit 3 according to the first embodiment described above and a plurality of wind adjusting ribs 41 are provided. It is.

  The wind adjustment rib 41 is a member that winds the cooling air W so as to suppress the divergence of the cooling air W. The wind adjustment rib 41 is formed in a plate shape perpendicular to the horizontal surface and parallel to the main scanning direction. The wind adjustment rib 41 is disposed in the vicinity of the upstream side of each ink jet head 21. That is, the wind adjustment ribs 41 are disposed between the inkjet heads in the front-rear direction of the head rows LA to LD and in the vicinity of the upstream side of the uppermost inkjet head 21.

  When the blowing fan 37 and the suction fan 39 are driven in the printing unit 3A, the cooling air W flows in the head holder 22 as shown in FIG.

  As shown in FIG. 10, in the printing unit 3A, the wind adjustment rib 41 suppresses the escape of the cooling air W that has hit the ink jet head 21 in the left-right direction. For example, a part of the cooling air W that has flowed in the left direction by hitting the uppermost stream inkjet head 21 of the head row LB is turned backward by the wind adjustment rib 41 on the upstream side of the uppermost stream inkjet head 21 of the head row LA. Be done. Thus, the cooling air W that has flown to the left side of the head row LA without the wind adjustment rib 41 can be applied to the uppermost stream inkjet head 21 of the head row LA by the wind adjustment rib 41.

  As described above, in the second embodiment, the divergence of the cooling air W can be suppressed by the wind adjustment rib 41, and the loss of the cooling air W can be reduced. Thereby, the cooling efficiency of the inkjet head 21 can be improved.

Third Embodiment
A third embodiment in which the printing unit of the above-described embodiment is changed will be described. FIG. 11 is a perspective view of the printing unit in the third embodiment. FIG. 12 is a plan view of the printing unit shown in FIG. 13 is a cross-sectional view taken along the line C-C of FIG.

  As shown in FIGS. 11 to 13, the printing unit 3 </ b> B in the third embodiment has a configuration in which a plurality of inclined members 42 are provided to the printing unit 3 </ b> A in the second embodiment described above.

  The inclined member 42 causes the cooling air W flowing above the head rows LA to LD to flow downward and leads it to the head rows LA to LD. The inclined members 42 are disposed above the head rows LA to LD. The inclined member 42 is disposed in the vicinity of the front side (upstream side) of the inkjet head 21 at the center of each of the head rows LA to LD in the front-rear direction. In other words, the inclined members 42 are arranged in the front-rear direction in the vicinity of the rear side (downstream side) of the uppermost stream inkjet head 21 of each of the head rows LA to LD. The inclined member 42 has an inclined surface 42 a inclined so that the rear side is lower than the front side.

  In the printing unit 3B, as shown in FIG. 14, the cooling air W passing above the head rows LA to LD hits the inclined surface 42a of the inclined member 42 and flows downward along the inclined surface 42a to the head arrays LA to LD. Led. As a result, the cooling air W passing through the head rows LA to LD is strengthened, and the cooling efficiency of the inkjet head 21 is improved.

  Here, as described above, the temperature of the cooling air W becomes higher toward the rear side (downstream side). On the other hand, since the inclined member 42 is disposed in the vicinity of the rear side of the uppermost ink jet head 21 of each head row LA to LD, the cooling air W having a relatively low temperature is sent to the head rows LA to LD from above. be able to.

  As described above, in the third embodiment, since the cooling air W passing above the head rows LA to LD is guided to the head rows LA to LD by the inclined members 42, the cooling efficiency of the inkjet head 21 can be further improved.

Fourth Embodiment
A fourth embodiment in which the printing unit of the above-described embodiment is changed will be described. FIG. 15 is a perspective view of the printing unit in the fourth embodiment. FIG. 16 is a plan view of the printing unit shown in FIG. FIG. 17 is a cross-sectional view taken along the line D-D of FIG.

  As shown in FIGS. 14 to 16, the printing unit 3 </ b> C in the fourth embodiment is different from the printing unit 3 in the first embodiment described above in the plurality of wind adjusting ribs 41 similar to the printing unit 3 </ b> A in the second embodiment. It is the added configuration.

  When the blowing fan 37 and the suction fan 39 are driven in the printing unit 3C, the cooling air W flows in the head holder 22 as shown in FIG.

  As shown in FIG. 18, in the printing unit 3 </ b> C, similarly to the printing unit 3 </ b> A of the second embodiment described above, the wind adjustment rib 41 suppresses the escape of the cooling air W hitting the inkjet head 21 in the left-right direction. Thereby, the divergence of the cooling air W can be suppressed, and the loss of the cooling air W can be reduced.

  Further, in the printing unit 3C, similarly to the printing unit 3 of the first embodiment, the suction unit 32 sucks air via the ducts 40A to 40D, whereby the divergence of the cooling air W is suppressed and the straightness improves. Do. Thus, the cooling air W is concentrated toward the ducts 40A to 40D, and the wind speed is increased. As a result, it is possible to suppress the decrease in the cooling performance of the inkjet head 21 on the downstream side.

  As described above, in the fourth embodiment, since the ducts 40A to 40D and the wind adjustment rib 41 are combined, the cooling efficiency of the inkjet head 21 can be further improved.

(Other embodiments)
As described above, although the present invention has been described by the first to fourth embodiments, it should not be understood that the description and the drawings, which form a part of this disclosure, limit the present invention. Various alternative embodiments, examples and operation techniques will be apparent to those skilled in the art from this disclosure.

  In the third embodiment described above, the inclined members 42 are disposed one by one for each of the head rows LA to LD, but a plurality of inclined members 42 may be disposed for each of the head rows LA to LD. For example, the inclination member 42 may be disposed near the upstream side of all the inkjet heads 21.

  The inclined member 42 of the third embodiment may be added to the printing unit 3C of the fourth embodiment described above.

  Thus, it is a matter of course that the present invention includes various embodiments and the like which are not described herein. Accordingly, the technical scope of the present invention is defined only by the invention-specifying matters according to the scope of claims appropriate from the above description.

DESCRIPTION OF SYMBOLS 1 inkjet printing apparatus 2 conveyance part 3, 3A, 3B, 3C printing part 21 inkjet head 22 head holder 23 head cooling part 26 thermal radiation part 31 blowing part 32 suction part 36 blowing chamber 36a-36d blowing port 37 blowing fan 38 suction chamber 38a -38d suction port 39 suction fan 40A to 40D duct 41 adjustment rib 42 inclined member 42a inclined surface LA to LD head row W cooling air

Claims (3)

A plurality of head rows extending in the head arranging direction, and a plurality of ink jet heads arranged in a staggered manner so that positions in the head arranging direction are shifted between the adjacent head rows;
A blowing unit for blowing air to the head row from one side of the head arrangement direction;
A suction unit that sucks air on the other side of the head array direction with respect to the head row;
An ink jet printing apparatus comprising: a plurality of plate-like baffle ribs perpendicular to a horizontal surface and parallel to the head arrangement direction, disposed on the one side of the head arrangement direction of each ink jet head.   2. The apparatus according to claim 1, further comprising a plurality of inclined members disposed above each head row and having inclined surfaces formed such that the other side in the head arrangement direction is lower than the one side. Inkjet printing device. The suction unit is
A plurality of suction ports respectively disposed on extensions of the head rows on the other side of the head arrangement direction with respect to the plurality of head rows;
The ink jet printing apparatus according to claim 1, further comprising: a plurality of tubular ducts extending from the suction port to the head row side.