JP2008183837A - Fluid ejection device and maintenance device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid jetting apparatus and a maintenance device capable of reducing an amount of a fluid unnecessarily consumed when cleaning a fluid jetting head. <P>SOLUTION: The maintenance device 23 provided for an inkjet printer having a recording head 19 capable of jetting ink from a nozzle 21 comprises: a cap member 24 formed so as to be able to suck the ink from the nozzle 21 in the case of generating a negative pressure on the condition of contacting to the recording head 19 so as to enclose the nozzle 21; and a tube pump 28 capable of depressurizing the inside of the cap member 24. The maintenance device 23 further comprises a negative pressure regulator 30 for limiting a negative pressure value generated in the cap member 24 within a predetermined threshold value when depressurizing the inside of the cap member 24 by the tube pump 28. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fluid ejecting apparatus such as an ink jet printer and a maintenance device provided in the fluid ejecting apparatus.

  2. Description of the Related Art Conventionally, ink jet printers (hereinafter simply referred to as “printers”) are widely known as fluid ejecting apparatuses that eject fluid from nozzles of a fluid ejecting head. In such a printer, the ink is thickened by evaporation of the ink solvent from the nozzle opening of the recording head (fluid ejecting head), and the nozzle may be clogged. In addition, when bubbles are mixed into the nozzle from the nozzle opening, printing defects such as missing dots may occur.

  In order to solve these problems, for example, in the printer disclosed in Patent Document 1, so-called head cleaning is performed in which ink, bubbles, or the like thickened from the nozzles of the recording head is sucked and discharged. A cleaning mechanism (maintenance device) that performs the head cleaning includes a cap (cap member) formed so as to be in contact with the recording head in a state of surrounding the nozzle opening, a cap tube connected to the cap, and the cap tube And a tube pump (suction means) connected to the.

The tube pump includes a pump tube, a pump roller, etc., one end of which is connected to the cap tube, and the pump tube is sequentially crushed along the longitudinal direction by the pump roller while the cap is in contact with the recording head. Negative pressure is generated upstream of the pump tube (in the cap and in the cap tube). Due to the generation of the negative pressure in the cap, ink is sucked and discharged from the nozzle of the recording head through the cap.
JP 2001-63102 A

  By the way, the tube pump of the cleaning mechanism in Patent Document 1 has a relatively variable suction capacity among the pumps, and therefore the amount of ink sucked from the nozzles of the recording head varies when performing head cleaning. In this case, the variation in the suction capacity of the tube pump is caused by a variation in the size of each component constituting the tube pump, a variation in the ability of the motor for driving the tube pump, or the like.

  Here, in order to perform the head cleaning, it is necessary to suck a necessary amount of ink from the nozzle of the recording head. However, considering the variation in the suction capacity of the tube pump, the suction capacity of the tube pump is usually the highest. It is set so that an amount of ink necessary for performing head cleaning when it is low is sucked from the nozzles of the recording head. For this reason, when the tube pump has a high suction capability, ink is sucked from the nozzles of the recording head more than necessary (excess) when performing head cleaning, so that the amount of ink consumed wasted. There was a problem that it would increase.

  The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide a fluid ejecting apparatus and a maintenance apparatus that can reduce the amount of fluid that is wasted when the fluid ejecting head is cleaned.

  In order to achieve the above object, a maintenance device according to the present invention is a maintenance device provided in a fluid ejecting apparatus having a fluid ejecting head capable of ejecting fluid from a nozzle, and contacts the fluid ejecting head so as to surround the nozzle. When a negative pressure is generated inside the cap member in contact with the cap member, the cap member is formed so as to be able to suck fluid from the nozzle; suction means capable of sucking the inside of the cap member; Negative pressure regulating means for regulating so that the value of the negative pressure generated in the cap member does not become larger than a preset threshold when the is sucked.

  According to this invention, even if there is variation in the suction capacity of the suction means, the negative pressure restriction means restricts the negative pressure value generated in the cap member from becoming larger than a preset threshold value. When cleaning is performed, variation in the amount of fluid sucked from the nozzle is suppressed. Therefore, it is possible to reduce the amount of fluid that is wasted when cleaning the fluid ejecting head.

  In the maintenance device of the present invention, the negative pressure regulating means opens or closes the cap member, a fluid discharge passage interposed between the cap member and the suction means, and the inside of the cap member with respect to the atmosphere. Is provided in at least one of the air release paths having the air release valve.

According to the present invention, since the number and arrangement positions of the negative pressure regulating means can be selected, it is possible to increase the degree of freedom in design.
In the maintenance device according to the present invention, the negative pressure regulating means is generated in the cap member so as to be arranged in an air suction port for sucking the air into the cap member and to close the air suction port. A sealing member biased by a predetermined biasing force that opposes the negative pressure, and the biasing force is greater than the negative pressure when the value of the negative pressure generated in the cap member is greater than the threshold value. It is set to be smaller.

  According to the present invention, when the value of the negative pressure generated in the cap member becomes larger than the threshold value, the seal member biased in the arrangement mode that closes the air suction port is caused by the negative pressure larger than the biasing force. It is moved in the direction opposite to the direction of closing the air inlet. That is, when the value of the negative pressure generated in the cap member becomes larger than a preset threshold value, the closed state of the air suction port by the seal member is released, and air is sucked from the air suction port. The cap member communicates with the atmosphere. For this reason, it becomes possible to regulate so that the value of the negative pressure generated in the cap member does not become larger than a preset threshold value without performing special control.

In the maintenance device of the present invention, the negative pressure regulating means includes a fluid absorbing material that covers the atmospheric air inlet from the direction of the atmospheric side when viewed from the atmospheric inlet.
According to this invention, when the fluid leaks from the atmosphere suction port to the outside on the atmosphere side, the leaked fluid is absorbed by the fluid absorbent. For this reason, it is possible to suppress the fluid leaking from the air suction port from dripping.

  In the maintenance device of the present invention, the negative pressure regulating means includes a valve device that allows the cap member to communicate with the atmosphere when the valve opening operation is performed, and a value of the negative pressure generated in the cap member. And a control means for opening and closing the valve device based on a detection result by the pressure detection means, and the control means is configured to control the pressure above the threshold value that is preset and stored. When the negative pressure value detected by the detection means becomes large, the valve device is opened.

  According to the present invention, when the pressure detecting means detects that the value of the negative pressure generated in the cap member is larger than the preset threshold value, the control means opens the valve device. The cap member communicates with the atmosphere. Therefore, various cleanings can be suitably performed by finely setting the threshold according to the type of cleaning of the fluid ejecting head.

  In the maintenance device of the present invention, the negative pressure regulating means includes a pressure detection means for detecting a negative pressure value generated in the cap member, and a driving state of the suction means based on a detection result by the pressure detection means. Control means for controlling, and when the negative pressure value detected by the pressure detection means reaches the threshold value, the control means stops driving the suction means.

  According to the present invention, when the pressure detecting means detects that the value of the negative pressure generated in the cap member has reached the preset and stored threshold value, the control means stops driving the suction means. It is regulated that the value of the negative pressure generated at the time is larger than the threshold value.

  In the maintenance apparatus of the present invention, the negative pressure regulating means includes a temperature detecting means for detecting an ambient temperature of the cap member, and a threshold changing means for changing the threshold based on the ambient temperature detected by the temperature detecting means. It has.

According to the present invention, the threshold value can be changed in consideration of the atmospheric temperature, so that the fluid ejection head can be suitably cleaned even if the atmospheric temperature changes.
In the maintenance apparatus of the present invention, the negative pressure regulating means includes a fluid type detecting means for detecting the type of the fluid ejected from the nozzle, and the threshold based on the type of the fluid detected by the fluid type detecting means. And a threshold value changing means for changing.

  According to the present invention, the threshold value can be changed in consideration of the type of fluid. Therefore, even when the type of fluid ejected from the fluid ejecting head changes, the fluid ejecting head can be suitably cleaned. It becomes possible.

  The fluid ejecting apparatus according to the present invention includes a fluid ejecting head capable of ejecting a fluid from a nozzle, and a maintenance unit for performing maintenance of the fluid ejecting head. Consists of.

  According to this invention, even if there is variation in the suction capacity of the suction means, the negative pressure restriction means restricts the negative pressure value generated in the cap member from becoming larger than a preset threshold value. The variation in the amount of fluid sucked from the nozzles during cleaning is reduced. Therefore, it is possible to reduce the amount of fluid that is wasted when cleaning the fluid ejecting head.

(First embodiment)
Hereinafter, an embodiment in which a fluid ejecting apparatus according to the invention is embodied in an ink jet printer will be described with reference to the drawings. In the following description, when referring to “front-rear direction”, “vertical direction”, and “left-right direction”, unless otherwise specified, “front-rear direction”, “vertical direction”, It shall be the same as the “left-right direction”.

  As shown in FIG. 1, an ink jet printer 11 as a fluid ejecting apparatus includes a frame 12 having a substantially rectangular box shape. A platen 13 is extended at the lower part in the frame 12 along the left-right direction which is the longitudinal direction thereof. On the platen 13, the recording paper P as a target is fed from the rear side by a paper feeding mechanism (not shown) based on driving of a paper feeding motor 14 provided at the lower back of the frame 12.

  A guide shaft 15 is installed above the platen 13 in the frame 12 along the longitudinal direction of the platen 13. A carriage 16 is supported on the guide shaft 15 so as to be capable of reciprocating along the axial direction (left-right direction) of the guide shaft 15. That is, the carriage 16 is supported so as to be reciprocally movable along the longitudinal direction of the guide shaft 15 by inserting the guide shaft 15 through a support hole 16a formed penetrating in the left-right direction.

  A driving pulley 17a and a driven pulley 17b are rotatably supported at positions corresponding to both end portions of the guide shaft 15 on the inner surface of the rear wall of the frame 12. An output shaft of a carriage motor 18 serving as a drive source for reciprocating the carriage 16 is connected to the drive pulley 17a. An endless timing belt connected to the carriage 16 is connected between the pair of pulleys 17a and 17b. 17 is hung. Accordingly, the carriage 16 is movable in the left-right direction via the endless timing belt 17 by the driving force of the carriage motor 18 while being guided by the guide shaft 15.

  A recording head 19 as a fluid ejecting head is provided on the lower surface side of the carriage 16, and an ink cartridge 20 for supplying ink as a fluid to the recording head 19 is detachably mounted on the carriage 16. ing. The ink in the ink cartridge 20 is supplied from the ink cartridge 20 to the recording head 19 by driving a piezoelectric element (not shown) provided in the recording head 19, and the nozzle forming surface 19a of the recording head 19 (see FIG. 2). ) Is ejected onto the recording paper P fed onto the platen 13 from a plurality of nozzles 21 (see FIG. 2) formed in the above), and printing is performed.

  A maintenance device 23 as a maintenance unit for performing maintenance such as cleaning of the recording head 19 is provided in a home position area (non-printing area) that does not correspond to the recording paper P located at the right end in the frame 12. ing.

Next, the maintenance device 23 will be described in detail.
As shown in FIG. 2, the maintenance device 23 includes a cap member 24 having a bottomed square box shape and a lifting device (not shown) for lifting and lowering the cap member 24. Then, the maintenance device 23 raises the cap member 24 by the lifting device while the carriage 16 is moved to the home position region, so that the cap member 24 comes into contact with the nozzle forming surface 19 a of the recording head 19. Each nozzle 21 is enclosed.

  A projecting portion 25 projects downward from a front position on the bottom wall of the cap member 24, and a discharge path 25 a for ejecting ink from the cap member 24 is vertically provided in the projecting portion 25. It is formed penetrating in the direction. A base end side (upstream side) of a discharge tube 26 made of a flexible material is connected to the protrusion 25, and a front end side (downstream side) of the discharge tube 26 is disposed in a waste ink tank 27 having a rectangular parallelepiped shape. Has been inserted. In this case, the passage in the discharge tube 26 constitutes a fluid discharge path for discharging the ink in the cap member 24 into the waste ink tank 27.

  Further, a tube pump as a suction means capable of sucking the inside of the cap member 24 from the cap member 24 side toward the waste ink tank 27 side at a midway position of the discharge tube 26 between the cap member 24 and the waste ink tank 27. 28 is disposed. Then, by driving the tube pump 28 in a state where the cap member 24 is in contact with the nozzle forming surface 19a of the recording head 19 so as to surround each nozzle 21, the ink thickened from each nozzle 21 is sucked together with bubbles and the like. The so-called cleaning is performed in which the ink is discharged into the waste ink tank 27 through the cap member 24 and the discharge tube 26. The waste ink tank 27 contains a waste ink absorbing material 29 that absorbs and holds the ink discharged into the waste ink tank 27.

  In addition, a value of the negative pressure generated in the cap member 24 when the inside of the cap member 24 is sucked by the tube pump 28 is preliminarily set in the middle position of the discharge tube 26 between the cap member 24 and the tube pump 28. A negative pressure regulating device 30 as a negative pressure regulating means for preventing the pressure from exceeding a set threshold value N is provided.

Next, the tube pump 28 will be described in detail.
As shown in FIG. 2, the tube pump 28 has a bottomed cylindrical case 31 fixed to the frame 12 (see FIG. 1), and the case 31 has a circular shape in plan view. A foil 32 is accommodated so as to be rotatable about a wheel shaft 33 provided at the axial center of the case 31. And in this case 31, the intermediate part 26a of the discharge tube 26 is accommodated so that the inner peripheral wall 31a of the case 31 may be followed.

  The pump foil 32 is formed with a pair of arcuate roller guide grooves 34 and 35 that bulge outwardly so as to face each other with the wheel shaft 33 interposed therebetween. One end of each of the roller guide grooves 34 and 35 is located on the outer peripheral side of the pump wheel 32, and the other end is located on the inner peripheral side of the pump wheel 32. That is, both the roller guide grooves 34 and 35 gradually extend away from the outer peripheral portion of the pump wheel 32 as they go from one end to the other end. A pair of rollers 36 and 37 as pressing means are inserted and supported in both roller guide grooves 34 and 35 through rotation shafts 36a and 37a, respectively. The rotating shafts 36a and 37a are slidable in the roller guide grooves 34 and 35, respectively.

  When the pump wheel 32 is rotated in the forward direction (the arrow direction in FIG. 2), both rollers 36 and 37 move to one end side (the outer peripheral side of the pump wheel 32) of both roller guide grooves 34 and 35, The middle portion 26a of the discharge tube 26 rotates while being crushed (pressed) sequentially from the upstream side to the downstream side. By this rotation, a negative pressure is generated in the discharge tube 26 upstream of the tube pump 28 and in the cap member 24, and the generation of this negative pressure causes the cap member 24 to pass through the discharge tube 26. Suction to the waste ink tank 27 side.

  On the other hand, when the pump wheel 32 is rotated in the reverse direction (the direction opposite to the arrow direction in FIG. 2), both rollers 36 and 37 are on the other end side of both roller guide grooves 34 and 35 (inner peripheral side of the pump wheel 32). Move to. By this movement, both rollers 36 and 37 are in light contact with the intermediate portion 26a of the discharge tube 26, respectively, and the negative pressure state in the discharge tube 26 upstream of the tube pump 28 and in the cap member 24 is eliminated. The

Next, the cap member 24 will be described in detail.
As shown in FIG. 2, the cap member 24 is provided with a rectangular frame rubber cap seal member 40 so as to cover the upper end of the cap member 24, and the ink absorbing material 41 is provided in the cap member 24. Is arranged. Further, a cylindrical atmosphere release pipe 42 extending so as to penetrate the bottom wall 24a in the vertical direction is provided at a position closer to the rear of the bottom wall 24a of the cap member 24. The passage is an atmosphere open path 42a.

  Further, a portion of the air release pipe 42 above the bottom wall 24 a of the cap member 24 passes through the ink absorbing material 41, and the upper end thereof is substantially flush with the upper surface of the ink absorbing material 41. On the other hand, an air release valve 43 is provided at the lower end of the portion of the air release pipe 42 below the bottom wall 24 a of the cap member 24.

  When the atmosphere release valve 43 is opened, the cap member 24 is brought into communication with the atmosphere via the atmosphere release path 42a (a state opened to the atmosphere), and the atmosphere release valve 43 is closed. When the valve is operated, the cap member 24 is brought into a non-communication state (closed state with respect to the atmosphere) through the atmosphere opening path 42a. The cap member 24 surrounds each nozzle 21 when the cap seal member 40 is in contact with the nozzle formation surface 19a of the recording head 19. In this state, the nozzle formation surface 19a of the recording head 19 and the ink absorption are absorbed. A slight gap is formed between the upper surface of the material 41.

Next, the negative pressure regulating device 30 will be described in detail.
As shown in FIG. 2, the negative pressure regulating device 30 includes a case 45 having a rectangular parallelepiped shape that is long in the front-rear direction, and the case 45 is located in the middle of the discharge tube 26 between the cap member 24 and the tube pump 28. It is arranged to be incorporated into the position. That is, at the midway position of the discharge tube 26 between the cap member 24 and the tube pump 28, the discharge tube 26 is cut, and the upstream end of both ends of the cut tube 26 at the cut portion. The part is connected from the upper side of the case 45, and the downstream end is connected from the front side of the case 45.

  In this case, the case 45 communicates with the inside of the discharge tube 26 upstream of the case 45 in the discharge tube 26 and the inside of the discharge tube 26 downstream of the case 45 in the discharge tube 26. Therefore, it can be said that the inside of the case 45 constitutes a part of the fluid discharge path.

  An air inlet 46 is formed in the center of the rear wall of the case 45 so as to penetrate the inside and outside of the case 45. The air inlet 46 is provided on the outer surface of the rear wall of the case 45. An ink absorbing material 47 as a fluid absorbing material is attached so as to cover from the outside on the atmosphere side when viewed from the mouth 46. A front end of a coil spring 48 as a biasing member that can be expanded and contracted in the front-rear direction is fixed to a central portion of the inner surface of the front wall of the case 45, and a rear end of the coil spring 48 is a plate-like seal housed in the case 45. The member 49 is fixed to the front surface 49a. Therefore, the seal member 49 is supported by the coil spring 48 in the case 45. The vertical length of the seal member 49 is shorter than the distance between the inner surfaces of the case 45 in the vertical direction.

  The seal member 49 always receives the urging force from the coil spring 48, and the rear surface 49b is in close contact with the inner surface of the rear wall of the case 45 so as to cover the air intake port 46 from the inside. Sealed (closed). In this case, the coil spring 48 has a preset negative pressure value generated in the cap member 24 when the biasing force applied to the seal member 49 is sucked into the cap member 24 by the tube pump 28. It is set to be smaller than the negative pressure when it becomes larger than the threshold value N. In this embodiment, the threshold value N in this embodiment is set to a value such that an amount of ink necessary for cleaning is sucked from the nozzles 21 of the recording head 19 based on experiments and simulations performed in advance. ing.

Next, the operation of the maintenance device 23 will be described.
When the recording head 19 is cleaned, the cap member 24 is first lifted with the carriage 16 moved to the home position region. Then, the cap seal member 40 of the cap member 24 comes into contact with the nozzle forming surface 19 a of the recording head 19, and each nozzle 21 is surrounded by the cap member 24.

  In this state, when the tube pump 28 is driven and the pump wheel 32 is rotated in the forward direction (the arrow direction in FIG. 2), both rollers 36 and 37 move the intermediate portion 26a of the discharge tube 26 from the upstream side to the downstream side. Then, the pressure in the discharge tube 26 upstream of the tube pump 28, the case 45 of the negative pressure regulating device 30, and the cap member 24 are sucked and negative pressure is generated. When a negative pressure is generated in the cap member 24, the ink having increased viscosity is sucked from each nozzle 21 of the recording head 19 by the negative pressure, and the ink is absorbed in the cap member 24 and the discharge tube 26 (in the case 45). Is discharged into the waste ink tank 27.

  Here, in the case where the cap member 24 is excessively sucked due to variations in the suction capacity of the tube pump 28 and the value of the negative pressure generated in the cap member 24 becomes larger than the threshold value N, the negative pressure causes The seal member 49 is moved forward against the urging force of the coil spring 48. Then, the rear surface 49b of the seal member 49 and the inner surface of the rear wall of the case 45 are separated from each other, and the sealing state of the air suction port 46 by the seal member 49 is released.

  When the sealed state of the air suction port 46 is released, the air is sucked into the case 45 from the air suction port 46 and the negative pressure value generated in the cap member 24 is reduced. When the value of the negative pressure generated in the cap member 24 becomes equal to or less than the threshold value N, the negative pressure becomes smaller than the biasing force of the coil spring 48, and the sealing member 49 moves rearward by the biasing force of the coil spring 48. Then, the rear surface 49b of the seal member 49 is again brought into close contact with the inner surface of the rear wall of the case 45 so as to cover the atmospheric suction port 46, and the atmospheric suction port 46 is sealed.

  Thus, even if the cap pump 24 is sucked more than necessary (excessive) because the tube pump varies and the tube pump 28 having an excessively large suction capacity is used, negative pressure regulation is performed. The value of the negative pressure generated in the cap member 24 by the action of the device 30 is regulated so as not to be larger than the threshold value N. For this reason, variation in the amount of ink sucked from the nozzles 21 during cleaning is suppressed, and the amount of ink consumed unnecessarily (unnecessarily) during cleaning is reduced.

  When the pump wheel 32 is rotated in the reverse direction (the direction opposite to the arrow direction in FIG. 2) after the cleaning of the recording head 19 is completed, the rollers 36 and 37 are moved to the other end sides of the roller guide grooves 34 and 35. The negative pressure state in the discharge tube 26, the case 45, and the cap member 24 upstream of the tube pump 28 is eliminated.

  Further, for example, when the negative pressure regulating device 30 operates abnormally and ink in the case 45 leaks to the outside from the air suction port 46, the leaked ink is absorbed by the ink absorbing material 47. For this reason, since the ink leaking from the inside of the case 45 to the outside through the air suction port 46 is suppressed, the surroundings are hardly contaminated with ink.

As described above, according to the first embodiment described in detail, the following effects can be obtained.
(1) Even if the suction capacity of the tube pump 28 varies, the negative pressure generated in the cap member 24 by the negative pressure regulating device 30 when cleaning is applied to the coil spring 48. It is regulated not to become larger than the threshold value N set by the power. For this reason, even if the suction capability of the tube pump 28 is increased, it is possible to suppress variations in the amount of ink sucked from the nozzles 21 during cleaning. Accordingly, it is possible to reduce the amount of ink that is wasted when the recording head 19 is cleaned.

  Further, by limiting the limit value of the negative pressure value generated in the cap member 24 during cleaning as the threshold value N, in the ink in the recording head 19 and in the ink supply path upstream of the recording head 19. The generation of minute bubbles in the ink due to the reduced pressure can be suppressed. Therefore, the success rate of cleaning can be improved, and the waiting time until the next operation after the cleaning is performed can be shortened.

  Incidentally, if minute bubbles are generated in the ink in the recording head 19 and in the ink supply path on the upstream side of the recording head 19, the bubbles may not be removed even if cleaning is performed, and the cleaning may fail. . Further, once minute bubbles are generated in the ink in the recording head 19 and in the ink supply path on the upstream side of the recording head 19, it is necessary to wait until the bubbles are dissolved again in the ink and disappear. I will have to.

  (2) The biasing force of the coil spring 48 is set to be smaller than the negative pressure when the value of the negative pressure generated in the cap member 24 becomes larger than the threshold value N. For this reason, when the value of the negative pressure generated in the cap member 24 becomes larger than the threshold value N, the seal member 49 that seals the air suction port 46 is resisted against the urging force of the coil spring 48. The suction port 46 can be moved forward in the direction opposite to the sealing direction. In other words, when the value of the negative pressure generated in the cap member 24 is greater than the threshold value N, the sealing state of the atmosphere suction port 46 by the seal member 49 is released, so that the inside of the cap member 24 can be communicated with the atmosphere. The value of the negative pressure generated in the cap member 24 can be mechanically regulated so as not to exceed the threshold value N without performing special control.

  Further, since the coil spring 48 capable of obtaining a stable spring load is used as the biasing member, the biasing force when the seal member 49 is biased by the coil spring 48 can be stabilized. Therefore, depending on whether or not the value of the negative pressure generated in the cap member 24 is larger than the threshold value N, the sealing state of the atmosphere suction port 46 by the seal member 49 is released, or the atmosphere suction port 46 is opened by the seal member 49. The seal member 49 can be moved with high accuracy when it is in a sealed state.

  (3) Since the ink absorbing material 47 is stuck on the outer surface of the rear wall of the case 45 of the negative pressure regulating device 30 so as to cover the air suction port 46 from the outside, the negative pressure regulating device 30 is abnormal, for example. When the ink is leaked to the outside from the air suction port 46 by performing a proper operation, the leaked ink can be absorbed by the ink absorbing material 47. For this reason, it is possible to suppress the ink leaking from the case 45 to the outside through the air suction port 46, so that the surrounding contamination due to the ink dripping can be effectively suppressed.

  (4) By limiting the limit value of the negative pressure value generated in the cap member 24 during cleaning as the threshold value N, the cap in the cap seal member 40 in contact with the nozzle forming surface 19a of the recording head 19 Variations in the amount of elastic deformation accompanying suction within the member 24 can be suppressed. For this reason, since the distance between the nozzle forming surface 19a of the recording head 19 and the upper surface of the ink absorbing material 41 in the cap member 24 during cleaning is stabilized, the distance between the nozzle forming surface 19a and the upper surface of the ink absorbing material 41 is reduced. be able to. As a result, the ink remaining on the nozzle forming surface 19a can be reduced, or the suction space volume in the cap member 24 (region where the ink absorbing material 41 does not exist) can be reduced.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described focusing on differences from the first embodiment.
As shown in FIG. 3, in the second embodiment, the negative pressure regulating device 30 in the first embodiment is changed to a negative pressure regulating device 60 having another configuration. That is, the negative pressure regulating device 60 includes a pressure sensor 61 as pressure detecting means for detecting a negative pressure value generated in the cap member 24, and a temperature sensor as temperature detecting means for detecting the ambient temperature of the cap member 24. 62, and a control unit 63 as a threshold value changing unit and a control unit electrically connected to the pressure sensor 61 and the temperature sensor 62, respectively. The control unit 63 is electrically connected to the tube pump 28 and controls the driving state of the tube pump 28.

  Further, the control unit 63 stores a predetermined threshold value N in advance, and whether or not the value of the negative pressure generated in the cap member 24 based on the input signal from the pressure sensor 61 is larger than the threshold value N. It comes to judge. Further, the negative pressure regulating device 60 includes an electromagnetic valve 64 as a valve device disposed so as to be incorporated in the middle position of the discharge tube 26 between the cap member 24 and the tube pump 28.

  The electromagnetic valve 64 is electrically connected to the control unit 63 and is configured to be opened and closed by the control unit 63 so that the inside of the cap member 24 can be opened and closed with respect to the atmosphere via the discharge tube 26. ing. That is, the control unit 63 determines whether or not the value of the negative pressure generated in the cap member 24 is larger than a preset threshold value N based on the input signal from the pressure sensor 61. When this determination is affirmative, the control unit 63 opens the electromagnetic valve 64 to bring the cap member 24 into communication with the atmosphere, and when this determination is negative, the control unit 63 The valve 64 is closed so that the inside of the cap member 24 is not in communication with the atmosphere.

  Further, the control unit 63 calculates the ambient temperature of the cap member 24 based on the input signal from the temperature sensor 62, and changes the value of the threshold value N set and stored in advance based on the calculation result. It has become. That is, the control unit 63 changes the threshold value N to be smaller as the atmospheric temperature of the cap member 24 is higher, and changes the threshold value N to be larger as the atmospheric temperature of the cap member 24 is lower. It has become. This is because, during cleaning, the higher the ambient temperature of the cap member 24, the easier the generation of minute bubbles in the ink in the recording head 19 and the like, and the lower the ambient temperature of the cap member 24, the more the ink in the recording head 19 and the like. This is because minute bubbles are hardly generated.

Next, the operation of the maintenance device 23 will be described.
When the recording head 19 is cleaned, the cap member 24 is first lifted with the carriage 16 moved to the home position region. Then, the cap seal member 40 of the cap member 24 comes into contact with the nozzle forming surface 19 a of the recording head 19, and each nozzle 21 is surrounded by the cap member 24.

  In this state, when the control unit 63 drives the tube pump 28, the inside of the cap member 24 is sucked through the inside of the discharge tube 26 on the upstream side of the tube pump 28, and negative pressure is generated. When a negative pressure is generated in the cap member 24, the ink having increased viscosity is sucked from each nozzle 21 of the recording head 19 by the negative pressure, and the ink is discharged into the waste ink through the cap member 24 and the discharge tube 26. It is discharged into the tank 27.

  Here, when the controller 63 determines that the inside of the cap member 24 is excessively sucked due to variation in the suction capacity of the tube pump 28 and the value of the negative pressure generated in the cap member 24 is larger than the threshold value N. The electromagnetic valve 64 is opened by the control unit 63. When the solenoid valve 64 is opened, the cap member 24 is in communication with the atmosphere, so the negative pressure value in the cap member 24 decreases, and the control unit 63 sets the negative pressure value to the threshold value. When it is determined that it is N or less, the control unit 63 closes the electromagnetic valve 64.

  As described above, even when the cap pump 24 is sucked more than necessary (excessive) by using the tube pump 28 having a suction capacity that is excessively large, the cap member 24 is operated by the negative pressure regulating device 60. The limit value is regulated so that the value of the negative pressure generated in 24 does not become larger than the threshold value N. For this reason, variation in the amount of ink sucked from the nozzles 21 during cleaning is suppressed, and the amount of ink consumed unnecessarily (unnecessarily) during cleaning is reduced.

As described above, according to the second embodiment described in detail, the following effects can be obtained.
(5) Since the control unit 63 can change the threshold value N in consideration of the atmospheric temperature, even if the atmospheric temperature changes, cleaning can be performed without generating minute bubbles in the ink in the recording head 19 or the like. It can be suitably performed.

  (6) Since the threshold value N can be freely changed by the control unit 63, various threshold values N can be set according to the type of cleaning (strong cleaning such as choke cleaning or weak cleaning). Can be suitably performed.

(Example of change)
In addition, you may change each said embodiment as follows.
As shown in FIG. 4, in the first embodiment, the negative pressure regulating device 30 may be incorporated in the side wall 24 b of the cap member 24. In this case, the storage chamber 65 having a rectangular shape in cross section formed in the side wall 24 b of the cap member 24 functions as the case 45. A communication hole 66 that connects the inside of the storage chamber 65 and the cap member 24 is formed in the central portion of the front end of the storage chamber 65. Even if it does in this way, the effect similar to the effect of said (1)-(4) can be acquired. Furthermore, since the negative pressure regulating device 30 is provided adjacent to the inside of the cap member 24, the response of the negative pressure regulating device 30 can be improved.

  As shown in FIG. 5, in the first embodiment, the negative pressure regulating device 30 may be provided so as to be incorporated at a midway position between the cap member 24 and the atmosphere release valve 43 in the atmosphere release pipe 42. In this case, a communication hole 67 that connects the inside of the case 45 and the air release path 42 a is formed in the central portion of the front end of the case 45. Even if it does in this way, the effect similar to the effect of said (1)-(4) can be acquired.

  As shown in FIGS. 2, 4, and 5, in the first embodiment, the negative pressure regulating device 30 includes the intermediate position of the discharge tube 26 between the cap member 24 and the tube pump 28, The side wall 24 b and the atmosphere release pipe 42 may be provided at at least one of the intermediate positions between the cap member 24 and the atmosphere release valve 43. That is, the negative pressure regulating device 30 may be provided in all of these three, or may be provided in two of these three. In this way, the number of negative pressure regulating devices 30 and the range of selection of the arrangement positions are widened, so that the degree of design freedom can be increased.

  As shown in FIG. 6, in the negative pressure regulating device 30 of the first embodiment, the air suction port 46 is sealed from the inside by a plate-like elastic valve 68 made of an elastic member instead of the coil spring 48 and the seal member 49. You may make it do. In this case, the lower end of the elastic valve 68 is fixed to the lower side of the air inlet 46 on the inner surface of the rear wall of the case 45. When the value of the negative pressure in the case 45 communicating with the inside of the cap member 24 becomes larger than the threshold value N, the elastic valve 68 is bent so that the upper side of the elastic valve 68 falls forward due to the negative pressure at this time ( By elastically deforming (state indicated by a two-dot chain line in FIG. 6), the sealing state of the atmosphere suction port 46 by the elastic valve 68 is released, and the inside of the case 45 communicates with the atmosphere via the atmosphere suction port 46. It is supposed to be. On the other hand, the elastic valve 68 has its own elastic restoring force (biasing force) when the air is sucked into the case 45 from the air suction port 46 and the negative pressure value in the case 45 becomes a threshold value N or less. As a result, the original shape before bending (a state in which the air suction port 46 indicated by a solid line in FIG. 6 is sealed) is returned. If it does in this way, in addition to being able to acquire the effect similar to the effect of said (1)-(4), in addition, the number of parts of the negative pressure control apparatus 30 can be decreased.

  As shown in FIG. 7, in the negative pressure regulating device 30 of the first embodiment, instead of the coil spring 48 and the seal member 49, the air suction port 46 is sealed from the inside by an elastic valve 69 having a bowl shape. May be. That is, the elastic valve 69 includes four elastic plates 69a having an isosceles triangular plate shape in plan view, and a base end portion (bottom side) of each elastic plate 69a is an air suction port on the inner surface of the rear wall of the case 45. 46 is fixed so as to surround the four directions of up, down, left and right. Each elastic plate 69a is in a state in which the remaining sides other than the base end portion (bottom side) are in close contact with one of the remaining both sides other than the base end portions (bottom sides) of the adjacent elastic plates 69a. It has become. In this state, the air suction port 46 and the case 45 are isolated from each other by the elastic plates 69a.

  When the value of the negative pressure in the case 45 communicating with the cap member 24 becomes larger than the threshold value N, the elastic valve 69 causes the elastic plates 69a to be separated from each other by the negative pressure at this time. By being elastically deformed (state indicated by a two-dot chain line in FIG. 7), the sealing state of the air suction port 46 by the elastic valve 69 is released, and the inside of the case 45 communicates with the atmosphere via the air suction port 46. It is like that. On the other hand, when the air is sucked into the case 45 from the air suction port 46 and the negative pressure value in the case 45 becomes equal to or less than the threshold value N, the elastic valve 69 is caused by the elastic restoring force of each elastic plate 69a. Each elastic plate 69a returns to its original shape before being elastically deformed (in a state where the air suction port 46 shown by a solid line in FIG. 7 is sealed). Even if it does in this way, the effect similar to the effect of said (1)-(4) can be acquired.

  As shown in FIG. 8, in the negative pressure regulating device 60 of the second embodiment, when the temperature sensor 62 is omitted and the ink cartridge 20 is mounted on the carriage 16, the IC chip provided in the ink cartridge 20 70 and the control unit 63 may be configured to be electrically connected. In this case, various types of information such as the ink type of the ink cartridge 20 are stored in the IC chip 70, and when the IC chip 70 and the control unit 63 are electrically connected, the control unit 63 performs the IC chip operation. Various information is read from 70.

  Then, the control unit 63 stores the threshold stored by itself based on whether the ink type of the ink cartridge 20 read from the IC chip 70 is, for example, water-based ink or solvent-based ink such as alcohol. The value of N is changed. That is, when the ink type of the ink cartridge 20 is a solvent-based ink such as alcohol, the control unit 63 changes the stored threshold value N so as to decrease the ink type of the ink cartridge 20. When the ink is water-based ink, the stored threshold value N is changed so as to increase.

  This is because, when cleaning, if the ink type of the ink cartridge 20 is a solvent-based ink such as alcohol, minute bubbles are likely to be generated in the ink in the recording head 19 or the like, and the ink type of the ink cartridge 20 is different. This is because, in the case of water-based ink, minute bubbles are hardly generated in the ink in the recording head 19 or the like. In this manner, the control unit 63 detects whether the ink type of the ink cartridge 20 is, for example, water-based ink or solvent-based ink such as alcohol, and the threshold N is determined based on the detection result. Since it changes, it can be said that it functions as a fluid type detection means and a threshold value change means.

  In this way, since the threshold value N can be changed in consideration of the type of ink in the ink cartridge 20, the recording head 19 is preferably cleaned even if the type of ink ejected from the recording head 19 changes. It can be carried out.

  In the second embodiment, instead of the electromagnetic valve 64, an on-off valve that is opened and closed by driving the valve body by a motor may be used as the valve device. In this case, the drive of the motor is controlled by the control unit 63.

  In the second embodiment, the negative pressure regulating device 60 determines that the value of the negative pressure generated in the cap member 24 has reached the threshold value N based on the input signal from the pressure sensor 61 by the control unit 63. In this case, the control unit 63 may be configured to stop driving the tube pump 28. In this way, it is possible to restrict the negative pressure value generated in the cap member 24 from becoming larger than the threshold value N.

  -In 2nd Embodiment, it corresponds to each case where the atmospheric temperature of the cap member 24 is previously high temperature (30 degreeC or more), medium temperature (20 degreeC or more-less than 30 degreeC), and low temperature (less than 20 degreeC) in the control part 63 beforehand. A table in which the threshold value N is set is stored, and the value of the threshold value N is changed based on the table and the ambient temperature of the cap member 24 calculated based on the input signal from the temperature sensor 62. It may be.

In the first embodiment, the ink absorbing material 47 may be omitted.
In the first embodiment, instead of the coil spring 48, an elastic member such as a leaf spring or an elastomer may be used as the urging member.

  In each of the above embodiments, the cap member 24 may be configured to surround both the nozzle formation surface 19a (lower surface) and the side surface of the recording head 19 when the cap member 24 abuts on the recording head 19.

  In each of the above embodiments, the fluid ejecting apparatus is a so-called off-carriage in which the ink cartridge is installed at a place other than on the carriage in the ink jet printer, and the ink of the ink cartridge is supplied to the recording head through the ink supply tube. It may be a type of printer. In addition, the fluid ejecting apparatus is a so-called full line in which the recording head 19 has an overall shape corresponding to the length in the width direction (left-right direction) of the recording paper P in the direction intersecting the conveyance direction (front-back direction) of the recording paper P. It may be embodied in a type (line head type) printer.

  In each of the above embodiments, the fluid ejecting apparatus is embodied in the ink jet printer 11. However, the present invention is not limited to this, and fluid other than ink (liquid or liquid in which particles of functional material are dispersed or mixed in the liquid) Body, and fluid bodies such as gels) may be embodied in a fluid ejecting apparatus that ejects or discharges the body. For example, a liquid material ejecting apparatus that ejects a liquid material that is dispersed or dissolved in materials such as electrode materials and color materials (pixel materials) used in the manufacture of liquid crystal displays, EL (electroluminescence) displays, and surface-emitting displays. Further, a liquid ejecting apparatus that ejects a bio-organic matter used for biochip manufacturing, or a liquid ejecting apparatus that ejects a liquid that is used as a precision pipette and serves as a sample may be used. In addition, transparent resin liquids such as UV curable resin to form liquid injection devices that pinpoint lubricant oil onto precision machines such as watches and cameras, and micro hemispherical lenses (optical lenses) used in optical communication elements. A liquid ejecting apparatus that ejects a liquid onto the substrate, a liquid ejecting apparatus that ejects an etching solution such as acid or alkali to etch the substrate, and a fluid ejecting apparatus that ejects a fluid such as a gel (for example, a physical gel) It may be. The present invention can be applied to any one of these fluid ejecting apparatuses. In the present specification, the term “fluid” is a concept that does not include a fluid consisting only of gas. Examples of the fluid include liquid (inorganic solvent, organic solvent, solution, liquid resin, liquid metal (metal melt), etc. ), Liquids, fluids, and the like.

1 is a perspective view of an ink jet printer according to a first embodiment. The cross-sectional schematic of the maintenance apparatus of 1st Embodiment. Sectional schematic of the maintenance apparatus of 2nd Embodiment. Sectional drawing of the negative pressure control apparatus of the example of a change. Sectional drawing of the negative pressure control apparatus of the example of a change. The principal part cross-sectional enlarged view of the negative pressure control apparatus of the example of a change. The principal part cross-sectional enlarged view of the negative pressure control apparatus of the example of a change. The cross-sectional schematic of the maintenance apparatus of the example of a change.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Inkjet printer as fluid ejecting device, 19 ... Recording head as fluid ejecting head, 21 ... Nozzle, 23 ... Maintenance device as maintenance means, 24 ... Cap member, 26 ... Discharge tube forming fluid discharge path, DESCRIPTION OF SYMBOLS 28 ... Tube pump as suction means, 30, 60 ... Negative pressure control apparatus as negative pressure control means, 42a ... Air release path, 43 ... Air release valve, 46 ... Air intake port, 47 ... Ink as fluid absorbing material Absorber, 48 ... Coil spring as urging member, 49 ... Seal member, 61 ... Pressure sensor as pressure detecting means, 62 ... Temperature sensor as temperature detecting means, 63 ... Control means, threshold value changing means and fluid type detecting means Control unit as 64, solenoid valve as valve device, N as threshold value.

Claims (9)

In a maintenance device provided in a fluid ejecting apparatus having a fluid ejecting head capable of ejecting fluid from a nozzle,
A cap member formed so as to be able to suck fluid from the nozzle when a negative pressure is generated inside the fluid ejecting head in a state of being in contact with the fluid ejecting head so as to surround the nozzle;
A suction means capable of sucking the cap member;
Negative pressure regulating means for regulating so that the value of the negative pressure generated in the cap member does not become larger than a preset threshold when the inside of the cap member is sucked by the suction means. Maintenance equipment. The negative pressure regulating means includes the cap member, a fluid discharge path interposed between the cap member and the suction means, and an atmosphere having an atmosphere release valve for opening or closing the inside of the cap member with respect to the atmosphere. The maintenance device according to claim 1, wherein the maintenance device is provided in at least one of the open paths. The negative pressure restricting means includes a predetermined air pressure inlet for sucking air into the cap member and a predetermined pressure facing the negative pressure generated in the cap member so as to close the air suction port. A sealing member biased by a biasing force,
3. The biasing force is set to be smaller than a negative pressure when a negative pressure value generated in the cap member is larger than the threshold value. The maintenance device described in 1. The maintenance apparatus according to claim 3, wherein the negative pressure regulating means includes a fluid absorbing material that covers the atmospheric air inlet from the direction of the atmospheric side when viewed from the atmospheric inlet. The negative pressure restricting means includes a valve device that allows the inside of the cap member to communicate with the atmosphere when the valve opening operation is performed, and a pressure detecting means that detects a value of the negative pressure generated in the cap member. And a control means for opening and closing the valve device based on the detection result by the pressure detection means,
2. The control device according to claim 1, wherein the valve device is opened when a negative pressure value detected by the pressure detection device becomes larger than the threshold value preset and stored. The maintenance device described in 1. The negative pressure restricting means includes a pressure detecting means for detecting a negative pressure value generated in the cap member, and a control means for controlling a driving state of the suction means based on a detection result by the pressure detecting means. And
The maintenance device according to claim 1, wherein the control unit stops driving the suction unit when a negative pressure value detected by the pressure detection unit reaches the threshold value. The negative pressure restricting means includes temperature detecting means for detecting an atmospheric temperature of the cap member, and threshold changing means for changing the threshold based on the atmospheric temperature detected by the temperature detecting means. The maintenance device according to claim 5 or 6. The negative pressure regulating means includes a fluid type detecting means for detecting the type of the fluid ejected from the nozzle, and a threshold changing means for changing the threshold based on the type of the fluid detected by the fluid type detecting means. The maintenance device according to claim 5, wherein the maintenance device is provided. In a fluid ejecting apparatus including a fluid ejecting head capable of ejecting a fluid from a nozzle and maintenance means for performing maintenance of the fluid ejecting head,
A fluid ejecting apparatus comprising the maintenance device according to any one of claims 1 to 8.

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