JP2005240765A - Tube pump and liquid jetting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow pressing rollers to roll smoothly without causing a tube in a tube pump to buckle. <P>SOLUTION: The tube pump 30 is equipped with a case 31, a fastening part 41, and a pressing means 51. A recess 35 as a concave curved surface having an approximately circular arc section is provided at the inner wall 34 of the case 31 in a position downstream of a tube pressed part 23b. The tube pressed part 23b dislocated to downstream by the first press roller 54 constituting the pressing means 51 is accommodated in the recess 35. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tube pump and a liquid ejecting apparatus.

  2. Related Art Conventionally, an ink jet printer (hereinafter simply referred to as a printer) is known as a liquid ejecting apparatus that ejects liquid onto a target. In such a printer, in order to reduce ejection failure of ink, cleaning for ejecting bubbles, thickened ink, and the like from ejection nozzles that eject ink is appropriately performed. In this cleaning, after the nozzle forming surface on which the injection nozzle is formed is sealed with a cap member, the space (in the cap member) that is airtight between the nozzle forming surface and the cap member is decompressed by a suction pump. In other words, a space having a negative pressure is formed on the ejection direction side of the ejection nozzle, and the thickened ink, bubbles, and the like are ejected to eliminate clogging of the ejection nozzle, thereby avoiding ink ejection failure.

  As a suction pump used in this cleaning, a tube pump including a flexible tube (hereinafter simply referred to as a tube) is known. In general, a tube pump is a tube disposed along the inner wall of a case formed in a cylindrical shape, a pressure roller that presses the tube toward the inner wall, and the pressure roller rolls along the circumferential direction of the inner wall. And a rotating body to be used. When the rotating body rotates, the pressing roller rolls along the inner wall while crushing the tube against the inner wall. As a result, the ink or the like in the tube pump is pushed downstream, and the upstream ink or the like is sucked into the tube pump.

  However, when the pressing roller located on the downstream side of the tube pump rolls again to the upstream side of the tube pump, if the pressing roller does not crush the tube, the extruded ink or the like flows back into the tube pump. The suction operation is intermittent. As a result, there is a possibility that the negative pressure in the cap member is unnecessarily fluctuated, resulting in poor cleaning.

  Therefore, conventionally, as such a tube pump, one that avoids an intermittent suction operation has been proposed. For example, Patent Literature 1 describes a tube pump in which a tube is disposed in a spiral shape at 360 ° or more along the inner wall of the case, that is, at least one tube along the inner wall. In this tube pump, the rolling pressure roller begins to crush again the tube located in the upstream side while crushing the tube located in the downstream side in the overlapping portion of the tubes. Thereby, the inside of the cap member provided in the upstream can be continuously sucked.

In addition, for example, a method is known in which two or more pressure rollers are provided, and any one of the pressure rollers always crushes the tube to prevent intermittent backflow of air or ink.
JP 2001-301195 A

  By the way, in such a tube pump, the upstream end and the downstream end of the tube are positioned and fixed by a fixture such as a clamp. This avoids the displacement of the tube position where the tube located outside the case is drawn into the case or the tube accommodated inside the case is pushed out of the case, that is, the displacement of the tube position between the inside and outside of the case. Yes.

However, the tube in the case has not been positioned along the inner wall. Therefore, the tube is displaced (biased) from the upstream side toward the downstream side as the pressing roller rolls. Thereby, the tube corresponding to the amount of deviation from the upstream side is accumulated on the downstream side, and at the end, the tube is buckled at the downstream side position. This buckled tube greatly varies the rolling of the pressing rotor. As a result, the driving torque (sliding load) of the tube pump is increased, resulting in a problem that the suction efficiency of the tube pump is lowered and the rolling of the pressing roller is unnecessarily stopped.

  The present invention has been made in view of the above problems, and provides a tube pump that smoothly rolls a pressing roller without buckling a tube in the tube pump, and a liquid ejecting apparatus including the tube pump. is there.

  The tube pump according to the present invention includes a flexible tube, a bottomed cylindrical case that accommodates a middle portion of the flexible tube, and the tube is sequentially pushed from the upstream side to the downstream side along the inner wall of the case. A tube pump comprising: a pressing roller that rolls in a circumferential direction of the inner wall of the case while being crushed; and a fixing portion that fixes an upstream side and a downstream side of a middle portion of the flexible tube to the case. A concave portion was formed in the inner wall corresponding to the downstream portion of the tube, and the pressing roller crushed the flexible tube also in the concave portion.

  According to the tube pump of the present invention, the tube displaced downstream by the pressing roller rolling in the circumferential direction of the inner wall of the case can be accommodated in the recess. Therefore, there is no possibility that the tube provided in the case buckles on the downstream side. As a result, the pressing roller can be smoothly rolled and the sliding load of the tube pump is not increased.

  In this tube pump, the pressure roller is urged in a direction in which the pressure roller crushes the tube, and the pressure roller moves in a direction in which the tube is crushed.

  According to this tube pump, the pressing roller can be urged and moved in the direction of crushing the tube. Therefore, in the recess, the pressing roller can smoothly crush the tube.

In this tube pump, the concave portion has a curved surface having an arcuate cross section.
According to this tube pump, since the concave portion is formed in a circular arc shape, the pressing roller can smoothly roll along the inner wall of the concave portion. Therefore, it is possible to mitigate the impact when the pressing roller enters the recess or when the pressing roller moves out of the recess.

  The liquid ejecting apparatus according to the aspect of the invention includes a sealing unit that seals a nozzle forming surface of a liquid ejecting head that ejects the liquid supplied from the liquid storing unit from the ejecting nozzle. A flexible tube communicating with a space formed by the nozzle forming surface, a bottomed cylindrical case that accommodates a middle portion of the flexible tube, and the tube from the upstream side along the inner wall of the case A tube pump comprising: a pressing roller that rolls in the circumferential direction of the inner wall of the case while sequentially crushing to the downstream side; and a fixing member that fixes the upstream side and the downstream side of the intermediate portion of the flexible tube to the case. A recess is formed in the inner wall corresponding to the downstream portion of the flexible tube.

According to the liquid ejecting apparatus of the present invention, the tube that is shifted to the downstream side by the pressing roller that rolls in the circumferential direction of the inner wall of the case can be accommodated in the recess. Therefore, there is no possibility that the tube provided in the case buckles on the downstream side. As a result, the load of the tube pump can be suppressed and the suction efficiency can be maintained. As a result, the space formed by the sealing means and the nozzle forming surface can be sucked to an appropriate pressure as appropriate.

(First embodiment)
Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, an ink jet printer 10 (hereinafter simply referred to as a printer 10) as a liquid ejecting apparatus includes a frame 11, a guide member 12, a carriage 13, an ink cartridge 14 as a liquid storage unit, a platen 15, and a liquid. A recording head 16 as an ejection head is provided.

  The frame 11 covers the entire apparatus of the printer 10. A guide member 12 is installed on the frame 11 along the longitudinal direction. A carriage 13 is inserted into and supported by the guide member 12 so as to be movable. The carriage 13 is connected and driven to a carriage motor 18 via a timing belt 17. When the carriage motor 18 is rotationally driven, the driving force is transmitted to the carriage 13 via the timing belt 17. Upon receiving this driving force, the carriage 13 reciprocates along a direction along the guide member 12 (main scanning direction X).

  A platen 15 is installed on the frame 11 in parallel with the guide member 12. The platen 15 is a support base that supports the paper P as a target. The platen 15 is provided with a paper feed mechanism (not shown). When a paper feed motor (not shown) is driven, the paper feed mechanism feeds the paper P along a direction (sub-scanning direction Y) perpendicular to the main scanning direction X.

  As shown in FIG. 2, a recording head 16 is mounted on a surface below the carriage 13 and facing the paper P. A nozzle forming surface 19 is formed on the lower surface of the recording head 16, and the nozzle forming surface 19 is provided with a plurality of ejection nozzles (not shown). An ink cartridge 14 is detachably mounted on the carriage 13. The ink cartridge 14 supplies the recording head 16 with ink as a liquid contained therein. The recording head 16 ejects ink supplied from the ink cartridge 14 from an ejection nozzle as ink droplets by driving a piezo element (not shown).

  The printer 10 feeds the paper P along the sub-scanning direction Y and reciprocates the carriage 13 along the main scanning direction X. At the same time, the printer 10 drives the piezo element with an image signal generated based on the print image data to eject ink droplets from the recording head 16. Thus, the printer 10 performs printing on the paper P.

  As shown in FIG. 1, a non-printable area (home position) that is one side of the frame 11 is provided with a cleaning mechanism 20. As shown in FIG. 2, the cleaning mechanism 20 includes a cap holder 21, a cap 22 as a sealing means, a flexible tube 23 (hereinafter simply referred to as a tube 23), a waste liquid tank 24, and a tube pump 30. Yes.

  The cap holder 21 is supported by an elevating part (not shown) attached to the frame 11 so as to be vertically movable. On the cap holder 21, a square frame-shaped cap 22 is provided. When the recording head 16 is at the home position and the cap holder 21 moves upward, the upper edge of the cap 22 seals the nozzle forming surface 19. As shown in FIG. 2, a sheet-like absorbent material 22 a is fixed to the bottom of the cap 22. The absorbent 22a absorbs the ink ejected into the cap 22. A suction port 22b through which ink or the like is sucked is formed through the bottom surface of the cap 22.

  As shown in FIG. 2, a tube 23 is connected to the suction port 22b. As shown in FIG. 3, in this embodiment, the tube 23 is formed by connecting and integrating two tubes 25 and 26 by an attachment portion 27, and is made of a flexible member such as silicon rubber. Shall be formed. The tubes 25 and 26 are formed with flow paths 25a and 26a through which air, ink, and the like flow, respectively. As shown in FIG. 2, the tube 23 communicates the suction port 22 b and the waste liquid tank 24 via the tube pump 30. The tube pump 30 is a pump that is driven when a pump motor (not shown) is driven to rotate, and that sucks the inside of the cap 22. The waste liquid tank 24 is a tank for storing discharged ink and the like, and a waste liquid absorbing material 24a is stacked therein. The waste liquid absorber 24a is formed of a porous material and absorbs ink and the like.

  The cleaning mechanism 20 seals the nozzle forming surface 19 with the cap 22 and then sucks the inside of the cap 22 with the tube pump 30 to form a negative pressure. As a result, the thickened ink or the like in the recording head 16 is discharged into the cap 22. At the same time, the ink discharged into the cap 22 is sucked into the tube pump 30 and discharged to the waste liquid tank 24. As a result, the cleaning mechanism 20 cleans the recording head 16.

As shown in FIG. 4, the tube pump 30 includes a case 31, a fastening portion 41 as a fixing member, and a pressing means 51 in detail.
As shown in FIG. 5, the case 31 is formed in a bottomed cylindrical shape, and a support hole 33 is formed through the center of the bottom surface 32. A recess 35 is formed in a part of the inner wall 34 of the case 31. The recessed portion 35 is a recessed portion formed from the upper side of the case 31 to the lower side of the bottom surface 32 toward the lower side, and is formed in a curved surface having an arcuate cross section when viewed from the plane direction. The concave portion 35 is formed with substantially the same curvature as that of a first pressing roller 54 described later. A cutout portion 36 is formed in one side portion of the recess portion 35 on the wall portion of the case 31 so as to cut out from the upper side to the front side of the bottom surface 32. In the cutout portion 36, a groove portion 37 is provided so as to extend outward in the radial direction of the case 31 and open on the upper side. Inside the groove portion 37, two fitting convex portions 38 and 39 extending in the vertical direction are provided so as to face each other.

  As shown in FIG. 4, a fastening portion 41 as a fixing means is disposed in the groove portion 37. As shown in FIG. 5, the fastening portion 41 is formed in a substantially rectangular parallelepiped shape, and fitting grooves 42 and 43 extending in the vertical direction are formed on opposite side surfaces thereof. The fastening portion 41 is provided with an insertion hole 44 penetrating in the radial direction of the case 31. Then, the fastening portion 41 is fitted and fixed to the case 31 by fitting the fitting grooves 42 and 43 into the fitting convex portions 38 and 39 of the groove portion 37, respectively.

  As shown in FIG. 5, the tubes 25, 26 are inserted in the fastening portion 41 (insertion hole 44) in a state of being arranged in the vertical direction, and the tube upstream end portion 28, which is the middle portion of the tubes 25, 26, the tube The downstream end portion 29 and the tube pressed portion 23b are positioned.

The tube upstream end portion 28 is connected to the suction port 22 b on the flow path side for sucking air, ink, or the like into the tube pump 30. The tube downstream end portion 29 is connected to the waste liquid tank 24 on the flow path side for discharging ink or the like sucked from the tube upstream end portion 28 side. The tube upstream end portion 28 and the tube downstream end portion 29 are bundled with the fastening portion 41 to form a bundle portion 23a (see FIG. 6). The tube pressed portion 23 b is a portion of the tube 23 between the tube upstream end portion 28 and the tube downstream end portion 29, and is accommodated along the inner wall 34 in a planar Ω shape. The tube pressed portion 23 b is arranged so that the portion located on the recess 35 formed in the inner wall 34 is closest to the tube downstream end portion 29.

  Then, the ink or the like in the cap 22 is sucked into the tube pump 30 from the tube upstream end portion 28, passes through the recess 35 along the inner wall 34, and then passes through the tube downstream end portion 29 to the outside of the tube pump 30. It is discharged to the waste liquid tank 24.

  A pressing means 51 is provided inside the tube pressed portion 23b so as to cover the tube pressed portion 23b from above. As shown in FIG. 5, the pressing unit 51 includes a rotating member 52, a support member 53, a first pressing roller 54, and a second pressing roller 55.

  The rotating member 52 includes a rotating shaft 52a and a disk 52b that are integrally formed. The rotating shaft 52a is connected to and driven by a pump motor (not shown) through the support hole 33, and receives the driving force to rotationally drive the disk 52b. The rotation shaft 52a is arranged so that the center thereof is located on the axis A. The disk 52b is provided so that the center thereof is located on the axis A of the rotation shaft 52a and orthogonal to the rotation shaft 52a.

As shown in FIG. 5, a support member 53 is provided on the lower side of the disk 52b. The support member 53 is provided with an upper plate 53a on the upper side and a lower plate 53b on the lower side. The upper plate 53a and the lower plate 53b are accommodated in sliding contact with the lower surface of the disk 52b and the bottom surface 32 of the case 31, respectively. The support member 53 has a through hole (not shown) penetrating in the vertical direction at the center thereof, and the rotating shaft 52a is inserted into the through hole. The inner diameter of the through hole is longer than the outer diameter of the rotating shaft 52a. Accordingly, the support member 53 is supported so as to be movable in the radial direction with respect to the rotation shaft 52a. The support member 53 is elastically biased toward the outer side in the radial direction (in this embodiment, the first and second pressing rollers 54 and 55 side) by a spring member (not shown) with respect to the disk 52b. Therefore, when the disk 52b rotates together with the rotating shaft 52a, the support member 53 receives the driving force and is rotationally driven while being urged radially outward by the spring member.

As shown in FIG. 5, the support member 53 includes a first pressing roller 54 and a second pressing roller 55. The first pressing roller 54 is a cylindrical roller and is rotatably supported between the upper plate 53a and the lower plate 53b. The second pressing roller 55 is a cylindrical roller having an outer diameter smaller than the outer diameter of the first pressing roller 54, and is also rotatably supported between the upper plate 53a and the lower plate 53b. When the rotating shaft 52a rotates in the direction of the arrow shown in FIG. 6, the first and second pressing rollers 54 and 55 revolve around the rotating shaft 52a and the tube pressed portion 23b accommodated in the case 31 is moved. The inner wall 34 rotates (rolls) while being crushed. The first and second pressing rollers 54 and 55 always apply an elastic force in the direction of crushing the tube pressed portion 23b (excluding the bundle portion 23a) to the inner wall 34 by the spring member (not shown). Shall. Here, the elastic force by the spring member is a force by which the first and second pressing rollers 54 and 55 facing the inner wall 34 can crush the tube pressed portion 23b. The same applies to the concave portion 35. The first pressing roller 54 moves in the direction of pressing the tube pressed portion 23b along the shape of the concave portion 35, and pushes the tube pressed portion 23b by the elastic force of the spring member. Can be crushed. On the other hand, when the first pressing roller 54 opposes the bundle portion 23a, there is no wall of the case 31 on the tube pressed portion 23b side facing the first pressing roller 54. 23b cannot be crushed. Therefore, when the first pressing roller 54 opposes the bundle portion 23a, the subsequent second pressing roller 55 assists in crushing the tube pressed portion 23b.

Therefore, when the first pressing roller 54 is at a position opposite to the bundle portion 23 a, the subsequent second pressing roller 55 is crushed the tube pressed portion 23 b toward the inner wall 34. Further, when the second pressing roller 55 is at a position opposite to the bundle portion 23a, the preceding first pressing roller 5
4 crushes the tube pressed portion 23 b toward the inner wall 34. In other words, in the tube pump 30, either one of the first and second pressing rollers 54 and 55 always crushes the tube pressed portion 23b to avoid backflow of ink or the like upstream.

  The sliding load of the tube pump 30 configured as described above will be described with reference to FIGS. 6, 7 and 9, in order to show the relationship between the first and second pressing rollers 54 and 55 and the tube pressed portion 23b, the support member 53 is omitted for convenience of description.

First, when the first pressing roller 54 is opposed to the bundle portion 23a, the rotation angle θ of the rotation shaft 52a is set to 0 °. The rotation angle θ has a positive direction counterclockwise around the axis A.
Now, when the rotation angle θ is 0 °, the first pressing roller 54 comes into contact with the bundle portion 23a, and the second pressing roller 55 crushes the tube pressed portion 23b on the downstream side. At this time, since the wall of the case 31 does not exist on the side of the tube pressed portion 23b facing the first pressing roller 54, the first pressing roller 54 is positioned radially outward from the position shown in FIG. Therefore, the urging force by the spring is weakened, and the sliding load of the tube pump 30 is relatively small as compared with the case shown in FIG. From this state, that is, from the state where the rotation angle θ is 0 °, the first pressing roller 54 rolls while moving radially inward until the rotation angle θ moves to θ1 shown in FIG. In this movement process, the first pressing roller 54 receives a reaction force in the circumferential direction from the tube, so the sliding load of the tube pump 30 increases momentarily.

  Thereafter, until the rotation angle θ reaches from θ1 to θ2 shown in FIG. 8, the first pressing roller 54 rotates while maintaining its radial position, so that the sliding load of the tube pump 30 becomes substantially constant. At this time, that is, in the process of the rotation angle θ from θ1 to θ2 shown in FIG. 8, the tube pressed portion 23b on the upstream side of the first pressing roller 54 can bend along the inner wall 34, and the first pressing roller 54 biases the tube pressed portion 23b to the downstream side. Then, the biased tube pressed portion 23b is received in the recess 35.

  And if the 1st press roller 54 opposes the recessed part 35, it will move to a radial direction outer side according to the elastic force by a spring member. At this time, since the radial position of the first pressing roller 54 is outside the radial position of the first pressing roller 54 facing the bundle portion 23a, the sliding load of the tube pump 30 causes the first pressing roller 54 to bundle. This is smaller than when facing the portion 23a (when the rotation angle θ is 0 °).

  Thereafter, in the process in which the first pressing roller 54 reaches from the concave portion 35 to the bundle portion 23a, the first pressing roller 54 rolls while moving the radial position inward and moves outward again. The dynamic load once decreases and then decreases again. As a result, the sliding load of the tube pump 30 is significantly lower than the sliding load (one-dot chain line shown in FIG. 8) of the tube pump 70 (see FIG. 9) having no recess 35.

And since the recessed part 35 is formed in circular arc surface shape at this time, compared with the case where the recessed part 35 is made into V groove shape, the 1st press roller 54 rolls on the recessed part 35 comparatively smoothly, The tube pressed part 23b is crushed. When the rotation angle θ further becomes 0 ° with the rotation of the rotation shaft 52a, the second pressing roller 55 pushes air, ink or the like to the tube downstream end portion 29 and discharges it out of the tube pump 30.

  In this way, the tube pump 30 avoids buckling of the tube pressed portion 23b, smoothly rolls the first and second pressing rollers 54 and 55, and suppresses the sliding load while suppressing the sliding load. Aspirate and discharge.

According to the above embodiment, the following effects can be obtained.
(1) According to this embodiment, the recess 35 is provided in the inner wall 34 on the downstream side of the tube pump 30 so that the displacement of the tube pressed portion 23b by the first pressing roller 54 is absorbed in the recess 35. did. Therefore, the first and second pressing rollers 54 and 55 can be rolled without forming buckling in the tube pressed portion 23b.

  (2) According to the present embodiment, the concave portion 35 is formed into a curved surface having a circular arc cross section, and the first pressing roller 54 rolls along the curved surface. Therefore, the first pressing roller 54 can smoothly advance and retract with respect to the recess 35. In addition, since the first pressing roller 54 can crush the tube pressed portion 23b accommodated in the recess 35, there is no possibility that the suction of the tube pump 30 becomes intermittent.

  (3) According to the present embodiment, the tube pump 30 provided with the recess 35 in the inner wall 34 on the downstream side is provided in the cleaning mechanism 20 of the ink jet printer 10. Accordingly, since the suction efficiency of the tube pump 30 does not decrease or the suction operation does not stop unnecessarily, an appropriate negative pressure can be formed in the cap 22, and the suction and discharge operation of the tube pump 30 can be performed. There is no risk of causing poor cleaning.

In addition, you may change the said embodiment as follows.
In the above embodiment, one recess 35 is provided, but this may be changed and a plurality of recesses 35 may be provided.

  In the above embodiment, the concave portion 35 is formed in a curved surface having a curvature substantially the same as the curvature of the first pressing roller 54. However, it may be larger than the curvature of the first pressing roller 54, and may be the first or second pressing roller 54. , 55 may be large enough to crush the tube pressed portion 23b accommodated in the recess 35.

  In the above embodiment, the tube pressed portion 23b is provided in an Ω shape that does not intersect both ends along the inner wall 34. However, the tube pressed portion 23b may be provided in an α shape that intersects both ends. Moreover, you may provide in circular arc shape.

In the above-described embodiment, the first and second pressing rollers 54 and 55 are provided. However, the first and second pressing rollers 54 and 55 may be configured by one or three or more pressing rollers that always crush the tube pressed portion 23b.
In the above embodiment, the support member 53 is urged via the spring member. However, the support member 53 may be composed of other elastic members, such as rubber, and the first and second pressing rollers 54 and 55 may have a diameter. Anything that urges outward in the direction may be used.

  In the above embodiment, the tube 23 is composed of the two tubes 25 and 26, and the tubes 25 and 26 are connected by the attachment portion 27. However, the tube 23 is composed of only one flexible tube. You may make it do. Moreover, you may make it comprise with 3 or more flexible tubes, and you may make it a some tube not be connected.

  In the above embodiment, the support member 53 is configured to bias the first and second pressing rollers 54 and 55. However, in the recess 35, the first or second pressing rollers 54 and 55 change the tube pressed portion 23b. If it can be crushed, it does not have to be energized.

1 is a perspective view of an ink jet printer that embodies the present embodiment. Similarly, the principal part schematic sectional drawing of an ink jet type printer. Similarly, the fragmentary perspective view of a flexible tube. Similarly, the perspective view of a tube pump. Similarly, the exploded perspective view of a tube pump. Similarly, the general | schematic plane sectional view explaining the effect | action of a tube pump. Similarly, the general | schematic plane sectional view explaining the effect | action of a tube pump. Similarly, the characteristic figure which shows the relationship between a rotation angle and a sliding load. Similarly, the general | schematic plane sectional view explaining the effect | action of a tube pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Inkjet printer as a liquid ejecting apparatus, 14 ... Ink cartridge as a liquid storing means, 16 ... Recording head as a liquid ejecting head, 22 ... Cap as a sealing means, 23 ... Flexible tube, 23a ... Bundle , 30 ... tube pump, 31 ... case, 34 ... inner wall, 35 ... recess, 41 ... fastening portion as a fixing member, 52a ... rotating shaft, 54 ... first pressing roller, 55 ... second pressing roller, A ... shaft Heart, P ... paper as a target,
θ: rotation angle.

Claims (4)

A flexible tube, a cylindrical case with a bottom that accommodates a middle portion of the flexible tube, and an inner wall of the case while sequentially crushing the tube from the upstream side to the downstream side along the inner wall of the case. In a tube pump comprising a pressing roller that rolls in the circumferential direction, and a fixing portion that fixes the upstream side and the downstream side of the intermediate portion of the flexible tube to the case,
A tube pump, wherein a recess is formed in the inner wall corresponding to a downstream portion of the flexible tube, and the pressing roller crushes the flexible tube also in the recess. The tube pump according to claim 1, wherein
The pressing roller is
The tube pump, wherein the pressing roller is urged in a direction to crush the tube, and the pressing roller moves in a direction to crush the tube. The tube pump according to claim 1, wherein
2. The tube pump according to claim 1, wherein the concave portion has a curved surface with an arcuate cross section. In a liquid ejecting apparatus including a sealing unit that seals a nozzle forming surface of a liquid ejecting head that ejects liquid supplied from a liquid storing unit from an ejecting nozzle.
A flexible tube communicating with the space formed by the sealing means and the nozzle forming surface, a bottomed cylindrical case that accommodates a middle portion of the flexible tube, and along the inner wall of the case A pressing roller that rolls in the circumferential direction of the inner wall of the case while sequentially crushing the tube from the upstream side to the downstream side, and a fixing member that fixes the upstream side and the downstream side of the intermediate portion of the flexible tube to the case A tube pump consisting of
A liquid ejecting apparatus, wherein a concave portion is formed in the inner wall corresponding to a downstream portion of the flexible tube.

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