JP2013185476A - Pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pump device capable of increasing pressing force of a roller pressing a tube obtained by biasing force of a biasing member oscillating an oscillating member.SOLUTION: A pump device comprises: a roller 36 having a roller shaft 36a movably held along a bending hole 34, revolving about a pump shaft 31 as a rotating member 32 is rotated, and moving between a first position at which a tube 26 supported at an inner wall surface is pressed by the movement of a roller shaft along the bending hole in conformity with a rotation direction of the rotating member and a second position at which the pressing force applied to the tube is more relaxed than the pressing force at the first position; and a coil spring 41 biasing an oscillating member in a direction in which the roller approaches the tube supported at the inner wall surface. The first position is closer to an oscillation shaft 33a of the oscillating member than the second position.

Description

  The present invention relates to a pump device, and more particularly to a pump device having a configuration in which a roller rotates while pressing a flexible tube.

  For example, in a liquid ejecting apparatus having a liquid ejecting head that forms an image or the like by ejecting liquid onto an object such as paper, in order to maintain the ejection characteristics for properly ejecting liquid from the liquid ejecting head, A head maintenance mechanism is provided.

  In the maintenance mechanism, in order to maintain various ejection characteristics of the liquid ejecting head, for example, the liquid ejecting head is capped with a cap, and the ejected characteristics are recovered by sucking the thickened liquid from the nozzle by the pump device. Is done. At this time, as the pump device, the pressing member (roller) supported by the rotating body that is rotationally driven by the driving source (motor) is displaced so as to approach the flexible tube supported by the device housing. A so-called tube pump having a configuration of pressing and rotating while crushing the tube is often used.

  As described above, in the tube pump used in the maintenance mechanism, if there is variation in the amount (entrance amount) by which the roller pressing the tube crushes the tube, the rotational torque of the pump varies. For this reason, in order to suppress the variation in the amount of the rollers that crush the tube, there is a problem that the shape accuracy (component accuracy) and mounting accuracy (assembly accuracy) of each member constituting the tube pump must be increased. It was.

  Therefore, as a technique for solving such a problem, for example, as described in Patent Document 1, a lever (oscillator) that supports a roller that presses a flexible tube is used, and the roller presses the tube. A configuration has been proposed in which a spring (biasing body) is urged in the direction. According to this configuration, since the amount that the roller crushes the tube (the amount of entry) is determined by the elastic force of the spring, the increase in the driving torque of the tube pump due to variations in component accuracy and assembly accuracy is prevented, and the pump with low driving torque is prevented. You can get it.

Japanese Patent Laid-Open No. 10-76681

  By the way, in recent years, the application of the liquid ejecting apparatus has been expanded, and for example, a solvent-based ink (for example, a pigment ink or an ultraviolet curable ink) different from a water-based ink may be used. For this reason, a solvent-resistant hard tube may be used in a tube pump in order to cope with solvent-based ink. In such a case, it is necessary to increase the pressing force with which the roller crushes the tube.

  However, the configuration proposed in Patent Document 1 is a structure in which the position where the roller presses the tube moves away from the rotation fulcrum of the lever biased by the spring. For this reason, with the rotation fulcrum of the lever as the reference position, the distance from the reference position to the position where the roller presses the tube is substantially equal to the distance from the reference position to the position where the spring biases the roller. Will press the tube with a force approximately equal to the biasing force of the spring. Therefore, in order to increase the pressing force to cope with the hard tube of the solvent resistant system, it is necessary to enlarge the spring, and as a result, the pump device becomes large.

  The present invention has been made in view of the above problems, and its main object is to increase the pressing force of a roller that presses a tube obtained by the urging force of the urging body that oscillates the oscillating body. It is to provide a pump device.

  In order to achieve the above object, a pump device according to the present invention comprises a flexible tube, a pump frame having a support surface that supports the tube in an arc shape, and an arc of the tube supported by the support surface. A rotating body that rotates about a central axis, and a rocking body that is pivotally supported by the rotating body and has a change-shaped portion in which a distance from the arc central axis changes in the rotation direction of the rotating body; A shaft portion is held so as to be movable along the change shape portion, revolves around the arc center axis along with the rotation of the rotating body, and the shaft portion changes according to the rotation direction of the rotation body. The first position that presses the tube supported by the support surface and the pressing force applied to the tube are more relaxed than the pressing force at the first position. A roller that moves between two positions; and a biasing body that biases the rocking body in a direction in which the roller approaches the tube supported by the support surface, and the first position is: The position is closer to the rocking center of the rocking body than the second position.

  According to this configuration, the pressing force by which the roller presses the tube is obtained by the urging force of the urging member that oscillates the oscillating body, and the roller approaches the oscillation center at the first position at which the tube is pressed. The roller pressing force obtained by the urging force can be increased.

  In the pump device according to the present invention, the urging position of the oscillating body urged by the urging body is a position away from the shaft portion of the roller that has moved from the oscillating center to the first position. is there.

According to this configuration, in the first position, the roller can obtain a pressing force with a force larger than the urging force of the urging body that oscillates the oscillating body.
In the pump device according to the aspect of the invention, the rocking body includes a contact portion that is in contact with the rotating body and the roller is restricted from swinging in a direction approaching the tube supported by the support surface, When the roller moves to the first position, the contact portion is urged in a direction approaching the tube by the urging force of the urging body without contacting the rotating body.

  According to this configuration, since the pressing force of the roller that presses the tube is given by the biasing force of the biasing body, an appropriate pressing force can be given to the tube. Moreover, since the rocking | swiveling body is rock | fluctuated by the contact part in the direction which approaches a tube, it can control the crushing amount of the tube which a roller presses.

  In the pump device of the present invention, the roller that revolves with the rotation of the rotating body abuts on the roller when moving from the first position to the second position during the rotation of the rotating body. The buffer body includes a semi-cylindrical curved portion and two long plate-shaped plate portions formed continuously from both ends of the curved portion. It is formed.

  According to this configuration, during the rotating operation of the rotating body, the sudden movement from the first position to the second position of the roller caused by releasing from the pressed state is a semi-cylindrical curved portion in the buffer body. And a pump device that suppresses the generation of impact sound when the roller stops moving at the second position because it is prevented by the deformation (displacement) in each of the two plate-shaped portions of the long plate shape and is restrained from slow movement. Is obtained.

  In the pump device of the present invention, the derivative that guides the roller to move from the second position to the first position during rotation of the rotating body by being displaced in contact with the revolving roller. The derivative is formed to have a bent shape in which the tip portion is bent in the direction of contact with the revolving roller.

  According to this configuration, since the roller that is released from the pressed state and is in the second position during the rotation operation of the rotating body is reliably guided to the first position by the derivative, the reliability of the suction operation is high. A pump device is obtained.

The perspective view which shows schematic structure of the maintenance unit which has a pump apparatus as one Embodiment which concerns on this invention. The perspective view which looked at some members in the see-through | perspective state of the pump apparatus of embodiment. The perspective sectional view showing the structure around the coil spring which urges the rocking body in the pump device of the embodiment. The disassembled perspective view of the component which presses a tube in the pump apparatus of embodiment. The schematic diagram which shows the effect | action as a tube pump in the pump apparatus of embodiment. The schematic diagram which shows the buffering operation | movement with respect to the roller of a buffer material in a pump apparatus. The schematic diagram which shows the guidance operation | movement with respect to the roller of a guidance material in a pump apparatus. The schematic diagram which shows the modification of the biasing body which biases a rocking | swiveling body in a pump apparatus.

  Hereinafter, a liquid ejecting apparatus including a liquid ejecting head that ejects ink as liquid in an embodiment embodying the present invention in a pump device provided in a maintenance mechanism for maintaining the liquid ejecting head will be described with reference to the drawings. I will explain.

  As shown in FIG. 1, in the liquid ejecting apparatus, the liquid ejecting head 12 is made to face the paper P as a medium, and ink is ejected from the nozzles 13 provided in the liquid ejecting head 12, so To print. Accordingly, the liquid ejecting head 12 is maintained at a predetermined timing so that ink is correctly ejected from the nozzles 13 in accordance with the image to be printed. That is, in the liquid ejecting apparatus, the maintenance mechanism 11 of the liquid ejecting head 12 is disposed outside the printing area of the paper P, and the liquid ejecting head 12 is moved to the position where the maintenance mechanism 11 is disposed. Then, maintenance is performed by sucking out thickened ink or the like from the nozzle 13 in the liquid ejecting head 12.

  For example, the maintenance mechanism 11 is raised by the elevating mechanism 15 and comes into contact with the liquid ejecting head 12 so as to surround the nozzle 13, a tube 16 a having one end connected to the cap 14, and one end to the waste liquid container 18. And an inserted tube 16b. The other ends of the tube 16a and the tube 16b are arranged between the cap 14 and the waste liquid container 18 and connected to a pump device 20 for sucking the inside of the cap 14 from the cap 14 side toward the waste liquid container 18 side. Has been. The maintenance mechanism 11 includes a drive mechanism 19 that drives the pump device 20. The drive mechanism 19 is driven by a drive source (motor) 17 and performs various drives in the maintenance mechanism 11 such as driving the lifting mechanism 15.

The pump device 20 is a so-called tube pump and functions as a suction pump. That is,
The pump device 20 includes a pump case 21 having a semicircular arc shape in part on the inner wall surface 21a, and a pump case 22 having both sides in the arc axis direction (the front and back direction in the drawing) of the pump case 21 being substantially flat. The device casing is covered with And the flexible tube 26 is arrange | positioned along the inner wall surface 21a of the pump case 21, and each other end of the tubes 16a and 16b is connected to the connection members 23a and 23b attached to the both ends. . Therefore, the inner wall surface 21 a functions as a support surface that supports the tube 26. In FIG. 1, the pump case 22 on the front side of the drawing is omitted.

  In the present embodiment, a portion of the tube 26 is curved in a substantially semicircular shape and supported in an arc shape by the arc-shaped portion of the inner wall surface 21a between the connecting member 23a and the connecting member 23b. The arc-shaped portion of the tube 26 revolves around the pump shaft 31 while being pressed by two roller 36 as pressing members provided at positions opposite to each other with the pump shaft 31 interposed therebetween. It operates as a pump).

  That is, the pump device 20 has a substantially S-shaped rotation that rotates integrally with the pump shaft 31 with respect to the pump shaft 31 that is rotatably supported at both ends of the pump case 22 provided on both sides of the pump case 21. The body 32 is fixed. Two oscillating bodies 33 attached so as to be able to oscillate with the oscillating shaft 33a pivotally supported with respect to the rotating body 32 as a center of oscillating are disposed at positions facing each other across the pump shaft 31. Each swinging body 33 is provided with a bent hole 34. The bending hole 34 has a long hole portion 34b formed by inclining the longitudinal direction so that the distance from the pump shaft 31 changes in the rotation direction of the rotating body 32, and a distance from the pump shaft 31 in the long hole portion 34b. A short hole part 34a continuously formed so as to be bent with respect to the long hole part 34b from the farthest part is formed. Therefore, the short hole part 34 a is the part farthest from the pump shaft 31 in the bent hole 34, in other words, the part closest to the tube 26.

  The bent hole 34 functions as a changed shape portion in which the distance from the axis of the pump shaft 31 changes in the rotation direction of the rotating body 32. That is, the roller 36 has a roller shaft 36 a serving as a shaft portion inserted and held in each of the bent holes 34, and the roller shaft 36 a is movable along the bent holes 34. When the rocking body 33 rotates along the tube 26 in the direction from the connecting member 23a side to the connecting member 23b side with the rotation of the rotating body 32, the roller 36 is relatively rotated by the roller shaft 36a. Moves in the bent hole 34 from the position of the long hole part 34b to the position of the short hole part 34a. As a result of the movement of the roller shaft 36a in this way, the roller 36 moves (centrifuges) in a direction away from the pump shaft 31, enters the tube 26 and presses it, and rotates while maintaining this pressed state. Operates as a tube pump (suction pump). Accordingly, at the position where the roller 36 presses the tube 26 (first position), the roller shaft 36a is positioned at the short hole portion 34a, and the position where the pressing force applied to the tube 26 of the roller 36 is relaxed (second position). ), The roller shaft 36a is located in the long hole portion 34b.

  In the present embodiment, the roller 36 is thus positioned where the roller shaft 36a, which is the shaft portion, moves along the bending hole 34, and where the pressing force applied to the tube 26 is relieved. Move between. In addition, the roller 36 enters the tube 26 as it moves away from the pump shaft 31 and rotates while pressing the tube 26. The oscillator 33 is connected to the tube 16b from the connection member 23a side to which the tube 16a is connected. This is the direction of rotation toward the connected connecting member 23b. In the present embodiment, rotation in this direction is referred to as CW rotation, and rotation in the opposite direction is referred to as CCW rotation.

  Further, the pump device 20 includes a buffer body 24 and a derivative 25 attached to the pump case 21 in a state where the base end side is inserted and fixed and the tip end side is displaceable. These are formed of an elastomer or an elastic material, and are formed so as to be displaced while being deformed in the revolving direction of the roller 36 when the roller 36 revolves around the pump shaft 31. This modification of the buffer body 24 and the derivative 25 will be described later including the action of the buffer body 24 and the derivative 25.

Next, the structure of the pump device 20 will be described in detail with reference to FIGS.
As shown in FIG. 2, in the pump device 20 of the present embodiment, two tube pumps functioning as suction pumps are incorporated in pump cases 21 and 22 so as to overlap in the axial direction of the pump shaft 31. The two tube pumps have the same structure, and the roller 36 is incorporated so as to be displaced from each other by approximately 90 degrees in the rotation direction of the pump shaft 31. Therefore, here, the structure of the tube pump illustrated in FIG.

  As shown in FIGS. 2 and 3, the pump shaft 31 has a cam shape 31 c formed at the tip portion of the shaft, and a rotating member (for example, a drive gear) (not shown) of the pump mechanism 31 is engaged with the cam shape 31 c. As a result, the power of the drive source 17 is transmitted and rotated. In this embodiment, the rotator 32 is formed integrally with the pump shaft 31, has a plane whose normal is the axial direction of the pump shaft 31, and overlaps with a predetermined interval in the axial direction of the pump shaft 31. Thus, the two rotation side board parts 32s which have a substantially S-shaped shape are provided. Further, a connecting portion 32d that extends along the axial direction of the pump shaft 31 and connects the two rotating side plate portions 32s is provided.

  The oscillator 33 has a substantially arcuate planar shape in which the axial direction of the pump shaft 31 is a normal direction, and a slight gap is provided between the two rotary side plate portions 32s in the axial direction of the pump shaft 31 by the connecting portion 33d. It is formed to have two swinging side plate portions 33 s that are connected to each other with a space that can be inserted at a distance. A swing shaft 33 a is provided at one end of the arcuate plane of the two swing side plate portions 33 s so as to overlap in the axial direction of the pump shaft 31, and is provided on the rotary side plate portion 32 s of the rotating body 32. It is inserted into the round shaft hole 32a and attached so as to be rotatable (swingable). The two oscillating bodies 33 are attached to symmetrical positions that overlap each other when they rotate 180 degrees with respect to the rotating body 32 around the pump shaft 31.

  Further, when the swinging body 33 is attached to the rotating body 32 so as to be swingable, the swinging range is regulated around the swinging shaft 33a. That is, in each of the two oscillating side plate portions 33 s, a rectangular convex portion 33 b protrudes along the axial direction of the pump shaft 31 at the other end of the arcuate plane opposite to the oscillating shaft 33 a. Is provided. On the other hand, each of the rotation side plate portions 32s of the rotator 32 has a substantially rectangular hole 32b with which the protrusion 33b abuts, and the protrusion 33b moves (swings) around the swing shaft 33a in the hole. It is provided in a size that can be moved). As a result, the convex part 33b provided in the rocking body 33 functions as a contact part, and the hole 32b provided in the rotating body 32 functions as a contacted part, whereby the two rocking bodies 33 rotate. The swing range is regulated according to the movable range of the convex portion 33b in the hole 32b of the body 32.

  In addition, a bending hole 34 is provided in each of the two oscillating side plate portions 33 s of the oscillating body 33 so as to overlap in the axial direction of the pump shaft 31. The roller shafts 36 a on both sides of the roller 36 are inserted into the two bending holes 34, respectively, and are movable along the bending holes 34.

  In the present embodiment, as shown in FIG. 3, the swing body 33 is a coil as an urging body that urges the roller 36 in a direction in which the roller 36 presses the tube 26, that is, a direction approaching the tube 26 supported by the inner wall surface 21 a. A spring 41 is provided. The coil spring 41 is inserted in a compressed state between the connection part 32d and the connection part 33d. Therefore, the oscillating body 33 is always urged by the coil spring 41 in the direction in which the roller 36 approaches the tube 26 around the oscillating shaft 33a.

  In the present embodiment, the cylindrical protrusions of a size that can be accommodated on the inner diameter side of the coil spring 41 are provided in the connecting portion 32d and the connecting portion 33d so that the inserted coil spring 41 is stably inserted. The portions 32g and 33g are formed so as to face each other. The urging position at which the coil spring 41 urges the oscillating body 33, that is, the position of the projection 33g is located farther from the oscillating shaft 33a than the position of the roller shaft 36a that moves the bending hole 34. Is formed. Therefore, the urging position where the coil spring 41 urges the oscillating body 33 is a position away from the roller shaft 36a located at the short hole portion 34a of the bending hole 34 with respect to the oscillating shaft 33a.

  By the way, in the tube pump of this embodiment having such a structure, the rotating body 32, the rocking body 33, the roller 36, and the coil spring 41 are inserted into their respective predetermined locations without using a fixing member separately. And has a structure that can be attached. These structures will be described with reference to FIG.

  As shown in FIG. 4, the rocking body 33 is formed with insertion grooves 34 e into which the roller shafts 36 a on both sides of the roller 36 are respectively inserted in the rocking side plate portion 33 s so as to communicate with the short hole portion 34 a in the bending hole 34. Has been. When the roller shaft 36a is inserted into the insertion groove 34e, the oscillating body 33 is bent so that the space between the opposing oscillating side plate portions 33s is slightly widened, and the roller shaft 36a is allowed to move in the insertion groove 34e. . As a result, the roller shaft 36a is inserted into the short hole portion 34a in the bent hole 34 from the insertion groove 34e.

  Next, in the rotator 32, insertion grooves 32e into which the oscillating shafts 33a on both sides of the oscillating body 33 are respectively inserted are communicated with the shaft holes 32a in the rotator 32, and inclined on the insertion side of the oscillating shaft 33a. 32c is provided. Therefore, the swing shaft 33a is guided by the inclined surface 32c and inserted into the insertion groove 32e. At this time, the oscillating body 33 is bent so that the distance between the opposing oscillating side plate portions 33s is slightly narrow at least at the location where the oscillating shaft 33a is formed, and the oscillating shaft 33a is allowed to move in the insertion groove 32e. As a result, the swing shaft 33a is inserted into the shaft hole 32a.

  Further, in the rotating body 32, a direction in which the convex portion 33b provided in the rocking body 33 is inserted into the hole portion 32b formed at the end portion on the opposite side to the shaft hole 32a in the rotating side plate portion 32s. A slope 32f is formed at the end on the side. On the other hand, an inclined surface 33c is formed on the convex portion 33b on the side facing the inclined surface 32f when inserted into the hole 32b. Therefore, the convex portion 33 b is guided by the inclined surface 32 f and the inclined surface 33 c and inserted into the hole portion 32 b, and engages in the axial direction of the pump shaft 31. At this time, the oscillating body 33 bends so that the distance between the opposing oscillating side plate portions 33s is slightly narrow at least at the place where the convex portion 33b is formed, or the rotating body 32 has at least a hole between the rotating side plate portions 32s. The convex portion 33b is allowed to move into the hole portion 32b by being bent so as to spread a little at the formation location of 32b. As a result, the convex portion 33b is smoothly inserted into the hole portion 32b.

  The coil spring 41 is inserted between the coupling part 32d and the coupling part 33d in a compressed state when the rocking body 33 is attached to the rotating body 32. Specifically, after the swing shaft 33a is inserted into the shaft hole 32a, one end side of the coil spring 41 is attached to a cylindrical protrusion 32g provided on the surface side facing the swing body 33 at the connection portion 32d. Then, before the convex portion 33b is inserted into the hole portion 32b, the other end of the uncompressed coil spring 41 shown by a two-dot chain line in the drawing is attached to the connecting portion 33d of the oscillator 33. Then, while the coil spring 41 is compressed, the rocking body 33 is swung toward the rotating body 32 until the convex portion 33b of the rocking body 33 is inserted into the hole 32b. In this way, two oscillating bodies 33 and two coil springs 41 are attached to the rotating body 32.

  In the present embodiment, two tube pumps are disposed in the axial direction of the pump shaft 31, and each of the tube pumps has a cam shape 31c in a state where the pump pumps 21 and 22 are assembled. And rotate together. Therefore, for example, when ink is sucked from the nozzles divided into two color inks other than black ink and black ink, the ink in the two caps can be sucked separately by the respective tube pumps.

  Next, an effect | action when the pump apparatus 20 of this embodiment operate | moves as a tube pump is demonstrated with reference to FIG. In FIG. 5, for convenience of explanation, only the components related to the explanation of the action are shown, and the rotating body 32 is cut along a plane intersecting the pump shaft 31 and the front side of the drawing is removed. Has been. Also, in FIG. 5, among the two oscillating bodies 33 pivotally supported by the rotating body 32, the oscillating body 33A on the upper side of the drawing is a state in which the roller 36 presses the tube 26. The swinging body 33B on the side is in a state where the roller 36 is not pressing the tube 26.

  In the tube pump, when the roller 36 is released from the state of pressing the tube 26, for example, when the rotating body 32 rotates CCW, the roller 36 moves into the long hole portion 34 b in the bent hole 34 so as to move away from the tube 26. To position. In this case, the oscillating body 33B oscillates around the oscillating shaft 33a because the connecting portion 33d is urged by the coil spring 41, but the convex portion 33b located in the hole 32b is oscillated by the oscillation. It abuts on the opening edge of the portion 32b (the lower opening edge in FIG. 5). Therefore, the rocking body 33 and the roller 36 are regulated so as not to move to the tube 26 side.

  In the tube pump, when operating as a suction pump, the roller 36 and the oscillating body 33 move from the state indicated by the oscillating body 33B to the state indicated by the upper oscillating body 33A in FIG. Displace. That is, when the pump shaft 31 (rotary body 32) rotates CW, the roller 36 (two-dot chain line in the figure) whose pressing state is started by entering the tube 26 revolves around the pump shaft 31, The shaft 36 a moves from the position of the long hole portion 34 b in the bent hole 34 to the short hole portion 34 a and moves to a position farthest from the pump shaft 31. As a result, the roller 36 becomes a position (first position) where the flexible tube 26 is pressed and crushed. In the present embodiment, in the state where the roller shaft 36a is positioned in the short hole portion 34a, the rocking body 33A is a hole in which the protrusion 33b provided on the opposite side of the rocking shaft 33a is provided in the rotating body 32. It will be in the separated state which does not contact | abut to an opening edge in the part 32b. In other words, the hole portion 32b and the convex portion 33b are provided at positions where such a state is exhibited in the rotating body 32 and the swinging body 33, respectively.

  Therefore, the pressing force with which the roller 36 crushes the tube 26 is a force having a magnitude corresponding to the urging force of the coil spring 41. That is, as shown in FIG. 5, the biasing force with which the coil spring 41 biases the connecting portion 33d is a force F1, and the distance between the position where the force F1 acts on the connecting portion 33d and the swing shaft 33a, The distance in the direction orthogonal to the direction in which the force F1 is applied is the length L1. The urging force that the oscillating body 33 urges the roller shaft 36a is defined as a force F2, and is the distance between the position of the roller shaft 36a on which the force F2 acts and the oscillating shaft 33a, and is orthogonal to the direction in which the force F2 is applied. Let the distance in the direction to be the length L2. Then, the force F2 becomes F2 = F1 × L1 ÷ L2.

  Of course, since the force F2 is a pressing force by which the roller 36 crushes the tube 26, the pressing force is determined according to the biasing force of the coil spring 41. Further, since the pressing force is a value obtained by multiplying the urging force of the coil spring 41 by L1 / L2, the length L1, that is, the distance from the swinging shaft 33a to the insertion position of the coil spring 41 in the connecting portion 33d is increased. As a result, the pressing force of the tube 26 can be increased. Alternatively, the pressing force of the tube 26 can be increased by shortening the length L2, that is, the distance between the swing shaft 33a and the short hole portion 34a in the bent hole 34.

  In the pump device 20, during the suction operation, the roller 36 that revolves around the pump shaft 31 while pressing the tube 26 may move suddenly by being temporarily released from the pressed state of the tube 26. . At that time, when the roller shaft 36a moving along the bent hole 34 in the rocking body 33 collides with the end of the long hole portion 34b in the bent hole 34, abnormal noise (collision sound) is generated. There is.

  Therefore, in the present embodiment, a buffer body 24 is provided that cushions and suppresses the roller 36 so that the roller 36 released from the pressed state of the tube 26 does not move suddenly. The buffer operation (action) of the buffer body 24 will be described with reference to FIG.

  As shown in FIG. 6, when the roller 36 that revolves around the pump shaft 31 along with the CW rotation of the rotating body 32 is released from the pressed state against the tube 26, the arrow Fk in the figure during the rotation of the rotating body 32. As shown by, it moves rapidly from the position of the short hole part 34a to the position of the long hole part 34b. At this time, the buffer body 24 is provided so as to move the roller 36 gently by being deformed (displaced) while being in contact with the moving roller 36.

  The shock absorber 24 is provided with a semi-cylindrical curved portion 24 a that abuts the roller 36 on the tip side. And two plate-like parts 24b1 and 24b2 continuously formed in a long plate shape from both ends of the semi-cylindrical curved part 24a toward the base end side are provided, and the buffer body 24 has a substantially U-shape. Is formed. Further, the base end sides of the two plate-like portions 24b1 and 24b2 are connected by a flat plate portion, and at least the flat plate portion is inserted into the pump case 21 and fixed. Therefore, the buffer 24 functions as a deformable portion where the curved portion 24a other than the fixed base end side and the two plate-like portions 24b1 and 24b2 can be deformed by elastic deformation. In other words, the buffer body 24 is formed such that the deformed portion has the curved portion 24a and the two plate-like portions 24b1 and 24b2.

  That is, when the roller shaft 36a moves suddenly along the bending hole 34 in the rocking body 33, the buffer body 24 is brought into contact with the roller 36 so that the curved portion 24a comes into contact with the cylindrical shape and is collapsed on both sides. The parts 24b1 and 24b2 are displaced while being deformed so as to bend. As a result, the buffer body 24 is deformed from the state before contact indicated by reference numeral 24A to the state indicated by reference numeral 24B, and at the same time, deformation (displacement) of the three portions including the curved portion 24a and the plate-like portions 24b1 and 24b2. ) To stably buffer the rapidly moving roller 36 and move the roller 36 gently.

  In the tube pump, when the rotating body 32 rotates in the CCW direction opposite to the suction operation, the buffer 36 is buffered so as not to prevent the movement (revolution) of the roller 36 that revolves around the pump shaft 31 in the CCW rotation direction. The body 24 can be deformed from the state before contact indicated by reference numeral 24A to the state indicated by reference numeral 24C.

  Further, in the pump device 20, during the suction operation as a tube pump, the roller 36 is temporarily released from the pressed state, and the roller 36 in which the roller shaft 36 a is positioned in the long hole portion 34 b in the bent hole 34 enters the tube 26 again. It is necessary to revolve around the pump shaft 31 while pressing the tube 26.

  Therefore, in this embodiment, a derivative that guides the roller 36 released from the pressed state of the tube 26 so that the roller shaft 36a is reliably moved from the long hole portion 34b to the short hole portion 34a in the bent hole 34. 25. The guidance operation (action) of the derivative 25 will be described with reference to FIG.

  As shown in FIG. 7, in the state where the roller 36 revolving around the pump shaft 31 with the CW rotation of the rotating body 32 is released from the pressed state against the tube 26, the rotating body 32 is rotating during the rotation of the rotating body 32. As indicated by the dotted line, the roller shaft 36a moves from the position of the short hole part 34a to the position of the long hole part 34b. Therefore, the derivative 25 is provided so as to move the roller shaft 36a from the long hole part 34b to the short hole part 34a by being displaced while abutting the moving (revolving) roller 36.

  The derivative 25 has a hook-shaped bent shape in which a distal end portion 25a is bent in a direction in which the roller 36 revolving during a suction operation in the tube pump approaches, and a base end portion of the derivative 25 has a substantially T-shape. Has been. The base end portion of the derivative 25 is inserted into the pump case 21 and fixed. Therefore, the distal end portion 25a rotates around the fixed proximal end portion of the derivative 25 and is displaced while its bent shape is deformed.

  That is, when the revolving roller 36 comes into contact with the tip portion 25a of the derivative 25, as shown by a two-dot chain line in the figure, the derivative 25 has its bent portion while the tip portion 25a bends in the revolution direction as the roller 36 revolves. The roller 36 is captured. As a result, the derivative 25 returns from the deformed state indicated by reference numeral 25B to the state before deformation indicated by reference numeral 24A, and the roller shaft 36a is moved from the long hole portion 34b as indicated by the arrow Fr while capturing the roller 36. It moves to the short hole part 34a. After the roller shaft 36a moves to the short hole part 34a, the derivative 25 is deformed again as shown by reference numeral 25B by the roller 36 revolving at that position, and the revolving of the roller 36 is continued. Will continue.

  In the tube pump, when the rotating body 32 rotates in the CCW direction, which is opposite to the suction operation, a derivative is used so as not to prevent the movement (revolution) of the roller 36 that revolves around the pump shaft 31 in the CCW rotation direction. 25 can be deformed (displaced) from the state before deformation indicated by reference numeral 25A to the state indicated by reference numeral 25C.

According to the embodiment described above, the following effects can be obtained.
(1) The pressing force by which the roller 36 presses the tube 26 is obtained by the urging force of the coil spring 41 that swings the swinging body 33. At the position where the roller 36 presses the tube 26, the roller shaft 36a is the swinging shaft. Since it approaches 33a, the pressing force of the roller 36 obtained by the urging force of the coil spring 41 can be increased. Therefore, even if the tube 26 is a hard solvent-resistant tube, the roller 36 can stably crush the tube 26.

  (2) Since the connecting portion 33d (projecting portion 33g) serving as the biasing position of the swinging body 33 biased by the coil spring 41 is located away from the short hole portion 34a with respect to the swinging shaft 33a, A pressing force having a force larger than the urging force of the coil spring 41 that swings the swing body 33 is obtained.

  (3) When the roller shaft 36a is at the position of the short hole portion 34a, the convex portion 33b does not come into contact with the opening edge of the hole portion 32b of the rotating body 32, so that the pressing force of the roller 36 pressing the tube 26 is It is given by the biasing force of the coil spring 41. Therefore, an appropriate pressing force can be applied to the tube 26. Moreover, since the rocking | swiveling body 33 is rock | fluctuated in the direction approaching the tube 26 by the convex part 33b, it can regulate the crushing amount of the tube 26 which the roller 36 presses. Further, the rocking body 33 incorporated in the rotating body 32 is held by the rotating body 32 in a state where its rocking range is restricted, so that the roller 36 is positioned within a predetermined distance from the pump shaft 31. Accordingly, when the pump device is assembled by inserting the roller 36 inside the arcuate tube 26, a pump device that can be easily assembled is obtained.

  (4) During the rotating operation of the rotating body 32, the sudden movement of the roller shaft 36a from the short hole portion 34a to the long hole portion 34b caused by releasing from the pressed state is a semi-cylinder in the U-shaped buffer body 24. It is blocked by the deformation of the curved portion 24a having a shape and the two plate-like portions 24b1 and 24b2 having a long plate shape, and is restrained from gradual movement. Therefore, the pump device 20 that suppresses the generation of impact sound when the roller 36 stops moving in the long hole portion 34b is obtained.

  (5) Since the distal end portion 25a of the derivative 25 is formed to have a bent shape that comes into contact with the revolving roller 36, the roller 25a is released from the pressed state during the rotating operation of the rotating body 32. , The roller shaft 36a is reliably guided by the derivative 25 to the short hole part 34a. Therefore, the pump device 20 having high reliability for the suction operation can be obtained.

In addition, you may change each said embodiment into another embodiment as follows.
In the above embodiment, the coil spring 41 is used as the biasing body that biases the swinging body 33, but it is needless to say that the coil spring 41 is not necessarily limited. For example, as shown in FIG. 8, a bellows-shaped portion 43 formed integrally with the rocking body 33A may be used as the biasing body that biases the rocking body 33A. That is, while the tip of the bellows-shaped portion 43 (indicated by a two-dot chain line in the figure) extending from the connecting portion 33d of the rocking body 33 is brought into contact with the connecting portion 32d of the rotating body 32, the bellows-shaped portion 43 is bent. By incorporating the oscillating body 33 (33A) into the rotating body 32, the bent bellows-shaped portion 43 functions as an urging body.

  Alternatively, as shown in FIG. 8, a torsion spring 45 may be used as a biasing body that biases the swinging body 33B. That is, the twisted portion of the ring-shaped spring is arranged concentrically with the pump shaft 31, and the end portions of the respective springs are in contact with the connecting portion 33d of the oscillating body 33 and the connecting portion 32d of the rotating body 32. The torsion spring 45 functions as an urging body by incorporating the oscillating body 33B into the rotating body 32 while bending the respective spring ends.

  In the above embodiment, the pump device 20 may not necessarily include the derivative 25. For example, when the pump device 20 is arranged so that the roller shaft 36a receives a force that moves from the long hole part 34b side to the short hole part 34a side by the dead weight of the roller 36, the derivative 25 is not necessarily required.

  In the above embodiment, the pump device 20 does not necessarily need to include the buffer body 24. For example, even if the revolving roller 36 is released from the pressed state of the tube 26, the buffer 24 is not necessarily required if the roller 36 does not move rapidly.

  In the above-described embodiment, the rocking body 33 is a contact portion that makes contact with the one portion (opening edge) of the hole 32b of the rotating body 32 so as to be restricted from swinging in the biasing direction. The convex portion 33b may not necessarily be provided. For example, when the tube 26 is supported in an arc shape of 360 degrees or more on the inner wall surface 21a of the pump case 21 and the revolving roller 36 always faces the tube 26, the roller 36 is released from the pressed state of the tube 26. In this case, the roller 36 comes into contact with the opposite tube 26 to restrict the swinging of the swinging body 33. Therefore, in such a case, it is not necessary to provide the convex portion 33b that regulates the swing range of the swing body 33.

  In the above embodiment, the urging position of the oscillating body 33 urged by the coil spring 41 is not necessarily a position away from the position of the short hole portion 34a with respect to the oscillating shaft 33a. For example, when a large urging force is obtained by the coil spring 41, even if the oscillating body 33 is urged at a position closer to the oscillating shaft 33a than the short hole portion 34a, the size is the same as that of the above embodiment. Energizing power is obtained.

  In the pump device 20 of the above embodiment, the two tubes 26 having a semicircular arc shape are disposed along the axial direction of the pump shaft 31 and are configured to rotate while pressing them. It is not limited to. For example, at least one tube 26 may be provided, or a larger number such as three may be provided. Further, in the tube 26 disposed along the inner wall surface 21a of the pump case 21, the range pressed by the roller 36 may be 360 degrees that is not a semicircle, that is, 180 degrees, but substantially the entire circumference. . In this case, the arrangement shape of the tube 26 is a so-called Ω-shape in which both ends are bundled. Furthermore, the range pressed by the roller 36 may be 360 degrees or more. In this case, the arrangement shape of the tube 26 is a so-called α-shape that is a spiral shape.

  In the above embodiment, the pump device 20 is embodied in a pump device used in a maintenance mechanism provided in an ink jet type liquid ejecting apparatus that ejects ink. However, other liquids other than ink are ejected or discharged. The present invention may be embodied in a pump device used in the liquid ejecting apparatus. The present invention can be applied to a pump device used in various liquid ejecting apparatuses including a liquid ejecting head that ejects a minute amount of liquid droplets. The droplet means a state of the liquid ejected from the liquid ejecting apparatus, and includes a liquid that is tailed in a granular shape, a tear shape, or a thread shape. The liquid here may be any material that can be ejected by the liquid ejecting apparatus. For example, it may be in a state in which the substance is in a liquid phase, such as a liquid with high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts ) And liquids as one state of the substance, as well as particles in which functional material particles made of solid materials such as pigments and metal particles are dissolved, dispersed or mixed in a solvent. Further, representative examples of the liquid include ink and liquid crystal as described in the above embodiment. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot melt inks. As a specific example of the liquid ejecting apparatus, for example, a liquid containing a material such as an electrode material or a color material used for manufacturing a liquid crystal display, an EL (electroluminescence) display, a surface emitting display, or a color filter in a dispersed or dissolved form. There is a liquid ejecting apparatus for ejecting. Alternatively, it may be a liquid ejecting apparatus that ejects a bio-organic material used for biochip manufacturing, a liquid ejecting apparatus that ejects a liquid that is used as a precision pipette and a sample, a printing apparatus, a micro dispenser, or the like. 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 or a liquid ejecting apparatus that ejects an etching solution such as an acid or an alkali to etch the substrate may be employed. The present invention can be applied to a pump device used in any one of these liquid ejecting apparatuses.

  DESCRIPTION OF SYMBOLS 11 ... Maintenance mechanism, 16a, 16b ... Tube, 20 ... Pump apparatus, 24 ... Buffer body, 24a ... Curve part as a deformation part, 24b1, 24b2 ... Plate-like part as a deformation part, 25 ... Derivative, 25a ... Tip part , 26 ... tube, 32 ... rotating body, 32b ... convex part as a contact part, 33, 33A, 33B ... rocking body, 36 ... roller, 36a ... roller shaft as shaft part.

Claims (5)

A flexible tube;
A pump frame having a support surface for supporting the tube in an arc shape;
A rotating body that rotates around an arc central axis of the tube supported by the support surface;
An oscillating body that is pivotally supported by the rotator and has a change-shaped portion in which a distance from the arc center axis changes in the rotation direction of the rotator;
A shaft portion is held so as to be movable along the change shape portion, revolves around the arc center axis along with the rotation of the rotating body, and the shaft portion changes according to the rotation direction of the rotation body. And a second position where the pressing force applied to the tube is more relaxed than the pressing force at the first position. A roller that moves between and
A biasing body that biases the rocking body in a direction in which the roller approaches the tube supported by the support surface;
With
The pump device according to claim 1, wherein the first position is closer to a swing center of the swing body than the second position. The pump device according to claim 1,
The urging position of the oscillating body urged by the urging body is a position away from the shaft portion of the roller moved to the first position from the oscillating center. apparatus. The pump device according to claim 1 or 2,
The oscillator is
A contact portion that is in contact with the rotating body and is restricted from swinging in a direction in which the roller approaches the tube supported by the support surface;
When the roller moves to the first position, the contact portion is biased in a direction approaching the tube by a biasing force of the biasing body without contacting the rotating body. Pump device. The pump device according to any one of claims 1 to 3,
When the roller that revolves with the rotation of the rotating body moves from the first position to the second position during the rotation of the rotating body, the shock absorber is deformed while contacting the roller. ,
The buffer body is formed such that the deformed deformation portion has a semi-cylindrical curved portion and two long plate-shaped plate portions continuously formed from both end portions of the curved portion. A pump device characterized by. The pump device according to any one of claims 1 to 4,
A derivative for guiding the roller to move from the second position to the first position during rotation of the rotating body by contacting and displacing the revolving roller;
2. The pump device according to claim 1, wherein the derivative is formed to have a bent shape in which a tip portion is bent on a side in contact with the revolving roller.