Tube pump and printing device

Abstract

To properly provide a tube pump capable of operating quietly.SOLUTION: A tube pump 200 for sending fluid comprises a tube 202, rollers 206 and a roller holder 208. The roller holder 208 has a guide groove 300 which defines a range in which the roller 206 can move relative to the roller holder 208 by passing a shaft of the roller 206 therethrough. The roller holder 208 has an inside face 302 and an outside face 304 as faces constituting the guide groove 300 on the roller holder 208, the inside face 302 having a protrusion 312 protruding to a side toward the outside face 304.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a tube pump and a printing device. [Background technology]

[0002] Conventionally, tube pumps that use a tube to deliver fluid have been used in various technical fields. For example, Patent Document 1 discloses the use of a tube pump (tube-type pump device) in an inkjet printing device that performs printing using an inkjet method. The tube pump includes, for example, a tube and a roller, and delivers a fluid such as a liquid by squeezing the tube with the roller. In this case, for example, the roller is rotated around a predetermined central axis to repeatedly squeeze a predetermined section of the tube with the roller. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-172887 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a tube pump, when the roller finishes squeezing the tube, it moves due to the elasticity of the tube, which may generate a striking sound (crash sound) that is an unpleasant noise. More specifically, in a tube pump, a member in which a guide groove for holding the roller shaft is formed may be used as a roller holder, which is a member for holding the roller. Also, a groove that allows the roller shaft to move within a certain range may be used as the guide groove. In this case, when the tube is to be squeezed, the roller holder holds the roller shaft at, for example, one end position of the guide groove. Then, in this case, when the tube is finished being squeezed, the roller may move vigorously through the guide groove toward the other end due to the elasticity of the tube. As a result, the roller may hit the end of the guide groove, and the striking sound generated at the time of the collision may become an unpleasant noise for the user.

[0005] In response to this, various configurations for preventing the occurrence of such hitting sounds have been studied. For example, Patent Document 1 discloses a configuration using a guide member that contacts the roller to limit the movement of the roller. However, a new, more preferable configuration for preventing the occurrence of such hitting sounds is still desired. Therefore, an object of the present invention is to provide a tube pump and a printing device that can solve the above problems. [Means for solving the problem]

[0006] The inventors of the present application conducted extensive research into a configuration that can adequately prevent the generation of hammering noises caused by the movement of the roller shaft in the guide groove of the roller holder. They discovered that the hammering noises can be adequately prevented by providing a convex portion on the surface that constitutes the guide groove, which is closer to the central axis that is the center of the rotation of the roller. Further extensive research led to the discovery of the characteristics necessary to achieve this effect, and the present invention was arrived at.

[0007] In order to solve the above-mentioned problems, the present invention provides a tube pump that uses an elastic tube to send a fluid, the tube comprising: a roller that pushes out the fluid inside the tube by moving the tube along a partial section of a flow path through which the tube sends the fluid while squashing the tube; and a roller holder that is a member that moves the roller while holding the axis of the roller, and that rotates the roller around a predetermined central axis so that the roller repeatedly passes along a path along the partial section. The roller holder has a groove that passes the axis of the roller to define a range in which the roller can move relative to the roller holder, A guide groove is formed with one end side at the rear and the other end side at the front in the direction of movement of the roller along the partial section in the direction in which the fluid is pushed out, and the roller holder has, as surfaces that constitute the guide groove, an inner surface that guides the movement of the roller shaft on a side closer to the central axis than the roller shaft, and an outer surface that faces the inner surface across the roller shaft, and while the roller is moved along the partial section, the roller shaft is held at a rear end position that is the end position of the guide groove that is rear in the direction of movement, and the inner surface has a convex portion that protrudes toward the outer surface.

[0008] In this configuration, the guide groove has a convex portion, which can appropriately prevent, for example, the roller that has jumped out from the rear end position of the guide groove from colliding forcefully with the opposite end of the guide groove. This can also appropriately prevent, for example, loud hitting noises caused by the roller colliding with the wall surface of the guide groove. Therefore, with this configuration, for example, it is possible to appropriately provide a tube pump that is highly quiet.

[0009] In this configuration, the tube is arranged such that at least a portion of the tube is curved in an arc shape, for example. The roller holder rotates about a central axis determined according to the arc-shaped portion of the tube while holding the axis of the roller by a guide groove, for example, to cause the roller to revolve around the central axis. In this case, the above-mentioned partial section is a section that includes the arc-shaped portion of the tube. With this configuration, for example, the roller can appropriately handle the tube and appropriately deliver a fluid such as a liquid.

[0010] The above-mentioned partial section can be considered, for example, as a stroke section in which the roller strokes the tube. In addition, in this case, when the roller passes through this partial section, the roller comes to a position other than the curved portion of the tube and leaves the tube. In this configuration, it is preferable to hold the roller on the rear end position side of the guide groove even during the period when the roller is away from the tube. More specifically, in this case, for example, while the roller holder rotates in the direction in which the fluid is pushed out, the roller holder holds the roller shaft between the rear end position of the guide groove and the convex portion. With this configuration, for example, it is possible to more appropriately and reliably prevent the roller that has jumped out from the rear end position of the guide groove from colliding with the opposite end of the guide groove. In addition, the operation of holding the roller shaft in this way can be considered to hold the roller shaft on one end side of the guide groove, regardless of whether the roller is in contact with the tube or not, during forward rotation in which the roller holder rotates in the direction in which the fluid is pushed out.

[0011] In addition, in this configuration, when the roller holder is rotated in the reverse direction opposite to the forward rotation, it is possible to hold the shaft of the roller at the other end side of the guide groove opposite to the one end side that holds the shaft of the roller during forward rotation. More specifically, in this case, when the roller holder is rotated in the reverse direction, the roller holder holds the shaft of the roller, for example, on the other end side of the convex portion of the guide groove. With this configuration, for example, it is possible to appropriately reverse the roller while appropriately retracting the roller. Also, in this case, it is possible to make the inclination of one end side of the convex portion larger than the inclination of the other end side. With this configuration, for example, it is possible to more reliably prevent the roller from moving beyond the convex portion during forward rotation, and to allow the roller to appropriately move beyond the convex portion when switching from reverse to forward rotation.

[0012] Also, just before the roller leaves the tube, the roller comes into contact with the tube, for example, near the end of the arc-shaped part of the tube. Also, it is considered that the part of the tube in contact with the roller gradually expands from the crushed state as the roller moves. In this case, the convex part on the inner surface of the guide groove comes into contact with the roller pressed by the gradually expanding tube, and prevents the roller from moving forward (to the other end side) of the convex part in the guide groove, for example. With this configuration, for example, the axis of the roller can be appropriately held between the rear end position of the guide groove and the convex part. Also, with this configuration, the outer surface of the guide groove has a concave part that is concave in a direction away from the inner surface, for example, at a position facing the convex part on the inner surface. With this configuration, for example, the width of the guide groove can be appropriately secured at the position where the convex part is provided.

[0013] The tube pump having the above configuration may be used in, for example, a printing device that performs printing by an inkjet method. In this case, the printing device may include, for example, an inkjet head that ejects ink, an ink container that stores ink to be supplied to the inkjet head, and an ink supply path that supplies ink from the ink container to the inkjet head using a tube pump. With this configuration, for example, it is possible to appropriately suppress the hitting noise generated in the tube pump and appropriately provide a highly quiet printing device. The printing device may also include a maintenance unit or the like that performs maintenance on the inkjet head. In this case, it is also possible for the maintenance unit to, for example, suck ink from the inkjet head using a tube pump. Effect of the Invention

[0014] According to the present invention, for example, a tube pump with high noise reduction can be appropriately provided. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram illustrating a printing device 100 according to an embodiment of the present invention. FIG. 1(a) shows an example of the configuration of the main parts of the printing device 100. FIG. 1(b) shows an example of the configuration of an ink supply path 108. FIG. 1(c) shows an example of the configuration of a maintenance unit 114. [Diagram 2] 2A and 2B are diagrams illustrating general features of the tube pump 200. Figures 2A and 2B show examples of states of the tube pump 200 at different times during normal rotation of the tube pump 200 of the reference example. [Diagram 3] 3A and 3B are diagrams for explaining in detail the features of the tube pump 200 of this embodiment. Fig. 3A shows an example of the configuration of the tube pump 200 of this embodiment. Fig. 3B shows a comparison of the shapes of the guide groove 300 of the reference embodiment and this embodiment. [Figure 4] 4(a) to 4(c) are diagrams illustrating modified examples of the configuration of the guide groove 300. FIG. [Diagram 5] 5(a) to (c) are diagrams illustrating modified examples of the configuration of the guide groove 300. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining a printing device 100 according to an embodiment of the present invention, and FIG. 1(a) shows an example of the configuration of the main parts of the printing device 100. In this example, the printing device 100 is an inkjet printer that performs printing on a medium 50 to be printed by an inkjet method, and includes a plurality of inkjet heads 102, a platen 104, a plurality of main tanks 106, an ink supply path 108, a carriage 110, a scan drive unit 112, a maintenance unit 114, and a control unit 120. Except for the points described below, the printing device 100 may have the same or similar features as a known inkjet printer. For example, the printing device 100 may further include a configuration that is the same or similar to a known inkjet printer in addition to the configuration illustrated in FIG. 1.

[0017] The inkjet heads 102 are ejection heads that eject ink onto the medium 50. In this example, each of the inkjet heads 102 has a plurality of nozzles and ejects ink of a different color. More specifically, in the illustrated configuration, each of the inkjet heads 102 ejects ink of a color of Y (yellow), M (magenta), C (cyan), and K (black). The platen 104 is a platform member that faces the inkjet heads 102 and holds the medium 50. The main tanks 106 are ink containers that store ink to be supplied to the inkjet heads 102. In this example, each of the main tanks 106 stores ink of a different color, and supplies ink to any of the inkjet heads 102 via an ink supply path 108. For example, an ink bottle or an ink cartridge can be suitably used as the main tank 106. The ink supply passage 108 is a path for supplying ink from the multiple main tanks 106 to the multiple inkjet heads 102. The carriage 110 is a holding member for holding the multiple inkjet heads 102.

[0018] The scan driver 112 is a driver that causes the inkjet heads 102 to perform a scanning operation in which the inkjet heads 102 move relative to the medium 50. In this example, the scan driver 112 causes the inkjet heads 102 to perform a main scanning operation and a sub-scanning operation. In this case, the main scanning operation can be considered to be, for example, an operation of ejecting ink while moving relative to the medium 50 in a predetermined main scanning direction. The sub-scanning operation can be considered to be, for example, an operation of moving relative to the medium 50 in a sub-scanning direction perpendicular to the main scanning direction. The maintenance unit 114 is configured to perform a maintenance operation on the inkjet heads 102. In this example, the maintenance unit 114 performs maintenance on the inkjet heads 102 by sucking the ink out of the inkjet heads 102 through suction. The control unit 120 is, for example, a part including a CPU of the printing device 100, and controls the operation of each part of the printing device 100 according to a program (for example, firmware) that controls the operation of the printing device 100. According to this example, for example, printing can be appropriately performed on the medium 50 by the inkjet method.

[0019] In this example, the printing device 100 is an example of a configuration using a tube pump, and the above operation is performed using the tube pump in the ink supply path 108 and the maintenance unit 114. FIG. 1(b) is a diagram showing an example of the configuration of the ink supply path 108, and shows a simplified example of a path for supplying ink from one main tank 106 corresponding to one color of ink to the inkjet head 102. FIG. 1(c) is a diagram showing an example of the configuration of the maintenance unit 114, and shows a simplified example of a configuration for suctioning one inkjet head 102 corresponding to one color of ink. In this example, the ink supply path 108 has the configuration shown in FIG. 1(b) for each ink color. In addition, the maintenance unit 114 has the configuration shown in FIG. 1(c) for each ink color.

[0020] As shown in the figure, the ink supply path 108 has a tube pump 200 for sending ink in the middle of the ink flow path that supplies ink from the main tank 106 to the inkjet head 102. With this configuration, for example, it is possible to appropriately supply ink to the inkjet head 102. Furthermore, the maintenance unit 114 has a capping unit 152 and the tube pump 200. The capping unit 152 is a member that covers the nozzle surface of the inkjet head 102 when performing maintenance on the inkjet head 102. Furthermore, the tube pump 200 in the maintenance unit 114 sucks ink from the nozzles of the inkjet head 102 by performing suction on an enclosed space including the nozzle surface of the inkjet head 102 that is formed by covering with the capping unit 152. Furthermore, in this case, the tube pump 200 discharges the sucked ink into an ink recovery container or the like. With this configuration, for example, it is possible to appropriately perform maintenance on the inkjet head 102.

[0021] Next, the features of the tube pump 200 used in the printing device 100 of this example will be described in more detail. For ease of explanation, a tube pump 200 having a different configuration from the tube pump 200 used in this example will be described first. Fig. 2 is a diagram for explaining the general features of the tube pump 200, and shows an example of the configuration of a tube pump 200 having a different configuration from the tube pump 200 used in this example (hereinafter, referred to as the tube pump 200 of the reference example). Figs. 2(a) and (b) show examples of the states of the tube pump 200 at different times when the tube pump 200 of the reference example rotates in the forward direction.

[0022] In FIG. 2, for convenience of illustration, the configuration of the main parts of the tube pump 200 is appropriately simplified. The tube pump 200 of the reference example shown in FIG. 2 can be considered as, for example, a tube pump 200 in which the characteristic parts of the tube pump 200 used in the printing device 100 of the present example are omitted. More specifically, as will be described in more detail later, the tube pump 200 used in the present example has the same or similar characteristics as the tube pump 200 of the reference example, except for the shape of the guide groove 300 in the roller holder 208 and matters related to this shape. Therefore, in the following, common reference symbols are used for the present example and the reference example, and the characteristics of the tube pump 200 of the reference example will be described together with the characteristics of the tube pump 200 of the present example. The differences between the tube pump 200 of the present example and the tube pump 200 of the reference example will be described in more detail later.

[0023] The tube pump 200 is a pump that pumps liquid such as ink, and includes a tube 202, a frame 204, a plurality of rollers 206, and a roller holder 208. In this case, the liquid pumped by the tube pump 200 can be considered as an example of a fluid. The tube 202 is a tube through which the liquid pumped by the tube pump 200 passes. In this example, the tube 202 is a flexible tube having elasticity, and is arranged so that at least a portion of the tube 202 is curved in an arc shape. More specifically, in the case of the illustrated configuration, the tube 202 is arranged so that a portion of the tube 202 is curved in an arc shape along a support surface formed on the frame 204. In this case, the tube 202 can be considered to be arranged in a U-shape, for example, as shown in the figure. The frame 204 is a housing that holds the tube 202 and the roller holder 208, and holds a portion of the tube 202 along the support surface curved in an arc shape, and holds the roller holder 208 so that the support surface and a portion of the roller holder 208 face each other across the tube 202. This also causes the frame 204 to hold the tube 202 such that the tube 202 is sandwiched between the support surface and the roller holders 208 .

[0024] The rollers 206 are rollers for squeezing the tube 202, and as shown in Fig. 2(a) for example, they move along a section of the flow path through which the tube 202 sends liquid while squashing the tube 202, thereby pushing out the liquid inside the tube 202. In this case, the operation of the rollers 206 can be considered as, for example, an operation of squeezing the tube 202 in a fixed direction along the tube 202 arranged in a U-shape. The rollers 206 have an axis parallel to a direction perpendicular to the direction in which they move while squeezing the tube 202, and are held by the roller holder 208 by passing this axis through a guide groove 300 of the roller holder 208.

[0025] The roller holder 208 is a member that moves the roller 206 while holding the shaft of the roller 206, and rotates the roller 206 around a predetermined central axis so that the roller 206 repeatedly passes along a path along a portion of the tube 202. The roller 206 is rotated around the central axis, for example, by moving the roller 206 so that the shaft of the roller 206 rotates around an axis that is parallel to the shaft of the roller 206 and passes through a predetermined central position. In addition, this central axis is determined, for example, in accordance with the arc-shaped portion of the tube 202. More specifically, in this example, this central axis is an axis that passes through the center of a circle corresponding to the arc-shaped portion of the tube 202. In addition, the roller holder 208 is a wheel-shaped member that rotates around this central axis, and rotates about the central axis while holding the shafts of the rollers 206 by each of the guide grooves 300, thereby rotating the rollers 206 around the central axis.

[0026] In this example, the guide groove 300 in the roller holder 208 is a groove that penetrates the roller holder 208. The guide groove 300 can be considered, for example, as a groove that defines the range in which the roller 206 can move relative to the roller holder 208 by passing the shaft of the roller 206 through it. The guide groove 300 can also be considered, for example, as a configuration that guides the movement of the roller 206 between the stroke position and the retreat position described below. More specifically, in the case of the illustrated configuration, the guide groove 300 is a groove in which the position that is the rear end side when the tube pump 200 rotates forward is the stroke position, and the other end, the front end side, is the retreat position. In this case, the forward rotation of the tube pump 200 can be considered, for example, as a state in which the roller holder 208 rotates in a direction in which the liquid in the tube 202 is pushed out. The forward rotation of the tube pump 200 can be considered, for example, as a state in which the roller 206 moves in a direction in which the tube pump 200 pumps liquid. In the illustrated configuration, for example, the operation of rotating roller holder 208 in the direction of the arrow shown in FIG. 2(a) can be considered as the operation during normal rotation. The plucking position can be considered as, for example, the position of roller 206 that plucking tube 202. In this example, the plucking position is the position on the rear end side of guide groove 300 during normal rotation. Therefore, the plucking position can be considered as, for example, the end position (rear end position) on the rear side of guide groove 300 in the movement direction. The retreat position can be considered as, for example, the position where roller 206 retreats away from tube 202. In this example, the retreat position is the end position (front end position) of guide groove 300 on the opposite side from the plucking position.

[0027] During forward rotation, the roller 206 that moves along a portion of the tube 202 is held at a stroking position in the guide groove 300 of the roller holder 208, as shown in FIG. 2(a), for example, and moves while squashing the tube 202. In this case, the section where the roller 206 moves while squashing the tube 202 can be considered, for example, as a stroking section in the range of movement of the roller 206 that revolves around the central axis. In this example, the stroking section is a section that includes an arc-shaped portion of the tube 202. According to this example, for example, the roller 206 can appropriately handle the tube 202, and the liquid in the tube 202 can be appropriately delivered.

[0028] In the illustrated configuration, the portion of the range of movement of the roller 206 revolving around the central axis other than the stroke section becomes a non-contact section where the roller 206 and the tube 202 do not come into contact, for example, as shown by the double arrow in FIG. 2(b). In this case, as shown in FIG. 2(b), for example, at the timing when the roller 206 passes through the stroke section and moves to the non-contact section, the roller 206 is bounced up by the elastic force (repulsive force) of the tube 202, and moves toward the retreat position on the other end side of the guide groove 300. Such a movement of the roller 206 can be, for example, a movement in a direction away from the stroke position according to the elastic force of the tube 202. In this case, in the tube pump 200 of the reference example, it is considered that a loud hitting sound is generated due to the collision between the wall surface of the guide groove 300 and the roller 206. In contrast, in the tube pump 200 of the present example, the shape of the guide groove 300 is made different from that of the tube pump 200 of the reference example, so that the generation of a loud hitting sound is appropriately prevented. Therefore, the features of the tube pump 200 of this embodiment will be described in detail below.

[0029] Fig. 3 is a diagram for explaining in detail the features of the tube pump 200 of this example. Fig. 3(a) shows an example of the configuration of the tube pump 200 of this example. Fig. 3(b) is a diagram for comparing the shapes of the guide groove 300 of the reference example and this example. In Fig. 3(b), the diagram on the left shows the shape of the guide groove 300 in the roller holder 208 of the tube pump 200 of the reference example. The diagram on the right shows the shape of the guide groove 300 in the roller holder 208 of the tube pump 200 of this example.

[0030] As described above, the tube pump 200 of this example has the same or similar features as the tube pump 200 of the reference example, except for the shape of the guide groove 300 in the roller holder 208 and matters related to this shape. More specifically, as shown in the figure, the tube pump 200 of this example also has a tube 202, a frame 204, a plurality of rollers 206, and a roller holder 208, like the tube pump 200 of the reference example. Furthermore, except for the points described below, the components in FIG. 3 that are given the same reference numerals as those in FIG. 2 may have the same or similar features as the components in FIG. 2. Furthermore, except for the points described below, the tube pump 200 may have the same or similar features as a known tube pump.

[0031] 3(a), in the tube pump 200 of this example, in the stroke section during forward rotation, the roller 206 is held in the stroke position of the guide groove 300 and moves while squeezing the tube 202. However, in this example, the shape of the guide groove 300 is different from that of the tube pump 200 of the reference example, and therefore the movement of the roller 206 at the time of leaving the stroke section and entering the non-contact section differs from the movement of the roller 202 in the reference example. The movement of the roller 206 in this example will be described in more detail later.

[0032] In this embodiment and the reference embodiment, the guide groove 300 can be considered as a groove in which one end side is the rear side and the other end side is the front side in the direction in which the roller 206 moves along the stroke section during forward rotation. The roller holder 208 has an inner side surface 302 and an outer side surface 304 as surfaces constituting the guide groove 300, as shown in FIG. 3(b). In this case, the inner side surface 302 can be considered as, for example, a surface constituting the side surface of the guide groove 300 on the inside of the roller holder 208. The inner side of the roller holder 208 can be considered as, for example, a side that is farther from the tube 202 in terms of the positional relationship with the tube 202 in the stroke section. The inner side surface 302 can also be considered as, for example, a surface that guides the movement of the roller 206 on the side closer to the central axis of rotation of the roller holder 208 than the axis of the roller 206. The outer surface 304 can be considered, for example, as a surface that constitutes the side surface of the guide groove 300 at a position that is more outer than the inner surface 302 of the roller holder 208. The outer side of the roller holder 208 can also be considered, for example, as a side that is closer to the tube 202 in relation to the tube 202 in the stroke section. In addition, the outer surface 304 can also be considered, for example, as a surface that faces the inner surface 302 across the axis of the roller 206.

[0033] As can be understood from the illustrated configuration, the roller holder 208 further has, as a surface constituting the guide groove 300, a surface connecting the inner surface 302 and the outer surface 304 at one end side and the other end side of the guide groove 300 which are the stroke position and the retreat position. In this example and the reference example, the guide groove 300 is bent at the retreat position as shown in the drawings. Therefore, the roller holder 208 has a surface for constituting such a bent portion as a surface connecting the inner surface 302 and the outer surface 304 on the retreat position side. Also, with this configuration, the guide groove 300 holds the shaft of the roller 206 at the stroke position while the roller 206 is moved along the stroke section during forward rotation.

[0034] 3(b), the guide groove 300 in the roller holder 208 of the tube pump 200 of this example is different from the guide groove 300 in the roller holder 208 of the tube pump 200 of the reference example in terms of, for example, the presence or absence of a convex portion 312. More specifically, in this example, the inner surface 302 of the guide groove 300 has a convex portion 312 protruding toward the outer surface 304. The convex portion 312 can be considered to be, for example, a bump formed in the guide groove 300. In addition, in response to the inner surface 302 having the convex portion 312, in the tube pump 200 of this example, the outer surface 304 of the guide groove 300 has a concave portion 314 that is concave in a direction away from the inner surface 302 at a position facing the convex portion 312 on the inner surface 302. In this case, the concave portion 314 is concave so that the width of the guide groove 300 at the position of the convex portion 312 is equal to or greater than the width of the roller 206. With this configuration, for example, it is possible to appropriately prevent the roller 206 from not passing through the position of the convex portion 312 in the guide groove 300. In addition, this also makes it possible to appropriately ensure the width of the guide groove 300 even at the position where the convex portion 312 is provided.

[0035] More specifically, in the inner surface 302 of the guide groove 300 of this example, the portion other than the convex portion 312 is curved so as to get closer to the central axis as it moves away from the handing position, as shown in the figure, for example. In addition, when focusing on the distance from the outer periphery of the roller holder 208, the portion other than the convex portion 312 on the inner surface 302 can also be considered to be curved so that the distance from the outer periphery of the roller holder 208 increases as it moves away from the handing position. In this case, the outer periphery of the roller holder 208 can be considered to be, for example, the position through which the part of the roller holder 208 farthest from the central axis passes as the roller holder 208 rotates.

[0036] In contrast, in this example, the convex portion 312 on the inner surface 302 has a surface that becomes farther from the central axis as it moves away from the stroke position, and thus protrudes toward the outer surface 304. In this case, for example, as shown in the figure, it can be considered that at least a part of the surface that is closer to the stroke position among the surfaces that constitute the convex portion 312 becomes farther from the central axis as it moves away from the stroke position. It can also be considered that the convex portion 312 includes, for example, a portion that approaches the outer periphery of the roller holder 208 as it moves away from the stroke position. With this configuration, for example, the convex portion 312 can be appropriately formed on the inner surface 302. Also, in this case, it can be considered that the guide groove 300 in the tube pump 200 of the reference example is curved so as to become closer to the central axis as it moves away from the stroke position over the entire inner surface 302.

[0037] In this example, while the roller holder 208 rotates in the normal direction, the roller holder 208 holds the shaft of the roller 206 between the rear end position of the guide groove 300 and the protrusion 312 by the guide groove 300 having the protrusion 312. As a result, the roller holder 208 holds the roller 206 at the rear end position of the guide groove 300 even while the roller 206 is separated from the tube 202 in the non-contact section after passing the stroke section. In this configuration, for example, the roller 206 can be appropriately prevented from moving to the retreat position of the guide groove 300 during normal rotation. Also, as a result, even if the roller 206 receives a force from the tube 202 in a direction away from the stroke position of the guide groove 300, the roller 206 that has jumped out of the stroke position can be more appropriately and reliably prevented from colliding with the opposite end of the guide groove with force. Also, as a result, for example, it is possible to appropriately prevent a loud hitting sound caused by the collision between the wall surface of the guide groove 300 and the roller 206. Therefore, according to this embodiment, for example, it is possible to appropriately provide a highly quiet tube pump 200. Furthermore, by using such a tube pump 200 in the printing device 100 (see FIG. 1), for example, it is possible to appropriately provide a highly quiet printing device 100.

[0038] Here, in this example, the operation of holding the shaft of the roller 206 by the guide groove 300 during forward rotation can be considered to be, for example, holding the shaft of the roller 206 on one end side of the guide groove 300 regardless of whether the roller 206 is in contact with the tube 202. As can be understood from the matters described above, the convex portion 312 can be formed, for example, so as not to interfere with the function of the guide groove 300 and so that the shaft of the roller 206 does not move beyond the convex portion 312 to the retracted position side during forward rotation. In addition, when the function of the convex portion 312 is considered more generally, it can be considered to be, for example, reducing the momentum of the roller 206 jumping out from the stroke position. In this case, reducing the momentum of the roller 206 can be considered to be, for example, reducing the momentum of the roller 206 compared to the case of using a guide groove 300 without the convex portion 312. The use of the guide groove 300 without the convex portion 312 can be considered to be, for example, the use of the guide groove 300 corresponding to the configuration in which the convex portion 312 is removed from the guide groove 300 in the tube pump 200 of this example. The guide groove 300 corresponding to the configuration in which the convex portion 312 is removed can be considered to be, for example, the same or similar guide groove 300 as the guide groove 300 in the tube pump 200 of the reference example. In addition, the guide groove 300 corresponding to the configuration in which the convex portion 312 is removed can be considered to be, for example, the use of an inner surface 302 that is smoothly curved in a state in which the convex portion 312 is removed, as shown by the dashed line in the right-hand drawing of FIG. 3(b).

[0039] In this example, the convex portion 312 is formed in the vicinity of the stroke position between the stroke position and the retreat position in the guide groove 300, as shown in the figure, for example. In this case, the convex portion 312 can be formed so as to come into contact with the roller 206 at the timing when the roller 206, having passed through the stroke section, leaves the tube 202. The contact of the convex portion 312 with the roller 206 can be considered, for example, as the contact of the convex portion 312 with the shaft of the roller 206. The timing when the roller 206, having passed through the stroke section, leaves the tube 202 can be considered, for example, as the timing when the roller 206 moves from the stroke section to the non-contact section due to the rotation of the roller holder 208. The timing when the roller 206 moves from the stroke section to the non-contact section can be considered, for example, as the timing including the timing immediately before the roller 206 leaves the tube 202. In the case of the tube pump 200 of this example, immediately before the roller 206 leaves the tube 202, the roller 206 is in contact with the tube 202 near the end of the arc-shaped portion of the tube 202. In this case, when the roller 206 passes through the stroke section, the roller 206 leaves the tube 202 by coming to a position other than the curved portion of the tube 202. Also, it is considered that the portion of the tube 202 in contact with the roller 206 gradually expands from a crushed state as the roller 206 moves. In this case, the gradual expansion of the tube 202 immediately before the roller 206 leaves the tube 202 can be considered as, for example, the tube 202 being gradually less crushed at the position in contact with the roller 206 due to the movement of the roller 206, compared to the state in which the tube 202 is most crushed in the stroke section.

[0040] In this case, the convex portion 312 on the inner surface 302 of the guide groove 300 can be considered to come into contact with the roller 206 that is being pushed by the gradually expanding tube 202 and is about to move away from the stroke position when the tube 202 and the roller 206 are in contact with each other. The convex portion 312 comes into contact with the roller 206 that is receiving the elastic force of the gradually expanding tube 202, and thereby prevents the shaft of the roller 206 from moving beyond the convex portion 312 to the waiting position side, that is, forward of the convex portion 312 in the guide groove 300 during forward rotation of the tube pump 200, at the timing when the roller 206 moves away from the tube 202. As a result, when the roller 206 passes through the stroke section due to the rotation of the roller holder 208 during forward rotation, the convex portion 312 prevents the roller 206 that is receiving a force from the tube 202 in the direction away from the stroke position from moving beyond the convex portion 312. With this configuration, for example, when the tube pump 200 rotates in the forward direction, the shaft of the roller 206 can be appropriately held between the stroke position in the guide groove 300 and the protrusion 312. Therefore, according to this example, for example, it is possible to prevent the roller 206 from colliding with the wall surface of the guide groove 300 at the retreat position. This also makes it possible to more appropriately prevent, for example, the generation of loud hitting noises due to the collision between the wall surface of the guide groove 300 and the roller 206.

[0041] In this case, the convex portion 312 can be considered to restrict the movement of the roller 206, for example, at the timing when the roller 206 separates from the tube 202. The convex portion 312 can also be considered to hold down the roller 206, for example, until the tube 202 expands.

[0042] In addition, the tube pump 200 may also perform a reverse rotation operation in which the roller holder 208 rotates in the opposite direction to that during forward rotation. In the case of the tube pump 200 of this example, during reverse rotation, the roller holder 208 holds the shaft of the roller 206 on the retreat position side of the convex portion 312 in the guide groove 300. In this case, the retreat position side in the guide groove 300 can be considered to be, for example, the other end side opposite to one end side that holds the shaft of the roller 206 during forward rotation. With this configuration, for example, the roller holder 208 can be appropriately reversed while appropriately retreating the roller 206 to a position where it does not contact the tube 202.

[0043] 2 and 3, the tube pump 200 may further include, for example, an elastic member that comes into contact with the roller 206 when the roller holder 208 rotates. The elastic member moves the roller 206 backward in the rotation direction by coming into contact with the roller 206 that moves in the rotation direction of the roller holder 208. As a result, the elastic member moves the roller 206 to a stroke position when the tube pump 200 rotates forward, and moves the roller 206 to a retracted position when the tube pump 200 rotates reverse. As such an elastic member, a member that is the same as or similar to an elastic member used in a known tube pump can be suitably used.

[0044] Next, supplementary explanations of the configuration described above and modified examples will be given. As can be understood from the above explanation, the shape of the convex portion 312 of the guide groove 300 is not limited to the shape specifically shown in Fig. 3 and can be modified in various ways as long as the shape can appropriately prevent loud hitting sounds from being generated due to collision between the wall surface of the guide groove 300 and the roller 206. In this case, it is preferable to determine the shape and arrangement of the convex portion 312 according to the characteristics such as the size and elasticity of the tube 202 (see Fig. 3), for example.

[0045] In this regard, when considering the point of preventing the roller 206 from moving beyond the convex portion 312, it is considered preferable to form the convex portion 312 in a large size or a convex portion 312 with a high protruding height. However, in this case, backflow of liquid is likely to occur during reverse rotation. More specifically, as described above, during reverse rotation, for example, the roller 206 moves from the stroke position to the retracted position as the roller holder 208 rotates. However, when the size of the convex portion 312 is large, it becomes difficult for the roller 206 to move from the stroke position to the retracted position, and a small amount of liquid is likely to backflow.

[0046] Therefore, it is preferable to determine the shape of the convex portion 312 while taking into consideration the appropriate prevention of such backflow. In this case, for example, it is considered to determine the position and shape of the convex portion 312 so that the amount of backflow that occurs falls within a preset allowable range. More specifically, the height of the convex portion 312 is considered to be, for example, a height that does not interfere with the movement of the roller 206 that moves from the stroke position to the retreat position during reverse rotation. In this case, not interfering with the movement of the roller 206 can be considered to be, for example, that the problematic backflow of liquid is not caused by the influence of the convex portion 312. In addition, in order to prevent the backflow of liquid during reverse rotation, for example, it is considered to make the width of the guide groove 300 at the position of the convex portion 312 wider than other parts. In this case, for example, it is considered to increase the width of the guide groove 300 at the position of the convex portion 312 by making the amount of recession of the recess 314 larger than the height of the protrusion of the convex portion 312.

[0047] As can be understood from the above description, it is considered that the tube 202 is used by appropriately switching between forward and reverse rotation. Then, at the timing of switching from forward to reverse and from reverse to forward, the roller 206 moves over the convex portion 312 in the guide groove 300. For this reason, it is considered preferable that the guide groove 300 and the convex portion 312 are shaped so that the roller 206 is held at the rear end side in the rotation direction of the roller holder 208 during forward and reverse rotation, and the roller 206 moves over the convex portion 312 when the rotation direction of the roller holder 208 is changed. With this configuration, the tube pump 200 can be made to appropriately perform forward and reverse rotation.

[0048] In this example, the roller 206 in the retreat position during reverse rotation is not in contact with the tube 202 and is therefore not subjected to the elastic force of the tube 202. In this case, it can be considered that preventing the roller 206 from moving by the convex portion 312 is particularly important during forward rotation of the tube pump 200. For this reason, the convex portion 312 can be formed, for example, in a shape in which the inclination of the stroke position side (one end side) is greater than the inclination of the retreat position side (the other end side). In this case, the inclination of the stroke position side being greater than the inclination of the retreat position side can be considered to be, for example, the maximum inclination of the stroke position side and the retreat position side, respectively. With this configuration, for example, it is possible to more reliably prevent the roller 206 from moving beyond the convex portion 312 during forward rotation, and to allow the roller 206 to move more appropriately beyond the convex portion 312 when switching from reverse rotation to forward rotation.

[0049] 3, the guide groove 300 may be formed, for example, as a through hole penetrating the roller holder 208 formed as an integral part. In this case, the wall surfaces of the guide groove 300, such as the inner surface 302 and the outer surface 304, may be formed, for example, from the same material as that constituting the roller holder 208. In contrast, in a modified example of the configuration of the guide groove 300, for example, as shown in FIG. 4(a), the protrusion 312 may be formed from a separate member that is added later.

[0050] 4 and 5 are diagrams for explaining modified configurations of the guide groove 300. FIGS. 4(a) to (c) and 5(a) to (c) show various modified configurations of the guide groove 300. In the modified configuration shown in FIG. 4(a), the convex portion 312 is formed by a convex member 402 that is attached later. In this case, for example, it is considered that after a through hole corresponding to a part other than the convex portion 312 in the guide groove 300 is formed in the roller holder 208 (see FIG. 3), the convex member 402 is attached to a predetermined position of the through hole. Even in such a configuration, for example, the function of the convex portion 312 described above can be appropriately realized. In addition, in this case, by forming the convex portion 312 by the convex member 402, for example, the convex portion 312 of various shapes can be more easily and appropriately formed. In addition, this also makes it possible to adjust the characteristics of the convex portion 312 in various ways. For example, a rubber member made of rubber can be suitably used as the convex member 402. In addition, the convex member 402 may be made of various materials other than rubber. In this case, for example, an elastic material or a material with higher shock-absorbing properties than the material constituting the wall surface of the guide groove 300 other than the convex portion 312 may be used. The material with higher shock-absorbing properties may be, for example, a material that is more likely to absorb shock when colliding with another member. With this configuration, for example, even when the shaft of the roller 206 collides with the convex portion 312, the impact of the collision can be appropriately reduced. In addition, the convex member 402 may be made of the same material as the material constituting the wall surface of the guide groove 300 other than the convex portion 312.

[0051] In the above, the configuration in which the recess 314 is formed to match the shape of the protrusion 312 has been mainly illustrated and described. In contrast, the shape of the recess 314 may be other than the same as that of the protrusion 312. In this case, the fact that the shape of the recess 314 is the same as that of the protrusion 312 can be considered to mean, for example, that the surface constituting the convex shape of the protrusion 312 and the surface constituting the concave shape of the recess 314 are the same. More specifically, the recess 314 may be formed in a shape different from that of the protrusion 312, for example, as shown in FIG. 4(b). In this case, the recess 314 may be formed in a shape that is easier to process than the same shape as that of the protrusion 312. For example, as shown in FIG. 4(b), when the protrusion 312 having a curved surface is formed, the recess 314 having a flat surface may be formed. In addition, the recess 314 may be formed in a range wider than the range facing the protrusion 312, for example, as shown in FIG. 4(b). In the above, the configuration for forming the convex portion 312 having a curved surface has been mainly illustrated and described. With this configuration, for example, the convex portion 312 having various shapes can be appropriately formed. In addition, this makes it possible to appropriately form the convex portion 312 having a shape that makes it difficult for the roller 206 to move toward the retracted position side from the convex portion 312 during normal rotation, and makes it easy for the roller 206 to move beyond the convex portion 312 when the direction of rotation of the roller holder 208 is changed. In contrast, depending on the quality required for the tube pump 200, it is also possible to form the convex portion 312 having a flat surface, for example, as shown in FIG. 4(c). With this configuration, for example, the processing of the convex portion 312 can be more easily performed.

[0052] In the above, the position of the convex portion 312 is mainly illustrated and described as being slightly away from the rear end of the guide groove 300 during forward rotation. In this case, the position of the convex portion 312 may be set to a position where the shaft of the roller 206 can be held between the convex portion 312 and the rear end position of the guide groove 300. More specifically, the position of the convex portion 312 may be set to a position where the distance between the convex portion 312 and the rear end position of the guide groove 300 is equal to or greater than the width of the shaft of the roller 206. With this configuration, for example, it is possible to appropriately prevent the influence of the convex portion 312 on the roller 206 held in the stroke position. In this case, the distance between the convex portion 312 and the rear end position of the guide groove 300 may be considered to be, for example, the distance between the part of the inner surface 302 that rises up compared to other parts due to the presence of the convex portion 312 and the rear end position of the guide groove 300, or the like. This distance can also be considered as, for example, the distance between the bottom position of the convex portion 312 that starts to rise in the direction away from the central axis of the roller holder 208 and the rear end position of the guide groove 300 .

[0053] In contrast, in a modified configuration of the guide groove 300, for example, as shown in FIG. 5(a), a convex portion 312 may be formed so as to protrude from a position closer to the rear end of the guide groove 300 toward the outer surface 304. In this case, for example, as shown by a dashed line in the figure, a virtual position smoothly connected to a portion constituting the retreat position side on the inner surface 302 may be considered to be the convex portion 312, and the portion protruding from this position toward the outer surface 304 may be considered to be the convex portion 312. In this case, for example, in a state in which the shaft of the roller 206 is held between the apex of the convex portion 312 and the rear end position of the guide groove 300 during normal rotation, the shaft of the roller 206 may be considered to be held between the rear end position of the guide groove 300 and the convex portion 312. Even when such a convex portion 312 is formed, for example, by forming the convex portion 312 so that the shaft of the roller 206 is held between the rear end position of the guide groove 300 and the convex portion 312 during normal rotation, it is possible to appropriately prevent a loud hitting sound from being generated due to a collision between the wall surface of the guide groove 300 and the roller 206. In the case of the modified example shown in FIG. 5(a), similarly to the configuration described above, for example, the portion having a surface that becomes farther from the central axis as it moves away from the stroke position can be considered as the convex portion 312.

[0054] In addition, when the characteristics of the convex portion 312 are considered in this way, it can be considered that the convex portion 312 is formed, for example, in the guide groove 300 shown in FIG. 5(b). More specifically, in the modified example shown in FIG. 5(b), the guide groove 300 has a bent portion 316 in which the inner surface 302 and the outer surface 304 are bent. In addition, it can be considered that a part of the inner surface 302 becomes a surface that becomes farther from the central axis as it moves away from the stroke position. Therefore, in this case, it can also be considered that the guide groove 300 has the convex portion 312. In addition, even in this configuration, for example, by forming the convex portion 312 so that the axis of the roller 206 is held between the rear end position of the guide groove 300 and the convex portion 312 during forward rotation, it is possible to appropriately prevent, for example, a loud hitting sound caused by the collision between the wall surface of the guide groove 300 and the roller 206.

[0055] As described above, for example, the guide groove 300 having the configuration shown in FIG. 5(b) can also prevent the generation of loud hitting sounds due to the collision between the wall surface of the guide groove 300 and the roller 206. However, in this case, the presence of the convex portion 312 may affect the entire inner surface 302 and the outer surface 304, making it difficult to design the shape of the guide groove 300. Therefore, it is preferable that the convex portion 312 is shaped so that a part of the inner surface 302 protrudes, for example, as in the configuration shown in FIG. 3 and FIG. 4. It is also preferable that the convex portion 312 is formed so as not to affect the roller 206 in the stroke position. Therefore, it is more preferable that the convex portion 312 is formed at a position away from the rear end of the guide groove 300, as in the configuration shown in FIG. 3 and FIG. 4.

[0056] In the above, the configuration in which the convex portion 312 is formed at a position close to the rear end of the guide groove 300 during normal rotation has been mainly described. In contrast, from the viewpoint of reducing the momentum of the roller 206 before it reaches the retracted position, it is also possible to form the convex portion 312 at a position closer to the retracted position, as shown in FIG. 5(c), for example. More specifically, for example, in the guide groove 300 having the configuration shown in FIG. 3 and FIG. 4, it can be considered that the convex portion 312 is formed at a position closer to the rear end (rear end during normal rotation) of the guide groove 300 than the front end (front end during normal rotation) of the guide groove 300. In contrast, for example, in the guide groove 300 shown in FIG. 5(c), it can be considered that the convex portion 312 is formed at a position closer to the front end than the rear end of the guide groove 300, that is, at a position closer to the retracted position. In this case, it is also possible to form the convex portion 312 at a position away from the retracted position at the front end of the guide groove 300 so that the convex portion 312 and the roller 206 come into contact with each other before the roller 206 reaches the retracted position.

[0057] Here, when the convex portion 312 is formed as shown in FIG. 5(c), at the timing when the roller 206 leaves the stroke section and enters the non-contact section due to the rotation of the roller holder 208 during forward rotation, for example, the roller 206, which has left the tube 202, moves toward the waiting position, and the roller 206 collides with the convex portion 312 during the movement. In this case, it is considered that the collision between the convex portion 312 and the roller 206 generates a hitting sound. However, even in this case, it is possible to make the hitting sound generated when the roller 206 comes into contact with the convex portion 312 smaller than the hitting sound generated when the front end of the guide groove 300 and the roller 206 collide with each other when the convex portion 312 is not formed. More specifically, for example, when the front end of the guide groove 300 and the roller 206 collide with each other without the convex portion 312 being formed, the roller 206 collides with the wall surface of the guide groove 300 in a state where the roller 206 moves almost straight, generating a loud hitting sound. On the other hand, when the convex portion 312 and the roller 206 come into contact with each other before the roller 206 reaches the waiting position, the impact at the time of collision can be reduced by, for example, inclining the surface constituting the convex portion 312 with respect to the moving direction of the roller 206. This can also appropriately prevent, for example, a loud hitting sound from being generated. In this case, it is preferable to form the convex portion 312 so that the roller 206 does not move beyond the convex portion 312 during normal rotation. It is also possible to form the convex portion 312 in a shape that causes the roller 206 to move beyond the convex portion 312. In this case, it is possible to form the convex portion 312 so that, for example, the movement of the roller 206 is not completely stopped when the roller 206 comes into contact with the roller 206, but the momentum of the movement of the roller 206 is reduced. Even when configured in this way, for example, the volume of the hitting sound generated when the convex portion 312 and the roller 206 come into contact with each other can be appropriately reduced. In this case, by using the convex portion 312 to reduce the momentum of the movement of the roller 206, even if the wall surface of the guide groove 300 subsequently collides with the roller 206 at the front end of the guide groove 300, the volume of the impact sound caused by this collision can be appropriately reduced.

[0058] Furthermore, from the perspective of reducing the momentum of roller 206 before it reaches the retracted position, in a further modified example of guide groove 300, even if convex portion 312 is formed in a position closer to the rear end of guide groove 300 during forward rotation, it is also possible to form convex portion 312 in a shape that causes roller 206 to move over convex portion 312 at the timing when roller 206 leaves the stroke section and enters the non-contact section. In this case as well, by reducing the momentum of the movement of roller 206 by convex portion 312, it is possible to appropriately prevent the generation of loud hitting sounds compared to, for example, a case in which convex portion 312 is not formed.

[0059] In the above, the configuration of the printing device 10 (see FIG. 1) has been mainly described in terms of the case where ink is ejected onto a medium. In this case, the printing device 10 can be considered as an inkjet printer or the like that draws a two-dimensional image on a medium. In contrast, in a modified example of the configuration of the printing device 10, it is also possible to use a 3D printer (3D printing device) or the like that forms a three-dimensional object as the printing device 10. In this case as well, by using the tube pump 200 described above, it is possible to appropriately provide, for example, a printing device 100 that is highly quiet. [Industrial Applicability]

[0060] The present invention can be suitably used in, for example, a tube pump. [Explanation of symbols]

[0061] 100 printing device, 102 inkjet head, 104 platen, 106 main tank, 108 ink supply path, 110 carriage, 112 scan drive unit, 114 maintenance unit, 120 control unit, 152 capping unit, 200 tube pump, 202 tube, 204 frame, 206 roller, 208 roller holder, 300 guide groove, 302 inner surface, 304 outer surface, 312 convex portion, 314 concave portion, 316 bent portion, 402 convex member, 50 medium

Claims

1. A tube pump that uses an elastic tube to send a fluid, The tube through which the fluid passes; a roller that moves while squeezing the tube along a portion of a flow path through which the tube transports the fluid, thereby pushing out the fluid inside the tube; a roller holder which is a member for moving the roller while holding the axis of the roller, and which rotates the roller around a predetermined central axis so that the roller repeatedly passes along a path along the partial section; Equipped with a guide groove is formed in the roller holder, the guide groove being a groove through which a shaft of the roller passes to define a range in which the roller can move relative to the roller holder, the guide groove having one end side on a rear side and the other end side on a front side in a moving direction in which the roller moves along the partial section in a direction in which the fluid is pushed out, The roller holder has a surface that constitutes the guide groove, an inner surface that guides the movement of the shaft of the roller on a side closer to the central axis than the shaft of the roller; an outer surface which faces the inner surface across the axis of the roller; having While moving the roller along the partial section, a shaft of the roller is held at a rear end position that is a rear end position in the moving direction of the guide groove; The inner surface has a protrusion protruding toward the outer surface, a range of movement of the roller that rotates around the central axis in a direction in which the fluid is pushed out includes a stroke section in which the roller moves while squeezing the tube, and a non-contact section in which the roller does not come into contact with the tube, Immediately before the timing at which the roller separates from the tube, the portion of the tube in contact with the roller gradually expands from a crushed state as the roller moves, and the roller approaches the convex portion on the inner surface from a state in which it is not in contact with the convex portion, thereby coming into contact with the convex portion, A tube pump characterized in that the convex portion on the inner surface comes into contact with the roller as it is pushed by the tube which gradually expands while the tube and the roller are in contact, thereby preventing the roller from moving toward the other end in the guide groove beyond the convex portion.

2. A tube pump that uses an elastic tube to send a fluid, The tube through which the fluid passes; a roller that moves while squeezing the tube along a portion of a flow path through which the tube transports the fluid, thereby pushing out the fluid inside the tube; a roller holder which is a member for moving the roller while holding the axis of the roller, and which rotates the roller around a predetermined central axis so that the roller repeatedly passes along a path along the partial section; Equipped with a guide groove is formed in the roller holder, the guide groove being a groove through which a shaft of the roller passes to define a range in which the roller can move relative to the roller holder, the guide groove having one end side on a rear side and the other end side on a front side in a moving direction in which the roller moves along the partial section in a direction in which the fluid is pushed out, The roller holder has a surface that constitutes the guide groove, an inner surface that guides the movement of the shaft of the roller on a side closer to the central axis than the shaft of the roller; an outer surface which faces the inner surface across the axis of the roller; having While moving the roller along the partial section, a shaft of the roller is held at a rear end position that is a rear end position in the moving direction of the guide groove; The inner surface has a protrusion protruding toward the outer surface, the portion of the tube in contact with the roller gradually expands from a crushed state as the roller moves, and the roller moves from a state in which it is not in contact with the convex portion on the inner surface to a state in which it approaches the convex portion, thereby coming into contact with the convex portion; A tube pump characterized in that the convex portion on the inner surface comes into contact with the roller as it is pushed by the tube which gradually expands while the tube and the roller are in contact, thereby preventing the roller from moving toward the other end in the guide groove beyond the convex portion.

3. The tube is arranged so that at least a portion of the tube is curved in an arc shape, the roller holder rotates about the central axis determined in accordance with the arc-shaped portion of the tube while holding the shaft of the roller by the guide groove, thereby causing the roller to rotate about the central axis; At the timing when the roller has passed through the partial section, the roller is separated from the tube, 3. The tube pump according to claim 1, wherein the roller holder holds the shaft of the roller between the rear end position of the guide groove and the convex portion while the roller holder rotates in a direction in which the fluid is pushed out.

4. 4. The tube pump according to claim 3, wherein, during reverse rotation in which the roller holder is rotated in a direction opposite to a direction in which the fluid is pushed out, the roller holder holds the shaft of the roller on the other end side of the convex portion in the guide groove.

5. 5. The tube pump according to claim 4, wherein the inclination of the one end side of the convex portion is greater than the inclination of the other end side.

6. 6. The tube pump according to claim 1, wherein the outer surface has a recess, which is recessed in a direction away from the inner surface, at a position facing the protrusion on the inner surface.

7. A printing apparatus that performs printing by an inkjet method using the tube pump according to any one of claims 1 to 6, An inkjet head that ejects ink; an ink container for storing ink to be supplied to the inkjet head; an ink supply path for supplying ink from the ink container to the inkjet head using the tube pump; A printing device comprising:

8. A printing device that performs printing using an inkjet method, An inkjet head that ejects ink; a maintenance unit that performs maintenance on the inkjet head; Equipped with 7. A printing apparatus, wherein the maintenance unit has the tube pump according to claim 1, and uses the tube pump to suck ink from the inkjet head.

Images