JP2003206870A - Tube pump and ink jet recording device using the tube pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tube pump increasing a sucking efficiency. <P>SOLUTION: A flexible tube 51 is disposed in an arc shape along a tube support surface 52 and sequentially pressed down by receiving a pressing by a roller 43 to produce a negative pressure. Elastic recovering bodies 60 having an outside curvature smaller than that of a cross section orthogonal to the longitudinal direction of the tube are formed in the tube 51 integrally with each other along the longitudinal direction of the tube. These elastic recovering bodies 60 act so as to recover the tube to an original shape immediately after receiving the pressing by the roller 43. Thus, the tube pump increasing the sucking efficiency by the presence of the elastic recovering bodies 60 is provided. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube pump which sequentially presses flexible tubes arranged in an arc shape by rollers to generate pressure by utilizing the deformation of the tubes.
Also, the present invention relates to an ink jet recording apparatus equipped with this tube pump and provided with a maintenance means for the recording head that sucks and discharges ink from the recording head by utilizing the negative pressure generated by the tube pump.

[0002]

2. Description of the Related Art In an ink jet recording apparatus,
Due to the handling of liquid called ink, a maintenance process is performed to forcibly suck and eject ink from the print head when filling the print head with ink or to prevent clogging of the nozzle openings in the print head due to volatilization of the ink solvent. Is executed. Forcibly discharging ink to eliminate clogging of the recording head or when air bubbles remain in the recording head is called a cleaning operation, and printing is performed after a long pause of the recording device. Is restarted, or when the user recognizes a print quality defect such as print blur and operates a cleaning switch or the like.

In this cleaning operation, the recording head is sealed by the capping means and a negative pressure is applied so that the ink is sucked and discharged from the nozzle openings of the recording head and the ink discharged into the capping means is discharged. An operation is performed in which the nozzle forming surface of the recording head is wiped by a wiping member in which the rubber material is formed into a strip shape after being sent to the tank.

On the other hand, as a means for applying a negative pressure to the capping means, a so-called tube pump, which has a relatively simple structure and can be easily downsized, and which does not cause contamination in the mechanism for sucking and discharging ink, is often used. ing. This tube pump is equipped with a pressure roller that comes into pressure contact with the inner peripheral surface of a flexible tube arranged in an arc shape, and this roller sequentially pressurizes and deforms the tube to generate pressure inside the tube. Is done like this.

[0005]

By the way, in the above-mentioned tube pump, when this is used as the negative pressure generating means, the negative pressure generated by the restoring action of the flexible tube after the flexible tube is pressure-contacted by the pressure roller. You will use pressure. Therefore, a tube used for this purpose is desired to have a structure capable of immediately restoring its original shape against negative pressure after the pressure contact by the roller is released. For this reason, the tube used in this tube pump has a substantially circular original cross section made of, for example, silicone rubber, which is highly flexible and capable of exhibiting a certain degree of elastic restoring force. Tubes are often used.

However, in the above-mentioned tube pump, when the tube receives a negative pressure to some extent, the negative pressure causes a problem that the diameter is reduced and the suction efficiency is reduced. For this reason, when a tube material whose elastic restoring force is increased is used, the hardness of the tube is inevitably increased, so that it is necessary to increase the pressure contact force of the roller for closely contacting the inner diameter of the tube. Therefore, mechanical stress is further applied to a mechanical portion for driving the roller and abrasion of the tube is promoted, which causes another problem that durability of the tube pump is deteriorated.

The present invention has been made by paying attention to the above-mentioned problems, and the suction efficiency of the pump can be improved by making it possible to increase the restoring force of the tube used in the tube pump. It is an object of the present invention to provide a tube pump that can be used, and an object of the present invention is to provide an inkjet recording apparatus that can ensure a reliable maintenance operation of a recording head by using this tube pump. .

[0008]

SUMMARY OF THE INVENTION A tube pump according to the present invention made to achieve the above object is a pump frame having a tube support surface for restricting the outer shape of a flexible tube in an arc shape, and the pump. Pressure is generated inside the flexible tube arranged in an arc shape along the tube supporting surface of the frame and by sequentially pressurizing and deforming the flexible tube by contacting the inner peripheral surface of the flexible tube. A tube pump provided with a pressure roller for allowing the tube to be provided with an elastic restoration body having a smaller external curvature than the external curvature of a cross section orthogonal to the longitudinal direction of the tube. It is characterized in that it is integrally formed along.

In this case, it is possible to preferably employ a structure in which the elastic restoring body is formed along both side portions of the tube which is orthogonal to the direction in which the pressure roller is pressed. As a preferred form thereof, the outer shape of the cross section orthogonal to the longitudinal direction of the tube is elliptical. In another preferred embodiment, the outer shape of the cross section of the tube which is orthogonal to the longitudinal direction is oval.

On the other hand, a structure in which the elastic restoring body is formed along the inner peripheral surface of the tube with which the pressure roller is brought into pressure contact can be preferably employed. In this case, a plurality of elastic restoration bodies may be formed along the inner peripheral surface of the tube with which the pressure roller is in pressure contact.

Further, a structure in which the elastic restoring body is formed by a thick portion can also be suitably adopted. As a preferred form thereof, the thick portion is formed along the inner peripheral surface of the tube with which the pressure roller is in pressure contact. In this case, a plurality of the thick portions may be formed along the inner peripheral surface of the tube with which the pressure roller is in pressure contact, and along the both side portions of the tube orthogonal to the direction in which the pressure roller is in pressure contact. The thick portion may be formed in some cases.

In a preferred embodiment of the tube pump having the above-mentioned structure, the pressure roller is provided with respect to the pump wheel which is rotated by the power from the driving means, in the axial direction and the outer peripheral direction of the pump wheel. And a roller supporting groove formed with a gradient in the radial direction.

According to the tube pump constructed as described above, the elastic restoring body having a smaller external curvature than the external curvature of the cross section of the tube orthogonal to the longitudinal direction is formed. It works so as to effectively restore the tube to the original shape immediately after being pressed by the roller. In this case, in the configuration in which the elastic restoring bodies are formed along both side portions of the tube orthogonal to the direction in which the pressure roller is pressed (for example, the outer shape of the cross section is elliptical or oval), the left and right elastic restoring bodies are However, it exerts a so-called spring effect, and acts to effectively restore the elastic tube to its original shape.

Further, in the structure in which the elastic restoring body is formed along the inner peripheral surface of the tube with which the pressure roller is in pressure contact, along the inner peripheral surface of the tube with which the pressure roller is in contact with
In other words, the rib as a hard body is arranged, and the restoring force of the tube concentrates on the hard body portion, which acts to increase the restoring force of the tube.

Further, in the case where the elastic restoring body is a thick portion, the action of the rib as the hard body can be further promoted, and the restoring force of the tube is similarly increased. . Therefore, by adopting each of the above-mentioned means, it is possible to enhance the elastic restoring force of the tube, thereby improving the suction efficiency of the tube pump.

On the other hand, the ink jet recording apparatus according to the present invention seals the ink jet recording head for ejecting ink droplets corresponding to print data, the nozzle forming surface of the recording head, and the negative pressure from the pump unit. An ink jet recording apparatus including a capping unit that receives pressure and sucks ink from a recording head, wherein the tube pump having the above-described configuration is provided as a pump unit.

According to the above-mentioned recording apparatus, it is possible to contribute to downsizing of the entire apparatus by using the tube pump having a high suction efficiency, and it is possible to expect a reliable maintenance operation of the recording head. A high-precision printing operation can be assured throughout.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an ink jet recording apparatus using a tube pump according to the present invention will be described first, and later the characteristic points of the tube pump according to the present invention will be described. FIG. 1 is a perspective view showing the basic structure of an ink jet recording apparatus to which the present invention is applied. In FIG. 1, reference numeral 1 is a carriage,
The carriage 1 is configured to be guided by a guide member 4 via a timing belt 3 driven by a carriage motor 2 and reciprocally moved in the axial direction of the platen 5.

Although not shown in the figure, an ink jet type recording head is mounted on the surface of the carriage 1 facing the recording paper 6 (the lower side surface in this embodiment), and the recording head is provided on the upper side thereof. A black ink cartridge 7 for supplying ink and a color ink cartridge 8 are detachably mounted.

In the figure, reference numeral 9 is a capping means arranged in the non-printing area (home position), which rises when the recording head mounted on the carriage 1 moves directly above, and the nozzle forming surface of the recording head is raised. It is configured so that it can be sealed. And below the capping means 9,
A tube pump 10, which will be described later, is arranged to apply a negative pressure to the internal space of the capping means 9.

The capping means 9 functions as a cover for preventing the nozzle openings of the recording head from drying during the rest period of the recording apparatus, and also applies a drive signal unrelated to printing to the recording head to eject ink droplets. It also functions as an ink receiver during a flushing operation for idle ejection, and also has a function as a cleaning unit that causes a negative pressure from the tube pump 10 to act on the recording head to suck and discharge the ink from the recording head.

In the vicinity of the printing area side of the capping means 9, a wiping mechanism 11 is equipped with a wiping member, which will be described later, formed of an elastic plate of rubber or the like in a strip shape.
When the carriage 1 reciprocates toward the capping means 9 side, a wiping member can be advanced on the movement path of the recording head to wipe the nozzle forming surface of the recording head when necessary. It is configured.

FIG. 2 shows an example of a driving force transmission mechanism for a recording paper feeding / discharging mechanism and a suction pump, which is installed in the above-described recording apparatus. Reference numeral 21 denotes a paper feed roller. A gear 22 is arranged at one end of the paper feed roller 21 so that the gear 22 is driven by a pinion 24 arranged on the shaft of the paper feed motor 23 through an idler 25. It is configured.

A gear 27 is arranged at one end of the paper feed roller drive shaft 26, and the moving gear 2 constitutes a clutch mechanism.
It is configured to engage with the gear 22 via 8 and transmit power to a cut sheet feeder (not shown) to feed (load) a recording sheet.

The moving gear 28 constituting the clutch mechanism.
Is normally held by a spring (not shown) at a position away from both gears 22, 27 as shown in FIG. 2, and is pushed by the carriage 1 moving to the end portion facing the home position to move in the axial direction, The gears 22 and 27 are interposed so that the meshes of the two are connected.

On the other hand, the tube pump 10 includes the pinion 24 arranged on the paper feed motor 23 and the idler 2 which is connected to the pinion 24.
9 and the discharge roller gear 30, the discharge roller 3
It is driven by a gear 32 attached to the other end of 1. The drive shaft 33 of the tube pump 10 is provided with a gear 35 that meshes with a gear 32 attached to the other end of the paper discharge roller 31 via an idler 34.

A cleaner cam 38 having an arm 37 which is frictionally rotated by being pushed by a spring 36 arranged on the back surface of the shaft 33, on which the gear 35 is mounted, is attached in a freely rotatable manner. The wiping member 39 made of an elastic material such as rubber can be moved in the horizontal direction by rotation.

As a result, when the motor 23 rotates in one direction, the wiping member 39 advances into the movement locus of the recording head so that its nozzle forming surface can be wiped, and the motor 23 rotates in the other direction. As a result, the wiping member 39 acts so as to be retracted from the movement trajectory of the recording head.

A ratchet wheel 40, an intermediate transmission wheel 41, and a pump wheel 42 are mounted on the drive shaft 33 of the tube pump 10 in a stacked manner. A projection 40a is formed on the surface of the ratchet wheel 40 facing the intermediate transmission wheel 41.
Are formed with protrusions 41a and 41b on both sides,
Further, the pump wheel 42 is provided with a protrusion 42c on the surface facing the intermediate transmission wheel 41.

As a result, the ratchet wheel 40 is rotated, and the projection 40a thereof is projected on the projection 41 of the intermediate transmission wheel 41.
By contacting a, the rotational force is transmitted to the intermediate transmission wheel 41, and the protrusion 4 formed on the intermediate transmission wheel 41.
The rotation force is transmitted to the pump wheel 42 by the contact of the protrusion 1b with the protrusion 42c formed on the pump wheel 42. Therefore, the paper feed motor 23
When the rotation direction of is switched, a rotation delay mechanism that delays rotation transmission of up to two rotations is formed between the ratchet wheel 41 and the pump wheel 42.

As will be described later in detail, the pump wheel 42 is provided with a roller support groove formed with a radial gradient between the axial direction and the outer circumferential direction of the pump wheel. Then, by rotating the pump wheel 42 in one direction, the pressure rollers 43a, 43 supported by the shaft holes are provided.
b is biased toward the outer peripheral direction to pressurize a tube (not shown) against the tube support surface formed on the pump frame 44 to generate a suction action. Further, the rotation of the pump wheel 42 in the other direction causes the rollers 43a, 43
b is biased in the axial direction of the foil 42 so that the release action that does not pressurize the tube can be switched.

The rotation delay mechanism formed between the ratchet wheel 40, the intermediate transmission wheel 41, and the pump wheel 42 is used to position the leading edge of the sheet and to move it to the back when the recording sheet is loaded from the cut sheet feeder. In order to execute the rush removal, it is necessary to drive the paper feed motor 23 to some extent in the forward and reverse directions, and in this case, the suction pump 10 acts so as not to transmit power.

Next, FIGS. 3 and 4 are perspective views showing a tube pump 10 for applying a negative pressure to the internal space of the capping means 9 described above. Note that FIG. 3 shows a state in which the pump is driven in the forward direction to execute the pump action, and FIG. 4 shows a case in which the pump is driven in the reverse direction to be in the release state. In the pump frame 44 that forms the outer shell of this tube pump, a tube support surface 52 that regulates the outer shape of the flexible tube 51 in an arc shape.
Are formed over a range of approximately 180 degrees. Further, in the pump frame 44, a disc-shaped pump wheel 42 that is rotated by receiving power from the drive motor 23 is disposed.

In this pump wheel 42, a pair of roller support grooves 42a, 42b, each having a radial gradient between the axial direction and the outer circumferential direction of the pump wheel, are intended for the drive shaft of the wheel 42. It is formed in each position. Then, in the support grooves 42a and 42b, spindles of the pressure rollers 43a and 43b are housed so as to be movable and rotatable along the groove direction, respectively.

L-shaped locking grooves 44a and 44b are formed in the pump frame 44 at positions facing the tube support surface 52 formed in the pump frame 44. Further, guide members 53a and 53b formed of an elastic material are fitted into the respective locking grooves 44a and 44b, and the guide members 53a and 53b are respectively fitted.
Of the pump wheel 42 is projected in the axial direction of the pump wheel 42.

In such a tube pump, as shown in FIG. 3, the pump wheel 42 is rotated in the forward direction (arrow A direction) to guide the guide members 53a, 53.
By b, the rollers 43a and 43b supported by the support grooves 42a and 42b are guided so as to guide the rollers 43a and 43b in the retreating direction of the support grooves 42a and 42b. That is, as shown in FIG. 3, when the pump wheel 42 is rotationally driven in the direction of arrow A, the rollers 43a and 43b are relatively pushed back by the guide members 53a and 53b made of an elastic material. Each of them is moved in the outer peripheral direction of the roller support groove, and is pressed into contact with the inner peripheral surface of the tube 51 regulated in an arc shape, and is crushed in order.

As a result, a negative pressure is generated in the tube 51 to give a negative pressure to the capping means 9. Then, the ink is forcibly discharged from the recording head by a negative pressure, and the ink discharged into the capping means 9 is further sucked and sent to a waste liquid tank (not shown).

On the other hand, as shown in FIG.
Is rotated in the opposite direction (arrow B direction), the rollers 43a and 43b are pushed back by the guide members 53a and 53b. As a result, each roller moves in the inner peripheral direction of the roller support grooves 42a and 42b, and the outer peripheral surface of the roller maintains a release state in which the outer peripheral surface slightly contacts the inner peripheral surface of the tube 51 which is regulated in an arc shape. It is possible to prevent the occurrence of failures such as sticking on the inner surface.

Reference numeral 54 in FIGS. 3 and 4
Reference numerals a and 54b denote insertion openings of the roller support shafts, and when each of the roller support shafts is inserted into the insertion openings 54a and 54b at the time of assembling the tube pump, the support grooves 42a and 42b are respectively provided with Each is used to move a roller.

Next, FIGS. 5 to 17 show cross-sectional shapes of the tubes preferably used in the above-mentioned tube pump,
Also, the preferred arrangement relationship of the tubes will be described. Each of them shows a state in which the pressure roller 43 is pressure-bonded in the arrow direction from the inner peripheral surface side of the tube 51 arranged in an arc shape along the tube support surface 52. In addition,
Each of the states shown in FIGS. 5 to 17 shows a state in which the pressure roller 43 is slightly in contact with the inner peripheral surface side of the tube 51, that is, the original state of the tube 51.

In the embodiment shown in FIG. 5, the elastic restoration body 60 having a smaller external curvature than the external curvature of the cross section orthogonal to the longitudinal direction of the tube is integrally formed. An example is shown in which the pressure roller 43 is formed along both side portions of the tube 51 orthogonal to the direction in which the pressure roller 43 is pressed. That is, in the form shown in FIG. 5, the outer shape of the tube cross section is elliptical, and the inner surface shape of the tube is also elliptical, and the wall thickness is substantially uniform along the circumferential direction of the tube. Is configured.

According to the configuration shown in FIG. 5, the roller 43
The elastic restoration bodies 60 each having a small outer curvature formed along both side portions of the tube 51 orthogonal to the direction in which the pressure contacts each other exert a function as a so-called spring member,
It acts to effectively restore the tube to its original shape.
That is, even if a negative pressure is applied to the inside of the tube by the driving action of the pump, the presence of the elastic restoring bodies 60 formed on both sides of the tube and having a small outer curvature causes
Works to effectively expand the tube. As a result, it is possible to prevent the suction efficiency of the pump from decreasing due to the negative pressure and improve the suction efficiency.

Further, according to this structure, when the tube 51 is pressed against the roller 43, the outer peripheral surface of the tube 51 immediately contacts the tube supporting surface 52 over a wide area. Therefore, the tube 51 is laterally displaced on the tube support surface 52 as it is repeatedly pressed by the roller 43, and the degree of damage to the tube can be reduced by contacting the pump wheel 42, for example. it can.

Further, in the above-mentioned structure, when compared with a tube pump using a perfectly circular tube, when the tube is designed to have the same cross-sectional area, the dimension in the direction in which the roller 43 presses is shortened. Can be made. In other words, the flatness of the tubes arranged in an arc can be increased, which can contribute to the reduction in the outer diameter of the tube pump.

In the embodiment shown in FIG. 6, the elastic restoration body 60 having a smaller outer curvature than the outer curvature of the cross section orthogonal to the longitudinal direction of the tube is integrally formed. Another example is shown, which is formed along both side portions of the tube 51 orthogonal to the direction in which the pressure roller 43 is pressed. That is, the form shown in FIG.
The outer shape of the tube cross section is oval, and the inner surface of the tube is also oval, and its wall thickness is configured to be substantially uniform along the circumferential direction of the tube. . Also in the configuration shown in FIG. 6, it is possible to obtain the same effect as that of the configuration shown in FIG.

In the embodiment shown in FIG. 7, the elastic restoration body 60 having a smaller external curvature than the external curvature of the cross section orthogonal to the longitudinal direction of the tube is the inner peripheral surface of the tube with which the pressure roller 43 is pressed. The example formed along with is shown. That is, in the form shown in FIG. 7, the outer shape of the cross section of the tube is a substantially isosceles triangular shape with each corner portion being an arc, and the inner surface shape of the tube is also substantially two sides with each corner portion being an arc. It is shaped like an equilateral triangle. The wall thickness is configured to be substantially uniform along the circumferential direction of the tube. Further, the apex angle portion, that is, the external curvature of the portion where the pressure roller 43 is in pressure contact is formed smaller than other portions.

According to the structure shown in FIG. 7, since the elastic restoring body 60 is formed along the inner peripheral surface of the tube arranged in the arc shape with which the pressure roller 43 is in pressure contact, it is, so to speak, a hard body. Of the ribs, the restoring force of the tube concentrates on the hard body portion, which acts to increase the restoring force of the tube. Thereby, the suction efficiency of the pump can be improved.

Further, according to this structure, the outer peripheral surface of the tube 51 arranged in an arc shape is in contact with the tube supporting surface 52 over a wide area. Therefore, the tube 51 is laterally displaced on the tube support surface 52 as it is repeatedly pressed by the roller 43, and the degree of damage to the tube can be reduced by contacting the pump wheel 42, for example. it can.

In the embodiment shown in FIG. 8, the elastic restoring body 60 having a smaller outer curvature than the outer curvature of the cross section orthogonal to the longitudinal direction of the tube is the inner peripheral surface of the tube with which the pressure roller 43 is pressed. 2 shows another example formed along the line. That is, as shown in FIG. 8, the basic outer shape of the tube 51 is an elliptical shape, and two elastic restorations with a small outer curvature are formed on the inner peripheral surface of the tube with which the pressure roller 43 is pressed. A body 60 is formed. And
The wall thickness is configured to be substantially uniform along the circumferential direction of the tube.

According to the configuration shown in FIG. 8, since the two elastic restoration bodies 60 are arranged along the inner peripheral surface of the tube arranged in the arc shape with which the pressure roller 43 is brought into pressure contact,
This is, so to speak, a function of a rib as a hard body, and the restoring force of the tube concentrates on the hard body portion, which acts to increase the restoring force of the tube. Thereby, the suction efficiency of the pump can be improved.

Further, according to this structure, the outer peripheral surface of the tube 51 arranged in an arc shape is in contact with the tube supporting surface 52 over a wide area. Therefore, the tube 51 is laterally displaced on the tube support surface 52 as it is repeatedly pressed by the roller 43, and the degree of damage to the tube can be reduced by contacting the pump wheel 42, for example. it can.

In the embodiment shown in FIG. 9, the elastic restoration body 60 having a smaller external curvature than the external curvature of the cross section orthogonal to the longitudinal direction of the tube is provided on the inner peripheral surface of the tube with which the pressure roller 43 is pressed. 10 shows another example formed along the line. That is, as shown in FIG.
The basic outer shape of No. 1 is an elliptical shape, and three elastic restoration bodies 60 having a small outer curvature are formed on the inner peripheral surface side of the tube with which the pressure roller 43 is in pressure contact. The wall thickness is configured to be substantially uniform along the circumferential direction of the tube.

According to the structure shown in FIG. 9, the same effect as that of the structure shown in FIG. 8 can be obtained. Further, the flatness of the tubes 51 arranged in an arc can be increased as compared with the configuration shown in FIG. This can contribute to reducing the outer diameter of the tube pump.

Next, in each of the embodiments shown in FIGS. 10 to 17, the elastic restoration body 60 having a smaller outer curvature than the outer curvature of the cross section orthogonal to the longitudinal direction of the tube is
An example constituted by the thick portion 62 is shown.

First, the structure shown in FIG. 10 has a pressure roller 43.
The thick portion 62 is formed along the inner peripheral surface of the tube 51 which is pressed against. That is, as shown in FIG. 10, the basic outer shape of the tube 51 is an elliptical shape, and the inner surface shape of the tube is also an elliptical shape. Then, on the inner peripheral surface side of the tube with which the pressure roller 43 is in pressure contact, the elastic restoration body 6 having a small outer curvature is formed.
0 is constituted by the thick portion 62.

According to the configuration shown in FIG. 10, the thick portion 6
Since the elastic restoration body 60 constituted by 2 is arranged along the inner peripheral surface of the tube 51 arranged in an arc shape, this exhibits the same action as the rib as the hard body described above. Therefore, this can increase the elastic restoring force of the tube and improve the suction efficiency of the pump.

Further, according to the structure shown in FIG. 10, since the basic outer shape of the tube 51 is an elliptical shape, the degree to which the tube 51 laterally shifts on the tube supporting surface 52 is similar to the above-described operation. It can be low, and thus the degree to which the tube is damaged can be reduced.

In the structure shown in FIG. 11, an elastic restoring body 60 constituted by a thick portion 62 is formed along the inner peripheral surface of the tube 51 arranged in an arc shape with which the pressure roller 43 is in pressure contact. Shows the configuration of. That is, as shown in FIG. 11, the basic outer shape of the tube 51 is oval, and the inner surface shape of the tube is also oval. Then, on the inner peripheral surface side of the tube with which the pressure roller 43 is in pressure contact, each elastic restoration body 60 having a small outer curvature is formed by two thick-walled portions 62 parallel to each other along the longitudinal direction of the tube.

Also in the configuration shown in FIG. 11, FIG.
Similarly to the example shown in FIG. 6, the double-thickened portion 62 exhibits the same action as the rib as a hard body. Therefore, this can increase the elastic restoring force of the tube,
The suction efficiency of the pump can be improved. Further, since the basic outer shape of the tube 51 is an elliptical shape, it is possible to reduce the degree of lateral displacement of the tube 51 on the tube supporting surface 52, similarly to the above-described action, and similarly, the tube The degree of damage can be reduced.

In the structure shown in FIG. 12, an elastic restoration body 60 constituted by a thick portion 62 is formed along the inner peripheral surface of the tube 51 arranged in an arc shape with which the pressure roller 43 is in pressure contact. The other structure is shown. That is, as shown in FIG. 12, the basic outer shape of the tube 51 is circular in cross section, and the inner surface shape of the tube is also circular. An elastic restoration body 60 having a small outer curvature is formed by a thick portion 62 on the inner peripheral surface side of the tube with which the pressure roller 43 is pressed.

Therefore, also in the structure shown in FIG. 12, the thick portion 62 forming the elastic restoring body 60 exhibits the same action as the rib as the hard body. Thereby, the elastic restoring force of the tube can be increased and the suction efficiency of the pump can be improved.

The structure shown in FIG. 13 shows an example in which the elastic restoration body 60 having a small outer curvature is formed by the thick portion 62 along both side portions of the tube orthogonal to the direction in which the pressure roller 43 is pressed. There is. That is, as shown in FIG. 13, the basic outer shape of the tube 51 has an elliptical cross section, and is arranged such that its major axis is orthogonal to the pressure contact direction of the pressure roller. The inner surface of the tube 51 is also elliptical, and its major axis is in the pressure contact direction of the pressure roller. As a result, as described above, the thick portion 62 is formed along both side portions of the tube orthogonal to the direction in which the pressure roller 43 is pressed.
Is formed.

According to the configuration shown in FIG. 13, the pair of thick portions 62 exerts a spring effect, and acts so as to effectively restore the elastic tube 51 to the original shape. Thereby, the elastic restoring force of the tube can be increased and the suction efficiency of the pump can be improved.

In the structure shown in FIG. 14, the elastic restoring member 60 constituted by the thick portion 62 is formed along the inner peripheral surface of the tube 51 arranged in an arc shape with which the pressure roller 43 is in pressure contact. Is shown. That is, as shown in FIG. 14, the basic outer shape of the tube 51 is elliptical in cross section, and its major axis is arranged in the pressure contact direction of the pressure roller. The inner surface of the tube 51 is also elliptical, and its major axis is in a direction orthogonal to the pressure contact direction of the pressure roller. Thereby, as described above, the thick portion 62 is formed along the inner peripheral surface of the tube 51 arranged in the arc shape with which the pressure roller 43 is brought into pressure contact.

Therefore, also in the structure shown in FIG. 14, the thick portion 62 forming the elastic restoring body 60 exhibits the same action as the rib as the hard body described above. Therefore, this can increase the elastic restoring force of the tube and improve the suction efficiency of the pump.

The structure shown in FIG. 15 is another example in which the elastic restoration body 60 having a small outer curvature is formed by the thick portion 62 along both side portions of the tube orthogonal to the direction in which the pressure roller 43 is pressed. Shows. That is, as shown in FIG. 15, the basic outer shape of the tube 51 has an elliptical cross section, and is arranged such that its major axis is orthogonal to the pressure contact direction of the pressure roller. The inner surface of the tube 51 has a substantially perfect circular shape.
As a result, as described above, the thick portion 6 is formed along both side portions of the tube orthogonal to the direction in which the pressure roller 43 is pressed.
2 is formed.

Also in the structure shown in FIG. 15, the pair of thick portions 62 exert a spring effect, and the elastic tube 51
To effectively restore the original shape. Thereby, the elastic restoring force of the tube can be increased and the suction efficiency of the pump can be improved. Further, since the basic outer shape of the tube 51 is an elliptical shape, it is possible to reduce the degree to which the tube 51 laterally shifts on the tube supporting surface 52 as in the case of the above-described action, and thus the tube is damaged. It is possible to reduce the degree of receiving.

In the structure shown in FIG. 16, an elastic restoration body 60 constituted by a thick portion 62 is formed along the inner peripheral surface of the tube 51 arranged in an arc shape with which the pressure roller 43 is in pressure contact. The other structure is shown. That is, as shown in FIG. 16, the basic outer shape of the tube 51 is elliptical in cross section, and the inner surface shape of the tube is also elliptical. An elastic restoration body 60 having a small outer curvature is formed by a thick portion 62 on the inner peripheral surface side of the tube with which the pressure roller 43 is pressed.

Therefore, also in the configuration shown in FIG. 16, the thick portion 62 of the elastic restoring body 60 exhibits the same action as that of the rib as a hard body. Therefore, this can increase the elastic restoring force of the tube and improve the suction efficiency of the pump.
Further, since the basic outer shape of the tube 51 is an elliptical shape, it is possible to reduce the degree to which the tube 51 laterally shifts on the tube supporting surface 52 as in the case of the above-described action, and thus the tube is damaged. It is possible to reduce the degree of receiving.

In the structure shown in FIG. 17, two elastic restoring bodies 60 each having a thick portion 62 are formed along the inner peripheral surface of the tube 51 arranged in an arc shape with which the pressure roller 43 is pressed. Has been done. That is, as shown in FIG. 17, the basic outer shape of the tube 51 is elliptical in cross section, and the inner surface shape of the tube is elliptical.

Therefore, also in the structure shown in FIG. 17, the two thick-walled portions 62 forming the elastic restoring body 60 exhibit the same action as the rib as the hard body described above. Therefore, this can increase the elastic restoring force of the tube and improve the suction efficiency of the pump. Further, since the basic outer shape of the tube 51 is an elliptical shape, the tube 5 has the same function as described above.
The degree of lateral deviation of 1 on the tube supporting surface 52 can be reduced, and therefore, the degree of damage to the tube can be reduced.

The tube pump according to the present invention described above can be suitably used particularly as a maintenance means of the recording head in the ink jet recording apparatus as shown in FIG. However, the tube pump according to the present invention can be expected to improve the suction efficiency even when it is used for other devices, and its characteristics can be fully utilized.

[0073]

As is apparent from the above description, according to the tube pump of the present invention, the elastic restoring body having a smaller outer curvature than the outer curvature of the cross section of the tube orthogonal to the longitudinal direction of the tube is provided. Since it is integrally formed along the longitudinal direction, the suction efficiency can be improved. Further, according to the configuration in which this is adopted as the maintenance means of the recording head in the ink jet recording apparatus, a reliable maintenance operation of the recording head can be expected, so that a highly accurate printing operation can be guaranteed for a long period of time.

[Brief description of drawings]

FIG. 1 is a perspective view showing a basic configuration of an ink jet recording apparatus to which the present invention is applied.

2 is a plan view showing an example of a driving force transmission mechanism provided in the recording apparatus shown in FIG.

FIG. 3 is a perspective view showing a state in which the wheel of the tube pump according to the present invention is normally driven to perform a pump driving action.

FIG. 4 is a perspective view showing a case where the wheel is also driven in the reverse direction to be in a release state.

5 is a cross-sectional view showing a first example of a tube that can be suitably adopted in the tube pump shown in FIGS. 3 and 4. FIG.

FIG. 6 is a sectional view showing a second example of the same tube.

FIG. 7 is a cross-sectional view showing a third example of the same tube.

FIG. 8 is a sectional view showing a fourth example of the same tube.

FIG. 9 is a sectional view showing a fifth example of the same tube.

FIG. 10 is a sectional view showing a sixth example of the same tube.

FIG. 11 is a sectional view showing a seventh example of the same tube.

FIG. 12 is a sectional view showing an eighth example of the tube.

FIG. 13 is a sectional view showing a ninth example of the same tube.

FIG. 14 is a sectional view showing a tenth example of the same tube.

FIG. 15 is a sectional view showing an eleventh example of the tube.

FIG. 16 is a sectional view showing a twelfth example of the same tube.

FIG. 17 is a sectional view showing a thirteenth example of the tube.

[Explanation of symbols]

1 carriage 2 Carriage motor 6 recording paper 7,8 ink cartridge 9 Capping means 10 tube pump 11 Wiping means 21 Paper feed roller 23 Paper feed motor 31 Paper ejection roller 42 pump wheel 42a, 42b Roller support groove 43, 43a, 43b Pressure roller 44 pump frame 51 flexible tube 52 Tube support surface 60 Elastic restoration body 62 thick part

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) F04C 13/00 B41J 3/04 102R 15/00 (72) Inventor Hitoshi Hayakawa 3-3-5 Yamato, Suwa City, Nagano Prefecture Seiko Epson Corporation F-term (reference) 2C056 EA14 EC24 EC57 JA03 JA13 JB04 JC08 JC20 3H044 AA00 BB00 CC12 CC19 DD03 DD12

Claims (12)

[Claims] 1. A pump frame having a tube support surface that regulates the outer shape of the flexible tube in an arc shape, a flexible tube arranged in an arc shape along the tube support surface of the pump frame, and the flexible frame. A tube pump provided with a pressure roller for generating pressure inside the tube by sequentially pressurizing and deforming the tube by press-contacting the inner circumferential surface of the flexible tube, wherein the tube has a longitudinal length of the tube. A tube pump, wherein an elastic restoration body having a smaller outer curvature than that of a cross section orthogonal to the direction is integrally formed along the longitudinal direction of the tube. 2. The tube pump according to claim 1, wherein the elastic restoration body is formed along both side portions of the tube orthogonal to a direction in which the pressure roller is pressed. 3. The tube pump according to claim 2, wherein the outer shape of the cross section of the tube orthogonal to the longitudinal direction is elliptical. 4. The tube pump according to claim 2, wherein the outer shape of the cross section of the tube orthogonal to the longitudinal direction is oval. 5. The tube pump according to claim 1, wherein the elastic restoration body is formed along an inner peripheral surface of a tube with which the pressure roller is in pressure contact. 6. The tube pump according to claim 5, wherein a plurality of the elastic restoration bodies are formed. 7. The tube pump according to claim 1, wherein the elastic restoration body is constituted by a thick portion. 8. The tube pump according to claim 7, wherein the thick portion is formed along the inner peripheral surface of the tube with which the pressure roller is in pressure contact. 9. The tube pump according to claim 8, wherein a plurality of the thick portions are formed. 10. The tube pump according to claim 7, wherein the thick portion is formed along both side portions of the tube orthogonal to a direction in which the pressure roller is in pressure contact. 11. The pressure roller is formed with a radial gradient between the axial direction and the outer circumferential direction of the pump wheel, which is rotated by the power from the driving means. The tube pump according to any one of claims 1 to 10, which is supported by a roller support groove. 12. An ink jet recording head for ejecting ink droplets corresponding to print data, and a nozzle forming surface of the recording head are sealed, and ink is sucked from the recording head by receiving a negative pressure from a pump unit. An ink jet recording apparatus comprising: a capping unit, wherein the tube pump according to any one of claims 1 to 11 is provided as the pump unit.