JP2001328285A - Tube pump and ink jet recorder comprising it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small and highly efficient tube pump and an ink jet recorder comprising it. SOLUTION: A V-groove in which a metal ball 24 can roll is made in the upper surface of a tube press plate at a position closer to the drive shaft side than the center 25c of the cross-section of a tube 25.

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 pressurizes a tube and generates pressure by using the deformation of the tube, and a recording device using the tube pump and utilizing a negative pressure generated by the tube pump. The present invention relates to an ink jet recording apparatus provided with a means for recovering ink ejection ability for discharging ink from a head, and an ink jet recording apparatus provided with this pump as a means for supplying ink from a main tank to a sub tank.

[0002]

2. Description of the Related Art Ink-jet recording apparatuses have been used in many printings, mainly color printing, in recent years, since noise at the time of printing is relatively small and small dots can be formed at a high density. Such an ink jet recording apparatus includes an ink jet recording head that receives supply of ink from an ink cartridge, and a paper feeding unit that moves recording paper relative to the recording head, and the recording head responds to a print signal. Recording is performed by ejecting ink droplets on recording paper while moving the recording paper to form dots.

[0003] In the ink jet type recording apparatus, since the ink is treated as a liquid as described above, in order to prevent the recording head from being filled with the ink and to prevent the nozzle opening from being clogged by the evaporation of the ink solvent, the ink is discharged from the recording head. A recovery process of the ink discharge capability for forcibly sucking and discharging is executed. Such a process of forcibly discharging the ink for eliminating clogging of the recording head or when bubbles remain in the recording head is called a cleaning operation, and is performed after a long period of suspension of the recording apparatus. When resuming printing or when the user recognizes poor print quality such as blurred print,
This is executed when the cleaning switch is operated.

In this cleaning operation, the recording head is sealed by a capping means and a negative pressure is applied to discharge ink from the nozzle openings of the recording head and to apply a negative pressure to the ink discharged into the capping means. And send it to the waste ink tank, and then use a cleaning member made of an elastic plate such as rubber.
A sequence for wiping the nozzle plate of the recording head is executed. The means for applying a negative pressure in the capping means or supplying ink from the main tank to the sub tank is relatively simple in structure and easy to miniaturize, and does not cause contamination in the mechanism for sucking and discharging ink. A so-called tube pump is used. This tube pump will be specifically described with reference to FIG.

The tube pump 50 has a tube support surface 52 for regulating the outer shape of the flexible tube 51 into an arc shape.
, A pump wheel 42 that is rotated by power from, for example, a paper feed motor as a driving means, and is formed with a radial gradient between the axial direction and the outer peripheral direction of the pump wheel 42. Rollers 43a and 43b are provided in the pair of roller support grooves 42a and 42b so as to be movable and rotatable in the longitudinal direction of the support grooves 42a and 42b, respectively.

The pump wheel 4 is located at a position facing the tube support surface 52 formed on the pump frame 44.
A pair of guide members 53a and 53b made of an elastic material protruding in the axial direction of the second shaft are disposed.

That is, L-shaped locking grooves 44a and 44b are formed in the pump frame 44, and these locking grooves 44a and 44b are formed.
The guide members 53a and 53b are respectively implanted in 4b.

According to this structure, the pair of guide members 53a and 53b act to guide the respective rollers in the retreating direction of the support grooves as the pump wheel rotates. As shown in FIG. 6, when the wheel 42 is driven forward (rotation in the direction A), the rollers 43a and 43b are pushed back by the guide members 53a and 53b made of a flexible material, whereby the rollers 43a and 43b are pressed. Are moved in the outer peripheral direction of the roller supporting grooves 42a and 42b so that the tubes 51 are sequentially crushed. Thereby, the reliability of the driving action of the pump can be improved.

In such a tube pump, the rollers 43a, 43b are rotated by rotating the pump wheel 42 in the forward direction (the direction of arrow A) as shown in FIG.
Moves in the outer peripheral direction of the roller support grooves 42a and 42b,
The tube 51 is rotated while being sequentially crushed, thereby generating a pressure in the tube and applying a negative pressure to the capping means. Then, the ink is forcibly discharged from the recording head by the negative pressure, and the ink discharged into the capping means is further suctioned and sent to the waste ink tank.

Conversely, by rotating the pump wheel 42 in the opposite direction (the direction of arrow B), the rollers 43a and 43b are brought into contact with the roller support grooves 42a and 4b.
The roller moves in the inner circumferential direction of 2b, whereby the roller keeps a release state in which the roller is slightly in contact with the tube, so that a failure such as sticking of the tube can be prevented.

The tube pump is used as a means for restoring the ink discharge ability for discharging ink from the recording head as described above, and also supplies the ink from a main tank for storing ink to a sub-tank provided on the recording head side. It is used as a supply means for supplying.

That is, in an ink jet recording apparatus provided for office use or business use, it is necessary to provide a large-capacity ink cartridge in order to cope with a relatively large amount of printing. The main tank is loaded into a mounting device (cartridge holder) arranged on the side of the apparatus main body, for example. On the other hand, a sub-tank is arranged on the carriage on which the recording head is mounted, supplies ink from the main tank to the sub-tank via an ink supply tube, and supplies ink from the sub-tank to the recording head. It is configured as follows.

In this type of ink jet recording apparatus, the tube pump is used as an ink supply means from the main tank to the sub tank.

[0014]

As described above, in the conventional tube pump, the rollers rotate while sequentially crushing the tube, thereby generating a pressure in the tube to apply a negative pressure.

Therefore, after the roller has passed, the crushed tube is restored to the initial state by the elastic force (self-restoring force) of the flexible tube itself.

Therefore, the thickness (the difference between the outer diameter and the inner diameter) of the flexible tube is required to some extent. If the thickness of the flexible tube is small, the flexible tube lacks the restoring force and cannot obtain a predetermined suction force. There was a technical problem.

On the other hand, when the thickness of the flexible tube is large, there is a technical problem that the inner diameter of the flexible tube becomes small and a predetermined suction amount cannot be secured. In addition, if the inner diameter of the flexible tube is made constant, the outer diameter becomes larger, and there is a technical problem that the entire tube pump becomes larger, and accordingly, the ink jet recording apparatus itself becomes larger. There were challenges.

Furthermore, in the conventional tube pump, since the crushed tube is restored to its initial state by its own elastic force (self-restoring force), there is a technical problem that the material of the tube is limited. there were. That is,
A metal tube made of aluminum or the like has a low elasticity and cannot be used as a tube of a conventional tube pump.

Further, the elastic force (self-restoring force) of the tube itself becomes a reaction force at the time of crushing, which causes an increase in the crushing load, and thus a problem that the efficiency of the pump is reduced.

Furthermore, since the crushed tube returns to the initial state due to the elastic force (self-restoring force) of the flexible tube itself, it is necessary to sufficiently consider the sticking of the tube.

The present invention has been made in view of the above-mentioned conventional problems. The basic structure of the present invention is different from that of the conventional tube pump, and a tube having no self-restoring force can be used. It is an object of the present invention to provide a high-efficiency tube pump, and to provide an ink jet recording apparatus using the same.

[0022]

According to the present invention, there is provided a tube pump having a tube which is sequentially crushed by a rocking means and is restored to an initial state. A rotating disk fixed to the drive shaft and rotating integrally therewith,
A tube pressing plate formed so as to be swingable in opposition to the rotating disk, a rocking means for rocking the tube pressing plate by receiving a rotational movement of the rotating disk, and a lower surface of the tube pressing plate A tube having an upper wall fixed thereto and a lower wall fixed to a case, wherein the swinging means is movably fitted between the rotating disk and the upper surface of the tube pressing plate. A groove for fitting the ball is formed on the upper surface of the tube pressing plate, and the center of the groove is located closer to the drive shaft than the center of the cross section of the tube.

In the aspect of the invention, since the groove is configured to be located closer to the drive shaft than the center of the cross section of the tube, the force by which the tube pressing plate crushes the tube is:
The tube works evenly, and the tube can be closed evenly. Therefore, it is not necessary to crush the tube more than necessary, and the tube can be closed with a small amount of crushing and a small load, so that the driving torque of the pump can be reduced, and as a result, a highly efficient pump can be obtained.

Further, the inclination of the tube pressing plate can be reduced, and as a result, a small pump can be obtained.

In addition, in the ink jet recording apparatus according to the present invention, which has been achieved to achieve the above-described object, the apparatus itself is miniaturized by using the above-mentioned tube pump as a pump unit for sucking ink from a recording head. , And a highly efficient and stable suction operation can be performed.

The ink jet recording apparatus according to the present invention, which has been made to achieve the above-mentioned object, uses the above-described tube pump as a means for supplying ink from the main tank to the sub-tank. And a stable and efficient supply operation can be performed.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet recording apparatus using a tube pump as a means for restoring the ink discharge ability according to the present invention will be described based on the embodiment shown in the drawings. FIG. 1 shows the overall configuration of an ink jet recording apparatus to which the present invention is applied.

In FIG. 1, reference numeral 1 denotes a carriage,
The carriage 1 is configured to be reciprocated in the axial direction of a platen 5 while being guided by a guide member 4 via a timing belt 3 driven by a carriage motor 2.

An ink jet type recording head 7 is mounted on the side of the carriage 1 facing the recording paper 6, and a black ink cartridge 8 for supplying ink to the recording head and a color ink cartridge 9 are detachably mounted above the recording head. Loaded as possible.

In the drawing, reference numeral 10 denotes a capping means disposed in a non-printing area (home position), which rises when the recording head mounted on the carriage 1 moves right above, and which is formed on the nozzle forming surface of the recording head. Is configured to be sealed. A tube pump 1 described below as a pump unit for applying a negative pressure to the internal space of the capping unit 10 is provided below the capping unit 10.
1 is arranged.

The capping means 10 functions as a lid for preventing the nozzle openings of the recording head from drying during the idle period of the recording apparatus, and also applies a driving signal unrelated to printing to the recording head to remove ink droplets. It functions as an ink receiver at the time of a flushing operation for performing idle discharge, and also has a function as a cleaning unit that suctions ink by applying a negative pressure from the tube pump 11 to the recording head.

In the vicinity of the printing area side of the capping means 10, a wiping means 12 having an elastic plate such as rubber is arranged so as to be able to advance and retreat in the horizontal direction. When reciprocating to the side, the wiping member can advance on the moving path of the recording head.

Next, based on FIG.
And the relationship between the capping means 10 will be described. Figure
2 schematically shows the configuration of the capping unit 10 mounted on the recording apparatus shown in FIG. 1 and the tube pump 11 and the like connected thereto.

The capping means 10 includes a rectangular cap case 10a having an open upper surface, and a cap member 10b made of a flexible material such as a rubber material housed in the cap case 10a. 1
Ob is formed such that its upper edge slightly protrudes from the cap case 10a. And the cap member 10
b, an ink absorbing material 10c formed of a porous material is accommodated in an inner bottom portion of the ink absorbing material 10c.
Is a holder 10d formed integrally with the cap member 10b.
Is held by

In the lower part of the cap case 10a,
A suction port 10e and an atmosphere opening port 10f are formed so as to penetrate the cap case 10a and the cap member 10b, respectively. And cap case 1
A tube pump 11 is connected to the suction port 10e of the tube pump 0a via a tube T1.
Is connected to an ink absorbent housed in a waste ink tank 13 as described later. Further, an atmosphere opening valve 14 is connected to the atmosphere opening port 10f of the cap case 10a via a tube T2.

On the other hand, reference numeral 7 in FIG. 2 denotes a recording head. When the recording head 7 is located above the capping means 10 as the carriage moves, the nozzle forming surface 7a is sealed by the cap member 10b. It is configured to be stopped (capping). A plurality of nozzle openings 7b are formed in the nozzle forming surface 7a, and black ink and each of yellow, cyan, magenta, and the like are generated by the vibration action of a piezoelectric vibrator 7c arranged corresponding to each nozzle opening 7b. It is configured to eject color ink.

In the above arrangement, the discharging of the residual air bubbles in the recording head or the ink supply path and the suction of the ink for eliminating the clogging of the nozzle openings are performed by recording the cap member 10b as shown in FIG. The air release valve 1 is brought into close contact with the nozzle forming surface 7 a of the head 7.
4 is performed with the valve closed.

By driving the tube pump 11 in this state, a negative pressure is applied to the internal space of the cap member 10b, and ink is sucked and discharged from the nozzle openings 7b of the recording head 7. After the tube pump 11 is driven for a certain period of time, it is stopped. Thereafter, when the negative pressure inside the cap member is reduced to some extent, when the atmosphere release valve 14 is opened, the atmosphere is introduced into the cap member and the negative pressure inside is released. Subsequently, by driving the tube pump 11 again with the atmosphere release valve 14 opened, the ink discharged into the cap member is supplied to the tube T1.
The operation of feeding the waste ink into the waste ink tank 13 is performed.

Next, the structure of the tube pump 11 will be described with reference to FIG.

The tube pump 11 has a drive shaft 21
A rotating disk 22 having elasticity fixed to the drive shaft 21; a tube pressing plate 23 formed to be swingable in opposition to the rotating disk 22; A metal ball 24 as a rocking means, which is interposed between the metal ball 24 and the plate 23 and presses the tube pressing plate 23 downward.
And a tube 25 whose upper wall is fixed to the tube pressing plate 23 and whose lower wall is fixed to the case.

The rotating disk 22 is made of an elastic material such as a metal and the like.
Generates a force that presses downward.

On the upper surface of the tube pressing plate 23, a V-shaped groove 23a in which the metal ball 24 can roll is formed. The V-shaped groove 23a is formed closer to the drive shaft 21 than the center 25c of the cross section of the tube 25. Further, a through hole 23b through which the drive shaft 21 penetrates is provided in a central portion of the tube pressing plate 23. A tapered portion 23c having a gradually decreasing diameter is formed at the tip of the through hole 23b, and a hole 23d having a constant diameter is formed continuously with the tapered portion 23c. Further, a peripheral wall portion 23e having an arc-shaped tip is formed around the rear end of the through hole 23d,
The peripheral wall portion 23e is configured to be in contact with the inner wall of the case 26.

The tube pressing plate 23 has a lower surface
A communication hole 23f for fixing the locking projection 25a provided on the upper wall of the tube 25 is provided. The communication hole 23f is formed continuously along the tube 25.

On the other hand, the case 26 is provided with a communication hole 26a for fixing a locking projection 25b provided on the lower wall of the tube 25.

Next, the operation of the tube pump 11 will be described with reference to FIGS.

When the drive shaft 21 is rotated from the state shown in FIG. 3 in the direction of the arrow, the metal ball 24 is rotated by the rotation of the drive shaft 21 so that the V-shaped groove 23 a on the upper surface of the tube pressing plate 23 is formed.
Move in. At this time, the metal ball 24 is
2, the tube pressing plate 23 moves while being inclined from the upper position to the lower position.

That is, when the metal ball 24 moves and is positioned, the tube pressing plate 23 is tilted (oscillated) from the upper position to the lower position, and presses and crushes the tube 25. The metal ball 2
4 moves sequentially as described above, so that the tube pressing plate 23 is sequentially inclined (oscillated) from the upper position to the lower position,
The tube is pressed and crushed sequentially.

As a result, as shown schematically in FIG. 5, the metal ball 24 sequentially inclines (oscillates) the tube pressing plate 23, so that a negative pressure is applied to the internal space of the cap member 10b, and the recording head The ink is sucked and discharged from the nozzle opening 7b of the nozzle 7.

After the tube pump 11 has been driven for a certain period of time, the rotation of the drive shaft 21 is stopped. Thereafter, when the negative pressure inside the cap member is reduced to some extent, when the atmosphere release valve 14 is opened, the atmosphere is introduced into the cap member and the negative pressure inside is released. Subsequently, the drive shaft 21 is rotated again with the atmosphere opening valve 14 opened, and the ink discharged into the cap member is sent to the waste ink tank 13.

Since the V-shaped groove 23a is formed closer to the drive shaft 21 than the center 25c of the cross section of the tube 25, the force by which the tube pressing plate 23 crushes the tube 25 in the crushed state of the tube. Works evenly on the tube 25, so that the crushing amount and the crushing load for closing the tube 25 can be reduced. Further, since the stable closed state of the tube can be always maintained, the swinging (tilting) operation of the tube pressing plate can be stabilized.
As a result, small size and high efficiency can be obtained.

Since the tube is sequentially crushed and restored to the initial state by the swinging operation of the tube pressing plate, it is sufficient that the tube has an elastic force capable of following the swinging operation of the tube pressing plate. Alternatively, it may be formed of a material having a lower self-restoring force or a material having a lower rigidity than tubes used in a conventional tube pump.

For example, an aluminum tube, an aluminum tube whose surface is coated with a resin, an aluminum tube laminated with a resin, a vinyl tube, or the like may be used.

As described above, by using a tube made of a material having a low self-restoring force or a material having a low rigidity, the crushing load of the tube can be reduced, and as a result, a highly efficient pump can be obtained.

Further, in the above embodiment, the ink jet recording apparatus using the tube pump as the means for restoring the ink discharge capability has been described. However, the present invention is not limited to this ink jet recording apparatus, and the present invention is not limited thereto. Naturally, an ink jet recording apparatus using a tube pump as a supply means for supplying ink from a main tank to a sub tank provided on the recording head side is also applicable.

[0055]

As is apparent from the above description, according to the present invention, a low-load, high-efficiency tube pump can be obtained.

In addition, an ink jet recording apparatus using this apparatus can perform more stable suction operation and supply operation, and can be made smaller and more efficient.

[Brief description of the drawings]

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

FIG. 2 is a conceptual diagram showing a capping means and a tube pump provided in the recording apparatus shown in FIG.

FIG. 3 is a sectional view showing a tube pump according to the embodiment of the present invention.

FIG. 4 is a sectional view showing a state where the tube pump shown in FIG. 3 is driven.

FIG. 5 is an operation conceptual diagram of the tube pump shown in FIG. 3;

FIG. 6 is a schematic view showing a conventional tube pump.

[Explanation of symbols]

 Reference Signs List 1 carriage 2 carriage motor 6 recording paper 8, 9 ink cartridge 10 capping means 11 pump unit (tube pump) 12 wiping means 21 drive shaft 22 rotating disk 23 tube pressing plate 23a V-shaped groove 23b through hole 23e peripheral wall 24 Metal ball 25 Tube 26 Case

Claims (6)

[Claims] 1. A tube pump having a tube which is sequentially crushed by an oscillating means and restored to an initial state, comprising: a drive shaft; a rotating disk fixed to said drive shaft and integrally rotating; A tube pressing plate formed so as to be swingable in opposition to the rotating disk, a rocking means for rocking the tube pressing plate by receiving a rotational movement of the rotating disk, and a lower surface of the tube pressing plate A tube having an upper wall fixed thereto and a lower wall fixed to the case, a groove for fitting the swinging means is formed on an upper surface of the tube pressing plate, and the center of the groove is A tube pump, which is located on the drive shaft side from the center of the cross section of the tube. 2. The oscillating means is a sphere interposed between the rotating disk and a tube pressing plate, and is movable in the groove. Tube pump. 3. The tube pump according to claim 2, wherein said groove is a V-shaped groove. 4. The tube pump according to claim 1, wherein the tube has an elastic force capable of following a swinging operation of the tube pressing plate by the swinging unit. 5. An ink jet recording head for ejecting ink droplets corresponding to print data, and a nozzle forming surface of the recording head is 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 tube pump according to any one of claims 1 to 4 as a pump unit. 6. An ink jet recording head that discharges ink droplets in accordance with print data, a main tank that stores ink discharged from the recording head, and a recording head that receives supply of ink from the main tank. An ink jet type recording apparatus comprising: a provided sub-tank; and an ink supply unit for supplying ink from the main tank to the sub-tank, wherein the ink is supplied to the tube pump according to any one of claims 1 to 4. An ink jet recording apparatus comprising: