JP2001301195A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small ink jet recorder comprising a pump having a single roller exhibiting suction efficiency equivalent to that of a pump having a plurality of rollers at a low cost. SOLUTION: A pump provided in the ink jet recorder comprises a flexible tube and a guide member which can mount the flexible tube arcuately over 360 deg. or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for ejecting ink from a nozzle to record on a recording member, and more particularly to an ink supply path for supplying ink to a nozzle or an ink discharge path for discharging ink from a nozzle. The present invention relates to a structure of a pump provided in a part of the pump.

[0002]

2. Description of the Related Art In the related art, in an ink jet recording apparatus, many recovery apparatuses have been proposed for recovering a normal state of an ink jet head in a state where ink near a nozzle is thickened or bubbles are mixed in the nozzle. I have.
In such a recovery device, a nozzle is covered with a cap, a pump provided in an ink discharge path communicating with the cap is driven, and ink is suctioned from the nozzle using a pressure (negative pressure) generated by the pump. There is also known a device provided with a discharging means.

[0003] In addition, there is known a supply device in which a pump is provided in an ink supply path connecting the ink tanks to the nozzles to supply the ink using pressure generated by the pump. One of the pumps used in such a recovery device and a supply device includes a flexible tube placed in an arc shape along a guide, and a rotating body that supports a roller that presses the flexible tube. There is proposed a tube pump that generates pressure by utilizing deformation of a tube. In such a tube pump, by rotating the rotating body, the rollers move while sequentially crushing the flexible tube, thereby generating pressure in the tube.

When two or more rollers are provided and the rotating body rotates,
Since at least one roller is always crushing the tube, the generated pressure can be accumulated,
It is preferable from the viewpoint of the efficiency of the pump. In the case of a single roller, when the roller comes off the guide, the pressure generated by sequentially crushing the tube is once returned to the atmospheric pressure, so that the generated pressure is not accumulated.

[0005]

When the number of rollers is one, since the pressure is not accumulated, the speed of generating the pressure (negative pressure) is low, and the ink is ejected from the head while the desired ink flow velocity is secured. The amount of ink is large and the efficiency of the pump is poor. Conventionally, in order to accumulate pressure, the problem has been dealt with by providing two or more rollers. As a result, there is a problem that the cost is increased due to the addition of rollers and the pump size is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide an ink jet recording apparatus having a tube pump capable of accumulating pressure with one roller.

[0007]

A flexible tube is provided in a part of an ink supply path for supplying ink to a nozzle or an ink discharge path for discharging ink from a nozzle, and a flexible tube is provided by a roller disposed on a rotating body. In an ink jet recording apparatus including a pump that generates pressure by sequentially pressing and deforming, the pump includes a pump in which the flexible tube is mounted at about 360 ° or more along an arcuate guide. I do.

According to the above construction, at least one roller is
With this configuration, the pump upstream tube is not opened to the pump downstream tube at the time of normal rotation of the pump, so that the pressure inside the pump upstream tube is accumulated.

According to a second aspect of the present invention, in the ink jet recording apparatus, the roller is moved between a first position where the rotating body presses the tube and a second position where the pressing force applied to the tube is reduced according to the rotation direction. Is movably supported.

[0010] According to the above configuration, by pressing the pump in the reverse direction, the pressing force of the roller against the tube is released, so that there is an additional effect that the plastic deformation and deterioration damage of the tube can be prevented.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An ink jet recording apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic view of an ink jet recording apparatus according to one embodiment of the present invention. The recording head 11 (shown in FIG. 2)
, And is moved by a carriage motor 13 via a belt 19 while being guided by a guide shaft 14. The cap 17 is for capping the nozzle 11A (shown in FIG. 2) of the recording head 11. A flexible tube 103 which is a component of the tube pump 15 is connected to the cap 17. Tube pump 15
Is driven by a pump motor 18. The ink in the nozzle 11A is sucked through the cap 17 by the negative pressure generated in the tube pump 15, and unnecessary ink is discharged to the waste ink tank 30 (shown in FIG. 2).
In the present embodiment, an example in which the pump is provided in a part of the ink discharge path will be described.

(Explanation of the structure of the pump) As shown in FIG. 2, the tube pump of this embodiment has a guide member 1 having an inner circumference of a circular arc, and a substantially 360 ° extending along the inner circumference of the guide member 1.
Over the above, the placed flexible tube 103,
A roller 4 for pressing the tube 103 is provided, and a rotating body 3 for supporting the roller 4 is provided. Further, as shown in the DD section (FIG. 3) of FIG. 2, the tube 103 is placed along the guide member 1 so as to be partially overlapped in the direction of the rotating shaft 7 of the rotating body 3. In FIG. 3, the tube 103B on the waste ink tank side is placed on the bottom side of the guide member 1, but the tube 103A on the cap side may be placed on the bottom side. The rotating body 3 is provided with an elongated hole 6 into which the shaft 5 of the roller 4 is fitted. The radius of the elongated hole 6 changes in the circumferential direction of the rotating body 3. Then, one end 8 of the elongated hole 6 (first
(Hereinafter, referred to as an operating position) is located farther from the rotary shaft 7, and when the shaft 5 of the roller 4 is at this position, the tube 103 is pressed, and the other end 9 of the elongated hole 6 is pressed.
(The second position, hereinafter referred to as a retracted position) is located at a position close to the rotating shaft 7, and when the shaft 5 of the roller 4 is at this position, the pressing of the tube 103 is weakened.

(Description of Operation of Pump) Next, the operation of the tube pump according to the present embodiment will be described with reference to FIG. The tube 103 forms an ink discharge path, and one end 103A of the tube 103 is connected to the cap 17 and the other end 10A.
3B is connected to the waste ink tank 30. When the rotating body 3 moves in the direction of arrow C (hereinafter, forward rotation), the shaft 5 of the roller 4 reaches the operating position, and the roller 4 presses the tube 103 with the inner peripheral surface of the guide member 1 as shown in FIG. While rotating. Then, a negative pressure is generated due to a change in volume of the crushed tube, and ink is sucked from the nozzle 11A.

By placing the flexible tube along the arc-shaped guide member 1 at about 360 ° or more, during normal rotation,
Regardless of the position of the roller, the tube is always pressed, so that it is located upstream of the pump (tube 103A).
The space in the tube (side) is not opened downstream (the tube 103B side) from the pump. It should be noted that depending on the diameter of the roller, it is not necessarily required to be 360 ° or more, and it has been confirmed in experiments that even if it is 340 ° or more, there is no functional problem.

That is, even if the pump has one roller, the pressure can be accumulated from the first rotation to the second rotation and from the second rotation to the third rotation by continuously rotating the pump.
It is possible to obtain a suction efficiency equivalent to that of a tube pump having a plurality of rollers.

When the suction operation required for the recovery of the recording head 11 (predetermined rotation) is completed, the motor 18 is stopped and the driving of the pump is stopped. If left in this state for a long time, there are problems such as permanent deformation of the tube and deterioration of durability. Therefore, in order to stop the pump, after stopping the rotating body 3 from normal rotation, the rotating body 3 is once rotated reversely,
After moving the roller 4 from the operating position 8 to the retracted position 9,
Stop again.

That is, by rotating the rotating body 3 in the reverse direction (direction B), the roller 4 at the operating position 8 (FIG. 2) moves to the retreat position 9 (FIG. 4). In this way, after the rotating body is reversed and stopped again, the roller 4 is in a state of lightly contacting the tube 103 as shown in FIG. As a result of the evaluation by the present inventors, even in this state, even if the pump continues to reverse,
Since the tube is hardly crushed, it has been confirmed that the ink once sucked does not flow backward, and there is no problem in the durability due to the deformation and permanent distortion of the tube.

Further, conventionally, when the above-described elongated hole is provided, there is a problem that when the roller is released from the elastic force of the tube during rotation of the rotating body, a collision sound between the roller and the rotating body is generated. On the other hand, in the present invention, the roller is always in contact with the tube during rotation, so that the roller is not released from the elastic force of the tube. That is,
The occurrence of collision noise between the roller and rotating body can be prevented,
It is possible to provide a much quieter pump even when driven.

[0019]

As described above, according to the pump of the present invention, a single roller can achieve the same suction efficiency as a pump having a plurality of rollers. Further, since only one roller is required, there is an effect that a small-sized and low-cost pump can be obtained. Also, depending on the direction of the rotating body, the roller moves to the operating position where the tube is sequentially crushed and the retracted position where the pressing force of the roller against the tube is released, so that when the pump is stopped, the tube is plastically deformed or deteriorated. No damage. Further, since there is no moment when the roller is released from the elastic force of the tube, it is possible to prevent the collision noise between the roller and the rotating body. In general, there is an effect that a high-efficiency, low-cost, small-sized, long-life, and silent pump can be obtained.

[Brief description of the drawings]

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

FIG. 2 is an embodiment of the tube pump of the present invention, and is an explanatory view showing a state where the pump is rotating forward.

FIG. 3 is a cross-sectional view showing a portion cut along a line DD in FIG. 2, and is an explanatory diagram showing a mounted state of a tube.

FIG. 4 is an embodiment of the tube pump of the present invention, and is an explanatory view showing a state where the pump is rotating in reverse.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Guide member 3 Rotating body 4 Roller 5 Roller rotating shaft 6 Slot 7 Rotation center 8 End of slot 6 remote from rotating shaft 7 9 End of slot 6 near rotating shaft 7 11 Recording head 11A Nozzle 12 Carriage 13 Carriage motor 14 Guide shaft 15 Tube pump 17 Cap 30 Waste ink tank 103 Tube 103A Tube cap connection side 103B Tube waste ink tank connection side

Claims (2)

[Claims] 1. A flexible tube provided in a part of an ink supply path for supplying ink to a nozzle or an ink discharge path for discharging ink from a nozzle and sequentially pressing and deforming a flexible tube by a roller disposed on a rotating body. In the ink jet recording apparatus provided with a pump for generating pressure, the flexible tube is moved along the arc-shaped guide member by about 3 mm.
An ink jet recording apparatus comprising a pump mounted at 60 ° or more. 2. The roller according to claim 1, wherein the roller can be moved to a first position where the rotating body presses the tube and a second position where the pressing force applied to the tube is reduced according to the rotation direction. An ink jet recording apparatus characterized in that it is supported.