JP2004322506A - Ink feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink feeder in which an ink feed passage is vacuum sealed in order to deal with high speed printing by sustaining deaeration performance of ink and, at the same time, ink flow rate is ensured. <P>SOLUTION: An ink tank 1 is normally vacuum sealed under a close valve state and the valve is opened at a moment in time when it is connected with an ink jet recorder. Since the ink channel is filled with ink by opening the valve and then ink is discharged slightly to the outside of the ink channel, the ink channel is coupled and ensured while preventing mixture of air. Furthermore, a sufficient ink flow rate is ensured by using a movable valve at a joint and setting an arbitrary ink passage diameter. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an inkjet recording apparatus, and more particularly, to an ink supply apparatus that supplies ink to an inkjet head that ejects ink droplets in response to a print signal.
[0002]
[Prior art]
2. Description of the Related Art An ink jet recording apparatus that prints characters, images, and the like on a printing medium by ejecting ink droplets from nozzles using energy of a piezoelectric element or a heating element provided in an ink jet head is well known. The inkjet recording apparatus includes a serial type in which an inkjet head is mounted on a carriage and performs printing in a process of reciprocating movement, and a line type in which an inkjet head is fixed and printing is performed while a recording medium is conveyed. In any of the ink jet recording apparatuses, an ink storage container is provided separately from the ink jet head, and a system for supplying ink from the ink tank to the ink jet head is provided.
[0003]
In order to maintain stable high-speed printing, it is necessary to prevent bubbles from flowing into the ink jet head or generating bubbles from the ink itself due to the impact due to the driving of the piezoelectric element, resulting in defective ejection of the ink jet head. . Therefore, a plug is provided in the ink storage container to maintain the degassed state of the ink so that the degassed ink previously filled in the ink storage container can be supplied to the inkjet head while maintaining the degassed state. Is disclosed (for example, see Patent Document 1).
[0004]
Further, a rubber stopper is provided in the ink reservoir, and a hollow needle is provided in the rubber stopper so that the degassed ink previously filled in the ink reservoir can be supplied to the inkjet head while maintaining the degassed state. A configuration for stabbing and forming an ink path is disclosed (for example, see Patent Document 2).
[0005]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-192739 [Patent Document 2]
JP-A-7-132611 [0006]
[Problems to be solved by the invention]
However, even with the above-described conventional configuration, it was not possible to prevent air from being mixed in the connection portion between the ink storage container and the ink supply path. That is, of the ink flowing out from the ink storage container toward the ink supply path, the ink flowing first comes into contact with the air remaining in the stopper, and it was not possible to maintain a completely degassed state. .
[0007]
Therefore, an object of the present invention is to provide an ink supply device that maintains vacuum sealing by itself before connection of an ink storage container and minimizes air entrapment of ink flowing out of the ink storage container even when connected to an ink supply path. Is to provide. Furthermore, in order to cope with a large amount of ink consumption due to high-speed printing, in order to shorten the ink filling time in the ink jet head, in a configuration in which a hollow needle is inserted into the rubber stopper in the ink storage container, the insertion force and the rubber stopper are generated. It is an object of the present invention to provide an ink supply device that secures an ink flow rate of 100 g / min or more, which has been difficult to achieve due to ink leakage due to cracks and air mixing.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention is directed to an ink tank, a tank cap connected to a supply connection port of the ink tank and having a valve structure incorporated therein, and a part of the tank cap which discharges ink. And a receiver provided at the ink tank connection portion of the ink supply path.
[0009]
According to a second aspect of the present invention, in the first aspect, the ink discharge hole is communicated with an ink waste tank.
[0010]
According to a third aspect of the present invention, in the first aspect of the present invention, the tank cap has a tapered shape and is configured to also serve as a positioning guide.
[0011]
According to a fourth aspect of the present invention, in the first aspect of the present invention, a cover having a shielding shutter is provided on the receiver, the shielding shutter is closed to protect the receiver, and after the ink tank is mounted. Is characterized in that it is configured to lock the tank cap.
[0012]
With the above configuration, in a state where the ink tank is removed from the ink jet recording apparatus, the ink supply connection port keeps the valve closed state, and when connected to the ink jet recording apparatus, the movable valve element is opened. By slightly discharging the ink to the outside of the ink path, the ink can be supplied to the inkjet head while preventing air from entering the ink flow path. Therefore, it is possible to prevent the leakage of the ink and the evaporation of the ink solvent while maintaining the performance of the degassed ink. Further, in the configuration of the present invention, an arbitrary flow path area can be set without being limited by the flow path area of the connection portion in principle, so that an ink flow path with a sufficient ink flow rate can be secured.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view schematically showing the structure of an ink jet recording apparatus equipped with the ink supply device of the present invention. In the figure, reference numeral 1 denotes an ink jet head, which is provided with a plurality of nozzles for ejecting ink droplets from the nozzles using energy of a piezoelectric element or a heating element. Reference numeral 2 denotes a filter unit that removes foreign matter in the ink. The inkjet head 1 and the filter unit 2 are connected by a tube 6. The filter unit 2 is connected to a manifold 5 via a tube 4. The manifold 5 has a function of increasing the ink transmission capacity when supplying ink from the sub tank 3 that temporarily stores the ink to the inkjet head 1.
[0014]
The manifold 5 and the sub-tank 3 are connected by an ink pipe 8, and a solenoid valve 9, a solenoid valve 10, and a manual stopper 12 are provided in the path of the ink pipe 8. The ink pipe 8 in the vicinity of the sub tank 3 has a path branched off from the path to the manifold 5, and a manual stopper 13 is provided on the way.
[0015]
On the other hand, a branch path is provided between the solenoid valve 9 and the solenoid valve 10 of the ink pipe 8, and the branch path is provided with a solenoid valve 11 and a detachable ink tank 6 for supplying ink to the sub-tank 3. I have. A tank cap 14 (described later) is attached to an ink discharge portion of the ink tank 6. A receiver 15 (described later) is provided at a portion of the ink pipe 8 mounted on the ink tank 6, and further communicates with the ink waste tank 25 via a tube. The ink waste tank 25 has a function of detecting the ink storage capacity based on the ink weight and notifying the tank replacement time.
[0016]
The ink tank 6 is flexible and sufficiently flexible, there is almost no change in pressure inside the tank due to a change in volume due to ink discharge, and a vacuum-tight state is maintained with an air-impermeable material. In this embodiment, a 1-liter aluminum bag coated with plastic is used as an ink tank.
[0017]
In the above-described ink jet recording apparatus, supply of the deaerated ink to the ink jet head 1 during printing is performed only in the sub tank 3. Therefore, during printing, the manual stopper 12, the solenoid valve 9, and the solenoid valve 10 are opened, and the solenoid valve 11 is closed.
[0018]
By continuing printing, the ink in the sub-tank 3 is reduced, and when an ink remaining amount sensor (not shown) provided in the sub-tank 3 indicates that the remaining amount of ink is small, the electromagnetic valve 9 is closed, and the electromagnetic valve is closed. 10 and the solenoid valve 11 are opened to supply degassed ink from the ink tank 6 to the sub tank 3. Since the ink tank 6 is arranged so that the water level is higher than that of the sub tank 3, ink is easily injected from the ink tank 6 into the sub tank 3. When the degassed ink is supplied in this state and the solenoid valve 11 is closed when the ink remaining amount sensor indicates the upper limit position, the ink supply to the ink tank 6 can be stopped. Thereafter, when printing is started again, the electromagnetic valve 11 may be closed and the electromagnetic valve 9 may be opened.
[0019]
FIG. 2 is an enlarged sectional view of the tank cap 14 provided at the ink discharge portion of the ink tank 6. The tank cap 14 covers the rib 28 of the ink tank 6. A valve 17 is accommodated in the tank cap 14 so as to be movable in the axial direction by a spring 20. An O-ring 23 is fitted inside the vicinity of the tip of the tank cap 14, and an O-ring 18 made of an elastic material is fitted to the valve 17. The tip of the tank cap 14 is tapered like the tapered portion 19.
[0020]
In the above configuration, before the tank cap 14 of the ink tank 6 is connected to a receiver described later, the O-ring 18 fitted to the valve 17 and the tapered portion 19 of the tank cap 14 are elastically moved by the urging force of the spring 20. Since it is in contact, the degassed ink in the ink tank 6 is vacuum-sealed while maintaining the degassed state.
[0021]
FIG. 3 is an enlarged sectional view of the receiver 15 provided on the ink pipe 8 side and connected to the tank cap 14. Inside the receiver 15, a joint 16 which is a connection port of the ink tank 6 with the tank cap 14 and a filter 31 for filtering when environmental dust or the like is mixed into the ink are mounted. The filter 31 is fitted into a filter chamber 39 via a filtering 29 and an O-ring 32 provided around the filter 31. Therefore, when the filter 31 is replaced, the filtering 29 can be removed and replaced by itself without replacing the receiver 15 body. The receiver 15 is provided with an ink discharge hole 24 so as to communicate with the joint 16, and the ink discharge hole 24 is connected to an ink waste tank 25 via a tube.
[0022]
FIG. 4 is a cross-sectional view showing a state in which the tank cap 14 and the receiver 15 of the present invention are being mounted, and FIG. 5 is a cross-sectional view showing a state after the tank cap 14 and the receiver 15 of the present invention have been mounted. is there.
[0023]
Before the connection of the tank cap 14, the ink path on the receiver 15 side is shut off by the electromagnetic valve 11. The ink inside the joint 16 is discharged from the joint hole 22, and the ink level is held at a position below the joint hole 22.
[0024]
When the tank cap 14 of the ink tank 6 is connected to the receiver 15, the guide portion 21 formed as a taper at the tip of the tank cap 14 also functions as a positioning guide to be inserted into the receiver 15. It is accurately guided and opposed to the joint 16 inside the receiver 15. Then, when the tank cap 14 and the receiver 15 start contacting, the valve 17 which has been elastically contacted by the spring 20 is pushed by the joint 16 to be in the valve-open state. The ink flows down as shown by the ink flow 33 in FIG. Although the inside of the joint 16 is filled with the ink that has flowed down, the ink can be discharged as waste ink 34 from an ink discharge hole 24 provided below the joint hole 22. The discharged ink is stored in the ink waste tank 25 via a tube under the natural flow of its own weight. This discharged ink is ink near the tip of the ink tank 6 and may contain air in the process of connecting the tank cap 14 and the receiver 15, and may cause trouble in printing. For disposal.
[0025]
In the process of connecting the tank cap 14 and the receiver 15, when the tank cap 14 moves further, the O-ring 23 fitted at the tip of the tank cap 11 passes through the joint hole 22, and the seal shown in FIG. A connected, vacuum-sealed ink stream 35 can be established.
[0026]
FIG. 6 is a sectional view showing a state where the cover 36 is provided on the receiver 15, and FIG. 7 is a plan view thereof. As shown in the figure, a shutter 26 is provided above the cover 36, and when the ink tank 6 is not mounted, the shutter 26 is closed by the urging force of the spring 27 to prevent environmental dust and the like from entering the ink and the ink path. To prevent.
[0027]
FIG. 8 is a sectional view showing a state in which the tank cap 14 is connected to the receiver 15 with the cover 36, and FIG. 7 is a plan view thereof. The shutter 26 is attached while being manually opened before the tank cap 14 is attached. Thereafter, when the hand is released from the shutter 26, the shutter 26 is closed by the urging force of the spring 27, and the rib portion 28 is engaged to prevent the ink tank 6 from coming off. When separating the ink tank 6, it is preferable to manually open the shutter 26 and then remove it.
[0028]
【The invention's effect】
As described above, according to the present invention, when the ink tank is detached from the ink jet recording apparatus, the degassing state of the ink is maintained in a vacuum sealed state, and when the ink tank is mounted on the ink jet recording apparatus, the ink tank according to the present invention is used. The connection mechanism maintains a vacuum-sealed state, and ink that may come into contact with air can be removed before the ink is supplied. Furthermore, after the ink-jet recording apparatus is mounted on the inkjet recording apparatus, the ink-tight state is closed by an O-ring, and the vacuum-sealed state is achieved. It is possible to maintain the state. In this manner, by maintaining the ink in a vacuum-sealed state, it is possible to prevent the performance of the deaerated ink from being maintained, prevent ink from leaking, volatilize the ink solvent, mix air bubbles, and mix environmental dust.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing an example of an ink jet recording apparatus to which the present invention is applied.
FIG. 2 is a sectional view schematically showing a tank cap.
FIG. 3 is a sectional view showing the internal structure of the receiver.
FIG. 4 is a sectional view showing a state where the tank cap and the receiver of the present invention are being mounted.
FIG. 5 is a cross-sectional view showing a state after the tank cap and the receiver of the present invention have been mounted.
FIG. 6 is a sectional view showing a state where a cover is provided on the receiver.
FIG. 7 is a plan view of FIG. 6;
FIG. 8 is a cross-sectional view showing a state where a tank cap is attached to a receiver with a cover.
FIG. 9 is a plan view of FIG. 9;
[Explanation of symbols]
1 is a head, 2 is a filter unit, 3 is a sub tank, 4 is a tube, 5 is a manifold, 6 is an ink tank, 7 is a supply pipe, 8 ink pipes, 9, 10, and 11 are solenoid valves, and 12 and 13 are manually stopped. Stopper, 14 is a tank cap, 15 is a receiver, 16 is a joint, 17 is a valve, 18 is an O-ring, 19 is a tapered portion, 20 is a spring, 21 is a guide, 22 is a joint hole, 23 is an O-ring, 24 is an ink discharge hole, 25 is an ink waste tank, 26 is a shutter, 27 is a spring, 28 is a rib, 29 is filtering, 30 is a filter chamber, 31 is a filter, and 32 is an O-ring.

Claims (4)

An ink tank, a tank cap connected to a supply connection port of the ink tank and incorporating a valve structure, and a receiver provided with an ink discharge hole in a part thereof and provided at an ink tank connection part of an ink supply path. An ink supply device comprising: The ink supply device according to claim 1, wherein the ink discharge hole communicates with an ink waste tank. 2. The ink supply device according to claim 1, wherein the tank cap has a tapered shape and is configured to also serve as a positioning guide. The receiver is provided with a cover having a shielding shutter, the shielding shutter is closed to protect the receiver, and the tank cap is locked after the ink tank is mounted. The ink supply device according to claim 1, wherein:

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