JP2012076276A - Liquid tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect the storage quantity of a liquid tank storing a liquid.SOLUTION: A waste ink tank includes a first foam 3 and a plurality of liquid sensors 4 which are housed in a casing 2. The liquid sensor 4 includes a second foam 42 disposed inside a guide body 41 having a circular shape opened at both ends. The bottom surface of the second foam 42 is in contact with the first foam 3. An electrode 43 disposed on the upper surface of the second foam 42 and a contact 44 fixed to the housing 2 so as to face the electrode 43 constitute a pressing switch. The expansion rate in absorption of waste ink related to the first foam 3 is smaller than the expansion rate related to the second foam 42.

Description

  The present invention relates to a liquid tank that stores liquid.

  2. Description of the Related Art An ink jet printer having a waste ink tank for storing ink discarded when performing maintenance or the like of an ink jet head is known. A foam made of a highly absorbent resin material is disposed inside the waste ink tank. The waste ink discarded in the waste ink tank is held in the waste ink tank by being absorbed by the foam. In such a waste ink tank, a pressure switch is disposed at the top of the foam, and the foam expanded as the waste ink is absorbed presses the pressure switch, so that the amount of waste ink stored in the waste ink tank is limited to the upper limit. There is known a technique for detecting that it has reached (for example, see Patent Document 1).

JP 2002-127464 A

  In the above-described waste ink tank, since the foam expands from a portion that first comes into contact with the waste ink, the shape of the foam tends to be distorted as it expands. At this time, even though the foam has room to absorb the waste ink, a part of the distorted foam may press the switch, so the amount of waste ink stored in the waste ink tank can be accurately detected. difficult.

  An object of the present invention is to provide a liquid tank that can accurately detect the amount of liquid stored.

  The liquid tank of the present invention is arranged in a housing having an inflow port through which liquid flows and an internal space of the housing, and absorbs the liquid flowing in from the inflow port and expands its volume. An absorber, a second absorber, a pressure switch that is disposed at a predetermined position in the internal space and detects the amount of liquid in the internal space by being pressed by the expanded second absorber; and the second absorber The guide wall which faces the outer peripheral surface which faced the direction orthogonal to a perpendicular direction is provided. The second absorbent body and the first absorbent body are sequentially arranged below the push switch in the vertical direction, and an expansion coefficient when the liquid relating to the first absorbent body is absorbed is the second absorbent body. Smaller than the expansion coefficient.

  According to the present invention, the liquid flowing in from the inlet is absorbed by the first absorber, and then the liquid absorbed by the first absorber is absorbed by the second absorber. As the second absorber absorbs the liquid, the second absorber expands along the guide wall, and the expanded second absorber presses the pressing switch. As a result, the amount of liquid stored in the internal space can be detected. At this time, since the expansion rate of the first absorber is small, the occurrence of distortion when the first absorber absorbs the liquid is suppressed, and the amount of liquid stored in the liquid tank can be accurately detected.

  In this invention, it is preferable that the lower surface regarding the perpendicular direction of the said 2nd absorber and the said 1st absorber are spaced apart. According to this, the liquid in the liquid tank reaches the height of the second absorber because the second absorber absorbs the exuded liquid after the liquid has oozed out of the first absorber. Can be detected accurately.

  Moreover, in this invention, it is preferable that the said guide wall has faced the outer peripheral surface whole region which faced the direction orthogonal to the said perpendicular direction of a said 2nd absorber. According to this, the press switch can be pressed more accurately by reliably expanding the second absorber that has absorbed the liquid along the vertical direction.

  At this time, it is more preferable that the shape of the space defined by the guide wall is similar to that of the second absorber. According to this, since the contact pressure with the guide wall is made uniform when the second absorbent body that has expanded by absorbing liquid contacts the guide wall, the second absorbent body is efficiently expanded in the vertical direction. Can be made.

  Moreover, in this invention, it is preferable that at least one part of the lower surface regarding the perpendicular direction of the said 1st absorber is spaced apart from the inner wall face of the said housing | casing. According to this, it is possible to increase the storage amount while preventing the liquid tank from leaking.

  Furthermore, in the present invention, it is preferable that the inflow port is disposed on an upper surface in the vertical direction of the internal space. According to this, the liquid leakage of the liquid tank from the inflow port can be prevented.

  In addition, in the present invention, it is preferable to further include a guide wall that guides the liquid flowing in from the inlet to the vicinity of the bottom surface in the vertical direction of the internal space. According to this, since the inflowing liquid can be guide | induced to the downward vicinity regarding the perpendicular direction of a 1st absorber, the amount of storage can be detected still more correctly.

  In the present invention, it is preferable that the plurality of switches are arranged in the vertical direction. According to this, the storage amount of the liquid tank can be detected in stages.

  According to the present invention, the liquid flowing in from the inlet is absorbed by the first absorber, and then the liquid absorbed by the first absorber is absorbed by the second absorber. As the second absorber absorbs the liquid, the second absorber expands along the guide wall, and the expanded second absorber presses the pressing switch. As a result, the amount of liquid stored in the internal space can be detected. At this time, since the expansion rate of the first absorber is small, the occurrence of distortion when the first absorber absorbs the liquid is suppressed, and the amount of liquid stored in the liquid tank can be accurately detected.

1 is a schematic side view of an ink jet printer having a waste ink tank according to a first embodiment of the present invention. It is sectional drawing of the waste ink tank shown in FIG. (A) It is an enlarged view of the liquid sensor shown in FIG. (B) It is sectional drawing of the IIIB-IIIB line | wire shown to Fig.3 (a). FIG. 4 is an enlarged plan view of the contact shown in FIG. 3. It is sectional drawing of the liquid sensor which shows a mode that the liquid sensor shown in FIG. 3 detected the ink. It is sectional drawing of the liquid sensor which concerns on a modification. It is sectional drawing of the liquid sensor which concerns on 2nd Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
As shown in FIG. 1, the ink jet printer 101 includes a transport unit 20 that transports paper from the right to the left in FIG. 1, and yellow, cyan, magenta, and black ink on the paper transported by the transport unit 20. It has four inkjet heads 10 that discharge droplets, respectively.

  The transport unit 20 includes two belt rollers 6 and 7 and an endless transport belt 8 wound around the rollers 6 and 7. The sheet placed on the outer peripheral surface of the conveyor belt 8 is conveyed leftward in FIG. A paper discharge tray 14 is disposed on the downstream side in the transport direction of the four inkjet heads 10. The paper transported in the transport direction is sequentially discharged under the four inkjet heads 10 and then discharged to the paper discharge tray 14. That is, the ink jet printer 101 is a line type color ink jet printer in which a plurality of ejection openings from which ink droplets are ejected in the main scanning direction orthogonal to the transport direction are arranged.

  In addition, the ink jet printer 101 can perform a purge operation for discharging air bubbles or thickened ink remaining in the ink jet head 10 from the ejection port. The ink jet printer 101 includes a waste ink tray 50 that receives ink discharged from the discharge port in the purge operation, and a waste ink tank 1 that stores the ink discharged to the waste ink tray 50. The waste ink tray 50 is disposed at a retracted position that does not face the four inkjet heads 10 in a normal state. When the purge operation is started, the waste ink tray 50 is moved from the retracted position to the maintenance position facing the four inkjet heads 10. Thereafter, the ink is discharged from the discharge port of each inkjet head 10 toward the waste ink tray 50. The ink discharged to the waste ink tray 50 flows into the waste ink tank 1 through the waste ink pipe 51.

  The waste ink tank 1 will be described in detail. As shown in FIG. 2, the waste ink tank 1 includes a housing 2 having a rectangular parallelepiped shape, a first form 3 and a plurality of liquid sensors 4 housed in the housing 2. An inflow port 21 is formed on the upper surface of the housing 2 in the vertical direction (hereinafter, the vertical relationship is based on the vertical direction). A waste ink pipe 51 is connected to the inflow port 21. Waste ink that has flowed from the waste ink pipe 51 in the purge operation flows into the internal space of the waste ink tank 1 (housing 2) via the inlet 21. In addition, a guide wall 22 extending from the vicinity of the inlet 21 on the top surface to the vicinity of the bottom surface is disposed in the internal space of the housing 2.

  The first foam 3 is a porous body that is filled over almost the entire internal space of the housing 2 and absorbs ink and holds the absorbed ink. The first foam 3 is formed of an absorber that has an extremely small volume increase due to ink absorption. A rectangular notch 31 is formed on the lower surface of the first form 3. Thereby, a part of the lower surface of the first form 3 is separated from the bottom surface of the internal space of the housing 2. As shown by the arrow in FIG. 2, the waste ink that has flowed into the internal space of the housing 2 from the inlet 21 flows down downward so as to be guided to the guide wall 22 while being absorbed by the first foam 3. The waste ink that has flowed downward spreads in the horizontal direction on the bottom surface of the housing 2. At this time, the waste ink that cannot be held by the first form 3 in the vicinity of the bottom surface of the internal space oozes out from the first form 3 and accumulates in the space defined by the notch 31. As the amount of waste ink flowing from the inflow port 21 increases, waste ink overflowing from the space rises in the first form 3 while being absorbed by the first form 3 again.

  The liquid sensor 4 is for detecting the amount of waste ink stored in the internal space of the housing 2, and is disposed on the top surface of the housing 2 and the right side surface in FIG. . On the side surface, three liquid sensors 4 are arranged along the vertical direction. In FIG. 2, a total of four liquid sensors 4, one on the upper surface and three on the side surface, appear in the extending direction orthogonal to the vertical direction of the waste ink tank 1 in this embodiment. A plurality of sets of these four liquid sensors 4 are arranged along the line.

  As shown in FIGS. 3A and 3B, the liquid sensor 4 includes a guide body 41, a second form 42, an electrode 43, and a contact 44.

  The guide body 41 has a cylindrical shape with both ends opened in the vertical direction, and is arranged in a cylindrical or rectangular cutout formed in the first foam 3. The second form 42 has a cylindrical shape and is disposed so as to be accommodated inside the guide body 41. The bottom surface of the second form 42 is in contact with the first form 3. Further, the entire outer peripheral surface of the second form 42 facing the direction perpendicular to the vertical direction faces the inner wall surface of the guide body 41. Further, the outer shape of the second form 42 is similar to the shape of the internal space defined by the guide body 41. The second form 42 is a porous body that absorbs waste ink. When the second form 42 absorbs waste ink and has a maximum volume, the outer shape of the second form 42 matches the shape of the internal space defined by the guide body 41. FIG. 3 shows a state before the second form 42 absorbs waste ink. The expansion coefficient when the waste ink related to the first form 3 is absorbed is smaller than the expansion coefficient related to the second foam 42.

  The electrode 43 has a disc shape and is fixed to the center of the upper surface of the second foam 42. The contact 44 is fixed to the inner wall surface of the housing 2 so as to face the electrode 43. Therefore, the contact 44, the electrode 43, the second form 42, and the first form 3 are sequentially arranged downward in the vertical direction. As shown in FIG. 4, the contact 44 is divided into two by a notch 42a. As will be described later, when the electrode 43 is pressed and comes into contact with the contact 44, the two parts of the contact 44 that are divided are electrically connected.

  As shown in FIG. 5, when the waste ink absorbed by the first form 3 moves upward and reaches the bottom surface of the second form 42, the second form 42 expands while absorbing the waste ink from the bottom surface. At this time, the second form 42 expands upward while being guided by the inner wall surface of the guide body 41. As a result, the second form 42 presses the electrode 43 toward the contact 44. When the second form 42 absorbs a predetermined amount of waste ink, the electrode 43 and the contact 44 come into contact with each other. At this time, the two divided portions of the contact 44 are electrically connected via the electrode 43. As a result, the contact 44 is turned ON. Thus, the electrode 43 and the contact 44 are part of the pressing switch. A control device (not shown) accurately detects that the amount of waste ink in the waste ink tank 1 is stored up to the height of the liquid sensor 4 by detecting the liquid sensor 4 with the contact 44 turned ON. be able to.

  As described above, according to the waste ink tank 1 of the present embodiment, the waste ink that flows in from the inlet 21 is absorbed by the first form 3, and then the waste ink that is absorbed by the first form 3 is the liquid sensor 4. In the second form 42. As the second form 42 absorbs waste ink, the second form 42 expands along the inner wall surface of the guide body 41 and turns on the contact 44. At this time, since the expansion rate of the first form 3 is small, distortion is suppressed from occurring when the first form 3 absorbs the waste ink, and the amount of waste ink stored in the waste ink tank 1 is accurately detected. be able to.

  Further, since the inner wall surface of the guide body 41 faces the entire outer peripheral surface of the second form 42, the second form 42 that has absorbed the waste ink can be accurately expanded along the vertical direction. Thereby, the electrode 43 and the contact 44 can be made to contact reliably.

  Furthermore, since the shape of the space defined by the guide body 41 is similar to that of the second form 42, the second form 42 expanded by absorbing the waste ink comes into contact with the inner wall surface of the guide body 41. Since the contact pressure with the inner wall surface is made uniform, the second foam 42 can be efficiently expanded in the vertical direction.

  Further, since a part of the lower surface of the first form 3 in the vertical direction is separated from the bottom surface of the internal space of the housing 2, a space formed by the first foam 3 and the bottom surface of the internal space of the housing 2. In addition, waste ink can be stored. As a result, the amount of storage can be increased while preventing waste ink leakage from the waste ink tank 1.

  Furthermore, since the inflow port 21 is disposed on the upper surface of the housing 2, it is possible to suppress waste ink from leaking from the inflow port.

  In addition, since the guide wall 22 extends from the vicinity of the inlet 21 to the vicinity of the bottom surface of the internal space of the housing 2, the waste ink flowing from the inlet 21 is guided to the vicinity of the bottom surface of the first form 3. Therefore, the amount of storage can be detected more accurately.

  Moreover, since the three liquid sensors 4 are arranged along the vertical direction, the amount of storage can be detected in stages.

<Modification>
In the present embodiment, the bottom surface of the second foam 42 is in contact with the first foam 3. However, as shown in FIG. 6, the bottom surface of the second foam 142 and the first foam 3 are separated from each other. In addition, a protrusion protruding from the outer peripheral surface of the second foam 142 may be supported by the guide wall 41. This protrusion may be formed of the same material as the second foam 142 or may be formed of a material different from that of the second foam 142. According to this, after the waste ink oozes out from the first form 3, the second form 142 absorbs the spilled waste ink, so that the waste ink in the waste ink tank 1 reaches the height of the second form 142. It is possible to accurately detect that it has arrived.

<Second Embodiment>
A second embodiment will be described. In addition, about the member and function part substantially the same as 1st Embodiment, the code | symbol same as 1st Embodiment is attached | subjected and the description is abbreviate | omitted. As shown in FIG. 7, the liquid sensor 204 of the waste ink tank according to the second embodiment includes a guide body 241, a second form 42, an electrode 43, and a contact 44. The guide body 241 has a bottomed cylindrical shape with an upper end opened. An opening 241 a is formed at the lower end of the outer peripheral surface of the guide body 241. The second form 42 is disposed on the bottom surface in the guide body 241. Therefore, the bottom surface of the second foam 42 is not in contact with the first foam 3. Moreover, the area | region except the area | region which faces the opening 241a among the outer peripheral surfaces which faced the direction orthogonal to the perpendicular direction of the 2nd form 42 has faced the inner wall surface of the guide body 41. FIG.

  When the waste ink absorbed in the first form 3 moves upward and reaches the opening 241a of the guide body 241, the waste ink that has oozed from the first form 3 enters the guide body 241 through the opening 241a. To do. The waste ink that has entered spreads horizontally on the bottom surface of the guide body 241. At this time, the second form 42 expands while absorbing waste ink from the bottom surface. Along with this, the second form 42 expands while being guided by the inner wall surface of the guide body 241, and pushes up the electrode 43 upward. When the second form 42 absorbs a predetermined amount of waste ink, the electrode 43 and the contact 44 come into contact with each other. In addition, from the viewpoint of accurately detecting the storage amount, it is preferable that the opening 241 a of the guide body 241 faces the side opposite to the inflow port 21. Thereby, it is possible to prevent waste ink partially passing through the first form 3 from entering from the inflow port 21.

  According to the waste ink tank of the present embodiment, the second form 42 expands along the inner wall surface of the guide body 41 as the waste ink is absorbed, and the contact 44 is turned on. At this time, since the expansion rate of the first form 3 is small, distortion is suppressed when the first form 3 absorbs the waste ink, and the amount of waste ink stored in the waste ink tank is accurately detected. Can do.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. In the first embodiment described above, the guide body 41 has a cylindrical shape with both ends opened, and the inner wall surface of the guide body 41 is configured to face the entire outer peripheral surface of the second foam 42. As long as the expansion of the foam 42 can be guided upward, the guide body may have another shape. For example, the guide member may be a plate member extending in the vertical direction, or a plurality of such plate members may be disposed so as to surround the second foam 42. The guide body may be a cylinder having a planar shape other than a circle.

  Furthermore, in the first embodiment described above, the shape of the space defined by the guide body 41 and the second form 42 are similar to each other. However, the shape of the space defined by the guide body 41 and the second shape 42 are similar to each other. 2 The form 42 may not be similar.

  In the first embodiment described above, the inflow port 21 is arranged on the upper surface of the housing 2, but may be formed on the side surface or the bottom surface of the housing 2.

  In addition, in the first embodiment described above, the guide wall 22 extends from the vicinity of the inflow port 21 to the vicinity of the bottom surface of the internal space of the housing 2, but the guide wall is in the vicinity of the inflow port 21. It may be configured to extend from the center of the internal space of the housing 2 to the vicinity of the center of the internal space, or may be configured such that no guide wall is disposed in the internal space of the housing 2.

  In the first embodiment described above, the three liquid sensors 4 are arranged along the vertical direction on the side surface of the housing 2, but the number of arranged liquid sensors 4 is one or Two, four or more, or a configuration in which the liquid sensor 4 is not disposed on the side surface of the housing 2 may be employed.

  Furthermore, in the first embodiment described above, the liquid sensor 4 is disposed on the upper surface and one side surface of the housing 2, but the liquid sensor 4 may be disposed on any surface of the housing 2. . For example, the liquid sensor 4 may be disposed only on the upper surface of the housing 2, may be disposed on only one side surface, or may be disposed on a plurality of side surfaces.

  In addition, in the above-described first embodiment, the electrode 43 and the contact 44 are configured as a pressure switch, but instead of the electrode 43 and the contact 44, another type of pressure switch (for example, an electrostatic switch) is used. Etc.) may be arranged.

  In the above-described embodiment, the electrode 43 is provided in the housing 2, but a switch is provided in the contact 44 in consideration of corrosion of the electrode due to liquid, etc. A configuration may be adopted in which the expanded second form 42 abuts and the contact 44 is deformed by pressurizing the surface of the contact 44 and the internal switch is turned on (energized). In addition, the wall surface of the housing 2 facing the second foam 42 is made of a material that is easily deformed, and the expanded second foam 42 pushes the wall surface of the housing 2 that is easily deformed to protrude the wall surface to the outside. In addition, a pressing switch that detects the amount of liquid in the housing 2 may be configured by pressing the switch provided outside with the protruding portion.

  The present invention is also applicable to a liquid tank that stores liquid other than waste ink.

DESCRIPTION OF SYMBOLS 1 Waste ink tank 2 Housing | casing 3 1st form 4, 204 Liquid sensor 10 Inkjet head 21 Inflow port 22 Guide wall 41,241 Guide body 42 Second form 43 Electrode 44 Contact 50 Waste ink tray 51 Waste ink pipe

Claims (8)

A housing having an inlet for liquid to flow in;
A first absorber and a second absorber which are disposed in an internal space of the housing and absorb the liquid flowing in from the inflow port to expand its volume;
A pressure switch that is disposed at a predetermined position in the internal space and detects the amount of liquid in the internal space by being pressed by the expanded second absorber;
A guide wall facing the outer peripheral surface facing the direction orthogonal to the vertical direction among the outer peripheral surfaces of the second absorbent body;
The second absorber and the first absorber are arranged in order below the vertical direction of the push switch,
A liquid tank, wherein an expansion coefficient when the liquid related to the first absorber is absorbed is smaller than the expansion coefficient related to the second absorber.   2. The liquid tank according to claim 1, wherein a lower surface of the second absorbent body in the vertical direction and the first absorbent body are separated from each other.   3. The liquid tank according to claim 1, wherein the guide wall faces the entire outer peripheral surface of the second absorbent body facing in a direction orthogonal to the vertical direction.   The liquid tank according to claim 3, wherein the shape of the space defined by the guide wall is similar to that of the second absorber.   5. The liquid tank according to claim 1, wherein at least a part of a lower surface of the first absorber in the vertical direction is separated from an inner wall surface of the housing.   The liquid tank according to claim 1, wherein the inflow port is disposed on an upper surface of the internal space with respect to a vertical direction.   The liquid tank according to claim 1, further comprising a guide wall that guides the liquid flowing in from the inflow port to a vicinity of a bottom surface in a vertical direction of the internal space.   The liquid tank according to claim 1, wherein the plurality of switches are arranged in the vertical direction.

Images