JP5300565B2 - Valve mechanism, exhaust apparatus equipped with the valve mechanism, and inkjet recording apparatus - Google Patents

Description

  The present invention relates to a valve mechanism, an exhaust device including the valve mechanism, and an ink jet recording apparatus.

  Some ink jet recording apparatuses are provided with a buffer tank for temporarily storing ink supplied from a mounted ink tank. In such an ink jet recording apparatus, an ink tank and an ink jet recording head are connected via a buffer tank, and ink in the ink tank is supplied to the ink jet recording head via the buffer tank. The buffer tank is connected to the inkjet recording head and the ink tank by tubes.

  Since rubber, resin, and the like forming a tube connecting the ink tank and the buffer tank allow a small amount of air to pass therethrough, the air that has passed through the tube enters the buffer tank. In addition, when the ink tank is removed from the tube when the ink tank is replaced, the end of the tube on the side to which the ink tank is connected is opened, so that air enters the buffer tank from the end. When air enters the buffer tank, the air may enter the ink as bubbles. When ink mixed with bubbles is supplied from the buffer tank to the ink jet recording head, the ink jet recording head may not normally eject ink droplets, resulting in recording failure.

  In such an ink jet recording apparatus, in order to prevent the above-described recording failure, it is conceivable that, for example, an exhaust device provided with a pump is connected to the buffer tank and the inside of the buffer tank is exhausted by the pump. In this case, however, the pump tries to suck out not only air but also ink in the buffer tank. When the ink in the buffer tank is sucked out, the sucked ink is wasted, and a malfunction may occur in the exhaust device, and the subsequent exhaust may not be performed normally. Therefore, it is desirable that the exhaust device has a mechanism for discharging only the air in the buffer tank and preventing the ink from being discharged.

  FIG. 7 is a cross-sectional view of the valve mechanism 157 provided between the pump and the buffer tank in order to discharge only the air in the buffer tank and not to discharge the ink in the buffer tank. The valve mechanism 157 includes a lower flow path member 178 in which a flow path 182 is formed, and an upper flow path member 179 in which a flow path 183 is formed. The flow path 182 is connected to a buffer tank (not shown), and the flow path 183 is connected to a pump (not shown). The lower flow path member 178 is provided with a float chamber 164 that communicates with the flow path 182 and accommodates a spherical float member 163.

  The valve mechanism 157 includes a seal member 175 sandwiched between the lower flow path member 178 and the upper flow path member 179. The seal member 175 is made of an elastic material such as rubber. The seal member 175 is formed in a conical shape so that the diameter decreases from the lower side to the upper side, and an opening 184 that allows the float chamber 164 and the flow path 183 to communicate with each other is provided. On the lower surface of the seal member 175, a rib 176a is provided over the entire circumference of the opening 184. A rib 176b is provided on the upper surface of the seal member 175 on the back side of the rib 176a. The ribs 176 a are pressed by the lower flow path member 178 and are in close contact with the upper surface of the lower flow path member 178, and separate the float chambers 164 of the lower flow path member 179. Further, the rib 176 b is pressed by the upper flow path member 179 and is in close contact with the upper surface of the upper flow path member 179, and separates the flow paths 183 of the upper flow path member 179.

  A plurality of openings 184 are formed in the seal member 175 side by side, and the seal member 175 is provided as a single component as a whole. The seal member can be separated for each opening and made into separate parts. However, this increases the number of parts, which increases the manufacturing cost of the valve mechanism, and reduces the size of one part. Gets worse.

  The air in the buffer tank is discharged by the pump through the flow path 182, the float chamber 164, the opening 184 and the flow path 183. When the exhaust in the buffer tank is completed, the ink in the buffer tank enters the float chamber 164 from the flow path 182 as shown in FIG. As the ink level rises, the float member 163 floating on the ink level rises, and eventually the float member 163 contacts the opening 184 to close the opening 184. Thereby, it is possible to prevent the ink from being sucked out into the flow path 183 by the pump.

JP 2000-301737 A

  In the seal member 175 of the valve mechanism 157 shown in FIG. 7, the pressing force applied to the ribs 176a and 176b from the flow path members 178 and 179 tends to be absorbed by deforming portions around the ribs 176a and 176b. In the seal member 175 provided as one component, since the portions other than the opening 184 are integrally formed without a gap, the outer periphery of the ribs 176a and 176b is constrained over the entire periphery. Therefore, the portions outside the ribs 176a and 176b of the seal member 175 are not easily deformed. On the other hand, the opening 184 inside the ribs 176a and 176b of the seal member 175 is easily deformed because the surface is open.

  When the opening 184 of the seal member 175 is deformed and the surface of the opening 184 is distorted, a gap is generated between the opening 184 and the float member 163 even if the float member 163 contacts the opening 184. Ink flows out to the flow path 183 through the gap. As described above, in the valve mechanism 157, it is difficult to maintain excellent sealing performance by the float member 163 and the opening 184.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a valve mechanism having excellent sealing performance, an exhaust device including the valve mechanism, and an ink jet recording apparatus.

  In order to achieve the above object, the valve mechanism of the present invention includes a first flow path member in which a plurality of first flow paths are formed, and a plurality of second flows that make a pair with each of the first flow paths. A second flow path member in which a path is formed, the first flow path member and the second flow path member, and each first flow path and each second flow path A seal member having an opening to be communicated; and a lid member that contacts the opening to close the opening, and is spaced apart from the opening to open the opening. A first pressing portion that is provided around the opening of the surface facing the first flow path member and separates the first flow paths in a state of being pressed by the first flow path member; The second channel is provided around the opening on the surface facing the second channel member and separates the second channels in a state of being pressed by the second channel member. Having a pressing portion, the first pressing portion and provided close to the outer periphery of the second pressing portion, and the relatively deformable deformation absorbers than the other portion.

  ADVANTAGE OF THE INVENTION According to this invention, the valve mechanism excellent in the sealing performance, the exhaust apparatus provided with the same, and an inkjet recording device can be provided.

It is a schematic block diagram of the ink supply system provided with the valve mechanism which concerns on one Embodiment of this invention. It is a sectional side view of the buffer tank and valve mechanism of the ink supply system shown in FIG. It is the figure which expanded and showed the valve mechanism shown in FIG. It is a bottom view of the sealing member of the valve mechanism shown in FIG. It is the figure which showed the modification of the valve mechanism shown in FIG. It is a schematic block diagram of the inkjet recording device provided with the ink supply system shown in FIG. It is a sectional side view of a general valve mechanism.

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

  FIG. 1 is a schematic diagram illustrating an ink supply system of an ink jet recording apparatus using a valve mechanism according to an embodiment of the present invention, and illustrates one ink color.

  The ink jet recording head 1 includes a recording element chip 51 in which a plurality of orifices 52 for discharging ink, which is a liquid for recording on a recording medium, and a sub tank 53 connected in common to each orifice 52. Have. The sub tank 53 of the inkjet recording head 1 is connected to a main tank 56 that supplies ink via a buffer tank 54 for primary storage of ink. The sub tank 53 and the buffer tank 54 are connected by a supply tube 55a, and the buffer tank 54 and the main tank 56 are connected by a supply tube 55b.

  Ink supply to the sub tank 53 of the ink jet recording head 1 is performed using a cap 69 provided so as to seal the orifice 52 and a pump 61 connected to the cap 69. Ink is introduced into the sub tank 53 from the main tank 56 through the buffer tank 54 by performing a suction operation by the pump 61 with the orifice 52 sealed with the cap 59.

  A valve mechanism 57 is provided above the buffer tank 54 in the vertical direction, and the valve mechanism 57 is connected to a pump 61 via an exhaust tube 58. The pump 61 is provided with a switching valve 60, and the switching valve 60 can switch the connection destination of the pump 61 from the cap 59 to the exhaust tube 58. When the connection destination of the pump 61 is the exhaust tube 58, the air that has entered the buffer tank 54 by the pump 61 can be discharged. Thus, the pump 61, the exhaust tube 58 and the valve mechanism 57 constitute an exhaust device for exhausting the buffer tank 54. The valve mechanism 57 is a mechanism for the pump 61 to suck out only the air that has entered the buffer tank 54 and prevent the ink in the buffer tank 54 from being sucked out.

  FIG. 2 is a view for explaining the valve mechanism 57 shown in FIG. 1 in more detail, and shows one ink color. The valve mechanism 57 includes a first flow path member 78 in which a first flow path 82 is formed, and a second flow path 83 in which a first flow path member 78 is formed and arranged on the upper side in the vertical direction of the first flow path member 78. 2 flow path members 79. The flow path 82 is connected to the space in the buffer tank 54, and the flow path 83 is connected to the pump 61 via the exhaust tube 58 shown in FIG. A float chamber 64 that communicates with the flow path 82 and accommodates a spherical float member 63 is provided on the upper part of the lower flow path member 78. The float member 63 is formed to have a lower density than the ink so as to float on the ink. In order to make the density of the float member 63 smaller than the density of the ink, the float member 63 can be made of, for example, a material having a density lower than that of the ink, or can be made hollow. The float member 63 is formed of a material that does not easily react with ink, such as polypropylene, in order to prevent corrosion by the ink.

  FIG. 3 is an enlarged view of the valve mechanism 57 shown in FIG. 2, and shows two ink colors. The valve mechanism 57 has a seal member 75 sandwiched between a lower flow path member 78 and an upper flow path member 79. The seal member 75 is made of an elastic material such as rubber. The seal member 75 is provided with an opening 84 that allows the float chamber 64 and the flow path 83 to communicate with each other. The opening 84 is formed in a conical shape so that the diameter decreases from the lower end to the upper end. The float member 63 that is a sphere can be in close contact with the conical surface of the opening 84 from the lower side in the vertical direction, and functions as a lid member that closes the opening 84.

  The seal member 75 is provided around the opening 84 on the lower surface facing the lower flow path member 78 so as to protrude downward over the entire circumference, and is pressed against the upper surface of the lower flow path member 78. The rib 76a which is a press part is provided. The seal member 75 is a second pressing portion that protrudes upward at a position on the back side of the rib 76 a on the upper surface facing the upper flow path member 79 and is pressed against the lower surface of the upper flow path member 79. Ribs 76b are provided. The ribs 76 a are pressed against the lower flow path member 78 and elastically deformed, thereby being brought into close contact with the upper surface of the lower flow path member 78 and separating the float chambers 64 of the lower flow path member 79. Further, the ribs 76 b are pressed against the upper flow path member 79 and elastically deformed, thereby being in close contact with the upper surface of the upper flow path member 79 and separating the flow paths 83 of the upper flow path member 79. Thereby, the valve mechanism 57 can prevent air from entering the float chamber 64 from between the lower flow path member 78 and the upper flow path member 79. Further, it is possible to prevent ink from leaking between the lower flow path member 78 and the seal member 75.

  FIG. 4 is a bottom view of the seal member 75. FIG. 4A shows a state in which the openings 84 for four ink colors are arranged in a staggered manner. FIG. 4B shows an enlarged opening 84 for one color of the seal member 75 shown in FIG. 4A. The seal member 75 is provided with a deformation absorbing portion 86 that is proximate to the outer periphery of the rib 76a and is relatively easily deformed.

  The deformation absorbing portion 86 is formed with a slit (notch) 80 that is a penetrating portion penetrating in the thickness direction. The slits 80 are formed at three equal intervals along the rib 76 a, and the inside of the deformation absorbing portion 86 of the seal member 75 is connected to the outside of the deformation absorbing portion 86 only by the support portion 85 between the slits 80. ing. Accordingly, since the pressing force applied to the ribs 76a and 76b of the seal member 75 is concentrated and transmitted to the support portion 85, the support portion 85 is easily deformed, and accordingly, the slit 80 is also deformed so that the width d4 is reduced. As described above, in the seal member 75, the pressing force applied to the ribs 76a and 76b is absorbed by the deformation of the deformation absorbing portion 86, so that the opening 84 is not easily deformed.

  In the present embodiment, the support portion 85 of the deformation absorbing portion 86 has the same thickness as the other portions of the seal member 75, but the support portion 85 of the deformation absorption portion 86 is relatively relative to the other portions of the seal member 75. By making it thinner, the deformation absorbing portion 86 can be further easily deformed.

  When the suction operation by the pump 61 (see FIG. 1) is performed in the state shown in FIG. 2, the ink from the main tank 56 (see FIG. 1) enters the buffer tank 54 as the pump 61 sucks out the air in the buffer tank 54. Supplied. As a result, the ink level in the buffer tank 54 rises. The pump 61 sucks the ink in the buffer tank 54 from the flow path 82 into the float chamber 64 when the buffer tank 54 is exhausted and the buffer tank 54 is filled with ink. Then, as shown in FIG. 3, the float member 63 floats on the ink, and the float member 63 can move in the vertical direction as the liquid level of the ink changes. Accordingly, when the suction operation by the pump 61 is further continued, the liquid level of the ink in the float chamber 64 rises, and accordingly, the float member 63 moves upward and enters the opening 84. The float member 63 further rises toward the virtual vertex of the surface of the conical opening 84 and comes into contact with the surface of the opening 84. In the seal member 75 including the deformation absorbing portion 86, the surface of the opening 84 is maintained in a conical shape. Therefore, at this time, the float member 63 is in close contact with the entire periphery of the surface of the opening 84 so that the opening 84 is formed. Blocked.

  When the opening 84 is closed by the float member 63, the float chamber 64 and the flow path 83 are separated, and the pump 61 cannot suck air from the float chamber 64 into the flow path 83. The float member 63 protrudes above the ink level, and closes the opening 84 at a position higher than the ink level. Therefore, in the exhaust device including the valve mechanism 57, the pump 61 is used when the buffer tank 54 is exhausted. Does not suck ink into the flow path 83. As described above, in the valve mechanism 57, it is possible to ensure excellent sealing performance by the float member 63 and the opening 84.

  When the ink jet recording apparatus having the ink supply system shown in FIG. 1 after exhausting the buffer tank 54 repeats the recording operation, air gradually enters the buffer tank 54 again. The air that has entered the buffer tank 54 enters the float chamber 64 through the flow path 82 as bubbles. When the bubbles rise in the float chamber 64 and reach the opening 84, the liquid level of the ink in the float chamber 64 is lowered, so that the float member 63 is separated from the surface of the opening 84 and the opening 84 is opened again. The

  In this embodiment, the seal member 75 of the valve mechanism 57 is formed of rubber having a hardness of 40 ° with a thickness t shown in FIG. 3 of 1 mm. Further, the pitch d1 of the openings 84, which is the distance between the centers of the openings 84 adjacent to each other shown in FIG. Further, the diameter d2 of the upper end of the opening 84 shown in FIG. 4B of the seal member 75 before assembly of the valve mechanism 57 is set to 2 mm, the outer diameter d3 of the rib 76a is set to about 7 mm, and the width d4 of the slit 80 is set. About 1 mm. Further, the amount of crushing of each rib 76a by the lower flow path member 78 and the amount of crushing of each rib 76b by the upper flow path member 79 after assembly of the valve mechanism 57 were each 0.3 mm. In the valve mechanism 57 according to the present embodiment, the shape of the opening 84 of the seal member 75 hardly changed after assembly, and the diameter d2 of the upper end of the opening 84 was maintained at 2 mm over the entire circumference.

  As a comparative example, a valve mechanism configured similarly to the valve mechanism 57 according to the present embodiment was manufactured except that the deformation member 86 was not provided in the seal member. In the valve mechanism according to the comparative example, the opening of the seal member is deformed after assembly, and the maximum value of the diameter of the upper end of the opening corresponding to d2 shown in FIG. It was 8 mm. For this reason, even when the opening of the seal member is closed with the float member, a gap is generated between the opening and the float member.

  In the valve mechanism 57 according to the present embodiment, the slit 80 is formed in the deformation absorbing portion 86 of the seal member 75, but the deformation absorbing portion is configured to be more easily deformed than other portions of the seal member. It only has to be done. As an example of the deformation absorbing portion, the deformation absorbing portion 86a of the seal member 75a shown in FIG. 5 can be considered. The deformation absorbing portion 86a is easily deformed because it is formed relatively thinner than other portions of the seal member 75a. Therefore, in the valve mechanism 57, the pressing force applied to the seal member 75a is absorbed by the deformation absorbing portion 86a being deformed. Therefore, even in the valve mechanism 57a, the opening 84a of the seal member 75a is not easily deformed, so that the float member 63 is in close contact with the seal member 75a as shown in FIG. 5A. In addition, in the deformation | transformation absorption part 86a, although the thin part formed relatively thinly compared with the other part of the sealing member 75a is formed over the perimeter of a rib, the deformation | transformation absorption part 86a is restricted to such a structure. Absent. For example, the deformation absorbing portion 86a may be formed with a plurality of thin portions formed along a part of the outer periphery of the rib.

  FIG. 6 is a schematic configuration diagram of an ink jet recording apparatus to which the valve mechanism according to the present embodiment can be applied. This ink jet recording apparatus includes the ink supply system shown in FIG. This ink jet recording apparatus conveys a recording medium S, a carriage 2 that holds an ink jet recording head 1 that ejects ink onto the recording medium S and reciprocally scans, an ink supply unit 3 that holds a removable main tank 56, and the like. And a transport unit 4 to be used. The ink supply unit 3 is provided with the buffer tank 54 and the valve mechanism 57 shown in FIG. In this ink jet recording apparatus, the ink jet recording head 1 is reciprocally scanned in the direction of arrow B by the carriage 2, and the recording medium S is intermittently transported by the transport unit 4, while ink is ejected to the recording medium S by the ink jet recording head 1. To do. Thereby, in this ink jet recording apparatus, it is possible to perform recording in the recording area of the recording medium S.

  In this embodiment, the exhaust device provided with the valve mechanism 57 is used for exhausting the buffer tank 54. However, this exhaust device can also be used for exhausting other tanks such as the sub tank 53, for example. Is possible.

DESCRIPTION OF SYMBOLS 1 Inkjet recording head 54 Buffer tank 57 Valve mechanism 58 Exhaust tube 61 Pump 63 Float member 64 Float chamber 75 Seal member 76a, 76b Rib 78 Lower channel member 79 Upper channel member 80 Slit 82 Channel 83 Channel 84 Opening 85 Supporting part 86 Deformation absorbing part

Claims (9)

A first flow path member in which a plurality of first flow paths are formed; a second flow path member in which a plurality of second flow paths that are paired with the first flow paths are formed; A seal member sandwiched between the first flow path member and the second flow path member and having an opening for communicating the first flow path and the second flow path; and the opening A lid member that abuts to close the opening and opens the opening away from the opening;
The seal member is provided around the opening on a surface facing the first flow path member, and separates the first flow paths while being pressed by the first flow path member. And a second portion that separates the second flow paths in a state of being pressed by the second flow path member and provided around the opening of the surface facing the second flow path member. And a deformation absorbing portion that is provided in the vicinity of the outer periphery of the first pressing portion and the second pressing portion and that is relatively deformable relative to other portions.   The valve mechanism according to claim 1, wherein the deformation absorbing portion includes a through portion that penetrates in the thickness direction of the seal member.   The valve mechanism according to claim 2, wherein the penetrating portion is a slit formed along the outer periphery of the first pressing portion and the second pressing portion.   The valve mechanism according to claim 1, wherein the deformation absorbing portion includes a thin portion that is formed to be relatively thinner than other portions of the seal member.   The valve mechanism according to claim 4, wherein the thin portion is formed along the entire circumference of the first pressing portion and the second pressing portion.   The lid member is disposed vertically below the opening, and the position where the opening is closed and the opening are opened in accordance with a change in the liquid level of the liquid flowing from the first flow path. The valve mechanism according to any one of claims 1 to 5, wherein the valve mechanism moves between positions.   The second flow path member is disposed on the upper side in the vertical direction of the first flow path member, and the opening portion is located on the second flow path member side from the end on the first flow path member side. The valve mechanism according to claim 6, wherein a diameter is conically reduced toward an end portion, and the lid member is a sphere that can be in close contact with the opening. In an exhaust device for a tank storing liquid,
A valve mechanism according to claim 6 or 7 and a pump communicated with a second flow path of the valve mechanism, wherein the pump has a first flow path of the valve mechanism communicated with an upper part. After the tank is evacuated, the liquid in the tank is sucked into the valve mechanism from the first flow path, and the lid member of the valve mechanism increases the liquid level of the liquid in the valve mechanism. Accordingly, the exhaust device moves to a position to close the opening of the valve mechanism. In an inkjet recording apparatus that discharges liquid onto a recording medium,
9. An ink jet recording apparatus comprising: the exhaust apparatus according to claim 8; and a tank to which the exhaust apparatus is connected to store the liquid.

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