JP2010099954A - Differential pressure regulating valve and ink cartridge having the differential pressure regulating valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a differential pressure regulating valve in which a reaction force generated by deformation is reduced, and to provide an ink cartridge having the differential pressure regulating valve. <P>SOLUTION: The differential pressure regulating valve 1 has a peripheral part 4 and a thin film 5 in the peripheral part 4 which has a thickness thinner than that of the peripheral part 4, and is composed of an elastic material. The thickness of the thin film 5 is uneven. The ink cartridge 3 has the differential pressure regulating valve 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a peripheral portion and a thin film portion having a smaller thickness than the peripheral portion in the peripheral portion, and relates to a differential pressure valve made of an elastic material and an ink cartridge including the differential pressure valve.

  The ink jet recording apparatus is used by attaching an ink cartridge containing ink to a holder of the ink jet recording apparatus and supplying the ink to the recording head.

  In such an ink cartridge, a differential pressure valve that opens when a predetermined pressure difference is generated between an ink chamber containing ink and a connection chamber loaded with a negative pressure is attached to the ink cartridge. is there. The ink cartridge described here is an example of a liquid cartridge.

  For example, the differential pressure valve of Patent Document 1 is elastically deformable based on a pressure difference and has a cylindrical peripheral edge. The ink cartridge is sandwiched between a differential pressure valve and a valve lid having a substantially cylindrical differential pressure valve holding portion that fixes the peripheral portion by being inserted inside the peripheral portion of the differential pressure valve, and a valve member And an urging member that urges the valve in a direction of separating the valve from the valve lid.

JP 2004-237720 A

  However, since the differential pressure valve of the ink cartridge as described above generates a reaction force when the valve is deformed by the differential pressure and the deformation amount is suppressed, the amount of ejected ink is insufficient. Have. In general, the differential pressure valve is made thin for the purpose of reducing such reaction force, but further reduction of reaction force during deformation is required against the background of the need for higher accuracy of ink discharge amount. It has been. The inventor has found that the main cause of the reaction force in the thinned differential pressure valve is that most of the resin constituting it is oriented in a certain direction. That is, when most of the resin is oriented in a certain direction, the differential pressure valve is deformed due to pressure being applied, and a reaction force is likely to be generated during the deformation. In general, the thinner the resin is injection-molded, the easier it is to orient the resin in a certain direction. Therefore, especially when an ultra-thin differential pressure valve of about 1 mm is injection-molded, the reaction force during deformation is not reduced. It will be enough.

  Therefore, an object of the present invention is to provide a differential pressure valve in which the reaction force during deformation is reduced by devising the shape of the manufactured differential pressure valve. Another object of the present invention is to provide an ink cartridge having such a differential pressure valve.

  In order to achieve the object, the first invention is a differential pressure valve made of an elastic material having a peripheral portion and a thin film portion having a smaller thickness than the peripheral portion in the peripheral portion, and the thin film portion is convex. It is a differential pressure | voltage valve characterized by having a part.

  In the first invention, it is preferable that the differential pressure valve has a disc shape and the convex portion extends in the circumferential direction.

  Furthermore, in the first invention, it is preferable that the differential pressure valve has a disk shape and the convex portion extends in the width direction.

  Furthermore, in the first invention, the thinnest portion of the thin film portion is preferably 1 mm or less.

  The second invention is an ink cartridge comprising the above-described differential pressure valve of the first invention.

  According to the present invention, by optimizing the shape of the differential pressure valve, it is possible to provide a differential pressure valve with reduced reaction force generated during deformation. In addition, it is possible to provide an ink cartridge provided with such a differential pressure valve.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1A is a top view of a differential pressure valve according to the present invention, and FIG. 1B is a cross-sectional view in the width direction thereof. FIG. 2A is a cross-sectional view of an ink cartridge including the differential pressure valve shown in FIG. FIG. 2B is a cross-sectional view of the ink cartridge showing that the negative pressure is generated in the ink cartridge to supply the ink and the ink flows, and FIG. FIG. 6 is a cross-sectional view of the ink cartridge in a state where there is no ink. 3 (a) is a top view of another differential pressure valve according to the present invention, and FIG. 3 (b) is a cross-sectional view in the width direction thereof.

As shown in FIGS. 1A and 1B, a differential pressure valve 1 according to the present invention is a disc-shaped valve made of resin, and is fixed to a central convex portion 2 and an ink cartridge 3 at the center thereof. The peripheral portion 4 and the thin film portion 5 which is located between the central convex portion 2 and the peripheral portion 4 and which is deformed by the differential pressure generated in the ink cartridge 3 are provided. The thin film portion 5 is provided with two convex portions 6 and 6, and the thickness of the thin film portion 5 is not uniform when viewed in the circumferential direction. When the differential pressure valve 1 is injection-molded into a shape in which the thickness is not uniform in the circumferential direction as described above, the flow of the resin is disturbed at the portion that becomes the convex portion 6 at the time of molding, and the extrusion at the time of the resin flow The molecular orientation along the direction is disturbed, and the orientation of the resin after injection molding becomes non-uniform throughout. Therefore, the reaction force when the differential pressure valve 1 is deformed is effectively reduced, and the differential pressure valve is accurately deformed according to the pressure, so that the ink 7 with high accuracy can be supplied.
As shown in FIG. 2A, the differential pressure valve 1 is fixed at a predetermined position in the ink cartridge 3. FIG. 2A shows the ink cartridge 3 in an initial state in which the differential pressure valve 1 is closed. When the supply of the ink 7 is started, first, as shown in FIG. 2B, a negative pressure proportional to the desired discharge amount of the ink 7 is applied to the connection chamber 8, so that the connection chamber 8 side Ink is ejected from the head portion (black arrow), and a pressure difference is generated between the connecting chamber 8 and the ink chamber 9 clogged with the ink 7. Due to the pressure difference, the differential pressure valve 1 is deformed (deformed in the direction of the white arrow), the differential pressure valve 1 is opened, and ink is supplied from the ink chamber 9 into the ink cartridge 3. Next, as shown in FIG. 2C, the pressure difference between the ink chamber 8 and the connecting chamber 9 is reduced and the differential pressure valve is deformed to the original position as the negative pressure in the connecting chamber 9 decreases. The ink 7 is ejected from the head portion on the ink chamber 3 side (black arrow). As soon as the supply of the predetermined amount of ink 7 is completed, the differential pressure valve 1 is closed again, and the supply of the ink 7 is stopped.
Note that the shape of the differential pressure valve 1 is not limited to the shape shown in FIG. 1, and may be other shapes, for example, as shown in FIGS. 3A and 3B. It can also be set as the shape which provided the convex part 6 connected to the circumferential direction on the thin film part 5 of this.

  The thinnest portion of the differential pressure valve 1 is preferably 1 mm or less. Conventionally, when a differential pressure valve 1 is manufactured by injection molding a resin having a thickness of 1 mm or less, most of the resin is oriented in a certain direction, and the reaction force when the differential pressure valve 1 is deformed is not effectively reduced. However, when the differential pressure valve 1 of the present invention adopting the above-described shape is injection-molded, for example, even if the resin is easily oriented 1 mm or less, the resin is effectively prevented from being oriented in a certain direction. It becomes possible. Therefore, the effect of the present invention is particularly effectively exhibited when the resin is easily oriented in a certain direction at 1 mm or less.

Further, the resin constituting the differential pressure valve 1 is a thermoplastic elastomer of a copolymer comprising at least one polymer block mainly composed of a vinyl aromatic compound and at least one polymer block mainly composed of a conjugated diene compound. Can be configured. At this time, as the additive, for example, a plasticizer, a flame retardant, an antibacterial agent, a light stabilizer, an ultraviolet absorber, an antioxidant, an inorganic or organic filler, a colorant, and oil can be used. In order to impart resin fluidity, polyolefins such as polypropylene and polyethylene may be added.
As the thermoplastic elastomer, for example,
1) a block copolymer of crystalline polyethylene and ethylene / butylene-styrene random copolymer obtained by hydrogenating a block copolymer of polybutadiene and butadiene-styrene random copolymer,
2) It is obtained by hydrogenating a block copolymer of polybutadiene and polystyrene, a block copolymer of polyisoprene and polystyrene, or a block copolymer of polybutadiene or ethylene-butadiene random copolymer and polystyrene. For example, a diblock copolymer of crystalline polyethylene and polystyrene, a styrene-ethylene / butylene-styrene triblock copolymer (SEBS), a styrene-ethylene / propylene-styrene triblock copolymer (SEPS), etc. Among them, a styrene-ethylene / butylene-styrene block copolymer or a styrene-ethylene / propylene-styrene block copolymer can be exemplified.

  Note that the above description shows only a part of the embodiment of the present invention, and these configurations can be combined with each other or various modifications can be made without departing from the gist of the present invention. . For example, the differential pressure valve 1 in the illustrated example includes a central convex portion 2, but the central convex portion 2 is not necessarily required depending on the configuration of the ink cartridge 3. Moreover, although the differential pressure valve 1 of the example of illustration is all disk shape, it can also be set as another shape as needed.

  Next, a differential pressure valve of the prior art in which the thickness of the thin film portion is constant (conventional example) and a differential pressure valve according to the present invention in which the thickness of the thin film portion is not uniform (Invention Examples 1 to 3) are respectively prototyped. Since the performance evaluation was performed, it will be described below.

  The conventional example has the configuration shown in FIG. 4 and, when viewed in the cross section in the width direction, a thin film portion having a width of 6.0 mm and a thickness of 0.4 mm, a central convex portion having a width of 3.0 mm and a thickness of 0.2 mm, and And a peripheral portion having a width of 3.0 mm and a thickness of 1.0 mm. Inventive Example 1 has the configuration shown in FIG. 1, and has a width of 6.0 mm and a thickness of 0 having a convex part with a width of 2.0 mm and a thickness of 0.4 mm partially in the circumferential direction when viewed in the cross section in the width direction. A thin film portion having a thickness of 4 mm, a central convex portion having a width of 3.0 mm and a thickness of 0.2 mm, and a peripheral portion having a width of 3.0 mm and a thickness of 1.0 mm are provided. Invention Example 2 has the configuration shown in FIG. 3 and is 2.0 mm wide and 0.2 mm thick when viewed in the cross section in the width direction, and has a convex portion communicating in the circumferential direction, width 6.0 mm, thickness. A thin film portion having a thickness of 0.4 mm, a central convex portion having a width of 3.0 mm and a thickness of 0.2 mm, and a peripheral portion having a width of 3.0 mm and a thickness of 1.0 mm are provided. Invention Example 3 has the configuration shown in FIG. 5 and, as viewed in the cross section in the width direction, convex portions having a width of 0.5 mm and a thickness of 0.4 mm are partially provided in the circumferential direction on both the back and front of the differential pressure valve. (The convex portion on the front surface is indicated by a solid line, and the convex portion on the back surface is indicated by a dotted line), a thin film portion having a width of 6.0 mm and a thickness of 0.4 mm, a central convex having a width of 3.0 mm and a thickness of 0.2 mm And a peripheral portion having a width of 3.0 mm and a thickness of 1.0 mm. Each differential pressure valve was manufactured by an injection molding method using a polymer mainly composed of a styrene-ethylene / propylene-styrene (SEPS) copolymer as a raw material.

  The reaction force of the differential pressure valve is reduced by measuring the reaction force generated when the peripheral portion of the differential pressure valve is fixed and the central convex portion is deformed so as to move 1 mm downward, and the results and invention of the conventional example Evaluation was made by comparing the results of Examples 1-3. The results are shown in Table 1.

  As is clear from the results in Table 1, the inventive examples 1 to 3 had a reduced reaction force during deformation as compared with the conventional example.

  As is apparent from the above description, the present invention can provide a differential pressure valve with a reduced reaction force during deformation. In addition, an ink cartridge having such a differential pressure valve can be provided.

(A) is a top view of the differential pressure valve according to the present invention, and (b) is a cross-sectional view in the width direction (Invention Example 1). (A) is a cross-sectional view of an ink cartridge including the differential pressure valve shown in FIG. 1, and (b) is a cross-sectional view when a negative pressure is generated in a connecting chamber of the ink cartridge in order to supply ink. FIG. 8C is a cross-sectional view of the ink cartridge in which the differential pressure valve is closed again after (b). (A) is a top view of the other differential pressure valve according to the present invention, and (b) is a cross-sectional view in the width direction (Invention Example 3). (A) is a top view of the differential pressure valve of a prior art example, (b) is the width direction sectional drawing. (A) is a top view of the differential pressure valve of Invention Example 2, and (b) is a cross-sectional view in the width direction thereof.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Differential pressure valve 2 Center convex part 3 Ink cartridge 4 Peripheral part 5 Thin film part 6 Convex part 7 Ink 8 Connection chamber 9 Ink chamber 10 Head part

Claims (5)

In the differential pressure valve made of an elastic material having a thin film portion having a smaller thickness than the peripheral portion in the peripheral portion and the peripheral portion,
The thin film portion has a convex portion.   The differential pressure valve according to claim 1, wherein the differential pressure valve has a disk shape, and the convex portion extends in a circumferential direction.   The differential pressure valve according to claim 1 or 2, wherein the differential pressure valve has a disc shape, and the convex portion extends in a width direction.   The differential pressure valve according to any one of claims 1 to 3, wherein the thinnest portion of the thin film portion is 1 mm or less.   An ink cartridge comprising the differential pressure valve according to claim 1.

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