JP2022118368A - Pressure regulating unit, liquid jet head and liquid jet device - Google Patents

Abstract

To provide a pressure regulating unit, a liquid jet head, and a liquid jet device that are improved in the ability to discharge bubbles in a channel.SOLUTION: A pressure regulating unit, which includes a channel including a first chamber 53, a second chamber 54, and a through-hole 41, comprises: a first channel member 31 having a partition wall 40 with the through-hole 41 formed therein and a first wall portion 34 extended in a first direction from the partition wall 40; a second channel member 33 having a sealing portion 33a and a second wall portion 33b extended in a second direction form the sealing portion 33a; and a valve body 90. The partition wall 40 has a fixation surface 40a fixed to an end of the second wall portion 33b. The first wall portion 34 is disposed with a space S1 left from the sealing portion 33a. The first wall portion has a communication passage 46 allowing communication between a space S2, defined between the first wall portion 34 and the second wall portion 33b, and the first chamber 53. A portion 461 located furthest in the second direction in the communication passage 46 is disposed in the second direction relative to the space S1.SELECTED DRAWING: Figure 6

Description

The present invention relates to a pressure regulating unit having a valve element therein, a liquid ejecting head for ejecting liquid, and a liquid ejecting apparatus.

2. Description of the Related Art As a liquid ejecting apparatus that ejects a liquid onto a medium to be ejected, for example, an ink jet recording apparatus that ejects ink as a liquid to print on a medium to be ejected, such as paper or a recording sheet, is known.

In such an ink jet recording apparatus, ink is supplied from a liquid reservoir such as an ink tank to the ink jet recording head through a supply pipe such as a tube, and the ink supplied from the liquid reservoir is supplied to the ink jet recording head. Some eject ink droplets from nozzles. In addition, there has been proposed a pressure regulating unit provided with a valve body in the middle of the flow path so that the ink supplied from the liquid reservoir is supplied to the ink jet recording head at a predetermined pressure. .

The pressure regulating unit switches between an open valve-like body in which the two liquid chambers are in communication and a closed valve-like body in which the two liquid chambers are not in communication by moving the valve body, and divides the two liquid chambers. A configuration is disclosed in which the partition wall and the side wall of the liquid chamber in which the flange portion, which is the proximal end portion of the valve element, moves are formed of different members (see, for example, Patent Document 1).

In addition, the pressure regulating unit has a configuration in which the side wall of the liquid chamber in which the flange portion, which is the base end of the valve body, moves extends from the partition wall. A configuration is disclosed in which the positioning of the valve body with respect to the liquid chamber and the posture of the valve body are stabilized (see, for example, Patent Document 2).

JP 2015-168063 A JP 2019-143674 A

However, when Patent Document 2 is applied to Patent Document 1 for the purpose of positioning the valve body and stabilizing the posture, and the side wall is extended from the partition wall, the side wall is extended from the opposing member facing the partition wall for fixing to the partition wall. There is a problem that a gap is generated between the inner circumference of the wall and the outer circumference of the side wall extending from the partition.

Moreover, the partition wall and the opposing member are fixed by bonding the tip of the wall of the opposing member to a fixing surface provided on the partition wall. Therefore, if the tip of the side wall of the partition wall abuts the facing member, there is a risk that a gap will occur between the tip of the wall of the facing member and the fixed surface of the partition wall, resulting in poor adhesion. On the other hand, if the end of the side wall and the opposing member are arranged with a space therebetween so that they do not come into contact with each other, the liquid chamber and the gap between the inner periphery of the wall of the opposing member and the outer periphery of the side wall can be formed through the space. will communicate. Therefore, there is a possibility that a gas-liquid interface may occur in the pressure adjustment unit due to air bubbles entering the gap from the liquid chamber. At the gas-liquid interface, there is a problem that the components in the liquid become foreign matter when the liquid dries, and the foreign matter adheres to the sealing portion, thereby degrading the sealing performance. Further, if air bubbles exist in the liquid chamber, the air bubbles absorb the pressure change in the liquid chamber, and there is a problem that the valve body cannot be operated normally. Furthermore, if air bubbles are present in the liquid chamber, the air bubbles may be ejected downstream at an unexpected timing, causing problems such as ejection failure of ink droplets due to the air bubbles.

Such a problem is not limited to pressure adjustment units used in liquid jet heads typified by ink jet recording heads, and similarly exists in pressure adjustment units used in other devices.

An aspect of the present invention for solving the above problems is a pressure regulating unit comprising a flow path including a first chamber, a second chamber, and a through hole for allowing liquid to flow from the first chamber to the second chamber. A partition wall defining the first chamber and the second chamber and having the through hole formed therein, and a first wall portion defining the first chamber and extending from the partition wall in a first direction. a sealing portion facing the partition wall and defining the first chamber; and a direction opposite to the first direction from the sealing portion so as to surround the first wall portion. a second wall portion extending in a second direction; and a second flow channel member that opens and closes the flow channel by relatively moving in the first direction and the second direction with respect to the partition wall. a valve body, wherein the partition wall has a fixing surface fixed to the end portion of the second wall portion in the second direction, and the first wall portion is spaced from the sealing portion; The first wall portion is provided with a spaced-apart communication path that allows communication between the gap formed between the outer periphery of the first wall portion and the inner periphery of the second wall portion and the first chamber. In the pressure adjustment unit, a portion of the communication path that is formed and located closest to the second direction is arranged in the second direction with respect to the spacing.

According to another aspect of the present invention, there is provided a liquid ejecting head comprising: the pressure adjusting unit according to the above aspect; and a nozzle for ejecting the liquid supplied from the second chamber of the pressure adjusting unit. It is in.

Further, according to another aspect of the present invention, there is provided a pressure regulating unit according to the above aspect, a liquid reservoir for storing liquid to be supplied to the first chamber of the pressure regulating unit, and the second chamber of the pressure regulating unit. and a nozzle for ejecting liquid supplied from a liquid ejecting apparatus.

1 is a plan view showing a schematic configuration of a printing apparatus according to Embodiment 1; FIG. FIG. 3 is a cross-sectional view of the pressure regulating unit according to Embodiment 1; 4 is an enlarged cross-sectional view of a main part of the pressure regulating unit according to Embodiment 1. FIG. 4 is a bottom view of the vicinity of the base end portion and the first wall portion of the valve body according to Embodiment 1. FIG. 4 is a perspective view of the vicinity of the base end of the valve body according to Embodiment 1. FIG. 4 is an enlarged cross-sectional view of a main part of the pressure regulating unit according to Embodiment 1. FIG. 4 is a perspective view of the vicinity of the first chamber according to Embodiment 1. FIG. 4 is a cross-sectional view of the vicinity of the first chamber showing the movement of air bubbles according to Embodiment 1. FIG. FIG. 10 is a cross-sectional view of the vicinity of the first chamber showing movement of air bubbles in a comparative configuration; FIG. 4 is a cross-sectional view illustrating a valve-opening body of the pressure regulating unit according to Embodiment 1; It is a bottom view near the base end part of the valve body of a modification, and a 1st wall part. FIG. 10 is a cross-sectional view of a main part of a pressure regulating unit according to Embodiment 2; FIG. 11 is a cross-sectional view of a main part of a pressure regulating unit according to Embodiment 3;

The present invention will be described in detail below based on embodiments. However, the following description shows one aspect of the present invention, and can be arbitrarily changed within the scope of the present invention. In each figure, the same reference numerals denote the same members, and the description thereof is omitted as appropriate. Also, in each figure, X, Y, and Z represent three spatial axes orthogonal to each other. The directions along these axes are referred to herein as the X, Y, and Z directions. The direction in which the arrow points in each figure is defined as the positive (+) direction, and the direction opposite to the arrow is defined as the negative (-) direction. The Z direction indicates the vertical direction, the +Z direction indicates the vertically downward direction, and the −Z direction indicates the vertically upward direction. Furthermore, the three spatial axes of X, Y, and Z, which do not limit the positive and negative directions, will be described as the X axis, Y axis, and Z axis. Further, in each of the following embodiments, as an example, the "first direction" is the +Z direction, and the "second direction" is the -Z direction.

(Embodiment 1)
FIG. 1 is a plan view showing a schematic configuration of an ink jet recording apparatus 1, which is an example of a "liquid ejecting apparatus" according to Embodiment 1 of the present invention.

As shown in FIG. 1, an ink jet recording apparatus 1, which is an example of a "liquid ejecting apparatus," ejects ink, which is a type of liquid, as ink droplets onto a medium (not shown) such as printing paper and lands on them. It is a printing device that prints an image or the like by arranging dots formed on a medium. In addition to recording paper, any material such as a resin film or cloth can be used as the medium.

Such an ink jet recording apparatus 1 includes a body frame 12 having a rectangular shape in plan view. A medium support member 13 that supports a medium (not shown) extends in the body frame 12 along the main scanning direction, which is the +X direction. The medium is fed onto the medium support member 13 along the sub-scanning direction, which is the +Y direction, by the conveyance unit 10 configured by the medium roller 23 and the medium roller motor 11 that drives the medium roller 23 . It's becoming A rod-shaped guide shaft 14 extending parallel to the +X direction is provided on the −Z direction side of the medium support member 13 in the body frame 12 .

A carriage 15 is supported by the guide shaft 14 so as to be able to reciprocate along the X axis, ie, move in the +X direction and the −X direction. The carriage 15 is connected to a carriage motor 17 provided on the body frame 12 via an endless timing belt 16 that is stretched between a pair of pulleys 16 a provided on the body frame 12 . As a result, the carriage 15 is reciprocated along the guide shaft 14 by driving the carriage motor 17 .

A head unit 18 is provided on the −Z direction side of the carriage 15 so as to face the medium support member 13 . The head unit 18 includes an ink jet recording head (hereinafter simply referred to as a recording head) 19, which is an example of the "liquid jet head" of the present embodiment, and a pressure adjustment unit 30 that adjusts the pressure of ink supplied to the recording head 19. and have.

A plurality of nozzles 28 are provided on the surface of the recording head 19 facing the medium support member 13 in the +Z direction. , ink droplets are ejected from each nozzle 28 onto the medium on the medium support member 13 to perform printing.

The liquid container 22 is a “liquid storage unit” that stores individual colors or types of ink ejected from the recording head 19 . As the liquid container 22, for example, an ink cartridge detachable from the ink jet recording apparatus 1, a bag-like ink pack formed of a flexible film, an ink tank capable of replenishing ink, or the like can be used. In this embodiment, five liquid containers 22 are provided.

A plurality of liquid containers 22 are detachably attached to a liquid container holder 21 provided at the end of the body frame 12 in the +X direction. That is, the liquid container 22 of this embodiment is made up of an ink cartridge. Each liquid container 22 attached to the liquid container holder 21 is connected to the pressure adjustment unit 30 via a supply pipe 24 such as a tube. The pressure adjustment unit 30 adjusts the pressure of ink supplied from each liquid container 22 through each supply pipe 24 and supplies the ink to the recording head 19 . Although only one pressure adjustment unit 30 is shown in FIG. 1, the pressure adjustment unit 30 is provided for each color or type of ink supplied from the liquid container 22 . Further, in this embodiment, the liquid container holder 21 is provided on the body frame 12 , but the present invention is not limited to this, and the liquid container holder 21 may be provided on the carriage 15 .

A maintenance unit 26 for performing maintenance such as cleaning of the recording head 19 is provided in the home position area of the carriage 15 at a position near one end in the +X direction within the body frame 12 . The maintenance unit 26 includes a cap 27 and a suction pump (not shown) capable of sucking the inside of the cap 27 . The cap 27 abuts on the recording head 19 so as to surround each nozzle 28 of the recording head 19 and receives ink ejected from each nozzle 28 by flushing. Then, by sucking the inside of the cap 27 with a suction pump while the cap 27 is in contact with the recording head 19 so as to surround each nozzle 28 of the recording head 19, the thickened ink and bubbles from each nozzle 28 are capped. So-called cleaning is performed by forcibly discharging the toner into the inside 27 .

The pressure regulation unit 30 of this embodiment will be described with reference to FIGS. 2 to 10. FIG. 2 is a cross-sectional view of the pressure adjustment unit 30. FIG. FIG. 3 is an enlarged view of the vicinity of the first chamber 53 in FIG. FIG. 4 is a bottom view of the vicinity of the base end portion 92 of the valve body 90 and the first wall portion 34. FIG. FIG. 5 is a perspective view of the vicinity of the base end portion 92 of the valve body 90. As shown in FIG. FIG. 6 is a cross-sectional view taken along line AA' of FIG. FIG. 7 is a perspective view of the vicinity of the first chamber 53. FIG. FIG. 8 is a cross-sectional view of the vicinity of the first chamber 53 showing movement of the bubble B. FIG. FIG. 9 is a cross-sectional view of the vicinity of the first chamber 53 showing movement of air bubbles B in a comparative configuration. FIG. 10 is a cross-sectional view taken along the line AA' in FIG. 4, showing the valve open state.

As shown in FIG. 2, the pressure adjustment unit 30 includes a housing 31 corresponding to the "first flow path member", a cover member 32 arranged in the -Z direction with respect to the housing 31, and a On the other hand, it has a sealing member 33 corresponding to a "second flow path member" arranged in the +Z direction, a valve element 90, a first chamber 53, and a second chamber . The housing 31, the cover member 32, and the sealing member 33 are made of resin, for example. The first chamber 53 and the second chamber 54 constitute part of a flow path for supplying ink to the nozzles 28 . The first chamber 53 and the second chamber 54 are arranged side by side in this order in the -Z direction, which is the second direction.

The housing 31 includes a partition wall 40 that separates the first chamber 53 and the second chamber 54 from each other, and a partition wall 40 that extends in the +Z direction, which is the "first direction", so as to define the first chamber 53. and an annular first wall portion 34 . In the present embodiment, the shape of the end of the first wall portion 34 in the +Z direction is a plane perpendicular to the +Z direction, except for the portion where the groove portion 35 and the communication path described later are formed.

A sealing member 33 is arranged on the +Z direction side of the housing 31 . In the present embodiment, the sealing member 33 includes a sealing portion 33a that faces the partition wall 40 and defines the first chamber 53, and a sealing portion 33a that surrounds the outer circumference of the first wall portion 34 and extends from the sealing portion 33a in the second direction. , and the second wall portion 33b extending in the +Z direction is formed. In other words, the sealing member 33 is formed with a second wall portion 33b that forms a cylindrical concave portion so as to cover the outer periphery of the first wall portion 34 . That is, the sealing portion 33a defines the bottom surface of the recess that covers the outer periphery of the first wall portion 34, and the second wall portion 33b defines the side surface of the recess. The first wall portion 34 is covered with the sealing member 33 to define a first chamber 53 in which the valve body 90 is accommodated. The first chamber 53 can also be called a "valve housing chamber". The sealing member 33 is provided with an inflow port 48 through which ink flows into the first chamber 53 . As shown in FIG. 3, the first wall portion 34 is spaced apart from the sealing portion 33a. That is, the +Z-direction end surface of the first wall portion 34 and the -Z-direction surface of the sealing portion 33a opposed thereto are not in contact with each other, and a space S1 is provided between them. Note that the interval S1 includes a groove portion 35 provided in the first wall portion 34, which will be described later in detail.

A gap S2 is formed between the inner peripheral surface of the first wall portion 34 and the outer peripheral surface of the second wall portion 33b. That is, the outer peripheral surface of the first wall portion 34 and the inner peripheral surface of the second wall portion 33b are not in contact with each other. That is, when viewed in the +Z direction, the inner diameter of the second wall portion 33b is slightly larger than the outer diameter of the first wall portion 34, and the inner diameter of the second wall portion 33b and the first wall portion 34 A gap S2 is formed between them due to the difference between the outer diameter and the inner diameter. The width W1 of the gap S2 in the radial direction can be rephrased as the difference between the inner diameter of the second wall portion 33b and the outer diameter of the first wall portion . Note that the width W1 of the gap S2 is preferably thinner than the thickness W2 of the first wall portion 34 . That is, it is preferable to satisfy the relationship W1<W2. By making the gap S2 thinner than the thickness of the first wall portion 34 in this way, it is possible to make it difficult for air bubbles to enter the gap S2. Further, by providing the gap S2 between the first wall portion 34 and the second wall portion 33b, the first wall portion 34 can be easily inserted into the second wall portion 33b, and the assembly can be easily performed. . In addition, in order to fill the gap S2 between the first wall portion 34 and the second wall portion 33b with an adhesive or the like, a structure for injecting the adhesive or the like is required. There is a risk that the adhesive may become foreign matter, causing valve closing failure due to poor sealing between the valve element 90 and the valve seat 42, or that the foreign matter may flow out to the recording head 19, resulting in ink ejection failure or the like. In the present embodiment, since the gap S2 is not filled with an adhesive or the like, a structure for injecting the adhesive or the like is not required, and no structural change is required. It is possible to suppress the occurrence of valve closing failure and ink droplet ejection failure due to sealing failure between 90 and valve seat 42 .

The first chamber 53 is defined by fixing the −Z direction side end of the second wall portion 33b to the fixing surface 40a, which is the +Z direction side surface of the partition wall 40 outside the first wall portion 34. be done. That is, the partition wall 40 has a fixing surface 40a that is fixed to the −Z direction side end of the second wall portion 33b. The fixing surface 40a of this embodiment is a plane provided outside the first wall portion 34 along the XY plane defined by the X axis and the Y axis. In addition, the fixing surface 40a extends up to the area that becomes the gap S2. Therefore, the end of the gap S2 on the -Z direction side is defined by the fixed surface 40a. In addition, the fixed surface 40a is positioned in the −Z direction with respect to the surface of the partition wall 40 on the +Z direction side where the through hole 41 opens. Although the method of fixing the fixing surface 40a and the second wall portion 33b is not particularly limited, it is preferable to bond the two with an adhesive. In other words, the housing 31 and the sealing member 33 are preferably joined with an adhesive. By bonding the housing 31 and the sealing member 33 with an adhesive in this manner, a sealing member such as rubber is provided between the housing 31 and the sealing member 33 to prevent leakage of ink from the flow path. Ink leakage from the flow path provided between the housing 31 and the sealing member 33 can be suppressed without using the sealing member 33, and the two can be fixed to each other. Further, by providing the fixing surface 40a to which the second wall portion 33b is fixed on the outside of the first wall portion 34, when the fixing surface 40a and the second wall portion 33b are adhered, excess adhesive is The wall portion 34 can suppress movement to the through hole 41 that communicates the first chamber 53 and the second chamber 54 provided in the partition wall 40 . Therefore, the through hole 41 is clogged with adhesive, resulting in an increase in flow resistance, and the adhesive adheres to the valve seat 42, which will be described later in detail. can be suppressed. Moreover, the bonding between the second wall portion 33b and the fixing surface 40a of the partition wall 40 can be reliably performed by providing the space S1 between the first wall portion 34 and the sealing portion 33a. In other words, if the first wall portion 34 and the sealing portion 33a are in contact with each other, the gap between the second wall portion 33b and the fixing surface 40a may occur due to manufacturing errors of the first wall portion 34 and the sealing portion 33a. There is a possibility that adhesion failure between the two may occur due to the occurrence of gaps or variations in the gap. In addition, there is a risk that ink may leak due to poor adhesion in other flow paths provided between the housing 31 and the sealing member 33, such as the filter chamber 44, which will be described later in detail. By setting the first wall portion 34 to a length that does not contact the sealing portion 33a, that is, by providing a space S1 between the two, the second wall portion 33b and the fixing surface 40a can be connected even if a manufacturing error occurs. can be reliably adhered to each other, and leakage of ink from the flow path can be suppressed. In addition, the inner peripheral surface of the first wall portion 34 may be annular, and the first wall portion 34 itself may not be annular. In addition, the term “annular” is not limited to one that is continuous all around. parts may be present. In the present embodiment, the first wall portion 34 is provided with a groove portion 35 that opens in the +Z direction and a communicating passage 46 that penetrates the first wall portion 34 in the thickness direction, although the details will be described later.

A concave opening 52 is formed on the −Z direction side of the housing 31 , and a flexible resin film 61 is arranged so as to cover the opening 52 . The film 61 is adhered and fixed to the housing 31 together with the cover member 32 . A second chamber 54 is defined between the housing 31 and the film 61 by arranging the film 61 so as to cover the opening 52 . The second chamber 54 can also be called a "pressure chamber". The surface of the film 61 opposite to the surface facing the second chamber 54 is in contact with the atmosphere.

A pressure receiving member 81 is arranged on the surface of the film 61 on the second chamber 54 side. The pressure receiving member 81 is made of a material having higher rigidity than the film 61, and is made of a thin plate such as SUS. One end of the pressure receiving member 81 is supported at the joint between the housing 31 and the cover member 32 . When the film 61 bends in the +Z direction, the pressure receiving member 81 also displaces in the +Z direction. The film 61 and the pressure receiving member 81 may or may not be adhered. The pressure-receiving member 81 in this embodiment is formed in a downward U shape when viewed in the -Y direction. Note that the pressure receiving member 81 may have a flat shape.

A filter chamber 44 defined by a concave portion provided in the sealing member 33 is arranged on the +Z direction side of the +Y direction end of the second chamber 54 . The filter chamber 44 and the second chamber 54 communicate with each other via the filter 45 . The filter 45 is fixed between the sealing member 33 and the housing 31 by bonding them. This filter 45 removes foreign matters and the like contained in the ink flowing into the filter chamber 44 from the second chamber 54 . The filter 45 is made of, for example, metal mesh or non-woven fabric. At the bottom surface of the filter chamber 44 on the +Z direction side, an outflow hole 47 is formed to allow the ink from which foreign substances and the like have been removed by the filter 45 to flow out to the recording head 19 . Although the pressure regulation unit 30 is provided with the filter 45 in this embodiment, the pressure regulation unit 30 does not have to be provided with the filter 45 .

As shown in FIGS. 3 and 8, the partition wall 40 has a through hole 41 extending in the −Z direction from the first chamber 53 toward the second chamber 54 in order to allow the first chamber 53 and the second chamber 54 to communicate with each other. is formed.

The valve body 90 includes a base end portion 92 housed in the first chamber 53, a cylindrical shaft portion 91 protruding from the base end portion 92 in the −Z direction, and an elastic member provided on the upper surface side of the base end portion 92. a member 93; In this embodiment, the base end portion 92 and the shaft portion 91 are made of resin such as polypropylene or polyparaphenylenebenzobisoxazole. The elastic member 93 is made of elastic rubber.

The base end portion 92 in this embodiment has a substantially disk-like shape. An outer diameter R1 of the base end portion 92 in a cross section perpendicular to the +Z direction is larger than an outer diameter R2 of the shaft portion 91 in a cross section perpendicular to the +Z direction. The base end portion 92 can also be called a flange portion or a collar portion. The shaft portion 91 is inserted into the through hole 41 formed in the partition wall 40 , and its tip contacts the pressure receiving member 81 arranged in the second chamber 54 . The elastic member 93 is provided inside the outer periphery of the base end portion 92 and outside the shaft portion 91 when viewed in the -Z direction. A protrusion is formed on the upper surface side of the elastic member 93 at a portion that contacts the valve seat 42 . The elastic member 93 is not provided on the portion of the side surface of the shaft portion 91 that is inserted into the through hole 41 and on the outer peripheral surface of the base end portion 92 .

An annular valve seat 42 is provided around the through-hole 41 on the +Z direction side surface of the partition wall 40 on the first chamber 53 side. The valve seat 42 serves as a “seal portion” that closes the flow path of the ink to the nozzle 28 by coming into contact with the elastic member 93 provided on the valve body 90 . In this embodiment, the valve seat 42 is separate from the partition wall 40 and made of metal. As the metal, for example, SUS or titanium can be used. The surface of the valve seat 42 on the +Z direction side with which the elastic member 93 contacts may be subjected to liquid-repellent treatment such as fluorine coating. The valve seat 42 is fixed to the partition wall 40 with an adhesive. Such a valve seat 42 is arranged in the -Z direction with respect to the fixed surface 40a. In other words, the valve seat 42 of the present embodiment is positioned in the -Z direction from the end of the gap S2 on the -Z direction side.

In this embodiment, the partition wall 40 has an annular recess 43 that is recessed in the −Z direction from the portion where the valve seat 42 is provided when viewed in the +Z direction. This concave portion 43 has a function of receiving excess adhesive protruding from between the valve seat 42 and the partition wall 40 when the valve seat 42 is adhered to the partition wall 40 .

A coil spring 94 , which is an example of a biasing member, is interposed between the sealing member 33 and the base end portion 92 in the first chamber 53 . The +Z side end of the coil spring 94 is positioned by a truncated conical first projection 36 formed on the −Z direction side surface of the sealing portion 33 a of the sealing member 33 . The −Z direction side end of the coil spring 94 fits into the second protrusion 37 formed on the +Z direction side surface of the base end portion 92 of the valve body 90 . In addition to the coil spring, for example, a leaf spring or a disc spring can be used as the biasing member.

As shown in FIGS. 4 and 5, in the present embodiment, the second convex portion 37 into which the end of the coil spring 94 on the -Z direction side is fitted is formed in a substantially cross shape. The base end portion 92 has a sliding contact portion 38 that can slide on the inner peripheral surface of the first wall portion 34 on its outer peripheral portion. The sliding contact portion 38 protrudes from the bottom surface of the base end portion 92 in the +Z direction. In this embodiment, the sliding contact portions 38 are provided at two locations facing each other with the second convex portion 37 interposed therebetween. A portion of the base end portion 92 where the sliding contact portion 38 is not provided forms a recessed non-sliding contact portion 39 a that forms a gap 39 with the first wall portion 34 . That is, the non-sliding contact portion 39a is formed to have a recessed shape with respect to an imaginary circular shape including the sliding contact portion 38 when viewed in the +Z direction. Thereby, a gap 39 is formed between the non-sliding contact portion 39 a and the first wall portion 34 . That is, the sliding contact portion 38 and the non-sliding contact portion 39a are continuously provided along the outer periphery of the valve body 90 when viewed in the +Z direction at the base end portion 92 of the valve body 90 . In this embodiment, the gap 39 formed by the non-sliding portion 39a is provided at two positions so as to sandwich the second convex portion 37 therebetween. Ink that has flowed into the first chamber 53 from the inflow port 48 passes through these gaps 39 and travels from the first chamber 53 to the through hole 41 . The numbers of the sliding contact portions 38 and the gaps 39 can be arbitrarily set, and may be one or three or more. Note that the sliding contact portion 38 only needs to be in sliding contact with the first wall portion 34 , and may not always be in sliding contact with the first wall portion 34 . For example, among the plurality of sliding contact portions 38 , the sliding contact portion 38 that does not actually make sliding contact with the first wall portion 34 may be included.

Here, as shown in FIG. It has a positioning area 95 shorter than the shortest distance G2 to the inner peripheral surface. In this embodiment, the positioning area 95 is positioned on the outer peripheral surface of the sliding contact portion 38 . Hereinafter, the distance G1 is also referred to as the interval G1 between the base end portion 92 and the first wall portion 34, and the distance G2 is also referred to as the interval G2 between the shaft portion 91 and the through hole 41. That is, in this embodiment, the distance G1 between the base end portion 92 and the first wall portion 34 is smaller than the distance G2 between the shaft portion 91 and the through hole 41 . A distance G1 between the base end portion 92 and the first wall portion 34 is such that the sliding contact portion 38 can slide on the inner peripheral surface of the first wall portion 34 . Note that the interval G1 is the distance from the center of the base end portion 92 to the outer peripheral surface of the base end portion 92 and the distance from the center of the first chamber 53 to the inner peripheral surface of the first wall portion 34 in plan view in the +Z direction. It can be rephrased as the difference from the distance to In addition, the interval G2 is the maximum distance from the center of the shaft portion 91 to the outer peripheral surface of the portion of the shaft portion 91 inserted into the through hole 41 in plan view in the +Z direction, and In other words, it is the difference from the shortest distance to the inner peripheral surface of the hole 41 . Further, the interval G1 can be rephrased as half the difference between the inner diameter R3 of the first chamber 53 and the outer diameter R1 of the base end portion 92 . Also, the interval G2 can be rephrased as half the difference between the inner diameter R4 of the through-hole 41 and the outer diameter R2 of the portion of the shaft portion 91 inserted into the through-hole 41 .

Further, as shown in FIG. 3, in the present embodiment, the interval G1 is shorter than the shortest distance G3 between the shaft portion 91 and the inner peripheral surface of the valve seat 42. As shown in FIG. The distance G3 is hereinafter also referred to as the gap G3 between the shaft portion 91 and the valve seat 42 . That is, in this embodiment, the distance G1 between the base end portion 92 and the first wall portion 34 is smaller than the distance G3 between the shaft portion 91 and the valve seat 42 . In this embodiment, the interval G2 and the interval G3 are substantially the same. Note that the interval G3 is the maximum distance from the center of the shaft portion 91 to the outer peripheral surface of the portion of the shaft portion 91 inserted into the through hole of the valve seat 42 in a plan view in the +Z direction, In other words, it is the difference between the shortest distance from the center of the through hole to the inner peripheral surface of the through hole of the valve seat 42 . Further, the interval G3 can be rephrased as half the difference between the inner diameter R5 of the valve seat 42 and the outer diameter R2 of the portion of the shaft portion 91 inserted into the through-hole of the valve seat 42 . The length of the positioning region 95 along the Z-axis is longer than the length of the through hole 41 and the valve seat 42 along the Z-axis. Therefore, by making the distance G1 between the base end portion 92 and the first wall portion 34 smaller than the distance G2 between the shaft portion 91 and the through hole 41 and the distance G3 between the shaft portion 91 and the valve seat 42, the valve Inclination with respect to the Z axis when the body 90 moves in the +Z direction and the -Z direction can be suppressed. Therefore, the valve body 90 can be controlled to have a correct posture with respect to the through hole 41 , and deformation of the shaft portion 91 of the valve body 90 and the through hole 41 and tilting of the valve body 90 can cause the valve body 90 and the valve seat to move. It is possible to suppress the occurrence of poor adhesion with 42 . That is, in the present embodiment, the sliding contact portion 38 of the valve body 90 and the first wall portion 34 define the attitude of the valve body 90 moving in the +Z direction and the -Z direction. Also, the sliding contact portion 38 of the valve body 90 contacts the inner peripheral surface of the first side wall 34 integrally formed with the partition wall 40 having a through hole 41 into which the shaft portion 91 of the valve body 90 is inserted. Therefore, compared to the case where the first side wall is formed on the sealing member 33 which is separate from the partition wall 40 in which the through hole 41 is formed, and the sliding contact portion 38 is in contact with the first side wall, the valve body 90 and the valve seat 42, and the attitude of the valve body 90 during the reciprocal movement in the +Z direction and the -Z direction tends to be stable.

As shown in FIGS. 3, 4, and 5, a portion of the first wall portion 34, more specifically, a portion of the end portion of the first wall portion 34 on the +Z direction side, is provided in the -Z direction. A groove portion 35 is provided which is recessed toward. The groove portion 35 radially penetrates the first wall portion 34 and communicates with the first chamber 53 . The groove portion 35 is provided in a portion of the first wall portion 34 where the inflow port 48 provided in the sealing member 33 opens to the first chamber 53 . That is, the inflow port 48 and the groove 35 have an overlapping range when viewed in the +Z direction. Ink that has flowed in from the inlet 48 flows into the first chamber 53 via the groove 35 . In the present embodiment, the depth of the groove 35 along the −Z direction, that is, the distance from the end of the first wall 34 in the +Z direction to the bottom surface 351, which is the end of the groove 35 in the −Z direction, is It is smaller than the maximum thickness of the base end portion 92, that is, the thickness of the sliding contact portion 38 provided at the base end portion 92 along the -Z direction. Note that the depth along the -Z direction of the groove portion 35 is not limited to this, and can be set arbitrarily. In the present embodiment, one groove portion 35 is provided on the first wall portion 34, but it may be provided at a plurality of locations.

Further, as shown in FIGS. 4 to 7, the first wall portion 34 communicates a gap S2 between the first wall portion 34 and the second wall portion 33b with the inner side of the first wall portion 34. A communication passage 46 is provided. The communication path 46 is provided so as to penetrate the first wall portion 34 in the thickness direction, that is, in the radial direction centered on the valve body 90 when viewed from the +Z direction. In addition, the communication path 46 of the present embodiment is a so-called slit that is opened at the end of the first wall portion 34 in the +Z direction. A first end portion 461, which is the portion of the communication path 46 located most in the -Z direction, is arranged in the -Z direction with respect to the interval S1. Here, the “gap” between the first wall portion 34 and the sealing portion 33a in the present embodiment means the end portion of the +Z direction side end portion of the first wall portion 34 that does not include the communication path 46 and the sealing portion 33a. It is between the stopping part 33a. That is, in the present embodiment, the communication path 46 is provided to open at the +Z direction side end of the first wall 34 , but the end of the first wall 34 other than the opening of the communication path 46 is provided. and the sealing portion 33a face each other in the +Z direction. The widest dimension of the interval S1 along the Z-axis is the portion where the groove portion 35 is provided. In other words, the bottom surface 351 of the groove portion 35 is the portion of the space S1 that is located most in the -Z direction.

A first end portion 461, which is the most −Z direction side portion of the communication path 46, is arranged in the −Z direction from the interval S1. Here, the fact that the first end 461 is located in the −Z direction from the space S1 means that the first end 461 does not overlap the space S1 and is − It says that it is located in the Z direction. That is, the first end portion 461 of the communication path 46 is positioned in the −Z direction from the bottom surface 351 of the groove portion 35 . In other words, the communicating path 46 and the groove 35 open at the +Z direction end of the first wall 34 , and the length of the communicating path 46 on the Z axis is longer than the groove 35 . In this embodiment, the first end 461 of the communication path 46 is arranged at the same position as the fixing surface 40a with respect to the -Z direction. In other words, the length of the communication path 46 along the Z axis is the same as that of the first wall portion 34 . As described above, since the valve seat 42 is positioned in the -Z direction relative to the fixed surface 40a, the first end 461 of the communication path 46 of the present embodiment is arranged in the +Z direction relative to the valve seat 42. ing.

As shown in FIGS. 4 and 5, a plurality of such communication paths 46 are provided at intervals in the circumferential direction of the first wall portion 34 when viewed in the +Z direction. In this embodiment, four communication paths 46 are provided in the first wall portion 34 . Note that the number and positions of the communication paths 46 are not particularly limited to this. For example, the number of communication paths 46 may be one, or two or more.

Moreover, as shown in FIGS. 4 and 5 , at least part of the communicating path 46 is provided so as not to overlap the sliding contact portion 38 when viewed from the communicating path 46 toward the center of the valve body 90 . That is, when viewed from the communicating path 46 toward the center of the valve body 90 in the plane direction of the XY plane defined by the X axis and the Y axis, at least a portion of the communicating path 46 overlaps with the sliding contact portion 38. It is designed to prevent By preventing at least a part of the communication path 46 from overlapping the sliding contact portion 38 in this manner, the area of the sliding contact portion 38 in sliding contact with the inner peripheral surface of the first wall portion 34 is reduced by providing the communication path 46 . can be suppressed, and the positioning region 95 can improve the positioning accuracy of the valve body 90 and improve the posture stabilization.

In addition, when viewed from the communicating path 46 toward the center of the valve body 90 , the length L1 of the communicating path 46 overlapping the sliding contact portion 38 is preferably smaller than the length L2 of not overlapping the sliding contact portion 38 . That is, it is preferable to satisfy L1<L2. Alternatively, it is preferable that the total length L1 of each communicating passage 46 overlapping the sliding contact portion 38 is smaller than the total length L2 of the communicating passage 46 not overlapping the sliding contact portion 38 . By relatively shortening the length of the communication path 46 that overlaps the sliding contact portion 38 in this way, it is possible to further suppress the decrease in the positioning area 95 .

By providing the communication passage 46 in the first wall portion 34 in this way, as shown in FIG. It can move to the opening side of the hole 41 . That is, since the bubble B is likely to move toward the proximal end of the first wall portion 34 in the −Z direction due to buoyancy, the first wall portion 34 has the first end portion 461 in the −Z direction rather than the space S1. By providing the passage 46 , the bubble B can get over the first wall portion 34 via the communication passage 46 and move toward the through hole 41 inside the first wall portion 34 . In particular, in the present embodiment, since the first end 461 of the communication path 46 is provided at the same position as the fixed surface 40a in the -Z direction, the air bubble B moves from the fixed surface 40a to the +Z direction of the first wall portion 34. The bubble B can be moved to the inside of the first wall portion 34 only by moving along the XY plane without moving over the direction, that is, without moving the bubble B in the +Z direction. Therefore, by providing the first end portion 461 of the communicating path 46 at the same position as the fixed surface 40a in the -Z direction, it is possible to further facilitate the movement of the air bubble B and improve the air bubble discharge performance. In addition, since the first end 461 on the -Z direction side of the communication passage 46 of the present embodiment is provided at the same position as the fixed surface 40a on the Z axis, the first end 461 is positioned closer to the valve seat 42 than the valve seat 42. Located in the +Z direction. Therefore, the air bubble B that has moved from the first end portion 461 to the inside of the first wall portion 34 moves toward the through hole 41 in an oblique direction having a -Z direction component. Therefore, the air bubbles B that have passed through the communication path 46 are less likely to enter the recess 43 and are more likely to move toward the through hole 41 .

On the other hand, as shown in FIG. 9, when the communication path 46 is not provided in the first wall portion 34, the air bubble B entering the gap S2 climbs over the first wall portion 34 and passes through the gap S1. It must move inside the first wall 34 . Further, even if the groove portion 35 is provided in the first wall portion 34 , since the bottom surface 351 of the groove portion 35 is relatively located on the +Z direction side, the air bubble B can pass through the groove portion 35 to the first wall portion 34 . Difficult to move inside. In other words, the bubble B cannot overcome the first wall portion 34 and move inside the first wall portion 34 via the gap S1 unless it moves in the +Z direction against the buoyancy. B tends to stay.

By providing the communication passage 46 in the first wall portion 34 in this manner, the air bubble B in the gap S2 can be easily moved to the inside of the first wall portion 34. Therefore, as shown in FIG. Further, when the valve body 90 moves in the +Z direction and the first chamber 53 and the second chamber 54 are brought into communication with each other, the bubble B in the first chamber 53 flows through the through hole 41 into the second chamber. It can be moved to the 54 side, and the air bubbles B can be easily discharged from the second chamber 54 to the outside. Therefore, by discharging the air bubbles B in the first chamber 53, it is possible to suppress the generation of the gas-liquid interface, thereby suppressing the generation of foreign matter at the gas-liquid interface. By suppressing the generation of foreign matter in the first chamber 53, it is possible to suppress valve closing failure, that is, sealing failure due to foreign matter being caught between the valve body 90 and the valve seat 42. It is possible to prevent ink droplets from flowing downstream and causing ejection failures of ink droplets from the nozzles 28 .

In addition, since it is possible to suppress the air bubbles B from staying in the first chamber 53, it is possible to suppress the air bubbles B from absorbing the pressure change of the ink in the first chamber 53. It is possible to suppress variations in pressure. Furthermore, since the air bubbles B can be prevented from remaining in the first chamber 53, the air bubbles B in the first chamber 53 are discharged to the downstream side of the recording head at an unexpected timing, and the ink droplets due to the air bubbles are discharged. It is possible to suppress the occurrence of problems such as ejection failure.

In addition, since the communication path 46 is provided without completely eliminating the first wall portion 34 , the first wall portion 34 allows the positioning of the valve body 90 along the surface direction of the XY plane and the +Z movement of the valve body 90 . It is possible to stabilize the posture when moving in the direction and -Z direction. In particular, a plurality of communication passages 46 in this embodiment are provided at intervals along the outer periphery of the valve body 90 . Therefore, the bubble B in the gap S2 can be easily moved to the inside of the first wall portion 34, and the valve body 90 can be controlled to the correct posture by the first wall portion 34. As shown in FIG.

The opening/closing operation of the valve body 90 configured as described above will be described. In the following description, it is assumed that the first chamber 53 and the second chamber 54 are filled with ink by the initial filling of ink into the nozzles 28 or previous ejection of ink. As shown in FIG. 3, the coil spring 94 urges the valve body 90 in the -Z direction, which is the direction in which the valve is always closed. In the closed state of the valve body 90, the elastic member 93 is in contact with the valve seat 42 to close the through hole 41, that is, the first chamber 53 and the second chamber 54 are out of communication.

When ink is ejected from the recording head 19 while the first chamber 53 and the second chamber 54 are not communicated with each other, the amount of ink in the second chamber 54 decreases. As a result, as shown in FIG. 10, the pressure in the second chamber 54 becomes negative due to the pressure difference from the atmospheric pressure, and the film 61 and the pressure receiving member 81 are bent toward the second chamber 54 side. Then, the pressure receiving member 81 pushes the tip of the shaft portion 91 in the +Z direction, and the valve body 90 is pushed down toward the first chamber 53 side.

When the valve body 90 is pushed down against the biasing force of the coil spring 94, the elastic member 93 is separated from the valve seat 42, and the valve body 90 is opened. When the valve element 90 is in the valve open state, the through hole 41 is open, that is, the valve element is in the open state in which the first chamber 53 and the second chamber 54 are communicated.

When the valve body 90 is open, ink in the first chamber 53 flows into the second chamber 54 through the through hole 41 . When the second chamber 54 is sufficiently replenished with ink, the negative pressure in the second chamber 54 is released and the pressure receiving member 81 and the film 61 return to their original positions. As shown, the valve body 90 is closed. In this manner, the opening and closing operation of the valve body 90 constantly adjusts the pressure in the second chamber 54 to a substantially constant pressure.

As described above, the pressure adjustment unit 30 of the present invention includes the first chamber 53, the second chamber 54, and the through hole 41 for causing the liquid ink to flow from the first chamber 53 to the second chamber 54. and a flow path including. The pressure adjustment unit 30 includes a partition wall 40 that separates the first chamber 53 and the second chamber 54 and has a through hole 41 formed therein, and a partition wall 40 that separates the first chamber 53 from the partition wall 40 in the +Z direction, which is the first direction. and a housing 31 which is a first flow channel member having an extended first wall portion 34 . In addition, the pressure adjustment unit 30 includes a sealing portion 33a that faces the partition wall 40 and defines the first chamber 53, and a second pressure sensor that surrounds the first wall portion 34 from the sealing portion 33a in a direction opposite to the +Z direction. and a second wall portion 33b extending in the −Z direction, which is the direction. The pressure adjustment unit 30 also includes a valve element 90 that opens and closes the flow path by moving relative to the partition wall 40 in the +Z direction and the −Z direction. The partition wall 40 also has a fixing surface 40a fixed to the −Z direction end of the second wall portion 33b. Further, the first wall portion 34 is arranged with an interval S1 with respect to the sealing portion 33a. A communication passage 46 is formed in the first wall portion 34 to allow communication between the gap S2 formed between the outer periphery of the first wall portion 34 and the inner periphery of the second wall portion 33b and the first chamber 53. A first end portion 461, which is the portion of the communication path 46 located most in the -Z direction, is arranged in the -Z direction with respect to the interval S1.

Thus, by providing the communicating path 46 in the first wall portion 34 and arranging the first end 461 of the communicating path 46 in the -Z direction from the gap S1, the air bubble B entering the gap S2 is It can be easily moved inside the first wall 34 via 46 . Therefore, it is possible to suppress the generation of foreign substances at the air-liquid interface between the air bubbles B and the liquid ink due to the air bubbles B remaining in the gap S2. It is possible to suppress the valve closing failure due to the deterioration of the sealing performance. In addition, since it is possible to suppress the air bubbles B from remaining in the gap S2, the air bubbles B act as a buffer that absorbs the pressure of the ink in the first chamber 53, and the pressure for opening or closing the valve is reduced. Variation can be suppressed, and the operating pressure of the valve body 90 can be stabilized. Furthermore, since it is possible to suppress the air bubble B from remaining in the gap S2, the air bubble B flows out downstream of the second chamber 54 at an unexpected timing and is supplied to the recording head 19. It is possible to suppress problems such as ejection failure of ink droplets.

In addition, by providing the space S1 between the first wall portion 34 and the sealing portion 33a, the second wall portion 33b and the fixing surface 40a may be separated from each other due to manufacturing errors of the first wall portion 34 and the sealing portion 33a. The second wall portion 33b and the fixing surface 40a of the partition wall 40 can be reliably adhered to each other by suppressing the occurrence of gaps between the two and the occurrence of variations in the gaps, thereby suppressing leakage of ink from the flow path. can.

In addition, by providing the first wall portion 34 having the communication path 46 without completely eliminating the first wall portion 34, the positioning of the valve body 90 along the surface direction of the XY plane by the first wall portion 34, The attitude of the valve body 90 can be stabilized when moving in the +Z direction and the -Z direction.

Furthermore, by providing a gap S2 between the first wall portion 34 and the second wall portion 33b, the first wall portion 34 can be easily inserted into the second wall portion 33b, and assembly can be easily performed. . In addition, in order to fill the gap S2 between the first wall portion 34 and the second wall portion 33b with an adhesive or the like, a structure for injecting the adhesive or the like is required. There is a risk that the adhesive may become foreign matter, causing valve closing failure due to poor sealing between the valve element 90 and the valve seat 42, or that the foreign matter may flow out to the recording head 19, resulting in ink ejection failure or the like. In the present embodiment, since the gap S2 is not filled with an adhesive or the like, a structure for injecting the adhesive or the like is not required, and no structural change is required. It is possible to suppress the occurrence of valve closing failure and ink droplet ejection failure due to sealing failure between 90 and valve seat 42 .

In addition, in the pressure adjustment unit 30 of the present embodiment, in the −Z direction, which is the second direction, the first end portion 461, which is a portion of the communication path 46, is arranged at the same position in the −Z direction as the fixed surface 40a. preferably. By arranging the first end 461 of the communication path 46 at the same position as the fixing surface 40a in the -Z direction in this way, the communication path 46 can be opened at the position closest to the -Z direction side of the gap S2 defined by the fixing surface 40a. can communicate with the first chamber 53 . Therefore, the air bubble B in the gap S2 can be easily moved to the inside of the first wall portion 34 via the communication path 46, and the air bubble discharging property can be improved.

In addition, in the pressure regulating unit 30 of the present embodiment, the partition wall 40 has a valve seat 42 that is a seal portion that closes the flow path by coming into contact with the valve body 90 , and a second valve that is a part of the communication path 46 . The one end 461 is preferably arranged in the +Z direction, which is the first direction, relative to the valve seat 42 . According to this, the air bubble B that has moved from the first end portion 461 to the inside of the first wall portion 34 tends to move toward the through hole 41 inside the valve seat 42 in an oblique direction having a -Z direction component. , the air bubbles B are easily discharged from the through holes 41 .

Moreover, in the pressure adjustment unit 30 of the present embodiment, the width W1 of the gap S2 is preferably smaller than the thickness W2 of the first wall portion 34 . By making the width W1 of the gap S2 smaller than the thickness W2 of the first wall portion 34, that is, by setting W1<W2, it is possible to make it difficult for the air bubble B to enter the gap S2.

In addition, in the pressure regulating unit 30 of the present embodiment, it is preferable that a plurality of communication passages 46 be provided at intervals along the outer periphery of the valve body 90 when viewed in the +Z direction, which is the first direction. By providing a plurality of communication paths 46 in the first wall portion 34 in this way, it is possible to improve the ability to discharge air bubbles from the gap S2.

In addition, in the pressure regulating unit 30 of the present embodiment, the valve body 90 is in sliding contact with the outermost first wall portion 34 along the outer periphery of the valve body 90 when viewed in the +Z direction, which is the first direction. and a non-sliding portion 39a that does not slide against the first wall portion 34. At least a part of the communicating passage 46 extends from the communicating passage 46 toward the center of the valve body 90 Looking at it from above, it is preferable that it does not overlap with the sliding contact portion 38 . By preventing at least a part of the communication path 46 from overlapping the sliding contact portion 38 in this manner, the area of the sliding contact portion 38 in sliding contact with the inner peripheral surface of the first wall portion 34 is reduced by providing the communication path 46 . can be suppressed, and the positioning region 95 can improve the positioning accuracy of the valve body 90 and improve the posture stabilization.

Further, the ink jet recording apparatus 1, which is the liquid ejecting apparatus of the present invention, includes the above-described pressure adjustment unit 30 and a liquid storage section for storing ink, which is the liquid to be supplied to the first chamber 53 of the pressure adjustment unit 30. A container 22 and a nozzle 28 for ejecting ink supplied from the second chamber 54 of the pressure adjustment unit 30 are provided.

In such an ink jet recording apparatus 1, it is possible to improve the ability to discharge air bubbles in the first chamber 53, and to suppress ejection failures of ink droplets due to air bubbles.

In the present embodiment, the first end portion 461 of the communicating path 46 is provided at the same position as the fixed surface 40a in the +Z direction, but the present invention is not particularly limited to this. As shown in FIG. 3, the first end 461 of the communication path 46 is preferably located in the -Z direction with respect to the center C of the gap S2 in the +Z direction.

Also, the first end portion 461 of the communication path 46 is preferably positioned in the -Z direction, which is closer to the through hole 41 than the position where the gap S2 is equally divided into three with respect to the +Z direction. That is, when the positions obtained by equally dividing the gap S2 into three are C1 and C2 in order in the +Z direction, the communication path 46 is preferably positioned in the -Z direction with respect to C1.

Also, the first end portion 461 of the communication path 46 is preferably positioned in the -Z direction, which is closer to the through hole 41 than the position where the gap S2 is equally divided into four parts in the +Z direction. That is, when the positions obtained by equally dividing the gap S2 into four are C11, C12, and C13 in order in the +Z direction, the communication path 46 is preferably positioned in the -Z direction with respect to C11.

10, the first end portion 461 of the communication passage 46 is in a state where the valve body 90 opens the flow path, that is, the valve body 90 communicates the first chamber 53 and the second chamber 54. It is preferable that the first end portion 461 of the communicating passage 46 is positioned in the −Z direction from the sliding contact portion 38 in the closed valve open state. That is, in the valve-opening body, the first end portion 461 is preferably positioned in the -Z direction rather than the first end portion 381, which is positioned closest to the -Z direction of the sliding contact portion . In this way, in the valve-opening body, by arranging the first end portion 461 in the -Z direction relative to the sliding contact portion 38, the air bubble B in the gap S2 can be removed from the first wall portion 34 in the valve-open state. It can be easily moved to the −Z direction side where the through hole 41 opens from the inner sliding contact portion 38 . Therefore, the air bubbles B can be easily moved to the second chamber 54 through the through hole 41 . Incidentally, if the first end portion 461 of the valve-opening body is arranged at the same position as the sliding contact portion 38, when the air bubble B in the gap S2 moves into the first wall portion 34, the sliding contact portion 38 hinders the air bubble B from moving toward the through-hole 41 side.

6, the first end portion 461 of the communication passage 46 is in a state where the valve body 90 closes the flow path, that is, the valve body 90 communicates the first chamber 53 and the second chamber 54. In the non-closed state, the first end portion 461 of the communication passage 46 is preferably located in the -Z direction relative to the sliding contact portion 38. As shown in FIG. That is, in the valve-closing body, the first end portion 461 is preferably positioned in the −Z direction more than the first end portion 381 of the sliding contact portion 38, which is positioned in the −Z direction. Incidentally, in the closed valve body, the valve body 90 is positioned on the most −Z direction side, and in the open valve body, the valve body 90 is positioned in the +Z direction from the closed valve body. For this reason, the fact that the first end 461 of the communication path 46 in the valve closed body is positioned in the -Z direction relative to the sliding contact portion 38 means that in the valve open body the first end 461 of the communication path 46 slides. It includes being positioned in the −Z direction from the contact portion 38 . By arranging the first end portion 461 in the -Z direction relative to the sliding contact portion 38 in the valve-closing body in this way, the air bubble B in the gap S2 in both the valve-closing body and the valve-opening body It can be easily moved to the -Z direction side where the through-hole 41 is opened from the sliding contact portion 38 inside the first wall portion 34, and the air bubble discharging property can be improved.

In the present embodiment, part of the communicating path 46 does not overlap the sliding contact portion 38 when viewed from the communicating path 46 toward the center of the valve body 90, but the present invention is not particularly limited to this. Here, FIG. 11 shows a modification of the communication path 46. As shown in FIG. FIG. 11 is a bottom view of the base end portion 92 of the valve body 90 and the vicinity of the first wall portion 34. FIG. As shown in FIG. 11, when viewed from the communicating path 46 toward the center of the valve body 90 in the plane direction of the XY plane defined by the X axis and the Y axis, the communicating path 46 is entirely a sliding contact portion. 38 so as not to overlap. That is, the communicating path 46 is provided so as to overlap the non-sliding portion 39a when viewed from the communicating path 46 toward the center of the valve body 90 in the planar direction of the XY plane. That is, two communication paths 46 are provided corresponding to the two non-sliding contact portions 39a. By preventing the communication path 46 from completely overlapping the sliding contact portion 38 in this way, it is possible to suppress a decrease in the positioning region 95 between the sliding contact portion 38 and the first wall portion 34 . Therefore, the posture of the valve body 90 can be controlled by the first wall portion 34 with higher accuracy.

(Embodiment 2)
FIG. 12 is a cross-sectional view of a main part of a pressure regulating unit according to Embodiment 2 of the present invention. In addition, the same code|symbol is attached|subjected to the member similar to embodiment mentioned above, and the overlapping description is abbreviate|omitted.

As shown in FIG. 12, a first end portion 461, which is the portion closest to the −Z direction side of the communicating path 46 provided in the first wall portion 34, is in the “second direction” with respect to the fixing surface 40a. located in the Z direction. That is, the first end portion 461 of the communication path 46 is provided so as to form a concave portion on the -Z direction side surface of the partition wall 40 . In addition, the first end 461 of the communication path 46 of the present embodiment is positioned in the −Z direction from the fixed surface 40a on the Z axis, and is positioned in the +Z direction from the bottom surface of the recess 43 on the −Z direction side. The first end portion 461 may be provided at the same position as the bottom surface of the recess 43 on the Z axis, that is, flush with the bottom surface of the recess 43 .

Also, in the pressure adjustment unit 30 of the present embodiment, the first end portion 461, which is part of the communication path 46, is arranged in the -Z direction, which is the second direction, relative to the fixed surface 40a. By arranging the first end portion 461 of the communication path 46 in the -Z direction relative to the fixing surface 40a in this way, the communication path 46 is positioned on the most -Z direction side of the gap S2 defined by the fixing surface 40a. It can be communicated with one chamber 53 . Therefore, the air bubble B in the gap S2 can be easily moved to the inside of the first wall portion 34 via the communication path 46, and the air bubble discharging property can be improved.

(Embodiment 3)
FIG. 13 is a cross-sectional view of a main part of a pressure regulating unit according to Embodiment 3 of the present invention. In addition, the same code|symbol is attached|subjected to the member similar to embodiment mentioned above, and the overlapping description is abbreviate|omitted.

As shown in FIG. 13 , the communication passage 46 is provided so as to penetrate the first wall portion 34 in the thickness direction, that is, in the radial direction centered on the valve body 90 when viewed from the +Z direction. Further, the communication path 46 is a so-called “opening” provided so as not to open at the end of the first wall portion 34 in the +Z direction. In addition, "opening" means that the 1st wall part 34 which defines the said opening continues over the circumferential direction of opening.

Even with such a communication path 46, as in the first embodiment described above, the air bubble B (see FIG. 8) that has entered the gap S2 passes through the through hole inside the first wall portion 34 via the communication path 46. It is easy to move to the 41 side. Therefore, the air bubbles B in the first chamber 53 can be discharged from the through hole 41 to the downstream side of the second chamber 54 and the like, and the retention of the air bubbles B in the first chamber 53 can be suppressed. For this reason, it is possible to suppress valve closing failure due to foreign matter being generated at the interface between the bubble B remaining in the gap S2 and the liquid ink, and the foreign matter lowering the sealing performance between the valve body 90 and the valve seat 42. can. In addition, since it is possible to suppress the air bubbles B from remaining in the gap S2, the air bubbles B in the gap S2 act as a buffer that absorbs the pressure, causing variation in the pressure for opening or closing the valve. can be suppressed, and the operating pressure of the valve body 90 can be stabilized. Furthermore, since it is possible to suppress the air bubble B from remaining in the gap S2, the air bubble B flows out downstream on the second chamber 54 side at an unexpected timing, is supplied to the recording head 19, and is supplied to the recording head 19 by the air bubble. It is possible to suppress problems such as ejection failure of ink droplets.

In addition, by providing the space S1 between the first wall portion 34 and the sealing portion 33a, the second wall portion 33b and the fixing surface 40a may be separated from each other due to manufacturing errors of the first wall portion 34 and the sealing portion 33a. The second wall portion 33b and the fixing surface 40a of the partition wall 40 can be reliably adhered to each other by suppressing the occurrence of gaps between the two and the occurrence of variations in the gaps, thereby suppressing leakage of ink from the flow path. can.

In addition, by providing the first wall portion 34 having the communication path 46 without completely eliminating the first wall portion 34, the positioning of the valve body 90 along the surface direction of the XY plane by the first wall portion 34, The attitude of the valve body 90 can be stabilized when moving in the +Z direction and the -Z direction.

Furthermore, by providing a gap S2 between the first wall portion 34 and the second wall portion 33b, the first wall portion 34 can be easily inserted into the second wall portion 33b, and assembly can be easily performed. . In addition, in order to fill the gap S2 between the first wall portion 34 and the second wall portion 33b with an adhesive or the like, a structure for injecting the adhesive or the like is required. There is a risk that the adhesive may become foreign matter, causing valve closing failure due to poor sealing between the valve element 90 and the valve seat 42, or that the foreign matter may flow out to the recording head 19, resulting in ink ejection failure or the like. In the present embodiment, since the gap S2 is not filled with an adhesive or the like, a structure for injecting the adhesive or the like is not required, and no structural change is required. It is possible to suppress the occurrence of valve closing failure and ink droplet ejection failure due to sealing failure between 90 and valve seat 42 .

Note that the position of the communication path 46, which is a through hole, of the present embodiment with respect to the sliding contact portion 38, the position of the first end portion 461 of the communication path 46, and the like are the same as those of the above-described first embodiment, so the description will be repeated. are omitted.

(Other embodiments)
Although each embodiment of the present invention has been described above, the basic configuration of the present invention is not limited to the above.

For example, although the configuration in which the second chamber 54 is located on the -Z direction side with respect to the first chamber 53 is illustrated, the second chamber 54 and the first chamber 53 are not particularly limited to this, and the second chamber 54 and the first chamber 53 are arranged along the X axis and the Y axis. It may be arranged along the surface direction of the XY plane defined by the axis. That is, unless the second chamber 54 is positioned in the +Z direction with respect to the first chamber 53, the pressure regulating unit 30 is not limited to the posture in which the valve element 90 moves along the Z axis shown in FIG. A posture in which the body 90 moves along a direction intersecting the Z-axis may also be used. When the valve body 90 moves along the direction intersecting the Z-axis in this way, the first direction and the second direction are the direction intersecting the +Z direction and the direction intersecting the -Z direction, respectively.

In each of the above-described embodiments, the inflow port 48 is arranged at a position facing the tip of the first wall portion 34 in the +Z direction. It may be arranged inside the portion 34 . In addition, in the configuration having the communication path 46 of the present invention, the inlet 48 can be arranged outside the first wall portion 34, that is, at a position facing the gap S2 in the +Z direction. Note that when the inlet 48 is arranged inside the first wall portion 34 , the groove portion 35 may not be provided in the first wall portion 34 . Further, in Embodiment 1 described above, the groove portion 35 is provided, but the present invention is not limited to this. may That is, the communicating passage 46 may also serve as the groove portion 35 .

Further, in each of the above-described embodiments, the head unit 18 configured by the recording head 19 and the pressure adjusting unit 30 has been exemplified. There may be. That is, the head unit 18 in each embodiment described above may correspond to a "liquid jet head".

Further, in the pressure regulating unit 30 of each embodiment described above, the configuration in which one inflow port 48 and one outflow hole 47 are provided for the channel having the first chamber 53 and the second chamber 54 is illustrated. The number of inlets 48 and outlet holes 47 may be two or more, and the number of inlets 48 and outlet holes 47 may be different.

In the above-described example, the ink jet recording apparatus 1 has a structure in which the liquid container 22, which is the liquid reservoir, is mounted on the liquid container holder 21 of the body frame 12. However, the liquid reservoir is not limited to this. may be mounted on the carriage 15 . Moreover, the pressure adjustment unit 30 is not limited to being mounted on the carriage 15, and the pressure adjustment unit 30 and the recording head 19 may be connected via a supply pipe such as a tube.

Further, the present invention broadly targets liquid jet heads in general, and can be used, for example, for recording heads such as various ink jet recording heads used in image recording apparatuses such as printers. In addition, the present invention is used in the production of color material ejection heads used in the manufacture of color filters for liquid crystal displays and the like, electrode material ejection heads used in the formation of electrodes such as organic EL displays and FEDs (field emission displays), and biochips. It can also be applied to a bioorganic matter ejection head or the like.

Further, although the inkjet recording apparatus 1 has been described as an example of the liquid ejecting apparatus, the liquid ejecting apparatus can also be used in liquid ejecting apparatuses using other liquid ejecting heads described above.

Further, the present invention broadly targets pressure adjustment units in general, and can be used for devices other than liquid ejecting apparatuses and liquid ejecting heads.

DESCRIPTION OF SYMBOLS 1... Inkjet-type recording apparatus (inkjet-type recording apparatus), 10... Conveyance part, 11... Medium roller motor, 12... Body frame, 13... Medium support member, 14... Guide shaft, 15... Carriage, 16... Timing belt, 16a... pulley, 17... carriage motor, 18... head unit, 19... recording head (liquid jet head), 21... liquid container holder, 22... liquid container (liquid reservoir), 23... medium roller, 24... supply pipe, 26... maintenance unit, 27... cap, 28... nozzle, 30... pressure adjusting unit, 31... housing (first channel member), 32... cover member, 33... sealing member (second channel member), 33a Sealing portion 33b Second wall portion 34 First wall portion 35 Groove portion 351 Bottom surface 36 First convex portion 37 Second convex portion 38 Slide contact portion 381 Third 1 end 39 gap 39a non-sliding portion 40 partition wall 40a fixed surface 41 through hole 42 valve seat (seal portion) 43 concave portion 44 filter chamber 45 filter , 46... Communication path 461... First end 47... Outflow hole 48... Inflow port 52... Opening 53... First chamber 54... Second chamber 61... Film 81... Pressure receiving member 90... Valve body 91 Shaft portion 92 Base end portion 93 Elastic member 94 Coil spring 95 Positioning region S1 Spacing S2 Gap

Claims (12)

A pressure regulating unit comprising a flow path including a first chamber, a second chamber, and a through hole for allowing liquid to flow from the first chamber to the second chamber,
A partition wall defining the first chamber and the second chamber and formed with the through hole, and a first wall portion defining the first chamber and extending from the partition wall in a first direction. 1 channel member;
a sealing portion facing the partition wall and defining the first chamber; and a second sealing portion extending in a second direction opposite to the first direction so as to surround the first wall portion a second flow path member having two walls;
a valve body that opens and closes the flow path by relatively moving in the first direction and the second direction with respect to the partition wall;
with
The partition has a fixing surface fixed to the end of the second wall in the second direction,
The first wall portion is spaced apart from the sealing portion,
A communication path is formed in the first wall portion to allow communication between a gap formed between an outer periphery of the first wall portion and an inner periphery of the second wall portion and the first chamber,
A pressure regulating unit, wherein a portion of the communicating path that is closest to the second direction is arranged in the second direction with respect to the spacing. The valve body has a sliding contact portion that is in sliding contact with the first wall portion,
2. The pressure according to claim 1, wherein in a valve-open state in which the valve element opens the flow path, the portion of the communicating passage is arranged in the second direction relative to the sliding contact portion. adjustment unit. 3. The pressure according to claim 2, wherein in a valve closed state in which the valve body closes the flow path, the portion of the communicating passage is arranged in the second direction relative to the sliding contact portion. adjustment unit. 2. In the second direction, the portion of the communication path is arranged at the same position as the fixing surface in the second direction or in the second direction relative to the fixing surface. 4. The pressure regulating unit according to any one of 1 to 3. The partition has a seal portion that closes the flow path by coming into contact with the valve body,
The portion of the communication path is arranged in the first direction with respect to the seal portion,
The pressure regulation unit according to any one of claims 1 to 4, characterized in that: The pressure adjustment unit according to any one of claims 1 to 5, wherein the width of the gap is thinner than the thickness of the first wall. The pressure regulating unit according to any one of claims 1 to 6, wherein a plurality of the communication passages are provided at the intervals along the outer periphery of the valve body when viewed in the first direction. . The valve body has a sliding contact part that is in sliding contact with the outermost first wall along the outer circumference of the valve body as viewed in the first direction, and a sliding contact part that is not in sliding contact with the first wall. continuously having a non-sliding contact portion;
The pressure according to any one of claims 1 to 7, wherein at least part of the communicating path does not overlap the sliding contact portion when viewed from the communicating path toward the center of the valve body. adjustment unit. 9. The communication path according to any one of claims 1 to 8, wherein the communication path is a slit that penetrates in the thickness direction of the first wall portion and opens at a tip portion of the first wall portion in the first direction. pressure regulation unit as described above. The communication path is an opening penetrating the first wall in the thickness direction,
The pressure regulation unit according to any one of claims 1 to 8, characterized in that: a pressure regulating unit according to any one of claims 1 to 10;
a nozzle for ejecting the liquid supplied from the second chamber of the pressure adjustment unit;
A liquid jet head comprising: a pressure regulating unit according to any one of claims 1 to 10;
a liquid reservoir for storing the liquid to be supplied to the first chamber of the pressure regulation unit;
a nozzle for injecting the liquid supplied from the second chamber of the pressure regulation unit;
A liquid ejecting device comprising:

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