JP6470104B2 - Pressure buffer, liquid jet head, and liquid jet recording apparatus - Google Patents

Description

  The present invention relates to a pressure buffer, a liquid jet head, and a liquid jet recording apparatus.

  2. Description of the Related Art Conventionally, there has been an ink jet type liquid jet recording apparatus that ejects ink (liquid) onto a recording medium such as recording paper conveyed in a predetermined direction and records images, characters, and the like on the recording medium. Are known. This type of liquid jet recording apparatus supplies ink from a liquid container (ink tank) to a liquid jet head (inkjet head) via a liquid supply pipe (ink supply pipe). Then, ink is ejected to the recording medium from the nozzle holes of the head chip provided in the liquid ejecting head. Thereby, recording can be performed on the recording medium.

  In addition, this type of liquid jet recording apparatus is provided with a carriage (moving means) that reciprocates in a direction orthogonal to the conveyance direction of the recording medium. A plurality of inkjet heads are mounted on the carriage. Then, the ink jet is ejected and the ink jet head is reciprocated to sequentially record in the width direction of the recording medium.

  By the way, in the liquid jet recording apparatus as described above, the liquid supply pipe swings as the liquid jet head reciprocates, so that the pressure of ink flowing out of the liquid supply pipe varies. Therefore, conventionally, the liquid ejecting head is provided with a pressure buffer for absorbing ink pressure fluctuations.

  The pressure buffer is provided so as to close the concave portion (chamber), a main body portion having a concave portion (chamber) for storing ink, an upstream pipe line and a downstream pipe line communicating with the concave portion, and a peripheral portion of the concave portion. A thin film (flexible film) that is fixed to the main body, and a cover that is provided so as to close the recess from above the thin film and overlaps the main body at the peripheral edge of the recess. Then, the upstream side pipe line and the liquid container are connected via a liquid supply pipe, and the downstream side pipe line and the head chip are connected. Under such a configuration, the thin film bends according to the pressure variation of the ink, and the volume in the recess changes. Thereby, the pressure fluctuation of the ink supplied from the liquid supply to the pressure buffer is absorbed (see, for example, Patent Document 1).

  Here, in order to prevent excessive bending of the thin film, an urging member made of a leaf spring or the like may be provided in the recess. This urging member is configured to be elastically deformable in the film thickness direction of the thin film, and the seating surface can be contacted and separated from the thin film. The area of the seating surface is set as large as possible so that the entire thin film can be held by this seating surface.

JP 2008-110599 A

By the way, when the head chip is initially filled with ink, the concave portion of the pressure buffer is also filled with ink. At this time, an urging member is attached to the thin film, and a space is formed between the thin film and the urging member. And this space may remain as a bubble in the recess filled with ink.
If the bubbles remain, the bubbles may flow into the head chip at an unintended timing when the liquid jet recording apparatus is driven. In such a case, ink ejection failure of the head chip occurs.

  Accordingly, the present invention has been made in view of the above-described circumstances, and provides a pressure buffer, a liquid jet head, and a liquid jet recording apparatus that can prevent bubbles from remaining and prevent ink ejection defects. It is.

  In order to solve the above-described problem, a pressure buffer according to the present invention includes a main body having a recess for storing a liquid, an upstream pipe formed on the main body, and communicated with the recess. A conduit, a thin film provided to close the recess, and fixed to the main body at the periphery of the recess; and a peripheral edge of the recess provided to close the recess from above the thin film A pressure buffer comprising: a cover that overlaps the main body portion; and a biasing member that is provided between the concave portion and the thin film and is elastically deformable in a film thickness direction of the thin film. And at least one of the urging members is provided with a bubble escape portion for allowing bubbles present in the liquid stored in the recess to escape to the downstream pipe line.

  Thus, by providing the bubble escape portion in at least one of the cover and the biasing member, it is possible to prevent bubbles from remaining in the pressure buffer. As a result, poor liquid ejection can be prevented.

  The pressure shock absorber according to the present invention is disposed so that a mating surface of the main body portion and the cover is oriented in a direction intersecting a vertical direction, and the concave portion and the downstream side pipe line are disposed on an upper portion in the vertical direction of the concave portion. The communication portion is formed, and at least one of the cover and the urging member is provided with the bubble escape portion in the upper part in the vertical direction.

  Here, the bubbles move upward in the vertical direction of the pressure buffer due to buoyancy. For this reason, in a state where the mating surface of the main body portion and the cover is oriented in a direction intersecting the vertical direction, a pressure relief is provided by providing a bubble escape portion at the upper part of at least one of the cover and the urging member in the vertical direction. It is possible to prevent bubbles from remaining in the vessel.

  In the pressure shock absorber according to the present invention, the urging member has a seating surface that can contact and separate from the thin film.

  With this configuration, when the pressure in the pressure buffer increases, the thin film can be separated from the urging member to change the volume in the pressure buffer to a desired size. On the other hand, when the pressure in the pressure buffer decreases, the thin film comes into contact with the seating surface of the urging member, and the volume in the pressure buffer is desired while preventing the thin film from being bent and damaged. The size can be changed.

  In the pressure shock absorber according to the present invention, the bubble escape portion is a gap forming portion for forming a gap between the cover and the seating surface of the biasing member.

  By forming the gap in this way, the bubbles can be smoothly discharged to the downstream pipe line via the gap. For this reason, it is possible to prevent bubbles from remaining in the pressure buffer.

  In the pressure shock absorber according to the present invention, the gap forming portion is a recess formed in at least one of the cover and the seat surface.

  By comprising in this way, a clearance gap can be formed between a thin film and the bearing surface of a biasing member with a simple structure.

  The pressure shock absorber according to the present invention is characterized in that a part of the seat surface is cut out to form the recess.

  By comprising in this way, a recessed part can be formed with a simple structure and the cheap pressure buffer which can prevent a bubble remaining can be provided.

  The pressure shock absorber according to the present invention is characterized in that at least one through hole is formed in an upper part in the vertical direction of the seating surface.

  By comprising in this way, the bubble which stops between a thin film and a seat surface can be guide | induced to a bubble escape part via a through-hole. For this reason, it is possible to reliably prevent bubbles from remaining in the pressure buffer.

  The pressure shock absorber according to the present invention is characterized in that at least one through hole is formed in a lower portion in the vertical direction of the seating surface.

  By configuring in this way, for example, even when the urging member is assembled with the up and down directions reversed, at least one through hole is positioned at the upper part in the vertical direction of the urging member. Can do. For this reason, it is possible to reliably prevent bubbles from remaining in the pressure buffer.

  A liquid ejecting head according to the present invention includes the pressure buffer described above and an ejecting unit that is connected to the downstream pipe line and ejects the liquid.

  With such a configuration, it is possible to reliably prevent the liquid ejection failure of the liquid ejection head due to the bubbles.

  A liquid jet recording apparatus according to the present invention is connected between the liquid jet head described above, a liquid container that contains the liquid, and between the liquid container and the pressure buffer, and distributes the liquid. A liquid supply pipe, and a pump motor connected to the position of the liquid supply pipe and configured to press or move the liquid inside the liquid supply pipe are provided.

  With this configuration, it is possible to provide a liquid jet recording apparatus that can prevent defective liquid jetting and improve the quality of recording on a recording medium.

  According to the present invention, bubbles can be prevented from remaining in the pressure buffer. As a result, poor liquid ejection can be prevented.

1 is a perspective view showing a liquid jet recording apparatus in an embodiment of the present invention. 1A and 1B show a liquid jet head according to an embodiment of the present invention, in which FIG. 1A is a perspective view, and FIG. It is a disassembled perspective view of the pressure buffer in embodiment of this invention. It is a top view of the main-body part in embodiment of this invention. It is a top view of the cover in the embodiment of the present invention. It is a schematic sectional drawing of the pressure buffer in embodiment of this invention. It is the A section enlarged view of FIG. It is operation | movement explanatory drawing at the time of the initial stage filling of the pressure buffer in embodiment of this invention, Comprising: (a)-(d) has each shown the behavior of the ink for every time passage. It is a perspective view of the energizing member in the modification of the embodiment of the present invention. It is a perspective view of the energizing member in the modification of the embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings.

(Liquid jet recording device)
FIG. 1 is a perspective view showing a liquid jet recording apparatus 1.
The liquid ejecting recording apparatus 1 includes a pair of transport mechanisms 2 and 3 that transport a recording medium S such as paper, a liquid ejecting head 4 that ejects ink (liquid) onto the recording medium S, and an ink on the liquid ejecting head 4. And a scanning unit 6 that scans the liquid ejecting head 4 in a direction (sub-scanning direction) substantially orthogonal to the conveyance direction (main scanning direction) of the recording medium S.
In the following description, the sub-scanning direction is described as the X direction, the main scanning direction is defined as the Y direction, and the direction orthogonal to both the X direction and the Y direction is described as the Z direction.

Here, the liquid jet recording apparatus 1 is mounted and used such that the X direction and the Y direction are horizontal directions and the Z direction is a vertical direction. In other words, in a state where the liquid jet recording apparatus 1 is placed, the liquid jet head 4 is configured to scan the recording medium S along the horizontal direction (X direction, Y direction). In addition, the ink droplets are ejected from the liquid ejecting head 4 downward in the vertical direction (downward in the Z direction), and the ink droplets are landed on the recording medium S.
In the following description, the upper side in the vertical direction is simply referred to as the upper side in the Z direction and the lower side in the vertical direction is simply referred to as the lower side in the Z direction.

  The pair of transport mechanisms 2 and 3 are respectively provided with grid rollers 20 and 30 extending in the X direction, pinch rollers 21 and 31 extending in parallel with the grid rollers 20 and 30, and grid rollers although details are not shown. And a driving mechanism such as a motor for rotating the shafts 20 and 30 around the axis.

  The liquid supply means 5 includes a liquid container 50 that stores ink, and a liquid supply pipe 51 that connects the liquid container 50 and the liquid ejecting head 4. A plurality of liquid containers 50 are provided. Specifically, liquid tanks 50Y, 50M, 50C, and 50B containing four types of inks of yellow, magenta, cyan, and black are provided side by side. A pump motor M is provided in each of the liquid tanks 50Y, 50M, 50C, 50B. Thereby, the ink can be pressed and moved to the liquid ejecting head 4 through the liquid supply pipe 51. The liquid supply pipe 51 is formed of a flexible hose having flexibility that can correspond to the operation of the liquid ejecting head 4 (carriage unit 62).

  The liquid container 50 is not limited to the liquid tanks 50Y, 50M, 50C, and 50B that contain four types of inks of yellow, magenta, cyan, and black, and a liquid tank that contains multicolor inks. May be provided.

  The scanning means 6 extends in the X direction, a pair of guide rails 60, 61, a carriage unit 62 slidable along the pair of guide rails 60, 61, and moves the carriage unit 62 in the X direction. And a drive mechanism 63. The drive mechanism 63 rotates a pair of pulleys 64 and 65 disposed between the pair of guide rails 60 and 61, an endless belt 66 wound between the pair of pulleys 64 and 65, and one pulley 64. A drive motor 67 to be driven.

The pair of pulleys 64 and 65 are disposed between both ends of the pair of guide rails 60 and 61, respectively, and are disposed with an interval in the X direction. The endless belt 66 is disposed between the pair of guide rails 60 and 61. A carriage unit 62 is connected to the endless belt 66.
A plurality of liquid jet heads 4 are mounted on the base end portion 62 a of the carriage unit 62. Specifically, liquid ejecting heads 4Y, 4M, 4C, and 4B that individually correspond to four types of inks of yellow, magenta, cyan, and black are mounted side by side in the X direction.

(Liquid jet head)
2A and 2B show the liquid jet head 4, where FIG. 2A is a perspective view and FIG. 2B is a partially broken perspective view of FIG.
As shown in FIG. 2A and FIG. 2B, the liquid ejecting head 4 is electrically connected to the ejecting unit 70 that ejects ink to the recording medium S (see FIG. 1) and the ejecting unit 70. The connected control circuit board 80 and the pressure buffer 90 interposed between the ejection unit 70 and the liquid supply pipe 51 are provided on the bases 41 and 42. Note that the bases 41 and 42 may be integrally formed.

The ejection unit 70 includes a flow path substrate 71 connected to the pressure buffer 90 via a connection unit 72, an actuator 73 that ejects ink as droplets onto the recording medium S, an actuator 73, and a control circuit substrate 80. And a flexible wiring 74 electrically connected to each other.
The actuator 73 is made of, for example, a PZT (lead zirconate titanate) ceramic substrate, and is formed to be long in the Y direction. A plurality of channel grooves (not shown) are formed in the actuator 73, and ink corresponding to these channel grooves is filled. Each of the liquid jet heads 4 (4Y, 4M, 4C, 4B) is provided on the bases 41, 42 so that the actuators 73 are arranged in the X direction.

  The flexible wiring 74 has a role of transmitting a drive signal from the control circuit board 80 to the actuator 73. When a drive signal is output to the actuator 73, the actuator 73 is deformed based on this drive signal. As a result, the volume of each channel groove changes, and ink droplets are ejected from the actuator 73.

  The control circuit board 80 will be described in detail. The control circuit board 80 includes a control unit 81 that generates a drive pulse of the actuator 73 based on a signal such as pixel data from a main body control unit (not shown) of the liquid jet recording apparatus 1. And a sub-board 82 provided on the control circuit board 80. Further, on the sub-board 82, a socket 85 connected to a connector 95 extending from the pressure buffer 90, a sensor circuit unit 83 electrically connected to the socket 85, a sensor circuit unit 83, and a main body control unit (not configured) And a socket 84 for connecting to the socket (shown).

(Pressure buffer)
Next, the pressure buffer 90 will be described in detail.
FIG. 3 is an exploded perspective view of the pressure buffer 90.
As shown in FIGS. 2 and 3, the pressure buffer 90 buffers the pressure fluctuation of the ink supplied from the liquid supply pipe 51 to the ejection unit 70. The pressure buffer 90 is connected so that the main body 91 and the cover 92 overlap each other, and an urging member 97 and a thin film 96 are provided between the main body 91 and the cover 92. Then, the main body portion 91 of the pressure buffer 90 is fixed to the base portion 42. At this time, the mating surface 91a of the main body 91 with the cover 92 faces the X direction.

FIG. 4 is a plan view of the main body 91.
As shown in FIGS. 3 and 4, the main body 91 is formed of, for example, a high-density polyethylene (HDPE) in a substantially rectangular flat plate shape in plan view so as to face the YZ plane. An upstream pipe line 101 projects from one side in the Y direction (left side in FIG. 4) on the side portion on the upper side in the Z direction of the main body 91. The upstream pipeline 101 is connected to the liquid supply pipe 51 in a watertight manner. On the other hand, a downstream pipe line 102 projects from a side portion of the main body portion 91 on the lower side in the Z direction, approximately at the center in the Y direction. The downstream pipe line 102 is connected to the connection part 72 of the injection part 70 in a watertight manner.

In addition, a concave portion 103 is formed on most of the main body portion 91 on the side of the mating surface 91a with the cover 92. The concave portion 103 is formed in a substantially quadrangular shape so that the planar view shape thereof corresponds to the planar view shape of the main body portion 91. An upstream communication portion 104 is formed on the bottom surface 103a of the recess 103 on the lower side in the Z direction.
The upstream communication portion 104 communicates the recess 103 with the upstream pipeline 101. Further, the opening 104a on the bottom surface 103a side of the recess 103 in the upstream communication portion 104 is formed to be long in the Y direction. The upstream communication portion 104 is formed such that the end portion of the opening 104 a on the upstream pipeline 101 side communicates with the upstream pipeline 101.

Further, a downstream side communication portion 105 having a substantially L shape in plan view is formed on the mating surface 91 a of the main body portion 91 along the periphery of the recess 103. In the downstream side communication portion 105, one end at the top in the Z direction communicates with the Z direction upper end inner side surface 103 b of the recess 103, and the other end communicates with the downstream side conduit 102. The Z-direction upper end inner side surface 103 b of the recess 103 is formed obliquely so as to gradually go upward in the Z direction as it goes to the connection portion 103 c between the recess 103 and the downstream communication portion 105.
In addition, a pair of protrusions 108 a and 108 b for attaching the urging member 97 are formed on the bottom surface 103 a of the recess 103.

FIG. 5 is a plan view of the cover 92.
As shown in FIGS. 3 and 5, the cover 92 is a flat plate formed in a substantially square shape in plan view so as to face the YZ plane so as to correspond to the plan view shape of the main body 91. is there. The cover 92 is provided so as to close the recess 103 of the main body 91, and the peripheral edge of the cover 92 is fixed to the mating surface 91 a of the main body 91 (the peripheral edge of the recess 103 in the main body 91).

A bulging portion 107 that bulges toward the opposite side of the concave portion 103 is formed at a portion corresponding to the concave portion 103 of the cover 92. The size of the bulging portion 107 in plan view is set to be slightly smaller than the size of the recess 103 in plan view.
A plurality of screw fixing portions 108 for fixing the cover 92 to the main body portion 91 are formed around the bulging portion 107 of the cover 92. Thereby, the watertightness between the main-body part 91 and the cover 92 is ensured.

  Further, the cover 92 is formed with a gap forming recess 109 at the upper end in the Z direction of the bulging portion 107 and substantially in the center in the Y direction. Similar to the bulging portion 107, the gap forming concave portion 109 is bulged toward the opposite side of the concave portion 103. Further, the gap forming recess 109 is formed such that the position of the upper end in the Z direction substantially coincides with the position of the inner surface 103 b in the Z direction upper end of the recess 103. In other words, the gap forming recess 109 is formed so as to be opposed to the recess 103 in the X direction at the upper part of the recess 103 in the Z direction (see the two-dot chain line in FIG. 4). The gap forming recess 109 is for smoothly guiding bubbles generated when ink is filled into the recess 103 to the downstream communication portion 105 (details will be described later).

  Further, an air passage 110 is formed in the cover 92 at the upper end in the Z direction of the bulging portion 107 and on the other side in the Y direction (the right side in FIG. 5) from the gap forming recess 109. The air passage 110 is also formed to bulge toward the opposite side to the concave portion 103, similarly to the bulging portion 107. The inside of the cover 92 is communicated with the outside air via the air passage 110 so that no differential pressure is generated between the cover 92 and the outside air.

The urging member 97 is formed by pressing a plate-shaped spring steel. The urging member 97 has a substantially rectangular shape in plan view so as to be slightly smaller than the outer shape of the concave portion 103 of the main body portion 91 and is flat, and has a seat surface portion 111 that can contact and separate from the thin film 96. .
A plurality of through holes 114 are formed in the seat surface portion 111 in the upper and lower directions in the Z direction. The plurality of through holes 114 formed in the Z direction upper portion of the seat surface portion 111 and the plurality of through holes 114 formed in the lower portion of the seat surface portion 111 in the Z direction are arranged in a row in the Y direction.

  Further, the seat surface portion 111 is provided with a pair of leg portions 112a and 112b formed by forming a cut portion 111a in the seat surface portion 111. Each leg part 112a, 112b is in a state where the respective base part is connected to the seat surface part 111, and is bent and extended from the base part toward the concave part 103 side. And each leg part 112a, 112b is extended diagonally so that the extension direction may follow a Y direction and it may become a mutually opposite direction. Note that the legs 112a and 112b may be formed so as to extend along the Z direction depending on the shape of the notch 111a.

  In addition, fitting holes 113a and 113b that can be fitted into the protrusions 108a and 108b formed in the recess 103 are formed at the tips of the legs 112a and 112b, respectively. The urging member 97 is fixed to the concave portion 103 of the main body 91 by fitting the fitting holes 113a and 113b into the protrusions 108a and 108b. Then, the leg portions 112 a and 112 b are elastically deformed, so that the seat surface portion 111 is displaced along the depth direction of the recess 103.

6 is a schematic cross-sectional view of the pressure buffer 90, and FIG. 7 is an enlarged view of a portion A in FIG. In FIGS. 6 and 7, the scale of each member is appropriately changed in order to make each member a recognizable size.
As shown in FIGS. 3, 6, and 7, a thin film 96 is disposed on the main body 91 so as to close the recess 103 after the urging member 97 is attached. A thin film 96 is welded and fixed to the mating surface 91 a (peripheral edge of the recess 103) of the main body 91, and the recess 103 is sealed by the thin film 96.

The thin film 96 is a flexible film and is preferably made of a material having corrosion resistance or the like with respect to the ink supplied from the liquid container 50. The thin film 96 has a multilayer structure so that it can be welded to the main body 91.
More specifically, as shown in detail in FIG. 7, the thin film 96 has a three-layer structure of, for example, a low-density polyethylene (LDPE) layer 96a, a silica layer 96b, and a nylon layer 96c. And it arrange | positions in the state which orient | assigned the polyethylene layer 96a of the same quality as the main-body part 91 to the main-body part 91 side. Thereby, the mating surface 91a of the main body 91 and the thin film 96 can be thermally welded.

  As described in detail in FIG. 6, the thin film 96 configured in this manner is thermally welded to the main body 91 in a state in which a slack portion 96d is formed. Since the slack portion 96d is formed in the thin film 96, the thin film 96 can be greatly bent. Further, when the space Kd1 between the thin film 96 and the concave portion 103 is at atmospheric pressure and equal pressure, the thin film 96 is adjusted so as to be bent toward the cover 92 side opposite to the concave portion 103. It is welded.

  On the other hand, in the urging member 97, the protrusion height from the mating surface 91a when the space Kd1 between the thin film 96 and the concave portion 103 is equal to the atmospheric pressure is smaller than the deflection amount of the thin film 96. Is set to Therefore, when the space Kd1 is equal to the atmospheric pressure, that is, in a state where the thin film 96 is bent toward the cover 92, the gap Ks is provided between the thin film 96 and the seating surface portion 111 of the biasing member 97. Is to be formed.

(Operation during initial filling of pressure buffer)
Next, the operation at the time of initial filling of the pressure buffer 90 will be described based on FIG.
FIG. 8 is an operation explanatory diagram at the time of initial filling of the pressure buffer 90, and (a) to (d) show the behavior of the ink over time.
Here, when the liquid jet recording apparatus 1 is used, it is necessary to fill ink into a channel groove (not shown) formed in the actuator 73 of the liquid jet head 4 in advance. Therefore, before use of the liquid jet recording apparatus 1, the pump motor M provided in each of the liquid containers 50 (liquid tanks 50Y, 50M, 50C, 50B) is driven, and the liquid supply pipe 51 and the pressure buffer 90 are driven. Then, the ink is pressed and moved to the liquid ejecting head 4. This is called initial filling.

As shown in FIG. 8A, the ink I that has flowed into the upstream pipe 101 of the pressure buffer 90 via the liquid supply pipe 51 from the liquid container 50 further passes through the upstream communication section 104. It flows into the lower part of the recess 103 in the Z direction.
As shown in FIG. 8B, when the ink I further flows into the recess 103, the water level of the ink I in the recess 103 rises. At this time, due to the surface tension acting on the ink I, the water level of the ink I on the inner surface side of the recess 103 rises faster than the water level of the ink I at the center in the Y direction of the recess 103.

As shown in FIG. 8C, when the ink I further flows into the recess 103, a bubble Kh is formed at the upper end in the Z direction of the recess 103 and in the vicinity of the central portion in the Y direction.
Here, as the inside of the concave portion 103 is pressurized when the ink I rises, the thin film 96 (see FIGS. 3 and 6) and the seating surface portion 111 of the urging member 97 adhere to each other, and these urging members 97 A space is formed between the seat portion 111 and the seat surface portion 111. This space contributes to the bubble Kh. In addition to the buoyancy acting on the bubble Kh, a plurality of through holes 114 are formed in the upper portion of the seat surface 111 in the Z direction. Thus, the bubbles Kh are collected at the upper end in the Z direction of the recess 103 and in the vicinity of the central portion in the Y direction.

  The cover 92 has a gap forming recess 109 at the upper end in the Z direction and substantially at the center in the Y direction. Furthermore, since the thin film 96 is a flexible film, the thin film 96 bends along the shape of the gap forming recess 109 as the inside of the recess 103 is pressurized. That is, the thin film 96 is lifted (separated) from the seat surface portion 111 of the urging member 97 at a location where the gap forming recess 109 is formed. Thereby, a gap is formed between the thin film 96 and the seat surface portion 111. Here, the gap forming concave portion 109 is formed so as to face the concave portion 103 in the X direction at the upper portion of the concave portion 103 in the Z direction (see a two-dot chain line in FIG. 4).

For this reason, a gap is formed between the thin film 96 and the seat surface portion 111 at the upper end in the Z direction of the recess 103, and the bubbles Kh are discharged to the downstream communication portion 105 through this gap.
As a result, as shown in FIG. 8D, the bubble Ih is not left in the pressure buffer 90 and is filled with the ink I at the time of initial filling.
The ink I discharged to the downstream communication unit 105 then flows into the actuator of the ejection unit 70 (see FIG. 2), and is further discharged to the outside via a nozzle (not shown). For this reason, bubbles do not remain in the ink I supply line.

When the liquid jet recording apparatus 1 is operated after the initial filling is completed, the liquid jet head 4 (carriage unit 62) is moved back and forth. The liquid supply pipe 51 swings. The pressure fluctuation of the ink accompanying this oscillation is absorbed by the pressure buffer 90. That is, the thin film 96 in the pressure buffer 90 is deflected by the pressure variation of the ink, and the volume of the space Kd1 (see FIG. 6) in the pressure buffer 90 changes. Thereby, the pressure of the ink in the space Kd1 is adjusted.
Here, the air passage 110 formed in the cover 92 prevents a differential pressure between the cover 92 and the outside air. For this reason, the thin film 96 is easily displaced (bends and deforms) due to the pressure fluctuation of the ink. As a result, the pressure buffer 90 can reliably absorb ink pressure fluctuations.

  Thus, in the pressure buffer 90 described above, a plurality of through holes 114 are formed in the Z direction upper part of the seating surface portion 111 of the biasing member 97. In addition, a gap forming recess 109 that communicates with the recess 103 and the downstream communication portion 105 is formed in the upper portion of the cover 92 in the Z direction. For this reason, the bubble Kh generated in the pressure buffer 90 smoothly flows to the downstream communication portion 105 using the buoyancy of the bubble Kh, the through hole 114 of the biasing member 97, and the gap forming recess 109 of the cover 92. And discharged. Therefore, it is possible to prevent the bubbles Kh from remaining in the pressure buffer 90, and it is possible to prevent ink ejection failure by the liquid ejecting head 4.

  A plurality of through holes 114 are also formed in the lower portion in the Z direction on the seat surface portion 111 of the urging member 97. For this reason, even when the operator assembles the urging member 97 upside down at the time of assembling the pressure shock absorber 90, the through hole 114 can be arranged at the upper part in the Z direction of the seating surface portion 111. Therefore, the bubbles Kh can be smoothly discharged to the downstream side communication portion 105 through the through hole 114.

The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention.
For example, in the above-described embodiment, the case where the bubble Kh generated in the pressure buffer 90 at the time of initial filling is discharged to the downstream side communication unit 105 has been described. However, the generation of the bubbles Kh in the pressure buffer 90 is not limited to the initial filling, and the bubbles accumulate in the middle of the ink flow path even after the initial filling, and these bubbles are generated when the liquid jet recording apparatus 1 is driven. In some cases, the pressure buffer 90 may enter. Even in such a case, the bubbles can be smoothly discharged to the downstream communication portion 105 through the gap forming recess 109.

  Further, in the above-described embodiment, the case where the pressure buffer 90 is arranged so that the mating surface 91a of the main body 91 with the cover 92 faces the X direction has been described. And the case where the gap formation recessed part 109 was formed in the cover 92 at the Z direction upper end of the bulging part 107 was demonstrated. However, the present invention is not limited to this, and the mating surface 91a (the direction of the pressure buffer 90) with the cover 92 of the main body 91 can be arranged in various directions. Desirably, even if the mating surface 91a does not completely face the X direction, the mating surface 91a may be oriented at least in a direction intersecting the Z direction. The position of the gap forming recess 109 may be determined according to the arrangement direction of the pressure buffer 90.

  Furthermore, in the above-described embodiment, the gap forming recess 109 is formed in the cover 92, and the plurality of through holes 114 are formed in the biasing member 97, and the gaps in the pressure buffer 90 are formed by the gap forming recess 109 and the through holes 114. In the above description, the bubbles generated in the above are smoothly discharged to the downstream communication portion 105. However, the present invention is not limited to this, and it is sufficient that at least one of the gap forming recess 109 and the through hole 114 is formed. Further, instead of the gap forming recess 109 and the through-hole 114, a bubble escape that communicates the space between the thin film 96 generated when the ink is filled and the seat surface portion 111 of the urging member 97 and the downstream communication portion 105 is communicated. It suffices if a structure is provided.

  That is, the above-described embodiment describes the gap forming recess 109 and the through hole 114 for forming a gap between the thin film 96 and the seating surface portion 111 of the biasing member 97 as an example of the bubble escape structure. For this reason, for example, the gap forming concave portion 109 and the through hole 114 may be eliminated, and a plurality of convex portions 115 may be provided above and below the Z direction in the seating surface portion 111 of the biasing member 97 as shown in FIG. Even in such a configuration, a gap can be formed between the thin film 96 and the seat surface portion 111. The projecting portion 115 may project to the side opposite to the thin film 96 in addition to projecting to the thin film 96 side. When the convex portion 115 is protruded to the opposite side of the thin film 96, a plurality of concave portions are formed on the surface of the seat surface portion 111 on the thin film 96 side, and a gap is formed between the thin film 96 and the seat surface portion 111 by the concave portion. Can be formed.

  Further, as shown in FIG. 10, a plurality of notched recesses 116 may be formed in the seat surface portion 111 instead of the through hole 114. Even in such a configuration, the space between the thin film 96 and the seating surface portion 111 of the urging member 97 generated during ink filling and the downstream communication portion 105 communicate with each other through the notch recess 116. Can be made.

  Furthermore, in the above-described embodiment, a case has been described in which the plurality of through holes 114 are formed above and below the Z direction in the seating surface portion 111 of the biasing member 97. However, the present invention is not limited to this, and it is only necessary that one through hole 114 is formed at least above and below the seat surface portion 111 in the Z direction.

DESCRIPTION OF SYMBOLS 1 ... Liquid jet recording apparatus 4 ... Liquid jet head 70 ... Jet part 90 ... Pressure buffer 91 ... Main-body part 91a ... Matching surface (peripheral part) 92 ... Cover 96 ... Thin film 97 ... Energizing member 101 ... Upstream side pipe line 102 ... downstream side pipe 103 ... concave part 103c ... connection part (communication part) 104 ... upstream communication part (communication part) 105 ... downstream communication part (communication part) 109 ... gap formation concave part (gap formation part) 111 ... seat surface part (Seat surface) 114 ... through hole I ... ink M ... pump motor

Claims (10)

A main body having a recess for storing liquid;
An upstream conduit and a downstream conduit formed in the main body and communicating with the recess;
A thin film provided so as to close the recess, and fixed to the main body at a peripheral edge of the recess;
A cover that is provided so as to close the concave portion from above the thin film, and is overlapped with the main body portion at a peripheral edge portion of the concave portion;
An urging member provided between the concave portion and the thin film and elastically deformable in a film thickness direction of the thin film;
A pressure buffer comprising:
At least one of the cover and the urging member is provided with a bubble escape portion that allows bubbles present in the liquid stored in the recess to escape to the downstream pipe line. Pressure buffer. The mating surface of the main body and the cover is arranged so as to face the direction intersecting the vertical direction,
A communication part between the concave part and the downstream pipe line is formed in the upper part in the vertical direction of the concave part,
2. The pressure buffer according to claim 1, wherein at least one of the cover and the biasing member is provided with the bubble escape portion at an upper part in a vertical direction.   The pressure buffer according to claim 2, wherein the urging member has a seating surface that can contact and separate from the thin film.   The pressure shock absorber according to claim 3, wherein the bubble escape portion is a gap forming portion for forming a gap between the cover and the seating surface of the biasing member.   The pressure buffer according to claim 4, wherein the gap forming portion is a recess formed in at least one of the cover and the seat surface.   The pressure buffer according to claim 5, wherein the recess is formed by cutting out a part of the seat surface.   The pressure buffer according to any one of claims 3 to 6, wherein at least one through hole is formed in an upper part in the vertical direction of the seating surface.   The pressure buffer according to claim 7, wherein at least one through hole is formed in a lower portion of the seating surface in the vertical direction. The pressure buffer according to any one of claims 1 to 8,
An injection unit connected to the downstream pipe line and for injecting the liquid;
A liquid ejecting head comprising: A liquid ejecting head according to claim 9;
A liquid container for containing the liquid;
A liquid supply pipe connected between the liquid container and the pressure buffer to circulate the liquid;
A pump motor connected to the position of the liquid supply pipe and configured to press or move the liquid inside the liquid supply pipe;
A liquid jet recording apparatus comprising:

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