JP2011207236A - Liquid jetting apparatus and liquid storing container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid jetting apparatus capable of easily obtaining necessary valve closing responsibility even if used as a valve apparatus used for so-called choke cleaning and relaxing the restriction of the arrangement position of an outlet in the valve apparatus, and to provide a liquid storing container.SOLUTION: A differential pressure valve 41 includes: a base material 44; and a film member 45 for sealing an opening 43a of a recessed part 43 formed at the base material 44. An annular projection 46 having an inner diameter larger than a diameter of an inlet passage 47 is formed approximately at the center of the bottom face of the recessed part 43. A valve chamber 50 is composed of a first flow path 51 composed of the outside part of the projection 46 and a second flow path 52 composed of the inside part of the projection 46. The opening diameter A of the opening 46a is set ≥1/2 of a diameter B of a diaphragm 45a being a bending deformable part of the film member 45 and ≥5 times of a diameter C of the inlet passage 47. Therefore, even if the side communicating with the second flow path 52 is made to be the inlet opening 47a and the side communicating with the first flow path 51 is made to be the outlet opening 49a, a valve can be opened and closed.

Description

  The present invention relates to a liquid ejecting apparatus and a liquid container including a valve device in which a part of a wall surface forming a fluid flow path is formed by a flexible member that is bent by a pressure difference inside and outside the fluid flow path. A liquid ejecting apparatus and a liquid container in which the valve device is configured to close when the fluid is discharged from the outlet and the fluid flow path is decompressed, and to open when the fluid is supplied and pressurized from the inlet. Concerning the container.

  2. Description of the Related Art Conventionally, an ink jet recording apparatus, which is one of liquid ejecting apparatuses, includes a cleaning device (maintenance device) that prevents and eliminates clogging of a recording head nozzle that is provided to eject ink as a liquid. It has been. The cleaning device includes a cap capable of sealing the region where the nozzles of the recording head are formed, and a suction pump capable of reducing the pressure in the sealed cap. During cleaning, the recording head is sealed with a cap, and the inside of the cap is decompressed by a suction pump, so that foreign matter such as thickened ink, bubbles, and paper dust are sucked and discharged from the nozzle together with the ink. It was.

  By the way, bubbles are easily mixed in the ink when the ink cartridge is replaced, and easily stay in the ink flow path from the ink cartridge to the nozzle of the recording head. In particular, the ink flow path easily stays in a chamber where the ink flow path is wider than the cross-sectional area of the other flow path at the place where the filter or valve is provided. This is because in this type of chamber, the ink flow rate slows down and the force that pushes out the bubbles becomes weak, and the buoyancy causes the bubbles to be relatively difficult to discharge, such as the upper wall or upper corner (corner) of the chamber. This is because they gather and stay. Such stagnant bubbles cause a decrease in ink filling properties in the ink flow path. In addition, the accumulated bubbles gradually grow at the location where they stay and flow to the recording head when they have grown to some extent, which may lead to a drop in printing quality, such as causing missing dots where ink is not ejected from the nozzles. . In addition to bubbles, foreign matter mixed in the ink for some reason was relatively difficult to be discharged from the ink flow path. And even if this kind of air bubbles and foreign matters are sucked from the nozzles by the cleaning device, the flow rate is not sufficiently high, so it is difficult to discharge them.

  Therefore, a differential pressure valve as a valve device is provided in the middle of the ink flow path from the ink cartridge to the recording head, and in the process of sucking ink from the nozzle by the cleaning device, the differential pressure valve is closed and opened to increase the ink. 2. Description of the Related Art An ink jet recording apparatus that performs so-called choke cleaning that discharges at a flow rate is known (for example, see Patent Documents 1 and 2). When performing choke cleaning, first the ink supply is stopped, the ink is sucked from the nozzle by the cleaning device to close the differential pressure valve, and the negative pressure in the ink flow path downstream from the closed position is sufficiently low. Is accumulated, ink supply is resumed and the differential pressure valve is opened to discharge ink at a high flow rate. The valve device (differential pressure valve) used in this choke cleaning is called a choke valve, and a part of the wall surface of the valve chamber is formed by a flexible member such as a film that bends due to a pressure difference between the inside and the outside. When the ink is sucked and the ink in the valve chamber decreases and the pressure is reduced, the valve is closed, and when the inlet is pressurized by supplying the ink, the valve is opened.

  For example, Patent Document 2 discloses a differential pressure valve (valve device) shown in FIG. As shown in the figure, a cylindrical projection 204 protrudes at a substantially central position on the bottom surface of the recess 203 formed on the upper surface of the base material 202 constituting the differential pressure valve 201, and is formed on the tip surface of the projection 204. An open outflow passage 206 (communication hole) is formed through the base material 202. Further, the inflow passage 205 is formed through the base material 202 so as to open to a position on the bottom surface of the recess 203 at the outside of the projection 204. Further, the opening of the recess 203 is sealed with a film 207 (flexible member) having a high gas barrier property.

  At the time of choke cleaning, the ink is sucked from the nozzles of the recording head by the cleaning device (suction means) in a state where the supply of the pressurized ink to the inflow path 205 is stopped by stopping the driving of the pressure pump, and the ink introduction chamber 209 Ink in the (valve chamber) is discharged from the outflow path 206. When the ink in the ink introduction chamber 209 is reduced and the internal pressure is lowered, the seal member 208 adhered to the lower surface of the film 207 is in close contact with the front end surface of the protrusion 204 and closes the opening (outlet). The differential pressure valve 201 is closed. By continuing the suction in this valve closed state, negative pressure is accumulated in the ink flow path downstream from the valve closing position. When sufficient negative pressure is accumulated, when the pressure pump is re-driven and pressure ink is supplied into the ink introduction chamber 209 through the inflow passage 205, the pressure in the ink introduction chamber 209 increases and the film is increased. The valve 207 is opened by separating from the protrusion 204, and the ink flows out to the outflow path 206 at once by this valve opening.

JP 2001-38925 A JP-A-2005-96404

  However, the bubbles tend to gather in the ink introduction chamber 209 around the corners away from the protrusions 204 and are located far away from the opening of the outflow path 206. For this reason, even if the ink is discharged all at once by opening the valve at the time of chalk cleaning, the bubbles accumulated in the corners are difficult to be discharged. Of course, the opening position (outlet position) of the outflow path 206 may be set to a position where bubbles are likely to accumulate. It was necessary to arrange at a position facing the substantially central portion, that is, at a substantially central position of the bottom surface of the recess 203. For this reason, due to the structure of the differential pressure valve 201, it is difficult to change the opening position (outlet position) of the outflow path 206. That is, the arrangement position of the outlet is restricted, and the degree of freedom of the layout is extremely low. Therefore, it is unavoidable to arrange the valve device in a direction in which bubbles tend to collect at the outlet, and in this case, there is a problem that the arrangement direction of the valve device is restricted. Further, if the valve structure is changed to solve such a problem and the flow path diameter of the inflow path becomes large, when ink is sucked through the outflow path 206, ink is sucked and discharged from the outflow path 206. On the other hand, a considerable flow rate of ink flows into the ink introduction chamber 209 through the inflow path 205, and the valve closing response is impaired. If the required time until the valve is closed due to the loss of the valve closing response, another problem arises that the amount of ink that is wasted is increased. In a device that handles fluid such as gas in addition to liquid such as ink, the same problem may occur in the differential pressure valve that is used when performing choke cleaning.

  The present invention has been made in view of the above problems, and its purpose is to easily obtain the required valve closing response when so-called choke cleaning is performed, and to arrange the outlet in the valve device. An object of the present invention is to provide a liquid ejecting apparatus and a liquid container that can alleviate positional constraints.

  The present invention is a liquid ejecting apparatus including a valve device, wherein the valve device forms a part of a wall surface forming a fluid flow path and is flexible due to a pressure difference between the inside and the outside of the fluid flow path. A member, and a valve seat having an opening that is provided so as to be able to contact in a state where the flexible member is bent in a direction in which the volume of the fluid flow path is reduced, and has an opening that is closed in a state of corresponding contact. The fluid flow path communicates with each other through the opening in a valve-open state where the flexible member does not close the opening, and is in a non-communication state when the flexible member closes the opening. A path and a second flow path, and the first flow path is formed on the flexible member at a portion outside a contact portion where the flexible member contacts the valve seat in the valve-closed state. The first flow path is provided so as to receive a fluid pressure and communicates with the outlet. The second flow path is provided so that the fluid pressure of the second flow path is applied to the flexible member through the opening in the valve-closed state, and communicates with the inflow port. The gist of the invention is that it has a cross-sectional area larger than the opening area of the inlet. In addition, an inflow port refers to the flow-path opening which makes the opening area the flow-path cross-sectional area which prescribes | regulates the flow volume (or flow-path resistance) of the fluid which flows in into a 2nd flow path.

  According to this, since the second flow path has a flow path cross-sectional area larger than the opening area of the inlet, the opening of the valve seat portion can be set to an opening area wider than the inlet. . That is, it is possible to widen the opening of the valve seat portion while keeping the inflow port narrow. Therefore, it is possible to increase the ratio of the opening area of the opening to the area of the flexible member that can be deformed (partition wall). Thereby, when applying a pressure through the inflow port while applying a negative pressure to the valve device in the closed state through the outflow port, the flexible member in contact with the valve seat portion becomes a fluid in the first flow path. The ratio of the pressure receiving area that receives the fluid pressure (pressurization) of the second flow path to the pressure receiving area that receives pressure (negative pressure) can be increased. Therefore, the force in the valve opening direction can be secured, and the valve opening for separating the flexible member from the valve seat portion becomes possible. As described above, even a valve structure in which the flow passage opening on the side that is in communication with the opening of the valve seat portion and is likely to be restricted in position is used as an inflow port functions as a valve device. For example, it becomes possible to arrange the outlet at a position where undesired foreign fluids mixed in the fluid in the fluid flow path can be easily discharged, and it is possible to improve the discharge of foreign matters in the valve device. For example, when the fluid is a liquid, it is possible to position the outlet at a position where the bubble discharge property is good in the valve device, thereby improving the bubble discharge property. In addition, since the opening of the valve seat can be enlarged while keeping the inlet narrow, when the negative pressure is applied through the outlet and the valve device is closed, the fluid in the valve device is sucked and discharged from the outlet. As the pressure in the valve device decreases due to the above, a relatively high flow resistance is applied to the fluid that flows into the valve device through the inlet. Therefore, when the negative pressure is applied, the volume in the valve device is quickly reduced, and the valve closing response of the valve device is kept good. Therefore, even if it is used as a valve device used for so-called choke cleaning, it is easy to obtain the required valve closing response, and the restriction on the arrangement position of the outlet in the valve device is eased so that it is unnecessary from the valve device. Improves material discharge.

  In the liquid ejecting apparatus according to the aspect of the invention, it is preferable that the valve seat portion is an annular protrusion that surrounds the second flow path. In addition, the protrusion should just form at least one part among the flow-path inner wall surfaces of a 2nd flow path by the internal peripheral surface.

  According to this, since the valve seat portion is an annular protrusion, it is possible to set a wide opening of the valve seat portion (opening of the second flow path) while keeping the inflow port appropriately narrow. Thus, for example, when a negative pressure is applied to the valve device through the outlet and the valve device is closed, the pressure is reduced (reduction of fluid) in the valve device due to the negative pressure, so that the valve device flows into the valve device through the inlet. It is possible to set the flow passage cross-sectional area of the inflow passage to an appropriate value so that the flow passage resistance necessary for closing the valve device is applied to the fluid.

  In the liquid ejecting apparatus of the present invention, the large cross-sectional area channel as the first channel, the interrupted area channel as the second channel, and the inflow channel communicating with the interrupted area channel at the inlet It is preferable that the flexible member is arranged so as to face the opening of the protrusion.

  According to this, by providing the interrupted area flow path and the protrusion, the opening of the valve seat portion is set to a size necessary for opening the valve device while keeping the inflow path (small cross-sectional area flow path) narrow. It becomes possible to do. Therefore, the channel port on the side communicating with the interrupted area channel side can be arranged as an inflow port (for example, on the inner bottom surface of the protrusion). For this reason, an outflow port can be arrange | positioned in the wider location which becomes the outer side of the processus | protrusion on the inner wall surface of a large cross-sectional area flow path, and the restriction | limiting of the arrangement position of an outflow port can be eliminated. In addition, since the flow path through which the fluid that is going to flow into the fluid flow path when a negative pressure is applied to the outlet is a small cross-sectional area flow path, the flow resistance required for the fluid passing through this small cross-sectional area flow path is The valve closing response of the valve device can be improved. Furthermore, although the position of the inlet is restricted by the position communicating with the interruption area flow path on the inner peripheral side of the protrusion, the inner diameter of the protrusion is relatively wide, so the position can be freely set within the wide protrusion. it can.

  In the liquid ejecting apparatus according to the aspect of the invention, the fluid is sucked through the outlet, and thereby the fluid flow path becomes negative pressure. It is preferable to close the opening of the valve seat.

  According to this, the fluid in the valve device is sucked through the outlet and negative pressure is created in the valve device, and the opening of the valve seat is closed by the flexible member displaced in the direction in which the volume in the valve device decreases. Is done. The fluid that is about to flow into the valve device through the inlet during the valve closing process of the valve device has a relatively high flow resistance because the inlet (inflow path) is relatively narrow. Decreases rapidly. As a result, the valve device closes quickly.

In the liquid ejecting apparatus according to the aspect of the invention, it is preferable that the opening of the opening by the flexible member is released by supplying a fluid through the inlet and pressurizing the second flow path.
According to this, the fluid is supplied through the inlet to the valve device in the closed state, and the inside of the second flow path is pressurized. The portion that closes the opening of the flexible member is pressurized by the pressurization of the second flow path, and a force in the valve opening direction is applied to the flexible member. At this time, since a force in the valve opening direction is applied to the portion that closes the opening of the flexible member by the relatively wide opening, the flexible member can be separated from the valve seat (protrusion), and the flexible member The obstruction of the opening by the sex member is released. That is, the valve device is opened.

  In the liquid ejecting apparatus according to the aspect of the invention, the flow path cross-sectional area of the outflow path communicating with the first flow path at the outflow port may be such that the flexible member is the valve seat when a negative pressure is applied through the outflow port. It is preferable that the value is set such that the fluid in the fluid flow path can be reduced to such an extent that it can abut against the portion.

  According to this, while ensuring a wide pressure receiving area for receiving the fluid pressure of the second flow path, the flow path cross-sectional area of the inflow path is suppressed small, and a negative pressure is applied to the flow path cross-sectional area of the inflow path through the outlet. When this is done, the value is set such that the fluid in the fluid flow path can be reduced to such an extent that the flexible member can come into contact with the valve seat. When negative pressure is applied to the valve device through the outlet to close the valve device, the fluid in the valve device flows out through the outlet, and the inside of the valve device is reduced. Fluid flows in. At this time, the fluid that is about to flow into the valve device through the inflow path is subjected to flow path resistance corresponding to the flow path cross-sectional area of the inflow path, and the inflow amount is suppressed to be smaller than the outflow amount. As a result, the fluid in the fluid flow path is reduced, and the valve member is closed when the flexible member comes into contact with the valve seat portion. Therefore, the valve device can be closed when negative pressure is applied to the outlet, and the valve device can be opened when pressure is applied through the inlet while applying negative pressure through the outlet.

  Furthermore, in the liquid ejecting apparatus according to the aspect of the invention, the liquid ejecting apparatus includes an outflow path that communicates with the first flow path at the outflow port, and an inflow path that communicates with the second flow path at the inflow port. The ratio of the channel cross-sectional area of the inflow path to the cross-sectional area is such that when a negative pressure is applied through the outflow path, the first flow rate at which the fluid in the fluid path flows out through the outflow path is determined by the outflow. It is preferable that the second flow rate at which the fluid flows into the fluid flow path through the inflow path as the pressure in the fluid flow path decreases is set to a value that is maintained until the valve is closed.

  According to this, since the ratio of the flow passage cross-sectional area of the inflow passage to the flow passage cross-sectional area of the outflow passage is set to a predetermined value, the fluid in the fluid flow passage when the negative pressure is applied through the outflow passage The first flow rate at which the fluid flows out through the outflow passage is maintained larger until the valve is closed than the second flow rate at which the fluid flows into the fluid passage through the inflow passage due to the pressure reduction in the fluid passage due to the outflow. The Therefore, the valve device can be closed.

  In the liquid ejecting apparatus according to the aspect of the invention, it is preferable that the cross-sectional area of the inflow path communicating with the second flow path at the inlet is five times or more. According to this, since the opening area of the opening is not less than 5 times the cross-sectional area of the flow path of the inflow path, a large pressure receiving area for receiving the fluid pressure of the second flow path is secured, and the flow path breakage of the inflow path The area can be kept small and the flow path resistance can be kept large. Therefore, when a negative pressure is applied to the outflow port, a relatively large flow path resistance is applied to the fluid passing through the inflow passage, so that the valve device is opened when the inflow passage is pressurized while applying a negative pressure to the outflow port. In addition, the valve closing response of the valve device is not impaired.

  In the liquid ejecting apparatus according to the aspect of the invention, the area of the partition wall that is a portion that can be bent and deformed by the pressure difference in the flexible member, the opening area of the opening, and the second flow path communicate with the second inlet. It is preferable that the flow passage cross-sectional area of the inflow passage to be set is set so as to decrease sequentially in this order.

  According to this, the area of the partition wall portion in the flexible member, the opening area of the opening, and the flow path cross-sectional area of the inflow path are set so as to sequentially decrease in this order. For this reason, the pressure receiving area (opening area of the opening) where the flexible member that is in contact with the valve seat portion and closes receives the liquid pressure of the second flow path through the opening is larger than the opening area of the inflow port. Yes. Further, the ratio of the opening area of the opening to the area of the partition wall is increased.

  Thereby, when applying pressure to the inflow port while applying negative pressure to the outflow port, the flexible member in the valve-closed state corresponds to the pressure receiving area that receives the fluid pressure (negative pressure) of the first flow path. Since the ratio of the pressure receiving area that receives the fluid pressure (pressurization) of the second flow path becomes large and the force in the valve opening direction can be secured, the flexible member can be opened away from the valve seat. It becomes. In this way, even if the side that is easily connected to the opening of the valve seat portion and is subject to position restrictions is used as an inflow port, it functions as a valve device. The side can be an outlet. Therefore, for example, it is possible to arrange the outlet at a position where undesired foreign fluids mixed in the fluid in the fluid flow path are easily discharged, and it is possible to improve the foreign matter dischargeability in the valve device. For example, when the fluid is a liquid, it is possible to position the outlet at a position where the bubble discharge property is good in the valve device, thereby improving the bubble discharge property.

  In the liquid ejecting apparatus according to the aspect of the invention, when the ratio of the opening area of the opening to the area of the partition wall is applied through the inlet while applying a negative pressure through the outlet, the valve seat portion The partition wall portion that is in contact with the peripheral portion receives the negative pressure of the first flow path in the peripheral region that is outside the contact location, and acts on the peripheral region to close the valve in the valve closing direction and the opening. When the pressure of the second flow path is received via the valve, the valve opening direction force acting on the substantially central region of the partition wall portion is applied to the substantially central region of the partition wall portion based on both forces. It is preferable that the bending moment is set larger than a bending moment acting on the peripheral region, and is set to a value equal to or greater than a predetermined value that satisfies a valve opening condition that enables the partition wall to be separated from the valve seat.

  According to this, when the valve is opened after the negative pressure is accumulated in the choke cleaning, the valve device is pressurized through the inlet while the negative pressure is applied through the outlet. At this time, a force in the valve closing direction acts on the peripheral region outside the contact portion of the partition wall portion that is in contact with the valve seat portion based on receiving the negative pressure of the first flow path. Further, at this time, a force in the valve opening direction based on the pressure applied to the second flow path through the opening by the partition wall acts on the substantially central region of the partition wall. Since the ratio of the opening area of the opening to the area of the partition wall is set to a value not less than a predetermined value that satisfies the valve opening condition, the bending moment based on the force in the valve opening direction acting on the substantially central region of the partition wall However, the bending moment based on the force in the valve closing direction acting on the peripheral region of the partition wall is superior, and the partition wall (flexible member) can be separated from the valve seat. That is, the valve device can be opened in choke cleaning.

  In the liquid ejecting apparatus according to the aspect of the invention, it is preferable that an opening area of the opening is ¼ or more of an area of the partition wall. According to this, when negative pressure is applied through the outflow port and pressurization is applied through the inflow port, the partition wall portion in the valve-closed state receives the fluid pressure (pressurization) of the second flow path through the opening. Since the area is secured at least ¼ of the area of the partition wall, a force in the valve opening direction necessary for separating the partition wall from the valve seat can be secured. In this case, when the valve is opened in choke cleaning, the valve device is used under the condition that the negative pressure of the first flow path and the pressurization of the second flow path are substantially equal, and the negative pressure of the first flow path. The valve device can be opened in both cases where the second flow path is used under stronger conditions. For example, liquid ejection in which choke cleaning is performed using pressurization by a pressurizing unit for pressurizing and supplying liquid to the liquid ejecting head and negative pressure by a suction unit for cleaning that sucks liquid from a nozzle of the liquid ejecting head It is suitable for application to an apparatus.

  In the liquid ejecting apparatus according to the aspect of the invention, the partition portion that is in contact with the valve seat portion may have the opening with respect to a pressure receiving area that receives the fluid pressure of the first flow path in a peripheral region outside the contact portion. The ratio of the pressure receiving area for receiving the fluid pressure of the second flow path in the substantially central region through the valve seat portion when a negative pressure is applied through the outlet and a pressure is applied through the inlet. The partition wall portion that is in contact with the peripheral portion receives the negative pressure of the first flow path in the peripheral region, and acts on the peripheral region of the partition wall portion in the valve closing direction and the opening through the opening. The bending moment acting on the substantially central region of the partition wall based on both forces when receiving the force in the valve opening direction acting on the substantially central region of the partition wall based on receiving pressure of the two flow paths is The partition wall portion becomes larger than the bending moment acting on the peripheral region. May preferably be set to the valve opening condition is satisfied the predetermined value or more values for enabling away from parts.

  According to this, when the valve is opened after the negative pressure is accumulated in the choke cleaning, the valve device is pressurized through the inlet while the negative pressure is applied through the outlet. At this time, a force in the valve closing direction acts on the peripheral region outside the contact portion of the partition wall portion that is in contact with the valve seat portion based on receiving the negative pressure of the first flow path. Further, at this time, a force in the valve opening direction based on the pressure applied to the second flow path through the opening by the partition wall acts on the substantially central region of the partition wall. Then, the partition wall portion in contact with the valve seat portion is substantially in the central region through the opening with respect to the pressure receiving area for receiving the fluid pressure of the first flow path in the peripheral region outside the contact portion. Since the ratio of the pressure receiving area for receiving the pressure of the second flow path is set to a value equal to or greater than a predetermined value, the bending moment based on the force in the valve opening direction acting on the substantially central region of the partition wall portion is The bending moment based on the force in the valve closing direction acting on the peripheral region of the partition wall is superior, and the partition wall (flexible member) can be separated from the valve seat. That is, the valve device can be opened in choke cleaning.

  In the liquid ejecting apparatus according to the aspect of the invention, the liquid storing unit that stores the liquid, the liquid ejecting head that ejects the liquid from the nozzle, the liquid supply path that guides the liquid from the liquid storing unit to the liquid ejecting head, A suction unit that sucks the liquid from the nozzle of the liquid ejecting head; and a pressurizing unit that pressurizes the liquid sent from the liquid storing unit to the liquid ejecting head side through the liquid supply path. The liquid storage means or the liquid supply path is preferably provided in the middle.

  According to this, the valve device is provided in the liquid storage means, or is provided in the middle of the liquid supply path that guides the liquid from the liquid storage means to the liquid ejecting head. When cleaning the liquid supply path by exchanging liquid, the suction device applies a negative pressure through the outlet of the valve device to close the valve device, and the negative pressure continues to be applied after the valve is closed. As a result, a negative pressure is accumulated in the liquid supply path downstream of the valve closing position. At a predetermined stage where the negative pressure is accumulated, pressurization is applied through the inlet by the pressurizing means. By applying pressure to the inflow port, the liquid flows into the valve device through the inflow port, thereby opening the valve device, and the liquid pressurized by the valve opening passes through the liquid supply path where negative pressure is accumulated. It flows at a high flow rate. As a result, the liquid supply path is cleaned. In the valve device, there is no restriction on the arrangement position of the outlet, and the outlet can be set at an appropriate position according to the arrangement direction of the valve device, so that the bubble discharge performance in the valve device during cleaning can be improved. Moreover, since the freedom degree of the arrangement position of an outflow port increases, the restriction | limiting of the arrangement direction of the valve apparatus in a liquid ejecting apparatus is lose | eliminated, and the freedom degree of the arrangement direction of a valve apparatus increases. For example, the valve device can be arranged in an orientation that can be easily connected to the liquid supply path, or the valve device can be arranged compactly in an arrangement orientation that can be accommodated in a given arrangement space. A compact assembly can be improved.

  In the liquid ejecting apparatus of the invention, the valve device is closed by sucking the liquid from the nozzle of the liquid ejecting head by the suction means and applying a negative pressure to the outlet, and after the valve is closed, the valve is closed. At a predetermined stage where negative pressure is accumulated downstream from the valve location, liquid is supplied from the liquid storage means to the liquid ejecting head side through the liquid supply path by the pressurizing means to pressurize the inlet. It is preferable that cleaning is performed by opening the valve device by applying the liquid to the valve device and the liquid supply flow channel on the downstream side of the valve device. According to this, since so-called choke cleaning can be performed, and it is possible to select the position where the bubbles in the liquid in the fluid flow path are easily discharged and to set the outlet, it is thus possible to discharge bubbles during choke cleaning. Can be improved.

  In the liquid ejecting apparatus according to the aspect of the invention, the valve device is disposed in a state where the flexible member is positioned on the opposite side in the gravitational direction, and the outlet port is located on the wall surface of the first flow path on the opposite side in the gravitational direction. It is preferable to open to the position.

  According to this, the valve device is arranged in a state where the flexible member is positioned on the opposite side (upper side) in the gravity direction, and the bubbles in the liquid in the first flow path are opposed to the gravity direction in the liquid by the buoyancy. It moves to the side and is located in the upper end position in a fluid flow path. Since the outflow port is opened at a position opposite to the gravitational direction (upper side) on the wall surface of the first flow path, bubbles are guided to the outflow port during choke cleaning.

  In the liquid ejecting apparatus according to the aspect of the invention, the valve device may be disposed in a direction in which a direction intersecting the direction of gravity is a bending direction of the flexible member, and the outlet port is the flexible member that forms the first flow path. It is preferable to open to the position on the opposite side to the gravity direction on the inner wall surface other than the sex member.

  According to this, the valve device is disposed in a direction in which the direction intersecting the direction of gravity is the direction in which the flexible member bends, and bubbles in the liquid in the first flow path move in the liquid by the buoyancy in the direction of gravity. It moves to the opposite side and is located at the upper end position in the fluid flow path. Since the outflow port opens at a position opposite to the gravity direction on the inner wall surface of the first flow path, bubbles are guided to the outflow port during the chalk cleaning.

  In the liquid ejecting apparatus according to the aspect of the invention, the inner wall surface of the fluid flow path in the valve device may be inclined with respect to the direction of gravity so that the bubbles moving by buoyancy in the liquid in the fluid flow path can be guided to the outlet. It is preferable to have a guide surface. According to this, since it is possible to guide the bubbles to be moved in the liquid in the liquid flow path by buoyancy to the outlet along the guide surface formed on the inner wall surface, the bubbles can be easily discharged from the liquid outlet.

  The gist of the present invention is a liquid storage container that is used detachably attached to a liquid ejecting apparatus, and includes the valve device provided in the liquid ejecting apparatus of the invention. According to this, by attaching the liquid container to the liquid ejecting apparatus, the valve apparatus is attached to the liquid ejecting apparatus, and the same effect as the invention of the liquid ejecting apparatus can be obtained by the valve apparatus.

FIG. 2 is a plan view of the ink jet recording apparatus according to the first embodiment. FIG. 3 is a cross-sectional view of an ink cartridge shown together with a cartridge holder. FIG. 3 is a partial cross-sectional view illustrating a recording head and a cleaning device. The ink pressure circuit diagram of a chalk cleaning device. The model perspective view of a differential pressure valve. The sectional side view which shows the valve opening state of a differential pressure valve. The sectional side view which shows the valve closing state of a differential pressure valve. The sectional side view explaining the valve opening conditions of a differential pressure valve. 1 is a block diagram showing an electrical configuration of an ink jet recording apparatus. The side sectional view of the differential pressure valve in a 2nd embodiment. The side sectional view of the differential pressure valve in a 3rd embodiment. The sectional side view which shows the differential pressure valve of a modification. The sectional side view of the modification different from FIG. The top view of the modification different from FIG. The sectional side view of the differential pressure valve in prior art.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a plan view of the ink jet recording apparatus with the outer case removed. A platen 13 extends along the main scanning direction (left and right direction in FIG. 1) in a main body case 12 (main body frame) formed of a substantially rectangular parallelepiped box that opens on the upper side (the front side in FIG. 1). It is erected. A recording medium (not shown) as a target sent via a paper feeding means (not shown) is conveyed in the sub-scanning direction (vertical direction in FIG. 1) with the lower surface supported by the platen 13.

  Further, a rod-shaped guide shaft 14 is installed in the main body case 12 so as to extend in parallel with the platen 13 in a state where the axial direction thereof coincides with the main scanning direction. A guide shaft 14 is inserted between the rear side walls of the carriage 15 and is supported so as to be reciprocally movable in the axial direction with respect to the guide shaft 14. A timing belt 17 is wound around a pair of pulleys 16a and 16b that are respectively pivotally supported at two positions separated by a predetermined distance in the main scanning direction at the rear portion (upper portion in FIG. 1) of the main body case 12. Is fixed to the timing belt 17 at the back side (upper side in FIG. 1). In FIG. 1, the right pulley 16 a is connected to a drive shaft of a carriage motor 18 that is supported near the rear right end position of the main body case 12, and the timing belt 17 is driven by the forward and reverse driving of the carriage motor 18. The carriage 15 is configured to reciprocate along the guide shaft 14.

  A recording head 20 having a plurality of nozzles 20a (see FIG. 3) for ejecting ink as liquid toward the platen 13 is provided on the lower surface of the carriage 15 facing the platen 13. Further, a tank (not shown) capable of temporarily storing ink is provided on the carriage 15 and a valve unit 21 (also referred to as a sub tank) that can supply the ink in the tank to the recording head 20 in a state in which the pressure is adjusted is mounted. Has been. In the present embodiment, a total of four valve units 21 are provided for each ink color, and the pressure of the ink of each color of black, yellow, magenta, and cyan is adjusted by each valve unit 21, respectively, and the recording head 20. To be supplied.

  Four ink cartridges 23 corresponding to the ink colors are detachably loaded in the cartridge holder 24 provided at one end (the right end in FIG. 1) of the main body case 12. FIG. 2 shows one of the four ink cartridges 23. The ink cartridge 23 includes an ink case 31 having a substantially rectangular parallelepiped shape and an ink pack in which the entirety is accommodated in the ink case 31. 32. The ink pack 32 is formed into a bag shape by a flexible film having gas barrier properties, and a bag portion 32a in which ink as a liquid is sealed, and an ink supply fixed to an end portion of the bag portion 32a. Part 32b. In the ink pack 32, only the ink supply part 32 b is exposed from the ink case 31, and the other part is accommodated in the ink case 31 in an airtight state. Accordingly, a gap 33 is formed between the ink case 31 and the ink pack 32. The ink cartridge 23 may be configured to store a plurality of color ink packs in one case.

  As shown in FIG. 2, the cartridge holder 24 has a main body 24a, and an ink supply needle 24b and an air introduction needle 24c that project substantially perpendicularly from the loading surface (right surface in FIG. 2) of the main body 24a. Further, an ink supply pipe portion 24d and an air introduction pipe portion 24e are projected from the back surface of the main body 24a (the left surface in the figure). The main body 24a is composed of a flow path forming member in which a large number of flow paths are formed. Specifically, in the main body 24a, an ink flow path (not shown) that communicates the ink supply needle 24b and the ink supply pipe section 24d, and an air flow (not illustrated) that communicates the air introduction needle 24c and the air introduction pipe section 24e. The same number of paths as ink colors are formed. Further, the lower surface of the loaded ink cartridge 23 is supported by a guide plate portion 24f extending substantially horizontally from the lower portion of the main body 24a. The cartridge holder 24 may be connected to the loaded ink cartridge 23 by a connecting structure other than the needle structure.

  In a state where the ink cartridge 23 is loaded in the cartridge holder 24, the ink supply needle 24b is inserted into the ink supply portion 32b, and the air introduction needle 24c is inserted into the communication hole 31a formed in the ink case 31. ing. The air introduced from the air introduction tube 24e is introduced into the gap 33 in the ink case 31 through a needle hole (air outlet hole) (not shown) formed at the tip of the air introduction needle 24c. It is possible to increase the pressure at 33 and generate a force that crushes the ink pack 32. When the ink pack 32 is crushed, the ink in the ink pack 32 is sent into the cartridge holder 24 through a needle hole (ink introduction hole) (not shown) formed at the tip of the ink supply needle 24b. The ink is supplied in a pressurized state from an ink supply pipe portion 24d protruding from the back surface of the main body 24a.

  As shown in FIG. 1, each cartridge holder 24 is connected to each valve unit 21 through an ink supply tube 35. Accordingly, ink is supplied from the ink cartridge 23 to the valve unit 21 through the ink supply tube 35 with an ink pressure corresponding to the air pressure introduced into the gap 33 in the ink case 31. One end portion on the upstream side of the ink supply tube 35 is connected to the ink supply tube portion 24d of the cartridge holder 24 shown in FIG.

  As shown in FIG. 1, a pressurizing pump 25 is provided above the loading position of the ink cartridge 23 while being supported by the main body case 12. The pressurizing pump 25 can suck the atmosphere and discharge it as pressurized air, and the discharged pressurized air is supplied to the pressure detector 38 through the pressurizing tube 37.

  The pressure detector 38 detects the pressure of the air supplied from the pressurizing pump 25. Based on the detected pressure of the pressure detector 38, the drive of the pressurizing pump 25 is controlled. Therefore, the pressurized air supplied from the pressurizing pump 25 is adjusted so that the pressure is within a predetermined range. The pressure detector 38 is connected to the air introduction tube portion 24e (see FIG. 2) of the cartridge holder 24 through the four air supply tubes 39, and the pressure in the gap 33 of the ink cartridge 23 is within a predetermined range. Compressed air adjusted in this way is introduced.

  As described above, the ink pack 32 of each ink cartridge 23 is crushed by the pressurized air supplied from the pressure pump 25 to the gap 33, and the ink in the ink pack 32 is pressurized against the corresponding valve unit 21. Supplied in a dry state. The pressurized ink temporarily stored in the tank in the valve unit 21 is supplied to the recording head 20 with the pressure adjusted.

  At this time, based on the image data, the carriage 15 is moved in the main scanning direction, and in the moving process, the ink is ejected from the nozzles of the recording head 20, and the ink is ejected from the recording head 20 by the paper feeding means. By alternately performing the paper feeding operation for moving the storage medium in the sub-scanning direction, it is possible to perform printing on the recording medium.

  The cleaning device 26 is provided in a non-printing area (home position) on the movement path of the carriage 15. On the upper surface of the cleaning device 26, a cap 26a formed of an elastic material such as an elastomer that can be sealed in close contact with the nozzle forming surface 20b (see FIG. 3) of the recording head 20 is disposed. As shown in FIG. 3, the cap 26 a moves (rises) in a direction approaching the recording head 20 in conjunction with the movement of the carriage 15 to the home position, and the nozzle formation surface of the recording head 20. The predetermined region including all the nozzles 20a in 20b can be sealed. The cleaning device includes an elevating mechanism (not shown) having a lever that is engaged with and pushed by the carriage 15 immediately before the carriage 15 finishes moving to the home position. The cap 26a is lifted when the lever of the lifting mechanism is pushed by the carriage 15 and moves in the upward direction along the oblique guide portion. When the carriage 15 is separated from the home position, a biasing force of a biasing spring (not shown) is raised. Thus, it is configured to move downward in the downward direction along the oblique guide portion.

  An absorber 26b containing ink is disposed inside the cap 26a, and the nozzle forming surface 20b of the recording head 20 is sealed by the cap 26a during the rest period of the ink jet recording apparatus 11. Thus, the inside of the cap 26a is kept in a high humidity state to prevent thickening of the ink in the nozzle 20a.

  Further, a discharge pipe 26c for discharging ink, bubbles, foreign matters (paper dust and the like) is provided at the bottom of the cap 26a, and one end of the ink discharge tube 26d is connected to the discharge pipe 26c. Has been. The other end of the ink discharge tube 26d is connected to a waste liquid tank 27 (see FIG. 4).

  A tube pump 26e (suction pump) is provided in the middle of the ink discharge tube 26d, and a suction force is applied to the inside of the cap 26a by the suction operation of the tube pump 26e so that a negative pressure is formed. . Then, thickened ink, foreign matter, bubbles, and the like are discharged to the waste liquid tank through the ink discharge tube 26d. Thereby, the recording head 20 is cleaned.

  On the other hand, as shown in FIG. 1, the cleaning device 26 is provided with a wiping member 26f in which an elastic material such as rubber is formed in a strip shape adjacent to the printing region side of the cap 26a. Then, the wiping member 26f advances in the vertical direction to the moving path of the recording head 20 as necessary, so that the nozzle forming surface 20b is wiped when the recording head 20 moves away from the home position. The residual ink adhering to 20b is removed and the meniscus of the ink in the nozzle is adjusted.

<Valve unit>
Next, a schematic configuration of the ink supply device will be described with reference to FIG. As shown in FIG. 4, the air pressurized from the pressure pump is introduced into the gap 33 in the ink case 31 and the ink pack 32 is crushed, so that the ink pressurized to a predetermined pressure from the ink pack 32 is obtained. It is sent to the valve unit 21. The valve unit 21 includes a differential pressure valve 41 (choke valve) and a pressure adjustment valve 42 as valve devices, and the ink supplied into the valve unit 21 is sent to the pressure adjustment valve 42 through the differential pressure valve 41. The pressure adjustment valve 42 is configured to supply pressure to the recording head 20 while adjusting the pressure. The differential pressure valve 41 and the pressure adjustment valve 42 are provided for each ink flow path for each ink color.

  The differential pressure valve 41 is for closing the ink flow path connected to the recording head 20 when performing choke cleaning. Further, the pressure adjustment valve 42 is for supplying ink to the recording head 20 as appropriate. The ink is discharged from the recording head 20 and the ink pressure in the recording head 20 is lowered, so that the lower limit of the ink pressure allowable range is reached. When the pressure reaches the pressure, the valve opens and supplies ink to the recording head 20, while the ink is supplied to the recording head 20 and closes when the ink pressure rises to the upper limit of the allowable ink pressure range. . The pressure adjustment valve 42 limits the amount of ink introduced into the recording head 20 to suppress ink leakage from each nozzle 20a due to excessive introduction of ink. As long as the above-described opening / closing operation is performed, the pressure regulating valve 42 is configured by a known valve such as a check valve, a differential pressure valve, or a self-sealing valve. The self-sealing valve always closes when the valve body is pushed in the valve closing direction by the biasing force of the spring, the valve chamber is depressurized to a predetermined pressure, and the diaphragm resists the biasing force of the spring. It is an on-off valve that opens by pushing the valve body in the valve opening direction by bending inward.

<Differential pressure valve>
Next, the differential pressure valve 41 built in the valve unit 21 will be described in detail with reference to FIGS. FIG. 5 is a perspective view of the differential pressure valve. 6 and 7 are sectional views of the differential pressure valve. FIG. 6 shows a valve open state, and FIG. 7 shows a valve closed state. In the description of the structure of the differential pressure valve 41, the upward direction in each figure will be described as the upper side of the differential pressure valve for convenience.

  As shown in FIG. 5, the differential pressure valve 41 includes a substantially plate-like substrate 44 having a predetermined shape in plan view (square shape in the present embodiment) and having a recess 43 on the surface (upper surface), and a surface 44 a of the substrate 44. A film member 45 (diaphragm) as a flexible member fixed in a state of sealing the opening 43a of the recess 43; The recess 43 has a circular opening 43a and is formed with the same inner diameter over the depth direction. The film member 45 is made of a synthetic resin film having a high gas barrier property having a predetermined thickness (for example, a predetermined value in a range of 10 μm to 1 mm) that can provide flexibility, and the concave portion 43 is provided so as to ensure a predetermined fixing allowance. For example, it is formed in a circular shape having a larger size than the opening 43a.

  In this embodiment, both the base material 44 and the film member 45 are made of synthetic resin, and the film member 45 is fixed to the base material 44 by heat welding. Therefore, as a material for both, a combination of thermoplastic resins that can be fixed by thermal welding is used. Any thermoplastic resin may be used as long as it is a heat-weldable combination. However, in this embodiment, the same material is used for both, so that the adhesive strength is easily secured. (PP) or polyethylene terephthalate (PET) is used. Further, since it is only necessary to be able to perform heat welding, for example, a synthetic resin material (for example, a thermoplastic material having the same material as that of the film member 45) capable of heat-welding the film member 45 only on the surface layer to which the film member 45 is fixed. May be formed. Of course, other fixing methods other than thermal welding, such as using an adhesive, can be employed. In that case, not only thermoplastic resins but also synthetic resins can be used as appropriate materials such as metals and ceramics. . Moreover, as long as it can fix, other welding methods, such as vibration welding, may be employ | adopted.

  As shown in FIG. 5 to FIG. 7, an annular protrusion 46 is formed on the substantially central portion of the bottom surface of the recess 43 so as to be concentric with the recess 43 in plan view. Near the center on the inner bottom surface of the protrusion 46, an inlet 47a of an inflow passage 47 that protrudes from the substantially center position of the bottom surface of the base member 44 and passes through the inside of the inflow pipe portion 48 shown in FIGS. . Further, as shown in FIGS. 5 to 7, an outflow passage 49 is formed through the side portion of the base material 44 (right side portion in FIGS. 6 and 7), and the outflow passage 49 is formed on the inner peripheral surface of the recess 43. One end is open, and the other end forms a linear flow path that opens to the end face of the flange portion 44 b formed to extend to the peripheral edge of the base material 44. The outlet 49 a of the outflow passage 49 that opens onto the inner wall surface of the recess 43 is located at substantially the upper end in the depth direction on the inner peripheral wall (side wall) of the recess 43. In addition, although the protrusion 46 was made into an annular shape in the present embodiment, it may be an annular shape, and may be an elliptical shape or a polygonal shape (for example, a triangle, a quadrangle, a hexagon, etc.).

  A region surrounded by the inner wall surface of the recess 43 (including the outer peripheral surface of the protrusion 46) and the film member 45 is a valve chamber 50 (choke chamber). The valve chamber 50 includes a first flow path 51 as a large cross-sectional area flow path formed from an outer region of the protrusion 46 in the valve chamber 50 and an interruption formed by being surrounded by an inner peripheral surface of the protrusion 46 formed from an inner region of the protrusion 46. It consists of a second channel 52 as an area channel. And the inflow path 47 connected with the 2nd flow path 52 through the inflow port 47a becomes a small cross-sectional area flow path.

  The differential pressure valve 41 is assembled horizontally to the valve unit 21 (in a state where the outer surface of the film member 45 faces upward) in a state where atmospheric pressure is applied to the outer surface of the film member 45. In this example, the differential pressure valve 41 is assembled in an assembly recess recessed in the base material of the valve unit 21, and in this assembly state, the outflow passage 49 opens at a relative position on the inner wall surface of the assembly recess. The opening of the ink flow path (not shown) is connected to the periphery of the ink flow path sealed with a seal member. Further, an ink supply tube 35 of a corresponding ink color connected to the cartridge holder 24 is connected to the inflow pipe portion 48 of the differential pressure valve 41.

  The differential pressure valve 41 is an open / close valve that opens and closes when the film member 45 is bent by a pressure difference between the inside and outside of the valve chamber 50. That is, when the pressure in the valve chamber 50 is reduced below the atmospheric pressure, the film member 45 bends in the direction of decreasing the volume of the valve chamber 50 and comes into contact with the valve seat surface 46b formed by the flat tip surface of the protrusion 46, The opening 46a is closed. When the opening 46 a is closed by the film member 45, the differential pressure valve 41 is closed, and communication between the first flow path 51 and the second flow path 52 is blocked. Then, when the film member 45 is separated from the projection 46 due to a pressure difference between the inside and outside of the valve chamber 50, the valve is opened, and the first flow path 51 and the second flow path 52 are communicated with each other through the opening 46a. In the film member 45, a circularly deformable partition wall portion corresponding to the opening 43a is a diaphragm 45a. When the valve is opened and closed, the portion of the diaphragm 45a is displaced. The film member 45 can be changed to a material other than synthetic resin, such as an elastomer or rubber, as long as the film member 45 bends due to a pressure difference between the inside and outside of the valve chamber 50.

  At the time of printing, pressurized ink flows from the inflow path 47 into the valve chamber 50 by driving the pressurizing pump 25, and the inside of the valve chamber 50 is pressurized to a predetermined ink pressure. In this pressurized state, as shown in FIG. 6, the film member 45 is in a valve-opened state separated from the protrusion 46. Under this pressurized state, the inner surface of the film member 45 is pressurized, so that the film member 45 bulges in a circular arc shape from the flat state shown in FIG. 6 to the outside (atmosphere side). On the other hand, when performing choke cleaning, driving of the pressurizing pump 25 is stopped and the pressurization from the inflow passage 47 is stopped. In this non-pressurized state, the differential pressure valve 41 is open as shown in FIG. However, in this example, since the internal pressure of the valve chamber 50 is not released and the pressure remains, the film member 45 remains bulged outward. Under this non-pressurized state, when ink is sucked from the nozzle 20a of the recording head 20 by the cleaning device 26, the ink in the valve chamber 50 is forcibly sucked and discharged from the outflow passage 49, and the valve chamber The inside of 50 becomes negative pressure due to the decrease in ink, and as shown in FIG. When the film member 45 comes into close contact with the protrusion 46, the opening 46a is closed and the differential pressure valve 41 is closed.

  Thereafter, the driving of the pressurizing pump 25 is resumed at a predetermined stage where the negative pressure is sufficiently accumulated in the ink flow path from the valve closing position of the differential pressure valve 41 to the nozzle 20a of the recording head 20. Has been. The driving start timing of the pressurizing pump 25 is determined by a CPU 61 described later in accordance with setting conditions obtained in advance by a preliminary experiment or the like. For example, when the suction operation time measured by a timer (not shown) reaches the set time, The driving of the pressure pump motor 73 (shown in FIG. 9) is restarted and the pressurizing pump 25 is redriven. Of course, the number of rotations of the tube pump 26e (or the tube pump motor 74 shown in FIG. 9) after the start of the suction operation is measured, and when the measured total number of rotations reaches the set number of rotations, the pressure pump motor 73 is driven. A configuration for restarting can also be adopted.

  Here, in this embodiment, as shown in FIG. 6, the opening diameter (inner diameter) φA of the protrusion 46 (second flow path 52), the opening diameter (diameter) φB of the recess 43 (first flow path 51), the inflow Assuming that the flow path diameter of the path 47 (that is, the opening diameter of the inlet 47a) φC, there is a relationship of φB> φA> φC. Of course, in the present embodiment in which the first flow path 51, the second flow path 52, and the inflow path 47 have the same inner diameter over the length of the flow path, the magnitude relationship between the inner diameters of these flow paths is φB > ΦA> φC. In the process of accumulating a negative pressure in the ink flow path under the non-pressurized state in the chalk cleaning, the ink in the valve chamber 50 flows out of the outlet 49a while the film member 45 is in the valve-opened state separated from the protrusion 46. While the ink is sucked and discharged from the ink, the ink flows into the valve chamber 50 through the inflow passage 47 due to the pressure reduction in the valve chamber 50 accompanying the decrease in ink. At this time, in order to close the differential pressure valve 41 quickly, it is necessary to keep the ratio of the ink inflow amount to the ink outflow amount small. For this purpose, it is necessary to keep the flow path diameter C of the inflow path 47 small. In this embodiment, the flow path diameter C is set to a relatively small value from this viewpoint.

  The ink outflow amount from the outflow path 49 is determined by the flow path diameter, the flow path length, the pressure difference between the inlet and the outlet of the outflow path 49, and the ink inflow amount from the inflow path 47 is the flow path diameter, flow It is determined by the path length and the pressure difference between the inlet and outlet of the inflow channel 47. Here, the pressure difference between the inlet and outlet of the flow path is determined by the influence of pressure loss due to the flow resistance that the fluid (ink) passing through the flow path receives. The resulting pressure loss increases, and the flow rate is reduced. Considering these conditions, the flow path diameter φC (that is, the flow path cross-sectional area) of the inflow path 47 is set so that the differential pressure valve 41 can be closed quickly. However, since the flow path diameter C of the inflow path 47 determines the flow rate of the ink supplied from the inflow path 47 in order to open the differential pressure valve 41 in the closed state, the valve opening response is kept good and printing is performed. In order to smoothly supply ink, it is not preferable to make it too small, so this point is also set. Of course, the inflow path 47 does not need to have the same diameter over the entire length of the flow path, and may have a configuration in which, for example, a throttle portion (orifice) is provided in the flow path of the inflow path 47 as long as the flow rate can be controlled. . When the throttle part is employed, the flow rate greatly depends on the throttle diameter, so the throttle diameter (opening diameter C) is set to an appropriate value. Details of the condition of the channel diameter (opening diameter of the channel opening) C and the like will be described later.

Further, the opening diameter φB of the concave portion 43 is a pressure receiving area (film pressure) that the film member 45 receives a negative pressure (ink pressure) in the valve chamber 50 at the time of ink suction in the process of the differential pressure valve 41 from the valve open state to the valve close state. ^{= π · B 2/4)} , namely to define the area of the diaphragm 45a. The valve closing force acting on the film member 45 is determined by the product of the pressure receiving area and the pressure difference between the negative pressure and the atmospheric pressure.

  In order to open the differential pressure valve 41 in the closed state shown in FIG. 7 by applying a pressure to the inflow passage 47 while applying a negative pressure to the outflow passage 49, the film member 45 has a second flow path. A pressing force (valve opening force) determined from a pressure receiving area that receives the pressure of the ink in 52 and a pressure value ΔPpos (= Ppos−Patm) that is a differential pressure between the pressure Ppos and the atmospheric pressure Patm is a predetermined pressure. Must be greater than or equal to the value. That is, the diaphragm 45a that can be bent and deformed facing the opening 43a of the concave portion 43 in the film member 45 has an annular periphery extending from the ink in the first flow path 51 to the periphery of the contact portion with the protrusion 46 in the valve-closed state. While receiving negative pressure in the region, pressure is applied in the central region from the ink in the second flow path 52 through the opening 46a. In order for the diaphragm 45a to be separated from the protrusion 46, it is necessary that the force applied by the pressure applied to the central region of the diaphragm 45a overcomes the force generated by the negative pressure applied to the peripheral region. Therefore, the opening diameter φA of the protrusion 46 is set such that the ratio (A / B) to the opening diameter φB (that is, the diaphragm diameter) of the recess 43 is greater than or equal to a predetermined value at which the differential pressure valve 41 can be opened. . Since the ink pressure in the second flow path 52 in the pressurized state is substantially constant but varies within a predetermined range, the opening diameter is set so that the differential pressure valve 41 can be opened even at the lowest ink pressure within the predetermined range. φA is set.

  In order to specify the conditions of the opening diameters A, B, and C (channel diameter), an experiment was conducted to evaluate the condition of the opening diameter φA that can be opened using the differential pressure valve 41 having the configuration shown in FIG. The step difference between the surface 44a and the protrusion 46, that is, the gap between the diaphragm 45a and the protrusion 46 at the differential pressure “0” was set to 0.3 mm. Further, the negative pressure ΔPneg received by the diaphragm 43a from the fluid in the first flow path 51 in the state of being sucked and closed is 30 kPa, and when the pressure is applied to open the valve, the fluid in the second flow path 52 The pressure (positive pressure) ΔPpos received by 45a was 30 kPa. Here, the negative pressure ΔPneg refers to a differential pressure (= Patm−Pneg) between the negative pressure Pneg that is the ink pressure in the first flow path 51 and the atmospheric pressure Patm, and the pressurization (positive pressure) ΔPpos is This indicates the pressure difference (= Ppos−Patm) between the pressure Ppos, which is the ink pressure in the second flow path 52, and the atmospheric pressure Patm.

  As the film member 45, PET (polyethylene terephthalate) having a thickness of 12 μm and CPP (unstretched polypropylene film) having a thickness of 25 μm were used. The dimension ratio B / C of the opening diameter φB (diaphragm diameter) of the recess 43 to the flow path diameter φC of the inflow channel 47 was set to “about 10”. In addition, three types of differential pressure valves 41 of 1/3, 1/2, and 2/3 were prepared for the dimensional ratio A / B of the opening diameter φA of the protrusion 46 to the opening diameter φB (diaphragm diameter) of the recess 43.

  As a result of the evaluation, it was found that the valve opening condition for opening the differential pressure valve 41 requires that the dimension ratio A / B of the opening diameter φA of the protrusion 46 to the opening diameter φB of the recess 43 is “½ or more”. . No particular effect was observed due to the difference in the material of the film member 45. From the above, it is desirable that the dimensional ratio is B: A: C = 10: 5 or more: 1. The material of the film member 45 may be a synthetic resin other than PET or CPP. For example, OPP (biaxially stretched polypropylene film), ONY (biaxially stretched nylon), CNY (unstretched nylon), PVA (polyvinyl alcohol), PI (polyimide), PC (polycarbonate), TAC (triacetyl cellulose), PS (Polystyrene), PE (polyethylene), etc. can be used.

  Here, in the above evaluation example, the negative pressure ΔPneg applied to the diaphragm 45 a in the peripheral area facing the first flow path 51 is equal to the pressure ΔPpos applied to the central area facing the second flow path 52. Of course, these differential pressures ΔPneg and ΔPpos may be different. In this case, the ratio A at which the valve opening force based on the pressurization applied to the central region of the diaphragm 45a overcomes the valve closing force based on the negative pressure applied to the peripheral region and the film member 45 can be separated from the protrusion 46. / B is determined based on the suction ink pressure determined by the capacity of the tube pump 26e and the pressure ink pressure determined by the capacity of the pressure pump 25. When the valve opening condition indicated by the ratio A / B is determined, the opening diameter φA of the opening 46a and the opening diameter φB (diaphragm diameter) of the recess 43 may be set so as to satisfy the valve opening condition.

  Next, the valve opening conditions indicated by the ratio A / B will be described with reference to FIG. FIG. 8 shows the differential pressure valve when the application of pressure to the inflow passage 47 is resumed while applying a negative pressure to the outflow passage 49 after closing the valve during choke cleaning. When opening the differential pressure valve 41, the tube pump 26e continues to be driven and ink suction from the nozzle 20a is continued, and the drive of the pressurizing pump 25 is resumed, so that air enters the gap 33 of the ink cartridge 23. By being introduced, the ink pressure corresponding to the air pressure is increased. As a result, in the differential pressure valve 41, the pressure Ppos is applied to the inflow passage 47 while the negative pressure Pneg due to nozzle suction is applied to the outflow passage 49. In the closed state of the differential pressure valve 41, the diaphragm 45a abuts against the protrusion 46 and closes the opening 46a, whereby the first flow path 51 and the second flow path 52 are blocked from communication. For this reason, the first flow path 51 communicating with the outflow path 49 becomes negative pressure Pneg, and the second flow path 52 communicating with the inflow path 47 becomes pressurized (positive pressure) Ppos.

On the diaphragm 45a, a force Fneg in the valve closing direction based on the negative pressure ΔPneg (= Patm−Pneg) acts on the first pressure receiving area A1, which is a ring-shaped peripheral area facing the first flow path 51, while opening the diaphragm 45a. A force Fpos in the valve opening direction based on the pressure ΔPpos (= Ppos−Patm) acts on the second pressure receiving area A2 which is a circular central area facing the second flow path 52 through 46a. Here, when the pressure receiving area of the first pressure receiving area A1 is S1 and the pressure receiving area of the second pressure receiving area A2 is S2, the valve closing direction force Fneg and the valve opening direction force Fpos are respectively expressed as follows. .
Fneg = ΔPneg · S1 (1)
Fpo s = ΔPpos · S2 (2)
As shown in FIG. 8, the force Fpos in the valve opening direction based on the pressurization applied to the second pressure receiving region A2 acts on the central portion of the diaphragm 45a. Since the second pressure receiving region A2 where the force Fpos in the valve opening direction is applied is a central portion that is a distance away from the fulcrum O (fixed point) that fixes the diaphragm 45a around the periphery, the peripheral edge thereof is related to the bending moment. The diaphragm 45a can be moved in the valve opening direction with less force than that of the portion. On the other hand, the ring-shaped first pressure receiving region A1 located outside the protrusion 46 where the force Fneg in the valve closing direction due to the negative pressure acts is located at the periphery of the diaphragm 45a and has a short distance from the fulcrum O. In order to obtain a bending moment that balances with the bending moment due to the force acting on the center of the plate, a larger force is required.

Since fluid pressure is applied to the diaphragm 45a, an evenly distributed load in which the negative pressure Pneg of the fluid acts uniformly on the surface acts on the first pressure receiving region A1, and the fluid pressure Ppos also on the surface in the second pressure receiving region A2. Uniformly distributed load that works uniformly works. For this reason, when considering the bending moment, the distance from the fulcrum O for each point of each minute region distributed in the radial direction of the diaphragm 45a is added and averaged, and the bending moment is estimated using the distance obtained by the added average. . That is, the distance from the fulcrum O for each point of the minute region distributed in the radial direction in the ring-shaped first pressure receiving region A1 is averaged, and the force Fneg is located at a position away from the fulcrum O by the addition average distance d1. Consider it working. Further, the distance from the fulcrum O for each point of the minute area distributed in the radial direction in the second pressure receiving area A2 is averaged, and the force Fpos acts at a position away from the fulcrum O by the distance d2 of the addition average. I reckon. The bending moment Mneg based on the valve closing direction force Fneg acting on the first pressure receiving region A1 and the bending moment Mpos based on the valve opening direction force Fpos acting on the second pressure receiving region A2 are respectively expressed by the following equations.
Mneg = Fneg · d1 (3)
Mpos = Fpos · d2 (4)
The valve opening condition is Mpos> Mneg. When the opening diameter φA of the protrusion 46 and the opening diameter φB (diaphragm diameter) of the recess 43 shown in FIG. 6 are used, the pressure receiving areas S1 and S2 and the distances d1 and d2 are expressed by the following equations. However, the radial width in the close contact area with the valve seat surface 46b where the diaphragm 45a does not receive negative pressure is ignored.
S1 = π · (B ² −A ² ) / 4 (5)
^{S2 = π · A 2/4} ... (6)
d1 = (B−A) / 4 (7)
d2 = (2B−A) / 4 (8)
Here, the radial width of the portion where the diaphragm 45a is not in close contact with the valve seat surface 46b and receiving negative pressure is ignored, and it is considered that negative pressure also acts on that portion. Negative pressure does not work. Therefore, when adopting the above-described formula that the negative pressure is also considered to act on the close part, the force based on the negative pressure is an excessive value from the actual value, so the valve opening condition may be Mpos ≧ Mneg . When the valve opening condition Mpos ≧ Mneg is obtained using the above equations (1) to (8), the following equation is obtained.
A / B ≧ {ΔPneg / (3ΔPp os + ΔPneg)} ^1/2 (9)
As can be seen from the above equation (9), the ratio of the opening diameter φA of the opening 46a to the opening diameter φB (diaphragm diameter) of the recess 43 is determined according to the pressurization value ΔPpos and the negative pressure value ΔPneg. For example, if the pressurization value ΔPpos and the negative pressure value ΔPneg are equal, it can be seen from the above equation (9) that A ≧ B / 2 and that the aperture diameter φA should be ½ or more of the aperture diameter φB. This is consistent with the result of the evaluation experiment.

Further, the valve opening condition (9) is expressed by the following equation when expressed using the pressure receiving areas S1 and S2.
S2 / S1 ≧ ΔPneg / 3Ppos (10)
For example, if the pressurization value ΔPpos and the negative pressure value ΔPneg are equal, from the above equation (10), S2 / S1 ≧ 1/3, and the pressure receiving area S2 (opening area of the opening 46a) is 1/3 of the pressure receiving area S1. This should be done.

Furthermore, when the opening area (diaphragm area) of the recess 43 is S, the valve opening condition is expressed by the following equation.
S2 / S ≧ ΔPneg / (3ΔPpos + ΔPneg) (11)
For example, if the pressure value ΔPpos is equal to the negative pressure value ΔPneg, S2 / S ≧ 1/4 from the above equation (11), and the opening area S2 of the opening 46a is equal to the opening area S (diaphragm area) of the recess 43. What is necessary is just to make it 1/4 or more. That is, the opening area of the protrusion 46, that is, the first pressure receiving area S1 where the ink pressure of the pressurized ink acts in the closed state of the diaphragm 45a, is based on the assumption that the negative pressure value ΔPneg and the pressure value ΔPpos are the same value. If the total pressure receiving area S of the diaphragm 45a is 1/4 or more, the differential pressure valve 41 can be opened during choke cleaning. In the case of the present embodiment, the first flow path 51 and the second flow path 52 are both flow paths having the same flow path diameter (that is, flow path cross-sectional area) over the depth direction of the flow path. As for the valve opening condition, the flow path cross-sectional area of the second flow path 52 (interrupt area flow path) is changed to the flow break of the first flow path 51 (large cross-sectional area flow path) using these flow path cross-sectional areas. It can be said that it may be 1/4 or more of the area.

  Here, A / B ≧ 1/2, S2 / S1 ≧ 1/3, and S2 / S ≧ 1/4 are obtained as valve opening conditions when the pressure value ΔPpos and the negative pressure value ΔPneg are equal. However, the opening of the differential pressure valve 41 when these valve opening conditions are satisfied is not limited to when ΔPpos = ΔPneg. Even when the pressure value ΔPpos is weaker than the negative pressure value ΔPneg, the differential pressure valve 41 can naturally be opened.

  In this embodiment, the opening shape of the opening 46a and the opening shape of the recess 43 are both circular. However, when the shape is similar to that other than the circular shape, the opening represented by the above equation (9) is used. The valve conditions hold as well. In this case, the length ratio (similarity ratio) of the corresponding portions of the openings 43a and 46a having the similar relationship may be determined based on the above equation (9). Examples of the shape other than the circle include an ellipse, a triangle, a quadrangle, a pentagon, a hexagon, and a polygon more than an octagon. Further, even in a combination of shapes not having a similar relationship, the maximum dimension (for example, the diameter of the circumscribed circle) of the opening (diaphragm) of the recess is B, and the minimum dimension (for example, the diameter of the inscribed circle) of the protrusion is A. Then, the above equation (9) is established as the valve opening condition.

  In this embodiment, the position of the projection 46 with respect to the diaphragm 45a is determined so that the center line of the opening 43a (that is, the diaphragm 45a) of the recess 43 and the center line of the opening 46a (that is, the projection 46) coincide. . However, the center lines of the two may be slightly deviated within an allowable range. This permissible deviation amount is remarkably reduced when the opening diameter φA near the lower limit (B / 2) is set in the settable range of the opening diameter φA determined from the valve opening conditions. However, when a larger opening diameter φA (for example, 2B / 3) with a margin in the lower limit value is set, the valve opening condition is satisfied even if the amount of deviation becomes somewhat large. Further, when the center line deviates beyond the allowable range, the valve opening condition may be obtained again, and the opening size of the protrusion may be determined from the obtained valve opening condition.

Further, when a differential pressure ΔPneg (= Patm−Pneg) is applied to a circular diaphragm having a radius B / 2 and a fixed thickness t, the displacement ω (r) at a point r from the center of the diaphragm is Assuming that the Young's modulus and Poisson's ratio of the material constituting the diaphragm are E and ν, respectively, it is expressed by the following equation as a function of r.
ω (r) = 3/16 · {(1−ν ² ) / (E · t ³ )} · ΔPneg · (r ² − (B / 2) ² ) ² (12)
From this equation (12), the surface 44a can be closed by the diaphragm 45a when a negative pressure ΔPneg is applied to the diaphragm 45a in the open state in the differential pressure valve 41 whose opening diameter is φA. The step amount G between the projection 46 and the gap G between the diaphragm 45a and the projection 46 (when the differential pressure is 0) is as follows. That is, in the above equation (12), the displacement ω (r) when r = A / 2 may be a value greater than or equal to the gap G (G ≦ ω (A / 2)). Therefore, the condition of the gap G that can be closed is expressed by the following equation.
G ≦ 3/16 · {(1−ν ² ) / (E · t ³ )} · ΔPneg · ((A / 2) ² − (B / 2) ² ) ² (13)
In the present embodiment, in a normal time other than the choke cleaning, the ink pressure in the valve chamber 50 becomes higher than the atmospheric pressure Patm due to the pressurization, and the diaphragm 45a bulges outside (atmosphere side). The valve can be opened even if (gap) is zero. Therefore, since the step amount G = 0 is allowed, A = B is also allowed from the above equation (13). However, in order to ensure that the valve is closed, the opening 46a is opened. The diameter φA is desirably 80% or less of the opening diameter φB of the recess 43. Therefore, when used in the pressure range used in the ink jet recording apparatus 11, a desirable valve opening condition is 1/2 ≦ A / B ≦ 4/5. When this is expressed in terms of area, 1/3 ≦ S2 / S1 ≦ 16/9 and 1/4 ≦ S2 / S ≦ 16/25. When the negative pressure Pneg and the pressure Ppos fluctuate within a certain range, the maximum negative pressure within the fluctuation range is adopted for the negative pressure Pneg in order to ensure the opening of the differential pressure valve 41. For the pressure Ppos, it is preferable to employ the minimum pressure within the fluctuation range.

  In order to obtain a good valve closing response during choke cleaning, as described above, it is necessary to keep the ratio of the ink inflow amount to the ink outflow amount in the valve chamber 50 during ink suction small. Immediately after the start of ink suction, the pressure difference between the suction pressure (negative pressure) in the cap 26a and the ink pressure in the valve chamber 50 is large. On the other hand, the ink pressure between the valve chamber 50 and the upstream position of the inflow passage 47 The pressure difference is small. As the ink suction proceeds, the ink pressure in the valve chamber 50 gradually decreases, so that the differential pressure between the inlet and outlet of the outflow passage 49 gradually decreases and the inlet and outlet of the inflow passage 47 are reduced. The differential pressure between them gradually increases. For this reason, while the outflow amount from the outflow port 49 reduces gradually, on the other hand, the inflow amount from the inflow port 47a increases gradually. Therefore, first, in order to be able to close the differential pressure valve 41, the diaphragm 45a can be bent and deformed by a predetermined displacement ω (r) at which the diaphragm 45a can abut against the protrusion 46 before the magnitude relationship between the outflow amount and the inflow amount is reversed. Required at a minimum.

For example, when the gap of the differential pressure valve 41 is Go, the negative pressure ΔPneg required to close the valve is as follows from the above equation (13).
ΔPneg ≧ 16 Go · {(E · t ³ ) / (1-ν ² )} / 3 ((A / 2) ² − (B / 2) ² ) ² (14)
When the value on the right side of the equation (14) is ΔPnegmin, the differential pressure valve 41 is closed when ΔPneg reaches the minimum negative pressure ΔPnegmin required for valve closing. In order to be able to close the differential pressure valve 41, the outflow amount in the valve chamber 50 is the inflow amount until the negative pressure ΔPneg, which is the pressure difference between the inside and outside of the valve chamber 50 in the valve closing process, reaches this minimum negative pressure ΔPnegmin. It is necessary to continue the state of being more than.

By the way, the flow rate Q of the fluid passing through the flow path is expressed by the following equation.
Q = (πr ⁴ p / 8η) (p1−p2) / L (15)
Here, r is the flow path radius, p1 is the pressure on the upstream side (inlet side) of the flow path, p2 is the pressure on the downstream side (outlet side) of the flow path (hence the pressure difference Δp = p1−p2), and η is the fluid The viscosity coefficient (viscosity) of (ink), L is the channel length, and p is the average pressure of the fluid in the channel (= (p1 + p2) / 2).

Therefore, when the negative pressure ΔPneg reaches the minimum negative pressure ΔPnegmin, the flow rate Q1 flowing out from the outflow passage 49 and the flow rate Q2 flowing in from the inflow passage 47 are as follows using the above equation (15). Shown in
Q1 = (πr1 ⁴ (P1 + Pnegmin) / 16η) (Pnegmin−P1) / L1 (16)
Q2 = (πr2 ⁴ (P2 + Pnegmin) / 16η) (P2−Pnegmin) / L2 (17)
Here, r1 is the flow path radius of the outflow path 49, r2 is the flow path radius of the inflow path 47, P1 is the fluid pressure on the outlet side of the outflow path 49, P2 is the fluid pressure on the inlet side of the inflow path 47, and Pnegmin is the valve The fluid pressure (minimum negative pressure) in the chamber 50, L 1 is the flow path length of the outflow path 49, and L 2 is the flow path length of the inflow path 47.

  When the fluid pressure in the valve chamber 50 is at the lowest negative pressure Pnegmin that can be closed, the fact that the inflow amount Q2 is smaller than the outflow amount Q1 (Q1> Q2) indicates that the differential pressure valve 41 can be closed. It becomes a condition. However, if the required time T until the valve closes becomes long, the ink is wasted and discarded at the negative pressure accumulation stage of the chalk cleaning. Here, the amount of decrease in the volume of the valve chamber 50 from the start of choke cleaning to the closing of the differential pressure valve 41 is ΔVo, and the outflow amount Q1 of the outflow passage 49 and the inflow amount Q2 of the inflow passage 47 have a short required time T. Assuming that the flow rate difference is ΔQ (= Q1−Q2) assuming that there is almost no change in the period, the required time T (seconds) until the valve is closed is represented by T = ΔVo / ΔQ. This required time T is a required time until the differential pressure valve 41 is closed in choke cleaning. By shortening the required time T, the required pressure T is not used for accumulating negative pressure before the valve closing, and is wasted and discarded. You can use less ink. In order to suppress the amount of ink that is wasted and discarded unnecessarily, for example, it is desirable to close the valve within 2 seconds at the latest from the start of suction (start of introduction of negative pressure into the valve chamber 50). Then, since T ≦ 2 should be satisfied, 2 ≦ ΔVo / (Q1−Q2) is obtained, and thereby, the flow of the inflow path with respect to the flow path radius r1 of the outflow path that satisfies Q1 ≦ (ΔVo + 2Q2) / 2 is satisfied. The road radius r2 may be set.

  Here, under the pressurization stop state before starting the choke cleaning, the pressure regulating valve 42 on the downstream side is closed, so that the pressure remains in the valve chamber 50, and the diaphragm 45a bulges outward. Is in a state. Since the above equation (12) holds even when the pressure ΔPpos is used instead of the negative pressure ΔPneg, the displacement at the pressure ΔPpos is ω (r) pos, and the displacement at the negative pressure ΔPneg is ω (r) neg. Then, ΔVo is obtained by calculating ∫2πrω (r) posdr + ∫2πrω (r) negdr in the integration range r = 0 to B / 2. Of course, in actuality, the calculated value does not always hold, the friction coefficient of the inner wall surface of the flow path, the difference between whether the fluid passing through the flow path is laminar or turbulent, the change in the flow path diameter, the flow path Conditions depend on various factors such as the presence or absence of bending. Therefore, each value necessary for specifying r2 with respect to the flow path radius r1, such as ΔVo, Pneg (or ΔPneg), is obtained by measurement, or a differential pressure valve in which various parameters such as a diaphragm, an opening diameter, and a flow path diameter are changed. It is desirable to prepare a plurality of 41 samples, conduct an experiment to check whether the valve is actually opened or closed, or evaluate the response speed of the valve closing, and set conditions from the experimental results. The channel diameter C (= 2 · r2) is determined based on the value of the channel radius r2 determined with respect to the channel radius r1.

  In the present embodiment, the flow path diameter D of the outflow path 49 is set to a predetermined value within a range of 0.5 mm to 3 mm, for example. And since the pressure difference of the both ends of the outflow path 49 where the negative pressure by suction force is given is sufficiently larger than the pressure difference of the both ends of the inflow path 47 in the non-pressurized state, the flow path diameter C of the inflow path 47 is The flow path diameter D is set to a value shorter than the flow path diameter D in the range of 0.5 mm or more. Therefore, the flow path diameter C is set to a predetermined value within a range of 0.5 mm to 3 mm within a range satisfying C ≦ D. Here, the flow rates Q1 and Q2 are proportional to the fourth power of the flow path radii r1 and r2 (flow path diameters C and D) from the above equations (16) and (17). With respect to the flow rate Q2, the flow rate Q2 decreases in proportion to the fourth power of (r2 / r1) with respect to the flow rate Q1. Therefore, even when the flow path diameter C is slightly smaller than the flow path diameter D, good valve closing response is ensured. The flow path diameters C and D are not limited to a certain amount in the upstream ink flow path when bubbles or foreign matters in the ink are not clogged and the ink is discharged from the recording head 20 and consumed during printing. It is set to a value that causes ink flow that exceeds the flow velocity.

  As for the inflow passage 47 in which the flow path diameter C needs to be kept small in relation to the flow passage diameter D in this way, the opening 46a that is closed by the diaphragm 45a when the valve is closed while keeping the flow passage diameter C small. Is set widely. That is, by providing an annular protrusion 46 having an inner diameter sufficiently larger than the channel diameter C on the bottom surface of the recess 43, the pressure applied to the diaphragm 45a when the valve is opened while keeping the channel diameter C small. The opening diameter A of the opening 46a that determines the pressure receiving area S2 is made larger than 5 times the flow path diameter C, and the ratio of the opening diameter A to the opening diameter B (diaphragm diameter) of the recess 43 is set to be larger than 1/2. ing. Since A, B, C, and D can be set so as to satisfy these conditions, the differential pressure valve 41 having a configuration in which the positional relationship between the outflow path and the inflow path is reversed with respect to the configuration of the conventional differential pressure valve. The valve opening response from the closed state at the time of choke cleaning can be realized and the differential pressure valve 41 functions effectively while maintaining good valve closing response. In addition, as for the inflow path 47, when the flow rates Q1 and Q2 are the lowest negative pressure Pnegmin at which the differential pressure valve 41 can be closed, as long as Q1> Q2 is satisfied, a throttle portion is provided in the middle of the inflow path 47. It can also be.

  Next, the electrical configuration of the ink jet recording apparatus 11 configured as described above will be described. As shown in FIG. 9, the ink jet recording apparatus 11 includes a CPU 61, a ROM 62, and a RAM 63. The ink jet recording apparatus 11 includes an input unit 65, a first motor drive circuit 67, a second motor drive circuit 68, a third motor drive circuit 69, and a head drive circuit 70. These are connected to each other via a bus 64.

  The input unit 65 is provided in the main body case 12 or the like of the ink jet recording apparatus 11. When the input unit 65 is operated by the user, the CPU 61 inputs an ON signal from the input unit 65. The CPU 61 is connected to the carriage motor 18 via the first motor drive circuit 67 and outputs a drive control signal for controlling the carriage motor 18.

  The CPU 61 is connected to the pressure pump motor 73 via the second motor drive circuit 68 and outputs a drive control signal for driving the pressure pump motor 73. The pressurizing pump motor 73 is connected to the pressurizing pump 25 so that power can be transmitted. In the present embodiment, when the pressurizing pump motor 73 is driven forward, pressurized air is sent from the pressurizing pump 25 and driving of the pressurizing pump motor 73 is stopped, so that the pressurizing pump 25 is stopped. The supply of pressurized air from is stopped.

  Further, the CPU 61 is connected to the tube pump motor 74 via the third motor drive circuit 69 and outputs a drive control signal for rotating the tube pump motor 74 forward and backward. The tube pump motor 74 is connected to the tube pump 26e so that power can be transmitted. When the tube pump motor 74 is driven forward, the tube pump 26e is driven to perform a suction operation in which a negative pressure is introduced into the cap 26a, and the drive of the tube pump motor 74 is stopped. The suction operation in the tube pump 26e is stopped.

  Further, the CPU 61 is connected to the recording head 20 via the head driving circuit 70, and with respect to an ejection driving element (not shown) (for example, a piezoelectric vibration element) for ejecting ink from the nozzle 20a provided in the recording head 20. A nozzle drive signal is output. The CPU 61 operates in accordance with various programs stored in the ROM 62 and temporarily stores the calculation processing results and the like in the RAM 63. More specifically, the ROM 62 stores a choke cleaning program and other programs.

  Next, the operation of the ink jet recording apparatus 11 configured as described above will be described. First, the operation during printing will be described. Each ink supply channel from the ink pack 32 to the recording head 20 is filled with ink of each color. The pressure pump motor 73 is driven by the CPU 61 via the second motor drive circuit 68, and the ink in the ink pack 32 is pressurized by the pressurized air introduced into the gap 33 of the ink cartridge 23. Maintained in a state. Therefore, at the time of printing, the ink is supplied from the ink cartridge 23 to the valve unit 21 in a pressurized state.

  The ink of each color introduced into the valve unit 21 in a pressurized state is supplied to the inflow path 47 of the differential pressure valve 41 corresponding to each color. As shown in FIG. 6, the ink supplied to the valve chamber 50 through the inflow passage 47 is maintained at a predetermined pressure higher than the atmospheric pressure based on the pressurization. Therefore, the differential pressure valve 41 is opened in a state where the film member 45 is separated from the protrusion 46 and is slightly expanded outward (atmosphere side) by pressurization.

  The pressure adjusting valve 42 provided on the flow path between the differential pressure valve 41 and the recording head 20 is closed because a necessary amount of ink is supplied to the recording head 20 while printing is stopped. When printing is started based on the image data, ink is ejected from the recording head 20, and ink in the pressure chamber of the pressure adjustment valve 42 is supplied to the recording head 20 according to the amount of ink ejection. The As a result, when the ink in the pressure chamber of the pressure adjustment valve 42 decreases and the ink pressure in the pressure chamber decreases below a predetermined pressure, the pressure adjustment valve 42 opens. As a result of opening the pressure regulating valve 42, when ink flows into the pressure chamber of the pressure regulating valve 42, the pressure of the ink in the pressure chamber increases. As a result, the pressure adjustment valve 42 is closed. In this way, a necessary amount of ink is supplied to the recording head 20, and an excessive ink pressure is not applied to the recording head 20, so that leakage of ink from the nozzle 20a is suppressed. As a result, during printing, ink adjusted to a substantially constant pressure within a predetermined range is stored in the pressure chamber of the pressure adjustment valve 42, and the stability of ink supply to the recording head 20 is ensured. It has become so.

  In the differential pressure valve 41, when the pressure adjustment valve 42 is opened, ink in the valve chamber 50 is supplied from the outflow path 49 to the pressure adjustment valve 42 side, and the ink that has flowed out flows into the inflow path 47. Into the valve chamber 50.

  Next, the operation of the ink jet recording apparatus 11 during choke cleaning will be described. In the present embodiment, choke cleaning is performed by operating the input unit 65 (see FIG. 9) by the user. The CPU 61 having input an ON signal based on the operation of the input unit 65 first drives the carriage motor 18 according to the choke cleaning program to move the carriage 15 to the home position. As the carriage 15 moves to the home position, the cap 26a is raised via the cap lifting mechanism to seal the nozzle forming surface 20b of the recording head 20. Further, the CPU 61 proceeds to a pressure reduction stage based on the input of the ON signal from the input unit 65, stops driving the pressurizing pump motor 73, and stops sending pressurized air from the pressurizing pump 25.

  Subsequently, the CPU 61 proceeds to the suction stage, drives the tube pump motor 74, and introduces a negative pressure into the cap 26a by the suction operation of the tube pump 26e. As a result, ink is sucked from the nozzles of the recording head 20 and ink in the pressure chamber of the pressure adjustment valve 42 starts to decrease. Then, when the pressure in the pressure chamber of the pressure adjustment valve 42 becomes a predetermined pressure or less, the pressure adjustment valve 42 is opened in the same manner as in the printing. As a result, the ink flows into the pressure chamber of the pressure regulating valve 42 from the upstream side, and the ink that has flowed in flows out of the valve chamber 50 of the differential pressure valve 41 located on the upstream side. During this choke cleaning, the ink introduced from the inflow passage 47 is in a non-pressurized state, and the ink outflow amount from the outflow passage 49 in the valve chamber 50 is reduced from the inflow passage 47 by setting the flow passage diameters C and D. The ink in the valve chamber 50 starts to decrease over the ink inflow amount. When the film member 45 bends inwardly of the valve chamber 50 due to the reduced pressure accompanying the decrease in the ink in the valve chamber 50 and the pressure decreases below a predetermined pressure, the film member 45 abuts against the protrusion 46 and closes the opening 46a. . As a result, the differential pressure valve 41 is closed. At this time, the differential pressure valve 41 is quickly closed within a predetermined time within 2 seconds from the start of the suction operation, and a good valve closing response is obtained. As a result, the amount of ink passing through the opening 46a from the start of the suction operation to the closing of the differential pressure valve 41 can be reduced, so that the amount of ink that is wasted and discarded by the end of the negative pressure accumulation stage can be reduced.

  By continuing the suction operation by the tube pump 26e, a negative pressure is accumulated on the downstream side of the diaphragm 45a closing the opening 46a. The CPU 61 measures the driving time of the tube pump motor 74 in accordance with the choke cleaning program. When the driving time elapses a predetermined time, the CPU 61 proceeds to the pressure increasing stage and restarts the driving of the pressurizing pump motor 73.

  As a result, the supply of pressurized air from the pressure pump 25 is resumed, and ink is supplied from the ink cartridge 23 to the valve unit 21 in a pressurized state. Then, the ink is supplied in a pressurized state into the valve chamber 50 through the inflow passage 47 of the differential pressure valve 41, and the pressurized ink pressure is applied to the portion closing the opening 46a of the diaphragm 45a, so that the central portion of the diaphragm 45a (the first portion) 2 pressure receiving area A2) is strongly pressed. At this time, since the opening diameter A of the opening 46a is ensured to be ½ or more of the opening diameter B (that is, the diaphragm diameter) of the recess 43, as shown in FIG. 8, it is applied to the central region of the diaphragm 45a through the opening 46a. A sufficient force Fpos in the valve opening direction based on the pressure ΔPpos is ensured. Then, the bending moment Mpos based on the valve opening direction force Fpos acting on the central region of the diaphragm 45a exceeds the bending moment Mneg based on the valve closing direction force Fneg acting on the peripheral region of the diaphragm 45a, and the diaphragm 45a is separated from the protrusion 46. To do. As a result, the differential pressure valve 41 is opened.

  By opening the differential pressure valve 41, the ink flows from the upstream side at once to try to eliminate the negative pressure accumulated in the flow path on the downstream side of the opening 46a in the valve chamber 50, and the ink whose flow velocity is instantaneously increased. Flows. As a result, bubbles and foreign matter staying on the valve chamber 50 and the downstream flow path are discharged from the nozzle 20a of the recording head 20 together with the ink. Thereafter, when the driving time of the tube pump motor 74 reaches a preset total driving time, the driving of the tube pump motor 74 is stopped. Then, when the driving of the tube pump motor 74 is stopped, the CPU 61 ends the processing of the choke cleaning program. By stopping the driving of the tube pump motor 74, the suction operation is completed at the timing when at least the ink in the valve chamber 50 is discharged from the nozzle 20a of the recording head 20 when the differential pressure valve 41 is opened.

  During the choke cleaning, the bubbles gather in the valve chamber 50 due to the buoyancy in the valve chamber 50 of the differential pressure valve 41, and the bubbles grow to a large size due to the decompression in the negative pressure accumulation process. In this embodiment, since the outlet 49a is opened at a position near the upper end of the side wall surface in the valve chamber 50, when ink flows out at once, the bubbles gathered on the upper side in the valve chamber 50 The air is smoothly discharged from the outlet 49 a that opens near the upper end of the side wall surface of the chamber 50. Thus, as a result of the chalk cleaning, the ink filling property in the ink jet recording apparatus 11 is improved.

As described above in detail, according to the first embodiment, the following effects can be obtained.
(1) By providing the annular protrusion 46, the second flow path 52 as the interrupted area flow path surrounded by the inner peripheral surface of the protrusion 46 is communicated with the inflow path 47 as the small cross-sectional area flow path. The diaphragm 45a, which is provided and closed, secures the pressure receiving area received from the pressurized ink in the second flow path 52 by an area necessary for opening the valve. Therefore, the bending moment Mpos based on the force Fpos in the valve opening direction due to the pressure ΔPpos received by the diaphragm 45a through the opening 46a in the central region becomes the force Fneg in the valve closing direction due to the negative pressure ΔPneg received by the diaphragm 45a in the peripheral region. Since the bending moment Mneg can be made larger, the differential pressure valve 41 can be opened. As described above, the flow path communicating with the second flow path 52 formed by being surrounded by the inner peripheral surface of the projection 46 having the opening 46a closed by the diaphragm 45a when the valve is closed is replaced with the outflow path in the conventional structure. Thus, the inflow passage 47 can be formed. For this reason, since it can comprise so that the outflow port 49a may open on the inner wall face of the recessed part 43, the restriction | limiting of the arrangement position of the outflow port 49a can be eliminated.

  Then, the restriction on the position of the outlet 49a is eliminated, so that the flow of the differential pressure valve 41 to the upper end position (the end position on the opposite side in the gravitational direction) on the inner wall surface of the recess 43 in a state where the differential pressure valve 41 is assembled to the ink jet recording apparatus 11. The outlet 49a can be positioned. For this reason, the air bubbles collected at the upper position in the ink in the valve chamber 50 by the buoyancy can be smoothly flowed out to the outlet 49a, so that the air bubble discharge performance is improved during the chalk cleaning.

  (2) When the differential pressure valve 41 is placed flat so that the film member 45 is positioned on the upper side as in the present embodiment, the air bubbles move in the direction of antigravity on the inner wall surface of the recess 43 in the antigravity direction side. The outlet 49a can be positioned so as to open near the end position, that is, near the upper end position. Therefore, the bubbles in the ink collected above the valve chamber 50 are easily discharged smoothly from the outlet 49a when the valve is opened in the choke cleaning. Accordingly, it is possible to improve the bubble discharge performance by chalk cleaning.

(3) The opening diameter φA of the projection 46 with respect to the opening diameter φB of the concave portion 43 is set to satisfy the following valve opening condition: A / B ≧ {ΔPneg / (3ΔPpos + ΔPneg)} ^1/2 It was set to hold. For this reason, even if the negative pressure Δneg and the pressure ΔPpos are different from each other over a range that can be said to be substantially equal, the opening diameter A of the opening 46a can be set to a value that enables the valve opening with respect to the diaphragm diameter B. Therefore, regardless of the values of the negative pressure Δneg and the pressure ΔPpos, if the protrusion 46 is provided so as to ensure the opening diameter A that satisfies the valve opening condition, the differential pressure valve 41 can be reliably opened. .

  (4) In the case where the shape of the diaphragm 45a and the shape of the opening 46a are the same, including a circular shape, the relationship is similar to each other, S2 / S ≧ ΔPneg shown in the above equation (11) as the valve opening condition The opening area (second pressure receiving area S2) of the opening 46a with respect to the opening area S (diaphragm area) of the recess 43 is set so that / (3ΔPpos + ΔPneg) is established. Therefore, even if the diaphragm 45a and the opening 46a have a shape other than a circle that cannot be expressed by a diameter, the protrusion 46 can be provided so that the opening area of the opening 46a that satisfies the valve opening condition is secured, and the differential pressure valve 41 is opened. Can be valved.

  (5) The opening diameter φA of the annular protrusion 46 is set to be ½ or more of the opening diameter φB of the recess 43. That is, the opening area of the protrusion 46, that is, the second pressure receiving area S2 on which the pressure of the pressurized ink acts in the closed state of the diaphragm 45a is set to ¼ or more of the total pressure receiving area S of the diaphragm 45a. Therefore, at the time of choke cleaning, when the application of pressure to the inflow passage 47 is resumed when a sufficient negative pressure is accumulated after the differential pressure valve 41 is closed, the diaphragm 45a is separated from the protrusion 46, and the difference is increased. The pressure valve 41 can be opened. In particular, as in the ink jet recording apparatus 11, the pressurization pump 25 and the tube pump 26e having the ability of the pressurization ΔPpos and the negative pressure ΔPneg to be substantially equal to each other or the pressurization ΔPpos to be greater than the negative pressure ΔPneg In the configuration used, even if the side communicating with the second flow path 52 formed on the inner peripheral surface of the protrusion 46 is the inflow path 47, the differential pressure valve 41 can be reliably opened at the time of choke cleaning.

  (6) Since the outlet 49a may be set at a position where the bubble discharge performance is improved according to the arrangement direction of the differential pressure valve 41, the arrangement direction of the differential pressure valve 41 can also be set freely. Therefore, the degree of freedom in the arrangement direction of the differential pressure valve 41 is also increased. Therefore, the differential pressure valve 41 can be compacted by assembling the differential pressure valve 41 in a direction in which the connection with the tube or the pipe is good and improving the pipe connectivity, or by arranging in a direction that fits in a given installation space. It can be assembled to.

  (7) The opening diameter φA of the opening 46a was set to be not less than 5 times the flow path diameter φC while keeping the flow path diameter (opening diameter of the inlet 47a) φC of the inflow passage 47 small. Therefore, the ink outflow amount Q1 from the outflow passage 49 immediately after the start of the suction operation can be continuously maintained larger than the ink inflow amount from the inflow passage 47 until the valve is closed, and within two seconds from the start of the suction operation. The differential pressure valve 41 can be closed, and a good valve closing response can be obtained after the suction operation is started.

  (8) The protrusion 46 is positioned so as to face the substantially central portion of the diaphragm 45a in a state where the center line of the diaphragm 45a is aligned with each other. For this reason, the distance d2 from the fulcrum O to the second pressure receiving region A2 where the force in the valve opening direction works can be earned long, and the opening acting on the central region of the diaphragm 45a is divided by the pressurization value and the opening area of the opening 46a. A large bending moment in the valve direction can be secured. Therefore, the valve opening for separating the diaphragm 45a from the protrusion 46 can be performed with a small pressure. Alternatively, the valve 45 for separating the diaphragm 45a from the protrusion 46 can be opened by the opening 46a having a small opening area.

  (9) The protrusion 46 is annular, and the second pressure receiving area A2 where the diaphragm 45a receives pressure through the opening 46a is circular. For this reason, the addition average distance d2 from the fulcrum O to the second pressure receiving region A2 where the force in the valve opening direction works can be earned longer than other shapes of the same area, and the pressure value and the opening area of the opening 46a can be obtained. On the other hand, a large bending moment in the valve opening direction acting on the central region of the diaphragm 45a can be secured. Therefore, the valve opening for separating the diaphragm 45a from the protrusion 46 can be performed with a smaller pressure. Alternatively, the valve 45 for separating the diaphragm 45a from the protrusion 46 can be opened by the opening 46a having a small opening area.

  (10) Although the arrangement position of the inflow port 47 a is restricted on the inner bottom surface of the projection 46, it may be located anywhere as long as it is on the inner bottom surface of the projection 46. In the present embodiment, the opening diameter A of the protrusion 46 is a large diameter that is ½ or more of the opening diameter B (diaphragm diameter) of the recess 43, so that the arrangement position of the inflow port 47a is also the same as in the conventional valve device. The degree of freedom of arrangement position can be increased compared to the outlet.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. This embodiment is an example in which the configuration of the differential pressure valve is different. Since the configuration of the ink jet recording apparatus 11 is the same as that of the first embodiment, the same members are denoted by the same reference numerals and description thereof is omitted, and only the configuration of the differential pressure valve will be described based on FIG. .

  The basic structure of the differential pressure valve 81 shown in FIG. 10 is the same as that of the differential pressure valve 41 in the first embodiment. The difference is that the differential pressure valve 41 in the first embodiment is assembled in a flat position where the base material 44 is horizontally arranged with the surface of the film member 45 facing upward, in the present embodiment. The base member 44 is assembled vertically so that the surface of the film member 45 faces sideways. Therefore, the position of the outflow passage 49 in the first embodiment is changed so that the valve chamber 50 opens at a position opposite to the direction of gravity, and the concave portion 43 is in a vertically placed state as shown in FIG. An outflow path 82 is formed so as to open on the upper wall surface. When choke cleaning is performed, bubbles in the ink gather in the upper part of the valve chamber 50 on the opposite side in the direction of gravity, and bubbles whose diameter has become larger due to pressure reduction during ink suction are discharged from the outlet 82a of the outflow path 82. It is the structure which gathers in the vicinity position.

  For this reason, when the pressure pump 25 is re-driven during ink suction during choke cleaning and the differential pressure valve 81 is opened and ink is discharged all at once, bubbles located near the outflow port 82a are preferentially used. Will be discharged. As described above, the differential pressure valve 81 according to the present invention uses the flow channel located inside the projection with which the film member 45 abuts when the valve is closed as an inflow channel, and opens on the inner wall surface located outside the projection in the recess. An outflow channel can be set. Therefore, the opening of the outflow passage can be set at a free position on the inner wall surface located outside the protrusion in the recess. On the other hand, conventionally, since the communication hole of the protrusion is the outflow path, the opening position of the outflow path is restricted to the center position of the bottom surface of the recess. For this reason, the arrangement direction of the differential pressure valve for making it difficult for bubbles to stay in the valve chamber is also restricted. In this embodiment, since there is no restriction on this kind of layout, the differential pressure valve 81 can be placed vertically, and the outlet 49a of the outlet passage 49 is placed on the inner wall surface on the opposite side in the gravity direction in the valve chamber 50. Can be positioned.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG. This embodiment is an example in which the configuration of the differential pressure valve is different. Since the configuration of the ink jet recording apparatus 11 is the same as that of the first embodiment, the same reference numerals are assigned to the same member names and the description thereof is omitted, and only the configuration of the differential pressure valve is described based on FIG. To do.

  As shown in FIG. 11, the differential pressure valve 91 has a plate-like base material 94 having a concave portion 93 on one side surface, and a state in which the opening of the concave portion 93 is sealed on the surface 94 a (right side surface in the figure). And a film member 95 as a flexible member fixed to the head. The recess 93 is formed to have a circular opening on the surface 94a of the base 94. The film member 95 is made of a synthetic resin film having a size wider than the opening of the recess 93 and having a predetermined thickness so that flexibility can be obtained. Both the base member 94 and the film member 95 are made of the same synthetic resin as in the first embodiment, and the film member 95 is fixed to the base member 94 by heat welding.

  As shown in FIG. 11, an annular projection 96 that is concentric with the concave portion 93 protrudes substantially at the center of the bottom surface of the concave portion 93. The inflow path 97 formed through the base 94 opens an inflow port 97a on the inner bottom surface of the protrusion 96 and extends downward along the back surface (left side surface in FIG. 11) of the base 94. It communicates with the inside of the inflow pipe portion 98 that protrudes downward from the lower end portion of the. The outflow passage 99 formed through the base 94 has an outlet 99a that opens to the upper end surface of the recess 93, extends upward from the outlet 99a through a predetermined path, and extends upward from the upper end of the base 94. It communicates with the discharge pipe part 100 protruding to the side. A portion of the inflow path 97 that extends along the back surface of the base 94 is a channel groove 94b that is recessed in the back surface of the base 94, and is thermally welded to the back surface of the substrate 94 so as to cover the channel groove 94b. The film member 95 is surrounded and formed.

  The side circumferential surface of the recess 93 is formed into a tapered slope 93a (tapered surface) whose depth becomes shallower toward the outer circumferential side. Further, the protrusion 96 is formed in a tapered shape such that the radial thickness gradually decreases toward the tip. For this reason, the inner peripheral surface of the protrusion 96 is formed in a truncated cone-shaped inclined surface 96a in which the flow path cross section gradually becomes narrower in the depth direction (left direction in FIG. 11). Further, the outer peripheral surface of the protrusion 96 is formed on a slope 96b (a slope having an outer peripheral surface shape of a truncated cone) whose outer peripheral diameter gradually decreases toward the tip side. The differential pressure valve 91 is assembled to the ink jet recording apparatus 11 such that the direction of deflection of the film member 95 (the horizontal direction in FIG. 11) is substantially perpendicular to the direction of gravity (the vertical direction in FIG. 11). The slopes 96b, 96a, 93a formed on the inner wall surface of the valve chamber 102 are inclined with respect to the direction of gravity in such a direction that bubbles moving in the ink in the valve chamber 102 due to buoyancy can be guided to the outlet 99a. Yes.

  As described above, the inclined surfaces 96b, 96a, and 93a are formed on the inner peripheral surface of the valve chamber 102 of the differential pressure valve 91, so that bubbles in the ink in the valve chamber 102 move upward along the inclined surfaces 96b, 96a, and 93a. Moving. For this reason, when the differential pressure valve 91 is placed vertically as shown in FIG. 11, the outer peripheral surface and inner peripheral surface of the projection 96 become an upper wall surface on which bubbles are likely to accumulate, but the upper wall surface moves upward by buoyancy. The slopes 96b, 96a, 93a are inclined so as to guide the bubbles to be directed to the outlet 99a. For this reason, it becomes easy to collect bubbles in the vicinity of the outflow port 99 a located at the upper end surface of the valve chamber 102. Therefore, it becomes easier to discharge the bubbles in the valve chamber 102 during the chalk cleaning.

In addition, embodiment is not limited above, The following structures are also employable.
(Modification 1) In the above embodiment, the annular protrusion 46 is provided, but the valve seat portion is not limited to being an annular protrusion. That is, as long as the flexible member (diaphragm) can be contacted in a valve-closed state, the contact target is not limited to an annular protrusion. For example, as shown in FIG. 12, a differential pressure valve 110 having no protrusion may be used. That is, as shown in the figure, a concave portion 112 having a diameter smaller than the diameter of the concave portion 111 is formed in a substantially central portion of the concave portion 111 provided in the surface 44 a of the base material 44. An inlet 47 a of the inflow passage 47 is opened on the bottom surface of the recess 112, and the inner region of the recess 112 is a second flow path 52. The depth of the recess 111 is substantially equal to the depth of the tip end surface of the projection 46 in the first embodiment, and the peripheral portion of the opening 112a on the bottom surface of the recess 111 is in contact with the valve seat portion 113 with which the diaphragm 45a abuts. It has become. Further, the first flow path 51 as a large cross-sectional area flow path does not have the same diameter in the depth direction, and a circumferential groove 111b having a larger diameter than the opening 111a is formed on the inner peripheral wall of the recess 111. The first flow path 51 has a flow path cross-sectional area wider than the opening area of the opening 111a. Even in such a configuration, the same function as in the above embodiment can be obtained because it functions as a differential pressure valve if the valve opening condition similar to that in the above embodiment is satisfied.

  (Modification 2) In the above-described embodiment, the inflow path 47 is formed as a small cross-sectional area flow path with the inflow port 47a opened on the inner bottom surface of the protrusion 46, but is not limited to this. For example, as shown in FIG. 13, a differential pressure valve 120 having no small cross-sectional area flow path may be used. That is, as shown in the figure, a weight-shaped hole 121 that expands toward the upper side is formed inside the protrusion 46, and the inner portion of the hole 121 serves as the second flow path 52. The opening end on the small diameter side (the lower end side in FIG. 13) of the second flow path 52 is an inflow port 47a. In this configuration, the interrupted area flow path is not the same diameter in the depth direction, and the differential pressure valve 120 does not have a small cross-sectional area flow path. As described above, even the differential pressure valve 120 having no small cross-sectional area flow path functions as a differential pressure valve if the valve opening condition is satisfied as in the above-described embodiment, so that the same effect as in the above-described embodiment can be obtained. The interrupted area channel has a part having a channel diameter less than 1/2 of the diaphragm diameter and a part having a channel diameter less than 5 times the inlet 47a, but the opening 46a is not less than 1/2 of the diaphragm diameter. The flow inlet 47a may be 5 times or more.

  (Modification 3) Although one differential pressure valve 41 is provided for each ink color, a valve device 130 in which a plurality of differential pressure valves 131 are integrally provided on a common base as shown in FIG. It can also be adopted. That is, as shown in the figure, a plurality of (for example, the same number (four) as the cartridges) recesses 43 are formed on the surface of the base material 132, and an annular protrusion is formed at the substantially central portion of the bottom surface of each recess 43. 46 are provided. One film member 133 is fixed to the surface of the base material 132 by heat welding so as to seal the openings of the plurality of recesses 43. Moreover, the structure which provides a differential pressure valve in the front and back both surfaces of a base material is also employable. For example, an annular protrusion is provided in the center of the bottom surface of the recess 43 provided on each of the front and back surfaces of the base material, and a film member as a flexible member is fixed to the front and back surfaces of the base material so as to seal the concave portion. Can be adopted. In this case, the opening on the outside of the inflow passage 47 may be opened on the end surface of the base material 132 in the same manner as the outflow passage 49.

  (Modification 4) In the above embodiment, the diameter of the first flow path is larger than the diameter of the second flow path. However, the present invention is not limited to this. For example, as long as the opening diameter of the opening in the valve seat portion is ½ or more of the diaphragm diameter, the second flow path may have a portion that is larger than the diameter of the first flow path.

  (Modification 5) The number of openings in the valve seat is not limited to one. For example, the structure which has several opening in the front end surface of a truncated cone-shaped protrusion is employable. In this case, the opening diameter of each opening is less than ½ of the diaphragm diameter. In this case, the opening area of the opening (the total opening area of the plurality of openings) is ¼ or more of the diaphragm area. I just need it. Also, the number of inlets is not limited to one. For example, when the second flow path is constituted by a plurality of recesses, a configuration in which one inlet is provided on the bottom surface of each recess constituting the second flow path. Can be adopted. Of course, it is also possible to employ a configuration in which a plurality of inflow ports 47a are opened on the inner bottom surface of the protrusion in the first to third embodiments. In this way, when there are a plurality of N inlets 47a, the condition B ≦ 5C when there is one inlet is derived using the fact that the channel resistance (pressure loss) is inversely proportional to the fifth power of the channel diameter. Adopt conditions.

  (Modification 6) The shapes of the diaphragm (that is, the opening of the concave portion) and the opening of the valve seat portion are not limited to being circular. If the diaphragm and the opening of the valve seat have substantially the same shape having a similar relationship, the length ratio (similarity ratio) of the corresponding portion of the opening relative to the diaphragm may be ½ or more. If the condition of 1/2 or more is satisfied, the valve opening condition is satisfied.

  (Modification 7) As long as the opening area of the opening is ¼ or more of the diaphragm area, the portion where the second channel 52 has a larger channel cross-sectional area than the maximum channel cross-sectional area of the first channel 51 You may have. Moreover, as long as the opening area of the opening 46a is 5 times or more of the opening area of the inlet 47a, the inflow path may have a channel cross-sectional area larger than the channel cross-sectional area of the second flow path. Absent.

  (Modification 8) Although the differential pressure valves 41, 81, 91, 110, 120, 131 as valve devices are provided in the middle of the liquid supply path, the differential pressure valves as valve devices may be provided in the ink cartridge 23. When the differential pressure valve is provided in the ink cartridge 23 configured so that the inside of the ink case 31 is pressurized with air, the differential pressure valve is preferably provided in a state where the outer surface of the diaphragm is open to the atmosphere. For example, an airtight chamber and an air release chamber in which the ink pack 32 is housed in the ink case 31 are provided, and the ink supply unit 32b of the ink pack 32 is disposed in the air release chamber and communicates with the ink supply unit 32b. A differential pressure valve is also placed in the open air chamber. Further, a configuration in which the differential pressure valve is formed integrally with the ink supply unit 32b can be employed. Of course, the differential pressure valve as the valve device can be provided in an ink cartridge other than the ink pack type. For example, in an ink cartridge having an ink chamber in which ink is stored or an ink cartridge containing a porous body filled with ink, a differential pressure valve can be provided on a supply flow path in the ink case.

  (Modification 9) The present invention is not limited to the valve opening method of applying pressure to the inflow port while applying negative pressure to the outflow port. For example, after closing the valve by applying a negative pressure to the outlet, the open / close valve provided in the middle of the discharge pipe of the cap is closed to maintain the inside of the ink supply path at a negative pressure and the suction pump is stopped. A cleaning method that applies pressure to the inlet can be employed.

  (Modification 10) The pressurizing means is not essential. For example, it may be configured to pressurize using the water head pressure of ink as the liquid in the cartridge. In this case, an on-off valve is provided on the upstream side of the inflow passage 47, the on-off valve is closed during choke cleaning, and the on-off valve is opened when the differential pressure valve 41 is opened to apply pressure to the inflow passage 47.

  (Modification 11) The reference pressure that determines the pressure difference indicated by negative pressure and pressurization is not limited to atmospheric pressure. For example, the fluid pressure outside the diaphragm may be higher than atmospheric pressure or lower than atmospheric pressure. For example, the outer surface of the diaphragm may be in contact with a liquid having a set pressure instead of the atmosphere.

  (Modification 12) It is possible to employ a configuration in which the urging spring described in Patent Document 1 is provided and the diaphragm is pressed from the outside by the urging spring. In this case, when the ink cartridge is removed from the holder, the film can be brought into contact with the protrusion to reliably close the opening. As a result, when the ink cartridge is not loaded, the ink staying in the ink flow path downstream from the opening can be prevented from leaking from the ink supply needle of the holder.

  (Modification 13) A restriction plate described in Patent Document 2 may be provided. The displacement in the direction of increasing the volume of the valve chamber 50 is restricted with respect to the film member that is bent by the pressure difference between the inside and outside of each valve chamber 50. During choke cleaning, it can be displaced immediately to a position necessary for cleaning, so the time until the flow path downstream of the valve chamber 50 is closed is shortened, and the opening seal for the start of driving the tube pump is reduced. The responsiveness of the part K can be improved.

  (Modification 14) In the above-described embodiment, the liquid ejecting apparatus is embodied as an ink jet recording apparatus. However, the liquid ejecting apparatus is not limited to this, and includes other liquids other than ink (including liquid materials in which functional material particles are dispersed). The present invention can also be embodied in a liquid ejecting apparatus that ejects water. For example, for manufacturing liquid chips and biochips for spraying liquid materials containing dispersed or dissolved materials such as electrode materials and color materials used in the manufacture of liquid crystal displays, EL (electroluminescence) displays, and surface-emitting displays. It may be a liquid ejecting apparatus that ejects a biological organic material to be used, or a liquid ejecting apparatus that ejects a liquid as a sample that is used as a precision pipette. In addition, transparent resin liquids such as UV curable resin to form liquid injection devices that pinpoint lubricant oil onto precision machines such as watches and cameras, and micro hemispherical lenses (optical lenses) used in optical communication elements. May be a liquid ejecting apparatus that ejects liquid onto the substrate, or a liquid ejecting apparatus that ejects an etching solution such as acid or alkali to etch the substrate. The present invention can be applied to any one of these liquid ejecting apparatuses.

  (Modification 15) Furthermore, the fluid is not limited to a liquid. For example, a gas may be used. In a liquid ejecting apparatus that handles gas as a fluid, suction is performed by suction means from a gas discharge port of the liquid ejecting apparatus to apply a negative pressure to the outflow port to close the valve device, and then the negative pressure is sufficiently accumulated. The present invention can be applied to a liquid ejecting apparatus that performs choke cleaning that applies pressure to the inflow port later and pushes gas to the downstream side at once. In the liquid ejecting apparatus using such a fluid as a gas, it is possible to dispose the outflow port at a position where the foreign gas contained in the gas is easily discharged in the valve device. For example, by setting the outflow port at a position where it is easy to discharge the impure gas or suspended fine particles, etc. that have been contained in the intended gas by mixing or chemical reaction, using the difference in specific gravity, for example, Impurity discharge from the can be improved. For example, in a liquid ejecting apparatus including a pressurized liquid supply device that supplies liquid by pressurizing a bag body in which liquid is sealed with gas, a valve device is provided on the pressure gas flow path, and the flow path It may be configured to perform chalk cleaning. Further, the cleaning device provided in the liquid ejecting apparatus may be configured such that a valve device is provided in a flow path through which the waste liquid sucked from the nozzle of the liquid ejecting head flows, and choke cleaning is performed by flowing a gas through the flow path. Furthermore, a gas dissolver for dissolving a specific gas in the liquid, for example, is provided in the middle of the flow path upstream from the liquid ejecting head, and a valve device is provided on the flow path for supplying a gas to be dissolved in the liquid. A configuration may be used in which the flow path is choke cleaned with gas.

Hereinafter, the technical idea grasped | ascertained from the said embodiment and each modification is described.
(1) It has an inflow passage which communicates with the second flow path at the inflow port, and the second flow path has a larger cross-sectional area than the inflow path. Item 14. The liquid ejecting apparatus according to any one of Items 1 to 13. The second flow path is not limited to being an interrupted area flow path.

  (2) The partition wall and the opening of the protrusion have substantially the same shape that is substantially similar to each other, and the similarity ratio of the opening to the partition wall is 1/2 or more. The liquid ejecting apparatus according to any one of claims 9 to 13. According to this, since the partition wall and the opening of the projection are substantially the same shape and have a similar relationship, and the similarity ratio of the opening to the partition wall is 1/2 or more, a negative pressure is applied to the outlet. After the valve is closed, when the pressurization is applied to the inflow passage while applying a negative pressure to the outflow port, the valve device can be opened.

  (3) The partition wall and the opening both have a substantially circular shape, and the diameter of the opening is ½ or more of the diameter of the partition wall. The liquid ejecting apparatus described. According to this, since both the partition wall and the opening are substantially circular, the flexible member can be closed with a small negative pressure, and after applying a negative pressure to the liquid outlet, the outlet is closed. When applying pressure to the inflow passage while applying negative pressure to the valve, the valve device can be opened.

  (4) The pressure receiving area for receiving the fluid pressure of the second flow path in the substantially central region through the opening is the pressure receiving area for receiving the fluid pressure of the first flow path in the peripheral region outside the contact portion. The liquid ejecting apparatus according to claim 12, wherein the liquid ejecting apparatus is 1/3 or more of an area. According to this, when the negative pressure of the first flow path where the partition wall receives pressure in the peripheral area and the pressurization of the second flow path received in the substantially central area via the opening are used under substantially equal conditions. However, the valve device can be opened in either case where the second flow path is weaker than the negative pressure in the first flow path. For example, liquid ejection in which choke cleaning is performed using pressurization by a pressurizing unit for pressurizing and supplying liquid to the liquid ejecting head and negative pressure by a suction unit for cleaning that sucks liquid from a nozzle of the liquid ejecting head It is suitable for application to an apparatus.

  (5) The liquid ejecting apparatus according to any one of (5) to (12), wherein the protrusion is positioned to face a substantially central portion of the partition wall. According to this, since the projection is located opposite to the substantially central portion of the partition wall portion, the valve opening for separating the flexible member from the valve seat portion (projection) can be performed with a smaller pressure.

  (6) The liquid ejecting apparatus according to any one of (5) to (12), wherein the protrusion has an annular shape. According to this, since the projection is annular, the valve opening for separating the flexible member from the valve seat portion (projection) can be performed with a smaller pressure.

  (7) A liquid ejecting apparatus including a valve device, wherein the valve device forms a part of a wall surface that forms a fluid flow path and bends due to a pressure difference between inside and outside of the fluid flow path; A continuously disposed large cross-sectional area flow path having different cross-sectional areas, an interrupted area flow path, a small cross-sectional area flow path into which liquid flows, and a liquid outlet port communicating with the large cross-sectional area flow path The protrusion is formed so as to surround the interruption area flow path, and is arranged so that the flexible member and the seal surface (46b) where the interruption area flow path opens are opposed to each other. A liquid ejecting apparatus.

  (8) A liquid ejecting apparatus including a valve device, a pressurized fluid supply means, and a suction means, wherein the valve device seals a base material provided with a recess and an opening of the recess. And a flexible member that bends due to a pressure difference between the inside and outside of the valve chamber; and the flexible member that can be brought into contact with the valve chamber when the flexible member is bent in a direction that reduces the volume of the valve chamber. A provided valve seat portion, an inflow passage that is closed when the flexible member abuts on the valve seat portion and is connected to a pressurized fluid supply means, and the flexible member is connected to the valve seat portion. The valve chamber communicates with the inflow passage in a separated state, and opens on the inner wall surface of the valve chamber so that the communication with the inflow passage is blocked while the flexible member is in contact with the valve seat portion. And an outflow passage used in connection with the suction means, and the minimum cross-sectional area of the inflow passage is in the suction means When the fluid in the valve chamber is sucked through the outflow passage, a flow passage resistance that can reduce the fluid in the valve chamber so that the flexible member can come into contact with the valve seat portion is provided. The pressure receiving area that is set to a flow path cross-sectional area that can be applied to the valve seat and that receives the fluid pressure of the pressurized fluid that flows into the flexible member from the pressurized fluid supply means through the inflow passage. Is a pressure receiving area that allows the flexible member to be separated from the valve seat when the inflow path is pressurized during suction from the outflow path.

  DESCRIPTION OF SYMBOLS 11 ... Inkjet recording apparatus as a liquid ejecting apparatus, 20 ... Recording head as a liquid ejecting head, 0a ... Nozzle, 21 ... Valve unit, 23 ... Ink cartridge as liquid storage means and liquid container, 24 ... Cartridge holder, DESCRIPTION OF SYMBOLS 25 ... Pressure pump which comprises pressurization means, 26 ... Cleaning apparatus as suction means, 26a ... Cap, 26e ... Tube pump which comprises suction means, 31 ... Ink case, 32 ... Ink pack which comprises liquid storage means 35 ... Ink supply tube constituting the liquid supply path, 37 ... Pressurizing tube constituting the pressurizing means, 39 ... Air supply tube constituting the pressurizing means, 41, 81, 91, 110, 120, 131 ... Valve Differential pressure valve as a device, 43, 93, 111 ... concave portion, 43a, 111a ... opening of concave portion, 44, 4, 132 ... Base material, 45, 95, 133 ... Film member as flexible member, 45a ... Diaphragm, 46, 96 ... Projection as valve seat part, 46a ... Opening of projection (valve seat part), 46b ... Valve seat surface, 47, 97 ... Inlet passage as a small cross-sectional area passage, 47a, 97a ... Inlet, 49, 82, 99 ... Outlet passage, 49a, 82a, 99a ... Outlet, 50, 102 ... Fluid passage , A first flow path as a large cross-sectional area flow path, 52 a second flow path as an interruption area flow path, 73 a pressure pump motor constituting a pressurizing means, and 74 a suction means. Tube pump motor, 93 ... concave portion, 93a, 96a, 96b ... slope as guide surface, 112a ... valve seat opening, 113 ... valve seat portion, 130 ... valve device, A ... opening diameter of the recess (diaphragm) Diameter), B ... Opening diameter of protrusion, C ... Inflow (Inflow path) diameter, A1 ... first pressure receiving region, A2 ... second pressure receiving region, S ... opening area of the opening of the recess (diaphragm area, total pressure receiving area), S1 ... first pressure receiving area for receiving negative pressure 1 pressure receiving area, S2: second pressure receiving area as an opening area (pressure receiving area receiving pressure), ΔPneg, negative pressure (differential pressure), ΔPpos, pressurizing (differential pressure), d1 , D2 ... distance, Fneg ... force in the valve closing direction, Fpos ... force in the valve opening direction, Mneg ... bending moment, Mpos ... bending moment.

Claims (18)

A liquid ejecting apparatus including a valve device,
The valve device is
A flexible member that forms a part of a wall surface that forms a fluid flow path and bends due to a pressure difference inside and outside the fluid flow path;
A valve seat having an opening which is provided so as to be able to abut in a state where the flexible member is bent in a direction to reduce the volume of the fluid flow path and which is closed in a state of corresponding contact;
The fluid flow path communicates with each other through the opening in a valve-open state where the flexible member does not close the opening, and is in a non-communication state when the flexible member closes the opening. A path and a second flow path,
In the first flow path, the fluid pressure of the first flow path is applied to the flexible member at a portion outside the contact portion where the flexible member contacts the valve seat portion in the valve closed state. And communicate with the outlet,
The second flow path is provided so that the fluid pressure of the second flow path is applied to the flexible member through the opening in the valve-closed state and communicates with an inflow port,
The liquid ejecting apparatus according to claim 1, wherein the second flow path has a flow path cross-sectional area larger than an opening area of the inlet.   The liquid ejecting apparatus according to claim 1, wherein the valve seat portion is an annular protrusion that surrounds the second flow path. A large cross-sectional area flow path as the first flow path, an interrupted area flow path as the second flow path, and a small cross-sectional area flow path as an inflow path communicating with the interrupted area flow path at the inlet. Prepared,
The liquid ejecting apparatus according to claim 2, wherein the flexible member is disposed so as to face the opening of the protrusion.   When the fluid is sucked through the outlet, the inside of the fluid channel becomes negative pressure, and the opening of the valve seat portion is closed by the flexible member displaced in a direction in which the volume in the fluid channel decreases. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is a liquid ejecting apparatus.   The liquid ejecting apparatus according to claim 4, wherein the fluid is supplied through the inflow port and the inside of the second flow path is pressurized, whereby the opening of the opening by the flexible member is released. .   The flow passage cross-sectional area of the outflow passage communicating with the first flow passage at the outflow port is such that the flexible member can come into contact with the valve seat portion when a negative pressure is applied through the outflow port. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is set to a value capable of reducing the fluid in the flow path.   A flow path of the inflow path with respect to a flow path cross-sectional area of the outflow path, having an outflow path communicating with the first flow path at the outflow port and an inflow path communicating with the second flow path at the inflow port; The ratio of the cross-sectional areas is such that when a negative pressure is applied through the outflow passage, the first flow rate at which the fluid in the fluid passage flows out through the outflow passage is reduced by the decompression in the fluid passage due to the outflow. 7. The value according to claim 1, wherein the second flow rate is set to a value that is maintained to be larger than the second flow rate at which the fluid flows into the fluid flow path through the inflow path. The liquid ejecting apparatus described.   The opening area of the opening is not less than five times the flow path cross-sectional area of the inflow path communicating with the second flow path at the inflow port. Liquid ejector.   Of the flexible member, the area of the partition wall, which is a portion that can be bent and deformed by the pressure difference, the opening area of the opening, and the flow path cross-sectional area of the inflow path communicating with the second flow path at the inflow port The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is set so as to sequentially become smaller in this order.   The ratio of the opening area of the opening to the area of the partition wall is such that the partition wall portion in contact with the valve seat portion when a pressure is applied through the inlet while a negative pressure is applied through the outlet. , The force in the valve closing direction acting on the peripheral region based on receiving the negative pressure of the first flow channel in the peripheral region outside the contact point, and the second flow channel through the opening. A bending moment acting on the substantially central region of the partition wall acts on the peripheral region based on both forces when receiving a force in the valve opening direction acting on the substantially central region of the partition wall based on receiving pressure. 10. The method according to claim 1, wherein the value is set to a value equal to or greater than a predetermined value that satisfies a valve opening condition that is greater than a bending moment and allows the partition wall portion to be separated from the valve seat portion. The liquid ejecting apparatus described.   The liquid ejecting apparatus according to claim 9, wherein an opening area of the opening is ¼ or more of an area of the partition wall.   The partition wall portion in contact with the valve seat portion receives the fluid pressure in the first flow path in the peripheral region outside the contact location, and the first central region through the opening in the first region. The ratio of the pressure receiving area for receiving the fluid pressure of the two flow paths is such that the partition wall portion in contact with the valve seat portion when a negative pressure is applied through the outlet and a pressure is applied through the inlet. In response to receiving the negative pressure of the first flow path in the peripheral area, the force in the valve closing direction to act on the peripheral area of the partition wall and the pressurization of the second flow path through the opening The bending moment acting on the substantially central region of the partition wall based on both forces is larger than the bending moment acting on the peripheral region when receiving a force in the valve opening direction acting on the substantially central region of the partition wall based on The valve opening that enables the partition portion to be separated from the valve seat portion Liquid ejecting apparatus according to any one of claims 1 to 11, characterized in that it is set to a value equal to or greater than a predetermined value that satisfies the matter. A liquid storage means for storing liquid, a liquid jet head for jetting the liquid from a nozzle, a liquid supply path for guiding the liquid from the liquid storage means to the liquid jet head, and the nozzle of the liquid jet head A suction unit that sucks the liquid, and a pressurizing unit that pressurizes the liquid sent from the liquid storage unit to the liquid ejecting head through the liquid supply path,
The liquid ejecting apparatus according to claim 1, wherein the valve device is provided in the middle of the liquid storage unit or the liquid supply path.   The suction device sucks the liquid from the nozzle of the liquid jet head and applies a negative pressure to the outlet, thereby closing the valve device and, after the valve closing, a negative pressure downstream from the valve-closing position. At a predetermined stage in which the pressure is accumulated, the liquid is supplied from the liquid storage means to the liquid ejecting head side through the liquid supply path by the pressurizing means, and the pressure is applied to the inflow port to thereby control the valve device. The liquid ejecting apparatus according to claim 13, wherein cleaning is performed by opening the valve and causing the liquid to flow through the valve device and the liquid supply flow channel on the downstream side of the valve device by opening the valve.   The valve device is disposed in a state where the flexible member is positioned on the opposite side in the gravitational direction, and the outlet port opens at a position on the opposite side in the gravitational direction on the wall surface of the first flow path. The liquid ejecting apparatus according to claim 14.   The valve device is arranged in a direction in which the direction intersecting the direction of gravity is the direction in which the flexible member bends, and the outlet is the gravity on the inner wall surface other than the flexible member forming the first flow path. The liquid ejecting apparatus according to claim 14, wherein the liquid ejecting apparatus opens at a position opposite to the direction.   The inner wall surface of the fluid channel in the valve device has a guide surface that is inclined with respect to the direction of gravity so as to guide bubbles moving in the liquid in the fluid channel by buoyancy to the outlet. The liquid ejecting apparatus according to claim 14, wherein the liquid ejecting apparatus is a liquid ejecting apparatus. A liquid storage container used detachably attached to a liquid ejecting apparatus,
A liquid container comprising the valve device according to any one of claims 1 to 17.

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