JP6501592B2 - Ink jet recording device - Google Patents

Description

  The present invention relates to an inkjet recording apparatus.

  Techniques relating to inkjet recording devices have been proposed. For example, Patent Document 1 discloses an ink jet printing apparatus in which an ink jet head and a large-capacity ink tank are integrally moved and printed. In this inkjet printing apparatus, an inkjet head is attached to the lower end of the support guide, an ink tank on the top, and an ink chamber on the center. An ink tank ink passage is attached between the ink tank and the ink chamber. The ink chamber has a first ink chamber and a second ink chamber. An air reservoir in the upper part of the second ink compartment communicates with the air buffer through a tube and further communicates with the vacuum pump. The tube bifurcates along the way, and a pressure regulator is attached to the bifurcated tube. A vacuum pump is driven to create a negative pressure in the air reservoir. Pressure adjustment is performed by attaching a manometer to the air buffer and adjusting the opening of the pressure regulator.

JP, 2006-44015, A

  In the inkjet recording apparatus, the ink is ejected from the nozzle formed in the inkjet head. In the ink jet recording apparatus, an ink tank different from the main tank for storing the ink may be provided. In this ink tank, the ink supplied from the main tank is stored in a storage chamber formed inside the ink tank. The ink stored in the storage chamber flows out of the ink tank, flows through the first connection portion, and is supplied to the ink jet head. That is, the storage chamber and the inkjet head communicate with each other through the first connection channel formed inside the first connection portion. In the ink jet recording apparatus, the storage chamber is depressurized and maintained at a negative pressure lower than the atmospheric pressure. This is to form a meniscus on the nozzle while preventing the ink from leaking from the nozzle of the inkjet head. In the ink jet recording apparatus, by forming a stable meniscus on the nozzle, preferable ink discharge can be realized, and the quality of an image to be recorded can be stabilized. In order to stabilize the meniscus, it is necessary to stabilize the pressure (negative pressure) of the storage chamber in a constant state.

  An object of the present invention is to provide an ink jet recording apparatus capable of stabilizing a storage chamber of an ink tank for storing ink supplied to an ink jet head at a predetermined negative pressure value.

  According to one aspect of the present invention, there is provided an ink jet head having a nozzle for discharging ink, an ink tank having a storage chamber formed therein for storing ink supplied to the ink jet head, and the ink jet head from the ink tank A first connection portion including a first connection flow path through which the ink supplied to the reservoir flows and brings the reservoir chamber and the inkjet head into communication, and a negative pressure whose internal chamber formed inside by a vacuum pump is depressurized from atmospheric pressure A buffer tank including a first flow passage portion formed by a through hole penetrating a wall forming the inner chamber and forming a first portion of a second connection flow passage which brings the inner chamber and the storage chamber into communication with each other And a second connection portion including a second flow passage portion forming a second portion of the second connection flow passage, which communicates with the first flow passage portion, and the second connection flow A switching valve that switches between a first state for opening the second connection state and a second state for closing the second connection flow path, and the second end on the side of the first end when the switching valve is in the first state A third flow passage portion forming a third portion of the second connection flow passage, in communication with the flow passage portion and in communication with the storage chamber on the side of the second end opposite to the first end portion; A third connection portion, the ink jet head connected to the ink tank by the first connection portion, the buffer tank, the second connection portion, the switching valve, and the third connection portion. And a carriage mounted in a connected state.

  According to this, it is possible to shorten the second connection flow path through which the inner chamber of the buffer tank and the storage chamber of the ink tank are communicated, as compared with the inkjet recording apparatus in which the buffer tank is not mounted on the carriage. The pressure in the reservoir can be maintained constant at a predetermined negative pressure value. It is possible to improve responsiveness to pressure fluctuations in the storage chamber.

  In the ink jet recording apparatus, the second connection portion is formed of a block-shaped member in which a through hole serving as the second flow passage portion is formed, and the buffer tank has a through hole serving as the first flow passage portion. The first flow path portion and the second flow path portion are fixed to the wall portion in a continuous state, the switching valve is fixed to the second connection portion, and the first connection is fixed to the carriage. A second connection portion in which the ink jet head is connected to the ink tank by the second portion, the buffer tank is fixed to the buffer tank, the switching valve is fixed to the second connection portion, It may be made to be mounted in the state where it was connected by three connection parts. According to this, the first channel portion and the second channel portion can be in a continuous state. By forming the second connection portion as a block-like member and fixing it to the wall portion of the buffer tank, the degree of sealing of the inner chamber of the buffer tank can be enhanced. It is possible to suppress the inflow of air into the internal chamber.

  In the ink jet recording apparatus, the second connection portion may be formed of a second material having a thermal conductivity higher than that of the first material forming the buffer tank. In this case, the buffer tank may be formed of a resin material, and the second connection portion may be formed of a metal material. According to this, the switching valve can be cooled. When the switching valve is a solenoid valve, the switching valve generates heat. The heat generated by the switching valve, which is a solenoid valve, is transmitted to the second connection portion. It can suppress that the heat transmitted to the second connection part is transmitted to the buffer tank. For example, expansion of the buffer tank due to heat can be suppressed. The weight of the buffer tank can be reduced. The weight increase of the carriage can be suppressed.

  According to the present invention, it is possible to obtain an ink jet recording apparatus capable of stabilizing the storage chamber of the ink tank storing the ink supplied to the ink jet head at a predetermined negative pressure value.

FIG. 1 is a perspective view showing a schematic configuration of an inkjet recording apparatus. FIG. 2 is a partial cross-sectional view taken along a line DD shown in FIG. It is a perspective view which shows schematic structure of a buffer tank and a 2nd connection part.

  Embodiments for carrying out the present invention will be described using the drawings. The present invention is not limited to the configurations described below, and various configurations can be adopted in the same technical idea. For example, part of the configuration described below may be omitted or replaced with another configuration or the like. Other configurations may be included. In each drawing, the illustration of the electrical wiring connecting the predetermined parts is omitted as appropriate. Hatching indicates the cross section. The broken line is a hidden line.

<Ink jet recording apparatus>
The inkjet recording apparatus 10 will be described with reference to FIGS. 1 and 2. In the inkjet recording apparatus 10, the recording medium 15 is conveyed, and an image is recorded on the recording surface 16 of the recording medium 15. In the inkjet recording apparatus 10, an image is recorded for various recording media 15. Examples of the recording medium 15 include a fabric or a building material. In the embodiment, the case where the recording medium 15 is a long cloth is illustrated (see FIG. 1). The ink colors used to record the image are four colors of black, magenta, yellow and cyan. The ink colors may be colors other than these. The number of ink colors may be three or less or five or more. The pattern attached to the portion of the recording medium 15 illustrated on the downstream side in the transport direction in FIG. 1 corresponds to the image recorded on the recording medium 15.

  As shown in FIG. 1, the inkjet recording apparatus 10 includes a transport unit 20, main tanks 30K, 30M, 30Y and 30C, supply connection parts 31K, 31M, 31Y and 31C, and subtanks 32K, 32M, 32Y and 32C. , Supply valves 34K, 34M, 34Y, 34C, first connection parts 35K, 35M, 35Y, 35C, ink jet heads 40K, 40M, 40Y, 40C, carriage 50, moving part 60, control device 70, A decompression unit 80 is provided.

  The transport unit 20 transports the recording medium 15 along the longitudinal direction of the recording medium 15. The recording medium 15 conveyed by the conveyance unit 20 passes through the carriage 50 on which the inkjet heads 40K, 40M, 40Y, and 40C are mounted. As the transport unit 20, for example, a belt conveyor is employed. However, the transport unit may be a transport device different from this. The type of the transport unit is appropriately selected according to the recording medium 15 to be transported. In the embodiment, the direction in which the recording medium 15 is transported by the transport unit 20 is referred to as “transport direction”. The transport direction is orthogonal to the main scanning direction. The main scanning direction is a direction in which the carriage 50 is reciprocated by the moving unit 60 as described later. The main scanning direction coincides with the short direction of the recording medium 15. The short direction of the recording medium 15 is the width direction of the recording medium 15. The transport direction and the opposite direction may be referred to as a "sub-scanning direction" with respect to the above-described main scanning direction. In the embodiment, a direction orthogonal to each of the transport direction and the opposite direction is referred to as a “main scanning direction”. The transport direction and the opposite direction are referred to as "sub-scanning direction".

  The main tank 30K stores black ink. The supply connection portion 31K connects the main tank 30K and the sub tank 32K. A supply valve 34K is provided in the middle of the supply connection portion 31K. The supply valve 34K is an electromagnetic valve that opens and closes the fifth connection flow path formed inside the supply connection portion 31K. When the supply valve 34K is in the first state, the fifth connection flow path by the supply connection portion 31K is in the open state. The first state is a state in which the supply valve 34K is open. In this case, the storage chambers 33 of the main tank 30K and the sub tank 32K communicate with each other through the fifth connection flow path by the supply connection portion 31K. When the supply valve 34K is in the second state, the fifth connection flow path by the supply connection portion 31K is in the closed state. The second state is a state in which the supply valve 34K is closed. The supply valve 34K is brought into the first state when the black ink is supplied to the sub tank 32K, and brought into the second state with the end of the supply.

  The black ink flows out of the main tank 30K, flows through the supply connection portion 31K and the supply valve 34K, and is supplied to the sub tank 32K. The black ink supplied to the sub tank 32K flows through the first connection portion 35K and is supplied to the ink jet head 40K. That is, the sub tank 32K is an ink tank which additionally stores the black ink supplied to the ink jet head 40K. The black ink supplied to the sub tank 32K is stored in the storage chamber 33 formed inside the sub tank 32K. The first connection portion 35K connects the sub tank 32K and the inkjet head 40K. The first connection portion 35K is a flow path through which the black ink supplied from the sub tank 32K to the ink jet head 40K flows. The storage chamber 33 of the sub tank 32K and the ink jet head 40K communicate with each other through a first connection channel formed inside the first connection portion 35K.

  The main tank 30M stores magenta ink. The supply connection unit 31M connects the main tank 30M and the sub tank 32M. A supply valve 34M is provided in the middle of the supply connection portion 31M. The supply valve 34M is an electromagnetic valve that opens and closes the fifth connection flow path formed inside the supply connection portion 31M. When the supply valve 34M is in the first state, the fifth connection flow path by the supply connection unit 31M is in the open state. In the first state, the supply valve 34M is open. In this case, the storage chambers 33 of the main tank 30M and the sub tank 32M communicate with each other through the fifth connection flow path by the supply connection portion 31M. When the supply valve 34M is in the second state, the fifth connection flow path by the supply connection portion 31M is in the closed state. The second state is a state in which the supply valve 34M is closed. The supply valve 34M is brought into the first state when the magenta ink is supplied to the sub tank 32M, and is brought into the second state with the end of the supply.

  The magenta ink flows out of the main tank 30M, flows through the supply connection portion 31M and the supply valve 34M, and is supplied to the sub tank 32M. The magenta ink supplied to the sub tank 32M flows through the first connection portion 35M and is supplied to the ink jet head 40M. That is, the sub tank 32M is an ink tank which stores the magenta ink supplied to the ink jet head 40M as a subsidiary. The magenta ink supplied to the sub tank 32M is stored in a storage chamber 33 formed inside the sub tank 32M. The first connection portion 35M connects the sub tank 32M and the inkjet head 40M. The first connection portion 35M is a flow path through which the magenta ink supplied from the sub tank 32M to the ink jet head 40M flows. The storage chamber 33 of the sub tank 32M and the ink jet head 40M communicate with each other through a first connection flow path formed inside the first connection portion 35M.

  The main tank 30Y stores yellow ink. The supply connection unit 31Y connects the main tank 30Y and the sub tank 32Y. A supply valve 34Y is provided in the middle of the supply connection unit 31Y. The supply valve 34Y is an electromagnetic valve that opens and closes the fifth connection channel formed in the inside of the supply connection portion 31Y. When the supply valve 34Y is in the first state, the fifth connection flow path by the supply connection portion 31Y is in the open state. The first state is a state in which the supply valve 34Y is open. In this case, the storage chambers 33 of the main tank 30Y and the sub tank 32Y communicate with each other through the fifth connection flow path by the supply connection portion 31Y. When the supply valve 34Y is in the second state, the fifth connection flow path by the supply connection portion 31Y is in the closed state. The second state is a state in which the supply valve 34Y is closed. The supply valve 34Y is set to the first state when the yellow ink is supplied to the sub tank 32Y, and is set to the second state with the end of the supply.

  The yellow ink flows out of the main tank 30Y, flows through the supply connection portion 31Y and the supply valve 34Y, and is supplied to the sub tank 32Y. The yellow ink supplied to the sub tank 32Y flows through the first connection portion 35Y and is supplied to the ink jet head 40Y. That is, the sub tank 32Y is an ink tank which stores the yellow ink supplied to the ink jet head 40Y as a subsidiary. The yellow ink supplied to the sub tank 32Y is stored in the storage chamber 33 formed inside the sub tank 32Y. The first connection portion 35Y connects the sub tank 32Y and the inkjet head 40Y. The first connection portion 35Y is a flow path through which yellow ink supplied from the sub tank 32Y to the ink jet head 40Y flows. The storage chamber 33 of the sub tank 32Y and the ink jet head 40Y communicate with each other through a first connection channel formed inside the first connection portion 35Y.

  The main tank 30C stores cyan ink. The supply connection portion 31C connects the main tank 30C and the sub tank 32C. A supply valve 34C is provided in the middle of the supply connection portion 31C. The supply valve 34C is an electromagnetic valve that opens and closes the fifth connection channel formed inside the supply connection portion 31C. When the supply valve 34C is in the first state, the fifth connection flow path by the supply connection portion 31C is in the open state. The first state is a state in which the supply valve 34C is open. In this case, the main tank 30C and the storage chamber 33 of the sub tank 32C communicate with each other through the fifth connection flow path by the supply connection portion 31C. When the supply valve 34C is in the second state, the fifth connection flow path by the supply connection portion 31C is in the closed state. The second state is a state in which the supply valve 34C is closed. The supply valve 34C is brought into the first state when cyan ink is supplied to the sub tank 32C, and is brought into the second state with the end of the supply.

  The cyan ink flows out of the main tank 30C, flows through the supply connection portion 31C and the supply valve 34C, and is supplied to the sub tank 32C. The cyan ink supplied to the sub tank 32C flows through the first connection portion 35C and is supplied to the ink jet head 40C. That is, the sub tank 32C is an ink tank which stores the cyan ink supplied to the ink jet head 40C as a subsidiary. The cyan ink supplied to the sub tank 32C is stored in a storage chamber 33 (see FIG. 2) formed inside the sub tank 32C. The first connection portion 35C connects the sub tank 32C and the inkjet head 40C. The first connection portion 35C is a flow path through which cyan ink supplied from the sub tank 32C to the ink jet head 40C flows. As shown in FIG. 2, the storage chamber 33 of the sub tank 32C and the inkjet head 40C communicate with each other through a first connection channel formed inside the first connection portion 35C.

  The subtanks 32K, 32M, 32Y and 32C have the same configuration. Therefore, the storage chambers 33 of the sub tanks 32K, 32M, 32Y have the same shape as the storage chamber 33 of the sub tank 32C. Therefore, in the embodiment, in addition to the storage chamber 33 of the sub-tank 32C, each storage chamber of the sub-tanks 32K, 32M, 32Y, which is not shown, is also attached with a reference numeral "33" and called "storage chamber 33".

  The inkjet head 40 K is an inkjet head that ejects black ink and records an image with the black ink. A plurality of nozzles for ejecting black ink are formed in the inkjet head 40K. The inkjet head 40M is an inkjet head that ejects magenta ink and records an image with the magenta ink. A plurality of nozzles for ejecting magenta ink are formed in the inkjet head 40M. The inkjet head 40Y is an inkjet head that ejects yellow ink and records an image with the yellow ink. A plurality of nozzles for ejecting yellow ink are formed in the inkjet head 40Y. The inkjet head 40C is an inkjet head that ejects cyan ink and records an image using the cyan ink. A plurality of nozzles for ejecting cyan ink are formed in the inkjet head 40C.

  In FIG. 2, the configuration given the symbol “N” corresponds to the nozzles formed in the inkjet head 40 </ b> C. In FIG. 2, four nozzles are illustrated. The number of nozzles in the inkjet heads 40K, 40M, 40Y, and 40C is appropriately determined in consideration of various conditions. The number of nozzle rows in the main scanning direction is also appropriately determined in consideration of various conditions. The number of nozzle rows is the number in which the nozzle rows of the plurality of nozzles aligned in the sub-scanning direction are arranged in the main scanning direction.

  The ink jet heads 40 K, 40 M, 40 Y, and 40 C are mounted on the carriage 50 in a state where the ink jet heads 40 K, 40 M, 40 Y, and 40 C are positioned at predetermined positions. The ink jet heads 40K, 40M, 40Y and 40C are mounted on the carriage 50 in a state of being adjacent to each other in the main scanning direction as shown in FIG. The arrangement order of the inkjet heads 40K, 40M, 40Y and 40C may be different from that shown in FIG. The arrangement order of these is appropriately determined in consideration of various conditions.

  The sub-tanks 32K, 32M, 32Y, 32C and the first connection portions 35K, 35M, 35Y, 35C are also mounted on the carriage 50. That is, the sub tank 32K is mounted on the carriage 50 in a state of being connected to the inkjet head 40K by the first connection portion 35K. The sub tank 32K is provided above the ink jet head 40K. The sub tank 32M is mounted on the carriage 50 in a state of being connected to the inkjet head 40M by the first connection portion 35M. The sub tank 32M is provided above the ink jet head 40M. The sub tank 32Y is mounted on the carriage 50 in a state of being connected to the inkjet head 40Y by the first connection portion 35Y. The sub tank 32Y is provided above the inkjet head 40Y. The sub tank 32C is mounted on the carriage 50 in a state of being connected to the inkjet head 40C by the first connection portion 35C. The sub tank 32C is provided above the ink jet head 40C. In addition to this, a part of the configuration of the decompression unit 80 is also mounted on the carriage 50. This point will be described later.

  The moving unit 60 reciprocates the carriage 50 in the main scanning direction. The moving unit 60 includes two pulleys 61 and 62, a timing belt 63, and a motor 64, as shown in FIG. The two pulleys 61 and 62 are respectively provided on both sides in the main scanning direction with reference to the transport unit 20. A motor 64 is connected to the pulley 61. The pulley 62 is rotatably supported. The pulley 61 rotates as the motor 64 rotates. The timing belt 63 is stretched over the pulleys 61 and 62 under tension. The carriage 50 is attached to the timing belt 63 via the support portion 51. In FIG. 1, the supply connection portions 31K, 31M, 31Y, and 31C and a suction connection portion 81 described later are illustrated in a simplified state. The supply connection portions 31 K, 31 M, 31 Y, 31 C and the suction connection portion 81 are provided in a state capable of coping with the reciprocating movement of the carriage 50 in the main scanning direction.

  The control device 70 includes a control unit 71 and a pressure input unit 72. The control unit 71 includes, for example, a CPU, a storage device, and a RAM. The CPU executes arithmetic processing and controls various processes executed by the inkjet recording apparatus 10. The storage device is configured by, for example, a non-volatile memory and / or a hard disk. The storage device stores programs of various processes executed by the inkjet recording apparatus 10. For example, a program related to image recording is stored. The RAM is a storage area when the CPU executes a program stored in the storage device. Predetermined data is stored in the RAM during the execution of the process.

  The pressure input unit 72 receives the input of the pressure setting value of the pressure of each storage chamber 33 of the sub tanks 32K, 32M, 32Y, and 32C. The operator inputs a pressure setting value to the pressure input unit 72. The control unit 71 acquires the pressure setting value received by the pressure input unit 72. The control unit 71 controls the pressure reducing unit 80 in accordance with the acquired pressure setting value. The pressure reducing unit 80 reduces the pressure of each storage chamber 33 of the sub tanks 32K, 32M, 32Y, and 32C to a negative pressure lower than the atmospheric pressure (1013 hPa). The description regarding the pressure reduction unit 80 will be described later.

  The inkjet recording apparatus 10 includes a liquid feed pump (not shown) in addition to the components described above. Four liquid feed pumps are provided corresponding to the number of ink colors. The four liquid transfer pumps are respectively provided to the supply connection portions 31K, 31M, 31Y, and 31C. The ink of each color stored in the main tanks 30K, 30M, 30Y, and 30C is supplied to the sub tanks 32K, 32M, 32Y, and 32C by a liquid feeding pump for each color. The supply of the inks of the respective colors to the subtanks 32K, 32M, 32Y and 32C may be performed by a known liquid feeding unit different from the liquid feeding pump. For example, the inside of the main tanks 30K, 30M, 30Y, and 30C may be pressurized or the like. The liquid transfer unit is also provided to a known inkjet recording apparatus. Even in the inkjet recording apparatus 10, the same liquid feeding unit as that of a known inkjet recording apparatus can be employed. Therefore, the description of the liquid transfer unit is omitted.

<Decompression section>
The decompression unit 80 will be described with reference to FIGS. 1 to 3. The decompression unit 80 includes a suction connection 81, a suction valve 82, a vacuum pump 83, a buffer tank 84, a second connection 90, switching valves 95K, 95M, 95Y and 95C, and a third connection 96K, A 96M, 96Y, 96C, an open valve 98, and a pressure sensor 99 are provided.

  As shown in FIG. 1, the suction connection unit 81 connects the buffer tank 84 and the vacuum pump 83. A suction valve 82 is provided in the middle of the suction connection portion 81. The suction valve 82 is an electromagnetic valve that opens and closes the third connection flow path formed inside the suction connection portion 81. When the suction valve 82 is in the first state, the third connection flow path by the suction connection portion 81 is opened. In the first state, the suction valve 82 is open. In this case, the vacuum pump 83 and the internal chamber 85 of the buffer tank 84 communicate with each other. The vacuum pump 83 sucks the air in the internal chamber 85 (see FIG. 3) of the buffer tank 84. The drawn air flows through the suction connection 81 to the vacuum pump 83 side. When the suction valve 82 is in the second state, the third connection flow path by the suction connection portion 81 is closed. The second state is a state where the suction valve 82 is closed. In this case, the suction of air in the internal chamber 85 by the vacuum pump 83 is stopped.

  The buffer tank 84 is a buffer tank when the storage chambers 33 of the sub tanks 32K, 32M, 32Y, and 32C have a negative pressure. The internal chamber 85 is a space formed inside the buffer tank 84. With the suction of air by the vacuum pump 83, the pressure in the internal chamber 85 becomes negative. In the inkjet recording apparatus 10, the pressure of each storage chamber 33 of the sub tanks 32K, 32M, 32Y, 32C is set to a predetermined pressure value or a predetermined pressure value by adjusting the pressure of the internal chamber 85 as described later. Adjusted to range.

  The internal chamber 85 and the storage chamber 33 of the sub tank 32K are connected by the second connection portion 90, the switching valve 95K, and the third connection portion 96K. The internal chamber 85 and the storage chamber 33 of the sub tank 32K communicate with each other. The internal chamber 85 and the storage chamber 33 of the sub tank 32M are connected by the second connection portion 90, the switching valve 95M, and the third connection portion 96M. The internal chamber 85 and the storage chamber 33 of the sub tank 32M are in communication with each other. The internal chamber 85 and the storage chamber 33 of the sub tank 32Y are connected by the second connection portion 90, the switching valve 95Y, and the third connection portion 96Y. The internal chamber 85 and the storage chamber 33 of the sub tank 32Y communicate with each other. The internal chamber 85 and the storage chamber 33 of the sub tank 32C are connected by the second connection portion 90, the switching valve 95C, and the third connection portion 96C. The internal chamber 85 and the storage chamber 33 of the sub tank 32C communicate with each other. Air flows between the internal chamber 85 and the storage chambers 33 of the sub tanks 32K, 32M, and 32Y 32C.

  In the embodiment, a flow path through which the inner chamber 85 and the storage chamber 33 of the sub tank 32K are brought together is referred to as a “second connection flow path K”. A flow path through which the internal chamber 85 and the storage chamber 33 of the sub tank 32M are brought together is referred to as a "second connection flow path M". A flow path through which the internal chamber 85 and the storage chamber 33 of the sub tank 32Y are brought together is referred to as a "second connection flow path Y". A flow path through which the internal chamber 85 and the storage chamber 33 of the sub tank 32C are brought together is referred to as a "second connection flow path C". An arrow C shown in FIG. 2 corresponds to the second connection channel C.

  In the buffer tank 84, the volume of the internal chamber 85 is made larger than the total volume of the storage chambers 33 of the sub tanks 32K, 32M, 32Y, and 32C. In the buffer tank 84, as shown in FIG. 3, four through holes 86, 87, 88, 89 are formed through the wall portion forming the inner chamber 85. In the embodiment, the through holes 86, 87, 88, 89 are provided in the main scanning direction in the wall portion on the upstream side in the transport direction among the two wall portions facing in the transport direction. The through hole 86 is provided on the first side in the main scanning direction. The through hole 87 is adjacent to the through hole 86 on the first side in the main scanning direction. The through hole 88 is adjacent to the through hole 87 on the first side in the main scanning direction. The through hole 89 is provided adjacent to the through hole 88 on the first side in the main scanning direction and on the second side in the main scanning direction. In the buffer tank 84, the through hole 86 is a first flow passage portion that forms a first portion of the second connection flow passage K. The through hole 87 serves as a first flow passage portion that forms a first portion of the second connection flow passage M. The through hole 88 is a first flow passage portion that forms a first portion of the second connection flow passage Y. The through hole 89 serves as a first flow passage portion that forms a first portion of the second connection flow passage C.

  The second connection portion 90 is formed of a block-shaped member as shown in FIG. The member forming the second connection portion 90 is a material having a thermal conductivity higher than that of the material forming the buffer tank 84. For example, the buffer tank 84 is formed of a resin material, and the second connection portion 90 is formed of a metal material. As a metal material which forms the 2nd connection part 90, aluminum is mentioned, for example. The second connection 90 may be referred to as a manifold.

  Four through holes 91, 92, 93, 94 are formed in the block-like member to be the second connection portion 90. The through holes 91, 92, 93, 94 are provided in the main scanning direction at the same intervals as the through holes 86, 87, 88, 89 of the buffer tank 84 described above. The through hole 91 is provided on the first side in the main scanning direction. The through hole 92 is adjacent to the through hole 91 on the first side in the main scanning direction. The through hole 93 is adjacent to the through hole 92 on the first side in the main scanning direction. The through hole 94 is provided adjacent to the through hole 93 on the first side in the main scanning direction and on the second side in the main scanning direction. In the second connection portion 90, the through hole 91 is a second flow passage portion that forms a second portion of the second connection flow passage K. The through hole 92 serves as a second flow passage portion that forms a second portion of the second connection flow passage M. The through hole 93 is a second flow passage portion that forms a second portion of the second connection flow passage Y. The through hole 94 is a second flow passage portion that forms a second portion of the second connection flow passage C.

  In the second connection portion 90, the through hole 91 corresponds to the through hole 86 of the buffer tank 84, the through hole 92 corresponds to the through hole 87 of the buffer tank 84, and the through hole 93 corresponds to the through hole 88 of the buffer tank 84. The through hole 94 is fixed to the buffer tank 84 in a state where the through hole 94 matches the through hole 89 of the buffer tank 84.

  The switching valve 95K is provided between the second connection portion 90 and the third connection portion 96K. The switching valve 95K is a solenoid valve. The switching valve 95K switches to a first state in which the second connection flow path K is opened and a second state in which the second connection flow path K is closed. The first state is a state in which the switching valve 95K is open, and the second state is a state in which the switching valve 95K is closed. In the inkjet head 40K, the black ink may be clogged in the nozzle that discharges the black ink. In such a case, in the inkjet recording apparatus 10, maintenance processing is performed in which the storage chamber 33 of the sub tank 32K is pressurized and the black ink is forcibly discharged. The switching valve 95 </ b> K is switched to the second state, for example, when the above-described maintenance process is performed by the inkjet recording apparatus 10. When the maintenance process is not performed and the recording process described later is performed by the inkjet recording apparatus 10, the switching valve 95K is in the first state.

  The switching valve 95M is provided between the second connection portion 90 and the third connection portion 96M. The switching valve 95M is a solenoid valve. The switching valve 95M switches to a first state in which the second connection flow path M is opened and a second state in which the second connection flow path M is closed. The first state is a state in which the switching valve 95M is open, and the second state is a state in which the switching valve 95M is closed. In the inkjet head 40 </ b> M, the magenta ink may be clogged at the nozzle that ejects the magenta ink. In such a case, in the inkjet recording apparatus 10, a maintenance process is performed in which the storage chamber 33 of the sub tank 32M is pressurized and the magenta ink is forcibly ejected. The switching valve 95M is switched to the second state, for example, when the maintenance processing as described above is performed by the inkjet recording apparatus 10. When the maintenance process is not performed and the recording process described later is performed by the inkjet recording apparatus 10, the switching valve 95M is in the first state.

  The switching valve 95Y is provided between the second connection portion 90 and the third connection portion 96Y. The switching valve 95Y is a solenoid valve. The switching valve 95Y switches between a first state in which the second connection flow path Y is opened and a second state in which the second connection flow path Y is closed. The first state is a state in which the switching valve 95Y is open, and the second state is a state in which the switching valve 95Y is closed. In the inkjet head 40 </ b> Y, the yellow ink may be clogged in the nozzle that discharges the yellow ink. In such a case, in the inkjet recording apparatus 10, maintenance processing is performed in which the storage chamber 33 of the sub tank 32Y is pressurized and the yellow ink is forcibly ejected. The switching valve 95Y is switched to the second state, for example, when the above-described maintenance process is performed by the inkjet recording apparatus 10. When the maintenance process is not performed and the recording process described later is performed by the inkjet recording apparatus 10, the switching valve 95Y is in the first state.

  The switching valve 95C is provided between the second connection portion 90 and the third connection portion 96C. The switching valve 95C is a solenoid valve. The switching valve 95C switches between a first state in which the second connection flow path C is opened and a second state in which the second connection flow path C is closed. The first state is a state in which the switching valve 95C is open, and the second state is a state in which the switching valve 95C is closed. In the ink jet head 40 </ b> C, the cyan ink may be clogged at the nozzle for ejecting the cyan ink. In such a case, in the inkjet recording apparatus 10, maintenance processing is performed in which the storage chamber 33 of the sub tank 32C is pressurized and the cyan ink is forcibly ejected. The switching valve 95C is switched to the second state, for example, when the above-described maintenance process is performed by the inkjet recording apparatus 10. When the maintenance process is not performed and the recording process described later is performed by the inkjet recording apparatus 10, the switching valve 95C is in the first state.

  The above-described maintenance process in the inkjet heads 40K, 40M, 40Y, and 40C may be performed at the same timing. In addition, the above-described maintenance process in the inkjet heads 40K, 40M, 40Y, and 40C may be performed periodically at a predetermined timing. In FIG. 1 and FIG. 2, the illustration of the pressurizing mechanism for pressurizing the storage chambers 33 of the sub tanks 32K, 32M, 32Y and 32C is omitted.

  The third connection portion 96K connects the switching valve 95K and the sub tank 32K. The third connection portion 96 </ b> K includes a third flow passage portion that forms a third portion of the second connection flow passage K. The third connection portion 96M connects the switching valve 95M and the sub tank 32M. The third connection portion 96M includes a third flow passage portion that forms a third portion of the second connection flow passage M. The third connection portion 96Y connects the switching valve 95Y and the sub tank 32Y. The third connection portion 96Y includes a third flow passage portion that forms a third portion of the second connection flow passage Y. The third connection portion 96C connects the switching valve 95C and the sub tank 32C. The third connection portion 96C includes a third flow passage portion that forms a third portion of the second connection flow passage C.

  The connection form of the storage chambers 33 of the inner chamber 85 and the sub-tanks 32K, 32M, 32Y, 32C communicated by the second connection flow paths K, M, Y, C is the same. The switching valves 95K, 95M, 95Y, 95C are the same solenoid valve. The third connection portions 96K, 96M, 96Y, 96C have the same configuration. In the embodiment, the connection form of the internal chamber 85 and the storage chambers 33 of the sub tanks 32K, 32M, 32Y and 32C will be described by taking the internal chamber 85 and the storage chamber 33 of the sub tank 32C as an example.

  As described above, when the second connection portion 90 is fixed to the buffer tank 84, the through hole 89 of the buffer tank 84 and the through hole 94 of the second connection portion 90 are continuous (see FIG. 2). That is, in the second connection flow path C, the first flow path portion by the through hole 89 and the second flow path portion by the through hole 94 communicate with each other. For example, an O-ring 97 is sandwiched between the opening edge of the through hole 89 of the buffer tank 84 and the opening edge of the through hole 94 of the second connection portion 90 (see FIG. 2). Thereby, the sealing at the boundary between the first flow passage portion by the through hole 89 and the second flow passage portion by the through hole 94 is secured. In FIG. 3, the O-ring 97 and the groove portion for accommodating the O-ring 97 are not shown.

  In the third connection portion 96C, the first end is fixed to the switching valve 95C, and the second end is fixed to the sub tank 32C. That is, in the second connection flow path C, when the switching valve 95C is in the first state, the third flow path portion and the second flow path portion communicate with each other on the first end side of the third connection portion 96C. . Furthermore, in the second connection channel C, the third channel portion communicates with the storage chamber 33 of the sub tank 32C on the side of the second end of the third connection portion 96C regardless of the state of the switching valve 95C. Fixing of the switching valve 95C and the third connecting portion 96C performed on the side of the first end and fixing of the sub tank 32C and the third connecting portion 96C performed on the side of the second end are performed, for example, via known joints. Be done. In FIGS. 1 to 3, the illustration of such a joint is omitted.

  The open valve 98 is an electromagnetic valve that opens and closes a fourth connection flow path by a through hole (not shown) passing through a wall portion forming the internal chamber 85. In the embodiment, the wall portion described above is a wall portion which is the first side in the main scanning direction, of the two wall portions opposed in the main scanning direction. The release valve 98 leads to the atmosphere on the opposite side of the internal chamber 85. That is, when the open valve 98 is in the first state, the internal chamber 85 of the buffer tank 84 is open to the atmosphere. When the open valve 98 is in the second state, the connection to the atmosphere is closed. In the first state, the open valve 98 is open, and in the second state, the open valve 98 is closed. Fixing of the release valve 98 to the buffer tank 84 has, for example, the same structure as fixing of the switching valves 95K, 95M, 95Y, 95C to the buffer tank 84. However, the open valve 98 may be fixed to the buffer tank 84 via a tubular member such as the third connection portions 96K, 96M, 96Y, 96C.

  The pressure sensor 99 measures the pressure in the internal chamber 85. The measured value measured by the pressure sensor 99 is input to the control unit 71. The control unit 71 acquires the measurement value measured by the pressure sensor 99. The control unit 71 adjusts the pressure of the internal chamber 85 in accordance with the measurement value. This adjustment is performed, for example, with the pressure of the internal chamber 85 as the pressure set value or the pressure of the internal chamber 85 within a predetermined range based on the pressure set value.

  In the pressure reducing portion 80, the buffer tank 84, the second connection portion 90, the switching valves 95K, 95M, 95Y, 95C, the third connection portions 96K, 96M, 96Y, 96C, the open valve 98, the pressure sensor 99 , Mounted on the carriage 50. That is, in the carriage 50, the inkjet heads 40K, 40M, 40Y, 40C and the buffer tank 84 which are respectively connected to the sub tanks 32K, 32M, 32Y, 32C by the first connection portions 35K, 35M, 35Y, 35C Mounted in a state of being connected by the second connection portion 90 fixed to the 84, the switching valves 95K, 95M, 95Y, 95C fixed to the second connection portion 90, and the third connection portions 96K, 96M, 96Y, 96C It is done. An open valve 98 and a pressure sensor 99 are also attached to the buffer tank 84 mounted on the carriage 50. Although the description is omitted in the above, the fixing of the second connection portion 90 to the buffer tank 84 and the fixing of the switching valves 95K, 95M, 95Y, 95C to the second connection portion 90 are performed by, for example, screws.

<Ink jet recording method>
In the inkjet recording apparatus 10, when an image is recorded on the recording medium 15, the inkjet recording method is executed. The inkjet recording method includes a recording step and a conveyance step. The transport process is a process of transporting the recording medium 15 by the transport unit 20. The recording step is a step of recording an image on the recording medium 15 conveyed by the conveyance unit 20. The inkjet recording method is controlled by the control unit 71. The inkjet recording method is started as follows. That is, the inkjet recording method is started at the timing when the start command of the recording of the image is input to the control device 70 and the control unit 71 acquires it. The control unit 71 that has acquired the start command controls the moving unit 60, the inkjet heads 40K, 40M, 40Y, and 40C, and the transport unit 20. Along with this, the recording process and the transport process are performed in an interlocked manner.

  In the recording step, in the moving unit 60, the motor 64 connected to the pulley 61 reciprocates clockwise and rotates counterclockwise. As the motor 64 rotates, the pulleys 61 reciprocate and rotate in the left and right directions. An arc-shaped arrow shown inside the pulley 61 in FIG. 1 indicates the rotation direction of the pulley 61. When the motor 61 rotates in the predetermined direction and the pulley 61 rotates counterclockwise, the timing belt 63 also rotates counterclockwise. The pulley 62 rotates following the timing belt 63 rotating leftward. Along with this, the carriage 50 moves from the second side to the first side in the main scanning direction. When the carriage 50 reaches the first moving end in the main scanning direction, the rotation direction of the motor 64 is reversed, and the pulley 61 rotates to the right. When the pulley 61 rotates to the right, the timing belt 63 also rotates to the right. The pulley 62 rotates following the timing belt 63 rotating right. Along with this, the carriage 50 moves from the first side to the second side in the main scanning direction. When the carriage 50 reaches the moving end on the second side in the main scanning direction, the rotation direction of the motor 64 is reversed again, and the pulley 61 rotates left again.

  In the recording process, ink of each color is ejected toward the recording medium 15 from the nozzles formed in the inkjet heads 40 K, 40 M, 40 Y, and 40 C, respectively. The ejection of the ink of each color is performed at a predetermined timing at which the carriage 50 is moving in the main scanning direction according to the operation of the moving unit 60 described above. Ink droplets of each color ink ejected from the nozzles of the inkjet heads 40 K, 40 M, 40 Y, and 40 C land on the recording surface 16 of the recording medium 15. An image is recorded on the recording surface 16 of the recording medium 15 by the ink droplets of each color that has landed. In the recording step, when the recording of the image is continued, the amount of ink stored in each storage chamber 33 of the sub tanks 32K, 32M, 32Y, 32C decreases. In this case, the ink of the reduced color is appropriately supplied from the main tanks 30K, 30M, 30Y and 30C to the sub tanks 32K, 32M, 32Y and 32C.

  The recording process is performed in a state in which the storage chambers 33 of the sub tanks 32K, 32M, 32Y, and 32C are adjusted to a predetermined negative pressure value. Adjustment of the pressure of the storage chamber 33 is realized by adjusting the pressure of the inner chamber 85 of the buffer tank 84 communicated with the storage chamber 33 as described above. The pressure of the internal chamber 85 is controlled by the control unit 71. That is, the control unit 71 outputs a control signal to predetermined units in accordance with the measurement value acquired from the pressure sensor 99 and the acquired pressure setting value.

  For example, it is assumed that the measurement value acquired from the pressure sensor 99 is higher than the upper limit value corresponding to the pressure setting value. The state where the measured value is higher than the upper limit value means the state where the measured value is closer to the atmospheric pressure than the upper limit value. In this case, the control unit 71 outputs a start signal to the vacuum pump 83, outputs an open signal to the suction valve 82 and the switching valves 95K, 95M, 95Y, 95C, and outputs a close signal to the open valve 98. The start signal is a control signal for starting the operation of the vacuum pump 83. The release signals output to the suction valve 82 and the switching valves 95K, 95M, 95Y, 95C are control signals for switching the suction valve 82 and the switching valves 95K, 95M, 95Y, 95C to the first state. The closing signal output to the release valve 98 is a control signal for switching the release valve 98 to the second state. The vacuum pump 83 starts driving in response to the start signal. The suction valve 82 is switched to the first state in response to the open signal, and the third flow path portion by the suction connection portion 81 is in the open state. The release valve 98 switches to the second state in response to the closing signal. The switching valves 95K, 95M, 95Y, 95C are switched to the first state, or the first state is maintained. At this timing, when the switching valves 95K, 95M, 95Y and 95C are in the first state, the output of the open signal to the switching valves 95K, 95M, 95Y and 95C may be omitted. Along with this, the air in the internal chamber 85 is sucked by the vacuum pump 83, and the pressure in the internal chamber 85 decreases.

  It is assumed that the air in the internal chamber 85 is sucked, and the measured value obtained from the pressure sensor 99 becomes the lower limit value according to the pressure setting value. In this case, the control unit 71 outputs a stop signal to the vacuum pump 83 and outputs a closing signal to the suction valve 82. The stop signal is a control signal for stopping the operation of the vacuum pump 83. The closing signal output to the suction valve 82 is a control signal for switching the suction valve 82 to the second state. The vacuum pump 83 stops driving in response to the stop signal. The suction valve 82 switches to the second state in response to the closing signal, and the third flow path portion by the suction connection portion 81 is in the closed state. Along with this, the suction of air from the internal chamber 85 is stopped. In the switching valves 95K, 95M, 95Y, 95C, the first state is continued.

  It is assumed that the air in the internal chamber 85 is sucked, and the measured value obtained from the pressure sensor 99 becomes lower than the lower limit value corresponding to the pressure setting value. The state where the measured value is lower than the lower limit value means that the lower limit value is closer to the atmospheric pressure than the measured value. In this case, the control unit 71 outputs a stop signal to the vacuum pump 83, outputs a close signal to the suction valve 82, and outputs an open signal to the open valve 98. The release signal output to the release valve 98 is a control signal for switching the release valve 98 to the first state. The vacuum pump 83 stops driving as described above, and the suction valve 82 also switches to the second state. The release valve 98 switches to the first state in response to the release signal, and the internal chamber 85 is released to the atmosphere. Along with this, air flows into the inner chamber 85, and the pressure in the inner chamber 85 increases. In the switching valves 95K, 95M, 95Y, 95C, the first state is continued.

  The control unit 71 repeatedly executes the control described above. By such control, the pressure of the internal chamber 85 is adjusted to a predetermined range based on the pressure setting value acquired from the pressure input unit 72. In other words, the pressure of the storage chamber 33 is adjusted to a predetermined range based on the pressure setting value acquired from the pressure input unit 72.

  It is assumed that the above-described maintenance process is performed on all or part of the inkjet heads 40K, 40M, 40Y, and 40C. In this case, the control unit 71 outputs a closing signal to the switching valve corresponding to the inkjet head that is the target of the maintenance process among the switching valves 95K, 95M, 95Y, and 95C. For example, when all the inkjet heads 40K, 40M, 40Y, and 40C are targets of the maintenance process, the control unit 71 outputs closing signals to the switching valves 95K, 95M, 95Y, and 95C, respectively. The closing signals output to the switching valves 95K, 95M, 95Y, 95C are control signals for switching the switching valves 95K, 95M, 95Y, 95C to the second state. The switching valves 95K, 95M, 95Y, 95C switch to the second state in response to the closing signal, and the second connection flow paths K, M, Y, C are in the closed state. At this time, the supply valves 34K, 34M, 34Y, 34C are brought into the second state.

  In the transport process, the transport unit 20 transports the recording medium 15 in the transport direction in response to the reciprocation of the carriage 50 in the main scanning direction described above. That is, the conveyance of the recording medium 15 by the conveyance unit 20 is intermittently performed according to the reciprocating movement of the carriage 50 in the main scanning direction. The moving unit 60 operates until the recording of the image is completed. Therefore, the reciprocating movement of the carriage 50 in the main scanning direction is repeated until the recording of the image is completed. For example, after the recording of the image is completed, the conveyance unit 20 stops at a predetermined timing. Along with the stop of the transport unit 20, the transport of the recording medium 15 in the transport direction also ends. The inkjet recording method ends with the stop of the transport unit 20.

<Effect of the embodiment>
According to the embodiment, the following effects can be obtained.

  (1) In the inkjet recording apparatus 10, the inkjet heads 40K, 40M, 40Y, and 40C and the buffer tank 84 are mounted on the carriage 50. In the carriage 50, the inkjet heads 40K, 40M, 40Y, and 40C are connected to the subtanks 32K, 32M, 32Y, and 32C, respectively, by first connection portions 35K, 35M, 35Y, and 35C. In the carriage 50, the inkjet heads 40K, 40M, 40Y and 40C and the buffer tank 84 are connected by the second connection portion 90, the switching valves 95K, 95M, 95Y and 95C, and the third connection portions 96K, 96M, 96Y and 96C. Be done.

  Therefore, the second connection flow path K, M, Y, C which brings the storage chambers 33 of the sub-tanks 32K, 32M, 32Y, 32C and the internal chamber 85 of the buffer tank 84 into communication with each other It can be shortened compared to the device. The pressure in each storage chamber 33 of the sub tanks 32K, 32M, 32Y, 32C can be maintained constant at a predetermined negative pressure value. The responsiveness to pressure fluctuations of the storage chambers 33 of the sub tanks 32K, 32M, 32Y, 32C can be improved.

  (2) The second connection portion 90 is formed of a metal material having a thermal conductivity higher than that of the resin material forming the buffer tank 84. Solenoid valves are employed as the switching valves 95K, 95M, 95Y, 95C. The switching valves 95K, 95M, 95Y, 95C, which are solenoid valves, may generate heat. When the switching valves 95K, 95M, 95Y, 95C generate heat, the heat generated by the switching valves 95K, 95M, 95Y, 95C is transmitted to the second connection portion 90. Therefore, the switching valves 95K, 95M, 95Y, 95C can be cooled. It can suppress that the heat transmitted to the second connection portion 90 is transmitted to the buffer tank 84. For example, expansion of the buffer tank 84 due to heat can be suppressed. The buffer tank 84 can be reduced in weight. The inertial force acting on the carriage 50 reciprocating in the main scanning direction by the moving unit 60 can be reduced.

<Modification>
Embodiments can also be as follows. Several configurations of the modifications shown below can be combined appropriately and adopted. In the following, different points from the above will be described, and the description of the same points will be appropriately omitted.

  (1) In the above, the second connection portion 90 is formed of a block-shaped member. Four through holes 91, 92, 93, 94 are formed in the block-like member to be the second connection portion 90. The second connection between the buffer tank 84 and the switching valve 95K may be formed by a tubular member such as the third connection 96K. The tubular second connection portion includes a second flow passage portion which is a second portion of the second connection flow passage K. The second connection between the buffer tank 84 and the switching valve 95M may be formed by a tubular member such as the third connection 96M. The tubular second connection portion includes a second flow passage portion which is a second portion of the second connection flow passage M. The second connection between the buffer tank 84 and the switching valve 95Y may be formed by a tubular member such as the third connection 96Y. The tubular second connection portion includes a second flow passage portion which is a second portion of the second connection flow passage Y. The second connection between the buffer tank 84 and the switching valve 95C may be formed by a tubular member such as the third connection 96C. The tubular second connection portion includes a second flow passage portion which is a second portion of the second connection flow passage C.

  (2) In the above, the buffer tank 84 is formed of a resin material. The buffer tank may be made of, for example, a material having a high thermal conductivity such as aluminum. It is assumed that the heat from the second connection portion 90 is transferred to the buffer tank. In this case, this heat can be dissipated smoothly from the buffer tank. By using an aluminum buffer tank, the weight of the buffer tank can be reduced.

  (3) In the above, the case where the inkjet recording apparatus 10 is a serial type has been described as an example (see FIG. 1). In the inkjet recording apparatus 10, as described above, the moving unit 60 reciprocates the carriage 50 in the main scanning direction and discharges the ink to record an image on the recording medium 15. The above-mentioned structure (see FIG. 2) in which the inkjet head for each color and the buffer tank are mounted on the carriage and the second connection portion, the switching valve for each color, and the third connection portion for each color are connected (line type) The present invention is also applicable to an inkjet recording apparatus provided with the inkjet head of The line-type inkjet head is mounted on the carriage in a state where the plurality of nozzles are aligned in the main scanning direction that coincides with the short direction of the recording medium 15. The range in the main scanning direction in which the nozzles are aligned is, for example, the width of the recording medium 15 or more. The ink jet heads for the respective colors are mounted on the carriage in a state of being adjacent in the sub scanning direction. The buffer tank is mounted on the carriage on which the ink jet heads for the respective colors are mounted. The ink jet head and buffer tank for each color mounted on the carriage and connected to the sub tanks for each color by the first connection for each color, the second connection, the switching valve for each color, and the third for each color Connected by connection.

DESCRIPTION OF SYMBOLS 10 inkjet recording device, 15 recording medium, 16 recording surface 20 conveyance part, 30K, 30M, 30Y, 30C main tank 31K, 31M, 31Y, 31C supply connection part 32K, 32M, 32Y, 32C Sub tank, 33 storage chamber 34K, 34M , 34Y, 34C Supply valve 35K, 35M, 35Y, 35C First connection 40K, 40M, 40Y, 40C Inkjet head 50 Carriage, 51 Support, 60 Movement, 61, 62 Pulley 63 Timing Belt, 64 Motor, 70 Control Apparatus, 71 control unit 72 pressure input unit, 80 pressure reducing unit, 81 suction connection unit, 82 suction valve 83 vacuum pump, 84 buffer tank, 85 internal chamber 86, 87, 88, 89 through hole, 90 second connection unit 91, 92, 93, 94 through holes, 95K, 95M, 95Y, 95C switching valve 96K, 96M, 96Y, 96C third connection, 97 O ring, 98 open valve 99 pressure sensor

Claims (4)

An inkjet head provided with a nozzle for ejecting ink;
An ink tank in which a storage chamber for storing the ink supplied to the inkjet head is formed;
A first connection portion including a first connection flow path through which the ink supplied from the ink tank to the inkjet head flows and which brings the storage chamber and the inkjet head into communication with each other;
An internal chamber formed inside by a vacuum pump is set to a negative pressure reduced from atmospheric pressure, and forms a first portion of a second connection flow path for connecting the internal chamber and the storage chamber, and forms the internal chamber A buffer tank including a first flow passage portion formed by a through hole penetrating the wall portion;
A second connection portion including a second flow passage portion forming a second portion of the second connection flow passage, which communicates with the first flow passage portion;
A switching valve that switches between a first state in which the second connection flow path is opened and a second state in which the second connection flow path is closed;
When the switching valve is in the first state, the storage chamber communicates with the second flow passage on the side of the first end, and on the side of the second end opposite to the first end. A third connection portion including a third flow passage portion forming a third portion of the second connection flow passage, which communicates with each other;
The ink jet head connected to the ink tank by the first connection portion, and the buffer tank are mounted in a state of being connected by the second connection portion, the switching valve, and the third connection portion. An inkjet recording apparatus comprising: The second connection portion is
It is formed of a block-like member in which a through hole which becomes the second flow path portion is formed,
The first flow path portion and the second flow path portion are fixed in a continuous state on the wall portion of the buffer tank in which a through hole which is the first flow path portion is formed,
The switching valve is fixed to the second connection portion,
The ink jet head connected to the ink tank by the first connection portion, the second connection portion in which the buffer tank is fixed to the buffer tank, and the second connection portion are fixed to the carriage. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is mounted in a state of being connected by the switched valve and the third connection portion.   The ink jet recording apparatus according to claim 2, wherein the second connection portion is formed of a second material having a thermal conductivity higher than that of the first material forming the buffer tank. The buffer tank is formed of a resin material.
The inkjet recording apparatus according to claim 3, wherein the second connection portion is formed of a metal material.

Images