Liquid injection device

Abstract

To provide a liquid jet device which can reduce the sizes of a first flow channel member and a second flow channel member.SOLUTION: A liquid jet device includes a liquid jet head which includes one of a first flow channel member and a second flow channel member and jets a liquid, and a flow channel structure including the other of the first flow channel member and the second flow channel member, wherein the first flow channel member has a base part and a first flow channel pipe that has a flow channel through which liquid flows formed therein and projects in an insertion direction from the base part, the second flow channel member has a connection surface having a first opening to which the first flow channel pipe is inserted and a first guide part arranged in a direction opposite to the insertion direction with respect to the connection surface, the first flow channel pipe includes a first insertion part inserted to the first opening, and a first guided part which is guided to the first guide part before the first insertion part is inserted to the first opening in connection operation, and the first guided part is arranged between the first insertion part and the base part.SELECTED DRAWING: Figure 10

Description

Technical Field

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[0001] The present disclosure relates to the technology of liquid injection devices.

Background Art

[0002] Conventionally, a liquid discharge device including a liquid supply member having a liquid supply path for supplying a liquid and a positioning pin, and a liquid discharge head having an opening into which the liquid supply path is inserted and a positioning opening into which the positioning pin is inserted is known (Patent Document 1). In this technology, the length of the positioning pin is longer than the length of the liquid supply path. Thus, after the positioning pin is inserted into the positioning opening to position the liquid supply member and the liquid discharge head, the liquid supply path is inserted into the opening.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional technology, in order to position the liquid supply member and the liquid discharge head, a positioning pin is provided at a position different from the liquid supply path. Therefore, there is a risk that the liquid supply member may be enlarged in a direction perpendicular to the insertion / removal direction of the liquid supply path with respect to the opening. Further, in the conventional technology, in order to insert the positioning pin into the positioning opening before inserting the liquid supply path into the opening, it is necessary to make the length of the positioning pin longer than the length of the liquid supply path. Thus, there is also a risk that the liquid supply member may be enlarged in the insertion / removal direction of the liquid supply path with respect to the opening.

Means for Solving the Problems

[0005] (1) According to a first embodiment of the present disclosure, a liquid injection device is provided. The liquid injection device comprises a liquid injection head that includes one of a first flow path member and a second flow path member and injects a liquid, and a flow path structure that includes the other of the first flow path member and the second flow path member, wherein the liquid injection device is capable of a connection operation to connect the first flow path member to the second flow path member by moving the first flow path member relative to the second flow path member in the insertion direction, the first flow path member having a base portion and a first flow path pipe having a flow path formed therein through which liquid flows and protruding from the base portion in the insertion direction, the second flow path member having a connection surface having a first opening into which the first flow path pipe is inserted, and a first guide portion arranged in the opposite direction to the insertion direction with respect to the connection surface, the first flow path pipe including a first insertion portion that is inserted into the first opening, and a first guided portion that is guided by the first guide portion before the first insertion portion is inserted into the first opening in the connection operation, the first guided portion being arranged between the first insertion portion and the base portion.

[0006] (2) A liquid injection device is provided according to a second embodiment of the present disclosure. The liquid injection device comprises a liquid injection head that includes one of a first flow channel member and a second flow channel member and injects a liquid, and a flow channel structure that includes the other of the first flow channel member and the second flow channel member, wherein the liquid injection device is capable of a connection operation that connects the first flow channel member to the second flow channel member by moving the first flow channel member relative to the second flow channel member in the insertion direction, the first flow channel member having a base portion and a first flow channel pipe having a flow channel formed inside through which liquid flows and protruding from the base portion in the insertion direction, and the second flow channel member is the The first flow channel has a connecting surface having a first opening into which a flow channel tube is inserted, and a first guide portion arranged in the opposite direction to the insertion direction with respect to the connecting surface, wherein the first flow channel tube includes a first insertion portion inserted into the first opening and a first guided portion arranged between the first insertion portion and the base portion, and the distance in the insertion direction from the end of the first guide portion in the opposite direction to the insertion direction to the connecting surface is greater than the distance in the insertion direction from the connection portion between the first insertion portion and the first guided portion to the end of the first insertion portion in the insertion direction. [Brief explanation of the drawing]

[0007] [Figure 1] A schematic diagram showing a liquid injection device in the first embodiment. [Figure 2] An exploded perspective view showing part of the flow channel structure and liquid injection head configuration. [Figure 3] Exploded perspective view of the liquid spray head. [Figure 4] A view of the flow path connecting member from the third outer surface. [Figure 5] A view of the flow path connecting member in the connected state, seen from the third outer surface. [Figure 6] A diagram showing the internal structure of the flow channel connecting member. [Figure 7] This figure shows the internal structure of the flow path connecting member and the second flow path member in the connected state. [Figure 8] A view of the flow path connecting member from the second outer surface. [Figure 9]View of the flow path connection member in the connected state as seen from the second outer surface side. [Figure 10] First diagram showing the first flow path member and the second flow path member during the connection operation. [Figure 11] Diagram showing the first flow path member and the second flow path member after the connection operation is completed. [Figure 12] Second diagram showing the first flow path member and the second flow path member during the connection operation. [Figure 13] Diagram showing the cross-sectional shapes of the opening and the guide portion in the first embodiment. [Figure 14] Diagram for explaining the connection mode between the guide portion and the guided portion in the first embodiment. [Figure 15] Diagram for explaining an example of the mode of preventing misinsertion in the first embodiment. [Figure 16] Table summarizing the mode of preventing misinsertion in the first embodiment. [Figure 17] Diagram showing the configuration of the first flow path member and the second flow path member in the second embodiment. [Figure 18] Diagram showing the configuration of the first flow path member and the second flow path member in the third embodiment. [Figure 19] Diagram showing the cross-sectional shapes of the first guided portion and the first insertion portion in the third embodiment. [Figure 20] Diagram showing the configuration of the first flow path member and the second flow path member in the fourth embodiment. [Figure 21] Diagram for explaining the cross-sectional shapes of the opening and the guide portion in the fifth embodiment. [Figure 22] Diagram for explaining the connection mode between the guide portion and the guided portion in the fifth embodiment. [Figure 23] Diagram for explaining an example of the mode of preventing misinsertion in the fifth embodiment. [Figure 24] Table summarizing the mode of preventing misinsertion in the fifth embodiment.

Mode for Carrying Out the Invention

[0008] A. First Embodiment: FIG. 1 is a schematic diagram showing a liquid ejection device 1 according to the first embodiment. The liquid ejection device 1 is an inkjet printing device that ejects ink, which is an example of a liquid, as droplets onto a medium PA. The liquid ejection device 1 of the present embodiment is a so-called line type printing device in which a plurality of nozzles NZ for ejecting ink are distributed over the entire range in the width direction of the medium PA. The medium PA is typically printing paper. Note that the medium PA is not limited to printing paper, and may be a printing target of any material such as a resin film or fabric, for example.

[0009] The liquid ejection device 1 includes a control unit 3, a medium conveyance mechanism 4, a supply circulation mechanism 5, and a liquid ejection head 20.

[0010] The control unit 3 controls the operations of each element of the liquid ejection device 1. The control unit 3 includes, for example, a processing circuit such as a CPU or an FPGA, and a storage circuit such as a semiconductor memory. Various programs and various data are stored in the storage circuit. The processing circuit realizes various controls by executing various programs and appropriately using various data. The CPU is an abbreviation for Central Processing Unit. The FPGA is an abbreviation for Field Programmable Gate Array.

[0011] The medium conveyance mechanism 4 is controlled by the control unit 3 and conveys the medium PA in the conveyance direction DM. The medium conveyance mechanism 4 includes a long conveyance roller along the width direction of the medium PA and a motor for rotating the conveyance roller. Note that the medium conveyance mechanism 4 is not limited to a configuration using a conveyance roller, and may be a configuration using a drum or an endless belt that conveys the medium PA in a state where it is adsorbed to the outer peripheral surface by an electrostatic force or the like, for example.

[0012] The supply circulation mechanism 5 is a mechanism for supplying liquid to the liquid ejection head 20 and collecting the liquid from the liquid ejection head 20. The supply circulation mechanism 5 includes a main tank 51, a recovery side sub-tank 53, a supply side sub-tank 52, a first intermediate flow path 54, a second intermediate flow path 55, a first pump 58, a second pump 59, and a flow path structure 50.

[0013] The main tank 51 stores ink as a liquid. The main tank 51 is, for example, an ink cartridge that can be attached to and detached from the liquid injection device 1, a bag-shaped ink pack made of a flexible film, or an ink tank that can be refilled with ink. The type of liquid stored in the main tank 51 is arbitrary. In this embodiment, the liquid injection device 1 is equipped with multiple main tanks 51 according to the type of ink. Specifically, the liquid injection device 1 is equipped with a main tank 51 for storing cyan ink, a main tank 51 for storing magenta ink, a main tank 51 for storing yellow ink, and a main tank 51 for storing black ink. Although there are multiple components such as the main tanks 51 in the supply circulation mechanism 5 according to the number of main tanks 51, Figure 1 shows only representative components of the supply circulation mechanism 5 corresponding to one main tank 51.

[0014] The recovery-side sub-tank 53 recovers the liquid discharged from the injection section 10 of the liquid injection head 20 via a flow path connecting member 60 provided on the liquid injection head 20 and a recovery flow path 57 provided on the flow path structure 50. The recovery-side sub-tank 53 stores the recovered liquid. The recovery-side sub-tank 53 is also connected to the main tank 51 via a first intermediate flow path 54. Driven by the first pump 58, the liquid from the main tank 51 is supplied to the recovery-side sub-tank 53 via the first intermediate flow path 54. The recovery-side sub-tank 53 is also connected to the supply-side sub-tank 52 via a second intermediate flow path 55. Driven by the second pump 59, the liquid from the recovery-side sub-tank 53 is supplied to the supply-side sub-tank 52 via the second intermediate flow path 55. The main tank 51 may be connected to the supply-side sub-tank 52 instead of the recovery-side sub-tank 53.

[0015] The supply-side sub-tank 52 supplies liquid to the flow path connecting member 60 via a supply flow path 56 provided in the flow path structure 50. The first intermediate flow path 54, the second intermediate flow path 55, the supply flow path 56, and the recovery flow path 57 (described later) are, for example, tubes through which the liquid flows. The first intermediate flow path 54, the second intermediate flow path 55, the supply flow path 56, and the recovery flow path 57 only need to be able to allow the liquid to flow, and may be, for example, structures with grooves or recesses formed therein through which the liquid flows. The first pump 58 and the second pump 59 are driven by commands from the control unit 3.

[0016] Figure 2 is an exploded perspective view showing part of the configuration of the flow channel structure 50 and the liquid injection head 20. Figure 2 depicts three mutually orthogonal spatial axes, the X, Y, and Z axes. The arrows on the X, Y, and Z axes point in the positive directions along the X, Y, and Z axes, respectively. These positive directions along the X, Y, and Z axes are designated as the X1, Y1, and Z1 directions, respectively. The directions opposite to those pointed to by the X, Y, and Z axes are the negative directions along the X, Y, and Z axes, respectively. These negative directions along the X, Y, and Z axes are designated as the X2, Y2, and Z2 directions, respectively. Directions along the X, Y, and Z axes that are not positive or negative are called the X, Y, and Z directions, respectively. The same applies to the figures and explanations shown hereafter. In this embodiment, the X1 direction is the direction of gravity.

[0017] The flow channel structure 50 includes a supply channel 56, a recovery channel 57, and a first flow channel member 7. The supply channel 56 connects the supply-side sub-tank 52 and the first flow channel member 7. The recovery channel 57 connects the recovery-side sub-tank 53 and the first flow channel member 7. The supply channel 56 and the recovery channel 57 are provided separately for each type of ink.

[0018] As shown in Figure 2, in this embodiment, the flow path structure 50 is provided with a plurality of supply flow paths 56 and a plurality of recovery flow paths 57. Specifically, the flow path structure 50 includes four supply flow paths 56 and four recovery flow paths 57. Each of the four supply flow paths 56 is a flow path for supplying cyan, magenta, yellow, or black ink from the supply-side sub-tank 52 to the liquid spray head 20. Each of the four recovery flow paths 57 is a flow path for flowing cyan, magenta, yellow, or black ink from the liquid spray head 20 to the recovery-side sub-tank 53.

[0019] The first flow path member 7 shown in Figure 2 is a flow path member that connects the liquid storage tanks 51-53 shown in Figure 1 with the liquid injection head 20. As shown in Figure 2, the liquid injection device 1 is configured to allow a connection operation in which the first flow path member 7 is connected to the second flow path member 8 by moving the first flow path member 7 relative to the second flow path member 8 in the insertion direction DI. In this embodiment, the insertion direction DI is the Z1 direction. This connection operation connects the liquid storage tanks 51-53 shown in Figure 1 with the liquid injection head 20. In other words, as shown in Figure 2, the second flow path member 8 is a flow path member that is paired with the first flow path member 7 and connects the liquid storage tanks 51-53 with the liquid injection head 20. In this embodiment, the first flow path member 7 is provided in the flow path structure 50, and the second flow path member 8 is provided in the flow path connecting member 60. Details of the second flow path member 8 will be described later.

[0020] As shown in Figure 2, the first flow channel member 7 has a base portion 70 and one or more flow channel tubes 71 to 78 that protrude in the insertion direction DI from the opposing surface 70b of the base portion 70 that faces the second flow channel member 8 during connection operation. In this embodiment, the first flow channel member 7 has a plurality of flow channel tubes 71 to 78. The plurality of flow channel tubes 71 to 78 have internal flow channels 718 to 788 through which liquid flows. A plurality of supply channels 56 and a plurality of recovery channels 57 according to the type of ink are connected to the internal flow channels 718 to 788 of the corresponding flow channel tubes 71 to 78.

[0021] As shown in Figure 2, in this embodiment, the multiple flow channels 71-78 are the first flow channel 71, the second flow channel 72, the third flow channel 73, the fourth flow channel 74, the fifth flow channel 75, the sixth flow channel 76, the seventh flow channel 77, and the eighth flow channel 78. Each of the four flow channels among the multiple flow channels 71-78 (hereinafter sometimes referred to as recovery flow channels) communicates with the multiple inter-member flow channels 190 described later, which are provided in the second flow channel member 8 on the insertion direction DI side, and communicates with one of the four recovery flow channels 57 on the side opposite to the insertion direction DI. In other words, each of the internal flow channels formed inside the four recovery flow channels causes one of the cyan, magenta, yellow, or black inks recovered from the spray section 10 of the liquid spray head 20 to flow into one of the four recovery flow channels 57. Furthermore, of the multiple flow channels 71-78, each of the four flow channels (hereinafter sometimes referred to as supply flow channels) that are different from the four flow channels mentioned above is connected to one of the multiple inter-member flow channels 190 described later, which are provided in the second flow channel member 8 on the insertion direction DI side, and is connected to one of the four supply flow channels 56 on the side opposite to the insertion direction DI. In other words, each of the internal flow channels formed inside the four supply flow channels causes one of the cyan, magenta, yellow, or black inks supplied from the supply flow channel 56 to flow towards the liquid spray head 20. In other embodiments, the flow channels 71-78 may be flow channel needles with flow channels formed inside through which liquid flows.

[0022] Figure 3 is an exploded perspective view of the liquid injection head 20. The liquid injection head 20 includes a support member 22, an injection section 10, a common flow path member 30 communicating with the injection section 10, and a flow path connecting member 60 communicating with the common flow path member 30.

[0023] The support member 22 supports the injection unit 10 and the common flow path member 30. Most of the injection unit 10 is housed within the support member 22. The portion of the injection unit 10 in the X1 direction, including the injection surface F1, is located outside the support member 22. The injection surface F1 is exposed to the outside. The common flow path member 30 is housed within the support member 22. The support member 22 includes a frame portion 23. The frame portion 23 has a rectangular shape when viewed in the X-axis direction. The frame portion 23 has side walls 24-27.

[0024] As shown in Figure 3, the injection unit 10 has a plurality of terminal connecting pipes 160 protruding toward the common flow channel member 30, a plurality of internal head flow channels (not shown), and a nozzle NZ as shown in Figure 1. Each of the plurality of terminal connecting pipes 160 communicates with a corresponding internal head flow channel. The plurality of internal head flow channels also communicate with a corresponding nozzle NZ. The nozzle NZ injects the liquid supplied from the common flow channel member 30 shown in Figure 3. As shown in Figure 1, the liquid injected from the nozzle NZ lands on the medium PA. As shown in Figure 3, the injection units 10 are arranged in a direction intersecting the transport direction DM to form a line head 100.

[0025] The injection unit 10 further includes a connector 19. An electrical path for electrically connecting to the control unit 3 shown in Figure 1 is connected to the connector 19. As a result, the injection unit 10 is controlled by the control unit 3.

[0026] As shown in Figure 3, the common flow path member 30 connects the flow path connecting member 60 and the injection unit 10. The common flow path member 30 is formed by stacking a first common flow path substrate 31 and a second common flow path substrate 32 in the X-axis direction. The first common flow path substrate 31 is located on the injection unit 10 side. The second common flow path substrate 32 is located on the flow path connecting member 60 side. The second common flow path substrate 32 has one or more substrate-side connecting pipes 35 that protrude towards the flow path connecting member 60 side. The substrate-side connecting pipes 35 are provided for each type of ink and the application of the ink. The application of the ink here refers to whether the ink is, for example, supply-side ink supplied to the injection unit 10 for printing by spraying ink onto a medium PA, or recovery-side ink discharged from the injection unit 10 and recovered. In this embodiment, the common flow path member 30 has a plurality of substrate-side connecting pipes 35. The substrate-side connecting pipes 35 are connected to the flow path connecting member 60.

[0027] As shown in Figure 3, the common flow channel member 30 further has a plurality of internal flow channels 33 that communicate with each of the plurality of substrate-side connecting pipes 35. The internal flow channels 33 are flow channels formed inside the common flow channel member 30 by stacking a first common flow channel substrate 31 and a second common flow channel substrate 32. The internal flow channels 33 are formed, for example, by a groove formed in the first common flow channel substrate 31 and the second common flow channel substrate 32 that closes this groove. Some of the plurality of internal flow channels 33 are flow channels that supply liquid supplied from the flow channel connecting member 60 to the injection unit 10. The remaining internal flow channels 33 are flow channels that allow liquid from the injection unit 10 to flow into the flow channel connecting member 60. The first common flow channel substrate 31 of the common flow channel member 30 further has a plurality of common connection parts on the surface facing the injection unit 10 that are connected to a plurality of end-side connecting pipes 160 of the injection unit 10. Each of the plurality of common connection parts communicates with the corresponding internal flow channel 33.

[0028] As shown in Figure 2, each of the multiple substrate-side connecting pipes 35 of the common flow channel member 30 is connected to the receiving flow channel member 9 of the flow channel connecting member 60. This allows the internal flow channel 33 and the inter-member flow channel 190 to communicate. The common flow channel member 30 in this embodiment has eight substrate-side connecting pipes 35. Each of the four substrate-side connecting pipes 35 forms a flow channel for recovering cyan, magenta, yellow, or black ink from the injection unit 10. The remaining four substrate-side connecting pipes 35 each form a flow channel for supplying cyan, magenta, yellow, or black ink to the injection unit 10.

[0029] As shown in Figure 2, the flow path connecting member 60 is a member for connecting the liquid injection head 20 to the flow path structure 50. In other words, the flow path connecting member 60 is a member for connecting the common flow path member 30 and the flow path structure 50. In this embodiment, the shape of the flow path connecting member 60 is a plate shape with the smallest dimension in the Y direction. The flow path connecting member 60 is fixed to the common flow path member 30 by screws 98 and 99. The flow path connecting member 60 is provided with through holes 68 and 69 for inserting the screws 98 and 99.

[0030] As shown in Figure 2, the outer shape of the flow channel connecting member 60 is formed by a first outer surface fa1, a second outer surface fa2, a third outer surface fa3, a fourth outer surface fa4, a fifth outer surface fa5, and a sixth outer surface fa6. In this embodiment, the first outer surface fa1 forms the outer surface of the flow channel connecting member 60 on the X1 direction side. The second outer surface fa2 forms the outer surface of the flow channel connecting member 60 on the Z2 direction side. The third outer surface fa3 forms the outer surface of the flow channel connecting member 60 on the Y1 direction side. The fourth outer surface fa4 forms the outer surface of the flow channel connecting member 60 on the Y2 direction side. The fifth outer surface fa5 forms the outer surface of the flow channel connecting member 60 on the X2 direction side. The sixth outer surface fa6 forms the outer surface of the flow channel connecting member 60 on the Z1 direction side. Therefore, the first outer surface fa1 and the fifth outer surface fa5 face each other in the X direction. The third outer surface fa3 and the fourth outer surface fa4 face each other in the Y direction. The second outer surface fa2 and the sixth outer surface fa6 face each other in the Z direction. The first outer surface fa1 and the fifth outer surface fa5 intersect with the third outer surface fa3 and the fourth outer surface fa4, respectively. The third outer surface fa3 and the fourth outer surface fa4 intersect with the second outer surface fa2 and the sixth outer surface fa6, respectively. Note that the outer surfaces fa1 to fa6 of the flow path connecting member 60 are not limited to flat surfaces, but may also be surfaces with irregularities or curved surfaces. In this embodiment, the outer surfaces fa1 to fa6 intersect at orthogonal angles, but are not limited to this, and may intersect at an angle of 80° or more and less than 90°, for example.

[0031] Figure 4 is a view of the flow path connecting member 60 from the third outer surface fa3 side. Figure 5 is a view of the flow path connecting member 60 from the third outer surface fa3 side in the connected state, with the first flow path member 7 connected to the second flow path member 8. Note that, in order to avoid making the diagram complicated, in Figure 5, the flow path pipes 73 to 78 of the flow path pipes 71 to 78 of the second flow path member 8 are omitted from the illustration, and only the first flow path pipe 71 and the second flow path pipe 72 are shown. Figure 6 is a diagram showing the internal structure of the flow path connecting member 60. Figure 6 is a cross-sectional perspective view of the flow path connecting member 60 shown in Figure 4 when cut in the XZ plane, viewed from the Y1 direction side. Figure 7 is a diagram showing the internal structure of the flow path connecting member 60 and the second flow path member 8 in the connected state. Figure 7 is a cross-sectional perspective view of the flow path connecting member 60 and the second flow path member 8 shown in Figure 5 when cut in the XZ plane, viewed from the Y1 direction side.

[0032] As shown in Figures 6 and 7, the flow path connecting member 60 comprises a plurality of inter-member flow paths 190 that connect the common flow path member 30 and the flow path structure 50, a receiving flow path member 9 provided at one end of the inter-member flow path 190, and a second flow path member 8 provided at the other end of the inter-member flow path 190. In this embodiment, the receiving flow path member 9 is formed on the first outer surface fa1 of the flow path connecting member 60, as shown in Figure 4. The second flow path member 8 is formed on the second outer surface fa2.

[0033] In this embodiment, as shown in Figure 7, the flow path connecting member 60 has eight inter-member flow paths 190. Each of the multiple inter-member flow paths 190 connects the first to eighth flow path pipes 71 to 78 of the second flow path member 8, which is provided in the flow path structure 50 shown in Figure 2, to each of the multiple substrate-side connecting pipes 35 of the common flow path member 30. In other words, each of the four inter-member flow paths 190 of the eight inter-member flow paths 190 allows one of the cyan, magenta, yellow, or black inks recovered from the spray section 10 of the liquid spray head 20 to flow into one of the four recovery flow path pipes. The remaining four inter-member flow paths 190 allow one of the cyan, magenta, yellow, or black inks supplied from the four supply flow path pipes to flow towards the spray section 10.

[0034] The receiving channel member 9 has multiple receiving openings 93 into which each of the multiple substrate-side connecting pipes 35 shown in Figure 2 is inserted. The multiple receiving openings 93 are formed at positions corresponding to each of the multiple substrate-side connecting pipes 35 provided in the common channel member 30. In this embodiment, as shown in Figure 2, the multiple substrate-side connecting pipes 35 are arranged in a single row along the Z direction. Therefore, the multiple receiving openings 93 are arranged in a single row along the Z direction, as shown in Figures 6 and 7. The channel connection member 60 in this embodiment has eight multiple receiving openings 93. As shown in Figure 7, each of the multiple receiving openings 93 forms one end of each of the multiple inter-member channel 190. As a result, as shown in Figure 2, the internal channel 33 of the common channel member 30 and the inter-member channel 190 of the channel connection member 60 are in communication.

[0035] Figure 8 is a view of the flow path connecting member 60 from the second outer surface fa2 side. Figure 9 is a view of the flow path connecting member 60 from the second outer surface fa2 side in the connected state where the first flow path member 7 is connected to the second flow path member 8. Note that in Figure 9, the base portion 70 is shown by a dotted line. Figure 10 is the first figure showing the first flow path member 7 and the second flow path member 8 during the connection operation of the first flow path member 7 to the second flow path member 8. In Figure 10, a part of the 11-11 cross section of Figure 9 is schematically illustrated. Figure 11 is a figure showing the first flow path member 7 and the second flow path member 8 after the connection operation is completed, that is, in the connected state where the first flow path member 7 is connected to the second flow path member 8. Figure 12 is the second figure showing the first flow path member 7 and the second flow path member 8 during the connection operation of the first flow path member 7 to the second flow path member 8. In Figure 12, a part of the 13-13 cross section of Figure 9 is schematically illustrated.

[0036] As shown in Figures 10 and 12, the second flow channel member 8 has a connecting surface 820 with openings 821 to 828 into which the flow channel pipes 71 to 78 are inserted, a base portion 80 having the connecting surface 820, one or more guide portions 81 to 84, and an intermediate portion 89 provided between the guide portions 81 to 84 and the base portion 80. Note that the intermediate portion 89 is not shown in Figures 6 and 7.

[0037] The openings 821-828 shown in Figures 10 and 12 may, for example, open horizontally along the Y and Z directions, or open in the anti-gravity direction along the X2 direction. Furthermore, the openings 821-828 may open diagonally downward or diagonally upward in the direction of gravity. In this embodiment, the shape of the openings 821-828 is circular, but it is not limited to this. The shape of the openings 821-828 is sufficient as long as it allows for the insertion of the corresponding insertion parts 715-785, described later.

[0038] As shown in Figures 10 and 12, in this embodiment, the multiple openings 821 to 828 are the first opening 821 into which the first flow channel pipe 71 is inserted, the second opening 822 into which the second flow channel pipe 72 is inserted, the third opening 823 into which the third flow channel pipe 73 is inserted, the fourth opening 824 into which the fourth flow channel pipe 74 is inserted, the fifth opening 825 into which the fifth flow channel pipe 75 is inserted, the sixth opening 826 into which the sixth flow channel pipe 76 is inserted, the seventh opening 827 into which the seventh flow channel pipe 77 is inserted, and the eighth opening 828 into which the eighth flow channel pipe 78 is inserted. Each of the multiple openings 821 to 828 forms the other end of each of the multiple inter-member flow channels 190.

[0039] Furthermore, in this embodiment, as shown in Figure 8, the eight openings 821 to 828 are arranged in two rows along either a first straight line R1 or a second straight line R2 along the X direction. The first straight line R1 is located in the Y1 direction relative to the second straight line R2. Specifically, the first opening 821, the fifth opening 825, the seventh opening 827, and the third opening 823 are arranged in a single row along the first straight line R1 in this order from the X2 direction to the X1 direction. The second opening 822, the sixth opening 826, the eighth opening 828, and the fourth opening 824 are arranged in a single row along the second straight line R2 in this order from the X2 direction to the X1 direction. As shown in Figure 8, when viewed in the insertion direction DI, the quadrilateral with the centers of the first opening 821, the second opening 822, the third opening 823, and the fourth opening 824 as its vertices is a parallelogram.

[0040] As shown in Figure 6, each of the openings 821 to 828 in this embodiment is formed by a sealing member 80s made of an elastic material such as an elastomer and a recess in which the sealing member 80s is housed. The recess in which the sealing member 80s is housed is provided on the connecting surface 820 of the base portion 80 shown in Figures 10 and 11, and as shown in Figure 6, an opening connected to the inter-member flow path 190 is formed on the bottom surface of the recess. Note that the sealing member 80s is not shown in Figures 10 to 12. The sealing member 80s is substantially cylindrical in shape with a hole formed through it in the Z1 direction. As shown in Figure 7, when each of the flow path pipes 71 to 78 is inserted into each of the openings 821 to 828, the outer surfaces of the insertion portions 715 to 785 of the flow path pipes 71 to 78 come into contact with the inner surfaces of the respective sealing members 80s, thereby creating a liquid-tight connection between the first flow path member 7 and the second flow path member 8.

[0041] As shown in Figures 10 and 12, the flow channels 71-78 of the first flow channel member 7 are formed at positions corresponding to the openings 821-828 of the second flow channel member 8. Therefore, in this embodiment, as shown in Figure 9, the eight flow channels 71-78 provided in the first flow channel member 7 are arranged in two rows along either the first straight line R1 or the second straight line R2 along the X direction. As shown in Figure 9, when viewed in the insertion direction DI, the quadrilateral with the first flow channel 71, the second flow channel 72, the third flow channel 73, and the fourth flow channel 74 as vertices is a parallelogram.

[0042] As shown in Figures 10 and 12, the guide portions 81 to 84 are positioned in the opposite direction to the insertion direction DI with respect to the connection surface 820. The guide portions 81 to 84 are used to position the flow path structure 50 and the flow path connection member 60 of the liquid injection head 20 during the connection operation of the first flow path member 7 to the second flow path member 8. Specifically, the guide portions 81 to 84 restrict the relative movement of the first flow path member 7 to the second flow path member 8 in the vertical direction perpendicular to the insertion direction DI. In this embodiment, the vertical direction perpendicular to the insertion direction DI is the direction along the XY plane. The guide portions 81 to 84 have guide surfaces 81i to 84i that contact the guided portions 711 to 741 provided on the flow path tubes 71 to 74 of the first flow path member 7. During the connection operation, the outer surfaces 711s to 741s of the guided portions 711 to 741 contact the guide surfaces 81i to 84i of the guide portions 81 to 84, thereby restricting the relative vertical movement of the first flow path member 7 relative to the second flow path member 8, which is perpendicular to the insertion direction DI. In other words, the guided portions 711 to 741 are positioning members that are paired with the guide portions 81 to 84, and during the connection operation, they are used to position the flow path structure 50 and the flow path connection member 60 of the liquid injection head 20. Details of the guided portions 711 to 741 will be described later.

[0043] Furthermore, as shown in Figures 11 and 12, the guide portions 81 to 84 restrict the relative movement of the first flow channel member 7 in the insertion direction DI relative to the second flow channel member 8. The guide portions 81 to 84 have end faces 81t to 84t that come into contact with the opposing surface 70b of the base portion 70 of the first flow channel member 7 during the connection operation. During the connection operation, the opposing surface 70b of the base portion 70 comes into contact with the end faces 81t to 84t, thereby restricting the relative movement of the first flow channel member 7 in the insertion direction DI relative to the second flow channel member 8.

[0044] In this embodiment, as shown in Figure 9, four guide sections 81 to 84 are provided on the second flow channel member 8. The multiple guide sections 81 to 84 are the first guide section 81, the second guide section 82, the third guide section 83, and the fourth guide section 84. The first guide section 81 is formed to surround a part of the first opening 821 from the fifth outer surface fa5 side. The second guide section 82 is formed to surround a part of the second opening 822 from the fifth outer surface fa5 side. The third guide section 83 is formed to surround a part of the third opening 823 from the first outer surface fa1 side. The fourth guide section 84 is formed to surround a part of the fourth opening 824 from the first outer surface fa1 side. In this embodiment, the shape of each guide section 81 to 84 is a semi-cylindrical shape that surrounds a part of the corresponding opening 821 to 824. As a result, the guide sections 81-84 can guide the guided sections 711-741 of the flow path pipes 71-74.

[0045] The number of guide portions 81-84 is not limited to these. For example, there may be one or two guide portions 81-84, or there may be five or more. Also, the position of the guide portions 81-84 is not limited to these. The guide portions 81-84 only need to be formed in a position that can guide the guided portions 711-741, and may be formed to surround at least a part of other openings 825-828, such as the fifth opening 825. Furthermore, the shape of the guide portions 81-84 only needs to be a shape that can guide the guided portions 711-741, and may be a box shape or a plate shape, for example.

[0046] As shown in Figures 10 and 12, each of the multiple flow channels 71 to 78 provided in the first flow channel member 7 includes either a guided portion 711 to 741 or a support portion 751 to 781, and an insertion portion 715 to 785 that is inserted into the corresponding opening 821 to 828.

[0047] As shown in Figures 10 and 12, the insertion portions 715 to 785 are the portions of the flow path pipes 71 to 78 that are inserted into the corresponding openings 821 to 828. In this embodiment, the first flow path pipe 71 has a first insertion portion 715 that is inserted into the first opening 821. The second flow path pipe 72 has a second insertion portion 725 that is inserted into the second opening 822. The third flow path pipe 73 has a third insertion portion 735 that is inserted into the third opening 823. The fourth flow path pipe 74 has a fourth insertion portion 745 that is inserted into the fourth opening 824. The fifth flow path pipe 75 has a fifth insertion portion 755 that is inserted into the fifth opening 825. The sixth flow path pipe 76 has a sixth insertion portion 765 that is inserted into the sixth opening 826. The seventh flow path pipe 77 has a seventh insertion portion 775 that is inserted into the seventh opening 827. The eighth flow channel pipe 78 has an eighth insertion portion 785 that is inserted into the eighth opening 828. In this embodiment, the shape of the insertion portions 715 to 785 is cylindrical, having internal flow channels 718 to 788 inside. However, the shape of the insertion portions 715 to 785 is not limited to this, and any shape that can be inserted into the corresponding openings 821 to 828 is acceptable.

[0048] As shown in Figures 10 and 12, in connection operation, flow path tubes 71 to 74, which are formed in a position to contact guide portions 81 to 84, are provided with guided portions 711 to 741 having outer surfaces 711s to 741s that can contact the guide surfaces 81i to 84i of guide portions 81 to 84. The guided portions 711 to 741 are positioned between the corresponding insertion portions 715 to 745 and the base portion 70. In the connected state, when viewed in the insertion direction DI, a portion of the guided portions 711 to 741 is located between the corresponding insertion portions 715 to 745 and the corresponding guide portions 81 to 84. In this embodiment, the dimension W1 of the guided portions 711 to 741 in the vertical direction perpendicular to the insertion direction DI is larger than the dimension W2 of the corresponding insertion portions 715 to 745 in the vertical direction perpendicular to the insertion direction DI. Furthermore, the distance L1 from the end faces 81t to 84t of the guide sections 81 to 84, opposite to the insertion direction DI, to the connecting surface 820, is greater than the dimension L2 of the corresponding insertion sections 715 to 745. The dimension L2 of the insertion sections 715 to 745 refers to the distance L2 from the connecting portion 717 to 747 between the insertion sections 715 to 745 and the guided sections 711 to 741, corresponding to each guide section 81 to 84, to the tip portion 715p to 745p of the insertion section 715 to 745 in the insertion direction DI. In other words, the length L1 from the end faces 81t to 84t of the guide sections 81 to 84 to the connecting surface 820 is longer than the length L2 of the insertion sections 715 to 745 along the insertion direction DI. As a result, during the connection operation, the guided portions 711 to 741 are guided by the guide portions 81 to 84 before the insertion portions 715 to 745 are inserted into the corresponding openings 821 to 824. In this embodiment, as shown in Figures 10 and 12, the shape of each guided portion 711 to 741 is a cylindrical shape having internal pipe passages 718 to 788 and capable of engaging and contacting the corresponding guide portions 81 to 84. However, the shape of the guided portions 711 to 741 is not limited to this, and any shape that is capable of engaging and contacting the corresponding guide portions 81 to 84 is acceptable.

[0049] As shown in Figures 10 and 12, the first flow channel pipe 71 has a first guided portion 711 which is guided by the first guide portion 81. The first guided portion 711 has a first outer surface 711s which is in contact with the guide surface 81i of the first guide portion 81. The second flow channel pipe 72 has a second guided portion 721 which is guided by the second guide portion 82. It has a second outer surface 721s which is in contact with the guide surface 82i of the second guide portion 82. The third flow channel pipe 73 has a third guided portion 731 which is guided by the third guide portion 83. The third guided portion 731 has a third outer surface 731s which is in contact with the guide surface 83i of the third guide portion 83. The fourth flow channel pipe 74 has a fourth guided portion 741 which is guided by the fourth guide portion 84. The fourth guided portion 741 has a fourth outer surface 741s that contacts the guide surface 84i of the fourth guide portion 84.

[0050] As shown in Figures 10 and 12, in this embodiment, the dimensions L2 of the insertion sections 715-785 and the dimensions L3 of the guide sections 81-84 are the same, but are not limited to this. The dimensions L3 of the guide sections 81-84 referred to here are the distance L3 in relation to the insertion direction DI from the end faces 81t-84t of the guide sections 81-84 in the direction opposite to the insertion direction DI to the connection sections 817, 827, 837, 847 between the guide sections 81-84 and the intermediate section 89. The distance L1 in relation to the insertion direction DI from the end faces 81t-84t of the guide sections 81-84 to the connection surface 820 should be greater than the corresponding dimensions L2 of the insertion sections 715-745. Therefore, for example, the dimensions L3 of the guide sections 81-84 may be smaller than the dimensions L2 of the corresponding insertion sections 715-745 along the insertion direction DI.

[0051] As shown in Figures 10 and 12, in the connection operation, in the flow path pipes 75 to 78 formed in positions where guide sections 81 to 84 are not provided, support sections 751 to 781 are provided instead of guided sections 711 to 741. The support sections 751 to 781 are positioned between the corresponding insertion sections 755 to 785 and the base section 70, and each has an outer surface 751s to 781s. In this embodiment, the shape of the support sections 751 to 781 is the same as the shape of the guided sections 711 to 741. That is, the shape of the support sections 751 to 781 is cylindrical, with internal flow paths 718 to 788 inside. Furthermore, the dimension W5 of the support sections 751 to 781 in the vertical direction perpendicular to the insertion direction DI is larger than the dimension W2 of the corresponding insertion sections 755 to 785 in the vertical direction perpendicular to the insertion direction DI. In other words, in this embodiment, the diameters of the support portions 751 to 781 in the vertical direction perpendicular to the insertion direction DI are larger than the diameters of the corresponding insertion portions 755 to 785 in the vertical direction perpendicular to the insertion direction DI. However, the shape of the support portions 751 to 781 is not limited to this. For example, the dimension W5 of the support portions 751 to 785 in the vertical direction perpendicular to the insertion direction DI may be the same as the dimension W2 of the corresponding insertion portions 755 to 785 in the vertical direction perpendicular to the insertion direction DI.

[0052] As shown in Figure 11, the fifth flow channel pipe 75 is in contact with the second flow channel member 8 only at its fifth insertion portion 755, which is inserted into the fifth opening 825. The sixth flow channel pipe 76 is in contact with the second flow channel member 8 only at its sixth insertion portion 765, which is inserted into the sixth opening 826 shown in Figure 12. As shown in Figure 11, the seventh flow channel pipe 77 is in contact with the second flow channel member 8 only at its seventh insertion portion 775, which is inserted into the seventh opening 827. The eighth flow channel pipe 78 is in contact with the second flow channel member 8 only at its eighth insertion portion 785, which is inserted into the eighth opening 828 shown in Figure 12.

[0053] As shown in Figure 9, the first flow channel 71, the second flow channel 72, the third flow channel 73, and the fourth flow channel 74 are flow channel tubes that are guided by guide sections 81 to 84. The fifth flow channel 75, the sixth flow channel 76, the seventh flow channel 77, and the eighth flow channel 78 are flow channel tubes that are not guided by guide sections 81 to 84. In other words, in this embodiment, during the connection operation, the guided sections 711 to 741 provided on the four flow channel tubes 71 to 74 are guided by the corresponding guide sections 81 to 84, thereby positioning the flow channel structure 50 and the flow channel connecting member 60 of the liquid injection head 20.

[0054] Figure 13 is a diagram illustrating the cross-sectional shapes of the openings 821-828 and guide portions 81-84 in the first embodiment. In Figure 13, the flow path connecting member 60 is shown as viewed from the same second outer surface fa2 side as in Figure 8. Also in Figure 13, virtual circles C1-C4 formed by the guide surfaces 81i-84i of the semi-cylindrical guide portions 81-84 are shown by dashed lines. In this case, the diameters of the virtual circles C1-C4 correspond to the inner diameters of the guide portions 81-84. In Figure 13, the ratio of the inner diameters of the guide portions 81-84 is shown numerically.

[0055] In this embodiment, the inner diameter of the second guide portion 82 and the inner diameter of the fourth guide portion 84 are the same. That is, the shape and area of ​​the virtual circle C2 related to the second guide portion 82 are the same as the shape and area of ​​the virtual circle C4 related to the fourth guide portion 84. Also, the inner diameter of the first guide portion 81 is larger than that of the second guide portion 82 and the fourth guide portion 84. In other words, the area of ​​the virtual circle C1 related to the first guide portion 81 is larger than the area of ​​the virtual circle C2 related to the second guide portion 82 and the area of ​​the virtual circle C4 related to the fourth guide portion 84. That is, the shape of the virtual circle C1 related to the first guide portion 81 is different from the shape of the virtual circle C2 related to the second guide portion 82 and the shape of the virtual circle C4 related to the fourth guide portion 84. Also, the inner diameter of the third guide portion 83 is smaller than that of the second guide portion 82 and the fourth guide portion 84. In other words, the area of ​​the virtual circle C3 related to the third guide section 83 is smaller than the area of ​​the virtual circle C2 related to the second guide section 82 and the area of ​​the virtual circle C4 related to the fourth guide section 84. That is, the shape of the virtual circle C3 related to the third guide section 83 is different from the shape of the virtual circle C2 related to the second guide section 82 and the shape of the virtual circle C4 related to the fourth guide section 84.

[0056] Figure 14 is a diagram illustrating the cross-sectional shape of the guided portions 711-741 and the connection configuration between the guide portions 81-84 and the guided portions 711-741 in the first embodiment. Figure 14 illustrates the case when the connection operation is performed correctly. Here, "when the connection operation is performed correctly" means that the guided portions 711-741 are guided by the corresponding guide portions 81-84. Figure 14 illustrates the state of the guide portions 81-84 and the guided portions 711-741 in the connected state, as viewed from the second outer surface fa2 side, the same as in Figure 9. In Figure 14, the shape of the openings 821-828 is also shown with dashed lines. In Figure 14, the ratio of the cross-sectional areas of the guided portions 711-741 and the support portions 751-781 is represented by numbers.

[0057] In this embodiment, the cross-sectional area of ​​the second guided portion 721 with respect to the vertical direction perpendicular to the insertion direction DI is the same as the cross-sectional area of ​​the fourth guided portion 741 with respect to the vertical direction perpendicular to the insertion direction DI. In other words, the cross-sectional shape of the second guided portion 721 with respect to the vertical direction perpendicular to the insertion direction DI is the same as the cross-sectional shape of the fourth guided portion 741 with respect to the vertical direction perpendicular to the insertion direction DI. Furthermore, the cross-sectional area of ​​the first guided portion 711 with respect to the vertical direction perpendicular to the insertion direction DI is larger than the cross-sectional area of ​​the second guided portion 721 with respect to the vertical direction perpendicular to the insertion direction DI and the cross-sectional area of ​​the fourth guided portion 741 with respect to the vertical direction perpendicular to the insertion direction DI. In other words, the cross-sectional shape of the first guided portion 711 with respect to the vertical direction perpendicular to the insertion direction DI is different from the cross-sectional shape of the second guided portion 721 with respect to the vertical direction perpendicular to the insertion direction DI and the cross-sectional shape of the fourth guided portion 741 with respect to the vertical direction perpendicular to the insertion direction DI. Furthermore, the cross-sectional area of ​​the third guided portion 731 in the vertical direction perpendicular to the insertion direction DI is smaller than the cross-sectional area of ​​the second guided portion 721 in the vertical direction perpendicular to the insertion direction DI and the cross-sectional area of ​​the fourth guided portion 741 in the vertical direction perpendicular to the insertion direction DI. In other words, the cross-sectional shape of the third guided portion 731 in the vertical direction perpendicular to the insertion direction DI is different from the cross-sectional shape of the second guided portion 721 in the vertical direction perpendicular to the insertion direction DI and the cross-sectional shape of the fourth guided portion 741 in the vertical direction perpendicular to the insertion direction DI. Note that the cross-sectional area of ​​the guided portions 711 to 741 referred to here is the area of ​​the region surrounded by the outer edges when the guided portions 711 to 741 are cut in a plane perpendicular to the insertion direction DI.

[0058] As shown in Figure 14, when the connection operation is performed correctly, that is, when the connection state of the first flow channel member 7 to the second flow channel member 8 is appropriate, the shapes of each guide portion 81-84 and the shapes of each guided portion 711-741 match. In other words, when the connection operation is performed correctly, the area of ​​the virtual circles C1-C4 related to each guide portion 81-84 and the cross-sectional area of ​​each guided portion 711-741 in the vertical direction perpendicular to the insertion direction DI are approximately the same. Therefore, when the connection operation is performed correctly, as shown in Figure 10, the guided portions 711-741 do not interfere with the guide portions 81-84. Furthermore, while the guided portions 711-741 are being guided by the guide portions 81-84, the guided portions 711-741 are guided with almost no gap formed between them. In other words, the flow path structure 50 and the flow path connecting member 60 of the liquid injection head 20 are positioned while the guide surfaces 81i to 84i of the guide sections 81 to 84 and the outer surfaces 711s to 741s of the guided sections 711 to 741 are in general contact.

[0059] Figure 15 is a diagram illustrating an example of how to prevent misinsertion in the first embodiment. Here, misinsertion refers to the connection of the first flow channel member 7 to the second flow channel member 8 in an arrangement different from the correct arrangement shown in Figure 14. In other words, misinsertion means that the first flow channel member 7 is connected to the second flow channel member 8 after being rotated by a predetermined angle around the Z-axis along the insertion direction DI from the correct arrangement, or that the first flow channel member 7 is connected to the second flow channel member 8 while being misaligned relative to the second flow channel member 8. Figure 15 illustrates an example of misinsertion in which an attempt is made to connect the first flow channel member 7 to the second flow channel member 8 while the first flow channel member 7 is misaligned relative to the second flow channel member 8. Specifically, Figure 15 illustrates a case in which the insertion portions 715 to 785 of the first flow channel member 7 are inserted into the openings 821 to 828 of the second flow channel member 8 while the first flow channel member 7 is misaligned along the first arrangement direction DH1 from the correct arrangement shown in Figure 14. The first alignment direction DH1 referred to here is the direction along which the first guide portion 81 and the adjacent guide portion 82 are aligned, as shown in Figure 8, and is the direction from the third outer surface fa3 side to the fourth outer surface fa4 side in the connected state. In this embodiment, the first alignment direction DH1 is the direction along which the first guide portion 81 and the second guide portion 82 are aligned, as shown in Figure 15, and is a direction that includes the X1 direction component and the Y2 direction component. In Figure 15, the ratio of the cross-sectional areas of the guided portions 711 to 741 and the support portions 751 to 781 is represented by numbers.

[0060] When attempting to connect the first flow channel member 7 to the second flow channel member 8 while the first flow channel member 7 is misaligned from its correct position along the first alignment direction DH1, the first guided portion 711 is guided by the second guide portion 82, and the third guided portion 731 is guided by the fourth guide portion 84. At this time, the cross-sectional area of ​​the first guided portion 711 in the vertical direction perpendicular to the insertion direction DI is larger than the area of ​​the virtual circle C2 related to the second guided portion 721. In other words, the outer shape of the first guided portion 711 is larger than the inner diameter of the second guide portion 82. Therefore, when performing a connection operation that moves the first flow channel member 7 relative to the second flow channel member 8 in the insertion direction DI, the first guided portion 711 interferes with the second guide portion 82, making it impossible to connect the first flow channel member 7 to the second flow channel member 8. Thus, it is possible to prevent the first flow channel member 7 from being mistakenly connected to the second flow channel member 8 when the first flow channel member 7 is misaligned from its correct position along the first alignment direction DH1.

[0061] Figure 16 is a table summarizing the methods for preventing incorrect insertion in the first embodiment. As shown in Figures 14 and 16, if the first flow channel member 7 is misaligned from its correct position along the second arrangement direction DH2, the second guided portion 721 is guided by the first guide portion 81, and the fourth guided portion 741 is guided by the third guide portion 83. At this time, the cross-sectional area of ​​the fourth guided portion 741 in the vertical direction perpendicular to the insertion direction DI is larger than the area of ​​the virtual circle C3 related to the third guide portion 83. In other words, the outer shape of the fourth guided portion 741 is larger than the inner diameter of the third guide portion 83. Therefore, when performing a connection operation to move the first flow channel member 7 relative to the second flow channel member 8 in the insertion direction DI, the fourth guided portion 741 interferes with the third guide portion 83, making it impossible to connect the first flow channel member 7 to the second flow channel member 8. Therefore, when the first flow channel member 7 is misaligned from its correct position along the second arrangement direction DH2, it is possible to prevent the first flow channel member 7 from being mistakenly connected to the second flow channel member 8.

[0062] As shown in Figures 14 and 16, if the first flow channel member 7 is misaligned from its correct position along the third arrangement direction DH3, none of the guided portions 711 to 741 will be guided by the guide portions 81 to 84. Instead, the seventh support portion 771 will be guided to the third guide portion 83, and the eighth support portion 781 will be guided to the fourth guide portion 84. In this embodiment, as shown in Figure 14, the shape of the seventh support portion 771 of the seventh flow channel pipe 77 and the shape of the eighth support portion 781 of the eighth flow channel pipe 78 are the same as the shape of the second guided portion 721 and the fourth guided portion 741 of the second flow channel pipe 72. In other words, the cross-sectional area of ​​the seventh support portion 771 and the eighth support portion 781 with respect to the vertical direction perpendicular to the insertion direction DI is the same as the cross-sectional area of ​​the second guided portion 721 and the fourth guided portion 741 with respect to the vertical direction perpendicular to the insertion direction DI. Therefore, the cross-sectional area of ​​the seventh support portion 771 in the vertical direction perpendicular to the insertion direction DI is larger than the area of ​​the virtual circle C3 related to the third guide portion 83. In other words, the outer shape of the seventh support portion 771 is larger than the inner diameter of the third guide portion 83. As a result, when performing a connection operation to move the first flow path member 7 relative to the second flow path member 8, the seventh support portion 771 interferes with the third guide portion 83, making it impossible to connect the first flow path member 7 to the second flow path member 8. Thus, it is possible to prevent the first flow path member 7 from being mistakenly connected to the second flow path member 8 when the first flow path member 7 is misaligned from its correct position along the third arrangement direction DH3.

[0063] As shown in Figures 14 and 16, when the first flow path member 7 is rotated 180° around the Z-axis along the insertion direction DI from its correct position, the first guided portion 711 is guided by the fourth guide portion 84. At this time, the cross-sectional area of ​​the first guided portion 711 in the vertical direction perpendicular to the insertion direction DI is larger than the area of ​​the virtual circle C1 related to the fourth guide portion 84. In other words, the outer shape of the first guided portion 711 is larger than the inner diameter of the fourth guide portion 84. Therefore, when performing a connection operation to move the first flow path member 7 relative to the second flow path member 8 in the insertion direction DI, the first guided portion 711 interferes with the fourth guide portion 84, making it impossible to connect the first flow path member 7 to the second flow path member 8. Thus, it is possible to prevent the first flow path member 7 from being mistakenly connected to the second flow path member 8 when the first flow path member 7 is reversed around the Z-axis along the insertion direction DI from its correct position.

[0064] As shown in Figures 14 and 16, the case where the first flow path member 7 rotates around the Z-axis along the insertion direction DI from its correct position will be described. In this case, the guided parts 721 to 741 other than the first guided part 711 interfere with the guide parts 82 to 84 other than the first guide part 81. Therefore, in this case, the first flow path member 7 cannot be connected to the second flow path member 8. Thus, when the first flow path member 7 is rotated around the Z-axis along the insertion direction DI from its correct position, it is possible to prevent the first flow path member 7 from being mistakenly connected to the second flow path member 8.

[0065] According to the first embodiment described above, as shown in Figures 10 and 12, the guide portions 81 to 84 are arranged in the direction opposite to the insertion direction DI with respect to the connection surface 820. The guided portions 711 to 741 are arranged between the corresponding insertion portions 715 to 745 and the base portion 70. The distance L1 from the end faces 81t to 84t of the guide portions 81 to 84 in the direction opposite to the insertion direction DI to the connection surface 820 is greater than the dimension L2 of the corresponding insertion portions 715 to 745. This allows the guided portions 711 to 741 to be guided by the guide portions 81 to 84 before the insertion portions 715 to 785 are inserted into the openings 821 to 828 during the connection operation of the first flow path member 7 to the second flow path member 8. In other words, according to the first embodiment described above, there is no need to provide a positioning member at a different position from the flow path pipes 71 to 78 through which the liquid flows in order to position the flow path structure 50 and the flow path connection member 60 of the liquid injection head 20. Therefore, the first flow channel member 7 and the second flow channel member 8 can be miniaturized in both the insertion direction DI of the first flow channel member 7 relative to the second flow channel member 8 and the vertical direction perpendicular to the insertion direction DI. As a result, the flow channel structure 50 and the flow channel connecting member 60 can be miniaturized in the three-dimensional directions of the X, Y, and Z directions.

[0066] Furthermore, according to the first embodiment described above, as shown in Figures 11 and 12, the base portion 70 can restrict the relative movement of the first flow channel member 7 in the insertion direction DI relative to the second flow channel member 8 by bringing its opposing surface 70b into contact with the end faces 81t to 84t of the guide portion 81 during the connection operation. This makes it possible to define the amount of insertion of the first flow channel member 7 into the second flow channel member 8 when performing the connection operation.

[0067] Furthermore, according to the first embodiment described above, as shown in Figures 10 and 12, the guide portions 81-84 and the base portion 70 used for positioning also serve to define the insertion amount of the first flow channel member 7 into the second flow channel member 8 when performing the connection operation. Therefore, there is no need to provide a separate member to define the insertion amount of the first flow channel member 7 into the second flow channel member 8 when performing the connection operation. This makes it possible to suppress the enlargement of the first flow channel member 7 and the second flow channel member 8 in the vertical direction perpendicular to the insertion direction DI of the first flow channel member 7 into the second flow channel member 8.

[0068] Furthermore, according to the first embodiment described above, as shown in Figures 10 and 14, the guide portions 81 to 84 can restrict relative movement of the first flow channel member 7 in the vertical direction perpendicular to the insertion direction DI of the second flow channel member 8 during the connection operation.

[0069] Furthermore, according to the first embodiment described above, as shown in Figures 10 and 12, when viewed in the insertion direction DI, a portion of the guided portions 711 to 741 is positioned between the corresponding insertion portions 715 to 745 and the corresponding guide portions 81 to 84. This reduces the possibility that the tip portions 715p to 745p of the insertion portions 715 to 745 may come into contact with the guide portions 81 to 84 during connection.

[0070] Furthermore, according to the first embodiment described above, as shown in Figures 10 and 12, multiple flow channels 71 to 78 protrude from a single base portion 70 in the insertion direction DI. As a result, as shown in Figure 2, the multiple flow channels 71 to 78 can be moved integrally. Therefore, the connection operation between the first flow channel member 7 and the second flow channel member 8 can be performed smoothly.

[0071] Furthermore, according to the first embodiment described above, as shown in Figure 14, the cross-sectional area of ​​the second guided portion 721 in the vertical direction perpendicular to the insertion direction DI is smaller than the cross-sectional area of ​​the third guided portion 731 in the vertical direction perpendicular to the insertion direction DI. Also, the cross-sectional area of ​​the third guided portion 731 in the vertical direction perpendicular to the insertion direction DI is smaller than the cross-sectional area of ​​the first guided portion 711 in the vertical direction perpendicular to the insertion direction DI. In other words, the cross-sectional shape of the first guided portion 711 in the vertical direction perpendicular to the insertion direction DI, the cross-sectional shape of the second guided portion 721 in the vertical direction perpendicular to the insertion direction DI, and the cross-sectional shape of the third guided portion 731 in the vertical direction perpendicular to the insertion direction DI are different from each other. As a result, as shown in Figure 16, it is possible to prevent the first flow path member 7 from being connected to the second flow path member 8 in an arrangement different from the correct arrangement shown in Figure 14. In other words, it is possible to reduce the erroneous insertion of the first flow path member 7 into the second flow path member 8.

[0072] Furthermore, according to the first embodiment described above, as shown in Figures 11 and 14, among the plurality of flow path tubes 71 to 78, there are flow path tubes 75 to 78 that, in the connected state, contact the second flow path member 8 only with insertion portions 755 to 785, which are the portions inserted into the corresponding openings 825 to 828. As shown in Figure 16, even if among the plurality of flow path tubes 71 to 78 there are flow path tubes 75 to 78 that are not guided by guide portions 81 to 84, the erroneous insertion of the first flow path member 7 into the second flow path member 8 can be reduced. In other words, it is sufficient to form guide portions 81 to 84 for one or more of the plurality of flow path tubes 71 to 78, and the erroneous insertion of the first flow path member 7 into the second flow path member 8 can be reduced without forming guide portions 81 to 84 for all of the plurality of flow path tubes 71 to 78.

[0073] Furthermore, according to the first embodiment described above, as shown in Figures 10 and 12, the distance L1 from the end faces 81t to 84t of the guide sections 81 to 84 in the direction opposite to the insertion direction DI to the connection surface 820 is greater than the dimension L2 of the corresponding insertion sections 715 to 745. This reduces the possibility that the tip portions 715p to 785p of the insertion sections 715 to 785 will come into contact with the connection surface 820, even if the first flow channel member 7 is misaligned with respect to the second flow channel member 8. Therefore, it is possible to suppress the adhesion of liquid ink to the connection surface 820 by preventing the tip portions 715p to 785p of the insertion sections 715 to 785 from coming into contact with the connection surface 820. This prevents the first ink from flowing into the flow channels 190, 718 to 788 that flow the second ink which is different from the first ink, thereby preventing color mixing and increasing ink consumption.

[0074] Furthermore, according to the first embodiment described above, as shown in Figure 14, four guide portions 81 to 84 are provided on the second flow channel member 8. This makes it possible to improve the positioning accuracy of the first flow channel member 7 relative to the second flow channel member 8.

[0075] Furthermore, according to the first embodiment described above, as shown in Figure 14, the guided portions 711 to 741 are formed on the first flow channel 71, the second flow channel 72, the third flow channel 73, and the fourth flow channel 74, which are located at the end of the plurality of flow channel tubes 71 to 78. In other words, the guided portions 711 to 741 are provided on the flow channel tubes 71 to 74 located at both ends in the arrangement direction of the flow channel tubes 71 to 78 along the longitudinal direction of the convex polygon enclosing the plurality of flow channel tubes 71 to 74, i.e., along the X direction, to perform positioning. In this way, for example, during the connection operation of the first flow channel member 7 to the second flow channel member 8, the correct arrangement can be easily visually confirmed, thereby further improving positioning accuracy.

[0076] B. Second Embodiment: Figure 17 shows the configuration of the first flow channel member 7E and the second flow channel member 8E in the second embodiment. Figure 17 illustrates the first flow channel member 7E and the second flow channel member 8E in a connected state, where the first flow channel member 7E is connected to the second flow channel member 8E. In this embodiment, a configuration is described in which the first flow channel member 7E can be fixed to the second flow channel member 8E after the connection operation of the first flow channel member 7E to the second flow channel member 8E has been performed correctly. Components identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0077] In the first embodiment, as shown in Figures 10 and 12, the guide portions 81 to 84 were arranged in the opposite direction to the insertion direction DI relative to the connection surface 820, without directly protruding from the connection surface 820, but the embodiment is not limited to this. In the embodiment shown in Figure 17, the guide portions 81E to 84E protrude from the connection surface 820 in the opposite direction to the insertion direction DI. In other words, the guide portions 81E to 84E are formed integrally with the connection surface 820. With this configuration, the connection surface 820 having openings 821 to 828 into which the insertion portions 715 to 785 are inserted and the guide portions 81 to 84 are formed integrally, so the positioning accuracy of the first flow path member 7E relative to the second flow path member 8E can be further improved. Furthermore, with this configuration, the first flow path member 7E and the second flow path member 8E can be miniaturized in the insertion direction DI of the first flow path member 7E relative to the second flow path member 8.

[0078] Furthermore, in the first embodiment, as shown in Figures 10 and 12, an intermediate section 89 was arranged between the guide sections 81-84 and the connecting surface 820, but this is not the only embodiment. The second flow channel member 8E of this embodiment, shown in Figure 17, does not have an intermediate section 89. In other words, each of the guide surfaces 81i-84i is continuous along the Z2 direction from the connecting surface 820 to the end faces 81t-84t. In other words, the guide sections 81E-84E are provided in the range from the connecting surface 820 to the end faces 81t-84t. Therefore, the distance L1 from the end faces 81t-84t to the connecting surface 820 in the direction opposite to the insertion direction DI of the guide sections 81E-84E is greater than the dimension L2 of the corresponding insertion sections 715-785. Also, the dimension L3 of the guide sections 81E-84E and the distance L1 are the same in this embodiment. In this context, the dimension L3 of the guide sections 81E to 84E refers to the distance L3 from the end faces 81t to 84t on the opposite side of the insertion direction DI of the guide sections 81E to 84E to the connecting surface 820, relative to the insertion direction DI. In other words, the dimension L3 of the guide sections 81E to 84E in this embodiment is larger than the dimension L2 of the insertion sections 715 to 785.

[0079] Furthermore, in this embodiment, after the connection operation of the first flow path member 7E to the second flow path member 8E is performed correctly, the base portion 70E and the guide portions 81E and 83E are fixed by fixing members 91 and 92. The fixing members 91 and 92 are, for example, screws or pins. If the fixing members 91 and 92 are pins, for example, a spring or the like may be provided to bias the pins in the fixing direction. In this embodiment, the fixing direction is the same direction as the insertion direction DI and is along the Z1 direction. The base portion 70 has base-side fixing holes 708 and 709 for inserting the fixing members 91 and 92. The guide portions 81E and 83E have guide-side fixing holes 819 and 839 for receiving the fixing members 91 and 92. If the fixing members 91 and 92 are screws, for example, screw grooves may be formed in the base-side fixing holes 708 and 709 and the guide-side fixing holes 819 and 839, respectively. The type and position of the fixing members 91 and 92 are not limited to those shown. The base portion 70E and the guide portions 81E and 83E may be fixed at one point by the fixing members 91 and 92, or at three or more points. Furthermore, it is not essential that the base portion 70E and the guide portions 81E and 83E are fixed by the fixing members 91 and 92.

[0080] According to the second embodiment described above, as shown in Figure 17, fixing holes 708, 709, 819, and 839 for receiving fixing members 91 and 92 are formed in the guide portions 81E and 83E and the base portion 70E, respectively. In other words, the guide portions 81E and 83E and the base portion 70E, which are used for positioning, are also used as fixing positions and serve as fixed members. Therefore, the first flow path member 7E can be fixed to the second flow path member 8E without providing separate fixing positions for fixing the fixing members 91 and 92. As a result, the first flow path member 7E and the second flow path member 8E can be miniaturized in the vertical direction perpendicular to the insertion direction DI of the first flow path member 7E relative to the second flow path member 8E.

[0081] Furthermore, according to the second embodiment described above, as shown in Figure 17, after the connection operation of the first flow path member 7E to the second flow path member 8E is performed correctly, the base portion 70E and the guide portions 81E and 83E can be fixed by the fixing members 91 and 92. This prevents the connection between the first flow path member 7E and the second flow path member 8E from being unintentionally released.

[0082] C. Third Embodiment: Figure 18 shows the configuration of the first flow channel member 7F and the second flow channel member 8 in the third embodiment. In Figure 18, the first flow channel pipe 71F and the area around the first guide portion 81 of the first flow channel member 7F and the second flow channel member 8 are shown as excerpts. Figure 19 shows the cross-sectional shapes of the first guided portion 711F and the first insertion portion 715F in the third embodiment. In Figure 19, the first guided portion 711F and the first insertion portion 715F are shown as viewed through from the tip portion 715p side of the first insertion portion 715F. In Figure 19, the internal flow channel 718 is not shown. In this embodiment, some of the configurations of the first guided portion 711F and the first insertion portion 715F differ from those of the first embodiment. Components identical to those in the first embodiment are given the same reference numerals and their descriptions are omitted.

[0083] In the first embodiment, as shown in Figures 10 and 12, the guided portions 711 to 741 were formed such that the dimension W1 of the guided portions 711 to 741 in the direction perpendicular to the insertion direction DI was larger than the dimension W2 of the corresponding insertion portions 715 to 745 in the direction perpendicular to the insertion direction DI. In contrast, in this embodiment, as shown in Figure 18, the dimension W1 of the first guided portion 711F in the direction perpendicular to the insertion direction DI and the dimension W20 of the first insertion portion 715F in the direction perpendicular to the insertion direction DI are the same. Furthermore, the cross-sectional area of ​​the first guided portion 711 in the direction perpendicular to the insertion direction DI is smaller than the cross-sectional area of ​​the first insertion portion 715 in the direction perpendicular to the insertion direction DI. Even in this configuration, by positioning a portion of the first guided portion 711F between the first insertion portion 715F and the first guide portion 81 when viewed in the insertion direction DI, the possibility of the tip portion 715p of the first insertion portion 715F touching the first guide portion 81 during connection can be reduced. The second flow channel 72, the third flow channel 73, and the fourth flow channel 74 may also be configured in the same way as the first flow channel 71F in this embodiment.

[0084] D. Fourth Embodiment: Figure 20 shows the configuration of the first flow channel member 7G and the second flow channel member 8G in the fourth embodiment. Figure 20 illustrates the state immediately after the connection operation of the first flow channel member 7G to the second flow channel member 8G is started. In this embodiment, some of the shapes of the guided portions 711G and 731G and some of the shapes of the guide portions 81G and 82G differ from those in the first embodiment. Components identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0085] In this embodiment, the first flow channel pipe 71G is positioned between the first guided portion 711G and the first insertion portion 715, and includes a first tapered portion 711p on the guided portion side, where the cross-sectional area in the vertical direction perpendicular to the insertion direction DI gradually decreases as it moves from the first guided portion 711G toward the first insertion portion 715. The third flow channel pipe 73G is positioned between the third guided portion 731G and the third insertion portion 735, and includes a second tapered portion 731p on the guided portion side, where the cross-sectional area in the vertical direction perpendicular to the insertion direction DI gradually decreases as it moves from the third guided portion 731G toward the third insertion portion 735. The first tapered portion 711p and the second tapered portion 731p are tapered portions formed between the guided portions 711, 731 and the insertion portions 715, 735, respectively. In the following, the boundary portions between the outer surfaces 711s, 713s and the guided portion-side tapering portions 711p, 731p will be referred to as the guided portion-side boundary portions 710p, 730p.

[0086] As shown in Figure 20, the first guide portion 81G is positioned at the connection point between the end face 81t and the guide surface 81i, and includes a first guide portion-side tapered portion 81p in which the cross-sectional area in the vertical direction perpendicular to the insertion direction DI gradually decreases as it moves from the guide surface 81i toward the end face 81t. The third guide portion 83G is positioned at the connection point between the end face 83t and the guide surface 83i, and includes a second guide portion-side tapered portion 83p in which the cross-sectional area in the vertical direction perpendicular to the insertion direction DI gradually decreases as it moves from the guide surface 83i toward the end face 83t. The first guide portion-side tapered portion 81p and the second guide portion-side tapered portion 83p are tapered portions formed at the connection points between the guide surfaces 81i, 83i and the end faces 81t, 83t, respectively. Hereinafter, the boundary portions between the guide surfaces 81i, 83i and the guide portion-side tapered portions 81p, 83p will be referred to as guide portion-side boundary portions 810p and 830p.

[0087] As shown in Figure 20, when tapering portions 81p, 83p, 710p, and 730p are provided on at least one of the guide portions 81, 83 and the guided portions 711, 731, as in this embodiment, the distances L10 and L20 are preferably as follows: The distance L10 in the insertion direction DI from the guide portion side boundary portions 810p, 830p to the connection surface 820 is preferably greater than the distance L20 in the insertion direction DI from the guided portion side boundary portions 710p, 730p to the tip portions 715p, 735p of the insertion portions 715, 735. In this way, during the connection operation, the guided portions 711G, 731G, on which the tapering portions 711p, 731p are provided, can be guided to the guide portions 81G, 83G before the insertion portions 715, 735 are inserted into the corresponding openings 821, 823.

[0088] According to the above embodiment, the flow channels 71G and 73G are positioned between the guided portions 711G and 731G and the insertion portions 715 and 735, and include portions 710p and 730p in which the cross-sectional area perpendicular to the insertion direction DI gradually decreases from the guided portions 711G and 731G toward the insertion portions 715 and 735. By providing the flow channels 71 and 73 with these tapered portions 711p and 731p on the guided portion side, it is possible to facilitate contact between the guide portions 81G and 83G and the guided portions 711G and 731G during the connection operation of the first flow channel member 7G to the second flow channel member 8G. In other words, by providing a tapered portion between the guided portions 711G and 731G and the insertion portions 715 and 735, the insertability of the first flow channel member 7G toward the second flow channel member 8G can be improved.

[0089] According to the above embodiment, the guide portions 81G and 83G are arranged at the connection portion between the end faces 81t and 83t and the guide surfaces 81i and 83i, and include portions 81p and 83p in which the cross-sectional area in the vertical direction perpendicular to the insertion direction DI gradually decreases from the guide surfaces 81i and 83i toward the end faces 81t and 83t. In this way, by providing the guide portion-side tapered portions 81p and 83p at positions corresponding to the guided portion-side tapered portions 711p and 731p provided on the flow channel pipes 71G and 73G, it is possible to further facilitate contact between the guide portions 81G and 83G and the guided portions 711G and 731G during connection. In other words, by providing tapered portions in the guide portions 81G and 83G at positions corresponding to the guided portion-side tapered portions 711p and 731p during connection, the insertability of the first flow channel member 7G into the second flow channel member 8G can be further improved.

[0090] Note that the guide-side tapering sections 81p and 83p shown in Figure 20 are not essential components, and the liquid injection device 1 may, for example, have only the guided-side tapering sections 711p and 731p without the guide-side tapering sections 81p and 83p. Also, in the example shown in Figure 20, the guided-side tapering sections 711p and 731p are provided in the first flow channel 71G and the third flow channel 73G, respectively, but this disclosure is not limited to this. The second flow channel 72 and the fourth flow channel 74 guided by the guide sections 82 and 84 shown in Figure 12 may also have the same configuration as the first flow channel 71G and the third flow channel 73G in this embodiment.

[0091] E. Fifth Embodiment: Figure 21 is a diagram illustrating the cross-sectional shapes of the openings 821-828 and guide sections 81J-84J in the fifth embodiment. Figure 21 shows the flow path connecting member 60 in this embodiment as viewed from the same second outer surface fa2 side as in Figure 13. Also in Figure 21, virtual circles C10, C20, C30, and C40 formed by the guide surfaces 81i-84i of the semi-cylindrical guide sections 81J-84J are shown by dashed lines. In this case, the diameters of the virtual circles C10, C20, C30, and C40 correspond to the inner diameters of the guide sections 81J-84J. In Figure 21, the ratio of the inner diameters of the guide sections 81J-84J is shown numerically. The shape of each guide section 81J-84J is a semi-cylindrical shape that surrounds a part of the corresponding openings 821-824, similar to the first embodiment.

[0092] In this embodiment, as shown in Figure 21, the inner diameters of the first guide section 81J, the second guide section 82J, the third guide section 83J, and the fourth guide section 84J are all different. Specifically, the inner diameter of the second guide section 82J ​​is smaller than the inner diameter of the third guide section 83. In other words, the area of ​​the virtual circle C20 related to the second guide section 82J ​​is smaller than the area of ​​the virtual circle C30 related to the third guide section 83J. That is, the shape of the virtual circle C20 related to the second guide section 82J ​​is different from the shape of the virtual circle C30 related to the third guide section 83J. Also, the inner diameter of the third guide section 83J is smaller than the inner diameter of the fourth guide section 84J. In other words, the area of ​​the virtual circle C30 related to the third guide section 83J is smaller than the area of ​​the virtual circle C40 related to the fourth guide section 84J. In other words, the shape of the virtual circle C30 related to the third guide section 83J is different from the shape of the virtual circle C40 related to the fourth guide section 84J. Also, the inner diameter of the fourth guide section 84J is smaller than the inner diameter of the first guide section 81J. To put it another way, the area of ​​the virtual circle C40 related to the fourth guide section 84J is smaller than the area of ​​the virtual circle C10 related to the first guide section 81J. In other words, the shape of the virtual circle C40 related to the fourth guide section 84J is different from the shape of the virtual circle C10 related to the first guide section 81J.

[0093] Figure 22 is a diagram illustrating the cross-sectional shape of the guided portions 711J to 741J and the connection configuration between the guide portions 81J to 84J and the guided portions 711J to 741J in the fifth embodiment. Similar to Figure 14, Figure 22 illustrates the case when the connection operation is performed correctly. Figure 22 shows the guide portions 81J to 84J and the guided portions 711J to 741J in the connected state, viewed from the same second outer surface fa2 side as in Figure 14. Figure 22 also illustrates the shapes of the openings 821 to 828 using dashed lines. Furthermore, Figure 22 shows the ratio of the cross-sectional areas of the guided portions 711J to 741J and the support portions 751J to 781 using numbers. Each guided portion 711J to 741J and each insertion portion 715 to 785 are cylindrical in shape, similar to the first embodiment.

[0094] In this embodiment, the cross-sectional area of ​​the second guided portion 721J with respect to the vertical direction perpendicular to the insertion direction DI is smaller than the cross-sectional area of ​​the third guided portion 731J with respect to the vertical direction perpendicular to the insertion direction DI. Furthermore, the cross-sectional area of ​​the third guided portion 731J with respect to the vertical direction perpendicular to the insertion direction DI is smaller than the cross-sectional area of ​​the fourth guided portion 741J with respect to the vertical direction perpendicular to the insertion direction DI. Also, the cross-sectional area of ​​the fourth guided portion 741J with respect to the vertical direction perpendicular to the insertion direction DI is smaller than the cross-sectional area of ​​the first guided portion 711J with respect to the vertical direction perpendicular to the insertion direction DI. In other words, the cross-sectional shapes of the first guided portion 711J, the second guided portion 721J, the third guided portion 731J, and the fourth guided portion 741J with respect to the vertical direction perpendicular to the insertion direction DI are different. Therefore, in this embodiment, the cross-sectional shapes of the guide portions 81J to 84J and the guided portions 711J to 741J differ from those of the first embodiment shown in Figures 13 and 14. Other components are the same as in the first embodiment. Components identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0095] In this embodiment, as shown in Figure 22, when viewed in the insertion direction DI, the first line segment Li1 connecting the second guided portion 721J and the third guided portion 731J intersects with the second line segment Li2 connecting the fourth guided portion 741J and the first guided portion 711J. The first line segment Li1 is the line segment connecting the second guided portion 721J, which has the smallest cross-sectional area in the vertical direction perpendicular to the insertion direction DI, and the third guided portion 731J, which has the next smallest cross-sectional area in the vertical direction perpendicular to the insertion direction DI after the second guided portion 721J. The second line segment Li2 is the line segment connecting the first guided portion 711J, which has the largest cross-sectional area in the vertical direction perpendicular to the insertion direction DI, and the fourth guided portion 741J, which has the next largest cross-sectional area in the vertical direction perpendicular to the insertion direction DI after the first guided portion 711J.

[0096] Furthermore, in this embodiment, as shown in Figure 22, when viewed in the insertion direction DI, the quadrilateral whose vertices are the first flow channel 71J, the second flow channel 72J, the third flow channel 73J, and the fourth flow channel 74J is both a rectangle and a parallelogram. In other words, when viewed in the insertion direction DI, the smallest convex polygon enclosing the first guided portion 711J, the second guided portion 721J, the third guided portion 731J, and the fourth guided portion 741J is a parallelogram.

[0097] As shown in Figure 22, when the connection operation is performed correctly, that is, when the connection state of the first flow channel member 7J to the second flow channel member 8J is appropriate, the shapes of each guide portion 81J to 84J and the shapes of each guided portion 711J to 741J will match. In other words, when the connection operation is performed correctly, the areas of the virtual circles C10, C20, C30, and C40 related to each guide portion 81J to 84J will be approximately the same as the cross-sectional area of ​​each guided portion 711J to 741J in the vertical direction perpendicular to the insertion direction DI. Therefore, when the connection operation is performed correctly, as shown in Figure 22, the guided portions 711J to 741J will not interfere with the guide portions 81J to 84J. Then, while the guided portions 711J to 741J are being guided by the guide portions 81J to 84J, the guided portions 711J to 741J are guided with almost no gap formed between them. That is, the guide surfaces 81i to 84i of the guide portions 81J to 84J and the outer surfaces 711s to 741s of the guided portions 711J to 741J are in general contact as the flow path structure 50 and the flow path connecting member 60 of the liquid injection head 20 are positioned.

[0098] Figure 23 is a diagram illustrating an example of an embodiment for preventing incorrect insertion in the fifth embodiment. As an example of incorrect insertion, Figure 23 illustrates a case where the first flow channel member 7J is rotated 180° around the Z axis along the insertion direction DI from the correct arrangement shown in Figure 22, and an attempt is made to connect the first flow channel member 7J to the second flow channel member 8J. In other words, Figure 23 illustrates a case where the first flow channel member 7J is reversed around the Z axis along the insertion direction DI from the correct arrangement, and an attempt is made to insert the insertion portions 715 to 785 of the first flow channel member 7J into the openings 821 to 828 of the second flow channel member 8J. Note that in Figure 23, the ratio of the cross-sectional areas of the guided portions 711J to 741J and the support portions 751J to 781 is represented by numbers.

[0099] When attempting to connect the first flow channel member 7J to the second flow channel member 8J, after the first flow channel member 7J has been rotated 180° around the Z-axis along the insertion direction DI from its correct position, the third guided portion 731J is guided by the second guide portion 82J. At this time, the cross-sectional area of ​​the third guided portion 731J in the vertical direction perpendicular to the insertion direction DI is larger than the area of ​​the virtual circle C20 related to the second guide portion 82J. In other words, the outer shape of the third guided portion 731J is larger than the inner diameter of the second guide portion 82J. Therefore, when performing a connection operation that moves the first flow channel member 7J relative to the second flow channel member 8J in the insertion direction DI, the third guided portion 731J interferes with the second guide portion 82J.

[0100] Furthermore, when attempting to connect the first flow channel member 7J to the second flow channel member 8J while the first flow channel member 7J has been rotated 180° around the Z-axis along the insertion direction DI from its correct position, the first guided portion 711J is guided by the fourth guide portion 84J. At this time, the cross-sectional area of ​​the first guided portion 711J in the vertical direction perpendicular to the insertion direction DI is larger than the area of ​​the virtual circle C40 related to the fourth guide portion 84J. In other words, the outer shape of the first guided portion 711J is larger than the inner diameter of the fourth guide portion 84J. Therefore, when performing a connection operation that moves the first flow channel member 7J relative to the second flow channel member 8J in the insertion direction DI, the first guided portion 711J interferes with the fourth guide portion 84J. As a result, it is not possible to connect the first flow channel member 7J to the second flow channel member 8J. Therefore, when the first flow channel member 7J is inverted from its correct position around the Z-axis along the insertion direction DI, it is possible to prevent the first flow channel member 7J from being mistakenly connected to the second flow channel member 8J.

[0101] Figure 24 is a table summarizing the methods for preventing incorrect insertion in the fifth embodiment. As shown in Figures 22 and 24, if the first flow channel member 7J is misaligned from its correct position along the first arrangement direction DH1, the first guided portion 711J will be guided by the second guide portion 82J, and the third guided portion 731J will be guided by the fourth guide portion 84J. At this time, the cross-sectional area of ​​the first guided portion 711J in the vertical direction perpendicular to the insertion direction DI is larger than the area of ​​the virtual circle C20 related to the second guide portion 82J. In other words, the outer shape of the first guided portion 711J is larger than the inner diameter of the second guide portion 82J. Therefore, when performing a connection operation to move the first flow channel member 7J relative to the second flow channel member 8J in the insertion direction DI, the first guided portion 711J interferes with the second guide portion 82J, making it impossible to connect the first flow channel member 7J to the second flow channel member 8J. Therefore, when the first flow channel member 7J is misaligned from its correct position along the first arrangement direction DH1, it is possible to prevent the first flow channel member 7J from being mistakenly connected to the second flow channel member 8J.

[0102] As shown in Figures 22 and 24, when the first flow channel member 7J is displaced from its correct position in the second alignment direction DH2, the second guided portion 721J is guided to the first guide portion 81J. Then, the fourth guided portion 741J is guided to the third guide portion 83J. At this time, the cross-sectional area of ​​the fourth guided portion 741J in the vertical direction perpendicular to the insertion direction DI is larger than the area of ​​the third guide portion 83J related to the virtual circle C30. In other words, the outer shape of the fourth guided portion 741J is larger than the inner diameter of the third guide portion 83J. Therefore, when performing a connection operation to move the first flow channel member 7J relative to the second flow channel member 8J in the insertion direction DI, the fourth guided portion 741J interferes with the third guide portion 83J, making it impossible to connect the first flow channel member 7J to the second flow channel member 8J. Therefore, when the first flow channel member 7J is misaligned from its correct position along the second arrangement direction DH2, it is possible to prevent the first flow channel member 7J from being mistakenly connected to the second flow channel member 8J.

[0103] As shown in Figures 22 and 24, when the first flow path member 7J is displaced from its correct position in the third arrangement direction DH3, the seventh support portion 771 is guided to the third guide portion 83J, and the eighth support portion 781 is guided to the fourth guide portion 84J. At this time, the cross-sectional area of ​​the seventh support portion 771 in the vertical direction perpendicular to the insertion direction DI is larger than the area of ​​the virtual circle C30 related to the third guide portion 83J. In other words, the outer shape of the seventh support portion 771 is larger than the inner diameter of the third guide portion 83J. Therefore, when performing a connection operation to move the first flow path member 7J relative to the second flow path member 8J in the insertion direction DI, the seventh support portion 771 interferes with the third guide portion 83J, making it impossible to connect the first flow path member 7J to the second flow path member 8J. Thus, when the first flow path member 7J is displaced from its correct position along the third arrangement direction DH3, it is possible to prevent the first flow path member 7J from being mistakenly connected to the second flow path member 8J.

[0104] As shown in Figures 22 and 24, when the first flow path member 7J is displaced from its correct position in the fourth arrangement direction DH4, the fifth support portion 751 is guided to the first guide portion 81J, and the sixth support portion 761 is guided to the second guide portion 82J. At this time, the cross-sectional area of ​​the sixth support portion 761 in the vertical direction perpendicular to the insertion direction DI is larger than the area of ​​the virtual circle C20 related to the second guide portion 82J. In other words, the outer shape of the sixth support portion 761 is larger than the inner diameter of the second guide portion 82J. Therefore, when performing a connection operation to move the first flow path member 7J relative to the second flow path member 8J in the insertion direction DI, the sixth support portion 761 interferes with the second guide portion 82J, making it impossible to connect the first flow path member 7J to the second flow path member 8J. Thus, when the first flow path member 7J is displaced from its correct position along the fourth arrangement direction DH4, it is possible to prevent the first flow path member 7J from being mistakenly connected to the second flow path member 8J.

[0105] As shown in Figures 22 and 24, when the first flow channel member 7 is reversed from its correct position and misaligned in the first arrangement direction DH1, the fourth guided portion 741J is guided to the second guide portion 82J. At this time, the cross-sectional area of ​​the fourth guided portion 741J in the vertical direction perpendicular to the insertion direction DI is larger than the area of ​​the virtual circle C20 related to the second guide portion 82J. In other words, the outer shape of the fourth guided portion 741J is larger than the inner diameter of the second guide portion 82J. Therefore, when performing a connection operation to move the first flow channel member 7J relative to the second flow channel member 8J in the insertion direction DI, the fourth guided portion 741J interferes with the second guide portion 82J, making it impossible to connect the first flow channel member 7J to the second flow channel member 8J. Thus, it is possible to prevent the first flow channel member 7J from being mistakenly connected to the second flow channel member 8J when the first flow channel member 7J is reversed from its correct position and misaligned along the first arrangement direction DH1.

[0106] As shown in Figures 22 and 24, when the first flow channel member 7 is reversed from its correct position and misaligned in the second alignment direction DH2, the first guided portion 711J is guided to the third guide portion 83J. At this time, the cross-sectional area of ​​the first guided portion 711J in the vertical direction perpendicular to the insertion direction DI is larger than the area of ​​the virtual circle C30 related to the third guide portion 83J. In other words, the outer shape of the first guided portion 711J is larger than the inner diameter of the third guide portion 83J. Therefore, when performing a connection operation to move the first flow channel member 7J relative to the second flow channel member 8J in the insertion direction DI, the first guided portion 711J interferes with the third guide portion 83J, making it impossible to connect the first flow channel member 7J to the second flow channel member 8J. Thus, it is possible to prevent the first flow channel member 7J from being mistakenly connected to the second flow channel member 8J when the first flow channel member 7J is reversed from its correct position and misaligned along the second alignment direction DH2.

[0107] As shown in Figures 22 and 24, when the first flow channel member 7J is reversed from its correct position and shifted in the third alignment direction DH3, none of the guided portions 711J to 741J are guided by the guide portions 81J to 84J. Instead, the sixth support portion 761 is guided by the third guide portion 83J, and the fifth support portion 751 is guided by the fourth guide portion 84J. At this time, the cross-sectional area of ​​the sixth support portion 761 in the vertical direction perpendicular to the insertion direction DI is larger than the area of ​​the virtual circle C30 related to the third guide portion 83J. In other words, the outer shape of the sixth support portion 761 is larger than the inner diameter of the third guide portion 83J. Therefore, when performing a connection operation to move the first flow channel member 7J relative to the second flow channel member 8J, the sixth support portion 761 interferes with the third guide portion 83J, making it impossible to connect the first flow channel member 7J to the second flow channel member 8J. Therefore, when the first flow channel member 7J is inverted from its correct position and then misaligned along the third arrangement direction DH3, it is possible to prevent the first flow channel member 7J from being mistakenly connected to the second flow channel member 8J.

[0108] As shown in Figures 22 and 24, when the first flow channel member 7J is reversed from its correct position and shifted in the fourth alignment direction DH4, none of the guided portions 711J to 741J are guided by the guide portions 81J to 84J. Instead, the eighth support portion 781 is guided to the first guide portion 81J, and the seventh support portion 771 is guided to the second guide portion 82J. At this time, the cross-sectional area of ​​the seventh support portion 771 in the vertical direction perpendicular to the insertion direction DI is larger than the area of ​​the virtual circle C20 related to the second guide portion 82J. In other words, the outer shape of the seventh support portion 771 is larger than the inner diameter of the second guide portion 82J. Therefore, when performing a connection operation to move the first flow channel member 7J relative to the second flow channel member 8J, the seventh support portion 771 interferes with the second guide portion 82J, making it impossible to connect the first flow channel member 7J to the second flow channel member 8J. Therefore, when the first flow channel member 7J is inverted from its correct position and then misaligned along the fourth arrangement direction DH4, it is possible to prevent the first flow channel member 7J from being mistakenly connected to the second flow channel member 8J.

[0109] As shown in Figures 22 and 24, the case where the first flow channel member 7J rotates around the Z-axis along the insertion direction DI from its correct position will be described. In this case, the guided parts 721J to 741J other than the first guided part 711J interfere with the guide parts 82J to 84J other than the first guide part 81J, so the first flow channel member 7J cannot be connected to the second flow channel member 8J. Therefore, when the first flow channel member 7J rotates around the Z-axis along the insertion direction DI from its correct position, it is possible to prevent the first flow channel member 7J from being mistakenly connected to the second flow channel member 8J.

[0110] According to the fifth embodiment described above, as shown in Figure 22, the cross-sectional area of ​​the second guided portion 721J in the vertical direction perpendicular to the insertion direction DI is smaller than the cross-sectional area of ​​the third guided portion 731J in the vertical direction perpendicular to the insertion direction DI. Also, the cross-sectional area of ​​the third guided portion 731J in the vertical direction perpendicular to the insertion direction DI is smaller than the cross-sectional area of ​​the fourth guided portion 741J in the vertical direction perpendicular to the insertion direction DI. Furthermore, the cross-sectional area of ​​the fourth guided portion 741J in the vertical direction perpendicular to the insertion direction DI is smaller than the cross-sectional area of ​​the first guided portion 711J in the vertical direction perpendicular to the insertion direction DI. Looking at the insertion direction DI, the first line segment Li1 connecting the second guided portion 721J and the third guided portion 731J intersects with the second line segment Li2 connecting the fourth guided portion 741J and the first guided portion 711J. As a result, as shown in Figure 24, even if the first flow channel member 7J is misaligned from its correct position in any of the alignment directions DH1 to DH4, the erroneous insertion of the first flow channel member 7 into the second flow channel member 8 can be reduced.

[0111] Furthermore, according to the fifth embodiment described above, as shown in Figure 23, even if the first flow channel member 7 is reversed around the Z-axis along the insertion direction DI from its correct position, the erroneous insertion of the first flow channel member 7 into the second flow channel member 8 can be reduced.

[0112] Furthermore, according to the fifth embodiment described above, as shown in Figures 22 and 24, even if the first flow channel member 7 is reversible around the Z-axis along the insertion direction DI from its correct position and then becomes misaligned, it is possible to reduce the erroneous insertion of the first flow channel member 7 into the second flow channel member 8.

[0113] Furthermore, according to the fifth embodiment described above, as shown in Figures 22 and 24, even if the first flow channel member 7 is misaligned from its correct position in any of the following directions: the first arrangement direction DH1, the second arrangement direction DH2, the third arrangement direction DH3, or the fourth arrangement direction DH4, misinsertion can be reduced.

[0114] Furthermore, according to the fifth embodiment described above, as shown in Figures 22 and 24, even if the first flow channel member 7 rotates from its correct position around the Z-axis along the insertion direction DI, the erroneous insertion of the first flow channel member 7 into the second flow channel member 8 can be reduced.

[0115] Furthermore, according to the fifth embodiment described above, as shown in Figure 22, the quadrilateral whose vertices are the first flow channel 71J, the second flow channel 72J, the third flow channel 73J, and the fourth flow channel 74J is a parallelogram. In this way, as shown in Figure 23, it is possible to more reliably prevent the first flow channel member 7J from being mistakenly connected to the second flow channel member 8J when the first flow channel member 7J is inverted around the Z-axis along the insertion direction DI from its correct position.

[0116] Note that the cross-sectional area and shape of the guided portions 711J to 741J in the vertical direction perpendicular to the insertion direction DI shown in Figure 22, and the area and shape of the virtual circles C10, C20, C30, and C40 of the corresponding guide portions 81J to 84J are not limited to those shown. Also, the cross-sectional area and shape of the support members 751, 761, 771, and 781 in the vertical direction perpendicular to the insertion direction DI are not limited to those shown, and may have other areas or shapes.

[0117] F. Other embodiments: F-1: Other Embodiments 1: In other embodiments, when the first flow channel member 7 has a plurality of flow channel pipes 71 to 78, the first flow channel member 7 may have one guided portion, and the second flow channel member 8 may have one guide portion that guides the guided portion. In this case, for example, the one guided portion may be provided on flow channel pipes 71 to 74 located at the ends of the flow channel pipes 71 to 78 in the arrangement direction. The cross-sectional area of ​​the one guided portion with respect to the vertical direction perpendicular to the insertion direction DI may be different from, for example, the cross-sectional area of ​​the other support portion with respect to the vertical direction perpendicular to the insertion direction DI. Even in such a configuration, the possibility of the first flow channel member 7 being misaligned from its correct position or rotated around the Z-axis along the insertion direction DI can be reduced.

[0118] F-2: Other Embodiments 2: In other embodiments, when the first flow channel member 7 has a plurality of flow channel pipes 71 to 78, the first flow channel member 7 may have two guided portions, and the second flow channel member 8 may have two guide portions that guide the guided portions. In this case, for example, the two guided portions may be provided on flow channel pipes 71 to 74 located at both ends in the arrangement direction of the flow channel pipes 71 to 78. Furthermore, the cross-sectional areas of the two guided portions in the vertical direction perpendicular to the insertion direction DI may be different from each other. Even in such a configuration, the possibility of the first flow channel member 7 being misaligned from its correct position or rotated around the Z-axis along the insertion direction DI can be reduced.

[0119] F-3: Other Embodiments 3: In other embodiments, when the first flow channel member 7 has a plurality of flow channel pipes 71 to 78, the first flow channel member 7 may have three guided portions, and the second flow channel member 8 may have three guide portions that guide the guided portions. In this case, for example, the three guided portions may be provided on flow channel pipes 71 to 74 located at both ends in the arrangement direction of the flow channel pipes 71 to 78. Furthermore, the cross-sectional areas of the two guided portions in the vertical direction perpendicular to the insertion direction DI may be different from each other. Even in such a configuration, the possibility of the first flow channel member 7 being misaligned from its correct position or rotated around the Z-axis along the insertion direction DI can be reduced.

[0120] F-4: Other Embodiments 4: In the above embodiment, as shown in Figure 2, the first flow path member 7 was provided in the flow path structure 50, and the second flow path member 8 was provided in the flow path connecting member 60 of the liquid injection head 20. However, the disclosure is not limited thereto. The first flow path member 7 may also be provided in the flow path connecting member 60. If the first flow path member 7 is provided in the flow path connecting member 60, the second flow path member 8 is provided in the flow path structure 50. Even in this configuration, during the connection operation, the guided portions 711 to 741 are guided by the guide portions 81 to 84 before the insertion portions 715 to 785 are inserted into the openings 821 to 828, thereby enabling positioning of the flow path structure 50 and the flow path connecting member 60 of the liquid injection head 20. Furthermore, even in this configuration, there is no need to provide a positioning member at a different location from the flow path tubes 71 to 78 through which the liquid flows. Therefore, the first flow path member 7 and the second flow path member 8 can be miniaturized in both the insertion direction DI of the first flow path member 7 relative to the second flow path member 8 and the vertical direction perpendicular to the insertion direction DI. This makes it possible to miniaturize the flow channel structure 50 and the flow channel connecting member 60 in the three-dimensional directions of the X, Y, and Z directions.

[0121] F-5: Other Embodiments 5: In the above embodiment, as shown in Figures 10 and 12, the first flow channel member 7 had eight flow channel tubes 71 to 78, and the second flow channel member 8 had eight openings 821 to 828 into which the eight flow channel tubes 71 to 78 were inserted. However, the disclosure is not limited thereto. The number of flow channel tubes 71 to 78 and openings 821 to 828 may be between 1 and 7, or between 9 and 828. In other words, in the above embodiment, two types of flow channels 56 and 57 were formed as flow channels 56 and 57 connected to the first flow channel member 7, but the disclosure is not limited thereto, and the liquid injection device 1 may, for example, have only a supply flow channel 56. Also, in the above embodiment, there were four types of ink: cyan, magenta, yellow, and black, but the disclosure is not limited thereto, and the types of ink flowing inside the first flow channel member 7 and the second flow channel member 8 may be between 1 and 3, or between 5 and 8.

[0122] G. Other forms: This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features of the embodiments corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate.

[0123] (1) According to a first embodiment of the present disclosure, a liquid injection device is provided. The liquid injection device comprises a liquid injection head that includes one of a first flow path member and a second flow path member and injects a liquid, and a flow path structure that includes the other of the first flow path member and the second flow path member, wherein the liquid injection device is capable of a connection operation to connect the first flow path member to the second flow path member by moving the first flow path member relative to the second flow path member in the insertion direction, the first flow path member having a base portion and a first flow path pipe having a flow path formed therein through which liquid flows and protruding from the base portion in the insertion direction, the second flow path member having a connection surface having a first opening into which the first flow path pipe is inserted, and a first guide portion arranged in the opposite direction to the insertion direction with respect to the connection surface, the first flow path pipe including a first insertion portion that is inserted into the first opening, and a first guided portion that is guided by the first guide portion before the first insertion portion is inserted into the first opening in the connection operation, the first guided portion being arranged between the first insertion portion and the base portion. In this configuration, during the connection operation of the first flow path member to the second flow path member, the guided portion is guided by the guide portion before the insertion portion is inserted into the opening, thereby enabling positioning of the flow path structure and the liquid injection head. In other words, there is no need to provide a positioning member at a location different from the flow path tube in order to position the flow path structure and the liquid injection head. Therefore, the first flow path member and the second flow path member can be miniaturized in both the insertion direction of the first flow path member to the second flow path member and in the vertical direction perpendicular to the insertion direction.

[0124] (2) In the above embodiment, the base portion may be characterized in that it contacts the first guide portion to restrict the relative movement of the first flow channel member with respect to the second flow channel member in the insertion direction. According to this embodiment, the contact between the base portion and the first guide portion can restrict the relative movement of the first flow channel member with respect to the second flow channel member in the insertion direction. This makes it possible to define the amount of insertion of the first flow channel member into the second flow channel member when performing a connection operation.

[0125] (3) In the above embodiment, the base portion and the first guide portion may be fixed by a fixing member. In this embodiment, the guide portion and the base portion used for positioning can also be used as a fixing position and can also serve as a fixed member. Therefore, there is no need to provide a separate fixing position for fixing the fixing member. As a result, the first flow path member and the second flow path member can be miniaturized in the vertical direction perpendicular to the insertion direction of the first flow path member into the second flow path member.

[0126] (4) In the above embodiment, when the second flow channel member is connected to the first flow channel member, a part of the first guided portion may be located between the first insertion portion and the first guide portion when viewed in the insertion direction. This embodiment reduces the possibility that the tip of the first insertion portion may come into contact with the first guide portion during the connection operation.

[0127] (5) In the above embodiment, the first flow channel member may have a plurality of flow channel tubes including the first flow channel tube, each of the plurality of flow channel tubes having a flow channel formed inside for liquid to flow and protruding from the base portion in the insertion direction, and the connecting surface may have a plurality of openings including the first opening into which each of the plurality of flow channel tubes is inserted. In this embodiment, a plurality of flow channel tubes protrude from a single base portion. This makes it possible to move the plurality of flow channel tubes together. Therefore, the connection operation between the first flow channel member and the second flow channel member can be performed smoothly.

[0128] (6) In the above embodiment, the plurality of flow tubes include a second flow tube, the plurality of openings include a second opening into which the second flow tube is inserted, the second flow member further has a second guide portion arranged in the opposite direction to the insertion direction with respect to the connection surface, the second flow tube includes a second insertion portion inserted into the second opening, and a second guided portion which is guided by the second guide portion before each of the plurality of flow tubes is inserted into each of the plurality of openings during the connection operation, the second guided portion is arranged between the second insertion portion and the base portion, and the cross-sectional shape of the second guided portion with respect to the vertical direction perpendicular to the insertion direction is different from the cross-sectional shape of the first guided portion with respect to the vertical direction perpendicular to the insertion direction. According to this embodiment, the cross-sectional shape of the first guided portion with respect to the vertical direction perpendicular to the insertion direction is different from the cross-sectional shape of the second guided portion with respect to the vertical direction perpendicular to the insertion direction. This makes it possible to prevent the first flow member from being connected to the second flow connecting member in an arrangement different from the correct arrangement. In other words, it is possible to reduce the erroneous insertion of the first flow channel member into the second flow channel member.

[0129] (7) In the above embodiment, the plurality of flow channels include a third flow channel, the plurality of openings include a third opening into which the third flow channel is inserted, the second flow channel member further has a third guide portion arranged in the opposite direction to the insertion direction with respect to the connection surface, the third flow channel includes a third insertion portion inserted into the third opening, and a third guided portion which is guided by the third guide portion before each of the plurality of flow channels is inserted into each of the plurality of openings during the connection operation, the third guided portion is arranged between the third insertion portion and the base portion, and the cross-sectional shape of the third guided portion in the vertical direction perpendicular to the insertion direction is different from the cross-sectional shape of the first guided portion and the cross-sectional shape of the second guided portion. According to this embodiment, the erroneous insertion of the first flow channel member into the second flow channel member can be further reduced.

[0130] (8) In the above embodiment, the plurality of flow tubes include a fourth flow tube, the plurality of openings include a fourth opening into which the fourth flow tube is inserted, the second flow member further has a fourth guide portion arranged in the opposite direction to the insertion direction with respect to the connection surface, the fourth flow tube includes a fourth insertion portion inserted into the fourth opening, and a fourth guided portion which is guided by the fourth guide portion before each of the plurality of flow tubes is inserted into each of the plurality of openings in the connection operation, the fourth guided portion is arranged between the fourth insertion portion and the base portion, and the cross-sectional shape of the fourth guided portion in the vertical direction perpendicular to the insertion direction is different from the cross-sectional shape of the first guided portion, the cross-sectional shape of the second guided portion and the cross-sectional shape of the third guided portion. According to this embodiment, the erroneous insertion of the first flow member into the second flow member can be further reduced.

[0131] (9) In the above embodiment, the cross-sectional area of ​​the second guided portion with respect to the vertical direction perpendicular to the insertion direction is smaller than the cross-sectional area of ​​the third guided portion with respect to the vertical direction perpendicular to the insertion direction, the cross-sectional area of ​​the third guided portion with respect to the vertical direction perpendicular to the insertion direction is smaller than the cross-sectional area of ​​the fourth guided portion with respect to the vertical direction perpendicular to the insertion direction, the cross-sectional area of ​​the fourth guided portion with respect to the vertical direction perpendicular to the insertion direction is smaller than the cross-sectional area of ​​the first guided portion with respect to the vertical direction perpendicular to the insertion direction, and the line segment connecting the second guided portion and the third guided portion intersects with respect to the insertion direction. In this embodiment, for example, the possibility of the first flow channel member being mistakenly connected to the second flow channel member when the first flow channel member is misaligned from its correct position or rotated around an axis along the insertion direction can be more reliably reduced.

[0132] (10) In the above embodiment, the quadrilateral whose vertices are the first flow channel, the second flow channel, the third flow channel, and the fourth flow channel, when viewed in the insertion direction, may be a parallelogram. According to this embodiment, the possibility of the first flow channel member being mistakenly connected to the second flow channel member when the first flow channel member is inverted around an axis along the insertion direction from its correct position can be reduced even more reliably.

[0133] (11) In the above embodiment, the plurality of flow channels may include a fifth flow channel, the plurality of openings may include a fifth opening into which the fifth flow channel is inserted, and in the connected state in which the second flow channel member is connected to the first flow channel member, the fifth flow channel member contacts the second flow channel member only with respect to the portion inserted into the fifth opening. According to this embodiment, even if some of the plurality of flow channels include a flow channel that is not guided by the guide portion, the erroneous insertion of the first flow channel member into the second flow channel member can be reduced.

[0134] (12) In the above embodiment, the first guide portion may be characterized in that it protrudes from the connection surface in the direction opposite to the insertion direction. In this embodiment, since the connection surface having an opening into which the insertion portion is inserted and the guide portion are integrally formed, the positioning accuracy of the first flow path member relative to the second flow path member can be improved.

[0135] (13) In the above embodiment, the first flow channel tube may be characterized in that it is positioned between the first guided portion and the first insertion portion and includes a portion in which the cross-sectional area in the vertical direction perpendicular to the insertion direction gradually decreases as it moves from the first guided portion toward the first insertion portion. According to this embodiment, the guide portion and the guided portion can be made to come into contact during the connection operation of the first flow channel member to the second flow channel member. In other words, the insertability of the first flow channel member toward the second flow channel member can be improved.

[0136] (14) A second embodiment of the present disclosure provides a liquid injection device. The liquid injection device comprises a liquid injection head that includes one of a first flow channel member and a second flow channel member and injects a liquid, and a flow channel structure that includes the other of the first flow channel member and the second flow channel member, wherein the liquid injection device is capable of a connection operation that connects the first flow channel member to the second flow channel member by moving the first flow channel member relative to the second flow channel member in the insertion direction, the first flow channel member having a base portion and a first flow channel pipe having a flow channel formed inside through which liquid flows and protruding from the base portion in the insertion direction, and the second flow channel member is the first The first flow channel has a connecting surface having a first opening into which a flow channel tube is inserted, and a first guide portion positioned in the opposite direction to the insertion direction relative to the connecting surface, wherein the first flow channel tube includes a first insertion portion inserted into the first opening and a first guided portion positioned between the first insertion portion and the base portion, and the distance in the insertion direction from the end face of the first guide portion in the opposite direction to the insertion direction to the connecting surface is greater than the distance in the insertion direction from the connection portion between the first insertion portion and the first guided portion to the end of the first insertion portion in the insertion direction. In this form, the distance in the insertion direction from the end face of the first guide portion in the opposite direction to the insertion direction to the connecting surface is greater than the distance in the insertion direction from the connection portion between the first insertion portion and the first guided portion to the end of the first insertion portion in the insertion direction. In this way, during the connection operation of the first flow channel member to the second flow channel member, the flow channel structure and the liquid injection head can be positioned such that the guided portion is guided by the guide portion before the insertion portion is inserted into the opening. In other words, there is no need to provide a positioning member at a location different from the flow channel pipe in order to position the flow channel structure and the liquid injection head. Therefore, the first flow channel member and the second flow channel member can be miniaturized in both the insertion direction of the first flow channel member relative to the second flow channel member and in the vertical direction perpendicular to the insertion direction.

[0137] Not all of the components of each form of the present disclosure described above are essential, and it is possible to modify, delete, replace with other new components, or delete some of the limitations of some of the components as appropriate in order to solve some or all of the problems described above or to achieve some or all of the effects described herein. Furthermore, it is also possible to combine some or all of the technical features included in one form of the present disclosure described above with some or all of the technical features included in another form of the present disclosure described above to form an independent form of the present disclosure in order to solve some or all of the problems described above or to achieve some or all of the effects described herein.

[0138] This disclosure can also be implemented in various forms other than liquid injection devices. For example, it can be implemented in forms such as a method for manufacturing a liquid injection device. [Explanation of symbols]

[0139] 1...Liquid injection device, 3...Control unit, 4...Media transport mechanism, 5...Supply circulation mechanism, 7,7E,7F,7G,7J...First flow path member, 8,8E,8G,8J...Second flow path member, 9...Receiving flow path member, 10...Injection section, 19...Connector, 20...Liquid injection head, 22...Support member, 23...Frame section, 24~27...Side walls, 30...Common flow path member, 31...First common flow path substrate, 32...Second common flow path substrate, 33...Internal flow path, 35...Substrate side connecting pipe, 50...Flow path structure, 51...Main tank, 52...Supply side sub-tank, 53...Recovery side sub-tank, 54...First intermediate flow path, 55...Second 2 intermediate flow paths, 56... supply flow path, 57... recovery flow path, 58... first pump, 59... second pump, 60... flow path connecting member, 70, 70E... base part, 70b... opposing surface, 71, 71F, 71G, 71J... first flow path pipe, 72, 72J... second flow path pipe, 73, 73G, 73J... third flow path pipe, 74, 74J... fourth flow path pipe, 75... fifth flow path pipe, 76... sixth flow path pipe, 77... seventh flow path pipe, 78... eighth flow path pipe, 80... base part, 81, 81E, 81G, 81J... first guide part, 81i... guide surface of the first guide part, 81p... first tapering part on the guide part side, 81t... end face of the first guide part, 82, 82J...Second guide section, 82t...End face of the second guide section, 83, 83G, 83J...Third guide section, 83i...Guiding surface of the third guide section, 83p...Second tapering section on the guide section side, 83t...End face of the third guide section, 84, 84J...Fourth guide section, 84i...Guiding surface of the fourth guide section, 84t...End face of the fourth guide section, 89...Intermediate section, 91, 92...Fixing member, 93...Receiving opening, 100...Line head, 160...End-side connecting pipe, 190...Inter-member flow path, 708, 709...Base-side fixing hole, 710p, 730p...Boundary section on the guided section side, 711, 711F, 711G, 7 11J...First guided section, 711p...First tapering section on the guided section side, 711s...First outer surface, 715, 715F...First insertion section, 715p...Tip of the first insertion section, 717...Connection section, 718...First internal flow path, 721, 721J...Second guided section, 721s...Second outer surface, 725...Second insertion section, 725p...Tip of the second insertion section, 728...Second internal flow path, 731, 731G, 731J...Third guided section, 731p...Second tapering section on the guided section side, 731s...Third outer surface, 735...Third insertion section, 735p...Tip of the third insertion section, 738...Third internal flow path, 741,741J...4th guided section, 741s...4th outer surface, 745...4th insertion section, 745p...tip of the 4th insertion section, 748...4th internal pipe flow path, 751...5th support section, 751s...outer surface of the 5th support section, 755...5th insertion section, 755p...tip of the 5th insertion section, 758...5th internal pipe flow path, 761...6th support section, 761s...outer surface of the 6th support section, 765...6th insertion section, 765p...tip of the 6th insertion section End section, 768... sixth internal pipe flow path, 771... seventh support section, 771s... outer surface of the seventh support section, 775... seventh insertion section, 775p... tip of the seventh insertion section, 778... seventh internal pipe flow path, 781... eighth support section, 781s... outer surface of the eighth support section, 785... eighth insertion section, 785p... tip of the eighth insertion section, 788... eighth internal pipe flow path, 810p... guide section side boundary, 817, 827, 837, 847... connection Parts, 819, 839... Guide-side fixing holes, 820... Connection surface, 821... First opening, 822... Second opening, 823... Third opening, 824... Fourth opening, 825... Fifth opening, 826... Sixth opening, 827... Seventh opening, 828... Eighth opening, C1~C4, C10, C20, C30, C40... Virtual circles, DH1... First alignment direction, DH2... Second alignment direction, DH3... Third alignment direction, DH 4…Fourth alignment direction, DI…Insertion direction, DM…Conveying direction, F1…Spray surface, L1, L10, L20…Distance, L2, L3, W1, W2, W5, W20…Dimensions, Li1…First line segment, Li2…Second line segment, NZ…Nozzle, PA…Media, R1…First straight line, R2…Second straight line, fa1…First outer surface, fa2…Second outer surface, fa3…Third outer surface, fa4…Fourth outer surface, fa5…Fifth outer surface, fa6…Sixth outer surface

Claims

1. A liquid injection device, A liquid injection head that includes one of the first flow channel member and the second flow channel member and injects liquid, A flow channel structure comprising the other of the first flow channel member and the second flow channel member, The liquid injection device is capable of connecting the first flow path member to the second flow path member by moving the first flow path member relative to the second flow path member in the insertion direction, The first flow channel member is The base part, It has a first flow channel tube that has a flow channel formed inside through which liquid flows and protrudes from the base portion in the insertion direction, The second flow channel member is A connecting surface having a first opening into which the first flow channel pipe is inserted, It has a first guide portion that is positioned in the opposite direction to the insertion direction with respect to the connection surface, The first flow channel tube is, A first insertion portion inserted into the first opening, The connection operation includes a first guided portion which is guided by the first guide portion before the first insertion portion is inserted into the first opening, A liquid injection device characterized in that the first guided portion is positioned between the first insertion portion and the base portion.

2. A liquid injection device according to claim 1, The liquid injection device is characterized in that the base portion contacts the first guide portion to restrict the relative movement of the first flow path member with respect to the second flow path member in the insertion direction.

3. A liquid injection device according to claim 2, A liquid injection device characterized in that the base portion and the first guide portion are fixed together by a fixing member.

4. A liquid injection device according to claim 1, A liquid injection device characterized in that, in a connected state in which the second flow channel member is connected to the first flow channel member, a part of the first guided portion is located between the first insertion portion and the first guide portion when viewed in the insertion direction.

5. A liquid injection device according to claim 1, The first flow channel member has a plurality of flow channel tubes, including the first flow channel tube. Each of the aforementioned plurality of flow channels has a flow channel formed inside through which liquid flows and protrudes from the base portion in the insertion direction. The liquid injection device is characterized in that the connecting surface has a plurality of openings, including the first opening, into which each of the plurality of flow path tubes is inserted.

6. A liquid injection device according to claim 5, The plurality of flow channels include a second flow channel, The plurality of openings include a second opening into which the second flow channel tube is inserted. The second flow channel member further has a second guide portion arranged in the opposite direction to the insertion direction with respect to the connection surface, The second flow channel tube is A second insertion portion inserted into the second opening, The connection operation includes a second guided portion which is guided by the second guide portion before each of the plurality of flow path tubes is inserted into each of the plurality of openings, The second guided portion is positioned between the second insertion portion and the base portion. A liquid injection device characterized in that the cross-sectional shape of the second guided portion in the vertical direction perpendicular to the insertion direction is different from the cross-sectional shape of the first guided portion in the vertical direction perpendicular to the insertion direction.

7. A liquid injection device according to claim 6, The plurality of flow channels include a third flow channel, The plurality of openings include a third opening into which the third flow channel tube is inserted. The second flow channel member further has a third guide portion arranged in the opposite direction to the insertion direction with respect to the connection surface, The third flow channel tube is, A third insertion portion inserted into the opening of the third opening, The connection operation includes a third guided portion which is guided by the third guide portion before each of the plurality of flow path tubes is inserted into each of the plurality of openings, The third guided portion is positioned between the third insertion portion and the base portion. A liquid injection device characterized in that the cross-sectional shape of the third guided portion in the vertical direction perpendicular to the insertion direction is different from the cross-sectional shape of the first guided portion and the cross-sectional shape of the second guided portion.

8. A liquid injection device according to claim 7, The plurality of flow channels include a fourth flow channel, The plurality of openings include a fourth opening into which the fourth flow channel pipe is inserted. The second flow channel member further has a fourth guide portion arranged in the opposite direction to the insertion direction with respect to the connection surface, The fourth flow channel tube is, A fourth insertion portion inserted into the fourth opening, The connection operation includes a fourth guided portion which is guided by the fourth guide portion before each of the plurality of flow path tubes is inserted into each of the plurality of openings, The fourth guided portion is positioned between the fourth insertion portion and the base portion. A liquid injection device characterized in that the cross-sectional shape of the fourth guided portion in the vertical direction perpendicular to the insertion direction is different from the cross-sectional shape of the first guided portion, the cross-sectional shape of the second guided portion, and the cross-sectional shape of the third guided portion.

9. A liquid injection device according to claim 8, The cross-sectional area of ​​the second guided portion with respect to the vertical direction perpendicular to the insertion direction is smaller than the cross-sectional area of ​​the third guided portion with respect to the vertical direction perpendicular to the insertion direction. The cross-sectional area of ​​the third guided portion with respect to the vertical direction perpendicular to the insertion direction is smaller than the cross-sectional area of ​​the fourth guided portion with respect to the vertical direction perpendicular to the insertion direction. The cross-sectional area of ​​the fourth guided portion with respect to the vertical direction perpendicular to the insertion direction is smaller than the cross-sectional area of ​​the first guided portion with respect to the vertical direction perpendicular to the insertion direction. A liquid injection device characterized in that, when viewed in the insertion direction, the line segment connecting the second guided portion and the third guided portion and the line segment connecting the fourth guided portion and the first guided portion intersect.

10. A liquid injection device according to claim 9, A liquid injection device characterized in that, when viewed in the insertion direction, the quadrilateral whose vertices are the first flow channel, the second flow channel, the third flow channel, and the fourth flow channel is a parallelogram.

11. A liquid injection device according to claim 5, The aforementioned plurality of flow channels include a fifth flow channel, The plurality of openings include a fifth opening into which the fifth flow channel tube is inserted. A liquid injection device characterized in that, in a connected state in which the second flow channel member is connected to the first flow channel member, the fifth flow channel pipe contacts the second flow channel member only with respect to the portion inserted into the fifth opening.

12. A liquid injection device according to claim 1, The liquid injection device is characterized in that the first guide portion protrudes from the connection surface in the direction opposite to the insertion direction.

13. A liquid injection device according to claim 1, A liquid injection device characterized in that the first flow channel tube is arranged between the first guided portion and the first insertion portion, and includes a portion in which the cross-sectional area in the vertical direction perpendicular to the insertion direction gradually decreases as it moves from the first guided portion toward the first insertion portion.

14. A liquid injection device, A liquid injection head that includes one of the first flow channel member and the second flow channel member and injects liquid, A flow channel structure comprising the other of the first flow channel member and the second flow channel member, The liquid injection device is capable of connecting the first flow path member to the second flow path member by moving the first flow path member relative to the second flow path member in the insertion direction, The first flow channel member is The base part, It has a first flow channel tube that has a flow channel formed inside through which liquid flows and protrudes from the base portion in the insertion direction, The second flow channel member is A connecting surface having a first opening into which the first flow channel pipe is inserted, It has a first guide portion that is positioned in the opposite direction to the insertion direction with respect to the connection surface, The first flow channel tube is, A first insertion portion inserted into the first opening, The first insertion portion and the base portion are disposed between them, A liquid injection device characterized in that the distance from the end face of the first guide portion in the direction opposite to the insertion direction to the connecting surface is greater than the distance from the connection portion between the first insertion portion and the first guided portion to the end of the first insertion portion in the insertion direction.

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