Coupling member, flow path connection mechanism, and ink jet recording apparatus

Abstract

To facilitate the cleaning work of a coupling member.SOLUTION: A coupling member comprises a valve housing and a hollow movable valve that is disposed radially inward of the valve housing and axially displaceable relative to the valve housing. The hollow movable valve is displaced in an axial direction relative to the valve housing between a connection state in which the coupling member is connected to another coupling member and a disconnection state in which the connection is released, allows liquid to flow in the connection state, and restricts liquid flow in the disconnection state. In the connection state, a gap is formed in a radial direction between a predetermined portion of the hollow movable valve and the valve housing. The hollow movable valve has a flow port penetrating the predetermined portion in the radial direction.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present invention relates to a coupling member for circulating a liquid, a flow path connecting mechanism, and an inkjet recording apparatus. [Background technology]

[0002] Inkjet recording devices use ink as a liquid. In other words, ink is circulated within the device. Such an inkjet recording device is disclosed in, for example, Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-198984 Summary of the Invention [Problem to be solved by the invention]

[0004] Inkjet recording devices are equipped with a flow path connection mechanism that includes a coupling member connected to a tube to allow ink to flow. The coupling member has, for example, a cylindrical body with the interior thereof serving as a flow path. A valve is disposed inside the cylindrical body. In this configuration, ink accumulates in the gap between the cylindrical body and the valve. This makes cleaning the coupling time-consuming.

[0005] The present invention has been made in consideration of the above points, and has an object to provide a coupling member, a flow path connecting mechanism, and an inkjet recording apparatus that can facilitate the cleaning work of the coupling member. [Means for solving the problem]

[0006] To solve the above problems, a coupling member according to a first aspect of the present invention is a cylindrical body having an axis extending in a predetermined direction as a central axis, having a liquid flow path therein, and allowing liquid to flow in the axial direction, and includes a cylindrical valve housing centered on the central axis, and a hollow movable valve arranged radially inward of the valve housing, also cylindrical and centered on the central axis, and displaceable in the axial direction relative to the valve housing. The hollow movable valve displaces its axial position relative to the valve housing between a connected state in which the coupling member and another coupling member are connected and a disconnected state in which the connection is disconnected, thereby allowing liquid to flow in the connected state and restricting liquid flow in the disconnected state. In the connected state, a gap is generated radially between a predetermined portion of the hollow movable valve and the valve housing. The hollow movable valve has a flow port radially penetrating the predetermined portion.

[0007] A flow path connection mechanism according to a second aspect of the present invention includes the above-mentioned coupling member as a first coupling member, and further includes a second coupling member that is axially connected to the first coupling member, has a liquid flow path therein, and axially flows the liquid together with the first coupling member.

[0008] An inkjet recording apparatus according to a third aspect of the present invention includes the above-described coupling member, the liquid is ink, and printing is performed using the ink. [Effects of the Invention]

[0009] According to the configuration of the present invention, the cleaning work of the coupling member can be easily performed. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of an inkjet recording apparatus according to an embodiment. [Figure 2] 1 is a plan view of a printing unit of an inkjet printing apparatus according to an embodiment. [Figure 3] FIG. 1 is a perspective view of a flow path connection mechanism according to one embodiment. [Figure 4]1 is a perspective view of a state in which the first coupling member and the second coupling member are disconnected according to one embodiment; FIG. [Figure 5] FIG. 1 is a cross-sectional view of a flow path connection mechanism according to one embodiment. [Figure 6] FIG. 2 is an exploded perspective view of a first coupling member according to one embodiment. [Figure 7] FIG. 2 is a cross-sectional view of a first coupling member according to one embodiment. [Figure 8] FIG. 10 is an exploded perspective view of a second coupling member according to one embodiment. [Figure 9] FIG. 10 is a cross-sectional view of a second coupling member according to one embodiment. [Figure 10] FIG. 1 is a perspective view of a connecting member according to one embodiment. [Figure 11] 10 is a perspective view showing the positional relationship between a connecting protrusion and a guide groove when a first coupling member is inserted into the inside of a connecting member according to one embodiment. FIG. [Figure 12] 10 is a plan view showing the positional and dimensional relationship between a connection protrusion and a connection hole according to one embodiment. FIG. [Figure 13] 10 is a cross-sectional view illustrating a state at the moment when a first coupling member and a second coupling member are separated from each other according to one embodiment. FIG. [Figure 14] FIG. 2 is a perspective view of a first valve housing according to one embodiment. [Figure 15] FIG. 10 is a perspective view of a first valve housing according to a first modified example. [Figure 16] FIG. 10 is a perspective view of a first valve housing according to a second modified example. [Figure 17] 10A and 10B are diagrams illustrating transitions in the positional relationship between the connecting protrusion and the connecting hole when connecting and disconnecting the first coupling member and the second coupling member according to one embodiment. [Figure 18] 3 is a perspective view of the concave-convex portions and their surroundings of the first coupling member and the second coupling member according to one embodiment. FIG. [Figure 19]5A to 5C are diagrams illustrating transitions in the positional relationship between the concave-convex portions of the first coupling member and the second coupling member according to one embodiment. [Figure 20] FIG. 4 is an enlarged plan view of a concave-convex portion according to one embodiment. [Figure 21] FIG. 2 is a plan view of a connecting member according to one embodiment, as viewed from an axial direction. [Figure 22] FIG. 10 is an enlarged view of a protrusion of a connecting member according to one embodiment. [Figure 23] 10A and 10B are diagrams illustrating a circumferential backlash between a connecting protrusion and a guide groove according to an embodiment. [Figure 24] 10A and 10B are diagrams for explaining circumferential backlash between a connecting protrusion and an engagement region of a connecting hole according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Configuration of Inkjet Recording Apparatus> 1, the inkjet recording apparatus 500 of this embodiment is an inkjet recording type printer. The inkjet recording apparatus 500 includes a device main body 510, a paper supply unit 520, a paper transport unit 530, a recording unit 540, a drying unit 550, a paper discharge unit 560, and a control unit 570.

[0012] The paper supply unit 520 stores paper P as a recording medium. The paper supply unit 520 feeds out the paper P one sheet at a time. The paper transport unit 530 transports the paper P fed out from the paper supply unit 520. The paper P passes through the recording unit 540 and the drying unit 550 in this order. The recording unit 540 performs recording on the paper P (in other words, image formation). The drying unit 550 dries the image (i.e., ink) recorded on the paper P. Thereafter, the paper transport unit 530 discharges the paper P to the paper discharge unit 560.

[0013] The paper transport section 530 includes a first belt transport section 531 and a second belt transport section 532. The first belt transport section 531 and the second belt transport section 532 each have an endless belt that is stretched and capable of rotating. The first belt transport section 531 and the second belt transport section 532 each adsorb and hold the paper P on the outer circumferential surface of the belt. The belt rotates in this state, thereby transporting the paper P.

[0014] When double-sided recording is performed, after recording on one side, paper transport section 530 distributes paper P to reversing transport section 534 by branching section 533. Reversing transport section 534 switches back paper P and returns paper P to the upstream side of recording section 540 in the paper transport direction. This turns paper P upside down. Paper transport section 530 transports paper P again, with its front and back now turned upside down.

[0015] The recording unit 540 is located above the first belt conveying unit 531 and faces the paper P conveyed by the first belt conveying unit 531 (specifically, the belt) at a predetermined distance. The recording unit 540 has a line-type inkjet recording head 541.

[0016] 2, the recording head 541 includes a plurality of (for example, three) recording heads 541B, 541C, 541M, and 541Y corresponding to four colors, black, cyan, magenta, and yellow, respectively. The three recording heads 541 for each color are arranged in a staggered pattern in the paper width direction Dw, which is perpendicular to the paper transport direction Dc.

[0017] The recording head 541 has a plurality of ink ejection nozzles 542. The plurality of ink ejection nozzles 542 are arranged in the paper width direction Dw. The recording unit 540 ejects ink from the recording heads 541B, 541C, 541M, and 541Y toward the paper P transported by the first belt transport unit 531. In this way, an image is recorded on the paper P.

[0018] 1, the drying unit 550 is disposed downstream in the paper conveying direction from the recording unit 540. The second belt conveying unit 532 conveys the paper P in the drying unit 550. The drying unit 550 dries the ink adhering to the paper P while the paper P is being conveyed by the second belt conveying unit 532.

[0019] Although not shown, the control unit 570 includes various electronic components such as a processing circuit (e.g., a CPU) and memory (e.g., a ROM and a RAM). The control unit 570 controls the operation of each component provided in the inkjet recording apparatus 500 based on a control program and control data. The paper supply unit 520, the paper transport unit 530, the recording unit 540, and the drying unit 550 each receive commands from the control unit 570 individually and perform recording on the paper P in coordination with each other.

[0020] The inkjet recording device 500 also includes an ink supply unit 580. The ink supply unit 580 holds an ink container (not shown). The ink container stores ink. The ink supply unit 580 supplies ink from the ink container to the device main body 510. The ink is supplied to the recording unit 540. The recording head 541 ejects the ink supplied from the ink container.

[0021] Here, a tube TU (see FIG. 5) is used to supply ink from the ink supply unit 580 to the device main body 510. The ink is supplied from the ink supply unit 580 to the device main body 510 via the tube TU. In other words, the tube TU circulates the ink.

[0022] The tube TU is divided in the middle. A flow path connection mechanism 1000 (see FIGS. 3 to 5), which will be described later, is disposed at the divided portion of the tube TU. The flow path connection mechanism 1000 relays the divided portion of the tube TU and allows ink to circulate at the divided portion of the tube TU. In this configuration, the ink corresponds to the "liquid."

[0023] <Configuration of flow path connection mechanism> The inkjet recording apparatus 500 includes a flow path connection mechanism 1000 as shown in Figures 3 to 5. The flow path connection mechanism 1000 includes a first coupling member 1 and a second coupling member 2. Both the first coupling member 1 and the second coupling member 2 correspond to the "coupling member."

[0024] The first coupling member 1 and the second coupling member 2 are each a cylindrical body with a central axis CA that extends in a predetermined direction. In the following description, the direction in which the central axis CA extends (i.e., the direction corresponding to the "predetermined direction") will be referred to as the "axial direction," the circumferential direction about the central axis CA will be referred to as the "circumferential direction," and the direction perpendicular to the central axis CA will be referred to as the "radial direction." Within the radial direction, the direction approaching the central axis CA will be referred to as the "radially inward direction," and the direction away from the central axis CA will be referred to as the "radially outward direction."

[0025] The first coupling member 1 and the second coupling member 2 are each connected to a tube TU, and have their interiors (i.e., the interior of the cylindrical bodies) as ink flow paths, allowing ink to flow in the axial direction. That is, the first coupling member 1 and the second coupling member 2 are each cylindrical bodies whose axial direction is the ink flow direction.

[0026] The first coupling member 1 and the second coupling member 2 can be connected to each other in the axial direction. By connecting the first coupling member 1 and the second coupling member 2, the flow path paths of the first coupling member 1 and the second coupling member 2 are communicated in the axial direction, allowing ink to flow in the axial direction. Note that the connection between the first coupling member 1 and the second coupling member 2 can be released.

[0027] Fig. 3 shows a state in which the first coupling member 1 and the second coupling member 2 are connected. Fig. 4 shows a state in which the first coupling member 1 and the second coupling member 2 are disconnected. Fig. 5 is a cross-sectional view of the state in which the first coupling member 1 and the second coupling member 2 are connected. The cross-section shown in Fig. 5 corresponds to a cross-section taken along a plane including the central axis CA.

[0028] <Configuration of the first coupling member> As shown in Fig. 6, the first coupling member 1 includes a first member 11 and a second member 12. The first member 11 and the second member 12 are fixed to each other. By fixing the first member 11 and the second member 12 to each other, the first member 11 and the second member 12 are connected to each other in the axial direction. Fig. 7 shows a cross-sectional view (a cross-sectional view of the first coupling member 1 alone) of the state in which the first member 11 and the second member 12 are fixed to each other. The cross-section shown in Fig. 7 corresponds to a cross-section cut along a plane including the central axis CA.

[0029] A tube TU is connected to the first member 11. A second coupling member 2 (i.e., another coupling member) is connected to the second member 12. In the following description, of the two axial sides of the first coupling member 1, the side to which the tube TU is connected will be referred to as one axial side of the first coupling member 1, and the side to which the second coupling member 2 is connected will be referred to as the other axial side of the first coupling member 1. Note that, inside the first coupling member 1, ink may flow from one axial side to the other, or from the other axial side to one side.

[0030] The first member 11 has a tube connecting portion 111. The tube connecting portion 111 is cylindrical and has a central axis CA as its center. The tube connecting portion 111 is disposed on one side of the first member 11 in the axial direction. When the tube connecting portion 111 is inserted into the tube TU, the tube TU is connected to the first member 11.

[0031] The first member 11 also has an outer fitting portion 110. The outer fitting portion 110 is disposed on the other axial side of the first member 11. The outer fitting portion 110 has a cylindrical shape centered on a central axis CA.

[0032] The second member 12 has a cylindrical shape centered on a central axis CA. Ink flows through the inside of the second member 12.

[0033] The second member 12 holds the first valve mechanism V1 therein. That is, the first coupling member 1 has the first valve mechanism V1 located radially inward. The first valve mechanism V1 is disposed radially inward of the second member 12. The first valve mechanism V1 has a hollow movable valve 101, a compression coil spring 102, and a support 103. The hollow movable valve 101 and the support 103 are each molded from resin.

[0034] The first valve mechanism V1 has a first valve housing. The second member 12 corresponds to the "first valve housing." That is, the first valve housing is cylindrical and has a center on a central axis CA.

[0035] The hollow movable valve 101 is disposed radially inward of the second member 12. The hollow movable valve 101 has a cylindrical shape centered on a central axis CA. Ink flows inside the hollow movable valve 101 in the axial direction. That is, ink flows inside the second member 12.

[0036] The hollow movable valve 101 has a seal portion 1011 on its outer circumferential surface. The seal portion 1011 is a portion where a seal material Or is arranged. The seal material Or of the seal portion 1011 is an O-ring made of an elastic material such as rubber. The seal material Or is fitted onto the outer circumferential surface of the hollow movable valve 101 to form the seal portion 1011. The outer circumferential portion of the seal material Or of the seal portion 1011 is in close contact with the inner circumferential surface of the second member 12. This restricts the axial flow of ink radially outward from the hollow movable valve 101.

[0037] The compression coil spring 102 is disposed radially inward of the second member 12. The compression coil spring 102 generates an axial biasing force. As a result, the compression coil spring 102 biases the hollow movable valve 101 toward the other axial side. In other words, the compression coil spring 102 biases the hollow movable valve 101 toward the connection side with the second coupling member 2.

[0038] However, in a disconnected state (the state shown in FIG. 7) in which the connection between the first coupling member 1 and the second coupling member 2 is released, movement of the hollow movable valve 101 to the other axial side is restricted. Therefore, the hollow movable valve 101 will not fall off from the radially inner side of the second member 12 to the outside of the second member 12.

[0039] The compression coil spring 102 biases the first member 11 toward one side in the axial direction. That is, the compression coil spring 102 biases the first member 11 in a direction away from the second member 12. However, the first member 11 and the second member 12 are fixed to each other. Therefore, the first member 11 will not come off the second member 12.

[0040] The support pillar 103 extends in the axial direction. The support pillar 103 is disposed radially inward of the second member 12 so as to penetrate the hollow movable valve 101 in the axial direction. That is, the support pillar 103 is disposed radially inward of the hollow movable valve 101. The support pillar 103 also penetrates the compression coil spring 102 in the axial direction radially inward of the second member 12. The support pillar 103 does not displace axially relative to the second member 12.

[0041] The support 103 has a first seal portion 100 on its outer peripheral surface. That is, the first coupling member 1 has the first seal portion 100 radially inward. The first seal portion 100 is a portion of the support 103 to which an annular seal material Or is attached. In the following description, the seal material Or attached to the support 103 will be referred to as the first seal material Or1. The support 103 has an endless first seal groove (reference number omitted) that extends continuously in the circumferential direction. The first seal material Or1 is disposed in the first seal groove.

[0042] The first seal material Or1 is an O-ring made of an elastic material such as rubber. The first seal portion 100 is formed by fitting the first seal material Or1 onto the outer peripheral surface of the support 103. The outer peripheral portion of the first seal material Or1 can be tightly attached to the inner peripheral surface of the hollow movable valve 101. In other words, the first seal portion 100 can be tightly attached to the inner peripheral surface of the hollow movable valve 101 (specifically, the first protrusion 1012 described below).

[0043] The first seal portion 100 comes into close contact with the inner circumferential surface of the hollow movable valve 101, thereby restricting the flow of ink inside the second member 12. In other words, the first seal portion 100 restricts the flow of ink inside the first coupling member 1.

[0044] The hollow movable valve 101 has a first protrusion 1012 on its inner circumferential surface that protrudes radially inward as a part that comes into close contact with the first seal part 100. The first protrusion 1012 extends annularly without interruption in the circumferential direction. In other words, the first protrusion 1012 is an endless protrusion in the circumferential direction. The first protrusion 1012 is a part whose inner diameter is smaller than other parts of the hollow movable valve 101.

[0045] The second member 12 also has an inner fitting portion 120. The inner fitting portion 120 is disposed on one axial side of the second member 12. Specifically, of the cylindrical body serving as the second member 12, one axial side portion serves as the inner fitting portion 120.

[0046] The outer fitting portion 110 of the first member 11 and the inner fitting portion 120 of the second member 12 fit together. Specifically, the inner fitting portion 120 fits inside the outer fitting portion 110. In other words, the inner fitting portion 120 is inserted inside the outer fitting portion 110. In this state, the inner circumferential surface 1100 of the outer fitting portion 110 and the outer circumferential surface 1200 of the inner fitting portion 120 are in at least partial contact with each other.

[0047] The first member 11 and the second member 12 are fixed to each other with the outer fitting portion 110 and the inner fitting portion 120 fitted to each other. Laser welding is used to fix the first member 11 and the second member 12. Specifically, with the outer fitting portion 110 and the inner fitting portion 120 fitted to each other, a laser is irradiated from the radially outer side of the outer fitting portion 110 to the fitted portion between the outer fitting portion 110 and the inner fitting portion 120. This causes the resins of the outer fitting portion 110 and the inner fitting portion 120 to be welded to each other at the interface between them. That is, the first member 11 and the second member 12 are fastened to each other at their fitted portions.

[0048] In the first coupling member 1 of this embodiment, in order to precisely fix the first member 11 and the second member 12 together, the inner peripheral surface 1100 of the outer fitting portion 110 and the outer peripheral surface 1200 of the inner fitting portion 120 each have a tapered shape that widens in a direction away from the central axis CA from one axial side to the other. That is, the inner diameter of the outer fitting portion 110 gradually increases from one axial side to the other. The outer diameter of the inner fitting portion 120 gradually increases from one axial side to the other.

[0049] With this configuration, the radial clearance between the inner peripheral surface 1100 of the outer fitting portion 110 and the outer peripheral surface 1200 of the inner fitting portion 120 can be minimized. By reducing this clearance, rattle between the first member 11 and the second member 12 is suppressed. Furthermore, the coaxiality between the first member 11 and the second member 12 is increased. As a result, the first member 11 and the second member 12 can be fixed with high precision. As a result, ink leakage from the connection point between the first member 11 and the second member 12 can be suppressed. In other words, liquid leakage from the first coupling member 1 can be suppressed.

[0050] The radial clearance between the inner peripheral surface 1100 of the outer fitting portion 110 and the outer peripheral surface 1200 of the inner fitting portion 120 (hereinafter simply referred to as the clearance) is 0.1 mm or less, thereby enabling the first member 11 and the second member 12 to be fixed with higher precision.

[0051] Here, in a configuration in which the inner fitting portion 120 is fitted inside the outer fitting portion 110, the dimensions of each component must be set so that the inner diameter of the outer fitting portion 110 is larger than the outer diameter of the inner fitting portion 120.

[0052] If neither the inner peripheral surface 1100 of the outer fitting portion 110 nor the outer peripheral surface 1200 of the inner fitting portion 120 is tapered, fitting the inner fitting portion 120 into the outer fitting portion 110 becomes difficult if the clearance is too small. For this reason, the dimensions of each component are set taking into consideration the ease of fitting when the inner diameter of the outer fitting portion 110 is at the minimum value of the tolerance range and the outer diameter of the inner fitting portion 120 is at the maximum value of the tolerance range. For example, when the tolerance is 0.03 mm, the inner diameter of the outer fitting portion 110 is set to 10.04 mm and the outer diameter of the inner fitting portion 120 is set to 9.96 mm. In this case, the maximum inner diameter of the outer fitting portion 110 is 10.07 mm and the minimum outer diameter of the inner fitting portion 120 is 9.93 mm, resulting in a maximum clearance of 0.14 mm.

[0053] On the other hand, in a configuration (this embodiment) in which the inner peripheral surface 1100 of the outer fitting portion 110 and the outer peripheral surface 1200 of the inner fitting portion 120 are each tapered, it is possible to prevent difficulty in fitting the inner fitting portion 120 into the outer fitting portion 110, even if the clearance is small. Therefore, for example, when the tolerance is 0.03 mm, the inner diameter of the outer fitting portion 110 is set to 10.01 mm, and the outer diameter of the inner fitting portion 120 is set to 9.98 mm. In this case, the maximum value of the inner diameter of the outer fitting portion 110 is 10.04 mm, and the minimum value of the outer diameter of the inner fitting portion 120 is 9.95 mm, so the maximum clearance is 0.09 mm (i.e., 0.1 mm or less).

[0054] Furthermore, in the first coupling member 1 of this embodiment, the light absorptance of the outer fitting portion 110 is lower than that of the inner fitting portion 120. The outer fitting portion 110 is a part of the first member 11, and the inner fitting portion 120 is a part of the second member 12. In other words, the constituent materials of the first member 11 and the second member 12 have different light absorptances.

[0055] Because the light absorption rate of the outer fitting portion 110 is lower than that of the inner fitting portion 120, when a laser is irradiated from the radially outer side of the outer fitting portion 110, the laser efficiently passes through the outer fitting portion 110 and is absorbed by the inner fitting portion 120. This allows the first member 11 and the second member 12 to be fixed together by laser welding. As a result, although the first member 11 and the second member 12 are separate members, it is possible to easily obtain a first coupling member 1 composed of the first member 11 and the second member 12.

[0056] When laser welding is used, costs can be reduced in manufacturing the first coupling member 1 (i.e., parts costs can be reduced) compared to when two-color molding is used in manufacturing the first coupling member 1 composed of the first member 11 and the second member 12. Furthermore, when laser welding is used, no adhesive is required to fix the first member 11 and the second member 12, so there is no decrease in reliability due to uneven application of the adhesive, deterioration of the adhesive, etc.

[0057] Moreover, in the first coupling member 1 of this embodiment, the outer fitting portion 110 has an engagement hole 110a that penetrates the outer fitting portion 110 in the radial direction. The inner fitting portion 120 has an engagement protrusion 120a that protrudes radially outward from the inner fitting portion 120.

[0058] The engagement hole 110a and the engagement protrusion 120a are engageable with each other. When the engagement protrusion 120a is inserted into the engagement hole 110a, the engagement hole 110a and the engagement protrusion 120a engage with each other. The outer fitting portion 110 has a plurality of engagement holes 110a arranged at positions that are point-symmetrical about the central axis CA. The inner fitting portion 120 has a plurality of engagement protrusions 120a that engage when inserted into the respective engagement holes 110a. That is, the inner fitting portion 120 has a plurality of engagement protrusions 120a that are arranged at positions that are point-symmetrical about the central axis CA.

[0059] In a configuration in which the outer fitting portion 110 has an engagement hole 110a and the inner fitting portion 120 has an engagement protrusion 120a, when the outer fitting portion 110 and the inner fitting portion 120 are fixed together by laser welding, the first member 11 and the second member 12 can be temporarily fastened by engaging the engagement hole 110a with the engagement protrusion 120a. This improves the workability of the laser welding process.

[0060] Furthermore, when the first member 11 and the second member 12 are temporarily fastened together by engaging the engaging protrusion 120a with the engaging hole 110a, the outer fitting portion 110 can be elastically deformed overall (specifically, deformed into an elliptical shape) to easily engage the engaging protrusion 120a with the engaging hole 110a. As a result, the first member 11 and the second member 12 can be easily temporarily fastened together without damaging the outer fitting portion 110 and the inner fitting portion 120.

[0061] Furthermore, if the engagement of the engagement protrusion 120a with the engagement hole 110a is maintained after the first member 11 and the second member 12 are fixed by laser welding, stress is likely to occur at the engagement point between the engagement hole 110a and the engagement protrusion 120a, which may cause damage to the engagement point between the engagement hole 110a and the engagement protrusion 120a and the surrounding area.

[0062] Therefore, in the first coupling member 1 of this embodiment, a gap G1 (see FIG. 7) is provided between the engagement hole 110a and the engagement projection 120a in the axial direction when the first member 11 and the second member 12 are fixed together. This makes it possible to suppress stress from occurring at the engagement point between the engagement hole 110a and the engagement projection 120a.

[0063] <Configuration of the second coupling member> As shown in Fig. 8, the second coupling member 2 includes a first member 21 and a second member 22. The first member 21 and the second member 22 are fixed to each other. By fixing the first member 21 and the second member 22 to each other, the first member 21 and the second member 22 are connected to each other in the axial direction. Fig. 9 shows a cross-sectional view (a cross-sectional view of the second coupling member 2 alone) of the state in which the first member 21 and the second member 22 are fixed to each other. The cross-section shown in Fig. 9 corresponds to a cross-section cut along a plane including the central axis CA.

[0064] A tube TU is connected to the first member 21. A first coupling member 1 (i.e., another coupling member) is connected to the second member 22. In the following description, of the two axial sides of the second coupling member 2, the side to which the tube TU is connected will be referred to as one axial side of the second coupling member 2, and the side to which the first coupling member 1 is connected will be referred to as the other axial side of the second coupling member 2. Note that, inside the second coupling member 2, ink may flow from one axial side to the other, or from the other axial side to one side.

[0065] The first member 21 has a tube connecting portion 211. The tube connecting portion 211 is cylindrical and has a center on a central axis CA. The tube connecting portion 211 is disposed on one side in the axial direction of the first member 21. When the tube connecting portion 211 is inserted into the tube TU, the tube TU is connected to the first member 21.

[0066] The first member 21 also has an outer fitting portion 210. The outer fitting portion 210 is disposed on the other axial side of the first member 21. The outer fitting portion 210 has a cylindrical shape centered on a central axis CA.

[0067] The second member 22 has a cylindrical shape centered on a central axis CA. Ink flows through the inside of the second member 22.

[0068] The second member 22 has a seal portion 221 on its outer circumferential surface. The seal portion 221 is a portion where a seal material Or is arranged. The seal material Or of the seal portion 221 is an O-ring made of an elastic material such as rubber. The seal material Or is fitted onto the outer circumferential surface of the second member 22 to form the seal portion 221.

[0069] In a connected state in which the first coupling member 1 and the second coupling member 2 are connected (the state shown in FIGS. 3 and 5), the second member 22 of the second coupling member 2 is fitted inside the second member 12 of the first coupling member 1. In this state, the outer circumferential portion of the sealing material Or of the sealing portion 221 of the second coupling member 2 is in close contact with the inner circumferential surface of the second member 12 of the first coupling member 1. As a result, in a state in which the second member 22 of the second coupling member 2 is fitted inside the second member 12 of the first coupling member 1 (i.e., the connected state), the axial flow of ink radially outward of the second member 22 of the second coupling member 2 is restricted.

[0070] The second member 22 holds the second valve mechanism V2 therein. That is, the second coupling member 2 has the second valve mechanism V2 located radially inward. The second valve mechanism V2 is disposed radially inward of the second member 22. The second valve mechanism V2 has a movable valve 201 and a compression coil spring 202. The movable valve 201 is a resin-molded product.

[0071] The second valve mechanism V2 has a second valve housing. The second member 22 corresponds to the "second valve housing." That is, the second valve housing is cylindrical and has a center on the central axis CA.

[0072] The movable valve 201 is disposed radially inward of the second member 22. The movable valve 201 is cylindrical and centered on a central axis CA. Ink flows in the axial direction between the second member 22 and the movable valve 201 in the radial direction. That is, ink flows inside the second member 22.

[0073] The movable valve 201 has a second seal portion 200 on its outer peripheral surface. That is, the second coupling member 2 has the second seal portion 200 radially inward. The second seal portion 200 is a portion of the movable valve 201 to which an annular seal material Or is attached. In the following description, the seal material Or attached to the movable valve 201 will be referred to as the second seal material Or2. The movable valve 201 has an endless second seal groove (reference number omitted) that extends continuously in the circumferential direction. The second seal material Or2 is disposed in the second seal groove.

[0074] The second seal material Or2 is an O-ring made of an elastic material such as rubber. The second seal portion 200 is formed by fitting the second seal material Or2 onto the outer peripheral surface of the movable valve 201. The outer peripheral portion of the second seal material Or2 can be in close contact with the inner peripheral surface of the second member 22. In other words, the second seal portion 200 can be in close contact with the inner peripheral surface of the second member 22 (specifically, the inclined surface 2220 of the second protrusion portion 222 described later).

[0075] The second seal portion 200 is in close contact with the inner circumferential surface of the second member 22, thereby restricting the flow of ink inside the second member 22. In other words, the second seal portion 200 restricts the flow of ink inside the second coupling member 2.

[0076] The second member 22 has a second protruding portion 222 on its inner circumferential surface that protrudes radially inward and serves as a portion that comes into close contact with the second seal portion 200. The second protruding portion 222 extends annularly without interruption in the circumferential direction. In other words, the second protruding portion 222 is an endless protruding portion in the circumferential direction. The second protruding portion 222 is a portion whose inner diameter is smaller than that of other portions of the second member 22.

[0077] The compression coil spring 202 is disposed radially inward of the second member 22. The compression coil spring 202 generates an axial biasing force. As a result, the compression coil spring 202 biases the movable valve 201 toward the other axial side. In other words, the compression coil spring 202 biases the movable valve 201 toward the connection side with the first coupling member 1.

[0078] However, in a disconnected state (the state shown in FIG. 9) in which the connection between the first coupling member 1 and the second coupling member 2 is released, movement of the movable valve 201 to the other axial side is restricted. Therefore, the movable valve 201 does not fall off from the radially inner side of the second member 22 to the outside of the second member 22.

[0079] The compression coil spring 202 biases the first member 21 toward one side in the axial direction. That is, the compression coil spring 202 biases the first member 21 in a direction away from the second member 22. However, the first member 21 and the second member 22 are fixed to each other. Therefore, the first member 21 will not come off the second member 22.

[0080] The second member 22 also has an inner fitting portion 220. The inner fitting portion 220 is disposed on one axial side of the second member 22. Specifically, of the cylindrical body serving as the second member 22, a portion on one axial side serves as the inner fitting portion 220.

[0081] The outer fitting portion 210 of the first member 21 and the inner fitting portion 220 of the second member 22 fit together. Specifically, the inner fitting portion 220 fits into the inner side of the outer fitting portion 210. In other words, the inner fitting portion 220 is inserted into the inner side of the outer fitting portion 210. In this state, the inner circumferential surface 2100 of the outer fitting portion 210 and the outer circumferential surface 2200 of the inner fitting portion 220 are in at least partial contact with each other.

[0082] The first member 21 and the second member 22 are fixed to each other with the outer fitting portion 210 and the inner fitting portion 220 fitted to each other. Laser welding is used to fix the first member 21 and the second member 22. Specifically, with the outer fitting portion 210 and the inner fitting portion 220 fitted to each other, a laser is irradiated from the radially outer side of the outer fitting portion 210 to the fitted portion between the outer fitting portion 210 and the inner fitting portion 220. This causes the resins of the outer fitting portion 210 and the inner fitting portion 220 to be welded to each other at the interface between them. That is, the first member 21 and the second member 22 are fastened to each other at their fitted portions.

[0083] In the second coupling member 2 of this embodiment, similarly to the first coupling member 1, in order to precisely fix the first member 21 and the second member 22, the inner peripheral surface 2100 of the outer fitting portion 210 and the outer peripheral surface 2200 of the inner fitting portion 120 each have a tapered shape that widens in a direction away from the central axis CA from one side to the other in the axial direction. That is, the inner diameter of the outer fitting portion 210 gradually increases from one side to the other in the axial direction. The outer diameter of the inner fitting portion 220 gradually increases from one side to the other in the axial direction.

[0084] In this configuration, rattle between the first member 21 and the second member 22 is suppressed, and the coaxiality between the first member 21 and the second member 22 is increased, so that the first member 21 and the second member 22 can be fixed with high precision. As a result, fluid leakage from the second coupling member 2 can also be suppressed.

[0085] In the second coupling member 2 of this embodiment, the radial clearance between the inner peripheral surface 2100 of the outer fitting portion 210 and the outer peripheral surface 2200 of the inner fitting portion 220 is 0.1 mm or less.

[0086] Furthermore, in the second coupling member 2 of this embodiment, the light absorptance of the outer fitting portion 210 is lower than the light absorptance of the inner fitting portion 220.

[0087] Furthermore, in the second coupling member 2 of this embodiment, the outer fitting portion 210 has an engaging hole 210a that penetrates the outer fitting portion 210 in the radial direction. The inner fitting portion 220 has an engaging protrusion 220a that protrudes radially outward from the inner fitting portion 220. The outer fitting portion 210 has a plurality of engaging holes 210a that are arranged at positions that are point-symmetrical about the central axis CA. The inner fitting portion 220 has a plurality of engaging protrusions 220a that are inserted into and engage with the plurality of engaging holes 210a, respectively.

[0088] As a result, the manufacturing process for the second coupling member 2 also achieves the same effects as the manufacturing process for the first coupling member 1. That is, the workability of the laser welding process can be improved. Furthermore, when the engaging protrusions 120a are engaged with the engaging holes 110a to temporarily fasten the first member 21 and the second member 22, damage to at least one of the outer fitting portion 210 and the inner fitting portion 220 can be suppressed.

[0089] Furthermore, in the second coupling member 2 of this embodiment, a gap G2 (see FIG. 9) is provided between the engagement hole 210a and the engagement projection 220a in the axial direction when the first member 21 and the second member 22 are fixed together, which makes it possible to suppress stress from occurring at the engagement point between the engagement hole 210a and the engagement projection 220a.

[0090] <Connection structure between first coupling member and second coupling member> The flow path connection mechanism 1000 includes a connecting member 3 as shown in FIG. 10. The connecting member 3 connects the first coupling member 1 and the second coupling member 2. The connecting member 3 is attached to the second coupling member 2. The connecting member 3 may be one component of the second coupling member 2. With the connecting member 3 attached to the second coupling member 2, the operation of connecting the first coupling member 1 and the second coupling member is performed.

[0091] The connecting member 3 has a cylindrical shape centered on a central axis CA. The connecting member 3 is disposed so that its inner peripheral surface faces radially opposite the outer peripheral surface of the second coupling member 2. In other words, the connecting member 3 covers the second coupling member 2 from the radially outer side.

[0092] The connecting member 3 is rotatable about the central axis CA when attached to the second coupling member 2. In a disconnected state (the state shown in FIG. 4) where the connection between the first coupling member 1 and the second coupling member 2 is released, the connecting member 3 can be freely rotated manually.

[0093] To rotatably mount the connecting member 3 to the second coupling member 2, the connecting member 3 has a plurality of protrusions 3a on its inner peripheral surface that are spaced apart from one another in the circumferential direction. The protrusions 3a protrude radially inward from the inner peripheral surface of the connecting member 3.

[0094] The second coupling member 2 has an endless groove 2a that extends continuously in the circumferential direction. The groove 2a is formed on the outer peripheral surface of the first member 21. That is, the first member 21 has the groove 2a on its outer peripheral surface.

[0095] The protrusion 3a of the connecting member 3 is fitted into the groove 2a of the second coupling member 2. This restricts axial movement of the connecting member 3 relative to the second coupling member 2. In other words, it is possible to prevent the connecting member 3 from moving axially relative to the second coupling member 2 and becoming detached from the second coupling member 2.

[0096] When the connecting member 3 is displaced in the circumferential direction, the protrusions 3a move in the circumferential direction along the grooves 2a. At this time, the circumferential movement of the protrusions 3a is guided by the grooves 2a. As a result, the connecting member 3 rotates around the central axis CA.

[0097] The first coupling member 1 has a connecting protrusion 10 (see FIG. 11) that protrudes radially outward. The connecting protrusion 10 protrudes radially outward from the outer peripheral surface of the first coupling member 1. The connecting protrusion 10 protrudes radially outward from the outer peripheral surface of the second member 12. A plurality of connecting protrusions 10 are provided. The plurality of connecting protrusions 10 are arranged at intervals from one another in the circumferential direction.

[0098] The connecting member 3 has a connecting hole 30 that penetrates radially. The connecting hole 30 is a hole into which the connecting protrusion 10 can be inserted radially. In other words, the connecting hole 30 is a hole that can engage with the connecting protrusion 10. A plurality of connecting holes 30 are provided, the number of which is the same as the number of connecting protrusions 10. One connecting hole 30 is assigned to each of the multiple connecting protrusions 10. The multiple connecting protrusions 10 are fitted into the corresponding connecting hole 30, respectively. The multiple connecting protrusions 10 are engaged with the corresponding connecting hole 30, respectively. This brings about a connected state in which the first coupling member 1 and the second coupling member 2 are connected.

[0099] The first coupling member 1 (i.e., the second member 12) is inserted axially into the inside of the connecting member 3. By inserting the first coupling member 1 into the inside of the connecting member 3, the connecting protrusion 10 can be engaged with the connecting hole 30. The state during this insertion operation is shown in Figure 11.

[0100] To enable the first coupling member 1 to be inserted into the inside of the connecting member 3, the connecting member 3 has a guide groove 300 on its inner circumferential surface. The guide groove 300 is recessed radially outward from the inner circumferential surface of the connecting member 3 and extends in the axial direction. The guide groove 300 extends in the axial direction from the end face of the connecting member 3 on the connection side with the first coupling member 1 (i.e., the end face in the axial direction) to reach the connecting hole 30. One guide groove 300 is assigned to each of the multiple connecting holes 30. When the first coupling member 1 is inserted into or removed from the inside of the connecting member 3, the connecting protrusion 10 passes through the guide groove 300 in the axial direction.

[0101] As shown in Fig. 12, the connection hole 30 has a wide region 301 and a narrow region 302 which have different axial opening widths. In Fig. 12, the axial opening width of the wide region 301 on the boundary side with the narrow region 302 is indicated by W1, and the axial opening width of the narrow region 302 is indicated by W2. Also in Fig. 12, the axial width of the connection protrusion 10 is indicated by W.

[0102] The opening width W1 of the wide region 301 is larger than the opening width W2 of the narrow region 302. The opening width W1 of the wide region 301 is also larger than the width W of the connecting protrusion 10. On the other hand, the opening width W2 of the narrow region 302 is smaller than the width W of the connecting protrusion 10.

[0103] In a connected state in which the first coupling member 1 and the second coupling member 2 are connected, the connecting protrusion 10 engages with the edge of the wide region 301 of the connecting hole 30. Specifically, the wide region 301 has an engagement region 3011. The engagement region 3011 is a region of the wide region 301 that has a larger axial opening width than the other regions. The engagement region 3011 is a region of the wide region 301 that has the largest axial opening width. The engagement region 3011 is also a region whose circumferential width is larger than the circumferential width of the connecting protrusion 10. In a connected state in which the first coupling member 1 and the second coupling member 2 are connected, the connecting protrusion 10 is fitted into the engagement region 3011 of the wide region 301, and engages with the edge of the engagement region 3011. That is, in the connected state, the state shown in FIG. 12 is obtained.

[0104] When viewed from the radial direction, the connection hole 30 has an opening shape as shown in Fig. 12. When viewed from the radial direction, one edge of the connection hole 30 in the axial direction (herein referred to as the one edge) extends in a straight line in a direction perpendicular to the central axis CA. On the other hand, when viewed from the radial direction, the other edge of the connection hole 30 on the opposite side of the one edge in the axial direction (herein referred to as the other edge) extends in a stepped manner in a direction perpendicular to the central axis CA.

[0105] In a connected state in which the first coupling member 1 and the second coupling member 2 are connected, the first coupling member 1 and the second coupling member 2 are urged in directions away from each other by the urging forces of the compression coil springs 102 and 202. Because the connecting member 3 is attached to the second coupling member 2, when the second coupling member 2 is displaced in the axial direction, the connecting member 3 is also displaced in the axial direction together with the second coupling member 2. As a result, the connecting protrusion 10 engages with the other edge of the engagement region 3011 (i.e., part of the edge extending in a stepped manner).

[0106] <Condition of the valve mechanism when connected and disconnected> In the following description, in order to easily distinguish between the second member 12 of the first coupling member 1 and the second member 22 of the second coupling member 2, the second member 12 of the first coupling member 1 will be referred to as the first valve housing 12, and the second member 22 of the second coupling member 2 will be referred to as the second valve housing 22.

[0107] When the first coupling member 1 and the second coupling member 2 are connected, the second valve housing 22 is inserted axially into the inside of the first valve housing 12. By inserting the second valve housing 22 into the inside of the first valve housing 12, the second valve housing 22 comes into axial contact with the hollow movable valve 101. As the insertion of the second valve housing 22 into the inside of the first valve housing 12 continues, the hollow movable valve 101 is pressed by the second valve housing 22 in a direction against the biasing force of the compression coil spring 102.

[0108] This causes the hollow movable valve 101 to be displaced in a direction against the biasing force of the compression coil spring 102. Specifically, the first protrusion 1012 is displaced to a position where it is not in close contact with the first seal portion 100 (i.e., the first seal material Or1). As a result, ink can flow inside the first coupling member 1 (see FIG. 5).

[0109] Furthermore, as the second valve housing 22 is inserted into the first valve housing 12, the support 103 comes into axial contact with the movable valve 201. As the insertion of the second valve housing 22 into the first valve housing 12 continues, the movable valve 201 is pressed by the support 103 in a direction against the biasing force of the compression coil spring 202.

[0110] This causes the movable valve 201 to be displaced in a direction against the biasing force of the compression coil spring 202. Specifically, the second seal portion 200 (i.e., the second seal material Or2) is displaced to a position where it is not in close contact with the second protrusion 222. As a result, ink can flow inside the second coupling member 2 (see FIG. 5).

[0111] As a result, in a connected state in which the first coupling member 1 and the second coupling member 2 are connected, that is, in a state in which the second valve housing 22 is axially inserted inside the first valve housing 12, the ink flow paths of the first coupling member 1 and the second coupling member 2 are connected to each other. In the connected state, ink flows inside the hollow movable valve 101, and ink flows inside the second valve housing 22.

[0112] In this embodiment, in a disconnected state in which the first coupling member 1 and the second coupling member 2 are disconnected, that is, in a state in which the second valve housing 22 is removed from inside the first valve housing 12, the biasing force of the compression coil spring 102 holds the first protrusion 1012 in a position in which it is in close contact with the first seal portion 100 (see FIG. 7). This restricts the flow of ink inside the first coupling member 1 (specifically, inside the hollow movable valve 101). As a result, in the disconnected state, it is possible to prevent ink from leaking from the first coupling member 1.

[0113] Furthermore, in the disconnected state, the biasing force of the compression coil spring 202 holds the second seal portion 200 in a position where it is in close contact with the second protrusion 222 (see FIG. 9). This restricts the flow of ink inside the second coupling member 2 (specifically, inside the second valve housing 22). As a result, in the disconnected state, it is possible to prevent ink from leaking from the second coupling member 2.

[0114] When the connected state changes to the disconnected state, that is, when the second valve housing 22 is removed from inside the first valve housing 12, first, the first seal portion 100 (i.e., the first seal material Or1) comes into close contact with the first protrusion 1012, and the second seal portion 200 (i.e., the second seal material Or2) comes into close contact with the second protrusion 222 (herein referred to as the sealed state). The state when (the moment at which) the second valve housing 22 is removed from inside the first valve housing 12 is shown in Figure 13.

[0115] Then, while the second valve housing 22 remains sealed, it is removed from inside the first valve housing 12. That is, after the sealed state is achieved, the second valve housing 22 separates from the hollow movable valve 101, and the support 103 separates from the movable valve 201. This makes it possible to prevent ink from scattering when (at that moment) the second valve housing 22 is removed from inside the first valve housing 12.

[0116] Moreover, in this embodiment, the second protrusion 222 of the second valve housing 22 has an inclined surface 2220 (see FIG. 9). The inclined surface 2220 is inclined in a direction approaching the central axis CA toward the connection side with the first coupling member 1. In other words, a portion of the inner circumferential surface of the second valve housing 22 is inclined in a direction approaching the central axis CA toward the connection side with the first coupling member 1. The inclined surface 2220 is located at the end of the second valve housing 22 on the connection side with the first coupling member 1 (i.e., the end in the axial direction).

[0117] In a disconnected state in which the first coupling member 1 and the second coupling member 2 are disconnected, the movable valve 201 is urged toward the connection side with the first coupling member 1 by the urging force of the compression coil spring 202. That is, the urging force of the compression coil spring 202 urges the second seal portion 200 toward the second protrusion 222. This causes the second seal portion 200 (specifically, the second seal material Or2) to come into close contact with the inclined surface 2220 of the second protrusion 222. As a result, it is possible to easily seal the second coupling member 2 so that ink does not leak.

[0118] In this embodiment, the support 103 has a valve protrusion 1031 that protrudes in the axial direction. The movable valve 201 has a valve recess 2011 that is recessed in the axial direction. The valve protrusion 1031 protrudes in the axial direction in the shape of a cylinder centered on the central axis CA. The valve recess 2011 has a circular opening centered on the central axis CA. When viewed in the axial direction, the diameter of the valve protrusion 1031 is smaller than the diameter of the opening of the valve recess 2011. This allows the valve protrusion 1031 to be fitted into the valve recess 2011.

[0119] In this embodiment, the second valve housing 22 is inserted into the first valve housing 12 with the valve protrusion 1031 fitted into the valve recess 2011. In this state, as the second valve housing 22 continues to be inserted into the first valve housing 12, the support 103 presses the movable valve 201, and the movable valve 201 is displaced in a direction against the biasing force of the compression coil spring 202. As a result, the first coupling member 1 and the second coupling member 2 are connected. That is, in the connected state, the valve protrusion 1031 is fitted into the valve recess 2011.

[0120] With this configuration, the attitude of the movable valve 201 is stable, so that when the first coupling member 1 and the second coupling member 2 are released from each other, tilt of the movable valve 201 in the axial direction is suppressed, and the movable valve 201 is smoothly biased in the axial direction by the biasing force of the compression coil spring 202. In other words, even if the spring load of the compression coil spring 202 is low, the movable valve 201 is smoothly displaced in the axial direction.

[0121] This allows the spring load of compression coil spring 202 to be reduced. By reducing the spring load of compression coil spring 202, when connecting first coupling member 1 and second coupling member 2, that is, when inserting second valve housing 22 into first valve housing 12 and pressing movable valve 201 with support 103, the connection operation can be performed with less force. As a result, the workability of the connection operation is improved. Furthermore, when disconnecting first coupling member 1 and second coupling member 2, movable valve 201 displaces smoothly in the axial direction, which also improves the workability of the disconnection operation.

[0122] The support 103 and the movable valve 201 are each molded from resin. The outer diameter of the support 103 is smaller than the outer diameter of the movable valve 201. In other words, the thickness of the support 103 in the radial direction is smaller than that of the movable valve 201.

[0123] In the manufacture of resin molded products, the temperature difference between the surface and interior of the resin molded product causes dimensional errors in the finished product. The thicker the resin molded product, the greater the temperature difference, resulting in poorer dimensional accuracy of the resin molded product.

[0124] Therefore, in this embodiment, a valve protrusion 1031 is provided on the support 103, and a valve recess 2011 is provided on the movable valve 201. The second seal portion 200 is provided in a portion that overlaps radially with the valve recess 2011. That is, a second seal groove (reference numeral omitted) is formed in a portion of the outer circumferential surface of the movable valve 201 that overlaps radially with the valve recess 2011.

[0125] In this configuration, the portion where the second seal groove is formed is a portion with a small thickness. This allows the second seal groove to be formed with high precision. That is, the attachment precision of the second seal material Or2 to the movable valve 201 is improved.

[0126] <Cleaning of coupling components> The first coupling member 1 displaces the axial position of the hollow movable valve 101 relative to the first valve housing 12 between a connected state in which the second coupling member 2 is connected and a disconnected state in which the second coupling member 2 is not connected. As a result, the first coupling member 1 allows ink to flow in the connected state, but restricts the flow of ink in the disconnected state.

[0127] Furthermore, the first coupling member 1 has a shape that can prevent the hollow movable valve 101 from falling off from the first valve housing 12. Specifically, as shown in FIG. 7, the hollow movable valve 101 has a flange 101a with an outer diameter larger than other portions of the hollow movable valve 101. The first valve housing 12 has a small-diameter portion (reference number omitted) with a small inner diameter and a large-diameter portion (reference number omitted) with an inner diameter larger than that of the small-diameter portion, and has a step portion at the boundary between the small-diameter portion and the large-diameter portion as a retaining portion 12a. In the disconnected state, the flange 101a engages with the retaining portion 12a in the axial direction. This prevents the hollow movable valve 101 from falling off from the first valve housing 12.

[0128] In this configuration, when the first coupling member 1 and the second coupling member 2 are in a connected state, a gap G is generated between a predetermined portion of the hollow movable valve 101 and the first valve housing 12 in the radial direction (see FIG. 5). The predetermined portion is the portion of the hollow movable valve 101 that faces the large diameter portion of the first valve housing 12 in the connected state in the radial direction.

[0129] For example, before shipping the inkjet recording apparatus 500, the first coupling member 1 and the second coupling member 2 are connected to allow ink to flow. Then, when shipping the inkjet recording apparatus 500, cleaning of the ink flow path is performed with the first coupling member 1 and the second coupling member 2 connected.

[0130] Here, ink tends to accumulate in the gap G between the hollow movable valve 101 and the first valve housing 12. If the ink in the gap G is not properly discharged, it becomes difficult to replace the ink in the gap G with the storage liquid. This makes the cleaning operation take a long time.

[0131] 14, the hollow movable valve 101 has a flow port 1010 in a predetermined portion (i.e., a portion that faces the large diameter portion of the first valve housing 12 in the radial direction in the connected state). The flow port 1010 penetrates a predetermined portion of the hollow movable valve 101 in the radial direction. For example, the axial width of the flow port 1010 is equal to or greater than the radial thickness of the hollow movable valve 101. Furthermore, there are multiple flow ports 1010 (for example, two), and they are evenly arranged in the circumferential direction around the central axis CA.

[0132] In this embodiment, by providing the hollow movable valve 101 with a flow port 1010, ink accumulated in the gap G between the hollow movable valve 101 and the first valve housing 12 can be discharged through the flow port 1010. This makes it easier to clean the first coupling member 1.

[0133] The shape of the flow port 1010 is not limited to the shape shown in FIG.

[0134] For example, the flow port 1010 may have a shape as shown in FIG. 15. In a first modified example shown in FIG. 15, the hollow movable valve 101 has a plurality of (for example, two) flow ports 1010. Each of the plurality of flow ports 1010 extends in the circumferential direction. Furthermore, the plurality of flow ports 1010 are arranged in a staggered pattern around the entire circumferential direction of the hollow movable valve 101. With this configuration, the flow ports 1010 are provided around the entire circumferential direction of the hollow movable valve 101. This allows ink that has accumulated in the gap G between the hollow movable valve 101 and the first valve housing 12 to be efficiently discharged.

[0135] Furthermore, the flow port 1010 may have a shape as shown in FIG. 16. In a second modified example shown in FIG. 16, the hollow movable valve 101 has one flow port 1010. The flow port 1010 extends in a spiral shape. Furthermore, the circumferential length of the flow port 1010 is longer than one circumferential revolution of the hollow movable valve 101. In other words, the flow port 1010 extends so as to make one or more revolutions around the hollow movable valve 101 in the circumferential direction. With this configuration, the flow port 1010 is provided around the entire circumferential circumference of the hollow movable valve 101. This allows ink that has accumulated in the gap G between the hollow movable valve 101 and the first valve housing 12 to be efficiently discharged.

[0136] 15 and 16, low-rigidity portions having multiple ends of the flow port 1010 in the axial direction appear. In FIGS. 15 and 16, the low-rigidity portions are surrounded by dashed lines. In the configuration shown in FIG. 15, low-rigidity portions appear in at least two places, whereas in the configuration shown in FIG. 16, the low-rigidity portion appears in only one place. As a result, the configuration shown in FIG. 16 can suppress a decrease in rigidity of the hollow movable valve 101 more than the configuration shown in FIG. 15.

[0137] 14 to 16, the seal material Or is omitted from the illustration.

[0138] <Rotation restriction by the uneven surface of the coupling member> When connecting the first coupling member 1 and the second coupling member 2, the second member 12 of the first coupling member is inserted inside the connecting member 3, and in this state, the connecting member 3 is rotated in one direction relative to the first coupling member 1. This brings the connecting protrusion 10 to a position where it can axially engage with the connecting hole 30, and the connecting protrusion 10 and the connecting hole 30 engage with each other in the axial direction. In other words, the first coupling member 1 and the connecting member 3 engage with each other in the axial direction. As a result, the first coupling member 1 and the second coupling member 2 are connected.

[0139] Specifically, when the first coupling member 1 is inserted axially into the inside of the connecting member 3, the connecting protrusion 10 and the guide groove 300 are aligned in the circumferential direction (see FIG. 11 ). In this state, the first coupling member 1 is inserted axially into the inside of the connecting member 3. In other words, when the first coupling member 1 is inserted into the inside of the connecting member 3, the connecting protrusion 10 passes through the guide groove 300 in the axial direction. In yet other words, the insertion of the first coupling member 1 is performed so that the connecting protrusion 10 moves axially along the guide groove 300. As a result, the connecting protrusion 10 reaches the connecting hole 30.

[0140] The guide groove 300 is connected to the narrow region 302 of the connection hole 30, not the wide region 301. That is, when the first coupling member 1 is inserted, the connection protrusion 10 is guided to the narrow region 302 by the guide groove 300. Therefore, simply inserting the first coupling member 1 into the inside of the connection member 3 does not allow the connection protrusion 10 to be engaged with the connection hole 30 in the axial direction.

[0141] To axially engage the connecting protrusion 10 with the connecting hole 30, it is necessary to insert the first coupling member 1 into the inside of the connecting member 3 and then rotate the connecting member 3 in one direction relative to the first coupling member 1. Specifically, after inserting the first coupling member 1 into the inside of the connecting member 3, it is necessary to rotate the connecting member 3 so that it transitions through the states shown in the upper diagram, the middle diagram, and the bottom diagram in Figure 17 in that order. Note that in Figure 17, in each state, the left-right direction of the drawing corresponds to the axial direction, and the up-down direction of the drawing corresponds to the circumferential direction.

[0142] When the connecting member 3 rotates relative to the first coupling member 1, the circumferential position of the connecting protrusion 10 is displaced relative to the connecting hole 30. This allows the connecting protrusion 10 to move from the narrow region 302 to the wide region 301 (specifically, the engagement region 3011). As a result, the connecting protrusion 10 can be engaged with the connecting hole 30 in the axial direction.

[0143] However, when the connecting member 3 is rotated relative to the first coupling member 1, if the first coupling member 1 rotates together with the connecting member 3, the connecting protrusion 10 cannot be brought to a position where it can axially engage with the connecting hole 30. In other words, even if the connecting member 3 is rotated in one direction, the connecting protrusion 10 cannot be axially engaged with the connecting hole 30.

[0144] To address this issue, in this embodiment, as shown in FIG. 18, the first coupling member 1 and the second coupling member 2 are each provided with a rotation restricting portion. The first coupling member 1 and the second coupling member 2 each have a concave-convex portion R that is concave and convex in the axial direction as the rotation restricting portion. The concave-convex portion R includes a plurality of convex portions that are periodically arranged in the circumferential direction. In other words, the concave-convex portion R includes a plurality of convex portions that are arranged at a predetermined periodic angle θ in the circumferential direction. The areas between adjacent convex portions in the circumferential direction are concave portions. Hereinafter, as necessary, the concave-convex portion R of the first coupling member 1 may be designated by the symbol R1, and the concave-convex portion R of the second coupling member 2 may be designated by the symbol R2 to distinguish them.

[0145] The concave-convex portion R is provided on each of the axially opposing portions of the first coupling member 1 and the second coupling member 2. That is, the concave-convex portion R1 is provided on the axial end of the second member 12 of the first coupling member 1. The concave-convex portion R2 is provided on the axial end of the second member 22 (i.e., the second valve housing 22) of the second coupling member 2. This allows the concave-convex portions R of the first coupling member 1 and the second coupling member 2 to engage with each other in the circumferential direction. The convex portions of the concave-convex portion R1 fit into the concave portions of the concave-convex portion R2, and the convex portions of the concave-convex portion R2 fit into the concave portions of the concave-convex portion R1, thereby allowing the concave-convex portions R of the first coupling member 1 and the second coupling member 2 to engage with each other in the circumferential direction. By inserting the first coupling member 1 into the connecting member 3, the concave-convex portions R of the first coupling member 1 and the second coupling member 2 to engage with each other in the circumferential direction.

[0146] In this configuration, when the connecting member 3 is rotated relative to the first coupling member 1, the concave-convex portions R of the first coupling member 1 and the second coupling member 2 are engaged with each other in the circumferential direction, thereby preventing the first coupling member 1 from rotating together with the connecting member 3. This improves the efficiency of the connection work between the first coupling member 1 and the second coupling member 2. It also improves the efficiency of the disconnection work (described in detail later) for disconnecting the first coupling member 1 and the second coupling member 2. In addition, it is possible to prevent the tube TU connected to the first coupling member 1 from twisting unintentionally, eliminating the need for the work of untwisting (or work of preventing) the tube TU.

[0147] In this embodiment, the first coupling member 1 and the second coupling member 2 have compression coil springs 102 and 202, respectively. When the first coupling member 1 and the second coupling member 2 are in a connected state, the first coupling member 1 and the second coupling member 2 are urged to move away from each other in the axial direction by the urging forces of the compression coil springs 102 and 202.

[0148] At this time, since the connecting protrusion 10 is located in the wide region 301 (specifically, the engagement region 3011), the state transitions from the state shown in the interrupted diagram in Fig. 17 to the state shown in the bottom diagram. As a result, as shown in Fig. 19, the state transitions from one in which the concave-convex portions R of the first coupling member 1 and the second coupling member 2 are engaged with each other in the circumferential direction (the state shown in the upper diagram in Fig. 19) to one in which the concave-convex portions R of the first coupling member 1 and the second coupling member 2 are separated from each other in the axial direction (the state shown in the lower diagram in Fig. 19). In other words, the engagement between the concave-convex portions R of the first coupling member 1 and the second coupling member 2 is released.

[0149] The recessed and projecting portions R of the first coupling member 1 and the second coupling member 2 are spaced apart from each other in the axial direction, allowing the first coupling member 1 and the second coupling member 2 to freely rotate. As a result, if twisting of the tube TU is discovered after the first coupling member 1 and the second coupling member 2 are connected, the twisting of the tube TU can be resolved while maintaining the connection between the first coupling member 1 and the second coupling member 2.

[0150] In this embodiment, the uneven portion R has a shape as shown in Fig. 20 when viewed from the radial direction. In Fig. 20, the axial direction is indicated by a double-headed arrow Da. That is, in Fig. 20, the left-right direction of the drawing corresponds to the axial direction, and the up-down direction of the drawing corresponds to the circumferential direction.

[0151] The convex portions of the concave-convex portion R are tapered from their bases to their tips. This makes it easy to fit the convex portions of one concave-convex portion R into the concave portions of the other concave-convex portion R, regardless of the circumferential positions of the first coupling member 1 and the second coupling member 2. In other words, the concave-convex portions R of the first coupling member 1 and the second coupling member 2 can be easily engaged with each other.

[0152] In this embodiment, the first side surface S1 of the convex portion of the concave-convex portion R, which faces one circumferential side, is inclined at an angle of 45° or more with respect to a direction perpendicular to the central axis CA when viewed from the radial direction. That is, the first side surface S1 is a surface whose first angle θ1, which is the angle between the first side surface S1 and the direction perpendicular to the central axis CA when viewed from the radial direction, is 45° or more. This makes it even easier to fit the convex portion of one concave-convex portion R into the concave portion of the other concave-convex portion R.

[0153] In this embodiment, the second side surface S2 of the convex portion of the concave-convex portion R, which faces the other side opposite to the first side surface S1 in the circumferential direction, is a surface whose second angle θ2, which is the angle between the central axis CA and a direction perpendicular to the central axis CA, is larger than the first angle θ1 when viewed from the radial direction. For example, the first angle θ1 is approximately 45°, and the second angle θ2 is approximately 90°.

[0154] In this embodiment, the second side surfaces S2 of the one concave-convex portion R and the other concave-convex portion R engage with each other in the circumferential direction, thereby stabilizing the engagement between the one concave-convex portion R and the other concave-convex portion R in the circumferential direction.

[0155] <Axial end face shape of connecting member> When connecting the first coupling member 1 and the second coupling member 2, it is necessary to rotate the connection member 3. If the body of the connection member 3 can be pinched with fingers, the operation of rotating the connection member 3 is easy. However, there are cases where the installation space for the flow path connection mechanism 1000 is narrow. In such cases, the body of the connection member 3 cannot be pinched with fingers, making the operation of rotating the connection member 3 difficult.

[0156] Therefore, in this embodiment, as shown in Figures 21 and 22, the connecting member 3 has a protrusion 31 that protrudes in the axial direction on its axial end surface. The protrusion 31 protrudes in the axial direction from the end surface of the connecting member 3 opposite the side connected to the first coupling member 1. The end surface of the connecting member 3 opposite the side connected to the first coupling member 1 serves as a working surface that an operator touches with their fingers when rotating the connecting member 3. In the following description, for convenience, the end surface of the connecting member 3 opposite the side connected to the first coupling member 1 will be referred to as the working surface. The protrusion 31 functions as a non-slip surface for fingers on the working surface of the connecting member 3.

[0157] In this configuration, when rotating the connecting member 3, the pad of a finger is pressed against the working surface of the connecting member 3, causing the finger to engage the protrusion 31. In this state, moving the finger in the circumferential direction rotates the connecting member 3. This eliminates the need to pinch the body of the connecting member 3 with the fingers. As a result, even if the installation space for the flow path connection mechanism 1000 is narrow, the operation of rotating the connecting member 3 becomes easy. In other words, the workability of the operation of connecting the first coupling member 1 and the second coupling member 2 is improved. Incidentally, the workability of the operation of disconnecting the first coupling member 1 and the second coupling member 2 (details of which will be described later) is also improved.

[0158] In this embodiment, the ink flow paths of the first coupling member 1 and the second coupling member 2 are connected in the axial direction by inserting the second coupling member 2 inside the first coupling member 1. In this configuration, no seal material is required to prevent liquid leakage between the first coupling member 1 and the second coupling member 2 and the connecting member 3 in the radial direction.

[0159] Therefore, in this embodiment, the connecting member 3 can rotate without sliding against the sealing material for preventing leakage. As a result, the connecting member 3 can be easily rotated by simply pressing the pad of a finger against the working surface of the connecting member 3 and moving it in the circumferential direction, without having to pinch the body of the connecting member 3 with your fingers.

[0160] In this embodiment, there are multiple protrusions 31. The multiple protrusions 31 are evenly arranged at angles of 45° or less in the circumferential direction around the central axis CA. This allows the pad of a finger to be easily pressed against the location of the protrusion 31 on the connecting member 3, regardless of the circumferential position of the connecting member 3.

[0161] In this embodiment, the protrusions 31 protrude hemispherically in the axial direction from the working surface of the connecting member 3. The diameter φ of the protrusions 31 as viewed in the axial direction is at least twice the protruding height H of the protrusions 31 (i.e., the width in the axial direction). By setting these dimensions, the protrusions 31 can reliably function as anti-slip devices. Furthermore, the fingers do not feel pain when they come into contact with the protrusions 31.

[0162] <Disengagement of the connection protrusion and the connection hole> For example, for maintenance purposes, the connection between the first coupling member 1 and the second coupling member 2 is released. To release the connection between the first coupling member 1 and the second coupling member 2, it is necessary to release the engagement between the connecting protrusion 10 and the connecting hole 30.

[0163] When the engagement between the connecting protrusion 10 and the connection hole 30 is released, the connecting member 3 is rotated so that the states change in the order of the state shown in the lower diagram, the state shown in the middle diagram, and the state shown in the upper diagram in Figure 17. That is, by rotating the connecting member 3 from a state in which the connecting protrusion 10 is engaged with the wide region 301 (specifically, the engagement region 3011), the circumferential positions of the connecting protrusion 10 and the guide groove 300 are aligned. This allows the first coupling member 1 and the second coupling member 2 to be pulled away from each other in the axial direction, thereby releasing the engagement between the connecting protrusion 10 and the connection hole 30.

[0164] If the connecting protrusion 10 gets caught on the edge of the connecting hole 30 in the axial direction when the first coupling member 1 and the second coupling member 2 are pulled apart from each other in the axial direction, it will be difficult to pull the second coupling member 2 away from the first coupling member 1. In this case, forcibly pulling the second coupling member 2 away from the first coupling member 1 could cause a malfunction.

[0165] To prevent such inconvenience, in the present embodiment, the narrow region 302 has an axial opening width W2 that is smaller than the axial width W of the connecting protrusion 10. In this configuration, by rotating the connecting member 3 in one direction (i.e., the direction in which the connecting member 3 is rotated when connecting the first coupling member 1 and the second coupling member 2) from a state in which the connecting protrusion 10 and the wide region 301 are engaged (i.e., a connected state in which the first coupling member 1 and the second coupling member 2 are connected), at least a portion of the connecting protrusion 10 enters radially inward of the outer edge of the narrow region 302 (see the upper diagram in FIG. 17 ).

[0166] Then, with at least a portion of the connecting protrusion 10 inserted radially inward of the outer edge of the narrow region 302, the first coupling member 1 and the second coupling member 2 are pulled apart in the axial direction. This prevents the connecting protrusion 10 from getting caught in the axial direction on the edge of the connecting hole 30. In other words, the second coupling member 2 can be smoothly pulled apart from the first coupling member 1. This improves the workability of the disconnection operation for releasing the connection between the first coupling member 1 and the second coupling member 2.

[0167] When at least a portion of the connecting protrusion 10 is fitted radially inwardly into the outer edge of the narrow region 302, the circumferential positions of the connecting protrusion 10 and the guide groove 300 coincide. Therefore, by fitting at least a portion of the connecting protrusion 10 into the radially inwardly into the outer edge of the narrow region 302, the second coupling member 2 can be moved in the axial direction away from the first coupling member 1. At this time, the connecting protrusion 10 passes through the guide groove 300, so there is no problem in that the connecting protrusion 10 comes into contact with the connecting member 3 and obstructs the axial movement of the second coupling member 2.

[0168] Furthermore, in this embodiment, the boundary portion 30a between the wide region 301 and the narrow region 302 of the edge of the connection hole 30 is inclined with respect to a direction perpendicular to the central axis CA when viewed from the radial direction. This prevents the connection protrusion 10 from getting caught on the boundary portion 30a between the wide region 301 and the narrow region 302, which would hinder the rotation of the connection member 3, when the connection protrusion 10 is inserted radially inward into the outer edge of the narrow region 302 by rotating the connection member 3. In other words, the connection protrusion 10 can be smoothly moved from the wide region 301 to the narrow region 302.

[0169] The connecting protrusion 10 has a shape as shown in Fig. 23 and Fig. 24 in a cross section cut along a plane perpendicular to the central axis CA. That is, the circumferential corners of the connecting protrusion 10 are round-chamfered. However, this is not limited thereto, and the circumferential corners of the connecting protrusion 10 may be C-chamfered. By round-chamfering or C-chamfering the circumferential corners of the connecting protrusion 10, it is possible to further prevent the connecting protrusion 10 from getting caught on the boundary portion 30a between the wide region 301 and the narrow region 302, thereby inhibiting rotation of the connecting member 3.

[0170] <Dimensions of the connecting protrusion> In the operation of connecting the first coupling member 1 and the second coupling member 2, first, the connecting protrusion 10 is fitted into the guide groove 300, and in this state, the first coupling member 1 is inserted inside the connecting member 3. That is, the connecting protrusion 10 passes through the guide groove 300 in the axial direction. At this time, the connecting protrusion 10 moves in the axial direction while being guided by the guide groove 300. Therefore, the rotation of the connecting member 3 (i.e., displacement in the circumferential direction) is restricted by the connecting protrusion 10.

[0171] As the first coupling member 1 continues to be inserted into the connecting member 3, the concave-convex portions R of the first coupling member 1 and the second coupling member 2 begin to come into contact with each other. At this time, the connecting protrusion 10 is still fitted into the guide groove 300 (the state shown in the upper diagram in FIG. 17). In other words, the rotation of the connecting member 3 is restricted by the connecting protrusion 10.

[0172] When the concave-convex portions R of the first coupling member 1 and the second coupling member 2 begin to come into contact with each other, the convex portions of one and the other concave-convex portions R may butt against each other. In this case, the convex portions of one concave-convex portion R are displaced circumferentially relative to the convex portions of the other concave-convex portion R, causing the convex portions of one concave-convex portion R to fit into the concave portions of the other concave-convex portion R.

[0173] If the convex portions of one uneven portion R do not displace circumferentially relative to the convex portions of the other uneven portion R, the convex portions of the one and other uneven portions R will remain in contact with each other. In this case, the one and other uneven portions R cannot be engaged with each other.

[0174] For this reason, an appropriate amount of backlash is provided between the connecting protrusion 10 and the guide groove 300 in the circumferential direction. This will be explained in detail below. In the following explanation, the arrangement periodic angle of the multiple convex portions of the concave-convex portion R (i.e., the predetermined periodic angle θ) will be referred to as the convex portion periodic angle.

[0175] In the following description, the rotation angle of the connecting member 3 from a state in which the connecting protrusion 10 fitted into the guide groove 300 abuts against one circumferential side surface of the guide groove 300 until the connecting member 3 is rotated so that the connecting protrusion 10 abuts against the other circumferential side surface of the guide groove 300 is referred to as the first rotation angle. The angle obtained by subtracting the angle θa shown in the upper diagram of FIG. 23 from the angle θb shown in the lower diagram of FIG. 23 corresponds to the first rotation angle. The upper diagram of FIG. 23 shows a state in which the connecting protrusion 10 abuts against one side surface of the guide groove 300. The lower diagram of FIG. 23 shows a state in which the connecting protrusion 10 abuts against the other side surface of the guide groove 300.

[0176] In this embodiment, the first rotation angle is equal to or greater than half the convex portion periodic angle. This allows the convex portions of one uneven portion R to be smoothly fitted into the concave portions of the other uneven portion R when the first coupling member 1 is inserted into the connecting member 3. As a result, the workability of connecting the first coupling member 1 and the second coupling member 2 is improved.

[0177] Note that the operation of disconnecting the first coupling member 1 and the second coupling member 2 also requires rotating the connecting member 3 relative to the first coupling member 1. Specifically, in the disconnecting operation, the connecting member 3 is first pressed in a direction against the biasing forces of the compression coil springs 102 and 202 (hereinafter, this direction will be referred to as the counter-biasing direction). This causes the concave-convex portions R of the first coupling member 1 and the second coupling member 2 to engage with each other in the circumferential direction. That is, the state transitions from the state shown in the lower diagram of FIG. 19 to the state shown in the upper diagram.

[0178] Thereafter, the connecting member 3 is rotated in the other direction opposite to the one direction (i.e., the direction in which the connecting member 3 is rotated when connecting the first coupling member 1 and the second coupling member 2). At this time, the concave-convex portions R of the first coupling member 1 and the second coupling member 2 are engaged with each other in the circumferential direction, causing the connecting member 3 to rotate relative to the first coupling member 1. In other words, the connecting hole 30 is displaced circumferentially relative to the connecting protrusion 10. As a result, the connecting protrusion 10 enters radially inward of the outer edge portion of the narrow region 302. As a result, the first coupling member 1 becomes capable of being removed from inside the connecting member 3.

[0179] When the connecting member 3 is pressed in the counter-bias direction, the convex portions of the concave-convex portions R of the first coupling member 1 and the second coupling member 2 may butt against each other. In this case, it is necessary to fit the convex portions of one concave-convex portion R into the concave portions of the other concave-convex portion R by displacing the convex portions of the other concave-convex portion R in the circumferential direction relative to the convex portions of the other concave-convex portion R.

[0180] Therefore, an appropriate amount of play is also provided in the circumferential direction between the connecting protrusion 10 and the connecting hole 30 in the connected state. In other words, an appropriate amount of play is provided in the circumferential direction between the engaging region 3011 of the connecting hole 30 and the connecting protrusion 10. This will be described in detail below.

[0181] In the following description, the rotation angle of the connecting member 3 from a state in which the connecting protrusion 10 fitted into the engagement region 3011 abuts against one inner edge in the circumferential direction of the engagement region 3011 until the connecting member 3 is rotated so that the connecting protrusion 10 abuts against the other inner edge in the circumferential direction of the engagement region 3011 is referred to as the second rotation angle. The angle obtained by subtracting the angle θc shown in the upper diagram of FIG. 24 from the angle θd shown in the lower diagram of FIG. 24 corresponds to the second rotation angle. The upper diagram of FIG. 24 shows a state in which the connecting protrusion 10 abuts against one inner edge of the engagement region 3011. The lower diagram of FIG. 24 shows a state in which the connecting protrusion 10 abuts against the other inner edge of the engagement region 3011.

[0182] In this embodiment, the second rotation angle is equal to or greater than half the convex portion periodic angle. This allows the convex portions of one uneven portion R to be smoothly fitted into the concave portions of the other uneven portion R when the connecting member 3 is pressed in the opposite direction to the biasing force to release the connection between the first coupling member 1 and the second coupling member 2. As a result, the workability of the operation to release the connection between the first coupling member 1 and the second coupling member 2 is improved.

[0183] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims.

[0184] For example, in the above embodiment, an inkjet recording apparatus that circulates ink within the apparatus has been described, but the present invention is not limited to inkjet recording apparatuses and can also be applied to apparatuses that circulate liquids other than ink. That is, the flow path connection mechanism including the coupling member can circulate liquids other than ink. [Explanation of symbols]

[0185] 1 First coupling member (coupling member) 2 Second coupling member (coupling member) 12 Second component (valve housing) 101 hollow movable valve 500 Inkjet recording device 1000 Flow path connection mechanism 1010 Distribution port G Gap

Claims

1. A coupling member that is a cylindrical body having an axis extending in a predetermined direction as a central axis, has a liquid flow path therein, and allows the liquid to flow in the axial direction, a cylindrical valve housing centered on the central axis; a hollow movable valve disposed radially inward of the valve housing, having a cylindrical shape centered on the central axis, and displaceable in an axial direction relative to the valve housing, the hollow movable valve is displaced in an axial position with respect to the valve housing between a connected state in which the coupling member is connected to another coupling member and a disconnected state in which the connection is released, thereby allowing the liquid to flow in the connected state and restricting the flow of the liquid in the disconnected state; In the connected state, a gap is generated between a predetermined portion of the hollow movable valve and the valve housing in the radial direction, The hollow movable valve has a flow port that penetrates the predetermined portion in a radial direction.

2. the hollow movable valve has a plurality of the flow ports, 2. The coupling member according to claim 1, wherein the plurality of flow ports each extend in a circumferential direction and are arranged in a staggered pattern in the circumferential direction over the entire circumferential circumference of the hollow movable valve.

3. 2. The coupling member according to claim 1, wherein the flow port extends in a spiral shape and has a circumferential length longer than one circumferential length of the hollow movable valve.

4. The coupling member according to any one of claims 1 to 3 is provided as a first coupling member, a second coupling member that is axially connected to the first coupling member, has a flow path for the liquid therein, and together with the first coupling member, allows the liquid to flow in the axial direction;

5. A coupling member according to any one of claims 1 to 3, the liquid is ink, An inkjet recording apparatus that performs printing using the ink.

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