Pipe fittings

Abstract

To provide a pipe joint capable of coupling and removing a joint member opening / closing a valve in a narrow environment.SOLUTION: A pipe joint (500) is equipped with an elbow type pipe joint (10) and a straight type pipe joint (310). The elbow type pipe joint has a first pipe connecting portion (21), a second pipe connecting portion (22), a hollow valve storage portion (23) having a valve storage space, and a first flat valve device (100) that is stored in the valve storage portion and rotates to switch a first valve-opening state and a first valve-closing state. A straight type pipe joint has a joint body (310), a valve seat portion (311) that is provided in the joint body and is formed with a second opening, and a second flap valve device (400) that is stored in the joint body and rotates to switch a second vale-closing state and a second valve-opening state.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a pipe fitting. [Background technology]

[0002] Various pipe fittings have been proposed for connecting two pipes. These fittings have two components, such as a "plug and socket" or a "male and female pipe fitting," each with an internal valve structure, which transitions from a closed state to an open state when the fittings are connected. For example, the pipe fitting disclosed in Patent Document 1 has a valve structure known as a plunger valve. When the plug and socket are connected, a component within the socket pushes back a cylindrical outer valve component within the plug in the axial direction, thereby releasing the sealing engagement between the outer valve device within the plug and an inner valve component (plunger) disposed within the outer valve component. Furthermore, when the socket is connected, the valve component is pushed back axially by the inner valve component within the plug, releasing the sealing engagement between the valve component and the components surrounding it. The pipe fitting disclosed in Patent Document 2 also has a valve structure known as a plunger valve. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-29933 [Patent Document 2] Japanese Patent Application Publication No. 2019-138380 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in pipe fittings with plunger valves such as those described in Patent Documents 1 and 2, the valve member (valve element) housed inside switches between an open state and a closed state by axially stroking, so they have no choice but to employ an axially long structure to ensure a predetermined stroke length. This poses a problem in that they cannot be used in environments where the predetermined stroke length cannot be ensured, such as narrow spaces such as the engine compartment of a vehicle. Therefore, there is a demand for pipe fittings that can connect and disconnect coupling members, which involves the opening and closing of the valve, in narrow environments. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms. According to one aspect of the present disclosure, there is provided a pipe fitting including an elbow pipe fitting and a straight pipe fitting that are removably connected to each other.In this pipe joint, the elbow-type pipe joint comprises a first cylindrical pipe connection portion to which the straight-type pipe joint is connected, a second cylindrical pipe connection portion having a second central axis intersecting a first central axis of the first pipe connection portion, a hollow valve accommodating portion connected to the first pipe connection portion and the second pipe connection portion, respectively, and having a valve accommodating space communicating with a first inner hole of the first pipe connection portion and a second inner hole of the second pipe connection portion, and a first flap valve device accommodated in the valve accommodating portion, which, by rotating, can be configured to switch between a first open state in which the first inner hole and the second inner hole are communicated, and a second open state in which the first inner hole and the the straight-type pipe fitting is a cylindrical fitting body having one end to which the elbow-type pipe fitting is connected and another end to which another pipe can be connected, the fitting body having the same central axis as the first central axis; a valve seat portion provided inside the fitting body and having a second opening for communicating the one end with the other end inside the fitting body; and a second flap valve device housed in the fitting body, which by rotating can switch between a second closed state in which the second opening is sealed and a second open state in which the second opening is sealed. a second flap valve device configured to switch between a first closed state and a second open state in which a port is opened, and a second open state in which a port is opened, the first flap valve device including a cylindrical valve seat member with a bottom having a first opening and a central axis parallel to the first central axis, the valve seat member being arranged so that the bottom is in contact with the valve accommodating space; a first valve body configured to be rotatable about a first rotation axis perpendicular to both the first central axis and the second central axis, the first valve body being configured to achieve the first closed state by sealing the first opening and the first open state by opening the first opening; and a first elastic member that biases the first valve body to seal the first opening, and the second flap valve device has: a fixed member that is arranged along the inner wall of the fitting body and has a second rotation axis attached thereto that is parallel to the first rotation axis; a second valve body that is configured to be rotatable around the second rotation axis and that achieves the second closed state by sealing the second opening and the second open state by opening the second opening; and a second elastic member that is attached to the fixed member and biases the second opening to seal.

[0006] (1) According to one aspect of the present disclosure, there is provided a pipe fitting including an elbow pipe fitting and a straight pipe fitting that are removably connected to each other. The elbow pipe fitting includes a first cylindrical pipe connection portion to which the straight pipe fitting is connected, a second cylindrical pipe connection portion having a second central axis intersecting a first central axis of the first pipe connection portion, hollow valve accommodating portions connected to the first pipe connection portion and the second pipe connection portion, respectively, and having valve accommodating spaces that communicate with a first inner hole of the first pipe connection portion and a second inner hole of the second pipe connection portion, and a first flap valve device accommodated in the valve accommodating portion, which, when rotated, switches between a first open state in which the first inner hole and the second inner hole communicate with each other and a first closed state in which the first inner hole and the second inner hole are blocked from each other. and a first flap valve device, and the straight-type pipe fitting is a cylindrical fitting body having one end to which the elbow-type pipe fitting is connected and another end to which another pipe can be connected, the fitting body having the same central axis as the first central axis, a valve seat portion provided inside the fitting body and having a second opening for connecting the one end and the other end inside the fitting body, and a second flap valve device housed in the fitting body that rotates to switch between a second closed state in which the second opening is sealed and a second open state in which the second opening is opened. According to this embodiment of the pipe fitting, the elbow pipe fitting includes a first pipe connection portion and a second pipe connection portion having intersecting central axes (first and second central axes), a valve housing portion, and a first flap valve device housed in the valve housing portion and rotating to switch between a first open state and a second closed state. The straight pipe fitting includes a second flap valve device that rotates within the fitting body to switch between a second open state and a second closed state. Therefore, the first and second flap valve devices can be opened and closed even in situations where only a narrow space is available along the first and second central axes. This allows the elbow pipe fitting and the straight pipe fitting to be connected and disconnected in a confined environment. Additionally, because the valves are opened and closed by the first and second flap valve devices, flow path resistance (pressure loss) can be reduced compared to a plunger valve. Furthermore, since the opening and closing of the valve is achieved by the first flap valve device and the second flap valve device, the structure can be made more compact compared to a plunger valve that requires a structure that extends in the axial direction. (2) In the pipe fitting of the above aspect, the first flap valve device comprises: a bottomed tubular valve seat member having a bottom where a first opening is formed and a central axis parallel to the first central axis, the valve seat member being arranged so that the bottom is in contact with the valve accommodating space; a first valve body configured to be rotatable about a first rotation axis perpendicular to both the first central axis and the second central axis, the first valve body realizing the first closed state by sealing the first opening and the first open state by opening the first opening; the second flap valve device may have a fixed member disposed along the inner wall of the fitting body and having a second rotation axis attached thereto that is parallel to the first rotation axis; a second valve body configured to be rotatable about the second rotation axis, the second valve body realizing the second closed state by sealing the second opening and the second open state by opening the second opening; and a second elastic member attached to the fixed member, the second elastic member urging the second opening to seal. According to this type of pipe fitting, the first flap valve device has a bottomed cylindrical valve seat member having a bottom where the first opening is formed, a first valve body, and a first elastic member, and the second flap valve device has a second valve body and a second elastic member, so that when the elbow pipe fitting and the straight pipe fitting are not connected, the first elastic member biases the first valve body to seal the first opening to achieve a first closed valve state, and the second elastic member biases the second valve body to seal the second opening to achieve a second closed valve state. On the other hand, when the elbow pipe fitting and the straight pipe fitting are connected, the first valve body can rotate to open the first opening to achieve a first open valve state, and the second valve body can rotate to open the second opening to achieve a second open valve state. (3) In the pipe fitting of the above aspect, the second opening may be formed in the valve seat portion so that a fourth central axis of the second opening is inclined at an angle of 30 degrees to 60 degrees with respect to a first central axis of the fitting body. According to this embodiment of the pipe fitting, the second opening is formed in the valve seat portion so that the fourth central axis of the second opening is inclined at an angle of 30 to 60 degrees relative to the first central axis of the fitting body. Therefore, when the second valve element is pushed along the first central axis by the same distance, the cross-sectional area of ​​the flow path inside the fitting body can be increased, thereby reducing pressure loss, compared to when the fourth central axis is parallel to the first central axis. Furthermore, since the inclination angle is 30 to 60 degrees, the cross-sectional area of ​​the flow path inside the fitting body in the second open state can be increased compared to when the inclination angle is relatively small. On the other hand, the force required to transition from the second closed state to the second open state can be reduced compared to when the inclination angle is relatively large. Furthermore, compared to when the inclination angle is relatively large, the load applied to the second elastic member is small in both the second open state and the second closed state, thereby reducing damage to the second elastic member. (4) In the pipe fitting of the above embodiment, the second opening may be formed in the valve seat portion so as to have an elliptical external shape when viewed in the direction of the fourth central axis of the second opening, and the second valve body may be a second main body portion that seals the second opening in the second closed valve state, and may have a second main body portion that has an elliptical external shape when viewed in the direction of the fourth central axis in the second closed valve state. In this pipe fitting, the second opening is formed in the valve seat portion so as to have an elliptical appearance when viewed in the direction of the fourth central axis of the second opening. Therefore, compared to a perfectly circular second opening, the opening area of ​​the second opening having a fourth central axis tilted relative to the first central axis can be increased. This further reduces pressure loss. Furthermore, the second valve element has a second main body portion with an elliptical appearance when viewed in the direction of the fourth central axis in the second closed state, thereby reliably sealing the second opening. (5) In the pipe fitting of the above form, the first valve body has a first pressing portion exposed to an inner space of the valve seat member that communicates with the first inner bore in the first closed valve state, and the first pressing portion is provided on a side of the first valve body that is closer to the first rotation axis in a direction parallel to the second center axis, and the second valve body has a second pressing portion that protrudes toward the one end of the fitting body in the second closed valve state, and the second pressing portion is provided on a side of the second valve body that is closer to the second rotation axis in a direction along the longitudinal axis of the second main body, and when the elbow-type pipe fitting and the straight-type pipe fitting are connected, the first pressing portion and the second pressing portion may press against each other in a direction parallel to the first center axis, and the first flap valve device may be in the first open valve state, and the second flap valve device may be in the second open valve state. In this pipe fitting, the first pressing portion is located on the side of the first valve body closer to the first rotation axis in a direction parallel to the second central axis. Therefore, when the first pressing portion is pressed by a straight-type pipe fitting (second pressing portion) for the same length along the first central axis, the first valve body can be rotated through a larger angle, compared to a configuration in which the first pressing portion is located on the side farther from the first rotation axis. This increases the flow path cross-sectional area in the valve storage space, thereby further reducing pressure loss. Additionally, the second pressing portion is located on the side of the second valve body closer to the second rotation axis in a direction along the major axis of the elliptical second main body portion, compared to a configuration in which the second pressing portion is located on the side farther from the second rotation axis. This increases the flow path cross-sectional area within the fitting body, thereby further reducing pressure loss. Furthermore, when the elbow-type pipe fitting and the straight-type pipe fitting are connected, the first pressing portion and the second pressing portion press against each other in a direction parallel to the first central axis, and the first flap valve device is in a first open valve state and the second flap valve device is in a second open valve state. Therefore, by connecting the elbow-type pipe fitting and the straight-type pipe fitting, the interiors of the fittings can be connected to each other. (6) In the pipe fitting of the above embodiment, the first opening may be formed in the bottom portion so that the third central axis of the first opening is parallel to the first central axis and is located farther from the first rotation axis than the first central axis along a direction parallel to the second central axis, and the second opening may be formed in the valve seat portion so that, when viewed in the direction of the fourth central axis, the center of the second opening is located farther from the second rotation axis in a direction along the long axis than an intersection of the second opening and the first central axis. According to this form of pipe fitting, the first opening is formed in the bottom portion so that the third central axis of the first opening is parallel to the first central axis and is located farther from the first rotation axis along a direction parallel to the second central axis compared to the first central axis.Therefore, when the straight-type pipe fitting is connected to the first pipe connection portion, the central axis of the straight-type pipe fitting is connected so that it coincides with the first central axis C1, and in a configuration in which the first pressing portion is pressed by a portion on the central axis of the straight-type pipe fitting (the second pressing portion), the first pressing portion provided on the side of the first valve body closer to the first rotation axis in the direction along the second central axis can be pressed with greater accuracy. In addition, the second opening is formed in the valve seat portion so that, when viewed in the direction of the fourth central axis, the center of the second opening is located farther from the second rotation axis in the direction along the long axis than the intersection of the second opening and the first central axis.Therefore, when the elbow-type pipe fitting is connected to the fitting body, the central axis of the elbow-type pipe fitting is connected to coincide with the first central axis, and in a configuration in which the second pressing part is pressed by a portion on the central axis of the elbow-type pipe fitting (first pressing part), the second pressing part provided on the side of the second valve body closer to the second rotation axis in the direction along the long axis can be pressed with greater accuracy. (7) In the pipe fitting of the above embodiment, the first valve body may further include a first main body portion having a first exposed surface exposed to the inner space in the first closed-valve state and a first seal portion connected to the first exposed surface and sealing the first opening in the first closed-valve state, and a rod-shaped first protrusion portion protruding from the first exposed surface and connected to the first pressing portion at its tip, and the second main body portion may further include a second exposed surface exposed at the one end side in the second closed-valve state and a second seal portion connected to the second exposed surface and sealing the second opening in the second closed-valve state, and the second valve body may further include a rod-shaped second protrusion portion protruding from the second exposed surface and connected to the second pressing portion at its tip. In this pipe fitting, the first valve body has a rod-shaped first protruding portion that protrudes from the first exposed surface and is connected to the first pressing portion at its tip, so that a portion of the first valve body other than the first pressing portion is prevented from being pressed when an elbow-type pipe fitting is connected to the first pipe connection portion. In addition, the second valve body has a rod-shaped second protruding portion that protrudes from the second exposed surface and is connected to the second pressing portion at its tip, so that a portion of the second valve body other than the second pressing portion is prevented from being pressed when a straight-type pipe fitting is connected to the fitting body. (8) In the pipe fitting of the above embodiment, the first protrusion may be arranged parallel to the first center axis in the first open valve state, and the second protrusion may be arranged parallel to the first center axis in the second closed valve state. In this pipe fitting, the first protrusion is arranged parallel to the first central axis in the first open state, thereby reducing the area of ​​the first protrusion when viewed in the direction of the first central axis. This reduces the pressure loss of the fluid flowing from the first inner bore into the valve housing space. In addition, the second protrusion is arranged parallel to the first central axis in the second closed state, thereby ensuring that the force applied to the second pressing portion is transmitted to the second main body when the elbow pipe fitting is connected. This allows the second closed state to be released smoothly with little force. (9) In the pipe joint of the above aspect, the contact surfaces of the first pressing portion and the second pressing portion that come into contact with each other may each be configured by a curved surface that is a set of involute curves. In this pipe fitting, the contact surfaces of the first pressing portion and the second pressing portion that come into contact with each other are both configured as curved surfaces that are a collection of involute curves, which prevents excessive displacement of the contact position between the first pressing portion and the second pressing portion, and because the contact portions can be configured as points or lines, the pressing force can be stably transmitted to the first valve body and the second valve body when the elbow pipe fitting and the straight pipe fitting are connected. This allows the first valve body and the second valve body to rotate smoothly and can be rotated with a small force. (10) In the pipe joint of the above aspect, the first pressing portion and the second pressing portion may contact each other on the first central axis. According to this form of pipe fitting, the first pressing portion and the second pressing portion contact each other on the first central axis, and therefore when the straight-type pipe fitting is inserted into the elbow-type pipe fitting in a direction along the first central axis, force is applied to the contact portion on the first central axis, thereby stabilizing the opening degree of the first valve body and the second valve body compared to a configuration in which the first pressing portion and the second pressing portion contact each other other than on the first central axis. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view showing an external configuration of a pipe joint according to an embodiment of the present disclosure. [Figure 2] 1 is a perspective view showing an external configuration of a pipe joint according to an embodiment of the present disclosure. [Figure 3] FIG. 2 is a perspective view showing the external configuration of an elbow-type pipe joint. [Figure 4] FIG. 2 is a perspective view showing the external configuration of an elbow-type pipe joint. [Figure 5] FIG. 2 is a perspective view showing the external configuration of an elbow-type pipe joint. [Figure 6] FIG. 2 is a cross-sectional view showing a cross section of a pipe joint. [Figure 7] FIG. 3 is a perspective view showing the detailed configuration of a first flap valve device. [Figure 8] FIG. 3 is a perspective view showing the detailed configuration of a first flap valve device. [Figure 9] 10 is an explanatory diagram showing the positional relationship between a first central axis of the first pipe connecting portion and a third central axis of the first opening. FIG. [Figure 10] FIG. 3 is a perspective view showing the detailed configuration of a first valve body. [Figure 11] FIG. 3 is a perspective view showing the detailed configuration of a first valve body. [Figure 12] FIG. 2 is a perspective view showing the external configuration of a straight pipe joint. [Figure 13] FIG. 2 is a perspective view showing the external configuration of a straight pipe joint. [Figure 14]FIG. 2 is a perspective view showing the external configuration of a straight pipe joint. [Figure 15] FIG. 2 is a perspective view showing the external configuration of a joint body. [Figure 16] FIG. 2 is a perspective view showing the external configuration of a joint body. [Figure 17] FIG. 4 is a perspective view showing the detailed configuration of a second flap valve device. [Figure 18] FIG. 4 is a perspective view showing the detailed configuration of a second flap valve device. [Figure 19] FIG. 4 is a perspective view showing the detailed configuration of a second valve body. [Figure 20] FIG. 4 is a perspective view showing the detailed configuration of a second valve body. [Figure 21] 10 is an explanatory diagram for explaining the effect of the fourth central axis being inclined with respect to the first central axis. FIG. [Figure 22] FIG. 2 is a cross-sectional view showing a cross section of a pipe joint. [Figure 23] FIG. 2 is a cross-sectional view showing a cross section of a pipe joint. [Figure 24] FIG. 2 is a cross-sectional view showing a cross section of a pipe joint. [Figure 25] FIG. 2 is a cross-sectional view showing a cross section of a pipe joint. DETAILED DESCRIPTION OF THE INVENTION

[0008] A. Implementation: A1. Pipe Fitting 500 consists of: 1 and 2 are perspective views showing the external configuration of a pipe fitting 500 according to an embodiment of the present disclosure. The pipe fitting 500 is used to connect two pipes together in a small space. Specifically, the pipe fitting 500 is used to connect two pipes together when their central axes do not coincide with each other (i.e., when the pipes intersect at a predetermined angle). The predetermined angle may be any angle except 0 degrees. In this embodiment, the "two pipes" refer to pipes for circulating a cooling medium, such as pure water, LLC (Long Life Coolant), air, or oil, to regulate the temperature of a battery module in a battery pack mounted on a vehicle and housing multiple batteries in a battery case. Of the two pipes connected to the pipe fitting 500, one pipe 323 is shown in FIGS. 1 and 2, but the other pipe is omitted. The pipe 323 is provided inside the battery pack case and is connected to a pipe outside the battery pack case via the pipe fitting 500. The pipe fitting 500 is disposed in the battery pack case. The pipe fitting 500 is not limited to a pipe for circulating a cooling medium for temperature adjustment in the battery pack described above, but may be used in any location to connect pipes for circulating any type of medium.

[0009] As shown in FIGS. 1 and 2, the pipe fitting 500 includes an elbow-type pipe fitting 10 and a straight-type pipe fitting 310.

[0010] A2. Elbow type pipe fitting 10 configuration: 3 to 5 are perspective views showing the external configuration of the elbow pipe fitting 10. The elbow pipe fitting 10 comprises a first pipe connecting portion 21, a second pipe connecting portion 22, a valve accommodating portion 23, a retainer 30, and a first flap valve device 100. The first pipe connecting portion 21, the second pipe connecting portion 22, and the valve accommodating portion 23 are integrally formed.

[0011] The first pipe connecting portion 21 has a cylindrical external shape and can be connected to a straight pipe fitting 310. An inner hole h1 of the first pipe connecting portion 21 (hereinafter referred to as the "first inner hole h1") and a central axis C1 of the first pipe connecting portion 21 (hereinafter referred to as the "first central axis C1") are parallel to the Z axis. A valve accommodating portion 23 is connected to the first pipe connecting portion 21 in the +Z direction. A straight pipe fitting 310 is connected to the first pipe connecting portion 21 in the -Z direction. As shown in FIG. 5, an engaging member 101 and a first seal member 102 are attached to the first inner hole h1 of the first pipe connecting portion 21.

[0012] The second pipe connecting portion 22 has a cylindrical external shape and can be connected to a pipe (not shown). An inner hole h2 of the second pipe connecting portion 22 (hereinafter referred to as the "second inner hole h2") and a central axis C2 of the second pipe connecting portion 22 (hereinafter referred to as the "second central axis C2") are parallel to the Y axis. A valve accommodating portion 23 is connected to the second pipe connecting portion 22 in the -Y direction. A pipe (not shown) can be connected to the second pipe connecting portion 22 in the +Y direction. The pipe that can be connected to this second pipe connecting portion 22 may be a joint having a valve device therein, or may be a simple pipe simply provided with an inner hole.

[0013] The valve accommodating portion 23 is connected to the first pipe connecting portion 21 and the second pipe connecting portion 22, and has a hollow structure having a valve accommodating space h3 that communicates with the first inner hole h1 and the second inner hole h2.

[0014] FIG. 6 is a cross-sectional view of the pipe fitting 500. FIG. 6 shows a cross-section taken along the VI-VI line in FIG. 1. A first flap valve device 100 is accommodated in the valve accommodation space h3. The -Z-direction end of the first flap valve device 100 contacts the first seal member 102. The -Z-direction end of the first seal member 102 contacts the engaging member 101. That is, the first seal member 102 is sandwiched between the first flap valve device 100 and the engaging member 101 in the Z-axis direction, sealing the gap between the first flap valve device 100 and the engaging member 101. Unlike FIGS. 1 and 2, FIG. 6 shows the pipe fitting 500 in a state in which the elbow-type pipe fitting 10 and the straight-type pipe fitting 310 are not connected. In this state, the first flap valve device 100 is in a first closed state in which the first inner bore h1 and the second inner bore h2 are blocked. The detailed configuration of the first flap valve device 100 will be described later.

[0015] As shown in Figures 1 to 5, the retainer 30 has a generally U-shaped shape in a plan view. When the straight-type pipe fitting 310 is connected to the first pipe connecting portion 21, the retainer 30 is attached so as to sandwich the first pipe connecting portion 21 and engages with the tip of the straight-type pipe fitting 310 in the +Z direction. A pair of engaging portions 31 shown in Figures 5 and 6 are formed at the tips of both arm portions of the retainer 30. These pair of engaging portions 31 are inserted into the first inner hole h1 from openings formed on the side surfaces of the first pipe connecting portion 21 and engage with engaging portions (not shown) formed at the tip of the straight-type pipe fitting 310 in the +Z direction. This completes the prevention of the straight-type pipe fitting 310 from slipping out of the elbow-type pipe fitting 10.

[0016] A3. Detailed configuration of the first flap valve device 100: 7 and 8 are perspective views showing the detailed configuration of the first flap valve device 100. In addition to the first flap valve device 100, Fig. 7 shows an engagement member 101 and a first seal member 102. The engagement member 101 has an annular external shape. As shown in Fig. 7, an engagement groove 103 is formed on the outer circumferential surface of the engagement member 101, and the engagement member 101 engages with the -Z direction end of the valve accommodating portion 23 and the +Z direction end of the first pipe connecting portion 21 via this engagement groove 103.

[0017] The first flap valve device 100 includes a valve seat member 110, a first valve body 150, and a first elastic member 130. The valve seat member 110 has a bottom 111 in which a first opening 112 is formed, and has a cylindrical external shape with a bottom. In the first closed valve state shown in FIGS. 5, 7, and 8, the first opening 112 is sealed by the first valve body 150. The bottom 111 has an outer surface (surface facing the +Z direction) exposed to the valve accommodating space h3 as shown in FIG. 6, and an inner surface (surface facing the -Z direction) exposed to the first inner hole h1 as shown in FIG.

[0018] FIG. 9 is an explanatory diagram showing the positional relationship between the first center axis C1 of the first pipe connection portion 21 and the third center axis C3 of the first opening 112. FIG. 9 schematically shows a cross section of the first pipe connection portion 21 and the valve seat member 110, and the second pipe connection portion 22, the valve accommodating portion 23, the retainer 30, and the like are omitted. Also, in FIG. 9, a thick arrow indicates a locus T1 of the position of the rotation axis when the first valve body 150 rotates. The first valve body 150 rotates about a rotation axis parallel to the X-axis direction. The first valve body 150 also moves in the Z-axis direction depending on the connection state with the straight pipe fitting 310. Therefore, the rotation axis of the first valve body 150 moves along a locus T1 parallel to the Z-axis direction. 9, the first opening 112 is formed on the bottom 111 of the valve seat member 110 so that a central axis C3 of the first opening 112 (hereinafter referred to as the "third central axis C3") is parallel to the first central axis C1 of the first pipe connection portion 21 and is located farther from the rotation axis (trajectory T1) of the first valve body 150 than the first central axis C1 along a direction parallel to the Y-axis direction (a direction parallel to the second central axis C2). The reason for such a misalignment between the first central axis C1 and the third central axis C3 in the Y-axis direction will be described later. The "central axis C3 of the first opening 112" refers to an axis that passes through the center of the first opening 112 and coincides with a normal line when the first opening 112 is viewed as a plane.

[0019] 6 to 8, the valve seat member 110 includes, in addition to the above-mentioned first opening 112, a first elastic member support portion 113 and a pair of first bearing portions 114. The bottom portion 111, the first elastic member support portion 113 and the first bearing portions 114 are integrally formed.

[0020] The first elastic member support portion 113 is formed on the -Y direction end of the +Z direction surface of the bottom portion 111. The first elastic member support portion 113 has an external shape of a rectangular pillar protruding from the bottom portion 111 in the +Z direction. The first elastic member support portion 113 supports the first elastic member 130. In this embodiment, the first elastic member 130 is formed of a bent leaf spring. The first elastic member support portion 113 fixes one end 132 of the leaf spring. In this way, the first elastic member support portion 113 causes the one end 132 of the first elastic member 130 to function as a fixed end.

[0021] The pair of first bearing portions 114 are formed at the −Y direction end of the +Z direction surface of the bottom portion 111, sandwiching the first elastic member support portion 113 in the X axis direction. The first bearing portions 114 rotatably support the pair of first shaft portions 153 of the first valve body 150. However, in this embodiment, in the normal state, the first bearing portions 114 and the first shaft portions 153 are not in contact with each other, and the first shaft portions 153 are positioned further in the +Z direction than the first bearing portions 114 and are not in contact with each other. Therefore, in the normal state, the first bearing portions 114 merely function to prevent excessive positional displacement of the first shaft portions 153 when the first valve body 150 rotates. However, even if an abnormal state occurs in which the position of the first shaft portion 153 is located in the -Z direction from the intended position due to design tolerances or assembly errors of the first seal portion 159 provided on the first valve body 150, the first bearing portion 114 can rotatably support the first shaft portion 153 because there is a gap between the first shaft portion 153 and the first bearing portion 114 in the normal state.

[0022] 10 and 11 are perspective views showing the detailed configuration of the first valve body 150. The first valve body 150 is configured to be rotatable about a first rotation axis that moves along a trajectory T1 shown in FIG. 9 when connected to the straight pipe fitting 310 and is perpendicular to both the first central axis C1 and the second central axis C2. The first valve body 150 achieves a first closed state by sealing the first opening 112 of the bottom portion 111, and achieves a first open state by opening the first opening 112.

[0023] In addition to the pair of first shaft portions 153 described above, the first valve body 150 also includes a first main body portion 155, a pair of first elastic member guide portions 151, a pair of support arm portions 152, a first protrusion portion 157, a first pressing portion 158, and a first seal portion 159. Note that the first seal portion 159 is omitted in Figures 10 and 11. The first seal portion 159 is shown in Figures 7 and 8 described above.

[0024] The first main body portion 155 has a thin, cylindrical exterior shape with one end surface (hereinafter referred to as the "first exposed surface 156") formed in a conical shape. In the first open state, the first exposed surface 156 is the surface against which the coolant flowing in from the first pipe connection portion 21 and moving in the +Z direction through the first inner hole h1 collides within the valve storage space h3. Because the first exposed surface 156 is conical, the coolant that collides with the first exposed surface 156 can be directed toward the second inner hole h2. As shown in FIG. 6, in the first closed state, the central axis direction (thickness direction) of the first main body portion 155 is parallel to the Z axis. As shown in FIG. 6, in the first closed state, the first exposed surface 156 is exposed to the inner space SP1 of the valve seat member 110.

[0025] As shown in Fig. 8, the pair of first elastic member guide portions 151 are provided a predetermined distance apart from each other in the X-axis direction on the surface opposite the first exposed surface 156, i.e., on surface S1, which is the end surface of the first main body portion 155 in the +Z direction. The pair of first elastic member guide portions 151 have a substantially quadrangular prism-like external shape and protrude in the +Z direction from surface S1. As shown in Figs. 7 and 8, on surface S1, the first folded portion 133 of the first elastic member 130 is disposed in region SP2 sandwiched between the pair of first elastic member guide portions 151. The length of region SP2 in the X-axis direction is longer than the length of the first folded portion 133 in the X-axis direction.

[0026] Here, the configuration of the first elastic member 130 will be described. As described above, the first elastic member 130 is composed of a bent leaf spring, and the end 132 in the -Y direction is fixed by the first elastic member support portion 113. In addition to the end 132 described above, the first elastic member 130 includes a first intermediate portion 131 connected to the end 132, and a first folded portion 133 connected to the first intermediate portion 131 and located at the end opposite the end 132. As described above, the end 132 is a fixed end, while the first intermediate portion 131 and the first folded portion 133 are free. In other words, the first intermediate portion 131 and the first folded portion 133 are not fixed to the first valve body 150 or the valve seat member 110, and are capable of deformation and movement due to applied stress. The end of the first elastic member support portion 113 in the +Z direction substantially coincides with the end of the end 132 in the +Z direction. The +Z-direction end of the first elastic member support portion 113 and the end portion 132 is located in the +Z direction relative to the surface S1. Therefore, as shown in FIGS. 7 and 8, the first intermediate portion 131, which is connected to the end portion 132 and the first folded portion 133, is obliquely disposed so as to be positioned in the -Z direction as it approaches the +Y direction. As shown in FIGS. 7 and 8, an opening is provided in the first intermediate portion 131 to reduce weight and the biasing force. As shown in FIGS. 6 to 8, the first folded portion 133 is bent so as to form a slope opposite to the first intermediate portion 131, with the portion where it contacts the surface S1 of the valve seat member 110 (bottom portion 111) as a boundary. The released first folded portion 133 slides on the surface S1 so that the position where it contacts the surface S1 changes when switching between the first open state and the first closed state. During this movement, the pair of first elastic member guide portions 151 restrict the first folded portion 133 from being excessively displaced in the X-axis direction and coming out of the region SP2.

[0027] As shown in FIGS. 10 and 11 , the pair of support arms 152 have a thin, plate-like appearance that is substantially triangular in plan view. The pair of support arms 152 are spaced apart from each other by a predetermined distance in the X-axis direction. The +Y-direction ends of the pair of support arms 152 are connected to the bottom 111, and the -Y-direction ends are spaced apart from the bottom 111. The above-mentioned pair of first shafts 153 are provided at the ends of the pair of support arms 152 that are away from the bottom 111. Therefore, as shown in FIGS. 7 and 8 , in an assembled state, the pair of support arms 152 cantilever-support the first valve body 150 as the first shafts 153 are supported by the first bearings 114.

[0028] 10 and 11, the first protruding portion 157 has a rod-like external shape, protrudes from the first exposed surface 156, and its tip is connected to the first pressing portion 158. The first pressing portion 158 has a curved plate-like external shape. A surface S2 (hereinafter referred to as the "contact surface S2") of the first pressing portion 158 is opposite in the thickness direction to the surface connected to the tip of the first protruding portion 157, and comes into contact with the second pressing portion 458 (contact surface S4) of the straight-type pipe fitting 310 when connected to the straight-type pipe fitting 310.

[0029] The contact surface S2 is composed of a curved surface that is a collection of involute curves. In other words, the contact surface S2 is a curved surface whose cross section is an involute curve. An involute curve is a plane curved surface whose normal always touches a fixed circle. The reason why the contact surface S2 is composed of a curved surface whose cross section is an involute curve will be explained later.

[0030] A4. Straight pipe fitting 310 configuration: 12 to 14 are perspective views showing the external configuration of a straight-type pipe fitting 310. The straight-type pipe fitting 310 includes a fitting body 321 and a flange 322. FIGS. 15 and 16 are perspective views showing the external configuration of the fitting body 321. The fitting body 321 has a cylindrical external shape with a first center axis C1 parallel to the Z axis. The straight-type pipe fitting 310 has openings at one end in the +Z direction and the other end in the -Z direction. As shown in FIGS. 14 and 16, the fitting body 321 has a valve seat portion 311 with a second opening 312 formed therein. Note that FIGS. 12 to 16 show a state in which the second opening 312 is sealed by a second valve body 450 of a second flap valve device 400 (described later) (second closed state). As shown in FIG. 15, the fitting body 321 has a flange mounting portion 324 that is a circumferential groove. As shown in Figures 12 to 14, a flange 322 is attached to the flange attachment portion 324. The flange 322 has a plurality of engaging portions 325. The engaging portions 325 engage with the elbow-type pipe fitting 10 when the straight-type pipe fitting 310 and the elbow-type pipe fitting 10 are connected. As shown in Figure 15, a plurality of claw portions 326 and a second seal member 302 are provided on the circumference of the fitting body 321 in the -Z direction. The plurality of claw portions 326 engage with the pipe 323 when the pipe 323 is connected. The second seal member 302 is sandwiched between the pipe 323 and the fitting body 321, and seals the gap between the pipe and the fitting body 321.

[0031] As shown in FIG. 6 , a second flap valve device 400 is housed inside the fitting body 321. The second flap valve device 400 seals the second opening 312 when the straight pipe fitting 310 and the elbow pipe fitting 10 are not connected. The detailed configuration of the second flap valve device 400 will be described later. A second seal portion 459 is sandwiched between the second flap valve device 400 and the fitting body 321. The second seal portion 459 seals the gap between the second flap valve device 400 and the fitting body 321. The second opening 312 is an opening that connects both ends of the fitting body 321 in the Z-axis direction. The second opening 312 is also inclined so that it is positioned in the −Z direction as it approaches the −Y direction. In other words, the fourth center axis C4 of the second opening 312 is inclined with respect to the first center axis C1 of the fitting body 321. Specifically, the fourth central axis C4 is inclined at 45 degrees with respect to the first central axis C1. The angle of inclination is not limited to 45 degrees and may be any angle between 30 degrees and 60 degrees. The reason why the fourth central axis C4 is inclined with respect to the first central axis C1 will be described later. The second opening 312 is formed in the valve seat portion 311 such that, when viewed in the direction of the fourth central axis C4, the center P1 of the second opening 312 is located farther from the second rotation axis of the second valve body 450 than an intersection P2 between the second opening 312 and the first central axis C1 in the direction along the major axis. The offset between the center P1 and the intersection P2 will be described later.

[0032] A5. Detailed configuration of the second flap valve device 400: 17 and 18 are perspective views showing the detailed configuration of the second flap valve device 400. The second flap valve device 400 includes a fixed member 410, a second valve body 450, and a second elastic member 430.

[0033] The fixing member 410 is a rectangular plate-shaped member extending in the X-axis direction and the Z-axis direction. As shown in FIG. 18 , engagement grooves 411 are formed on both ends of the fixing member 410 in the X-axis direction. As shown in FIG. 16 , the fixing member 410 is disposed inside the joint body 321 by engaging the engagement grooves 411 with grooves provided along the inner wall of the joint body 321. As shown in FIGS. 17 and 18 , the fixing member 410 includes a second elastic member fixing portion 412. The second elastic member fixing portion 412 is provided on the −Y-direction surface of the fixing member 410 and fixes the second elastic member 430. In this embodiment, the second elastic member 430 is formed of a bent leaf spring. The second elastic member fixing portion 412 fixes one end of the leaf spring. As a result, the second elastic member fixing portion 412 causes one end of the second elastic member 430 to function as a fixed end.

[0034] The fixed member 410 includes an engagement groove 411, a second elastic member fixing portion 412, and a pair of second bearing portions 414. The pair of second bearing portions 414 are formed at the end of the fixed member 410 in the +Z direction, at both ends in the X-axis direction. The second bearing portions 414 rotatably support a pair of second shaft portions 453 of the second valve body 450. In this embodiment, the second bearing portions 414 are provided with a gap, i.e., play, that allows the second shaft portions 453 to move in the +Z direction and the -Y direction. The play is provided so that the second shaft portions 453 can move in a direction parallel to the fourth central axis C4 of the second opening 312. The movement of the second valve body 450 along the play will be described later.

[0035] 19 and 20 are perspective views showing the detailed configuration of the second valve body 450. The second valve body 450 is configured to be rotatable about a second rotation axis parallel to the X-axis direction when connected to the elbow pipe fitting 10. The second valve body 450 achieves a second closed state by sealing the second opening 312 of the valve seat portion 311, and achieves a second open state by opening the second opening 312.

[0036] In addition to the pair of second shaft portions 453 described above, the second valve body 450 also includes a second main body portion 455, a pair of second elastic member guide portions 451, a second protrusion portion 457, a second pressing portion 458, and a support portion 452.

[0037] The second main body portion 455 has a thin, cylindrical exterior shape. In the second closed state, the second main body portion 455 has a fourth center axis C4 that is the same as the second opening 312. When viewed along the fourth center axis C4, the second main body portion 455 has an elliptical exterior shape that seals the second opening 312. As described above, the fourth center axis C4 is inclined with respect to the first center axis C1. FIG. 21 is an explanatory diagram for explaining the effect of the fourth center axis C4 being inclined with respect to the first center axis C1. The left side of FIG. 21 schematically illustrates the fitting body 321 and the second main body portion 455 of this embodiment. The dashed line on the left side of FIG. 21 indicates the position of the second main body portion 455 in the second closed state. The solid line on the left side of FIG. 21 indicates the position of the second main body portion 455 when the end of the second main body portion 455 facing the -Y and +Z directions is pushed a distance d1 from the +Z direction in a direction parallel to the first central axis C1, resulting in the second open state. The right side of FIG. 21 schematically illustrates a pipe 600 and a valve 650 as a comparative example. The pipe 600 is a straight pipe having a central axis C10. An opening 620 having a central axis C20 parallel to the central axis C10 is provided within the pipe 600. The valve 650 has a central axis C20 parallel to the central axis C10 and is configured to be rotatable about a rotation axis parallel to the X-axis direction. The valve 650 switches between a closed state in which the opening 620 is sealed and an open state in which the opening 620 is opened by rotation. The dashed line on the right side of FIG. 21 indicates the position of the valve 650 in the closed state. The solid line on the right side of FIG. 21 indicates the position of the valve 650 in the open state, where the end of the valve 650 facing the -Y and +Z directions is pushed a distance d1 from the +Z direction in a direction parallel to the central axes C10 and C20. As is apparent from FIG. 21 , when the second main body portion 455 and the valve 650 are pushed the same distance d1, the inclination of the fourth central axis C4 relative to the first central axis C1 in this embodiment makes it possible to increase the cross-sectional area of ​​the flow path near the second main body portion 455 in the second open state, as viewed in the direction of the first central axis C1, compared to the comparative example. This further reduces the pressure loss of the coolant flowing inside the fitting body 321. For this reason, in this embodiment, the fourth central axis C4 is inclined relative to the first central axis C1.

[0038] Furthermore, the tilt angle is preferably 30 to 60 degrees. If the angle is small (for example, less than 30 degrees), the flow path cross-sectional area in the second open valve state will be small. On the other hand, if the angle is large (for example, more than 60 degrees), the force transmitted from the +Z direction when connecting to another joint will escape in the X-axis or Y-axis direction, increasing the force required to push the second main body portion 455. Furthermore, in both the second closed valve state and the second open valve state, the force applied to the second elastic member 430 will be greater than when the angle is small, which may cause damage to the second elastic member 430. For this reason, the tilt angle is preferably 30 to 60 degrees.

[0039] 20, the pair of second elastic member guide portions 451 are provided at a predetermined distance from each other in the X-axis direction on a surface S3, which is the end surface of the second main body portion 455 in the -Z direction. The second elastic member guide portions 451 have a substantially rectangular prism-like external shape and protrude in the -Z direction from the surface S3. As shown in FIGS. 16 and 18, on the surface S3, the second folded portion 433 of the second elastic member 430 is disposed in a region SP3 sandwiched between the pair of second elastic member guide portions 451. The length of the region SP3 in the X-axis direction is longer than the length of the second folded portion 433 in the X-axis direction.

[0040] The configuration of the second elastic member 430 will now be described. As described above, the second elastic member 430 is composed of a bent leaf spring, and its end in the +Y direction is fixed by the second elastic member fixing portion 412. In addition to the end, the second elastic member 430 includes a second intermediate portion 431 connected to the end and a second folded portion 433 connected to the second intermediate portion 431 and located at the end opposite the end. As described above, while the end is a fixed end, the second intermediate portion 431 and the second folded portion 433 are open. In other words, the second intermediate portion 431 and the second folded portion 433 are not fixed to the second valve body 450 and can deform and move due to applied stress. As shown in FIG. 6, the second intermediate portion 431 is obliquely positioned so that it is positioned in the -Z direction as it approaches the -Y direction. As shown in FIGS. 16 and 18, the second intermediate portion 431 has an opening to reduce weight and biasing force. 16 and 18, second folded portion 433 is bent so as to form a slope opposite to second intermediate portion 431, with the portion where second folded portion 433 contacts surface S3 of second main body portion 455 as a boundary. When second folded portion 433 is released and switches between the second open state and the second closed state, it slides along surface S3 so that the position where it contacts surface S3 changes. During this movement, the pair of second elastic member guide portions 451 prevent second folded portion 433 from being excessively displaced in the X-axis direction and moving out of region SP3.

[0041] As shown in FIGS. 19 and 20, the support portion 452 is provided between the second shaft portion 453 and the second main body portion 455, and connects the second shaft portion 453 near the center in the X-axis direction to the second main body portion 455.

[0042] 17 to 20, the second protrusion 457 has a rod-like external shape. The second protrusion 457 protrudes from a second exposed surface 456, which is the surface of the second main body 455 in the +Z direction, and is connected at its tip to a second pressing portion 458. The second pressing portion 458 has a curved plate-like external shape. A surface S4 (hereinafter referred to as the "contact surface S4") of the second pressing portion 458 is opposite in the thickness direction to the surface connected to the tip of the second protrusion 457, and comes into contact with the first pressing portion 158 (contact surface S2) of the elbow pipe fitting 10 when the straight pipe fitting 310 and the elbow pipe fitting 10 are connected.

[0043] The contact surface S4 is composed of a curved surface that is a collection of involute curves. In other words, the contact surface S4 is a curved surface whose cross section is an involute curve. An involute curve is a plane curved surface whose normal line is always tangent to a fixed circle. The reason why the contact surface S4 is composed of a curved surface whose cross section is an involute curve will be explained later.

[0044] A6. Connection and disconnection operation between elbow type pipe fitting 10 and straight type pipe fitting 310: 22 to 25 are cross-sectional views showing a cross section of the pipe fitting 500. Like Fig. 6, Figs. 22 to 25 show a cross section taken along the VI-VI cross section line in Fig. 1. Figs. 22 to 25 chronologically show how the elbow pipe fitting 10 and the straight pipe fitting 310 are connected and the first flap valve device 100 and the second flap valve device 400 open. In this embodiment, the first elastic member 130 and the second elastic member 430 are configured so that the first flap valve device 100 enters the first open state after the second flap valve device 400 enters the second open state.

[0045] 22, when the straight pipe fitting 310 moves in the +Z direction relative to the elbow pipe fitting 10, the fitting body 321 is inserted into the inner hole h1 of the first pipe connecting portion 21. At this time, the fitting body 321 is inserted so that the central axis of the first pipe connecting portion 21 and the central axis of the fitting body 321 coincide with each other. As the fitting body 321 is inserted, the contact surface S2 of the first pressing portion 158 comes into contact with the contact surface S4 of the second pressing portion 458. At this time, the contact portion A is on the first central axis C1.

[0046] As shown in FIG. 23 , as the insertion of the fitting body 321 progresses further from the state shown in FIG. 22 , the first pressing portion 158 presses the second pressing portion 458 in the −Z direction. In this embodiment, the contact surfaces S2 and S4 are configured as curved surfaces that are a collection of involute curves. Therefore, as the first pressing portion 158 presses the second pressing portion 458, the contact portion A of the first pressing portion 158 and the second pressing portion 458 is displaced in a curved shape on the contact surface S4 along the longitudinal direction of the contact surface S4. This causes the second valve body 450 to rotate in the direction of the arrow shown in FIG. 23 around the second shaft portion 453. Due to this rotation, the second valve body 450 as a whole is pushed and displaced in the −Z direction, and enters the second open state. Therefore, as shown in FIG. 23, the second opening 312 is opened, and the inner hole h1 of the first pipe connection portion 21 communicates with the +Z and -Z openings of the fitting body 321 via the second opening 312. The arrows shown near the second flap valve device 400 in FIGS. 22 to 25 indicate the locus T2 of the position of the second rotation axis when the second valve body 450 rotates. As described above, the second bearing portion 414 has play to allow the second shaft portion 453 to move in a direction parallel to the fourth central axis C4 of the second opening 312. Therefore, the second valve body 450 rotates about the second rotation axis parallel to the X-axis direction, and the second rotation axis of the second valve body 450 moves along the play in the +Y and -Z directions. As a result, the second rotation axis of the second valve body 450 moves along the locus T2 parallel to the fourth central axis C4.

[0047] As shown in FIG. 24, when the insertion of the fitting body 321 progresses further from the state shown in FIG. 23, the second pressing portion 458 presses the first pressing portion 158 in the +Z direction. As described above, the contact surface S2 and the contact surface S4 are configured as curved surfaces that are a collection of involute curves. Therefore, the contact portion A of the first pressing portion 158 and the second pressing portion 458 is displaced in a curved shape on the contact surface S2 along the longitudinal direction of the contact surface S2. As a result, the first valve body 150 rotates around the first shaft portion 153 in the direction of the arrow shown near the first flap valve device 100 in FIG. 24. This rotation pushes and displaces the first valve body 150 as a whole in the +Z direction. Therefore, as shown in FIG. 24, the first opening 112 is opened, and the first inner bore h1, the second inner bore h2, and the valve accommodation space h3 communicate with each other via the first opening 112.

[0048] 25, as the insertion of the fitting body 321 progresses further from the state in Fig. 24, the second pressing portion 458 presses the first pressing portion 158 further in the +Z direction, further increasing the opening of the first opening 112. When the tip of the fitting body 321 in the +Z direction hits the bottom portion 111, the insertion of the fitting body 321 is stopped, and the worker attaches the retainer 30 to the first pipe connection portion 21, completing the connection between the elbow pipe fitting 10 and the straight pipe fitting 310.

[0049] As shown in FIGS. 24 and 25 , a cooling medium flow path connecting the first inner hole h1, the valve housing space h3, and the inner hole h2 is formed through a gap formed in the first opening 112 in the +Y direction from the first valve body 150. This flow path is the shortest path connecting the first inner hole h1 and the second inner hole h2. This reduces pressure loss. Note that, as shown in FIG. 25 , the first valve body 150 rotates and moves in the +Z direction compared to the first closed state shown in FIG. 22 . As a result, a cooling medium flow path connecting the first inner hole h1, the valve housing space h3, and the inner hole h2 is also formed through a gap formed in the first opening 112 in the −Y direction from the first valve body 150. This flow path passes between the first valve body 150 and the first elastic member support portion 113, and then goes around the side of the first elastic member 130 or passes through the opening of the first elastic member 130 toward the second inner hole h2. Here, as shown in FIGS. 22 to 25, in the valve accommodating portion 23, the inner walls 231 at the +Z direction end and the -Y direction end are formed as inclined surfaces with the -Z direction and the +Y direction as their approximate normal directions. In other words, the inner walls of the valve accommodating portion 23 are formed so as to be chamfered. As a result, in the first open state shown in FIG. 25, the flow path passing through the first elastic member 130 side can be made compact, and by shortening this flow path, pressure loss can be reduced.

[0050] As shown in Figures 6 and 22 to 25, the first pressing portion 158 is provided on a side of the first valve body 150 that is closer to the first rotation axis (trajectory T1) in a direction parallel to the second center axis C2 and the Y axis when viewed in the +Z direction. "The side closer to the first rotation axis in a direction parallel to the second center axis C2 and the Y axis" means the side closer to the first rotation axis when the first valve body 150 is divided into two in a direction parallel to the Y axis direction. In this way, because the first pressing portion 158 is provided on a side of the first valve body 150 that is closer to the first rotation axis when viewed in the +Z direction, the first valve body 150 is pressed in the +Z direction by the straight-type pipe fitting 310 (second pressing portion 458) on the side closer to the first rotation axis. Therefore, compared to a configuration in which the first pressing portion 158 is provided on the side farther from the first rotation axis, when the first valve body 150 is pressed in the +Z direction by the straight pipe fitting 310 (second pressing portion 458) by the same length along the first central axis C1, the first valve body 150 can be rotated by a larger angle. This increases the flow path cross-sectional area of ​​the coolant near the first valve body 150 within the valve accommodation space h3, thereby further reducing pressure loss.

[0051] In this embodiment, the installation manner of the first protrusion 157 and the first pressing portion 158 is adjusted so that the above-mentioned first pressing portion 158 is provided closer to the first rotation axis in a direction parallel to the second center axis C2 and the Y axis. Specifically, as shown in Fig. 6, the first protrusion 157 is formed so as to extend in the -Y direction and the -Z direction from the center of the first valve body 150 (first exposed surface 156) in the first closed valve state. Therefore, the first pressing portion 158 (contact surface S2) provided at the tip of the first protrusion 157 is located closer to the rotation axis in a direction parallel to the second center axis C2 and the Y axis when viewed in the +Z direction.

[0052] Furthermore, in order to allow the first valve body 150 to be pressed in the +Z direction by the straight-type pipe fitting 310 (second pressing portion 458) on the side closer to the first rotation axis, the "positional deviation in the Y-axis direction between the first central axis C1 of the first inner bore h1 and the third central axis C3 of the first opening 112" described with reference to FIG. 9 is formed. Specifically, the first opening 112 is formed in the bottom portion 111 of the valve seat member 110 so that the third central axis C3 of the first opening 112 is located farther from the first rotation axis along a direction parallel to the second central axis C2 and the Y-axis. Therefore, the central axis of the first valve body 150 that seals the first opening 112 is located farther from the first rotation axis (trajectory T1) along the Y-axis direction than the first central axis C1 in the first closed state. On the other hand, the straight-type pipe fitting 310 is inserted into the first inner bore h1 so that its central axis coincides with the first central axis C1 of the first inner bore h1. Therefore, in the first closed valve state, the first pressing portion 158 is pressed in the +Z direction by the straight pipe joint 310 (second pressing portion 458) on the side of the first valve body 150 closer to the first rotation axis.

[0053] 25, in the first open state, the first protrusion 157 is disposed parallel to the first central axis C1. In other words, the first protrusion 157 is disposed so that its central axis is parallel to the first central axis C1 of the first inner hole h1. This reduces the area of ​​the first protrusion 157 as viewed in the Z-axis direction. This reduces the pressure loss of the coolant that flows through the first inner hole h1 in the +Z direction and into the valve housing space h3.

[0054] 6 and 25, the second pressing portion 458 is provided on the second valve body 450 on a side closer to the second rotation axis (trajectory T2) in the direction along the major axis of the elliptical second main body portion 455, as viewed in the direction of the fourth center axis C4. "The side closer to the second rotation axis in the direction along the major axis of the second main body portion 455" means the side closer to the second rotation axis when the second valve body 450 is divided into two parts in the direction along the major axis of the second main body portion 455. In this way, because the second pressing portion 458 is provided on the side of the second valve body 450 closer to the second rotation axis, as viewed in the direction of the fourth center axis C4, the second valve body 450 is pressed in the -Z direction by the elbow pipe fitting 10 (first pressing portion 158) on the side closer to the second rotation axis. Therefore, compared to a configuration in which the second pressing portion 458 is provided on the side farther from the second rotation axis, when the elbow pipe fitting 10 (first pressing portion 158) presses the second valve body 450 in the −Z direction by the same length along the first center axis C1, the second valve body 450 can be rotated by a larger angle. This increases the flow path cross-sectional area of ​​the coolant near the second valve body 450, thereby further reducing pressure loss.

[0055] 6 and 22, the second protrusion 457 is arranged parallel to the first central axis C1 of the fitting body 321 in the second closed valve state. Therefore, when the fitting body 321 and the elbow pipe fitting 10 are connected in a direction parallel to the first central axis C1, the force applied to the second pressing portion 458 is reliably transmitted to the second body portion 455, so the second closed valve state can be smoothly released.

[0056] 6, in order to have the second valve body 450 pressed in the -Z direction by the elbow pipe fitting 10 (first pressing portion 158) on the side closer to the second rotation axis, the valve seat portion 311 is formed so that the center P1 of the second opening 312 is located farther from the second rotation axis (locus T2) in the direction along the major axis of the elliptical second opening 312 than the intersection P2 of the second opening 312 and the first central axis C1 when viewed in the direction of the fourth central axis C4. Furthermore, in the second closed state, the center of the second main body portion 455 that seals the second opening 312 is also located farther from the second rotation axis (locus T2) in the direction along the major axis of the elliptical second main body portion 455 than the intersection P2 of the second opening 312 and the first central axis C1 when viewed in the direction of the fourth central axis C4. On the other hand, the elbow pipe fitting 10 is connected so that its central axis coincides with the first central axis C1 of the fitting body 321. Therefore, in the second closed valve state, the second pressing portion 458 is pressed in the −Z direction by the elbow pipe fitting 10 (second pressing portion 458) on the side of the second valve body 450 closer to the second rotation axis.

[0057] Because contact surface S2 and contact surface S4 are both curved surfaces that are a collection of involute curves, when the first pressing portion 158 and the second pressing portion 458 contact and press against each other, contact portion A moves along the curved surfaces, allowing the first valve body 150 and the second valve body 450 to rotate. This prevents the position of contact portion A from being displaced excessively in the X-axis and Y-axis directions, allowing the first valve body 150 and the second valve body 450 to rotate smoothly. Because the longitudinal directions of contact surface S2 and contact surface S4 are aligned in the Y-axis direction when viewed in the Z-axis direction, contact portion A is point- or line-shaped. This allows a greater pressure to be applied to the first valve body 150 and the second valve body 450 than in a configuration where contact occurs via a surface.

[0058] Furthermore, contact surface S2 and contact surface S4 are configured as curved surfaces that are a collection of involute curves, and contact surface S2 and contact surface S4 are configured to contact on the first central axis C1. That is, when contact portion A is a point, contact portion A is on the first central axis C1, and when contact portion A is a line, contact portion A intersects with the first central axis C1. With this configuration, when the straight pipe fitting 310 is inserted into the elbow pipe fitting 10 in a direction along the first central axis C1, a force is applied to contact portion A on the first central axis C1, which makes it possible to stabilize the opening degree of the first valve body 150 and the second valve body 450 compared to a configuration in which contact portion A is located somewhere other than on the first central axis C1.

[0059] According to the pipe fitting 500 of the embodiment described above, the elbow pipe fitting 10 includes the first pipe connection portion 21 and the second pipe connection portion 22 having intersecting central axes (first central axis C1 and second central axis C2), the valve housing portion 23, and the first flap valve device 100 that is housed in the valve housing portion 23 and rotates to switch between a first open state and a second closed state, and the straight pipe fitting 310 includes the second flap valve device 400 that rotates within the fitting body 321 to switch between the second open state and the second closed state. Therefore, the first flap valve device 100 and the second flap valve device 400 can be opened and closed even in a situation where only a narrow space can be secured in the direction along the first central axis C1 and the second central axis C2. This allows the elbow pipe fitting 10 and the straight pipe fitting 310 to be connected and disconnected in a narrow environment. In addition, since the opening and closing of the valve is achieved by the first flap valve device 100 and the second flap valve device 400, flow path resistance (pressure loss) can be reduced compared to a plunger valve. Also, since the opening and closing of the valve is achieved by the first flap valve device 100 and the second flap valve device 400, the configuration can be made more compact compared to a plunger valve, which requires a configuration that extends in the axial direction.

[0060] Furthermore, the first flap valve device 100 has a bottomed cylindrical valve seat member 110 having a bottom 111 in which a first opening 112 is formed, a first valve body 150, and a first elastic member 130, and the second flap valve device 400 has a second valve body 450 and a second elastic member 430.Therefore, when the elbow-type pipe fitting 10 and the straight-type pipe fitting 310 are not connected, the first elastic member 130 urges the first valve body 150 to seal the first opening 112, thereby realizing a first closed valve state, and the second elastic member 430 urges the second valve body 450 to seal the second opening 312, thereby realizing a second closed valve state. On the other hand, when the elbow-type pipe fitting 10 and the straight-type pipe fitting 310 are connected, the first valve body 150 can rotate to open the first opening 112 and realize a first open valve state, and the second valve body 450 can rotate to open the second opening 312 and realize a second open valve state.

[0061] The second opening 312 is formed in the valve seat 311 so that the fourth central axis C4 of the second opening 312 is inclined at an angle of 30 to 60 degrees relative to the first central axis C1. Therefore, when the second valve body 450 is pushed along the first central axis C1 by the same distance, the cross-sectional area of ​​the flow path inside the fitting body 321 can be increased, and pressure loss can be reduced, compared to when the fourth central axis C4 of the second opening 312 is parallel to the first central axis C1. Furthermore, because the inclination angle is 30 to 60 degrees, the cross-sectional area of ​​the flow path inside the fitting body 321 in the second open state can be increased, compared to when the inclination angle is relatively small. On the other hand, the force required to transition from the second closed state to the second open state can be reduced, compared to when the inclination angle is relatively large. Furthermore, compared to a configuration with a relatively large angle of inclination, the load applied to the second elastic member 430 is small in both the second open valve state and the second closed valve state, so damage to the second elastic member 430 can be suppressed.

[0062] Furthermore, since the second opening 312 is formed in the valve seat 311 so as to have an elliptical external shape when viewed in the direction of the fourth central axis C4, the opening area of ​​the second opening 312, which has the fourth central axis C4 tilted with respect to the first central axis C1, can be made larger than when it is circular. This further reduces pressure loss. Furthermore, since the second valve body 450 has the second main body portion 455 with an elliptical external shape when viewed in the direction of the fourth central axis C4 in the second closed state, the second opening 312 can be reliably sealed.

[0063] Furthermore, since the first pressing portion 158 is provided on the side of the first valve body 150 closer to the first rotation axis in the direction parallel to the second center axis C2, when the first pressing portion 158 is pressed by the straight pipe fitting 310 (second pressing portion 458) by the same length along the first center axis C1, the first valve body 150 can be rotated by a larger angle compared to a configuration in which the first pressing portion 158 is provided on the side farther from the first rotation axis. This makes it possible to increase the flow path cross-sectional area in the valve accommodation space h3 and further reduce pressure loss. In addition, as viewed in the direction of the fourth center axis C4, the second pressing portion 458 is provided on the second valve body 450 closer to the second rotation axis in the direction along the major axis of the elliptical second main body portion 455. Therefore, compared to a configuration in which the second pressing portion 458 is provided on the side farther from the second rotation axis, when the second pressing portion 458 is pressed by the elbow pipe fitting 10 (first pressing portion 158) by the same length along the first center axis C1, the second valve body 450 can be rotated by a larger angle. This increases the flow path cross-sectional area inside the fitting body 321, thereby further reducing pressure loss. Furthermore, when the elbow-type pipe fitting 10 and the straight-type pipe fitting 310 are connected, the first pressing portion 158 and the second pressing portion 458 press against each other in a direction parallel to the first center axis C1, and the first flap valve device 100 is in a first open valve state and the second flap valve device 400 is in a second open valve state. Therefore, by connecting the elbow-type pipe fitting 10 and the straight-type pipe fitting 310, the interiors of the fittings can be connected to each other.

[0064] Furthermore, the first opening 112 is formed on the bottom 111 so that the third central axis C3 of the first opening 112 is parallel to the first central axis C1 and is located farther from the first rotation axis along a direction parallel to the second central axis C2 than the first central axis C1.Therefore, when the straight-type pipe fitting 310 is connected to the first pipe connection portion 21, the central axis of the straight-type pipe fitting 310 is connected so that it coincides with the first central axis C1, and in a configuration in which the first pressing portion 158 is pressed by a portion on the central axis of the straight-type pipe fitting 310 (the second pressing portion 458), the first pressing portion 158 provided on the side of the first valve body 150 closer to the first rotation axis in the direction along the second central axis C2 can be pressed with greater accuracy. In addition, the second opening 312 is formed in the valve seat portion 311 so that, when viewed in the direction of the fourth center axis C4, the center P1 of the second opening 312 is located farther from the second rotation axis in the direction along the long axis than the intersection P2 between the second opening 312 and the first center axis C1.Therefore, when the elbow-type pipe fitting 10 is connected to the fitting body 321, the center axis of the elbow-type pipe fitting 10 is connected so as to coincide with the first center axis C1, and in a configuration in which the second pressing portion 458 is pressed at a portion on the center axis of the elbow-type pipe fitting 10 (the first pressing portion 158), the second pressing portion 458 provided on the side of the second valve body 450 closer to the second rotation axis in the direction along the long axis can be pressed with greater accuracy.

[0065] Furthermore, the first valve body 150 has a rod-shaped first protruding portion 157 that protrudes from the first exposed surface 156 and is connected to the first pressing portion 158 at its tip, which prevents a portion of the first valve body 150 other than the first pressing portion 158 from being pressed when the elbow-type pipe fitting 10 is connected to the first pipe connection portion 21. In addition, the second valve body 450 has a rod-shaped second protruding portion 457 that protrudes from the second exposed surface 456 and is connected to the second pressing portion 458 at its tip, which prevents a portion of the second valve body 450 other than the second pressing portion 458 from being pressed when the straight-type pipe fitting 310 is connected to the fitting body 321.

[0066] Furthermore, because the first protrusion 157 is disposed parallel to the first central axis C1 in the first open state, the area of ​​the first protrusion 157 when viewed in the direction of the first central axis C1 can be reduced. This reduces the pressure loss of the fluid when it flows from the first inner hole h1 into the valve accommodation space h3. In addition, because the second protrusion 457 is disposed parallel to the first central axis C1 in the second closed state, the force applied to the second pressing portion 458 when the elbow pipe fitting 10 is connected is reliably transmitted to the second main body portion 455. This allows the second closed state to be released smoothly with a small force.

[0067] Furthermore, contact surfaces S2, S4 of the first pressing portion 158 and the second pressing portion 458 that come into contact with each other are both configured from curved surfaces that are a collection of involute curves, so excessive displacement of the contact position between the first pressing portion 158 and the second pressing portion 458 can be suppressed, and because contact portion A can be configured as a point or a line, a pressing force can be stably transmitted to the first valve body 150 and the second valve body 450 when connecting the elbow pipe fitting 10 and the straight pipe fitting 310. This allows the first valve body 150 and the second valve body 450 to rotate smoothly and can be rotated with a small force.

[0068] Furthermore, since the first pressing portion 158 and the second pressing portion 458 contact each other on the first central axis C1, when the straight-type pipe fitting 310 is inserted into the elbow-type pipe fitting 10 in a direction along the first central axis C1, force is applied to the contact portion A on the first central axis C1. Therefore, the opening degree of the first valve body 150 and the second valve body 450 can be stabilized compared to a configuration in which the first pressing portion 158 and the second pressing portion 458 contact each other other than on the first central axis C1.

[0069] B. Other Embodiments: (B1) In the above embodiment, the first pipe connection portion 21, the second pipe connection portion 22, and the valve accommodating portion 23 were integrally formed, but at least some of these may be configured to be separate from each other.

[0070] (B2) In the above embodiment, the first elastic member 130 and the second elastic member 430 were composed of leaf springs, but they are not limited to leaf springs and may be composed of any type of elastic member capable of biasing the first valve body 150 and the second valve body 450, such as a coil spring or a cylindrical member made of elastomer.

[0071] (B3) In the above embodiment, the valve seat member 110 may be omitted. Specifically, for example, the valve accommodating portion 23 may have a structure in which a plate-shaped partition wall that crosses the valve accommodating space h3 is provided therein, and an opening is provided in the partition wall, and the first valve body 150 seals or opens the opening. Even with such a configuration, the same effects as those of the pipe fitting 500 of the embodiment can be achieved.

[0072] (B4) In the above embodiment, at least one of contact surface S2 and contact surface S4 may be a curved surface that is a part of a spherical surface, instead of a curved surface that is a set of involute curves. Furthermore, at least one of contact surface S2 and contact surface S4 may be a flat surface. Even in this configuration, second pressing portion 458 can press first pressing portion 158 in the +Z direction, and first pressing portion 158 can receive force from second pressing portion 458.

[0073] (B5) The elbow pipe fitting 10 of the above embodiment is merely one example and can be modified in various ways. For example, the first pressing portion 158 may be provided on the first valve body 150, on a side farther from the rotation axis in a direction parallel to the second center axis C2 (Y-axis), or in a central position. The first protruding portion 157 may also be omitted from the first valve body 150. In such a configuration, for example, the first exposed surface 156 may be configured as a curved surface that is a collection of involute curves, and the first exposed surface 156 may be configured to be pressed by the straight pipe fitting 310. In such a configuration, the first exposed surface 156, the first pressing portion 158, and the contact surface S2 may coincide with each other. The first pressing portion 158 may also be configured to intersect the first center axis C1 rather than be parallel to it in the first open state. The first protruding portion 157 may also be configured to intersect the first center axis C1 in the first open state.

[0074] (B6) The straight-type pipe fitting 310 of the above embodiment is merely one example and can be modified in various ways. For example, the second pressing portion 458 may be provided on the second valve body 450, on a side farther from the rotation axis in a direction parallel to the second center axis C2 (Y-axis), or at a central position. The second protruding portion 457 may also be omitted from the second valve body 450. In such a configuration, for example, the second exposed surface 456 may be configured as a curved surface that is a collection of involute curves, and the second exposed surface 456 may be configured to be pressed by the elbow-type pipe fitting 10. In such a configuration, the second exposed surface 456, the second pressing portion 458, and the contact surface S4 may coincide with each other. The second pressing portion 458 may be configured to intersect the first center axis C1 rather than be parallel to it in the second closed-valve state. The second protruding portion 457 may be configured to intersect the first center axis C1 in the second open-valve state.

[0075] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0076] 10... elbow type pipe fitting, 21... first pipe connection portion, 22... second pipe connection portion, 23... valve accommodating portion, 30... retainer, 31... engaging portion, 100... first flap valve device, 101... engaging member, 102... first seal member, 103... engaging groove, 110... valve seat member, 111... bottom portion, 112... first opening, 113... first elastic member support portion, 114... first bearing portion, 130... first elastic member, 131... first intermediate portion, 132... end portion, 133... first folded portion, 15 0...first valve body, 151...first elastic member guide portion, 152...support arm portion, 153...first shaft portion, 153...shaft portion, 155...first main body portion, 156...first exposed surface, 157...first protrusion portion, 158...first pressing portion, 159...first seal portion, 231...inner wall, 302...second seal member, 310...straight type pipe joint, 311...valve seat portion, 312...second opening, 321...joint body, 322...flange, 323...piping, 324...flange mounting portion, 32 5...engagement portion, 326...claw portion, 400...second flap valve device, 410...fixing member, 411...engagement groove, 412...second elastic member fixing portion, 414...second bearing portion, 430...second elastic member, 431...second intermediate portion, 433...second folded portion, 450...second valve body, 451...second elastic member guide portion, 452...support portion, 453...second shaft portion, 455...second main body portion, 456...second exposed surface, 457...second protruding portion, 458...second pressing portion, 459...second Seal part, 500...pipe fitting, 600...piping, 620...opening, 650...valve, 800...fitting, C1...first center axis, C10...center axis, C2...second center axis, C20...center axis, C3...third center axis, C4...fourth center axis, P ...center, S1...face, S2...contact surface, S3...face, S4...contact surface, SP1...inner space, SP2...area, SP3...area, A...contact part, T1...locus, T2...locus, h1...first inner hole, h2...second inner hole, h3...valve accommodation space

Claims

1. A pipe joint comprising an elbow-type pipe joint and a straight-type pipe joint which are connectable to each other in an insertable and removable manner, The elbow-type pipe joint is a cylindrical first pipe connection portion to which the straight pipe joint is connected; a cylindrical second pipe connection portion having a second central axis intersecting the first central axis of the first pipe connection portion; a hollow valve accommodating portion connected to the first pipe connecting portion and the second pipe connecting portion, respectively, and having a valve accommodating space communicating with a first inner hole of the first pipe connecting portion and a second inner hole of the second pipe connecting portion, respectively; a first flap valve device accommodated in the valve accommodating section, the first flap valve device rotating to switch between a first open state in which the first inner hole and the second inner hole are in communication with each other and a first closed state in which the first inner hole and the second inner hole are blocked from each other; The straight pipe joint is a cylindrical fitting body having one end to which the elbow-type pipe fitting is connected and another end to which another pipe can be connected, the fitting body having the same central axis as the first central axis; a valve seat portion provided inside the joint body and having a second opening formed therein for communicating the one end and the other end inside the joint body; a second flap valve device housed in the joint body, the second flap valve device rotating to switch between a second closed state in which the second opening is sealed and a second open state in which the second opening is opened; the first flap valve device, a cylindrical valve seat member having a bottom with a first opening formed therein and a central axis parallel to the first central axis, the valve seat member being disposed so that the bottom is in contact with the valve accommodating space; a first valve body configured to be rotatable about a first rotation axis perpendicular to both the first central axis and the second central axis, the first valve body realizing the first closed state by sealing the first opening and the first open state by opening the first opening; a first elastic member that biases the first valve body so as to seal the first opening, the second flap valve device, a fixing member disposed along an inner wall of the joint body and having a second rotation shaft attached thereto, the second rotation shaft being parallel to the first rotation shaft; a second valve body configured to be rotatable around the second rotation axis, the second valve body realizing the second closed state by sealing the second opening and the second open state by opening the second opening; a second elastic member attached to the fixing member, the second elastic member biasing the fixing member to seal the second opening; Pipe fittings.

2. 2. The pipe joint according to claim 1, The second opening is formed in the valve seat portion such that a fourth center axis of the second opening is inclined at an angle of 30 degrees to 60 degrees with respect to a first center axis of the joint body. Pipe fittings.

3. 3. The pipe joint according to claim 2, the second opening is formed in the valve seat portion so as to have an elliptical external shape when viewed in the direction of the fourth central axis of the second opening, the second valve body has a second main body portion that seals the second opening in the second closed valve state, the second main body portion having an elliptical external shape when viewed in the direction of the fourth central axis in the second closed valve state. Pipe fittings.

4. 4. The pipe joint according to claim 3, the first valve body has a first pressing portion exposed to an inner space of the valve seat member that communicates with the first inner hole in the first closed state, the first pressing portion is provided on the first valve body on a side closer to the first rotation axis in a direction parallel to the second center axis, the second valve body has a second pressing portion that protrudes toward the one end side of the joint body in the second closed state, the second pressing portion is provided on the second valve body on a side closer to the second rotation axis in a direction along the major axis of the second main body portion, When the elbow-type pipe fitting and the straight-type pipe fitting are connected, the first pressing portion and the second pressing portion press each other in a direction parallel to the first central axis, so that the first flap valve device is in the first open valve state and the second flap valve device is in the second open valve state. Pipe fittings.

5. 5. The pipe joint according to claim 4, the first opening is formed in the bottom portion such that a third central axis of the first opening is parallel to the first central axis and is located farther from the first rotation axis than the first central axis along a direction parallel to the second central axis, the second opening is formed in the valve seat portion such that, as viewed in the direction of the fourth central axis, the center of the second opening is located farther from the second rotation axis in the direction along the long axis than an intersection of the second opening and the first central axis. Pipe fittings.

6. 6. The pipe joint according to claim 5, The first valve body is a first main body portion including a first exposed surface exposed to the internal space in the first valve closed state and a first seal portion connected to the first exposed surface and sealing the first opening in the first valve closed state; a rod-shaped first protruding portion that protrudes from the first exposed surface and is connected to the first pressing portion at a tip end; and the second main body portion further includes a second exposed surface that is exposed on the one end side in the second closed valve state, and a second seal portion that is continuous with the second exposed surface and seals the second opening in the second closed valve state, The second valve body further includes a rod-shaped second protruding portion that protrudes from the second exposed surface and is connected to the second pressing portion at a tip thereof. Pipe fittings.

7. 7. The pipe joint according to claim 6, the first protrusion is disposed parallel to the first central axis in the first open state, The second protrusion is disposed parallel to the first central axis in the second closed state. Pipe fittings.

8. The pipe joint according to any one of claims 4 to 7, a contact surface of the first pressing portion and a contact surface of the second pressing portion that come into contact with each other are both formed by a curved surface that is a collection of involute curves;

9. 9. The pipe joint according to claim 8, The first pressing portion and the second pressing portion contact each other on the first central axis.

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