Pipe joint structure and pipe connection method

Abstract

To enable workability improvement while downsizing a fluid pipe in a radial direction and simplifying a structure.SOLUTION: A pipe joint structure comprises: a joint body 4 attached in an attaching posture spanning both a first fluid pipe 1 and a second fluid pipe 2 in the state of covering an outer periphery of a packing 3, pressing the packing 3 against both the first fluid pipe 1 and the second fluid pipe 2; and an attaching part 5 for attaching the joint body 4 in the attaching posture against both the first fluid pipe 1 and the second fluid pipe 2. The attaching part 5 allows freely changing its posture between a locking posture locking outer peripheries 13 and 23 of both the first fluid pipe 1 and the second fluid pipe 2 and a non-locking posture unlocking them. The pipe joint structure is configured to freely attach the joint body 4 to both fluid pipes in the locking state by changing to the locking posture and equipped with a posture change operation part 6 for performing posture change operation changing the attaching part 5 from the non-locking posture to the locking posture.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a pipe joint structure for connecting an end of a first fluid pipe and an end of a second fluid pipe in a sealed state, and to a pipe connecting method. [Background technology]

[0002] As the above-mentioned pipe joint structure, a gasket is provided between the end of the first fluid pipe and the end of the second fluid pipe, and the gasket seals the gap between the end of the first fluid pipe and the end of the second fluid pipe (see, for example, Patent Documents 1-4).

[0003] In the pipe joint structures described in Patent Documents 1-4, a first flange and a second flange are provided on the split end side of a joint body having a split structure covering the outer periphery of the packing, and by tightening and fixing the first flange and the second flange with fasteners such as bolts and nuts, the packing is pressed against the first fluid pipe and the second fluid pipe in a sealed state, and the gap between the end of the first fluid pipe and the end of the second fluid pipe is sealed with the packing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 59-013782 [Patent Document 2] Japanese Utility Model Application Publication No. 62-032287 [Patent Document 3] Japanese Utility Model Application Publication No. 05-079172 [Patent Document 4] Japanese Patent Application Publication No. 09-032987 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Documents 1-4, the first and second fluid pipes are connected to each other and the tightening force used to tighten and fix the first and second flanges with fasteners is used to press the packing into a sealed state, so it is necessary to provide a first and second flange.

[0006] Both the first flange and the second flange are shaped to protrude outward from the outer periphery of the fluid pipe in the radial direction of the fluid pipe, resulting in a large structure in the radial direction of the fluid pipe, which leads to a complex structure.

[0007] Furthermore, in Patent Documents 1-4, in order to connect the first fluid pipe and the second fluid pipe in a connected state and to press the gasket into a sealed state, multiple operations must be performed, such as an alignment operation to align the connecting hole portion of the first flange with the connecting hole portion of the second flange, an insertion operation to insert fasteners such as bolts and nuts into those holes, and a tightening operation to tighten the fasteners. Moreover, since the operations themselves are troublesome, there is room for improvement in terms of operability.

[0008] In view of this situation, a main object of the present invention is to provide a pipe joint structure that can reduce the size of a fluid pipe in the radial direction, simplify the structure, and improve workability. [Means for solving the problem]

[0009] A first characteristic configuration of the present invention is a sealing device including a packing for sealing a gap between an end of a first fluid pipe and an end of a second fluid pipe; a joint body that is attached in an attachment position spanning both the first fluid pipe and the second fluid pipe in a state where it covers an outer circumferential portion of the packing and presses the packing against both the first fluid pipe and the second fluid pipe; an attachment portion that attaches the joint body to both the first fluid pipe and the second fluid pipe in an attachment attitude; the mounting portion is configured to be freely changeable between an engagement position in which it engages with outer circumferential portions of both the first fluid pipe and the second fluid pipe and an unlocking position in which it releases the engagement, and to be configured so that the fitting body can be attached to both fluid pipes in an engaged state by being in the engagement position, The locking mechanism includes a position change operation unit that performs a position change operation to change the mounting portion from the unlocked position to the locked position.

[0010] When attaching the joint body, a packing is attached between the end of the first fluid pipe and the end of the second fluid pipe, and the joint body is placed in an attachment position covering both the first fluid pipe and the second fluid pipe while covering the outer periphery of the packing, and then a position change operation is performed with the position change operation unit. This allows the attachment part to be changed from the non-locking position to the locking position, and the joint body to be attached to the fluid pipe in the attachment position with the attachment part in the locking position, so that the joint body in the attachment position can reliably maintain the connection of both fluid pipes in the locked state and can press the packing in an appropriate sealed state. Therefore, in order to maintain the connection of both fluid pipes and press the packing in an appropriate sealed state, it is only necessary to perform a position change operation with the position change operation unit, which reduces the number of work steps and simplifies the work itself, thereby improving workability.

[0011] Furthermore, since the fitting main body only needs to cover the outer periphery of the gasket, the amount of outward protrusion from the outer periphery of the fluid pipe in the radial direction of the fluid pipe can be reduced, thereby making the fluid pipe smaller in the radial direction and simplifying the structure.

[0012] A second characterizing configuration of the present invention is that the joint body is formed of a cylindrical body having a larger diameter than the outer diameters of both the first fluid pipe and the second fluid pipe and in close contact with the outer periphery of the packing.

[0013] For example, it is possible to adopt a split structure in which the joint body is split into two split bodies in the circumferential direction of the fluid pipe. However, in this split structure, a connecting structure is required to connect the split bodies to each other in order to place the joint body in the mounting position, which may lead to a complex structure. In addition, a connecting operation is required to connect the split bodies to each other, which increases the number of work steps and may be disadvantageous in terms of workability.

[0014] Therefore, according to this configuration, the joint body is a cylindrical body having a larger diameter than the outer diameters of both the first fluid pipe and the second fluid pipe. As a result, for example, the joint body can be placed in the mounting position simply by inserting both the first fluid pipe and the second fluid pipe into the joint body, making a connecting structure and connecting work unnecessary, thereby simplifying the structure and improving workability.

[0015] A third characterizing configuration of the present invention is that the gasket is provided with, in a continuous state, an inner abutment portion abutting against inner peripheral portions of both the first fluid pipe and the second fluid pipe, an intermediate abutment portion abutting against an end edge portion of the first fluid pipe and an end edge portion of the second fluid pipe, and an outer abutment portion abutting against outer peripheral portions of both the first fluid pipe and the second fluid pipe.

[0016] The inner wall of the fluid pipe is provided with a surface treatment layer such as a lining. When the end of the first fluid pipe and the end of the second fluid pipe are hermetically connected with a packing, if a fluid such as water flows through the opposing space between the end edge of the first fluid pipe and the end edge of the second fluid pipe, the fluid may penetrate between the inner wall of the fluid pipe and the lining layer, which may cause the surface treatment layer to peel off. Therefore, it is required to prevent a fluid such as water from flowing through the opposing space between the end edge of the first fluid pipe and the end edge of the second fluid pipe.

[0017] Therefore, according to this configuration, the packing has the inner contact portion, the intermediate contact portion, and the outer contact portion continuously present in the radial direction of the fluid pipe. This not only blocks the inner periphery side and the outer periphery side of the fluid pipe, but also blocks the opposing space between the end edge portion of the first fluid pipe and the end edge portion of the second fluid pipe with the intermediate contact portion. Therefore, it is possible to appropriately seal the space between the end portions of the first fluid pipe and the second fluid pipe while preventing fluid from flowing through the opposing space between the end edge portion of the first fluid pipe and the end edge portion of the second fluid pipe.

[0018] A fourth characteristic configuration of the present invention is such that the mounting portion is provided with a first biting portion that can be freely bitten into outer circumferential portions of both the first fluid pipe and the second fluid pipe, the attitude change operation unit performs a first biting operation as the attitude change operation by applying a pressing force to the first biting portion to press it against an outer periphery of the fluid pipe, thereby causing the first biting portion to bite into the outer periphery of the fluid pipe, The locking position is set in a position in which the first biting portion is bitten into the outer periphery of the fluid pipe.

[0019] According to this configuration, by the posture change operating unit performing the first biting operation, the mounting unit takes an interlocking posture in which the first biting portion is interlocked with the outer periphery of the fluid pipe, and the coupling body can be attached to the outer periphery of the fluid pipe. This allows the coupling body to be firmly attached to the outer periphery of the fluid pipe in an interlocking state, so that the packing can be pressed against the fluid pipe in an appropriately sealed state, and the gap between the end of the first fluid pipe and the end of the second fluid pipe can be appropriately sealed.

[0020] Furthermore, since the mounting portion is set in an engagement position by having the first biting portion bite into the outer periphery of the fluid pipe, the mounting portion can be appropriately changed to the engagement position without adding any new structure to the outer periphery of the fluid pipe, thereby simplifying the structure.

[0021] A fifth characteristic configuration of the present invention is a fluid pipe including a fitting groove on an outer periphery of each of the first fluid pipe and the second fluid pipe, The mounting portion includes a fitting portion that fits into the fitting groove portion, the attitude change operation unit performs a fitting operation of fitting the fitting portion into the fitting groove portion as the attitude change operation, The locking position is set in a position in which the fitting portion is fitted into the fitting groove portion.

[0022] According to this configuration, by performing the fitting operation with the posture change operation unit, the attachment unit takes an locked posture in which the fitting portion is fitted into the fitting groove portion, and the joint main body can be attached to the outer periphery of the fluid pipe. This allows the joint main body to be firmly attached to the outer periphery of the fluid pipe in an locked state, so that the packing can be pressed against the fluid pipe in an appropriately sealed state, and the gap between the end of the first fluid pipe and the end of the second fluid pipe can be appropriately sealed.

[0023] Moreover, despite the relatively simple structure of fitting the fitting portion into the fitting groove portion, the fitting body can be firmly attached in an engaged state to the outer periphery of the fluid pipe, thereby enabling strong attachment while simplifying the structure.

[0024] A sixth characteristic configuration of the present invention is such that the mounting portion includes a second biting portion that can be freely bitten into outer circumferential portions of both the first fluid pipe and the second fluid pipe, and a pressing portion that presses the second biting portion toward the outer circumferential portions of the fluid pipes, the posture change operation unit performs a second biting operation as the posture change operation by applying a pressing force to the pressing unit to press the pressing unit against an outer circumferential portion of the fluid pipe, so as to cause the second biting portion to bite into the outer circumferential portion of the fluid pipe in a state in which the pressing unit presses the second biting portion, the engaging position is set to a position in which the second biting portion is bitten into an outer circumferential portion of the fluid pipe, The second biting portion of the mounting portion is integral with the packing, The pressing portion of the mounting portion is provided integrally with the joint body.

[0025] According to this configuration, by the posture change operating unit performing the second biting operation, the mounting unit assumes an interlocking posture in which the second biting portion is interlocked with the outer peripheries of both fluid pipes arranged at the connection position, and the joint body can be securely attached to the outer peripheries of both fluid pipes in a pipe connection state. This allows the joint body to be securely attached to the outer peripheries of the fluid pipes in an interlocking state, so that the packing can be pressed against the fluid pipes in an appropriately sealed state, thereby appropriately sealing the gap between the end of the first fluid pipe and the end of the second fluid pipe.

[0026] Furthermore, since the second biting portion is formed integrally with the gasket, whereas the pressing portion is formed integrally with the joint body, suitable shapes and materials can be used for the second biting portion and the pressing portion, respectively, and the second biting portion and the pressing portion can each be configured in an appropriate manner.

[0027] A seventh characteristic configuration of the present invention is a pipe connecting method for connecting an end of a first fluid pipe and an end of a second fluid pipe in a sealed state, comprising: a packing that seals between an end of the first fluid pipe and an end of the second fluid pipe; a joint body that is attached in an attachment position spanning both the first fluid pipe and the second fluid pipe in a state where it covers an outer circumferential portion of the packing and presses the packing against both the first fluid pipe and the second fluid pipe; an attachment portion that attaches the joint body to both the first fluid pipe and the second fluid pipe in an attachment attitude; the mounting portion is configured to be freely changeable between an engagement position in which it engages with outer circumferential portions of both the first fluid pipe and the second fluid pipe and an unlocking position in which it releases the engagement, and to be configured so that the fitting body can be attached to both fluid pipes in an engaged state by being in the engagement position, A posture change operation unit is provided for changing the posture of the attachment portion from a non-locking posture to a locking posture, a positioning step of attaching the packing between an end of the first fluid pipe and an end of the second fluid pipe and positioning the joint body at an attachment position; The present invention is characterized in that an attachment step is performed in which the joint body is attached to both the first fluid pipe and the second fluid pipe in an attachment attitude by performing a attitude changing operation with the attitude changing operation unit.

[0028] When attaching the joint body, an arrangement step and an attachment step are performed in sequence. In the attachment step, the attachment portion is changed from the unlocked position to the locked position, and the joint body can be attached to both fluid pipes in the attachment position with the attachment portion in the locked position. With the joint body in the attachment position, the two fluid pipes can be locked and maintained in a connected state, and at the same time, the packings can be pressed against the fluid pipes in an appropriate sealed state. Therefore, in order to press the packings against the fluid pipes in a sealed state, only the attachment step is required, and the number of work steps is small, making the work itself simple and improving workability.

[0029] An eighth characteristic configuration of the present invention is a pipe connecting method for connecting an end of a first fluid pipe and an end of a second fluid pipe in a sealed state, comprising: a packing that seals between an end of the first fluid pipe and an end of the second fluid pipe; a joint body that is attached in an attachment position spanning both the first fluid pipe and the second fluid pipe in a state where it covers an outer circumferential portion of the packing and presses the packing against both the first fluid pipe and the second fluid pipe; an attachment portion that attaches the joint body to both the first fluid pipe and the second fluid pipe in an attachment attitude; the mounting portion is configured to be freely changeable between an engagement position in which it engages with outer circumferential portions of both the first fluid pipe and the second fluid pipe and an unlocking position in which it releases the engagement, and to be configured so that the fitting body can be attached to both fluid pipes in an engaged state by being in the engagement position, A posture change operation unit is provided for changing the posture of the attachment portion from a non-locking posture to a locking posture, a first arrangement step of attaching the packing to a pre-attached fluid pipe of the first fluid pipe and the second fluid pipe and arranging the joint body at an attachment position; a first attachment step of changing the position of the attachment portion corresponding to the pre-attached fluid pipe from a non-locking position to a locking position and attaching the coupling body to the pre-attached fluid pipe; a second arrangement step of bringing a post-attachment fluid pipe out of the first fluid pipe and the second fluid pipe close to the pre-attachment fluid pipe, attaching the packing to the post-attachment fluid pipe, and arranging the coupling body at an attachment position; a second mounting step of changing the position of the mounting portion corresponding to the post-installation fluid pipe from a non-locking position to a locking position and mounting the joint body to the post-installation fluid pipe.

[0030] When attaching the packing and the joint body to the first fluid pipe and the second fluid pipe, depending on the location of the first fluid pipe and the second fluid pipe, it may be difficult to secure a working space, etc. In this case, if all the work needs to be done at the location of the first fluid pipe and the second fluid pipe, it will be significantly disadvantageous in terms of workability.

[0031] Therefore, according to this configuration, the first arranging step and the first mounting step are performed, so that the packing and the joint body can be attached to the pre-attached fluid pipe in advance. As a result, the first arranging step and the first mounting step can be performed at a location separate from the location where the first fluid pipe and the second fluid pipe are arranged, so that the work can be performed with sufficient work space secured, improving workability.

[0032] Moreover, according to this configuration, by subsequently performing the second positioning step, the post-attached fluid pipe can be positioned at a desired position relative to the packing and the joint body simply by moving the post-attached fluid pipe closer to the pre-attached fluid pipe. Thus, by simply performing the simple task of moving the post-attached fluid pipe closer to the pre-attached fluid pipe, the joint body can be properly positioned at the attachment position while the packing can be properly attached to the post-attached fluid pipe as well. Finally, by performing the second attachment step, the attachment portion can be changed to the locking position, and the joint body can be properly attached to the post-attached fluid pipe as well. [Brief description of the drawings]

[0033] [Figure 1] FIG. 13 is a perspective view showing a state in which the first fluid pipe and the second fluid pipe are connected. [Diagram 2] Perspective view of the joint body [Diagram 3] 1 is a cross-sectional view showing an arrangement step in the process of connecting the first fluid pipe and the second fluid pipe; [Figure 4] 11 is a cross-sectional view showing a mounting step in the process of connecting the first fluid pipe and the second fluid pipe; FIG. [Diagram 5] FIG. 11 is a cross-sectional view showing a state in which the first fluid pipe and the second fluid pipe are connected. [Figure 6] FIG. 11 is a cross-sectional view showing a first arrangement step in the process of connecting the first fluid pipe and the second fluid pipe. [Figure 7] FIG. 11 is a cross-sectional view showing a first attachment step in the process of connecting the first fluid pipe and the second fluid pipe; [Figure 8] FIG. 11 is a cross-sectional view showing a second arrangement step in the process of connecting the first fluid pipe and the second fluid pipe. [Figure 9] FIG. 11 is a cross-sectional view showing a second attachment step in the process of connecting the first fluid pipe and the second fluid pipe; [Figure 10] 11 is a cross-sectional view showing a process of connecting a first fluid pipe and a second fluid pipe in the second embodiment. [Figure 11] 11 is a cross-sectional view showing a process of connecting a first fluid pipe and a second fluid pipe in the second embodiment. [Figure 12] FIG. 11 is a cross-sectional view showing a state in which a first fluid pipe and a second fluid pipe are connected in a second embodiment. [Figure 13] FIG. 13 is a perspective view showing a state in which a first fluid pipe and a second fluid pipe are connected in a second embodiment; [Figure 14] FIG. 13 is a perspective view of a joint body and a packing in a third embodiment; [Figure 15] 13 is a cross-sectional view showing a process of connecting a first fluid pipe and a second fluid pipe in the third embodiment. [Figure 16] 13 is a cross-sectional view showing a process of connecting a first fluid pipe and a second fluid pipe in the third embodiment. [Figure 17] FIG. 13 is a cross-sectional view showing a state in which the first fluid pipe and the second fluid pipe are connected in the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a pipe joint structure and a pipe connecting method according to the present invention will be described with reference to the drawings. [First embodiment] As shown in Fig. 1, this pipe joint structure is for connecting in a sealed state an end of a first fluid pipe 1 and an end of a second fluid pipe 2. The first fluid pipe 1 and the second fluid pipe 2 are identical fluid pipes of the same diameter and shape, and can be applied to indoor facility piping, for example, as fire extinguishing facility piping.

[0035] As shown in FIG. 3, the end of the first fluid pipe 1 and the end of the second fluid pipe 2 are connected with a predetermined gap therebetween, and the gap is blocked with a gasket 3, thereby connecting the end of the first fluid pipe 1 and the end of the second fluid pipe 2 in a hermetic state.

[0036] When connecting the first fluid pipe 1 and the second fluid pipe 2, they are connected by centering so that the center of the first fluid pipe 1 and the center of the second fluid pipe 2 are at the same position. The pipe axial direction of the first fluid pipe 1 and the pipe axial direction of the second fluid pipe 2 are the same direction (X direction in FIG. 3), and the radial direction of the first fluid pipe 1 and the radial direction of the second fluid pipe 2 are the same direction (Y direction in FIG. 3). Therefore, hereinafter, the pipe axial direction of the first fluid pipe 1 and the second fluid pipe 2 will be abbreviated as the "pipe axial direction", and the radial direction of the first fluid pipe 1 and the second fluid pipe 2 will be abbreviated as the "radial direction".

[0037] As shown in FIG. 3 , this pipe joint structure includes a packing 3 that seals the gap between the end of the first fluid pipe 1 and the end of the second fluid pipe 2, a joint body 4 that is attached in an attachment position spanning both the first fluid pipe 1 and the second fluid pipe 2 while covering the outer periphery of the packing 3, and a mounting portion 5 that attaches the joint body 4 in an attachment position to both the first fluid pipe 1 and the second fluid pipe 2.

[0038] The packing 3 and the joint body 4 may be integrated into one piece, or may be separate pieces. As shown in Figures 2 and 3, the joint body 4 and the mounting portion 5 are provided integrally.

[0039] (rubber seal) The packing 3 is formed in a cylindrical shape and is made of an elastic body such as rubber that is elastically deformable. As shown in Fig. 3, the packing 3 is attached in a state where it is sandwiched between the end of the first fluid pipe 1 and the end of the second fluid pipe 2, and abuts against the end of the first fluid pipe 1 and the end of the second fluid pipe 2 to close the gap between the ends of both fluid pipes 1, 2, thereby sealing the gap between the end of the first fluid pipe 1 and the end of the second fluid pipe 2.

[0040] 3, the packing 3 has a cross section formed in the shape of a horizontal "H," and is provided with an inner contact portion 31, an intermediate contact portion 32, and an outer contact portion 33, which are successively provided from the inner side in the radial direction (Y direction). Therefore, by press-fitting the end portion of the first fluid pipe 1 and the end portion of the second fluid pipe 2 from the pipe axial direction (X direction) into the annular fitting recess 35 of the packing 3, which opens in both pipe axial directions (X direction), the fitting surfaces of the annular fitting recess 35 of the packing 3 and the end portion of the first fluid pipe 1 and the end portion of the second fluid pipe 2 are tightly fitted in a sealed state.

[0041] As shown in Fig. 3, the inner contact portion 31 is formed in a shape extending in the pipe axis direction (X direction) and has two contact surfaces that contact both fluid pipes 1, 2, namely, an inner contact surface 31a that contacts the inner periphery 11 of the first fluid pipe 1 and an inner contact surface 31b that contacts the inner periphery 21 of the second fluid pipe 2. Both end portions of the inner contact portion 31 in the pipe axis direction (X direction) are formed in an inclined shape approaching the first fluid pipe 1 and the second fluid pipe 2 as they approach the end portions. The inner contact surface 31a is formed in a seal surface shape such as a labyrinth seal structure facing the inner periphery 11, 21 of both fluid pipes 1, 2, and abuts against the inner periphery 11, 21 of both fluid pipes 1, 2 to prevent the flow of fluid between the inner periphery 11, 21 of both fluid pipes 1, 2.

[0042] 3, the intermediate contact portion 32 is formed in a shape extending in the radial direction (Y direction) and has two contact surfaces that contact both fluid pipes 1, 2, namely, an intermediate contact surface portion 32a that contacts the end edge portion 12 of the first fluid pipe 1 and an intermediate contact surface portion 32b that contacts the end edge portion 22 of the second fluid pipe 2. The intermediate contact surface portion 32a is formed in the shape of a seal surface such as a labyrinth seal structure facing the end edges 12, 22 of both fluid pipes 1, 2, and by contacting the end edges 12, 22 of both fluid pipes 1, 2, it prevents the flow of fluid between the end edges 12, 22 of both fluid pipes 1, 2.

[0043] 3, the outer contact portion 33 is formed in a shape extending in the pipe axis direction (X direction) and has two contact surfaces that contact both fluid pipes 1, 2, namely, an outer contact surface 33a that contacts the outer periphery 13 of the first fluid pipe 1 and an outer contact surface 33b that contacts the outer periphery 23 of the second fluid pipe 2. The thickness of the outer contact portion 33 in the radial direction (Y direction) is set to a predetermined thickness that is greater than the thickness of the inner contact portion 31. The outer contact surface 33a is formed in the shape of a seal surface such as a labyrinth seal structure facing the outer peripheries 13, 23 of both fluid pipes 1, 2, and prevents the flow of fluid between the outer peripheries 13, 23 of both fluid pipes 1, 2 by contacting the outer peripheries 13, 23 of both fluid pipes 1, 2.

[0044] Here, the sealing performance can be improved by applying a liquid sealant in advance to the contact surfaces, such as the inner contact surface 31a, the intermediate contact surface 32a, and the outer contact surface 33a.

[0045] As shown in Fig. 3, the packing 3 has an inner side portion 34 integrally formed therewith, continuing from the inner contact portion 31 toward the inside in the radial direction (Y direction). A circular recess 34a recessed outward is disposed in the center of the inner side portion 34 in the pipe axial direction (X direction), and extension portions 34b extending in the pipe axial direction (X direction) are disposed on both sides of the recess 34a. The extension portions 34b are provided in an inclined position positioned inward in the radial direction (Y direction) toward their tips, and are formed in the shape of a protrusion that narrows toward their tips.

[0046] 3, when the packing 3 receives fluid pressure from the inside in the radial direction (Y direction), the fluid pressure is received by the recess 34a of the inner side portion 34 and the inner periphery of the extended portion 34b, and the fluid pressure acts on the side widening the extended portion 34b. As a result, the packing 3 elastically deforms in the side widening the extended portion 34b, and a force acts on the side pressing the inner abutment surface portion 31a of the inner abutment portion 31 against the inner periphery portions 11, 21 of both fluid pipes 1, 2, so that the flow of fluid between the inner periphery portions 11, 21 of both fluid pipes 1, 2 and the inner abutment surface portion 31a can be appropriately blocked.

[0047] (Joint body) As shown in Fig. 2, the joint body 4 is formed of a cylindrical body, and its inner diameter is set to be larger than the outer diameters of both the first fluid pipe 1 and the second fluid pipe 2. As shown in Fig. 3, the joint body 4 has a central portion in the pipe axial direction (X direction) that forms a bulging portion 41 that bulges outward in the radial direction (Y direction), and both sides of the bulging portion 41 form reduced diameter portions 42 that reduce inward in the radial direction (Y direction).

[0048] 3, the bulge 41 covers the outer periphery of the packing 3 while abutting against the outer periphery of the outer contact portion 33 of the packing 3. The inner diameter of the bulge 41 is set to, for example, the outer diameter of the fluid pipes 1, 2 plus the thickness of the outer contact portion 33 of the packing 3. As a result, the joint body 4 is in close contact with the outer periphery of the packing 3 while covering it.

[0049] (Mounting part) 3, the joint body 4 has an end portion beyond the reduced diameter portion 42 in the pipe axial direction (X direction) formed as an attachment portion 5, and the joint body 4 and the attachment portion 5 are integrally provided. The attachment portion 5 is in an engagement position in which it engages with the outer circumferential portions 13, 23 of both fluid pipes 1, 2, as shown in FIG.

[0050] The joint body 4 is attached in an engaged state to both fluid pipes 1, 2 at the attachment portion 5, so that the packing 3 is pressed against both fluid pipes 1, 2 in a sealed state, as shown in Fig. 5. At this time, the inner contact portion 31 of the packing 3 is pressed against the inner peripheries 11, 21 of both fluid pipes 1, 2 in a sealed state, the middle contact portion 32 of the packing 3 is pressed against the end edges 12, 22 of both fluid pipes 1, 2 in a sealed state, and the outer contact portion 33 of the packing 3 is pressed against the outer peripheries 13, 23 of both fluid pipes 1, 2 in a sealed state.

[0051] As shown in Fig. 2, the mounting part 5 has a plurality of notches 51 formed at predetermined intervals in the circumferential direction of both fluid pipes 1, 2, facilitating deformation in the radial direction (Y direction) toward the diameter increasing side and toward the diameter decreasing side. The mounting part 5 is configured so that its position can be freely changed between an engagement position in which it is deformed toward the diameter decreasing side as shown in Fig. 5 and an unlocked position in which it is deformed toward the diameter increasing side as shown in Fig. 3. The engagement position of the mounting part 5 is a position in which it is engaged with the outer peripheries of both fluid pipes 1, 2 as shown in Fig. 5.

[0052] 5, the mounting portion 5 is provided with a first biting portion 52 on its inner periphery that can be freely bitten into the outer periphery portions 13, 23 of both fluid pipes 1, 2 in order to engage with the outer periphery portions 13, 23 of both fluid pipes 1, 2. The first biting portion 52 is formed, for example, in a shape that includes a plurality of triangular projections that protrude inward in the radial direction (Y direction).

[0053] (Posture change control unit) 3 and 5, there is provided a position change operation unit 6 that performs a position change operation to change the position of the mounting part 5 from the unlocked position (see FIG. 3) to the locked position (see FIG. 5). The position change operation unit 6 is formed in a cylindrical shape and disposed in contact with the outer periphery of the mounting part 5, and is provided so as to be freely movable in the pipe axis direction (X direction).

[0054] 3, the attitude change operation unit 6 is configured, for example, by a nut having an operation unit side threaded portion 61 formed on its inner periphery which screws into an attachment unit side threaded portion 53 formed on the outer periphery of the attachment unit 5. By rotating the attitude change operation unit 6, the attachment unit side threaded portion 53 screws into the operation unit side threaded portion 61, so that the attitude change operation unit 6 is movable in the pipe axial direction (X direction).

[0055] As shown by the arrow in Fig. 4, the position change operation unit 6 moves from the joint body 4 toward the two fluid pipes 1, 2 in the pipe axial direction (X direction), thereby deforming the attachment part 5 to the diameter reducing side so as to approach the outer peripheries 13, 23 of both fluid pipes 1, 2, and applying a pressing force to the first biting portion 52 to press it toward the outer peripheries 13, 23 of both fluid pipes 1, 2. As a result, the position change operation unit 6 applies a pressing force to the first biting portion 52 to press it toward the outer peripheries 13, 23 of both fluid pipes 1, 2, as a position change operation, as shown in Fig. 5, thereby performing a first biting operation in which the first biting portion 52 bites into the outer peripheries 13, 23 of both fluid pipes 1, 2.

[0056] In this way, by performing the first biting operation with the position change operating unit 6, the position of the mounting unit 5 is changed to an engagement position in which the first biting portion 52 is bitten into the outer circumferential portions 13, 23 of both fluid pipes 1, 2, as shown in Figure 5, and the fitting body 4 is attached to the outer circumferential portions 13, 23 of both fluid pipes 1, 2 in an attachment position spanning the first fluid pipe 1 and the second fluid pipe 2.

[0057] At this time, the direction in which the first biting portion 52 bites into the outer circumferential portions 13, 23 of both fluid pipes 1, 2 is toward the central portion of the joint body 4 in the pipe axial direction (X direction). As a result, as the first biting portion 52 bites into the outer circumferential portions 13, 23 of both fluid pipes 1, 2, both fluid pipes 1, 2 are drawn closer to each other. Therefore, a force acts on the intermediate abutment surface portion 32a of the intermediate abutment portion 32 in a direction pressing the end edge portions 12, 22 of both fluid pipes 1, 2 against the intermediate abutment surface portion 32a, so that it is possible to appropriately block the flow of fluid between the end edge portions 12, 22 of both fluid pipes 1, 2 and the intermediate abutment surface portion 32a.

[0058] A description will be given of a pipe connection method for connecting in a sealed state an end of a first fluid pipe 1 and an end of a second fluid pipe 2. As the pipe connection method, for example, the end of the first fluid pipe 1 and the end of the second fluid pipe 2 can be connected in a sealed state by sequentially performing an arrangement step and an attachment step.

[0059] The arrangement step is a step of attaching the packing 3 between the end of the first fluid pipe 1 and the end of the second fluid pipe 2, and arranging the joint body 4 at the attachment position, as shown in Fig. 3. By carrying out this arrangement step, the packing 3 is attached between the end of the first fluid pipe 1 and the end of the second fluid pipe 2 in such a state that the inner abutment portion 31 of the packing 3 abuts against the inner peripheries 11, 21 of both fluid pipes 1, 2, the middle abutment portion 32 of the packing 3 abuts against the end edges 12, 22 of both fluid pipes 1, 2, and the outer abutment portion 33 of the packing 3 abuts against the outer peripheries 13, 23 of both fluid pipes 1, 2. The joint body 4 is arranged in a state of covering the outer periphery of the packing 3, and the joint body 4 is arranged at the attachment position spanning the first fluid pipe 1 and the second fluid pipe 2.

[0060] The mounting process is a process of mounting the joint body 4 in a mounting posture to both the first fluid pipe 1 and the second fluid pipe 2 by performing a posture change operation with the posture change operation unit 6 as shown in Fig. 4, as shown in Fig. 5. As shown by the arrow in Fig. 4, the posture change operation unit 6 is moved in the pipe axis direction (X direction) to perform a first biting operation in which a pressing force is applied to the first biting portion 52 to press it against the outer peripheries 13, 23 of both fluid pipes 1, 2, as a posture change operation, so that the first biting portion 52 bites into the outer peripheries 13, 23 of both fluid pipes 1, 2. By this first biting operation, the posture of the mounting unit 5 is changed to a locking posture in which the first biting portion 52 bites into the outer peripheries 13, 23 of both fluid pipes 1, 2, and the joint body 4 is mounted to the outer peripheries 13, 23 of both fluid pipes 1, 2 in a mounting posture spanning the first fluid pipe 1 and the second fluid pipe 2.

[0061] As an example of a pipe connection method, as shown in Figures 3 to 5, a method in which the gasket 3 and the fitting body 4 are attached to both fluid pipes 1, 2 together by sequentially performing an arrangement process and an installation process is shown, but the pipe connection method is not limited to this and other pipe connection methods can also be applied.

[0062] For example, as another pipe connection method, a method can be adopted in which the packing 3 and the joint body 4 are first attached to the first fluid pipe of the first fluid pipe 1 and the second fluid pipe 2, and then the packing 3 and the joint body 4 are secondly attached to the second fluid pipe of the first fluid pipe 1 and the second fluid pipe 2, and the packing 3 and the joint body 4 are attached separately to both of the two fluid pipes 1, 2.

[0063] In this other pipe connection method, a first arrangement process shown in FIG. 6, a first installation process shown in FIG. 7, a second arrangement process indicated by the white arrow in FIG. 7 and FIG. 8, and a second installation process shown in FIG. 9 and FIG. 5 are carried out in sequence.

[0064] The first arrangement step is a step of attaching a packing 3 to a pre-attached fluid pipe (first fluid pipe 1) and arranging a joint body 4 at an attachment position, as shown in Fig. 6. Fig. 6 shows a case where the pre-attached fluid pipe is the first fluid pipe 1, but the second fluid pipe 2 can also be the pre-attached fluid pipe.

[0065] The first attachment step is a step of attaching the coupling body 4 to the pre-attached fluid pipe (first fluid pipe 1) by changing the position of the attachment part 5 corresponding to the pre-attached fluid pipe (first fluid pipe 1) from a non-locking position to a locking position as shown in Fig. 7. As shown by the arrow in Fig. 7, the right-side position change operation part 6 is moved in the pipe axis direction (X direction) to perform a first biting operation on the right-side attachment part 5, and the first biting portion 52 of the right-side attachment part 5 is caused to bite into the outer periphery 13 of the pre-attached fluid pipe (first fluid pipe 1), thereby attaching the coupling body 4 to the pre-attached fluid pipe (first fluid pipe 1).

[0066] The second arrangement process is a process of bringing the post-attached fluid pipe (second fluid pipe 2) close to the pre-attached fluid pipe (first fluid pipe 1), attaching a gasket 3 to the post-attached fluid pipe (second fluid pipe 2), and arranging the fitting body 4 in the installation position, as shown by the white arrow in Figure 7 and in Figure 8.

[0067] The second attachment step is a step of attaching the joint main body 4 to the retrofit fluid pipe (second fluid pipe 2) by changing the position of the attachment part 5 corresponding to the retrofit fluid pipe (second fluid pipe 2) from the unlocked position to the locked position as shown in Fig. 9. As shown by the arrow in Fig. 9, the left position change operation part 6 is moved in the pipe axis direction (X direction) to perform a first biting operation on the left attachment part 5, and the first biting part 52 of the left attachment part 5 is bitten into the outer circumferential part 23 of the retrofit fluid pipe (second fluid pipe 2), thereby attaching the joint main body 4 to the retrofit fluid pipe (second fluid pipe 2).

[0068] In this way, by performing the first arranging step and the first mounting step, the packing 3 and the joint body 4 can be attached to the pre-attached fluid pipe (first fluid pipe 1), and the pre-attached fluid pipe (first fluid pipe 1) to which the packing 3 and the joint body 4 are attached can be freely moved. Therefore, even if the location where the first fluid pipe 1 and the second fluid pipe 2 are arranged is a location where it is difficult to secure a working space, such as above the ceiling, the first arranging step and the first mounting step can be performed at a location where a sufficient working space can be secured, such as on the ground, thereby improving workability. Moreover, at the location where the first fluid pipe 1 and the second fluid pipe 2 are arranged, it is only necessary to perform the second arranging step and the second mounting step, and the number of steps that must be performed in a narrow space can be reduced, and in this respect, workability can also be improved.

[0069] Second Embodiment The second embodiment is an alternative embodiment to the first embodiment in terms of the configuration for locking the mounting portion 5 to the outer peripheries 13, 23 of both fluid pipes 1, 2. Other configurations are similar to those of the first embodiment, so the same reference numerals are used and the description thereof is omitted. Below, the configuration for locking the mounting portion 5 to the outer peripheries 13, 23 of both fluid pipes 1, 2 will be mainly described with reference to Figs. 10 to 12.

[0070] Incidentally, Fig. 10 corresponds to Fig. 3 of the first embodiment and shows the arrangement process. Fig. 11 corresponds to Fig. 4 of the first embodiment and shows the installation process. Fig. 12 corresponds to Fig. 5 of the first embodiment and shows the state in which the first fluid pipe 1 and the second fluid pipe 2 are connected.

[0071] In the first embodiment, as shown in FIG. 5 , the mounting portion 5 is provided with a first biting portion 52 on its inner periphery that can freely bite into the outer periphery 13, 23 of both fluid pipes 1, 2 in order to engage with the outer periphery 13, 23 of both fluid pipes 1, 2, and the mounting portion 5 is engaged with the outer periphery 13, 23 of both fluid pipes 1, 2 by having the first biting portion 52 bite into the outer periphery 13, 23 of both fluid pipes 1, 2.

[0072] 10, the outer peripheries 13, 23 of both fluid pipes 1, 2 are provided with a fitting groove 71, and the mounting part 5 is provided on its inner periphery with a fitting part 72 that fits into the fitting groove 71. Thus, as shown in FIG. 12, the fitting part 72 is fitted into the fitting groove 71, thereby locking the mounting part 5 to the outer peripheries 13, 23 of both fluid pipes 1, 2.

[0073] The attitude change operation unit 6 is disposed in contact with the outer periphery of the attachment unit 5 as in the first embodiment, and is provided so as to be movable in the tube axis direction (X direction). Unlike the first embodiment, the attitude change operation unit 6 is moved in the tube axis direction (X direction) by using various jigs or the like.

[0074] 11, by using various tools or the like to move the position change operation unit 6 from the joint body 4 toward the two fluid pipes 1, 2 in the pipe axial direction (X direction), the attachment unit 5 is deformed toward the diameter reducing side so as to approach the outer peripheries 13, 23 of the two fluid pipes 1, 2, and a pressing force is applied to the fitting portion 72 to press it toward the outer peripheries 13, 23 of the two fluid pipes 1, 2. As a result, the position change operation unit 6 performs a fitting operation to fit the fitting portion 72 into the fitting groove portion 71 as a position change operation.

[0075] By performing the fitting operation using the position-changing operating unit 6, the position of the mounting part 5 is changed to an engagement position in which the fitting portion 72 of the mounting part 5 is fitted into the fitting groove portions 71 of the outer peripheries 13, 23 of both fluid pipes 1, 2, as shown in Figure 12, and the joint body 4 is attached to the outer peripheries 13, 23 of both fluid pipes 1, 2 in an attachment position spanning the first fluid pipe 1 and the second fluid pipe 2.

[0076] At this time, the fitting direction between the fitting groove 71 and the fitting portion 72 is toward the central portion of the joint body 4 in the pipe axial direction (X direction). As a result, the fitting groove 71 and the fitting portion 72 are fitted together, and thus the two fluid pipes 1, 2 are drawn closer to each other. Therefore, a force acts on the intermediate abutment surface 32a of the intermediate abutment portion 32 in a direction pressing the end edges 12, 22 of the two fluid pipes 1, 2 against the intermediate abutment surface 32a, so that the flow of fluid between the end edges 12, 22 of the two fluid pipes 1, 2 and the intermediate abutment surface 32a can be appropriately prevented.

[0077] Third Embodiment The third embodiment is an embodiment in which the configuration of the mounting portion 5 in the first embodiment is different. Other configurations are similar to those in the first embodiment, so the same reference numerals are used and the description thereof is omitted. The following mainly describes the configuration of the mounting portion 5 with reference to Figs. 13 to 17.

[0078] 13 to 15, in the third embodiment, the mounting portion 5 is provided with, in addition to a second biting portion 81 that can be freely bitten into the outer circumferential portions 13, 23 of both fluid pipes 1, 2, a pressing portion 82 that presses the second biting portion 81 toward the outer circumferential portions 13, 23 of both fluid pipes 1, 2. The second biting portion 81 is provided integrally with the packing 3, and the pressing portion 82 is provided integrally with the joint body 4, as shown in FIG.

[0079] As shown in FIG. 15 , in the joint body 4, as in the first embodiment, a bulge 41 is disposed in the central portion in the pipe axial direction (X direction), but the end portion from the bulge 41 is formed into a stepped shape that is recessed one step inward in the radial direction (Y direction), and the end portion from the bulge 41 is provided as a pressing portion 82.

[0080] 15, the second biting portion 81 is disposed with a part of it embedded in the outer contact portion 33 of the packing 3, and is provided in a position extending in the pipe axial direction (X direction). The inner periphery of the second biting portion 81 is provided with, for example, a plurality of triangular projections that protrude inward in the radial direction (Y direction).

[0081] 15, the second biting portion 81 and the pressing portion 82 are arranged to overlap with each other in the radial direction (Y direction) with the second biting portion 81 located on the inner side and the pressing portion 82 located on the outer side and in contact with each other. This allows the pressing portion 82 to press the second biting portion 81 against the outer circumferential portions 13, 23 of both fluid pipes 1, 2 by deforming the pressing portion 82 to expand its diameter in the radial direction (Y direction).

[0082] 13 and 14, the pressing portion 82 has a plurality of notches 51 formed at predetermined intervals in the circumferential direction of the fluid pipes 1, 2, facilitating deformation in the radial direction (Y direction) toward the diameter increasing side and toward the diameter decreasing side. The pressing portion 82 is configured to be freely changeable between a pressing position in which it is deformed toward the diameter decreasing side as shown in Fig. 17 and a non-pressing position in which it is deformed toward the diameter increasing side as shown in Fig. 15.

[0083] 15, similarly to the first embodiment, the attitude change operating unit 6 is configured by, for example, a nut having an operating unit side threaded portion 61 formed on its inner periphery which threads into a pressing unit side threaded portion 83 formed on the outer periphery of a pressing unit 82. By rotating the attitude change operating unit 6, the pressing unit side threaded portion 83 threads into the operating unit side threaded portion 61, so that the attitude change operating unit 6 is movable in the pipe axial core direction (X direction).

[0084] As shown in Figures 15 to 17, the position-changing operation unit 6 is configured to change the position of the mounting portion 5 from the non-locking position to the locking position by changing the position of the pressing portion 82 from the non-pressing position to the pressing position.

[0085] 16, the position change operation unit 6 moves from the joint body 4 toward the two fluid pipes 1, 2 in the pipe axial direction (X direction), thereby deforming the pressing portion 82 to the diameter reducing side so as to approach the outer peripheries 13, 23 of both fluid pipes 1, 2, and applying a pressing force to the pressing portion 82 to press it toward the outer peripheries 13, 23 of both fluid pipes 1, 2. As a result, the position change operation unit 6 applies a pressing force to the pressing portion 82 to press it toward the outer peripheries 13, 23 of both fluid pipes 1, 2, as a position change operation, thereby performing a second biting operation in which the second biting portion 81 is bitten into the outer peripheries 13, 23 of both fluid pipes 1, 2 while the pressing portion 82 is pressing the second biting portion 81.

[0086] In this way, by performing the second biting operation with the position change operating unit 6, the position of the mounting unit 5 is changed to an engagement position in which the second biting portion 81 is bitten into the outer circumferential portions 13, 23 of both fluid pipes 1, 2, as shown in Figure 17, and the fitting body 4 is attached to the outer circumferential portions 13, 23 of both fluid pipes 1, 2 in an attachment position spanning the first fluid pipe 1 and the second fluid pipe 2.

[0087] At this time, the direction in which the second biting portion 81 bites into the outer circumferential portions 13, 23 of both fluid pipes 1, 2 is toward the central portion of the joint body 4 in the pipe axial direction (X direction). As a result, as the second biting portion 81 bites into the outer circumferential portions 13, 23 of both fluid pipes 1, 2, both fluid pipes 1, 2 are drawn closer to each other. Therefore, a force acts on the intermediate abutment surface portion 32a of the intermediate abutment portion 32 in a direction pressing the end edge portions 12, 22 of both fluid pipes 1, 2 against the intermediate abutment surface portion 32a, so that it is possible to appropriately block the flow of fluid between the end edge portions 12, 22 of both fluid pipes 1, 2 and the intermediate abutment surface portion 32a.

[0088] [Another embodiment] Other embodiments of the present invention will be described below. Note that the configurations of the embodiments described below are not limited to being applied alone, but may also be applied in combination with the configurations of other embodiments.

[0089] (1) In the above first and third embodiments, a screw-type structure using a screw thread is used to move the attitude-changing operation unit 6 in the tube axis direction (X direction). However, as in the second embodiment, the attitude-changing operation unit 6 can also be moved in the tube axis direction (X direction) using various types of jigs, and the type of structure to be adopted can be changed as appropriate.

[0090] (2) In the above second embodiment, an example was shown in which various jigs were used to move the posture-changing operating unit 6 in the tube axis direction (X direction). However, as in the first and third embodiments, a screw-type structure using a screw thread can also be adopted, and the type of structure adopted can be changed as appropriate.

[0091] (3) In the above embodiment, the shapes and configurations of the joint body 4 and the packing 3 can be appropriately changed. [Explanation of symbols]

[0092] 1 1st fluid pipe 2 2nd fluid pipe 3. Packing 4. Joint body 5 Mounting part 6 Attitude change control unit 11 Inner circumference of first fluid pipe 12 Edge portion of first fluid pipe 13 Outer periphery of first fluid pipe 21 Inner circumference of second fluid pipe 22 End edge portion of second fluid pipe 23 Outer periphery of second fluid pipe 31 Inner side contact part 32 Intermediate contact part 33 Outer side contact part 52 First bite part 71 Fitting groove 72 Fitting part 81 Second bite part 82 Pressing part

Claims

1. a packing that seals between an end of the first fluid pipe and an end of the second fluid pipe; a joint body that is attached in an attachment position spanning both the first fluid pipe and the second fluid pipe in a state where it covers an outer circumferential portion of the packing and presses the packing against both the first fluid pipe and the second fluid pipe; an attachment portion that attaches the joint body to both the first fluid pipe and the second fluid pipe in an attachment attitude; the mounting portion is configured to be freely changeable between an engagement position in which it engages with outer circumferential portions of both the first fluid pipe and the second fluid pipe and an unlocking position in which it releases the engagement, and is configured to be freely attachable to both fluid pipes in an engaged state by being in the engagement position, A pipe joint structure comprising a position change operation portion that performs a position change operation to change the position of the attachment portion from a non-locking position to a locking position.

2. 2. The pipe joint structure according to claim 1, wherein the joint body is formed of a cylindrical body having a diameter larger than outer diameters of both the first fluid pipe and the second fluid pipe and in close contact with an outer periphery of the packing.

3. 3. The pipe joint structure according to claim 1 or 2, wherein the packing is provided in a continuous state with an inner abutment portion abutting against inner peripheral portions of both the first fluid pipe and the second fluid pipe, an intermediate abutment portion abutting against an end edge portion of the first fluid pipe and an end edge portion of the second fluid pipe, and an outer abutment portion abutting against outer peripheral portions of both the first fluid pipe and the second fluid pipe.

4. the mounting portion is provided with a first biting portion that can be freely bitten into outer circumferential portions of both the first fluid pipe and the second fluid pipe, the attitude change operation unit performs a first biting operation as the attitude change operation by applying a pressing force to the first biting portion to press it against an outer periphery of the fluid pipe, so as to cause the first biting portion to bite into the outer periphery of the fluid pipe, 3. The pipe joint structure according to claim 1, wherein the engagement position is set to a position in which the first biting portion is bitten into an outer periphery of the fluid pipe.

5. The first fluid pipe and the second fluid pipe are provided with a fitting groove on their outer peripheries, The mounting portion includes a fitting portion that fits into the fitting groove portion, the attitude change operation unit performs a fitting operation of fitting the fitting portion into the fitting groove portion as the attitude change operation, 3. The pipe joint structure according to claim 1, wherein the locking position is set to a position in which the fitting portion is fitted into the fitting groove portion.

6. the mounting portion includes a second biting portion that can be freely bitten into outer circumferential portions of both the first fluid pipe and the second fluid pipe, and a pressing portion that presses the second biting portion toward the outer circumferential portions of the fluid pipes, the posture change operation unit performs a second biting operation in which a pressing force is applied to the pressing unit to press the pressing unit against an outer circumferential portion of the fluid pipe, and the second biting portion is caused to bite into the outer circumferential portion of the fluid pipe in a state in which the pressing unit presses the second biting portion, the engaging position is set to a position in which the second biting portion is bitten into an outer circumferential portion of the fluid pipe, The second biting portion of the mounting portion is integral with the packing, 3. The pipe joint structure according to claim 1, wherein the pressing portion of the mounting portion is provided integrally with the joint body.

7. A pipe connecting method for connecting an end of a first fluid pipe and an end of a second fluid pipe in a sealed state, comprising: a packing that seals between an end of the first fluid pipe and an end of the second fluid pipe; a joint body that is attached in an attachment position spanning both the first fluid pipe and the second fluid pipe in a state where it covers an outer circumferential portion of the packing and presses the packing against both the first fluid pipe and the second fluid pipe; an attachment portion that attaches the joint body to both the first fluid pipe and the second fluid pipe in an attachment attitude; the mounting portion is configured to be freely changeable between an engagement position in which it engages with outer circumferential portions of both the first fluid pipe and the second fluid pipe and an unlocking position in which it releases the engagement, and is configured to be freely attachable to both fluid pipes in an engaged state by being in the engagement position, A posture change operation unit is provided for changing the posture of the attachment portion from a non-locking posture to a locking posture, a positioning step of attaching the packing between an end of the first fluid pipe and an end of the second fluid pipe and positioning the joint body at an attachment position; A pipe connecting method comprising: performing an attachment step of attaching the coupling body to both the first fluid pipe and the second fluid pipe in an attachment attitude by performing an attitude change operation with the attitude change operation unit.

8. A pipe connecting method for connecting an end of a first fluid pipe and an end of a second fluid pipe in a sealed state, comprising: a packing that seals between an end of the first fluid pipe and an end of the second fluid pipe; a joint body that is attached in an attachment position spanning both the first fluid pipe and the second fluid pipe in a state where it covers an outer circumferential portion of the packing and presses the packing against both the first fluid pipe and the second fluid pipe; an attachment portion that attaches the joint body to both the first fluid pipe and the second fluid pipe in an attachment attitude; the mounting portion is configured to be freely changeable between an engagement position in which it engages with outer circumferential portions of both the first fluid pipe and the second fluid pipe and an unlocking position in which it releases the engagement, and is configured to be freely attachable to both fluid pipes in an engaged state by being in the engagement position, A posture change operation unit is provided for changing the posture of the attachment portion from a non-locking posture to a locking posture, a first arrangement step of attaching the packing to a pre-attached fluid pipe of the first fluid pipe and the second fluid pipe and arranging the joint main body at an attachment position; a first attachment step of changing the position of the attachment portion corresponding to the pre-attached fluid pipe from a non-locking position to a locking position and attaching the coupling body to the pre-attached fluid pipe; a second arrangement step of bringing a post-attachment fluid pipe out of the first fluid pipe and the second fluid pipe close to the pre-attachment fluid pipe, attaching the packing to the post-attachment fluid pipe, and arranging the joint body at an attachment position; a second attachment step of changing the position of the attachment portion corresponding to the retrofit fluid pipe from a non-locking position to a locking position and attaching the coupling body to the retrofit fluid pipe.

Images