Pipe coupling

Abstract

To provide a pipe coupling having novel constitution.SOLUTION: There is provided a pipe coupling such that a coupling body 11 is provided with an inner cylinder part 14 inserted into a pipe 17, and also fitted with an outer cylinder body 12 surrounding the inner cylinder part 14, the outer cylinder body 12 has a confirmation window 23 formed to view the pipe 17 into which the inner cylinder part 14 is inserted, and an opening edge located at the confirmation window 23 radially outside the outer cylinder body 12 has an area, located before and after in the axial direction of the outer cylinder body 12, expanded radially outward, wherein a part of the region of the opening edge of the confirmation window 23 is not expanded on the outer peripheral surface of the outer cylinder body 12, and data 32 related to the pipe coupling is displayed in the region which is expanded as it is not expanded.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pipe joint. [Background technology]

[0002] Pipe fittings that allow pipes to be easily connected are used in hot and cold water supply systems for buildings, etc. One such pipe fitting is known, for example, from Patent Document 1. This pipe fitting includes a fitting body, an outer cylinder, and a see-through cylinder.

[0003] The fitting body has an inner cylindrical portion and a stepped portion. The inner cylindrical portion is inserted into the pipe. The stepped portion abuts against the pipe when the pipe is inserted into the inner cylindrical portion. A seal member is attached to the outer peripheral surface of the inner cylindrical portion. The seal member abuts against the inner peripheral surface of the pipe. This seal member seals the gap between the inner peripheral surface of the pipe and the outer peripheral surface of the inner cylindrical portion.

[0004] The outer cylindrical body is attached to the joint body so as to surround the inner cylindrical portion. An inspection window is formed in the outer cylindrical body. This inspection window makes it possible to visually check the pipe into which the inner cylindrical portion is inserted. A transparent or semi-transparent see-through cylindrical body that covers the inspection window is arranged inside the outer cylindrical body. An insertion space for receiving the pipe is formed between this see-through cylindrical body and the inner cylindrical portion. The see-through cylindrical body prevents foreign matter from entering the insertion space from the outside through the inspection window.

[0005] In the above-described pipe fitting, a pipe is inserted into the inner cylindrical portion of the fitting body as follows: After arranging the pipe and the inner cylindrical portion on the same axis, the pipe is brought close to the inner cylindrical portion. As a result, the pipe is inserted into the inner cylindrical portion and into the insertion space of the pipe fitting. Then, the pipe abuts against the stepped portion of the fitting body, thereby determining the insertion position of the pipe relative to the insertion space. Simply by inserting the pipe into the insertion space in this way, the pipe is connected to the pipe fitting. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-140902 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a pipe joint with a novel configuration. [Means for solving the problem]

[0008] In order to achieve the above object, the invention of claim 1 is a pipe fitting having an inner tubular portion provided in a fitting body to be inserted into a pipe, an outer tubular body attached to the fitting body so as to surround the inner tubular portion, and an inspection window formed in the outer tubular body for visually checking the pipe into which the inner tubular portion has been inserted, wherein an opening edge located radially outward of the outer tubular body in the inspection window has areas located in front and behind the axial direction of the outer tubular body that are expanded radially outward, and a part of the area of ​​the opening edge on the outer peripheral surface of the outer tubular body is not expanded, and data related to the pipe fitting is displayed in the expanded area due to the lack of expansion.

[0009] The invention of claim 2 is the same as claim 1, in that the opening edge of the confirmation window located radially outward of the outer cylinder body is not partially expanded in only one of the areas located on the insertion side of the pipe, out of the areas located on the front or rear side of the axial direction of the outer cylinder body. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. [Figure 2] FIG. 3 is a cross-sectional view showing a lock ring and a split ring of the pipe joint and their surroundings. [Figure 3] 2 is an enlarged view showing a portion surrounded by a dashed line in the pipe joint of FIG. 1. [Figure 4]FIG. [Figure 5] FIG. 2 is a perspective view showing the transparent cylinder. [Figure 6] 2 is a plan view showing the pipe joint as viewed from above in FIG. 1. FIG. [Figure 7] 7 is a cross-sectional view of the pipe joint of FIG. 6 taken along the line VII-VII. [Figure 8] FIG. 2 is a cross-sectional view showing the pipe joint. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of a pipe joint will be described below with reference to FIGS. As shown in FIG. 1, the pipe joint includes a joint body 11, an outer cylindrical body 12, and a transparent cylindrical body 13.

[0012] <Coupling body 11> The joint body 11 is formed in a cylindrical shape. The joint body 11 is provided with an inner tubular portion 14 and a step portion 15. The inner tubular portion 14 is formed in approximately the right half of the joint body 11 in FIG. 1. An attachment portion 22 having a larger diameter than the inner tubular portion 14 is formed to the left of the inner tubular portion 14 of the joint body 11 in FIG. 1. The inner tubular portion 14 side of this attachment portion 22, i.e., the side wall on the right side in FIG. 1, forms the step portion 15.

[0013] A plurality of annular grooves 18 extending along the outer peripheral surface of the inner cylindrical portion 14 are formed in the outer peripheral surface. The plurality of annular grooves 18 are positioned in parallel at predetermined intervals in the axial direction of the inner cylindrical portion 14. A seal ring 19 is housed in each of the annular grooves 18. The seal rings 19 are attached to the outer peripheral surface of the inner cylindrical portion 14 by being housed in the annular grooves 18.

[0014] An insertion guide 16 and a pipe 17 are inserted into the inner cylindrical portion 14. When the pipe 17 is inserted into the inner cylindrical portion 14, the insertion guide 16 moves integrally with the pipe 17 in the insertion direction (leftward in FIG. 1). The insertion guide 16 serves as the end of the pipe 17, more specifically, the leading end of the pipe 17 in the insertion direction. The insertion guide 16 prevents the seal ring 19 from coming out of the annular groove 18 due to contact with the end face of the pipe 17 in the insertion direction when the pipe 17 is inserted into the inner cylindrical portion 14.

[0015] By inserting the pipe 17 into the inner cylindrical portion 14, the leading end (insertion guide 16) of the pipe 17 in the insertion direction comes into contact with the step portion 15. This determines the position of the pipe 17 in the insertion direction. At this time, the inner cylindrical portion 14 is inserted inside the pipe 17, and the seal ring 19 comes into contact with the inner circumferential surface of the pipe 17. The seal ring 19 functions as a sealing member that seals the gap between the inner circumferential surface of the pipe 17 and the outer circumferential surface of the inner cylindrical portion 14.

[0016] <Outer cylinder 12> The outer cylindrical body 12 is attached to the joint body 11 so as to surround the inner cylindrical portion 14. The outer cylindrical body 12 includes a first cylinder 20 and a second cylinder 21.

[0017] The first tube 20 is attached to the attachment portion 22 of the joint body 11. More specifically, an attachment groove 22a is formed on the outer peripheral surface of the attachment portion 22, extending in an annular shape along the outer peripheral surface. The left end portion of the first tube 20 in FIG. 1 is fitted into this attachment groove 22a, thereby attaching the first tube 20 to the attachment portion 22. An observation window 23 is formed in the first tube 20. This observation window 23 makes it possible to visually confirm the pipe 17 into which the inner tube portion 14 is inserted. The above-mentioned transparent tube body 13 is disposed inside the first tube 20. An outward-facing claw portion 34 is formed on the outer peripheral surface of the first tube 20, at a position closer to the right end of the first tube 20 in FIG. 1 than the observation window 23.

[0018] The second cylinder 21 is attached to the right end of the first cylinder 20 in FIG. 1. Inward claws 24 are formed on the left end of the inner circumferential surface of the second cylinder 21 in FIG. 1. When the inner circumferential surface of the left end of the second cylinder 21 is fitted onto the outer circumferential surface of the right end of the first cylinder 20, the inward claws 24 of the second cylinder 21 climb over the outward claws 34 of the first cylinder 20. This brings the inward claws 24 and the outward claws 34 into contact with each other to prevent the second cylinder 21 from being pulled out of the first cylinder 20. The right end of the inner circumferential surface of the second cylinder 21 in FIG. 1 has a smaller diameter than the left end of the inner circumferential surface.

[0019] As shown in Figure 2, a lock ring 25 and a split ring 26 are arranged inside the second cylinder 21, between the inner circumferential surface of the second cylinder 21 and the right end portion of the first cylinder 20 in Figure 2. The lock ring 25 and the split ring 26 are intended to prevent the pipe 17 inserted into the inner cylinder portion 14 from slipping out of the inner cylinder portion 14. By attaching the second cylinder 21 to the first cylinder 20, the lock ring 25 and the split ring 26 are sandwiched between the inner circumferential surface of the second cylinder 21 and the right end portion of the first cylinder 20 in Figure 2. In this way, the lock ring 25 and the split ring 26 are held in place by the pipe joint.

[0020] The pipe 17 is inserted into the pipe fitting that holds the lock ring 25 and split ring 26. More specifically, the pipe 17 is inserted between the inner peripheral surface of the outer tubular body 12 of the pipe fitting and the outer peripheral surface of the inner tubular portion 14 of the fitting body 11. The lock ring 25 is formed with a retaining piece 25a that protrudes diagonally inward. As described above, when the pipe 17 is inserted into the pipe fitting, the retaining piece 25a of the lock ring 25 bites into the outer peripheral surface of the pipe 17, preventing the pipe 17 from coming out of the pipe fitting. The split ring 26 is positioned to maintain the inclination angle of the retaining piece 25a of the lock ring 25 and supports the outer peripheral surface of the pipe 17. When the pipe 17 moves in the removal direction (the direction opposite to the insertion direction), the split ring 26 reduces its diameter to prevent the pipe 17 from coming out.

[0021] <Transparent cylinder 13> As shown in Fig. 1, the transparent cylinder 13 is disposed inside the first cylinder 20, thereby covering the confirmation window 23 from the inside of the first cylinder 20. The transparent cylinder 13 prevents foreign matter from entering the inside of the first cylinder 20 from the outside through the confirmation window 23. The transparent cylinder 13 is made of a transparent or translucent material.

[0022] An insertion space 27 for receiving the pipe 17 is formed between the transparent cylindrical body 13 and the inner cylindrical portion 14 of the joint body 11. The end face 13a located at the rear side of the insertion space 27 in the transparent cylindrical body 13, i.e., on the left side in Fig. 1, is located further rearward than the stepped portion 15 of the joint body 11 (left side in Fig. 1).

[0023] Figure 3 shows an enlarged view of the area of ​​the pipe joint surrounded by the dashed line in Figure 1. As can be seen from Figure 3, an accommodation space 28 is formed between the outer peripheral surface of the attachment portion 22 of the joint body 11 and the inner peripheral surface of the first tube 20 of the outer tube body 12. The accommodation space 28 is for accommodating the end portion near the end face 13a of the transparent tube body 13. The accommodation space 28 is located further back (left side in Figure 3) than the stepped portion 15 in terms of the insertion direction of the pipe 17 (left direction in Figure 3).

[0024] By accommodating the end portion of the transparent cylinder 13 near the end face 13a in this accommodation space 28, the end face 13a is positioned further back (left side in FIG. 3 ) than the stepped portion 15 of the joint body 11. At this time, the end portion of the transparent cylinder 13 near the end face 13a is sandwiched between the outer peripheral surface of the attachment portion 22 of the joint body 11 and the inner peripheral surface of the first cylinder 20 of the outer cylinder 12.

[0025] An abutment portion 29 is formed on the transparent cylinder 13. The abutment portion 29 is formed so as to protrude from the inner periphery of the transparent cylinder 13. The abutment portion 29 abuts against the step portion 15 of the joint body 11 on the outer periphery side of the joint body 11, further than the abutment position of the pipe 17 (insertion guide 16). The abutment portion 29 is located near the end face 13a, and abuts against the step portion 15 as described above when the end of the transparent cylinder 13 near the end face 13a is accommodated in the accommodation space 28. By the abutment portion 29 abutting against the step portion 15 in this way, the transparent cylinder 13 is positioned in the insertion direction of the pipe 17 into the pipe joint, i.e., the leftward direction in FIG. 3 .

[0026] As shown in FIG. 1, a flange 30 is formed on the end of the transparent cylinder 13 opposite the end face 13a. This flange 30 also positions the transparent cylinder 13 in the insertion direction of the pipe 17 into the pipe joint. That is, a recess 31 is formed on the inner peripheral surface of the right end of the first cylinder 20 in FIG. 1, and when the abutment portion 29 abuts against the step portion 15, the flange 30 abuts against the inner surface of the recess 31. This also positions the transparent cylinder 13. When the flange 30 abuts against the inner surface of the recess 31, it also positions the transparent cylinder 13 in the withdrawal direction of the pipe 17. As shown in FIGS. 4 and 5, a plurality of flanges 30 are formed at equal intervals around the circumferential direction of the transparent cylinder 13.

[0027] As shown in FIG. 2 , a plurality of seal rings 19 abut against the inner circumferential surface of the pipe 17, thereby forming a seal between the inner circumferential surface of the pipe 17 and the outer circumferential surface of the inner cylindrical portion 14. All of the plurality of seal rings 19 are positioned inside the transparent cylindrical body 13. That is, the position of the annular groove 18 of the inner circumferential surface 14 of the joint body 11 is determined so that all of the plurality of seal rings 19 are positioned inside the transparent cylindrical body 13. Therefore, when the plurality of seal rings 19 are pressed against the inner circumferential surface of the pipe 17, the pressing force of all of the seal rings 19 acts on the inner circumferential surface of the transparent cylindrical body 13 via the pipe 17. As a result, a more stable seal is formed between the inner circumferential surface of the pipe 17 and the outer circumferential surface of the inner cylindrical portion 14 by the plurality of seal rings 19.

[0028] Next, the confirmation window 23 of the outer cylinder body 12 (first cylinder 20) and the structure around it will be described. Fig. 6 shows the pipe joint as seen from above in Fig. 1, and Fig. 7 is a cross-sectional view of the pipe joint taken along the line VII-VII of the arrows in Fig. 6. As shown in Figs. 6 and 7, the opening edge 23a of the confirmation window 23 located on the radially inner side of the first tube 20 is formed as follows. That is, the vicinity of the opening edge 23a of the confirmation window 23 is formed so as to extend in the radial direction of the first tube 20. Furthermore, both ends of the opening edge 23a located at the front and rear of the circumferential direction of the first tube 20 (top and bottom in Fig. 6) are each arc-shaped.

[0029] 6 and 7, the opening edge 23b of the confirmation window 23 located on the radially outer side of the first tube 20 is formed as follows: That is, the vicinity of the opening edge 23b of the confirmation window 23 is formed so as to expand radially outward from a portion of the confirmation window 23 near the opening edge 23a that extends in the radial direction of the first tube 20. As a result, regions of the opening edge 23b located in front of and behind the axial direction of the first tube 20 (both on the left and right sides in FIG. 6) expand radially outward of the first tube 20.

[0030] A portion of the area of ​​the opening edge 23b of the confirmation window 23 is not expanded and extends radially of the first cylinder 20 (in a direction perpendicular to the plane of the paper in FIG. 6). As a result, an expanded area is generated on the outer peripheral surface of the first cylinder 20 due to the opening edge 23b not being expanded. Data 32 related to the pipe joint is displayed in this area.

[0031] As shown in FIG. 1, when the leading end (insertion guide 16) of pipe 17 in the insertion direction abuts against step portion 15, the position of pipe 17 in the insertion direction is determined. At this time, as shown in FIG. 6, the boundary between pipe 17 and insertion guide 16 is located at the middle of confirmation window 23 in the axial direction (left-right direction in FIG. 6) of outer tube body 12 (first tube 20). That is, the position of confirmation window 23 in first tube 20 is determined in this manner. Therefore, it is possible to visually confirm the boundary between pipe 17 and insertion guide 16 through confirmation window 23 from outside the pipe fitting. An insertion mark 33 is formed on the outer peripheral surface of first tube 20 near the above-mentioned middle of confirmation window 23.

[0032] Next, the connection between the pipe joint and the pipe 17 will be described. Before being connected to the pipe fitting, the pipe 17 is aligned on the same axis as the inner cylindrical portion 14 of the fitting body 11 and then moved in a direction approaching the inner cylindrical portion 14. As a result, as shown in FIG. 8, the pipe 17 is inserted into the inner cylindrical portion 14 and into the insertion space 27 of the pipe fitting. The pipe 17 abuts against the insertion guide 16 arranged in the insertion space 27 and then moves together with the insertion guide 16 to the rear of the insertion space 27 (to the left in FIG. 8). Then, as shown in FIG. 1, when the leading end (insertion guide 16) of the pipe 17 in the insertion direction abuts against the step portion 15, the position of the pipe 17 in the insertion direction is determined. In this way, the pipe 17 is connected to the pipe fitting simply by inserting the pipe 17 into the insertion space 27. When the pipe 17 is connected to the pipe fitting, the retaining piece 25a of the lock ring 25 bites into the outer peripheral surface of the pipe 17, preventing the pipe 17 from slipping out of the pipe fitting. Furthermore, when the pipe 17 moves in the removal direction (the direction opposite to the insertion direction), the split ring 26 reduces its diameter, thereby preventing the pipe 17 from being removed.

[0033] As described above, when the leading end (insertion guide 16) of the pipe 17 in the insertion direction abuts against the stepped portion 15, the leading end is located closer to the inner periphery of the joint body 11 than the abutment position of the abutment portion 29 of the transparent cylinder 13 against the stepped portion 15. In other words, the abutment position of the abutment portion 29 against the stepped portion 15 is located closer to the outer periphery of the joint body 11 than the leading end of the pipe 17 against the stepped portion 15. Therefore, the abutment portion 29 of the transparent cylinder 13 does not prevent the leading end of the pipe 17 from abutting against the stepped portion 15. When the leading end (insertion guide 16) of the pipe 17 abuts against the stepped portion 15, the boundary between the insertion guide 16 and the pipe 17 is located midway in the axial direction of the outer cylinder 12 at the confirmation window 23, as shown in FIG. 6 . In other words, the boundary between the insertion guide 16 and the pipe 17 is located corresponding to the insertion mark 33 near the confirmation window 23.

[0034] Next, the function and effect of the pipe joint of this embodiment will be described. (1) The end face 13a of the transparent cylinder 13, more specifically, the end face 13a corresponding to the tip of the pipe 17 in the insertion direction into the insertion space 27, is located further back in the insertion direction of the pipe 17 than the stepped portion 15 of the fitting body 11. That is, the end of the transparent cylinder 13 near the end face 13a is accommodated in the accommodation space 28 between the outer circumferential surface of the fitting body 11 and the inner circumferential surface of the outer cylinder 12, so that the end face 13a of the transparent cylinder 13 is located further back in the insertion direction of the pipe 17 than the stepped portion 15 of the fitting body 11. As a result, the end of the transparent cylinder 13 is sandwiched between the outer circumferential surface of the fitting body 11 and the inner circumferential surface of the outer cylinder 12. Because the end of the transparent cylinder 13 is sandwiched between the outer circumferential surface of the fitting body 11 and the inner circumferential surface of the outer cylinder 12 in this way, rattling of the transparent cylinder 13 with respect to the outer cylinder 12 can be suppressed.

[0035] (2) The abutting portion 29 of the transparent cylinder 13 abuts against the step portion 15 of the joint body 11, thereby positioning the transparent cylinder 13 in the insertion direction of the pipe 17 relative to the inner cylindrical portion 14. Furthermore, the abutting portion 29 of the transparent cylinder 13 abuts against the step portion 15 of the joint body 11 on the outer circumferential side of the joint body 11 relative to the abutment position of the tip end of the pipe 17 in the insertion direction. For this reason, the abutting portion 29 of the transparent cylinder 13 does not prevent the pipe 17 from abutting against the step portion 15 of the joint body 11. Therefore, because the abutting portion 29 of the transparent cylinder 13 prevents the tip end of the pipe 17 from abutting against the step portion 15 of the joint body 11, it is possible to prevent the pipe 17 from being inserted too shallowly into the inner cylindrical portion 14 of the joint body 11.

[0036] If the abutment portion 29 of the transparent cylinder 13 were to prevent the pipe 17 from abutting against the stepped portion 15 of the fitting body 11, the pipe 17 would not be inserted deep enough into the inner cylinder portion 14 of the fitting body 11. To address this, the axial length of the fitting body 11 would have to be increased. However, because the abutment portion 29 of the transparent cylinder 13 does not prevent the pipe 17 from abutting against the stepped portion 15 of the fitting body 11, there is no need to take such a measure. As a result, it is not necessary to increase the axial length of the fitting body 11, which makes the pipe fitting more compact.

[0037] (3) The opening edge 23b of the confirmation window 23 of the outer cylinder 12 (first cylinder 20) located on the radially outer side of the outer cylinder 12 expands radially outward in regions located in front of and behind the axial direction of the outer cylinder 12 at the opening edge 23b. This makes it easier to see the pipe 17 inserted into the insertion space 27 through the confirmation window 23.

[0038] (4) A part of the region of the opening edge 23b of the confirmation window 23 extends in the radial direction of the first tube 20 without being widened. As a result, an expanded region is generated on the outer peripheral surface of the first tube 20 due to the opening edge 23b not being widened. This region can be used as a region for displaying data 32 related to the pipe joint.

[0039] (5) The vicinity of the opening edge 23a of the check window 23 located on the radially inner side of the first tube 20 is formed to extend in the radial direction of the first tube 20. Furthermore, the vicinity of the opening edge 23b of the check window 23 located on the radially outer side of the first tube 20 is formed to expand radially outward from the portion of the check window 23 near the opening edge 23a that extends in the radial direction of the first tube 20. This not only makes it easier to view the pipe 17 inserted into the inner tube portion 14 inside the outer tube body 12 through the check window 23, but also has the following advantage: That is, since the vicinity of the opening edge 23a of the check window 23 extends in the radial direction, the vicinity of the opening edge 23a is thickened, and therefore the strength of the check window 23 near the opening edge 23a can be increased.

[0040] (6) Both ends of the opening edge 23a of the observation window 23, located at the front and rear of the first tube 20 in the circumferential direction (top and bottom in FIG. 6), are arc-shaped. This eliminates any angular portions at both ends of the opening edge 23a. Therefore, the angular portions at both ends can prevent stress from concentrating at those points and causing cracks.

[0041] (7) When the insertion position of the pipe 17 inserted into the insertion space 27 of the pipe fitting is determined, that is, when the leading end of the pipe 17 in the insertion direction abuts against the stepped portion 15 of the fitting body 11, the boundary between the insertion guide 16 and the pipe 17 is located corresponding to the confirmation window 23. More specifically, the boundary between the insertion guide 16 and the pipe 17 is located midway in the axial direction of the outer cylindrical body 12 at the confirmation window 23. Whether or not the boundary is located midway in the confirmation window 23 can be determined by comparing the insertion mark 33 located near the confirmation window 23 with the boundary. Therefore, based on the comparison between the insertion mark 33 and the boundary, it can be determined whether or not the pipe 17 has been inserted to the determined position.

[0042] (8) When the pipe 17 is inserted into the inner cylindrical portion 14 of the joint body 11, the seal ring 19 is pressed against the inner peripheral surface of the pipe 17. This seals the gap between the inner peripheral surface of the pipe 17 and the outer peripheral surface of the inner cylindrical portion 14 by the seal ring 19. A plurality of seal rings 19 are positioned in the inner cylindrical portion 14 of the joint body 11 so as to be parallel to each other at predetermined intervals in the axial direction of the inner cylindrical portion 14. All of these seal rings 19 are positioned inside the transparent cylindrical body 13. Therefore, the pressing force of all of the plurality of seal rings 19 acts on the inner peripheral surface of the transparent cylindrical body 13 via the pipe 17. As a result, the plurality of seal rings 19 more stably seal the gap between the inner peripheral surface of the pipe 17 and the outer peripheral surface of the inner cylindrical portion 14.

[0043] The above embodiment can be modified as follows, for example: The above embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. Three or more seal rings 19 may be provided, or only one may be provided.

[0044] The position of the contact portion 29 on the see-through tube 13 may be changed as appropriate. The flange 30 does not necessarily have to be formed on the viewing cylinder 13. When the leading end (insertion guide 16) of the pipe 17 in the insertion direction abuts against the stepped portion 15 of the fitting body 11, the boundary between the insertion guide 16 and the pipe 17 does not necessarily have to be located at the midpoint of the confirmation window 23 in the axial direction of the outer cylindrical body 12. If the boundary is located at a position other than the midpoint of the confirmation window 23, the position of the insertion mark 33 near the confirmation window 23 is changed to correspond to that position.

[0045] It is not necessary to form the insertion mark 33 on the outer peripheral surface of the outer cylinder body 12 (first cylinder 20). In this case, since both ends of the opening edge 23a of the confirmation window 23 located at the front and rear in the circumferential direction of the first cylinder 20 are arc-shaped, it is conceivable that the apex of the arc can be used to determine whether the pipe 17 has been inserted to the specified position.

[0046] The opening edge 23a of the confirmation window 23 does not necessarily have to have arcuate ends located at the front and rear in the circumferential direction of the first cylinder 20. The confirmation window 23 may be omitted.

[0047] The data 32 relating to the pipe joint on the outer peripheral surface of the first cylinder 20 may be omitted. Parts of the areas located in front of and behind the axial direction of the first tube 20 at the opening edge 23b of the confirmation window 23 are not expanded radially outward of the first tube 20, but are configured to extend radially of the first tube 20. However, this structure is not essential, and part of the areas may be expanded radially outward of the first tube 20.

[0048] The above-mentioned area at the opening edge 23 b of the confirmation window 23 does not necessarily have to expand outward in the radial direction of the first cylinder 20 . Although the vicinity of the opening edge 23a of the confirmation window 23 is formed to extend in the radial direction of the first cylinder 20, the confirmation window 23 may be formed to widen from the opening edge 23a toward the opening edge 23b.

[0049] The insertion guide 16 may be omitted. Next, the technical concept that can be understood from the above embodiment will be described. (A) The fitting body is provided with an inner cylindrical portion to be inserted into the pipe, an outer cylindrical body is attached to the joint body so as to surround the inner cylindrical portion; a pipe fitting having a confirmation window formed in the outer cylindrical body for visually checking the pipe into which the inner cylindrical portion is inserted, A pipe fitting in which the opening edge of the confirmation window located radially outward of the outer cylindrical body has regions located in front and behind the axial direction of the outer cylindrical body that are expanded radially outward.

[0050] According to this configuration, the opening edge located radially outward of the outer cylinder body in the confirmation window expands radially outward in the area located in front of and behind the axial direction of the outer cylinder body at the opening edge, making it easier to see the pipe inserted into the insertion space through the confirmation window.

[0051] (B) A pipe fitting as described in (A) above, in which a portion of the area of ​​the opening edge on the outer peripheral surface of the outer tube is not expanded, and data related to the pipe fitting is displayed in the expanded area due to the non-expansion.

[0052] According to the above configuration, an area for displaying data relating to the pipe joint can be secured on the outer peripheral surface of the outer cylindrical body. (C) The fitting body is provided with an inner cylindrical portion to be inserted into the pipe, an outer cylindrical body is attached to the joint body so as to surround the inner cylindrical portion; a pipe fitting having a confirmation window formed in the outer cylindrical body for visually checking the pipe into which the inner cylindrical portion is inserted, A pipe fitting in which the confirmation window extends radially in the vicinity of an inner opening edge in the radial direction of the outer cylindrical body, and expands from that portion toward an outer opening edge.

[0053] With this configuration, the vicinity of the opening edge on the outer side in the radial direction of the outer cylinder of the check window widens as it moves outward from the outer cylinder, making it easier to see through the check window the pipe inserted inside the outer cylinder. Also, since the vicinity of the opening edge on the inner side in the radial direction of the outer cylinder of the check window extends in the radial direction, the vicinity of the opening edge becomes thicker, thereby increasing the strength of the vicinity of the opening edge on the inner side in the radial direction of the outer cylinder of the check window.

[0054] (D) The fitting body is provided with an inner cylindrical portion to be inserted into the pipe, an outer cylindrical body is attached to the joint body so as to surround the inner cylindrical portion; a pipe fitting having a confirmation window formed in the outer cylindrical body for visually checking the pipe into which the inner cylindrical portion is inserted, A pipe fitting in which the inner opening edge of the confirmation window in the radial direction of the outer cylindrical body has both ends located at the front and rear in the circumferential direction each having an arc shape.

[0055] According to this configuration, the opening edge of the check window on the inside in the radial direction of the outer cylinder body, and both ends located at the front and rear in the circumferential direction of the opening edge, are each arc-shaped, so there are no angular portions at either end, which prevents stress from concentrating at those points and causing cracks.

[0056] (E) The fitting body is provided with an inner cylindrical portion to be inserted into the pipe, an outer cylindrical body is attached to the joint body so as to surround the inner cylindrical portion; a confirmation window is formed in the outer cylindrical body for visually confirming the pipe into which the inner cylindrical portion is inserted; an insertion space for receiving the pipe is formed between the outer cylinder and the transparent cylinder; An insertion guide for guiding the insertion of the pipe is disposed in the insertion space, a step portion is formed in the joint body to define the insertion position of the pipe received in the insertion space by abutting against the insertion guide, In the specified state, the boundary between the pipe and the insertion guide is visible through a confirmation window, In the specified state, the boundary between the pipe and the insertion guide is located midway between the confirmation window in the axial direction of the outer cylindrical body, and an insertion mark is formed on the outer surface of the outer cylindrical body near the midway between the confirmation window.

[0057] With this configuration, when the insertion position of the pipe inserted into the insertion space is determined, the boundary between the insertion guide and the pipe is located midway in the confirmation window in the axial direction of the outer tube. Whether the boundary is located midway in the confirmation window can be determined by comparing the boundary with an insertion mark near the confirmation window. Therefore, based on the comparison between the insertion mark and the boundary, it can be determined whether the pipe has been inserted to the determined position.

[0058] (F) The fitting body is provided with an inner cylindrical portion to be inserted into the pipe, a seal member is attached to an outer peripheral surface of the inner cylindrical portion to abut against an inner peripheral surface of the pipe and to seal between the inner peripheral surface of the pipe and the outer peripheral surface of the inner cylindrical portion; an outer cylindrical body is attached to the joint body so as to surround the inner cylindrical portion; a confirmation window is formed in the outer cylindrical body for visually confirming the pipe into which the inner cylindrical portion is inserted; a transparent or semi-transparent see-through cylinder covering the confirmation window is disposed inside the outer cylinder; an insertion space for receiving the pipe is formed between the inner cylindrical portion and the transparent cylindrical body; a step portion formed in the joint body that abuts against the pipe received in the insertion space to determine the insertion position of the pipe, The pipe joint has an abutment portion formed on the transparent cylinder that abuts against the step portion of the joint body on the outer circumferential side of the abutment position of the pipe.

[0059] According to this configuration, the abutting portion of the transparent cylinder abuts against the stepped portion of the coupling body, thereby positioning the transparent cylinder in the insertion direction of the pipe relative to the inner cylindrical portion. Furthermore, the abutting portion of the transparent cylinder abuts against the stepped portion of the coupling body on the outer circumferential side of the abutting position of the pipe. Therefore, the abutting portion of the transparent cylinder does not prevent the pipe from abutting against the stepped portion of the coupling body. Therefore, the abutting portion of the transparent cylinder prevents the pipe from abutting against the stepped portion of the coupling body, thereby preventing the pipe from being inserted too shallowly into the inner cylindrical portion of the coupling body. If the abutting portion of the transparent cylinder were to prevent the pipe from abutting against the stepped portion of the coupling body, the pipe might be inserted too shallowly into the inner cylindrical portion of the coupling body. To address this issue, the axial length of the coupling body would have to be increased. However, with the above-mentioned configuration, the abutment of the pipe against the step portion of the fitting body is not prevented by the abutment portion of the transparent cylinder, so there is no need to take the measures described above. As a result, the axial length of the fitting body does not need to be long, making the pipe fitting more compact.

[0060] (G) The fitting body is provided with an inner cylindrical portion to be inserted into the pipe, a plurality of sealing members are attached to the outer peripheral surface of the inner cylindrical portion in the axial direction of the joint body to contact the inner peripheral surface of the pipe and seal between the inner peripheral surface of the pipe and the outer peripheral surface of the inner cylindrical portion; an outer cylindrical body is attached to the joint body so as to surround the inner cylindrical portion; a confirmation window is formed in the outer cylindrical body for visually confirming the pipe into which the inner cylindrical portion is inserted; a transparent or semi-transparent see-through cylinder covering the confirmation window is disposed inside the outer cylinder; a pipe joint having an insertion space for receiving the pipe formed between the inner cylindrical portion and the transparent cylindrical body, A pipe joint in which all of the plurality of sealing members are located inside the transparent cylinder.

[0061] When the sealing member is pressed against the inner peripheral surface of the pipe, the pressing force acts on the inner peripheral surface of the transparent cylinder through the pipe, thereby sealing the gap between the inner peripheral surface of the pipe and the outer peripheral surface of the inner cylindrical portion. With the above configuration, since all of the multiple sealing members are located inside the transparent cylinder, all of the sealing members can seal the gap between the inner peripheral surface of the pipe and the outer peripheral surface of the inner cylindrical portion.

[0062] (H) The fitting body is provided with an inner cylindrical portion to be inserted into the pipe, an outer cylindrical body is attached to the joint body so as to surround the inner cylindrical portion; a confirmation window is formed in the outer cylindrical body for visually confirming the pipe into which the inner cylindrical portion is inserted; a transparent or semi-transparent see-through cylinder covering the confirmation window is disposed inside the outer cylinder; an insertion space for receiving the pipe is formed between the inner cylindrical portion and the transparent cylindrical body; a step portion formed in the joint body that abuts against the pipe received in the insertion space to determine the insertion position of the pipe, A pipe fitting in which an end face of the transparent cylinder located at the rear side of the insertion space is located further rearward than the stepped portion.

[0063] According to this configuration, the end face of the transparent cylinder, specifically the end face corresponding to the leading end of the pipe in the insertion direction into the insertion space, is located further back in the pipe insertion direction than the stepped portion of the fitting body. As a result, the vicinity of the end face of the transparent cylinder is sandwiched between the outer peripheral surface of the fitting body and the inner peripheral surface of the outer cylindrical body. Because the vicinity of the end face of the transparent cylinder is sandwiched between the outer peripheral surface of the fitting body and the inner peripheral surface of the outer cylindrical body in this way, rattling of the transparent cylinder relative to the outer cylindrical body can be suppressed. [Explanation of symbols]

[0064] 11... fitting body, 12... outer cylinder, 13... see-through cylinder, 13a... end face, 14... inner cylinder portion, 15... step portion, 16... insertion guide, 17... pipe, 18... annular groove, 19... seal ring, 20... first cylinder, 21... second cylinder, 22... mounting portion, 22a... mounting groove, 23... confirmation window, 23a, 23b... opening edge, 24... inward claw portion, 25... lock ring, 25a... anti-pullout piece, 26... split ring, 27... insertion space, 28... accommodation space, 29... abutment portion, 30... flange, 31... recess, 32... data, 33... insertion mark, 34... outward claw portion.

Claims

1. The fitting body is provided with an inner cylindrical portion to be inserted into the pipe, an outer cylindrical body is attached to the joint body so as to surround the inner cylindrical portion; a pipe fitting having a confirmation window formed in the outer cylindrical body for visually checking the pipe into which the inner cylindrical portion is inserted, an opening edge of the check window located on the outer side in the radial direction of the outer cylindrical body is expanded outward in the radial direction in regions located in front and behind the axial direction of the outer cylindrical body, A pipe fitting in which a portion of the area of ​​the opening edge on the outer peripheral surface of the outer tube is not expanded, and data related to the pipe fitting is displayed in the expanded area due to the non-expansion.

2. 2. A pipe fitting according to claim 1, wherein the opening edge of the confirmation window located radially outward of the outer tubular body is not partially expanded in only one of the regions located on the front or rear side in the axial direction of the outer tubular body, the region being located on the insertion side of the pipe.

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