Flexible Pipe Fittings

Abstract

To provide a flexible pipe joint capable of eliminating the need for a constructor to do marking work and of easily learning a construction failure.SOLUTION: A pipe joint 1 is the flexible pipe joint for connecting bellows flexible pipes having a plurality of crest parts and trough parts alternately arranged along the axial direction. With the flexible pipe inserted from one end to a predetermined position, the flexible pipe is sealed and prevented from coming off. At one end of the inner peripheral face of the pipe joint 1, a mark making part 9 is provided for making a mark on a coating body in contact with the coating body which coats the flexible pipe when inserting the flexible pipe.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a flexible pipe joint to which a bellows-shaped flexible pipe is connected. [Background technology]

[0002] Metal bellows-shaped flexible pipes are widely used for indoor gas piping, etc. Various pipe fittings are used to connect these flexible pipes to gas valves, steel pipes, etc. In recent years, one-touch pipe fittings have also been put into practical use, which allow installation to be completed simply by inserting the flexible pipe into the pipe fitting without the need for tools.

[0003] A flexible pipe has multiple peaks and valleys arranged alternately along the axial direction. The outer periphery of the flexible pipe is covered with a coating. When connecting a flexible pipe to a pipe fitting, several peaks of the coating are removed from the tip of the flexible pipe, and then the flexible pipe is inserted into the pipe fitting. When connecting a flexible pipe, it is important that the flexible pipe is inserted sufficiently into the pipe fitting. If the insertion depth of the flexible pipe is insufficient, it becomes difficult to fully utilize the performance of the pipe fitting. Therefore, the insertion depth of the flexible pipe is specified.

[0004] Conventionally, the insertion length of a flexible pipe is controlled by markings applied to the covering. The marking work to apply this marking is performed by an installer using, for example, a flexible pipe jig. Patent Document 1 describes a flexible pipe jig that has an engagement portion that engages with the tip of the flexible pipe and a main portion that is arranged in the longitudinal direction of the flexible pipe. A through hole is formed in the main portion of this jig, and through this through hole, it is possible to apply a marking to the surface of the covering at a position corresponding to the length of the flexible pipe to be inserted into the pipe joint.

[0005] 7 and 8 show an example of a conventional flexible pipe joint (hereinafter simply referred to as a pipe joint). FIG. 7 shows the state before the flexible pipe is inserted, and FIG. 8 shows the state after the flexible pipe is connected. In FIGS. 7 and 8, the pipe joint is shown in half-section, but in FIG. 8, the flexible pipe is not shown in half-section. As shown in FIG. 7, the pipe joint 11 includes a joint body 12 into which a flexible pipe T (see FIG. 8) is inserted from one end. Inside the joint body 12, there are arranged a part of a press nut 13, an elastic member 14 that is expandable and contractible in the axial direction, a holding member 15 that holds the elastic member 14 in a compressed state, a moving member 16, a ring-shaped seal member 17 that is in close contact with the flexible pipe T, and a retainer 18. In addition, a lip packing 19 that provides a watertight seal between the outer surface of a cover C (see FIG. 8) and the inner surface of the press nut 13 is attached to one end of the inner circumferential surface of the pipe joint 11.

[0006] As shown in Figure 8, when a flexible pipe T is inserted into this pipe joint, the engagement between the holding member 15 and the joint body 12 is released, thereby releasing the compressed state of the elastic member 14. Then, as the elastic member 14 expands, the seal member 17 slides and is compressed in the axial direction. This causes the seal member 17 to come into close contact with the outer circumferential surface of the flexible pipe T. Furthermore, as the elastic member 14 expands, the diameter of the retainer 18 contracts, and the claw portions 18a fit into the valleys of the flexible pipe T. This causes the retainer 18 to catch on the outer circumferential surface of the flexible pipe T, preventing the flexible pipe T from slipping out.

[0007] For example, if marking 20 is applied to the outer coating C of the flexible pipe T, during normal installation, the flexible pipe T is inserted until the marking 20 is hidden. Then, when the marking 20 becomes invisible from the outside of the pipe joint 11, the installer determines that the flexible pipe T has been fully inserted into the pipe joint 11. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-108173 Summary of the Invention [Problem to be solved by the invention]

[0009] As described above, it is possible to manage the insertion depth of a flexible pipe by using marking. However, the marking work increases the number of steps required for connecting a flexible pipe, which increases the burden on the installer. Furthermore, manual marking work can lead to mistakes in the marking position. It is also possible that the installer may forget to mark. As a result, there is a concern that the flexible pipe may not be inserted sufficiently. Therefore, it is desirable to eliminate manual marking work, or even to eliminate the marking work altogether.

[0010] Incidentally, with the pipe joint shown in Figure 7, the flexible pipe T is connected in the following procedure: (1) The flexible pipe T is inserted straight into the inner hole of the pipe joint 11 until it is connected, and then (2) the flexible pipe T is pulled straight in the withdrawal direction, and the process is complete once it is confirmed that the flexible pipe T does not come out. Also, if the pipe joint 11 is configured with an indicator, the installation is completed when the installer confirms that the indicator appears.

[0011] In the pipe fitting 11 connected in the above-described procedure, there is a risk of the flexible pipe T being unintentionally pulled out when the installer pulls the flexible pipe T during the confirmation procedure (2) above. Specifically, after the compressed state of the elastic member 14 is released, the seal member 17 normally slides quickly and the retainer 18 engages with the flexible pipe T. However, due to a decrease in the sliding properties of the seal member 17, the flexible pipe T may be pulled out by one to two extra threads before the retainer 18 engages with the flexible pipe T. In this specification, this type of event is referred to as "unintentional pullout of the flexible pipe."

[0012] FIG. 9 shows an example of a state in which the flexible pipe T has unintentionally come loose. FIG. 9 illustrates a state in which the flexible pipe T has been pulled out by one additional thread compared to the normal connection state (see FIG. 8). While the seal member 17 would normally be in close contact with the flexible pipe T at the apexes of the first and second threads from the tip, in FIG. 9, the seal member 17 is in close contact with the flexible pipe T only at the apex of the first thread from the tip, which may result in insufficient contact. Furthermore, depending on the degree of pulling, the flexible pipe T may be pulled out by two threads compared to the normal connection state. Even in such an insufficient connection state, the flexible pipe itself will not come loose as long as the retainer 18 is engaged with the flexible pipe T. Therefore, an installer may mistakenly believe that the connection has been completed correctly even when it has not. Therefore, a mechanism capable of detecting such improper installation is required during installation.

[0013] The present invention has been made in consideration of the above circumstances, and aims to provide a flexible pipe joint that eliminates the need for marking work by the installer and makes it easy to detect installation defects. [Means for solving the problem]

[0014] The flexible pipe joint of the present invention is a flexible pipe joint for connecting a bellows-shaped flexible pipe having a plurality of peaks and valleys arranged alternately along the axial direction, and is a joint in which the flexible pipe is sealed and prevented from coming loose when the flexible pipe is inserted from one end to a predetermined position, and is characterized in that one end of the inner surface of the flexible pipe joint has a marking portion that comes into contact with a covering body that covers the flexible pipe when the flexible pipe is inserted and marks the covering body.

[0015] In the present invention, the mark functions as an indicator that clearly indicates improper installation. Specifically, according to the present invention, if the flexible pipe is not inserted sufficiently, the mark is exposed to the outside of the pipe joint when the flexible pipe is pulled to check the connection. The installer can visually recognize the improper installation by checking the exposed mark.

[0016] In the present invention, the marking portion is characterized in that it also functions as a packing that seals the outer peripheral surface of the covering body and the pipe joint.

[0017] In the present invention, it is also preferable that the marking portion comes into contact with the coating and deposits a colored lubricant onto the coating.

[0018] In addition, in the present invention, the marking portion may have a contact portion that extends toward the inner diameter side before the flexible tube is inserted, and the contact portion may come into contact with the covering body when the flexible tube is inserted and deform in the insertion direction of the flexible tube. [Effects of the Invention]

[0019] The flexible pipe coupling of the present invention, with its above-described configuration, makes it easy to determine improper installation when the flexible pipe is connected in an incorrect position due to unintentional disconnection of the flexible pipe, etc. Furthermore, since the mark is automatically provided upon insertion of the flexible pipe, the installer does not need to mark the flexible pipe before inserting it, thereby improving installation efficiency. This also helps prevent mistakes and forgetting to mark the flexible pipe. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a half-sectional view of a first embodiment of a pipe joint according to the present invention. [Figure 2] 10A and 10B are diagrams for explaining the insertion operation of the flexible tube. [Figure 3]10 is a cross-sectional view of the upper half of a flexible pipe in the middle of being inserted. [Figure 4] 10 is a cross-sectional view of the upper half of the flexible pipe when connected. [Figure 5] FIG. 10 is a diagram for explaining determination of an insufficient connection state. [Figure 6] FIG. 4 is a partially enlarged view of a second embodiment of a pipe joint according to the present invention. [Figure 7] FIG. 1 is a half-sectional view of a conventional pipe joint. [Figure 8] FIG. 8 is a half-sectional view of the pipe joint of FIG. 7 in a state where a flexible pipe is connected. [Figure 9] FIG. 10 is a half-sectional view showing an insufficient connection. DETAILED DESCRIPTION OF THE INVENTION

[0021] (First embodiment) A first embodiment of a pipe fitting according to the present invention will be described with reference to Fig. 1. Fig. 1 is a half-side cross-sectional view of the pipe fitting 1, with the upper half above the central axis O of the pipe fitting 1 being a cross-sectional view and the lower half being a side view. A flexible pipe T (see Fig. 2) is connected to one end (left side of the figure) of the pipe fitting 1 in Fig. 1, and another pipe, gas equipment, or the like is connected to the other end (right side of the figure). In the present invention, the direction along the central axis O of the pipe fitting 1 is referred to as the axial direction, the direction perpendicular to the central axis O in a plan view seen from the axial direction is referred to as the radial direction, and the direction going around the central axis O in the plan view is referred to as the circumferential direction.

[0022] Fig. 1 shows the state before a flexible pipe T is inserted. As shown in Fig. 1, the pipe fitting 1 comprises a cylindrical fitting body 2, a press nut 3, a portion of which is inserted into the fitting body 2, an elastic member 4 that is expandable and contractible in the axial direction, a holding member 5 that holds the elastic member 4 in a compressed state, a movable member 6, a ring-shaped sealing member 7 that comes into close contact with the flexible pipe T, and a retainer 8. The pipe fitting 1 also has attached thereto a marking portion 9, a fireproof packing 10a, a stop ring 10b, an O-ring 10c for sealing the press nut 3 and the fitting body 2, and a selectively permeable member 10d.

[0023] The joint body 2 has an inner bore 21 at one end into which the flexible pipe T is inserted, and an external thread portion 27 on the outer circumferential surface of the other end. The inner diameter of the inner bore 21 decreases in stages toward the other end, with a first step portion 24 and a second step portion 25 formed therein. An inner circumferential groove 26 is formed between the first step portion 24 and the second step portion 25, with which the claw portion 52 of the retaining member 5 engages. In addition, inner circumferential grooves 22 and 23 are formed on the inner circumferential surface of the joint body 2 at one end.

[0024] The press nut 3 is a cylindrical metal member with a through hole. The press nut 3 abuts against the retainer 8 and has a tip portion with an inclined surface 31. The outer circumferential surface of the press nut 3 is formed with an outer circumferential groove 32 into which part of the stop ring 10b enters. An O-ring 10c and a marking portion 9 are fitted in the other groove portions of the press nut 3, respectively.

[0025] The elastic member 4 is a coil spring that can expand and contract in the axial direction. Before the flexible pipe is inserted, the elastic member 4 is held in a compressed state by the holding member 5. The holding member 5 is a metal ring-shaped member with an L-shaped cross section. The holding member 5 has a support portion 51 that supports the elastic member 4 at one end and a claw portion 52 at the other end. The claw portion 52 is formed by bending the end of a circular arc plate portion 53 that extends approximately axially from the inner diameter edge of the hollow, disk-shaped support portion 51 outward in the radial direction. The holding member 5 holds the elastic member 4 in a compressed state between the support portion 51 and the first step portion 24 of the joint body 2, and the claw portion 52 is engaged with the inner circumferential groove 26 of the joint body 2. Furthermore, the inner circumferential surface of the holding member 5 is supported by the moving member 6, preventing the claw portion 52 from releasing its engagement with the inner circumferential groove 26, thereby maintaining the compressed state of the elastic member 4. The moving member 6 is a member that can move to the inner side of the joint body 2 when the flexible pipe T is inserted, and is disposed on the inner diameter side of the holding member 5.

[0026] The seal member 7 comprises a seal body 71 made of a rubber material and a presser member 72 fixed to the end face of the seal body 71 on the inlet side of the joint body 2. The presser member 72 has an L-shaped cross section and is configured to hold the fireproof packing 10a. The seal body 71 has a cylindrical inner periphery that comes into close contact with the flexible pipe, and has an inner diameter that is slightly smaller than the outer diameter of the ridges of the flexible pipe T. In FIG. 1, the seal body 71 has a length that allows it to seal two ridges of the flexible pipe T. As the rubber material used for the seal body 71 needs to maintain sealing performance over a long period of time, nitrile butadiene rubber (NBR) is preferred in consideration of its gas resistance.

[0027] The retainer 8 is made of an elastically deformable material (e.g., engineering plastic) and is a ring-shaped member having a base on which an inclined surface 82 that abuts against the press nut 3 is formed. One end of the retainer 8 is divided into multiple segments by multiple axial grooves 83 formed in the circumferential direction, and a claw portion 81 is formed on the inner diameter side of the tip of each segment. The claw portion 81 is made of a metal material (e.g., brass). In the state shown in FIG. 1, the claw portion 81 has an inner diameter larger than the outer diameter of the ridge portion of the flexible pipe T, and is sized so that it does not get caught on the ridge portion when the flexible pipe T is inserted.

[0028] The fireproof packing 10a is a component that prevents gas leakage even when the pipe fitting 1 is exposed to high temperatures due to a fire or the like. The fireproof packing 10a is manufactured, for example, by kneading raw rubber, a graphite intercalation compound that thermally expands in an unfoamed state, and optionally a filler, softener, vulcanizing agent, etc. to obtain a rubber composition, filling the resulting mixture into a mold, molding the mixture, and then press-vulcanizing the mixture. The fireproof packing 10a thermally expands during a fire and fills the gap between the fitting body 2 and the flexible pipe T, thereby sealing the inner surface of the fitting body 2 and the outer surface of the flexible pipe T. In FIG. 1, the fireproof packing 10a has a rectangular cross section.

[0029] The stop ring 10b is a C-shaped member formed from a wire made of a springy metal material. As shown in FIG. 1, a portion of the stop ring 10b is fitted into the inner circumferential groove 22 of the fitting body 2, and the remaining portion is fitted into the outer circumferential groove 31 of the press nut 3, thereby fixing the fitting body 2 and the press nut 3 together. The O-ring 10c is fitted into an outer circumferential groove formed on the inlet side of the fitting body 2 relative to the outer circumferential groove 31 of the press nut 3. The O-ring 10c prevents water from entering the pipe fitting 1 from the outside, thereby making the pipe fitting 1 watertight. The selectively permeable member 10d is attached to a through-hole (e.g., a circular hole) provided in the press nut 3 opposite one end of the fitting body 2 and communicating with the outside air. The selectively permeable member 10d is a porous member that is permeable to gases but not liquids. In the event of a gas leak from the flexible pipe T, the selectively permeable member 10d is provided to allow the leaked gas to pass through and be detected by an external gas sensor or the like.

[0030] In the present invention, the pipe fitting 1 has a marking portion 9 at one end of the inner peripheral surface of the pipe fitting 1. The marking portion 9 comes into contact with the covering body C (see FIG. 2) when the flexible pipe T is inserted, thereby marking the covering body C. In the embodiment shown in FIG. 1, the marking portion 9 also functions as a packing that provides a watertight seal between the outer peripheral surface of the covering body C and the pipe fitting 1 (specifically, the inner peripheral surface of the press nut 3). The marking portion 9 is an annular member with a substantially L-shaped cross section, and is fitted into an inner peripheral groove formed on the inner diameter side of the press nut 3. The marking portion 9 has a lip portion 91 extending toward the inner diameter side and is formed of an olefin-based rubber such as EPDM. A colored lubricant (colored lubricant) is held on the surface of the lip portion 91.

[0031] Colored lubricants can be obtained, for example, by mixing a colorant such as a pigment or dye with a lubricant commonly used in the field of pipe fittings. Grease such as silicone grease or lubricating oil such as silicone oil is used as the lubricant. Grease is preferably used as the lubricant because it is easy to adhere the colored lubricant to the coating.

[0032] As the pigment, organic pigments and inorganic pigments can be used. Examples of organic pigments include polycyclic pigments such as phthalocyanine pigments and azo pigments. Examples of inorganic pigments include ultramarine and carbon black. Examples of dyes that can be used include solvent yellow, solvent orange, and anthraquinone. The colorant may be one that emits fluorescence when exposed to excitation light. For example, when construction is performed in a dark place, the fluorescence of the colorant can increase the visibility of the marker. Known commercially available colorants can be used.

[0033] The colorant is selected to have a color that is visible when the colored lubricant is attached to the coating C. It is preferable to use a black, red, or blue colorant because they have excellent visibility.

[0034] Next, the insertion operation of the flexible pipe T will be described with reference to Figures 2 to 4. Figure 2 shows the state where the insertion of the flexible pipe T has begun, Figure 3 shows the state where the insertion of the flexible pipe T has progressed further, and Figure 4 shows the state where the flexible pipe T has been connected. Figures 3(b) and 4(b) are enlarged views of the areas enclosed by dotted lines in Figures 3(a) and 4(a), respectively.

[0035] First, as shown in Figure 2, flexible pipe T is a corrugated metal pipe (e.g., a stainless steel pipe) with multiple peaks and valleys arranged alternately along the axial direction. Typically, the tip of flexible pipe T is cut at the valley position so that it is perpendicular to the axial direction. The flexible pipe T is inserted into pipe fitting 1 after several peaks (seven peaks in Figure 2) of the outer coating C are removed from the tip.

[0036] As shown in Figure 2, the flexible pipe T is inserted from one end of the pipe fitting 1 and passed through the inner periphery of the press nut 3 and the retainer 8. In the mid-insertion state shown in Figure 2, the lip portion 91 of the marker portion 9 has not yet come into contact with the covering body C.

[0037] FIG. 3 shows a state in which the insertion of the flexible pipe T has progressed from the state in FIG. 2 and its tip has hit the moving member 6. In this state, the lip portion 91 of the marking portion 9 is in contact with the covering C (see FIG. 3(b)). This causes the colored lubricant held in the lip portion 91 to be transferred to the covering C. The colored lubricant adhering to the covering C becomes the mark M for indicating installation defects. The mark M is applied to the outer surface of the covering C so as to extend axially from the tip of the covering C, and is applied according to the insertion depth of the flexible pipe T. The colored lubricant is applied to at least the portion of the lip portion 91 that comes into contact with the covering C.

[0038] In FIG. 3, the lip portion 91 of the marking portion 9 makes contact with the covering C and deforms in the insertion direction of the flexible tube while applying the mark M. By deforming in this manner, the covering C is less likely to be scratched when the mark M is applied. The shape of the lip portion 91 is not limited to the shape shown in FIG. 3. For example, the shape may be changed to make it easier to apply the colored lubricant to the covering C. Furthermore, the lip portion may have a flocked portion, and the colored lubricant may be applied by the flocked fibers.

[0039] As the flexible pipe T is further inserted from the state shown in FIG. 3, the movable member 6 moves toward the rear of the joint body 2, and as it moves, the claws 52 of the holding member 5 come out of the inner circumferential groove 26 of the joint body 2. Then, the compressed state of the elastic member 4 is released, and the elastic member 4 expands. This expansion force causes the seal member 7 to slide toward the inlet side of the joint body 2, and the retainer 8 is pushed via the seal member 7, so that the inclined surface 82 comes into close contact with the inclined surface 31 of the press nut 3, and the claws 81 contract in diameter and fit into the valleys of the flexible pipe T (see FIG. 4). This completes the connection of the flexible pipe T. The installer then performs a check by pulling the flexible pipe T.

[0040] As shown in Figure 4(b), when the connection is completed normally, the mark M is hidden inside the pipe fitting 1 and is not exposed to the outside. In this case, the installer determines that the connection has been completed normally when the mark M cannot be seen from the outside of the pipe fitting 1.

[0041] Next, Figure 5 shows a state in which the installer's inspection work has resulted in one thread of flexible pipe T coming loose. In this state, the flexible pipe T has come loose too much, exposing the mark M to the outside. In this case, the installer determines that the installation is defective because he or she can see the mark M from the outside of the pipe fitting 1.

[0042] As described above, in the pipe fitting of the first embodiment, a packing provided in the pipe fitting is configured to hold a colored lubricant, thereby serving as a marking portion, and the colored lubricant is transferred to the covering body when the flexible pipe is inserted. In other words, the pipe fitting has the function of automatically marking the covering body when the flexible pipe T is inserted. With this configuration, in the event of poor installation, the colored lubricant adhering to the covering body C is exposed to the outside, making it possible to clearly determine whether the installation is poor. In this way, the marking provided by the marking portion functions as an indicator that clearly indicates poor installation. Normally, in pipe fittings with an indicator function, it is determined that the installation has been performed correctly by confirming that the indicator has appeared, but in the case of the marking of the present invention, it is determined that the installation has been poor by confirming that the mark has appeared.

[0043] In the present invention, the marking portion is provided at one end of the inner peripheral surface of the pipe fitting, and the marking is provided so that the marking is hidden inside the pipe fitting during normal installation and is visible outside the pipe fitting during installation defects (for example, one-ridge missing or two-ridge missing). Specifically, as shown in Figure 4(b), when the flexible pipe T is connected in the correct position, the length L of the portion inside the pipe fitting 1 where the marking M is not provided (i.e., the length from the end face of the press nut 3 to one end of the marking M) is set to be shorter than the length p of one pitch of the flexible pipe T, so that the marking M will appear if the flexible pipe T is unintentionally disconnected, making it possible to reliably determine a poor connection.

[0044] (Second embodiment) Next, a second embodiment of a pipe fitting according to the present invention will be described with reference to Fig. 6. Fig. 6 shows an enlarged view of one end of a pipe fitting 1A. As shown in Fig. 6, a marking portion 9A and a lip packing 10e are each attached to one end of the inner peripheral surface of the press nut 3. Unlike the first embodiment described above, the marking portion 9A and the lip packing 10e are formed as separate members. In Fig. 6, the marking portion 9A is located closer to the inlet side of the fitting body 2 than the lip packing 10e.

[0045] The material of the marking portion 9A is not particularly limited, but is preferably a foamed elastic body such as urethane foam (urethane sponge) that has excellent cushioning properties. For example, the foamed elastic body holds ink colored with the coloring agent described above. In FIG. 6, the marking portion 9A extends toward the inner diameter side and has a tapered contact portion 91A. When the flexible tube T is inserted, the contact portion 91A comes into contact with the covering C to apply a mark to the covering C. The shape of the marking portion 9A can be changed as appropriate; for example, the contact portion may be brush-shaped.

[0046] The pipe fitting of the present invention is not limited to the above-described embodiment. In the pipe fitting, the specific method for providing the markings on the marking portion is not particularly limited, and may include coloring the outer surface of the coating as described above, or providing an indentation on the outer surface of the coating. The indentation method is suitable for situations where the installer cannot visually check the condition of the flexible pipe after installation, such as installation in a small space. In this case, after installation, the installer can determine whether the installation is faulty by touching the coating near the pipe fitting and feeling the indentation.

[0047] The pipe joint may also be configured so that the inside of the pipe joint can be visually inspected after installation. Specifically, for example, the press nut may be made of a transparent resin, so that it is possible to visually inspect from the outside of the pipe joint whether the mark attached to the cover has reached a predetermined position. This makes it possible to reliably determine whether the installation is correct, as well as whether the installation is faulty.

[0048] Furthermore, the pipe fitting of the present invention may be any fitting that seals and prevents a flexible pipe from coming loose when the flexible pipe is inserted from one end to a predetermined position, and the internal arrangement and configuration of the pipe fitting and the configuration of each component are not limited to those described above.

[0049] As described above, the pipe joint of the present invention eliminates the need for marking work by the installer and also makes it easy to detect installation defects. [Explanation of symbols]

[0050] 1: Pipe fittings (flexible pipe fittings) 2: Fitting body 21: Inner hole 22: Inner groove 23: Inner groove 24: First stage 25: Second stage 26: Inner groove 27: Male thread 3: Press nut 31: Inclined surface 32: Peripheral groove 4: Elastic member 5: Holding member 51: Support part 52: Claw part 53: Arc plate section 6: Moving parts 7: Sealing material 71: Seal body 72: Pressing member 8: Retainer 81: Claw part 82: Inclined surface 83: Axial groove 9: Marking section 91: Lip part (contact part) 9A: Marking section 91A: Contact part 10a: Fireproof packing 10b: Stop ring 10c: O-ring 10d: Selectively permeable material 10e: Lip packing T: Flexible pipe C: Covering body M: Eyeprint

Claims

1. A flexible pipe joint for connecting a bellows-shaped flexible pipe having a plurality of peaks and valleys alternately arranged along an axial direction, The flexible pipe joint is a joint in which the flexible pipe is inserted from one end thereof to a predetermined position, thereby sealing the flexible pipe and preventing it from coming off, A flexible pipe joint characterized in that one end of the inner surface of the flexible pipe joint has a marking portion that comes into contact with a covering body that covers the flexible pipe when the flexible pipe is inserted and marks the covering body.

2. 2. The flexible pipe joint according to claim 1, wherein the marking portion also functions as a packing that seals the outer peripheral surface of the covering body and the flexible pipe joint.

3. 3. A flexible pipe joint according to claim 1, wherein the marking portion comes into contact with the coating and applies a colored lubricant to the coating.

4. A flexible pipe fitting as described in any one of claims 1 to 3, characterized in that the marking portion has a contact portion that extends toward the inner diameter side before the flexible pipe is inserted, and the contact portion comes into contact with the covering body when the flexible pipe is inserted and deforms in the insertion direction of the flexible pipe.

Images