Flexible pipe fittings and construction methods

Abstract

Provides flexible pipe fittings and construction methods that can prevent flexible pipes from falling off and achieve miniaturization. The pipe fitting (1) is a flexible pipe fitting for connecting a flexible pipe (T1). The flexible pipe (T1) has a deformable portion (T11) formed by extending at least a portion of its outer periphery further outward than the peak. It has a press nut (3) fitted at a position opposite to the front end of the flexible pipe (T1) to the deformable portion (T11), a fitting body (2) for inserting the front end of the flexible pipe (T1) together with the end of the press nut (3), a locking mechanism for engaging the press nut (3) with the fitting body (2), and an annular sealing member disposed in the fitting body (2) and in close contact with the flexible pipe (T1). The flexible pipe (T1) is connected by engaging the press nut (3) with the fitting body (2). In this connected state, the deformable portion (T11) of the flexible pipe (T1) is locked at the end of the fitting body of the press nut (3) on the deep side, preventing the flexible pipe (T1) from falling off.

Description

Technical Field

[0001] This invention relates to a flexible pipe connector for connecting corrugated flexible pipes, and a method for constructing a flexible pipe connected to the flexible pipe connector. Background Technology

[0002] Indoor gas piping widely utilizes corrugated flexible metal conduits. Additionally, various pipe fittings are used to connect these flexible conduits to gas valves, steel pipes, and other components. In recent years, one-touch pipe fittings, which require no tools and allow installation simply by inserting the flexible conduit into the fitting, are also becoming increasingly practical.

[0003] For example, in Figure 14 and Figure 15 The image shows a flexible pipe fitting (hereinafter also referred to as a pipe fitting) as described in Patent Document 1. Figure 14 This shows the state before the flexible tube was inserted. Figure 15 This shows the state where the flexible tube is connected. (Example) Figure 14 As shown, the pipe fitting 11 has a fitting body 12 for inserting a flexible tube from one end. Inside the fitting body 12 are disposed a portion of a pressing nut 13, a retainer 18, an axially retractable elastic member 14, a guide member 15 for holding the elastic member 14 in a compressed state, a moving member 16, and an annular sealing member 17 that is in close contact with the outer peripheral surface of the flexible tube.

[0004] like Figure 15 As shown, when the corrugated flexible tube T1 is inserted relative to the pipe fitting, the engagement between the guide member 15 and the fitting body 12 is released, thereby releasing the compressed state of the elastic member 14. Then, as the elastic member 14 elongates, the sealing member 17 slides and is compressed axially. As a result, the sealing member 17 comes into close contact with the outer peripheral surface of the flexible tube T1. In addition, as the elastic member 14 elongates, the retainer 18 reduces in diameter, so that the claw portion 18a is housed in the valley portion of the flexible tube T1. Thus, the retainer 18 is engaged with the outer peripheral surface of the flexible tube T1, preventing the flexible tube T1 from falling off.

[0005] Prior art literature

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2011-52762 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] As described above, in conventional pipe fittings, a retainer is used to prevent the flexible tube from detaching. However, in such pipe fittings, a retainer (anti-detachment component) is required as a constituent element. Furthermore, because the retainer is housed, there is an axial length L2 of the pipe fitting (see reference). Figure 14 The pipe fittings tend to become longer. Therefore, there is room for further improvement in miniaturization.

[0010] The present invention was made in view of the following circumstances, and its object is to provide a flexible tube connector and a construction method for flexible tubes that can prevent the flexible tube from falling off and achieve miniaturization.

[0011] Solution for solving the problem

[0012] The flexible tube connector of the present invention is used to connect a corrugated flexible tube having multiple peaks and valleys alternately arranged along the axial direction. The flexible tube is characterized by having a deformable portion formed by extending at least a portion of its outer periphery further outward than the peaks. The flexible tube connector comprises: a pressing nut fitted at a position opposite to the front end of the flexible tube to the deformable portion; a connector body for inserting the front end of the flexible tube together with the end of the pressing nut; a locking mechanism for engaging the pressing nut with the connector body; and an annular sealing member disposed within the connector body and in close contact with the flexible tube. The flexible tube is connected by engaging the pressing nut with the connector body, and in this connected state, the deformable portion of the flexible tube is locked at the deep end of the connector body of the pressing nut to prevent the flexible tube from falling off.

[0013] In this invention, it is preferred that the engaging mechanism is a mechanism having a stop ring, an inner circumferential groove formed on the inner surface of the connector body, a retaining member that holds the stop ring in an expanded state within the inner circumferential groove, and an outer circumferential groove formed on the outer surface of the pressing nut. By inserting the pressing nut assembled to the flexible tube, the retaining member is pressed and the expanded state of the stop ring is released, and the stop ring engages by spanning the outer circumferential groove and the inner circumferential groove.

[0014] Furthermore, in this invention, it is more preferable that the retaining member has a hollow circular plate-shaped base that is pressed by the pressing nut, and a cylindrical portion that extends axially from the outer periphery of the base. A plurality of protrusions that are divided along the circumferential direction and bent outward are provided at the front end of the cylindrical portion. In the state before the pressing nut is inserted, the retaining member engages the plurality of protrusions with the engaging groove formed at a position closer to the inlet side of the connector body than the inner circumferential groove, thereby retaining the stop ring in an expanded diameter state.

[0015] Furthermore, in this invention, more preferably, an elastic member is disposed within the connector body between the sealing member and the stepped portion formed by the reduction of the inner diameter of the connector body, and the elastic member is compressed when connected to the flexible tube compared to the state before the insertion of the pressing nut.

[0016] Alternatively, in this invention, a claw portion may be provided on the outer surface of the connector body, and in the connected state with the flexible tube, the claw portion engages with the end of the connector body at the inlet side of the pressing nut.

[0017] Alternatively, in this invention, the deformed portion may be a generally disk-shaped portion in which the top of at least one peak extends outward to the outer diameter side.

[0018] The construction method of the flexible tube of the present invention connects a corrugated flexible tube with multiple peaks and valleys alternately arranged along the axial direction to a flexible tube connector. The flexible tube connector comprises: a pressing nut; a connector body for inserting the front end of the flexible tube together with the end of the pressing nut; a locking mechanism for locking the pressing nut into the connector body; and an annular sealing member disposed within the connector body and in close contact with the flexible tube. The construction method includes: a first cutting step, in which the flexible tube is cut together with its outer coating resin; a peeling step, in which the coating resin is peeled off; and a second cutting step. The process includes: a second cutting step in which the exposed front end of the flexible tube is cut off at the valley; an insertion step in which a pressing nut is inserted into the flexible tube; a deformation step in which a deformed portion is formed on the flexible tube at a position closer to the front end than the inserted pressing nut, extending at least a portion of the outer periphery outwards from the peak; and a locking step in which the pressing nut and the flexible tube are inserted together and locked into the connector body, thereby connecting the flexible tube. In this connected state, the deformed portion of the flexible tube is locked at the deep end of the connector body of the pressing nut to prevent the flexible tube from falling off.

[0019] In this invention, it is preferred that an automatic construction machine is used to perform at least one of the following processes: a first cutting process, a peeling process, a second cutting process, an insertion process, and a deformation process.

[0020] Invention Effects

[0021] The flexible tube connector of the present invention, by having such a structure, eliminates the need for a retainer as in conventional structures, thereby preventing the flexible tube from falling off and achieving miniaturization. Attached Figure Description

[0022] Figure 1 This is a single-side sectional view of the first embodiment of the pipe fitting of the present invention.

[0023] Figure 2 yes Figure 1 A three-dimensional view of the retaining component.

[0024] Figure 3 yes Figure 1 A three-dimensional view of the connector body.

[0025] Figure 4 Is Figure 1 A one-sided sectional view of a pipe fitting connected to a flexible tube.

[0026] Figure 5 yes Figure 4 Enlarged view of part A.

[0027] Figure 6 This is a single-side sectional view of the second embodiment of the pipe fitting of the present invention.

[0028] Figure 7 This is a process diagram illustrating the general outline of the construction method of the present invention.

[0029] Figure 8 This is a schematic diagram of an automatic construction machine used in the construction method of the present invention.

[0030] Figure 9 This is an explanatory diagram of the automated construction process for steps S1 to S3.

[0031] Figure 10 This is an explanatory diagram of the automated construction process for steps S4 to S5.

[0032] Figure 11 This is an explanatory diagram of process S6.

[0033] Figure 12 This diagram shows the confirmation action of the connection status of the flexible tube.

[0034] Figure 13 This is an explanatory diagram of the manual construction process for steps S1 to S3.

[0035] Figure 14 This is a single-sided sectional view of a conventional pipe fitting.

[0036] Figure 15 Is Figure 14 A one-sided sectional view of a pipe fitting connected to a flexible tube. Detailed Implementation

[0037] (First Implementation)

[0038] based on Figure 1 A first embodiment of the pipe fitting of the present invention will be described. Figure 1 This is a single-side sectional view of the pipe connector. The upper half of the pipe connector 1, which is above the central axis O, is shown in the sectional view, and the lower half is shown in the side view. In this invention, the direction along the central axis O of the pipe connector 1 is called the axial direction, the direction orthogonal to the central axis O in the top view from the axial direction is called the radial direction, and the direction around the central axis O in the top view is called the circumferential direction.

[0039] Figure 1The diagram shows the main component of the pipe fitting, namely the fitting body, before it is engaged with the press nut. The pipe fitting 1 is constructed by inserting a portion of the press nut 3 and engaging it with the fitting body 2. The fitting body 2 has an inner hole 21 at one end for inserting the press nut 3 and a flexible tube, and an external thread 25 on the outer circumferential surface at the other end. The inner diameter of the inner hole 21 decreases in stages towards the other end.

[0040] like Figure 1 As shown, the cylindrical connector body contains an elastic member 4, an annular sealing member 5, a retaining member 6, a spacer 8a, a fire-resistant gasket 8b, and a stop ring 8c. It should be noted that the connector body 2 does not contain a retainer 18 (see reference) which serves as an anti-detachment component for the flexible tube. Figure 14 An inner circumferential groove 22 is formed on the inner circumferential surface of one end of the connector body 2. Furthermore, a locking groove 23, with a shallower depth than the inner circumferential groove 22, is formed on the side of the inner circumferential groove 22 closer to the connector body inlet. Figure 1 In this state, the stop ring 8c is housed in the inner circumferential groove 22, and the protrusion 621 of the retaining member 6 is engaged in the engaging groove 23.

[0041] The elastic member 4 is a spring that can extend and retract freely in the axial direction. The elastic member 4 is positioned between the stepped portion 24, formed by the reduction of the inner diameter of the joint body 2, and the sealing member 5. Figure 1 In the middle, a hollow circular plate-shaped spacer 8a is sandwiched between the sealing member 5 and the elastic member 4, so that the restoring force of the elastic member 4 can be easily transmitted to the sealing member 5.

[0042] The sealing member 5 has a sealing body 51 made of rubber material and a pressing member 52 fixed to the end face of the connector body inlet side of the sealing body 51. The pressing member 52 has an L-shaped cross-section, forming a structure that retains the fire-resistant gasket 8b. The inner periphery of the sealing body 51 that is in close contact with the flexible tube has a cylindrical shape and an inner diameter slightly smaller than the outer diameter of the peak of the flexible tube. The sealing body 51 has a length capable of sealing both peaks of the flexible tube. As the rubber material used for the sealing body 51, nitrile rubber (NBR) is preferred, considering its gas resistance, based on the necessity of maintaining sealing performance over a long period.

[0043] The fire-resistant gasket 8b is a component used to prevent gas leakage even when the pipe joint 1 is exposed to high temperatures due to fire or other reasons. The fire-resistant gasket 8b is manufactured, for example, by filling a mold with a rubber composition obtained by mixing raw rubber, thermally expanding graphite intercalation compound in a non-foamed state, and fillers, softening materials, vulcanizing agents, etc., as needed, and then subjecting it to pressure vulcanization. During a fire, the fire-resistant gasket 8b thermally expands, thereby filling the gap between the joint body 2 and the flexible pipe, thus sealing the outer circumference of the flexible pipe. Figure 1In the middle, the refractory liner 8b has a rectangular cross section.

[0044] The retaining member 6 is, for example, a ring-shaped member made of a resin material (such as polyacetal). See reference. Figure 2 The three-dimensional diagram illustrates the retaining member 6. For example... Figure 2 As shown, the retaining member 6 has a hollow circular plate-shaped base 61 and a cylindrical portion 62 extending axially from the outer periphery of the base 61. A plurality of protrusions 621, divided along the circumferential direction and bent radially outward (outward), are provided at the front end of the cylindrical portion 62. Figure 1 As shown, the retaining member 6 is assembled within the connector body with its base 61 facing the deep side of the connector body, and the base 61 abuts against the fire-resistant gasket 8b. This base 61 is the portion pressed down by the pressing nut 3 when it is inserted. Furthermore, the retaining member 6 engages multiple protrusions 621 with the engaging groove 23 to retain the retaining ring 8c in an expanded-diameter state within the inner circumferential groove. It should be noted that the retaining ring 8c is a C-shaped member formed of wire, which is made of a flexible metal material.

[0045] An outer peripheral groove 26 is formed on the outer peripheral surface of one end of the connector body 2, and an indicator 7 is fitted into this outer peripheral groove 26. Figure 3 As shown, the indicator 7 has an opening at a circumferential location of the annular portion 71, allowing it to expand in diameter and fit into the outer peripheral groove 26. Additionally, the indicator 7 has a hook portion 72 extending from the annular portion 71 toward the inlet side of the connector body. Multiple hook portions 72 are formed at approximately equal intervals in the circumferential direction (in... Figure 3 (There are 3 in the middle). As described later, in the connected state with the flexible tube, the hook portion 72 and the end 33 of the connector body on the inlet side of the pressing nut (refer to) Figure 4 ) Engagement. It should be noted that the claw part may not be a separate component, but may be integrated with the connector body 2 by extending directly from the outer peripheral surface of the connector body 2.

[0046] return Figure 1 The press nut 3 is a cylindrical metal component with a through hole. A portion of the press nut 3 is inserted into the inner hole 21 of the connector body 2 and engaged. An outer peripheral groove 31 is formed on the outer peripheral surface of the press nut 3 for a portion of the retaining ring 8c to enter. In addition, an O-ring 8d, a lip gasket 8e, and a selective permeability member 8f are respectively assembled on the press nut 3.

[0047] The O-ring 8d is embedded in the outer circumferential groove 31 of the press nut 3, which is formed near the inlet side of the connector body. The O-ring 8d prevents water from seeping into the connector 1 from the outside, thus providing watertightness to the connector 1. Additionally, the lip gasket 8e is a ring-shaped member with a roughly L-shaped cross-section, embedded in the inner circumferential groove of the press nut 3. The lip gasket 8e provides a watertight seal between the outer circumferential surface of the flexible tube and the inner circumferential surface of the press nut 3.

[0048] The selective permeability member 8f is fitted into a through hole (e.g., a round hole) that communicates with external gas at a position opposite to one end of the press nut 3 and the connector body 2. The selective permeability member 8f is a porous member that allows gas to pass through but not liquid, and is provided to allow leaked gas to pass through and be detected by external gas sensors or the like in the event of a gas leak in the flexible tube.

[0049] Here, the pipe fitting 1 has an engagement mechanism that engages the pressing nut 3 with the fitting body 2. This engagement mechanism includes a stop ring 8c, a retaining member 6, an outer peripheral groove 31, and an inner peripheral groove 22. As described later, when engaging the pressing nut 3, the pressing nut 3 is pre-assembled onto the flexible tube, and the pressing nut 3 and the flexible tube are inserted into the fitting body 2. When the pressing nut 3 is inserted, the protrusion 621 of the retaining member 6 disengages from the engagement groove 23 and is pressed into the deeper part of the fitting body. The pressing nut 3 is engaged with the fitting body 2 through the aforementioned engagement mechanism, thereby connecting the flexible tube.

[0050] exist Figure 4 and Figure 5 The image shows the connection status of the flexible tube. Figure 4 In the connected state, the retaining member 6 is pressed deep into the connector body, and the retaining ring 8c disengages from the retaining member 6. The retaining ring 8c spans the outer peripheral groove 31 of the pressing nut 3 and the inner peripheral groove 22 of the connector body 2, thereby engaging the pressing nut 3 with the connector body 2. Furthermore, by inserting the pressing nut 3, compared to the state before insertion (… Figure 1 Compared to the previous state, the elastic member 4 is compressed in the axial direction. Moreover, through the restoring force of the elastic member 4 accompanying this compression, the sealing body 51 is compressed and comes into close contact with the outer peripheral surface of the flexible tube T1.

[0051] The flexible tube T1 is a corrugated metal tube (e.g., a stainless steel tube) with multiple peaks and valleys arranged alternately along the axial direction. In this invention, the flexible tube T1 has a deformed portion T11 formed by extending at least a portion of its outer periphery further outward than the peaks. Figure 4 In the flexible tube T1, the deformable portion T11 is formed by the fourth and fifth peaks starting from the front end T12. A portion of the flexible tube T1 is axially crushed by decreasing the distance (p) between the tops of these peaks, thereby expanding the tops of the peaks outwards to form the deformable portion T11. The deformable portion T11 is generally disk-shaped, with a portion protruding further outwards than the other peaks; this protruding portion functions as an anti-detachment part of the flexible tube. It should be noted that the position of the peaks constituting the deformable portion is not limited to... Figure 4 .

[0052] Figure 5 yes Figure 4 An enlarged view of part A. (See image below.) Figure 5 As shown, the deformable portion T11 of the flexible tube T1 is engaged between the end 32 of the connector body of the pressing nut 3 on the deep side and the sealing member 5. More specifically, the deformable portion T11 is engaged between the stepped portion 321 provided on the inner diameter edge of the end 32 and the pressing member 52 of the sealing member 5. The stepped portion 321 is a portion recessed towards the inlet side of the connector body to allow a portion of the deformable portion T11 to enter, and is formed over the entire circumference. In this way, by clamping the deformable portion T11 between the pressing nut 3 and the constituent members inside the connector body, even when the flexible tube T1 is operated in a pulling manner, the deformable portion T11 is engaged with the end 32 of the pressing nut 3, preventing the flexible tube T1 from falling off. Therefore, a retainer as in conventional structures is not required. Since a retainer is not required, there is no space in the connector body 2 for assembling a retainer, thus shortening the axial length of the pipe connector and enabling miniaturization of the pipe connector. In addition, it also leads to a reduction in the cost of the pipe connector.

[0053] In the pipe fitting of the present invention (refer to) Figure 4 In this context, compared to previous pipe fittings (see reference...), Figure 14 Compared to conventional pipe fittings, this invention shortens the axial length when the nut is engaged with the fitting body. For example, the axial length L2 of conventional pipe fittings is approximately 70 mm, while the axial length L1 of the pipe fitting of this invention is, for example, 60 mm or less, preferably 50 mm or less. It should be noted that the lower limit of the axial length L1 is, for example, 45 mm or more.

[0054] (Second Implementation)

[0055] based on Figure 6 A second embodiment of the pipe fitting of the present invention will be described. It should be noted that, for use with... Figures 1-5 The same structures as those in the first embodiment are labeled with the same reference numerals, and detailed descriptions are omitted. Figure 6 The connection status with the flexible tube is shown.

[0056] The pipe fitting of the first embodiment described above is a structure that seals the flexible pipe from the side. In contrast, the pipe fitting of the second embodiment is a structure that seals the flexible pipe from the end face. Figure 6 As shown, the deformable portion T11A of the flexible tube T1A connected to the pipe connector 1A is composed of a first peak and a second peak from the front end. Alternatively, the deformable portion T11A may be composed solely of the first peak from the front end. Furthermore, since the deformable portion T11A is formed at the front end of the flexible tube, it is easier to form the deformable portion compared to the pipe connector of the first embodiment. Additionally, the deformable portion T11A functions as an anti-detachment part and also contributes to sealing. The deformable portion T11A is in close contact with the end face of the connector body on the inlet side of the sealing member 5A, thereby ensuring a tight seal.

[0057] Sealing member 5A is, for example, made of rubber material with an L-shaped cross-section, forming the structure that retains the fire-resistant gasket 8b. NBR, etc., is used as the rubber material. Alternatively, a sealing gasket can be used as sealing member 5A to improve sealing performance. Furthermore, in... Figure 6 In this design, a leaf spring is used as the elastic component 4A.

[0058] In the pipe fitting 1A, the deformable part T11A is also secured between the pressing nut 3 and the constituent member (sealing member 5A) inside the fitting body, thereby preventing the flexible tube T1A from falling off. In addition, the pipe fitting 1A has a structure that seals at the end face, so the axial length of the fitting body 2A can be further shortened compared to the pipe fitting of the first embodiment.

[0059] The structure of the pipe fitting of the present invention can be any of the first and second embodiments described above, but from the viewpoint of reliable sealing, the first embodiment is preferred. Furthermore, in the first embodiment, surface pressure is generated by the contact between the peak of the flexible tube and the inner circumferential surface of the sealing body 51, ensuring sealing. Therefore, compression of the sealing member along the axis of the flexible tube is not necessary, and the elastic member can be omitted. On the other hand, from the viewpoint of processability of the deformable portion of the flexible tube and further miniaturization, the second embodiment is preferred. It should be noted that in the second embodiment, an elastic member is preferably provided to maintain sealing surface pressure.

[0060] The pipe fitting of the present invention is not limited to the embodiments described above. For example, the indicator 7 and the spacer 8a may be omitted. This allows for a further reduction in the number of components, in addition to reducing the number of retainers. Furthermore, the number of peaks constituting the deformable portion is not limited to two peaks; it may be one peak or more.

[0061] Next, the construction method of the present invention will be described.

[0062] The construction method of the present invention is a method of connecting a flexible pipe to the aforementioned pipe joint. This construction method includes at least the following: Figure 7 The six processes shown are (S1) to (S6). Specifically, they include: (S1) a first cutting process that cuts the flexible tube together with the outer coating resin; (S2) a peeling process that peels off the coating resin; (S3) a second cutting process that cuts off the exposed front end of the flexible tube; (S4) an insertion process that inserts a pressing nut into the processed flexible tube; (S5) a deformation process that forms a deformable part on the flexible tube; and (S6) an engagement process that inserts the pressing nut into the connector body and engages it.

[0063] Each of the above-mentioned steps S1 to S5 can be implemented through a manual construction process based on operator's manual operation or an automated construction process using an automatic construction machine. However, from the perspective of shortening construction time and suppressing deviations in construction quality caused by the operator, it is preferable to use an automatic construction machine for at least one of the above-mentioned steps S1 to S5. Hereinafter, the automatic construction machine will be described first.

[0064] Figure 8 The image shows a 3D view of an automated construction machine. (For example...) Figure 8 As shown, the automatic construction machine 9 includes an insertion port 91 for a flexible tube, an expandable and retractable chuck 92 arranged around the insertion port 91, a dust collection box 93, a magazine 94 for storing a pressing nut, and a cutting blade 95 for cutting the flexible tube. Additionally, although not shown in the figure, the automatic construction machine 9 includes a photographing mechanism capable of photographing the cut surface and the shape of the flexible tube, and a deformation mechanism for plastically deforming a predetermined peak of the flexible tube. Furthermore, for the automatic construction machine, it is preferable to implement leakage current countermeasures and countermeasures in case a finger is accidentally inserted into the insertion port 91 (such as an automatic stop function).

[0065] The dust collection box 93 stores the coating resin and the cut ends of the flexible tube produced in processes S1 to S3. It is preferable to install multiple dust collection boxes in the automatic construction machine 9 to form a structure that stores the coating resin and flexible tube separately. The cutting blade 95 is configured to move relative to the inserted flexible tube. For example, it can move axially and radially along the flexible tube, and move radially at a predetermined axial position in a manner close to the flexible tube, thereby cutting the flexible tube.

[0066] like Figure 8 As shown, when the flexible tube is inserted into the automatic construction machine 9 in the direction of the arrow, the diameter of the clamp 92 automatically expands or contracts in accordance with the diameter of the flexible tube. The diameter of the flexible tube is not particularly limited, for example, 10A to 25A. It should be noted that... Figure 8 In the automatic construction machine 9, it is configured as a single-port type with one insertion port 91, but it can also be configured as a multi-port type with multiple insertion ports (e.g., a 4-port type). In this case, it can also be configured such that the diameter of the clamp changes according to the corresponding insertion port when the insertion port is rotated.

[0067] The following description, with reference to the accompanying drawings, will explain each step of the automated construction process. It should be noted that the pipe fitting described above, based on the first embodiment, will be used as the pipe fitting.

[0068] (S1 process)

[0069] The S1 process involves cutting the flexible tube along with its outer resin coating. Figure 9In step S1 shown in (a), approximately two peaks are cut off from the front end of the flexible tube T1 inserted into the automatic construction machine using the cutting blade 95. It should be noted that the time required for step S1 based on the automatic construction machine is approximately 5 seconds.

[0070] (S2 process)

[0071] The S2 process is the process of peeling off the coated resin. Figure 9 In step S2 shown in (b), the coating resin is cut with the cutting blade 95, approximately 12 peaks above the cut surface from step S1. At this time, the radial movement of the cutting blade 95 is controlled in a manner that does not damage the inner flexible tube T1. It should be noted that the time required for step S2 based on the automatic application machine is approximately 5 seconds.

[0072] (S3 process)

[0073] The S3 process involves cutting the exposed flexible tube at the valley section. Figure 9 In step S3 shown in (c), approximately 6 to 7 peaks are cut from the cut surface in step S1 using the cutting blade 95. After cutting, it is preferable to photograph the cut surface produced in this step and confirm the cut surface through image judgment. Furthermore, it is preferable to record the confirmation result as tracking data. This allows for high-precision management of the cut surface of the flexible tube T1. It should be noted that the time required for step S3 based on the automatic construction machine is approximately 10 seconds.

[0074] (S4 process)

[0075] Step S4 involves inserting the press nut into the processed flexible tube. Figure 10 In step S4 shown in (a), a pressing nut 3 automatically supplied from the hopper is inserted into the flexible tube T1 after step S3. The pressing nut 3 is inserted to a position opposite to the front end of the flexible tube than the peak of plastic deformation in the subsequent step S5. After insertion, the lip gasket 8e of the pressing nut 3 is in close contact with the outer peripheral surface of the coated resin T2.

[0076] (S5 process)

[0077] Process S5 is a process of forming a deformable portion of a size on the outer periphery of the flexible tube, closer to the front end of the pressing nut, that will not detach from the pressing nut 3. Figure 10In step S5 shown in (b), the flexible tube T1 is deformed by a deformation mechanism installed on the automatic construction machine, such that the tops of the 4th and 5th peaks from the front end of the flexible tube T1 extend further outward than the tops of the other peaks. The periphery of the deformed portion T11 is located radially outward from the other peaks and is formed to be engaged with the pressing nut 3. This provides an anti-disengagement function. After deformation, it is preferable to photograph the shape of the flexible tube (including the deformed portion) and confirm the shape through image judgment. Furthermore, it is preferable to record the confirmation result as tracking data. It should be noted that the usage time of steps S4 and S5 based on the automatic construction machine is approximately 10 seconds. In addition, although not in Figure 10 As shown in the text, but Figure 6 In the second embodiment, a portion of the flexible tube is axially crushed by extending outward from the top of the first and second peaks (or only the first peak) from the front end, thereby forming a deformable portion.

[0078] (S6 process)

[0079] Step S6 involves inserting the compression nut, which is attached to the flexible tube, into and locking it into the connector body. This step is performed manually. Figure 11 As shown, when the pressing nut 3 and flexible tube T1 are inserted from one end of the connector body 2, a portion of the end 32 of the pressing nut 3 on the deep side of the connector body abuts against the base 61 of the retaining member 6, and the retaining member 6 is pressed into the deep side of the connector body. Thus, the protrusion 621 of the retaining member 6 disengages from the engaging groove 23 of the connector body 2. If the retaining member 6 is pressed further in, the expanded diameter state of the stop ring 8c is released, thereby reducing the diameter of the stop ring 8c and embedding it into the outer peripheral groove 31 of the pressing nut 3. Furthermore, the stop ring 8c spans the inner peripheral groove 22 and the outer peripheral groove 31, thereby engaging the connector body 2 with the pressing nut 3 (see reference). Figure 4 ).

[0080] After step S6, the connection status of the flexible tube can be verified. For example, ... Figure 12 As shown, by stretching the flexible tube connected to the pipe connector 1 straight in the direction of the arrow, it can be confirmed that the hook portion 72 of the indicator 7 has not fallen off and is in the normal position, thereby checking the connection status.

[0081] In the above Figure 9 and Figure 10 In steps S1 through S5, the use of automated construction machines is shown, but each step can also be performed manually. For example, in... Figure 13 The diagram shows the steps for each of the S1 to S3 processes.

[0082] In process S1, a stainless steel flexible tube cutter is used to cut the flexible tube along with the outer resin coating (see reference). Figure 13 (a)). In the S2 process, using a special tool for the coating resin, approximately 12 peaks of the coating resin are peeled off (see [reference]). Figure 13 (b)). In the S3 process, a flexible tube cutter is used to cut the exposed flexible tube at the valley with about 6 to 7 peaks remaining (see reference). Figure 13 (c) The time required for each of the S1 to S3 processes based on manual operation is approximately 40 seconds, 30 seconds, and 60 seconds, respectively. Furthermore, the S3 process requires more skill than the other processes, and manual operation sometimes results in deformations such as curling, defects, dents, flattening, and peaking on the cut flexible tube. Therefore, it is preferable to use an automated cutting machine for at least the S3 process to ensure consistent cutting quality.

[0083] It should be noted that although the illustrations are omitted, processes S4 and S5 can also be performed manually. Process S5 can be performed using a special fixture that plastically deforms the specified peak of the flexible tube.

[0084] Explanation of reference numerals in the attached figures:

[0085] 1. 1A... Pipe fitting (flexible pipe fitting);

[0086] 2. 2A... Connector body;

[0087] 21...inner hole;

[0088] 22...Inner circumferential groove;

[0089] 23... Slot;

[0090] 24...step section;

[0091] 25...external thread section;

[0092] 26... peripheral groove;

[0093] 3... Press the nut;

[0094] 31... peripheral groove;

[0095] 32...end;

[0096] 321...step section;

[0097] 33...end;

[0098] 4, 4A...elastic components;

[0099] 5, 5A... sealing components;

[0100] 51...Sealing body;

[0101] 52... Pressing component;

[0102] 6...retaining components;

[0103] 61...base;

[0104] 62...Cylindrical section;

[0105] 621...protrusion;

[0106] 7...Indicator;

[0107] 71... Annular part;

[0108] 72... Claw section;

[0109] 8a...spacer;

[0110] 8b... Refractory lining;

[0111] 8c...stop ring;

[0112] 8d...O-ring;

[0113] 8e...lip-shaped pad;

[0114] 8f...Select a translucent component;

[0115] 9...Automatic construction machine;

[0116] 91...Insert port;

[0117] 92...clamp;

[0118] 93...Dust collection box;

[0119] 94... silo;

[0120] 95...cutting edge;

[0121] T1, T1A... Flexible tubes;

[0122] T11, T11A...deformation parts;

[0123] T12...front end;

[0124] T2...coating resin.

Claims

1. A flexible pipe joint for connecting a corrugated flexible pipe having a plurality of peak portions and valley portions alternately arranged along an axial direction, characterized by, the flexible pipe having a deformation portion in which at least a part of an outer periphery is expanded more outwardly in a radial direction than the peak portions, the flexible pipe joint comprising: a pressing nut fitted to a position on an opposite side from a front end of the flexible pipe to the deformation portion; a joint body into which the front end of the flexible pipe is inserted together with an end portion of the pressing nut; a fitting mechanism that fits the pressing nut to the joint body; and a ring-shaped sealing member arranged in the joint body so as to be in close contact with the flexible pipe, the flexible pipe being connected by fitting of the pressing nut to the joint body, and in this connected state, the deformation portion of the flexible pipe is stopped at an end portion of the joint body on a deep side of the pressing nut, and the flexible pipe is prevented from coming off, the fitting mechanism being a mechanism having a stop ring, an inner peripheral groove formed on an inner surface of the joint body, a retaining member that retains the stop ring in a diameter-expanded state in the inner peripheral groove, and an outer peripheral groove formed on an outer surface of the pressing nut, the retaining member being pressed and the diameter-expanded state of the stop ring being released by fitting of the pressing nut inserted to the flexible pipe, and the stop ring being fitted straddling the outer peripheral groove and the inner peripheral groove.

2. The flexible pipe joint according to claim 1, characterized by, the retaining member having a hollow circular plate-shaped base portion pressed by the pressing nut, and a cylindrical portion extending in an axial direction from an outer periphery of the base portion, a plurality of projections being provided at a front end of the cylindrical portion and being divided in a circumferential direction and bent outwardly, the retaining member fitting the plurality of projections to a fitting groove formed at a position on an inlet side of the joint body to the inner peripheral groove in a state before the pressing nut is inserted, thereby retaining the stop ring in a diameter-expanded state.

3. A flexible pipe joint for connecting a corrugated flexible pipe having a plurality of peak portions and valley portions alternately arranged along an axial direction, characterized by, the flexible pipe having a deformation portion in which at least a part of an outer periphery is expanded more outwardly in a radial direction than the peak portions, the flexible pipe joint comprising: a pressing nut fitted to a position on an opposite side from a front end of the flexible pipe to the deformation portion; a joint body into which the front end of the flexible pipe is inserted together with an end portion of the pressing nut; a fitting mechanism that fits the pressing nut to the joint body; and a ring-shaped sealing member arranged in the joint body so as to be in close contact with the flexible pipe, the flexible pipe being connected by fitting of the pressing nut to the joint body, and in this connected state, the deformation portion of the flexible pipe is stopped at an end portion of the joint body on a deep side of the pressing nut, and the flexible pipe is prevented from coming off, an elastic member being arranged in the joint body between the sealing member and a stepped portion in which an inner diameter of the joint body is reduced in diameter, the elastic member being compressed in a state in which the flexible pipe is connected compared to a state before the pressing nut is inserted.

4. The flexible pipe joint according to claim 3, characterized by, the elastic member being a ring-shaped member. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4. The flexible pipe joint according to any one of claims 1, 2, and 3, characterized in that a hook portion is provided on an outer surface of the joint body, and in a state of connection with the flexible pipe, the hook portion is engaged with an end portion of the joint body on the inlet side of the press nut.

5. The flexible pipe joint according to any one of claims 1, 2, and 4, characterized in that the deformed portion is in a substantially disc shape in which a top of at least one of the peak portions expands outward in the radial direction.

6. A method of constructing a flexible pipe, which connects a corrugated flexible pipe in which a plurality of peak portions and valley portions are alternately arranged in the axial direction, and a flexible pipe joint, characterized in that the flexible pipe joint includes a press nut, a joint body into which a front end of the flexible pipe is inserted together with an end portion of the press nut, an engagement mechanism that engages the press nut with the joint body, and a ring-shaped sealing member that is arranged in the joint body and is in contact with the flexible pipe, the method of construction includes a first cutting step in which the flexible pipe is cut together with a covering resin on the outside, a peeling step in which the covering resin is peeled, a second cutting step in which a front end of the flexible pipe that is exposed is cut at the valley portion, a plug-in step in which the press nut is plugged into the flexible pipe, a deforming step in which a deformed portion in which at least a portion of the outer periphery expands more outward in the radial direction than the peak portion is formed at a position of the flexible pipe that is on a front end side relative to the plugged-in press nut, and an engagement step in which the press nut is engaged with the joint body together with the flexible pipe, the flexible pipe is connected by the engagement step, and in the connected state, the deformed portion of the flexible pipe is stopped at an end portion of the joint body on the deep side of the press nut, and the flexible pipe is prevented from coming off.

7. The method of constructing a flexible pipe according to claim 6, characterized in that at least any one of the first cutting step, the peeling step, the second cutting step, the plug-in step, and the deforming step is performed by an automatic construction machine.

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