CN111795245A

CN111795245A - Joint for flexible pipe

Info

Publication number: CN111795245A
Application number: CN201911111061.4A
Authority: CN
Inventors: 岩片真理夫; 宫崎贵幸
Original assignee: Koyo Sangyo Co Ltd
Current assignee: Koyo Sangyo Co Ltd
Priority date: 2019-04-08
Filing date: 2019-11-14
Publication date: 2020-10-20
Anticipated expiration: 2039-11-14
Also published as: JP7288661B2; CN111795245B; JP2020172947A

Abstract

The invention provides a joint (2) for a flexible pipe, which facilitates the insertion of a flexible pipe (1), wherein the joint (2) for the flexible pipe is provided with a joint body (10) and a sealing member (40). A joint body (10) is formed with a connection hole (12) into which a corrugated flexible pipe (1) is inserted. The sealing member (40) made of an elastic material is annularly arranged in the connection hole (12). A space between the outer peripheral surface of the flexible pipe (1) inserted into the connection hole (12) and the inner peripheral surface of the connection hole (12) is sealed by a sealing member (40). The sealing member (40) has a groove (43) on the outer peripheral portion on the back side in the insertion direction of the flexible pipe (1), and the groove (43) is used for forming a radial and axial gap between the sealing member (40) and the inner surface of the connection hole (12).

Description

Joint for flexible pipe

Technical Field

The present invention relates to a joint for a flexible pipe used for connecting corrugated flexible pipes.

Background

As a conventional joint for a flexible pipe, patent document 1 (japanese patent application laid-open No. 2000-186792) discloses a joint for a flexible pipe: the joint comprises a joint body and an annular sealing member made of an elastic material, wherein the joint body is internally provided with a connecting hole, and the sealing member is arranged in the connecting hole of the joint body. In the case of connecting a corrugated flexible pipe, the flexible pipe is inserted into a connection hole of a joint main body. At this time, a plurality of mountain portions at the distal end portion of the flexible tube enter the inner periphery of the seal member. The flexible pipe is inserted until the distal end of the flexible pipe abuts against the stop surface in the connecting hole, whereby the connection of the flexible pipe to the joint is completed. At this time, the space between the outer peripheral surface of the flexible pipe and the inner peripheral surface of the connection hole is sealed by the sealing member.

In the joint for a flexible pipe disclosed in patent document 1, when the flexible pipe is connected, a mountain portion of the flexible pipe entering the inner periphery of the seal member is pushed and deepened at the same time as the thick wall portion of the seal member is pressed. Accordingly, the wall thickness portion of the seal member is biased to the back side in the insertion direction, and the inner circumferential surface of the seal member on the back side bulges out.

Disclosure of Invention

A joint for a flexible pipe according to the present invention, which is made to solve the above-described problems, includes a joint body having a connection hole into which a corrugated flexible pipe is inserted, and an annular seal member made of an elastic material, and the seal member is disposed in the connection hole. The sealing member seals between the outer circumferential surface of the flexible pipe inserted into the connection hole and the inner circumferential surface of the connection hole. The sealing member has a first groove on an outer peripheral portion on a back side in an insertion direction of the flexible pipe, and the first groove is used for forming a radial and axial gap between the sealing member and an inner surface of the connection hole.

According to the above configuration, when the flexible tube enters the inner periphery of the seal member, the thick wall portion of the seal member that is to be pressed to the back side in the insertion direction escapes to the gap formed by the first groove at the outer peripheral portion of the seal member on the back side. This suppresses bulging of the inner peripheral surface of the seal member on the back side, and thus suppresses an increase in the insertion load of the flexible pipe, and facilitates insertion of the flexible pipe.

Preferably, the sealing member has a second groove for forming a radial gap between the sealing member and an inner peripheral surface of the connection hole, in an outer peripheral portion on a near side in an insertion direction of the flexible pipe.

According to the above configuration, when the flexible tube enters the inner periphery of the seal member, the near side of the seal member can be deflected in the radially outward direction by the gap formed by the second groove. This makes it possible to allow the thick wall portion of the seal member to escape even on the near side of the seal member, and thus the flexible pipe can be inserted more easily.

Preferably, a chamfered portion is formed at least at one of intersection portions between the inner peripheral surface and both end surfaces in the axial direction in the seal member.

With the above configuration, the amount of pressing of the seal member is reduced by the formation of the chamfered portion, and the bulging of the seal member is suppressed, so that the ease of insertion of the flexible tube can be improved. When the chamfered portion is disposed on the near side in the insertion direction of the flexible pipe, the chamfered portion constitutes a guide for inserting the flexible pipe into the inner periphery of the seal member, and therefore the flexible pipe can be smoothly inserted into the inner periphery of the seal member.

Preferably, the seal member is formed symmetrically with respect to a line that is orthogonal to an axis thereof and bisects the seal member into one end side and the other end side.

According to the above configuration, since the one end side and the other end side of the seal member are symmetrical, the seal member can be attached to the joint main body from either side. Thus, the assembling property of the joint for a flexible pipe can be improved without causing the installation of the sealing member in an incorrect direction.

In the seal member, the first recessed groove on the back side in the insertion direction is preferably formed deeper from the end surface on the back side in the insertion direction toward the opposite direction to the insertion direction than the chamfered portion on the back side as in the first recessed groove.

According to the above configuration, the first concave groove and the inner peripheral surface of the seal member have portions facing each other in the radial direction, and the effect of bending the seal member in the radial outward direction on the back side can be improved. That is, the effect of escaping the thick wall portion of the seal member can be improved, and the ease of insertion of the flexible tube can be improved.

According to the present invention, a joint for a flexible pipe into which a flexible pipe can be easily inserted can be provided.

Drawings

Fig. 1 is a sectional view of a joint for a flexible pipe according to a first embodiment of the present invention;

FIG. 2 is an enlarged sectional view of a key portion of the joint;

in fig. 3, (a) is an enlarged cross-sectional view of a seal member disposed in the joint, and (B) is an enlarged view of a round portion B of fig. 3 (a);

fig. 4 is an enlarged cross-sectional view showing a state after a flexible pipe is connected to the joint;

fig. 5 is a sectional view of a joint for a flexible pipe according to a second embodiment of the present invention;

fig. 6 is a sectional view of a joint for a flexible pipe according to a third embodiment of the present invention.

Description of the reference numerals

1: a flexible tube; 1 b: a bellows; 1 m: a mountain part; 2. 2A, 2B: a joint for a flexible pipe; 10. 10A, 10B: a connector body; 12: connecting holes; 14: an internal thread portion; 14 a: a snap ring groove; 15: a locking protrusion; 15 a: a clamping surface; 17: a sealing material accommodating part; 17 a: a small diameter part; 17 b: a large diameter portion; 17 c: a small diameter part; 17 d: a limiting surface; 17 e: an abutting surface; 17 f: a limiting surface; 18: a bellows housing portion; 18 a: a bellows support portion; 18 c: a stopping surface; 19: a step portion; 20. 20A: a nut (support member); 20B: a fixed cylinder (support member); 21: a large diameter portion; 22: a small diameter part; 22 a: an outer peripheral surface; 23: an external threaded portion; 23 a: a middle diameter part; 23 c: a snap ring groove; 24: an abutting surface; 25: a through hole; 25 b: a bellows support portion; 30. 30A: a clamping tool; 31: a base; 32: a locking piece; 33: a seat portion; 34: an outer peripheral plate portion; 35: a slit; 36: a relief hole; 40: a sealing member; 41: an end face; 42: an outer peripheral surface; 43: a groove (first groove); 43 a: an end peripheral surface; 43 b: an outer end face; 44: an end face; 45: a groove (second groove); 45 a: an end peripheral surface; 45 b: an outer end face; 46: an inner peripheral surface; 47. 48: chamfering the corner; l1: an axis; l2: a bisector; s: a space.

Detailed Description

[ first embodiment ]

A first embodiment of the present invention will be described below with reference to fig. 1 to 4. This embodiment is an embodiment in which the present invention is applied to a joint 2 for a flexible pipe, in which the joint 2 for a flexible pipe is used to connect a corrugated flexible pipe 1 for gas (hereinafter simply referred to as a flexible pipe) to a gas facility or the like.

The joint 2 shown in fig. 1 is referred to as a one-touch joint that can be connected by inserting the flexible pipe 1. This joint 2 mainly includes: a joint main body 10; a nut 20 (support member) attached to the joint body 10 and supporting the flexible pipe 1; an annular stopper 30 which is disposed in the joint body 10 and prevents the flexible pipe 1 from coming off the joint 2; and a seal member 40 for sealing between the inner peripheral surface of the joint body 10 and the outer peripheral surface of the flexible pipe 1.

The flexible pipe 1 is composed of a thin metallic corrugated pipe 1a and a resin coated pipe 1b that covers the outer periphery of the corrugated pipe 1 a. The corrugated tube 1a has mountain portions 1m and valley portions 1 v. The flexible pipe 1 is connected to the joint 2 in the following state: the coated pipe 1b is removed for several mountains at the front end of the corrugated pipe 1 a.

As shown in fig. 1 and 2, the nut 20 is formed in a tubular shape from a metal such as brass, and has a large diameter portion 21 on one end side (a right end side in fig. 1 and 2, and hereinafter, one end side and the other end side are respectively shown on the right end side and the left end side in fig. 1 to 4) and a small diameter portion 22 on the other end side, and has an external thread portion 23 having a smaller diameter than the large diameter portion 21 and a larger diameter than the small diameter portion 22 therebetween. The large-diameter portion 21 is formed in a circular shape in cross section in the present embodiment, but may be formed in a hexagonal shape in cross section. The tip of the nut 20 on the small diameter portion 22 side is a flat contact surface 24 against which the locking tool 30 can contact.

A through hole 25 for inserting the flexible tube 1 in the axial direction thereof is formed inside the nut 20. An annular recess 25a is formed in the inner peripheral surface of the through hole 25 on the one end side, and an annular T-shaped watertight seal 3 is attached to the annular recess 25 a.

A ventilation passage 26 penetrating in the radial direction is formed in the large diameter portion 21 of the nut 20, and the ventilation passage 26 is disposed on the back side of the annular recess 25 a. The vent path 26 is closed by the porous material 4. The porous material 4 allows gas to pass through and prevents liquid and solid from passing through.

The other end side of the through hole 25 is a bellows support portion 25 b. The bellows support portion 25b has an inner diameter equal to the outer diameter of the peak portion 1m of the bellows 1 a. The bellows support portion 25b supports the bellows 1a by bringing the ridge portion 1m of the bellows 1a inserted into the through hole 25 into contact with the inner peripheral surface thereof.

As shown in fig. 1, the joint body 10 is formed in a tubular shape from a metal such as brass, and is formed such that the outer diameter of one end side is larger than that of the other end side. A tapered male screw 11 is formed on the outer periphery of the other end portion of the small diameter of the joint body 10, and is attached to a gas appliance, another pipe, or the like. A tool engagement portion 11a for engaging a rotary fastening tool such as a wrench is formed on the outer peripheral surface of a portion adjacent to the tapered male screw 11 at the large-diameter end portion of the joint body 10. The tool hooking portion 11a has a hexagonal cross-sectional shape, but may have an octagonal cross-sectional shape or another shape.

A connection hole 12 to which the flexible tube 1 is connected is formed in one end side of the joint body 10, an air hole 13 having an inner diameter smaller than that of the connection hole 12 is formed in the other end side, and the air hole 13 is connected to the connection hole 12. As shown in fig. 1 and 2, the connection hole 12 is provided with, in order from the opening on the one end side toward the back side: a female screw portion 14, an engagement projection 15, a refractory expanding material accommodating recess 16, a sealing material accommodating portion 17, and a bellows accommodating portion 18. The flexible tube 1 is inserted into the connection hole 12 from the opening on one end side toward the back side.

The nut 20 is attached to the joint body 10 by screwing the male screw portion 23 of the nut 20 to the female screw portion 14 of the joint body 10. The threaded portion between the female screw portion 14 and the male screw portion 23 is sealed with an adhesive.

The locking protrusion 15 is formed to protrude radially inward from the inner circumferential surface of the connection hole 12. On the opening side of the coupling hole 12 of the locking projection 15, a flat locking surface 15a facing the abutment surface 24 of the nut 20 is formed.

As shown in fig. 1 and 2, in a state where the nut 20 is screwed to the joint body 10, as shown in fig. 2, a space S is formed, which is surrounded by the abutment surface 24 and the outer peripheral surface 22a of the small diameter portion 22 in the nut 20, and the female screw portion 14 and the locking surface 15a in the joint body 10.

The locking tool 30 is formed by pressing a metal thin plate material, and has an annular base 31 on the outer peripheral side and a plurality of locking pieces 32 on the inner peripheral side formed integrally with the base 31. The locking tool 30 is provided in the connection hole 12 with its axis directed in the same direction as the axis of the connection hole 12 of the joint main body 10.

The base 31 has a seat portion 33 at its inner peripheral portion and an outer peripheral plate portion 34 at its outer peripheral portion. The seat portion 33 has a flat surface, and the outer peripheral plate portion 34 is bent in the axial direction of the locking tool 30 on the outer peripheral side of the seat portion 33. In this embodiment, the outer peripheral plate portion 34 is bent toward the opening side of the connection hole 12 in a state where the stopper 30 is disposed in the connection hole 12.

The outer peripheral plate portion 34 has an inner diameter slightly larger than the outer diameter of the small diameter portion 22 of the nut 20. As shown in fig. 2, in the installation state of the locking tool 30, the outer peripheral plate portion 34 and a part of the seat portion 33 are accommodated in the space S. The stopper 30 in the state of being set in the connection hole 12 has axial and radial play in the connection hole 12.

The plurality of locking pieces 32 extend from the inner peripheral side of the seat 33, and are arranged along the circumferential direction of the seat 33 with narrow slits 35 therebetween. In the locking piece 32, in a state where the locking tool 30 is attached to the adapter 2 as shown in fig. 1, the locking piece 32 is inclined as follows: proceeding from the seat 33 inwards towards the joint 2, it develops in a radial and inward direction. The locking pieces 32 have the same shape, and the inclination angles of the locking pieces 32 are set to the same angle, but the shapes and inclination angles of the locking pieces 32 may be different.

The diameter of the inscribed circle of the tip of each of the plurality of locking pieces 32 is formed smaller than the outer diameter of the peak 1m of the corrugated tube 1 a. In the seat portion 33 of the base 31, a relief hole 36 is formed between the base ends of the adjacent locking pieces 32, and a plurality of the relief holes are arranged along the circumferential direction.

The refractory expansion O-ring 5 is attached to the refractory expansion material accommodating recess 16 adjacent to the rear side of the locking projection 15. The fireproof expansion O-ring 5 expands when the temperature is changed to a temperature at which the sealing member 40 disappears due to a fire or the like, and presses and contacts the outer peripheral surface of the corrugated tube 1a inserted into the connection hole 12 to seal the space between the outer peripheral surface of the corrugated tube 1a and the inner peripheral surface of the connection hole 12.

The sealing material accommodating portion 17 is adjacent to the back side of the refractory expansion material accommodating recess 16, and has a small-diameter hole portion 17a, a large-diameter hole portion 17b, and a small-diameter hole portion 17c formed in this order from the opening side of the coupling hole 12 toward the back side. The small-

diameter holes

17a and 17c have the same inner diameter. The step surface between the small-diameter hole portion 17a and the large-diameter hole portion 17b is a regulation surface 17d facing the back side, and the step surface between the large-diameter hole portion 17b and the small-diameter hole portion 17c is an abutment surface 17e facing the opening side. A regulating surface 17f facing the opening side is formed at the rear end edge of the small-diameter hole portion 17 c. The regulating surface 17d, the abutment surface 17e, and the regulating surface 17f are formed by planes orthogonal to the axis of the connection hole 12.

As shown in fig. 1 to 3(a), the sealing member 40 is formed in a ring shape from an elastic material such as rubber, and can elastically expand and reduce its diameter. The outer diameter of the seal member 40 is formed slightly larger than the inner diameter of the large-diameter hole 17b of the seal member housing 17. The inner diameter of the seal member 40 is formed smaller than the outer diameter of the peak portion 1m of the bellows 1a and larger than the outer diameter of the valley portion 1 v. The sealing member 40 is accommodated in the sealing member accommodating portion 17 in a non-pressed state with its axis L1 (fig. 3 a) aligned with the axis of the connection hole 12.

In the seal member 40 in the housed state, a groove 43 (first groove) is formed in an annular shape between an end surface 41 on the other end side in the axial direction (the back side in the insertion direction of the flexible pipe 1) and an outer peripheral surface 42. The recessed groove 43 has a rear end outer peripheral surface 43a and an outer end surface 43b, the end outer peripheral surface 43a extending parallel to the axis L1, and the outer end surface 43b being a plane orthogonal to the axis L1.

As shown in fig. 2, when the end surface 41 on the back side of the seal member 40 is brought into contact with the regulating surface 17f, the end outer peripheral surface 43a and the inner peripheral surface of the small-diameter hole portion 17c are opposed to each other with a gap in the radial direction, and the outer end surface 43b and the contact surface 17e are opposed to each other with a gap in the axial direction.

In the seal member 40 in the accommodated state, a groove 45 (second groove) is formed annularly between an end surface 44 on one end side in the axial direction (the near side in the insertion direction of the flexible pipe 1) and the outer peripheral surface 42. The groove 45 has an end outer peripheral surface 45a on the insertion direction front side and an outer end surface 45b, the end outer peripheral surface 45a extends parallel to the axis L1, and the outer end surface 45b is formed of a plane orthogonal to the axis L1.

As shown in fig. 2, when the end surface 41 on the far side is brought into contact with the regulating surface 17f, the outer peripheral surface 45a of the end portion on the near side in the insertion direction of the flexible tube 1 faces the inner peripheral surface of the small-diameter hole portion 17a with a gap in the radial direction, and the outer end surface 45b faces the regulating surface 17d with a gap in the axial direction. The sealing member 40 can move slightly in the axial direction thereof within the sealing material accommodating portion 17 of the attachment hole 12 within the following range: from the state where the end face 41 on the back side abuts against the regulating face 17f to the state where the end face 45b on the outer side of the recessed groove 45 abuts against the regulating face 17 d.

The seal member 40 has chamfered

portions

47 and 48 formed annularly at the intersection between the inner peripheral surface 46 and the axial end surfaces 41 and 44, respectively.

As shown in fig. 3(B), the axial length D1 of the back chamfered portion 47 from the back end surface 41 is smaller than the axial length D2 of the end outer peripheral surface 43a of the back groove 43. That is, the groove 43 is formed deeper than the chamfered portion 47 in the axial direction (the direction opposite to the insertion direction of the flexible pipe 1) from the end surface 41. This provides a portion where the end outer peripheral surface 43a and the inner peripheral surface 46 face each other in the radial direction.

As shown in fig. 3(a), the seal member 40 is formed symmetrically about a line L2, where the line L2 is orthogonal to the axis L1 of the seal member 40 and bisects the seal member 40 into one end side and the other end side.

As shown in fig. 1 and 2, the bellows housing portion 18 is adjacent to the seal member housing portion 17 via a stepped portion 19, and a bellows support portion 18a, a reduced diameter portion 18b, and a stop surface 18c are formed in this order from the opening side of the connection hole 12 toward the back side. The bellows support portion 18a has an inner diameter equal to the outer diameter of the peak portion 1m of the bellows 1 a. A stopper surface 18c is formed on the rear end edge of the reduced diameter portion 18b toward the opening side. When the tip of the bellows 1a abuts against the stop surface 18c, the bellows support portion 18a abuts against the inner peripheral surface of the ridge portion 1m of the bellows 1a to support the bellows 1 a.

Next, a case where the joint 2 is configured by the joint body 10, the nut 20, the locking tool 30, and the sealing member 40 having the above-described configuration will be described.

First, the seal member 40 is accommodated in the seal material accommodating portion 17 of the joint body 10 such that the end surface 41 thereof abuts against the restricting surface 17f, and the refractory expansion O-ring 5 is attached to the refractory expansion material accommodating recess 16.

Next, the locking tool 30 is fitted into the coupling hole 12 of the joint body 10, and the seat portion 33 of the locking tool 30 is disposed on the locking surface 15a of the locking projection 15. In this state, the nut 20 to which the T-shaped watertight sealing member 3 and the porous material 4 are attached is screwed into the joint body 10, and thus, the state shown in fig. 1 and 2 is obtained, the outer peripheral plate portion 34 of the locking tool 30 and a part of the seat portion 33 are accommodated in the space S, and the screw-threaded portion between the nut 20 and the joint body 10 is sealed with an adhesive. Thus constituting the joint 2. The retainer 30 is housed in the joint 2 with a radial and axial play, and the seat portion 33 is opposed to or abutted against the abutment surface 24 of the nut 20 and the locking surface 15a of the joint body 10.

In the case of configuring the joint 2, since the one end side and the other end side of the seal member 40 in the axial direction are symmetrical, the seal member 40 can be attached to the joint body 10 from either side. This prevents the sealing member 40 from being mounted in an incorrect orientation, thereby improving the ease of assembly of the joint 2.

Next, a process of connecting the flexible pipe 1 to the joint 2 will be described.

As shown in fig. 1, the flexible tube 1 is cut at the valley portion 1v of the corrugated tube 1a, the covered tube 1b having a few peaks at the tip is removed, and the flexible tube 1 in this state is inserted into the through hole 25 from the large-diameter portion 21 side of the nut 20. Then, the peak 1m at the tip of the bellows 1a abuts against the surface of the locking piece 32 of the locking tool 30, so that the locking tool 30 moves to the back side of the connection hole 12, and the seat 33 of the locking tool 30 abuts against the locking surface 15 a.

When the peak portion 1m abuts against the inclined locking piece 32, the outer peripheral plate portion 34 of the locking tool 30 and the outer peripheral surface 22a of the small diameter portion 22 of the nut 20 have a radial play therebetween, so that the axis of the locking tool 30 coincides with the axis of the bellows 1 a. This reduces the insertion load of the bellows 1a, and facilitates insertion of the flexible tube 1.

When the flexible tube 1 is further inserted, the locking piece 32 is pushed open by the elastic deformation of the ridge portion 1m of the corrugated tube 1a, and the ridge portion 1m of the corrugated tube 1a passes through the inner periphery of the locking piece 32.

When the flexible tube 1 is further inserted, the distal end portion of the bellows 1a is guided by the chamfered portion 48 of the seal member 40, and the inner periphery of the seal member 40 is expanded and enters the inner periphery. At this time, the bellows 1a presses the thick portion of the sealing member 40 on the front side in the insertion direction, and bends the sealing member 40 on the same side in the radially outward direction until the end outer peripheral surface 45a comes into contact with the inner peripheral surface of the small-diameter hole portion 17 a. This allows the pressed thick portion to escape at one end side (the side near the insertion direction) of the seal member 40.

As the bellows 1a is pushed inward, the thick portion of the seal member 40 is biased to the back side, but the thick portion of the seal member 40 can be released while the back side of the seal member 40 is deflected in the radially outward direction until the end outer peripheral surface 43a and the outer end surface 43b on the back side come into contact with the inner peripheral surface and the contact surface 17e of the small-diameter hole portion 17c, respectively. Also, the end surface 41 on the back side of the seal member 40 abuts against the bottom surface of the stepped portion 19 on the back side of the seal material housing portion 17, whereby the thick portion of the seal member 40 is released. Therefore, since the bulging of the inner peripheral surface 46 on the back side of the seal member 40 is suppressed, the increase in load for inserting the flexible tube 1 can be suppressed, and the flexible tube 1 can be easily inserted.

Further, the chamfered

portions

47 and 48 suppress the pressing and bulging of the seal member 40 in accordance with the amount of the wall thickness portion of the seal member 40 being shaved off. The chamfered portion 48 on the near side in the insertion direction of the flexible tube 1 serves as a guide when the corrugated tube 1a is inserted, and contributes to improvement of the ease of insertion of the flexible tube 1.

Further, as shown in fig. 3, in the seal member 40, the recessed

grooves

43 and 45 are formed deeper than the chamfered

portions

47 and 48 in the axial direction, and portions where the end outer

peripheral surfaces

43a and 45a face the inner peripheral surface 46 are provided, whereby the effect of flexure is improved. Therefore, the escaping effect of the thick wall portion of the seal member 40 is improved, and the ease of insertion of the flexible tube 1 is improved.

As shown in fig. 4, the flexible tube 1 is inserted until the tip of the bellows 1a abuts against the stop surface 18c of the bellows housing portion 18, whereby the connection of the flexible tube 1 to the joint 2 is completed. At this time, the sealing member 40 is pressed by the bellows 1a, and seals between the outer peripheral surface of the bellows 1a and the inner peripheral surface of the connection hole 12. Further, the T-shaped watertight seal 3 attached to the inner peripheral surface of the through hole 25 of the nut 20 is pressed against the outer peripheral surface of the covered pipe 1b to seal the space between the outer peripheral surface of the covered pipe 1b and the inner peripheral surface of the through hole 25.

Further, the stopper 30 prevents the flexible tube 1 from falling off by bringing the flexible tube 1 into a locked state or a lockable state by bringing the tip of the locking piece 32 into contact with or facing the inclined outer peripheral surface of the corrugated tube 1 a.

Further, the inner peripheral surface of the bellows support portion 18a of the joint body 10 and the inner peripheral surface of the bellows support portion 25b of the nut 20 abut against the ridge portion 1m of the bellows 1a, whereby the bellows 1a of the flexible pipe 1 is supported by the joint 2.

Next, a case where a force in the pull-out direction from the joint 2 acts on the flexible pipe 1 will be described.

When a force in the pull-out direction acts on the flexible tube 1, the stopper 30 that locks the outer peripheral surface of the corrugated tube 1a moves slightly, and the seat 33 abuts against the abutment surface 24 of the nut 20, thereby preventing the flexible tube 1 from being pulled out. At this time, since the outer end surface 45b of one end side (the side near the insertion direction of the flexible tube 1) of the seal member 40 faces the regulating surface 17d with an axial gap, the seal member can move in the pull-out direction while maintaining contact with the bellows 1a together with the movement of the flexible tube 1. This prevents friction between the outer peripheral surface of the bellows 1a and the inner peripheral surface 46 of the seal member 40, and therefore, does not impair sealability.

Next, another embodiment of the present invention will be described. In the following embodiments, only the configurations different from those of the above-described embodiments will be described, and the same reference numerals are given to the same components, and the description thereof will be omitted.

[ second embodiment ]

A second embodiment of the present invention will be described below with reference to fig. 5.

While the seal housing portion 17 has the small-diameter hole portion 17a, the large-diameter hole portion 17b, and the small-diameter hole portion 17c from the opening side of the coupling hole 12 toward the back side in the first embodiment, the seal housing portion 17 has only the small-diameter hole portion 17a and the large-diameter hole portion 17b in the present embodiment. Further, the bending direction of the outer peripheral plate portion 34 of the locking tool is made different.

In the stopper 30A, the outer peripheral plate portion 34 is bent in the opposite direction, i.e., in the same direction as the extending direction of the locking piece 32, toward the back side in the insertion direction of the flexible tube 1, unlike the outer peripheral plate portion 34 (fig. 1) of the stopper 30 of the first embodiment.

In the joint 2A for a flexible pipe according to this embodiment, the outer peripheral plate portion 34 of the stopper 30A is not bent toward the nut 20A, and therefore, unlike the first embodiment, it is not necessary to provide a small diameter portion having an outer diameter smaller than the inner diameter of the outer peripheral plate portion 34 at the tip end of the nut 20A. Therefore, the nut 20A has a large diameter portion 21 located on one end side and a male screw portion 23 located on the other end side and smaller than the large diameter portion 21, and the tip on the male screw portion 23 side is an abutment surface 24 against which the locking tool 30A can abut.

The locking tool 30A in the state of being set in the connection hole 12 has axial and radial play in the connection hole 12, and the tip of the outer peripheral plate portion 34 can abut against the locking surface 15a, and the seat portion 33 can abut against the abutment surface 24 of the nut 20A.

In the recessed groove 43 on the back side of the seal member 40 housed in the seal material housing portion 17, the end outer peripheral surface 43a faces the inner peripheral surface of the large diameter hole portion 17b with a gap in the radial direction, and the outer end surface 43b faces the regulating surface 17f with a gap in the axial direction. The gap formed by the groove 43 is formed larger than that of the first embodiment in both the radial direction and the axial direction. Therefore, the thick portion of the seal member 40 can be made to escape more.

In this embodiment, the structure of the joint 2 can be simplified to reduce the manufacturing cost, and the amount of leakage of the thick wall portion of the seal member 40 can be increased.

[ third embodiment ]

A third embodiment of the present invention will be described with reference to fig. 6.

In the first and second embodiments, the support members (

nuts

20 and 20A) are screwed to the joint

main bodies

10 and 10A, but in the present embodiment, a snap ring is used instead of the screw.

A fixed tube 20B is attached as a support member to a joint body 10B of a flexible pipe joint 2B shown in fig. 6. The inner peripheral surface of the connection hole 12 of the joint main body 10B is not formed with a female screw portion, but is formed with a snap ring groove 14a over the entire circumference at a portion slightly inward from the opening at one end side.

The fixed tube 20B is provided with an intermediate diameter portion 23a between the large diameter portion 21 on one end side and the small diameter portion 22 on the other end side, and the outer diameter of the intermediate diameter portion 23a is formed to be equal to or slightly smaller than the inner diameter of the opening side of the connection hole 12 of the joint main body 10B. The outer peripheral surface of the intermediate diameter portion 23a is not formed with a male screw portion, but is formed with a watertight O-ring groove 23b and a snap ring groove 23c in this order from one end side toward the other end side over the entire circumference. In a state where the fixed cylinder 20B is attached to the joint main body 10B, the

snap ring grooves

14a, 23c face each other.

A snap ring 6 is attached between the snap ring groove 23c of the fixed cylinder 20B and the snap ring groove 14a of the joint main body 10B, and the fixed cylinder 20B is prevented from moving in the axial direction. The stopper ring 6 is formed in a C-shape, is elastically formed so as to be capable of expanding and reducing in diameter, and is attached in a state of being reduced in diameter from the natural state.

The watertight O-ring 7 fitted to the watertight O-ring groove 23B is pressed by the inner peripheral surface of the opening-side end portion of the connection hole 12, and the space between the outer peripheral surface of the intermediate diameter portion 23a of the fixed cylinder 20B and the inner peripheral surface of the opening-side end portion of the connection hole 12 is watertight sealed.

Next, a case where the joint 2B is configured by the joint main body 10B and the fixed cylinder 20B configured as described above and the locking tool 30 will be described.

First, after the sealing member 40, the fire-resistant expansion O-ring 5, and the stopper 30 are housed in the joint body 10B, the watertight O-ring 7 is attached to the watertight O-ring groove 23B in the fixing tube 20B, and the fixing tube 20B is inserted into the opening of the connection hole 12 of the joint body 10B from the small diameter portion 22 in a state where the stopper ring 6 is press-fitted into the stopper ring groove 23c with the diameter reduced.

When the snap ring groove 23c of the fixed cylinder 20B and the snap ring groove 14a of the joint body 10B face each other, the snap ring 6 is slightly expanded in diameter and fitted into the snap ring groove 14a, and is positioned between the

snap ring grooves

14a, 23 c. Thereby, the fixed tube 20B is fixed to the joint body 10B so as to prevent the joint body 10B from moving in the axial direction. Further, the fixed tube 20B cannot be removed from the joint main body 10B. At this time, the watertight O-ring 7 is pressed by the inner peripheral surface of the opening-side end of the connection hole 12.

The present invention is not limited to the above-described embodiments, and can be modified as appropriate within a scope not departing from the gist thereof.

The shape of the groove and chamfered portion of the sealing member and the shape of the sealing material housing portion can be appropriately changed to adjust the insertion resistance when the flexible tube passes through the sealing member.

In the above embodiment, the groove and the chamfered portion are formed on both end sides in the axial direction of the seal member, but only the groove may be formed, only the groove may be formed on either side, or only the chamfered portion may be formed on either side.

The features of the first to third embodiments described above may be combined as appropriate with the structure of the joint main body, the support member, and the locking tool.

The present invention is also applicable to a joint for a corrugated pipe other than a corrugated pipe used for connecting a flexible pipe.

In the above embodiment, the joint main body and the support member (nut, fixing tube) are separate bodies, but may be integrated.

Industrial applicability

The present invention can be applied to a joint for a flexible pipe used for connecting corrugated flexible pipes.

Claims

1. A joint for a flexible pipe, comprising a joint body having a connection hole into which a corrugated flexible pipe is inserted, and an annular sealing member made of an elastic material, the sealing member being disposed in the connection hole, and a gap between an outer circumferential surface of the flexible pipe inserted into the connection hole and an inner circumferential surface of the connection hole being sealed by the sealing member,

the sealing member has a first groove on an outer peripheral portion on a back side in an insertion direction of the flexible pipe, and the first groove is used for forming a radial and axial gap between the sealing member and an inner surface of the connection hole.

2. The joint for flexible pipes according to claim 1,

the sealing member has a second groove on an outer peripheral portion of the flexible pipe on a near side in an insertion direction thereof, the second groove being configured to form a radial gap between the sealing member and an inner peripheral surface of the connection hole.

3. The joint for flexible pipes according to claim 1,

a chamfered portion is formed at least one of the intersections of the inner peripheral surface of the seal member and both end surfaces in the axial direction.

4. The joint for flexible pipes according to claim 2,

5. The joint for flexible pipes according to any one of claims 2 to 4,

the seal member is formed symmetrically with respect to a line that is orthogonal to an axis thereof and bisects the seal member into one end side and the other end side.

6. The joint for flexible pipes according to claim 3 or 4,

in the seal member, the first recessed groove on the back side in the insertion direction is formed deeper from the end surface on the back side in the insertion direction toward the opposite direction to the insertion direction than the chamfered portion on the back side as in the first recessed groove.

7. The joint for flexible pipes according to claim 5,