JP2014077494A - Pipe joint structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve airtightness between a pipe body and a nipple by securing an escape place for a pipe body material along with caulking deformation.SOLUTION: One of a nipple 2 and a sleeve 3 is subjected to caulking deformation toward a pipe body 1. Thus, there is no event that a material 1' for the pipe body 1, moving along with the caulking deformation, enters into a storage recessed part 4 provided in at least either a surface 2a of the nipple 2 opposed to the pipe body 1 or a surface 3a of the sleeve 3 opposed to the pipe body 1, and then the material 1' for the pipe body 1 is pushed out from between the nipple 2 and the sleeve 3 or is pressed and deformed toward the other.

Description

  The present invention relates to a pipe joint structure used for connecting a tubular body such as a deformable hose or tube formed of a soft material such as rubber or synthetic resin in close contact with a nipple disposed inside thereof. About.

Conventionally, as a pipe joint structure of this type, a metal outer tube having an outer diameter substantially equal to an inner diameter of a rubber hose fitted on the outer periphery of the rubber hose, and a metal inner tube inserted into the rubber hose with one end protruding outward from one end of the rubber hose. The part of the metal inner tube that has one end of the rubber hose and overlaps with the metal outer tube is enlarged by a caulking device in a right angle direction, and the rubber hose is attached between the enlarged portion and the metal outer tube. In some cases, a step portion having a small diameter is formed on one end side at the boundary between the enlarged portion of the tube and one end side, and the outer periphery of one end of the inner metal tube is threaded or a cap nut is continuously used as a connection portion. As a result, the rubber hose is compressed so that the inner diameter is enlarged, and a part of the rubber hose is preliminarily compressed on one end side, and this is supported by a step portion opposite to the direction of the internal pressure. The pressure resistance is improved (for example, refer to Patent Document 1).
In addition, an appropriate number of grooves are formed on the outer surface of the hose connection portion of the coupling body, and stepped portions having reduced outer diameters are provided at both ends of the connection portion, and the hose is provided outside the hose connection portion of the coupling body. Inserting and inserting a cannula having an inner diameter that matches the outer diameter of the hose on the outside of the connection part of the hose, the cannula is provided with a recess having a tightening ring at a position that matches the groove, In some cases, the cannula is tightened in the center direction from the outside, and both end portions of the cannula are wound in the center direction to form bent portions at the step portions at both end portions of the hose connection portion. As a result, the portion of the hose that is pressed from the outside by the fastening ring is indented into the groove of the coupling body (see, for example, Patent Document 2).

Japanese Utility Model Publication No. 55-015500 Japanese Utility Model Publication No. 50-015230

By the way, in such a conventional pipe joint structure, in order to ensure the airtightness between the two by pressing the hose against the inner metal pipe or the coupling body arranged inside thereof, a considerable amount of caulking ( Tightening amount) is required.
However, in the case of Patent Document 1, if the amount of expansion of the metal inner tube by the caulking device increases, the amount of compressive deformation of the rubber hose sandwiched between the metal outer tube and the corresponding amount increases accordingly. A large amount of the deformed rubber material flowed, and sometimes it protruded from the enlarged region of the metal inner tube and the adhesion region by the metal outer tube.
As a result, the protruding rubber material swells from the inner surface of the rubber hose, so the flow area of the fluid passing through the rubber hose decreases, causing pressure loss, and also swells from the outer surface of the rubber hose. There was a problem of getting worse.
Further, in the case of Patent Document 2, when the amount of tightening of the cannula increases, the amount of compressive deformation of the hose sandwiched between the coupling body also increases correspondingly. Since the escape area of the hose material that is compressed and deformed is limited to the groove and step that are recessed in the outer surface of the coupling body, all the pressure due to the hose material that has lost the escape area is I leaned towards the outside.
As a result, when the wall thickness of the coupling body is made relatively thin in order to ensure a large flow path diameter inside the coupling body, the coupling body is reduced in diameter by the pressure of the hose material that has lost its escape, and the coupling There is a problem in that the flow path area of the fluid passing through the inside of the main body is reduced, causing pressure loss.

  An object of the present invention is to cope with such a problem, and aims to improve the airtightness of the tube body and the nipple by ensuring the escape place of the tube material accompanying the caulking deformation. Is.

  In order to achieve such an object, the present invention provides a tubular body made of a deformable material, a nipple provided so as to be inserted along an inner surface of the tubular body, and the tubular body sandwiched outside the nipple. And the nipple or the sleeve is caulked and deformed toward the tube, and at least one of the surfaces of the nipple or the sleeve facing the tube, An accommodation recess is provided in which the material of the tubular body flowing along with the caulking deformation of the nipple or the sleeve enters.

According to the present invention having the above-described features, by either caulking deformation of either the nipple or the sleeve toward the tube, the material of the tube flowing along with the caulking deformation can be obtained from the surface facing the tube of the nipple. Or into the housing recess provided on at least one of the surfaces of the sleeve facing the tube, and the material of the tube protrudes from between the nipple and the sleeve or is deformed by being pressed toward the other of the nipple or the sleeve. There is nothing to do.
Therefore, it is possible to secure the escape place of the tube material accompanying the caulking deformation and improve the airtightness of the tube and the nipple.
As a result, even if the amount of caulking is increased, the compressed and deformed tubular material is not affected by the pipe material that is compressed and deformed and flows out of the area where the metal inner tube expands and the metal outer tube. It does not protrude from the caulking area of the body and does not bulge from the inner surface or the outer surface, so that it is possible to prevent pressure loss due to a decrease in fluid passing through the tubular body and to prevent deterioration of the appearance.
Furthermore, the thickness of the nipple corresponding to the coupling body is reduced compared to the conventional one in which the compression-deformed hose material loses its escape and all pressure is applied toward the outer surface of the coupling body. Even if it is made thin in order to ensure a large flow path diameter, the nipple is not reduced in diameter and pressure loss due to a decrease in fluid passing through the inside of the nipple can be prevented.

It is explanatory drawing which shows the pipe connection structure which concerns on embodiment of this invention, (a) is a longitudinal front view before crimping, (b) is a longitudinal front view after crimping. A modification is shown, (a) is a longitudinal front view before caulking, (b) is a longitudinal front view after caulking. A modification is shown, (a) is a longitudinal front view before caulking, (b) is a longitudinal front view after caulking. A modification is shown, (a) is a longitudinal front view before caulking, (b) is a longitudinal front view after caulking. A modification is shown, (a) is a longitudinal front view before caulking, (b) is a longitudinal front view after caulking. It is explanatory drawing which shows the pipe connection structure which concerns on the other Example of this invention, (a) is a partially notched front view before crimping, (b) is the partially notched front view after crimping. A modification is shown, (a) is a partially notched front view before caulking, (b) is a partially notched front view after caulking. A modification is shown, (a) is a partially notched front view before caulking, (b) is a partially notched front view after caulking. A modification is shown, (a) is a partially notched front view before caulking, (b) is a partially notched front view after caulking. A modification is shown, (a) is a partially notched front view before caulking, (b) is a partially notched front view after caulking.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
A pipe joint structure A according to an embodiment of the present invention is provided so as to be inserted along a pipe body 1 made of a deformable material 1 'and an inner surface 1a of the pipe body 1, as shown in FIGS. A nipple 2 to be provided and a sleeve 3 provided so as to cover the outer side of the nipple 2 with the tube body 1 interposed therebetween are provided as main components.
The nipple 2 or the sleeve 3 is integrally connected so as to sandwich the tube body 1 by being caulked and deformed toward the tube body 1.
More specifically, the nipple 2 is directed to the tubular body 1 and expanded in the radial direction thereof, or the sleeve 3 is directed to the tubular body 1 and deformed in the radial direction thereof to reduce the diameter between the nipple 2 and the sleeve 3. The tube body 1 is sandwiched and compressed and deformed, and the inner surface 1a and the outer surface 1b of the tube body 1 are brought into close contact with and integrated with the outer surface 2a of the nipple 2 and the inner surface 3a of the sleeve 3 facing each other.

The tubular body 1 is, for example, a flexible hose or tube formed of a deformable soft material such as a soft synthetic resin or rubber, and preferably has a smooth inner surface 1a and outer surface 1b.
As a specific example of the tubular body 1, as shown in FIGS. 1 (a), (b) to 10 (a), (b), between the inner layer 1c and the outer layer 1d formed into a cylindrical shape with a transparent or opaque material. In addition, it is preferable to use a material excellent in shape retention and pressure resistance, such as a laminate in which a plurality or a single reinforcing wire 1e is embedded.
Although not shown in the drawings as other examples, an adhesive layer is provided between the inner layer 1c, the outer layer 1d, and the reinforcing wire 1e, or a material that matches the fluid or gas passing through the inside of the tubular body 1 inside the inner layer 1c as necessary. An outermost layer made of a protective material is provided on the outer side of the outer layer 1d, and a reinforcing wire material such as a synthetic resin or metal cross-sectional rectangle and a reinforcing wire material such as a circular cross-section are spiraled as an intermediate layer For example, braided reinforcing wire such as glass fiber or flame retardant fiber, or embedded reinforcing wire made of metal or hard synthetic resin spirally, or soft synthetic resin with single layer structure It is also possible to use a tube-making body.

The nipple 2 is formed in a substantially cylindrical shape having an outer diameter substantially the same as the inner diameter of the tube body 1 so as to be inserted and faced along the inner surface 1a of the connection end portion in the tube body 1.
The sleeve 3 is formed in a substantially cylindrical shape having an inner diameter larger than the outer diameter of the tube body 1 so that the sleeve 3 can move along the outer surface 1b of the connection end portion of the tube body 1 and face the sleeve 3.
Either the nipple 2 or the sleeve 3 is compressed and deformed by pressing in the radial direction by a caulking machine (not shown), but is not restored and deformed by the repulsive force from the tube body 1, for example, deformable plastic such as aluminum Made of material.
The other of the nipple 2 or the sleeve 3 is made of a non-deformable rigid material such as a metal such as brass.

As specific examples of the nipple 2 and the sleeve 3, in the example shown in FIGS. 1A, 1B, 5A, and 5B, the nipple 2 is formed of a plastic material, and the tube body 1 is formed by a caulking machine. The sleeve 3 is formed of a rigid material.
Further, in the example shown in FIGS. 6A, 6B to 10A, 10B, the nipple 2 is formed of a rigid material, the sleeve 3 is formed of a plastic material, and the tubular body 1 is formed by a caulking machine. It is configured so that it can be deformed to reduce the diameter.

In the nipple 2 or the sleeve 3, at least one of the surfaces 2 a and 3 a facing the tube body 1 is accommodated with the material 1 ′ of the tube body 1 flowing along with the caulking deformation of the nipple 2 or the sleeve 3. A recess 4 is provided.
That is, either the outer surface 2a facing the inner surface 1a of the tubular body 1 in the nipple 2 or the inner surface 3a facing the outer surface 1b of the tubular body 1 in the sleeve 3, or the outer surface 2a and the inner surface 3a. Both are provided with receiving recesses 4 through which the material 1 ′ of the tube 1 can flow.

As a specific example of the housing recess 4, in the example shown in FIGS. 1A and 1B and FIGS. 3A and 5B to FIGS. 5A and 5B, an annular groove is formed on the inner surface 3 a of the sleeve 3. In the example shown in FIGS. 2 (a) and 2 (b), an annular groove 4 b is recessed in the outer surface 2 a of the nipple 2.
In the example shown in FIGS. 6A, 6B to 8A, 8B, the annular grooves 4d and 4e are formed in the outer surface 2a of the nipple 2 so as to be formed as shown in FIGS. In the example shown in FIGS. 10A and 10B, annular grooves 4f and 4g are formed in the inner surface 3a of the sleeve 3.

According to such a pipe joint structure A according to the embodiment of the present invention, the pipe body 1 is interposed between the nipple 2 and the sleeve 3 by caulking and deforming either the nipple 2 or the sleeve 3 toward the pipe body 1. Is compressed and deformed in the radial direction, and the material 1 'of the tube body 1 flows in accordance with the compression deformation. The material 1 ′ of the flowed tube 1 is applied to at least one of the (outer) surface 2 a facing the tube 1 of the nipple 2 or the (inner) surface 3 a facing the tube 1 of the sleeve 3. It enters into the provided accommodation recess 4. Therefore, the flow pressure of the material 1 ′ of the tube body 1 is reduced, and the material 1 ′ of the tube body 1 protrudes from between the nipple 2 and the sleeve 3 or is pressed toward the other of the nipple 2 or the sleeve 3 to be deformed. There is nothing to do.
Therefore, it is possible to secure the escape place of the material 1 ′ of the tube body 1 due to the caulking deformation and improve the airtightness of the tube body 1 and the nipple 2.
As a result, the compressed and deformed rubber material flows and protrudes from the constricted region of the enlarged portion of the metal inner tube and the metal outer tube. Even if the caulking amount is increased, the compressed and deformed tube body The material 1 ′ does not protrude from the crimped region of the tube body 1 and bulge out from the inner surface 1 a or the outer surface 1 b, so that pressure loss due to a decrease in fluid passing through the tube body 1 can be prevented and deterioration in appearance can also be prevented.
Furthermore, the thickness of the nipple 2 corresponding to the coupling body is larger than that of the above-mentioned Patent Document 2 in which the compression-deformed hose material loses the escape and all the pressure is applied toward the outer surface of the coupling body. Even if it is made thin in order to ensure a large flow path diameter, the nipple 2 is not deformed and pressure loss due to a decrease in fluid passing through the nipple 2 can be prevented.
Next, each embodiment of the present invention will be described with reference to the drawings.

In the first embodiment, as shown in FIGS. 1A, 1B and 5A, 5B, a deformable connecting portion 2b of the nipple 2 is inserted into the connecting end portion of the tube body 1. Then, the sleeve 3 that cannot be deformed is placed on the connecting end of the tube 1, and then the connecting portion 2 b of the deformable nipple 2 inserted into the tube 1 is expanded toward the tube 1 by the operation of the caulking machine. It is the one that has been crimped by diameter deformation.
The connection portion 2b of the nipple 2 is a portion including most of the axial direction excluding the base end portion 2c opposite to the tip end side of the nipple 2, and is in a cylindrical shape having a smaller diameter and thinner than the base end portion 2c. Is formed. Only the small diameter connecting portion 2b of the nipple 2 is inserted into the connecting end portion of the tube 1, and the caulking machine is used to expand and deform the connecting portion 2b so that the inner diameter of the connecting portion 2b is substantially the same as the inner diameter of the base end portion 2c. The inner surface of the connecting portion 2b whose diameter has been deformed is made to be substantially flush with the inner surface 1a of the tubular body 1 excluding the connecting end portion.
Further, in the first embodiment, a flange 5a is formed as a joint portion 5 at the base end of the nipple 2, and other pipes (not shown) or other devices are connected via connecting members (not shown) such as bolts and nuts. (Not shown) or the like.
In the case of the illustrated example, the flange 5a serving as the joint portion 5 is integrally formed at the base end of the nipple 2, but the flange 5a is formed separately from the nipple 2 and is detachably attached to the nipple 2. It is also possible.

More specifically, in the example shown in FIGS. 1A and 1B, a plurality of (two) annular concave grooves 4a are recessed at predetermined intervals in the axial direction on the inner surface 3a of the sleeve 3 as the accommodating concave parts 4, respectively. Has been established.
The caulking amount of the connecting portion 2b of the nipple 2 by the caulking machine is set so that the material 1 'of the tube body 1 that has flowed as the nipple 2 expands and enters the entire annular groove 4a without any gap. ing.
The shape of the annular groove 4a is formed in a rectangular cross section.
Although not shown as another example, the shape of the annular groove 4a can be changed to other shapes such as a semicircular cross section and a semielliptical cross section.
Further, in the example shown in FIGS. 1A and 1B, when the diameter of the connecting portion 2b of the nipple 2 is enlarged and deformed by a caulking machine, the distal end edge 2d of the nipple 2 is radially aligned with the distal end edge 3b of the sleeve 3. It is set so that it may be lined up on substantially the same plane.
Furthermore, other modified examples are shown in FIGS. 2 (a), 2 (b) to 5 (a), (b).

In the example shown in FIGS. 2 (a) and 2 (b), an annular groove 4 b is provided as an accommodation recess 4 on the outer surface 2 a of the nipple 2.
In the case of the illustrated example, a plurality of sets of annular grooves 4b on the outer surface 2a of the nipple 2 and annular protrusions 2e that bite into the inner surface 1a of the tube body 1 are alternately arranged in the axial direction of the nipple 2 in succession. It is formed to become.
The caulking amount of the connecting portion 2b of the nipple 2 by the caulking machine is set so that the material 1 ′ of the tube body 1 that has flowed as the nipple 2 expands and enters each annular groove 4b without any gap. .
Although not shown in the drawings as other examples, the annular protrusion 2e is formed in a cross-sectional mountain shape by an inclined surface opposite to the tapered inclined surface, or the annular protrusion 2e and the annular groove 4b are rectangular in cross section or cross section. It is also possible to form them alternately in other shapes such as a semicircle or a semi-elliptical section.
Further, in the example shown in FIGS. 2 (a) and 2 (b), an annular groove 4a is formed in the inner surface 3a of the sleeve 3 as the accommodating recess 4 as in the example shown in FIGS. 1 (a) and 1 (b). In addition to this, an annular groove 4b is recessed.
Further, although not shown as another example, it is possible to provide only the annular groove 4b without providing the annular groove 4a.

In the example shown in FIGS. 3A and 3B, a tapered annular groove 4 c that gradually expands toward the end edge of the sleeve 3 as an accommodating recess 4 at the axial end on the inner surface 3 a of the sleeve 3. Is recessed.
In the case of the illustrated example, a tapered annular concave groove 4 c is arranged on the distal end side of the inner surface 3 a of the sleeve 3 so as to expand toward the distal end edge 3 b of the sleeve 3.
The caulking amount of the connecting portion 2b of the nipple 2 by the caulking machine is such that the material 1 'of the tube 1 that has flowed as the nipple 2 expands and enters the tapered annular groove 4c without gaps, and the tube 1 The outer surface 1b is set so as to partially bulge and deform along the tapered annular groove 4c.
Further, although not shown as another example, instead of the tapered annular groove 4c as the accommodation recess 4, the base end side of the inner surface 3a of the sleeve 3 is directed toward the base end edge opposite to the front end edge 3b of the sleeve 3. It is also possible to dispose a tapered annular groove 4c that expands, or a pair of tapered annular grooves 4c that expand toward the distal end edge 3b and the proximal end edge of the sleeve 3. .
Further, in the example shown in FIGS. 3 (a) and 3 (b), as in the example shown in FIGS. 1 (a) and 1 (b), an annular groove 4a is provided in the inner surface 3a of the sleeve 3 as the accommodating recess 4. In addition, a tapered annular groove 4c is provided.
Although not shown as another example, the annular recess 4b is recessed on the outer surface 2a of the nipple 2 as shown in FIGS. 2 (a) and 2 (b), instead of the annular recess 4a. In addition to this, it is also possible to provide a tapered annular groove 4c or to provide only a tapered annular groove 4c without providing the annular groove 4a or the annular groove 4b. is there.

In the example shown in FIGS. 4A and 4B, the tip edge 3b of the sleeve 3 projects beyond the tip edge 2d of the nipple 2 when the diameter of the connecting portion 2b of the nipple 2 is increased by the caulking machine. Is set to
It is preferable that an annular protrusion 3c protruding from the other inner surface 3a is formed at the tip of the inner surface 3a of the sleeve 3.
The caulking amount of the connecting portion 2b of the nipple 2 by the caulking machine is such that the material 1 ′ of the tube body 1 that has flowed along with the diameter expansion deformation of the nipple 2 enters without any gap along the tip edge 2d of the nipple 2, The inner surface of the distal end edge 2d of the connection portion 2b whose diameter has been deformed and the inner surface 1a excluding the connection end portion in the tubular body 1 are set so as to be flush with each other.
Thereby, the fluid passing through the inside of the tube body 1 can pass smoothly without resistance.
Further, in the example shown in FIGS. 4 (a) and 4 (b), as in the example shown in FIGS. 1 (a) and 1 (b), an annular groove 4a is provided in the inner surface 3a of the sleeve 3 as the accommodating recess 4. doing.
Although not shown as another example, the annular recess 4b is recessed on the outer surface 2a of the nipple 2 as shown in FIGS. 2 (a) and 2 (b), instead of the annular recess 4a. It is also possible to set up.

In the example shown in FIGS. 5 (a) and 5 (b), the nipple 2 is deformed over the outer surface 2a of the nipple 2 and the inner surface 3a of the sleeve 3 as the connecting portion 2b of the nipple 2 is expanded by the caulking machine. The outer surface 2a and a locking means that engages with the outer surface 2a so as not to move in the axial direction are formed.
In the case of the illustrated example, the base end portion 3d of the sleeve 3 protrudes and contacts the outer surface 2a of the nipple 2, and a concave portion 3e is formed in the sleeve 3 as the locking means on the contact surface. In the outer surface 2a of the portion 2b, a convex portion 2f that engages with the concave portion 3e is formed as the locking means.
Accordingly, the nipple 2 is positioned in the axial direction with respect to the sleeve 3 by the concave portion 3e and the convex portion 2f serving as the locking means at the same time as the diameter expansion deformation of the connecting portion 2b of the nipple 2 by the caulking machine, and the quality due to the positional deviation. Decline can be prevented.
Further, in the example shown in FIGS. 5A and 5B, the annular recess 4a is provided in the inner surface 3a of the sleeve 3 as the accommodating recess 4 as in the example shown in FIGS. doing.
Although not shown as another example, the annular recess 4b is recessed on the outer surface 2a of the nipple 2 as shown in FIGS. 2 (a) and 2 (b), instead of the annular recess 4a. It is also possible to set up.

According to the pipe joint structure A according to the first embodiment of the present invention, the diameter of the nipple 2 is expanded toward the pipe body 1, and the pipe body 1 is formed on the inner surface 3 a facing the pipe body 1 in the sleeve 3 or on the nipple 2. An accommodation recess 4 (annular recesses 4a, 4b, 4c) is disposed on at least one of the outer surfaces 2a facing each other.
Therefore, the material 1 ′ of the tube body 1 that has flowed along with the diameter expansion of the nipple 2 can be accommodated in the accommodation recess 4 (annular grooves 4 a, 4 b, 4 c).
As a result, the flow pressure of the material 1 ′ of the tube body 1 decreases, and the material 1 ′ of the tube body 1 protrudes from the crimped region of the tube body 1 formed between the nipple 2 and the sleeve 3, and the inner surface 1 a and the outer surface. There is an advantage that it is possible to surely prevent the bulge from coming out.

In the second embodiment, as shown in FIGS. 6A, 6B, 10A, and 10B, the non-deformable connecting portion 2b of the nipple 2 is inserted into the connecting end portion of the tube body 1. FIG. 1 shows a configuration in which a deformable sleeve 3 is covered with a deformable sleeve 3 on the connecting end portion of the tube body 1 and then the deformable sleeve 3 is reduced in diameter toward the tube body 1 by an operation of a caulking machine. Unlike the first embodiment shown in FIG. 5, the other configuration is the same as that of the first embodiment.
The sleeve 3 is a caulking pipe formed in a thin cylindrical shape, and the sleeve 3 is deformed by a caulking machine so that the entire diameter of the sleeve 3 is smaller than the outer diameter of the tube 1. The sleeve 3 is also deformed at both ends in the axial direction to form bent portions 3f.
Further, in the second embodiment, a screw portion 5b as a joint portion 5 and a tool engaging portion 5c to be engaged with a tool such as a spanner or a wrench are formed at the base end of the nipple 2, and the screw portion 5b is connected to another pipe line ( It is connected by screwing to other devices (not shown) or the like.
In the case of the illustrated example, the screw portion 5b and the tool engaging portion 5c that form the joint portion 5 are integrally formed at the base end of the nipple 2, but the screw portion 5b and the tool engaging portion 5c are connected to the nipple 2. It can also be formed separately and detachably attached to the nipple 2.

In the example shown in FIGS. 6 (a) (b) to 10 (a) (b), an annular sealing material 6 is provided between the sleeve 3 and the tube 1, and an annular sealing material is provided on the outer surface 2a of the nipple 2. A groove 2g for sealing into which the inner surface 1a of the tubular body 1 pressed by the annular sealing material 6 enters is provided at a position opposite to the radial direction 6 and the other outer surface 2a of the nipple 2 or the sleeve 3 is provided. An accommodation recess 4 is disposed on at least one of the inner surfaces 3a of the inner surface 3a at a position that does not overlap with the annular sealing material 6 in the radial direction.
In the case of the illustrated example, a plurality (two) of O-rings having a circular cross section are arranged at predetermined intervals as the annular sealing material 6 between the outer surface 1b of the tube body 1 and the inner surface 3a of the sleeve 3. On the inner surface 3 a of the sleeve 3, an annular recess 3 g for positioning that engages with the annular seal material 6 is formed.
Although not shown in the drawings as another example, an annular sealing material 6 is not interposed between the sleeve 3 and the tube body 1 and the inner surface 3a of the sleeve 3 is formed smoothly without forming the annular recess 3g. The housing recess 4 is not disposed at a position that does not overlap with the sealing material 6 in the radial direction, but the capacity of the sealing groove 2g that is recessed at a position facing the annular sealing material 6 in the radial direction is increased, and is accommodated. It is also possible to function as the recess 4.

More specifically, in the example shown in FIGS. 6 (a) and 6 (b), a plurality (three) of annular recesses 4d as receiving recesses 4 are formed on the outer surface 2a of the nipple 2 with the seal recesses 2g interposed therebetween. It is recessed at predetermined intervals in the axial direction.
The amount of caulking of the sleeve 3 by the caulking machine is such that the material 1 ′ of the tube body 1 that has flowed as the sleeve 3 is reduced in diameter enters the annular grooves 4 d and the entire sealing groove 2 g without gaps. Is set.
The shapes of the annular concave groove 4d and the sealing concave groove 2g are formed in a rectangular cross section.
Although not shown as other examples, the shapes of the annular groove 4d and the sealing groove 2g can be changed to other shapes such as a semicircular cross section and a semielliptical cross section.
Furthermore, other modified examples are shown in FIGS. 7A and 7B to FIGS. 10A and 10B.

In the example shown in FIGS. 7 (a) and 7 (b), an annular groove 4e and a sealing groove 2g are recessed in the outer surface 2a of the nipple 2 so as to be continuous in the axial direction.
In the case of the illustrated example, a plurality of sets of annular grooves 4e and sealing grooves 2g, and annular protrusions 2e that bite into the inner surface 1a of the tube body 1 are alternately arranged in the axial direction of the nipple 2 respectively, It is formed to become.
The amount of caulking of the sleeve 3 by the caulking machine is such that the material 1 ′ of the tube body 1 that has flowed as the sleeve 3 is reduced in diameter enters each annular groove 4 e and the entire sealing groove 2 g without gaps. Is set.
Although not shown as another example, the annular groove 4e and the sealing groove 2g can be formed in a cross-sectional mountain shape by an inclined surface opposite to the tapered inclined surface.

In the example shown in FIGS. 8A and 8B, the annular recess 3g for positioning the annular sealing material 6 formed on the inner surface 3a of the sleeve 3 when the diameter of the sleeve 3 is reduced by the caulking machine. The outer surface 3h of the sleeve 3 is set so as to be flattened.
Further, in the example shown in FIGS. 8 (a) and 8 (b), as in the example shown in FIGS. 6 (a) and 6 (b), the annular concave groove 4d that becomes the housing concave portion 4 and the seal are formed on the outer surface 2a of the nipple 2. The concave grooves 2g are recessed at predetermined intervals in the axial direction.
Although not shown as other examples, as in the example shown in FIGS. 7 (a) and 7 (b), an annular groove 4e and a sealing groove 2g serving as a housing recess 4 are formed on the outer surface 2a of the nipple 2, respectively. It is also possible to provide a recess so as to be continuous in the axial direction.

In the example shown in FIGS. 9A and 9B, when the diameter of the sleeve 3 is reduced by the caulking machine, an annular groove 4f is formed in the inner surface 3a of the sleeve 3 as an accommodation recess 4. It is set.
In the case of the illustrated example, an annular groove 4f serving as the housing recess 4 and an annular recess 3g for positioning the annular sealing material 6 are respectively provided in the axial direction at predetermined intervals.
The amount of caulking of the sleeve 3 by the caulking machine is such that the material 1 ′ of the tube body 1 that has flowed as the sleeve 3 is reduced in diameter enters each annular concave groove 4 f and the entire sealing concave groove 2 g without gaps. Is set.
Further, although not shown as another example, the annular concave groove 4f and the sealing concave groove 2g serving as the accommodating concave portion 4 can be recessed so as to continuously form a cross-sectional waveform in the axial direction.

In the example shown in FIGS. 10 (a) and 10 (b), an annular groove 4g that expands toward the edge of the sleeve 3 is provided as an accommodation recess 4 at the axial end on the inner surface 3a of the sleeve 3. Yes.
In the case of the illustrated example, an annular groove 4g is arranged on the distal end side of the inner surface 3a of the sleeve 3 so as to expand toward the distal end edge 3b of the sleeve 3.
The amount of caulking of the sleeve 3 by the caulking machine is such that the material 1 'of the tube 1 that has flowed as the sleeve 3 is reduced in diameter enters the annular groove 4g without any gap, and the outer surface 1b of the tube 1 is an annular groove. It is set to bulge and deform partially along 4g.
Although not shown as another example, the housing recess 4 is expanded instead of the annular groove 4g toward the proximal end of the sleeve 3 on the proximal end of the inner surface 3a toward the proximal end opposite to the distal edge 3b of the sleeve 3. It is also possible to arrange the annular concave grooves 4g, or to arrange a pair of annular concave grooves 4g that expand toward the distal end edge 3b and the proximal end edge of the sleeve 3, respectively.
Further, in the example shown in FIGS. 10 (a) and 10 (b), as in the example shown in FIGS. 6 (a) and 6 (b), the annular recessed groove 4d and the sealing groove 4 are formed on the outer surface 2a of the nipple 2 as in the example shown in FIGS. A concave groove 2g is provided, and in addition to this, an annular concave groove 4g is provided.
Although not shown as another example, the annular recess 4f is recessed on the inner surface 3a of the sleeve 3 as shown in FIGS. 9A and 9B instead of the annular recess 4d as the housing recess 4. In addition to this, it is also possible to provide the annular groove 4g, or provide only the annular groove 4g without providing the annular groove 4d or the annular groove 4f.

According to such a pipe joint structure A according to the second embodiment of the present invention, the sleeve 3 is reduced in diameter toward the pipe body 1, and the outer surface 2 a facing the pipe body 1 in the nipple 2 or the pipe body in the sleeve 3. An accommodation recess 4 (annular recesses 4d, 4e, 4f, 4g) is disposed on at least one of the inner surfaces 3a facing 1.
Therefore, the material 1 ′ of the tube body 1 that has flowed as the sleeve 3 is reduced in diameter can be accommodated in the accommodation recess 4 (annular recesses 4 d, 4 e, 4 f, 4 g).
As a result, the flow pressure of the material 1 ′ of the tube body 1 decreases, and the material 1 ′ of the tube body 1 protrudes from the crimped region of the tube body 1 formed between the nipple 2 and the sleeve 3, and the inner surface 1 a and the outer surface. There is an advantage that it is possible to surely prevent the bulge from coming out.

In particular, as in the example shown in FIGS. 6A, 6B, 10A, and 10B, an annular sealing material 6 is provided between the sleeve 3 and the tube 1 so that the nipple 2 or the sleeve 3 When the housing recess 4 (annular grooves 4d, 4e, 4f, 4g) is arranged at a position that does not overlap the annular seal member 6 in the radial direction on at least one of the surfaces 2a, 3a facing the tube 1 This eliminates the need to form an annular groove (not shown) in order to partially embed an annular sealing material (not shown) such as an O-ring in the outer surface 2a of the nipple 2.
Therefore, the nipple 2 can be made thin.
As a result, there is an advantage that a large area of the fluid passing through the inside of the nipple 2 can be secured, and pressure loss due to a decrease in the fluid passing through the nipple 2 can be prevented.

In addition, the annular sealing material 6 provided between the sleeve 3 and the tubular body 1 described in the example shown in FIGS. 6A, 6B to 10A, 10B in the above-described second embodiment, An annular recess 3g provided in the sleeve 3 for positioning the annular sealing material 6 may be employed in the example shown in FIGS. 1 (a), (b) to 5 (a), (b) of the first embodiment.
Further, in the first embodiment described above, the case where the flange 5a is formed as the joint portion 5 at the base end of the nipple 2 is shown, but the present invention is not limited to this, and instead of the flange 5a, as in the above-described second embodiment. The threaded portion 5b and the tool engaging portion 5c may be formed on the top.
Moreover, in Example 2, although the case where the screw part 5b and the tool engaging part 5c were formed as the joint part 5 in the base end of the nipple 2 was shown, it is not limited to this, The screw part 5b and the tool engaging part Instead of 5c, a flange 5a may be formed as in the first embodiment.
Further, the joint portion 5 may be formed in a structure different from that of the flange 5a, the screw portion 5b, and the tool engaging portion 5c.

1 Tube 1 'Material (Tube material)
1a inner surface 2 nipple 2a surface (outer surface) 3 sleeve 3a surface (inner surface) 4 receiving recess 6 annular seal

Claims (4)

A tube of deformable material;
A nipple provided to be inserted along the inner surface of the tube;
A sleeve provided on the outside of the nipple so as to cover the tubular body.
The nipple or the sleeve is caulked and deformed toward the tubular body, and the nipple or the sleeve flows on at least one of the surfaces facing the tubular body in accordance with the caulking deformation of the nipple or the sleeve. A pipe joint structure characterized in that an accommodation recess into which the material of the pipe body enters is provided.   The diameter of the nipple is expanded toward the tubular body, and the accommodation recess is disposed on at least one of the surfaces of the nipple or the sleeve facing the tubular body. Pipe joint structure.   2. The sleeve according to claim 1, wherein the sleeve is reduced in diameter toward the tubular body, and the receiving recess is disposed on at least one of the surfaces of the nipple or the sleeve facing the tubular body. Pipe joint structure.   An annular sealing material is provided between the sleeve and the tubular body, and at least one of the surfaces of the nipple or the sleeve facing the tubular body at a position that does not overlap the annular sealing material in the radial direction. The pipe joint structure according to claim 1, wherein the housing recess is arranged.

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