JP3270036B2 - Crimping type pipe joint for connecting metal pipes and fastening method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crimp-type pipe joint for connecting metal pipes and a method of fastening the same, and more particularly, to a pipe joint having a fastening portion in which a fastening ring groove and a packing ring groove are formed. Metal that can be connected without damaging the outer peripheral surface of the connecting pipe when fastening to the connecting pipe by the crimping method, and that can prevent the connecting pipe from being easily detached from the pipe joint by the fastening ring, and can further prevent water leakage. The present invention relates to a crimp type pipe joint for pipe connection and a method for fastening the same.

[0002]

2. Description of the Related Art FIG. 1 is a partial sectional view showing a fastening structure of an example of a conventionally used crimp type pipe joint.

[0003] As shown in the figure, the crimp type pipe joint (10) is
Fitting (10) after inserting connecting pipe (A) to be connected
A crimping force is applied to the outer peripheral surface of the pipe joint to connect it to the connecting pipe (A) .The end of the pipe joint (10) is a part where the connecting pipe (A) is inserted, and a certain amount from one end. The fastening ring (12) and the packing ring (13) made of rubber material are interposed at intervals, forming a fastening portion (11) in which the fastening ring groove (11a) and the packing ring groove (11b) project by a predetermined amount. The inside diameter of the portion other than the fastening ring groove (11a) and the packing ring groove (11b) in the fastening portion (11) is the same. At this time, the fastening ring (12) interposed in the fastening ring groove (11a) has a disk spring shape and its tip has a sharp cutting edge.

[0004] When an attempt is made to fasten to the connecting pipe (A) using the pipe joint (10) configured as described above, first, the connecting pipe (A) is used.
(A) is inserted into the joint (11) of the pipe joint (10), and the joint (1
1st and 2nd formed to correspond to the cross-sectional shape of 1)
A plurality of crimping jigs (14) having crimp grooves (14a, 14b)
When the outer peripheral surface of the fastening portion (11) of the pipe joint (10) is crimped, the fastening portion (11) of the pipe joint (10) is crimped and reduced in diameter and the fastening interposed in the fastening ring groove (11a) The tip of the ring (12) bites into the connecting pipe (A) while applying a fastening force to the pipe joint (10) to be fastened, and furthermore, the packing ring (11b) interposed in the packing ring groove (11b). 13) is also pressed against the outer peripheral surface of the connecting pipe (A) by the crimping of the crimping jig (14), thereby maintaining airtightness.

FIG. 2 is an enlarged sectional view showing another conventional pipe joint. As shown in the figure,
In (15), an annular fastening ring groove (16a) and a packing ring groove (16b) are formed from the tip of the fastening part (16) into which the connecting pipe (B) to be connected is inserted while first contacting. A fastening ring (17) partially cut from a hard elastic material and a packing ring (18) made of a rubber material are interposed on the inner side.

When the pipe joint (15) having such a configuration is to be fastened to the connecting pipe (B), the connecting pipe (B) is inserted into the fastening ring groove (16a) of the fastening portion (16). The connecting pipe (B) in which a concave groove (19) is formed in advance so that the interposed fastening ring (17) can be recessed is connected to the connecting part (1) of the pipe joint (15).
6), the fastening ring (17) interposed in the fastening ring groove (16a) is expanded in the fastening ring groove (16a), and the concave groove (19) of the connection pipe (B) is fastened. When it is located on the ring (17) side, the fastening ring (17) is recessed into the groove (19) and fastened, and the packing inserted into the packing ring groove (16b) by inserting the connecting pipe (B). The ring (18) maintains airtightness while pressing the outer peripheral surface of the connecting pipe (B).

[0007]

However, in the above-mentioned conventional example (first example), since the fastening ring interposed in the fastening ring groove of the pipe joint is formed as a disc spring, a jig for crimping is used. The compression ring is subjected to elastic deformation and cannot be fastened to the pipe as a fastening ring itself, and the restoring force to restore the original shape weakens the fastening force. When the diameter of the fastening ring groove is reduced by crimping, the fastening ring cuts into the outer peripheral surface of the connecting pipe to perform the fastening.At this time, in the case of a thin metal pipe, the tip of the fastening ring may bite deeply into the outer peripheral face of the connecting pipe. For this reason, there is a problem that the fastening force is weak.

In addition, since the sharp cutting edge of the fastening ring cuts into the connecting pipe, the circumferential portion of the connecting pipe to which the fastening ring is fastened becomes thinner by the bite depth.
There is a problem that the connecting pipe is broken by a fatigue phenomenon due to an external shock such as continuous vibration.

The diameter of the packing ring groove is reduced at the same time that the crimping jig starts to press the fastening portion, and the reduced diameter is determined by crimping by contact with the crimping jig. When a plurality of crimping jigs are provided between the jigs, a part of the outer periphery of the packing ring groove is fitted into the space, and wrinkles are formed on the inner surface, so that airtightness cannot be maintained. Was.

Further, in the second conventional example, since the fastening ring is fastened by recessing into the concave groove of the connecting pipe without crimping the fastening portion of the pipe joint, it cannot be firmly fastened to the pipe joint. However, there is a problem that the connecting pipe is easily separated from the pipe joint.

SUMMARY OF THE INVENTION Accordingly, the present invention has been devised to solve the above-described problems, and has a fastening ring groove having a fastening ring having a surface on its inner surface, and a fixed ring groove having a fixed surface. When connecting the connecting pipe to a pipe joint having a fastening portion formed by a packing ring groove in which a packing ring made of an elastic material is interposed at a distance from the connecting pipe, the connecting pipe is reduced in diameter by a crimping method and fastened to the connecting pipe. As a result, the outer peripheral surface of the connecting pipe is fastened without being damaged by the fastening ring, so that damage to the connecting pipe and detachment from the pipe joint can be prevented. A metal pipe connection in which a crimping jig directly contacts the groove and does not apply any crimping force, and after a certain amount of crimping has progressed by the central crimping surface, it contacts the crimping groove and crimps Providing a crimp fitting and fastening method thereof.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention is directed to a metal material for expanding and plastically processing a circular metal pipe, fastening the pipe to a connecting pipe inserted therein, and maintaining airtightness. In a crimp-type pipe joint for connecting metal pipes having a fastening part in which an annular fastening ring and an elastic packing ring are interposed at a fixed interval from each other, an external force is applied to the inside of the receiving end of the fitting part. An annular protruding fastening ring groove interposing an O-shaped metal fastening ring of a shape and a material to be plastically deformed, and a cylindrical shape formed to have an inner diameter larger than the outer diameter of the connecting pipe in one direction from the fastening ring groove. A reduced-diameter interval portion, a packing ring groove annularly protruded with an outer diameter smaller than the outer diameter of the fastening ring groove for interposing an elastic packing ring at an end of the reduced-diameter interval portion, and a connecting pipe. At the time of insertion, A fastening portion comprising a pipe fixing portion having a stopper step formed so that the outer peripheral surface of the pipe can be inserted while being in contact with the inner peripheral surface thereof, and a stopper step can be stopped so as to be able to stop the distal end of the inserted connecting pipe. It is characterized by having.

Further, according to the present invention, in a method for fastening a connecting pipe using a crimp type pipe joint for connecting a metal pipe, a central crimping surface is formed at a central portion, and both sides thereof have the same shape and shape while being symmetrical to each other. After the pipe joint having the connecting pipe inserted into the fastening portion is inserted into a crimping device in which a plurality of crimping jigs having first and second arc-shaped crimping concave grooves formed in dimensions are mounted. The first and second crimping concave grooves and the central crimping surface of the crimping jig are contact-coupled so as to correspond to the fastening ring groove, the packing ring groove, and the reduced-diameter interval portion of the pipe joint, respectively. When the diameter-reducing plastic deformation is performed and the diameter-reducing deformation of the fastening portion is performed, the diameter-reducing deformation of the fastening ring groove and the diameter-reducing interval starts before the diameter-reducing deformation of the packing ring groove, and then the packing ring groove is pressed. In contact with the second crimp groove of the jig Begins, and the connection between the pipe joint and the connection pipe is performed by press-fitting the inner surface of the connection ring to the outer peripheral surface of the connection pipe by pressing the connection ring, thereby causing the connection pipe to be depressed toward the center thereof. And a reduced-diameter concave groove is formed in a contact portion with the fastening ring.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 3 is a view showing a crimp type pipe joint for connecting a metal pipe according to an embodiment of the present invention, and FIG. 7 shows a crimping apparatus for crimping a crimp type pipe joint according to the present invention. It is a drawing.

As shown in the drawing, the crimp-type pipe joint (100) according to the present invention is capable of expanding and plastically processing a circular metal pipe so as to maintain the fastening and airtightness with a connecting pipe (105) inserted therein. More specifically, the pipe fitting (1
The fastening portion (110) of the (00) is provided with an annular projection at the end of the receiving port,
A fastening ring groove (110a) in which an O-shaped metal fastening ring (120) in which the shape and the material of the material that are plastically deformed by an external force are not cut is interposed, and the fastening ring groove (110a) extends in one direction from the fastening ring groove (110a). A cylindrical reduced-diameter interval portion (110b) formed to have an inner diameter larger than the outer diameter of the connecting pipe (105), and a distal end of the reduced-diameter interval portion (110b) having an outer portion outside the fastening ring groove (110a). An annular projecting ring with an outer diameter smaller than the diameter, and a packing ring groove inside which an elastic packing ring (125) is interposed.
(110c), when the connecting pipe (105) is inserted at the end of the packing ring groove (110c), the outer circumferential surface of the connecting pipe (105) is inserted while being in contact with the inner circumferential face thereof, and inserted. A fastening part composed of a pipe fixing part (110d) in which a stop step is formed so that the tip part of the connecting pipe (105) to be stopped can be stopped.
(110).

Crimping type pipe joint (100) configured as described above
Is fastened to the connecting pipe (105) to be connected by the crimping device (130) shown in FIG. 7, and the crimping device (130) is provided with a plurality of jigs (135) for crimping.

At this time, the crimping jig (135) has a central crimping surface (135a) formed at the center portion so as to correspond to the reduced diameter interval portion (110b) of the pipe joint (100), and both sides thereof. Has a pipe fitting (10
0) and the first and second arc-shaped grooves (135b) and (135c) having the same shape and dimensions and being symmetrically formed to correspond to the fastening ring groove (110a) and the packing ring groove (110c). ) Is provided.

The pipe joint constructed as described above is fastened to the connecting pipe by a crimping device, which will be described below with reference to FIGS.

That is, as shown, after the connecting pipe (105) is inserted into the fastening part (110) of the pipe joint (100) up to the stop of the pipe fixing part (110d), the crimping jig (135) When the pipe joint (100) is installed in a crimping device (130) provided with a plurality of
A fastening ring groove (110a) forming a fastening portion (110) of (100)
And the outer peripheral surface of the reduced diameter interval portion (110b) is the first surface of the crimping jig (135).
The crimp groove (135b) comes into contact with the central crimp surface (135a), and at this time, the packing ring groove (110c)
a) The second crimping groove (1
It is installed in a state separated from 35c).

Thereafter, when the crimping device (130) is operated, the fastening portion (110) in contact with the first crimping groove (135b) and the central crimping surface (135a) of the crimping jig (135). Fastening ring groove (11
0a) and the reduced diameter interval portion (110b) start crimping diameter reduction before the packing ring groove (110c).

As the crimping diameter decreases, the fastening portion
(110) fastening ring (12a) interposed in the fastening ring groove (110a).
0) is depressed in the center direction while making surface contact with the outer peripheral surface of the connection pipe (105), and the connection pipe (105) is also provided with a reduced-diameter concave groove (105a) depressed in the center direction. It is formed so that the connection pipe (105) is fastened without detaching from the pipe joint (100).

Thereafter, when the packing ring groove (110c) is crimped, the outer diameter of the fastening ring groove (110a) is changed to the packing ring groove (110c).
The crimping proceeds until the outer diameter becomes the same as the outer diameter of the crimping jig. At this time, the crimping force applied to the packing ring groove (110c) is increased by the second crimping groove (135c) of the crimping jig (135). Before contacting and acting on the packing ring groove (110c),
10b) The central crimping surface (135) of the crimping jig (135)
First, the diameter is reduced by a certain amount by the pressing force in the center direction of the connecting pipe (105) received at the boundary surface from a), and then the second pressing groove (135c) comes into contact with the packing ring groove (110c) and is pressed. Then, airtightness with the connecting pipe (105) is provided.

[0023]

As can be understood from the above description, according to the present invention, the connection between the pipe joint and the connecting pipe is performed by pressing the inner surface of the connecting ring, which is in surface contact with the connecting pipe, by the pressing force of the pressing apparatus. The connection pipe is fastened without damaging the outer peripheral surface of the connection pipe, and the connection pipe is easily detached from the pipe joint by being hooked on the reduced diameter groove formed in the connection pipe when the pipe joint is crimped. At the same time, the crimping jig directly presses the packing ring groove part by a certain amount by the central crimping surface without directly applying crimping force, and then the jig contacts the crimping ring groove and crimping proceeds There is an effect that the packing ring groove can be pressure-bonded without distortion.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a fastening structure of a crimp type pipe joint according to an example of the related art.

FIG. 2 is a partial cross-sectional view illustrating another conventional pipe joint fastening structure.

FIG. 3 is an explanatory view showing a crimp-type pipe joint for connecting a metal pipe in one embodiment of the present invention.

FIG. 4 is an explanatory view showing a state where the crimping type pipe joint of FIG. 3 in which a connecting pipe is inserted is installed in a crimping device.

FIG. 5 is an explanatory view showing an initial stage in which the pipe joint of FIG. 4 is fastened to a connecting pipe by a crimping device.

FIG. 6 is an explanatory view showing a state where the pipe joint of FIG. 5 is fastened to a connecting pipe by a crimping device.

FIG. 7 is an explanatory view showing a crimping device for crimping the crimp type pipe joint of the present invention.

[Explanation of symbols]

 10 Crimping type pipe joint 11 Fastening part 11a Fastening ring groove 11b Packing ring groove 12 Fastening ring 13 Packing ring 14 Crimp jig 14a, 14b Crimp groove 15 Fitting 16 Fastening part 16a Fastening ring groove 16b Packing ring groove 17 Fastening ring 18 Packing ring 100 Fitting 105 Connecting pipe 105a Reducing groove 110a Reducing part 110a Reducing ring groove 110b Reducing interval 110c Packing ring groove 110d Pipe fixing part 120 Retaining ring 125 Packing ring 130 Crimping device 135 Crimp jig 135a Center Crimping surface 135b First crimping groove 135c Second crimping groove

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16L 13/14 F16L 21/00 F16L 21/02

Claims (2)

(57) [Claims] 1. A circular metal pipe is subjected to plastic expansion processing to form an annular fastening ring made of a metal material and an elastic packing ring for maintaining a fastening and airtightness with a connecting pipe inserted into the inside thereof at a predetermined interval. A crimp-type pipe joint for connecting a metal pipe having a fastening portion to be placed and interposed, an O-shape of a shape and a material which is annularly protruded at a receiving end of the fastening portion of the pipe joint and is plastically deformed inside by an external force. A fastening ring groove for interposing a metal fastening ring, a cylindrical reduced diameter interval portion formed to have an inner diameter larger than an outer diameter of the connection pipe in one direction from the fastening ring groove, and At the end portion, an annular projection is provided with an outer diameter smaller than the outer diameter of the fastening ring groove, and a packing ring groove in which an elastic packing ring is interposed, and at the end portion of the packing ring groove, when inserting the connecting pipe, Communicating Fastening composed of a pipe fixing portion having a stopper step formed so that the outer peripheral surface of the pipe can be inserted while being in contact with the inner peripheral surface thereof, and a tip end of the inserted connecting pipe can be stopped. A crimp-type pipe joint for connecting a metal pipe, characterized by having a portion. 2. A method for fastening a connecting pipe using a crimp type pipe joint for connecting metal pipes, wherein a central crimping surface is formed at a central portion, and both sides thereof are formed symmetrically to have the same shape and dimensions. After inserting a pipe joint having a connecting pipe inserted into a fastening portion into a crimping device having a plurality of crimping jigs having first and second arc-shaped crimping concave grooves, the crimping jig is inserted. The first and second crimping grooves and the central crimping surface of the fitting are contact-coupled so as to correspond to the fastening ring groove, the packing ring groove, and the reduced-diameter interval portion of the pipe joint, respectively, so that the fastening portion is reduced-diameter plastically deformed. When the diameter of the fastening portion is reduced, the reduction of the diameter of the fastening ring groove and the reduced-diameter portion starts before the reduction of the diameter of the packing ring groove. Contact with the second crimping groove of the tool Beginning, the fastening between the pipe joint and the connecting pipe, the inner surface of the fastening ring is pressed against the outer peripheral surface of the connecting pipe by the reduced pressure crimping of the fastening ring, and the connecting pipe is reduced in diameter while being compressed. A method for fastening a crimp-type pipe joint for connecting metal pipes, characterized in that it is depressed in the center direction and has a reduced diameter groove formed in a contact portion with a fastening ring.