JP2003232475A - Pipe joint structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide pipe joint structure that can sufficiently pressure-clamp and fasten a spigot of a pipe while effectively pressing a packing, at a low cost. <P>SOLUTION: In this pipe joint structure, one tapered side face 3b on one side of a packing body 3a of isosceles trapezoidal cross-section is placed to abut on the inner peripheral surface of a tapered edge part 1d of a pipe joint body 1, and a tapered part 4b of a presser fitting 4 is placed to abut on the other tapered side face 3b. Tapered piece parts 6b, 6c on both sides are placed to abut on the outer peripheral surface of a tapered edge part 1d of the pipe joint body 1 and the outer peripheral surface of a tapered part 4b of the presser fitting 4 to circumferentially provide a clamping band 6. The spigot of the pipe 2 is inserted in a socket 1c, and the clamping band 6 is tightened. The tapered edge part 1d of the pipe joint body 1 and the tapered part 4b of the presser fitting 4 thereby clamp the packing 3 to pressure-clamp and fasten the spigot of the pipe 2 inserted by elastic deformation. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint structure in which an end insertion port of a pipe is inserted into a receiving port of an end of a pipe joint body through a packing and the both are fastened by a fastening means.

[0002]

2. Description of the Related Art As a pipe joint structure of this type, there is an example described in Japanese Patent Publication No. 7-111225.

In the pipe joint structure of the same example, as shown in FIG. 7, the pipe joint body 01 is expanded from the central portion through the step portion 01a to a steel pipe 02.
Is provided with a receiving opening 01b having an inner diameter slightly larger than the outer diameter, and the tip has a tip bulging portion 01c bulging outward.

The packing 03 is composed of a packing body 03a whose cross section is an isosceles trapezoidal shape, a cylindrical portion 03b, and a tip bulging portion 03c. The tightening band 04 has taper pieces 04b and 04c on both inner and outer sides in the axial direction of the central cylindrical portion 04a, and the central cylindrical portion 04a has an outer periphery of the packing body 03a and a tip bulging portion 01 of the pipe joint body 01.
c, the outer tapered piece 04b presses the outer tapered side surface of the packing body, and the tip bent portion of the inner tapered piece 04c
04d holds down the outer peripheral surface of the socket 01b of the pipe joint body 01.

The tightening band 04 is superposed such that one end thereof can slide on the other end, and the brackets 05,
The tightening band 04 is tightened by screwing 05 with the bolt 06 and the nut, the steel pipe 02 is crimped and sandwiched via the packing 03, and the steel pipe 02 is fastened to the pipe joint body 01.

[0006]

The tightening of the tightening band 04 presses the packing 03 and crimps the inserted steel pipe 02 by elastic deformation. The axially inner half part of the tightening band 04 is the pipe joint body. Since the reduction of the diameter is restricted by the receiving port 01b of 01 and the bulging portion 01c of the tip, the reduction of the diameter of the outer half of the tightening band 04 that presses the packing 03 is also limited, and the packing There is a possibility that the steel pipe 02 cannot be pressed effectively and clamping of the steel pipe 02 is insufficient.

The tightening band 04 is asymmetrical on both the inner and outer sides in the axial direction, and is difficult to manufacture. Further, since both the inner and outer sides of the brackets 05, 05 are asymmetrical, and the fixing position to the tightening band 04 also affects the pressing force on the packing 03, it is necessary to ensure accuracy and the manufacturing cost of the fastening means becomes high.

The present invention has been made in view of the above points,
The purpose of this is to provide a pipe joint structure that can effectively press the packing to sufficiently crimp and clamp the insertion opening of the pipe for fastening at a low cost.

[0009]

In order to achieve the above object, the invention according to the first aspect of the present invention provides an end opening of a pipe through a packing in a receiving end of the pipe joint body. In a pipe joint structure that inserts and fastens both by fastening means,
The packing main body of the packing has an isosceles trapezoidal cross section and an annular shape with an inner diameter slightly larger than the outer diameter of the pipe, and the pipe joint main body is expanded from the central portion through a step portion. The packing main body is provided with a receiving opening having an inner diameter slightly larger than the outer diameter of the pipe, and the tip of the receiving opening forms a tapered end edge portion gradually expanding in the same taper shape on one tapered side surface of the packing main body. Of the packing main body has a pressing portion made up of a cylindrical portion having an inner diameter slightly larger than that of the central outer peripheral surface and the other tapered side surface of the packing main body, and the fastening means is symmetrical on both sides of the central cylindrical portion. A tightening band that forms a taper piece part that has the same taper shape as both tapered side surfaces of the packing body and overlaps so that one end can slide on the other end, and a tightening band that tightens the tightening band in the circumferential direction. And more The taper end edge inner peripheral surface of the pipe joint body with one taper side surface of the packing body abutting, and the other taper side surface of the packing body with the taper portion of the press fitting abutting, The tightening band is provided around the outer peripheral surface of the taper end edge and the outer peripheral surface of the taper portion of the holding metal fitting by contacting the taper strips on both sides, and the insertion opening of the pipe is inserted into the receiving opening to fasten the fastening. By tightening the tightening band by the tightening means of the means, the taper end edge portion of the pipe joint body and the taper portion of the pressing metal fitting pinch the packing to crimp and hold the insertion port of the tube inserted by elastic deformation. It has a pipe joint structure for fastening.

By tightening the tightening band by the tightening means of the tightening means, the tapered piece of the tightening band slides along the tapered end edge of the pipe joint body to reduce the diameter of the tightening band. The taper part of the slide contact the taper part of the press fitting to bring the press fitting closer to the fitting body, and the packing main body with the tapered end edge of the fitting body and the taper part of the press fitting that are symmetric in the axial direction The insertion opening of the tube inserted by elastic deformation by pinching from both sides can be crimped and pinched.

Since the taper end edge portion of the pipe joint body and the taper portion of the retainer clamped to the tightening band press the inner and outer tapered side surfaces of the packing body having an isosceles trapezoidal cross section vertically, respectively. Since the main body is symmetrically clamped from both sides and is elastically deformed effectively so as to bulge toward the center of the shaft, the insertion opening of the tube can be securely crimped and clamped.

The tightening band and the tightening means are formed symmetrically with each other on the inner and outer sides, so that the manufacturing is easy and the cost can be reduced.

According to a second aspect of the present invention, in the pipe joint structure according to the first aspect, one taper side surface of the packing main body is brought into contact with an inner peripheral surface of a tapered end edge portion of the pipe main body, and the other side of the packing main body is abutted. The tapered portion of the pressing fitting is brought into contact with the tapered side surface of the fitting, and the tapered piece portions on both sides are brought into contact with the outer peripheral surface of the tapered end edge portion of the fitting main body and the outer peripheral surface of the tapered portion of the holding fitting so that the tightening band is tightened. And tentatively assembling by loosely fastening by means of fastening means, inserting the insertion port of the pipe into the temporarily assembled receiving port, and fastening the fastening band by the fastening means of the fastening means. It is characterized in that the insertion opening of the pipe is clamped and clamped by clamping.

Since the packing and the press fitting can be temporarily assembled with the tightening band on the taper end edge of the pipe joint body, at the site, the insertion of the pipe is inserted into the temporarily assembled receiving port and tightened. If the band is tightened, it can be easily tightened and work efficiency can be improved.

According to a third aspect of the present invention, in the pipe joint structure according to the first or second aspect, the packing is formed from a packing body having an isosceles trapezoidal cross section to an inner circumference of a receiving port of the pipe joint body. A packing cylindrical portion that extends along the surface, and a tip bulging portion in which the tip of the packing cylindrical portion bulges in the axial center direction along the inner surface of the step portion of the pipe joint body, To do.

The packing cylindrical portion can be fitted into the receiving opening of the pipe joint body to facilitate the temporary assembly, and the tip bulge portion is interposed between the step portion of the pipe joint body and the end portion of the pipe. It is possible to avoid a direct collision between the two and to prevent a collision sound from being generated.

According to a fourth aspect of the invention, in the pipe joint structure according to the third aspect, the opening of the taper portion of the holding metal fitting is:
It is characterized in that a tapered end face whose diameter is gradually enlarged is formed on the outside.

Since the opening of the taper portion of the holding metal fitting forms a taper end surface whose diameter gradually increases on the outside, when the insertion opening of the pipe is inserted into the receiving opening of the pipe joint body in the temporarily assembled state, The tapered end surface of the opening guides the tip of the insertion opening of the tube, facilitates insertion, and improves work efficiency.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment according to the present invention will be described below with reference to FIGS. As shown in FIG. 3, the pipe joint main body 1 is symmetric on both sides and is expanded at both ends of the central cylindrical portion 1a through stepped portions 1b, 1b to form receiving ports 1c, 1c, respectively. The tip of 1c forms taper end edge portions 1d, 1d which are gradually expanded in a tapered shape at an inclination angle of 45 degrees.

The inner diameter of the central cylindrical portion 1a of the pipe joint body 1 is
It is equal to the inner diameter of the steel pipe 2 which is the member to be connected, and the pipe joint body 1
The inner diameter of the receiving port 1c is slightly larger than the outer diameter of the steel pipe 2.
The packing 3 is made of rubber, and as shown in FIGS. 1 and 2, the packing main body 3a has tapered side surfaces 3b, 3b whose both sides have an inclination angle of 45 degrees, and the cross section has an isosceles trapezoidal shape.
An annular shape whose inner diameter is slightly larger than the outer diameter of the steel pipe 2 is formed.

The packing 3 maintains its inner diameter from the packing main body 3a along the inner peripheral surface of the receiving port 1c of the pipe joint main body 1 so that the packing cylindrical portion 3c extends inward in the axial direction. Has a tip bulge portion 3d which bulges in the axial center direction along the inner surface of the step portion 1b of the pipe joint body 1.

The packing main body 3a is covered with an annular pressing member 4 from the outside in the axial direction. The holding metal fitting 4 is an annular member composed of a cylindrical portion 4a having an inner diameter slightly larger than the central outer peripheral surface of the packing body 3a and a taper portion 4b having the same inclination angle of 45 degrees on the tapered side surface 3b of the packing body 3a.

The inner diameter of the opening of the taper portion 4b is substantially equal to the inner diameters of the packing body 3a and the packing cylindrical portion 3c of the packing 3, and the opening end surface forms a tapered end surface 4c whose diameter gradually increases toward the outside.

As shown in FIG. 1, when the packing main body 3a is covered with the pressing metal fitting 4 from the outside in the axial direction, the tapered side surface 3b of the packing main body 3a is in contact with the tapered portion 4b of the pressing metal fitting 3 and the central outer peripheral surface of the packing main body 3a. A cylindrical portion 4a of the holding metal fitting 4 covers the outside with a slight gap, and a tightening margin S having an appropriate gap is provided between the cylindrical portion 4a and the tapered end edge portion 1d of the pipe joint body 1.

4 and 5 show an overall view of the fastening means 5. The tightening band 6 has tapered pieces 6b and 6c symmetrically on the inner and outer sides of the central cylindrical portion 6a in the axial direction, and one end of the tightening band 6 is superposed so as to slide on the other end.

Brackets 7 and 8 are welded to predetermined positions near both ends of the tightening band 6. Bracket 7,
8, the leg portions 7b, 7b, 8b, 8b extend in the centrifugal direction from the central tubular portions 7a, 8a at an angle of 90 degrees to each other, and the leg portions 7b, 7b, 8b, 8b taper the fastening band 6. Spot welding is performed on the pieces 6b and 6c.

The end of the tightening band 6 to which one of the brackets 7 is welded forms a overlapped portion 6d whose tip is slightly expanded in diameter from the welded portion of the bracket 7.

The tightening band 6 is formed into an annular shape, and the overlapping portion 6d is formed at one end.
Are overlapped so that they can slide on the other end, the brackets 7 and 8 face each other, and the leg portions 8 on both sides of the one bracket 8 are opposed to each other.
The hexagon socket head cap screw 9 inserted from the other bracket 7 through the washer 11 is screwed into the nut 10 that is sandwiched between b and 8b and applied to the central tubular portion 8a.
The tightening band 6 can be tightened by reducing the diameter by screwing.

Using the fastening means 5 as described above, the tightening band 6 is wrapped around the taper end 1d of the pipe joint body 1 and the outer circumference of the holding metal fitting 4. As shown in FIG. 1, the taper piece portion 6c on the inner side in the axial direction of the tightening band 6 is slidably contacted with the outer peripheral surface of the taper end edge portion 1d of the pipe joint body 1, and the taper piece portion 6b on the outer side in the axial direction is held by the pressing fitting 4. The holding metal fitting 4 can be held in sliding contact with the outer peripheral surface of the tapered portion 4b.

In this way, the packing cylindrical portion 3c of the packing 3 is fitted into the receiving port 1c of the pipe joint body 1 and the packing body 3
a is covered with a metal fitting 4 from the outside in the axial direction, a tightening band 6 of a fastening means 5 is wound around, and a bolt 9 is screwed into a nut 10,
Loosely tighten the cylinder 4 of the retainer 4 as shown in Fig. 1.
The temporary assembling state in which there is a tightening margin S at an appropriate interval between a and the taper end 1d of the pipe joint body 1 is set.

The packing 3 of the pipe joint body 1 in the temporarily assembled state
The insertion port of the steel pipe 2 is inserted into the receiving port 1c through the (see FIG. 2). When the insertion opening of the steel pipe 2 is inserted, the tapered end surface 4c that spreads out of the opening of the holding metal fitting 4 guides the insertion opening tip of the steel pipe 2 to facilitate the insertion, and the work efficiency can be improved.

Since the outer diameter of the steel pipe 2 is slightly smaller than the inner diameter of the packing 3, the steel pipe 2 is easily inserted and its tip abuts against the tip bulging portion 3d of the packing 3 as shown in FIG.

In this state, the bolt 9 of the fastening means 5 is attached to the nut.
When further tightening the tightening band 6 by screwing into 10,
The inner taper piece portion 6c of the tightening band 6 slides along the taper end edge portion 1d of the pipe joint body 1, and the outer taper piece portion 6b slides along the taper portion 4b of the holding metal fitting 4 for tightening. Since the diameter of the band 6 is reduced, the holding metal fitting 4 is moved inward in the axial direction so as to reduce the tightening margin S, and the packing body 3a is pinched between the band 3 and the taper end 1d of the pipe joint body 1. .

The taper end edge 1d of the pipe joint body 1 and the taper portion 4b of the retainer fitting 4 tightened on the tightening band 6 are
Inclination angle of packing body 3a, which has an isosceles trapezoidal cross section, 45
Since the inner and outer tapered side surfaces 3b and 3b are pressed vertically, the packing body 3a is effectively elastically deformed so as to be squeezed symmetrically from both sides at an angle of 45 degrees and bulge toward the center of the shaft. As shown in FIG. 3, the insertion opening of the steel pipe 2 can be securely crimped and clamped.

Therefore, the water tightness of the packing 3 can be secured by crimping, and the steel pipe 2 can be firmly connected to the pipe joint body 1 by a simple work without using a separate retaining member, and the pipe joint body 1 can be hydraulically connected. It is possible to reliably prevent the steel pipe 2 from falling out.

Particularly, by temporarily preliminarily assembling the packing 3 and the pressing metal fitting 4 with the tightening band 6 on the taper end 1d of the pipe joint body 1, the socket 1c of the pipe joint body 1 temporarily assembled at the site. If the insertion opening of the steel pipe 2 is inserted into and the tightening band 6 is tightened, it can be easily tightened and the working efficiency can be improved.

Since the tip bulging portion 3d of the packing 3 is interposed between the tip of the steel pipe 2 inserted into the receiving port 1c of the pipe joint body 1 and the step portion 1b of the pipe joint body 1, both It is possible to avoid a direct collision and prevent generation of a collision sound.

Not only the tightening band 6 but also the brackets 7 and 8
The fastening means 5 including is configured so that the inside and outside thereof are symmetrical with respect to each other in the axial direction, is easy to manufacture, and can reduce the cost.

A modified example shown in FIG. 6 can be considered as the fastening means. The tightening band 21 of the present fastening means 20 is
Similar to the tightening band 6, the central cylindrical portion 21a has tapered piece portions 21b and 21c symmetrically on both inner and outer sides in the axial direction, and one end portion is superposed so as to slide on the other end portion.

The brackets 22 and 23 welded to predetermined places near both ends of the tightening band 21 are members having the same shape, and are welded along the outer peripheral surface of the central cylindrical portion 21a of the tightening band 21. Tightening plate part vertically from the edges of the mounting base parts 22a, 23a
22b and 23b extend, the mounting bases 22a and 23a and the tightening plate 22
Both side edges of b and 23b are connected to the reinforcing side plates 22c and 23c.

As described above, the brackets 22 and 23 are structurally high in strength and rigidity, and the mounting bases 22a,
23a is welded to a predetermined position on the outer peripheral surface of the central cylindrical portion 21a of the tightening band 21 so that the tightening plate portions 22b and 23b face each other.

The tightening plate portion 22b of one bracket 22 is clamped by the reinforcing side plates 22c, 22c on both sides so that the nut 25
Is attached, and a bolt 24 penetrating the tightening plate portion 23b of the other bracket 23 through a washer is screwed into a nut 25 for tightening.

The brackets 22 and 23 have the same simple shape, and there are few spot welding points to the tightening band 21, so that the manufacturing is easy and the cost can be suppressed, and the strength required for tightening is easily secured. be able to.

In the above-mentioned embodiment, the holding metal fitting 4 is an annular member consisting of the cylindrical portion 4a and the tapered portion 4b, but it is also conceivable to divide this annular member in the circumferential direction and use it.

In this case, there is a tightening margin between the divided pieces divided in the temporary assembly state, and the divided pieces move inward in the axial direction by the tightening of the tightening band and simultaneously move in the axial center direction. Even if the packing is elastically deformed, the packing bulges toward the center of the shaft, and the insertion opening of the steel pipe can be securely crimped and clamped.

In the above-mentioned embodiments, the pipe joint main body is a pipe joint having a straight central axis and bilateral symmetry. However, the present invention is also applicable to pipe joints having a bent center, Y-shaped or T-shaped pipe joints, and the like. The invention is naturally applicable.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a temporarily assembled state of a pipe joint structure according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a steel pipe is inserted into a socket of the pipe joint body in the temporarily assembled state.

FIG. 3 is a partial cross-sectional side view showing a state in which a steel pipe is connected to a pipe joint body.

FIG. 4 is an overall side view of the fastening means.

FIG. 5 is a plan view of the same.

FIG. 6 is a perspective view showing a modified example of the fastening means.

FIG. 7 is a partial cross-sectional side view showing a conventional pipe joint structure.

[Explanation of symbols]

1 ... Pipe joint body, 2 ... Steel pipe, 3 ... Packing, 4 ... Press fitting, 5 ... Fastening means, 6 ... Tightening band, 7, 8 ... Bracket, 9 ... Bolt, 10 ... Nut, 11 ... Washer, 20 ... Fastening means, 21 ... tightening band, 22, 23 ... bracket, 24 ... bolt, 25 ... nut.

Claims (4)

[Claims] 1. In a pipe joint structure in which an end insertion port of a pipe is inserted into a receiving port of an end of the pipe joint main body through a packing, and both are fastened by a fastening means, both sides of the packing main body of the packing are The taper section has an isosceles trapezoidal shape, and the inner diameter forms an annular shape slightly larger than the outer diameter of the pipe, and the pipe joint body is expanded from the central portion through the step portion to an inner diameter slightly larger than the outer diameter of the pipe. And a tip end of the receiving opening forms a taper edge portion on one taper side surface of the packing main body, the diameter of which gradually increases in the same taper shape, and the inner diameter is slightly larger than the central outer peripheral surface of the packing main body. There is a holding metal fitting composed of a cylindrical portion and the same tapered taper portion on the other tapered side surface of the packing body, and the fastening means is symmetrical on both sides of the central cylindrical portion and has the same taper on both tapered side surfaces of the packing body. Shape And a tightening means for tightening the tightening band in the circumferential direction, and a taper of the pipe joint body. One taper side surface of the packing body is brought into contact with the inner peripheral surface of the end edge portion, and the taper portion of the pressing metal fitting is brought into contact with the other taper side surface of the packing body, and the outer peripheral surface of the taper end edge portion of the pipe joint body and Taper pieces on both sides are brought into contact with the outer peripheral surface of the tapered portion of the holding metal fitting, and the tightening band is provided around the insertion hole of the pipe, and the tightening means is tightened by the tightening means. The taper end edge portion of the pipe joint main body and the taper portion of the pressing fitting clamp the packing by tightening the band to crimp and clamp the insertion opening of the pipe inserted by elastic deformation. Pipe joint structure. 2. The taper end edge inner surface of the pipe joint body is in contact with one taper side surface of the packing body, and the other taper side surface of the packing body is in contact with the taper portion of the pressing fitting, Taper pieces on both sides are brought into contact with the outer peripheral surface of the taper end edge portion of the joint body and the outer peripheral surface of the taper portion of the pressing metal fitting, and the tightening band is provided around and loosely fastened by fastening means to temporarily assemble, Inserting the insertion port of the pipe into the provisionally assembled receiving port, clamping the packing by tightening the tightening band of the fastening means of the fastening means, crimping and clamping the insertion port of the pipe. The pipe joint structure according to claim 1, wherein 3. The packing includes a packing cylindrical portion extending from a packing body having an isosceles trapezoidal cross section along an inner peripheral surface of a receiving port of the pipe joint body, and a tip of the packing cylindrical portion. The pipe joint structure according to claim 1 or 2, further comprising: a tip bulge portion that bulges in an axial center direction along an inner surface of a step portion of the pipe joint body. 4. The pipe joint structure according to claim 3, wherein the opening of the tapered portion of the retainer has a tapered end surface whose diameter is gradually increased outward.