JPH1163324A - Pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a sealing capability by using an aligning member separated from a packing for reducing sliding resistance and pressing the packing uniformly. SOLUTION: For connecting pipe bodies 1, 2 together, a pressing ring 5, an aligning member 8, a packing 4 are fitted around the opening end of a spigot part 2a in this order, and then, the spigot 2a is inserted into a socket part 1a. Subsequently, flanges 1b, 5b in the socket part 1a and the pressing ring 5 respectively are temporarily locked mutually by means of T-head bolts 6 and nuts 7. Each of the nuts 7 is gradually fastened uniformly, the aligning member 8 is pressed in the axial direction by means of the pressing ring 5 so as to be brought into contact with the packing 4. An internal circumference edge in a ring type pressing part 5a around the pipe top in the pressing ring 5 is slid on a taper face 8a in the aligning member 8 so as to climb up, so that the whole of the pressing ring 5 is pushed upward toward the centering direction. The socket part 2a and the pressing ring 5 are aligned concentrically substantially, and when the nuts 7 are fastened further, the packing 4 is pushed into a gap 3, and watertighness can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint having a self-aligning function for a press wheel.

[0002]

2. Description of the Related Art For example, when piping water pipes or the like, pipes are connected by connecting a pipe with a press ring which is fitted into a socket of one pipe and an insertion port of the other pipe. Is used.

[0003] In a pipe joint having such a pressing ring, when the pressing ring is fastened to the receiving portion, the centers thereof must be aligned concentrically with each other.

[0004] That is, since the press ring is fitted to the insertion port with a slight play gap in the radial direction, when the pipe is connected, it is suspended from the top of the pipe by its own weight when the pipe is connected. The center is misaligned with respect to the center.

If the press ring is tightened to the receiving portion in this state, the tightening force of the mounting screw near the top of the pipe and the mounting screw near the bottom of the pipe become uneven, and the packing cannot be pressed uniformly. When the pipe expands or contracts due to an earthquake or the like, there is a risk of causing a water leakage accident or the packing to pop out from the bottom of the pipe.

As a solution to this problem, a pipe joint as shown in FIG. 7 is known.

[0007] This conventional pipe joint comprises a socket 1a of a right pipe 1 and a left pipe 2 loosely inserted into the socket 1a.
The packing 4 is inserted into the gap 3 between the opening 2a and the annular tongue 4a whose outer peripheral surface is gradually tapered outwardly on the inner peripheral edge of the side surface of the packing 4. Are connected in series.

[0008] Flange 5b of press ring 5 fitted externally to tube 2
Is tightened to the flange 1b of the socket 1a by the T-head bolt 6 and the nut 7, the inner peripheral edge of the right end of the annular pressing portion 5a of the pressing ring 5 rides on the outer peripheral surface of the tongue piece 4a and is pushed upward. As a result, the socket 1a and the pressing wheel 5 are automatically and concentrically aligned.

[0009]

In the conventional pipe joint described above, since the tongue piece 4a is formed integrally with the relatively soft packing 4 made of rubber or the like, especially when the pressing ring 5 is large and heavy, An annular pressing portion 5a is provided on the outer peripheral surface of the tongue piece 4a near the top of the pipe.
When the vehicle rides, the tongue piece 4a is strongly pressed in the radial direction, and the sliding resistance increases.

In this case, the packing 4 is locally pressed strongly against the outer peripheral surface of the insertion opening 2a and is not uniformly pressed.
Even if each bolt and nut 6, 7 are tightened evenly,
There is a difference between the pressing forces of the upper and lower packings 4, and the sealing performance may be impaired.

If the tongue piece 4a is formed integrally with the packing 4, it is not possible to use a commercially available packing, and it is necessary to newly manufacture a dedicated molding die or the like. The cost is high.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. By using an alignment member separated from the packing, the sliding resistance of the packing can be reduced and the packing can be pressed uniformly. It is another object of the present invention to provide an inexpensive pipe joint that can use ordinary packing.

[0013]

In order to achieve the above-mentioned object, a pipe joint according to the present invention has a receiving portion of one tube inserted into a receiving portion of the other tube, and a receiving portion of the other tube is loosely inserted. The packing inserted in the gap between the inner peripheral surface and the outer peripheral surface of the insertion part is strongly pressed by tightening the press ring that is externally fitted to the insertion part to the receiving part, and the two pipes are connected to each other. In the fitting, the outer peripheral surface has a tapered surface whose diameter is gradually reduced toward the pressing ring side, at least in a pipe top region of the outer peripheral surface of the insertion portion between the packing and the pressing ring, and A centering member is provided which pushes the pressing wheel in a centripetal direction to a position concentric with the receiving portion when the inner peripheral edge of the pressing portion of the pressing wheel rides on the surface.

It is preferable that the alignment member is made of a hard synthetic resin material having a small friction coefficient.

It is preferable to provide a needle-like projection on the packing-side end surface of the alignment member.

It is preferable to provide a permanent magnet at a key point of the alignment member.

It is preferable that the aligning member is formed of a material which can be elastically deformed in the radial direction and is formed in a partially circular shape.

It is preferable to provide a riding-out preventing piece extending outward on the packing-side end face of the aligning member.

According to the present invention, as the pressing wheel is gradually advanced to the receiving portion, the pressing portion of the pressing wheel rides on the tapered surface of the outer peripheral surface of the centering member, and pushes the entire pressing wheel in the centripetal direction. It is easily and concentrically aligned with the receptacle. In this alignment, the alignment member is separate from the packing, so that the packing is not strongly pressed in the radial direction, the sliding resistance is reduced, and the packing is uniformly pressed in the tube axis direction.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. The same members as those in the conventional example shown in FIG. 7 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, as in the conventional example, the receiving portion 1a
A packing 4 is inserted in a gap 3 between the packing 4 and the insertion portion 2a, and an insertion portion 2a between the packing 4 and the pressing ring 5 is provided.
A ring-shaped centering member 8 is externally fitted to the outer peripheral surface of.

The outer peripheral surface of the centering member 8 on the side of the pressing wheel 5 is
A gentle taper surface 8a whose diameter gradually decreases toward the side. The thickness of the aligning member 8 is set to be approximately one half of the maximum gap formed between the annular pressing portion 5a of the pressing wheel 5 and the insertion portion 2a.

The aligning member 8 is made of a relatively hard material having a small coefficient of friction, for example, a synthetic resin material such as ultra-high molecular weight polyethylene, fluororesin, polyacetal, and polycarbonate.

To connect the tubes 1 and 2, first,
From the opening end of a, the pressing wheel 5, the aligning member 8, and the packing 4 are
After external fitting in order, the insertion port 2a is inserted into the reception port 1a.

Next, after the packing 4 is inserted into the gap 3 to such an extent that it can be pushed in by hand, as shown in FIG.
The flanges 1b and 5b of the receiving portion 1a and the pressing wheel 5 are temporarily fixed to each other by a T-head bolt 6 and a nut 7. In this state, the pressing wheel 5 is suspended from the top of the insertion portion 2a by its own weight, and a gap is formed at the bottom of the tube.

Then, when each nut 7 is tightened gradually and evenly, the centering member 8 is pushed in the axial direction by the pressing wheel 5 and comes into contact with the packing 4. Still further, when the nut 7 is tightened, the inner peripheral edge of the annular pressing portion 5a near the top of the pressing wheel 5 slides on the tapered surface 8a of the aligning member 8 and rides up. It is pushed upward toward.

Then, when the annular pressing portion 5a moves to the upper surface of the horizontal portion of the centering member 8, as shown in FIG.
a and the press ring 5 are aligned substantially concentrically, and a substantially uniform gap is formed between the outer peripheral surface of the insertion portion 2a and the inner peripheral surface of the annular pressing portion 5a.

When the nut 7 is further tightened in this state,
The packing 4 is strongly pressed by the annular pressing portion 5a and is pushed into the gap 3, and the watertightness of the joint between the two pipes 1 and 2 is ensured.

At the time of centering of the pressing wheel 5, the annular pressing portion 5a can easily and smoothly ride on the tapered surface 8a of the centering member 8 having a small friction coefficient. Therefore, an excessive load acts on the alignment member 8 or the alignment member 8
There is no fear that the packing 4 will strongly press the packing 4, and the packing 4 will be pressed only in the tube axis direction by the pressing force of the pressing ring 5.

As a result, unlike the conventional pipe joint in which the alignment tongue is integrally formed with the packing 4, the packing 4 is not strongly pressed in the radial direction, and the sliding resistance is reduced. By tightening each nut 7 uniformly,
The pressing force of the packing 4 is also uniform, and the sealing performance can be improved.

FIGS. 3 and 4 show a modification of the centering member.

The centering member 9 shown in FIG. 3 has a semicircular two-piece structure so that it can be fitted on the outer peripheral surface of the insertion portion 2a. In the case of this example, it is preferable to fit outside so that the butted end faces are not located near the pipe top.

The centering member 10 shown in FIG. 4 is formed in a partially circular shape in which approximately one-fourth in the circumferential direction has been cut out, and is elastically deformed in the radially expanding direction as shown by the imaginary line, so that the centering member 10 is attached to the opening 2a. It is designed to fit.

As described above, if the centering members 9 and 10 are divided into two or are formed in a broken circle, the above-described ring-shaped centering member 8 can be
While it can be used only when newly connecting the pipes 1 and 2, it can be used for an existing pipe joint in which the insertion port 2a is inserted into the reception port 1a.

FIGS. 5 and 6 show modified examples of the centering members 8 and 9 having the above-mentioned two-divided or missing circular structure.

FIG. 5 shows an arrangement in which a plurality of needle-like projections 11 are continuously provided on the right end faces of the aligning members 8 and 9, and the needle-like projections 11 are pierced into the left end face of the packing 4. 2a.

FIG. 6 shows a tube 2 used when the tube 2 is made of an iron tube such as ductile cast iron. A permanent magnet 12 is embedded in a centering member 9.

By doing so, the aligning members 8 and 9
Is formed by the attraction force of the needle-like projection 11 or the magnet 12.
Since it is held on the outer peripheral surface of a and is prevented from falling and rotating in the circumferential direction, workability is improved.

FIG. 7 shows that the aligning members 8 and 9 are formed at the right end with a run-off preventing piece 13 projecting beyond the outer diameter of the aligning members 8 and 9. It is composed of a very thin member.

When the nut 7 is gradually tightened as shown in FIG. 8 using the aligning member 8, the annular pressing portion 5 a rides on the tapered surface 8 a of the aligning member 8. For example, when the aligning member 8 is difficult to slide forward, the pressing wheel 5 overtakes the aligning member 8 and does not serve as the aligning member 8. However, according to the present embodiment, the riding-up preventing piece 13 of the centering member 8 comes into contact with the annular pressing portion 5a of the pressing wheel 5, so that the centering member 8 moves forward together with the pressing wheel 5.

The present invention is not limited to the above embodiment. For example, the materials of the aligning members 8, 9 and 10 are as follows.
In addition to the above-mentioned synthetic resin, it may be formed of stainless steel or other metal which is hardly corroded (a metal which can be elastically deformed when formed into a broken circle) or hard rubber.

When the pipe 2 has a large diameter, it may be divided into two or more pieces.

Further, since the centering action of each centering member is performed by pushing up the pressing wheel 5 in a suspended state, the centering member formed in an arc shape is placed at least in the pipe top region of the insertion portion 2a. It may be provided only.

The present invention can, of course, be applied to various pipe joints having a detachment prevention mechanism.

[0045]

According to the present invention, the following effects can be obtained.

(A) Since the alignment member is provided separately from the packing, the packing is not strongly pressed in the radial direction at the time of alignment as in the prior art, so that the sliding resistance is reduced. The pressing force of the packing becomes substantially uniform, and the sealing performance can be greatly improved. In addition, since a commercially available normal packing can be used, the cost can be reduced.

(B) According to the second aspect of the invention, the centering member can slide smoothly on the outer peripheral surface of the insertion portion, and the pressing portion of the pressing wheel easily and smoothly rides on the tapered surface.

(C) According to the third and fourth aspects of the present invention, since the alignment member is held on the outer peripheral surface of the insertion portion, workability is improved.

(D) According to the invention of claim 5, it can be easily attached to an existing pipe.

(E) According to the sixth aspect of the present invention, since the pressing wheel advances reliably together with the alignment member, the function of the alignment member can be secured.

[0051]

[Brief description of the drawings]

FIG. 1 is a central longitudinal side view showing a state before a press wheel is tightened in an embodiment of the present invention.

FIG. 2 is a central vertical cross-sectional view showing a state after the press wheel tightening is completed.

FIG. 3 is a front view of an alignment member having a two-part structure.

FIG. 4 is also a front view of a centering member having a partially circular shape.

FIG. 5 is an enlarged vertical sectional view of a main part of an alignment member having needle-like projections.

FIG. 6 is an enlarged vertical sectional view of an alignment member in which a permanent magnet is embedded.

FIG. 7 is an enlarged vertical cross-sectional view of an alignment member having a run-off preventing piece.

FIG. 8 is an enlarged cross-sectional view showing a state at the time of press wheel tightening using the alignment member of FIG. 7;

FIG. 9 is a central longitudinal side view showing a conventional pipe joint.

[Explanation of symbols]

 1, 2 Pipe 1a Receptacle 1b Flange 2a Insertion 3 Gap 4 Packing 5 Pressing ring 5a Annular pressing part 6 T-head bolt 7 Nut 8, 9, 10 Alignment member 8a Tapered surface 11 Needle-like projection 12 Permanent magnet 13 Ride prevention piece

Claims (6)

[Claims] An insertion portion of the other tube is loosely inserted into a reception portion of one of the tubes, and is inserted into a gap between an inner peripheral surface of the reception portion and an outer peripheral surface of the insertion portion. In a pipe joint in which the packing is strongly pressed by fastening a press ring externally fitted to the insertion portion to the reception portion to connect the two pipes, an insertion portion between the packing and the press ring At least in the pipe top region of the outer peripheral surface, the outer peripheral surface forms a tapered surface whose diameter is gradually reduced toward the pressing wheel side, and the inner peripheral edge of the pressing portion of the pressing wheel rides on the tapered surface, so that the pressing ring is formed. A pipe joint comprising a centering member which is pushed up in a centripetal direction to a position concentric with a receiving portion. 2. The pipe joint according to claim 1, wherein the alignment member is made of a hard synthetic resin material having a small coefficient of friction. 3. An end face on the packing side of the centering member,
The pipe joint according to claim 1, further comprising a needle-like projection. 4. The pipe joint according to claim 1, wherein a permanent magnet is provided at a key point of the alignment member. 5. The pipe joint according to claim 1, wherein the aligning member is formed of a material that can be elastically deformed in a radial direction and is formed in a partially circular shape. 6. An end face on the packing side of the centering member,
The pipe joint according to claim 1, further comprising a riding-up preventing piece extending outward.