JP2001159482A - Pipe with pipe end core and mechanical joint for pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe with a pipe end core allowing a mechanical joint to be previously and temporarily assembled into one unit, on which the pipe end core is mounted for inserting the pipe mounted with a core packing, and to provide the mechanical joint. SOLUTION: The outer diameter of the pipe end core 17 is made smaller than the outer diameter of the pipe 11. A joint body 33 has a pipe end storage portion 43 for receiving the end of the pipe and a packing slide-contact portion 45 having a smaller inner diameter. The inner diameters of a packing 49, packing thrusting member 55, lock ring 57, lock ring thrusting member 63, seating member 81, and cap nut 71 are larger than the outer diameter of the pipe 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe used for water supply pipes, and more particularly to a steel pipe having a pipe end core and a joint used to connect the pipes.

[0002]

2. Description of the Related Art Steel pipes are used for water supply pipes. This tube is cut into lengths for use.
Rust is generated at the cut end during use when embedded and used. In order to prevent the rust from entering the pipe, a pipe end core is attached to the end, and is connected to another pipe or device using a mechanical joint. FIG. 2 shows an example of a conventional pipe having a pipe end core and a mechanical joint.

In the figure, reference numeral 1 denotes a pipe to be connected,
The tube 1 is made of, for example, steel. The connected end 1a
, A pipe end core 2 is press-fitted and attached at an insertion portion 2a at one end thereof. The distal end portion 2b of the pipe end core 2 is located outside the pipe 1 in a state where a shoulder 2c formed at the boundary with the press-fitting portion 2a is in contact with the end face of the pipe. A circumferential groove 2d is formed in the outer peripheral portion, and a packing or a core packing 3 for sealing between a joint body described later is received in the groove 2d. This packing 3
Is usually U-shaped to facilitate insertion into the joint.
The shape is U-shaped (U-packing) or V-shaped (V-packing). As shown in the drawing, the outer diameter of the tube end core 2 is substantially equal to the outer diameter of the tube 1, and the outer diameter of the core packing 3 in a free state (attached to the groove 2 d of the tube end core 2) is the outer diameter of the tube 1. It is getting bigger.

Reference numeral 4 denotes a mechanical joint. The joint body 5 has a small-diameter portion 5a, an intermediate portion 5b having an inner diameter larger than the small-diameter portion 5a, and a large-diameter portion 5d having an inner diameter larger than the intermediate portion 5b.
And a packing storage portion 5c including an inclined portion 5e. The inclined portion 5e is a portion connected from the large diameter portion 5d to the intermediate portion 5b, and has an inner peripheral surface which is inclined so as to gradually reduce the diameter toward the intermediate portion 5b. Reference numeral 6 denotes a packing arranged on the outer periphery of the pipe 1 and received in the packing storage portion 5c, and is compressed to seal between the pipe 1 and the joint body 5. Reference numeral 7 is a washer, and reference numeral 8 is a lock ring. The lock ring 8 is provided with a projection or a claw 8a on the inner periphery thereof, is further divided at a certain position in the circumferential direction, and is reduced in diameter by applying an external force. The outer circumference 8b side of the lock ring 8 is inclined, and its outer shape becomes smaller as it goes away from the washer 7. Reference numeral 9 denotes a cap nut, which is formed with a female screw that is screwed with a male screw formed on the outer periphery of the large diameter portion 5d of the packing storage portion 5c of the main body 5. Further, the inner peripheral side of the rear end is a radial slope corresponding to the outer periphery 8 b of the lock ring 8.

[0005] In the joint having the above-described structure, the pipe end core 2 is press-fitted into the pipe 1 and attached, and is inserted into the intermediate portion of the main body 5 with the core packing 3 mounted in the groove 2d. Then, when the cap nut 9 is screwed into the main body 5 and tightened, the lock ring 8 and the washer 7 move forward as the cap nut advances (moves to the right in FIG. 2), and the packing 6 is stored in the packing storage portion 5c. Compress. At this time, the diameter of the lock ring 8 gradually decreases, and finally the lock ring 8 bites the outer periphery of the tube 1. When the cap nut 9 is further turned to compress the packing 6, the pipe 1 also advances at the same time, and the distal end face of the pipe end core 2 comes into contact with the shoulder 5f between the small diameter section 5a and the intermediate section 5b of the main body 5. In this state, the space between the pipe 1 and the main body 5 is sealed by the core packing 3 and the packing 6. Then, since the lock ring 8 bites into the pipe 1, the lock ring 8 is prevented from coming off.

By the way, in the pipe and the joint having the above configuration, the outer diameter of the tip 2b of the pipe end core 2 is substantially equal to the outer diameter of the pipe 1, and the core packing 3 attached to the groove 2d is not used. The outside diameter is much larger than the outside diameter of the tube 1 in order to take a sufficient compression allowance. Therefore, the packing 6, the washer 7, the lock ring 8 and the
When the cap nut 9 is screwed into the main body 5 and temporarily fixed, the core packing 3 to which the core packing 3 is attached is inserted into the end of the pipe 1 and the core packing 3 is locked. It cannot be inserted by hitting the ring 8, the washer 7, and the packing 6. Further, even if the packing 6 can be deformed and inserted, the core packing 3 is damaged by the protrusion 8a on the inner peripheral side of the lock ring 8, and the sealing performance is reduced.

Therefore, when connecting the pipe 1 using a joint of this type, a cap nut 9, a lock ring 8, a washer 7 and a packing 6 are first mounted on the pipe 1, and then the pipe end core 2 is mounted on the distal end. After the core packing was mounted, the pipe 1 was inserted into the main body 5 and the nut 9 was turned and tightened. Since this work is performed at the site of the piping, it is necessary to manage each part individually, and the connection work at the site takes a long time.

Further, even after the lock ring 8 digs into the pipe 1, it is necessary to further tighten the cap nut 9 in order to sufficiently compress the packing 6 and obtain a good seal. Since it advances with respect to the main body 5, it is necessary to secure a certain clearance between the end 2b of the tube end core 2 and the shoulder 5f of the main body 5 in advance. Therefore, when the pipe 1 is inserted into the main body, once the pipe end core 2 is
Is inserted to a position where it comes into contact with the first part, and thereafter, it is returned backward by a certain length, so that the operation is complicated.

Further, when the cap nut 9 is rotated after the lock ring 8 has pierced the pipe 1, the pipe 1 is also rotated (co-rotation), and the opposite side of the connected pipe 1 is loosened. . To prevent it, use another tool to
To tighten the cap nut while preventing rotation of the tube 1.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems relating to the connection of a pipe with a conventional pipe end core, and is intended to improve the efficiency of pipe connection work. An object of the present invention is to provide a pipe with a pipe and a mechanical joint for the pipe.

[0011] Specifically, packing,
Provide a mechanical joint with a washer and a lock ring, temporarily fixing the cap nut to the joint body, providing these as a joint unit, and allowing the tube with the pipe end core and core packing attached to be directly inserted into the joint unit. Is the task.

Another object of the present invention is to provide a mechanical joint which can prevent the pipe from rotating when the cap nut is rotated after the lock ring has digged into the pipe.

It is still another object of the present invention to provide a tube with a tube end core that can be inserted into a mechanical joint without damaging the tube end core and the core packing.

It is still another object of the present invention to provide a pipe with a pipe end core which secures a clearance in advance for allowing the pipe to advance after the lock ring has broken into the pipe and does not require the pipe to be pulled back. It is an issue of.

[0015]

In order to solve the above-mentioned problems, according to the present invention, a pipe end core having an outer diameter smaller than the outer diameter of the pipe is attached to an end of the pipe and formed on the pipe end core. A core packing is attached to the circumferential groove to form a tube with a core at the tube end. On the other hand, the mechanical joint has a pipe end storage portion for storing the end of the pipe and a core packing sliding contact portion having a smaller inside diameter and a core packing slidingly contacting the main body, and surrounding the pipe such as packing, a lock ring and the like. The inner diameter of the member is larger than the outer diameter of the tube.

In one embodiment, the tube end core further comprises:
A deformable inclined extension is provided which extends obliquely with respect to the axial direction of the pipe from a packing receiving portion on which the core packing is mounted.

In still another embodiment, the lock ring and the cap nut are disposed in contact with the lock ring and the cap nut, and when the cap nut is tightened against the joint body, the force received from the cap nut is reduced. A pressing member that acts on the lock ring as an axial pressing force in the direction toward the packing, a radial pressure that reduces the diameter of the lock ring, and a surface between the cap nut and the pressing member that abut against each other. Done,
A thin sheet member made of a material having a low coefficient of friction.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings, but the scope of the present invention is not limited to the embodiments described below.

FIG. 1 is a cross-sectional view showing a state in which a pipe 11 with a pipe end core for piping according to the present invention is inserted into a mechanical joint 31, and a cap nut 71 has not yet been tightened. In the figure, reference numeral 11 denotes a pipe for piping. Tube 1
1 is made of steel. Connection end 13 which is the side to be connected
Is provided with a pipe end core 17.

In the present embodiment, the tube end core 17 is made of resin, and for example, polyethylene or the like can be used as a material. The pipe end core 17 is a hollow member, and has a cylindrical mounting portion 19 which is press-fitted into the connection end portion 13 of the pipe 11.
It has. Although not shown, a rib or fold extending in the circumferential direction is formed on the outer periphery of the mounting portion 19, and when the rib or the fold is pressed into the tube 11, the rib or fold is collapsed.
And the tube end core 17 can be sealed.

The tube end core 17 is coaxially connected to the mounting portion 19, and has a cylindrical core packing mounting portion 21 having a larger outer diameter than the mounting portion 19, and further includes a core packing mounting portion 21 to the mounting portion 19. And a cylindrical extension 23 extending coaxially to the opposite side and having a smaller outer diameter than the core packing mounting portion 21. A groove 25 extending in the circumferential direction is formed on the outer periphery of the core packing mounting portion 21. In this groove 25, a core packing 29 of the same type as the conventionally used U-packing or V-packing is received and mounted. An inclined portion 27 is formed extending from the root portion of the extension portion 23, that is, a portion connected to the core packing attachment portion 21 while being inclined with respect to the axis of the tube end core 17. In the present embodiment, the inclined portion 2
7 is an integrated divergent portion whose diameter increases as the distance from the core packing attachment portion 21 increases.
A type divided into a plurality in the circumferential direction may be used. This inclined portion 27 will be described later. The pipe end core 17 has an end face 22 on one side of the core packing mounting portion 21 and an end face 1 of the pipe 11.
5 is attached in a state of contact. As shown, the outer diameter of the core packing mounting portion 21 of the pipe end core 17 is smaller than the outer diameter of the pipe 11. Further, the outer diameter of the core packing 29 attached to the tube end core 17 is larger than the outer diameter of the core packing attaching portion 21 in a free state, that is, in an uncompressed state, enough to secure a compression allowance. However, it is smaller than the inner diameter of a lock ring 57 and the like described below,
In the present embodiment, the outer diameter is equal to the outer diameter of the tube 11 or is at most about 0.2 mm.

Reference numeral 31 denotes a mechanical joint, and reference numeral 33 denotes a joint main body. The joint main body 33 includes a packing storage portion 35 serving as an insertion port of the pipe 11, and the packing storage portion 3 is provided.
5 is a straight portion 37 on the end side and an inclined portion 39 connected thereto.
It consists of The straight portion 38 has a substantially cylindrical shape and includes an inner peripheral surface 38 having the same inner diameter, and the inclined portion 39 has an inner peripheral surface 40 whose inner diameter decreases as the distance from the straight portion 37 increases.
It has. On the outer periphery of the straight portion 37, a male screw 41 into which a cap nut 71 described later is screwed is formed.

Reference numeral 43 denotes a tube end storage portion formed following the packing storage portion 35, which is a portion for storing the end portion 13 of the tube 11 as shown in the drawing, has a substantially cylindrical shape, and has an inner diameter. Is slightly larger than the outer diameter of the tube 11. Code 4
Reference numeral 5 denotes a substantially cylindrical packing sliding contact portion having an inner diameter smaller than that of the tube end storage portion 43. The inner diameter is the same as or slightly larger than the outer diameter of the core packing attaching portion 21 of the tube end core 17, and Reference numeral 29 is a dimension that is sufficiently compressed in the radial direction. The joint main body 33 is further provided with a substantially cylindrical small-diameter portion 47 having an inner diameter smaller than that of the packing sliding contact portion 45. When the pipe 11 is inserted into the pipe joint main body 33 by a predetermined length, the tip end portion 28 of the inclined portion 27 of the pipe end core 17 is attached to the end surface 48 of the small diameter portion 47 on the packing sliding contact portion 45 side. It comes into contact.

Reference numeral 49 surrounds the periphery of the pipe 1 and
3 is an annular packing received in the packing storage portion 35, the outer peripheral surface 51 of which is in contact with the inner peripheral surfaces 38 and 40 of the packing storage portion 35. Inner diameter in free state is tube 1
In the state where the cap nut, which is larger than the outer diameter of No. 1 and is illustrated, and which will be described later, is not yet tightened, there is a slight gap between the inner peripheral surface 53 and the outer peripheral surface of the pipe 11.

Outside the packing 49, a plate-shaped packing pressing member 55 whose both side surfaces are substantially parallel is arranged. The packing pressing member 55 has an annular shape, the inner diameter of which is slightly larger than the outer diameter of the pipe 11, and the outer diameter of which is smaller than that of the packing housing 35.
The dimension corresponds to the inner diameter of the straight portion 37, and is movable in the axial direction of the joint body 33 along the straight portion 37.

The packing 4 is sandwiched between the packing pressing members 55.
A lock ring 57 is arranged on the side opposite to 9. The lock ring 57 is formed by dividing an annular member at a certain position in the circumferential direction. In a free state, there is a gap between both ends at that position, and when an external force is applied, the diameter is reduced while narrowing the gap. It is supposed to. Since this configuration is publicly known, detailed description is omitted. A claw 59 is formed on the inner peripheral side of the lock ring 57. Further, the outer peripheral surface 61 is formed on a slope such that the outer diameter decreases as the distance from the packing pressing member 55 increases. The inner diameter of the lock ring 57 in the illustrated state is larger than the outer diameter of the tube 11.

Reference numeral 63 denotes an annular lock ring pressing member, the inner peripheral surface 65 of which is a slope having a shape corresponding to the outer peripheral surface 61 of the lock ring 57, and this portion comes into contact with the lock ring 57. ing. The inner diameter of the lock ring pressing member 63 is larger than the outer diameter of the tube 11.

Reference numeral 71 denotes a cap nut, and its female screw 7
3 is screwed into the male screw 41 of the joint body 33,
It is attached to the joint body 33. As shown in the drawing, the cap nut 71 receives the lock ring 57, the lock ring pressing member 63, and the like therein, and has a top wall 75 thereof.
Is formed with a hole 77 into which the tube 11 is inserted. Then, the inner surface 79 of the top wall 75 is
Is opposed to the outer side surface 67. Inner surface 79 and outer surface 67
An annular thin sheet member 81 is disposed between the two. The sheet member 81 is made of a material having a relatively small coefficient of friction, for example, a resin such as Teflon.

The procedure for connecting the pipe 11 to the mechanical joint 31 will be described. The packing 49, the packing pressing member 55, the lock ring 57, the lock ring pressing member, the 63 sheet member 81 and the cap nut 71 are attached to the mechanical joint body. Are assembled in advance in the state shown in the figure to form a unit. In this state, the cap nut 71 need only be screwed into the main body 33 to such an extent that it does not come off, and it is not necessary to tighten the screw to compress the packing 49. The tube end core 17 is attached to the mechanical joint 31 made into a unit, and the tube 11 to which the core packing 29 is attached is inserted. At this time, as described above, the packing mounting portion 2 of the pipe end core 17 is used.
The outer diameter of the core packing 29 is smaller than the outer diameter of the pipe 11.
Is smaller than the inner diameter of the lock ring 57 or the like by the same degree or slightly larger than the outer diameter of the pipe 11.
Since the outer diameter of 1 is smaller than the inner diameter of the lock ring 57 and the like,
The lock ring 57 does not hinder the insertion of the tube 11, and the core packing 29 is not damaged. The pipe 11 has a tip end portion 28 of an inclined portion 27 of the pipe end core 17.
Until it contacts the inner surface 48 of the small diameter portion 47 of the joint body 33.

Next, the cap nut 71 is tightened. Cap nut 71
Is tightened against the joint body 33, the pressing force is applied to the sheet member 81, the lock ring pressing member 63, the lock ring 57, the packing pressing member 55, and the packing 49. It is crimped and seals this part. The lock ring 57 moves in the axial direction, and its diameter decreases, bites into the tube 11, and prevents the tube 11 from falling off. In addition, cap nut 7
When 1 is tightened, the inclined portion 27 of the tube end core 17 is deformed, so that the tube 11 is also moved with respect to the joint main body 33 and the packing 49 is further compressed. At this time, since the coefficient of friction of the sheet member 81 is small, even when the cap nut 71 rotates, slippage occurs between the cap nut 71 and the sheet member 81 or between the sheet member 81 and the lock ring pressing member 63, The lock ring 57 and the tube 11 are prevented from rotating together with the cap nut 71.

[0031]

As described in detail above, according to the present invention,
Since the mechanical joint is preassembled in advance, and the pipe with the pipe end core attached and the core packing attached thereto can be inserted, the efficiency of the pipe connection work is greatly improved. In this case, since the mechanical joint can be temporarily assembled and unitized and managed, it is extremely convenient compared to the conventional case where the mechanical joint is managed by individual parts. Further, the operation of pulling back the previously inserted tube by a predetermined length, which has been conventionally performed, is not required. In addition, rotation of the pipe when tightening the cap nut is also prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an attached state of a pipe and a mechanical joint according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a conventional pipe and a mechanical joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Pipe for pipe 17 Pipe end core 21 Packing attachment part 25 Groove 29 Core packing 27 Inclined extension part 31 Mechanical joint 33 Joint body 35 Packing storage part 43 Pipe end storage part 45 Packing sliding contact part 49 Packing 55 Packing pressing member 57 Lock Ring 63 Lock ring pressing member 71 Cap nut 81 Seat member

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshinori Nakata 3046, Sasaga, Matsumoto-shi, Nagano F-term in Nichigo Valve Co., Ltd. 3H015 CA01 CA03 CA13

Claims (4)

[Claims] 1. A steel pipe for use in water supply pipes having a pipe end core at least at one end of the pipe, wherein the pipe end core is inserted into the one end of the pipe. And a packing receiving portion that is located outside the pipe and receives a sealing core packing in a circumferential groove formed on the outer circumference thereof, and the outer circumference of the packing receiving section is at least the outer circumference of the pipe. A pipe having a pipe end core, which is smaller than an outer diameter at a predetermined length from one end. 2. A steel pipe used for a water supply pipe and having a pipe end core at least at one end of the pipe, wherein the pipe end core is inserted into the one end of the pipe. And a packing receiving portion which is located outside the pipe and receives a sealing core packing in a circumferential groove formed on the outer periphery thereof, and the pipe end core further comprises: A pipe for piping characterized by having a deformable inclined extension part which extends obliquely with respect to the axial direction of the pipe. 3. A hollow joint body for receiving a pipe for connection from one end side, a packing disposed in a packing storage portion provided inside the one end side of the joint body, and surrounding the pipe. A lock ring that is disposed outside the packing in the axial direction of the joint body, surrounds the pipe, and is reduced in diameter under the action of an external force. And a cap nut for exerting an axial pressing force in a direction toward the packing and a radial pressure for reducing the diameter of the lock ring, and the packing, the lock ring, and an inner diameter of the cap nut are provided. Greater than the outer diameter of the tube,
The joint body is provided adjacent to the packing accommodating portion, and has a tube receiving portion that receives the insertion side end of the tube, an inner diameter smaller than the tube receiving portion, and is attached to the insertion side end of the tube. A mechanical joint, wherein the core packing includes a packing sliding contact portion that slides in a liquid-tight manner. 4. A hollow joint main body for receiving a pipe for connection from one end side, a packing disposed in a packing storage portion provided inside the one end side of the joint main body, and surrounding the pipe. A lock ring disposed outside the packing in the axial direction of the joint body, surrounding the pipe, and reducing its diameter under the action of an external force; a cap nut screwed and attached to the joint body; Between the ring and the cap nut, they are arranged in contact with them, and when the cap nut is tightened against the joint body, the force received from the cap nut is applied to the lock ring with respect to the lock ring. The pressing force in the axial direction toward the packing, the pressing member acting as a radial pressure for reducing the diameter of the lock ring, and the cap nut and the pressing member abut on each other. A thin sheet member made of a material having a low coefficient of friction disposed between the surfaces.