JPH041431Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention uses a biting ring in an unprocessed state without providing grooves or welding shoulders at both connecting ends of the pipes to be connected. This relates to a housing-type pipe joint that prevents pipes from being pulled out.

[Prior Art] Conventionally, as shown in Fig. 3 disclosed in Japanese Utility Model Publication No. 56-39833, there is a ring-shaped gasket that straddles both connecting ends of a pipe to be connected, and a gasket that is to be connected to both ends of this gasket. It is fitted with a pair of split rings that have a sawtooth shape on the inside that bites into the outer periphery of the tube, and a tapered shape on the outside that becomes smaller in diameter toward each other, and is cylindrical and has a plurality of split rings, and the center of the inner circumferential surface. The housing is equipped with a concave groove for crimping the gasket, and a tapered groove for engaging the split ring on both ends of the inner circumferential surface, with the outer end gradually becoming smaller in diameter.The housing is tightened from the outer circumferential side, and after the pipe is connected, a pulling force is applied to the pipe. A housing-type pipe joint is known in which, when the split ring engages with the tapered surface of the housing, the diameter decreases as it moves outward, thereby biting into the pipe more strongly and exerting a force to prevent the pipe from being pulled out. .

[Problems to be solved by the invention] In the above pipe joint, when the housing is tightened,
There is a risk that the split ring may shift toward the larger diameter side of the groove, and the reliability of preventing the pipe from coming out is actually low. Furthermore, since the pipes must be connected while overcoming this problem, the connection work is troublesome. In addition, since split rings are generally serrated, the depth of bite is relatively shallow.For example, when connecting a resin-coated pipe, there is a risk that the resin-coated portion may peel off and the pipe may be pulled out. I couldn't help it. In addition, in piping to which a tube drawing force and axial compression force are applied alternately, or to piping to which only compression force is applied, the split ring hardly bites into the outer periphery of the tube, resulting in poor reliability of the piping. The present invention provides a pipe joint that solves the above problems.

[Means for solving the problem] The present invention includes a packing that surrounds the outer periphery of both connecting pipe ends where the pipes to be connected are brought into contact with each other,
A housing-type pipe joint that connects the pipe by fastening a plurality of housings divided on the pipe circumference to each other, the housing-type pipe joint having an annular packing tightly attached to the outer periphery of both ends of the connecting pipe, and a blade portion on the inner surface, A plurality of grip members each having a smooth spherical outer surface are arranged around the entire circumference of the tube, and a pair of lock members are held together in an annular shape by a rubber band, and a pair of lock members are provided approximately at the center of both ends of the connecting tubes. an annular packing groove for accommodating the annular packing at a portion thereof; and an annular packing groove for accommodating the annular packing at both outer sides of the groove, and an inner circumferential surface that accommodates the lock member at both outer sides of the groove and comes into contact with the outer surface of the end portion of the grip member, and both tapered surfaces having a small diameter on both sides. This is a housing-type pipe joint consisting of a housing having an annular locking groove formed in a substantially umbrella-shaped cross section.

[Function] The inner circumferential surface of the locking groove provided at both ends of the packing groove of the housing is formed into an umbrella-shaped tapered surface with a small diameter on both end sides, so it resists the stress of the tube's pulling force and compressive force. The locking member acts as a biting force against the outer circumferential surface of the pipe, and since the inner side of the locking member is provided with a cutting edge around the circumference, it stably engages with the umbrella-shaped inner circumferential surface of the locking groove, and the locking member acts in the direction of pulling out the pipe. ,
The diameter reduction of the locking member works stably in both compression directions. In addition, since the back side of the grip member is formed into a smooth spherical surface, it slides smoothly in the lock ring groove when the housing is tightened, and the diameter of the grip member is easily reduced. It is in a cutting state and the initial bite is easily performed.

[Example] An example of the present invention will be described with reference to the drawings. FIG. 1 is an enlarged sectional view of a connecting portion showing an embodiment of the present invention. An annular lip packing 3 is fitted over both connecting ends of the pipes 1 and 2 to be connected. Both ends of this packing 3 have circumferential blades on the inner surface,
On the outer surface, a locking member 4 is fitted onto the connecting pipes 1 and 2, and the locking member 4 is made up of a plurality of hemispherical grip members 4c arranged on the circumference and connected and held in an annular shape by a rubber band 4b. Further, a plurality of parts, for example, a two-part tightening housing 5 is provided, and the housing 5 is tightened with bolts and nuts. A packing groove 3a for uniformly compressing the back surface of the packing 3 over the entire circumference is provided in the center of the inner circumferential surface of the housing 5, and locks fitted into the tubes 1 and 2 are provided on the inner surfaces of both ends of the packing groove 3a. A locking groove 6 is provided in which the member 4 is loosely fitted, and the locking groove 6 has umbrella-shaped tapered surfaces 61 and 62 with small diameters on both ends of its inner peripheral surface. In addition, stopper surfaces 63 and 64 are provided at both ends of the lock ring groove 6 in the form of flanges.
The length and taper angle of the lock ring groove 6 are set to be longer than the diameter 4d of the grip member 4c so that the circumferential blade portion 4a of the lock member 4 bites into the pipes 1 and 2 to a predetermined depth. .

The results of an accuracy test of the housing type pipe joint of this example on a steel water pipe diameter of 300A are shown below.
Housing tightening torque: M22 bolt, 18Kgf・
m.

A Water pressure test results show that there is no leakage up to a sealed water pressure of 70Kgf/ ^cm2 , and the amount of pipe leakage at 70Kgf/ ^cm2 is approximately 10mm.

B. As a result of the bending test, a bending load is applied to the center of the pipe while a water pressure of 10 kgf/cm ² is applied inside the pipe. Maximum bending moment 6700Kgf・m.

No leakage up to a maximum bending angle of 8.2 degrees.

C Repeated pressurization Water pressure test: Water pressure of 5Kgf/cm ² and 20Kgf/cm ² is repeatedly applied every 10 seconds with the sample assembled.

No leaks or other abnormalities after 10,000 repetitions.

D. Repeated bending load test: A bending load with a bending angle of 1° is applied alternately from two directions to the center part with a water pressure of 10 kgf/cm ² enclosed.

Repeated over 200 times, no leaks or other abnormalities.

E. Tensile test: Both ends of a directly connected tube are pulled under a water pressure of 10 Kgf/cm ² .

No leaks or other abnormalities up to the maximum tensile load of 49 tons.
The amount of tube coming out at that time was 25mm.

F. Repeated expansion/contraction test, with a water pressure of 10 Kgf/cm ² enclosed, tension amount 8 mm and compression amount 6 mm (total width 14 mm) are conducted alternately.

No leaks or other abnormalities after 200 expansions and contractions.

G. External pressure test: Assemble the sample (atmospheric pressure inside the sample), seal both ends of the tube, place it in a pressurized container, and maintain the water pressure inside the container at 10 Kgf/cm ² .

The water pressure inside the container does not change even if it is kept for more than 72 hours.

H Flattening/stretching test: Apply a water pressure of 10 Kgf/cm ² to the sample to flatten the pipes on both sides of the joint by 5% of the outer diameter, and then apply tension and compression loads alternately with an expansion/contraction amount of ±6 mm (total width 12 mm).

No leaks or other abnormalities after 200 expansions and contractions.

I Shear test: Apply a shear load to the pipe on one side of the joint connection with a water pressure of 10 kgf/cm ² sealed inside the sample.

No leaks or other abnormalities up to a shear load of 35t.

The shear displacement at that time was 80mm.

J Submersion test, water depth 3m with sample assembled
Leave it in water. Water on the inside and outside of the pipe.

After being left unattended for over a month, I took it out and observed it, and there was no change in the corrosion state of the grip parts of the joint.

As mentioned above, it showed good results even in various severe tests, and was able to obtain sufficient performance as a joint for large-diameter underground water pipes.

In this embodiment, the grip member 4c has an outer diameter of 4d.
Although the circumferential blade part 4a is formed around the inner circumference of the cylindrical shape, the outer circumference may be formed into a polygonal shape, the inner blade part may be formed into a polygonal blade part, or the inner blade part may be formed into a polygonal shape. may be provided intermittently around the cylindrical periphery.

[Effect] With this configuration, the housing 5 is divided into two parts.
When tightened, the circumferential blade portion 4a of the lock member 4 will
Since they are provided alternately with the circumferential rubber bands 4b, they are pressed from the back side of the locking member 4 and the tubes 1, 2
It easily bites into the outer peripheral surface, and both tubes 1 and 2 are locked to the housing 5. Furthermore, after the pipes are connected, even if the pipe pulling force due to heating and cooling of the pipes and the axial compressive force are applied alternately, or even if only the compressive force is applied, the locking member 4 will not fit inside the umbrella-shaped taper of the locking groove 6. Due to the action of the peripheral surfaces 61 and 62, the locking groove bites deeper and provides stable and strong pipe locking performance in both axial directions. Because it is long, it can expand and contract accordingly, and the safety of the piping can be measured. In addition, since the cross section of the back side of the grip member is formed into a smooth convex surface, it slides smoothly on the umbrella-shaped taper inner circumferential surfaces 61 and 62 of the locking groove, making it easy to reduce the diameter of the grip member. It also cuts into the surface easily. In particular, when the tubes 1 and 2 are resin-coated tubes, the coating part and the tube body are completely bitten, and the depth of biting into the tube can be set to a predetermined depth by the stopper surfaces 63 and 64, so that the optimum biting state can be achieved. can be obtained. Further, since the rubber band 4b is an elastic body and easily expands and contracts, it is easy to attach it to the tube.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, FIG. 1 is an enlarged sectional view of the main part of the connection part, FIG. 2 is a diagram showing the locking member,
FIG. 3 is a sectional view of a main part of a conventional pipe joint. DESCRIPTION OF SYMBOLS 1, 2...Pipe, 3...Packing, 4...Lock member, 5...Housing, 6...Lock ring groove, 4a...Circumferential blade portion.

Claims (1)

[Claims for Utility Model Registration] A packing is provided that surrounds the outer periphery of the ends of both connecting tubes where the tubes to be connected are butted against each other, and the tubes are connected by fastening together housings that are divided into a plurality of pieces on the circumference of the tubes. The housing-type pipe joint includes: an annular gasket that tightly contacts the outer periphery of both ends of the connecting pipes; and a grip member that has a blade on the inner surface and a smooth spherical outer surface of the end that extends around the entire circumference of the pipe. a pair of locking members arranged in plurality and held together in an annular shape by a rubber band; an annular packing groove for accommodating the annular packing at approximately the center of both ends of the connecting pipes; and an annular packing groove on both outer sides of the groove. and a housing having an annular locking groove in which the locking member is accommodated and the inner circumferential surface in contact with the outer surface of the end of the grip member is formed into a substantially umbrella-shaped cross section with both tapered surfaces having a small diameter on both sides. A housing type pipe joint featuring the following.