JPS6333033Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a high-pressure pipe joint that is mainly used for large-diameter, relatively high-pressure pipes that are buried underground. The aim is to effectively prevent leakage by fixing the rubber-like elastic body inserted into the sealing recess and restraining the periphery to prevent the sealing stress from attenuating.

Conventional buried pipes usually have a socket on one side of the pipe body and a spigot on the other side, and are filled with packing material or caulking material, or the outer periphery of the opposing part of a straight pipe. There are some pipes that have a connecting ring installed in the pipe, and connect the connecting ring with caulking material between the connecting ring and the straight pipe.However, many of the pipes currently buried are leaking from the joints, and are not allowed to remain as they are. It is currently being used.

However, once buried, the repair is subject to many restrictions regarding the buried location, usage conditions, etc., and is accompanied by many practical difficulties.

In addition, all conventional buried pipes have measures to prevent leakage in the outward direction, and therefore, over a long period of time, leakage will occur from the contact surface between the caulking material and the pipe.

Therefore, as a joint for buried pipes, there is a need for a means that does not cause any concern that the sealing stress will attenuate over a long period of time.

Therefore, the inventors used a viscoelastic material such as a rubber-like material that has excellent sealing performance, and formed a sealing recess on the inner surface of the pipe into which the rubber-like elastic material was filled and pressed. The rubber-like elastic body is inserted into this recess, and a band-shaped metal ring having an outer diameter circumferential length for applying a predetermined designed pressure contact force is divided into at least two arc-shaped pieces.
By contacting the inserted rubber-like elastic body and restoring it to the band-shaped metal ring with the original outer diameter and connecting and fixing the divided parts, a strong pressure is applied to the rubber-like elastic body, and the rubber-like elastic body is sealed. A strong pressure contact stress is generated at the interface between the inside and outside of the recess and both sides.

When inserting the rubber-like elastic body, the rubber-like elastic body is formed so that when the rubber-like elastic body is pressurized and filled with a band-shaped metal ring, the inner diameter of the pipe and the inner diameter of the band-shaped metal ring almost match. In addition, the rubber-like elastic body is
In order to remove initial strain, it is preferable to apply plastic deformation before filling.

Further, if the wall surface of the sealing recess of the piping is a shallowly uneven surface or a rough finished surface, a preferable sealed state will be formed at the contact interface of the rubber-like elastic body. Also,
Protrusions of various shapes are formed on the rubber-like elastic body side as necessary. Further, by forming an uneven surface on the entire surface of the contact surface of the band-shaped metal ring that contacts the rubber-like material, a favorable and firm sealing state is formed in which no slippage occurs on the entire circumferential surface of the rubber-like material.

In other words, the rubber-like substance has its entire circumferential interface constrained in the sealing recess of the piping, so there is almost no attenuation of the sealing stress at the interface, so it exerts a sealing effect for a long time except for breakage. It is something.

Next, aspects of the invention will be explained based on embodiments shown in the illustrative drawings.

Figure 1 shows an enlarged partial cross section of the band-shaped rubber ring RB, which is filled into a sealing recess formed on the inner surface of the opposing part of the pipe, and is made of a rubber-like elastic body molded into a ring shape. , 1 is a band-shaped part, and this band-shaped part 1 has a contact surface that is brought into close contact with the inner surface of the sealing recess, as necessary, according to the inner surface condition of the pipe. Protrusions of various shapes are formed on the entire surface or a plurality of protrusions are formed as appropriate. 2
are protrusions, and this example illustrates the case where there are the least two protrusions. Furthermore, reinforcing protrusions 3 may be provided in the gaps between the metal rings on the opposite surface.

This reinforcing protrusion 3 is used for positioning when pressing with a band-shaped metal ring, and for positioning when pressing with a band-shaped metal ring.
RB also has the effect of suppressing deformation between the band-shaped metal rings due to plastic deformation. Also, during use, internal pressure acts on this reinforcing protrusion,
It is held as a supporting and restraining force of the rubber-like substance. However, in the case of one band-shaped metal ring, this reinforcing protrusion is eliminated.

The setting of this band-shaped rubber ring RB in the sealing recess is as shown in the partial cross section of the main part of the piping in FIG. The figure shows an example of piping.
1 is a pipe in which straight pipes are firmly connected with a joint ring 5 and a filling material 6.

Insert the band-shaped rubber ring RB shown in Fig. 1 into the sealing recess SC formed on the inner surface of the pipe joint, which is the opposite part of the pipe end, into the leakage part that is the connection part, and A band-shaped metal ring 7 having an outer diameter circumference that provides a designed pressure contact force is divided into at least two arc-shaped parts, which are brought into contact with a band-shaped rubber ring and expanded and restored to their original outer diameter. Then, the divided parts are connected and fixed.
That is, the band-shaped rubber ring RB, which is a viscoelastic body, is sealed in the sealing recess SC so as to be isolated from the outside.
This is to reduce the degree of freedom as much as possible to prevent the creep (CREEP) phenomenon caused by plastic deformation of the viscoelastic body.
Then, determine the degree of compression that will provide the necessary and appropriate contact force to ensure complete filling and stabilization in every nook and cranny, and then create a band-shaped metal whose arc has a predetermined outer diameter that is exactly equal to the arc of the compressed inner diameter of the band-shaped rubber ring. The entire circumference of the ring 7 is divided into the required number of divisions, and the divided band-shaped metal ring 7 is brought into the pipe, and the divided parts other than the expanded division part are connected to arc-shaped connecting plates. Connect and fix the parts so that there are no gaps, spread them out using a spreading device such as a hydraulic cinder or turnbuckle, and insert a spacer into the expanded split part.
A band-shaped rubber ring RB is enclosed and fixed by being expanded to become a band-shaped metal ring 7 having a predetermined outer diameter without any gaps.

Next, a method for restoring the arc-shaped divided portion of the band-shaped metal ring 7 to a band-shaped metal ring having a predetermined outer diameter will be described in detail based on illustrative drawings.

FIG. 3 is a front view showing an example of a split state of the band-shaped metal ring 7, where PF is the split part, and the split band-shaped metal ring is connected to the arc-shaped connecting plate 8 in the pipe.
Securely connect with bolts so that there are no gaps.
SU is a divisional part for expansion, and 9 is a bracket attached to both ends of the divisional part SU with bolts, and this bracket 9 has an expansion device such as a cylinder or turnbuckle operated by a piston with a manual hydraulic pump. are concatenated. 10 is fixed plate FP
With a spacer fixed on top, the expansion division SU
Spread it out, insert the spacer 10, form it into a band-shaped metal ring with a predetermined outer diameter, and then insert the spacer 10.
The fixed plate FP is fixed to the end of the metal ring with bolts.

FIG. 4 is a schematic enlarged front view showing the expansion device attached to the expansion division SU of the band-shaped metal ring 7 set inside the band-shaped rubber ring RB, and 11 is connected to the bracket 9 by a hydraulic cylinder; A piston 12 is connected to the bracket 9 on the opposite side. Reference numeral 13 denotes a hydraulic pressure introducing section, which is connected to a manual hydraulic pump (not shown) and performs expansion and contraction operations of the band-shaped metal ring 7.

FIG. 5 is a schematic enlarged front view showing how the spacer 10 is inserted into the expansion division SU of the band-shaped metal ring 7 set inside the band-shaped rubber ring RB. By fixing to the ring 7 with bolts, the band-shaped metal ring 7 having a predetermined outer diameter without any gaps seals and press-fits the band-shaped rubber ring RB into the sealing recess SC. After the band-shaped metal ring 7 is set, the bracket 9 and the expanding device such as the hydraulic cylinder are removed and the bolt holes are plugged. Please note that the division may be divided into 3 parts as necessary.
It is divided into two or more pieces, such as 2 pieces, 4 pieces, etc. Alternatively, the outer diameter may be restored to a predetermined outer diameter by expanding at a plurality of locations.

As shown in the example above, when expanding and connecting divided band-shaped metal rings, it is relatively easier to insert a spacer into the expansion dividing part and integrate it. It is also possible to expand and butt the divided ends together and fix them with an arcuate connecting plate. In short, a band-shaped metal ring having the required outer diameter is divided, and the parts are connected to restore the original band-shaped metal ring, and a band-shaped rubber ring is made into one band-shaped metal ring without any gaps.
The purpose is to maintain strong pressure contact around the entire circumference of the RB.

In the embodiment shown in FIG. 2, these strip-shaped metal rings 7 are used in two rows in parallel, and normally two rows are preferable, but depending on the width of the sealing recess SC, It may be one row. Moreover, there may be two or more rows.

As explained above, the high-pressure piping joint of this invention has a sealing recess formed on the inner surface of the joint.
A band-shaped rubber ring made of a rubber-like elastic body, which is a viscoelastic body, is enclosed in a recess with almost no degree of freedom, and is sealed from the inside by the expansion pressure force of a transparent band-shaped metal ring. Plastic deformation of the rubber-like elastic body is prevented, creep (CREEP) phenomenon of the viscoelastic body is prevented, and a uniform contact force is obtained all around the circumference, so there is no risk of sealing stress decay over a long period of time, and the piping Except for breakage, it has the characteristic of being able to exhibit a sealing effect for a long period of time.

[Brief explanation of the drawing]

Fig. 1 is an enlarged partial sectional view of the band-shaped rubber ring used in this invention, Fig. 2 is a partial sectional view of the main part of the high pressure piping joint of this invention, and Fig. 3 is:
FIG. 4 is a front view showing an example of the divided state of the band-shaped metal ring used in this invention, in which an expanding device is attached to the expansion division of the band-shaped metal ring set inside the band-shaped rubber ring. Outline enlarged front view,
FIG. 5 is a schematic enlarged front view showing a state in which a spacer is inserted into the expansion divided portion of the band-shaped metal ring. RS...Band-shaped rubber ring, 1...Band-shaped part of the band-shaped rubber ring, SC...Sealing recess, 4...Piping,
7...A band-shaped metal ring.

Claims (1)

[Scope of utility model registration request] A sealing recess is formed on the inner surface of the joint of both pipes,
A band-shaped rubber ring made of a rubber-like elastic body is inserted into the sealing recess, and the degree of compression is set so that the band-shaped rubber ring completely fills every corner of the sealing recess and a sufficient pressure force is obtained. Then, the entire circumference of a band-shaped metal ring having an arc of a predetermined outer diameter equal to the arc of the compressed inner diameter is divided into the required number of divisions, and the divided band-shaped metal ring is inserted into the pipe through an expansion gap. A high-pressure piping joint in which a band-shaped rubber ring is press-fitted and sealed in a sealing recess by means of forming a single band-shaped metal ring with a predetermined outer diameter and press-fitting the ring without connecting the rings.