JP3799105B2 - Pipe fitting - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pipe joint, and particularly to a pipe joint that can be suitably used for a large-diameter pipe.
[0002]
[Prior art]
Conventionally, various types of pipe joints such as a screw-in type, a mechanical type, and a plug-in type are known. A threaded type pipe joint is a type in which a threaded part of a pipe joint is screwed into a threaded part formed at the end of a pipe through a sealing material, and a mechanical type pipe joint is connected to a threaded part of an insertion port part into which a pipe is inserted. This is a type in which a seal member made of a rubber ring is brought into close contact with the outer periphery of a pipe by screwing a threaded portion of a press ring. With these two types of pipe joints, a large tightening tool such as a pipe wrench is required as a tightening tool when connecting large diameter pipes. It is said that the workability is further reduced when the connection work is performed, especially in the case of mechanical type pipe joints, because parts such as retainers for seal materials, lock rings and rubber rings must be set on the pipe. There were drawbacks. In plug-in type pipe joints, the pipes had to be grooved in order to ensure that the lock ring prevents the removal.
[0003]
[Problems to be solved by the invention]
The present invention has been made under the above circumstances, and an object of the present invention is to provide a pipe joint that does not necessarily require a large tightening tool when connecting large-diameter pipes.
[0004]
In addition, the present invention provides a pipe joint capable of performing work necessary for connection such as tightening with a small force even though it is not necessary to use a large tightening tool for connecting large diameter pipes. The purpose is to do.
[0005]
It is another object of the present invention to provide a pipe joint that does not require troublesome processing such as grooving of a pipe.
[0006]
Furthermore, an object of the present invention is to provide a pipe joint having a pipe retaining function.
[0007]
[Means for Solving the Problems]
The pipe joint according to the first aspect of the present invention includes an annular first recessed portion and an annular groove portion distributed on both sides in the axial direction sandwiching the first recessed portion at the inner peripheral portion of the tube insertion port portion. And a second recessed portion, wherein the first recessed portion and the annular groove portion are partitioned by an annular first partition wall provided in an inner peripheral portion of the insertion port portion, and the first recessed portion The second recessed portion is partitioned by an annular second partition wall provided in the inner peripheral portion of the insertion port portion, and the first recessed portion can be expanded and contracted and can be expanded and contracted to the insertion port portion by a reduced diameter. An annular sealing material made of a rubber ring that is in close contact with the outer periphery of the inserted tube and a band wound around the annular sealing material are accommodated, and a tightening operation for tightening the band to reduce the diameter thereof. A mechanism is provided, and the tightening operation mechanism is opened from an opening formed in the peripheral wall of the first recessed portion. A heat-resistant packing that is exposed to the outside of the insertion port portion and is in close contact with the outer periphery of the tube inserted into the insertion port portion is held in the annular groove portion. The portion is formed on an annular inclined surface that is inclined so that the diameter becomes smaller as it approaches the outer end portion of the insertion port portion, and the second insertion portion is inserted into the insertion port portion. A lock ring that has an inner diameter that surrounds and grips the tube and that is reduced in diameter when pressed against the inclined surface in the axial direction is held.
[0008]
In this pipe joint, when the band is reduced by operating the tightening operation mechanism, the annular sealing material is reduced in diameter together with the band and is brought into close contact with the outer periphery of the pipe inserted into the insertion port. Therefore, the gap between the pipe and the insertion port is closed by the annular sealing material, and the fluid is prevented from leaking. Since the tightening operation mechanism is exposed to the outside of the insertion port portion from the opening formed in the peripheral wall of the first recessed portion, a tightening tool capable of operating the tightening operation mechanism It becomes possible to perform the connecting work simply by using, and it is not always necessary to use a large tightening tool even when connecting a large-diameter pipe.
[0009]
Further, the first recessed portion and the annular groove portion are partitioned by an annular first partition wall provided in an inner peripheral portion of the insertion port portion, and the first recessed portion and the second recessed portion are Since it is partitioned off by an annular second partition wall provided in the inner peripheral portion of the insertion port portion, when the tube is inserted into the insertion port portion, a rubber ring accommodated in the first recess portion The annular sealing material is not dragged to the second recessed portion or the annular groove by the pipe. Similarly, the lock ring and the heat-resistant packing held in the second recessed portion or the annular groove portion are not dragged to the first recessed portion by the pipe.
[0010]
Furthermore, even if the insertion port is heated in the event of a fire, etc., the heat-resistant packing ensures the fluid sealing until the heat-resistant packing is heated to a temperature higher than its specific heat-resistant temperature. The
[0011]
Also, when the tube is inserted into the insertion port, the tube is surrounded by the lock ring, so when the tube is about to be pulled out, the lock ring moves with the tube and moves relative to the inclined surface. It is pressed in the axial direction. For this reason, the diameter of the lock ring is reduced and pressed against the tube, or is inserted into the tube to prevent the tube from being pulled out.
[0012]
A pipe joint according to a second aspect of the present invention is the pipe joint according to the first aspect, wherein the tightening operation mechanism includes a screw holder having a screw shaft insertion space fixed to one end of the band, and the screw holder. A screw shaft that is rotatably attached and cannot be moved back and forth in the axial direction and is inserted into the screw shaft insertion space, and the screw shaft that is provided at the other end of the band that is inserted into the screw shaft insertion space of the screw holder. A screw groove that meshes with the screw thread, and a tightening tool provided on the screw shaft and a rotation operation portion that can be engaged in the rotation operation direction.
[0013]
According to this pipe joint, the band is tightened only by rotating the rotation operation portion provided on the screw shaft using a tightening tool, and the annular sealing material is reduced in diameter. The portion of the pipe inserted into the insertion port is brought into close contact with the outer periphery to seal the portion.
[0014]
A pipe joint according to a third aspect of the present invention is the pipe joint according to the second aspect, wherein the rotation operation part is a head provided at one end of the screw shaft.
[0015]
In this pipe joint, even if the above-mentioned head is a polygonal head such as a hexagon on which a small spanner, which is a tightening tool, is externally fitted, a small hexagon wrench, which is a tightening tool, is inside. Even with a hexagonal hole head that has a hexagonal hole to be fitted, it is a grooved head that has a plus or minus groove for engaging a small screwdriver that is a tightening tool or a small flathead screwdriver. There may be.
[0016]
A pipe joint according to a fourth aspect of the present invention is the pipe joint according to any one of the first, second, and third aspects, wherein the second recessed portion is located on the axially outer side of the first recessed portion, The said annular groove part is located in the axial direction inner side of the said 1st recessed part.
[0017]
If it is this structure, since the said heat resistant packing will be hold | maintained in the said annular groove part provided in the position away from the outer end part of the said insertion port part, a flame will be a plug port part at the time of a fire It becomes difficult to reach the heat-resistant packing through a gap between the pipe and the pipe inserted therein. For this reason, the heat resistant packing is not easily heated directly by the flame, which helps to keep the seal maintaining time long by suppressing the temperature rise of the heat resistant packing at the time of a fire.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a partially cutaway side view of a pipe joint A according to a first embodiment of the present invention. The left half shows a state in which a pipe 100 is inserted into an insertion port 1 and the right half shows an insertion port. 1 shows a state in which the tube 100 is inserted and the band 3 is tightened. 2 is a cross-sectional view taken along line II-II in FIG. 1, and FIG. 3 is a partially broken front view of the tightening operation mechanism 4. As shown in FIG.
[0019]
In this pipe joint A, the insertion port 1 has a groove-shaped first recess 11, a second recess 12 positioned on the outer side in the axial direction of the first recess 11, and the first recess 11. An annular groove 13 is provided on the inner side in the axial direction. And the said 1st recessed part 11 and the said annular groove part 13 are partitioned off by the cyclic | annular 1st partition wall 14 provided in the inner peripheral part of the said insertion port part 1, and the said 1st recessed part 11 and the said 2nd The recessed portion 12 is partitioned by an annular second partition wall 15 provided on the inner peripheral portion of the insertion port portion 1.
[0020]
Both of the pair of annular wall surfaces 15, 15 facing in the axial direction in the first recessed portion 11 are annular surfaces orthogonal to the axis P-P of the insertion port portion 1. The first recessed portion 11 accommodates an annular sealing material 2 made of a rubber ring such as NBR, and a stainless steel band 3 wound around the annular sealing material 2.
[0021]
As shown in FIGS. 1 and 2, the annular sealing material 2 in a state where it is not tightened by the band 3 has an annular recess 21 having a large diameter at the center in the axial direction. Both side portions in the direction are annular edges 22 and 22 having a small diameter, and have a cylindrical shape having a certain length in the axial direction. Further, the annular sealing material 2 has lightened axial end surfaces on the pair of annular wall surfaces 15 and 15 of the first recessed portion 11 so as not to be displaced in the axial direction in the first recessed portion 11. They are sandwiched between the pair of annular wall surfaces 15 and 15 to such an extent that they hit each other.
[0022]
A long opening 16 in the circumferential direction is formed in the peripheral wall of the first recess 11 in the insertion port 1.
[0023]
The band 3 wound around the annular sealing material 2 is made of a metal band plate which is not easily rusted, for example, a stainless steel band plate. The shown tightening operation mechanism 4 is provided. The tightening operation mechanism 4 has a screw holder 41 fixed to one end of the band 3. The screw holder 41 is manufactured by bending a metal plate or the like, and its inner space is a screw shaft insertion space 42, and both axial ends of the screw shaft 43 inserted through the screw insertion space 42. The part is attached to the screw holder 41 so as to be freely rotatable and unable to advance and retract in the axial direction. The screw shaft 43 is provided with a hexagonal head 44 as a rotation operation portion, and a small spanner (not shown) as a tightening tool is fitted on the head 44 for rotation operation. It can be done. The other end portion 32 of the band 3 is inserted into the screw shaft insertion space 42 of the screw holder 41, and the other end portion 32 has a screw groove that meshes with the screw thread 45 of the screw shaft 43. 33 is formed.
[0024]
A part of the peripheral surface of the second recessed portion 12 is formed on an annular inclined surface 17 that is inclined so as to become smaller in diameter as it approaches the outer end portion of the insertion port portion 1. The second recessed portion 12 holds a lock ring 5 made of stainless steel having elasticity that has a missing circle portion at one place in the circumferential direction and can be reduced in diameter by the action of the missing circle portion. . The lock ring 5 is held by the second recessed portion 12 so as to face the inclined surface 17. The lock ring 5 has an inner diameter that surrounds and grips the tube 100 inserted into the lock ring 5 through the insertion port 1, and when the diameter of the lock ring 5 is reduced, The inner peripheral portion is pressed against or inserted into the tube 100 to prevent the tube 100 from being removed. Reference numeral 51 denotes a biting tooth provided in an annular shape on the inner peripheral portion of the lock ring 5.
[0025]
An annular heat-resistant packing 6 is held in the annular groove 13. The heat resistant packing 6 has a heat resistant performance that does not lose its sealing function even when the pipe joint A is heated by a fire. Such a heat resistant packing 6 corresponds to a packing made of chloroprene rubber and thermally expandable graphite, for example.
[0026]
The annular sealing material 2, the lock ring 5, and the heat resistant packing 6 are reduced in diameter so that the first recessed portion 11, the second recessed portion 12, and the annular groove portion 13 are formed from the outside of the insertion port portion 1. It is fitted and restored to its original natural state after being fitted. The band 3 provided with the tightening operation mechanism 4 is inserted into the first recessed portion 11 using the opening 16 of the insertion port portion 1, and the tightening operation mechanism 4 is opened to the opening 3. 16 is exposed to the outside of the insertion port 1. Therefore, the head 44 can be operated and rotated from the outside of the insertion port 1.
[0027]
In the pipe joint A configured as described above, when the pipe 100 is inserted into the insertion port 1, the tightening operation mechanism 4 is loosened as shown in the left half of FIG. The diameter has been expanded. Further, the lock ring 5 is not pressed against the inclined surface 17. Therefore, after the tube 100 is inserted through the lock ring 5 and the annular sealing material 2 in this order, the tube 100 is inserted into the heat-resistant packing 6, and when the tube 100 is completely inserted, The packing 6 is in close contact with the outer periphery of the tube 100 and maintains the fluid sealing performance at that location.
[0028]
After the tube 100 is inserted into the insertion port 1 as described above, a small wrench, wrench, or the like is provided from the outside of the insertion port 1 to the head 44 of the screw shaft 43 of the tightening operation mechanism 4. When the screwing tool 43 (not shown) is externally fitted and the screw shaft 43 is rotated in the tightening direction, the other end of the band 3 is pulled in the left direction in FIGS. The diameter of the annular sealing material 2 is reduced along with the diameter reduction. Due to the reduced diameter of the annular sealing material 2, the annular sealing material 2 is brought into close contact with the outer peripheral surface of the pipe 100 as shown in the right half of FIG.
[0029]
When the tube 100 is inserted into the insertion port 1, the lock ring 5 surrounds the tube 100 and holds the tube 100 as shown in the left half of FIG. Therefore, when the tube 100 is pulled in the drawing direction, the lock ring 5 moves together with the tube 100 and is pressed against the inclined surface 17 in the axial direction as shown in the right half of FIG. Diameter. Due to such a reduction in the diameter of the lock ring 5, the biting teeth 51 of the lock ring 5 are pressed against the pipe 100 or bite to prevent the pipe 100 from being pulled out.
[0030]
In this embodiment, the tightening operation mechanism 4 shown in FIGS. 2 and 3 is used, but other mechanisms may be employed as the tightening operation mechanism 4. It is also possible to provide a second recessed portion that holds the lock ring on the inner side in the axial direction of the first recessed portion, and an annular groove portion that holds the heat-resistant packing on the outer side in the axial direction of the first recessed portion.
[0031]
The pipe joint A of the embodiment described above includes one provided at one end or both ends of a long pipe, and one that is interposed between two pipes and connects these pipes. Of course, a T-shaped or cross-shaped one having three or four insertion ports 1 is also included.
[0032]
【The invention's effect】
According to the pipe joint according to the present invention, since the band tightening operation mechanism for reducing the diameter of the annular seal material is exposed outside the insertion port portion, the tightening operation mechanism can be operated. Connection work can be performed simply by using a small tightening tool such as a wrench or wrench, and there is no need to use a large tightening tool when connecting large diameter pipes. It doesn't require a lot of power
[0033]
Furthermore, according to the pipe joint of the present invention, since the annular seal member made of a rubber ring, the lock ring, and the heat-resistant packing are not dragged by the pipe inserted into the insertion port, the insertion of the pipe can be smoothly performed. Yes. In addition, due to the action of retaining the pipe by the lock ring, the pipe will not be pulled out from the insertion port even in the event of an earthquake, etc., and even if the functions of the annular sealing material and the tightening operation mechanism are impaired in the event of a fire, The heat resistant packing ensures fluid sealing. In particular, according to the invention according to claim 4, since it becomes difficult for the flame to reach the heat-resistant packing at the time of a fire, the temperature rise of the heat-resistant packing at the time of the fire is suppressed and the seal maintaining time is kept long. To help.
[Brief description of the drawings]
FIG. 1 is a partially cutaway side view of a pipe joint according to an embodiment of the present invention, in which a left half shows a state where a pipe is inserted into an insertion slot, and a right half tightens a band to the insertion slot. The state which connected the inserted pipe | tube is shown.
2 is a cross-sectional view taken along line II-II in FIG.
FIG. 3 is a partially cutaway front view of a tightening operation mechanism.
[Explanation of symbols]
A Pipe fitting 1 Insert 2 Portion seal material 3 Band 4 Tightening mechanism 5 Lock ring 6 Heat resistant packing 11 First recess 12 Second recess 13 Annular groove 14 First partition wall 15 Second partition wall 16 Opening 17 Inclined surface 31 One end 32 of the band 32 Other end 33 of the band Screw groove 41 Screw holder 42 Screw shaft insertion space 43 Screw shaft 44 Head (rotation operation section)
45 thread 100 pipe

Claims (4)

An annular first recessed portion, and an annular groove portion and a second recessed portion provided on both sides in the axial direction sandwiching the first recessed portion are provided on the inner peripheral portion of the tube insertion port portion, The first recessed portion and the annular groove portion are partitioned by an annular first partition wall provided in the inner peripheral portion of the insertion port portion, and the first recessed portion and the second recessed portion are the insertion port. It is partitioned by an annular second partition wall provided on the inner peripheral part of the part, and is closely attached to the outer periphery of the pipe inserted into the insertion port part by the reduced diameter and capable of expanding and contracting in the first recessed part. An annular seal member made of a rubber ring and a band wound around the annular seal member are accommodated, and a tightening operation mechanism for tightening the band to reduce the diameter is provided on the band, and the first recessed portion The tightening operation mechanism is exposed to the outside of the insertion port from an opening formed in the peripheral wall, and A heat-resistant packing that is in close contact with the outer periphery of the tube inserted into the insertion port portion is held in the groove portion, and a part of the peripheral surface of the second recessed portion is an outer end portion of the insertion port portion. Is formed in an annular inclined surface that is inclined so as to be smaller in diameter, and the second recessed portion has an inner diameter that surrounds and grips the tube inserted into the insertion port. And a lock ring whose diameter is reduced by being pressed against the inclined surface in the axial direction is held. The tightening operation mechanism includes a screw holder having a screw shaft insertion space fixed to one end portion of the band, and is rotatably attached to the screw holder so as not to advance and retract in the axial direction, and is inserted into the screw shaft insertion space. A screw shaft, a screw groove provided on the other end of the band inserted into the screw shaft insertion space of the screw holder and meshing with a thread of the screw shaft, and a tightening tool provided on the screw shaft The pipe joint according to claim 1, further comprising a rotation operation portion engageable in a rotation operation direction thereof. The pipe joint according to claim 2, wherein the rotation operation part is a head provided at one end of the screw shaft. The said 2nd recessed part is located in the axial direction outer side of the said 1st recessed part, The said annular groove part is located in the axial direction inner side of the said 1st recessed part, Either in Claim 1, Claim 2, or Claim 3 The described pipe joint.

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