JP4593409B2 - Expandable flexible joint structure - Google Patents

Description

  The present invention relates to an expansion / contraction flexible joint used in water pipes and the like.

  Generally, an expansion / contraction flexible joint is often used for a joint portion of a fluid pipe such as a water supply or a sewer. This expansion / contraction flexible joint follows the expansion and contraction when the connected pipes expand or contract due to the fluid pressure in the pipe or external force acting on the pipe due to earthquake or ground subsidence. Thus, the joint portion expands or contracts or deforms to prevent damage to equipment such as the pipe body and the valve.

  For example, as shown in FIG. 5, a conventional expansion / contraction flexible joint 1 has a large-diameter portion 2b whose inner diameter is larger than that of a general portion and a small-diameter portion 2a whose diameter is slightly smaller than that of the large-diameter portion 2b. These are formed in order from the front end of the receptacle toward the back. A joint pipe (insertion port) 3 is inserted into the receiving port 2, and the front end of the joint pipe 3 reaches the small-diameter portion 2 a.

  A flange portion 3a is formed at the front end of the joint pipe 3 so as to protrude outward over the entire circumference. The outer peripheral surface of the flange portion 3a and the inner peripheral surface of the small diameter portion 2a are predetermined in the radial direction. Are opposed to each other through a gap w. The small-diameter portion 2a extends further from the front end position of the inserted joint pipe 3 to the back, and the joint body (receiving port) 2 and the joint pipe 3 are relatively moved in the axial direction by a predetermined distance d. Can be done.

A cylindrical spacer 4, a seal ring 5, and a seal cover 6 are sequentially inserted into the large-diameter portion 2 b of the joint body 2 from the back to the front end side.
The end 4a on the inner side of the cylindrical spacer 4 is in contact with a step 2c between the small-diameter portion 2a and the large-diameter portion 2b of the receiving port. The cylindrical spacer 4 has an inner diameter of the main body 4b smaller than the outer diameter of the flange 3a and an inner diameter smaller than the outer diameter of the flange 3a at the end 4a on the back side. An inward protrusion is provided, and the flange portion 3a is deformed when the inward protrusion is pressed with a force greater than a predetermined force, and the flange portion 3a is allowed to pass.
The seal ring 5 is made of an elastic material such as rubber. One end of the seal ring 5 is in contact with the spacer 4 and the other end is a cap nut 7 screwed into the outer periphery of the joint body 2 through the seal cover 6. It is restrained by the collar part 7a.

The expansion / contraction flexible joint 1 absorbs the displacement of the pipe due to the extension when the pipe is about to be extended with respect to a predetermined pressure or an external force, prevents damage to the pipe or the device, and reduces the dimension of the gap w. If it is set to a large value, when the joint pipe 3 and the joint body 2 are bent, the bent (bent) can be dealt with (see Patent Document 1).
Japanese Patent Laid-Open No. 11-63339

  However, according to the expansion / contraction flexible joint 1, since the gap w between the inner peripheral surface of the small-diameter portion 2a of the receiving port 2 and the outer peripheral surface of the flange portion 3a of the joint pipe 3 is small, the external force that the joint portion tends to bend. Will act on the piping, the inner and outer peripheral surfaces will come into contact with each other. If the joint main body 2 and the joint pipe 3 are in direct contact with each other, the abutment may deform the pipe into an ellipse and cause water leakage. In addition, if the joint portion is greatly bent and the contact portion is strongly pressed, the pipe may be damaged, which is not preferable.

  In order to prevent this contact, it is considered effective to increase the gap w by thickening a sealing member such as the seal ring 5 in the radial direction. This is because, if the gap w becomes large, even if both pipes are bent largely across the joint portion, it is avoided that the inner and outer peripheral surfaces of the opposing pipes are directly touched via the gap w.

  However, even if the gap w is increased, the seal member such as the seal ring 5 requires a predetermined hardness from the viewpoint of durability and the like, and its deformation performance has a limit. Therefore, the joint portion corresponds to the limit. If it is greatly bent beyond the bending angle, the seal member cannot be deformed corresponding to the bending. For this reason, the seal member may move or come off, creating a gap between the seal member and the pipe, and causing water leakage from the gap.

  Further, when both pipes are pulled strongly in the opposite direction across the joint, the sealing member such as the seal ring 5 is piped from both sides by the inner wall of the end face wall of the cap nut 7 and the end face of the flange 3a of the joint pipe 3. Strong compression in the axial direction. When the degree of compression is large, the elasticity of the seal member is reduced and the deformation performance is deteriorated. If the deformation performance of the seal member is lowered, the bendable angle between the pipes that can be accommodated by the joint portion is lowered. For this reason, as in the case described above, a gap is formed between the seal member and the piping, which causes water leakage and causes piping damage, which is not preferable.

  In view of this, the first object of the present invention is to prevent water leakage even in the case of a large bend in an expansion / contraction flexible joint, and in particular, in a stretched state of the joint, the deformation performance of the seal member is improved. The second problem is to prevent the decrease.

In order to solve the first problem, in the present invention, the sealing member is sandwiched and fixed between the end face of the receiving port and the flange portion of the cap nut.
In this way, since the seal member is sandwiched and fixed between the receiving port and the cap nut, the seal member is prevented from moving or coming off even if the joint portion is greatly expanded or contracted or bent. obtain. For this reason, water leakage does not occur even for a large bend.

Further, in order to solve the second problem, the present invention provides a space between the outer peripheral surface of the flange portion of the insertion port and the inner peripheral surface of the receiving port opposite thereto, and the outer peripheral surface of the insertion port and the cap nut. The seal members were respectively placed in the spaces surrounded by the inner peripheral surface of the buttock.
In this way, when the seal member is strongly compressed in the tube axis direction, the seal member is deformed and enters each space. That is, the deformation of the seal member due to compression escapes to both the spaces. For this reason, even in the extended state of the joint portion, the elasticity of the seal member does not decrease and the deformation performance does not deteriorate.

  Since the present invention is configured as described above, the expansion / contraction flexible joint is prevented from leaking water even in the case of a large bend, and the deformation performance of the seal member is not deteriorated in the extended state of the joint portion.

  As an embodiment of the means for solving the above first problem, the insertion port is inserted with a seal member interposed in the receptacle, and the bag nut through which the insertion port passes is screwed into the outer periphery of the receptacle, and the bag The seal member is prevented from coming off to the rear end side of the insertion port by the flange portion of the nut, and by screwing the seal member, the rear end peripheral portion of the seal member is sandwiched and fixed between the flange portion and the end surface of the receiving port. This is a stretchable flexible joint structure.

  In the expansion / contraction flexible joint structure having the above-described configuration, an annular projecting portion projecting radially outward is provided on the peripheral edge of the rear end of the seal member, and the annular projecting portion is disposed between the end surface of the receiving port and the flange portion. If it is fixed by squeezing, the seal member is easily squeezed between the receiving port and the cap nut. Further, if the annular projecting portion is held and fixed, the sealed seal member is not easily detached even when the receiving port and the insertion port are greatly expanded or contracted or bent. For this reason, it can prevent more reliably that a sealing member moves with respect to a receptacle, or remove | deviates.

Further, as an embodiment of the means for solving the second problem, an insertion opening having a flange portion at the front end portion is inserted into the receiving opening, and the insertion opening of the insertion opening is disposed on the rear end side of the flange portion. A seal member is interposed between the outer peripheral surface and the inner peripheral surface of the receiving port. A cap nut through which the insertion port passes is screwed into the outer periphery of the receiving port, and the sealing member is prevented from coming off to the rear end side of the insertion port by a flange portion of the cap nut, and a rear end side end surface of the flange portion is provided. It abuts on the seal member.
A space is formed between the outer peripheral surface of the flange portion and the inner peripheral surface of the receiving port facing the flange portion; a space is formed between the outer peripheral surface of the insertion port and the inner peripheral surface of the flange portion; It is possible to adopt an expansion / contraction flexible joint structure that is disposed so as to face both spaces.

  In this case, when the seal member is sandwiched between the inner surface of the flange portion and the rear end side end surface of the flange portion and is strongly compressed in the tube axis direction, the deformation of the seal member due to the compression is caused by the two spaces. Therefore, the elasticity of the seal member does not decrease and the deformation performance does not deteriorate. For this reason, even in the extended state of the joint portion, it is possible to prevent water leakage and damage to the pipe without reducing the bendable angle between the corresponding pipes.

  In addition, in the structure which has arrange | positioned the said sealing member facing both said space, you may provide the above-mentioned cyclic | annular protrusion part in the sealing member. In this way, the sealing member can be easily squeezed, and the sealing member is firmly fixed between the cap nut and the receiving port. Therefore, when the sealing member is deformed due to extension of the joint portion, the sealing member It is effective in preventing the movement and disengagement.

Moreover, the following structures can be employ | adopted as a connection method of the insertion port and receiving port for setting it as the said expansion-contraction flexible joint structure.
That is, a sleeve is fitted on the outside of the cylindrical seal member, and then the rear end portion of the insertion port is press-fitted inside the seal member, and the rear end side end surface of the flange portion provided at the front end portion of the insertion port is formed. It abuts on the seal member.
In this connection method, after the receiving port is fitted to the outside of the sleeve, the sleeve is pulled out toward the rear end side, and then a cap nut penetrating the insertion port is screwed into the outer periphery of the receiving port.

  The resistance when the sleeve is fitted to the outside of the seal member and the resistance when the sleeve is pulled out from the seal member are smaller than the press-fit resistance when the receiving port is directly press-fitted to the outside of the seal member. It is possible to prevent the sealing member from being damaged. Also, before fitting the receptacle on the outer circumference of the sleeve, if the flange provided at the front end of the insertion port is in contact with the front end of the seal member and pressed firmly, the cap nut is screwed after fitting the receptacle At this time, it is not necessary to push the seal member into the receiving side. For this reason, screwing of a cap nut becomes light and work becomes easy.

One embodiment will be described with reference to FIGS.
The expansion / contraction flexible joint 10 of this embodiment is provided in a branch pipe 20 of a water faucet 11 attached to a water pipe 9 as shown in FIG. As shown in FIG. 1, the insertion port 13 is inserted into the receiving port 12 screwed into the branch pipe 20 via the packing 21 with a rubber seal member 15 interposed therebetween. Thus, the cap nut 17 having the insertion hole 18 for the insertion port 13 is screwed and fixed to the outer periphery of the receiving port 12 from the insertion port 13 side.

The insertion opening 13 has a flange portion 13a at the front end thereof, and the sealing member 15 has an outer peripheral surface 23 of the insertion opening 13 and an inner peripheral surface 22 of the receiving opening 12 on the rear end side of the flange portion 13a. Located between. Further, the rear end side end face 13 b of the flange portion 13 a is in contact with the front end of the seal member 15.
Since the inner peripheral surface 22 of the receptacle 12 has an inner diameter larger than the outer diameter of the outer peripheral surface 23a of the flange portion 13a, a space P is formed between the inner peripheral surface 22 and the outer peripheral surface 23a. .

  The sealing member 15 has a cylindrical shape having a through hole 15f at the center thereof, and before being press-fitted between the receiving port 12 and the insertion port 13, as shown in FIG. And a front end protruding portion 15c. In addition, an annular projecting portion 15a that projects radially outward over the entire circumference of the rear end peripheral edge portion is provided.

A flange 17a around the insertion hole 18 of the cap nut 17 screwed into the outer periphery of the receiving port 12 abuts on the rear end of the seal member 15, and the seal member 15 is inserted into the rear end side of the insertion port 13 by the contact. It is prevented from coming off so as not to slip out (see FIG. 1). Further, the annular projecting portion 15 a is clamped and fixed between the inner end surface 17 c of the flange portion 17 a of the cap nut 17 and the end surface 12 a of the receiving port 12.
At this time, since the inner diameter of the inner peripheral surface 28 of the insertion hole 18 of the cap nut 17 (the inner peripheral surface 28 of the flange portion 17a) is larger than the outer diameter of the outer peripheral surface 23 of the insertion port 13, A space Q is formed between the inner peripheral surface 28 and the outer peripheral surface 23 of the insertion opening 13.
The screw nut 17 is screwed into the receptacle 12 because the screw nut 17b corresponding to the screw portion 12b formed on the outer periphery of the receptacle 12 is formed on the inner periphery of the cap nut 17. , 17b.

  The connection method between the receiving port 12 and the insertion port 13 for forming the expansion / contraction flexible joint 10 will be described. As shown in FIG. 2A, a metal sleeve is provided on the outer side of the cylindrical seal member 15 over the entire length thereof. (Joint pipe) 16 is fitted. At this time, the annular protrusion 15a of the seal member 15 is also accommodated in the sleeve 16 (see FIGS. 2a and 2b).

The rear end portion 13c of the insertion port 13 is press-fitted into the through hole 15f inside the seal member 15 (see FIGS. 2b and 2c), and the front end portion of the insertion port 13 is used using the press-fitting jigs 24 and 25. The rear end side end surface 13b of the flange portion 13a provided on the seal member 15 is brought into contact with the seal member 15 (see FIGS. 2c and 2d). Since the taper portion 15b shown in FIG. 2B is provided in the through hole 15f of the seal member 15, the insertion port 13 is easily press-fitted.
At this time, the illustrated jig 25 is formed with a recess with which the rear end of the seal member 15 abuts, so that a bulging portion 15 e is formed at the rear end of the seal member 15. Further, the front end of the seal member 15 enters the space P to form a bulging portion 15d. The bulging portion 15d is obtained by deforming the front end side protruding portion 15c of the seal member 15 shown in FIG.

After the press-fitting jigs 24 and 25 are retracted, the receiving port 12 is fitted to the outside of the sleeve 16 (see FIGS. 2e and 2f). At this time, the outer periphery of the seal member 15 is protected by the sleeve 16, and the outer diameter of the sleeve 16 remains unchanged even after the insertion port 13 is press-fitted inside the seal member 15. Therefore, it is easy to fit the receiving port 12 outside the sleeve 16.
Thereafter, the sleeve 16 is pulled out toward the rear end side (see FIG. 2g). In this extraction, it is convenient to grasp the flange 16a provided at the rear end of the sleeve 16. At this time, the outer peripheral surface of the sleeve 16 is formed with a surface shape and surface roughness that are slippery in the axial direction, so that the drawing is smooth. Further, if a lubricant is applied to the outer peripheral surface of the seal member 15 as necessary, the drawing becomes even smoother. If the withdrawal of the sleeve 16 is smooth, an excessive force does not act on the seal member 15, so that unnecessary deformation of the seal member 15 can be suppressed and the sealing performance can be improved.

  Thereafter, the cap nut 17 is screwed into the outer periphery of the receptacle 12 (see FIGS. 2g and 2h). At this time, since the sealing member 15 and the flange portion 13a of the insertion port 13 are firmly pressed against each other by the aforementioned press-fitting jigs 24 and 25, the screwing of the cap nut 17 is smooth. By this screwing, the bulging portion 15e formed at the rear end of the seal member 15 enters the space Q, and the connection of the expansion / contraction flexible joint 10 is completed.

  The operation of the expansion / contraction flexible joint 10 will be described. First, in the state shown in FIG. 2h, when a force acts in a direction in which the joint portion bends (swings) due to an earthquake or the like, the seal member 15 flexibly responds to the bending. Deform. At this time, in the spaces P and Q, a clearance is set so that the receiving port 12 and the insertion port 13 do not directly contact each other, and the seal member 15 has a predetermined elastic force. The member is deformed so as to absorb the displacement of each member due to the bending of the joint, and the member is not damaged.

Further, since the annular projecting portion 15a is sandwiched and fixed between the cap nut 17 and the end surface 12a of the receiving port 12, the seal member 15 is attached to the seal member 15 when the joint portion is about to be bent. Even if a twisting force is applied, the position is always maintained. Therefore, the seal member 15 does not move or come off. Further, since the annular projecting portion 15a is always in pressure contact with the cap nut 17 and the receiving port 12, the water stopping performance is maintained throughout.
Further, according to this embodiment, since the volume of the seal member 15 is large, the seal member 15 is caused to fluidize by the rubber constituting the seal member 15 so that the seal member 15 has the inner peripheral surface 22 of the receptacle 12 and the outer peripheral surface 23 of the insertion port 13. Strongly adheres to etc. For this reason, the water stop performance is maintained at a high level.

Next, in the state shown in FIG. 2h, when a force acts in a direction in which the joint portion extends due to an earthquake or the like, the rear end side end surface 13b of the flange portion 13a pushes the seal member 15 to the rear end side.
The seal member 15 is compressed. By this compression, the water stop performance by the seal member 15 is further improved.
When the joint portion further expands, the seal member is disposed facing both the spaces P and Q, and therefore the deformation of the seal member 15 escapes in the direction of the arrow shown in FIG. 2h. For this reason, the seal member 15 can maintain the initial elastic force before the compression and continuously absorb the displacement of each member. Therefore, even if a force in the bending direction is applied in this extended state, water leakage due to the generation of the gap does not occur, and each member is not damaged.
Further, in this extended state, as the seal member 15 is deformed in the direction of the arrow shown in FIG. 2h, a twisting force in the direction of the arrow acts on the seal member 15. At this time, the annular projecting portion 15a of the seal member 15 is sandwiched and fixed between the cap nut 17 and the end surface 12a of the receiving port 12, so that the seal member 15 does not move against the twisting force. Fixed.

In addition, as shown in FIG. 4, the structure of this expansion-contraction flexible joint 10 can be employ | adopted also with respect to the insertion port 13 with a long length in an axial direction.
In each of the above embodiments, the seal member 15 having a rubber (SBR) hardness of 70 degrees is used.

Cutting front view of one embodiment The connection method of the expansion-contraction flexible joint of FIG. 1 is shown and the state at the time of fitting a sleeve on the outer side of a sealing member is shown. The connection method of the expansion-contraction flexible joint of FIG. 1 is shown, and the state before the insertion port is press-fitted inside the seal member is shown. The connection method of the expansion-contraction flexible joint of FIG. 1 is shown, and after the insertion port is press-fitted into the seal member, the state before using the press-fitting jig is shown. The connection method of the expansion-contraction flexible joint of FIG. 1 is shown, and the state which inserted the insertion port into the seal member completely is shown. The connection method of the expansion-contraction flexible joint of FIG. 1 is shown, and the state before fitting a receiving port on the outer side of a sleeve is shown. The connection method of the expansion-contraction flexible joint of FIG. 1 is shown, and the state which fitted the receptacle on the outer side of a sleeve is shown. The connection method of the expansion-contraction flexible joint of FIG. 1 is shown, and after pulling out the sleeve, the state before screwing the cap nut is shown. The connection method of the expansion-contraction flexible joint of FIG. 1 is shown and the state which screwed the cap nut is shown. Overall view of the water faucet with the expansion / contraction flexible joint of FIG. Overall view of a water faucet with an expansion / contraction flexible joint of another embodiment Cutting front view of conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,10 Expansion-contraction flexible joint 2,12 Receiving port 3,13 Insertion port 5,15 Seal member 7,17 Cap nut 11 Water faucet 12b, 12c, 17b, 20c Screw part 13a Flange part 13b Flange part rear end side end surface 13c Rear end 15a Annular protrusion 15b Tapered part 15c Front end protrusions 15d, 15e Swelling part 15f Through hole 16 Sleeve 7a, 17a Ridge part 17c Ridge inner end face 18 Insertion hole 20 Pipe line (branch pipe)
21 Packing 22 Inner peripheral surface of receiving port 23 Outer peripheral surface of insertion port 23a Outer peripheral surface of flange portion 24, 25 Press fitting jig 28 Inner peripheral surface of flange

Claims (1)

An insertion port 13 having a flange portion 13a at the front end thereof is inserted into the receiving port 12, and the outer peripheral surface 23 of the insertion port 13 and the inner peripheral surface 22 of the receiving port 12 are arranged on the rear end side of the flange portion 13a. A sealing member 15 is interposed therebetween, a cap nut 17 through which the insertion port 13 passes is screwed into the outer periphery of the receiving port 12, and the sealing member 15 is inserted into the rear end of the insertion port 13 by a flange portion 17 a of the cap nut 17. while retaining the side, the rear side end face 13b of the flange portion 13a is brought into contact with the sealing member 15, between the inner peripheral surface 22 of the outer peripheral surface 23a and the socket 12 opposite to that of the flange portion 13a forms a space P, forms a space Q between the outer peripheral surface 23 and the inner peripheral surface 28 of the flange portion 17a of the insert port 13 and to face the sealing member 15 on both space P, Q stretch Deflection A method of connecting the insert port 13 and the receptacle 12 for the joint structure,
A sleeve 16 is fitted to the outside of the cylindrical seal member 15, and then the rear end portion of the insertion port 13 is press-fitted inside the seal member 15, and the rear of the flange portion 13 a provided at the front end portion of the insertion port 13 The end face 13b is brought into contact with the seal member 15,
After fitting the receptacle 12 on the outside of the sleeve 16, the pull must be unplugged toward the sleeve 16 toward the rear end, the front end of the sealing member 15, the flange portion 13a outer peripheral surface 23a and the receptacle 12 of the said to face the space P between the inner peripheral surface 22 of the, then, by screwing the cap nut 17 that passes through the insert port 13 in the outer periphery of the receptacle 12, the rear end of the sealing member 15, the inserted A method of connecting the insertion port 13 and the receiving port 12, wherein the insertion port 13 faces the space Q between the outer peripheral surface 23 of the port 13 and the inner peripheral surface 28 of the flange portion 17 a .

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