JPH09280436A - Structure for airtightly or fluid-tightly sealing connecting end of synthetic resin pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the airtightness and fluid-tightness of a synthetic resin pipe connected to connected body by inserting and fitting a sleeve to the inner side of the connecting end of the synthetic resin pipe, and also mounting a spiral coil member on the outer side of the connecting end, then mounting a compression member on the outer side of this coil member. SOLUTION: One end side of a sleeve 10 is inserted to a connected body A, and an O-ring 40 is mounted between the connected body A and the sleeve 10. Tow pin holes 51 are formed in the connected body A, locking pins 50 are inserted to these pin holes 51 and locked to the grooves 12 of the sleeve 10, thereby the sleeve 10 is prevented from being slipped off. Coil members 20 are mounted on the outer side of a synthetic resin pipe B, and a compression member 30 is mounted on the outer side of this coil member 20. Member by which the diameters of the coil members 20 are shrunk, are employed as the compression member 30, therefore the diameters of the coil members 20 are shrunk by the compression of this compression member 30 so as to tighten the synthetic resin pipe B, and the sleeve 10 and the synthetic resin pipe B are strongly and airtightly or fluid-tightly connected to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for sealing a connecting end portion of a synthetic resin pipe in a gas-tight or liquid-tight manner in order to connect a synthetic resin pipe through which a fluid flows to a connected body.

[0002]

2. Description of the Related Art Conventionally, when connecting a synthetic resin pipe to another pipe, a joint such as an elbow joint or a branch joint (so-called header), or a connected body such as a faucet, the synthetic resin pipe is connected. Various structures have been devised as a structure for hermetically or liquid-tightly sealing the ends, for example, Japanese Utility Model Publication No. 3-5711.
Is disclosed in Japanese Patent Application Laid-Open Publication No. H10-26095. As shown in FIG. 9, when connecting a synthetic resin pipe to a connected body such as a steel pipe, the joint main body connected to the connected body in an airtight or liquid-tight manner and the connecting end of the synthetic resin pipe. A metal short tube inserted inside the section, a metal packing formed in a so-called abacus ball shape in which the central part bulges and the diameter decreases toward both ends, and the metal packing mounted on the outside of the synthetic resin tube, and this metal packing A nut for compressing and plastically deforming and connecting the synthetic resin pipe to the joint body in an airtight or liquid-tight manner. According to such a sealing structure, even if the synthetic resin pipe is inferior in strength, it is possible to hermetically or liquid-tightly seal the connecting end portion thereof.

[0003]

However, the conventional seal structure has the following problems.

First of all, the plastic deformation of the metal packing makes the joint body and the synthetic resin pipe air-tight or liquid-tight. This does not necessarily mean that the airtightness or the liquidtightness in the circumferential direction varies. In the case of high-pressure piping, this variation may cause leakage from a portion having low airtightness or liquidtightness.

Secondly, it is preferable that the inner diameter of the metal packing is slightly larger than the outer diameter of the synthetic resin pipe to be inserted therein. However, these dimensions have variations due to accuracy errors and the like. Here, if the inner diameter of the metal packing is smaller than the outer diameter of the synthetic resin tube, the metal packing cannot be inserted into the synthetic resin tube. Further, if the inner diameter of the metal packing is too large as compared with the outer diameter of the synthetic resin pipe, it becomes impossible to secure reliable airtightness or liquid tightness. Therefore, high dimensional accuracy is required for the outer diameter of the synthetic resin pipe and the inner diameter of the metal packing.

Thirdly, in order to plastically deform the metal packing, the joint body, the nut and the metal short pipe need strength higher than that of the metal packing, and these cannot be formed of synthetic resin or the like.

Fourth, the metal packing cannot be used again because it is plastically deformed once it is used.
Also, the synthetic resin pipe once connected to the joint body will have the plastically deformed metal packing integrated at the end, so in order to remove this synthetic resin pipe from the joint body and connect it again, Must be cut to form new ends and new metal packing must be used.

The present invention has been made in order to solve the above problems, and an object thereof is to provide uniform airtightness or liquid over the entire outer circumference of a synthetic resin pipe connected to a connected body. It is possible to secure the tightness, it is not necessary to have a highly accurate dimension such as the outer diameter of the synthetic resin pipe, and moreover, the member used for connection can be formed of a material such as synthetic resin. Another object is to provide a structure for sealing the connection end of a synthetic resin pipe that can be used repeatedly in an airtight or liquid-tight manner with a simple structure.

[0009]

In order to solve the above problems, the means adopted by the present invention will be described with reference to the reference numerals used in the drawings. In order to connect the synthetic resin pipe B through which the fluid flows to the connected body A, the connecting end of the synthetic resin pipe B is hermetically or liquid-tightly sealed. A sleeve 10 inserted into the inner side of the coil member, a coil member 20 that is wound in a spiral shape and is attached to the outside of the connecting end, and a coil member 20 that is attached to the outside of the coil member 20 and has a reduced diameter. And a compressing member 30 for making the connecting end of the synthetic resin pipe B air-tight or liquid-tight.

Next, the invention of claim 2 relates to "a coil member 2
0 is a structure that seals the connecting end of the synthetic resin pipe B in a gas-tight or liquid-tight manner according to claim 1, characterized in that the inside is sharply formed.

Next, the invention of claim 3 relates to "coil member 2
0 is configured to expand when the diameter reduction by the compression member 30 is released, and the connecting end portion of the synthetic resin pipe B according to claim 1 or 2 is airtight or liquidtight. It is a structure that seals.

Next, the invention of claim 4 is directed to a "sleeve 10".
Is formed integrally with the body A to be connected, wherein the connecting end of the synthetic resin pipe B according to any one of claims 1 to 3 is sealed airtightly or liquidtightly.

Next, a fifth aspect of the present invention provides a "compressing member 30.
Is a tubular body that is formed in a tubular shape and is divided into two in the circumferential direction, and the connecting end portion of the synthetic resin pipe B according to any one of claims 1 to 4 is airtight. Or structure that is liquid-tightly sealed "

Next, the invention of claim 6 is the "compressing member 30".
Is a tubular body having a substantially C-shaped cross section, and hermetically or liquid-tightly seals the connection end of the synthetic resin pipe B according to any one of claims 1 to 4. Construction"

Finally, the invention of claim 7 is the "compression member 3".
0 is a nut having a female screw formed on the inner surface on one end side and a taper surface 35 on the inner surface on the other end side that reduces in diameter toward the other end side. It is a structure for sealing the connection end portion of the synthetic resin pipe B described in any one of the above in an airtight or liquid-tight manner. "

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a structure for sealing a connecting end portion of a synthetic resin pipe B according to the present invention in an airtight or liquid-tight manner will be described in detail with reference to the drawings. In each of the following examples, an example in which the synthetic resin pipe B is connected to another pipe such as a steel pipe is shown, but the present invention is not limited to this, and another pipe for branching the pipe into a plurality of pipes, for example. Alternatively, a joint such as an elbow joint or a branch joint (so-called header), or a water faucet or the like can be used as the connected body A, and can be applied when connecting the synthetic resin pipe B to the connected body A.

FIG. 1 shows an example of an embodiment of the seal structure according to the present invention. One end side of the sleeve 10 is formed to have an outer diameter slightly smaller than the inner diameter of the connected body A such as a steel pipe, is inserted into the connected body A, and is connected to this in an airtight or liquid-tight manner. Here, the O-ring 40 is mounted between the connected body A and the sleeve 10, and the airtightness or liquid tightness between the connected body A and the sleeve 10 is secured. Further, the connected body A is provided with two pin holes 51, which are bored from the side surface of the connected body A and exposed to the inner surface of the connected body A, on the end side of the mounting portion of the O-ring 40. The groove 12 is provided on the outer surface of the sleeve 10 at a portion corresponding to the pin hole 51. Then, as shown in FIG. 2, by inserting the locking pin 50 bent into a substantially U-shape into the two pin holes 51 from the side surface of the connected body A, the groove 12 of the sleeve 10 is locked. The pin 50 is locked and the sleeve 10 is prevented from being pulled out from the connected body A. The two pin holes 5 on the outer surface of the connected body A
A recess 52 is provided between the two, and the locking pin 50 inserted into the pin hole 51 can be easily removed by inserting a tool such as a flat-blade screwdriver into the recess 52 and pulling it out. is there.

On the other hand, the other end of the sleeve 10 is fitted inside the synthetic resin pipe B. Here, the outer peripheral surface of the sleeve 10 is formed in a saw-tooth shape in cross section.
Is designed so as not to be easily pulled out from the synthetic resin pipe B.
A collar 11 is provided at the center of the sleeve 10. The collar portion 11 functions as a stopper for the synthetic resin pipe B inserted into the other end of the sleeve 10 and
As will be described later, it functions to prevent movement of the compression member 30.

On the outside of the synthetic resin pipe B in which the sleeve 10 is inserted and fitted, the coil member 2 which is spirally wound.
0 is attached. Here, the coil member 20 is formed by winding a wire having a trapezoidal cross section, and has a sharp inner side as in the invention of claim 2. In addition, in order to sharpen the inside of the coil member 20, not only a wire having a trapezoidal cross section is used, but also a wire having a triangular cross section or a wire having a partially sharp cross section is used. It may be wound so that the sharp side is on the inside.

The coil member 20 is formed of a spring steel material or a synthetic resin having a high restoring force.
When the diameter reduction by the compression member 30 which will be described later is released, the restoring force of the compression member 30 expands the original shape. If such a coil member 20 is adopted,
For example, when the synthetic resin pipe B connected to the connected body A is removed and then re-connected, the coil member 20 used for the connection can be easily removed from the synthetic resin pipe B, and the removal can be easily performed. The coil member 20 may be reused.

A compression member 30 for compressing the coil member 20 in the circumferential direction is mounted on the outer side of the coil member 20. By the compression by the compression member 30, the diameter of the coil member 20 is reduced to tighten the synthetic resin pipe B in the circumferential direction,
The sleeve 10 and the synthetic resin pipe B are firmly and air-tightly or liquid-tightly connected. Here, since the coil member 20 is uniformly reduced in diameter in the circumferential direction, the synthetic resin pipe B is uniformly tightened over the entire outer circumference, and therefore, the airtightness between the sleeve 10 and the synthetic resin pipe B or Liquid tightness becomes uniform in the circumferential direction.
Further, since the inside of the coil member 20 is sharply formed as described above, the coil member 20 bites into the outer surface of the synthetic resin pipe B and is firmly attached thereto, and reliable airtightness or liquid tightness is obtained.

By the way, it is preferable that the inner diameter of the coil member 20 is slightly larger than the outer diameter of the synthetic resin pipe B. However, since the coil member 20 itself can be expanded and contracted in diameter, the inner diameter of the coil member 20 can be reduced. Even if is smaller than the outer diameter of the synthetic resin pipe B, the coil member 20 can be reliably attached to the synthetic resin pipe B by expanding the diameter of the coil member 20. Further, even if the inner diameter of the coil member 20 is too larger than the outer diameter of the synthetic resin pipe B, the coil member 20 is
Since the diameter is reduced according to the compression force of the compression member 30, the synthetic resin pipe B can be reliably tightened by increasing the compression force.

The above-mentioned compression member 30 is not particularly limited in its shape as long as it can compress the coil member 20 in the circumferential direction to reduce the diameter of the coil member 20, but is not limited to a specific one. As the shape, for example, as shown in FIG. 3, as in the invention of claim 5, a tubular body formed in a tubular shape and divided into two in the circumferential direction, or as shown in FIG.
As a sixth aspect of the present invention, a cylindrical body having a substantially C-shaped cross section can be used. Such a compression member 30 is, for example, as shown in the drawing, contracted in the circumferential direction by tightening a screw 33 to reduce the diameter of the coil member 20. Among such compression members 30, the compression member 3 as shown in FIG.
Since 0 is divided into two in the circumferential direction, it is not necessary to previously mount the synthetic resin pipe B on the synthetic resin pipe B when connecting the synthetic resin pipe B to the connected body A, and the mounting workability on the synthetic resin pipe B is improved. Excellent in. The compression member 30 as shown in FIG.
Has a substantially C-shaped cross section, the compression member 3
At the time of 0 tightening, the diameter of the entire circumferential direction is reduced due to the blockage of the C-shaped cutout portion, and the tightening workability is excellent.

Further, in each of the examples shown in FIGS. 3 and 4, projections 31 and 3 protruding inward are provided at both end portions of the compression member 30.
2 are provided. As shown in FIG. 1, first, the protrusion 31 on the one end side, when mounted on the outer side of the coil member 20, has the end portion of the connection body A and the collar portion 11 of the sleeve 10.
This is to prevent the careless movement of the compression member 30 from the mounting portion, which is locked in the groove formed by. The protrusion 32 on the other end side is formed by the synthetic resin pipe B and the compression member 30.
This is to prevent the coil member 20 from accidentally coming out of the inside of the compression member 30 by closing the gap between the coil member 20 and the compression member 30. Since the coil member 20 has its entire length slightly elongated due to the diameter reduction, the compression member 30 has a space on its inner surface that can sufficiently accommodate the elongation of the coil member 20.

FIG. 5 shows another example of the embodiment of the seal structure according to the present invention. According to the fourth aspect of the invention, the sleeve 10 is integrally formed on the end portion of the connected body A such as a steel pipe, and the synthetic resin pipe B is attached to the sleeve 10, the coil member 20 and the compression member as described above. It is connected by 30 firmly and air-tightly or liquid-tightly. By integrally forming the sleeve 10 on the body A to be connected in this way,
It is possible to secure the solid integrity and air tightness or liquid tightness between the connected body A and the sleeve 10. Further, the work of connecting the connected body A and the sleeve 10 can be omitted,
It is also possible to simplify the work of connecting the connected body A and the synthetic resin pipe B. Also in this example, a compression member 30 such as a halved cylinder as shown in FIG. 3 or a compression member 20 such as a C-shaped cylinder as shown in FIG. 4 is employed. Therefore, between the synthetic resin pipe A and the sleeve 10 formed integrally therewith, a groove for locking the projection 31 on one side of the compression member 30 is formed and functions as a stopper for the synthetic resin pipe B to be connected. A brim portion 11 is provided.

FIG. 6 shows still another example of the embodiment of the seal structure according to the present invention. According to the invention of claim 7, the compression member 30 is provided with an internal thread 34 on the inner surface at one end side.
This is a nut having an inner surface on the other end side and a tapered surface 35 that reduces in diameter on the other end side. By using the compression member 30 as the nut in this way, the diameter of the coil member 20 can be easily reduced by tightening the nut, and the work of connecting the connected body A and the synthetic resin pipe B can be simplified. . In this example, the sleeve 10 formed separately from the connected body A such as a steel pipe is adopted, and the connected body A and the sleeve 10 are air-tightly or liquid-tightly connected via the O-ring 40. However, the sleeve 10 may be integrally formed at the end of the connected body A as in the invention of claim 4 described above. Further, in this example, on the outer surface of the end portion of the connected body A,
Although the example in which the male screw 36 to be screwed with the female screw 34 of the compression member 30 is provided and the compression member 30 is screwed to the connected body A is shown, the invention is not limited to this, and the male part 36 of the sleeve 10 or the like may be male. The screw 36 may be provided and the compression member 30 may be screwed to the sleeve 10.

FIG. 7 shows a modified example of the above embodiment, which is a cylindrical compression member 30 having a tapered surface 35 on its inner surface.
After the coil member 20 is reduced in diameter by forcibly covering the outer circumference of the coil member 20, the holding member 37 is attached to the outer circumference of the compression member 30, and the female screw 3
4 is screwed into the male screw 36 of the connected body A to form a synthetic resin pipe B.
May be connected to the connected body A and the compression member 30 may be prevented from being pulled out. In this case, the compression member 30
The removal prevention is not limited to the cylindrical holding member 37, but a divisible holding member (see FIG. 3 or 4) may be attached and fixed from the outside.

Finally, FIG. 8 shows still another example of the embodiment of the seal structure according to the present invention. This is the same as the sleeve 1 in the seal structure as shown in FIG.
The outer peripheral portion of 0 and the inner peripheral portion of the compression member 30 are provided with recesses 13 and 38 in which the coil member 20 is housed.
In this manner, when the compression member 30 is provided with the recessed portion 38 for accommodating the coil member 20, the coil member 20 fits well in the inner surface of the compression member 30, and the total length of the coil member 20 is unintentionally extended too much and its length direction. It is possible to prevent uneven tightening force. When the recess 13 for housing the coil member 20 is provided in the sleeve 10, not only the coil member 20 is stored in the sleeve 10 well, but also in the gap of the recess 13,
The synthetic resin pipe B sandwiched between the sleeve 10 and the coil member 20 is bent, and the sleeve 10 and the synthetic resin pipe B are firmly fixed.

[0029]

EFFECTS OF THE INVENTION According to the present invention having the above-described structure, the following effects can be obtained.

First, since the synthetic resin pipe is tightened by compressing and reducing the diameter of the spirally wound coil member in the circumferential direction, a uniform tightening force can be obtained in the circumferential direction of the synthetic resin pipe. Therefore, uniform airtightness or liquidtightness can be secured over the entire outer circumference of the synthetic resin pipe.

Secondly, the coil member itself has an expanded diameter.
Since the diameter can be freely reduced, even if the inner diameter of the coil member is smaller than the outer diameter of the synthetic resin pipe, the coil member can be securely attached to the synthetic resin pipe. Even if the diameter is larger than the diameter, the synthetic resin pipe can be securely tightened by the coil member, and high dimensional accuracy is not required for the synthetic resin pipe and the coil member.

Thirdly, since the coil member can be surely reduced in diameter by a slight compressive force of the compressing member, members such as the sleeve and the compressing member are made of synthetic resin or the like having strength lower than that of metal such as steel. It can also be formed by using, and is excellent in mass productivity and economical.

According to the inventions of claims 2 to 7,
The following effects can be obtained.

First, according to the second aspect of the invention, since the inside of the coil member is sharply formed, when the diameter of the coil member is reduced, the inside of the coil member bites into the outer periphery of the synthetic resin pipe and becomes firm. The airtightness or the liquidtightness between the sleeve and the synthetic resin tube, which are mounted, can be improved.

According to the third aspect of the present invention, even if the coil member is once used, if the compression by the compression member is released, the coil member expands in diameter due to its own restoring force, so that the coil member is made of synthetic resin. The coil member and the synthetic resin pipe can be reused.

Next, according to the invention of claim 4, since the sleeve is formed integrally with the connected body, the airtightness or the liquid tightness between the connected body and the sleeve can be secured. Further, since the work of connecting the connected body and the sleeve can be omitted, the work of connecting the synthetic resin pipe to the connected body can be simplified.

Next, according to the fifth aspect of the invention, since the compression member is a halved cylinder, not only is it inserted into the outer side of the synthetic resin pipe, but also the halved cylinder is used. The compression member can be attached to the synthetic resin pipe also by attaching each of them to the outside of the synthetic resin pipe from two directions, and the work of attaching the compression member can be diversified.

Next, according to the sixth aspect of the invention, since the compression member is a cylinder, the diameter of the coil member can be reduced by closing the C-shaped notch.
It is possible to simplify the work of tightening the compression member.
Further, by closing the C-shaped cutout portion, a compressive force that uniformly reduces the diameter of the coil member in the entire circumferential direction of the compression member is obtained, and the diameter of the coil member can be uniformly reduced in the circumferential direction.

Finally, according to the invention of claim 7, since the compression member is a nut, the diameter of the coil member can be reduced by tightening the nut, and the work of tightening the compression member is further simplified. Can be achieved. Also,
It is also possible to firmly connect the connected body and the compression member.

[Brief description of drawings]

FIG. 1 is a sectional side view showing an example of a seal structure according to each invention.

FIG. 2 is a perspective view showing an inserted state of a locking pin.

FIG. 3 is a perspective view showing an example of a compression member used in the invention of claim 5.

FIG. 4 is a perspective view showing an example of a compression member used in the invention of claim 6;

FIG. 5 is a sectional side view showing an example of the seal structure according to the invention of claim 4.

FIG. 6 is a sectional side view showing an example of a seal structure according to the invention of claim 7.

FIG. 7 is a sectional side view showing another example of the seal structure according to the invention of claim 7;

FIG. 8 is a sectional side view showing another example of the seal structure according to each invention.

FIG. 9 is a sectional side view showing a conventional seal structure.

[Explanation of symbols]

 A Connected object B Synthetic resin pipe 10 Sleeve 11 Collar part 12 Groove 13 Recess 20 Coil member 30 Compressing member 31 Protrusion 32 Protrusion 33 Screw 34 Female screw 35 Tapered surface 36 Male screw 37 Tapered member 38 Recess 40 O-ring 50 Locking pin 51 Pin hole 52 Recess

Claims (7)

[Claims] 1. A structure for sealing a connecting end portion of a synthetic resin pipe in an air-tight or liquid-tight manner in order to connect a synthetic resin pipe through which a fluid is circulated to a connected body. A sleeve inserted inside the end,
A composite comprising: a coil member that is wound in a spiral shape and is attached to the outside of the connection end portion; and a compression member that is attached to the outside of the coil member to reduce the diameter of the coil member. A structure that seals the connection end of the resin pipe in an airtight or liquid-tight manner. 2. A structure for airtightly or liquid-tightly sealing a connecting end portion of a synthetic resin pipe according to claim 1, wherein the coil member has a sharp inner side. 3. The coil member is configured to expand when the diameter reduction by the compression member is released, and the connecting end portion of the synthetic resin pipe according to claim 1 or 2 is formed. Airtight or liquid-tight seal structure. 4. The synthetic resin pipe according to claim 1, wherein the sleeve is formed integrally with the connected body so that the connecting end portion of the synthetic resin pipe is airtight or liquidtight. Sealing structure. 5. The compression member is a tubular body which is formed in a tubular shape and is bisected in the circumferential direction.
5. A structure for sealing the connecting end portion of the synthetic resin pipe according to claim 4 in an airtight or liquid-tight manner. 6. The compression member is a cylindrical body having a substantially C-shaped cross section, and the connecting end portion of the synthetic resin pipe according to claim 1 is hermetically sealed. Or a structure that seals liquid tightly. 7. The compression member is a nut having a tapered surface formed on the inner surface thereof.
The structure for sealing the connecting end portion of the synthetic resin pipe according to any one of 1 to 6 above in an airtight or liquidtight manner.