JP3434379B2 - Pipe fittings - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint for connecting pipes by combining two semi-cylindrical members.

[0002]

[Industrial application] In recent years, plastic pipes have been widely used as protective pipes for electric wires and cables and underdrain drainage pipes. As such a pipe, a straight pipe or a spiral wave is added (the peaks and valleys of the corrugations appear to be inclined with respect to the axial direction).
There are tubes with spiral waves, tubes with independent waves, where the peaks and valleys of the waveform appear at right angles to the axial direction. Conventionally, a cylindrical pipe joint has been used to connect these pipes. However, since the connection work of the cylindrical pipe joint is troublesome, recently, a pipe joint of a type in which a portion where the end portions of the pipes to be connected are butted is sandwiched between two semi-cylindrical members has been proposed.

FIG. 11 shows the basic construction of this type of pipe joint. This pipe joint is composed of a combination of two half-cylindrical members 13 that cover the pipe 11 to be connected by half a circumference. Each of the semi-cylindrical members 13 has a hard resin molded body 15 and a packing layer 17 made of an elastomer provided on the inner surface thereof. The hard resin molded body 15 has a shape in which coupling portions 21 with the other party are formed on both side edges of the half-cylindrical portion 19.

[0004]

In the conventional pipe joint, the inner peripheral surface of the semi-cylindrical member 13 is formed in a semicircular cross section with the same curvature as the outer peripheral surface of the pipe 11. Therefore, the two half cylinder members 13
When the pipe 11 is sandwiched by and tightened in the direction of arrow A, the force for tightening the pipe 11 is as shown by arrow B. That is, a large tightening force is generated in the tightening direction of the half cylinder member 13, but almost no tightening force is generated in the direction perpendicular to the tightening direction of the half cylinder member 13. Therefore, the two half cylinder members 13
The watertightness near the seam is insufficient and water leakage is likely to occur.

In view of the above problems, an object of the present invention is to provide a pipe joint having improved water tightness in the vicinity of the joint between the two semi-cylindrical members.

[0006]

In order to achieve this object, the pipe joint of the present invention comprises a combination of two semi-cylindrical members that cover the pipe to be connected by half a circumference, and each semi-cylindrical member is a semi-cylindrical part. a hard resin molded body on both side edges to form a coupling portion with the counterpart, in the pipe joint comprising a packing layer digits set on the inner surface thereof, the opening width S of the joint portion of the half cylinder member, the center of the opening width Less than twice the depth D at
Yes, the hard resin molded body of the semi-cylindrical member has a central portion in the circumferential direction.
The wall thickness is smaller than the wall thickness on both sides in the circumferential direction.
The cylindrical member is elastically deformable so that it can be spread out to both sides.
Has it, characterized in that (claim 1).

More preferably, the inner peripheral surface of the semi-cylindrical member has a radius of curvature of both side portions in the circumferential direction substantially the same as the radius of curvature of the outer peripheral surface of the connected pipe, and the radius of curvature of the central portion in the circumferential direction. Is formed to have a semi-elliptical cross section smaller than the radius of curvature of the outer peripheral surface of the pipe to be connected, and the hard resin molded body of the semi-cylindrical member has a wall thickness at the center in the circumferential direction that at both sides in the circumferential direction.
It is formed to be thinner than the thickness, and is elastically deformable so that the inner peripheral surface of the semi-cylindrical member approaches from a semi-elliptical cross section to a semi-circular cross section (claim 2).

More preferably, a lubricant is applied to the inner surface of the packing layer (claim 3).

[0009]

In the pipe joint constructed as described above, the inner diameter of the two semi-cylindrical members in the joint direction is smaller than the outer diameter of the pipe. The pipe is pushed into the member and elastically deformed so that the semi-cylindrical member is spread to both sides (the inner peripheral surface of the semi-cylindrical member approaches from a semi-elliptical cross section to a semi-circular cross section). As a reaction, the hard resin molded body generates an elastic restoring force, and presses the packing layer near the joint between the two semi-cylindrical members against the outer peripheral surface of the pipe. Therefore, the watertightness in the vicinity of the joint between the two semi-cylindrical members is improved.

In the pipe joint constructed as described above, both sides of the inner surface of the semi-cylindrical member are strongly pressed against the outer surface of the pipe when the pipe is clamped by the two semi-cylindrical members. Both side edges may be dragged inward of the semi-cylindrical member due to friction with the outer surface of the pipe. If the tightening of the semi-cylindrical member is completed in this state, a gap may be formed near the seam of the packing layer, resulting in insufficient water tightness. To prevent this, it is effective to apply a lubricant to the inner surface of the packing layer as described above. If a lubricant is applied, the frictional force between the inner surface of the semi-cylindrical member and the outer surface of the pipe will be reduced, and when tightening the two semi-cylindrical members, both edges of the packing layer will slide on the outer surface of the pipe, It will not be dragged towards you. Or even if it is dragged in, it immediately returns to its original state. Therefore, no gap is formed near the seam of the packing layer, and the watertightness is improved.

In the pipe joint of the present invention, it is desirable to form a convex portion and a concave portion for positioning when the two half-cylindrical members are combined on the mating surface of the hard resin molded body. With this configuration, the two half-cylindrical members cannot be joined unless the convex portion and the concave portion are fitted together, and the two half-cylindrical members are accurately positioned if the convex portion and the concave portion are fitted together. Therefore, it is possible to easily and surely obtain a proper connected state in which the peaks and the valleys on the inner circumferences of the two semi-cylindrical members are correctly and continuously connected.

In the pipe joint of the present invention, if the shape of the inner peripheral surface is formed so as to correspond to the outer peripheral surface of the straight pipe, the pipe joint can be used as a joint of the straight pipe, and similarly, the outer periphery of the spiral wave pipe and the independent wave pipe can be used. If formed so as to correspond to the surface, the joint of the spiral wave pipe,
It can be used as a joint for a pipe with independent wave.

As the material of the hard resin molded body in the pipe joint of the present invention, polyolefin resin, acrylonitrile-butadiene-styrene (ABS) resin, polyvinyl chloride (PVC) resin, etc. are usually used for pipe joints. Materials can be used.

As the material of the packing layer in the pipe joint of the present invention, vulcanized rubber such as natural rubber and synthetic rubber, and elastomer such as thermoplastic elastomer can be used. Among these, particularly, polystyrene-based such as hydrogenated styrene-isoprene-based thermoplastic elastomer (SIS or SEPS), styrene-butylene-based thermoplastic elastomer (SEBS), styrene-butadiene-based thermoplastic elastomer (SBS), or 1,2- Polybutadiene (1,2PB)
It is preferable to use thermoplastic elastomers such as series, polyolefin series, polyurethane series, polyester series, polyamide series, chlorinated polyethylene series, polyfluorocarbon series, polyvinyl chloride series, and fluorine series. When the thermoplastic elastomer is used, it is possible to adopt a means for directly laminating the packing layer on the inner surface of the hard resin molded body by the injection molding method, which facilitates the production of the half-cylindrical member.

The hardness of the thermoplastic elastomer used for the packing layer is preferably JIS A5 to 50,
It is more preferably 5 to 30. Within this range, the packing layer can reliably follow the stoppage of water even if the sink marks are generated in the pipe. Further, it is possible to prevent the watertightness from being deteriorated by the deformation of the packing layer due to the water pressure from the outside.

Further, the above-mentioned thermoplastic elastomer 10
20 parts by weight of a starch-based, cellulose-based, polyacrylic-based, poval-based, polyoxyethylene-based, or other water-swellable material, such as acrylic acid / vinyl alcohol copolymer, which swells when absorbed by water. It is more preferable to add about 1 part by weight as a material for the packing layer. When the water-swellable material is added within the above range,
When the water-swellable material comes into contact with water, the water-swellable material absorbs water and swells, so that the adhesion between the packing layer and the tube is improved, and higher water tightness is obtained.

In order to further strengthen the adhesion between the hard resin molded body and the packing layer when the packing layer is injection-molded on the hard resin molded body, polyolefin resin or ABS resin is used as the material of the hard resin molded body. When resin is used, the packing layer material is SEPS, SEBS, SBS
When a thermoplastic resin such as the above is used and a PVC resin is used as the material of the hard resin molded body, it is preferable to use the PVC thermoplastic elastomer as the material of the packing layer.

In the pipe joint of the present invention, when the thermoplastic elastomer is injection-molded on the inner surface side of the hard resin molded body, an injection hole is formed in the hard resin molded body. The position of this injection hole is preferably within 3 cm from the end surface of the hard resin molding, and more preferably within 1.5 cm. Within this range, the adhesion between the end portion of the hard resin molded body and the packing layer becomes stronger when injection molding is performed, and the effect of preventing the hard resin molded body and the packing layer from peeling off near the end portion is further improved. Because it becomes remarkable.

When the pipe joint of the present invention is a corrugated pipe joint in which a corrugated shape is formed on the inner peripheral surface of the semi-cylindrical member so as to correspond to the outer peripheral surface of the corrugated pipe, the injection hole is It is preferable to provide it in the trough portion of the thin wall. Furthermore, in this case, the position where the injection hole is provided is preferably within 2 pitches, more preferably within 1 pitch, of the corrugated pitch from the end surface of the hard resin molding. Within this range, the adhesion between the end portion of the hard resin molded body and the packing layer becomes stronger when injection molding is performed, and the effect of preventing the hard resin molded body and the packing layer from peeling off near the end portion is further improved. It will be noticeable.

Silicone oil or the like is used as a lubricant applied to the inner surface of the half cylinder member. To ensure water tightness, the coefficient of static friction between the packing material and the pipe material is 0.3.
In the following, it is preferable to use a lubricant having a content of 0.1 or less. The lubricant may be applied to the entire inner peripheral surface of the semi-cylindrical member, but may be applied sufficiently only to both sides in the circumferential direction of the inner peripheral surface of the semi-cylindrical member (near the side edges of the packing layer). can get.

The lubricant may be applied not only on the inner peripheral surface of the half-cylindrical member but also on the outer peripheral surface of the pipe to be connected. Further, the same effect can be obtained even if the lubricant is not applied to the inner peripheral surface of the semi-cylindrical member but is applied only to the outer peripheral surface of the pipe to be connected. In this case, after applying a lubricant to the outer peripheral surface of the pipe to be connected, the pipe may be clamped by two half-cylindrical members.

[0022]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(Embodiment 1) FIGS. 1 to 8 show an embodiment of the present invention. This pipe joint connects the spiral corrugated pipe 11, and is composed of a combination of two half cylinder members 13 that cover the spiral corrugated pipe 11 by half a circumference. The two half-cylindrical members 13 have the same shape and are assembled with their opposite ends oriented in opposite directions.
1 and 2 show the state before connecting the spiral corrugated tube 11, and FIGS. 3 and 4 show the state after connecting.

Each half-cylindrical member 13 is a hard resin molding 1.
A packing layer 17 made of a thermoplastic elastomer is provided on the inner surface of No. 5. The hard resin molded body 15 is formed by forming coupling portions 21 a and 21 b with the counterpart on both side edges of the semi-cylindrical portion 19. The material of the hard resin molded body 19 is, for example, polypropylene, and the material of the packing layer 17 is, for example, SEPS thermoplastic elastomer having a hardness of JIS A20.

Crests 23 are formed on the inner surface of the hard resin molding 15 at the same pitch as the troughs on the outer peripheral surface of the spiral corrugated tube 11 (see FIGS. 7 and 8). The packing layer 17 is
The cross-sectional shape combined with this mountain portion 23 is the tube with spiral wave 11
Is integrally provided on the inner surface of the hard resin molded body 15 so as to form a mountain portion 25 that tightly fits in the valley portion of the outer peripheral surface of the.

The connecting portion formed on both side edges of the semi-cylindrical portion 19 of the hard resin molded body 15 has a projecting edge 2 in which one side projects laterally.
1a, and the other is a hook 21b hooked on the projecting edge 21a. The projecting edge 21a is formed continuously in the longitudinal direction of the hard resin molded body 15, and the hook 2
1b is formed at a position closer to one end side from the central portion in the longitudinal direction of the hard resin molded body 15 (see FIG. 2).

As shown in FIG. 1, the first feature of this pipe joint is that the opening width S (width between valleys or peaks) at the joint portion of the half-cylindrical member 13 is That is, it is smaller than twice the depth D (depth to the valley portion or the mountain portion) at the center. Particularly in this example, the half cylinder member 1
The radius of curvature of both side portions P in the circumferential direction of the inner peripheral surface of 3 is substantially the same as the radius of curvature of the outer peripheral surface of the corrugated pipe 11, and the radius of curvature of the central portion Q in the circumferential direction of the outer peripheral surface of the connecting pipe 11. It is formed with a semi-elliptical cross section that is smaller than the radius of curvature. For this reason,
Half cylinder member 1 in the direction of the seam of the two half cylinder members 13
The opening width S measured at the valley portion (mountain portion) of 3 is the spiral corrugated tube 1
It is smaller than the outer diameter T of the mountain portion (valley portion) of No. 1. The opening width S may be smaller than the depth D by 3 to 8 mm. Alternatively, the opening width S may be smaller than the outer diameter T by 3 to 8 mm.

The second characteristic of this pipe joint is that the half-cylindrical member 13 is used.
Of the hard resin molded body 15 which is responsible for the mechanical strength of the semi-cylindrical member 13 has a wall thickness V at the central portion in the circumferential direction smaller than the wall thickness W at both side portions in the circumferential direction, and the inner peripheral surface of the semi-cylindrical member 13 has a semi-elliptical cross section. The shape is more suitable for elastically deforming from a shape to a semicircular cross section. When the elastic coefficient (kgf / mm ² ) of the material of the hard resin molded body 15 is M, the wall thickness V may be selected in the range of 60> M / V> 30.

Due to the above two characteristics, this pipe joint is
When the spiral corrugated pipe 11 is sandwiched between the two semi-cylindrical members 13 and tightened as shown in FIGS. 3 and 4, the spiral corrugated pipe 11 is pushed into the semi-cylindrical member 13, so that the semi-cylindrical member 13 is spread to both sides. Elastically deformed so that the inner peripheral surface of the semi-cylindrical member 13 approaches a semi-elliptical cross section from a semi-elliptical cross section.
As a reaction, the hard resin molded body 15 generates an elastic restoring force and presses the packing layer 17 near the joint between the two half-cylindrical members 13 against the outer peripheral surface of the corrugated pipe 11. Therefore, the watertightness in the vicinity of the joint between the two semi-cylindrical members 13 is improved.

In order to ensure the water tightness, the inner peripheral surface of the semi-cylindrical member 13 (that is, the inner peripheral surface of the packing layer 17).
It is preferable to apply a lubricant such as silicone oil to the above. If the lubricant is applied, the packing layer 17 and the spiral corrugated pipe 1 are tightened when the two half-cylindrical members 13 are tightened.
Since the friction with 1 becomes small, the both side edges of the packing layer 17 will not be dragged inward of the semi-cylindrical member 13. Or even if it is once pulled in, it immediately returns to its original state. Therefore, no gap is formed at the seam of the packing layer 17, and the watertightness can be made more reliable.

Although the lubricant may be applied to the entire inner peripheral surface of the semi-cylindrical member 13, the lubricant may be applied to the entire inner peripheral surface of the semi-cylindrical member 13.
Even if it is applied only to both side portions P in the circumferential direction, a sufficient effect can be obtained. The lubricant may be applied to both the inner peripheral surface of the semi-cylindrical member 13 and the outer peripheral surface of the spiral corrugated tube 11, or may be applied only to the outer peripheral surface of the spiral corrugated tube 11. Good.

This pipe joint is made up of two half cylinder members 13
When combining as shown in FIG. 3, a relatively large pressing force is required. For this reason, in this pipe joint, the top of the semi-cylindrical portion 19 of the hard resin molded body 15 is formed flat so that pressing force is easily applied.

The third characteristic of this pipe joint is that a convex portion 27 and a concave portion 29 are formed on the mating surface of the hard resin molded body 15 for mating the two half-cylindrical members 13. (See FIGS. 2 and 6). The convex portion 27 and the concave portion 29 are formed symmetrically with respect to the surface of the hard resin molded body 15 at the central portion in the longitudinal direction, which is perpendicular to the axis.
Therefore, when the two half-cylindrical members 13 are combined with their opposite ends facing each other, the convex portion 27 and the concave portion 29 are fitted together. In other words, if the two half-cylindrical members 13 are combined so that the convex portion 27 and the concave portion 29 are fitted to each other, a proper connection state can be obtained. That is, the two half-cylindrical members 13 can be assembled so that the peaks and troughs on the inner peripheral surface are correctly continuous.

The fourth characteristic of this pipe joint is that it is a semi-cylindrical member 13.
At the central portion Z in the longitudinal direction and the circumferential direction of the inner peripheral surface of the ridge portion 23 of the hard resin molded body 15 and the ridge portion 2 of the packing layer 17.
5 is omitted, and it is an arc surface having an inner diameter substantially the same as that of the valley portion (see FIGS. 6 and 7). Since the central portion Z is a portion that does not contribute to the watertightness or the pull-out strength of the spiral corrugated tube 11, it is possible to omit the peak portion in this way. If the mountain portion is omitted, the material cost can be reduced. Further, when the mountain portion is omitted in this manner, the force of crimping the portion relating to the watertightness to the pipe becomes large, so that the watertightness can be improved. Further, by using the recess of the central portion Z to drop the end portion of the pipe therein, it becomes easy to assemble the semi-cylindrical member with the pipe set.

(Embodiment 2) FIG. 9 shows another embodiment of the present invention. FIG. 9 is a sectional view of a portion corresponding to line BB in FIG. In this pipe joint, both ends in the longitudinal direction of the inner surface of the semi-cylindrical member 13 are set as pull-out preventing portions 31, a water blocking portion 33 is provided between the pull-out preventing portions 31 and the central portion 35, and the pull-out preventing portion 31 is The height of the mountain portion 23 of the hard resin molded body 15 is made higher than that of the water blocking portion 33 and the central portion 35, and the water blocking portion 33 has the packing layer 17 thicker than the pullout preventing portion 31. . The other structure is the same as that of the first embodiment. With this configuration, both the pullout strength and the watertightness of the corrugated pipe can be improved.

(Embodiment 3) FIG. 10 shows still another embodiment of the present invention. FIG. 10 is a sectional view of a portion corresponding to the line CC of FIG. In this pipe joint, protrusions 37 that bit into the packing layer 17 are formed near both ends in the circumferential direction of the inner peripheral surface of the hard resin molded body 15. The other structure is the same as that of the first embodiment.

In the pipe joint of the present invention, the inner diameter of the semi-cylindrical member 13 in the seam direction is smaller than the outer diameter of the pipe to be connected. The attached tube enters the semi-cylindrical member 13 while pushing the semi-cylindrical member 13 to both sides. At this time, since the hard resin molded body 19 and the corrugated pipe move relatively in opposite directions, the packing layer 17 sandwiched therebetween receives a shearing force, and the packing layer 17 at that portion is removed from the hard resin molded body 15. May peel off. When the protrusion 37 as described above is formed, the packing layer 17 near the seam is caught by the protrusion 37, so that the packing layer 17 is less likely to be peeled from the hard resin molded body 15.

Applying a lubricant to the inner peripheral surface of the semi-cylindrical member 13 is effective for preventing the packing layer 17 from peeling from the hard resin molding 15.

The pipe joint of the present invention is not limited to connecting corrugated pipes to each other, but also corrugated pipes and straight pipes, corrugated pipes and boxes, etc. It can also be used to connect to things.

[0040]

As described above, according to the present invention, the packing layer in the vicinity of the joint between the two semi-cylindrical members is pressed against the outer peripheral surface of the pipe to be connected, so that the watertightness in the vicinity of the joint is achieved. There is an advantage that the property is improved and water leakage can be prevented.

If a lubricant is applied to the inner peripheral surface of the packing layer, both side edges of the packing layer will not be dragged inward when the two half cylinder members are tightened. Or even if it is dragged in, it immediately returns to its original state. Therefore, no gap can be formed at the joint of the packing layers, so that the watertightness becomes more reliable.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of a pipe joint according to the present invention.

FIG. 2 is a right side view of the pipe joint of FIG.

FIG. 3 is a front view showing a state in which a pipe with a spiral wave is connected by the pipe joint of FIG.

FIG. 4 is a right side view of the state of FIG.

5 is a plan view (outer surface) of a half-cylinder member that constitutes the pipe joint of FIG. 1. FIG.

FIG. 6 is a bottom view (inner surface) of the semi-cylindrical member of FIG.

7 is a vertical sectional view taken along the line AA of FIG.

8 is a vertical cross-sectional view taken along the line BB of FIG.

FIG. 9 is a longitudinal sectional view showing a second embodiment of the pipe joint according to the present invention.

FIG. 10 is a cross-sectional view showing a third embodiment of the pipe joint according to the present invention.

FIG. 11 is a front view showing a conventional pipe joint.

[Explanation of symbols]

11: Tube with spiral wave 13: Half cylinder member 15: Hard resin molding 17: Packing layer 19: Half cylinder 21a: ridge (joint portion) 21b: Hook (joint part) 27: convex part 29: Recess

Front Page Continuation (72) Inventor Yasuhiro Tanaka 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (56) Reference JP-A-2-51698 (JP, A) JP-A-4-29695 (JP, A) JP 56-28383 (JP, A) JP 60-208689 (JP, A) JP 7-103372 (JP, A) JP 60-37492 (JP, A) Kaihei 1-182692 (JP, A) Actual Kaihei 6-44334 (JP, U) Actual Kaihei 4-93156 (JP, U) Actual Kaihei 4-36193 (JP, U) Actual Kaihei 2-143592 ( JP, U) SAIkai Sho 62-177990 (JP, U) JP-B 6-12156 (JP, B2) JP-B 5-59314 (JP, B2) JP-B 1-21271 (JP, Y2) US Patent 5190324 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16L 33/00-33/14 F16L 33/26 F16L 21/06 F16L 23/04-23/10

Claims (3)

(57) [Claims] 1. A combination of two half-cylindrical members (13) for covering the connecting pipe (11) by half a circumference, each half-cylindrical member (13) having a counterpart on both side edges of the half-cylindrical part (19). Hard resin molded body (1
5) and a packing layer (17) provided on the inner surface thereof, the opening width S at the seam of the semi-cylindrical member (13).
Is less than twice the depth D at the center of this opening width.
Ri, the semi-cylindrical rigid resin molded member (13) (15) is circumferential
The thickness (V) of the center part in the direction is the thickness of both sides in the circumferential direction.
It is made thinner than (W), and the half-cylindrical member (13) is pushed to both sides.
A pipe joint characterized by being elastically deformable so that it can be expanded . 2. A combination of two half-cylindrical members (13) covering the connecting pipe (11) by half a circumference, and each half-cylindrical member (13) is connected to the other side of the half-cylindrical part (19). Hard resin molded body (1
5) and a packing layer (17) provided on the inner surface thereof, in which the inner peripheral surface of the semi-cylindrical member (13) is connected to a pipe (radius of curvature of both side portions (P) in the circumferential direction). 11) is substantially the same as the radius of curvature of the outer peripheral surface, and the radius of curvature of the central portion (Q) in the circumferential direction is smaller than the radius of curvature of the outer peripheral surface of the pipe (11) to be connected,
The semi-elliptical cross section is formed, and the hard resin molded body (15) of the semi-cylindrical member (13) has a circumferential shape.
The thickness (V) of the center part in the direction is the thickness of both sides in the circumferential direction.
A pipe joint characterized in that it is formed thinner than (W) and is elastically deformable so that the inner peripheral surface of the semi-cylindrical member (13) approaches from a semi-elliptical cross section to a semi-circular cross section. 3. The pipe joint according to claim 1, wherein a lubricant is applied to the inner surface of the packing layer (17).