JP2000282556A - Joint for connection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint for connection capable of surely avoiding the infiltration of water or the like from the mutual connecting sections of underground buried pipes to the inside even in use for a prolonged term. SOLUTION: The joint for connection has a joint body for external fitting extending over the mutual one end sections of a plurality of adjacent underground buried pipes 1 under the state in which the mutual one end sections of the adjacent underground buried pipes 1, 1 in the pipe axial-center direction in the pipes 1 buried into a ground are abutted and clamps 4 for clamping each of both end sections 3B, 3B in the pipe axial direction of the joint body and conducting the mutual connection of the adjacent underground buried pipes 1 and sealing treatment under the state of external fitting. The joint, body is composed of a plastic material having resiliency, and the hardness of both end sections 3B, 3B in at least the pipe axial direction in the joint body is set at a value smaller than one of other sections.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of connecting underground buried pipes which are adjacent to each other in a pipe axis direction among a plurality of buried underground pipes used for connecting connecting portions such as handholes and manholes. The present invention relates to a connection joint used for connection.

[0002]

2. Description of the Related Art In order to connect underground pipes adjacent to each other in the pipe axis direction, for example, as shown in FIG. 6, an insertion portion 10A into which an underground pipe 1 can be inserted into each of both sides. , 10A, a sealing material 11 is provided at each end of the underground pipe 1 in each place, and one end of the underground pipe 1 is connected to one of the insertion portions 1 of the joint 10.
0A, and one end of the other underground pipe 1 is inserted into the other insertion portion 10A of the joint 10 so that adjacent underground pipes are connected in a sealed state. In addition, 10B shown in the figure is a protruding portion formed to protrude inward at substantially the center in the insertion direction of the joint 10 in order to regulate the insertion amount of the underground pipe 1.

In the above connection method, since only the underground pipe 1 is inserted into the joint 10, the sealing performance gradually decreases with long-term use, and the connection between the underground pipes is reduced. Water or the like may enter the inside, leaving room for improvement. Incidentally, it is conceivable that the degree of decrease in the sealing performance is reduced by dramatically increasing the sealing performance immediately after the connection.
The dimensional difference between the inner diameter of the insertion portion 10A of the joint 10 and the outer diameter of the underground pipe 1 is reduced, and the insertion portion 1 of the joint 10 is reduced.
This lowers the workability of inserting the underground pipe 1 into 0A, which is difficult to implement. In the configuration in which the underground pipe 1 is forcibly inserted into the insertion portion 10A of the joint 10 as described above, troubles such as damage or deformation of members may be caused. Immediately after that, the sealing performance could not be dramatically improved.

[0004]

SUMMARY OF THE INVENTION In view of the above situation, the present invention is intended to solve the problem that water and the like can be reliably prevented from entering the inside from the connection between underground pipes even during long-term use. It is an object of the present invention to provide a connection joint that can be used.

[0005]

The connecting joint according to the present invention comprises:
In order to solve the above-mentioned problem, in a state where one end of the underground pipes adjacent to each other in the pipe axis direction among a plurality of underground pipes buried in the ground abut one another, the adjacent underground pipes are buried. A joint main body for external fitting between one ends of the pipes, and a pipe axial direction of the joint main body in a state where the joint main body is externally fitted between one ends of the adjacent underground pipes. The joint body is made of elastic rubber or plastic, and is provided with a fastener for tightening each of both end portions to perform connection and sealing between the adjacent underground pipes, and the joint body is made of elastic rubber or plastic. The hardness of at least both ends in the tube axis direction is set to a value smaller (lower value) than the hardness of other portions. Therefore, in a state where the joint body is externally fitted across one end of adjacent underground pipes, by tightening both ends of the joint body in the pipe axis direction with a fastener, the adjacent underground pipes are connected to each other. The connection can be made in a sealed state by the elastic force of the pipe. In addition, by changing the tightening force by the tightening tool,
The sealing performance can be changed and adjusted. In addition, a seal function can be imparted only by changing the hardness of the joint body, and it is not necessary to separately form the seal material, and the separately formed seal material is jointed using an adhesive or the like. There is no need to attach it to the main unit. Further, there is no problem such as peeling of the separately formed sealing material.

When the joint body is formed of a cylindrical body, the number of members can be reduced as compared with the case where the joint body is formed by dividing the joint body into two parts. The sealing process can be completed only by tightening the parts having a small hardness value at both ends in the tube axis direction of the main body with a fastener.

The thickness of both ends of the joint body in the pipe axis direction is made smaller than the thickness of the other parts, and the inner surface of both ends of the joint body in the pipe axis direction is formed on the outer surface of the underground pipe. By forming the annular protrusions that come into contact, both ends of the joint body in the pipe axis direction can be easily tightened, and the sealing process is performed with a tightening operation force that only deforms the annular protrusions. It is possible to reduce the tightening operation force on both ends of the joint body in the pipe axis direction, and the sealing performance can be enhanced by the annular projection.

The fastener comprises an annular band and a screw body for expanding and contracting the band, and recesses into which the band can be inserted are formed on outer surfaces of both ends of the joint body in the axial direction of the joint. Accordingly, the concave portion can reliably prevent the band from moving in the pipe axis direction and coming off the joint body.

The hardness of the joint body at both ends in the tube axis direction is 4
By setting the hardness in the range of 0 ° to 60 ° and setting the hardness of the other parts in the range of 80 ° to 95 ° except for the both ends in the tube axis direction, the sealing performance at both ends in the tube axis direction and the tube shaft The shape-retaining strength of the portion excluding the both ends in the direction of the tube, that is, the middle portion in the tube axis direction can be favorably maintained.

[0010] By setting the hardness of the protruding portion to a value smaller (lower) than the hardness of both ends of the joint body in the tube axis direction, a reduction in the shape retention strength of both ends of the joint body in the tube axis direction is suppressed. However, the sealing performance can be further improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a plurality of underground pipes 1 for connecting between connecting parts such as handholes and manholes.
2 shows a state in which two of the underground pipes 1 and 1 are connected via a joint 2. The underground pipes 1, 1 are:
It is formed of a synthetic resin or the like, and has a spiral convex portion 1A and a spiral concave portion 1B, into which an optical cable, an information cable, a communication cable, and the like are passed.

The joint 2 is, as shown in FIGS.
A cylindrical joint body 3 having an inner diameter slightly larger than the outer diameter of the underground pipe 1, and four fasteners provided at both ends of the joint body 3 in the axial direction of the pipe axis, that is, at both longitudinal ends. 4 ... The joint body 3 is made of rubber and has a hard intermediate portion 3A whose hardness is set to approximately 90 °, and is located at both longitudinal ends of the intermediate portion 3A.
And both soft ends 3 having a hardness set to approximately 50 °
B and 3B. Also, both ends 3B, 3B
By making the thickness of the intermediate portion 3A thinner than the thickness of the intermediate portion 3A, the shape retention strength of the intermediate portion 3A can be increased, but the ends 3B, 3B are easily deformed in the diameter reducing direction and tightened. The operating force can be reduced. The greater the number of the fasteners 4, the more securely the fastening can be performed, but the number of the fasteners 4 is not limited to four as shown in the figure. The hardness of the intermediate portion 3A of the joint body 3 is set to approximately 90 °, and the hardness of the both end portions 3B, 3B is set to approximately 50 °. However, depending on the place of use, the hardness of the underground pipe 1, etc. Middle part 3 of 3
A between 40 ° and 60 °, and both ends 3B, 3B.
The hardness of B can be changed and adjusted between 80 ° and 95 °. The joint body 3 is optimally made of rubber, but may be made of polyurethane other than rubber, such as rubber, or various plastics having elasticity.

As shown in FIGS. 1 and 2, the fastening member 4 comprises a stainless steel band 4A having both ends overlapped to form an annular shape, and a screw body 4B for expanding and contracting the band 4A. By increasing the overlapping portion at both ends of the band 4A by rotating the screw body 4B in one direction, the band 4A can be reduced in diameter and the both ends 3B, 3B of the joint body 3 can be tightened. ing. The fasteners 4 are mounted so as to enter recesses 3b, 3b formed on the outer surfaces of both ends 3B, 3B of the joint main body 3, respectively. I try not to move. Further, both ends 3B of the joint body 3 are provided.
A pair of annular rectangular protrusions 3 protruding inward are provided on portions of the inner surface of 3B corresponding to the recesses 3b, 3b.
T and 3T are integrally formed so that the sealing performance can be enhanced. As shown in FIG. 5, the protrusions 3T, 3T are formed in a layer different from the ends 3B, 3B, and the hardness of the protrusions 3T, 3T is smaller than the hardness of the ends 3B, 3B (for example, By setting the hardness value to 40 °), the sealing performance may be further enhanced.
The shape and the degree of protrusion of the protrusions 3T, 3T can be freely changed.

A method of connecting the two underground pipes 1 and 1 will be described. First, as shown in FIG. 2, the fastener 4 is fitted into four recesses at both ends 3B and 3B of the joint body 3. Put in. The fastening tool 4 may be fitted from the beginning. After extrapolating one end of the joint body 3 provided with the fasteners 4 to one end of one underground pipe 1,
By moving the joint body 3 in the direction of the arrow in FIG. 3, that is, toward the other underground pipe 1, as shown in FIG.
The joint body 3 is set so that one end of each of the two underground pipes 1 and 1 is externally fitted in substantially the same range. In FIGS. 3 and 4, the fastener 4 is omitted in order to make the drawings complicated. In a state where the one end portions of the two underground pipes 1 and 1 abut each other, the joint body 3 is externally fitted over the one end portion,
By tightening the screw body 4B of the not-shown tightening tool 4, the joint body 3 is tightened in the radial direction, as shown by the partial arrow in FIG. , 1 by pressing the surface (outer surface), sealing
Connection of the two underground pipes 1, 1 can be completed. 3 and 4, the underground pipes 1, 1
Shows a state in which a gap is generated between one end portions of the underground pipes, but may be a state in which the end faces of the underground pipes 1 and 1 are in contact with each other, that is, a state in which there is no gap. If the joint body 3 is extrapolated to one end of the one underground pipe 1,
For example, in FIG. 3, even when the two ends of the two underground pipes 1 and 1 on the side away from each other are fixed, simply moving the joint body 3 in the direction of the arrow shown in FIG. It can be fitted over one end of the two underground pipes 1,1. However, as in the prior art shown in FIG. 6, it is necessary to move one underground pipe 1 to insert it into the joint 10, and as described above, the two underground pipes 1, 1 When each end is fixed, it is very difficult to move and insert one underground pipe 1 into the joint 10, and the present invention has an advantage that the connection can be easily made even in such a case. is there.

[0015]

According to the first aspect, the joint body is made of elastic rubber or plastic, and the hardness of at least both ends in the pipe axis direction of the joint body is smaller (lower) than other parts. By setting to a predetermined tightening force with a tightening tool, the sealing performance does not greatly decrease even in long-term use, and water or the like enters into the inside from the connection portion between the underground pipes as in the conventional case It is possible to provide a highly reliable connection joint capable of reliably avoiding this. In addition, it is not necessary to separately form the sealing material, and it is not necessary to attach the separately formed sealing material to the joint body using an adhesive or the like, which is advantageous in terms of manufacturing and cost. become. In addition, there is no problem such as peeling of the separately formed sealing material, and a connection joint having high commercial value can be obtained. There is also an advantage that the impact force applied to the joint body can be favorably absorbed by the elastic force of the joint body.

According to the second aspect of the present invention, the number of members can be reduced by forming the joint body with a cylindrical shape as compared with the case where the joint body is constituted by two parts. As described above, the sealing process can be completed only by tightening the small hardness portions at both ends in the pipe axis direction of the joint main body with a fastener, which is advantageous in terms of cost and connection work.

According to the third aspect, the thickness of the joint body at both ends in the pipe axis direction is formed to be smaller than the thickness of the other portions, and
By forming annular projections on the inner surfaces of both ends of the joint body in the pipe axis direction that contact the outer surface of the underground pipe, it is possible to reduce the tightening operation force on the both ends of the joint body in the tube axis direction. In addition, the sealing performance can be enhanced by the annular projection, and both the connection work surface and the performance surface can be improved.

According to the fourth aspect, the fastener comprises an annular band and a screw body for expanding / contracting the band, and the recesses into which the band can be inserted are formed on the outer surfaces of both ends of the joint body in the pipe axis direction. The concave portion can reliably prevent the band from moving in the pipe axis direction and coming off from the joint body, and the band can come off unexpectedly due to vibrations caused by land subsidence or earthquakes, etc. Can be reliably prevented, and a highly reliable and useful connection joint which is not limited to the place of use or the like can be obtained.

According to the sixth aspect, by setting the hardness of the protrusion to a value smaller (lower) than the hardness of both ends of the joint body in the tube axis direction, the shape-retaining strength of both ends of the joint body in the tube axis direction is set. The sealing performance can be further improved while suppressing the decrease in the sealing performance, which is advantageous in terms of manufacturing in which the sealing member is integrated into the joint, but is the same as that provided with a separate sealing member in the joint. Performance can be demonstrated.

[Brief description of the drawings]

FIG. 1 is a side view showing a state where two underground pipes are connected by a joint.

FIG. 2 is a perspective view showing a state immediately before attaching a fastener to a joint.

FIG. 3 is a cross-sectional view showing a state where a joint is externally fitted to one underground pipe.

FIG. 4 is a sectional view showing a state in which a joint is externally fitted to two underground pipes.

FIG. 5 is a sectional view of a main part showing another joint.

FIG. 6 is a partial cross-sectional side view showing a conventional method of connecting underground pipes.

[Explanation of symbols]

 1 Underground pipe 1A Convex part 1B Concave part 2 Joint 3 Joint body 3A Intermediate part 3B Both ends 3T Projection 3b Concave 4 Fastener 4A Band 4B Screw 10 Joint 10A Insertion part 10B Projection 11 Seal material

Claims (6)

[Claims] 1. An end of an adjacent underground pipe in a state where one end of an adjacent underground pipe in a pipe axis direction among a plurality of underground pipes embedded in the ground is abutted against each other. A joint main body for external fitting between the parts, and in a state where the joint main body is externally fitted between one ends of the adjacent underground pipes, both ends of the joint main body in the pipe axis direction are A fastener for tightening each and connecting the adjacent underground pipes and performing a sealing process, wherein the joint body is made of elastic rubber or plastic, and at least one of the joint bodies. A joint for connection wherein the hardness at both ends in the pipe axis direction is set to a value smaller than the hardness at other portions. 2. The connection joint according to claim 1, wherein said joint main body is cylindrical. 3. The joint body has a wall thickness at both ends in the pipe axis direction smaller than a wall thickness of the other portion, and the joint body has an inner surface at both ends in the pipe axis direction of the underground pipe. The connection joint according to claim 1 or 2, wherein an annular protrusion that contacts an outer surface is formed. 4. A fastening device comprising: an annular band; and a screw body for expanding and contracting the band, and recesses into which the band can be inserted are formed on outer surfaces of both ends of the joint body in the pipe axis direction. The connection joint according to claim 1 or 2, wherein 5. The hardness of both ends of the joint body in the tube axis direction is set in the range of 40 ° to 60 °, and the hardness of the other parts excluding the both ends in the tube axis direction is in the range of 80 ° to 95 °. The connection joint according to claim 1, wherein the connection joint is set to: 6. The connection joint according to claim 3, wherein the hardness of the projecting portion is set to a value smaller than the hardness of both ends of the joint body in the tube axis direction.