JPH11168816A - Coupling for conduit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent water from leaking into the body of a coupling which connects conduits. SOLUTION: A rubber packing 6 and a metal or synthetic resin collar 7 are arranged in a coupling body 3. The collar 7 makes the center of the coupling body 3 aligned with that of conduits 14. This design enables keeping the conduits 14 almost at the center position of the coupling body 3. Because the elastic deformation of the packing 6 becomes uniform inside the coupling body 3 and no strong pressure is produced in parts, it is possible to minimize the deterioration of the packing 6 which arises due to unbalanced pressure on changes as time goes by.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conduit joint suitable for connecting a conduit for protecting electric wires and cables.

[0002]

2. Description of the Related Art Wires are indispensable for buildings such as factories, buildings, and houses. When various types of electronic and electrical equipment are used recently, the number of wires and cables becomes large, and the inside and outside of the buildings are increased. The wires and the like run vertically and horizontally, and they are bundled and placed in a conduit. Actually, the storage of electric wires and cables in electric conduits is often used because they protect the electric wires and cables from rainwater and prevent the electric wires from being damaged by unexpected external forces such as when buried in concrete or in the soil. .

[0003] Electrical wiring work using conduits necessarily requires joints for connecting conduits and conduits or connecting conduits and switchboard boxes and the like. Has been proposed. As one of such conventional joints, a ring-shaped rubber packing is inserted into the joint main body from one end of a cylindrical joint main body, and two pipes to be connected are brought into contact with each other so that their respective end faces abut the rubber packing. There is known an apparatus in which a conduit to be connected is fixed to the joint body by inserting the joint body into the joint body from both ends of the joint body and then screwing a bolt from the outer peripheral surface side of the joint body (for example, Japanese Utility Model Laid-Open No. 57-95026). ).

[0004] In such a conventional joint for simply fixing an electric conduit by bolting, when rainwater enters the electric conduit through a connecting portion of the joint or when concrete is poured, the concrete milk is used. The intrusion sometimes caused a problem such as a partial blockage in the joint or the conduit.

[0005]

The inventors of the present invention have conducted intensive studies on the causes of the above-mentioned problems of the prior art, and have experimented with some means for countermeasures. The fact that relative movement occurs between the seals and the sealing between the packing body or the packing and the conduit, resulting in unevenness in the seal, and rainwater or the like enters the conduit from a part of the seal irregularity. In the case of using it, there is a part to which a water pressure of about 3 kg / cm ² is applied, and it is found that under such pressurizing conditions, the possibility of occurrence of the above-described leakage is a major cause of the problems of the prior art. Was. Therefore, it is an object of the present invention to propose a means described in detail below and to solve the problems of the conventional technology.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention basically has a rigid collar interposed between a pipe to be connected and a joint body and connected. The pipe to be firmly supported on the joint body so as not to rattle, and the gap between the inner peripheral face of the joint body and the outer peripheral face of the pipe to be connected is substantially constant in the circumferential direction. And keep it small. Further, by attaching the collar, a part of the collar presses the elastic packing in the joint body to cause elastic deformation, and seals a gap between the conduit tube and the packing, and a gap between the packing and the inner surface of the joint body in a watertight manner. . The adoption of such a collar ensures that even if the joint body is subjected to vibration or external force, the pipes that are to be connected to the joint body maintain the same relative relationship as in normal times, so that the packing and the conduit, and the joint body, Can be sufficiently maintained, and intrusion of rainwater or the like can be effectively prevented.

Specifically, the present invention relates to a cylindrical joint body, an elastic packing inserted into the joint body, and a metal or synthetic material which partially abuts the elastic packing to elastically deform the elastic packing. It consists of a resin collar and a bolt that is screwed into the joint body from the outer peripheral surface side and abuts against the outer surface of the pipe to be connected via the collar, and fixes the pipe to be connected to the joint body. Provide a joint for a conduit.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A joint 1 according to an example of the present invention comprises a joint body 3 having a cylindrical shape and a radially inwardly extending annular protruding piece 2 at the center of an inner peripheral surface as shown in FIGS. The inner peripheral surface has a tapered surface 4 whose diameter decreases toward the center in the longitudinal direction, and has screw holes 5 on both sides. A packing 6 made of an elastic material, for example, synthetic rubber or plastic, and a collar 7 made of metal or synthetic resin are inserted into the joint body 3.

The packing 6 has a cylindrical shape having an inner diameter suitable for inserting a conduit to be connected and, when connection is completed as will be described later, in close contact with the conduit and sealing in a watertight manner. Inward annular flange 8
And a plurality of spaced-apart annular lips 9 on its inner peripheral surface, and the packing 6 is inserted into the joint body 3 such that the outer surface of the inward flange 8 comes into contact with the annular protrusion 2 of the joint body 3. . The lip 9 is preferably provided with a plurality of annular protrusions that protrude radially inward along the circumferential direction of the inner peripheral surface of the elastic packing 6.

The collar 7 has an outwardly directed annular flange 10 at one end thereof and a drill hole 11 near its one end, and its outer peripheral surface is complementary to the tapered surface 4 of the inner peripheral surface of the joint body 3. The tapered surface 12 is shaped like a square. Color 7 is
As shown in FIG. 3, the diameter of the collar 7 can be reduced when the slit 13 is provided and the opposing end face of the slit 13 is brought close to the slit 13, and when the opposing end face is separated, the diameter of the collar 7 can be increased. In the embodiment, a slit cut out in a direction parallel to the axial direction of the joint body 3 is provided, but a slit 13 may be provided obliquely to the axial direction. The collar 7 is desirably provided such that when the collar 7 is inserted into the joint main body 3, the axis of the collar 7 is substantially the same as the axis of the joint main body. As a result, the conduit 14 can be maintained substantially at the center position of the joint body 3, and the elastic deformation of the packing 6 becomes uniform within the joint body 3 and there is no strong pressure. The deterioration of the packing 6 caused by the balance can be minimized.

It is desirable that the angle of the tapered surface 12 on the inner peripheral surface of the joint main body 3 is substantially the same as the angle of the tapered surface 4 of the collar 7, and the two tapered surfaces are in surface contact, and the insertion of the collar 7 described later is performed. Sometimes it can be inserted smoothly with minimal force. In the above-described embodiment, the tapered surfaces 12 and 4 are provided on both sides of the outer peripheral surface of the collar 7 and the inner peripheral surface of the joint body 3. However, the inner peripheral surface of the joint body 3 with which the collar 7 abuts. A configuration in which a tapered surface is provided on at least one of the outer peripheral surface of the collar 7 and the outer peripheral surface of the collar 7 is also possible. In this case, it is desirable that the end surface on the side where the tapered surface is not provided is chamfered.

By providing the collar 7 such that the diameter of the collar 7 is reduced temporarily as the collar 7 is inserted into the joint body 3, the inner peripheral surface of the collar 7 comes into close contact with the outer peripheral surface of the conduit 14, 14 can be positioned at the axis of the joint body 3 and the contact area between the collar 7 and the conduit 14 is increased, so that the electrical resistance value is reduced and safety measures such as grounding are easy at the time of earth leakage. is there.

More specifically, when the collar 7 has the tapered surface 4 only on the outer peripheral surface, the inner diameter of the pipe end of the joint body 3 is set to the maximum outer diameter and the minimum outer diameter on the tapered surface 4 of the collar 7. It is formed so as to be within the range. When only the inner peripheral surface of the joint body 3 has the tapered surface 12, the outer diameter of the tip of the collar 7 is set to be within the range between the maximum inner diameter and the minimum inner diameter on the tapered surface 4 of the joint main body. Formed. When both the collar 3 and the joint body 3 have tapered surfaces, the inner diameter of the pipe end of the joint body is formed so as to be within the range of the maximum outer diameter and the minimum outer diameter on the tapered surface of the collar. .

A method for connecting the joint body 3 and the conduit 14 will be described in detail. The packing 6 is inserted into the joint body 3 such that the outer surface of the inward flange 8 is in contact with the annular protruding piece 2, and the collar 7 is inserted so that its diameter does not decrease. In such a state, the conduit 14 having a diameter slightly smaller than the diameter of the collar 7 is inserted until its end face is in close contact with the surface of the inner flange 8 of the packing 6. At this time, the annular convex portion of the lip 9 and the outer surface of the conduit 14 come into contact with little frictional resistance and are elastically deformed, so that the conduit 14 can be easily inserted into the joint body.

Next, the collar 7, which has been inserted halfway into the joint body, is preferably fitted with the outward flange
Push until it touches the end face. By this insertion, the tip of the collar 7 presses the annular end of the packing 6 in the axial direction,
As a result, the packing 6 is elastically deformed.
The inner peripheral surface of the joint body 3 in contact with the outer peripheral surface of the conduit and the annular protruding piece 2 are elastically deformed so as to increase the thickness so as to be in close contact with each other. Enhance. In particular, since the space formed between the protrusions of the lip is compressed, the collar 7 can be easily inserted into the joint body 3 while deforming the packing 6.

Of course, even at a position where the outward flange 10 and the end face of the joint body 3 are separated from each other as long as the sealing by the packing 6 can be sufficiently performed. When the collar 7 is pushed in, the flange 1
The outer flange 10 can be easily pushed into the joint main body 3 until the outer flange 10 comes into contact with the end face by lightly tapping the "0" into a hammer, a mallet or the like with a tool.

After the collar 7 has been firmly inserted into the joint body 3 and the seal by the packing 6 has been determined as described above, the bolt 15 is screwed into the screw hole 5, and the end of the bolt 15 is inserted through the drill hole 11 into the conduit tube 14. To fix the conduit tube 14 to the joint body 3 (see FIG. 4).

By the connection between the joint body 3 and the conduit 14, the packing 6 is pushed by the collar, and the tip of the conduit 14 is kept in close contact with the surface of the inner flange 8 of the packing 6. Of the joint body 3 and the end face and the outer circumferential face of the conduit 14 to enhance the sealing effect. The slit 13 of the collar 7 adjusts the diameter of the collar 7 to the inner diameter of the joint body 3 and the outer diameter of the conduit 14, and holds them without play. Alternatively, a gap that causes water leakage between the conduit 14 and the packing 6 is not formed. The tapered surfaces 4, 12 help to make such a fit and allow the collar 7 to be tightly fitted to the joint body 3 by pushing the collar 7 sufficiently into the joint body 3. The conduit 14 is pressed against the opposite surface of the screw hole 5 by tightening the bolt 15, but the packing 6 is held by the presence of the collar 7,
Even if the conduit moves, the packing 6 is not excessively compressed, so that the sealing effect is effectively maintained.

A test was conducted in which water pressure was applied to the joint assembled as shown in FIG. 4 and the joint having the above-described structure of the conventional example. In the conventional example, water leakage was observed at a water pressure of 0.5 kg / cm ^2. In contrast, no water leakage into the joint body was observed in the joint shown in FIG. 4 even at a water pressure of 3.0 kg / cm ² . Further, vibration was applied to the joint assembled as shown in FIG. 4, but even if it took about five times or more as compared with the conventional example, the conduit tube did not loosen the joint body and there was no water leakage.

FIGS. 5 to 7 show another embodiment of the present invention. In this example, when the collar 7 is inserted into the joint body 3,
A rail is provided on one of the inner peripheral surface of the joint body 3 on the insertion port side of the collar 7 and the outer peripheral surface of the collar 7 so that the drilled hole 11 of the collar 7 easily aligns with the screw hole 5 of the joint body 3. A guide protruding in the shape of a groove or a stub is provided, and a groove guided by the guide is formed on the other side. In the example shown,
A rail-shaped guide 20 is formed on the inner peripheral surface of the joint body 3. The rail-shaped guide 20 preferably projects from the taper of the inner peripheral surface of the joint body 3 on the insertion opening side 20a of the collar 7 of the joint body 3, but coincides with the tapered surface on the insertion direction side 20b. Height.

A groove 21 is formed in the collar 7 in the collar 7 to extend in the longitudinal direction.
0 at the position where the groove 21 faces the joint body 3
Screw holes 5 and the drill holes 11 of the collar 7 are on a line that can be aligned. When the collar 7 is inserted into the joint main body 3 in this manner, by inserting the groove 21 so as to be guided by the guide 20, the drill hole 11 can be easily aligned with the position of the screw hole 5, and the bolt 15 can be inserted. To secure.

The above-mentioned groove 21 does not need to be provided separately from the above-mentioned other parts, and can be used together by the slit 13 of the collar 7, for example. In this case, since the distal end side 20b of the guide 20 is made to coincide with the tapered surface of the joint body 3 as described above, even when the diameter of the collar 7 is reduced and the slit 13 is to be closed with the insertion. ,
The guide 20 does not hinder the closing of the slit.

In the above-described embodiment, the structure in which the conduit 14 is connected to both ends of the joint body 3 has been described. However, the connection may be made to only one of the two sides.
On the other side, a joint body may be provided from a box such as a switchboard to connect a conduit to one side. In such a case, a step or the like with which the inward flange 8 of the packing 6 abuts may be provided instead of the above-described annular projecting piece 2.

Also, the connection of the conduit on one side has been described with the configuration of the pair of screw holes 5 and drill holes 11, but a plurality of screw holes and drill holes are formed on the axis or peripheral surface of the joint body. The configuration provided may be used.

The conduit 14 having a smooth outer peripheral surface is preferably used, but a corrugated tube can also be used.

【The invention's effect】

In the structure of the conventional joint, the center of the conduit may be inclined with respect to the joint main body, or may be connected with the axis thereof being shifted. In such a case, the conduit is locally attached to the packing. According to the present invention, the load acts and the packing deteriorates quickly, but according to the present invention, the addition of the collar causes the part of the collar to press the elastic packing in the joint main body to elastically deform the conduit, and at the same time, reduce the electric conduit. The joint body is firmly supported so as not to rattle, and the gap between the inner peripheral surface of the joint body and the outer peripheral surface of the pipe to be connected is sealed almost uniformly in the circumferential direction by packing. That effect can always be maintained.

Further, by providing the collar so that the axis of the collar is substantially the same as the axis of the joint main body when the collar is inserted into the joint main body, the conduit can be maintained substantially at the center of the joint main body. The elastic deformation of the packing becomes uniform in the joint body, and deterioration of the packing with respect to aging can be minimized.

Further, by providing a tapered surface on both or one of the outer peripheral surface of the collar and the inner peripheral surface of the joint body, the collar can be smoothly inserted into the joint body with a minimum force. Further, by providing a guide and a groove on the inner peripheral surface of the joint main body and the collar, it is possible to easily match the positions of the drilled hole of the collar and the screw hole of the joint main body when the collar is inserted.

Furthermore, by making the complementary angles of the tapered surface of the collar and the tapered surface of the joint body substantially the same, the collar can be inserted into the joint body with a small force. In addition, the lip provided on the inner peripheral surface of the packing can reduce the frictional resistance with the outer surface of the conduit, so that the conduit can be easily inserted into the joint body.

[Brief description of the drawings]

FIG. 1 is an exploded view of a joint according to an example of the present invention.

FIG. 2 is a side view as viewed from an arrow II-II in FIG.

FIG. 3 is a side view as viewed from arrows III-III in FIG. 1;

FIG. 4 is an assembly view of a joint according to an example of the present invention.

FIG. 5 is a side view of a joint body according to another example of the present invention.

FIG. 6 is a longitudinal sectional view taken along the line VI-VI of FIG. 5;

FIG. 7 is a side view of a collar according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Joint 3 Joint main body 4, 12 Tapered surface 5 Screw hole 6 Packing 7 Collar 8, 10 Flange 13 Slit 14 Conduit tube 15 Bolt 20 Guide 21 Groove

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Yoshinori Shimaguchi, Inventor Yoshinori Shimaguchi 1-1-1 Uchikanda, Chiyoda-ku, Tokyo Inside the Hitachi Plant Construction Co., Ltd. (72) Inventor Sozo Sakata 1-1-1, Uchikanda, Chiyoda-ku, Tokyo No. 14 Hitachi Plant Construction Co., Ltd. (72) Inventor Toshio Tanabe 1-11-1 Uchikanda, Chiyoda-ku, Tokyo Inside Hitachi Plant Construction Co., Ltd.

Claims (14)

[Claims] 1. A cylindrical joint body, an elastic packing inserted into the joint body, a metal or synthetic resin collar partially abutting the elastic packing to elastically deform the elastic packing, A joint for a conduit, comprising: a bolt screwed into the main body from the outer peripheral surface side thereof and abutting against the outer surface of the pipe to be connected via the collar, and fixing the pipe to be connected to the joint main body. 2. An inner peripheral surface of the joint main body has a tapered surface whose diameter is gradually reduced inward from an insertion opening side of the collar,
The conduit joint according to claim 1, wherein an outer peripheral surface of the collar has a tapered surface that can be complementary to a tapered surface of the joint main body. 3. The joint according to claim 2, wherein the angle of the tapered surface of the inner peripheral surface of the joint body is substantially the same as the angle of the tapered surface of the collar. 4. The joint for a conduit according to claim 1, wherein the collar is provided so that the diameter of the collar is temporarily reduced as the collar is inserted into the joint body. 5. The joint according to claim 4, wherein the collar has a slit cut out in a longitudinal direction. 6. The joint for a conduit according to claim 1, wherein the collar has a flange at one end thereof, and the flange can freely contact an end face of the joint body. 7. The conduit pipe joint according to claim 1, wherein a tapered surface is provided on at least one of an inner peripheral surface of the joint main body with which the collar abuts and an outer peripheral surface of the collar. 8. The conduit pipe according to claim 1, wherein an axis of the collar is substantially the same as an axis of the joint body when the collar is inserted into the joint body. Fittings. 9. The joint body has a guide protruding on one of an inner peripheral surface of the collar side of the collar and an outer peripheral surface of the collar, and the other has a groove guided by the guide. The conduit pipe joint according to any one of the above. 10. The conduit pipe joint according to claim 9, wherein the guide is formed on an inner peripheral surface of the joint main body, and the groove is a slit of the collar. 11. The conduit pipe joint according to claim 1, wherein the packing has an inward flange with which an end face of a pipe to be connected abuts. 12. The conduit pipe joint according to claim 1, wherein said packing has a plurality of spaced radially inwardly projecting lips on an inner peripheral surface thereof. 13. The joint according to claim 1, wherein the joint is bilaterally symmetric, and the joint body has an inwardly projecting annular projection at the center thereof.
2. The conduit pipe joint according to any one of 2. 14. A joint body having a cylindrical shape and having screw holes at both ends thereof and having tapered surfaces at inner circumferential surfaces at both ends, and an inward flange at one end thereof having an inner circumferential surface. A rubber packing having a lip, a metal or synthetic resin collar that is in contact with the rubber packing at one end and the outward flange at the other end is free to abut the end face of the joint body, and the collar has a slit and The outer peripheral surface is a tapered surface, and further has a bolt that is screwed into a screw hole of the joint body and abuts on the outer surface of the pipe to be connected via the collar, and the collar is reduced in diameter by a slit in the collar. Is a joint for a conduit for bringing a collar into close contact with a pipe to be connected and a taper surface contact between an outer peripheral surface of the collar and an inner peripheral surface of the joint body makes the collar adhere to the joint body.