JP7170468B2 - Pipe joint structure for sewage pipes - Google Patents

Description

TECHNICAL FIELD This invention relates to a pipe joint structure in a sewage pipeline.

A pipe joint structure in which a spigot of another cast iron pipe is inserted into the socket of one cast iron pipe and a rubber ring is interposed in the annular space between the inner peripheral surface of the socket and the outer peripheral surface of the spigot is often used. Are known.
Also, one cast iron pipe insertion port is inserted into one end socket of the cylindrical joint ring, another cast iron pipe insertion port is inserted into the other end socket of the joint ring, and A pipe joint structure in which a rubber ring is interposed in the annular space between the peripheral surface and the outer peripheral surface of each insertion port is also well known (see FIG. 2 of the present application, FIG. 3 (B) of Patent Document 1, etc.).
In some of these structures, an annular push ring is attached to the outer periphery of the insertion opening, and the rubber ring is pushed into the annular space by the push ring and fixed (see FIGS. 1 and 2 of the present application, Patent Document 1). See FIG. 1(B), FIG. 3(B), etc.).
In such a pipe joint, there is a technique in which a corrosion-resistant core is provided on the tip surface of the spigot in order to prevent the tip surface of the spigot from being corroded (see Patent Document 1, FIG. 1, FIG. 7, etc.).

JP-A-10-115395

By the way, sewage pipes (sewage), unlike water supply pipes (water supply), etc., contain various foreign substances and corrosive gases such as hydrogen sulfide (H ₂ S) in addition to water.
For this reason, it is conceivable to use the anticorrosion core to protect the front end surface of the spigot that constitutes the sewage pipe from corrosion.
However, in the conventional anti-corrosion structure using the anti-corrosion core or the like, the anti-corrosion core protrudes inward from the inner peripheral surface of the insertion port, and foreign matter may be caught in the protruding part (Patent Document 1 FIG. 1 (B), FIG. 3 ( B), etc.). If the stuck foreign matter remains, it will hinder the flow and generate hydrogen sulfide (H ₂ S) and the like, causing corrosion.
By the way, the pipe joint structure of Patent Document 1 is for a water supply pipeline, and there is almost no foreign matter or offensive odor. I don't get caught.

In view of the above circumstances, the present invention aims to prevent corrosion of the tip surface of the spigot and the outer peripheral surface of the sewer pipe without disturbing the flow, and to prevent the gap between the tip surface of the spigot and the inside of the pipe joint (the spigot). The object is to prevent hydrogen sulfide (H ₂ S) or the like from entering between the inlets.

In order to achieve the above object, the present invention inserts a spigot of another cast iron pipe into the socket of one cast iron pipe, and inserts the spigot into the annular space between the inner peripheral surface of the socket and the outer peripheral surface of the spigot In a pipe joint structure for a sewage pipe with a rubber ring interposed therebetween, an anti-corrosion elastic member is interposed between the front end surface of the insertion port and the inner end surface of the receptacle, and the anti-corrosion elastic member is located on the front end surface of the insertion port. A configuration is adopted in which the cover is covered and does not protrude from the inner surface of the insertion port and socket.

Also, one cast iron pipe insertion port is inserted into the socket at one end of the cylindrical joint ring, another cast iron pipe insertion port is inserted into the socket at the other end of the joint ring, and each of the sockets In a pipe joint structure for a sewage pipe in which a rubber ring is interposed in the annular space between the inner peripheral surface of the pipe and the outer peripheral surface of each insertion port, a corrosion-resistant elastic member is provided on the tip surface of the insertion port, and its corrosion resistance is The elastic member adopts a configuration that covers the tip surface of the insertion opening and does not protrude into the inner surface of the insertion opening.

In the pipe joint structure for sewage pipes constructed as described above, the anti-corrosion elastic member is used to prevent corrosion of the tip end surface of the insertion port and the inner surface of the receptacle. It does not impede flow and does not trap foreign objects.

In each of the above pipe joint structures, a spigot of another cast iron pipe is inserted into the socket of one cast iron pipe, and a rubber ring is interposed in the annular space between the inner peripheral surface of the socket and the outer peripheral surface of the spigot. It can be adopted for various pipe joint structures for sewage pipes. For example, it can be applied to a K-shaped pipe joint structure, a T-shaped pipe joint structure, or the like.

INDUSTRIAL APPLICABILITY According to the present invention constructed as described above, in a sewage pipeline, it is possible to effectively prevent corrosion of the spigot end surface and the inner surface of the receptacle forming a pipe joint, without interfering with the flow of sewage.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of an embodiment of a pipe joint structure for a sewage pipe of the present invention; Principal part cross-sectional view of the other embodiment Each figure is a cross-sectional view of the main part showing each example of the anti-corrosion elastic member. Each figure is a cross-sectional view of the main part showing further examples of the anti-corrosion elastic member. Principal part cross-sectional view of still another embodiment

A pipe joint structure according to an embodiment of the present invention is shown in FIG. and P2 are collectively referred to as P.), insert the insertion port 2, and insert the rubber ring 3 in the annular space a between the inner peripheral surface of the socket 1 and the outer peripheral surface of the insertion port 2. A ring-shaped push ring 4 is attached to the outer periphery of the insertion opening 2, and the rubber ring 3 is pushed into the ring space a by the push ring 4 and fixed. The rubber ring 3 is pushed in by inserting a T-shaped bolt 6 from the flange 5 of the socket 1 into the push ring 4 and screwing a nut 7 onto the bolt 6 . The degree of pushing is adjusted according to the degree of screwing.
The cast iron pipes P (P1, P2) are provided with an anti-corrosion layer 8 made of epoxy resin or the like on the inner peripheral surface thereof, and the inner peripheral surface of the socket 1 is coated with a coating layer 9 made of paint or the like to prevent the inner surface from being corroded. ing. The thickness of the anticorrosion layer 8 may be appropriately set, and is, for example, 300 μm or more. A coating layer 9 can also be applied to the outer peripheral surface of the distal end of the insertion port 2 . The thickness of the coating layer 9 of the insertion opening is about 100 μm.

The present invention is characterized in that an anti-corrosion elastic member 11 made of NBR (nitrile rubber) or the like having a substantially rectangular cross section and having an annular shape is interposed between the front end surface 2a of the insertion port 2 and the inner end surface 1a of the receptacle 1. It is a feature.
The anti-corrosion elastic member 11 is shaped so as not to protrude inward (downward in FIG. 1) from the inner peripheral surfaces b of the socket 1 and the insertion port 2 . In this embodiment, the thickness extends to the inner surface of the insertion port 2 excluding the anticorrosive layer 8, but it may have a thickness in the pipe radial direction up to the inner peripheral surface b.
Further, the thickness t of the anti-corrosion elastic member 11 in the pipe length direction does not affect the insertion allowance (entry margin) of the insertion port 2 into the socket 1, and the tip surface 2a of the insertion opening and the inner end surface 1a of the socket are corrosion-resistant. The elastic member 11 is appropriately set by experiments or the like so that the elastic member 11 is pressed with an appropriate pressing force. The anti-corrosion elastic member 11 can be fixed to the distal end surface of the insertion opening 2 with an adhesive or the like. By fixing in this way, the anti-corrosion elastic member 11 will not come off from the insertion opening 2 when the insertion opening 2 is inserted into the socket 1 . The anti-corrosion elastic member 11 can also be fixed to the inner end surface 1a of the socket 1 with an adhesive or the like. Alternatively, the anti-corrosion elastic member 11 can be fixed only by sandwiching and press-contacting between the tip end surface 2a of the insertion port and the inner end surface 1a of the receptacle port without using an adhesive.

The pipe joint structure of this embodiment is constructed as described above. The member 11 allows not only sewage but also corrosive gas such as hydrogen sulfide to pass through the gap between the front end surface 2a of the insertion port 2 and the inner surface 1a of the insertion port 1 between the outer surface of the insertion port 2 and the inner surface of the socket 1. do not get in between Therefore, corrosion of the outer surface of the insertion opening 2 and the inner surface of the receptacle 1 is suppressed. At this time, the inner peripheral surface of the socket 1 and the outer peripheral surface of the insertion port 2 are coated with a coating layer 9 to prevent corrosion. , the inner surface of the socket 1 and the outer surface of the insertion port 2 are effective in preventing corrosion.
In addition, since the anti-corrosion elastic member 11 does not protrude from the inner peripheral surface of the insertion port 2 and the inner peripheral surface b of the socket straight pipe portion, it does not block the flow of sewage and does not catch foreign matter.

FIG. 2 shows a pipe joint structure according to another embodiment of the invention. The pipe joint of this embodiment is also a K-type, and the insertion port 2 of one ductile cast iron pipe P is inserted into one end receptacle 21 of a tubular ductile cast iron joint ring 20, and the other end receptacle of the joint ring 20 is inserted. The insertion port 2 of another ductile cast iron pipe P is also inserted into the port 22, and the rubber ring 3 is inserted into the annular space a between the inner peripheral surface of each of the sockets 21 and 22 and the outer peripheral surface of each of the insertion ports 2 and 2. are interposed in a state in which the insertion openings 2 are projected into the sockets 21 and 22, respectively, and an annular push ring 4 is attached to the outer periphery of the insertion openings 2, and the rubber ring 3 is pushed by the push ring 4 into the annular space. It is a structure that is fixed by being pushed into a. The rubber ring 3 is similarly pushed in by inserting the T-shaped bolt 6 from the flange 25 of the sockets 21 and 22 into the push ring 4 and screwing the nut 7 onto the bolt 6 . The degree of pushing is adjusted according to the degree of screwing.
The cast iron pipe P is likewise formed with an anticorrosion layer 8 made of epoxy resin or the like on its inner surface. The inner peripheral surfaces of the sockets 21 and 22 and the outer peripheral surface of the insertion port 2 can be properly coated with a coating layer 9 made of the above-described paint or the like to prevent corrosion.

This embodiment is also characterized in that an annular anti-corrosion elastic member 31 such as NBR (nitrile rubber) is fixed to the tip surface 2a of the insertion port 2 with an adhesive or the like.
The anti-corrosion elastic member 31 is shaped so as not to protrude inward from the inner peripheral surface b of the insertion opening 2 . In addition, it has inner and outer circular arc-shaped lip pieces 32 and 33 directed toward the socket 1 over the entire circumference. Of these lip pieces 32 , 33 , one 32 is in pressure contact with the distal end outer peripheral surface of the insertion port 2 , and the other 33 is in pressure contact with the inner peripheral surface of the collar 20 .

The pipe joint structure of this embodiment is constructed as described above . It is isolated from sewage, and not only sewage but also corrosive gases such as hydrogen sulfide do not enter between the outer peripheral surface of the insertion port 2 and the inner peripheral surfaces of sockets 21 and 22 of the ring 20. For this reason, corrosion of the outer surface of the insertion port 2 and the inner surfaces of the sockets 21 and 22 at c during this time is suppressed.

In the embodiment of FIG. 1, the cross-sectional shape of the anticorrosive elastic member 11 is not limited to the above shapes, and the shapes (11a, 11b, 11c, 11d, 11e, 11f) and the like are conceivable. That is, one end of the anticorrosive elastic member 11 on the socket 1 side is rounded 11 ₁ (see FIG. 1), and further extended to the socket 2 side (FIG. 3(a), reference numeral 11a ₁ )), The circular portion 11c- ₂ may be connected to the front surface of the flat plate 11c- ₁ ((c) in the same figure), or the circular portion 11c- ₂ may be hollow 11d- ₂ ((d) in the same figure). Alternatively, the circular shape may be changed to a semicircular shape (Fig. 3(e)), or a portion _11f1 covering the entire outer circumference of the tip of the insertion port 2 may be added to Fig. 3(a) (Fig. 3(f)). can.

In the embodiment of FIG. 2, the cross-sectional shape of the anti-corrosion elastic member 31 is not limited to the shapes described above, and the shapes 31 (31a, 31b, 31c) shown in FIGS. be done. That is, the lip piece 33 can be fan-shaped (Fig. 1(a)), mountain-shaped (Fig. 1(b)), or mountain-shaped with valves (Fig. 1(c)), or Fig. 1(d)- As shown in (g), a corrosion-resistant elastic member 31 made of rubber or the like and having an L-shaped cross section is attached (fixed) to the tip of the spigot 2, and the outer peripheral surface of the tip of the spigot 2 and the socket of the joint ring 20 are attached (fixed). An O-ring 35 is fitted between the inner surfaces of 21 and 22 (Fig. 4(d)), a liner 36 is inserted between the insertion opening 2 and the sockets 21 and 22, and a liner 36 is inserted between the tip surfaces of the insertion openings 2 and 2 facing each other. (Fig. 3(e)), or, in Fig. 3(e), the liner 36 may be made to extend to both ends of sockets 21 and 22 of the joint ring 20 (inner sleeve) (Fig. 4(e)). f)), a lip piece 38 extending from one anti-corrosion elastic member 31 to the outer surface of the other anti-corrosion elastic member 31 is provided between the insertion openings 2, 2 (Fig. 4(g)). be able to. The O-ring 35, the liners 36 and 37, and the lip piece 38 are naturally anti-corrosion elastic members made of rubber or the like. However, if the outer peripheral portion 31d of the anti-corrosion elastic member 31 in FIGS. The insertion port 2 can be easily inserted (see (e) and (f) in the figure). At this time, the intervening portion 31e between the tip surface 2a of the spigot 2 and the liner 37 or between the tip faces 2a of the spigot has elasticity.

Although the pipe joint in each of the above embodiments was a K-type, the spigot of another ductile cast iron pipe is inserted into the socket of one ductile cast iron pipe, and the inner peripheral surface of the socket and the outer peripheral surface of the spigot are Of course, the present invention can be employed in various pipe joint structures having a rubber ring interposed in the annular space between them. For example, it can be employed in the T-shaped pipe joint structure, NS-type, and GX-type pipe joint structure shown in FIG. If it is used in the NS-type or GX-type pipe joint structure, the anti-corrosion elastic member is hardly affected by an earthquake and is extremely unlikely to shift because it is fixed by the detachment prevention function of the special push ring.
In addition, although the above-described embodiment was a ductile cast iron pipe, it goes without saying that the present invention can be applied to other cast iron pipes as well. Furthermore, the anti-corrosion elastic members 11, 11a, 11b, 11c, 11d, 11e, 11f, 31, 31a, 31b, and 31c are not limited to rubber, and may be made of any elastic material such as resin. . In this way, the embodiments disclosed this time should be considered as examples and not restrictive in all respects. It goes without saying that the scope of the present invention is indicated by the scope of claims, and that all modifications within the meaning and scope of equivalence to the scope of claims are intended to be included.

1 Socket 1a Socket inner end surface 2 Insertion opening 2a Insertion opening tip surface 3 Rubber ring 4 Push ring 5 Socket flange 6 T-shaped bolt 7 T-shaped bolt fastening nut 8 Anticorrosion layer (coating layer)
9 Coating layers 11, 11a, 11b, 11c, 11d, 11e, 11f, 31, 31a, 31b, 31c Corrosion-resistant elastic member 20 Joint rings 21, 22 Joint ring socket 25 Joint ring flanges P, P1, P2 Cast iron Pipe a Annular space b Inner surface of insertion port c Space between the outer peripheral surface of the insertion port and the inner peripheral surface of the socket

Claims (3)

Insert the insertion port (2) of another cast iron pipe (P2) into the socket (1) of one cast iron pipe (P1), and the inner peripheral surface of the socket (1) and the outer periphery of the insertion port (2) In a pipe joint structure for a sewage pipe in which a rubber ring (3) is interposed in the annular space (a) between the surfaces,
An anti-corrosive elastic member (11) is interposed between the tip end face (2a) of the insertion port (2a) and the back end face (1a) of the receptacle (1) so as to press the tip end face (2a) of the insertion port (2). ) and the inner surface (1a) of the socket (1), not only sewage but also corrosive gases such as hydrogen sulfide enter between the outer surface of the socket (2) and the inner surface of the socket (1). The anti-corrosion elastic member (11) covers the tip end surface (2a) of the insertion port and does not protrude to the inner peripheral surface (b) of the insertion port (2) and the socket (1). A pipe joint structure for sewerage that is designed as follows. Insert the insertion port (2) of a single cast iron pipe (P) into the port (21) at one end of the cylindrical ring (20), and also insert the port (22) at the other end of the ring (20). Insert the spigot (2) of another cast iron pipe (P) into the annular space (a) between the inner peripheral surface of each socket (21, 22) and the outer peripheral surface of each spigot (2) A pipe joint structure for a sewage pipe in which a rubber ring (3) is interposed in such a manner that the insertion port (2) protrudes into sockets (21, 22) ,
An anti-corrosion elastic member (31) is provided on the tip surface (2a) of the spigot, and the anti-corrosion elastic member (31) covers the tip surface (2a) of the spigot and does not protrude into the inner peripheral surface of the spigot. and the tip surface (2a) of the insertion opening (2) and the outer peripheral surface of the protruding insertion opening (2) are isolated from the sewage by the anticorrosive elastic member (31), and the insertion opening ( 2) Not only sewage water but also corrosive gases such as hydrogen sulfide are prevented from entering between the outer peripheral surface and the inner peripheral surface of the sockets (21, 22) of the ring (20) (c). Pipe joint structure for sewage pipes. A pipe joint structure for a sewage pipe, wherein the pipe joint structure according to claim 1 or 2 is a K-type or a T-type.

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