JP4260359B2 - Electric fusion saddle joint - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to an electric fusion saddle-type joint made of a thermoplastic resin that includes a saddle portion like a saddle joint or a service tee joint and is used to connect a branch pipe to a main pipe.
[0002]
[Prior art]
FIG. 1 shows a saddle joint of this kind of electrofused saddle joint, which is composed of a saddle part 2 projecting a flange 1 on both sides and a spigot 3 projecting on the saddle part. As shown in FIG. 2, a mat 6 having a heating wire 5 embedded in a spiral shape is usually attached to the seat surface of the saddle portion joined to the main pipe 4.
[0003]
When the saddle joint is electrically welded to the main pipe 4, the seat surface 5 of the saddle portion is applied to the main pipe 4, hung on the flange 1 using a tool (not shown), and clamped while holding the main pipe 4. I was energized.
[0004]
[Problems to be solved by the invention]
In saddle joints, if the diameter of the branch pipe to be connected is large and the diameter of the trunk or spigot that rises from the saddle is large, the fusion required for the annular fused portion of the seat surface where the heating wire is embedded is required. The landing area cannot be secured. This is even more so because it is necessary to provide a cold zone (indicated by reference numeral 7 in FIG. 2) in order to prevent the molten resin from sticking out at the outer periphery of the fusion part.
[0005]
There is no problem if the seat surface of the saddle part to be joined to the main pipe is widened accordingly, but the position of the collar part changes (in the saddle joint illustrated here, the collar 1 is displaced downward), the conventional clamping tool Clamping tools that can no longer be used and are compatible with these joints are needed.
[0006]
According to the present invention, even if the diameter of the branch pipe to be connected is large, a necessary fusion area and a sufficient cold zone can be secured without changing the position of the collar portion, and a conventional clamping tool can be used as it is. An object of the present invention is to provide an electrofusion saddle joint that can be used.
[0007]
[Means for solving problems]
The invention according to claim 1 has a saddle portion, a body portion or a spigot projecting from the saddle portion, and a flange projecting laterally on both sides of the saddle portion, and a heating wire on the seat surface of the saddle portion This is an electrofused saddle joint that is embedded in a spiral shape, extending the saddle part and projecting from the saddle, and forming an extension part of the saddle part seating surface by extending the saddle part seating surface on the circumference. In the electrofused saddle joint, the extension portion of the seat surface of the saddle portion has an arc shape so that a cold zone having a constant width is formed outside the heating wire embedded in a spiral shape. To do.
[0008]
If the seat surface of the saddle part is extended, the rigidity of the saddle part will increase and the adhesion to the pipe will be easily lost, but the rigidity of the saddle part will be reduced by forming the extension part in an arc shape and minimizing it to the minimum necessary. It is possible to reduce the increase and decrease the adhesiveness with the tube, thereby reliably performing the fusion.
[0009]
The invention according to claim 2 has a saddle portion, a body portion or a spigot projecting from the saddle portion, and a flange projecting laterally on both sides of the saddle portion, and a heating wire on the seat surface of the saddle portion in the electric fusion coupling which is embedded in the spiral, and so that a smaller diameter than the pores of holes formed in the saddle seat surface is formed on the hole and through Ru barrel or spigot is formed on the body portion or spigot that holes protrudes inwardly an annular projection projecting form the bottom end of, formed in protrusion in the peripheral side with disposing the inner peripheral portion of the heating wire buried in the saddle seat surface projecting portion The cold zone is made thin and the protrusions are stepped .
[0010]
According to each of the above inventions, even if the diameter of the branch pipe connected by expanding the seat surface of the saddle part to the outside or the inside is large, and the diameter of the trunk part or spigot protruding on the saddle part is large, The required fusion area and cold zone can be ensured without changing the position of.
[0011]
In the invention according to claim 2 , the protrusion has a thickness such that it does not melt due to heat generated by the heating wire during fusion, and a cold zone is also provided on the inner peripheral side. The cold zone only needs to have a function of preventing the molten resin from flowing out, and the cold zone may be thin. In particular, when the cold zone is cut when drilling with a hole saw, it is desirable to reduce the thickness of the cold zone because the torque during drilling is reduced.
[0012]
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3 shows an electrofused saddle joint according to an embodiment of the present invention, a saddle portion 12 having a flange 11 projecting laterally on both sides, a spigot 13 projecting on the saddle portion, The saddle portion seating surface joined to the main tube 4 is composed of an extension portion 14 of the saddle portion 12 that extends along the main body 4 from the flange 11 and extends on the circumference of the seat surface and bends downward. As shown in FIG. 4, a mat 16 in which a heating wire 15 is spirally embedded is attached. In the figure, 17 is a cold zone on the outer periphery of the fusion part in which the heating wire 15 is embedded.
[0014]
The electric fusion saddle joint shown in FIG. 5 has an arcuate extension 18 instead of the extension 14 shown in FIG. 4 so that a cold zone having a constant width is formed outside the heating wire embedded in a spiral shape. It is.
[0015]
FIG. 6 shows another embodiment of the electric fusion saddle joint. The hole 22 formed in the saddle portion seating surface 21 is formed in the spigot 23 and has a smaller diameter than the hole 24 in which a hole saw (not shown) is mounted. An annular protrusion 25 protrudes inwardly at the lower end of the hole 24, and a part of the inner peripheral side of the heating wire 26 embedded in the saddle portion seating surface 21 is disposed on the protrusion 25, and A thin-walled portion 27 having a cold zone is formed on the inside to form a step with the protrusion 25.
[0016]
【The invention's effect】
According to the first and second aspects of the present invention, even if the diameter of the branch pipe to be connected is large and the diameter of the trunk portion or spigot protruding on the saddle portion is large, the necessary melting without changing the position of the flange portion is required. A seating area and a cold zone can be secured, and a conventional clamping tool can be used as it is.
[0017]
According to the first aspect of the present invention, the increase in the rigidity of the saddle portion due to the formation of the extension portion is reduced, the adhesion with the tube can be maintained, and the fusion can be reliably performed. In the joint of the invention according to claim 4 2, it is possible to reduce the torque at the time of drilling by cutting the thin portion with a hole saw.
[Brief description of the drawings]
FIG. 1 is a side view of a conventional saddle joint.
FIG. 2 is a view showing a saddle portion seating surface.
FIG. 3 is a side view of a saddle joint according to the present invention.
FIG. 4 is a bottom view of a saddle portion of a joint serving as a reference for a saddle joint according to the present invention.
FIG. 5 is a front view of a saddle joint according to the present invention.
FIG. 6 is a cross-sectional view of a main part of another aspect of the saddle joint according to the present invention.
[Explanation of symbols]
1, 11 ··· 2, 12 · · Saddle part 3, 13, 23 · · Spigot 4 · Main pipe 5, 15, 26 · · Heating wire 6, 16 · · Mat 7, 17 · · Cold zone 14, 18 .. Extension part 21 of saddle part .. Seat surface 22, 24 of saddle part... Hole 25.

Claims (2)

An electric fuse having a saddle portion, a body portion or spigot projecting from the saddle portion, and flanges projecting laterally on both sides of the saddle portion, and a heating wire embedded in a spiral shape on the seat surface of the saddle portion a Chakutsugite, projecting from the flange by extending the saddle portion, the electric fusion saddle type joint obtained by forming an extension of the saddle portion seat surface obtained by extending the saddle seat surface on the circumference, An electrofusion saddle-type joint characterized in that an extension portion of the saddle portion seating surface has an arc shape so that a cold zone having a constant width is formed outside a heating wire embedded in a spiral shape. An electric fuse having a saddle portion, a body portion or spigot projecting from the saddle portion, and flanges projecting laterally on both sides of the saddle portion, and a heating wire embedded in a spiral shape on the seat surface of the saddle portion in wearing the joint, so that holes formed in the saddle seat surface is smaller than the hole formed in the hole and through Ru barrel or spigot, an annular under edge of the holes formed in the body portion or spigot The protrusion protrudes inwardly to form a protrusion, and an inner peripheral portion of the heating wire embedded in the seat surface of the saddle portion is disposed on the protrusion and the thickness of the cold zone formed on the inner peripheral side of the protrusion is increased. An electrofused saddle-type joint, characterized in that the protrusion is formed in a step shape in a thin shape .

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