JP2020185722A - Fitting for drain pipe and method for manufacturing the same - Google Patents

Abstract

To provide a fitting for a drain pipe and a method for manufacturing the same capable of preventing a bead from protruding on an inner surface.SOLUTION: A fitting 10 for a drain pipe is provided with a fitting body 1 and a socket 2 to be joined to each other. Each joint portion 3 and 4 of the fitting body 1 and the socket 2 has: a weld portion 3a and 4a on the outer circumferential side extending toward its opposite joint portion 4 and 3 and welded to each other; a stopper portion 3b and 4b on the inner circumferential side extending toward its opposite joint portion 4 and 3 and butted to each other; and a bead build up portion 3c and 4c formed between the weld portion 3a and 4a and the stopper portion 3b and 4b. In a cross-sectional view along a central line of the fitting 10 for a drain pipe, more than or equal to 90% of the bead build up portion 3c and 4c (=area A×B) of the fitting body 1 and the socket 2 is embedded with a bead 7a.SELECTED DRAWING: Figure 5

Description

The present invention relates to a drainage pipe joint and a method for manufacturing the same.

Drainage pipes are laid indoors or outdoors in the building. A typical drainage pipe is made of vinyl chloride. However, in food factories and the like, examples of using drainage pipes made of polypropylene, polyethylene, etc., which have heat resistance and chemical resistance, are increasing. This is because the temperature of the wastewater becomes high due to sterilization, and the wastewater may contain bactericidal chemicals. Since drainage pipes made of polypropylene, polyethylene, etc. cannot be joined with an adhesive, welding is used for joining these drainage pipes (see Patent Document 1).

By the way, there are many types of drainage pipe joints for connecting drainage pipes, such as cheese, elbows, sockets, and caps, and their diameters (sizes) are also various. When assorting drainage pipe fittings, it is not realistic in terms of cost to manufacture molds according to all types and sizes of drainage pipe fittings. Therefore, it is expected that the variation of the drainage pipe joint will be increased by individually manufacturing the common joint body and the common socket and welding the common joint body and the common socket according to the size.

When the socket is welded to the joint body, the following steps are performed in the same manner as when the conventional drain pipe is welded (see Patent Document 1). That is, as shown in FIG. 6A, a hot plate 23 is sandwiched between the joint surface of the first member 21 and the joint surface of the second member 22, and these joint surfaces are heated and melted. Then, as shown in FIG. 6B, the hot plate 23 is removed, and the joint surface of the first member 21 and the joint surface of the second member 22 are pressed against each other to be joined.

Japanese Unexamined Patent Publication No. 2003-311836

However, as shown in the cross-sectional view of FIG. 6C, when the first member 21 and the second member 22 are joined by welding, protrusions called beads 24a and 24b are generated on the inner and outer surfaces of the joint. In gas conduits and water pipes, these beads 24a and 24b have no problem in use, but in the case of drainage pipes containing foreign matter such as solids and residues in the drainage, foreign matter accumulates on the bead 24b protruding from the inner surface. , There is a risk of blocking the drain pipe.

Therefore, an object of the present invention is to provide a drainage pipe joint capable of preventing a bead from protruding to the inner surface and a method for manufacturing the same.

In order to solve the above problems, one aspect of the present invention is a drainage pipe joint including a first member and a second member to be joined to each other, and the joints of the first member and the second member are formed. An outer peripheral side welded portion that extends toward the mating joint and is welded to each other, an inner peripheral side stopper that extends toward the mating joint and is abutted against each other, and the welded portion and the stopper portion. It has a bead pool formed between the two members, and in a cross-sectional view along the center line of the drainage pipe joint, 90% or more of the bead pools of the first member and the second member are formed by beads. It is a joint for drainage pipes to be buried.

Another aspect of the present invention is a method for manufacturing a drain pipe joint including a first member and a second member to be joined to each other, and a joint portion of a partner is attached to each of the first member and the second member. A welded portion on the outer peripheral side extending toward the joint portion, a stopper portion on the inner peripheral side extending toward the joint portion of the other party, and a bead pool portion formed between the welded portion and the stopper portion are formed. The step includes a welding step of welding the welded portion of the first member and the welded portion of the second member to each other and abutting the stopper portion of the first member and the stopper portion of the second member against each other. This is a method for manufacturing a drainage pipe joint in which 90% or more of the bead pools of the first member and the second member are filled with beads in a cross-sectional view along the center line of the drainage pipe joint.

According to the present invention, the stopper portions of the first member and the second member prevent the beads from protruding to the inner surface of the drainage pipe joint. Further, since 90% or more of the bead pools of the first member and the second member are filled with beads, it is possible to prevent drainage and foreign matter from entering the bead pools.

It is a side view of the drainage pipe joint of one Embodiment of this invention. It is sectional drawing (cross-sectional view of the part II of FIG. 1) of the joint part of a joint body and a receiving port before welding. It is a process diagram of welding (a state where a hot plate is sandwiched between a joint body and a socket). It is a process diagram of welding (a state where a hot plate is pulled out and then a socket is moved to a joint body). It is sectional drawing (enlarged view of V part of FIG. 4) of the joint part of a joint body and a receiving port after welding. It is a figure which shows the welding process of the conventional drainage pipe (FIG. 6A shows the state which sandwiched the hot plate between the 1st member and the 2nd member, and FIG. A state in which the two members are welded is shown, and FIG. 6 (c) shows an enlarged view of part c of FIG. 6 (b)).

Hereinafter, the drainage pipe joint and the manufacturing method thereof according to the embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the drainage pipe joint of the present invention and the manufacturing method thereof can be embodied in various forms, and are not limited to the embodiments described in the present specification. The present embodiment is provided with the intention of allowing those skilled in the art to fully understand the scope of the invention by making sufficient disclosure of the specification.

FIG. 1 shows a side view of a drainage pipe joint 10 according to an embodiment of the present invention. The drainage pipe joint 10 includes a joint body 1 as a first member and a receiving port 2 as a second member. The drainage pipe joint 10 is used to connect the drainage pipe. A flow path through which drainage flows is formed on the inner surface of the joint body 1. The receiving port 2 is welded to the joint body 1. Reference numeral 7b is a bead that protrudes to the outer surface of the joint body 1 at the time of welding. The material of the drainage pipe joint 10 is a thermoplastic resin such as polypropylene or polyethylene. In this embodiment, the drainage pipe joint 10 shows an example of cheese, but the type of the drainage pipe joint is not limited to cheese, and may be an elbow, a socket, a cap, or the like.

A drainage pipe (not shown) is joined to the receiving port 2. A heating wire 11 (see FIG. 2) is provided in the receiving port 2. A drainage pipe inserted into the inner surface of the receiving port 2 is electrofused (called EF joining). EF joining is a joining method in which after inserting a drain pipe into the socket 2, the controller energizes the heating wire to generate heat, and the resin on the inner surface of the socket 2 and the outer surface of the drain pipe is heated and melted to fuse and integrate them. Is. Since EF bonding is known, further detailed description thereof will be omitted.

FIG. 2 shows a cross-sectional view of the joint portions 3 and 4 of the joint body 1 and the receiving port 2 before welding (cross-sectional view of the portion II in FIG. The joint portion 3 of the joint body 1 includes a welded portion 3a on the outer peripheral side extending toward the joint portion 4 of the receiving port 2, a stopper portion 3b on the inner peripheral side extending toward the joint portion 4 of the receiving port 2, and a welding portion 3a. It has a bead pool portion 3c formed between the stopper portion 3b and the stopper portion 3b. Both the welded portion 3a and the stopper portion 3b have a ring shape. The welded portion 3a protrudes toward the joint portion 4 by a height h from the stopper portion 3b. The thickness t1 of the welded portion 3a is thicker than the thickness t2 of the stopper portion 3b. At the time of welding, the volume (= t1 × h × peripheral length) of the molten resin of the welded portion 3a projects to the outer and inner surfaces of the welded portion 3a to form a bead. The bead pool portion 3c is cut out in a U shape in a cross-sectional view. The bead collecting portion 3c is a space for confining the bead protruding from the inner surface of the welding portion 3a. In the cross-sectional view, the welded portion 3a and the stopper portion 3b are both substantially square, but may be tapered or elliptical.

A heating wire 11 is embedded in the socket 2. A step 12 to which the drainage pipe is abutted is formed on the inner surface of the receiving port 2. The joint portion 4 of the receiving port 2 has a welded portion 4a on the outer peripheral side extending toward the joint portion 3 of the joint body 1, a stopper portion 4b on the inner peripheral side extending toward the joint portion 3 of the joint body 1, and a welded portion 4a. It has a bead pool portion 4c formed between the stopper portion 4b and the stopper portion 4b. Both the welded portion 4a and the stopper portion 4b have a ring shape. Similar to the joint portion 3 of the joint main body 1, the welded portion 4a projects toward the joint portion 3 of the joint main body 1 by a height h from the stopper portion 4b. The thickness t1 of the welded portion 4a is thicker than the thickness t2 of the stopper portion 4b. At the time of welding, the volume (= t1 × h × peripheral length) of the molten resin of the welded portion 4a protrudes to the outer and inner surfaces of the welded portion 4a to form a bead. The bead pool portion 4c is cut out in a U shape in a cross-sectional view. The bead collecting portion 4c is a space for confining the bead protruding from the inner surface of the welding portion 4a. In the cross-sectional view, the welded portion 4a and the stopper portion 4b are both substantially square, but may be tapered or elliptical.

3 to 5 show a process diagram of welding of the joint body 1 and the socket 2. As shown in FIG. 3, a hot plate 8 is sandwiched between the joint body 1 and the socket 2. The temperature of the hot plate 8 is higher than the melting points of the joint body 1 and the socket 2. Then, for example, the receiving port 2 is moved to the hot plate 8 by the operating jig, the welded portion 4a of the receiving port 2 is brought into contact with the hot plate 8, and the welded portion 3a of the joint body 1 is brought into contact with the hot plate 8. By the contact of the hot plate 8, the welded portions 3a and 4a of the joint body 1 and the receiving port 2 are melted. Here, the stopper portions 3b and 4b of the joint body 1 and the receiving port 2 are separated from the hot plate 8 and do not melt. Instead of the hot plate 8, an infrared heater or the like that can heat without contact may be used. Further, instead of moving the socket 2, the joint body 1 may be moved.

When the welded portions 3a and 4a of the joint body 1 and the receiving port 2 are melted, the joint body 1 and the receiving port 2 are separated from the hot plate 8 and the hot plate 8 is pulled out. Then, as shown in FIG. 4, the receiving port 2 is moved to the joint main body 1 by the operating jig, and the welding portion 3a of the joint main body 1 and the welding portion 4a of the receiving port 2 are pressed against each other for welding. The black-painted portion in FIG. 4 represents the molten resins 3a1 and 4a1 melted by the hot plate 8. In the operating jig, until the stoppers 3b and 4b of the joint body 1 and the socket 2 abut against each other, that is, until the gap between the stoppers 3b and 4b becomes zero, or the gap between the stoppers 3b and 4b becomes small. The socket 2 is moved to the joint body 1 until.

FIG. 5 shows a cross-sectional view (enlarged view of the V portion in FIG. 4) of the joint portion between the joint body 1 and the receiving port 2 after welding. When the welded portions 3a and 4a of the joint body 1 and the receiving port 2 are welded, the beads 7a and 7b project onto the inner and outer surfaces of the welded portions 3a and 4a. The beads 7a projecting from the inner surfaces of the welded portions 3a and 4a substantially fill the bead pool portions 3c and 4c. The bead 7a includes the bottom surfaces of the bead pools 3c and 4c of the joint body 1 and the socket 2 (the upper and lower surfaces of the bead pools 3c and 4c having a square cross section in FIG. 5) and the inner surfaces of the stoppers 3b and 4b (FIG. 5). It comes into contact with the left side surfaces of the stoppers 3b and 4b). The line 13 is a line representing the interface between the welded portions 3a and 4a and the bead 7a, but is not necessarily a line that clearly appears.

The bead 7a fills 90% or more, preferably 95% or more of the bead pools 3c and 4c (= area A × B) of the joint body 1 and the receiving port 2 in a cross-sectional view along the center line of the drainage pipe joint 10. .. On the other hand, the beads 7b protruding from the outer surfaces of the welded portions 3a and 4a remain exposed on the outer surface of the drainage pipe joint 10. This is because the bead 7b does not obstruct the flow of drainage.

Cross-sectional area V1 (= t1 × h × 2, in other words, bead 7a, 7b protruding to the inner and outer surfaces of the welded portions 3a, 4a of the joint body 1 and the socket 2 Area) and the cross-sectional area V2 (= area A × B) of the bead pools 3c and 4c of the joint body 1 and the socket 2 have the relationship of the following equation 1.

(Number 1)
V2 = (V1 / 2) × K ... (1)
K = 1.05-1.25.

The reason why V1 / 2 is set is that it is assumed that half and half of the beads are projected on the inner and outer surfaces of the welded portions 3a and 4a. Further, K = 1.05-1.25 is because the bead pools 3c and 4c are on the inner peripheral side of the welded portions 3a and 4a, and the peripheral lengths of the bead pools 3c and 4c are the welded portions 3a, This is because it is considered that it is shorter than the peripheral length of 4a, and that the ratio of the beads 7a and 7b protruding from the inner surface and the outer surface of the welded portions 3a and 4a varies depending on the welding conditions. Here, when K <1.05, the bead 7a may protrude from the bead collecting portions 3c and 4c and protrude to the inner surface of the stopper portions 3b and 4b. When K> 1.25, it becomes difficult to fill 90% or more of the bead pools 3c and 4c with the bead 7a. By establishing Equation 1, the bead pools 3c and 4c can be designed to have an optimum cross-sectional area V2.

The configuration of the drainage pipe joint 10 of the present embodiment and the manufacturing method thereof has been described above. According to the drainage pipe joint 10 of the present embodiment, the following effects are obtained.

The stopper portions 3b and 4b of the joint body 1 and the receiving port 2 prevent the bead 7a from protruding to the inner surface 10a of the drainage pipe joint 10. Since the inner surface 10a through which the drainage flows becomes smooth, it is possible to prevent foreign matter from staying on the inner surface 10a. Further, since 90% or more of the bead collecting portions 3c and 4c of the joint body 1 and the receiving port 2 are filled with the beads 7a, it is possible to prevent drainage and foreign matter from entering the bead collecting portions 3c and 4c. Therefore, the drainage pipe joint 10 can be kept in good hygiene.

Since the heating wire 11 is provided in the receiving port 2, the drainage pipe can be EF-joined to the drainage pipe joint 10.

1 ... Joint body (first member)
2 ... Receptacle (second member)
3 ... Joint part 3a ... Welding part 3a1 ... Molten resin 3b ... Stopper part 3c ... Bead pool part 4 ... Joint part 4a ... Welding part 4a1 ... Molten resin 4b ... Stopper part 4c ... Bead pool part 7a ... Bead 7b ... Bead 10 ... Drainage pipe joint 10a ... Inner surface 11 ... Heating wire

Claims (4)

A drainage pipe joint including a first member and a second member to be joined to each other.
The joints of the first member and the second member each extend toward the joint of the other and are welded to each other on the outer peripheral side, and extend toward the joint of the other and are abutted against each other. It has a stopper portion on the peripheral side and a bead pool portion formed between the welded portion and the stopper portion.
A drainage pipe joint in which 90% or more of the bead pools of the first member and the second member are filled with beads in a cross-sectional view along the center line of the drainage pipe joint. The first member is a joint body.
The drainage pipe joint according to claim 1, wherein the second member is a socket having a heating wire. A method for manufacturing a drainage pipe joint including a first member and a second member to be joined to each other.
At the joints of the first member and the second member, a welded portion on the outer peripheral side extending toward the joint portion of the partner, a stopper portion on the inner peripheral side extending toward the joint portion of the partner, and the welded portion The step of forming the bead pool portion formed between the stopper portion and the stopper portion, and
A welding step is provided in which a welding portion of the first member and a welding portion of the second member are welded to each other, and a stopper portion of the first member and a stopper portion of the second member are abutted against each other.
A method for manufacturing a drainage pipe joint in which 90% or more of the bead pools of the first member and the second member are filled with beads in a cross-sectional view along the center line of the drainage pipe joint. The cross-sectional area V1 of the molten resin of the welded portion of the first member and the second member in the cross-sectional view and the cross-sectional area V2 of the bead pool portion of the first member and the second member in the cross-sectional view are The method for manufacturing a drainage pipe joint according to claim 3, further comprising the relationship of the following formula 1.
(Number 1)
V2 = (V1 / 2) × K ... (1)
K = 1.05-1.25.

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