JP2005299827A - Universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a universal joint provided with a flange for inclining a socket in which a plastic pipe is inserted on each one side at a proper angle α for a face crossing a shaft axis of the socket orthogonally at the other end, capable of changing an angle formed by shaft axes of both sockets up to 0 to 45 degrees by turning either of flanges while the flanges are mutually joined, and provided with a fused part in which a heating wire is buried on a join face of either of the flanges to be joined to prevent occurrence of improper fusion due to intrusion of minute sand and dust into the fusion part. <P>SOLUTION: The flange 16 has large wall thickness, and an 0-ring 19 is mounted and sealed in a peripheral channel on an outer side from the fusion part 26 to prevent intrusion of minute sand and dust into the fusion part 26. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a universal joint used for connecting plastic pipes used for water and sewage pipes and gas pipes.

  In recent years, plastic pipes, especially polyethylene pipes, are widely used as water and sewage pipes and gas pipes because they are excellent in many respects such as corrosion resistance and earthquake resistance. In recent years, electrofusion joints have been frequently used as joints for connecting such plastic pipes. In this joint, a heating wire is embedded in the inner peripheral surface of the receiving port, and the connection by fusion with the tube is performed by inserting the end of the tube into the receiving port and then energizing the heating wire. It has become.

  Connection of plastic pipes using electric fusion joints can be easily performed by energizing the joints. In addition, the pipes can be prevented from coming off during fusion, and the clearance between the pipes and joints should be uniform over the entire circumference. In addition, in order to prevent the interface pressure at the time of fusion from escaping, it is necessary to center the pipe and the joint, so the pipe is fixed using a clamp.

  A plastic tube is relatively easy to bend because it is softer than a metal tube, but a tube with a large diameter is too thick to bend easily. Various universal joints have also been proposed in order to facilitate centering of pipes and joints. The following are disclosed in Patent Documents 1 to 3, and FIG. 1 shows an example of a universal joint disclosed in Patent Document 1 below. In this joint, flanges 2a and 2b are formed at each end of the short pipes 1a and 1b at an angle θ with respect to a plane perpendicular to the axis of the pipes 1a and 1b, and the flanges are joined together. By rotating the short pipe 1a or 1b, the angle formed by both the short pipes 1a and 1b can be changed within the range of θ to 2θ. After interposing the mat 3 with heating wire between the flanges 2a and 2b, hooking the flange 2b having a hook-like cross section on the flange 2a and joining both flanges 2a and 2b with the mat 3 interposed, The flanges are fused together by energizing the heating wire.

Figure 2 shows another example of a universal joint disclosed in Patent Document 3, both the socket 5a, the angle 5b and theta _1, both the difference between the short pipe 6 to be inserted into the receptacle 5a mouth 6a, 6b is located the angle as theta _2, the range of the angle formed between a difference port 6b of the receiving 5a and short pipe 6 of the joint 5 of 0~θ _{1 +} θ ₂ by short pipe 6 is rotated It can be changed with. In the figure, 7 is a plastic pipe, 8 is a fusion-bonding portion by heating wires embedded in the receiving ports 5a and 5b of the joint 5, and 9 is an electric fusion joint for connecting the plastic pipe and the outlet 6b of the short pipe 6. is there.

If the joint as described above is used, the angle formed by both the short pipes 1a and 1b is changed in accordance with the angle of the plastic pipes 7a and 7b to be connected, or the difference between the receiving port 5b of the joint 5 and the short pipe 6 is used. By changing the angle formed by the opening 6a, the short pipes 1a and 1b and the plastic pipe connected to the short pipe can be centered, or the plastic pipe 7a inserted into the joint 6a between the joint 5 and the short pipe 6 Can be easily centered.
JP 7-151288 A JP-A-6-346997 JP 2003-130278 A

Conventional universal joints have several problems. Taking this as an example of the universal joint shown in FIGS.
(1) When piping is performed in a groove formed by excavating the ground and the plastic pipes are connected using a universal joint as described above, the fusion part or joint in the mat 3 between the flanges 2a and 2b There is a possibility that fine sand, dust, dust, etc. may enter the fused part 8 of the receiving ports 5a, 5b and cause poor fusion,
(2) Resin heated and welded by energization shrinks as it cools after being fused, but in the universal joint shown in FIG. 1, the shrinkage in the radial direction of the flange 2b is smaller than the shrinkage in the radial direction of the flange 2a. Is too large, there is a possibility that both flanges 2a, 2b may peel off at the joint surface,
(3) In the universal joint shown in FIG. 1, the flange 2a having a hook-like cross section is secured to the flange 2b, and the flange 2a is retained by the flange 2b. Although it is thought that it is performed by combining, it is difficult to forcibly fit the flange 2a by elastically deforming the flange 2a, particularly in a high-rigidity joint such as a large-diameter joint,
(4) The joint surface between the flanges 2a and 2b and the joint surface between the receiving port 5a of the joint 5 and the short pipe 6 both have a large contact area, a large frictional resistance during rotation, and smoothly rotate. After welding, the flanges or the joint and short pipe are fixed, so the angle cannot be changed due to internal stress or when an external force is applied to the plastic pipe. Terminal pins are protrusively installed and easily become obstacles.
Etc.

  The first object of the present invention is to provide a universal joint in which minute sand, dust, dust or the like enters the fusion part and does not cause poor fusion. The second object is to provide a fusion joint. It is an object of the present invention to provide a universal joint in which both flanges are not peeled even if the flanges to be connected and connected have a difference in shrinkage between the flanges due to cooling after fusion.

  A third object of the present invention is to provide a universal joint having a flange that is fusion-bonded, one of which has a hook-shaped cross section and is hooked on the other flange to prevent the flange from being connected. Is intended to provide a universal joint that can be carried out without difficulty and the fourth purpose is that the angle can be changed smoothly, and the angle can be changed even after the melt tube is installed. In addition, an object of the present invention is to provide a universal joint that does not cause poor fusion due to fine sand, dust, dust, and the like.

  The invention according to claim 1 relates to a universal joint that achieves the first object, comprising at least two members that can be connected, each member having a receptacle or a receptacle into which a plastic pipe is inserted, and at least By rotating one member at the joint surface with another member connected to the member, the angle formed by the receiving ports of both members can be changed, and either of the joint surfaces of the two members is selected. One side is a thermoplastic joint made of a thermoplastic resin having a fusion part embedded with a heating wire, to which both members are fixed by energization of the heating line, at least outside of both sides of the fusion part Is equipped with an o-ring for sealing.

In the present invention, each member is at least one of a joint surface that intersects and inclines at a predetermined angle with the axis of the receiving port or the difference port, and a joint surface that intersects the joint surface at right angles or at a predetermined angle. Has a surface.
The fusion part may be provided on an inclined joining surface among these joining surfaces, but is preferably provided on a joining surface orthogonal to or intersecting with the inclined joining surface. As a result, the part covered from the outside on the joint surface provided with the fusion part is easily brought into close contact with the other part by shrinkage after the fusion, and the fusion can be surely performed.
Also, the o-ring can be made of metal, or can be made of an elastic material such as hard rubber.
Moreover, as a universal joint in the present invention, for example, as shown in FIG. 1, a structure in which inclined flanges 2a and 2b are connected to each other, and as shown in FIG. 2, the angle formed by the receiving ports 5a and 5b is θ. ₁ and the joint body 5 and, Saguchi 6a, the angle 6b and theta _2, consisting of short pipe 6 to the one of the differential port 6a is connected crowded difference rotatably receiving port 5a of the joint body 5 The thing etc. can be mentioned.

The invention according to claim 2 relates to a universal joint that achieves the second object, and is provided with at least two members that can be connected and have inclined flanges, and these members are receptacles or differentials into which a plastic pipe is inserted. The angle formed by the receiving ports of the two connected members can be changed by rotating at least one of the flanges in a state where the flanges are joined to each other. Is a thermoplastic joint made of thermoplastic resin to which both members are fixed by energizing the heating wire, and the outer flange is closer to the base of the flange than the fusion portion. It is characterized in that a thin part is provided in the
According to a third aspect of the invention, in the universal joint of the second aspect of the invention, of the flanges to be joined together, one of the flanges has a hook shape in cross section, and is hooked on the other flange to be prevented from being removed. It is characterized by that.

In the present invention, the flanges to be joined to each other are at least two of a joint surface that intersects and inclines at a predetermined angle with the shaft center of the receiving port or the outlet, and a joint surface that intersects the joint surface at right angles or at a predetermined angle. It has two joint surfaces.
The fused portion is provided on at least one of the plurality of bonding surfaces, preferably the latter bonding surface, that is, the bonding surface orthogonal to or intersecting with the former inclined bonding surface. The flange having a joint surface orthogonal to or intersecting with the inclined joint surface is formed so that one flange covers the other flange, but is provided on the joint surface orthogonal to or intersecting with the joint surface with the fused portion inclined. As a result, one of the flanges covering the other flange is easily brought into close contact with the other flange due to shrinkage after the fusion, and the fusion can be reliably performed.

  The invention according to claim 4 relates to a universal joint that achieves the third object, and is provided with at least two members that can be connected and have inclined flanges, and these members are receptacles or connectors into which plastic pipes are inserted. The angle formed by the receiving ports of the two connected members can be changed by rotating at least one of the flanges in a state where the flanges are joined to each other. A heating part embedded in the heating wire, and both members are fixed by energizing the heating wire, and one of the flanges to be joined to each other has a flange-like cross section. A flange made of a thermoplastic resin that is hooked to the other flange and is prevented from being pulled out, and the flange having a bowl-shaped cross section is hooked to the other flange to be joined and has a retaining function. Member is divided, characterized in that it is integrated with secured by the other portion and the fastening means.

  Examples of the fastening means in the present invention include butt fusion, adhesive bonding, bolts and nuts, and the like.

  The invention according to claim 5 relates to a universal joint that achieves the fourth object, comprising at least two members that can be connected, each member having a receptacle or a receptacle into which a plastic pipe is inserted, and at least A universal joint made of a thermoplastic resin, wherein the angle formed by the receiving ports of both members can be changed by rotating one member on a joint surface with another member connected to the member, The surface is provided with an o-ring for sealing, and has no fusion part in which a heating wire is embedded.

The invention according to claim 6 is the universal joint according to claim 5, characterized in that a concave portion is formed on one of the flanges to be joined, and a convex portion that fits into the concave portion is formed on the other.
The uneven | corrugated | grooved part in this invention may be provided only in one place of a flange, and may be provided in several places.

  According to the first aspect of the present invention, since the o-ring is arranged and sealed outside the fusion part, it prevents fine sand, dust, dust and the like from entering the fusion part and causing poor fusion. can do.

  According to the second aspect of the present invention, the flange having the thin portion is bent at the thin portion following the thermal contraction of the mating flange to which the flange is connected, so that a difference in shrinkage is generated between the two flanges after the heat fusion. Even if there is something wrong, both flanges can be prevented from peeling off.

  According to the invention of claim 3, after one flange is locked to the other flange, it is possible to prevent the flanges from being separated from each other even when an external force is applied or due to a stress generated during heat fusion. .

  According to the invention of claim 4, after joining both flanges, a member having a retaining function is fastened to one flange by fastening means, so that even a rigid flange can be reasonably surely secured. Both flanges can be secured.

  According to the invention according to claim 5, the joint surface is in line contact with the o-ring, and the angle can be smoothly changed by the rotation of the o-ring in the circumferential direction. In addition, the angle can be changed by external force acting on the plastic pipe, and since there is no fusion part with an embedded heating wire, projections such as terminal pins are not required on the outside, and the joint can be made compact. Also, there is an effect that there is no possibility of causing poor fusion due to fine sand, dust, dust and the like.

  According to the sixth aspect of the present invention, the flange has high bending rigidity due to the concavo-convex portion, and the sealing performance by the o-ring can be maintained for a long time.

Hereinafter, universal joints according to embodiments of the present invention will be described with reference to the drawings.
The universal joint 11 shown in FIGS. 3 and 4 is made of a thermoplastic resin, such as polyethylene, and is composed of two members 12 and 13 to be connected. One member 12 is a plastic made of polyethylene at one end, for example. While having the receiving port 15 in which the pipe | tube 14 is inserted, it has the thick flange 16 at the other end, and although not shown in the inner peripheral surface of the receiving port 15, the fusion | fusion part by which a heating wire is embed | buried is provided. And a pair of terminals 17 provided with terminal pins connected to the heating wire of the fused portion are provided on the outer peripheral surface of the receiving port. The flange 16 is inclined at an angle α with respect to a surface orthogonal to the axis o ₁ of the receiving port 15, and an o-ring 19 is attached to a circumferential groove formed on the outer peripheral surface outside the fused portion described later. .

  The other member 13 also has a receiving port 21 into which the plastic tube 14 is inserted at one end and a flange 23 provided with a recess 22 into which the flange 16 is fitted at the other end. Similar to the port 15, a fusion part (not shown) in which a heating wire is embedded on the inner peripheral surface is provided, and a pair of terminals 17 are provided to protrude on the outer peripheral surface. The flange 23 is provided with a fusion part 26 in which a heating wire is embedded in the inner peripheral surface of the recess, and a pair of terminals 25 project from the outer peripheral surface. Both flanges 16 and 23 are connected by being prevented from being pulled out by fitting a convex portion into a concave portion having a cross-sectional dovetail shape formed on the bottom surface of the recess. The members 12 and 13 can be integrally formed by molding a portion having the receiving ports 15 and 21 and a portion having the flanges 16 and 23. In this case, however, the structure for removing the core is complicated. It becomes. In order to simplify the structure of removing the core, the two parts may be formed separately and then connected by butt fusion.

  According to the universal joint 11 of the present embodiment, the angle α formed by both the receiving ports 15 and 21 is set to 0 to 45 by rotating any one member 12 or 13 within a range of 180 degrees from the state of FIG. It can be changed within the range of degrees. FIG. 4 shows a state when the member 12 is rotated 180 degrees from the state of FIG. 3. At this time, the angle formed by both the receiving ports 15 and 21 is 2α, that is, 45 degrees.

  In the universal joint 11 according to the present embodiment, the o-ring 19 is attached, so that it is possible to prevent fine sand, dust, dust, and the like from entering the fusion part 26 to cause poor fusion, and the fusion part. An appropriate clearance is provided between the flanges 16 and 23 provided with 26 so that one of the members 12 or 13 can be rotated. In addition to being able to perform smoothly, the clearance between the flanges 16 and 23 provided with the fusion part 26 can be maintained uniformly, and the fusion can be reliably performed.

  The universal joint 28 shown in FIGS. 5 and 6 is configured so that the angle β formed by both the receiving ports 15 and 21 in the universal joint 11 shown in FIGS. 3 and 4 can be changed within a range of 0 to 90 degrees. Therefore, in the universal joint 28 shown in FIG. 6, the angle β formed by the two receiving ports 15 and 21 is 90 degrees.

  The universal joint 31 shown in FIG. 7 forms a thin portion 32 by making a cut along the corner portion of the recess 22 on the root side from the fusion part 26 of the flange 23 in the universal joint 11 shown in FIGS. 3 and 4. The thin wall portion 32 makes it easier for the peripheral wall of the recess 22 to be constricted inward on the opening side.

  The universal joint 35 shown in FIG. 8 is the same as the universal joint shown in FIG. 1, except that the mat 3 with heating wire is omitted, and the circumferential groove formed on the surface perpendicular to the inner axis of the flange 38a at the end of the member 38 is o. Rings 36 and 37 are attached to seal both members 38 and 39 to be connected.

  The universal joint 41 shown in FIG. 9 is the same as the universal joint 35 shown in FIG. 8 except that a portion 38b that engages with the flange 39a and functions as a latch is formed separately from the flange 38a having a bowl-shaped cross section. It is a unit integrated by fusing, for example, butt fusing.

  A universal joint 45 shown in FIG. 10 is the same as the universal joint 41 shown in FIG. 9, in which a circumferential groove is also formed in the flange 39a and an o-ring 46 is mounted.

  The universal joint 51 shown in FIG. 11 is similar to the universal joint 45 shown in FIG. 10 in that the flange 39a is thickened to form the circumferential groove 52, while the flange 38a has a circumferential protrusion 53 that fits into the circumferential groove 52. By forming and enhancing the bending rigidity of the flanges 38a and 39a, the sealing by the o-rings 36, 37 and 46 is not impaired by bending.

  The universal joint 55 shown in FIG. 12 has the same thickness as that of the flange 23 in the universal joint 11 shown in FIG. 3 to improve the dimensional accuracy of the flange 16 and reduce the product weight. The electric fusion can be stably performed.

Cross section of conventional universal joint Cross section of another conventional universal joint Sectional view of the universal joint according to the present invention Sectional view of the universal joint shown in FIG. 3 with the angle changed to 45 degrees Sectional drawing of the deformation | transformation aspect of the universal joint which concerns on this invention Sectional view of the universal joint shown in FIG. 5 with the angle changed to 90 degrees Sectional drawing of another example of the universal joint which concerns on this invention Expanded sectional view of the main part of yet another example of a universal joint Expanded sectional view of the main part of yet another example of a universal joint Expanded sectional view of the main part of yet another example of a universal joint Expanded sectional view of the main part of yet another example of a universal joint Cross section of another example of universal joint

Explanation of symbols

1a, 1b ... Short pipes 2a, 2b, 16, 23, 38a, 39a ... Flange 3 ... Mat 11, 28, 31, 35, 41, 45, 51, 55 ... Universal joints 12, 13, 38, 39 ·· Member 14 · · Plastic pipes 15 and 21 · Receiving ports 17 and 25 · · Terminals 19, 36, 37, 46 · · O-ring 22 · · Recess 26 · · Fusion portion 32 · · Thin portion 52 .. Circumferential groove 53

Claims (6)

  It consists of at least two members that can be connected, and each member has a receptacle or a receptacle into which a plastic pipe is inserted, and at least one member is rotated at a joint surface with another member connected to the member. Thus, the angle formed by the receptacles of both members can be changed, and one of the joint surfaces of both members is provided with a fusion part in which a heating wire is embedded, and the heating wire is energized. A universal joint made of a thermoplastic resin to which both members are fixed, wherein a sealing o-ring is mounted on at least the outer side of both sides of the fused portion.   At least two members having inclined flanges that can be connected are provided. These members have a receptacle or a receptacle into which a plastic pipe is inserted, and at least one of the flanges is rotated with the flanges joined together. Thus, the angle formed by the receiving ports of both members to be connected can be changed, and the joint surface of both flanges is provided with a fusion part embedded with a heating wire on one side. A universal joint made of a thermoplastic resin to which a member is fixed, wherein the outer flange is provided with a thin part on the flange base side with respect to the fused part.   The universal joint according to claim 1, wherein one of the flanges joined to each other has a hook shape in cross section, and is latched to the other flange.   At least two members having inclined flanges that can be connected are provided. These members have a receptacle or a receptacle into which a plastic pipe is inserted, and at least one of the flanges is rotated with the flanges joined together. Thus, the angle formed by the receiving ports of the two members to be connected can be changed, and the joint surface of both flanges is provided with a fusion part embedded with a heating wire on one side, and both members are energized by energizing the heating wire. Of the flanges to be joined to each other, one of the flanges has a hook shape in cross section, and is hooked to the other flange to be secured. A universal joint with a flange having a hook-like cross section is divided into a member having a retaining function that is hooked to the other flange to be joined, and is fastened and integrated with the other part by fastening means. Universal joint, characterized in that.   It consists of at least two members that can be connected, and each member has a receptacle or a receptacle into which a plastic pipe is inserted, and at least one member is rotated at a joint surface with another member connected to the member. This is a universal joint made of a thermoplastic resin in which the angle formed by the receptacles of both members can be changed, and a fusion part in which a sealing o-ring is mounted on the joint surface and a heating wire is embedded Universal joint characterized by not having.   6. The universal joint according to claim 5, wherein a concave portion is formed on one of the flanges to be joined, and a convex portion that fits into the concave portion is formed on the other.

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