JP3549185B2 - A method and apparatus for joining a synthetic resin pipe and a bending prevention guide used for the same. - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a joining method for connecting a synthetic resin pipe such as a polyethylene pipe for water distribution to a joint or a valve, an apparatus used for this joining, and a guide for preventing bending at the time of joining.
[0002]
[Prior art]
Conventionally, as a method of joining polyethylene pipes for water distribution, an electrofusion method is often used. This electrofusion joining method uses a tubular joint in which a heating wire is embedded in the joint surface, a tube is inserted into this joint from both sides, and then electricity is supplied from a controller to heat the heating wire, and the inner surface of the joint and the outer surface of the tube This is a bonding method in which the two are integrated by heating and melting the resin to fuse them together.
[0003]
In addition, there has been conventionally proposed a mechanical joining method in which a pipe end of a polyethylene pipe is press-fitted to an outer surface of a metal joint.
[0004]
[Problems to be solved by the invention]
However, the conventional electrofusing method uses a controller and heat, so that it cannot be constructed in rainy weather and is not affected by the weather, and cannot be constructed in water. In addition, in the conventional press-fitting method, since a large force is applied to the polyethylene pipe at the time of press-fitting, the polyethylene pipe is bent at the joining portion, and it is difficult to perform a straight and correct joining. In addition, a large-scale apparatus is required for the press-fitting operation. Therefore, it is not suitable for on-site construction.
[0005]
In view of the above, the present invention provides a method and an apparatus for joining a synthetic resin pipe that can be constructed without being affected by the on-site environment by employing a mechanical method instead of a conventional electric heating method. Another object of the present invention is to provide a bonding method and a device which are simple in device configuration and handling and are particularly suitable for on-site construction. Another object of the present invention is to provide an anti-bending guide which can be used at the time of joining so that the tube is not bent and can always be joined straight.
[0006]
[Means for Solving the Problems]
The technical means of the method for joining a synthetic resin pipe of the present invention includes a hydraulic type provided between the synthetic resin pipe and the article to be joined when joining the pipe end of the synthetic resin pipe to the outer surface of the joint portion of the article to be joined. A press-fitting machine is used to apply a press-fitting pull-in force, and at the time of this pull-in, guide the outer surface of the synthetic resin pipe so as not to be displaced by a bending prevention guide attached to the joint, and further press-fit the pipe end into the joint. Another object of the present invention is to press-fit a metal tightening ring to the outside of a joint portion of a synthetic resin pipe by using a hydraulic press-fitting machine.
[0007]
The technical means of the apparatus for joining synthetic resin pipes of the present invention includes a hydraulic press-fitting machine that can be attached between the synthetic resin pipe or the tightening ring and the article to be joined, and a bending prevention device that is attached to the joint of the article to be joined. A guide and a tightening ring fitted on the outer surface of the joint portion of the synthetic resin tube. The object is to guide the outer surface of the tube end by the bending prevention guide so as not to be displaced when the synthetic resin tube is press-fitted.
[0008]
In addition, the hydraulic press-fitting machine includes a hydraulic cylinder and a mounting bracket to which the hydraulic cylinder is detachable, and a metal fitting is provided at a distal end of the retraction shaft of the hydraulic cylinder for connection to a workpiece. It is preferable to use a mounting bracket that has a split structure, can be fixed by bolting, and has two types, one for a polyethylene pipe and one for a tightening ring.
[0009]
The technical means of the bending prevention guide of the present invention includes a mounting portion that can be fixed to the joint portion of the joined body, a guide portion that contacts the outer surface of the synthetic resin pipe, and a connecting portion that connects the mounting portion and the guide portion. In other words, the whole structure has a split structure, and can be combined and separated freely.
[0010]
Further, it is preferable that the bending prevention guide can be united and fixed by screws at the mounting portion and the guide portion. Further, it is preferable that the connecting portion of the bending prevention guide has a small thickness and is provided with a notch so that slight elastic deformation is possible.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of a joining method and an apparatus therefor according to the present invention will be described with reference to examples in the drawings. The article to be joined in this embodiment is the water valve 1. FIGS. 1 to 6 show a stepwise construction process when the polyethylene pipe 2 is joined to the valve 1, and FIG. 1 shows a first construction process. In the figure, reference numeral 3 denotes a joint portion of the valve, and reference numeral 4 denotes a bending prevention guide. The guide 4 is attached to the joint portion 3. The fastening ring 5 is previously fitted into the polyethylene pipe 2. The hydraulic press-fitting machine 6 is mounted at a position near the end of the polyethylene pipe 2. Reference numeral 7 denotes a flange of the valve 1 having a bolt hole.
[0012]
Here, each member of the device will be described. Details of the bending prevention guide 4 are shown in FIGS. The guide 4 has a split structure, and includes an attachment portion 10, a connection portion 11, and a guide portion 12. The mounting portion 10 and the guide portion 12 are provided with bolt holes 13 and 14 in a flange portion thereof, so that the two guides 4 can be united and fixed by tightening with bolts 15 and 16. . Attachment of the guide 4 to the valve 1 is such that the joint portion 3 of the valve is first held by the two mounting portions 10 of the guide segment. At this time, the end face of the mounting portion 10 is completely brought into close contact with the base end flange of the valve joint portion 3 so that the core and the horizontality are accurately obtained, and then the bolt 15 is tightened to be firmly fixed. Next, the guide portion 12 is also tightened by the bolt 16. In this bolted state, the inner surface of the guide portion 12 becomes a perfect circle and matches the outer diameter of the polyethylene pipe 2. The connecting portion 11 has a small thickness and is appropriately notched so as to be able to be slightly elastically bent.
[0013]
The tightening ring 5 is made of metal and is for pressing the joint end of the polyethylene pipe 2 from the outer surface. The press-fitting machine 6 includes a hydraulic cylinder 20 and a fitting 21. It should be noted that two types of mounting brackets 21a and 21b are prepared for the mounting bracket 21 in accordance with the type of press-fitting operation, and the hydraulic cylinder 20 is appropriately replaced and used. Each of the mounting brackets 21 has a split structure, and is fixed by being tightened with bolts 22. A hydraulic cylinder 20 is mounted on each of the two halves. Reference numeral 23 denotes a retraction shaft of the hydraulic cylinder, and reference numeral 24 denotes a connection fitting attached to a tip of the shaft.
[0014]
Next, the joining procedure will be described. From the disassembled state in FIG. 1, first, the press-fitting machine 6 is attached to the polyethylene pipe 2. At this time, the mounting fitting of the press-fitting machine is a mounting fitting 21a for the polyethylene pipe, which is set so as to embrace the outer surface of the polyethylene pipe 2 and fastened with the bolt 22, so that no slippage occurs with the polyethylene pipe 2. Firmly. Further, the connection fitting 24 at the tip of the drawing shaft 23 of the press-fitting machine 6 is pinned to the flange 7 of the valve. Next, as shown in FIG. 2, the end of the polyethylene pipe 2 is butted against the joint 3 of the valve. Further, the mounting portion 10 of the bending prevention guide 4 is fixed to the joint portion 3 of the valve 1 by tightening the bolt 15 as described above, and the guide portion 12 is further tightened by the bolt 16 to be fixed in a perfect circle. However, sliding with the polyethylene pipe 2 is possible even if the guide portion 12 is tightened.
[0015]
After setting in this manner, subsequently, oil is supplied to the hydraulic cylinder 20 by a manual pump (not shown), and the two shafts 23 are pulled in parallel. Thereby, the polyethylene pipe 2 is forcibly pressed into the outside of the joint portion 3. At the time of press-fitting, since the outer surface of the polyethylene pipe 2 is pressed by the guide portion 12, the pipe is press-fitted straight without any positional deviation. In addition, a slight blur at the time of press-fitting is absorbed by the elastic deformation of the connecting portion 11, so that press-fitting can be performed smoothly. When the joining of the polyethylene pipe 2 has progressed to a certain extent (to such an extent that the pipe end cannot be seen from the cutout of the connecting portion 11), the press-fitting operation is temporarily stopped, and the bending prevention guide 4 is removed.
[0016]
Subsequently, the press-fitting operation is resumed from the state of FIG. 3 without any guide, and when the polyethylene pipe 2 is completely fitted to the end of the joint portion 3, the press-fitting operation is completed. Thereafter, the press-fitting machine 6 is once removed, and the tightening ring 5 previously fitted into the pipe is moved to a position immediately before press-fitting. Then, as shown in FIG. 4, the press-fitting machine 6 is attached to the rear end of the tightening ring 5 again. However, the mounting bracket of the press-fitting machine at this time is replaced with the mounting bracket 21b for the paired ring. An annular groove 25 for engaging the rear end of the tightening ring 5 is formed in the mounting member 21b. Accordingly, if the mounting bracket 21b is set at the rear end of the tightening ring 5 and tightened with the bolt 22, the mounting bracket 21b can be firmly fixed to the tightening ring 5. However, the mounting bracket 21b is not in contact with the polyethylene pipe 2. Next, when oil is fed to the hydraulic cylinder 20 from this state and the shaft 23 is retracted, the tightening ring 5 slides on the outer surface of the polyethylene pipe 2 and is forcibly fitted to the outside of the polyethylene pipe joint. . When the fitting is completed, the press-fitting machine 6 is removed. FIG. 6 shows a state where the joining is completed. After the joining on one side is completed in this way, subsequently, the polyethylene pipe is joined to the joint 3 on the opposite side of the valve in the same procedure.
[0017]
The present invention is not limited to the above embodiments, and can be freely modified and implemented within the scope of the claims. In particular, the form in which the bending prevention guide is united and fixed, the configuration of the press-fitting machine, and the detailed shape and structure of each member are free.
[0018]
【The invention's effect】
Since the joining method of the synthetic resin pipe of the present invention joins by a mechanical method called press-fitting, unlike the conventional electric heating method, reliable joining work can always be performed without being affected by the working environment such as bad weather. In addition, since a hydraulic system is employed as a power source, joining can be easily performed at any site. Further, according to the present invention, when the synthetic resin pipe is pulled in and fitted, the pipe end of the synthetic resin pipe is guided by the bending prevention guide so as not to be displaced, so that the synthetic resin pipe can always be joined straight to the workpiece. , Construction defects can be prevented. In addition, in the present invention, since the fastening ring is pressed into the outer surface of the joint, the joining strength is high and the joint is not easily detached. In addition, since the working steps of the present invention are simple, the joining of the synthetic resin pipes can be reliably performed in a short time and without any construction error.
[0019]
The joining device of the present invention has a simple structure of each member in addition to the above-mentioned functions and effects, so that the cost of the device and the construction is low, and further, the handling is simple.
[0020]
According to the third aspect, the hydraulic press-in machine has a simple structure, can be implemented at a low cost, and has advantages such as easy attachment / detachment to / from a synthetic resin tube and a tightening ring and high fixing strength.
[0021]
Since the bending prevention guide of the present invention has a split structure, it can be easily attached and detached, accurately guide the end of the synthetic resin tube, and can always achieve straight and accurate joining. In addition, since the structure is simple, manufacturing is easy.
[0022]
According to the fifth aspect, since the two divided bodies of the bending prevention guide are united and fixed by a screw method, the work at the time of separation and uniting is simple. In addition, since the fixing strength of the joined body to the joint portion is sufficient, and the contact strength to the synthetic resin pipe can be adjusted, a joining defect can be eliminated and accurate joining can always be performed.
[0023]
According to the sixth aspect, since the connecting portion of the bending prevention guide can be slightly elastically bent, a slight positional deviation generated at the time of press-fitting can be absorbed and smooth joining can be achieved.
[Brief description of the drawings]
FIG. 1 is a half sectional view of a first construction step using a bonding apparatus of the present invention.
FIG. 2 is a half sectional view of a second construction step.
FIG. 3 is a half sectional view of a third construction step. FIG. 4 is a half sectional view of a fourth construction step. FIG. 5 is an enlarged sectional view of a main part of FIG.
FIG. 6 is a half cross-sectional view of a joining completed state.
FIG. 7 is a perspective view of the bending prevention guide in a separated state.
FIG. 8 is a sectional view of a bending prevention guide.
[Explanation of symbols]
1 Valve (joint)
2 Polyethylene pipe 3 Valve joint part 4 Bend prevention guide 5 Tightening ring 6 Press-fitting machine 7 Valve flange 10 Mounting part 11 Connecting part 12 Guide part 13, 14 Bolt hole 15, 16 Tightening bolt 20 Hydraulic cylinder 21a, 21b Mounting Fitting 22 Tightening bolt 23 Retraction shaft 24 Connection fitting 25 Annular groove

Claims (6)

When joining the pipe end of the synthetic resin pipe to the outer surface of the joint of the article to be joined, a press-fitting and pulling force is applied by a hydraulic press-fitting machine provided between the synthetic resin pipe and the article to be joined, and at the time of this withdrawal, the joint is joined. Guides the outer surface of the synthetic resin pipe so that it does not move, and further presses the pipe end into the joint part, and then presses the metal end out of the joint end of the synthetic resin pipe. A method for joining synthetic resin pipes in which the tightening ring is press-fitted using a hydraulic press-fitting machine. Hydraulic press-fitting machine that can be mounted between the synthetic resin pipe or the tightening ring and the object to be joined, a bending prevention guide that is attached to the joint of the object to be joined, and tightening that is fitted to the outer surface of the joint of the synthetic resin pipe A joining device for a synthetic resin pipe, which comprises a ring and guides the outer surface of the pipe end with a bending prevention guide so as not to be displaced when the synthetic resin pipe is press-fitted. A hydraulic press-fitting machine is composed of a hydraulic cylinder and a mounting bracket to which the hydraulic cylinder is detachable. At the tip of the retracting shaft of the hydraulic cylinder, a metal fitting for connecting to a body to be joined is provided. 3. The synthetic resin pipe joining device according to claim 2, wherein the joining device has a split structure, can be fixed by bolting, and is provided with two types, one for a polyethylene tube and one for a tightening ring. It consists of a mounting part that can be fixed to the joint part of the body to be bonded, a guide part that contacts the outer surface of the synthetic resin pipe, and a connecting part that connects the mounting part and the guide part. A bendable guide that can be separated. 5. The bending prevention guide according to claim 4, wherein the mounting portion and the guide portion can be fixed together by screws. The bending prevention guide according to claim 4, wherein the connecting portion has a small thickness and is provided with a notch so that slight elastic deformation is possible.

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