JP2004138169A - Press type fitting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a press type fitting which can easily be discriminated from other fittings by seeing the presence or absence of a color because when the fitting is caulked by a press tool for piping construction, a color comes out from the pressed part. <P>SOLUTION: The press type fitting F for connecting a connection pipe to a socket 1 by a press tool is provided with a function capable of making a color come out from a pressure or heat sensitive piece 7, which is adhered on the periphery of the connection pipe at a portion separated a specified distance from the end face of the socket 1 in the axial direction of the fitting, due to pressurization on the piece attendant upon pressing. When pressure is applied to the piece attendant upon the caulking the pipe, a fresh color comes out from the portion. Accordingly, it can easily be checked whether the fitting has been mounted without being fastened dependent upon the presence or absence of the color. This contributes to the reduction of the number of fittings mounted without being fastened and the prevention of oil leakage. This also contributes to the improvement of the workability in inspection as well as the securing of the safety of piping. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press-fitting pipe joint of a piping construction type in which a connection pipe is joined by press working to caulk the periphery of the connection pipe.
[0002]
[Prior art]
The press-type pipe joint is formed by forming a pipe member such as stainless steel as a joint by plastic working or the like, and has a port in which an inner diameter of a portion where the connection pipe is inserted is expanded. In piping work, this port is caulked with a press tool and tightly bonded to the connection pipe by the constriction. However, press work alone is insufficient in airtightness and watertightness, and liquid leakage may occur. An annular groove that opens inward is provided in a part of the mouth, and an O-ring is fitted into the annular groove.
[0003]
Press fittings are the most important and indispensable items for which press work is required for pipes, but sometimes they are forgotten to be tightened. In some cases, a large accident could be caused by operating without forgetting the tightening. When the installation of the piping is completed, a water pressure (or air pressure) test is performed to check for water leaks. Therefore, the hydraulic test did not provide a reliable way to detect a forgotten closing.
[0004]
[Problems to be solved by the invention]
It was conceived that the O-ring would be devised so that the function of the O-ring would not be exerted only by inserting the connecting pipe so that the operator could find out that he had forgotten to tighten by a hydraulic test. Regarding this, if the idea is to allow the inner diameter of the O-ring to be slightly larger than the outer shape of the connecting pipe, and there is no inconvenience that the positioning when the connecting pipe is inserted becomes unstable, It has been proposed to provide a concave portion sandwiched between bulging convex portions in a part of an O-ring (Japanese Utility Model Publication No. 6-33258).
[0005]
According to this, at the stage where the connecting pipe is inserted, the concave portion of the O-ring is not completely crushed yet, so that a gap is formed between both the pipe joint and the connecting pipe through which water passes. Thus, a water leak should have occurred so that the user could confirm that the operator had forgotten to close the hydraulic pressure test. However, since the water leak did not actually occur, the operator could not detect the forgetting to close the hydraulic pressure test. In addition, this sacrifices the function of the O-ring, and there is a risk that the O-ring may come off from the annular groove due to the projection of the connecting pipe being inserted. And it could not be said to be a preferable measure as a pipe joint.
[0006]
SUMMARY OF THE INVENTION The present invention provides a press-type pipe joint capable of easily discriminating forgetting to close based on the presence or absence of coloration, because, when the pipe is swaged with a press tool for piping construction, the portion develops color. Aimed at.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a press-type pipe joint in which a connection pipe is joined to a receiving port by press working, on a circumference at a predetermined distance from the end face of the receiving port in the joint axial direction, A press-type pipe joint characterized in that a pressure-sensitive or heat-sensitive coloring piece is affixed thereto and has a function of being able to develop a color by pressurizing the piece during press work.
[0008]
[Action]
According to the above configuration, when a predetermined portion of the press-type pipe joint is swaged by press work for pipe connection, the pressure-sensitive or thermosensitive coloring tape piece is colored by the pressure or heating accompanying the press. Therefore, if there is color development, it means that the press work has been performed, so that the presence or absence of the press work is confirmed.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention is such that the pressure-sensitive or heat-sensitive coloring piece 7 attached to the receiving port 1 of the press-type pipe joint F is colored by the pressure or heating accompanying the press work. , Tape, film, paper and the like are used. Although only the coloring piece 7 may be adhered to a predetermined portion of the receptacle 1 with the base material 13 facing upward, it is preferable to cover the coloring piece 7 with a UV (ultraviolet) cut tape 9. Further, this may be an annular shape fitted or wound around the receptacle 1. However, as shown in FIG. 7, when the upper and lower dies 4 and 4 of the press tool T are fitted together as described above, when the upper and lower dies 4 and 4 are fitted together, the protrusion 30 protrudes from the space between the dies 4 and the wrinkle 31 at the inner angle 12. Is generated or cut, making it hard to see. In particular, the thicker the tape, the worse it looks dirty. Therefore, it is desirable that the inner surface 11 be sized so that the inner surface 11 is located between the inner angles 12 and 12 so as to be included in the pressing surface. Suitable shapes include, for example, circles, ellipses, oblongs, rectangles, squares, donut shapes, triangles, and the like. When the shape in which the dies 4 and 4 are combined is a hexagon, the number of coloring pieces to be attached is not limited to six, and may be one to five.
[0010]
The pressure-sensitive and heat-sensitive materials are not particularly limited, but it is suitable that both or one of the color developer and the color former is microencapsulated, ruptured by pressure and touched by both agents to form a color by a chemical change. is there. As the heat-sensitive coloring piece, for example, a heat-sensitive tape or thermo tape that changes color from white to red at about 60 ° C. can be used. In this case, a heater may be buried in the dies 2 and 2 of the press tool T, and heat may be applied to the coloring piece 7 to form a color when caulking.
[0011]
Irrespective of which material is used, the ability to develop color is reduced by receiving ultraviolet rays, which causes the color to fade even after the color is developed. Therefore, it is desirable to cover with a UV cut tape 9 or a cellophane tape (claim 2 later, claim 3). Therefore, such an example is described in the following embodiments. In the case of the UV cut tape 9, even if the cut rate of ultraviolet rays is the same as, for example, 99%, it is desirable that the transmittance is large and thin. The cellophane tape does not stretch, but has a good result in holding down the coloring pieces 7 probably because of the thin film thickness.
[0012]
The UV cut tape 9 is obtained by mixing an absorbent into the tape base material in order to block ultraviolet rays, but it has been found that a cellophane tape generally used in office work also has an effect of cutting ultraviolet rays. In any case, it is necessary to be as transparent as possible so that the color development can be seen. In addition, when the tape 9 is covered, the coloring piece 7 is protected at the time of press work, so that inconveniences such as the color developing out of color and the color developing adhering to the press tool T are prevented.
[0013]
The press-type pipe joint F is a metal pipe made of stainless steel, iron, copper, or the like, which is formed into a socket, an elbow, a tee, a reducer, or the like by plastic working or the like. May be located at the opening edge of the receptacle 1 (FIG. 1) or may be halfway between both ends of the receptacle 1.
[0014]
【The invention's effect】
As described above, according to the press-type pipe joint of the present invention, when pressure is applied by caulking of pipes, a vivid coloration appears at the place, and forgetting to tighten can be easily found depending on the presence or absence, and forgetting to tighten is reduced. Therefore, there is an excellent effect that not only the liquid leakage accident can be prevented beforehand and the safety of the piping can be ensured, but also the inspection workability can be improved.
[0015]
In particular, if the coloring pieces are covered with UV cut tape or cellophane tape, they have light resistance, high quality retention ability to maintain the color development function, and high anti-fading properties to maintain the color development state. It is possible to obtain certainty in the discovery, and it is possible to effectively prevent inconvenience that the color develops or adheres to the press tool.
[0016]
【Example】
Next, an embodiment of a press-type pipe joint according to the present invention will be described with reference to the drawings.
[0017]
FIG. 1 to FIG. 4 show an embodiment, in which a press-type pipe joint F is a socket, which is an expanded receiving member into which connecting pipes P, P can be inserted at both ends of a straight stainless steel pipe. Ports 1 and 1 are formed (FIG. 1), and annular concave grooves 3 and 3 are formed on the opening edges of the receiving ports 1 and 1 by curl press processing. Further, coloring pieces 7, 7,... As pressure-sensitive tape are stuck on the outer periphery of the receiving ports 1, 1 at regular intervals along the outer periphery at locations to be swaged with the press tool T (FIG. 4). A UV cut tape 9 is attached thereon.
[0018]
Further, in this case, the press tool T is caulked into a hexagon by the upper and lower dies 2 and 2 (FIGS. 3 and 4), and inner hexagonal projections 4 and 4 having both hexagons are formed on the inner surface. The coloring pieces 7, 7,... Are stuck so as to fall within the range where the six inner surfaces 11, 11,. Has been done.
[0019]
The color of the coloring piece 7 is obtained by laminating a group of the microcapsules 15 containing the color developing agent and a group of the micro capsules 16 containing the color developing agent. The paint is applied to the tape base 13 made of (PET) in the order of the developer and the color former. Then, the paint surface 18 is adhered to a predetermined position of the receiving port 1, and the UV cut tape 9 is attached thereon.
[0020]
The coloring piece 7 is formed in a rectangular shape, and the UV cut tape 9 is formed in a rectangular shape slightly wider than that. An adhesive 19 is applied to the back surface of the UV cut tape 9 to cover the coloring piece 7 and the surrounding portion 20 is adhered to the outer surface of the receptacle 1 (FIG. 2).
[0021]
In FIG. 3, in the left half without a cross section, the colored piece 7 is colored from gray to red by caulking, and this is seen through the transparent film substrate 13 and the UV cut tape 9. In this embodiment, the coloring piece 7 is doubly protected by the tape base material 13 and the UV cut tape 9, so that the deterioration due to ultraviolet rays is double prevented. In addition, it is possible to effectively prevent the inconvenience that the internal color protrudes outside and adheres to the press tool T.
[0022]
FIG. 5 shows another embodiment. In this case, as for the color-forming piece 7, a microcapsule 16 containing a colorant and a microcapsule 15 containing a colorant are placed on the upper surface of the tape base 13 with an adhesive 17. , 17 are sequentially applied, and the paint surface 18 is adhered to the UV cut tape 9, and then the UV cut tape 9 is attached to a predetermined portion of the receptacle 1, and the colored piece 7 is adhered to the surrounding portion 20. Is stopped.
[0023]
FIG. 6 shows still another embodiment. In this case, the color-developing piece 7 includes a microcapsule 15 containing a color developing agent and a microcapsule 16 containing a color developing agent on the upper and lower tape bases 13, 13. Adhesives 17, 17 are separately applied in a mixed state, and then combined. The adhesive is applied to the lower surface of the UV cut tape 9 with the adhesive 19, and then the UV cut tape 9 is attached to the outer surface of the receptacle 1. Affixed.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of a press-type pipe joint according to the present invention.
FIG. 2 is an explanatory cross-sectional view showing a portion where a coloring piece is attached in the press-type pipe joint.
FIG. 3 is a front view of a right half section showing the right half before press working and the left half after working in the press-type pipe joint.
FIG. 4 is a cross-sectional view showing a state immediately before press working as viewed from the direction of arrows AA in FIG. 3;
FIG. 5 is an explanatory sectional view corresponding to FIG. 2 and showing another embodiment.
FIG. 6 is an explanatory sectional view corresponding to FIG. 2 and showing still another embodiment.
FIG. 7 is an explanatory cross-sectional view of a receiving port showing an experimental example of press work.
[Explanation of symbols]
F Press fitting P Connection pipe 1 Receptacle 7 Coloring piece 9 UV cut tape 17 Adhesive to be paint surface 18 Paint surface

Claims (3)

In a press-type pipe joint of a type in which a connection pipe is joined to a receiving port by press work, a pressure-sensitive or thermosensitive coloring piece is attached on a circumference of a predetermined distance from the end face of the receiving port in the axial direction of the joint. A press-type pipe joint having a function of being able to develop a color by pressurizing the piece during construction. Regarding the application of the coloring piece, it is made to adhere to the joint side with a paint surface containing a pigment or dye for coloring as a main component, or added from above the coloring piece thus adhered, A relatively wide UV-cut tape or cellophane tape or the like to which an adhesive or an adhesive is applied is attached to the joint, and the coloring pieces are covered with the tape so that the coloring can be seen through. 2. The press-type pipe joint according to 1. Regarding the attachment of the coloring piece, a paint surface mainly containing a pigment or dye for coloring is fixed to a UV cut tape or a cellophane tape or the like wider than the piece, and the coloring piece is attached to a joint with the coloring piece facing down. 2. The press-type pipe joint according to claim 1, wherein said tape is attached and covered with said tape so that color development can be seen through.

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