JPS6337596Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to a curved pipe joint used to form an accurate curved pipe by combining multiple pieces.In particular, the central angle of the curve in the curved pipe section can be adjusted by combining a plurality of curved pipe joints. Even if it happens, it will be formed correctly as designed. Conventionally, when encountering a case where it is necessary to form a curved part in the middle of a pipe line, for example, a single-receptor, single-insertion curved pipe joint (hereinafter simply referred to as a pipe joint) 1, 2 as shown in Fig. 1a is used. A suitable number of them are joined to form a curved pipe with a predetermined radius and a predetermined central angle. Then, the socket 3b of the straight pipe 3 and the socket 4a of the straight pipe 4 are connected to the opening ends for connection left at both ends, that is, the socket 1a and the socket 2b, respectively, and connected to the straight pipe. go. When such a curved pipe section is designed to have a certain arbitrary curvature, as shown in Fig. 1a, from the opposite end faces of the insertion part 3b of the straight pipe 3 and the socket part 4a of the straight pipe 4, If the point where imaginary lines X and Y, which are perpendicular to the respective axes of both straight pipes 3 and 4 and extend toward the center of the curved pipe intersect, is the bending center point A of the curved pipe, then the bending center point A is The central arc Aa becomes the axis of the designed curved piping section, and the axis of the actual piping also follows this arc.
Must match Aa. However, the conventional pipe joint 1 is formed as a curved tube with the same curvature over the entire length of the face-to-face distance (from the end face of the socket part 1a to the end face of the socket part 1b) as shown in FIG. 1b. Instead, the axes of the socket part 1a and the socket part 1b are straight, and the socket part 1a and the socket part 1b are straight tubes of la and lb, respectively, and the intermediate part 1 connecting them is
c is formed as a curved portion. This is socket part 1
If a is curved, the cross-sectional shape of the seal packing 5 will not be the same all around the circumference as in the case of a straight pipe, and a special one will have to be prepared, and the sealing effect may deteriorate. Therefore, the socket part 1a had to be formed in the shape of a straight tube, and the insertion part into which it was inserted and joined had to be also formed in the shape of a straight tube. Therefore, when fittings 1 and 2 are connected to a curved piping section as shown in the figure, the insertion joint B becomes a straight tube, so the axes of fittings 1 and 2 that are actually installed are , will not match the designed axis, resulting in a pipe whose curved shape is interrupted every time the joint B appears. In other words, the center of curvature of the curved piping section is at two points, point P and point Q, both of which are far from the designed bending center point, and the piping axis of the curved piping section that is actually formed is centered around point P. It is formed by a curved axis Pa, a curved axis Qa centered on point Q, and a straight axis Ra connecting these curved axes Pa and Qa. In this way, the actual piping is different from the designed piping, so there are power cables inside the pipe,
When pulling in communication cables, the calculated value of the designed pulling tension differs from the actual pulling tension, which causes a decrease in the efficiency of work such as pulling in power cables and communication cables. Therefore, in actual piping work, the actual curved piping axis can be adjusted based on the design by using the clearance 2d between the socket 2a of the pipe fitting 2 and the insertion part 1b of the pipe fitting 1 shown in Fig. 1a. It is also possible to pipe with the axial center shifted so as to approximate the curved axis of If the piping is installed as described above, the flexibility of the conduit will be impaired. Due to the above-mentioned problems, a pipe fitting that can match the designed curved axis and the actual curved piping axis without impairing the conventional functions of pipe fittings such as sealing function and flexibility function is needed. is required. The present invention was developed in view of the above-mentioned circumstances, and it is possible to form a curved piping section into the correct curved shape as designed, and to obtain a curved piping that does not impair the sealing function or flexibility function of the conduit. The aim is to provide a new pipe joint configured to allow In other words, the structure of the present invention that achieves the above purpose is as follows.
A curved pipe joint in which an enlarged-diameter socket is formed on at least one side of a curved pipe part, and the inner and outer circumferential surfaces of the curved pipe part are composed of curved surfaces curved at a constant curvature along the axial direction. , the enlarged diameter socket part is formed to have a linear axis, and the axis of the enlarged diameter socket part is connected to the continuous part from the curved pipe part to the enlarged diameter socket part in the continuous part. The gist of this is that it is deflected toward the center of curvature of the curved tube with respect to the tangential line of the curve axis of the curved tube. The configuration and operation and effects of the present invention will be specifically explained below based on the drawings of the embodiments, but the embodiments below are merely specific examples, and any design changes made in accordance with the spirit of the preceding and following sections are not applicable. It is included in this invention. FIG. 2 is an explanatory cross-sectional view illustrating a curved pipe joint according to the present invention, and shows a one-side receiving and one-side insertion type. Further, FIG. 3 is an enlarged sectional view of the main part and illustrating the piping state. In these figures, the pipe joint 11 has a curved pipe portion 11c formed in an arc shape with a curved axis Sa centered at a bending center point S, and an enlarged diameter socket portion 11a at one end of the curved pipe portion 11c.
The axis T of the enlarged diameter socket part 11a is continuous from the curved axis Sa of the curved pipe part 11c to the root part 12 of the enlarged diameter socket part 11a (the end surface of the pipe insertion port to be connected reaches Slightly (θ°) in a straight line toward the curvature center point S side with respect to the tangent t of the axis Sa at the point where
It's deflected. Therefore, the curved pipe joint 11 has a shape in which the insertion part 11b formed in the curved pipe part 11c extends the curved pipe part 11c with the same curvature, and the enlarged diameter socket part 11a at the other end does not curve. It has a straight tube shape. Then, when another curved pipe 13 formed in exactly the same manner as the pipe joint 11 is inserted into the enlarged diameter socket 11a of the curved pipe joint 11 through the seal packing 15, the enlarged diameter socket 11a becomes as described above. Since it is formed to be deflected from the root portion 12 toward the bending center point S, the insertion portion 1 of the curved pipe 13
3b will be inserted along the axis T.
Therefore, the pipe joint 11 and the curved pipe 13 can be made into a common and continuous circular arc, and the curved axis Wa of the curved pipe 13 is on the extension line (the same curvature extension line) of the curved axis Sa on the pipe joint 11 side. It will overlap. That is, the pipe joint 11 and the curved pipe 13 can be made into a continuous curved pipe along the same axis of curvature. In this way, in the present invention, since the enlarged diameter socket part 11a is deflected toward the center of curvature, a curved pipe having a socket part curved with approximately the same radius of curvature as the curved pipe part 11c can be used. Therefore, there is no possibility that the curved pipe line is cut off at the insertion joint as in the conventional case, and a curved pipe line as designed can be provided. In addition, since the curved pipe portion 11c is formed with the same radius of curvature up to the tip of the socket, even if the pipe is cut to a desired length according to the distance between surfaces at the construction site, the shape of the socket will be the same under the same conditions. It can also be applied to curved piping paths having dimensions other than those indicated by standards such as so-called meters of pipes and meters of radius. FIG. 4 is a sectional view of a main part showing another embodiment of the present invention, in which the enlarged diameter socket 11a is deflected stepwise at two locations: the base 12 and the base 14 of the packing groove. The axis T' of the second stage is further deflected by θ ₁ ° toward the center of curvature. In this way, the deflection angle of the enlarged diameter socket, which is deflected toward the center of curvature of the curved pipe with respect to the tangential direction of the curved pipe axis, seemed to vary depending on the diameter and radius of curvature of the pipe joint. Therefore, when we investigated the preferred deflection angle, we obtained the results shown in Table 1.

[Table] As stated above, the preferred deflection angle is θ or θ+θ ₁ of around 1°, which is sufficient for application to curved pipe joints of various sizes. In manufacturing such a pipe joint, it is possible to heat a short pipe extruded in the conventional manner and then insert a curved mold into its inner cavity, but according to the conventional method, the curved part The roundness of the tube is likely to deteriorate, resulting in a rather flat cross-sectional shape, and for example, in the case of a power tube, there is a problem in that it is difficult to pull in the power cable. Therefore, it is recommended to use blow molding technology, insert the extruded tube into the outer mold while bending it, and then perform blowing. Furthermore, in the above embodiment, a single-receiver and single-insertion type pipe joint was described, but it goes without saying that it can also be applied to a double-receiver type pipe joint. It suffices if the axis of the curve is deflected toward the center of curvature.
The deflection angle is also not limited to the embodiment. Since the present invention is constructed as described above, the following effects can be obtained. A curved conduit as designed can be obtained. Since the curvature of the curved conduit can be made constant, the work of pulling cables and the like into the conduit can be carried out extremely smoothly based on the designed pulling tension. Since the curvature of the insertion port remains the same even when cut to match the desired distance between surfaces, connection can be made extremely easily without any deviation from the design. The seal packing can be used in common with those for straight piping, and does not reduce the sealing effect. Curved pipes can fully and effectively exhibit their flexibility against ground movements and earthquakes.

[Brief explanation of the drawing]

Figures 1a and b are cross-sectional views illustrating conventional piping connection states, Figure 2 is a cross-sectional view illustrating the curved pipe joint according to the present invention, Figure 3 is an enlarged explanatory view of the main parts, and Figure 4 is an illustration of other parts. FIG. 2 is an enlarged explanatory diagram of a main part showing an embodiment of the present invention. 1, 2...Curved pipe joint, 3, 4...Straight pipe, 11
a... Expanded diameter socket part, 11c... Curved pipe part.

Claims (1)

[Scope of utility model registration request] A curved pipe joint in which an enlarged-diameter socket is formed on at least one end side of a curved pipe part, and the curved pipe part is composed of a curved surface curved at a constant curvature along the coaxial direction of the inner and outer circumferential surfaces. At the same time, the enlarged diameter socket part is formed to have a linear axis, and in the continuous part from the curved pipe part to the enlarged diameter socket part, the axis of the enlarged diameter socket part is A curved pipe joint characterized in that the curved pipe part and the enlarged diameter socket part are continuous so that the curved pipe part and the enlarged diameter socket part are deflected toward the center of curvature of the curved pipe part with respect to the curve axis tangent of the curved pipe part in the continuous part. .