JPS6234066Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a flexible telescoping joint used to absorb the deflection and expansion/contraction of a tube in a fluid transport piping system.

Conventional technology This type of joint is often constructed using a bellows pipe, and in order to eliminate the disadvantage of fluid swirling in the bellows, conventionally a sleeve pipe is inserted into this type of joint to form a bellows section. However, in order to enable the bellows to expand, contract, and bend, it was necessary to make one end of the sleeve pipe a free end, and in particular, the joint was used for deflection. In order to prevent the free end of the sleeve tube from touching the inner wall of the bellows, the sleeve tube 3 must have a diameter as shown in FIG. It is necessary to fix the spacer 4 through the spacer 4, which has the disadvantage that the spacer 4 increases fluid resistance and becomes a source of eddy current. In addition, the flexible telescopic joint configured such that one end of the two sleeve pipes 3, 3 is fixed to the respective base pipes 2, 2, and the free ends thereof face each other, in addition to generating a vortex flow by the spacer 4,
When the joint is deflected in the lateral direction, a portion of the free end protrudes into the fluid passage, and the flow passage wall surface becomes discontinuous, causing a vortex flow here as well.
The disadvantage was that fluid entered the outside of the free end of the sleeve.

Problems to be Solved by the Invention The present invention eliminates the above-mentioned drawbacks and changes the shape of the sleeve tube and the structure near the attachment part so that the generation of vortex flow is extremely small and the area near the free ends of the opposing sleeve tubes is improved. An object of the present invention is to provide a flexible telescoping joint that does not extend beyond its free end.

Means for Solving the Problems In order to achieve the above object, the flexible telescopic joint of the present invention has a bellows pipe 1 whose both ends are fixed to the base pipes 2, 2.
In the flexible expansion joint formed by fitting the sleeve tubes 3 into the interior of the tube, one end surface of the two sleeve tubes 3 is directly fixed to the inner wall of the base tube 2, and
The tube diameter of the sleeve tube 3 is linearly decreased from the one end surface along the free end, and the entire circumference of the opposing free end of each sleeve tube 3 is smoothly bent outward with a curvature to increase the tube inner diameter. It is characterized by the fact that

Function The fluid that has flowed through the base tube enters the sleeve tube through the fixed portion of the sleeve tube, and flows into the other opposing sleeve tube from the free end of this sleeve tube.
At this time, even if the bellows tube is bent and bent,
The free end of the sleeve tube does not abut against the bellows tube, and the fluid is directed to the other opposite side without exiting outside the free end of the sleeve tube by the free end of the sleeve that is smoothly bent outward with curvature. It flows into the sleeve tube.

Embodiment FIG. 2 shows an embodiment of the invention. In the figure, two sleeve tubes 3, 3 have one end surface that is two base tubes 2, 2.
are directly fixed by welding, and their free ends face each other closely at the center of the bellows tube 1.
The sleeve tube 3 is formed so that the tube diameter decreases linearly from one fixed end surface along the free end, and the free end longitudinal section has a relatively large curvature R as shown in FIG. Either the inner diameter of the tube is enlarged, or it is bent outward with a small curvature r, as shown in FIG.

Effects of the invention Since the present invention has the above-mentioned configuration, the free end of the sleeve pipe and the pipe diameter can be adjusted not only when the entire joint expands and contracts in the axial direction, but also when it is bent laterally for deflection. The deviation of the central axes of both base tubes can be adjusted using the gap created by the difference in the inner diameter of the base tubes, and the free end of the sleeve tube does not come into contact with the bellows tube, so a spacer is not required when installing the sleeve tube. Therefore, a sleeve tube having almost the same diameter as the base tube can be installed inside the tube, which has the effect of suppressing turbulence and eddy currents occurring in the fluid passage to such an extent that they do not actually become a problem.

In addition, the entire circumference of the free end of the sleeve tube is smoothly bent outward with a curvature to increase the inner diameter of the tube. The fluid flows smoothly along the sleeve tube without entering the outside of the free end of the sleeve tube, and turbulence can be prevented.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view showing a conventional flexible telescopic joint, FIG. 2 is a vertical cross-sectional view showing an embodiment of the present invention,
3 and 4 are enlarged vertical cross-sectional views of the free end of the sleeve tube. 1... Bellows tube, 2... Base tube, 3... Sleeve tube, 4... Spacer, R, r... Radius of curvature.

Claims (1)

[Scope of utility model registration request] In a flexible expansion joint formed by fitting a sleeve pipe 3 into a bellows pipe 1 whose both ends are fixed to base pipes 2, 2, one end surface of each of the two sleeve pipes 3 is directly fixed to the inner wall of the base pipe 2. At the same time, the pipe diameter of the sleeve pipe 3 is linearly decreased from the one end surface along the free end, and the entire circumference of the opposing free end of each sleeve pipe 3 is smoothly bent outward with a curvature to form a pipe. A flexible telescopic joint characterized by an increased inner diameter.