JP2005257061A - Pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint having high airtightness at a connection part in connecting a flexible pipe to a sprinkler head mounting pipe. <P>SOLUTION: In this pipe joint, air tightness is maintained by pressing a packing between the flange of the flexible pipe and the mounting pipe with the tightening of a cap nut. A tapered cutout is formed in the opening end inner diameter surface of the mounting pipe. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

Detailed Description of the Invention

  The present invention relates to a pipe joint in which a gasket is interposed between a flexible pipe having a flange and a mounting pipe, and the flexible pipe and the mounting pipe are hermetically held and connected by a cap nut.

At the pipe joint, an elastic material packing is interposed between one pipe and the opening of the other pipe, and both pipes are screwed together and the packing is pressed to keep the two pipes airtight. The connecting method has been widely used (Japanese Patent Laid-Open No. 2002-54769).
In addition, fire extinguishing equipment (Japanese Patent Laid-Open No. 10-337338) in which a large number of branch pipes are provided on a water supply main pipe installed in an indoor ceiling or the like, and a sprinkler head is attached to the branch pipe using an attachment pipe is common. A pipe made from these branch pipes to the attachment pipes as a flexible pipe is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-96050.

Problems to be solved by the invention

  However, since the flexible tube has a thin plate thickness in order to exert its flexibility, the flange portion integrally formed with the flexible tube is not strong, and the tightening force of the cap nut is not evenly transmitted to the packing. Further, since the packing is only sandwiched between the flange portion of the flexible tube and the opening portion of the attachment tube, the area for the airtight holding where the packing is in contact with the flexible tube and the attachment tube is substantially the same as the original shape. For this reason, there is a problem that a large airtight effect cannot be expected as a joint, and water leakage occurs due to a change over time due to long-term use.

  This is disadvantageous as a sprinkler pipe joint that is subject to large water pressure indoors, and requires frequent maintenance and inspections for water leakage from the ceiling, which increases the labor and cost. There is a point.

  An object of the present invention is to provide a pipe joint capable of obtaining a large airtight effect by widening the contact area of the packing pressed between the flange portion of the flexible pipe and the mounting pipe.

Means for solving the problem

  In order to achieve the above object, a pipe joint according to the present invention is a pipe joint in which a flexible pipe having a flange and another mounting pipe are screwed and connected with a cap nut through packing, and an open end portion of the mounting pipe is connected. The inner diameter surface is notched in a tapered shape. And this taper-shaped open end part is notching half or more of the plate | board thickness of an attachment pipe.

  In the pipe joint configured as described above, when the cap nut is screwed into the attachment pipe, the packing is pressed against the open end of the attachment pipe by the flange portion of the flexible pipe. When the cap nut is further screwed into the mounting pipe, the packing is inserted to the back while being deformed along the opening because the open end of the mounting pipe is tapered. By this insertion, the packing is pressed between the flexible tube and the mounting tube in a wide area, and the airtightness of the portion is ensured and strengthened.

  1 is a front view in which a mounting tube 2 of a sprinkler head 11 is connected to a flexible tube 1 with a cap nut 3. FIG. 2 is a cross-sectional view showing a pipe joint according to the present invention. FIG. It is sectional drawing which shows the use condition of the pipe joint which concerns on this invention tightened, and it leaves the fitting part 4 fitted in the attachment pipe 2 at the edge part of the flexible pipe 1 made from stainless steel, and was formed into a flange 5 protrudes to the outer periphery and is integrally formed.

  A ring-shaped packing 6 made of an elastic material such as rubber is fitted to the fitting portion 4, and then the attachment tube 2 is fitted. A male screw 7 is provided on the outer periphery of the mounting tube 2, and a female screw 8 of the cap nut 3 is screwed to the male screw 7 to constitute a pipe joint.

  FIG. 4 shows a cross-sectional view of the main part of the mounting tube 2, and the open end portion of the mounting tube 2 is formed in a tapered shape 9 by notching the inner diameter surface. The tapered notch 9 desirably cuts at least half of the plate thickness of the mounting tube 2, and if the notch is cut to the same extent as the plate thickness, a greater effect is exhibited. An insulating collar 10 made of synthetic resin is interposed between the flexible tube 1 and the cap nut 3 to prevent electrical contact.

  When the cap nut 3 is further screwed into the attachment tube 2 from the state shown in FIG. 2, the flange portion 5 presses the packing 6 toward the attachment tube 2, and the packing 6 is brought into contact with the tapered portion 9 of the attachment tube 2. It is deformed to follow.

  FIG. 5 shows an enlarged cross-sectional view of the main part of the present invention. When the cap nut 3 is strongly screwed, the end of the packing 6 is finally in the gap between the fitting portion 4 of the flexible tube 1 and the mounting tube 2. The flexible tube 1 and the attachment tube 2 are connected in an airtight manner.

  FIG. 6 is a cross-sectional view showing a conventional pipe joint. When the cap nut 3 is tightened, the packing 6 is sandwiched between the flange portion 5 of the flexible tube 1 and the open end portion of the flexible tube 2.

The invention's effect

  As described above, the pipe joint according to the present invention has a tapered shape with the inner diameter of the open end of the mounting pipe cut out by half or more of the plate thickness, so that the packing is formed along the tapered surface by strongly screwing the cap nut into the mounting pipe. It is easily deformed, and is fitted to the fitting portion between the mounting tube and the flexible tube to increase the contact area and equalize the contact pressure, thereby ensuring the airtightness of both tubes. Further, when the tapered notch is about the same as the thickness of the mounting tube, the deformation of the packing and the insertion into the gap are smoother, the contact area is further increased, and the airtightness can be further strengthened.

  Therefore, the pipe joint of the present invention has a large hermetic effect, and exerts a very great effect on the sprinkler facility piping to which a large water pressure is applied.

  It is a front view which shows the use condition of the pipe joint which concerns on this invention.   It is sectional drawing which shows the principal part of the pipe joint which concerns on this invention.   It is principal part sectional drawing of the state which tightened the cap nut with the pipe joint which concerns on this invention.   It is a principal part expanded sectional view of an attachment pipe.   It is a principal part expanded sectional view of the pipe joint which concerns on this invention.   It is sectional drawing which shows the principal part of the conventional pipe joint.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flexible tube 2 Mounting tube 3 Cap nut 4 Fitting part 5 Flange 6 Packing 7 Male screw 8 Female screw 9 Tapered notch 10 Insulation collar

Claims (2)

  A gasket is interposed between a flexible tube having a flange and another mounting tube, and a cap nut is screwed to the mounting tube to tighten the packing between the flange and the mounting tube. A pipe joint wherein the pipes are connected in an airtight manner, wherein the inner diameter surface of the open end of the mounting pipe is cut out in a tapered shape.   2. A pipe joint according to claim 1, wherein the tapered cutout opening provided at the open end of the attachment pipe is at least half the plate thickness of the attachment pipe.

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