JPH0247352Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a pipe joint seal that seals a pipe joint portion that connects pipes.

(Prior art and its problems) This type of pipe joint seal, as shown in Fig. 3 (before screw tightening) and Fig. 4 (after screw tightening),
Inward flange 12 (annular wall) of fitting 10 and tube 14
A rubber seal 20 positioned by a metal support 18 is interposed between the end face 16 of the screw and the rubber seal 20, which is often threaded during on-site processing, resulting in "variations" in the thread length. The difference in length of the tapered pipe thread 22, which is easy to remove, is accommodated.

However, in such a conventional example, the support 18
There is also the problem that the seal 20 is required, which increases the number of parts and complicates the structure.

(Purpose of the invention) The object of the invention is to provide a pipe joint seal that can solve the above problems, has high seal reliability, and has a simple structure.

(Structure of the device) (1) Technical means The present invention is a pipe joint seal that seals the connection between a pipe and a joint each having a male threaded portion and a female threaded portion that screw together, and which Thin-walled, substantially cylindrical heel portion that presses against the annular wall that protrudes continuously from the female threaded portion, and whose axial cross-sectional shape opens toward the center of the pipe or fitting. This is a pipe joint seal characterized in that a substantially annular lip portion having a curved arc shape is integrally formed of an elastic material.

(2) Function The thick heel portion positions the entire seal, and the lip portion ensures liquid tightness.

(Example) A pipe joint seal to which the present invention is applied will be described with reference to FIG. In FIG. 1, parts given the same reference numerals as those in FIG. 3 indicate the same or equivalent parts.

In FIG. 1, which shows the state before screw tightening, a synthetic rubber with excellent water resistance and heat resistance, such as silicone rubber or ethylene/propylene rubber, is placed between the inward flange 12 of the joint 10 and the end surface 16 of the pipe 14. An integrated seal 30 made of an elastic material (hereinafter simply referred to as synthetic rubber) is interposed.

The seal 30 consists of a heel portion 32 and a lip portion 34, the heel portion 32 positions the entire seal 30, and the lip portion 34 maintains liquid tightness. The heel portion 32 has a relatively thick cylindrical shape, and the inner circumferential surface of the heel portion 32 is substantially flush with the inner circumferential surface of the tube 14. The lip portion 34 is the heel portion 3
The lip part 3 is provided continuously at the end of the lip part 3.
The axial cross-sectional shape of 4 is formed into a thin circular arc shape that is curved so as to open toward the center of the joint 10 and the pipe 14, and the outer periphery of the lip portion 34 is pressed into contact with the annular groove 36 of the joint 10. However, the tip of the lip portion 34 is in pressure contact with the inward flange 12.

Next, the action will be explained. In the tightened state shown in FIG. 2 in which the tapered pipe thread 22 is screwed in, the thin lip portion 34 deforms more than the heel portion 32 and comes into pressure contact with the inward flange 12 and the annular groove 36. Since the deformation range of the lip portion 34 is relatively large, “variations” in the thread length of the tapered pipe thread 22 are absorbed by the deformation of the lip portion 34.

Since the heel portion 32 is thick, the heel portion 32
The entire seal 30 is positioned by being pressed against the end surface 16 of the tube 14. Furthermore, when fluid flows inside the joint 10 and the pipe 14 at a high flow rate, negative pressure may act on the heel portion 32, but since the heel portion 32 is positioned as described above, the heel portion 32 is There is no fear of it flying out.

In addition, the pressure of the internal fluid acts on the lip portion 34,
By pressing the lip portion 34 outward, the pressure contact of the lip portion 34 with the inward flange 12 and the annular groove 36 becomes more reliable.

Further, since the seal 30 is an integral part made of synthetic rubber, the structure of the seal 30 is simplified, and parts management and installation are simplified.

(Effects of the invention) As explained above, the pipe joint seal according to the present invention is a pipe joint seal that seals the connection between a pipe and a joint each having a male threaded portion and a female threaded portion that screw together. A thick, approximately cylindrical heel portion that presses against the edge, and a thin, approximately annular lip that presses against an annular wall that protrudes continuously from the female screw portion and whose cross-sectional shape is an arc that opens inward. Since the parts are integrally formed of an elastic material, the following effects can be achieved.

The thin lip portion 34 deforms in a larger deformation range than the heel portion 32 while being pressed against the inward flange 12 and the annular groove 36, and the “variations” in the thread length of the tapered pipe thread 22 can be absorbed by the deformation of the lip portion 34. can.

Since the heel portion 32 is thick, the heel portion 32
The entire seal 30 is positioned by being pressed against the end surface 16 of the tube 14, and even if the fitting 10,
Even when fluid flows inside the pipe 14 at a high flow rate and negative pressure acts on the heel portion 32, the heel portion 32 is positioned as described above, so the heel portion 32 will not fly out inward. can be prevented.

In addition, the pressure of the internal fluid acts on the lip portion 34,
The lip portion 34 is pressed outward, and the pressure contact of the lip portion 34 with the inward flange 12 and the annular groove 36 becomes more secure.

Further, since the seal 30 is an integral part made of synthetic rubber, the structure of the seal 30 is simplified, and parts management and installation can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional partial view showing the state of the pipe joint seal to which the present invention is applied before screw tightening, FIG. 2 is a vertical cross-sectional partial view showing the same after screw tightening, and FIG. FIG. 4 is a partial vertical cross-sectional view showing a conventional example. 10...Joint, 12...Inward flange, 14...Pipe, 22...Tapered thread for pipe, 30...Seal, 32...Heel part, 34...
...Rip section.

Claims (1)

[Scope of utility model registration request] A pipe fitting seal that seals the connection between a pipe and a fitting that each have a male threaded part and a female threaded part that screw together, and has a thick, approximately cylindrical heel part that presses against the edge of the male threaded part, and a female threaded part. A substantially annular lip portion that is thin-walled and presses against the continuously protruding annular wall, and whose axial cross-sectional shape is curved in an arcuate shape so as to open toward the center of the pipe or joint. A pipe joint seal characterized by being integrally formed from an elastic material.