JP2920331B2 - Pipe fittings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint.

[0002]

2. Description of the Related Art Conventionally, a pipe joint shown in FIG. 2 is known.

This pipe joint comprises a tubular joint member (1), two tightening sleeves (ferrules) (2) (3) and a nut (4).
Consisting of

An outward flange (1a) is formed on the outer periphery of an intermediate portion of the joint member (1), and screws (5)
(6) are formed respectively. Large diameter part (1b) with a slightly larger inner diameter than the left part on the inner periphery on the right end side of the joint member (1)
Is formed, and a tapered surface (1c) inclined rightward inward is formed on the inner periphery of the right end.

[0005] Inside the large diameter portion (1b) of the joint member (1), a pipe is provided.
(7) is inserted from the right side, and a first tightening sleeve (2) and a second tightening sleeve (3) are fitted in order from the left around a pipe (7) projecting rightward from the joint member (1).

The outer peripheral surface (2a) of the first sleeve (2) is a tapered surface slightly inclined leftward, and a taper surface (2b) inclined rightward inward is formed on the inner periphery of the right end. The left portion of the first sleeve (2) enters the inside of the tapered surface (1c) of the joint member (1), and the outer peripheral surface (2a) is in contact with the tapered surface (1c).

[0007] A tapered surface (3a) inclined leftward is formed on the outer periphery of the left end of the second sleeve (3). An outward flange (3b) is formed on the outer periphery of the right end of the second sleeve (3), and a taper surface (3c) inclined slightly outward is formed on the outer periphery of the right end. The left end tapered surface (3a) of the second sleeve (3) is connected to the right end tapered surface (2a) of the first sleeve (2).
touches b).

[0008] An inward flange is formed on the inner periphery of the right end of the nut (4).
(4a) is formed, and this flange (4a) is
It fits around the tube (7) just to the right of the sleeve (3), and inside the nut (4) on the left-hand side, the second sleeve (3), the first sleeve (2) and the right end of the coupling member (1). Side part is inserted.

The left side surface of the flange (4a) of the nut (4) is slightly inclined inward, and this surface is
(3) is in contact with the right end tapered surface (3c).

A female screw (8) is provided on the inner periphery on the left end side of the nut (4).
Is formed on the right side of the joint member (1).
(6) is screwed.

By tightening the nut (4), the two sleeves (2) and (3) are connected to the joint member (1) and the flange of the nut (4).
(4a), whereby the two sleeves (2) and (3) are tightened, and the pipe (7) is fixed to the joint member (1).

[0012]

In the above-mentioned pipe joint, the first tightening sleeve (2) is provided between the outer peripheral surface of the pipe (7) and the joint member (1).
Is pressed against the tapered surface (1c), and a seal is formed between the pipe (7) and the coupling member (1) at this portion. For this reason,
When the liquid flows through the pipe (7), the first sleeve (2) of the pipe (7)
Liquid or foreign matter enters a narrow gap between the more distal end portion and the large-diameter portion (1b) of the joint member (1), and remains in this gap.

By the way, in a general pipe, an inert gas is blown into the pipe to perform a cleaning operation in order to remove a liquid remaining in the pipe and the pipe joint. Liquid cannot be removed,
For this reason, when the liquid flowing in the pipe and the liquid remaining in the gap are mixed to lower the purity of the liquid flowing in the pipe, or when a very reactive liquid flows, the liquid flowing in the pipe and the liquid remaining in the gap remain. There is a problem that a reaction product may be generated by reacting with a liquid to be produced, which is not particularly suitable for piping requiring high cleanliness.

An object of the present invention is to solve the above problems,
It is an object of the present invention to provide a pipe joint that can prevent liquid and foreign matter from remaining.

[0015]

SUMMARY OF THE INVENTION A pipe joint according to the present invention includes a tubular joint member having a pipe inserted into a large diameter portion formed at one end thereof, and a pipe projecting from one end of the tubular joint member. An end face of a pipe inserted into a large-diameter portion of a tubular joint member is provided in a pipe joint including a fitted tightening sleeve and a bag-shaped nut for tightening the tightening sleeve to fix the tube to the tubular joint member. An annular gasket is sandwiched between the shoulder portion of the opposed tubular joint member and a portion between the large diameter portion and the shoulder portion of the joint member has an inner diameter smaller than the large diameter portion and a width smaller than the gasket width. An annular protrusion to prevent overtightening is formed, and the nut is tightly tightened.
Then, the end face of the pipe hits the annular projection of the joint member,
It is characterized in that the upper nut cannot be tightened .

[0016]

The gasket is clamped between the end face of the tube inserted into the tubular joint member and the shoulder of the tubular joint member facing the end of the tube. No liquid or foreign matter enters the narrow gap, and therefore no liquid or foreign matter remains in this gap. Further, a portion between the large diameter portion and the shoulder portion of the joint member, and a little inside diameter is smaller and the width than the large-diameter portion is smaller tightening preventing annular projection from the gasket width is formed, a nut
When tightened strongly, the end face of the pipe hits the annular projection of the joint member.
The nut can no longer be tightened.
Because it is, damage to the gasket by tightening of nuts can be prevented.

[0017]

An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 shows an enlarged view of a main part of the pipe joint, and the same parts as those in the conventional example of FIG. 2 are denoted by the same reference numerals.

In FIG. 1, the large diameter portion (1b) of the joint member (1)
End face of the pipe (7) inserted in
There is a gap between the right-handed shoulder (1d) of (1), and an annular gasket (9) is clamped between them, at which point the pipe (7) and the joint member (1) are joined. ). The inside diameters of the pipe (7) and the coupling member (1) are substantially equal, and the inside diameter of the gasket (9) is substantially equal to or slightly smaller than these inside diameters. The gasket 9 used in this example is a ring-shaped coil spring covered with a metal ring having a C-shaped cross section, but is not limited to this. At the portion between the left end of the large-diameter portion (1b) and the shoulder (1d) of the joint member (1), an annular protrusion (a little smaller in inner diameter than the large-diameter portion (1b)) for preventing overtightening ( 1e) is formed. This protrusion
The width in the left-right direction of (1e) is slightly smaller than the width (diameter) in the left-right direction of the gasket (9).

The other points are the same as those of the conventional example shown in FIG.

In the above-mentioned pipe joint, a gasket (9) is sandwiched between the end face of the pipe (7) and the shoulder (1d) of the joint member (1), and the inner diameter of the gasket (9) is 7) and joint members
Since it is almost equal to or slightly smaller than the inner diameter of (1),
No recess is formed between the (7) and the joint member (1) in which liquid or foreign matter enters and remains. Since the gasket (9) seals between the pipe (7) and the joint member (1), the outer peripheral surface of the outer pipe (7) and the large diameter of the tubular joint member (1) are formed. Liquids and foreign substances do not enter the narrow gap between the inner peripheral surface of the portion (1b) and remain. Also nut
Even if (4) is strongly tightened, the left end face of the pipe (7) is
And the nut (4) cannot be further tightened. And this allows the nut
The gasket (9) is prevented from being damaged due to excessive tightening of (4).

In the above embodiment, two tightening sleeves are used, but one tightening sleeve may be used.

[0023]

According to the pipe joint of the present invention, as described above, the gasket clamped between the end face of the pipe inserted into the tubular joint member and the shoulder of the tubular joint member facing the end face. This prevents liquid and foreign matter from entering and remaining in the narrow gap between the outer pipe and the tubular joint member. Therefore, the liquid flowing in the pipe and the liquid remaining in the pipe joint are not mixed to reduce the purity, and they do not react to produce a reaction product. it can. Moreover, the nut is too tight
Gasket damage due to
Secured.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a pipe joint according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a pipe joint showing a conventional example.

[Explanation of symbols]

 (1) Tubular joint member (1b) Large diameter part (1d) Shoulder part (2) (3) Tightening sleeve (4) Nut (7) Pipe (9) Gasket

Claims (1)

(57) [Claims] 1. A tubular joint member having a tube inserted into a large-diameter portion formed on one end side, a clamping sleeve fitted around a tube protruding from one end side of the tubular joint member, and a clamping sleeve. In a pipe joint provided with a bag-shaped nut for tightening and fixing a pipe to a tubular joint member, a pipe-shaped joint between an end face of a pipe inserted into a large-diameter portion of the tubular joint member and a shoulder portion of the tubular joint member opposed thereto. An annular gasket is pinched and stopped, and a portion between the large diameter portion and the shoulder portion of the joint member is formed with an annular protrusion for preventing overtightening whose inner diameter is smaller than the large diameter portion and whose width is smaller than the gasket width. Have been
When the pipe is strongly tightened, the end face of the pipe will
And the nut can no longer be tightened
A pipe joint characterized by being made .