JPH0828769A - Structure of tube joint - Google Patents

Abstract

PURPOSE:To prevent fall-off of a hose, leak of liquid, or rupture of the hose in a tube joint with which the hose is engaged. CONSTITUTION:A seal part 2 comprising a protruded part and a groove part 8 is formed on the tip side, a lock part 3 provided with a stopper 7D is formed on the base side, a hose 1 is fitted on outer circumferences of the seal part 2 and the lock part 3, the outer circumference of the seal part 2 is locked by a leak-preventive band 5, and the outer circumference of the seal part 2 is stopped by a fall-off preventive band 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint structure in which a hose is fitted and the outer periphery of the hose is fastened with a band to prevent the hose from coming off.

[0002]

2. Description of the Related Art When connecting a hose made of an elastic material to a metal pipe, the hose is connected via a pipe joint. However, a conventionally known pipe joint prevents the hose from coming off, and the inner peripheral surface of the hose and the pipe joint. It is devised so that fluid does not leak through the gap between the joint and the outer peripheral surface.

As a means for preventing such a hose from coming off and leaking fluid, it is generally known to form a concavo-convex line on the outer periphery of a pipe joint and tighten the outer periphery of the hose with a band.

This will be explained with reference to the drawings. As shown in FIG. 3, a fitting portion 112 consisting of a circumferential convex portion 111 and a groove portion 115 is formed on the outer periphery of the pipe joint 110 in the joint length direction. It is known that a hose 113 is fitted in the fitting portion 112 and the outer periphery thereof is tightened by a band 114. Here, the function of the convex portion 111 and the groove portion 115 is to reduce the leakage of fluid by the labyrinth effect of the convex portion 111 and the groove portion 115. Further, the band 114 prevents the hose 113 from coming off.

However, according to the structure of the pipe joint shown in FIG. 3, there is no obstacle to the sliding of the band 114 in the pull-out direction, so that there is a problem that the hose 111 is easily pulled out by the force in the arrow P direction. It was Further, since the sliding resistance of the hose 113 in the pull-out direction (the direction of arrow P) is determined by the contact area between the inner peripheral surface of the hose 113 and the outer peripheral surface of the convex portion 111, the contact area of the known art shown in FIG. There is a problem that the hose 113 is relatively easy to pull out in this respect as well.

In order to improve such a drawback, the present inventor proposed (patent application) a pipe joint as shown in FIG. With reference to FIG. 4, along the outer periphery of the tip portion of the pipe joint 100, a stopper 101 having a wedge-shaped cross section that gently inclines upward from the tip to the root side and then reduces in diameter at a steep angle.
Are formed. The band 103 fastens the hose 102 on the root side of the stopper 101. Stopper 1
01 is for preventing the hose 102 from coming off from the pipe joint 100. That is, the force in the direction of arrow P in the figure acts on the hose 102 by the pressure fluid flowing through the hose 102, but the band 103 causes the stopper 1 to move.
01 hinders the sliding, and as a result, the hose 102 is prevented from coming off.

[0007]

However, according to the structure of the pipe joint shown in FIG. 4, a large force is exerted on the hose 102 in the direction of the arrow P in the portion 102A of the hose 102 which hits the edge 101A of the stopper 101. Load is applied. Further, since the pressure of the fluid directly acts on the location 102A, this also acts as a large load on the location 102A. As a result, two large loads act on the point 102A of the hose 102 by superposition, and the point 102A easily breaks, and there is a risk of fluid leakage from the point.

Further, since the outer surface of the pipe joint 100 is a flat surface, there is no labyrinth effect, and as a result, fluid may leak along the inner peripheral surface of the hose 102.

Therefore, an object of the present invention is to provide a structure of a pipe joint that improves the above-mentioned drawbacks and prevents the hose from coming off, the liquid from leaking, and the hose from breaking as much as possible.

[0010]

The pipe joint of the present invention has the following structure. A sealing portion composed of a plurality of convex portions and a groove portion along the joint length direction is formed on the tip side, and a locking portion formed in a cylindrical shape with an outer diameter smaller than the outer diameter of the convex portion of the sealing portion is provided. A pipe joint formed on the base side, a hose made of a flexible material fitted to the outer circumferences of the sealing portion and the locking portion, and mounted on the outer circumference of the sealing portion of the fitted hose 1
It comprises the above-mentioned leak-proof band and one or more slip-off prevention bands attached to the outer periphery of the locking portion of the hose.

[0011]

The locking portion prevents the hose from coming off, and the sealing portion prevents leakage from the inner peripheral surface of the hose.
Further, the force resulting from the superposition of both the load due to the pressure of the fluid and the load due to the sandwiching does not act on the hose, so that the hose is prevented from breaking.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows the structure of a pipe joint according to an embodiment of the present invention. Referring to the drawings, the hose 1 and the sealing portion 2
Of the hose 1 and the leak-preventing band 5 attached to the outer periphery of the sealing part 2 of the hose 1 fitted to the hose 1. A retaining band 6 attached to the outer periphery is provided.

The pipe joint 4 is made of a rigid material such as metal. Further, the sealing portion 2 is formed on the outer periphery of the pipe joint 4 on the tip end side from a plurality of convex portions 7A to 7D and a groove portion 8 along the joint length direction. Further, the locking portion 3 is formed in a cylindrical shape on the base side of the sealing portion 2 with an outer diameter smaller than the outer diameter of the convex portions 7A to 7D of the sealing portion 2. The reason why the sealing portion 2 is formed of a plurality of convex portions 7 is that by capturing the liquid in the groove 8 between the convex portions 7A to 7D, the liquid flowing along the inner peripheral surface of the hose 1 is exposed to the outside. It is intended to prevent leakage to the. (Labyrinth effect)

Although the sealing portion 2 of this embodiment has four convex portions, the number is not limited to this and may be two or more. Further, the convex portion 7A located closest to the tip end side is formed in a tapered shape so that the hose 1 can be easily fitted thereto. Even if a tensile force acts on the hose 1 in the direction of arrow P by the pressure fluid flowing through the hose 1, the convex portions 7A to 7A of the sealing portion 2
The convex portion 7D located closest to the root of the 7D is the hose 1
It functions as a stopper that obstructs sliding in the pulling direction. It should be noted that the present invention includes a structure in which a separate stopper structure is provided instead of the convex portion 7D.

The pipe joint 4 of the present embodiment is formed such that its root portion has an enlarged diameter, and a female screw 9 is formed on the inner peripheral surface of the base so that it can be connected to a pipe portion having a male screw (not shown). Has been done. However, an external thread may be formed on the outer circumference of the pipe joint 4, and in addition, an appropriate joint means such as a flange may be provided. Also, the leak-proof band 5,
The retaining band 6 tightens the hose 1 from the circumferential direction, and any structure may be selected. The hose 1 is made of a flexible material such as rubber or soft resin, and is commonly used.

According to the above-mentioned structure of the pipe joint, the hose is prevented from coming off, the liquid is leaked, and the hose is prevented from breaking as follows.

That is, a force acts on the hose 1 in the direction of arrow P by the pressure liquid flowing through the hose 1. However, sliding of the retaining band 6 is hindered by the convex portion 7D located closest to the root side, so that the hose 1 is prevented from coming off.

The labyrinth effect of the convex portion 7 and the groove portion 8 formed in the sealing portion 2 prevents fluid leakage.

Since the pressure of the fluid acting on the most proximal projection 7D functioning as a stopper gradually decreases through the sealing portion 2, the hose 1 and the most proximal projection 7D are reduced. The load acting between and is only the load due to the sandwiching, which is reduced compared with the load superimposed with the fluid pressure. For this reason, breakage of the hose 1 at the location is prevented.

The present invention is not limited to the above-mentioned embodiment, but various modifications can be implemented. For example, in the above-described embodiment, the number of the leakproof bands 5 and the number of the retaining bands 6 provided in each of the sealing portion 2 and the locking portion 3 are not limited to this, but one or two each. That's all.

Further, in the above-described embodiment, the sealing portion 2 has a rectangular convex shape, but it is not limited to this. For example, the pipe joint shown in FIG.
A to 7C are formed in a wedge-shaped cross-section that gradually inclines upward from the tip to the root side and then rounds and suddenly reduces in diameter. According to this, the hose can be easily fitted.

[0022]

The structure of the pipe joint of the present invention described above has the following effects. First, the stopper provided with the stopper reliably prevents the hose from coming off. Next, the leaking of the fluid is surely prevented by the sealing portion including the convex portion and the groove portion. Since the load acting on the hose is completely separated into that due to the pinching and that due to the pressure of the fluid, the load is reduced as compared with the polymerized one, and the hose is prevented from breaking.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the structure of a pipe joint of the present invention.

FIG. 2 is a vertical sectional view showing another embodiment of the structure of the pipe joint of the present invention.

FIG. 3 is a vertical cross-sectional view showing an example of the structure of a conventional pipe joint, in which a stopper is formed.

FIG. 4 is a vertical cross-sectional view showing another example of the structure of a conventional pipe joint in which a step portion is formed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hose 2 Sealing part 3 Locking part 4 Pipe joint 5 Leak-prevention band 6 Retaining band 7A to 7D Convex part 8 Groove 9 Female screw

Claims (3)

[Claims] 1. A sealing portion comprising a plurality of convex portions and a groove portion along the joint length direction is formed on the tip side, and is formed in a cylindrical shape with an outer diameter smaller than the outer diameter of the convex portion of the sealing portion. A structure of a pipe joint, characterized in that a locking portion provided with a stopper is formed on the base side. 2. A sealing portion comprising a plurality of convex portions and a groove portion along the joint length direction is formed on the tip side, and is formed in a cylindrical shape with an outer diameter smaller than the outer diameter of the convex portion of the sealing portion. A pipe joint in which a locking portion provided with a stopper is formed on the base side, a hose made of a flexible material fitted to the outer periphery of the sealing portion and the locking portion, and a sealing portion of the fitted hose A structure of a pipe joint, comprising: one or more leakproof bands attached to the outer circumference of the hose; and one or more retaining bands fitted to the outer circumference of the fitting part of the fitted hose. 3. The structure of the pipe joint according to claim 1, wherein the stopper is also used as a convex portion.