JPH03229091A - Hose swivel joint - Google Patents

Abstract

PURPOSE:To use a connection fitting as a connecting joint by fitting a tubular thread member in a sleeve being clamped to a hose body, attaching an O-ring to it, forming a radial pressure receiving surface, deriving pressure with a through hole in the sleeve and generating an axial reaction there. CONSTITUTION:A nipple fitting 10 is fitted in a hose body 14 and locked to a socket fitting 16. A thread member 18 with an external thread part 20 is fitted at the other end of the nipple fitting 10. A large diametral part 26 is formed in an end of the nipple fitting 10, and radial outward pressure receiving surfaces 30, 32 are installed in the terminal. A ring groove 34 with an O-ring 40 is installed in the thread part 18 too. The nipple fitting 10 has a through hole 42 through which pressure in the inner part of a fluid 44 is derived. In consequence, drawing axial tension is made so as to be negated by an action working on the pressure receiving surface.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a swivel joint for rotatably connecting a hose to various devices.

(Prior Art) A hose used for hydraulic or other piping generally has a connecting fitting attached to its end, and this connecting fitting can be connected to a counterpart via a joint. The connection between the hose connection fitting and the JllI handle is usually a screw connection.

By the way, when the hose is connected to the other party through such a joint, if the hose is not rotatable, the hose becomes twisted as the other party moves when the other party is a movable body. Therefore, in such cases, a swivel joint is used to rotatably connect the hose.

One of the conventionally used swivel joints is the one shown in FIG. A second sleeve 104 is connected to the opposite side, and is prevented from being pulled out in the axial direction. A thrust bearing 106 is interposed between them, and the first sleeve 102 and the second sleeve 104 are prevented from relative rotation. It is now possible to do so. That is, the hose can rotate freely.

(Problems to be Solved by the Invention) However, this joint 100 with a built-in bearing 106 has problems such as being complicated in structure, bulky, and expensive.

Therefore, the present inventor devised a simple swivel joint that does not use such a bearing, and filed the previous patent application (Japanese Patent Application No.
No. 272374). FIG. 4 shows an example of this. In FIG. 0, reference numeral 108 is a knee/pull fitting inserted and fixed to one end of the hose body 109, and together with a socket fitting 110, constitutes a hose connection fitting.

A cylindrical screw member 112 is fitted onto the other end of the nipple J4] 08 so as to be relatively rotatable, and an O-ring 114 is attached to the fitting surfaces thereof to seal the fitting surfaces. ing.

The outer peripheral surface of these nipple fittings 108 and the screw member 112
The inner circumferential surface of is formed in a step-like manner at corresponding portions, and engagements 116 and 11B are formed therein in the outward and inward directions in the radial direction, and the engagement surfaces 116 and 118 engage in the axial direction. It is now possible to That is, those engaging surfaces 116
, 118 prevents the nipple fitting 108 and the screw member 112 from coming off in the opposite direction.

Note that 120 is a locking ring that prevents relative movement of the screw member 112 in the right direction in the figure.

The swivel joint 122 of this example allows the hose connection fitting to be used as a joint for connecting to the other party, and unlike conventional joints with built-in bearings, the structure is simple and the cost is low. 4 various advantages.

(Problem to be Solved by the Invention) However, in this swivel joint 122, an axial force acts due to internal pressure under the state T1 in which the retaining surfaces 116 and 118 are engaged with each other, and this causes the retaining surfaces 116 and 118 to be It was found that there was a problem in that a large frictional force was generated between the mating surfaces 116 and 118, making it impossible for the wedge member 112 to smoothly rotate relative to each other, and therefore, when the hose was twisted, it was difficult to untwist it sufficiently smoothly. .

(Means for Solving the Problems) The present invention has been made to solve the above problems, and its gist is to provide a sleeve that is attached directly to the hose body or fixed to the hose body through a separate connection. A tubular screw member is fitted onto the outside so as to be relatively rotatable, and a pair of O-rings are attached to their fitting surfaces at a predetermined distance in the axial direction to seal the fitting surfaces. radially outward and inward pressure receiving surfaces are formed at corresponding portions of the outer circumferential surface of the sleeve and the inner circumferential surface of the threaded member, and a radial through hole is formed in the sleeve to form internal pressure receiving surfaces. The present invention is characterized in that the pressure is derived and the pressure is applied to the pair of pressure receiving surfaces to generate a reaction force in the axial direction.

(Operations and Effects of the Invention) As described above, the present invention is capable of making the fitting surface between the outer peripheral surface of the sleeve and the inner peripheral surface of the screw member O
The seal is sealed by a ring, and the internal pressure is guided between the O-rings through a through hole provided in the sleeve, and is applied to the outward and inward pressure-receiving surfaces formed on the sleeve and screw member, respectively. It is.

In this way, a reaction force acts between the pressure receiving surfaces due to the pressure, and this reaction force acts to cancel the axial force in the pulling direction acting on the sleeve and the screw member. Since the canceling force increases in proportion to the area of the pressure-receiving surface, by appropriately selecting the pressure-receiving area, it is possible to completely eliminate the axial force in the pulling direction on the sleeve and screw member. In this way, even when high pressure is introduced into the inside of the hose, the sleeve and threaded member can freely rotate relative to each other, and therefore, even if a torsional force is applied to the hose, it can easily return to its original state. .

The retaining surface for preventing the sleeve and the screw member from coming off may be provided separately from the pressure-receiving surface, or may be made to serve both as the pressure-receiving surface and the retaining surface. Depending on the case, it is also possible to omit such a retaining surface.

(Example) Next, embodiments of the present invention will be described in detail based on the drawings.

In FIGS. 1 and 2, reference numeral 10 denotes a nipple fitting that constitutes a part of the connection fitting of the hose 12, and the socket fitting 10 is inserted into the inside of the hose body 14 on one end side.
It is caulked and fixed together with 6.

A cylindrical screw member 18 is fitted onto the other end of the nipple fitting IO. The screw member 18 is provided with a male threaded portion 20, and this male threaded portion 20 is screwed into a female threaded hole 24 on the mating member 22 side.

A large diameter portion 26 having a larger outer diameter than the main body portion is formed at the end of the pull fitting 10, while the screw member 18 has a large diameter portion 26 formed therein.
A recess 28 of a corresponding diameter is formed, and a radially outwardly or inwardly facing pressure surface 30,32 is formed at each end.

An annular groove 34 is provided on the outer peripheral surface of the large diameter portion 26,
An O-ring 36 is attached there.

Also, at a position a predetermined distance apart in the axial direction, the screw member 1
An annular ring 11 is provided on the inner peripheral surface of the ring 8, and a second O-ring 40 is attached thereto. That is, the fitting surfaces of the outer circumferential surface of the nipple fitting lO and the inner circumferential surface of the screw member 18 are sealed by O-rings 36 and 40 at two locations separated by a predetermined distance in the axial direction.

A radial through hole 42 is formed in the nipple fitting 10 between the pair of O-rings 36, 40,
A portion of the pressure of the internal fluid 44 led to the fitting surface acts on each pressure receiving surface 30, 32.

In these figures, 46 is a locking ring for preventing relative movement of the spring member 14 in the right direction in the figures.

In the case of the swivel joint f of this example, when the pressure of the fluid is introduced into the inside of the hose 12, the pressure is P, the area of the tip surface A of the nipple fitting 10 is SA, and the area of the rear end surface B entering the inside of the hose body 14 is 58, a force of (SA-5s)P acts on the nipple fitting lO in the right direction in the figure.

On the other hand, since the pressure of this fluid also reaches the engaging and pressure-receiving surfaces 30° and 32, reaction forces in opposite directions are generated on these engaging surfaces. The magnitude of the reaction force is determined by the area of the pressure receiving surface 30, Sc
ScP. Therefore, a force equal to the magnitude obtained by subtracting ScP from L (S^-3B)P acts on the nipple fitting 10 in the right direction in the figure. Therefore, the pressure receiving surface 30
By increasing the pressure receiving area of the nipple fitting 10
The rightward pushing force (axial force) acting on the shaft can be offset by the reaction force.

If this axial force in the extrusion direction can be offset, the nipple fitting l
O and the threaded member 18 can freely rotate, and even if the hose 12 is twisted, it can easily return to its original state.

In the above embodiment, a part of the connecting fitting of the hose 12 is used as it is as a swivel joint, which is desirable because it has a simple and inexpensive structure, but in some cases, a swivel fitting can be used separately from the hose connecting fitting. It is also possible to configure This pond bed invention can be constructed with various modifications based on the knowledge of the manufacturer without departing from the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a swivel joint according to an embodiment of the present invention together with a hose end, and FIG. 2 is an enlarged sectional view of the main part of FIG. 1. FIG. 3 is a sectional view of a conventionally used swivel joint, and FIG. 4 is a sectional view showing an example of a swivel joint according to an earlier application of the present application. lO/Nipple fitting 14: Hose body 18: Screw member 30, 32: Pressure receiving surface 36.40: O ring 42: Through hole...''

Claims (1)

[Claims] A tubular threaded member is fitted onto a sleeve that is fixed to the hose body directly or via a separate connector so as to be relatively rotatable, and a pair of O-rings are attached to their fitting surfaces at a predetermined distance in the axial direction. At the same time, the O-rings are installed to seal the fitting surface, and radially outward and inward pressure receiving surfaces are respectively formed at corresponding portions of the outer circumferential surface of the sleeve and the inner circumferential surface of the threaded member between the O-rings. On the other hand, a radial through hole is formed in the sleeve to draw out internal pressure, and the pressure is applied to the pair of pressure receiving surfaces to generate an axial reaction force. Hose swivel fitting.