JPH07109270B2 - Swivel 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 swivel joint for rotatably connecting a hose or the like to various devices.

[Background Art] Generally, a hose used for hydraulics and other pipes is provided with a connecting fitting at an end thereof, and the connecting fitting can be connected to a mating side through a joint. There is.

When the hose is unrotatable when the hose is connected to the other side through such a joint, the hose is twisted as the other side moves when the other side is a movable body. . Therefore, in such a case, a swivel joint that rotatably connects the hoses is used.

One of the conventionally used swivel joints is shown in FIG. As shown, this swivel joint 100 has a first sleeve 102 connected to the other side such as a hose or a device and a second sleeve 104 connected to the opposite side, and these are prevented from coming off in the axial direction. At the same time, a thrust bearing 106 is provided between them so that the first sleeve 102 and the second sleeve 104 can rotate relative to each other. That is, the hose can rotate freely.

[0005]

However, the swivel joint 100 with the built-in thrust bearing 106 has a complicated structure and is bulky, and since the thrust bearing 106 is very expensive, the cost is high as a whole. There are drawbacks.

Further, in the case of this joint 100, although the first sleeve 102 and the second sleeve 104 are rotatable relative to each other by the thrust bearing 106, the first sleeve 102 and the second sleeve 104 are increased as the pressure of the fluid inside increases. There is also a problem that the axial force acting between the two becomes large, and the frictional resistance between the two becomes large accordingly, and the rotational torque proportionally increases.

Therefore, the present inventor has devised a simple swivel joint which does not use such a thrust bearing, and has proposed it in the previous patent application (Japanese Patent Application No. Hei 2-212269).
FIG. 5 shows an example thereof.

In the figure, reference numeral 108 denotes a nipple fitting fixed to the end portion of the hose body. Here, the nipple fitting 108 constitutes a part of the swivel joint. A screw member 110 having a male screw is relatively rotatably fitted to the outer peripheral surface of the nipple fitting 108 on the tip side.

The nipple fitting 108 is provided with a large diameter portion 112, and correspondingly, a recess 114 is formed on the inner surface side of the screw member 110.

The nipple fitting 108 and the screw member 11
O-rings 116 and 118 are attached to the fitting surface with 0 at two positions that are separated by a predetermined distance in the axial direction, and a pressure chamber 120 is defined between them.

A communication hole 122 is formed so as to communicate with the pressure chamber 120 so as to penetrate the nipple fitting 108 in the radial direction, and the pressure of the fluid inside the nipple fitting 108 is guided to the pressure chamber 120. ing.

As shown in the enlarged view of FIG. 6, on the outer peripheral surface of the nipple fitting 108 and the inner peripheral surface of the screw member 110, the pressure receiving surfaces 124 are provided so as to project into the pressure chamber 120.
Numeral 126 is formed, and these pressure receiving surfaces are affected by the pressure in the pressure chamber 120.

In the case of the swivel joint of this example, the pressure chamber 12
0 and the presence of the pressure receiving surfaces 124 and 126, the portion of d ₂ -d ₁ at the tip of the nipple fitting 108 (d ₁ is the nipple fitting 1
08, the diameter of the main body portion, d ₂ is the large diameter portion 11 at the tip
2), that is, the axial force acting on the nipple fitting 108 in the right direction (drawing direction) in the figure, the pressure receiving surface 12
The pressure (reaction force) acting on No. 4 can be canceled, and thus the axial force acting on the nipple fitting 108 can be reduced, and the relative rotational torque between the nipple fitting 108 and the screw member 110 can be reduced.

However, in the case of the swivel joint having this structure, when the area of the pressure receiving surface 124 is increased to obtain a large reaction force, the axial force acting on the tip surface of the nipple metal fitting 108 is inevitably increased (d ₂ The axial force and the reaction force acting in the −d ₁ portion always cancel each other out), and it was still insufficient for further lowering the relative rotational torque between the nipple fitting 108 and the screw member 110.

[0015]

The swivel joint of the present invention has been devised to solve such a problem, and its gist is (a) a tubular first member and (b) A tubular second member externally fitted to the tip side of the first member so as to be relatively rotatable, and (c) is mounted on the fitting surface of the first member and the second member at a position separated by a predetermined distance in the axial direction. A pressure chamber defined by a seal member, (d) a communication hole for guiding the fluid pressure inside the first member into the pressure chamber, and (e) the pressure from the main body of the first member and the second member. A pressure receiving surface that rises so as to protrude into the chamber, receives the action of the pressure in the pressure chamber in opposite directions, and generates a force in a direction that cancels the axial force in the drawing direction that acts on the first member by the fluid pressure, F)
A third seal member mounted on the fitting surface between the first member and the second member has a shutoff chamber defined on the tip side of the first member with respect to the pressure chamber.

[Operation and Effect of the Invention] In the present invention, the pressure receiving surface which rises in the pressure chamber is made large by the shut-off chamber formed on the tip side of the first member with respect to the pressure chamber, and accordingly the pressure is received. It is possible to take a large reaction force received on the surface. That is, it is possible to increase or decrease only the reaction force regardless of the axial force in the pulling direction that acts between the first member and the second member. It is possible to make the axial force acting between the first member and the second member due to the pressure equal to the reaction force in the direction of canceling the axial force, and to significantly reduce the rotational torque between the first member and the second member. it can.

Further, in the swivel joint of this structure, the magnitude of the reaction force increases in proportion to the increase of the fluid pressure, and therefore, unlike the above-mentioned swivel joint having the thrust bearing, regardless of the increase of the fluid pressure. Therefore, the rotational torque can be constantly suppressed to be extremely small, and the problem that the rotational torque increases due to the increase in pressure can be avoided.

Further, the swivel joint of the present invention does not need to incorporate an expensive thrust bearing, so that the structure is simple and, in particular, the cost can be remarkably reduced.

[0019]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a swivel joint which is an embodiment of the present invention, in which 10 is a cylindrical first member having a male screw 11 on the rear end (right end in the drawing) side, and its tip side. The cylindrical second member 12 is fitted to the outer peripheral surface of the so as to be relatively rotatable. The second member 12 comprises a female screw tube 14 and a cap nut 16 having an inwardly facing flange 15.

The female screw tube 14 has a female screw 18 on the inner peripheral surface on one end side and a male screw 20 on the outer peripheral surface on the other end side. The female screw 2 of the cap nut 16 is opposed to the male screw 20.
2 are screwed together. The female screw tube 14 and the cap nut 16 are liquid-tightly coupled via an O-ring 24.

A small-diameter portion 28 having an outer diameter smaller than that of the main body portion 26 is formed on the front end side of the first member 10, and a large-diameter portion 30 having a large outer diameter is formed adjacent to the small-diameter portion 28. The large-diameter portion 30 enters into the corresponding large-diameter annular recess 32 of the second member 12.

The axial rear surface of the large diameter portion 30 and the inward flange 15 front surface of the second member 12 are
The pressure receiving surfaces 34 and 36 are formed to rise radially outward and inward, respectively. These pressure receiving surfaces 34, 36
Also serves as an engagement surface for preventing the first member 10 and the second member 12 from coming off.

The outer peripheral surface of the large diameter portion 30 and the flange 1
An annular groove is formed on the inner peripheral surface of the ring 5, and O-rings 38 and 40 are attached to the annular groove, and a pressure chamber 42 is defined between the O-rings 38 and 40. A communication hole 44 is provided so as to penetrate the first member 10 in the radial direction so as to communicate with the pressure chamber 42, and the pressure of the fluid inside the first member 10 is guided to the pressure chamber 42. .

On the other hand, on the inner peripheral surface of the female screw tube 14 of the second member 12, an annular groove is formed at a portion corresponding to the small diameter portion 28 of the first member 10, and an O ring 46 is attached to this annular groove. A blocking chamber 48 is formed between the ring 46 and the O-ring 38. As shown in the figure, the shut-off chamber 48 is liquid-tightly sealed at both axial ends by a pair of O-rings 38 and 46, and the fluid pressure is not guided to this portion.

In the swivel joint of this embodiment, when the fluid is introduced into the first member 10, the pressure of the fluid acts on the tip surface of the first member 10 as shown by the arrow A in FIG. Is applied from the second member 12 to the right in the drawing.

On the other hand, the pressure of the fluid inside the first member 10 is also introduced into the pressure chamber 42 through the communication hole 44, and the pressure chamber 4
The pressure inside 2 acts on the pressure receiving surface 34 of the large diameter portion 30 of the first member 10 as shown by the arrow B. That is, in this pressure chamber 42, a reaction force in a direction of canceling the axial force acts.

In the swivel joint of this example, the presence of the shutoff chamber 48 reduces the area of the tip surface of the first member 10 to reduce the axial force acting on the first member 10 in the right direction in the drawing. It is possible to take. In addition to this, the presence of the shut-off chamber 48 also allows the reaction force shown by the arrow B to be independently and freely controlled by appropriately selecting the area of the pressure receiving surface 34, and the magnitude of the reaction force. The size can be set so as to completely cancel the axial force acting on the first member 10.

In this case, the first member 10 and the second member 12
The relative rotation torque between them is only the circumferential resistance due to the O-ring, and even when a high fluid pressure is introduced into the first member 10, the first member 10 and the second member 12 are relatively rotated relatively. be able to.

Incidentally, FIG. 3 shows the required rotational torque of the swivel joint having the structure of this embodiment in relation to the magnitude of the pressure introduced into the first member 10. However, (C) in the figure shows the measured value of the swivel joint of this example,
(A) shows the measured values of the above swivel joint with built-in thrust bearings, and (B) shows the measured values of the pressure swivel joint and the simple swivel joint having no communication hole as in the above example.

As is apparent from FIG. 3, the swivel joint having the structure of this example exhibits almost the same characteristics as the swivel joint having the thrust bearing built therein.

Moreover, in the case of the swivel joint of this example, it is not necessary to incorporate a thrust bearing, so that the structure is extremely simple and the price is remarkably low. By the way, in the case of the swivel joint of this example, the price is about one-fifth as compared with the one having the built-in thrust bearing.

Further, in the case of a swivel joint having a built-in thrust bearing, if the fluid pressure becomes higher, the axial force will increase accordingly and the required rotational torque will also increase. However, in the case of the swivel joint of this example, the rotational torque is Since it is not affected by the fluid pressure, it has a feature that a constant low rotational torque can be maintained even if the fluid pressure increases.

Although the embodiment of the present invention has been described in detail above, this is merely an example. For example, in the above example, the pressure receiving surface that receives the pressure in the pressure chamber and generates a reaction force also serves as the engagement surface for retaining the first member and the second member, but such an engagement surface is separately provided. It is also possible to form it, and it is also possible to use the first member or the second member so as to also serve as the connecting fitting or the mating member at the end of the hose.

Further, the present invention can be used as a joint for a pipe body other than a hose, and can be constructed in variously modified forms based on the knowledge of those skilled in the art without departing from the spirit of the invention. .

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a swivel joint which is an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the swivel joint.

FIG. 3 is a diagram showing measured values of required rotational torque of the swivel joint in comparison with other swivel joints.

FIG. 4 is a sectional view showing an example of a conventional swivel joint.

FIG. 5 is a diagram showing an example of a swivel joint according to a prior application of the present application.

6 is an enlarged cross-sectional view of a main part of the swivel joint of FIG.

[Explanation of symbols]

 10 1st member 12 2nd member 34,36 Pressure receiving surface 38,40,46 O ring 42 Pressure chamber 44 Communication hole 48 Blocking chamber

Claims (1)

[Claims] 1. (a) a tubular first member; and (b) a tubular second member fitted on the tip side of the first member so as to be relatively rotatable.
(C) A pressure chamber defined by a seal member mounted on the fitting surface between the first member and the second member at positions separated by a predetermined distance in the axial direction, and (d) a fluid inside the first member. A communication hole for guiding the pressure into the pressure chamber, and (e) rising so as to project into the pressure chamber from the main body of the first member and the second member, and receiving the action of the pressure in the pressure chamber in mutually opposite directions, A pressure receiving surface for generating a force in a direction for canceling the axial force in the pulling direction that acts on the first member by the fluid pressure, and (f) a third surface mounted on the fitting surface between the first member and the second member. A shut-off chamber defined by a seal member on the tip side of the first member with respect to the pressure chamber, and a swivel joint.