JP3325086B2 - Hose fittings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a hose joint attached to an end of a hose.

[0002]

2. Description of the Related Art A conventional hose joint is shown in FIG. A cylindrical nipple 3 is inserted into the end of the hose 1. A groove 5 is formed in the outer periphery of the nipple 3, and a seal packing 7 is fitted in the groove 5 to elastically support the inner peripheral surface of the hose 1. An expansion / contraction sleeve 9 is located on the outer peripheral side of the hose 1. The expansion / contraction sleeve 9 is provided with a plurality of slits 1 in the axial direction.
1 is formed so that the diameter can be greatly enlarged and reduced. A flange 13 is provided on the outer periphery of the base of the nipple 3, and a male screw 1 formed at the tip of the flange 13 is provided.
5, the female screw 19 of the cylindrical nut 17 is screw-connected. By this screw connection, the cylindrical nut 17 moves forward and backward. The inner peripheral surface of the cylindrical nut 17 is tapered, and presses the expansion / contraction sleeve 9 with the retraction to reduce the diameter of the expansion / contraction sleeve 9.

As described above, in a conventional hose joint,
Insert the nipple 3 into the end of the hose 1
Is rotated and retracted with a screw, the cylindrical nut 1
The tapered inner peripheral surface of 7 presses the expansion / contraction sleeve 9, which reduces the diameter and clamps the hose 1. The seal packing 7 elastically receives the hose 1,
The clamped state is maintained by the action of a spring. That is, in the clamped state, the hose 1 always receives the compressive stress, and the deformation increases with time due to the compressive stress, so that the stress is relaxed (creep phenomenon). Therefore, by providing the seal packing 7 having elasticity, the clamped state can be maintained by the elastic force of the seal packing 7 even when the stress is reduced in the hose 1.

[0004]

However, in the above-mentioned prior art, since the seal packing 7 is provided, the groove 5 has to be formed on the outer periphery of the nipple 3. For this reason, the nipple 3 cannot be removed from the molding die when the nipple 3 is molded with the resin, and the parting of the nipple 3 must be divided into a plurality of parts. . In addition, a convex part due to the parting was generated, and there was a possibility that water leakage occurred due to the convex part. Further, the displacement caused by the reduction in the diameter of the expansion / contraction sleeve 9 becomes large because the amount of distortion of the seal packing 7 as well as the amount of distortion of the hose 1 is added. For this reason, the expansion / contraction sleeve 9
Must be able to expand and contract greatly, so that many slits 11 were required. As described above, since a large number of slits 11 and the like need to be processed, the expansion / contraction sleeve 9 is difficult to be integrated with the nipple 3. The outer diameters of the nipple 3 and the seal packing 7 were constant in the axial direction. For this reason, the expansion / contraction sleeve 9
When the diameter decreases in order from the distal end of the expansion / contraction sleeve 9 due to the reduction of the diameter, the distal end strongly presses the hose 1 and clamps it. As a result, stress concentration occurs in a portion that is strongly pressed, and the stress relaxation is further promoted. An object of the present invention is to allow a nipple portion to be removed from a molding die at a time during molding, and to eliminate parting, thereby eliminating a convex portion. An object of the present invention is to provide a hose joint capable of suppressing stress relaxation without causing stress concentration.

[0005]

In order to achieve the above object, the invention according to claim 1 comprises a cylindrical nipple to be inserted into a hose, a hose having a reduced diameter located on the outer peripheral side of the hose. A hose joint comprising: an expansion / contraction sleeve that can be clamped; and a cylindrical nut that retreats with a screw formed on the outer periphery of a base of the nipple and presses the expansion / contraction sleeve on a tapered inner peripheral surface to reduce the diameter. A separate pressing sleeve forming a tapered circumferential surface of the cylindrical nut; and an elastic body provided on the inner circumferential surface of the cylindrical nut and pressing the pressing sleeve in an axial direction when the cylinder nut is retracted. And The invention according to claim 2 is characterized in that the outer peripheral surface of the nipple is provided with a taper angle, and the taper angle is substantially the same as the taper angle of the inner circumference when the diameter of the expansion / contraction sleeve is reduced.

[0006]

According to the first aspect, the pressing sleeve is pressed in the axial direction.
Since it has an elastic body, the cylindrical nut is retracted
When this occurs, the elastic body retains the elastic force. And
This elastic force, via the pressing sleeve and the expansion sleeve,
Acts on the hose as a clamping force. Therefore, for a long time
Even if the hose itself loses its elastic force due to
When the elastic force acts as a tightening force and suppresses stress relaxation,
In addition, the clamp state can always be maintained. further,
The elastic body is distorted by receiving force only in the axial direction.
When considering the displacement due to the decrease in the diameter of the leave, the elastic body
It is not necessary to consider the amount of distortion. In other words, the expansion / contraction sleeve
The displacement accompanying the diameter reduction is only the amount of strain of the hose. No.
In the invention of the second aspect, the outer peripheral surface of the nipple is provided with a taper angle.
The compression sleeve expands and contracts from the tip
The hose is the inner peripheral surface of the expansion / contraction sleeve and the outer peripheral surface of the nipple.
And clamped by

[0007]

An embodiment of the present invention will be described below with reference to FIG. The same parts as those in FIG. 2 of the conventional example are denoted by the same reference numerals. The inner peripheral surface 21 of the cylindrical nut 17 is a perfect cylinder, and a flange 23 is formed at the tip of the inner peripheral surface 21 toward the inside. The rubber flat packing as the elastic body 25 is axially supported by the flange 23. A pressing sleeve 27 is provided adjacent to the elastic body 25 and axially rearward. The pressing sleeve 27 has a tapered inner peripheral surface, and is pushed rearward in the axial direction via the elastic body 25 when the cylindrical nut 17 is retracted. The expansion / contraction sleeve 9 is located inside the pressing sleeve 27.
This expansion / contraction sleeve 9 can be reduced in the number of slits 11 unlike the conventional example. The amount of reduction as described below,
That is, since the displacement inward in the radial direction is small, the number of slits can be reduced. The base 29 of the expansion / contraction sleeve 9 is integrated with the nipple 3. When the inner peripheral surface of the expansion / contraction sleeve 9 is pressed by the pressing sleeve 27, the diameter of the distal end side becomes smaller, and the nipple 3 is provided with the taper angle φ on the outer peripheral surface in advance.

The operation of this embodiment will be described below. When the cylindrical nut 17 is rotated as in the prior art, the cylindrical nut 1 is rotated.
Reference numeral 7 retreats axially rearward (leftward in the figure). Due to this retreat, the elastic body 25 pressed by the flange 23 of the cylindrical nut 17 pushes the separate pressing sleeve 27 rearward in the axial direction.
Thus, the pressing sleeve 27 presses the expansion / contraction sleeve 9 radially inward by the tapered inner peripheral surface. By the pressing, the diameter of the expansion / contraction sleeve 9 is reduced in order from the distal end side, and the taper angle of the inner peripheral surface is increased. The hose 1 is clamped by this reduction in diameter. The nipple 3 supporting the inner peripheral side of the clamped hose 1 has a taper angle φ substantially the same as that of the expansion / contraction sleeve 9, so that the hose 1 is clamped from inside and outside by a surface. By being clamped by the surface as described above, stress concentration is prevented from being generated in the hose 1, and promotion of stress relaxation caused by the stress concentration can be suppressed. Therefore, it is possible to improve the creep resistance performance against the creep phenomenon in which the stress acts for a long time, the deformation increases with time, and stress relaxation occurs.

The clamped state is maintained by the elastic body 25 acting like a spring. Even if stress relaxation occurs in the hose 1 and the elasticity of the hose itself decreases, the elastic body 25
Due to the large elasticity, a function like a spring can be obtained and the clamped state can be maintained for a long time. And since this elastic body 25 is not provided on the outer periphery of the nipple 3 as in the related art,
The nipple 3 can be easily inserted into the hose 1. Further, since the elastic body is provided on the outer periphery of the nipple 3, it is not necessary to provide the groove 5 on the outer periphery as in the related art, so that the nipple 3 can be easily formed. That is, since there is no need to provide a groove, the shape of the nipple 3 is simple. Moreover, since it is tapered, it can be removed from the molding die at once during molding. Therefore, it is not necessary to perform the parting for dividing and molding as in the related art, and the projections due to the parting do not occur. Therefore, it is possible to prevent water from leaking from between the hose 1 and the nipple 3 due to the protrusion.

Although the elastic body 25 is distorted in the axial direction due to the clamping, this distortion does not affect the amount of reduction in the diameter of the expansion / contraction sleeve 9. That is, even if the elastic body 25 is distorted in order to maintain the clamped state, this distortion occurs only in the axial direction. For this reason, the contraction amount of the expansion / contraction sleeve 9, that is, the displacement in the inward direction of the diameter, is sufficient only for the distortion of the hose 1, and does not include the distortion of the seal packing as in the related art. Therefore, since a small amount of reduction is required, it is not necessary to provide a large number of slits in the expansion / contraction sleeve 9 in order to perform large expansion / contraction as in the related art. Since the number of slits can be reduced, the shape of the expansion / contraction sleeve 9 becomes simple, and it becomes possible to mold it integrally with the nipple 3.
Further, since the nipple 3 does not require a groove for providing an elastic body, the nipple 3 can have a sufficient thickness and an inner diameter can be increased.
Since the inner diameter is large, fluid energy loss of a fluid such as water at the hose joint can be reduced.

[0011]

According to the first aspect , the pressing sleeve is made of an elastic body.
The shaft is pressed in the axial direction.
Direction pressing force will always act. Press sleeve
The axial pressing force against the
It is the power to make it small. Thus the elastic force of the elastic body to press the pressing sleeve in the axial direction, because they act on the hose as a clamping force, against the stress relaxation of the hose always kept clamped state
I can respond . Therefore , it is not necessary to provide an elastic body on the outer periphery of the nipple as in the related art, and it is not necessary to form a groove on the outer peripheral surface of the nipple. Do not form a groove around the nipple
Since it is not necessary, the shape of the nipple can be simplified . did
Therefore, at the time of molded nipple can <br/> Rukoto preparative vent at a time from the molding die. In this way, you can remove
Therefore , it is not necessary to form the nipple by parting as in the related art, so that the cost can be reduced, and water leakage does not occur due to the convex portion generated at the time of parting. In addition, since the displacement of the diameter of the expansion / contraction sleeve in the inward direction is only the amount of distortion of the hose, a smaller amount of expansion / contraction than the conventional one is sufficient. Therefore, the number of slits can be reduced as compared with the conventional one, the shape of the expansion / contraction sleeve can be simplified, and it is also possible to integrally form the nipple. According to the second aspect, the hose is clamped by the surfaces, so that stress concentration on the hose can be avoided. By avoiding stress concentration in this manner, stress relaxation can be further suppressed, so that the hose can always be kept in a clamped state.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hose 3 Nipple 5 Groove 7 Seal packing 9 Expansion / contraction sleeve 11 Slit 13 Flange 15 Male screw 17 Cylindrical nut 19 Female screw 21 Inner peripheral surface 23 Flange 25 Elastic body 27 Pressing sleeve 29 Base φ Taper angle

Claims (2)

(57) [Claims] 1. A cylindrical nipple inserted into a hose, an expanding / contracting sleeve located on the outer peripheral side of the hose, the diameter of which can be reduced to clamp the hose, and a taper retracted by a screw formed on the outer peripheral of a base of the nipple. A cylindrical nut that presses the expansion / contraction sleeve on the inner peripheral surface of the shape to reduce the diameter, a separate pressing sleeve forming a tapered circumferential surface of the cylindrical nut, and a cylinder. An elastic body provided on the inner peripheral surface of the nut and pressing the pressing sleeve in the axial direction when the nut is retracted. 2. The nipple according to claim 1 , wherein a diameter of said expansion / contraction sleeve is reduced.
A taper angle approximately the same as the taper angle of the inner peripheral surface in the reduced state
The hose joint according to claim 1, wherein the outer peripheral surface has a degree .