JP3470460B2 - Hose joint structure and hose joint used therefor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved hose joint structure and a hose joint used therein.

[0002]

2. Description of the Related Art Conventionally, as such a hose joint structure and a hose joint used for the hose joint structure, see Japanese Utility Model Publication No. 63-37.
The one described in Japanese Patent No. 591 is known. That is, the fourth
As shown in the figure, in order to firmly connect the end portion of the high-pressure rubber hose 3 and the insert metal fitting 1, the end portion 3a of the rubber hose 3 is connected between the hose insertion portion of the insert metal fitting 1 and the tubular outer cylinder 2. The outer tube 2 is inserted into the cavity formed in the outer tube 2, and the outer tube 2 is caulked in the centripetal direction.
A joint structure of a hose in which an end 3a of the hose 3 is sandwiched between them is known.

Here, the rubber hose 3 has a wire reinforcing layer 6 embedded between an inner rubber layer 7 and an outer rubber layer 4, and the outer cylinder 2 has an axial hole extending from an opening 2e at one axial end to the other end. The axial hole has a large-diameter portion 2a provided adjacent to the opening 2e and an annular first projecting portion 2c provided adjacent to the other end of the large-diameter portion 2a and protruding in the centripetal direction. A plurality of annular second protruding portions 2d, 2d protruding in the centripetal direction are provided at the small diameter portion 2b provided via the spacers at intervals in the axial direction. The inner diameter of the top surface of the first protrusion 2c is equal to the inner diameter of the second top surface, and the top surface of the first protrusion 2c is parallel to the axis.

The outer rubber layer 4 is removed from the tip portion 5 of the hose end portion 3a, and the surface portion of the wire reinforcing layer 6 is exposed to improve the withdrawal resistance.

[0005]

However, in such a conventional connecting structure, the first annular projection 2 of the outer cylinder 2 is used.
There is a problem that stress concentration occurs in the vicinity of c, and the wire reinforcing layer 6 near the first annular protrusion 2c undergoes fatigue fracture of the wire 6 due to repeated stress for a long period of time, leading to rupture of the rubber hose.

On the other hand, the rubber hose 3 has tended to be used at a higher pressure than in the past in recent years, and in consideration of the withdrawal resistance, the outer cylinder 2 must be further caulked more strongly in the centering direction. A large stress concentration occurs near the annular protrusion 2c, and the durability of the rubber hose is impaired. As a measure to solve this, a method of lengthening the hose insertion end 1a and the outer cylinder 2 in the axial direction to scale up is conceivable. Therefore, the work space for the hose becomes small, the usability is deteriorated, and the connection structure of the hose is expensive.

The present invention has been invented in view of the above circumstances, and the hose connection capable of improving the durability of the hose with respect to higher high-pressure fluid without scaling up the connection structure of the hose. An object of the present invention is to provide a structure and a connection joint used for the structure.

[0008]

In order to achieve the above-mentioned object, (first means) a first means extends from one end in the axial direction to the other end, and the inner circumference of a hose end is on the one end side in the axial direction. A tubular joint body having an insertion end whose surface is insertable, a tubular portion having an opening at one end coaxially provided with a cavity on the outer periphery of the insertion end of the tubular joint body, A tubular socket having an annular bottom portion extending in the centripetal direction from the other end of the tubular portion, the annular bottom portion being fixed to the base portion of the insertion end portion, and the tubular socket disposed in the cavity. An inner surface rubber layer, an outer surface layer, an inner surface rubber layer, and a reinforcing layer disposed between the inner surface rubber layer, the inner surface rubber layer and the inner surface rubber layer having a diameter reduced in the centripetal direction and sandwiched between the insertion end portion and the cylindrical portion. In a hose joint structure having an end of a rubber hose provided, the tubular portion of the tubular socket is provided with an annular shape from the opening. Has an axial hole extending towards the bottom,
The axial hole is provided with a first hole provided adjacent to the opening, and a centripetal direction provided on the other end side of the first hole adjacent to the other end of the first hole. And a second hole having an inner diameter smaller than the inner diameter of the first hole provided through the first annular protrusion protruding in the direction of the first hole. An annular second taper surface having a diameter gradually decreasing from the other end toward the axial direction, the second taper surface being relative to the shaft.
Of a hose characterized by an inclination of 7 ° to 10 °
The joint structure is configured.

(Second Means) The second means is a tube provided with an insertion end portion extending from one end in the axial direction to the other end, and the inner peripheral surface of the end portion of the hose can be inserted into the one end side in the axial direction. -Shaped joint body, a cylindrical portion having an opening at one end arranged coaxially with a cavity on the outer periphery of the insertion end of the cylindrical joint body, and extending in the centripetal direction from the other end of the cylindrical portion In a hose joint having an annular bottom part and a tubular socket having the annular bottom part fixed to the base of the insertion end, the tubular part of the tubular socket is Has an axial hole extending toward the bottom of the first hole, and the axial hole includes a first hole provided adjacent to the opening, and the first hole on the other end side of the first hole. Of an inner diameter smaller than the inner diameter of the first hole provided adjacent to the other end of the first annular protrusion protruding in the centripetal direction. A plurality of second annular projections extending in the centripetal direction having an inner diameter smaller than the inner diameter of the first annular projection provided in the second hole and axially spaced from each other. Further, the first annular protrusion has an annular first taper surface whose diameter gradually decreases from the other end of the first hole toward the other end in the axial direction, and the first annular protrusion of the first annular protrusion. An annular second tapered surface having a gradually decreasing diameter toward the other end in the axial direction is provided on the top portion, and the second tapered surface is 7 ° to 10 ° with respect to the axis.
The hose joint is characterized by being inclined .

[0010]

[0011]

In the first means and the second means, as described above, the cylindrical portion of the socket has an axial hole extending from the opening to the other axial end, and the hole is axially adjacent to the opening. First provided
And a first hole provided on the other end side of the first hole through a first annular protrusion protruding adjacent to the other end of the first hole in the centripetal direction. A second hole having a diameter smaller than that of the first annular projections provided in the second hole at intervals in the axial direction and having a smaller inner diameter than the plurality of second holes extending in the centripetal direction. An annular projection, and the first annular projection has an annular first taper surface having a smaller diameter from the other end of the first hole toward the other end in the axial direction and the top of the first annular projection. And an annular second taper surface with a smaller diameter toward the other end in the axial direction.
Provided, annular second tapered surface is 7 ° to 10 ° with respect to the axis
By inclining , when high pressure acts on the hose,
It is possible to reduce the concentration of stress near the first annular protrusion,
It is possible to prevent the reinforcing layer from breaking near the first annular protrusion, and to improve the durability of the hose against a higher pressure fluid without scaling up the hose joint .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the figure, 10 is a tubular joint body made of a metal such as steel, and the axial direction one end 10a to the other end 10
b, a hose insertion end 11 having a central hole 10c and a plurality of recesses 11a formed in the center is provided on the one end 10a side in the axial direction, and a male screw part 12a and a nut part 12b are provided on the other end 10b side. And a fixing means 12 for fixing to a mating member (not shown).

The base portion 13 of the hose insertion end portion 11 is composed of an annular flange portion 13a protruding outward in the radial direction and an annular recess portion 13b formed between the nut portions 12b.

A metal cylindrical socket 20 having a cylindrical portion 21 coaxially provided with a cavity A on the outer circumference of the hose insertion end 11 is provided with a base portion 13 having an annular bottom portion 22 formed at the other end. It can be fixed to the annular recess 13b.

This axial hole 23 is provided with a first hole 23a provided adjacent to the opening 21a and a centripetal hole provided on the other end side of the first hole 23a adjacent to the first hole 23a. Through the first annular protrusion 24 protruding in the direction
Has a second hole 23b having an inner diameter smaller than the inner diameter of the second hole 23b.
Second annular protrusions 26, 27, 28 are formed.
And the inner diameter D of these second annular protrusions 26, 27, 28
2 has an inner diameter smaller than the inner diameter D1 of the first annular protrusion 24.

The first annular projection 24 extending in the centripetal direction is
An annular first tapered surface 24a having a diameter gradually decreasing from the other end 23t of the first hole 23a toward the other end in the axial direction is provided, and the top also has a gradually decreasing diameter toward the other end in the axial direction. The second tapered surface 24b is formed. This second
7 ° inclination angle Q of the tapered surface 24b with respect to the axis 10
It is in the range of °.

In this embodiment, the cylindrical socket 20 is
As shown in FIG. 2, after inserting the end portion 31 of the rubber hose 30 into the insertion end portion 11 of the joint body 10, the cylindrical portion 2 of the socket 20 is inserted.
The entire outer periphery of 1 is crimped in the centripetal direction to reduce the diameter, so that the rubber hose 30 is integrally fixed to the joint body 10 to form a hose joint structure as shown in FIG.

Specifically, the insertion end 11 of the joint body 10
Has an outer diameter of 19.5 mm, and the inner diameter of the hose end 31 is 19.5 mm so that the hose end 31 of the rubber hose 30 can be inserted.
It is approximately equal to 3 mm. A plurality of annular recesses 11a are formed in the insertion end 11 at intervals in the axial direction in order to improve the pull-out resistance.

A cavity A is coaxially formed on the outer circumference of the insertion end 11.
And the cylindrical socket 20 is arranged, and the annular bottom portion 22 formed at the other end of the cylindrical portion 21 is arranged so as to match the outer periphery of the annular concave portion 13b of the base end portion 13 of the insertion end portion 11. And a hose joint is constructed.

On the other hand, the rubber hose 30 has an inner rubber layer 30a made of nitrile rubber having a thickness of 1.5 mm and an outer diameter of 30 m.
It is formed by embedding and fixing a wire reinforcing layer 30c between an outer surface rubber layer 30b made of chloroprene rubber having a thickness of 1.4 mm and a thickness of 1.4 mm. Desirably, most of the hose end portion 31 leaves the base portion 31a from one end. The outer rubber layer is removed to expose the surface of the wire reinforcing layer 30c.
By removing the outer rubber layer in this way, it is possible to further improve the pulling resistance and the pressure resistance. Of course, it does not matter if the outer rubber layer is not removed in this way.

In this embodiment, the wire reinforcement layer is used as the reinforcement layer, but it is of course possible to use a fiber reinforcement layer such as nylon, and the outer rubber layer is made of urethane, santoprene, PVC or the like. Can be used.

The hose end 31 of the hose 30 is inserted into the annular cavity A formed between the insertion end 11 of the tubular joint body 10 and the tubular portion 21 of the tubular socket 20. By caulking the entire outer circumference of the socket 20 in the shape of a center in a centripetal direction, the socket 20
The annular bottom portion 22 is fitted in the annular recess 13b of the base end portion 13 of the insertion end portion 11, and the end portion 31 of the hose 30 is connected to the hose joint formed by the joint body 10 and the socket 20. The hose joint structure is constructed.

Before the outer diameter of the cylindrical socket 20 is reduced, the axial length is 52 mm, the first hole 23a has an inner diameter of 32.6 mm, and the second hole 23b has a second hole 23b. The inner diameter is 32.1 mm, and the inner diameter of the top of the first annular projection 24 is 29.5 mm.
The first annular taper surface 24a of is at 45 ° to the axis,
The second tapered surface 24b is formed so as to be inclined at 9 ° with respect to the axis.

Next, regarding the hose connection structure described above, a conventional example of substantially the same size (both the inner diameter of the first annular protrusion and the inner diameter of the second annular protrusion are equal to 29.5 mm, and A second taper surface 26 is provided on the top of the first annular protrusion.
The same will be described except for the structure having a top portion parallel to the axis without b).

First, the conventional connection structure for a hose was tested in a repeated impulse endurance test with a base pressure of 320 kg / cm ² at a repeated pressure of 1,000,000 times, but there was no abnormality as before. Next, for the impulse durability test with a base pressure of 350 kg / cm ² , the hose connection structures of Examples 1 to 5 and Comparative Examples 1 to 1 were used.
The comparison with the conventional hose connection structure described above as No. 4 is shown in Table 1 below and compared.

[0026]

[Table 1]

As can be seen from Table 1, in Comparative Examples 1 to 4 in which the first annular protrusion does not have the second annular taper, the rubber hose has the first annular shape with the end portion of the rubber hose being 400,000 times or less. It burst near the protrusion and did not satisfy the durability of 1,000,000 times or more.

On the other hand, in the embodiment of the present invention, as shown in the embodiment 1, the inner diameter D3 of the second annular protrusions 26, 27, 28 is set.
1 mm smaller than the first annular protrusion 24, and the second tapered surface 24b was provided on the top of the first annular protrusion 24, whereby the impulse durability test of 1,000,000 times could be cleared.

However, the second annular protrusions 26, 27, 28
If only the inner diameter D1 of each of the first annular projections 24 is reduced by 0.7 mm (the difference between D1 and D2 is 0.7 mm), the hose end will rupture after 400,000 times.
It was found that the durability was not satisfied at least 0,000 times and the durability was not much different from the conventional one. On the other hand, D1-
When the difference in D2 was increased to 1.2 mm, it was found that the hose end ruptured at 860,000 times and the durability was impaired.

In addition, from the fourth and fifth embodiments, the second
The durability decreases a little when the taper surface has an inclination angle of 9 ° and becomes smaller or larger . If it is below 7 °
When high pressure is applied to the inner space, stress is applied near the first annular protrusion.
Can't be fully mitigated. Again 10
If it is more than °, the pulling resistance will decrease and the durability will be impaired. Shi
Therefore, a range that satisfies a million times was found to be 7 ° ~10 °.

As described above, in this embodiment, the inner diameter D2 of the apex of the second annular protrusions 26, 27, 28 is set to be slightly smaller than the inner diameter D1 of the apex of the first annular protrusion 24 by about 1 mm. By doing so, it was possible to improve the durability without scaling up in the axial direction even under a higher pressure than before.

In the above embodiment, the cylindrical socket 20 has the hose end 31 and the insertion end 1 of the joint body 10.
1, the hose end 31 and the socket 20 are integrally fixed at the same time by connecting the hose end 31 to each other. However, as shown in FIG. The hose joint 50 can be fixed to form the hose joint 50.

In this case, the annular bottom portion 72 formed at the other end of the cylindrical socket 70 has the insertion end portion 61 of the joint body 60.
It is fixed in advance to the annular recess 63b formed in the base portion 63 by caulking, and the hollow portion B is provided on the outer periphery of the insertion end portion 61, and the tubular portion 71 of the socket 70 is concentrically arranged.

After inserting the hose end (not shown) into the cavity B, the tube 71 of the socket 70 is caulked in the centripetal direction so that the end of the hose is inserted into the insertion end 61 and the tube 71. A hose connection structure in which the hose and the hose joint 50 are fluid-tightly connected by being strongly sandwiched therebetween is configured.

The present invention can be implemented in other forms and modes as described above, and can be implemented in other forms and modes without departing from the gist of the present invention.

[Brief description of drawings]

FIG. 1 is a half sectional view showing an upper half of a joint structure of a hose of the present invention in section.

FIG. 2 is a half cross-sectional view showing an upper half in section for explaining an assembled state of the joint structure of the hose of FIG.

FIG. 3 is a half sectional view showing the upper half of another hose joint in section.

FIG. 4 is a half cross-sectional view showing the upper half of a conventional joint structure for a hose in cross section.

[Explanation of symbols]

10, 60: tubular joint body 11, 61: Insertion end 13, 63: base 20, 70: Cylindrical socket 21, 71: tubular part 22, 72: annular bottom 23: Axial hole 23a: first hole 33b: second hole 24: First annular protrusion 24a: First tapered surface 24b: second tapered surface 26, 27, 28: Second annular protrusion 30: Rubber hose 31: Hose end

Claims (2)

(57) [Claims] 1. A tubular joint main body having an insertion end portion extending from one end in the axial direction to the other end in the axial direction so that an inner peripheral surface of a hose end can be inserted, and the tubular joint. A cylindrical portion having an opening at one end arranged coaxially in the outer periphery of the insertion end of the main body and having an opening, and an annular bottom portion extending in the centripetal direction from the other end of the cylindrical portion, the annular bottom portion A cylindrical socket fixed to the base of the insertion end, and arranged in the cavity, the cylindrical part of the cylindrical socket having a diameter reduced in the centripetal direction, between the insertion end and the cylindrical part. A hose joint structure having an inner rubber layer, an outer surface layer, and an end portion of a rubber hose having the inner surface rubber layer and a reinforcing layer disposed between the outer surface layers, which are sandwiched, and the tubular structure The cylindrical portion of the socket has an axial hole extending from the opening toward the annular bottom, the axial hole being adjacent to the opening. Through a first hole provided on the other end side of the first hole, and a first annular protrusion projecting in the centripetal direction provided adjacent to the other end of the first hole on the other end side of the first hole. And a second hole having an inner diameter smaller than the inner diameter of the first hole provided in the first hole, and the inner diameter of the first annular protrusion provided in the second hole at an interval in the axial direction. A plurality of second annular protrusions having an inner diameter slightly smaller than that of the first hole, the first annular protrusions gradually decreasing in diameter from the other end of the first hole toward the other end in the axial direction. And an annular first tapered surface and
An annular second taper surface having a gradually decreasing diameter toward the other end in the axial direction at the top of the annular projection of the second taper surface.
Is inclined by 7 ° to 10 ° with respect to the axis
Hose joint structure. 2. A tubular joint main body having an insertion end portion extending from one end in the axial direction to the other end in the axial direction so that the inner peripheral surface of the end portion of the hose can be inserted, and the tubular main body. The joint body includes a tubular portion coaxially provided with a cavity on the outer periphery of the insertion end and having an opening at one end, and an annular bottom portion extending in the centripetal direction from the other end of the tubular portion. In a hose joint including a tubular socket having a bottom fixed to the base of the insertion end, the tubular portion of the tubular socket extends in the axial direction from the opening toward the annular bottom. The axial hole is provided adjacent to the opening, and the axial hole is provided on the other end side of the first hole and adjacent to the other end of the first hole. and a second hole of smaller inner diameter than the inner diameter of the first hole provided through the first annular projection projecting in the centripetal direction, which is, and second And a plurality of second annular projection extending in the centripetal direction of the inner diameter smaller than the inner diameter of the first annular projection provided at intervals in the axial direction into the hole, further first
Has a first tapered surface of an annular shape having a diameter that gradually decreases from the other end of the first hole toward the other end in the axial direction, and faces the other end in the axial direction at the top of the first annular projection. And an annular second taper surface having a gradually smaller diameter, and the second taper surface serves as an axis.
A hoe characterized by being inclined by 7 ° to 10 °
S fitting.