JPH1182843A - Hose with joint and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hose with a joint easily manufactured at a low cost and prevented from a lowering of sealing performance and the initiation of a crack even in the case of being used under high temperature and high pressure. SOLUTION: This hose with a joint consists of a joint 10 and a hose H. The joint 10 is provided with a cylindrical joint body 11 with a nipple part 12 provided at one end, and a cylindrical sleeve part 13 concentrically covering the outer periphery of the nipple part 12 and opened at one end. The hose H is insert-fitted between the sleeve part 13 and the nipple part 12. The sleeve part 13 is caulked at a plurality of main caulking parts 13c by spot caulking, and auxiliary caulking parts 13d caulked at a lower caulking rate than the main caulking parts 13c are provided between the respective main caulking parts 13c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hose with a joint in which a hose inserted into a nipple portion is clamped and held by clamping an outer sleeve portion by bale tightening, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Hose joints used in medium-to-high pressure fluid equipment such as power steering and hydraulic brakes are known.
It is required that the leakage pressure is high, that is, the sealing performance is excellent.

A typical example of such a hose joint is shown in FIG.
Shown in The joint 10 is made of metal, and has a cylindrical joint body 11 having a nipple portion 12 for inserting a hose at one end, and a concentrically covering the outer periphery of the nipple portion 12, and one end having an opening for hose insertion. And a cylindrical sleeve portion 13. The joint body 11 has a central through-hole 16, and an uneven portion 17 is formed on the outer peripheral surface of the nipple portion 12 to prevent the hose from coming off.

The joint body 10 having the nipple portion 12 and the sleeve portion 13 may be integrally formed in advance, but usually, as shown in FIG. 2, a ring-shaped sleeve is provided on the outer peripheral surface of the joint body 10. A locking groove 14 is provided, and the ring-shaped engaging portion 15 of the sleeve portion 13 is positioned in the sleeve locking groove 14, and the ring-shaped engaging portion 15 is pressed from the outer peripheral side and caulked, so that the sleeve portion 13 is formed. Are engaged with the joint body 10 to be integrated.

When a hose is connected to the joint 10, an end of the hose is inserted between the nipple 12 and the sleeve 13, and then, as shown in FIG.
In general, so-called bale tightening is performed, in which two or three locations are annularly pressed from the outside in the centripetal direction and caulked. That is, a crimping jig 20 having a plurality of annular convex portions 20a on the inner peripheral surface.
By pressing the sleeve portion 13 from the outside in the centripetal direction using a sleeve, the sleeve portion 13 is annularly contracted at substantially equal intervals to form a plurality of caulked portions 13a.
This is a method of holding the hose H between the nipple portion 12 and the nipple portion 12.

As another caulking method different from bale tightening, there is flat tightening shown in FIG. In this method, a central portion of the sleeve 13 excluding both ends is reduced in diameter at a constant rate and caulked by using a caulking jig having a smooth inner peripheral surface without a convex portion. The caulked portion 13b formed at the center of the sleeve portion 13 has a cylindrical shape with a constant outer diameter.

[0007]

In the case of the above-mentioned bale tightening,
The caulked portion 13a is caulked at a high caulking ratio (ratio of diameter reduction to the hose wall thickness) generally exceeding 30%, while the caulking portion is formed on both sides thereof as shown by dotted lines in FIG. The tool 20 does not come into contact with each other, and the result is obtained. For this reason, the difference in wall thickness in the axial direction of the crimped hose H is very large, and the hose H is easy to move when a high temperature or a high pressure is applied. H had the disadvantage that cracks occurred.

On the other hand, in flat tightening, as shown in FIG. 4, a wide range of the sleeve portion 13 is swaged at a lower swaging rate than bale tightening, so that the difference in wall thickness of the swaged hose H in the axial direction is small. In addition, it is unlikely that the seal H deteriorates due to the movement of the hose H or the hose H is cracked as in the case of the bale tightening described above.

However, the joint used for flat tightening is a hose H
In order to prevent the slippage, the uneven portion 17 of the nipple portion 12
In addition, it is necessary to form the concave and convex portions 18 on the inner peripheral surface of the cylindrical sleeve portion 13 by cutting. For this reason,
The joint for flat fastening has a disadvantage that the manufacturing cost is higher than that for the bales fastening.

The joint body 10 having the nipple portion 12
There is also a joint formed integrally with the sleeve 13 and the joint, but such a joint also has the above-mentioned disadvantages in bale fastening and flat fastening. Moreover, since the joint in which the nipple portion 12 and the sleeve portion 13 are integrated must be manufactured by cutting the peripheral wall of the cylindrical body from one end, the uneven portions 16 are formed on both the nipple portion 12 and the sleeve portion 13. In the case of flat fastening which needs to be provided, the processing becomes more difficult, and the production cost is unavoidably increased significantly.

The present invention has been made in view of such a conventional situation,
It is an object of the present invention to provide a hose with a joint which is easy and inexpensive to manufacture, does not cause deterioration in sealability or cracks in the hose even when used under high temperature or high pressure, and a method for manufacturing the same. I do.

[0012]

In order to achieve the above object, a hose with a joint provided by the present invention has a tubular through-hole body having a central through hole and a nipple at one end; A joint having a tubular sleeve portion concentrically covering the outer periphery of the joint and having an open end, and inserted between the sleeve portion and the nipple portion of the joint, and clamped by swaging by bale fastening of the sleeve portion. A hose with a joint comprising a pressure-held hose, wherein a plurality of main caulking portions are provided on the sleeve portion, and a sub-caulked between the main caulking portions at a caulking rate lower than that of the main caulking portions. It has a caulking part.

Further, according to the method for manufacturing a hose with a joint according to the present invention, a cylindrical joint body having a central through-hole and having a nipple at one end is covered concentrically with an outer periphery of the nipple. A joint for holding a hose end by clamping a hose end by bale tightening after inserting a hose end between a sleeve portion and a nipple portion of a joint having a tubular sleeve portion having an open end. In the method of manufacturing a hose with a
The sleeve portion is crimped from the outside in a centripetal direction by a plurality of main crimping portions, and at the same time, a crimping ratio between the main crimping portions is lower than that of the main crimping portions.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, when a sleeve portion of a joint is swaged by bale tightening, a normal swage portion (hereinafter, referred to as a main swage portion) is swaged and at the same time, the main swage portion is tightened. The part which has not been crimped between the parts is conventionally crimped at a crimping rate lower than that of the main crimping part. Thereby, the difference in wall thickness in the axial direction of the crimped hose can be reduced, the stress applied to the hose can be dispersed, the sealing performance can be improved, and the occurrence of cracks in the hose can be prevented.

The joint used in the present invention may be a conventional joint for bale fastening that has been conventionally used. For example,
As shown in FIG. 2, the joint 10 has a central through hole 16, and has a cylindrical joint body 11 having a nipple portion 12 for hose insertion at one end, and concentrically covers the outer periphery of the nipple portion 12. A cylindrical sleeve portion 13 having an open end. Also, as shown in FIG. 5, a joint body 11 made of a metal pipe having a constant thickness is used as the joint body of the joint 10.
In this case as well, the other end of the sleeve portion 13 is engaged with the outer peripheral surface, and an uneven portion 17 for preventing the hose from coming off is formed on the outer peripheral surface of the nipple portion 12 at one end.

The joint body 11 and the sleeve portion 13 are provided separately, and a ring-shaped engagement portion of the sleeve portion 13 is fitted into a ring-shaped sleeve locking groove 14 provided on the outer peripheral surface of the joint body 11 as shown in FIG. 15 with the ring-shaped engaging portion 1
The joint 5 and the sleeve portion 13 may be integrally formed in advance by pressing the outer peripheral side of the joint 5 and crimping it to engage with each other. When the joint body 11 and the sleeve portion 13 are provided separately, the sleeve portion 13 is usually manufactured by forging a metal block or drawing a metal cylinder.

Although there is no particular limitation on the hose connected to the joint, a normal medium-high pressure hose such as a Freon hose or a hydraulic hose is suitable. The structure of these hoses may be made of rubber, resin, or a combination thereof, and generally has a reinforcing layer made of fibers or cords inside.

In order to obtain a hose with a joint according to the present invention by connecting a hose to the joint, first, as shown in FIG. 1, a hose H is inserted between a sleeve portion 13 and a nipple portion 12 of a tubular joint 10. After inserting the end portion, the sleeve portion 13 is crimped from the outside in the centripetal direction using the crimping jig 21,
At the same time as forming the plurality of main caulking portions 13c, the sub-caulking portions 13d are formed by caulking between the main caulking portions 13c at a caulking rate lower than that of the main caulking portion 13c. The crimping rate of the main crimping portion 13c depends on the thickness of the hose H, but is 20% as in the conventional case.
The caulking rate of the sub caulking portion 13d is preferably lower by 5 to 15% than that of the main caulking portion 13c.

Therefore, the caulking jig 21 to be used has a plurality of annular convex portions 21a corresponding to the caulking rate of the main caulking portion 13c on the inner peripheral surface, and does not abut on the sleeve portion 13 conventionally. The portion between the annular convex portions 21a, which has become the depth, is set at a position where it can be pressed against the sleeve portion 13 as shown by a dotted line in FIG. 1, and the sub-caulking portion is pressed by the intermediate portion 21b. 13d is formed. Therefore, the caulking jig 21
The position of the intermediate portion 21b is determined to be a position where the crimping ratio is lower by 5 to 15% than the crimping ratio obtained by the annular convex portion 21a.
Although FIG. 1 illustrates the case where the number of the main caulking parts 13c is three (three steps), the number of the main caulking parts 13c may be two (two steps) or three or more.

The thus obtained hose with a joint of the present invention comprises a joint tightened in a bale and a hose H inserted between a sleeve portion 13 and a nipple portion 12 of the joint. By reducing the diameter at the caulking portion 13c and the sub-caulking portion 13d, the sleeve portion 13 and the nipple portion 12 are reduced.
The end of the hose H is clamped between them. The bale-tightened sleeve portion 13 has a main caulking portion 13c caulked at a normal caulking rate and an auxiliary caulking portion 13c therebetween.
Also in d, the caulking is performed at a caulking rate lower than that of the main caulking portion 13c. Joint body 1 made of a metal pipe shown in FIG.
The same applies to the case of a hose with a joint using No. 1. In the sleeve portion 13 tightened in a bale, the main caulking portion 13c is caulked at a normal caulking rate, and the sub-caulking portion 13d therebetween is also main caulked. It is caulked at a caulking rate lower than the caulking part 13c.

As a result, the difference in wall thickness in the axial direction of the crimped hose H becomes smaller than in the case of the conventional bale tightening, and the stress applied to the hose H is dispersed. Is suppressed. Therefore, the deterioration of the sealing performance caused by the repetition of the movement of the hose H and the risk of cracking of the hose H are eliminated.

[0022]

EXAMPLES A hose with a joint according to the present invention and a hose with a joint by conventional bale fastening and flat fastening were manufactured and their sealing properties were evaluated. That is, in the hose with the joint of the present invention, the joint body 11 having the nipple portion 12 shown in FIG.
And the inner diameter 9.7 m
As shown in FIG. 1, three-stage bale fastening was performed using a hose having a m and an outer diameter of 20.1 mm, an inner layer of H-NBR and an outer layer of CR and a reinforcing layer inside. At this time, the caulking rate of the main caulking section 13c is 32%, and the caulking rate of the sub caulking section 13d is 2%.
0%.

On the other hand, a conventional hose with a joint by bale fastening uses the same joint and hose as in the above-described embodiment of the present invention, and
As shown in FIG. 3 and FIG. 3, the bales are tightened in three stages, and the crimping ratio is 39% in the case of two stages and 37% in the case of three stages. The result was achieved without caulking. Further, in the conventional hose with a joint by flat fastening, the joint of FIG. 4 having the uneven portion 18 on the inner peripheral surface of the sleeve portion 13 is used, and the same hose as that of the above-described present invention is used. By flat tightening.

Each of the obtained hoses with joints was evaluated for sealability by a heat cycle impulse test at an oil temperature of 140 ° C. In this test, while the pressure was changed from 0 to 105 kgf / cm ² in 10 seconds per cycle, the ambient temperature was simultaneously lowered by -10 in 140 minutes per cycle.
C. to + 60 ° C., and the number of pressurization cycles until leakage occurred was measured.

As a result, in the case of the conventional hose with a joint formed by two-stage bale tightening, leakage occurs in a cycle of 0.5 to 90,000 times, and in the case of the conventional three-stage bale tightened by 1 to 4.5. Leaks occurred every ten thousand times. Inspection of a leaked hose with a conventional bale-tightened joint revealed that all of the two stages had 3
Most of the steps had cracks in the hose immediately below the caulked portion 13a. Further, in the conventional hose with a joint by flat tightening, no crack was generated in the hose.
Leaks occurred every ten thousand times.

On the other hand, the jointed hose of the present invention formed by three-stage bale tightening does not leak until the cycle reaches 3.3 to 550,000 times. No occurrence was observed. from this result,
The hose with a joint of the present invention has better sealing performance than that obtained by conventional bale fastening and flat fastening, and is particularly effective in improving sealing performance and preventing hose cracking, particularly in bale fastening using an inexpensive joint. I understand.

[0027]

According to the present invention, since a joint for bale fastening is used, it is easy to manufacture and inexpensive, and even when repeatedly used under high temperature and high pressure, it has excellent sealing properties and a hose. It is possible to provide a hose with a joint in which no crack is generated.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a main part for explaining a crimped state of a jointed hose by bale tightening of the present invention.

FIG. 2 is a schematic sectional view of a main part showing a joint for bale fastening.

FIG. 3 is a schematic sectional view of a main part for explaining a crimped state of a hose with a joint by conventional bale fastening.

FIG. 4 is a schematic sectional view of a main part showing a conventional hose with a joint by flat fastening.

FIG. 5 is a schematic sectional view showing a specific example of a hose with a joint by bale fastening according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Joint 11 Joint main body 12 Nipple part 13 Sleeve part 13a, 13b Caulking part 13c Main caulking part 13d Sub-caulking part 16 Central through hole 20, 21 Caulking jig 20a, 21a Annular convex part 21b Intermediate part H Hose

Claims (5)

[Claims] 1. A joint having a central through-hole and a tubular joint body having a nipple portion at one end, and a tubular sleeve portion concentrically covering the outer periphery of the nipple portion and having an open end. And a hose which is inserted between a sleeve portion and a nipple portion of the joint, and which is held by squeezing by bale fastening of the sleeve portion. A hose with a joint, comprising: a sub-crimping portion crimped at a lower crimping ratio than the main crimping portion between each main crimping portion together with the tightening portion. 2. The hose with a joint according to claim 1, wherein the caulking rate of each of the sub-caulking portions is lower than that of the main caulking portion by 5 to 15%. 3. The hose with a joint according to claim 1, wherein the joint main body is formed of a metal pipe having a constant thickness. 4. A joint comprising a tubular joint body having a central through hole and having a nipple portion at one end, and a tubular sleeve portion concentrically covering the outer periphery of the nipple portion and having an open end. A method of manufacturing a hose with a joint in which a hose end is inserted between a sleeve portion and a nipple portion and then the sleeve end is clamped and held by bale tightening of the sleeve portion. A method of manufacturing a hose with a joint, comprising: caulking in a plurality of main caulking portions in a centripetal direction from the center and simultaneously caulking between the main caulking portions at a caulking rate lower than that of the main caulking portions. 5. A space between each of the main caulking portions, which is 5 mm wider than the main caulking portion.
The method for producing a hose with a joint according to claim 4, wherein the hose is caulked at a caulking rate lower by 15%.