JP2002174382A - Hose connecting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connecting structure capable of high seal property without breaking an inner surface rubber even by the enhancement of fastening force to provide high seal property. SOLUTION: In this hose connecting structure, a hose 1 is inserted to a fitting formed of a nipple 2 and a socket 3, and the hose 1 is fixed to the fitting by fastening the socket 3. The circumferential surface of the nipple 2 has a ring-like recessed groove 7 of a specified shape and size in a dead end position of the inserted hose 1, and the socket 3 is fastened in a fastening part 6a just above the recessed groove 7. This structure is characterized by that (1) the fastening part outer diameter of the socket 3 is gradually increased toward the hose-side tip of the nipple, (2) the thickness of the socket 3 is gradually reduced toward the hose-side tip of the nipple, or (3) the outer diameter of the nipple 2 is gradually reduced toward the hose-side tip.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hose connection structure in which a nipple and a metal fitting composed of a socket provided on a concentric shaft thereof are fixed to a hose used in a wide temperature range from a high temperature to a low temperature. The connection structure of the present invention can be used, for example, for connection of a rubber hose and a resin hose such as a power steering hose, a high pressure hose for hydraulic pressure, and an air brake hose.

[0002]

2. Description of the Related Art An example of a conventional hose connection structure is shown in FIGS. 10 and 12 correspond to FIG.
FIG. 12 is an enlarged sectional view of a fixed portion of the hose connection structure of FIG. 11 and FIG.

[0003] In the hose connection structure shown in FIG.
The hose 1 is inserted into a fitting constituted by a nipple 2 and a socket 3 provided on a concentric axis of the nipple 2 until the hose 1 comes into contact with the inside of the socket flange (a dead end position) 5, and one portion of the socket 3 is set in the centripetal direction. The fitting is fixed to the hose 1 by the crimping part 6 pressed in the above manner.

[0004] The hose 1 is made of, for example, an inner rubber 1a and an outer rubber 1b of synthetic rubber that can withstand use from high to low temperatures, and has a reinforcing thread layer 1c having a strength to withstand the internal pressure of the hose.

[0005] The connection between the metal fitting and the hose 1 is required to maintain a sealing property for preventing leakage of the internal fluid when used for a long time in a wide temperature range from a high temperature to a low temperature.
Therefore, in order to enhance the sealing performance of the connection portion, a plurality of groove recesses 4 are provided on the outer peripheral surface of the nipple 2 located in the centripetal direction of the socket caulking portion 6. The groove recess 4 is provided at a position near the center in the length direction of the nipple.

When a high sealing property is required due to a high use internal pressure or the like, the reduced socket outer diameter of the caulking portion 6 is reduced, and the groove 4 of the nipple and the hose 1 are reduced.
It is necessary to increase the caulking force generated between the inner rubbers 1a of the groove.
There is a problem that the inner surface rubber 1a is broken at the boundary, and a seal leak occurs.

The hose connection structure shown in FIG.
The shape provided on the outer surface of the nipple 2 is different from the conventional example shown in FIG.

More specifically, the hose 1 is inserted into a mouthpiece constituted by a nipple 2 to be inserted into the hose 1 and a socket 3 provided concentrically with the nipple 2 until the hose 1 comes into contact with the inside of the socket flange 5. The fitting is fixed to the hose 1 by the crimping part 6 which presses two places in the centripetal direction.
In order to enhance the sealing performance of the connection portion, groove recesses 4 are provided at two places on the outer peripheral surface of the nipple 2 located in the centripetal direction of the two socket caulking parts 6. The groove recess 4 is provided at a position near the center in the length direction of the nipple 2.

In the connection structure shown in FIG. 11, when high sealing performance is required as in the conventional example shown in FIG.
It is necessary to reduce the reduced outer diameter of the socket of the caulking portion 6 and increase the caulking force generated between the groove concave portion 4 on the outer peripheral surface of the nipple and the inner rubber 1a of the hose 1. When the diameter is increased, there is a problem that the inner rubber 1a is broken at the boundary of the groove concave portion 4 and a seal leak occurs.

[0010]

When the caulking force is increased in order to obtain a high sealing pressure, the inner rubber 1a of the caulked portion 6 tends to escape to the outer periphery of the caulked portion having a low stress. In particular, the clearance of the inner rubber in the direction of the hose-side tip of the nipple 2 where the caulking force is lost, that is, the amount of movement increases. Further, when exposed to a high temperature, stress is applied to the inner rubber 1a due to expansion of the rubber, and the inner rubber is exposed to the nipple 2 having a lower stress.
Try to move toward the tip. When exposed to a low temperature, the crimping force generated in the nipple 2 and the inner rubber 1a is reduced by the contraction of the rubber, and the inner rubber 1a tends to move toward the tip of the nipple 2 due to the stress caused by the internal pressure of the hose 1. .

In the conventional connection structure, as shown in FIGS. 10 and 12, a groove concave portion 4 is provided in a portion where the inner rubber 1a is largely moved, so that the inner rubber 1a starts from the concave portion.
a is easily broken. As a result, it is necessary to increase the caulking force in order to enhance the sealing performance, but there is a limit in increasing the caulking force, and there is a limit in obtaining a high sealing performance.

An object of the present invention is to provide a connection structure capable of maintaining a high sealing property without breaking the inner surface rubber 1a even if a crimping force is increased to obtain a high sealing property.

[0013]

According to the present invention, a hose 1 is inserted into a metal fitting comprising a nipple 2 inserted into a hose 1 and a socket 3 provided on a concentric shaft with the nipple 2;
In a hose connection structure in which a metal fitting is fixed to the hose 1 by caulking the socket 3 in the centripetal direction, a ring-shaped groove 7 having a groove width x1 to 5 mm is provided at a dead end position of the inserted hose on the outer peripheral surface of the nipple 2. The radius of the shoulder 8a of the concave groove 7 is 0.5R or less or the C-plane is 0.5C or less, and the socket 3 is caulked with respect to the concave groove 7 at the upper portion 6a in the outer peripheral direction, The outer diameter of the caulked portion of the socket 3 is larger in the direction toward the hose end of the nipple 2; the thickness of the socket 3 is thinner in the direction toward the hose side of the nipple 2; The hose connection structure is characterized in that the outer diameter of the hose connection becomes smaller toward the hose-side tip.

In the present invention, when n is a positive numerical value, the radius of the shoulder of the groove formed on the surface is nR, which means that the shoulder is curved, that is, the cross section of the shoulder is an arc. , And the radius of a circle inscribed in the arc is n (mm).
In the present invention, when m is a positive numerical value, the fact that the C surface of the shoulder of the groove formed on the surface is mC means that the shoulder is planar, that is, the cross section of the shoulder is the groove. The shoulder is chamfered so as to form an oblique line with respect to the side wall (vertical direction) and the surface on which the groove is formed (horizontal direction), which means that the horizontal width of the oblique line is m (mm). .

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a hose connection structure in which a fitting is fixed to a hose 1. The fitting used in the present invention is a cylindrical nipple 2 inserted into a hose 1.
And a cylindrical socket 3 provided concentrically with the nipple 2 on the outer periphery of the hose insertion portion of the nipple 2, and the hose 1 in which the nipple 2 is inserted is formed by caulking the socket 3 in the centripetal direction. The nipple 2 can be clamped and fixed between the outer peripheral surface of the hose insertion portion and the inner peripheral surface of the socket 3. The nipple 2 and the socket 3 form a dead end of the hose 1 into which the nipple 2 has been inserted. The dead end of the hose 1 can be formed, for example, by a collar (socket collar) formed on the inner peripheral surface of the socket.

First Embodiment FIG. 1 is a partial sectional view showing a hose connection structure according to a first embodiment. FIG. 2 is an enlarged cross-sectional view of the fitting of the hose connection structure of FIG.

In the present embodiment, the hose 1 is inserted into a fitting composed of a nipple 2 and a socket 3 as in the conventional connection structure shown in FIGS.
A crimping press is performed at two places a and 6b, and the fitting and the hose 1 are fixed and the hose 1 is connected.

In the present invention, the nipple 2 having the ring-shaped groove 7 on the outer peripheral surface of the hose insertion portion is used. By using the nipple 2 having the ring-shaped groove 7, a high sealing property can be obtained.

The ring-shaped concave groove 7 of the nipple 2 used in the present invention is located at a dead end position of the hose 1, that is, at a position in contact with the inner side 5 of the socket flange. By using the nipple 2 having the ring-shaped groove 7 at the dead end position of the hose 1, it is possible to prevent the inner rubber 1 a of the hose 1 from breaking even when the caulking force of the socket 3 is increased.

Since the ring-shaped concave groove 7 is located farther from the hose-side tip of the nipple 2 where the inner rubber 1a of the hose 1 moves by a large amount and has a dead end due to the inner side of the socket flange 5, the ring-shaped concave groove 7 is located at the back of the nipple 2. The inner surface rubber 1a does not move in the direction. Therefore, the ring-shaped concave groove 7 is
acts to prevent the destruction of a. As a result, a method of reducing the caulking outer diameter of the caulking portion 6a for reducing the outer diameter of the socket directly above the ring-shaped groove 7 and increasing the caulking force, or
By a method of reducing the radius or C chamfer of the shoulder 8a of the ring-shaped groove 7 and locally increasing the caulking force (line sealing), a high sealing property can be obtained without breaking the inner surface rubber.

It is preferable that the groove width x of the ring-shaped concave groove 7 is formed so that the shoulder 8a does not approach the hose-side tip of the nipple 2 very much. In order to satisfy the condition, the groove width x of the ring-shaped concave groove 7 is usually set to 1 to 5 mm, preferably 2 to 3 mm. However, the preferred length of the groove width x is
Since it varies depending on the length of the nipple 2 and the crimped shape, it can be determined appropriately.

In the nipple 2 used in the present invention, the shoulder 8a of the ring-shaped concave groove 7 is formed so as to locally increase the caulking force, and the radius is 0.5R or less, preferably 0.1 to less. 0.3R or C plane is 0.5C or less, preferably 0.1 to 0.3C.

Nipple 2 used in the present embodiment
Has a plurality of groove recesses 4 at a location located between the longitudinal center of the hose insertion portion and the inside of the socket collar 5. By having the groove concave portion 4, the sealing property can be improved. The groove recess 4 is preferably provided at a position near the inner side of the socket flange 5 as far as possible from the end of the nipple 2 on the hose side.

The radius or the C surface of the shoulder 8c of the groove concave portion 4 is such that the caulking force is locally increased and the inner rubber 1a of the hose 1 is not destroyed. Preferably, the radius is larger than the C plane, for example, the radius is 0.5R or more, and the C plane is 0.5C or more. However, the preferable radius and the size of the C-plane vary depending on the inner diameter of the hose 1, the rubber material, and the like, and can be appropriately determined.

In the present embodiment, the caulking portion 6 is located immediately above the ring-shaped groove 7 of the nipple 2 in the outer peripheral direction.
A socket which is caulked in a and the outer diameter of the caulked portion becomes larger toward the tip of the nipple 2 on the hose side is used.
The socket 3 used in the present embodiment is caulked at a caulking portion B close to the hose-side tip so that the caulking force becomes smaller as the inner rubber 1a moves toward the hose-side tip of the nipple 2 with a large movement. The outer diameter φB is larger than the outer diameter φA of the caulked portion A near the inside of the socket sheath.
The ratio of φB to φA is preferably 1.010-1.
100, more preferably 1.02 to 1.08.

In the socket 3 in which the outer diameter of the crimping portion is larger in the direction toward the hose side of the nipple 2, the crimping force becomes smaller as the moving amount of the inner rubber 1a is larger in the direction toward the hose side of the nipple 2. So the inner rubber 1 of the hose 1
acts to prevent the destruction of a.

Second Embodiment FIG. 3 is a partial sectional view showing a hose connection structure according to a second embodiment. In the present embodiment, the nipple 2 used in the first embodiment is used, and the nipple 2 is used.
By using the socket 3 that is thinner toward the front end on the hose side, the caulking force of the portion where the amount of movement of the inner rubber 1a is large is reduced, and the destruction of the inner rubber 1a is prevented.

The socket 3 is moved so that the crimping force decreases as the inner rubber 1a moves to the tip end on the hose side where the movement is large.
The thickness tB of the crimped portion 6b near the tip of the hose side is the thickness tA of the crimped portion 6a near the inner side 5 of the socket flange.
Larger, the ratio of tB to tA is preferably 0.
It is 95-0.50, more preferably 0.8-0.7.

Third Embodiment FIG. 4 is a partial sectional view showing a hose connection structure according to a third embodiment.

In this embodiment, by using the nipple 2 whose outer diameter becomes smaller toward the distal end on the hose side, the caulking force of the portion where the movement of the inner rubber 1a is large is reduced, and the inner rubber 1a Prevent destruction. In the present embodiment, the socket 3 used in the first embodiment has a larger outer diameter toward the front end of the hose 3 or the second embodiment.
It is not necessary to use a socket 3 whose thickness is smaller as it goes in the direction of the hose end, and a socket 3 having a uniform outer diameter and thickness of the caulked portion can be used.

Nipple 2 used in this embodiment
The ratio of the outer diameter φE of the hose end portion E to the maximum outer diameter φF (the outer diameter at the position F) of the hose insertion portion is preferably 1.010 to 1.100, more preferably 1.02 to 1 .08.

[0032]

EXAMPLES The present invention will be specifically described below based on examples, but the present invention is not limited to only these examples.

Test Method In order to confirm the effects of the present invention, a thermal shock impulse test was performed on the connection structures of the following Examples 1-2 and Comparative Examples 3-10.

The thermal shock test always means 0 ← → 13.4M
The hose sample subjected to repeated pressurization of Pa was exposed in a thermostat at 100 ° C. for 1 hour, and then immediately transferred to a thermostat at −35 ° C. and exposed for 1 hour as one cycle, and the cycle was repeated. This is a test to confirm the number of cycles in which oil leaks from the connection between the hose and the hose. The thermal shock test is a test for evaluating the performance under conditions where the temperature, which is considered to be the strictest in maintaining the sealing performance of the hose connection, is impacted. The test oil was PSF
(Power steering fluid) was used.

Examples 1 and 2 and Comparative Examples 1 and 2 The hose 1 has an inner diameter of 10 mm and an outer diameter of 20 mm. The inner rubber 1a is made of H-NBR (hydrogenated nitrile butadiene rubber), and the reinforcing layer 1c is made of nylon. A power steering hose composed of EPDM (ethylene propylene diene rubber) and H-NBR blended rubber was used as the outer rubber 1b with two yarn braids.

The hose 1 is connected by the connection structure shown in FIG. 1 in the first embodiment, by the method shown in FIG. 5 in the second embodiment, by the connection structure shown in FIG. 9 in the comparative example 1, and by the connection structure shown in FIG.
Are connected by the connection structure shown in FIG. In the second embodiment, a nipple 2 having no groove recess 4 provided as an auxiliary to the first embodiment is used. FIG. 5 shows a hose connection structure according to the second embodiment. In Comparative Example 2, compared to Example 1, the inserted hose 1
The nipple 2 having no ring-shaped groove 7 at the dead end position was used.

The shoulder 8a of the ring-shaped groove 7 of the nipple used in Example 1 has a C surface of 0.1C, the shoulder 8b of the groove recess 4 has a radius of 0.4R, and each groove width x is 2 mm. did.
The shoulder 8a of the ring-shaped concave groove 7 of the nipple 2 used in Example 2 was a C surface of 0.1C, and the groove width x was 2 mm. The shoulder 8b of the groove concave part 4 of the nipple 2 used in Comparative Example 2 was 0.4R.

The results are shown in Table 1.

[0039]

[Table 1]

Comparative Examples 3 to 10 The same thermal shock impulse test was performed as in Example 2 except that the size of the C-plane and the groove width x of the shoulder 8a of the ring-shaped concave groove 7 were changed. Table 2 shows the results.

[0041]

[Table 2]

[0042]

According to the present invention, the use of the nipple 2 having the ring-shaped concave groove 7 at a position where the movement of the inner rubber 1a inside the caulked portion is small prevents the inner rubber 1a from being broken. Since the caulking force in the ring-shaped concave groove 7 can be locally increased, high sealing performance can be achieved and maintained.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a hose connection structure according to a first embodiment.

FIG. 2 is an enlarged sectional view of a fixing part of a fitting and a hose of the connection structure of FIG. 1;

FIG. 3 is a partial sectional view showing a hose connection structure according to a second embodiment.

FIG. 4 is a partial sectional view showing a hose connection structure according to a third embodiment.

FIG. 5 is a partial cross-sectional view illustrating a hose connection structure according to a second embodiment.

6 is an enlarged sectional view of a ring-shaped concave groove of a nipple in the connection structure of FIG.

FIG. 7 is a partial sectional view showing a hose connection structure of Comparative Example 2.

8 is an enlarged sectional view of a ring-shaped concave groove of a nipple in the connection structure of FIG.

FIG. 9 is a partial sectional view showing an example of a conventional hose connection structure.

FIG. 10 is an enlarged cross-sectional view showing a fixing part of a fitting and a hose of the connection structure of FIG. 9;

FIG. 11 is a partial sectional view showing an example of a conventional hose connection structure.

FIG. 12 is an enlarged sectional view showing a fixing portion of a fitting and a hose of the connection structure of FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hose 1a Inner rubber 1b Outer rubber 1c Reinforcement thread layer 2 Nipple 3 Socket 4 Groove concave part 5 Socket collar inside 6, 6a, 6b Clamping part 7 Ring-shaped concave groove 8a, 8b Shoulder

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Akira Nihama 1118 Sado, Bessho-cho, Himeji-shi, Hyogo F-term in Nichirin Himeji Plant (reference) 3H017 GA05

Claims (3)

[Claims] 1. A hose connection in which a hose is inserted into a fitting constituted by a nipple inserted into a hose and a socket provided on the nipple and a concentric shaft, and the fitting is fixed to the hose by caulking the socket in a centripetal direction. In structure
A ring-shaped groove having a groove width of 1 to 5 mm is provided at a dead end position of the inserted hose on the outer peripheral surface of the nipple, and the radius of the shoulder of the groove is 0.5R or less or the C surface is 0.5C or less. The hose connection structure, wherein the socket is swaged directly above the concave groove in an outer peripheral direction, and an outer diameter of a swaged portion of the socket increases toward a tip of the nipple on the hose side. 2. A hose connection in which a hose is inserted into a metal fitting composed of a nipple inserted into a hose and a socket provided on the nipple and a concentric shaft, and the metal fitting is fixed to the hose by caulking the socket in a centripetal direction. In structure
A ring-shaped groove having a groove width of 1 to 5 mm is provided at a dead end position of the inserted hose on the outer peripheral surface of the nipple, and the radius of the shoulder of the groove is 0.5R or less or the C surface is 0.5C or less. The hose connection structure, wherein the socket is swaged right above the concave groove in an outer peripheral direction, and the thickness of the socket is thinner toward the hose-side tip of the nipple. 3. A hose connection in which a hose is inserted into a fitting composed of a nipple inserted into a hose and a socket provided on the nipple and a concentric shaft, and the hose and the fitting are fixed by caulking the socket in a centripetal direction. In structure
A ring-shaped groove having a groove width of 1 to 5 mm is provided at a dead end position of the inserted hose on the outer peripheral surface of the nipple, and the radius of the shoulder of the groove is 0.5R or less or the C surface is 0.5C or less. The hose connection structure, wherein the socket is swaged at a position directly above the concave groove in an outer peripheral direction, and an outer diameter of the nipple becomes smaller toward a hose-side distal end.