JPH0135111Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to a hose joint having a structure in which a sleeve is caulked from the outside and the end of the hose is compressed between the sleeve and the nipple. The present invention can be used, for example, in hose joints for medium and high pressure hoses used in power steering, hydraulic brakes, etc., fuel hoses, Freon hoses, and the like. [Prior Art] There is a strong demand for hose joints, especially hose joints used for medium and high pressure hoses, to improve leakage pressure values. Therefore, the third
A hose joint having the structure shown in the figure is provided.
This hose joint includes a cylindrical nipple 100 having a ring-shaped sleeve locking groove 101 and a seal groove 102 on the outer circumferential surface, a metal sleeve having a ring-shaped engagement part 201 and a cylindrical caulking part 202. It consists of 200. When attaching this hose joint to the end of the hose 300, the ring-shaped engaging portion 201 of the sleeve 200 is inserted into the sleeve locking groove 1 of the nipple 100.
Position it at 01. Then, the end of the hose 300 is inserted into the space between the outer peripheral wall of the nipple 100 and the inner peripheral wall of the sleeve 200. In this state, the ring-shaped engaging portion 201 is strongly pressed in the direction of the outer circumferential surface, that is, in the direction of arrow F1, so that the inner circumferential wall of the ring-shaped engaging portion 201 is brought into close contact with and engaged with the sleeve locking groove 101. Next, the caulking portion 202 of the sleeve 200 is caulked with strong pressure from the directions of arrows F2 and F3, thereby bringing the inner surface of the hose 300 into close contact with the seal groove 102, thereby attaching the hose joint to the end of the hose 300. do. [Problems to be solved by the invention] In the hose joint described above, the sleeve 2
Since the end of the hose 300 is compressed by the nipple 100 and the nipple 100, the leakage pressure value can be considerably improved. However, there was a limit to the improvement in leakage pressure when used as a joint for medium-high pressure hoses. That is, the sleeve 200 has a ring-shaped engagement portion 20
Since it has a shape with 1, it is made separately from cold forged material and is hard at about Hv230. On the other hand, nipple 100
Because it has a relatively simple shape, it is formed from a commercially available seamless drawn pipe and has a low hardness of about Hv120.
Therefore, the ring-shaped engaging portion 201 of the sleeve 200 is pressed hard and the inner peripheral surface of the sleeve 200 is pressed tightly against the nipple 10.
Even if an attempt is made to bring the nipple 100 into close contact with the bottom surface of the sleeve locking groove 101 of the sleeve locking groove 101, the hardness of the nipple 100 is low.
01 tends to cave in. Therefore, the bondability between the ring-shaped engaging portion 201 and the sleeve locking groove 101 tends to deteriorate. As a result, the sleeve locking groove 1
The sealing performance with 01 was not sufficient. Therefore, when the hose 300 deteriorates and the sealing performance of the seal groove 102 deteriorates, the fluid flowing through the hose 300 tends to leak from the sleeve locking groove 101. The present invention was developed in view of the above-mentioned circumstances, and its purpose is to provide a hose joint that improves the sealing performance of the sleeve locking groove and thereby further improves the leakage pressure value. [Means for Solving the Problems] A hose joint according to the present invention includes: a cylindrical nipple having a ring-shaped sleeve locking groove circumferentially surrounding the outer peripheral surface remote from one end; and the sleeve locking groove. a ring-shaped engaging portion that is pressed from the outer circumferential direction to engage the inner circumferential surface; and a cylindrical caulking portion that covers the outer circumferential surface of the nipple coaxially with the nipple from the outer circumferential portion of the ring-shaped engaging portion. a metal sleeve having a metal sleeve; The nipple has a hardness of at least a portion having the sleeve locking groove of Hv140 to 250, and the hardness of at least the ring-shaped engagement portion of the sleeve is Hv90 to 120. The part of the nipple that has the sleeve locking groove is
The hardness of the ring-shaped engagement part of the sleeve is
Hv50~100 hard, by strongly pressing the ring-shaped engaging part of the sleeve into the sleeve locking groove, the inner circumferential surface of the ring-shaped engaging part and the protruding part are engaged, and the sleeve is caulked. The feature is that the part is caulked. Here, the term "ring-shaped" means continuous in the circumferential direction of the nipple or sleeve. The overall structure of the hose joint according to the present invention will be further explained below. The hose joint of the present invention is composed of a nipple and a sleeve coaxial with the nipple. Here, the nipple and sleeve are separate bodies. The nipple, which is a component of the present invention, is usually made of metal and is a cylindrical body inserted into the inner surface of the central hole at the end of the hose. The nipple has a central through hole. Fluids such as driving oil and air pass through this central through hole. The nipple may be formed from one cylindrical body or from two cylindrical bodies. When the nipple is formed from two cylindrical bodies, the cylindrical body with a small diameter and the cylindrical body with a large diameter are fitted and fixed together. A ring-shaped sleeve locking groove is formed on the outer peripheral surface of the nipple at a position away from one end of the nipple. The depth and width of the locking groove of the sleeve are appropriately selected depending on the material of the sleeve and nipple, the desired leakage pressure value, etc. Note that it is preferable that a seal groove is formed on the outer peripheral surface of the nipple. When the seal groove is formed in this manner, when the sleeve caulking portion is caulked, the inner surface of the hose fits into the seal groove and comes into close contact with the hose, thereby improving sealing performance. The sleeve, which is another component of the present invention, is a cylindrical body made of a metal material, such as a steel material, which can be plastically worked. The inner diameter of this sleeve is larger than the outer diameter of the nipple, so that the sleeve can cover the outer peripheral surface of the nipple. The sleeve has a ring-shaped engaging portion and a cylindrical caulking portion extending in the axial direction of the sleeve from the outer circumference of the ring-shaped engaging portion. The ring-shaped engaging portion is a portion that engages with the sleeve locking groove, and usually projects inwardly from the caulking portion. The caulking portion is a portion that is deformed by caulking using a jig or the like. Now, the main structure of the hose joint of the present invention will be explained. That is, the hardness of at least the portion of the nipple having the sleeve locking groove is Hv140 to 250.
It is. On the other hand, the hardness of at least the ring-shaped engaging portion of the sleeve is Hv90 to 120, and the hardness of the portion of the nipple having the sleeve locking groove is Hv50 higher than the hardness of the ring-shaped engaging portion of the sleeve. ~100 or more is set hard. In this case, it is preferable that the hardness is set to Hv80 or more. Here, Hv refers to Bitker's hardness. Bitkers hardness (Hv)
The measurement was carried out with a load of 300 g. Normally, the nipple should have approximately uniform hardness throughout. On the other hand, the sleeve should also have a substantially uniform hardness throughout. Of course, the sleeve is less hard than the nipple. Specifically, for example, the nipple may be formed by cold forging and remain hard, while the sleeve may be formed by cold forging and then annealing to soften the entire sleeve. can. On the bottom surface of the sleeve locking groove of the nipple, a protrusion that extends in the direction in which the sleeve locking groove extends and goes around the nipple is integrally formed with the nipple.
The number of protrusions is appropriately set depending on the type of fluid flowing through the hose, the material of the nipple or sleeve, the required leakage pressure value, etc., but it is generally preferable to set it to 1 to 5. In particular, two pieces are preferable. The height of the protrusion is appropriately set depending on the material of the nipple and the sleeve, but it is preferably within the depth of the sleeve locking groove. It is preferable that the cross-sectional shape of the protrusion has a rounded tip. This configuration is effective in preventing the tip of the protrusion from collapsing or being cut when the ring-shaped engagement part is strongly pressed against the sleeve engagement groove. This is because the bondability with the joint can be improved. Note that, depending on the case, a groove with a small diameter to fit with the tip of the protruding portion may be formed on the inner circumferential surface of the ring-shaped engagement portion. This is effective in making the protruding portion sink into the inner circumferential surface of the ring-shaped engaging portion. The inner peripheral surface of the ring-shaped engagement part has a surface roughness.
A smooth surface with a resistance of 25 μRz or less is preferable. There is an advantage that the smoother the inner peripheral surface of the ring-shaped engaging part, the greater the adhesion between the ring-shaped engaging part of the sleeve and the surface of the sleeve locking groove of the nipple. It is preferable that the sleeve locking groove including the protrusion has a circular wave shape with a circular arc having a predetermined curvature in a cross section passing through the axis of the nipple. Curvature is, for example, radius
It can be about 0.8mm. If the shape includes a circular wave shape in this way, it is possible to suppress defects such as notches from occurring in the sleeve locking groove. The hose attached to the hose joint may be a known hose, such as a rubber hose or a plastic hose, and preferably has a reinforcing layer embedded therein. Now, a typical method for attaching the hose joint of the present invention to the end of a hose will be described. First, in the first step, the ring-shaped engagement portion of the sleeve is positioned in the sleeve locking groove of the nipple with the nipple covered with the sleeve. In this state, insert the end of the hose into the space between the nipple and the sleeve in the same way as before. Next, in a second step, the ring-shaped engaging portion is strongly pressed against the sleeve locking groove from the direction of the outer circumferential surface using a jig or the like. Then, the hard protruding portion formed on the bottom surface of the hard sleeve locking groove bites into and engages with the inner peripheral surface of the ring-shaped engaging portion, which is softer than the nipple. As a result of the engagement between the inner circumferential surface of the ring-shaped engagement part and the protrusion as described above, the bonding strength between the ring-shaped engagement part of the sleeve and the sleeve locking groove of the nipple is improved. Next, in the third step, the caulking portion of the sleeve is strongly pressed in the centripetal direction of the sleeve using a caulking tool or the like. This strong pressure plastically deforms the caulked portion of the sleeve and caulks the sleeve to the hose. In this case, it is preferable to tighten the caulked portion of the sleeve in two stages, but it is not necessarily limited to two-stage bale tightening. [Effects of the invention] As described above, when the hose joint of the invention is used, the hardness of at least the portion of the nipple having the sleeve locking groove is Hv140 to 250, and that of the sleeve, at least the ring-shaped locking groove. The hardness of the joint is
Hv90-120, and the portion of the nipple having the sleeve locking groove is set to be harder than the ring-shaped engagement portion of the sleeve by Hv50-100 or more. Therefore, depression of the sleeve locking groove when applying strong pressure to the ring-shaped engaging portion can be suppressed compared to the conventional case. Further, since the structure is such that the hard protruding portion bites into and engages with the soft ring-shaped engagement portion, the biting is effectively performed. Therefore, the sealing performance between the ring-shaped engaging portion of the sleeve and the sleeve locking groove of the nipple can be reliably improved. Therefore, leakage of fluid from the sleeve locking groove can be suppressed, and the leakage pressure value of the hose joint can be improved. In particular, when the difference in hardness between the ring-shaped engaging portion and the sleeve locking groove is Hv80 or more, the improvement in the leakage pressure value is large. Furthermore, if the entire sleeve is made soft, the caulked portion of the sleeve is more likely to deform when caulked. Therefore, the caulking method during the caulking process is not directly transmitted to the joint portion between the ring-shaped engaging portion of the sleeve and the protruding portion of the sleeve locking groove of the nipple. Therefore, good connectivity between the ring-shaped engaging portion and the sleeve locking groove can be ensured. Therefore, it is effective in improving the sealing performance of the sleeve locking groove. Also, if the tip of the protrusion is rounded,
When the protruding portion and the ring-shaped engagement portion are engaged, it is possible to prevent the tip of the protruding portion from collapsing and being cut, which is advantageous in terms of improving sealing performance. Further, as exemplified in the embodiments described later, when the cross section of the sleeve locking groove including the protruding portion has a circular wave shape, the bottom surface of the sleeve locking groove also has a rounded shape. Therefore, as will be described in detail in the embodiments below, the fit between the sleeve locking groove and the inner circumferential surface of the ring-shaped engagement portion is improved, and the sealing performance can be further improved. Of course, the tips of the protrusions are also rounded, so
It is also effective in suppressing collapse and breakage of the protrusions. [First Embodiment] (Structure of the First Embodiment) FIGS. 1 and 2 show a first embodiment of the present invention. FIG. 1 is a sectional view showing the upper half of the nipple 1 and sleeve 2 before being attached to the hose, and the second
The figure is a sectional view showing the upper half of the device after it has been attached to a hose. A nipple 1, which is the main component of the hose joint of the first embodiment, will be described with reference to FIG. The nipple 1 is a member mainly having a cylindrical portion, and its hardness is about 190 in terms of Vickers hardness (Hv), which is harder than the sleeve 2. Note that Hv was measured under a load of 300 g. The material of the nipple 1 is mild steel. This nipple 1 has a central through hole 10 through which fluid such as driving oil and air flows. A ring-shaped sleeve locking groove 12 is formed on the outer peripheral surface of the nipple 1 at a position away from one end 11, as shown in FIG. In addition to the sleeve locking groove 12, the nipple 1 is formed with a plurality of ring-shaped seal grooves 13, 14, and 15 arranged in series in the axial direction. Note that 11a is a guide portion formed at one end 11. The sleeve 2, which is another component of the hose joint of this embodiment, has a cylindrical shape with an inner diameter larger than the outer diameter of the nipple 1, and is a member for caulking the hose to the nipple 1. The hardness of the sleeve 2 is approximately 110 in terms of Bitkers hardness (Hv). Therefore, the sleeve 2 is softer than the nipple 1. That is, in this embodiment, the nipple 1 is set to be Hv80 harder than the sleeve 2. Specifically, the sleeve 2 is formed by cold-forging mild steel as a raw material, heat-treating it at 600-950°C for about 5-180 minutes, and then slowly cooling (annealing). As shown in FIG. 1, this sleeve 2 has a thick ring-shaped engagement part 20 and a cylindrical caulking part 21 extending in the axial direction from the outer circumference of the ring-shaped engagement part 20. . Inner peripheral surface 20 of ring-shaped engaging portion 20
a is approximately parallel to the axis of the nipple 1, and the surface roughness of the inner circumferential surface 20a is approximately 5 μRz. Therefore, the inner peripheral surface 20a is a smooth surface. On the bottom surface of the sleeve locking groove 12 of the nipple 1, two protrusions 23 are formed integrally with the nipple 1. Since this protruding portion 23 is formed integrally with the nipple 1, it is harder than the ring-shaped engaging portion 20 of the sleeve 2. FIG. 4 is a schematic enlarged view of a cross section of the sleeve locking groove 12 including the protrusion 23. As shown in FIG. As shown in FIG. 4, the sleeve locking groove 12 including the protrusion 23
is a form including a circular wave shape with an arc of a predetermined curvature. Here, the tip of the protrusion 23 has a rounded shape with a radius R1, and the bottom surfaces 12a, 12b, 12c are as follows.
It has a roundness with a radius of R2. Radius R1 is approximately 0.1 to 0.5
mm, and the radius R2 is 0.5 to 5.0 mm. As shown in FIG. 1, the dimensional relationship of the first embodiment is as follows: the thickness of the caulking part 21 is t1, the thickness of the ring-shaped engaging part 20 is t3, the width of the sleeve locking groove 12 is l1, and the protrusion part If the height of 23 is h, then t1
is 1.6mm, t3 is 3.0mm, l1 is 3.3mm, h is 0.2mm
That's about it. Here, the inner diameter D1 of nipple 1 is 6.5
mm, outer diameter D2 is 10.2 mm, inner diameter D3 of caulking part 21
is 20mm, outer diameter D4 is 21.5mm, ring-shaped engagement part 20
The inner diameter D5 is 10.1 mm. Now, how to attach the hose joint of this embodiment to the rubber hose 3 in which the reinforcing layer 31 is embedded will be described. First, cover the nipple 1 with the sleeve 2. At this time, as shown in FIG. 1, the ring-shaped engaging portion 20 of the sleeve 2 is made to correspond to the sleeve locking groove 12. Also, the space 2 between the nipple 1 and the sleeve 2
Insert the end 3a of the rubber hose 3 into 5. Then, using a jig (not shown) or the like, the ring-shaped engaging portion 20 of the sleeve 2 is strongly pressed in the centripetal direction, that is, in the direction of the arrow F1. Then, as shown in FIG.
is embedded into the inner circumferential surface 20a of the soft ring-shaped engaging portion 20. As a result, the inner circumferential surface 20a of the ring-shaped engaging portion 20 and the protruding portion 23 engage with each other. In this engaged state, the ring-shaped engagement portion 2 of the sleeve 2
0 and the sleeve locking groove 12 of the nipple 1 is improved. Next, in this state, use a caulking tool or the like to rotate the caulking portion 21 of the sleeve 2 in the centripetal direction, that is, arrow F2.
and apply strong pressure in the F3 direction. This strong pressure plastically deforms the caulking portion 21, thereby caulking the caulking portion 21 of the sleeve 2 as shown in FIG. When caulking the caulking portion 21 in this manner, the soft caulking portion 21 stretches by about 80 Hv compared to the nipple 1. Therefore, the caulking force (caulking force in the directions of arrows F1 and F2) during caulking is directly transmitted to the joint between the inner circumferential surface 20a of the ring-shaped engagement portion 20 and the protrusion 23 of the sleeve locking groove 12. things are suppressed. Therefore, generation of a gap between the inner circumferential surface 20a and the sleeve locking groove 12 is suppressed. When the caulking part 21 is caulked as described above,
The end 3a of the rubber hose 3 is compressed between the nipple 1 and the sleeve 2. In this state, the inner peripheral surface side of the end 3a of the rubber hose 3 flows due to its elasticity and is pushed into the seal grooves 13, 14, 15 of the nipple 1, as shown in FIG. In this example, the hose 3 used had an inner diameter of 9.7 mm and an outer diameter of 20.5 mm. (Effects of the first embodiment) If the hose joint of the present embodiment is used, the structure is such that the soft ring-shaped engaging portion 20 and the hard protruding portion 23 engage with each other, as described above. Therefore,
Unlike the prior art, depression of the sleeve locking groove 12 can be suppressed, and the bonding strength between the ring-shaped engaging portion 20 of the sleeve 2 and the sleeve locking groove 12 of the nipple 1 can be improved. Therefore, the sleeve locking groove 12
The sealing performance of the seal can be improved, and the leakage pressure value can be correspondingly improved. By the way, as a means for forming a protrusion on the bottom surface of the sleeve locking groove 501, as shown in FIG.
A configuration in which 02 is installed upright is also conceivable. However, in this case, since the bottom surface 501a is flat, the ring-shaped engaging portion 60 is inserted into the sleeve locking groove 501.
When 0 is strongly pressed and engaged, a space 503 is often created on the root side of the protrusion 502, as shown in FIG. The reason for this is that, as shown in FIG. 6, there are many parts that are close to right angles to the corners X1, X2, X3, X4, and X5. Therefore, the fit between the sleeve locking groove 501 and the ring-shaped engaging portion 600 cannot be ensured sufficiently, and there is a problem that fluid leakage is likely to occur. In this regard, in this embodiment, the locking groove 12 including the protrusion 23 has a cross section including the axis of the nipple 1, and has a circular wave shape with a circular arc of a predetermined curvature, as shown in FIG. and corners like X1 to X5 do not exist. Therefore, as shown in FIG. 4, the bottom surface 12a,
The cross sections of 12b and 12c include arcs. Therefore, unlike the cases shown in FIGS. 6 and 7, the space 503 is not formed on the root side of the protrusion 23, or is hardly formed.
Therefore, the sleeve locking groove 12 and the ring-shaped engaging portion 20
The compatibility with the sleeve locking groove 12 is good, and the sealing performance of the sleeve locking groove 12 can be improved accordingly. (Test) (A) Leakage pressure test of the hose joint of the first embodiment In the hose joint shown in the first example, the hose joint was attached to the hose 3 in order to confirm the sealing performance improvement effect. The leakage pressure value was checked with the product in place. The test method is to heat rubber hose 3 to 150℃.
After holding the rubber hose 3 for 72 hours to cause some degree of deterioration, the rubber hose 3 was sufficiently filled with driving oil at room temperature, and then pressurized using a nozzle tester. At this time, if pressure exceeding the sealing force between the nipple 1 and the inner surface of the hose 3 is applied, driving oil leaks from the sleeve locking groove 12 described above. The value of the gauge pressure of the nozzle meter when the driving oil leaked as described above was taken as the value of the leakage pressure. The pressure increase rate was 1750±700Kg/ ^cm2 per minute.

【table】

【table】

[Table] As shown in Table 2, the test results were 400 kgf/cm ² or more when the hose crimping rate was 38%. Here, the term "hose crimping rate" means the rate of decrease in hose wall thickness in cross section. (B) Repeated pressure test (impulse durability life test) of the hose joint of the first example Repeated pressure test (impulse durability life test)
In accordance with JISB8360, the oil temperature was 120°C, the pressure fluctuation was 0105 kg/cm ² , and the cycle was 70 cpm. The lifespan was determined by the number of pressurizations until oil leakage occurred. As shown in Table 3, the test results showed a good lifespan of over 1 million units. (C) Hose joints of comparative examples Three hose joints of Comparative Example 1, Comparative Example 2, and Comparative Example 3 shown in Table 1 were prepared as comparative examples.
The hose joints of Comparative Examples 1 to 3 had substantially the same configuration as the hose joint of the first embodiment, and the method of attaching them to the hose was also basically the same. However, the presence or absence of a protrusion, the cross-sectional shape of the sleeve locking groove, the state of engagement between the sleeve locking groove and the ring-shaped engaging portion, and the hardness of the sleeve and nipple differ as shown in Table 1. For the three Comparative Examples 1 to 3 described above, a leak pressure test and a repeated pressurization test were conducted in the same manner as described above. The test results are shown in Tables 2 and 3. That is,
In the hose joint of Comparative Example 1, the hose crimping rate was
At 38%, the leakage pressure was 220 to 250 Kgf/cm ² , and the life in the repeated pressure test was only 200,000 times. In addition, in the hose joint of Comparative Example 2, the leakage pressure was 250 to 300 Kgf/cm ² when the hose crimping rate was 38%.
However, the lifespan in repeated tests was only 350,000 times. In addition, in the hose joint of Comparative Example 3, when the hose crimping rate was 38%, the leakage pressure was 250 to 300 kgf/
cm ² , 200Kgf/cm ² , and 300Kgf/cm ² , and the life in the repeated test was 700,000 times. (D) Evaluation As is clear from the test results shown in Tables 2 and 3, the leakage pressure of the hose joint according to the first example was 400 kgf/cm ^{2 or more, and the leakage pressure of the hose joint according to the first example was 400 kgf/cm 2} or more, and the leakage pressure of the hose joint according to the first example was 400 kgf/cm 2 or more, It can be seen that it is about 1.8 to 1.3 times the pressure and has increased dramatically. Further, it can be seen that the life of the hose joint according to the first example is more than 1 million times, which is 4 to 1.4 times longer than that of Comparative Examples 1 to 3, which is a dramatic increase. [Second Embodiment] In the first embodiment described above, the tip of the protrusion 23 is rounded. However, the protrusion 83 of the sleeve locking groove 80 according to the second embodiment shown in FIG. 8 is not rounded.

[Brief explanation of the drawing]

1 and 2 show a first embodiment of the present invention, FIG. 1 is a cross-sectional view showing the main part with the nipple covered with a sleeve, and FIG. 2 is a main part with the rubber hose attached. FIG. FIG. 3 is a sectional view of the main parts of a conventional hose joint. 4 and 5 show the main parts of the first embodiment of the present invention, FIG. 4 is an enlarged sectional view schematically showing the sleeve locking groove, and FIG. 5 is a ring-shaped sleeve locking groove. FIG. 3 is a cross-sectional view schematically showing a state in which the engaging portions are engaged. Figures 6 and 7 show possible forms of the sleeve locking groove, Figure 6 is an enlarged sectional view of the sleeve locking groove, and Figure 7 is a ring-shaped engaging portion engaged with the sleeve locking groove. It is an enlarged sectional view of the state. FIG. 8 is an enlarged sectional view of the vicinity of the sleeve locking groove according to the second embodiment of the present invention. In the figure, 1 is a nipple, 10 is a central through hole, and 11 is a nipple.
is one end, 12 is a sleeve locking groove, 2 is a sleeve,
20 is a ring-shaped engagement part, 20a is an inner peripheral surface, 21 is a caulking part, 23 is a protruding part, 3 is a rubber hose, 3a
indicate the ends of rubber hoses.

Claims (1)

[Claims for Utility Model Registration] (1) A cylindrical nipple having a ring-shaped sleeve locking groove circumferentially around the outer peripheral surface remote from one end; A metal sleeve having a ring-shaped engaging part with which an inner circumferential surface engages, and a cylindrical caulking part that covers the outer circumferential surface of the nipple coaxially with the nipple from the outer circumferential part of the ring-shaped engaging part. , the nipple has at least one protrusion extending in the direction in which the sleeve locking groove extends and goes around the nipple on the bottom surface of the sleeve locking groove, the nipple The hardness of at least a portion of the sleeve having the sleeve locking groove is Hv140 to 250, the hardness of at least the ring-shaped engagement portion of the sleeve is Hv90 to 120, and The ring-shaped engagement portion is harder than the ring-shaped engagement portion of the sleeve by 50 to 100 Hv or more, and the ring-shaped engagement portion is hardened by strongly pressing the ring-shaped engagement portion of the sleeve into the sleeve locking groove. A joint for a hose, characterized in that the inner circumferential surface of the sleeve is engaged with the protruding portion, and the caulking portion of the sleeve is caulked. (2) The part of the nipple with the sleeve locking groove is closer than the ring-shaped engagement part of the sleeve.
A hose joint as set forth in claim 1 of the utility model registration claim that has a hardness of Hv80 or more. (3) The hose according to claim 1, wherein the sleeve locking groove including the protrusion has a circular wave shape having a predetermined curvature in a cross section passing through the axis of the nipple. Fittings for use. (4) The hose joint according to claim 1, wherein the tip of the protrusion has a rounded cross section passing through the nipple axis. (5) The hose joint according to claim 1, wherein the number of protrusions is two, and the height of the protrusions is within the depth of the sleeve locking groove.