JP3387269B2 - Hose connection fitting - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hose connecting joint, and more particularly to a hose connecting joint connected to an end of a flexible hose used as a high pressure fluid supply pipe for piping of a vehicle or the like. Is.

[0002]

2. Description of the Related Art Conventionally, this kind of hose connecting joint has been used, for example, in a connecting portion of a return tube and a return hose in a pipe (PS pipe) of a power steering device of an automobile. As shown in FIG. 6, in this joint portion, a first annular bulging portion (first bead portion) 55 for preventing slippage and a second annular bulging portion (second bead portion) 51 for positioning are formed by beading. A rubber hose 52 is inserted into the molded tube 50 beyond the first bead portion 55 to a position where the end of the rubber hose 52 is locked to the second bead portion 51, and the first and second bead portions are inserted. 55,51
The clip 53 is tightened and fixed from the outer periphery between them.

Here, the bead processing is an annular bulge that bulges in a desired shape in the radial direction on the outer circumference of the tube by pressing (pressing) the tube with a mold having predetermined irregularities. It is a process of forming a portion (bead portion). The shape from the second bead portion 51 to the end portion of the tube 50, that is, the first hose 52 is inserted.
As the shape of the hose insertion portion including the bead portion 55, for example, those shown in FIGS. 7 and 8 are often used.

The hose insertion portion 60 shown in FIG. 7 has a straight first first straight portion 54 in order from the tube end portion.
And a first annular bulge portion (first bead portion) 55 protruding in the radial direction and a straight second straight portion 56 are continuously formed, and the first bead portion 55 is a concave arc portion. 57, a convex arc portion 58, and a concave arc portion 59. Here, the first bead portion 55 has a bilaterally symmetrical shape around the convex arc portion 58.

In this case, since the inner circumference 52a of the hose is guided by the straight first straight portion 54 when the hose is inserted, the hose 52 is inserted while being prevented from tilting. After the hose is inserted, the first bead portion 5
5 serves as pull-out resistance to prevent the hose 52 from coming off. In addition, the hose insertion portion 67 shown in FIG.
A first bead portion 61 projecting in the radial direction and a straight portion 62 having a straight shape are continuously formed in order from the tube end portion, and the first bead portion 61 has a diameter gradually increasing from the tube end portion. The first taper portion 63 having a larger taper shape, the convex arcuate portion 64 formed continuously with the first taper portion 63, and the first arcuate portion 64 continuing with the concave arcuate portion 64
The second taper portion 6 has a reverse taper shape which is steeper than the taper portion 63.
5 and a concave arc portion 66 connecting the second taper portion 65 and the straight portion 62.

With this, the hose 52 can be easily inserted into the tube 50 by the action of the tapered first taper portion 63 when the hose is inserted, and after the hose insertion is completed, the convex arc portion 64 and the The protruding shape in the radial direction formed by the two taper portions 65 serves as pull-out resistance to prevent the hose 52 from coming off. Here, the performance with respect to the disengagement / insertability of the hose 52, which is a required quality in such a joint portion, is determined by the outer diameters of the convex arc portions 58 and 64 in FIGS. 7 and 8, that is, the first bead portions 55 and 61. Secured by adjusting the outer diameter of the top of

[0007]

However, in the prior art, it is difficult to have sufficient performance in terms of slip-out and insertability in view of the component tolerance, and the failure rate is high in the high-pressure / high-load hydraulic path. There was the problem of becoming expensive.
The conventional characteristic shown by the alternate long and short dash line in FIG. 3 is that the displacement t and the load (insertion force) at the time of hose insertion in the hose insertion portion in which the first bead portion 55 formed of three arcs as shown in FIG. 7 is formed. ) F, experimental data showing the relationship of F. As shown in the experimental data, surge-like load increase occurs when the displacement (insertion amount) of the hose 52 is small. This is because the radius of curvature of the concave arc portion 57 and the convex arc portion 58 that form the first bead portion 55 is small, and therefore the end portion of the hose 52 is caught by the concave arc portion 57 of the first bead portion 55 and becomes a large resistance. This is because it ends up.

In addition, a surge-like first peak load
F_MAX1'After passing the first peak load F _MAX1Less than
Second peak load F_MAX2'Is occurring. this
Is outside the straight parts 54 and 56 in the hose insertion part.
The diameter A'is set slightly larger than the inner diameter a'of the hose.
Because it is fixed (φA '> φa'), the end of the hose
Abut the second straight portion 56 beyond the first bead portion 55
When it does, it abuts against the straight portion 56 from an acute angle direction.
As the hose 56 tries to contract,
A large resistance that the bite 56 bites into the second straight portion 56
This is because

As described above, the structure shown in FIG. 7 has a particular problem in the insertability such that a surge-like load is generated and the insertion force after passing the first bead portion 55 cannot be kept low. Further, the conventional characteristic shown by the chain double-dashed line in FIG.
The displacement (insertion amount) t and the load (insertion force) F at the time of hose insertion in the hose insertion portion in which the first bead portion 60 composed of the tapered portion 62 and the arc portion 63 as shown in FIG. 8 is formed.
It is the experimental data showing the relationship of, and as shown in this experimental data, the peak load F _MAX2 'which is equivalent to the above-mentioned second peak load also occurs in this case. That is, the first
Outer diameter of straight portion 61 excluding bead portion 60 φA ″
This is also because φA ″> φa ′ with respect to the inner diameter φa ′ of the hose. Therefore, even in this case, the first
There was a problem that the load (insertion force) F after passing over the bead portion 60 could not be kept low.

Further, in the hose inserting portion 67 shown in FIG. 8, since the shape of the hose introducing portion is tapered, the inserting direction of the hose 52 may not be stable at the beginning of inserting the hose, and the hose 52 may tilt. , There was a problem of poor insertability.

[0011]

The hose connection joint of the present invention has been made to solve the above-mentioned problems. According to the invention of claim 1, a retaining member radially protruding to the outer periphery of the tube is provided. In a hose connecting joint in which a hose is inserted beyond the bead part, in order from the tube end part into which the hose is inserted, the straight first part, the bead part, the straight part The second straight portion is continuously formed, and the bead portion includes a hose insertion side arc portion having a large radius of curvature on the hose insertion side and a bead back side arc portion having a small radius of curvature on the bead back side. And the outer diameter of the second straight portion is set to be smaller than the inner diameter of the hose of the hose.

Further, in the invention according to claim 2, in the hose connection joint according to claim 1, a short connecting the arc portion of the hose insertion side and the arc portion of the bead rear surface to the top of the bead portion. It is characterized in that a straight top straight portion is formed.

[0013]

With the above construction, in the invention according to the first aspect, when the hose is gradually inserted from the tube end, first, the inner circumference of the hose is guided by the first straight portion and smoothly inserted without tilting. It The hose end engages the hose insertion side arc part where the radius of curvature of the bead part is set large, and the hose end is guided by the hose insertion side arc part and gradually inserted into the hose while the hose inner diameter is gradually deformed. To go.

When the hose is further inserted, the end of the hose goes over the top of the bead, and the inner diameter of the hose gradually shrinks,
When the hose end is brought into contact with the second straight portion from an acute angle direction and further inserted, the hose end is guided and inserted into the second straight portion. Here, since the outer diameter of the second straight portion is set to be smaller than the inner diameter of the hose, the bead end portion comes into contact with the second straight portion from an acute angle direction and is guided and inserted into the second straight portion. In the process of inserting, the insertion resistance can be suppressed to be small and the insertion can be smoothly performed.

When the hose is completely inserted, the radius of curvature of the arc portion of the bead back side of the bead portion is set to be small and the outer diameter of the second straight portion is set to be smaller than the inner diameter of the hose. Since the step difference with the straight portion becomes large, the difficulty of pulling out the hose is increased, and the performance against pulling out the hose is significantly improved.
Further, in the invention according to claim 2, since the short straight-shaped top straight portion is formed at the top of the bead portion, when the hose end portion is further inserted through the hose insertion side arc portion, it becomes short. Although it relates to the straight top of the hose, the length of the straight top is short, so the amount of contact between the inner circumference of the hose and the bead at the top of the bead is kept small, and the hose does not increase in insertion force. It is possible to smoothly pass through the top straight portion. Further, by forming this short straight-shaped top straight portion, it is possible to easily manage the roundness at the top of the bead portion.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial vertical cross-sectional view of a hose connection joint, in which 10 is a tube made of a plastically deformable material such as iron. A first straight portion 11 having a straight shape, a first annular bulging portion (first bead portion) 12 for preventing a hose from protruding in a radial direction, a second straight portion 13 having a straight shape, and a first straight portion for positioning a hose. Two annular bulging portions (second bead portions) 14 are continuously formed.

Here, the first straight portion 11, the first bead portion 12, and the second straight portion 13 are the hose insertion portion 15, and are brought into contact with and locked by the second bead portion 14. The end of the flexible rubber hose 16 shown by the one-dot chain line is inserted, and in this state, it is clamped and fixed from the outer periphery by a clip (not shown). As shown in FIG. 2, the first bead portion 12 includes the first straight portion 1
1 having a large curvature concave arc portion 20, a large curvature convex arc portion 21 continuing to this concave arc portion 20, a short straight-shaped top straight portion 22 continuous to this convex arc portion 21, and this top straight It is composed of a convex arcuate portion 23 having a small curvature continuous to the portion 22, and a concave arcuate portion 24 having a small curvature continuous to the convex arcuate portion 23 and the second straight portion 13.

Here, the concave circular arc portion 20 and the convex circular arc portion 21 form a hose insertion side circular arc portion, and the convex circular arc portion 23 and the concave circular arc portion 24 form a rear side circular arc portion. , The hose insertion side arc portions 20 and 21 are the rear side arc portions 2
The radius of curvature is set to be larger than those of Nos. 3 and 24, and the first bead portion 12 has a laterally asymmetrical shape in FIG.

The outer diameter B of the second straight portion 13 is set to be slightly smaller than the inner diameter a of the rubber hose 16. Here, the inner diameter a of the hose is, for example, a =
When φ9.9 [mm], the first straight portion 1
The outer diameter A of 1 is A = φ10 [mm], the outer diameter B of the second straight portion 13 is φ9.7 ≦ B <φ9.9 [mm], the outer diameter of the top straight portion 22, that is, the first The bead diameter C of the bead portion 12 is set to 11.5 ≦ C ≦ 12.5 [mm], the radius of curvature R1 of the concave arc portion 20 which is the hose insertion side arc portion is 3 ≦ R1 ≦ 4 [mm], and the convex portion is convex. It is appropriate that the radius of curvature R2 of the arc portion 21 is 0.5 ≦ R2 ≦ 1.5 [mm]. At this time, the maximum value θ _max of the angle between the tangent line at any position in the concave arc portion 20 and the convex arc portion 21 and the first straight portion 11 or the second straight portion 13 is 20 ° ≦ θ. _It is suitable that _max ≤ 40 °.

The radius of curvature R3 of the convex arcuate portion 23 which is the arcuate portion on the back side of the bead is 0.3 ≦ R3 ≦ 1.5 [m
m], the radius of curvature R4 of the concave arc portion 24 is 0.1 ≦ R4
≦ 0.8 [mm], the straight length D of the first straight portion 11 is 1 ≦ D ≦ 2 [mm], and the straight length E of the top straight portion 22 is about 0 <E ≦ 0.5 [mm]. It is appropriate to do.

Although the outer diameter A of the first straight portion 11 is set to be slightly larger than the hose inner diameter a of the rubber hose 16 in the above description, like the second straight portion 13, φ9.7 ≦ A <φ9. It may be set to be slightly smaller than the inner diameter “a” of the rubber hose 16 as 0.99 [mm]. In FIG. 2, 17 is a chamfer formed at the end of the hose.

Next, the operation of inserting the hose into the hose connecting joint of the present invention having the above structure will be described with reference to the experimental data showing the relationship between the displacement and the inserting force when inserting the hose shown in FIG. . When the hose 16 is gradually inserted from the tube end, first, the hose inner circumference 16a is guided by the first straight portion 11 and smoothly inserted without tilting.

The end of the hose engages with the concave arc portion 20 of the first bead portion 12. The hose inner diameter is gradually deformed by the concave arc portion 20 so that the hose inner diameter is gradually deformed and smoothly inserted. 21 through the top straight portion 22
Up to. In this process, since the concave arc portion 20 and the convex arc portion 21, that is, the hose insertion side arc portion are configured with a large radius of curvature, the load F as the insertion force is as shown in FIG.
The load F is suppressed to be small like the experimental data of the present invention shown by the solid line, without the surge-like increase as in the conventional experimental data shown by the alternate long and short dash line.

When further inserted, the short straight-shaped top straight portion 22 is involved. However, since the top straight portion 22 is short, the inner circumference 16a of the hose 16 and the first bead portion 12 are provided at the top of the first bead portion 12. The hose end passes smoothly through the top straight portion 22 without a large increase in the load because the amount of contact with the hose is suppressed.

When the hose is further inserted, the end of the hose completely exceeds the first bead portion 12, and the inner diameter of the hose gradually shrinks, abuts against the second straight portion 13 from an acute angle direction, and is further inserted. Then, the end of the hose is guided by the second straight portion 13 and inserted. Here, since the outer diameter B of the second straight portion 13 is set to be slightly smaller than the inner diameter a of the hose, the hose end portion passes over the first bead portion 12 and contacts the outer periphery of the second straight portion 13 from the acute angle direction. The peak load F _MAX generated when they come into contact with each other is suppressed to be small, and the hose end portion is suppressed to have a small insertion resistance, so that the hose end is smoothly inserted into the second straight portion 13 without being caught.

Further, the bead end portion is the second straight portion 1
3 and is inserted to a position where it abuts on the second positioning bead portion 14. As described above, the inserting operation of the hose 16 into the hose inserting portion 15 of the tube 10 is completed, and in this state, the outer periphery of the second straight portion 13 is clamped and fixed by a clip (not shown).

Now, in the tube 10 of the rubber hose 16,
When the insertion of the rubber hose 16 is completed,
Inner circumference 16a and bead back side arc of the first bead portion 12
There is a slight gap 18 between the concave arc part 24
Is made. Next, using the experimental data shown in FIG. 4 and FIG.
The performance of the present invention against the hose disconnection will be described. here
In Fig. 4, the tube diameter was increased or decreased with respect to the hose inner diameter.
FIG. 5 is experimental data showing the change of the escape pressure P at the time.
The radius of curvature R3 of the convex arc portion 23 on the back side of the bead was changed
FIG. 4 is experimental data showing the change of the escape pressure P with time.
In both Fig. 5, reference pressure P_AThe experimental value is infinite with 1 as
It is the original one, and the release pressure reference value P_AAs a product
Is a reference value for judging whether the quality is good or not, and the release pressure reference value P _AAbove
It is acceptable if the condition that there is is satisfied.
In addition, ΔaB is a diameter difference between the hose inner diameter and the tube diameter.
It

In FIG. 4, it can be seen that the outlet pressure P tends to increase as the tube diameter is made smaller than the hose inner diameter. Therefore, as in the present invention, the second straight portion 13
By making the outer diameter B of the hose smaller than the inner diameter a of the hose,
Outer diameter of the top straight portion 22, that is, the first bead portion 12
It is clear that the step ΔBC with respect to the bead diameter C increases, so that the difficulty of pulling out increases and the performance against pulling tends to be improved.

The escape pressure P due to the change in the diameter difference ΔaB
Is effective when the tube diameter is close to the hose diameter, and if the diameter difference ΔaB increases by a predetermined amount or more, the escape pressure P becomes constant regardless of the increase in the diameter difference ΔaB. Further, in FIG. 5, it can be seen that the escape pressure P increases as the radius of curvature R3 of the bead back side convex arc portion 23 is reduced. Therefore, as in the present invention, the bead back side circular arc portion 23,
It is apparent that by setting the curvature radii R3 and R4 of 24 to be small, the difficulty of pulling out increases and the performance against pulling out is improved.

Further, this makes it possible to increase the dimensional tolerance of the bead diameter C. Further, in the above description, the second bead portion 14 for hose positioning is provided on the tube 10. However, this may be any other member as long as it locks the end of the hose to position the rubber hose 16, and is constituted by a separate member. However, the shape is not limited. Furthermore, in the above, in particular, a short straight-shaped top straight portion 22 is provided at the top of the first bead portion 12, and this top straight portion 22 is used to form the tube 1 when the first bead portion 12 is molded.
Since the outside of the plastically deformed radial direction of 0 is inscribed in the bead molding die, the roundness of the bead top can be easily controlled, and the bead top can be easily controlled. It is possible to prevent the hose 16 from coming off due to the variation in the roundness and the occurrence of oil leakage due to poor sealing. Furthermore, by shortening the straight length of the top straight portion 22, it is possible to suppress the amount of contact with the hose inner circumference 16a, so that it is possible to prevent an increase in contact resistance between the rubber hose 16 and the first bead portion 12.

In the above description, the straight portion having a short straight shape is provided at the top of the bead, but it may have an arc shape. Further, in the above description, these arcuate portions 20 and 21 are connected between the concave arcuate portion 20 and the convex arcuate portion 21, which are the arcuate portion on the hose insertion side, to form a tapered taper portion whose diameter gradually increases. You may do it.

Further, in the above, the inner diameter a of the hose is a = φ9.
An example of various dimensions of the hose insertion part in the case of 9 [mm] is shown, but when the inner diameter a of the hose changes, the dimensions of the hose insertion part of the tube 10 should be changed at the same rate. According to the configuration of the present invention, the effects of the present invention can be obtained. That is, various modifications and adaptations are possible without departing from the technical idea of the present invention.

[0033]

As described above, in the hose connecting joint of the present invention, in the invention according to claim 1, the radius of curvature of the arc portion on the hose insertion side which constitutes the bead portion is increased so that the arc portion on the rear surface of the bead is formed. By making the radius of curvature smaller and making the outer diameter of the straight part at the position beyond the bead smaller than the inner diameter of the hose, it is possible to greatly improve the ease of removal and insertion. Improves reliability in case. Furthermore, the dimensional tolerance of the bead diameter can be increased by greatly improving the detachability and insertability.

In addition, in the invention described in claim 2, in addition to the structure described in claim 1, a short straight portion is provided at the top of the bead between the arc portion on the hose insertion side and the arc portion on the back surface of the bead. Therefore, when molding the bead part, the outer part of the tube in the radial direction is inscribed internally by the bead part molding die to form the straight part, which facilitates the management of the roundness of the bead top. Therefore, it is possible to prevent the occurrence of oil leakage due to the hose coming off due to the variation in the roundness of the top of the bead and the poor seal. Furthermore, by shortening the length of the straight part at the top of the bead, the amount of contact between the hose inner circumference and the tube can be suppressed to a small amount, preventing an increase in contact resistance between the hose and the bead part and improving insertability. Can contribute to.

[Brief description of drawings]

FIG. 1 is a partial side view of a hose connection joint showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part in FIG.

FIG. 3 is experimental data showing changes in load with respect to displacement when a hose is inserted.

FIG. 4 is an experimental data showing a change in the escape pressure when the tube inner diameter is changed with respect to the hose inner diameter.

FIG. 5 is experimental data showing changes in the escape pressure when the radius of curvature of the convex arc portion on the rear surface of the bead is changed.

FIG. 6 is a connection state diagram of a conventional hose and a hose connection joint.

FIG. 7 is a partial side view of a conventional hose connection joint.

FIG. 8 is a partial side view of a conventional hose connection joint.

[Explanation of symbols]

10 tubes 11 1st straight section 12 First bead part 13 Second straight section 14 Second bead part 15 Hose insertion part 16 hoses 20 Concave arc part (arc part on hose insertion side) 21 Convex arc part (arc part on hose insertion side) 22 Top straight part 23 Convex arc part (bead back side arc part) 24 concave arc part (bead back side arc part)

Claims (2)

(57) [Claims] 1. A hose connecting joint in which a retaining bead portion protruding in a radial direction is provided on an outer circumference of a tube, and a hose is inserted beyond the bead portion, from a tube end portion into which the hose is inserted. In order, a straight first straight portion, the bead portion, and a straight second straight portion are continuously formed, and the bead portion is
A hose insertion side arc portion having a large radius of curvature on the hose insertion side and a bead back side arc portion having a small radius of curvature on the bead rear surface side, and the outer diameter of the second straight portion is the hose inner diameter of the hose. A hose connection joint characterized by being set smaller. 2. The hose connecting joint according to claim 1, wherein a short straight top straight portion connecting the arc portion on the hose insertion side and the arc portion on the back surface of the bead is formed at the top of the bead portion. A hose connection joint characterized in that