JPH04131587A - Hose joint structure - Google Patents

Abstract

PURPOSE:To maintain desirable sealing performance in hose joint structure for connecting an inner and an outer cylinders to a hose inserted between the inner and outer cylinders by setting the inclined face angle on the outer cylinder front end part side between approximately V-shape inclined faces of the fastening parts of the outer cylinder, larger than the inclined face angle on the rear end part side. CONSTITUTION:An inner cylinder 21 and an outer cylinder 22 respectively made of metal are formed integrally through a screw member 24, and a through hole 26 for inserting a pressure proof hose 25 is formed between both cylinders 21, 22. The outer cylinder 22 is provided with two fastening parts 28, 29. The first and second fastening parts 28, 29 are formed contractedly into approximately V-shape longitudinal section by a specified fastening jig after inserting one end part 25a of the hose 25 into the through hole 26, and the angle theta2 (atmospheric air side contact pressure gradient) of a second inclined face 31 on the front end part 22a side is set larger than the angle theta4 (atmospheric air side contact pressure gradient) of a fourth inclined face 33 on the rear end part 22b side. As a result, desirable sealing performance can be maintained for a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a hose joint structure used for hydraulic piping of equipment, etc.

As is well known in the art, for example, in hydraulic piping used in vehicle power steering systems, the end of a pressure-resistant hose is connected to a vane pump or the like using a highly sealable hose fitting. As an example, Jikko 2-81
Some of these are described in Publication No. 56, etc.

That is, the conventional hose joint structure, as shown in FIG.
A metal inner cylinder 1 having a male threaded part 3 at its tip connected to a discharge port of a vane pump, and a metal outer cylinder arranged on the outer periphery of the inner cylinder 1 and integrally formed through the male threaded part 3. 2, and an annular insertion hole 5 through which one end 4a of the pressure hose 4 is inserted is formed between the two.

After the one end 4a of the hose 4 is inserted into the insertion hole 5, the outer circumferential surface 2a of the outer cylinder 2 is inserted at two places in the axial direction, front and rear.
The hose 4 is crimped and connected to the inner cylinder 1 and the outer cylinder 2 by crimping them into a substantially V-shaped vertical section with a flat claw type crimping jig at a predetermined torque.

Problems to be Solved by the Invention By the way, in the above-described hose joint structure, the sealing conditions for the pressure-resistant hose 4 to which hydraulic pressure or hydraulic pressure is applied are such that the hose 4 is sealed at any of the locations where the pressure is applied, such as at the crimped portions 6 and 7. It is necessary that the contact pressure to the outer circumferential surface acts continuously on the circumference of the hose 4 without interruption, and that it is equal to or higher than the hydraulic pressure.

However, in an oil leak test of the hose under conditions where the oil pressure fluctuates and vibration conditions are applied, assuming that the vehicle is actually running or equipment is in operation, the hose 4 was There is a slight reciprocating motion (vibration) in the axial direction relative to the outer cylinder 1.2, so the sealing conditions are not necessarily limited to the above conditions, but also the conditions between the inner cylinder, the outer cylinders 1 and 2, and the hose 4. It became clear that it was also necessary to consider the shape of the contact pressure distribution on the sealing surface as a sufficient condition.

According to the sealing theory of reciprocating seals such as oil seals, in the seal contact pressure distribution shape, the hydraulic side contact pressure gradient is (di)/dx)oil, and the atmospheric side contact pressure gradient is (dp/clx)air. The sealing conditions are d
p/dx l oi l-M^X≧l dp/dx l
This is interpreted as a condition expressed in the air-MAX formula.

(p-contact pressure, x=coordinates of the contact portion, d=sign of differential) On the other hand, such a seal contact pressure distribution shape is based on the shape of the caulking portions 6, 7, that is, the opposing inclined surfaces 8, 9, . 't
It is governed by the angles o and 11.

However, in the conventional hose joint structure, the angles of the front and rear slopes 8, 9, 10, and 11 are set to be between the paths, without taking into account the sealing theory of oil seals, etc. as described above. There is. In other words, as shown in FIG. The angle θ of the second inclined surface 9 on the side is set to be approximately equal, and the angle θ3 of the third inclined surface 10 on the front side with respect to the vertical plane X of the second crimped portion 7 on the rear end side The angle θ4 of the fourth inclined surface 11 on the side is also set substantially equal.

Therefore, the conditions of the sealing theory of the sound seal cannot be satisfied, and the inner cylinder 1. Good sealing performance between the outer cylinder 2 and the hose 4 cannot be maintained.

Means for Solving the Problems The present invention has been devised in view of the problems in the conventional hose structure, and in particular, the central axis of the inner cylinder is fixed on the approximately ■-shaped inclined surface of the crimped portion of the outer cylinder. It is characterized in that the angle of the inclined surface on the front end side of the outer cylinder is set larger than the angle of the inclined surface on the rear end side with respect to a plane perpendicular to the outer cylinder.

Effect: According to the above configuration, the conditions derived from the oil seal sealing theory as described above can be satisfied. In other words,
By setting the slope angle of the front end of the outer cylinder of the caulking part to be larger than the slope angle of the rear end, the contact pressure acts strongly in the opposite direction to the hose insertion direction, which results in a good Seal performance can be maintained.

Example Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 shows an embodiment of the hose joint structure according to the present invention, in which reference numeral 21 indicates a metal inner cylinder, and 22 indicates an outer peripheral surface 2 of the inner cylinder 21.
This is a metal outer cylinder that covers the inner cylinder 21 and the outer cylinder 2.
2 is the front end portion 21a of each other.

21 and 22, and an annular insertion hole 26 through which one end 25a of the pressure hose 25 is inserted is formed between the two 21 and 22. The screw member 24 also includes a hexagonal head 24a to which a tool such as a spanner is engaged, and a hollow male threaded portion 24b at the tip of the hexagonal head 24a to be screwed onto a vane pump or the like of a power steering device. It consists of

The outer cylinder 22 has two parts extending in the axial direction approximately at the center of the outer circumferential surface 27.
Two caulking portions 28 and 29 are formed along the circumferential direction, and the first and second caulking portions 28 and 29 are formed along the circumferential direction. The second crimping portions 28 and 29 are formed by inserting one end portion 25a of the hose 25 into the insertion hole 26, and then constricting the second crimping portions 28, 29 to have a substantially V-shaped longitudinal section using a predetermined crimping jig. The first caulking portion 28 on the front end side of the outer cylinder 22 is formed at a first inclined surface 30 at an angle of 30 degrees on the front end part 22a side with respect to a plane X1 perpendicular to the central axis O of the inner cylinder 21, as shown in FIG. θI (hydraulic side contact pressure gradient) is
b side second inclined surface 31 angle θ, (atmosphere side contact pressure gradient)
is set smaller than.

That is, the first inclined surface 30 is formed substantially perpendicular to the central axis O and is set at a small angle θ, while the second
The inclined surface 31 is formed more gently than the first inclined surface 30 and is set at a larger angle θ.

In addition, the second crimped portion 29 on the rear end side has an angle θ of the third inclined surface 32 on the front end portion 22a side (hydraulic side contact pressure gradient) with respect to the vertical plane X with respect to the central axis O of the inner [21]. The angle θ4 of the fourth inclined surface 33 on the rear end portion 22b side is set larger than the angle θ4 (atmospheric side contact pressure gradient). That is, like the second inclined surface 31, the third inclined surface 32 is formed gently and set at a large angle θ3, while the fourth inclined surface 33, like the first inclined surface 30, is formed with a large angle θ3. It is formed substantially perpendicular to the angle θ4 and set at a small angle θ4.

Therefore, according to this embodiment, the second crimped portion 29 has a shape that conforms to the oil seal sealing theory;
In the first crimped portion 28, the opposite condition is met. That is, by setting the first inclined surface angle θ of the first crimped portion 28 to be smaller than the second inclined surface angle θ, the contact pressure is reduced to l dp/dx : oil as shown in the right column of FIG. -MA
X < l dp/dx l air-MAX.

Therefore, the pressure caused by the first crimping portion 28 is applied to the hose 2
5, the removal of the hose 25 acts strongly in the direction opposite to the direction of the distal end. As a result, even if the hose joint is vibrated and the hose 25 is continuously subjected to reciprocating motion (vibration) in the axial direction, the hose 25 will not be accidentally pulled out of the insertion hole 26, and the hose 25 will always be reliably pulled out. A connected state is obtained.

On the other hand, the third inclined surface angle θ of the second crimped portion 29.

By setting θ4 to be larger than the fourth slope angle θ4, the contact pressure becomes dp/dxl as shown in the left column of FIG.
oil-MAX> : dp/dx l air-M
It becomes AX. Therefore, the pressure exerted by the second crimping portion 29 acts strongly in the direction opposite to the direction in which the hose 25 is inserted. As a result, the contact surface pressure between the inner circumferential surface of the hose 25 and the outer circumferential surface 23 of the inner tube 21 near the second crimped portion 29 is high, and this surface pressure distribution is larger on the third inclined surface 32 side, so that it is always reliable. And good sealing performance is maintained.

It goes without saying that the present invention is not limited to the configuration of the embodiment described above, but can be applied to other hydraulic equipment.

Effects of the Invention As is clear from the above explanation, according to the hose joint structure according to the present invention, since the inclination angles of the front and rear crimped parts formed on the outer peripheral surface of the outer cylinder are respectively set to predetermined angles, Good sealing performance can be maintained over a long period of time.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view showing an embodiment of the hose joint structure of the present invention, Fig. 2 is an explanatory diagram of the main parts of this embodiment, and Fig. 3 is a diagram showing the relationship between the inclination angle of the crimped part and the hose according to the present embodiment. A characteristic diagram showing the contact pressure distribution of the inner cylinder, FIG. 4 is a sectional view of a main part showing a conventional hose joint structure, and FIG. 5 is an explanatory diagram of the main part of the conventional hose joint structure. 21... Inner cylinder, 22... Outer cylinder, 22a... Front end, 22b... Rear end, 23... Inner cylinder outer peripheral surface, 25...
...Hose, 25a...One end, 27...Outer cylinder outer peripheral surface, 29...Clinching part, 32...Third slope, 33
... Fourth inclined plane, O... Central axis, X... Vertical plane.

Claims (1)

[Claims] (1) One end of the hose is inserted between an inner cylinder and an outer cylinder that covers the outer peripheral surface of the inner cylinder, and the outer peripheral surface of the outer cylinder is crimped into a substantially V-shaped longitudinal section to connect the inner and outer cylinders. In a hose joint structure for connecting a hose, the angle of the inclined surface on the front end side of the outer cylinder is set at the rear of the substantially V-shaped slope of the caulked portion of the outer cylinder, with respect to a plane perpendicular to the central axis of the inner cylinder. A hose joint structure characterized by having a slope angle larger than that of the end side.