JP2013002515A - Hose fastening structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hose fastening structure capable of improving sealing characteristics and resistance to come-out between a hose and a connection part without losing durability or assemblability.SOLUTION: To one end part of a rubber hose 1, a connection part 3 of a metal-made pipe 2 is inserted and connected. Then, a resin-made socket 4 that exerts pressing force from the outer circumference of the rubber hose 1 toward the inside is attached and fastened. On the outer circumference of the connection part 3, a first bead part 6 for preventing the rubber hose from coming out from the tip end side and a second bead part 7 for restricting an insertion end of the rubber hose are formed. The socket 4 is attached between the first bead part 6 and the second bead part 7 and further, on the inner surface side of the socket 4, a plurality of resin-made inner teeth 5 in the shape of a protrusion is formed so as to be capable of tilting in the axial direction of the pipe 2 and the outer surface of the rubber hose 1 is held by the fastening force thereof.

Description

  The present invention relates to a fastening structure between a hose and a hose connection fitting.

  2. Description of the Related Art Conventionally, in a power steering apparatus, a return oil flow path returned from a steering apparatus body to a pump uses a rubber hose connected with a metal pipe joint (pipe). A hose clip (spring clip) using spring steel is known as a method for fixing the coupling portion between these rubber hoses and pipes and preventing the rubber hose from coming off or shifting (see, for example, Patent Document 1). As other examples, fixing by caulking (see, for example, Patent Document 2) and fastening by a screw-type fixing band are performed.

Japanese Utility Model Publication No. 5-1092 JP 2003-35388 A

  In recent years, hydraulic power steering devices are often used in large vehicles such as trucks, and the pressure applied to the low-pressure piping tends to increase as the hydraulic flow increases and the pressure increases, and the rubber hose may come off the pipe due to the high pressure. It is done. For this reason, the spring force of the spring clip is increased to increase the tightening force and the frictional force further improves the hose detachment prevention performance, but the durability of the rubber hose is reduced and the effect is small. Further, it is conceivable to reduce the inner diameter of the rubber hose and increase the adhesion of the connecting portion by the rubber hose itself, but the assembling property when the rubber hose is inserted is deteriorated. In addition, although a method of increasing the tightening force by caulking or screw band fixing is also taken, workability is deteriorated because it becomes difficult to insert a rubber hose when the vehicle is assembled in a later process.

  The present invention has been made in order to solve the above-mentioned problems, and its purpose is to improve the sealing performance and the disconnection resistance between the hose and the connecting portion without impairing the durability and assembling performance. It is in providing the hose fastening structure which can do.

  In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that in the fastening structure of the hose in which the flexible hose is fitted and connected to the connection portion of the metal tube and is fastened and fixed by the fastening member from the outer periphery. A first annular large-diameter portion for retaining the flexible hose and a second annular large-diameter portion that regulates the insertion end of the flexible hose are formed on the outer periphery of the portion; The fastening member fastens an outer peripheral surface of the flexible hose between the first annular large diameter portion and the second annular large diameter portion, and an inner diameter of a fastening portion of the flexible hose is , Which is made of a resin member smaller than the outer diameter of the flexible hose, and can be tilted in the axial direction of the metal tube on the inner surface side to be fitted with the flexible hose, and has a projecting cross section The gist is that a plurality of internal teeth made of an elastic member are formed in the circumferential direction.

  According to the said structure, a flexible hose is inserted in the connection part of a metal pipe, and it clamps and fixes to the outer periphery of the flexible hose of the connection part with a resin-made clamping member. At this time, a plurality of protrusion-shaped inner teeth provided in the circumferential direction on the inner surface side of the tightening member press and tilt the outer surface of the flexible hose, and sandwich the flexible hose with respect to the radial direction of the metal tube. ing. Since the tightening member and the metal tube are also mechanically held, the flexible hose is strongly fixed to the metal tube via the tightening member. As a result, the holding force between the flexible hose and the metal tube can be improved.

  It is possible to provide a hose fastening structure capable of improving the sealing property and the slip-proof performance between the hose and the connecting portion without impairing the durability and the assembling property.

It is sectional drawing of the connection part of the rubber hose of embodiment which concerns on this invention. It is detail drawing explaining the structure of a socket. (a), (b), (c) is a figure explaining the assembly | attachment procedure of a rubber hose, a pipe, and a socket.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
FIG. 1 is a cross-sectional view of a connection portion of a rubber hose 1 according to an embodiment of the present invention. A connection portion 3 of a metal pipe 2 is fitted and connected to one end portion of the rubber hose 1. A resin socket 4 on which a pressing force acts from the outer periphery to the inner side of the rubber hose 1 is attached to fasten and fix the rubber hose 1. A flare nut (not shown) is provided at the other end of the connecting portion 3 of the pipe 2 and is connected to a pump or the like by the flare nut.

  A first bead portion 6 for preventing the rubber hose from coming off and a second bead portion 7 for regulating the rubber hose insertion end are formed on the outer periphery of the connecting portion 3 from the front end side. The socket 4 is attached between the first bead portion 6 and the second bead portion 7 and holds the rubber hose 1 with its tightening force. Further, on the inner surface side of the socket 4, a plurality of resin-made internal teeth 5 having a projecting (wedge-shaped) cross section are formed so as to be able to tilt in the axial direction (withdrawal direction) over the entire circumference. Holding with tightening force.

FIG. 2 is a detailed diagram illustrating the structure of the socket 4.
The inner diameter a of the hole into which the pipe 2 of the socket 4 is inserted is larger than the outer diameter of the pipe 2 and the outer diameter of the second bead portion 7 provided in the connecting portion 3 of the pipe 2 with reference to FIG. It is formed smaller than. In addition, referring to FIG. 1, the inner diameter b of the inner teeth 5 of the socket 4 is formed to be smaller than the outer diameter of the rubber hose 1 when the socket 4 is not fitted to the outer periphery of the rubber hose 1. ing.

FIGS. 3A, 3B and 3C are diagrams for explaining the assembly procedure of the rubber hose 1, the pipe 2 and the socket 4 shown in FIG.
As shown in FIG. 3A, first, the socket 4 is inserted into the pipe 2 in which the first bead portion 6 and the second bead portion 7 are formed in advance in the connection portion 3 of the pipe 2. Next, as shown in FIG. 3B, the rubber hose 1 is inserted up to the second bead portion 7 of the pipe 2. At this time, the 2nd bead part 7 acts for rubber hose insertion end regulation. Subsequently, as shown in FIG. 3 (c), the socket 4 is inserted and fitted to the connection portion 3 toward the tip of the pipe 3. At this time, the tip end portion of the inner tooth 5 of the socket 4 is pushed and tilted by the rubber hose 1 in the direction opposite to the traveling direction of the socket 4 (withdrawal direction), so that the entire outer surface of the rubber hose 1 has a plurality of inner portions of the socket 4. The teeth 5 are tightened and held.

  As described above, according to the present embodiment, the rubber hose 1 is fitted and connected to the connection portion 3 of the pipe 2, and the resin socket 4 is fastened and fixed to the outer periphery of the rubber hose 1 of the connection portion 3. At this time, a plurality of protruding resin inner teeth 5 provided on the entire inner surface of the socket 4 press and tilt the outer surface of the rubber hose 1, and hold the rubber hose 1 in the radial direction of the pipe 2. Since the socket 4 and the pipe 2 are also mechanically held, the rubber hose 1 is strongly fixed to the pipe 2 through the socket 4 and the holding force between the rubber hose 1 and the pipe 2 is improved. To do. Further, since the plurality of internal teeth 5 are provided, the socket 4 comes to press against the rubber hose 1 in a wide range, and works effectively.

  By the said structure, without impairing durability and assembly | attachment property of the rubber hose 1, it is cheap and can improve the sealing performance between the rubber hose 1 and the connection part 3 of the pipe 2, and a slip-proof performance.

Although one embodiment according to the present invention has been described above, the present invention can also be implemented in other forms.
In the above embodiment, the inner teeth are provided over the entire inner periphery of the socket. However, the present invention is not limited thereto, and the inner teeth may be partially arranged, for example, in a staggered manner according to the required holding force. Further, the number of steps of the inner teeth may be changed according to the required holding force.
Moreover, in the said embodiment, although the internal tooth was formed with the resin-made members integral with the socket, you may use another elastic member.
In addition, various design changes can be made within the scope of matters described in the claims.

1: rubber hose, 2: pipe, 3: socket connection, 4: socket, 5: socket tooth,
6: first bead part of the pipe, 7: second bead part of the pipe,
a: Socket inner diameter, b: Socket inner tooth inner diameter

Claims (1)

In a hose fastening structure in which a flexible hose is fitted and connected to a connection part of a metal tube, and tightened and fixed with a fastening member from the outer periphery,
On the outer periphery of the connection portion, a first annular large diameter portion for preventing the flexible hose from coming off,
A second annular large-diameter portion that regulates the insertion end of the flexible hose is formed;
The fastening member fastens an outer peripheral surface of the flexible hose between the first annular large diameter portion and the second annular large diameter portion, and an inner diameter of a fastening portion of the flexible hose. Is made of a resin member smaller than the outer diameter of the flexible hose,
Hose fastening characterized in that a plurality of internal teeth made of an elastic member having a projecting section in the axial direction, which can be tilted in the axial direction of the metal tube, are formed in the circumferential direction on the inner surface side to be fitted with the flexible hose. Construction.

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