JP2005106175A - Hose connection structure and hose connection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure good sealability by increasing the hose pull off load in a hose connection structure. <P>SOLUTION: The hose connection structure is connected to a hose connection part 13 by pressing resin hose 30 into a hose connection part 13. Hose 30 is heated from an inside for connecting a connection end of the hose to a hose connection part 13. Module of elasticity of an inner layer 30a of hose 30 is dropped by the heating but module of elasticity of an outer layer 30b is kept high due to temperature gradient. When a connection end of the hose 30 is pressed into the hose connection part 13 under this condition, the hose 30 is connected to the hose connection part with riding over a ring shape projection 21 having a sharp outer circumference end of which curvature radius R is 0.2 mm or less. Since the connection end of the hose 30 restricts an inner layer 30a of a low module of elasticity by an outer layer 30b of high module of elasticity not to expand diameters, the ring shape projection part 21 of the inner layer 30a bites into the inner layer 30a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hose connection structure and a hose connection method in which a hose is press-fitted into a hose connection part to be connected to the hose connection part.

  Conventionally, as a hose connection structure of this type, it has a connecting pipe body that has a plurality of mountain-shaped and triangular cross-sectional protrusions on its outer peripheral surface, and a rubber hose is press-fitted into this connecting pipe body, A configuration is known in which the ring-shaped protrusion is bited into the inner wall of the hose to improve the sealing performance and the pull-out load.

  By the way, changing the hose from rubber to resin is being studied. However, in the resin hose, the ring-shaped protrusion does not sufficiently penetrate into the inner layer of the hose, the frictional force therebetween cannot be increased, and the sealing performance and the extraction load cannot be sufficiently increased. As means for solving such a problem, a technique is known in which a connecting end of a resin hose is softened by heating and press-fitted into a connecting pipe (for example, Patent Document 1).

  By the way, in recent years, as a specification of a hose, like a water hose of an automobile using a highly rigid resin material, further improvement in sealing performance, durability and reliability has been demanded.

JP 2002-106769 A

  An object of the present invention is to solve the above-described problems of the prior art, and to provide a hose connection structure and a hose connection method having high sealing performance and pull-out load.

The present invention made to solve the above problems
A hose connection structure that is connected to the hose connection part by press-fitting a connection end of a resin hose into the hose connection part,
The hose connection is
A connection main body having a flow path, and a ring-shaped protrusion projecting in a mountain shape and having an outer diameter larger than the inner diameter of the hose on the outer peripheral surface of the hose connection section,
The curvature of the outer peripheral end of the ring-shaped protrusion is 0.2 mm or less,
The connecting end of the hose is heated and press-fitted at a temperature lower than the melting point of the hose from the inside of the hose.

In this invention, in order to connect the connection end of a hose to a hose connection part, the connection end of a hose is heated from the inner side of this hose. This heating reduces the elastic modulus of the inner layer of the hose, but the elastic modulus of the outer layer remains high due to the temperature gradient. In this state, when the connection end of the hose is press-fitted into the hose connection portion, the hose connection portion is overcome and connected to the hose connection portion. At this time, the connecting end of the hose restrains the inner layer having a low elastic modulus from being expanded by the outer layer having a high elastic modulus, so that the ring-shaped protrusion bites into the inner layer. Moreover, since the curvature of the outer peripheral edge of the ring-shaped protrusion is sharpened to 0.2 mm or less, the amount of biting into the inner layer is large. Therefore, even if the hose is formed of a resin material having high rigidity, the ring-shaped protrusion can sufficiently bite into the inner layer, and high sealing performance and an increase in extraction load can be obtained.
The curvature of the outer peripheral edge may be an acute angle that is preferably 0.1 mm or less, and more preferably 0.

  Further, as a preferred embodiment of the hose connection method, heating is performed so that the elastic modulus of the outer layer portion of the hose is larger than the elastic modulus of the inner layer portion of the hose, and the connection end of the hose that generates the temperature gradient is used. Can be pressed into the hose connection part.

  In order to further clarify the configuration and operation of the present invention described above, preferred embodiments of the present invention will be described below.

(1) Schematic configuration of hose connection body FIG. 1 is a front view showing a hose connection structure according to an embodiment of the present invention. The hose connection structure is disposed in the engine room of the automobile. In FIG. 1, the hose connection structure includes a connection pipe 10, hoses 30 and 31 connected to both sides of the connection pipe 10, and a branch hose 32 connected to a central portion of the connection pipe 10. The hoses 30 and 31 connect an engine (not shown) and a radiator, and the branch hose 32 is connected to the throttle body.

(2) Configuration of each part (2) -1 Connection pipe 10
FIG. 2 is a cross-sectional view showing the hose connection structure. The connecting tube 10 is a resin tube that is branched in three directions and is injection-molded using glass fiber reinforced 6-6 nylon as a material. The tube body 11 and a hose connection integrally formed on both sides of the tube body 11 Parts 13 and 14, and a branch connection part 15 projecting from the central part of the pipe body 11. A main flow path 16 connected to the hoses 30 and 31 is formed in the pipe body 11 and the hose connection sections 13 and 14, and a branch flow branched and connected to the main flow path 16 is further formed in the branch connection section 15. A path 17 is formed.

(2) -2 Hose connection parts 13 and 14
Since the hose connection parts 13 and 14 are symmetrical and have the same configuration, the hose connection part 13 will be described as a representative. FIG. 3 is a perspective view showing the hose connecting portion 13. In FIG. 3, the hose connection portion 13 includes a cylindrical connection main body 13a (general portion) and ring-shaped protrusions 21, 22, and 23 protruding from the outer peripheral portion of the connection main body 13a.

FIG. 4 is an enlarged half-sectional view showing the vicinity of the hose connecting portion 13. The ring-shaped protrusions 21, 22, and 23 are formed in a mountain range that is inclined over three rows toward the center of the tube body 11. The ring-shaped protrusions 21, 22, 23 are connected to the hose from the frustoconical surfaces 21 a, 22 a, 23 a whose outer diameters increase from the front end side toward the rear end side, and the maximum outer diameters of the frustoconical surfaces 21 a, 22 a, 23 a. It has an acute angle surface 21b, 22b, 23b that extends to the connection body 13a of the portion 13 and intersects the frustoconical surfaces 21a, 22a, 23a at an acute angle, and from each of these forms a mountain-shaped right-angled triangle. FIG. 5 is an explanatory view showing the ring-shaped protrusion 21 in an enlarged manner. The ring-shaped protrusion 21 is formed such that the apex of the triangular cross section, that is, the curvature R of the outer peripheral end is 0.2 mm or less, preferably 0.1 mm or less. Further, the other ring-shaped protrusions 22 and 23 shown in FIG. 4 are also formed with the same curvature R as the ring-shaped protrusion 21. In order to form the ring-shaped protrusion 21 and the like with such a small curvature R, the molds Ma and Mb of the mold M are formed on the ring-shaped protrusion 21 when the connecting pipe is injection-molded as shown in FIG. It can be formed by dividing into parts. In this case, a sharp shape with a curvature R of approximately 0 can be obtained. Since the curvature R of the outer peripheral ends of the ring-shaped protrusions 21, 22, and 23 is formed small, a large pulling resistance force is generated when a tensile force acts on the hose 30 as will be described later.
Here, when the inner diameter of the hose 30 is 15.5 mm and the outer diameter is 19.5 mm, as shown in FIG. 5, the ring-shaped protrusion 21 has a diameter D of 18 mm and a height h1 of 0.1. 7 mm and the angle θ can be 24 °.

(2) -3 Locking end 24 and detent projection 26
Further, as shown in FIG. 3, the hose connection portion 13 is formed with a locking end 24 for the tip of the hose 30 to come into contact therewith. The locking end 24 has a step shape with a height of the thickness of the hose 30 from the connection main body 13 a of the hose connection portion 13.

  A detent projection 26 is formed from the locking end 24 toward the tip of the hose connecting portion 13. The anti-rotation protrusions 26 are protrusions for preventing the hose 30 from rotating with respect to the hose connection portion 13, and are formed at 2 to 4 locations (4 locations in FIG. 3) at equal intervals in the circumferential direction. FIG. 7 is a perspective view showing the vicinity of the rotation prevention protrusion 26. The anti-rotation protrusion 26 has a wedge shape protruding from the locking end 24 toward the tip of the hose connection portion 13. That is, the anti-rotation protrusion 26 becomes a sharpened portion 26a having a sharp tip, a locking end 24 side becomes an R-shaped hem portion 26b, and its height t is a wedge shape that is the same as or slightly larger than the thickness of the hose 30. ing. The sharpened portion 26a is sharp because it bites into the tip of the hose 30. On the other hand, the hem portion 26b has an R shape in order to increase the mechanical strength of the anti-rotation protrusion 26 itself. . The shape of the anti-rotation protrusion 26 is determined in consideration of the mechanical strength of the anti-rotation protrusion 26. For example, when the outer diameter of the tube body 11 is 23 mm, the height h is 2.5 mm and the width w may be 2 mm, height t may be 3.5 mm, and R of the skirt portion 26b may be 1.0 mm or less.

(2) -4 Hose 30
FIG. 8 is a half sectional view showing a state in which the hose 30 is press-fitted into the hose connection portion 13. As shown in FIG. 8, the hose 30 has a laminated structure of an inner layer 30a, an outer layer 30b, and an adhesive layer 30c that bonds the inner layer 30a and the outer layer 30b. The inner layer 30a is formed from a modified polyphenylene sulfide (PPS) (modified PPS) having excellent heat resistance and LLC (antifreeze) resistance, and has a thickness of about 0.5 mm. The outer layer 30b is made of a polyamide resin such as nylon-6 (PA) for improving salt damage resistance and has a thickness of 1.2 mm. The adhesive layer 30c is formed of a material obtained by mixing PA6 with modified PPS in order to adhere to the inner layer 30a and the outer layer 30b, and has a thickness of 0.3 mm.

(3) Action of hose connection structure (3) -1 Action of hose connection part 13 In a state where the hose 30 is press-fitted into the hose connection part 13, the ring-shaped protrusions 21, 22, and 23 bite into the inner wall of the hose 30. While improving the sealing performance of the hose 30, the hose 30 is prevented from being removed.

(3) -2 Action of Anti-rotation Protrusion 26 The anti-rotation protrusion 26 bites into the tip of the hose 30 and stops the hose 30 from rotating. By such a detent action, even if the hose 30 receives a large external force in the rotation direction with respect to the hose connection part 13, it does not rotate with respect to the hose connection part 13, and maintains the adhesiveness therebetween, There is no deterioration in sealing performance. In particular, in the case where the hose 30 is pre-shaped corresponding to the routing position for use as a water hose, even if the hose 30 interferes with other parts in the engine room and receives external force in the rotational direction, It does not rotate easily and therefore does not cause a deterioration in sealing performance.

  Further, the rotation preventing projection 26 is integrally projected from the hose connecting portion 13 and is not a separate part, so that the number of parts does not increase.

(4) Connection process of hose 30 to hose connection part 13 In order to press-fit the hose 30 into the hose connection part 13, the following processes are taken. That is, as shown in FIG. 9, the heater Ht is inserted into the hose 30 and heated from the inner layer of the hose 30. At this time, for example, by inserting a heater Ht set at about 190 to 200 ° C. into the hose 30, the inner layer portion of the hose 30 is heated to 150 ° C. and the outer layer surface temperature is set to 100 ° C. This heating reduces the elastic modulus of the inner layer of the hose 30, but the elastic modulus of the outer layer remains high due to the temperature gradient. Then, the hose 30 is press-fitted into the hose connection portion 13. At this time, the inner wall of the hose 30 gets over the ring-shaped protrusions 21, 22, 23 and press-fits until reaching the locking end 24, and the anti-rotation protrusion 26 is bited into the tip of the hose 30. In this state, the hose 30 is allowed to cool. As a result, the hose 30 is plastically deformed and hardened in a shape that follows the ring-shaped protrusions 21, 22, and 23 and bites into the anti-rotation protrusion 26.

(5) In addition to the effects described above, the following effects are achieved by the configuration of the above embodiment.
(5) -1 In the connection step described above, by heating from the inner layer 30a of the hose 30, the connection end of the hose 30 acts so that the outer layer 30b having a high elastic modulus does not expand the inner layer 30a having a low elastic modulus. Therefore, the ring-shaped protrusion bites into the inner layer 30a. Moreover, since the ring-shaped protrusions 21, 22, and 23 are sharpened so that the curvature R of the outer peripheral end thereof is 0.2 mm or less, the amount of biting into the inner layer 30a is large. Therefore, even if the hose is formed of a resin material having high rigidity, the ring-shaped protrusion can sufficiently bite into the inner layer 30a, and high sealing performance and an increase in the extraction load can be achieved.

  FIG. 10 is a graph for explaining the relationship between the drawing load at 120 ° C. and the preheating time corresponding to the curvature R of the ring-shaped protrusion 21 of the hose connecting portion 13. The solid line shows an example in which the curvature R is 0, and the broken line shows a comparative example in which the curvature R is 0.25 mm. The example is preheated so as to generate the above-described temperature gradient, while the comparative example is preheated until the inner layer and the outer layer of the connection end of the hose are uniform at 150 ° C. As can be seen from FIG. 10, it can be seen that this example has a larger pulling load than the comparative example. Further, the sealing pressure in this example was 2.3 MPa, and could exceed the comparative example of 1.5 MPa.

(5) -2 When the hose 30 is press-fitted into the hose connection portion 13, the hose 30 is heated to the softening temperature, so that it is easy to bite into the anti-rotation protrusion 26. Here, the heating temperature should just be plastically deformed by the temperature which does not exceed melting | fusing point of each layer which comprises the hose 30, for example, is 100-220 degreeC.

  The present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

  If the hose is a resin hose, it may be either a single layer or a multilayer as long as it does not hinder the ring-shaped protrusions from entering, and the material is not particularly limited.

It is a front view which shows the hose connection structure concerning one embodiment of this invention. It is sectional drawing which shows a hose connection structure. It is a perspective view which shows a hose connection part. It is a semi-sectional view which expands and shows the vicinity of the hose connection part before inserting a hose. It is explanatory drawing which expands and shows a ring-shaped protrusion. It is explanatory drawing explaining the parting of the injection molding of a ring-shaped protrusion. It is a perspective view which shows the vicinity of a rotation prevention protrusion. It is a half sectional view showing the state where the hose is press-fitted into the hose connection part. It is explanatory drawing explaining the operation | work which connects a hose to a hose connection part. It is a graph explaining the relationship between the drawing load according to curvatures, such as a ring-shaped protrusion of a hose connection part, and preheating time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Connection pipe 11 ... Pipe main body 13 ... Hose connection part 13a ... Connection main body 14 ... Hose connection part 15 ... Branch connection part 16 ... Main flow path 17 ... Branch Channels 21, 22, 23 ... Ring-shaped projections 21a, 22a, 23a ... frustoconical surfaces 21b, 22b, 23b ... acute angle surfaces 24 ... locking ends 26 ... locking projections 26a. .. Sharp point 26b ... Hem 30, 31 ... Hose 30a ... Inner layer 30b ... Outer layer 30c ... Adhesive layer 32 ... Branch hose Ht ... Heater M ... Mold Ma, Mb ... type

Claims (3)

A hose connection structure that is connected to the hose connection part by press-fitting a connection end of a resin hose into the hose connection part,
The hose connection is
A connection main body having a flow path, and a ring-shaped protrusion that protrudes in a mountain shape and whose outer diameter is larger than the inner diameter of the hose on the outer peripheral surface of the connection main body,
The curvature of the outer peripheral end of the ring-shaped protrusion is 0.2 mm or less,
The connecting end of the hose is heated and pressed from the inside of the hose at a temperature lower than the melting point of the hose,
Hose connection structure characterized by. A hose connection method for connecting a connection end of a resin hose to a hose connection part,
A connection main body having a flow path, and a ring-shaped protrusion that protrudes in a mountain shape and has an outer diameter larger than the inner diameter of the hose on the outer peripheral surface of the connection main body, the outer peripheral end of the ring-shaped protrusion A preparation step of preparing a hose connection part having a curvature of 0.2 mm or less;
A heating step of heating the connecting end of the hose from the inside of the hose to near the temperature at which the hose softens;
A press-fitting step of inserting the connection end of the hose softened by the heating into the hose connection part and press-fitting the hose into the connection structure; and
A hose connection method characterized by comprising: In the hose connection method according to claim 2,
The heating step includes a step of heating so that the elastic modulus of the outer layer portion of the hose is larger than the elastic modulus of the inner layer portion of the hose,
The said press-fit process is a hose connection method provided with the process of press-fitting the connection end of the hose which has produced the said temperature gradient in the said hose connection part.

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