JPH05185491A - Connecting structure of resin hose - Google Patents

Abstract

PURPOSE:To improve the life of a resin hose and prevent the connected part thereof from being deteriorated by inner part fluid by blow-molding a hose main body so that it consists of a thermoplastic resin material being rigid at least in its end part and preventing the occurrence and progress of cracks in the connected part at the time when a resin hose made up of a flexible injection-molded connecting part is connected to the opponent pipe. CONSTITUTION:While a resin hose 10 is constituted such that a connecting part 14 to be connected with an opponent side pipe body 24 consisting of flexible injection-molded thermoplastic resin is connected integrally to a blow-molded hose main body 12 consisting of thermoplastic resin being rigid at least in its end part, the opponent side pipe body 24 is allowed to be fitted into the inner part of the resin hose 10 until the insertion side end part thereof passes through the connected part 14 and reaches the end part of the hose main body 12 whereupon in keeping the state the resin hose 10 and the opponent side pipe body 24 are secured by clamp.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin hose connection structure suitable as a connection structure for connecting an air duct hose, a filler hose, etc. for automobiles to a mating pipe.

[0002]

BACKGROUND OF THE INVENTION For example, air duct hoses for automobiles,
In the field of filler hoses and the like, it has recently been studied to actually use resin hoses instead of rubber hoses.

This resin hose has a smaller specific gravity and can be made lighter in weight than a rubber hose, that one having a soft part and a hard part can be formed as an integrally molded product, and the design of the shape, etc. It has advantages such as high flexibility.

Here, the fact that an article having a soft portion and a hard portion can be formed as an integrally molded article means the following. For example, in the case of a rubber hose, it is difficult to configure the soft part and the hard part as an integrated product. In this case, the part requiring hardness is composed of a metal pipe, and other flexibility is required. For this part, rubber hose is used to assemble both parts, while in the case of a resin hose, while a hard resin material is used for the part that needs hardness, softness is required. A soft material is used for the portion to be formed, and the hard portion and the soft portion can be integrally formed by using these materials at the time of molding the hose. Thus, if the soft portion and the hard portion can be integrally formed as described above, the number of parts can be reduced and the cost can be reduced.

In the case of a rubber hose, which has a high degree of freedom in designing, for example, when the rubber hose has a flat cross section, the same portion is likely to be deformed when a negative pressure is applied. In this case, the use of a hard material means that even a flat shape can sufficiently withstand such a negative pressure, which means that there are few restrictions on the shape.

In the case of such a resin hose,
A blow molding method is preferably adopted as the molding method, and in this blow molding method, generally, a cylindrical and bag-shaped parison is inflated by blowing air and brought into close contact with the inner surface of the molding die, thereby forming a predetermined shape. In terms of molding, the outer surface can be accurately molded into a predetermined shape by a molding die, but the inner surface is molded in a free state, so the shape and dimensional accuracy are unavoidably deteriorated.

However, in the case of a hose, a mating pipe body such as a metal pipe is fitted and joined inside the connecting portion,
In that case, it may be necessary to secure the sealing property of the joint portion. In such a case, if the shape and dimensional accuracy of the inner surface of the connection portion are poor, that is, the inner diameter dimension and wall thickness vary, and uneven thickness If there is or there is unevenness on the inner surface, it is not possible to secure sufficient sealing performance at the joint with the mating tube.

Therefore, in the case of such a blow-molded resin hose, the inner surface of the connecting portion is polished and finished into a predetermined shape and size.

However, such polishing not only increases the hose manufacturing process, but also leaves polishing powder on the processed portion and its periphery. For this reason, a washing step for removing the polishing powder is also required, and the number of steps for manufacturing the hose is increased and the cost is increased.

Therefore, the inventor of the present invention blow-molds a thermoplastic resin as shown in FIG.
No. 0, set this in a mold 102 for molding, and invented a method of injection molding a cylindrical connection portion (here, axial end portion) 104 with the mating pipe body, and invented a method of No. 3-39145).

According to the present invention, the inner surface of the connecting portion can be formed into a predetermined shape and size at the same time when the hose is formed,
It is not necessary to polish the inner surface of the connection portion after molding the hose as in the conventional case.

Therefore, not only the polishing step can be omitted, but also the cleaning step for removing the remaining polishing powder thereafter becomes unnecessary, and the total number of steps can be reduced and the cost can be reduced.

In addition, when the connection portion of the hose is injection-molded according to the present invention, the inner surface of the connection portion can be formed with higher accuracy than the case where the inner surface of the connection portion is polished later. The reliability of the sealing property when a mating pipe such as a metal pipe is connected to the portion is improved.

Further, according to the present invention, there is an advantage that the hose body can be made of a hard resin material and the connecting portion can be made of a soft resin material.

For example, in an air duct hose for an automobile, a negative pressure acts on the hose during use. Therefore, if the hose body is made of a soft material, the hose body will be deformed, whereby the suction amount of air through the hose will be increased. It reduces and causes incomplete combustion of the engine. If the entire hose is made of a hard material in order to prevent this, the sealing property will be impaired when the end of the hose is joined to the mating tube.

However, if the hose body is made of a hard material and the connection portion is made of a soft material according to the present invention, the hose can be provided with mechanical strength such as negative pressure resistance, and at the same time the connection portion can be sealed well. Can be
Of course, the bellows portion may be partially formed in the hose body, or the bellows portion may be made of a soft resin to give flexibility to the hose as appropriate.

By the way, when connecting the mating pipes to the inner surface of the hose, usually, as shown in FIG. The mating tube 108 is fitted in and fixed.

However, in this case, when vibration or bending force is applied to the hose, (B)
As shown in (1), a large strain or stress is locally generated in the connecting portion 104 which is a soft portion. As a result, a crack may be generated or a crack may progress in the same portion, and eventually there is a risk of fracture.

[0019]

The invention of the present application has been made to solve such a problem. Thus, the invention of the present application is such that at least an end portion is formed by injection molding a soft thermoplastic resin into a blow-molded hose body made of a hard thermoplastic resin, and a connecting portion with a mating pipe body is integrally formed. While forming a resin hose by joining, the mating tubular body is fitted inside the resin hose until the insertion end of the mating pipe passes through the connecting portion and reaches the end of the hose body. The resin hose and the mating tubular body are fixed by the method (claim 1).

According to another invention of the present application, a fitting recess extending axially to the hose body is formed on the inner peripheral surface side of the connecting portion, and the mating tubular body is fitted into the fitting recess. It is characterized (claim 2).

Still another invention of the present application is characterized in that the hose body and the mating tubular body are fixed in a state where the abutting portion of the mating tubular body abuts the abutted portion of the hose body. (Claim 3).

[0022]

According to the invention of claim 1 above,
While maintaining the advantages of the prior invention of blow molding the hose body and injection molding the connection portion, the following advantages can be further obtained.

That is, according to the present invention, since the mating pipe is fitted into the hose and fixed until it passes through the connecting portion and reaches the end of the hose body, vibration and bending force applied to the hose when the hose is used. It is possible to prevent a large local strain or stress from being generated in the connection portion even when a stress is applied.

Further, in the connection structure of the present invention, since the mating pipe is fitted to the end of the hard hose body, that is, the soft material connection is made between the hard hose body end and the mating pipe. Since the parts do not substantially exist,
When a bending force or the like acts on the hose, the phenomenon that the hose bends largely does not occur in the middle soft portion, and the bending force acts uniformly on the entire hose.

Therefore, especially when there is a highly flexible part such as a bellows part or a soft resin part in the middle part of the hose body, the bending force is absorbed by the part and locally large at the soft connection part. The force will not be applied. As a result, it is possible to suppress the occurrence of cracks or the progress of cracks in the connection portion due to such local stress, and improve the hose life.

In addition, since the inner surface of the connection portion made of a soft resin material is not directly exposed to a predetermined fluid such as gasoline flowing through the hose or blow-by gas from the engine, the life of the fluid can be prevented from being shortened. ..

For example, in the case of a filler hose, since the soft resin material is inferior in gasoline permeation resistance to the hard resin material, when the connecting portion made of the soft resin material is directly exposed to gasoline, the gasoline is discharged to the outside from the same portion. Although a large amount of gas is permeated, in the connection structure of the present invention, since the connection part made of the soft resin material is not directly exposed to gasoline, the amount of gasoline permeation can be kept low.

In the case of the air duct hose, the soft resin material is inferior to the hard resin material in oil resistance and blow-by gas resistance, so that if the inner surface of the connection portion is exposed, the same portion is easily deteriorated. In the connection structure of the present invention, the inner surface of the connection portion is not directly exposed to these oils and blow-by gas, so deterioration due to them can be suppressed.

Further, since the connecting portion is not directly exposed to these fluids, it becomes possible to select a soft resin material having other high properties even if the gasoline resistance and oil resistance are slightly inferior. The degree of freedom in design also increases.

According to a second aspect of the present invention, a fitting concave portion extending to the hose body is formed on the inner peripheral surface side of the connecting portion, and the mating pipe body is fitted into the fitting concave portion. It is possible to make the inner surface flush with the mating tube, and to make the fluid flow smoothly inside the hose and the mating tube. Further, by forming the fitting concave portion on the inner peripheral surface side of the connection portion, it is possible to save an expensive soft resin material and obtain an advantage that the hose cost can be reduced.

According to a third aspect of the present invention, the hose and the mating tube are connected so that the abutting part of the mating tube is brought into contact with the abutted part of the hose body. By simply inserting the mating tube, the positioning can be performed automatically and the insertion amount can be made constant at all times.

[0032]

Embodiments of the present invention will now be described in detail with reference to the drawings. In FIG. 2, reference numeral 10 denotes a resin hose used as an air duct hose or the like, which includes a hose body 12 formed by blow molding a hard thermoplastic resin, and an injection molded hose body 12 with the hose body 12 set in a molding die. And a connection side end portion 14 made of a soft thermoplastic resin for connection with the mating metal pipe, which is integrally joined to the main body 12.

In this resin hose 10, a bellows portion 15 for imparting flexibility to the hose body 12 is provided in the central portion thereof. The bellows portion 15 may be made of a soft resin in order to increase the flexibility of the bellows portion 15.

In this hose 10, the hose body 1
As an example of a hard resin for 2, a Rockwell hardness of 94
(R scale) polypropylene resin (for example, EC-9B manufactured by Mitsubishi Petrochemical Co., Ltd.), and polypropylene resin having Shore A hardness of 75 as a soft resin material for the connection side end portion 14+
An example is EPDM polymer alloy (for example, Santoprene 101-75 manufactured by Japan Monsanto Co., Ltd.).

FIG. 1 shows a sectional structure around the end of the hose 10. As shown in the figure, in the case of the hose 10 of this example, a large diameter portion 16 is formed at the end of the hose body 12. A recess 18 is formed inside thereof.

On the other hand, a tubular fitting protrusion 20 extending in the axial direction is formed at the end 14 on the connection side, and the fitting protrusion 20 is fitted and fixed in the recess 18.

In the resin hose 10 of this example, the outer diameter of the connection side end portion 14 is made equal to the outer diameter of the large diameter portion 16 on the hose body 12 side, while the inner diameter is made larger than the inner diameter of the hose body 12. The entire inner surface of the connection side end 14 is formed as a fitting recess 22 having an annular cross section.

A mating metal pipe 24 is fitted into the fitting recess 22 through the opening of the connecting end 14, and its tip is brought into contact with the step 32 of the hose body 12 made of a hard resin material. .. Then, in this state, the outer peripheral portion of the connection side end portion 14 is clamped in the clamp groove 17 by the clamp member 19, so that the hose 10 and the mating metal pipe 24 are fixed and connected.

Here, the clamp member 19 has a band 21 and a fastening portion 23. When the fastening portion 23 is tightened by a bolt or the like, the diameter of the band 21 is reduced and the connection side end portion 1 is formed.
Tighten 4 inward. However, this clamp member 19 is merely an example, and various other clamp members can be used.

The inner diameter of the hose body 12 is made equal to the inner diameter of the mating metal pipe 24 so that their inner surfaces are flush with each other. In the case of the resin hose 10 of this example, since the hard metal pipe 24 directly abuts against the end of the hose body 12 made of a hard resin material, when the hose 10 is subjected to vibration or bending force, the It is effectively absorbed by the bellows portion 15 at the center of the hose body 12, and no large strain or local stress concentration occurs at the connection side end portion 14 made of a soft resin material. Therefore, the durable life of the hose 10 is improved.

Further, since the inner surface of the connection side end portion 14 is not directly exposed to a predetermined fluid such as blow-by gas, gasoline or other oil flowing inside the hose, deterioration due to their chemical action is prevented. Lifespan is improved.

Further, by forming the concave portion 22, the connection side end portion 1 is formed.
Since the amount of expensive soft resin material used for 4 can be reduced, the hose cost is also reduced.

The connection structure between the hose 10 and the metal pipe 24 can be various structures other than the above example. FIG. 3 shows a specific example thereof. In the example of FIG. 3 (A), the end portion of the hose body 12 is formed straight and the connection side end portion 14 is injection molded so as to cover the outer surface of the end portion. A fitting recess 22 having the same inner diameter as the outer diameter of the hose body 12 is formed on the inner surface side of the portion projecting from the hose body 12 in the axial direction, and a metal pipe 24 is fitted therein, and one end of the fitting recess 22 contacts the hose body 12. It is touched.

On the other hand, the example shown in FIG.
The connection-side end portion 14 is injection-molded so as to cover the outer surface of the end portion, and the step portion 26 is formed on the connection-side end portion 14.
Is provided so that the step portion 26 abuts on the end surface of the hose body 12.

The inner surface side of the portion of the connection side end portion 14 projecting from the hose body 12 is a fitting recess 22 having a diameter smaller than the outer diameter of the hose body 12, and a metal pipe 24 is fitted therein and one end Is brought into contact with the hose body 12.

In the example of FIG. 6C, after the corner portion 28 on the outer peripheral side of the end of the blow-molded hose body 12 is cut off, this is set in a mold and the connection-side end 14 is injection-molded. The hose body 12 of the connection side end 14
A fitting recessed portion 22 having the same inner diameter as the outer diameter of the cut-out portion is formed inside the portion protruding from, and a metal pipe 24 is fitted therein.

Further, in the example of (D), after blow molding, the outer peripheral surface of the hose body 12 is cut off over a certain length range,
After that, the connection-side end portion 14 is injection-molded, and the connection-side end portion 14 has an outer diameter equal to that of the hose body 12.

A fitting concave portion 22 is formed inside a portion of the connecting side end portion 14 which projects from the hose body 12 in the axial direction, and a metal pipe 24 is fitted and fixed therein.

FIGS. 4 and 5 show still another embodiment of the present invention. Of these, in FIG. 4B, as shown in FIG.
The fitting recess 22 is formed to have a diameter larger than the inner diameter of the metal pipe 24, and the step portion 33 is formed on the hose body 12, while the curved portion 30 is formed at the tip of the metal pipe 24 so that the metal pipe 24 is fitted into the fitting recess 22. An example in which the curved portion 30 is brought into contact with the step portion 32 of the hose body 12 and clamped by the clamp member 19 in this state is shown.

In the case of this example, the hose 10 and the metal pipe 24 in a state where the radially outwardly bulging portion of the curved portion 30 of the metal pipe 24 partially penetrates into the inside of the connection side end 14 made of a soft resin material. The connection with 24 will be made.

In this example, the hose 10 is a metal pipe 24.
Even when the hose body 12 and the metal pipe 24 are slightly inclined with respect to each other, there is an advantage that the contact state is maintained at the contact portion between the hose body 12 and the metal pipe 24.

FIG. 4C shows the curved portion 3 on the metal pipe 24.
The small diameter portion 34 following 0 is formed, and the curved portion 3 is formed in the same manner as in (B).
0 is brought into contact with the stepped portion 33 of the hose body 12, while the small diameter portion 34 is fitted to the inner surface of the hose body 12 (the arrow in the figure indicates the clamp portion by the clamp member. The same applies to the example).

Further, in FIG. 4D, a tapered portion 36 is formed on the metal pipe 24, and a small diameter portion 34 is formed following the tapered portion 36, and the tapered portion 36 is formed on the step portion of the hose body 12. This is an example in which the small diameter portion 34 is fitted to the inner surface of the hose body 12 while being brought into contact with 33.

Further, FIGS. 4E and 4F show the metal pipe 2
The curved protrusion 37 of 4 is formed at a position away from the tip,
The tip of the metal pipe 24 is connected to the step portion 3 of the hose body 12.
In this example, the curved projection 37 is made to abut on the connection side end portion 14 made of a soft resin material while being abutted on the connection portion 3.
These curved projections 37 effectively act as a stopper for the hose 10.

On the other hand, FIGS. 5G and 5H show the hose body 1.
This is an example in which the second end is slightly expanded into a trumpet shape, and the curved portion 30 at the tip of the metal pipe 24 fitted in the fitting recess 22 is brought into contact with the expanded end 38.

Further, (I) shows the curved portion 3 of the metal pipe 24.
In this example, 0 is brought into contact with the expanded end portion 38 and the small diameter portion 34 is fitted to the inner surface of the hose body 12.

Further, in (J), the tapered portion 36 of the metal pipe 24 is brought into contact with the expanded end portion 38, and the small diameter portion 3 following the tapered end portion 36 is abutted.
4 is an example in which the inner surface of the hose body 12 is fitted.

FIG. 6 shows still another embodiment of the present invention. In this example, as shown in (A), the inner diameter of the connection side end portion 14 is made the same as the inner diameter of the hose body 12, and their inner surfaces are made flush, and (B), (C),
The curved portion 30 of the metal pipe 24 as shown in FIG.
Alternatively, this is an example in which the rib portion 40 is brought into contact with the step portion 33 of the hose body 12.

In any of these cases (B), (C) and (D), the bulging portion of the curved portion 30 or the rib portion 40 of the metal pipe 24 outward in the radial direction is made of a soft resin material. It is in a state of biting into the side end portion 14. Based on the bite, the internal fluid is effectively prevented from entering between the hose body 12 and the metal pipe 24 and between the connection-side end portion 14 and the metal pipe 24. Further, the curved portion 30 and the rib portion 40 also serve to effectively prevent the metal pipe 24 and the hose 10 from coming off in the clamped state by the clamp member.

On the other hand, in (E), a saw-like projection 42 is formed on the outer peripheral surface of the fixed length portion of the metal pipe 24,
In this example, the projections 42 at the tip end are brought into contact with the stepped portion 33 of the hose body 12, and the projections 42 are made to bite into the connection side end portion 14.

Next, in FIG. 7, the inner diameter of the connection side end portion 14 is made equal to the inner diameter of the large diameter portion 16 of the hose body 12 as shown in (A), and shown in (B) and (C). As described above, the curved portion 30 of the metal pipe 24 is brought into contact with the tip of the large diameter portion 16 (in the case of (B)), or the tip of the metal pipe 24 is brought into contact with the step portion 33 of the hose body 12. The example ((C)) is shown.

Further, in (E) and (F), as shown in (D), a medium diameter portion 44 is formed in the hose body 12 so that the inner diameter of the connection side end portion 14 is the same as that of the medium diameter portion 44. And the curved portion 30 of the metal pipe 24 is replaced by the stepped portion 3 of the large diameter portion 16.
3 or the tip of the metal pipe 24 is brought into contact with the stepped portion 46 of the medium diameter portion 44.

FIG. 8 shows still another embodiment of the present invention. Of these, (B), (C), and (D) form the recessed portion 48 in the hose body 12 as shown in (A),
This is an example in which the curved portion 30 or the rib-shaped portion 40 of the metal pipe 24 is snap-fitted (elastically fitted),
Further, (E) is an example in which the concave portion 48 and the curved portion 30 and the like are snap-fitted, and clamping is performed by the clamp member 19 in the vicinity of these fitting portions.

Further, in (G), as shown in (F), a concave portion 48 and a step portion 33 are formed in the hose body to elastically fit the concave portion 48 and the curved portion 30, etc. This is an example in which the tip portion of the pipe 24 is brought into contact with the step portion 33.

The embodiment of the present invention has been described in detail above, but this is merely an example, and the present invention forms a connecting portion at the longitudinal end of the hose and connects it to the mating pipe body as in the above example. The present invention is applicable not only to the case where the hose is connected, but also to the case where a connecting part is provided on the side surface of the hose in the middle and the connecting part is connected to the mating pipe body. It can be configured with various modifications based on the knowledge of the trader.

[Brief description of drawings]

FIG. 1 is a diagram of an embodiment of a hose connection structure of the present invention.

FIG. 2 is a diagram showing an overall appearance of the hose of FIG.

FIG. 3 is a diagram of another embodiment of the present invention.

FIG. 4 is a diagram of yet another embodiment of the present invention.

FIG. 5 is a diagram of yet another embodiment of the present invention.

FIG. 6 is a diagram of yet another embodiment of the present invention.

FIG. 7 is a diagram of yet another embodiment of the present invention.

FIG. 8 is a diagram of yet another embodiment of the present invention.

FIG. 9 is a diagram of an embodiment according to the prior invention of the present application.

FIG. 10 is an explanatory diagram of a problem to be solved by the present invention.

[Explanation of symbols]

 10 Resin Hose 12 Hose Main Body 14 Connection Side End 22 Fitting Recess 24 Metal Pipe 30 Curved Part 32, 33, 46 Stepped Part 36 Tapered Part 37 Curved Protrusion 38 Expanded End 40 Rib Part 42 Protrusion

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location F16L 11/04 7123-3J // B29L 23:22 4F

Claims (3)

[Claims] 1. A connecting portion to a mating pipe body, which is formed by injection-molding a soft thermoplastic resin, is integrally joined to a blow-molded hose body having at least an end portion made of a hard thermoplastic resin. On the other hand, while constituting a resin hose, the mating tubular body is fitted into the resin hose until its insertion end passes through the connecting portion and reaches the end of the hose body, and the resin A connection structure for a resin hose, characterized in that a hose and the mating tube are fixed. 2. A fitting concave portion that extends axially to the hose body is formed on the inner peripheral surface side of the connecting portion, and the mating tubular body is fitted into the fitting concave portion. 1
Connection structure for resin hose described in. 3. The hose body and the mating tubular body are fixed such that the abutting portion of the mating tubular body abuts the abutted portion of the hose body. Connection structure for resin hose described in.