WO1997039270A1

WO1997039270A1 - Corrugated hose

Info

Publication number: WO1997039270A1
Application number: PCT/IT1997/000084
Authority: WO
Inventors: Palu' Attilio Dal
Original assignee: Valeo Sicurezza Abitacolo S.P.A.
Priority date: 1996-04-16
Filing date: 1997-04-16
Publication date: 1997-10-23
Also published as: IT239716Y1; ITTO960082U1

Abstract

A substantially cylindrical hose (1) for connection to a circuit for circulating operating fluid, in particular water of an engine cooling circuit, has a corrugated central portion (2) and two smooth lateral portions (3). The corrugated portion (2) has four identical, contiguous, continuous ribs (4) extending along respective substantially helical paths (P), so that the corrugated portion (2) is in the form of a common screw with a multi-start thread (4a, 4b, 4c, 4d). The corrugated portion (2), when undeformed, has a number of identical turns (5) of the same winding angle (α), and, in longitudinal half section, has an undulated profile defining a succession of alternating, mutually connected outer crests (6) and depressions (7).

Description

CORRUGATED HOSE

TECHNICAL FTKT.D

The present invention relates to a hose for an operating fluid circulating circuit.

BACKGROUND ART

For channeling operating fluids in general, and high-temperature operating fluids, such as liquids for cooling vehicle engines, in particular, hoses with reinforcing ribs are known to be used, as described in Italian Patent Application n. TO93U000113 filed on 21/5/93 by the present Applicant.

More specifically, known hoses comprise a number of separate intercalated circumferential ribs in respective planes perpendicularly to the hose axis; and a number of longitudinal ribs inserted between the circumferential ribs to limit elongation of the hose.

Though widely used, known hoses of the above type involve several drawbacks. Firstly, the longitudinal ribs, and more specifically the arrangement of the longitudinal with respect to the circumferential ribs, result in a variation in the flexural rigidity of the hose along the hose axis, in the sense that the flexibility of the various portions of the hose differs according to the presence or absence of the longitudinal ribs. Secondly, the presence of circumferential ribs extending perpendicular to the flow direction of the operating fluid results in localized load losses, in turbulence due to the fluid striking the circumferential ribs, and inevitably in undesired noise. DISCLOSURE OF INVENTION

It is an object of the present invention to provide a straightforward, low-cost hose designed to eliminate the aforementioned drawbacks.

According to the present invention, there is provided a hose for an operating fluid circulating circuit, and comprising at least one corrugated portion; characterized in that said corrugated portion comprises at least one continuous rib extending along a substantially helical path. BRIEF DESCRIPTION OF DRAWINGS

A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a partially sectioned side view of a hose in accordance with the present invention;

Figure 2 shows a section along line II-II in Figure 1.

BEST MODE FOR CARRYING OUT THE INVENTION Number 1 in Figure 1 indicates a substantially cylindrical hose for connection, in use, to a circuit (not shown) for circulating operating fluid, in particular water in an engine cooling circuit. Hose l has a longitudinal axis A, and comprises a central corrugated portion 2, and two smooth lateral portions 3. In the example described, corrugated portion 2 comprises four identical, contiguous, continuous ribs 4 extending along respective substantially helical paths P, so that corrugated portion 2 is in the form of a common screw comprising a thread with a number of starts 4a, 4b, 4c, 4d (Figures 1 and 2).

When undeformed, corrugated portion 2 comprises a number of identical turns 5 with respective equal winding angles α; and, in longitudinal half section, corrugated portion 2 comprises an undulated profile defining a succession of alternating, mutually connected outer crests 6 and depressions 7.

Each outer crest 6 is hollow, substantially U-shaped, and tapers outwards. More specifically, each outer crest 6 comprises a substantially flat intermediate portion 6a parallel to longitudinal axis A; and two substantially flat lateral portions 6b, 6c converging towards each other and towards intermediate portion 6a.

Each depression 7 is substantially V-shaped, and comprises a rounded vertex 7a.

Corrugated portion 2 is preferably a multilayer portion comprising an inner layer 2a of material resistant to high temperature and pressure of the operating fluid, e.g. polythene or polyethylene; an outer layer 2b of material resistant to corrosion, e.g. nylon; and an intermediate layer 2c connecting inner and outer layers 2a and 2b, and made, for example, of amide material capable of establishing strong chemical bonds with adjacent layers 2a and 2b.

The advantages of hose 1 are as follows. Firstly, by virtue of featuring continuous helical ribs 4, the flexibility of hose 1 is constant along the whole of longitudinal axis A, thus enabling hose 1 to adapt easily to different applications, regardless of the assembly route involved. Secondly, as compared with known solutions, the operating fluid flows more smoothly along hose 1 by being guided along the helical paths P defined by continuous ribs 4, thus reducing load losses and the noise level of the fluid inside hose 1.

Clearly, changes may be made to hose 1 as described and illustrated herein without, however, departing from the scope of the present invention.

In particular, outer crests 6 and depressions 7 may be shaped differently; hose 1 need not necessarily be a multilayer hose; and corrugated portion 2 may comprise a number of continuous ribs 4 other than that described. In particular, corrugated portion 2 may comprise a single continuous rib 4.

Claims

1) A hose (1) for an operating fluid circulating circuit, and comprising at least one corrugated portion (2) ; characterized in that said corrugated portion (2) comprises at least one continuous rib (4) extending along a substantially helical path (P) .

2) A hose as claimed in Claim 1, characterized in that said corrugated portion (2) , when undeformed, comprises a number of identical turns (5) ; the turns (5) having respective equal winding angles (α) .

3) A hose as claimed in Claim 1 or 2, characterized by comprising a number of identical, contiguous said ribs (4) . 4) A hose as claimed in any one of the foregoing Claims, characterized in that said corrugated portion (2) , in longitudinal half section, comprises an undulated profile defining a succession of alternating, mutually connected outer crests (6) and depressions (7) . 5) A hose as claimed in Claim 4, characterized in that each of said outer crests (6) tapers outwards.

6) A hose as claimed in Claim 4 or 5, characterized in that each of said outer crests (6) is hollow. 7) A hose as claimed in Claim 6, characterized in that each of said outer crests (6) is substantially U-shaped, and comprises a substantially flat intermediate portion (6a) parallel to a longitudinal axis (A) of the hose (1) , and two substantially flat lateral portions (6b) (6c) converging towards each other and towards the intermediate portion (6a) .

8) A hose as claimed in any one of the foregoing Claims from 4 to 7, characterized in that each of said depressions (7) is substantially V-shaped, and comprises a rounded vertex (7a) .

9) A hose as claimed in any one of the foregoing Claims, characterized in that at least said corrugated portion (2) is a multilayer portion.