WO2015177101A1

WO2015177101A1 - Media hose and use of a media hose to monitor a machine

Info

Publication number: WO2015177101A1
Application number: PCT/EP2015/060915
Authority: WO
Inventors: Stefan NEUBERT; Uwe RUDORF
Original assignee: Leoni Kabel Holding Gmbh
Priority date: 2014-05-20
Filing date: 2015-05-18
Publication date: 2015-11-26
Also published as: DE102014209599A1

Abstract

The media hose (2) serves for use at high temperatures and high pressures in particular in internal combustion engines, especially for measuring and monitoring a fluid inside the internal combustion engine. For this purpose, the media hose (2) comprises an inner cavity (6), which is surrounded by a flat wire coil (4), which is in turn surrounded by a braid (8), which is enclosed by an outer jacket (10). The structure consisting of flat wire coil (4), braid (8) and outer jacket (10) is bendable and resistant to buckling, resists temperatures of over 150° and is resistant to oils, lubricants and propellants. Moreover, the structure is configured for a bursting pressure in excess of 10 bar.

Description

description

Media hose and use of a media hose to monitor a machine

The invention relates to a media hose and its use for monitoring a machine, in particular an internal combustion engine.

The condition of machines is also partially checked by the condition of operating or working fluids of the machine. For this purpose, so-called media hoses are used, via which a connection to the fluid to be tested is produced. The media hose is therefore a type of sensor tube. This is used, for example, to check an operating pressure, etc.

There is often the problem that such media hoses are used in high-stress environments. Thus, for example, these are also used in the field of internal combustion engines, in particular of stationary or quasi-stationary large engines, for example, for marine applications (marine engines) or for power generation applications. Due to the proximity to the combustion region, the media hoses are often exposed to elevated temperatures, both from the outside by the emission of the combustion chamber as well as by the measured or derived fluids (gases) themselves. These temperatures are for example at 200 ° or above.

In addition, such media hoses must also be resistant to media especially against oils, lubricants and fuels. Due to the high pressures to be measured, for example, the exhaust pressure, they must be beyond be designed for high operating and bursting pressures. Typically, standards or classifications require a certain ratio of operating and bursting pressures.

From US 2008/0236696 A1 a heat-resistant sensor hose can be seen, which is used, for example, in diesel engines as sensor hose for a particle filter. This sensor tube has a multilayer structure consisting of an inner tube and an outer tube, each made of a crosslinked polymer, and a braid arranged therebetween.

Proceeding from this, the object of the invention is to provide a suitable for such a field of application media hose.

The object is achieved according to the invention by a media hose having the features of claim 1. The media tube is hereby designed for use at high temperatures and high pressures and in particular for use in internal combustion engines and especially for measuring and monitoring media within the internal combustion engine. The media tube has as a support member a flat wire coil which defines an internal cavity which is filled in use with the fluid. In this case, a flat wire helix is understood to mean a helix made of a steel strip, which is preferably wound at least almost to the point of impact, so that an at least largely closed sheath is created by the flat wire helix. The flat wire coil is finally surrounded by a particular closed mesh, which in turn is enveloped by an outer sheath. The entire structure of flat wire coil, braid and outer sheath is flexible in bending and at the same time kink-resistant and furthermore temperature resistant to above 150 ° C, preferably above 200 ° C and in particular up to 260 ° C. In addition, the structure is designed for a bursting pressure greater than 10 bar. Finally, the structure is also media-resistant to oils, lubricants and / or fuels. The media hose is therefore designed, in particular in the manner of a sensor hose, with an internal cavity, which is filled with a fluid during operation. This fluid is monitored in particular by means of a sensor.

The property of bending flexibility with simultaneous buckling strength is achieved in particular by the flat wire helix. Due to the at least largely closed flat wire helix, individual helical sections support one another at a bend, so that further bending is prevented and, as it were, an inherent anti-buckling protection is formed by the mutual support. The distance between two longitudinally successive winding sections is therefore dimensioned sufficiently small, so that we do not fall below a minimum bending radius we, i. upon reaching a minimum bending radius for which the media tube is designed, adjacent winding sections are supported against each other.

The temperature resistance is achieved by a suitable choice of material, in particular for the outer sheath, which is preferably formed as a plastic sheath consisting of high temperature resistant plastic.

The internal flat wire coil is also responsible for the resistance to high operating pressures, which also ensures the high bursting pressure. Parallel to this, however, the outer sheath is designed in such a way with regard to the selected sheath wall thickness and in dependence of the sheath material that it can withstand high pressures.

Due to the mesh as a direct intermediate layer between the flat wire coil and the outer jacket, a decoupling between these two elements is achieved, which has an advantageous effect on the desired bending flexibility. Due to the braid, the inner flat wire helix and the outer sheath are displaceable relative to each other. In particular, the closed configuration of the braid prevents casing material from penetrating through the braid into the intermediate spaces of the flat wire helix when the outer sheath is formed. Such penetration would be detrimental to the desired bending flexibility. Further- towards the closed mesh is used for advantageous sealing of any bending occurring between individual helical pitches in a bend. As a result, the outer sheath is reliably relieved of the pressure prevailing in the inner cavity at least somewhat. Under a closed mesh, a mesh is understood without gaps, so the mesh has an overlap of at least almost 100% to eg. of 90%, preferably 95% and in particular more than 98%.

The media resistance is finally ensured by suitable choice of material, in particular the outer jacket. The material of the outer shell is therefore such that it is not attacked by oils, lubricants and fuels.

In this case, flexible bending is understood to mean that the media hose has a bending elastic modulus of <1 .700 MPa. The determination of this flexural modulus of elasticity is based on the definition according to ISO

178: 2002 by means of a 3-point bending test, in which a test mandrel is moved against the media hose at a defined speed, so that a deflection takes place. From the force required for this purpose, the modulus of elasticity is determined. The modulus of elasticity of <1 .700 MPa applies in particular to media hoses with an outer diameter of 8 mm.

Under temperature resistant is generally the resistance of the media tube at a continuous operating temperature of z. B. 150 ° C and that over an assumed operating time of typically, for example, 20,000 hours. Over this assumed operating time, the physical properties, such as tensile strength and elongation, as well as the electrical properties must not change beyond a predetermined limit and only a few, in particular 5 percent.

By media resistance is meant that - in accordance with ISO

14752: 2007 - after storage in standard oils, such as B. IRM 902 and IRM 903 over a given period of time and at a defined temperature, for example Over 72 hours at 23 ° C, the outer diameter of the media tube does not change beyond a maximum allowable limit and does not accept the medium inadmissible. The change in the outer diameter is in particular <5%.

Under bursting pressure is finally understood the pressure at which the media tube loses its functionality and is no longer tight. The bursting pressure is typically at a multiple of the operating pressure.

Conveniently, the structure consisting of flat wire helix braid and outer sheath thereby has a hose diameter which is in the range of only 5mm to 50mm and in particular in the range of less than 20mm. Such a media hose is therefore designed in the manner of a measuring tube over which only relatively small amounts of fluid flow. The kink protection, however, at the same time ensures that a volume transfer performance, for which the media hose is designed, is not reduced by bending in an inadmissible manner.

In a preferred embodiment, the entire structure allows comparatively small bending radii, so that the media hose can be installed without kinking on tight installation spaces as a whole. The structure allows bending radii, which are only in the range of 5 to 10 times the diameter of the hose.

Conveniently, the flat wire coil has a thickness in the range of about 1 mm. Furthermore, the flat wire coil has a width which, for example, is 1.5 to 3 times its thickness. The width of the flat wire helix is understood in each case to be the width of the steel strip used for the flat wire helix.

The flat wire coil also preferably has a lay length which is only in the range of 1 to 3 times and in particular about 1, 5 times its width. In this case, lay length is understood to be the axial length which the flat wire helix makes for a 360 ° revolution about the inner cavity needed. The flat wire coil is therefore arranged very steeply with respect to a longitudinal orientation. This is favorable for the desired tight bend radius.

The flat wire coil is made of steel, in particular stainless steel. This ensures high media resistance to the fluids inside the media tube.

The flat wire coil is preferably formed as an at least nearly closed coil, i. their individual winding sections are each adjacent to each other at least almost immediately on impact. At most, small distances in the longitudinal direction of the tube are formed between adjacent winding sections, which are for example less than 10% of the width of the flat wire helix. In particular, the distances are less than 1, 5mm and preferably at or less than 1 mm.

The braid in a preferred embodiment is a glass fiber braid. Such is on the one hand media resistant and on the other temperature resistant. As an alternative to a glass fiber braid, it is also possible to use a braid or a wrap of a polyester yarn, a ceramic, another inorganic material or a PTFE or glass silk tape.

Such a glass fiber braid is particularly tight to produce. In addition, a good decoupling between the flat wire coil and the outer sheath is given over the glass silk braid.

The outer sheath is preferably an outer sheath of a high-temperature-resistant and media-resistant plastic. The jacket material has in particular a fluoroplastic and consists in particular of such. Such fluoroplastics are characterized by the required here good media resistance and high heat resistance. Conveniently, the jacket material here is selected from FEP (fluoroethylene propylene), PFA (perfluoroalkoxy) or MFA (tetrafluoroethylene perfluoromethylvinyl ether). These plastic materials have been found to be particularly suitable for the intended field of application. They each have a temperature resistance of greater than 200 ° C and show good media resistance.

In particular, the jacket material consists of PTFE (polytetrafluoroethylene). This shows a particularly high temperature resistance and a very good media resistance.

The outer jacket is optionally formed by extrusion or by wrapping. He is either single-layered or multi-layered. Depending on the material used, the outer sheath is still sintered after application of the plastic material in order to form the desired properties. This is done especially with the PTFE.

An outer sheath of sintered PTFE has a total temperature resistance up to 260 ° C. In addition, sintered PTFE is also characterized by a high mechanical strength. Another advantage is the fact that PTFE does not melt. As a result, the outer jacket does not soften even at high temperatures or short-term excess temperatures and retains its good properties.

In an expedient embodiment of the outer jacket is designed for the total bursting pressure, for the entire media tube is also designed. This is preferably greater than 10 bar. In general, the media hose is typically designed for an operating pressure of several bar, for example of at least 3 bar. The outer jacket is generally considered a pressure resistant

Hose formed, which is already designed for the required operating pressure, for example of at least 3 bar and especially for the bursting pressure. In order to withstand these high pressures, the outer jacket preferably has a jacket wall thickness in the range of greater than 0.5 mm, in particular in the range of greater than 0.7 mm. The maximum jacket wall thickness is typically in the range up to 3mm. The shell wall thickness depends on the particular requirements, in particular on the operating and bursting pressure and on the material used.

In a preferred embodiment, a functional element is further laid in the inner cavity. This is, for example, an electrical functional element, in particular a wire or an optical functional element, in particular an optical waveguide. In principle, the functional element can also be designed as a cable consisting of a plurality of individual components (optical / electrical). In particular, the functional element is a sensor or data line.

The object is further achieved by the use of such a media hose with the features of claim 15. The media hose is used in particular in highly stressed areas for monitoring a machine, in particular an internal combustion engine, namely for monitoring fluids of the internal combustion engine, especially for Monitoring an exhaust gas or for monitoring a combustion chamber of the engine. Under internal combustion engine is in particular a (quasi) stationary large engine, in particular diesel engine, understood, as it is used for example for power generation or as a marine engine. Such (quasi) stationary internal combustion engines typically have a power of several hundred kilowatts (for example greater than 500 kW) and in particular several megawatts.

The media hose is generally connected in operation to a fluid space of a machine, in particular an internal combustion engine. For this purpose, it is connected with its one end, for example in the region of an exhaust pipe or directly to the engine for establishing a connection to the combustion chamber of the engine. It serves to monitor or measure the fluid space (eg combustion chamber or exhaust gas space) contained fluids or the combustion process as such. At its other end, the media hose is connected to a sensor device, which in particular measures properties of the fluid conducted or contained in the median hose and / or in the fluid space. These properties are in particular the temperature and / or the pressure and / or the chemical composition or the presence of certain components, for example in the exhaust gas.

An embodiment of the invention will be explained in more detail with reference to FIGS. In each case, in a simplified representation:

Fig. 1 shows a cross section through a media hose as well

Fig. 2 is a fragmentary side view of the media tube.

The illustrated in the figures, the media tube 2 comprises a formed as an inner support structure flat wire coil 4, which surrounds an inner cavity 6. The flat wire coil 4 in turn is surrounded by a braid 8, in particular glass fiber braid. This braid 8 is finally surrounded by a plastic outer jacket 10. The flat wire coil 4, the braid 8 and the outer shell 10 form a (shell) structure of the media tube 2. Other elements, the structure is preferably not on.

The flat wire coil 4 is in the embodiment of a steel strip made of stainless steel, which is wound helically. The steel strip has an approximately rectangular cross-sectional area with a width b, which lies in the range between 3 and 8 mm and in particular at about 5 mm (see Fig. 2). Furthermore, the steel strip has a thickness d1 which is in the range between 0.6 and 1.3 mm and in the exemplary embodiment at 1 mm. The lay length of the entire flat wire coil 4 is in the range of 1 to 3 times the width b of the steel strip and in particular in the range of 1 to 2 mm. The helical pitch is therefore very steep. The lay length defines the axial length in the longitudinal direction of the media tube, which requires the steel strip for a 360 ° rotation. As can be seen in particular from FIG. 2, the individual turns of the Flat wire coil 4 in the longitudinal direction only a small distance from each other, so that a nearly closed shell is formed by the flat wire coil 4. The distance is maximum about in the range of thickness d1 and in the embodiment at about 1 mm.

The flat wire coil 4 defines an inner diameter D1, which is for example between 3 to 8 mm and in the exemplary embodiment at 5 mm. The flat wire coil 4 therefore has an outer diameter of approximately 6 mm in the exemplary embodiment, which at the same time defines the inner diameter of the braid 8. The braid 8 in turn has a thickness in the range of, for example, 0.3 to 0.5 mm. Thus results for the voltage applied directly to the braid 8 outer jacket 10 in the exemplary embodiment, a sheath inner diameter D3 of about 7mm. In general, this sheath inner diameter D3 is, for example, in the range between 5 and 10 mm.

The outer casing 10 itself finally has a total casing wall thickness d2 in the range, for example, from 0.5 to 3 mm. In the embodiment, the jacket wall thickness d2 is about 1 mm, so that a total of a total hose diameter D4 of the media tube 2 in the range of about 8mm results.

The outer jacket 10 is in the exemplary embodiment a preferably extruded outer jacket 10. In this case, in particular a fluorinated ethylene propylene (FEP) is used as jacket material. Alternatively, the outer shell 10 is formed by a banded and sintered PTFE. Instead of an extrusion, the outer jacket is formed by a winding of a belt and later sintering.

The structure described here consisting of flat wire coil 4, braid 8 and outer sheath 10 has the following properties in an advantageous embodiment: a very high bending flexibility down to even small bending radii in the range of, for example, 5 to 10 times the diameter of the hose D4,

a kink resistance through the flat wire coil 4 down to the small bending radii,

Limitation of the bending radius by the special design of the flat wire coil 4,

high pressure resistance to internal pressures in the inner cavity 6,

- good media resistance both from the inside and the outside to oils, lubricants and fuels,

- Loadable with operating pressures of several bar, in particular from 1 to 5 bar,

- designed for burst pressures in the range of greater than 10 bar overpressure,

- High temperature resistance of greater than 150 °, preferably greater than 200 °. Preferably, the media tube has a temperature resistance up to 260 °.

Due to this special structure, therefore, the media hose 2 is suitable for use even in highly stressed areas, for example an internal combustion engine for monitoring fluids, in particular gases of the internal combustion engine itself. The media hose 2 is therefore preferably connected in operation to an internal combustion engine, for example in the region of an exhaust pipe or directly for establishing a connection with the combustion chamber of the engine directly. It serves to monitor or measure the fluids contained in the combustion chamber or the combustion process as such.

In the figure, a arranged in the inner cavity 6 strand-shaped functional element 14 is further shown, which is designed for example as a sensor or data line. The functional element 14 is, for example, an electrical wire, a cable with several components or an optical fiber. The functional element 14 is preferably located loosely in the inner cavity 14, preferably without being attached to the (shell) structure. It is understood that the functional element 14 itself also has a high temperature must have durability and a high media resistance, since this functional element 14 is exposed to the fluid located in the inner cavity 6 in operation.

LIST OF REFERENCE NUMBERS

2 media hose

4 flat wire coil

6 internal cavity

8 braid

10 outer jacket

14 functional element

D1 inner diameter

D3 sheath inside diameter

D4 hose diameter d1 thick flat wire helix d2 sheath wall thickness b wide flat wire helix

Claims

claims

1 . Media hose (2) for use at high temperatures and high pressures, especially in internal combustion engines, especially for measuring and monitoring a fluid within the internal combustion engine, comprising an internal cavity (6) surrounded by a flat wire coil (4), wherein the flat wire coil (4) is surrounded by a braid (8), which is enveloped by an outer sheath (10), wherein the construction of flat wire coil (4), braid (8) and outer sheath (10) flexurally flexible and kink resistant, temperature resistant to above 150 ° C, media resistant to Oil, lubricants and fuels is designed for a bursting pressure greater than 10bar.

2. media hose (2) according to the preceding claim, wherein the structure has a hose diameter (D4) which is in the range of 5mm to 50mm and in particular in the range of less than 20mm.

3. media hose (2) according to the preceding claim, wherein the

Flat wire coil (4) has a thickness (d1) in the range of about 1 mm.

4. media tube (2) according to any one of the preceding claims, wherein the flat wire coil (4) has a lay length in the range of 1 to 3 times a width (b) of the flat wire coil (4) and in particular at 1, 5-fold the width (b) is located.

5. media hose (2) according to any one of the preceding claims, wherein the flat wire coil (4) is designed as an at least almost closed helix.

6. media hose (2) according to any one of the preceding claims, wherein the braid (8) is a glass fiber braid.

7. media tube (2) according to any one of the preceding claims, wherein the outer jacket (10) has a fluoroplastic as the jacket material.

8. media tube (2) according to any one of the preceding claims, wherein the jacket material of the outer sheath (10) is selected from FEP, PFA and MFA.

9. media tube (2) according to any one of the preceding claims, wherein the jacket material of the outer jacket (10) consists of PTFE.

10. media tube (2) according to any one of the preceding claims, wherein the outer jacket (10) is sintered.

1 1. Media hose (2) according to one of the preceding claims, wherein the outer jacket (10) is designed for the bursting pressure.

12. Media tube (2) according to any one of the preceding claims, wherein the outer jacket (10) has a jacket wall thickness (d) in the range of greater than 0.5 mm to 3 mm.

13. Media hose (2) according to one of the preceding claims, wherein in the inner cavity (6) a functional element (14) is laid.

14. media hose (2) according to the preceding claim, wherein it is the functional element (14) is a wire, a cable or a fiber optic cable and in particular a sensor or data line.

15. The use of the media tube (2) according to one of the preceding claims for monitoring a machine, in particular an internal combustion engine, in which via the media hose (2) is a connection to an interior of the machine for checking the state of a fluid located in the interior.

16. Use according to the preceding claim for monitoring an exhaust gas or for monitoring a combustion chamber.