WO2001065189A1

WO2001065189A1 - Gliding run segment

Info

Publication number: WO2001065189A1
Application number: PCT/CH2000/000107
Authority: WO
Inventors: Claude Fehlmann; Nicolas Fehlmann; Frédéric MORI
Original assignee: Promotionbobsleigh S.A.R.L.
Priority date: 2000-02-28
Filing date: 2000-02-28
Publication date: 2001-09-07
Also published as: AU2000226557A1; EP1259770A1

Abstract

The invention concerns a prefabricated self-supporting gliding run segment, consisting of a multilayer composite structure including from inside outwards: a mechanical layer protecting the underlying layers (11), a heat-exchanging layer consisting of a laminated cloth based on a three-dimensional fabric impregnated with resin (13), at least a heat insulating layer (16) and an outer skin. The ice is cooled by a coolant fluid flowing in the assembly of the laminated heat-exchanging layer.

Description

Sliding track segment

The present invention relates to a prefabricated self-supporting sliding track segment, consisting of a multilayer composite structure. The invention also relates to a sliding track.

The invention relates in particular to track segments and tracks intended for bobsleigh and luge competitions.

The bobsleigh or luge competition tracks are conventionally built on site, possibly in prefabricated elements made for a single site. The structure of the installation and the sliding surface are generally made of concrete and covered with a layer of ice. The installation usually comprises a cooling device consisting of a heat exchanger steel, which is fed e brine or ^'which evaporates ammonia. Such structures are very heavy and almost impossible to dismantle to be reused on another site. In addition, this type of heavy construction is irreversibly damaging to the environment of the site concerned.

In the area of sliding tracks for purely recreational and playful purposes, we have also proposed types of construction with less impact on the environment.

Document DE-7239729U describes track segments for the construction of artificial toboggan runs intended to be used as such, without being covered with a layer of snow or ice. These segments have the shape of a concave gutter, the inner face of which carries a coating made of a fluoropolymer or of stainless steel, ensuring at all times a good glide of the sledge runners.

Document FR-2481605 describes a track for sleds or for trolleys, the curves of which are calculated in such a way so that it can be used by inexperienced people. The track is made up of segments assembled together, mounted on supports provided with cardan joints to accompany deformations due to thermal variations and mechanical stresses linked to the passage of sleds or carriages. The flexibility of this structure does not allow it to be covered with a layer of ice.

Document GB-1418668 describes an artificial toboggan run, consisting of U-shaped segments, joined together, made of a flexible synthetic material which can take the form of a trench dug in the mountain. The track is intended to be used all year round by sliding sleds or by carriages rolling directly on the surface of the segments.

The document DE-3017921 describes a track for trolleys on wheels, consisting of assembled segments, of synthetic material, having a profile in the form of, the central part of the W carrying a braking coating, which, coming into contact with a pad brake of the carriage, allows the braking of the latter.

The aforementioned tracks, consisting of segments made of synthetic materials, are intended to be used without a layer of snow or ice, the pads or wheels of sleds or carriages being in direct contact with the more or less slippery surfaces of the track segments. These tracks are suitable for purely recreational use, but cannot be used for international luge or bobsleigh competitions.

The do ^c ument O / 07488 discloses a bobsleigh run consists of self-supporting precast segments, having a sandwich structure comprised of a thermal insulator arranged between two skins. The segments are coupled together and mounted on supports on the ground. A track assembled using these segments is adaptable to the geometry of the site, modifiable and dismountable. The sandwich structure contains an exchanger heat, constituted by a bundle of tubes of flexible material, regularly spaced, embedded in the inner skin of the structure; these tubes are connected to heat transfer fluid collectors. This cooling system allows the production and maintenance of a layer of ice, essential in competition.

However, the multitubular exchanger of document O98 / 07488 has certain faults. The installation of parallel tubes in the matrix of synthetic materials is difficult. Repair is almost impossible. In the segments of complex shapes intended to make the turns of the bobsled tracks, it is difficult to obtain identical lengths of tubing and, after installation of the assembly, it is almost impossible to purge certain tubing, due to multiple high points. As a result, the surface temperature of the runway is inhomogeneous, which has a negative effect on the quality of the ice cover.

An object of the invention is the production of sliding tracks, in particular for bobsleighs or sleds, which allow international competitions to take place, which are adaptable to the geometry of the site and which can be dismantled, but which do not have the aforementioned drawbacks . The object of the invention is in particular to improve the uniformity of the temperature of the surface of the segments. The invention also aims to obtain a homogeneous distribution of the dissipated cooling power and to improve the energy efficiency during the production of ice. The invention also aims to simplify and lower the cost of manufacturing the track segments.

These aims are achieved by prefabricated self-supporting segments of gliding tracks, consisting of a multilayer composite structure, which comprises a heat exchange layer consisting of two substantially parallel walls, separated by at least one spacer, maintaining a WO 01/65189 PCT / CH0O / OO107

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spacing between the two walls and allowing a heat transfer fluid to circulate between these two walls.

The spacing element may consist of a fluted interlayer sheet, glued or welded to the two parallel walls, giving the entire heat exchange layer a structure similar to that of a sheet of corrugated cardboard. Such structures made of PE sheets are commercially available and are used to make special packaging.

The ends of the splines are connected to fluid collectors. Thanks to such a structure of the heat exchange layer, a heat transfer fluid is capable of circulating therein, occupying almost all of the interior volume of the heat exchange layer. The distribution of this heat transfer fluid is therefore much more homogeneous than in the case of a heat exchanger consisting of a bundle of parallel tubes spaced between them, and the surface temperature of the sliding track, and therefore the quality of the ice, are more homogeneous.

Preferably, the heat exchange layer consists of two substantially parallel walls, separated by a plurality of spacing elements distributed and forming spacers between the two walls, defining a single interior space, within which is capable of circulating a coolant.

The circulation of the heat transfer fluid in a single flow instead of a plurality of separate flows facilitates the purging of the heat exchanger.

According to a preferred embodiment, the heat exchange layer is produced by means of a three-dimensional fabric impregnated with a resin. Three-dimensional fabrics, also known as distance fabrics or space fabrics, consist of two layers of fabric held at a distance by retaining threads ensuring a predominantly empty space, with a thickness generally between 3 and 16 mm, between the two layers of fabric.

In general, the fabrics themselves are produced with continuous yarns of textile glass, possibly with carbon fibers, and the impregnating resins are epoxy, polyester, phenolic or polyurethane resins.

In this light and rigid three-dimensional structure, the skins and the core are one, which ensures delamination resistance, cohesion and impact resistance. A heat exchanging layer consisting of a sandwich laminate based on three-dimensional fabric contributes to a large extent to stiffen the entire multilayer composite structure of the track segment.

The exchange layer according to the invention can be prefabricated, thermoformed, and assembled by adhesion to the neighboring layers of the multilayer composite structure.

The track segment according to the invention can comprise from the inside to the outside, by defining "inside" as the side which receives the layer of ice:

- a mechanical protection layer for the underlying layers,

- the aforementioned heat exchange layer, and,

- At least one insulating layer, reducing losses of frigories to the outside and helping to determine the mechanical properties of the multilayer composite structure as a whole. The mechanical protection layer may consist of woven or non-woven fibers, in particular aramid fibers, and a resin.

The insulating layer may itself have a sandwich structure with a core, preferably made of light material, arranged between two layers of fabric impregnated with resin. This light material is preferably a thermally insulating material. The layers of fabric impregnated with resin have a structural role, contributing to the mechanical properties of the assembly.

The multilayer composite structure of a track segment according to the invention can comprise ^~ other intermediate and / or intermediate layers. It may especially comprise, between the heat-exchange layer and the mechanical protection layer or between the heat-exchange layer and the insulating layer, or on both sides of the heat-exchange layer, a sealing layer, ^' made of fine fabric and sealant. This sealing layer can compensate for a possible lack of sealing of the heat exchange layer.

A layer between the heat exchanger layer and the inner surface of the track segment, for example a layer made of a sealant, may include a charge of heat conductive particles to improve heat transmission.

In a heat exchange layer made up of 2 walls separated by a plurality of discrete elements distributed under the surface and forming spacers, the circulation of the heat-transfer fluid can take place in any direction parallel to the interior surface of the track segment . Preferably, the interior of the heat exchange layer is in fluid communication, along the two respective lateral edges of the track segment with respectively an injection tube and a fluid evacuation tube. coolant. These tubes can be made integral with the corresponding lateral edges of the heat exchange layer, parallel to or along a generatrix of each of the two tubes. Of course, this generator is straight if the lateral edge and the corresponding tube are straight; this generator is a curve if the lateral edge and the associated tube are themselves curved. The area through which communication takes place between a tube and the interior of the heat exchange layer can be continuous over the entire length of the corresponding edge: it can be formed by the open edge of the heat exchange layer, the edge enters the tube via a longitudinal slit thereof. The lateral edge of the heat exchange layer can also be closed, an area close to the corresponding lateral edge of the exchange layer being pierced with a plurality of discrete openings in communication with the interior of the tube.

According to a preferred embodiment of a curved track segment, the injection tube is located on the lateral side having the shortest developed length, the communication between this injection tube and the interior of the heat exchange layer taking place over the entire length of the tube, via the open edge of the exchange layer, while the communication between the interior of the heat exchange layer and the heat transfer fluid evacuation tube is effected by a plurality of openings arranged along the corresponding lateral edge, the linear density of these openings of this edge, in a given longitudinal portion of this track segment, being an increasing function of the developed width of the track segment in this portion.

The terms "lateral" and "longitudinal" are used here with reference to the direction in which the track is rolled down.

In this embodiment, the pressure of heat transfer fluid at the injection level varies relatively little along the injection tube and the higher number of openings in the portions of the segment having the largest width compensates for the greater pressure drop due to the greater distance crossed by the fluid at this level and improves the distribution of the flow of heat-transfer fluid in the transverse direction of the track segment. This arrangement optimizes the homogeneity of the distribution of the cooling power over the entire interior surface of the track segment.

Other characteristics and advantages of the track segments and gliding tracks according to the invention will appear to those skilled in the art from the description below of a preferred embodiment of the invention, in relation to the drawing annexed, in which

FIG. 1 is a schematic view in cross section of a track segment,

FIG. 2 is a diagrammatic representation, in section, of the multilayer composite structure of a track segment, and

- Figure 3 is a schematic representation of the heat exchange layer and the injection and evacuation tubes in a developed view, flat, of a track segment.

Figure 1 illustrates a track 1 segment set up in the field. Foundation footings 2, the production of which depends on the nature of the ground, constitute support points and are produced on site. If the installation is dismantled, only these soles remain on site. These soles receive posts 3. These posts 3 can be cut to the desired length or can be telescopic. On the posts 3 are fixed cross members 4, which serve as support for the track segments 1. To reduce the number of foundation footings and posts, each cross member 4 can serve as a support point for two adjacent segments. The crosspieces 4 are extended inwards so as to serve as a support for an access bridge 5 which extends along the track. An additional cross-member improves the connection of the bridge 5 to the runway segment. Two adjacent segments are linked to each other so as to guarantee the continuity of the track, by assembly means known per se. These assembly means may include brackets (not shown in FIG. 1) inserted at the front ends of each segment during the manufacture of this segment, the two branches of two brackets facing each other being assembled by means of threaded rods and d 'nuts, one or more seals being inserted (s) between the brackets and the track segments, so as to retain water at the beginning of the formation of ice on the inner surface of the track. Excess water (rain or icing) is evacuated by openings made in the structure.

FIG. 2 schematically illustrates a section through the multilayer composite structure constituting the track segment of FIG. 1. We find from top to bottom of the figure, and from inside to outside of the structure:

- An inner skin 11 of the track segment, consisting of a layer of woven or non-woven fibers, for example aramid fibers, and of a resin impregnating these fibers. This layer provides mechanical protection for the underlying layers.

a layer 12 made up of a fine fabric and a sealant, ensuring the seal between the mechanical protection layer 11 and the heat exchange layer, in the event that the upper wall thereof presents a defect sealing.

- A heat exchange layer 13 consisting of a three-dimensional fabric of glass fibers embedded in a resin, forming a laminate.

The laminate is made by impregnating the three-dimensional fabric and polymerizing resin. During impregnation, the fabric is compressed but regains its initial height when the pressure is released. Fabrics up to 8 mm high regain their height without an auxiliary agent, while for thicker fabrics, it is necessary to intervene with a roller or other means in order to obtain the maximum thickness . Those skilled in the art will find sufficient indications for the implementation of these means in the technical documentation of manufacturers of three-dimensional fabrics, for example Parabeam (Holland) or Aunde (Germany). After polymerization, the two layers of fabric form the walls which are interconnected by transverse support wires, forming the core of the structure. Laminates based on three-dimensional fabrics are generally used for the manufacture of light and rigid, fire-resistant panels, in the manufacture of tanks, automotive parts and molds. The main advantages of using three-dimensional fabric in these areas of composite materials are:

- the walls and cores are one, which ensures resistance to delamination, cohesion and impact resistance;

- three-dimensional fabrics are compatible with epoxy, polyester, phenolic or polyurethane resins;

- the space between the skins can be injected with foam to increase fire resistance or hot oil for hot molding of tank walls or body parts of curved and complex shapes.

The use of the interstitial space between the two walls for the permanent circulation of a coolant, had not been considered until now.

a second sealing layer 14, made up of a fine fabric and a sealing product to obviate a possible lack of sealing of the lower wall of the heat exchange layer 13.

- an insulating layer for thermal insulation of the track segment from the outside, which also contributes to determining the mechanical properties of the entire multilayer composite structure, this insulating layer is itself made up

- a first structural layer 15 of fabric and resin

- a core 16 consisting of a thermal insulator, for example extruded polystyrene

- a second structural layer 17 of fabric and resin

By way of nonlimiting example, the multilayer composite structure according to the invention can have the following constitution:

Example 1

In this example, the same resin is used for all the layers of impregnated fibers. However, different resins can be used from one layer to another. Figure 3 is a schematic representation of the heat exchanger device of a track segment intended to make part of a bobsled track turn.

The zone located at the bottom of FIG. 3 is relatively narrow, with a width of the order of 3 m, and constitutes the junction with a straight line of the runway. The upper part, wider, on the order of 6 to 8 m, is intended to constitute a portion of a bend whose outer edge is raised. The heat transfer fluid is brought through the injection tube 21 and circulates therein in the direction of the arrow F. The tube is split over its entire length, along a generator, and in the slot 24 is inserted the edge of the heat-exchange laminate layer 22, for ^~ three-dimensional base fabric, which edge 23 is open as shown in the enlarged top and left view of Figure 3. the inner layer of the heat-exchange layer is significantly smaller than the diameter of the tube 21, and the hydrodynamic head loss due to the passage through the interior space of the heat exchange layer in the direction of the arrows F ′ is significantly higher than that due to the flow F in the tube 21. The fluid supply to the heat exchange layer is sufficiently distributed over the entire length of the track segment. The opposite lateral edge of the heat exchange layer penetrates through a longitudinal slot 25 in the evacuation tube 26. The corresponding lateral edge 27 of the laminated layer 22 is closed, but the region adjacent to the lateral edge is pierced with a plurality of holes 28 opening out inside the tube 26, as shown in the enlarged view at the top right of FIG. 3.

As shown in FIG. 3, the relative spacing of the holes 28 with the holes which are adjacent to them is inversely proportional to the developed width of the heat exchange layer in the longitudinal portion considered of the track segment. This arrangement of the discharge holes compensates for the differences in pressure drop due to variations in the width of the segment and causes a flow, so that the heat transfer fluid ensures a homogeneous distribution of the cooling capacity.

During manufacture, the injection and exhaust pipes are fixed to the laminated plate constituting the heat exchange layer, pre-cut and pre-drilled. During the manufacture of the multilayer composite structure, the junctions between the injection and evacuation tubes and the heat exchange layer as well as these tubes themselves are protected by the edges of the mechanical protection layer.

Claims

claims

1. Prefabricated, self-supporting sliding track segment, consisting of a multilayer composite structure, characterized in that said multilayer structure comprises a heat exchange layer consisting of two substantially parallel walls, separated by at least one spacer, maintaining a spacing between the two walls and allowing a heat transfer fluid to circulate between said two walls.

2. Track segment according to claim 1, characterized in that the heat exchange layer consists of two substantially parallel walls separated by a plurality of repar-rtis spacers and forming spacers between the two walls, defining a interior space, within which a heat transfer fluid may circulate.

3. Track segment according to claim 1 or 2, characterized in that the heat exchange layer consists of a three-dimensional fabric impregnated with resin.

4. Track segment according to claim 3, characterized in that the three-dimensional fabric consists of continuous son of textile glass.

5. Track segment according to one of claims 1 to 4, characterized in that it comprises, from the inside to the outside of said segment,

- a mechanical protection layer for the underlying layers,

- the said heat exchange layer, and

- at least one insulating layer

6. Track segment according to claim 5, characterized in that said insulating layer comprises at least one thermally insulating material.

7. Track segment according to one of claims 5 to 6, characterized in that said insulating layer comprises a core of thermally insulating material, arranged between two layers of fabrics impregnated with resin.

8. track segment according to one of claims 5 to 7, characterized in that said mechanical protection layer consists of aramid fibers and a resin.

9. Track segment according to one of claims 5 to 8 characterized in that said multilayer composite structure further comprises, between said heat exchange layer and said mechanical protection layer and / or said insulating layer, minus a sealing layer made of fabric and a sealing product.

10. Track segment according to any one of claims 1 to 9, characterized in that the interior of said heat exchange layer is in fluid communication, along the two respective lateral edges of the track segment, with respectively a injection tube and a heat transfer fluid evacuation tube, integral with the corresponding lateral edges of the heat exchange layer.

11. Track segment according to claim 10, characterized in that said fluid communications are effected by an opening of each of said tubes which follows a generator and receives a lateral edge of the heat exchanger layer.

12. Track segment according to claim 11, characterized in that the fluid communication between the injection tube and the interior of the heat exchange layer takes place over the entire length of the edge of the heat exchange layer.

13. Track segment according to one of claims 10 to 12, characterized in that the fluid communication between the interior of the heat exchange layer and the tube heat transfer fluid is evacuated by a plurality of openings adjacent to the corresponding side edge of the heat exchanger layer, said side edge being also closed.

14. Track segment according to claim 13, characterized in that the linear density of said openings in a longitudinal portion of the track segment is a decreasing function of the developed width of the track segment in said longitudinal portion.

15. Sliding track, characterized in that it consists of a plurality of segments according to any one of claims 1 to 14.

16. Sliding track according to claim 15, characterized in that the said segments are assembled on supports on the ground by adjustable assembly means, in particular telescopic poles.

17. Use of track segments according to any one of claims 1 to 14 for the construction of a bobsleigh track.