EP1467804B1 - Method for producing a structured running surface for gliding devices and a textured running surface produced according to said method - Google Patents

Description

The invention relates to a method for producing a structured running surface for sliding devices, e.g. Skis, as well as a structured tread produced by this method.

The sliding of skis on snow leads to the formation of a microscopic water film. To unite the effect of a controlled water film guide on the one hand and on the other hand, a targeted tearing of the water film, is through the AT 398 038 B a ski with a macrostructured tread in the form of straight and parallel to each other, running in the longitudinal direction of the ski longitudinal grooves has been proposed, wherein the longitudinal grooves between 3 and 20 mm in length, between 0.05 and 0.25 mm width and between 0.01 and 1 mm in depth and are arranged in rows and offset from one another in the longitudinal direction of the ski.

The potential energy during downhill gliding is converted into kinetic energy, resulting in energy losses through air resistance and frictional heat. Hiebei it was recognized that the sliding friction between snow and ski coating has different interdependent effects. On the one hand, external friction, which takes place directly between the tread and the snow, melts the snow crystal, creating a hydromechanical lubricant that considerably reduces the frictional resistance of the tread-snow system as the tread slides no longer on hard snow crystals but on the fine melted surface water film. Due to the toughness of the water, this water film causes an internal friction in the water film. Although this internal friction is substantially much lower than the outer, but it can come as a result of high flow velocity to generate negative pressure, as well as the formation of turbulence in the water film, which have a strong energy-absorbing and thus braking effect. Due to the direct mechanical contact of the snow crystals with the structure of the Running surface can lead to negative deformation phenomena of the contact materials tread and snow. These in turn depend on the geometric design of the tread structure and on the elastic properties of the materials used.

In ski construction, extruded polyethylene coverings are used as the covering material. For top-of-the-line products and in racing, especially skating rinks made of sintered, high molecular weight low-density polyethylene are in use. In order to achieve optimal sliding and driving performance of the skis, the running surfaces including the steel edges must be ground. This is done by band grinding or stone grinding.

The belt grinding is an abrasive belt whose band, binder, abrasive grain size and the way of working the ski run surface have been optimized.

Stones are bonded abrasives whose classification is based on different aspects: for example, the purpose or type of raw materials used, for example natural (glass, pumice, quartz, garnet, corundum, diamond) or artificial (silicon carbide, boron carbide , Cubic boron nitride, synthetic diamond), or increasing hardness (1000 to 7000 ^kp / mm ² according to KNOOP) and grain size (0 to 5000 μm).

The grinding wheels are then trued with special tools (such as diamonds, hard metals, ceramics, etc.), whereby special tread structures are achieved.

In the grinding sector, there is the problem that the abrasives (tape, stone) wear off (become dull), whereby no defined and consistent abrasive structure can be achieved. Accordingly, practice has shown that the known methods and means do not provide satisfactory results.

Investigations in the laboratory as well as in the practical slip test have shown that the macrostructure alone only influences part of the sliding process.

Laboratory surface measurements on the skiing area with a laser microscope (micro range) and an atomic force microscope (nanoscale) have shown in addition to the macrostructure a relief-like microstructure, similar to a mountain and valley landscape in the micro range, in which the "mountain heights" or "valley depths" in a size range <10 microns depth down to the nano and Angströmbereich move.

Practical knowledge has shown that this microstructure is crucial for the sliding process in addition to the macrostructure. This can best be compared to the "lotus effect" of self-cleaning surfaces, where micro-roughness also plays a very important role.

An optimally ground ski consists of a macrostructure (> 20 μm depth and optically visible) and a microstructure (<10 μm depth and visible only under the microscope).

The macrostructure is achieved during grinding by removing the grindstone with diamonds. Due to different settings (speed, feed, shape, infeed, etc.), the macro structure can be largely adapted to the requirements.

However, the microstructure can not be controlled by grinding and is dependent on a large number of factors.

These include the material parameters (material, manufacturing process, etc.), the grinding parameters (stone type, stripping conditions, grinding conditions, grinding machine, etc.) and the environmental conditions (temperature, humidity, space, etc.).

The practically achievable microstructures are so strongly different that racing skis for the top sport area all have to be practically tested, because the same ground skis differ in a downhill from 60 seconds to 1 second and more.

By conventional processing means, such as grinding, etc., although the nature of this microstructure is recognizable as a mountainous, undulating structure, it is undefined, i. depending on the abrasives, their natural grain, the composition and the machining of the grinding tools.

For wet snow coarse, for normal snow medium and for cold snow fine, flat running structures are required.

In addition to the size but also the shape of the microstructure is an important parameter for sliding on snow.

In question are spherical caps, parts of an ellipsoid, paraboloid or rectilinear V-shaped or U-shaped structures in different dimensions.

By the US 5 727 807 A For example, a ski has become known in which a macrostructure of the tread has been proposed for the purpose of correct sliding.

The CH-A-641 683 discloses a ski with a defined macro and microstructure. The macrostructure is made by means of an embossing process, and the microstructure is determined by the use of different materials.

By the AT 383 744 B a tread has become known in which instead of the usual in cross-country skis a return-inhibiting microstructure is proposed. Such climbing aids were produced by dry grinding by sanding the tread with abrasives with very abrasive means, with the result that a fur-like, hairy structure has arisen, based on the previous or alternative climbing aids, such as sticking on fur skins, seal skins u .ae. has presented an alternative.

The object of the invention is to improve the sliding properties of ski running surfaces compared to the known measures. This object is achieved by the measure of claim 1. If the microstructure and the macrostructure are produced in the same machining process, a rational production method with associated production improvement takes place.

There are several ways to influence the microstructure, but none of the mentioned documents would cause the skilled person to emboss the microstructure.

When embossing the ski is guided by a parallel guide exactly centered, the feed and the contact pressure are infinitely variable.

According to a further feature of the invention, the microstructure is produced by embossing rollers, whereby a simple design of the system at higher contact pressures than is possible with embossing bands, can be achieved.

Instead of embossing rollers embossing rollers can be used.

According to a further feature of the invention, the tread from front to rear on different structures.

According to a further feature of the invention, a defined micro- and macrostructure is applied simultaneously or in succession with the aid of embossing rolls or dies. The microstructure can be adjusted in these rolls, for example via fine hammer mechanisms with fine needles, hard metal needles or, for example, via laser processing of the roll. It is also possible to apply the microstructure by means of targeted sandblasting or targeted chemical interventions, such as various mordants, for example, to expose grain boundaries of the steel material or aluminum material of the rolls in order to specifically adjust the microstructures in the region of 10 μm depth and down to the nanoscale to be able to.

According to a further feature of the invention, the structuring is applied under the action of heat. Advantageously, the boundary layer of the covering surface is briefly heated to very high temperatures, so that the polyethylene enters the plastic state in which the pattern is embossed. By subsequent embossing with cold rollers, the plastic mass solidifies very quickly, and the profile or the relief remains behind in the embossing process.

A further subject of the invention is a running surface for sliding bodies, which has a structuring produced in the stamping process and contains a microstructure and / or a macrostructure. Such a tread can be made independently of the slider and applied to the slider. In the context of the invention, however, it is also provided to provide the slider with a tread on which the structuring is applied in the embossing process.

The terms "slipper" or "slide" are to be understood in the broadest sense of the word, including not only skis and snowboards, but also any other vehicle or vehicle to understand, in which the structuring of the invention improves the driving characteristics of the vehicle.

Further features of the invention will be explained in more detail with reference to the drawings, in which embodiments of the subject invention are shown.

• Fig. 1 eine Draufsicht der Skilauffläche;
• Fig. 2 den Ausschnitt A der Fig. 1 in größerem Maßstab;
• Fig. 3 einen Schnitt nach der Linie III-III der Fig. 2; die
• Fig. 4, 6, 7 und 9 bis 13 verschiedene Anordnungsmöglichkeiten von Mikrostrukturen;
• Fig. 5 einen Schnitt nach der Linie V-V der Fig. 4;
• Fig. 8 einen Schnitt nach der Linie VIII-VIII der Fig. 7; und die Fig. 14a bis 16d verschiedene Formen, die in den nachfolgend beschriebenen Anordnungen eingesetzt werden können.

Show it:

• Fig. 1 a plan view of the ski area;
• Fig. 2 the section A of Fig. 1 on a larger scale;
• Fig. 3 a section along the line III-III of Fig. 2 ; the
• Fig. 4, 6, 7 and 9 to 13 various possible arrangements of microstructures;
• Fig. 5 a section along the line VV the Fig. 4 ;
• Fig. 8 a section along the line VIII-VIII of Fig. 7 ; and the Fig. 14a to 16d various forms that can be used in the arrangements described below.

In Fig. 1 1 denotes a ski running surface on which a microstructure 2 and a macrostructure 3 are applied. Both the microstructure and the macrostructure can be embodied in various forms.

According to 4 and FIG. 5 For example, the microstructure is provided in a parallel array. The orders of magnitude are in the Length L to 100 microns, in width B to 20 microns, in depth T to 6 microns, the longitudinal distance A to 100 microns, and the line spacing Z to 100 microns.

Fig. 6 shows a microstructure with a staggered array. The angle α is advantageously between 20 ° and 70 °. By varying the parameters of length L, width B, depth T, longitudinal distance A and line spacing Z, arbitrary shapes can be achieved.

The FIGS. 7 and 8 show an asymmetric shape that has different sliding properties back and forth. This property is especially appreciated by cross-country skiers to allow both gliding and climbing.

Fig. 9 shows a diagonal pattern with a uniform row arrangement, wherein the lines are inclined at an angle β to the running direction.

Fig. 10 shows a diagonal pattern with alternating right and left structures.

Fig. 11 shows an X-shaped pattern.

Fig. 12 shows a tulip-shaped pattern, which can also be used as a climbing aid in cross-country skis.

Fig. 13 shows a star-shaped pattern, which has very good sliding properties, especially in wet snow conditions.

Fig. 14a shows a boat-shaped depression, which is uniform after Fig. 15a or non-uniformly Fig. 16a can be trained.

Fig. 14b shows a circular recess, which also, like Fig. 15b shows, uniform or corresponding Fig. 16b can be uneven.

Fig. 14c shows a square shape, which accordingly Fig. 15c evenly or how Fig. 16c shows, can be uneven.

Fig. 14d shows a needle-shaped form, which also according to Fig. 15d evenly or appropriately Fig. 16d can be uneven.

Claims (8)

1. A method for producing a structured running surface for sliding devices, such as skis or snowboard, characterized in that the structuring is produced by means of an embossing method and includes a regular microstructure which is preferably present in regions with a depth of less than 10 µm, and optionally includes a macrostructure known per se.
2. The method according to claim 1, characterized in that the microstructure is produced by roll embossing.
3. The method according to claim 1, characterized in that a defined micro- and macrostructure is simultaneously produced by means of embossing dies which have been treated by selective sand-blasting, selective chemical interferences, laser processing or mechanical processing.
4. The method according to claim 1, characterized in that a defined micro- and macrostructure is produced successively by means of embossing dies.
5. The method according to at least one of the above claims, characterized in that the structuring is produced under heat introduction.
6. The method according to claim 5, characterized in that the boundary layer of the coating surface is temporarily heated up to very high temperatures, with the structuring with cold embossing dies following thereupon.
7. A running surface for sliding bodies having a structured running surface, characterized in that a structuring produced by means of embossing method is provided which includes a regular microstructure and optionally also a macrostructure.
8. The running surface produced according to the method of claim 1, characterized in that the structuring (2, 3) is designed to be different in the transverse direction across the running surface (1) of the ski.

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