FI112850B - Wear surface construction in a hub deck - Google Patents

Description

Tread structure of the tire to be studded - sectional construction 112 and SÖ

The application relates to a tread structure according to the preamble of claim 1, which is a tread tire, in particular passenger and van tires, possibly also truck and bus tires.

The known studded tires are preferably friction tires in which the tread consists of a combination of a soft cap rubber layer and a harder base rubber layer, where both rubber grades are on average approximately equal. The Cap rubber on the surface of the tread surface of the tire provides grip and the base rubber between the tire body and Cap rubber gives the tire the stability needed for good traction.

In a known friction tire, the base rubber closer to the tire body has a hardness of about 67-72 sh ° A and the Cap rubber forming the tread layer has a hardness of about 55-63 sh ° A. Most of the tread height, which is equal to the groove depth, is made of elastic Cap rubber. In this case, the base flange of the stud is located in a hard Base rubber, which requires a relatively high force when driving on a hard tread to push the stud from its tip to the level of the tread surface. High puncture force causes significant wear on the road surface and tire noise. It also prevents the studs from being positioned in the center of the tire, which would otherwise provide the greatest benefit in terms of grip.

In order to reduce the pin puncture force, kit-'' has been developed according to FI-101 463: a tire tread structure having an outer flexible layer having a hardness of about 55-63 sh0A and an inner hard layer having a hardness of about 63- : 25 75 sh0A, preferably greater than 65, and typically greater than 67 sh0A. Below the bottom flange of the pins, that is, at the opposite end of the pin tip, there is a soft. · A softer rubber cushion embedded in the base layer and in contact with the bottom flange. In this way, the pin's pinning force is significantly reduced. The reduced puncture force also allows the pins to be positioned in the center zone of the tire.

'; It is an object of the present invention to reduce the needle force of the stud, improve the adhesion of the stud and lower the noise level without impairing grip or impairing runnability. This has been successful with the wear layer structure according to the characterizing part of claim 1.

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According to the invention, harder Base rubber is provided at least in the form of circumferential and transversely extending strips at the periphery of the tread, within a soft cap rubber layer so that the pin holes formed in the tread pattern blocks extend from the outer surface to the interstice base strips. a soft elastic layer such that the lower flanges of the studs to be attached to the stud holes are located entirely within the elastic layer below the intermediate base strips and the neck portions of the studs are at least substantially surrounded by the intermediate base layer.

In this way, the lower flange of the stud is contained within a soft elastic layer, whereby the force of the pis-10 of the stud when driving on hard surfaces is significantly reduced while the harder intermediate rubber encircles the stud's neck to enhance the stud's adhesion. As the pin stud's strength decreases, the noise level of the tires also decreases. The elastic outer surface of the tread cap rubber provides good grip and the circumferentially harder intermediate base strips provide the tread with the necessary stiffness.

According to a preferred embodiment of the invention, the intermediate base strips of the peripheral areas are interconnected by a middle base strip connecting the edge strips. The central strip may be formed by a strip parallel to the outer surface of the wear layer. Alternatively, the center strip may be formed by a flattened V-shaped strip, with the downwardly sloping portion 20 of the intermediate base layer touching or slightly above the lower edge of the wear layer. Tread. below the parallel intermediate base layer is a resilient layer of rubber or softer rubber over the entire width of the tread. Due to the elastic layer that reduces the needle strain, it is also possible to attach the studs to the wear surface. 'In the middle zone. Above the downwardly sloping intermediate base layer 25, there is a large amount of Cap rubber in the central zone, but not at all or slightly below it. The generous cap rubber layer in the center tread provides additional: '': possibilities for tread patterning.

. The core of the invention is that a thin intermediate base layer having a hardness of about 10 sh0A greater than the Cap layer hardness increases the pin's adhesion to the ring; · '30 and allows for a soft elastic layer between the intermediate base layer and the tire body and stabilizes the tread, which on average contains more than usual; “Elastic rubber.

•, v The intermediate basebands of the peripheral regions are each about a third or slightly more; · The full width of the tread. The width of the tire and the width of the tread 35 with it vary quite widely depending on the car type. In passenger cars and vans, the tire width can vary between 110 and 300 mm. The width of the intermediate base strips of the peripheral regions is at least one third of the width of the tread, whereby the width of the central zone is also one third of the total width or less. The central zone width may be reduced to a quarter of the total width, whereby the width of the peripheral 5 dips will increase accordingly.

The outer tread cap rubber layer is slightly thicker than the intermediate base layer and the elastic layer, the last two layers being approximately the same thickness. The thickness of the surface-facing Cap rubber layer ranges from 3.5 mm to 5.5 mm, preferably from 4 mm to 5 mm, and is most preferably 4.5 mm. The thicknesses of the intermediate base layer and the flexible layer vary between 2.5 mm and 4.5 mm, preferably between 3 mm and 4 mm, and most preferably are 3.5 mm. The elastic layer is absent in the center zone of the tread when the intermediate base layer deflects V-shaped downward in the central zone.

The driving characteristics of the tire are largely due to the hardness of the rubber in different zones. 15 The hardness of the soft Cap rubber giving the grip is 50 sh ° A-60 sh0A, most preferably about 55 sh0A, and the elastic layer below the intermediate base layer is the same or even 5 sh ° A less than the hardness of the Cap rubber, ie about 45 sh ° A -55 sh ° A. The hardness of the intermediate base layer, which provides tire stability and increases pin resistance, is about 10 sh ° A higher than that of the Cap layer, i.e. about 55 sh ° A to 70 sh ° A.

'': The diameter of the bottom flange of the studs to be attached to the stud holes can be 9 mm, up to 10 mm, '··, which contributes to the stud's stability. This is up to 2 mm more than a standard winter tire stud. The large diameter distribution is made possible by the Cap layer below the intermediate base layer, which is easily accessed by the lower flange of the pin; ' ·. j 25 to boil. The upper flange has a diameter of 6-8 mm and a stud height from the bottom of the lower flange, ···. the upper edge of the upper flange is 8-11 mm, but preferably 9-10 mm.

The tread structure according to the invention is particularly suitable for winter tires for passenger cars and luggage vans, but is also applicable for truck and bus tires.

In the following, some preferred embodiments of the invention will be described: With reference to the accompanying drawings, in which:; ', Figure 1 is a vertical sectional view of the structure of a studded wearable pin according to the invention prior to forming a pattern surface; 112850 4 Figure 2 likewise shows a vertical sectional view of a structure according to another preferred embodiment of a studded wear surface according to the invention; Figure 3 further shows a vertical sectional view of a structure according to a third preferred embodiment of a studded wear surface according to the invention; Figure 4 further shows a vertical sectional view of a structure according to a fourth preferred embodiment of a studded wear surface according to the invention; Figure 5 is a vertical sectional view of the edge portion of the tread structure of Figure 1 or 2 and a pin attached thereto; and Fig. 6 shows a pin having a diameter and a height dimension attached to a tread structure according to the invention.

Fig. 1 is a vertical sectional view of a passenger car tread 1 and a chassis structure 2 below it. The intermediate base layer 3 is formed by two tread strips 3a and 3b parallel to the tread surface. The edge strips are surrounded by 15 soft Cap layers 4 throughout. The width of the edge strips is slightly greater than one-third of the width of the tread, wherein the width of the center region between the strips is slightly less than one-third of the width of the tread.

In the finished tire, the pins 5 are located as shown in the figure. The treads of Fig. 1 as well as Figs. 2-4 have not yet been molded, thus missing pin holes and texturing. However, in Figure 1 the location of the pins is. : drawn. The pins 5 are interleaved in four circular rows, ·; in the tread above the intermediate strips. The neck of the stud is substantially; Completely surrounded by the intermediate base layer 3a and 3b respectively and the lower flange of the pin is completely below the intermediate base layer within the cap layer. Thanks to this arrangement 25, the grip of the stud on the tread is good because the neck is surrounded by · ': a rigid rubber layer; and the lower flange diameter may be larger than usual, because · ..: when the pin tip protrudes into the treads in planes with the outer surface P

The resistance of the cap layer is less than that of a conventional base layer. The Cap rubber zone in the center tread zone also provides additional tread patterning capabilities.

Figure 2 also shows a vertical section through a preferred tread structure. In it, the intermediate base layer extends from one edge of the layer to the other. The intermediate zones 3d and 3e of the intermediate base layer are approximately one-third straight and parallel to the tread, and the central zone 3f, up to one-third of the entire width of the layer, is flattened V in center to downward contact with the tire body. Due to the structure shown above, a zone 4f containing a high amount of Cap rubber is formed above the flattened V, which gives additional possibilities for the texturing. The edge zones 6d and 6e, below the intermediate base layer (3d, 3f), may have the same Cap rubber as above the intermediate layer, or alternatively, an even softer rubber than Cap. The lower layer is called the elastic layer.

Alternatively, the downwardly bent center portion may remain slightly above the bottom edge of the wear layer. An over-wide intermediate base layer gives the tire more rigidity and is more demanding in heavier cars and vans.

Figure 3 also shows a vertical section through a preferred tread structure. The intermediate basement layer 3 forms a straight layer 15 parallel to the tread, below which the tread edge zones have elastic rubber edge strips 6g and 6h and a Cap mixing strip therebetween. The top layer is Cap layer 4.

Fig. 4 is a vertical sectional view of the tread according to the invention showing a top Cap layer 4, an edge-to-edge intermediate 20 base layer 3 and a bottom edge-to-edge elastic layer 6.

Figures 2-4 have no pins or pinholes visible.

. '*: Figure 5 is a slightly larger scale vertical section of the second edge zone of the wear layer and the pin 5 attached thereto, the spike: /': portion of the pin protruding from the tread, the neck of the pin being surrounded by the intermediate base layer 3; ": 25 and the lower flange of the stud is completely within the elastic layer 6 below.

. , Figure 6 shows a loose stud and its height and diameter dimensions. The stud has a conventional structure and measures the thickness of the wear layer, with the bottom flange completely below the intermediate base layer and the neck substantially surrounded by the intermediate base layer.

Some advantageous treads according to the invention have been described above, but it is to be understood that there are other treads which differ from these but which fulfill the features of claim 1.

Claims (10)

Construction of a wear surface to be provided with studs, the structure of the surface comprising a soft Cap rubber layer (4) and a hardener Base rubber (3) between the tire body (2) and the Cap rubber layer (4), and the wear surface has pattern pieces: spaced apart from each other by rafters in the circumferential direction and in its axial direction, and the pattern pieces have double heels, characterized in that the hardener Base rubber (3) is provided at least in the edge areas of the wear surface. The cap rubber layer (4) in the form of strips (3a, 3b; 3d, 3e; 3) extending in the circumferential direction and in the transverse direction parallel to the wear surface, such that the double heels extend through said intermediate base strips (3a, 3b). ; 3d, 3e; 3) into a resilient layer (6) adjacent to the intermediate base strips, that the lower flanges of the studs (5) to be secured to the heel fall completely below the lower surface of the intermediate base strips (3a, 3b) ; 3d, 3e; 3) inside the resilient layer (6) which is off Cap-rubber or yet. softer rubber, and that the neck portions of the dumbbells (5) are at least mainly surrounded by intermediate base rubber. 112850 Construction according to claim 1, characterized in that the hardness of the cap rubber (4) is 50 sh ° A - 60 sh ° A, preferably 55 sh ° A, that the rubber hardness of the resilient layer (6) below the intermediate base the layer is the same or at most 5 sh ° A softer than the hardness of the Cap rubber (4), and that the hardness of the intermediate base rubber is 60 sh ° A-70 5 sh ° A. 3. A construction according to claim 1 or 2, characterized in that the intermediate base rubber forms a uniform layer (3) with the width of the surface layer and parallel to the outer layer (P) of the wear surface. 4. A construction according to claim 1 or 2, characterized in that the peripheral intermediate strips (3d, 3e) of the edge regions 10 are joined by an intermediate base strip (3f) in the form of a flattened V to a uniform intermediate base layer having only or no Cap rubber under the V-shaped part. 5. A construction according to claim 1 or 2, characterized in that the peripheral intermediate base strips (3a, 3b; 3d, 3e) of the edge regions each have a width of about one-third or more of the entire width of the wear surface (P). ). 6. A construction according to any preceding claim, characterized in that the thickness of the intermediate base strips (3a, 3b; 3d, 3e) or the layer (3) is about 2.5 - 4.5 mm, preferably 3 mm - 4 mm, heist 3.5 mm. Construction according to claim 6, characterized in that the thickness of the surface Cap rubber layer (4) in the edge areas of the wear surface is 3.5 mm - 5.5 mm, preferably 4 mm - 5 mm, heist 4.5 mm. and further that the thickness of the intermediate base strips (3a, 3b; 3d, 3e) in the edge areas of the wear surface and of the resilient layer (6) below the intermediate base layer (3) is 2.5 mm - 4.5 mm, preferably 3 mm - 4 mm, heist 3.5 mm, and that in the middle area of the wear surface the superficial Cap rubber layer (4) terminates in the intermediate base layer (3), or if this is missing, said middle region is entirely of Cap-v, rubber (4). Construction according to any of the preceding claims, characterized in that the diameter of the lower flange of the studs (5) to be fixed in the stud heels is 6 mm - 10 mm, of the Upper flange 6 mm - 8 mm, and that the height of the stud from the The lower edge of the lower flange to the upper edge of the upper flange is 8 mm - 11 mm, preferably 9 mm - 10 mm. 112850 9. Design according to any of the preceding claims, characterized in that it is suitable for winter tires in passenger and package cars, possibly also for tires in trucks and buses. 10. A construction according to any preceding claim, characterized in that in the tire there are studs (5) only in places where soft rubber (4; 6) is provided under the intermediate base rubber (3a, 3b; 3d, 3e; 3). reduces the pigeon force of the pigeon.