DE2952942A1 - TIRE WITH REDUCED NOISE AND METHOD FOR FORMING THE TIRE - Google Patents

Description

IFM-Akustikbyran AB, Warfvinges väg 26, S - 112 51 Stockholm, Sweden

Vehicle tires

The invention relates to a vehicle tire with reduced rolling noise generation and a method for its production.

A significant environmental problem in today's society is the generation of noise on paths and roads. At lower speeds and high accelerations outweighs the noise from the drive unit from the receiver's point of view in most cases compared to the noise generated by rolling.

At speeds over 50 km / h, however, the dominates through the tire rolling in contact with the road generated noise. This means that a lot of the noise problems that along roads and paths even in urban areas, caused by the noise generated between the tires and the road are. For these areas it would no longer help to reduce the noise from the drive units. The fact that it was generated between the tire and the road as it rolled Noise under most conditions at speeds over 50 km / h dominates within the total noise generation, contributes to a certain understandable dislike of manufacturers. of Motor vehicles to further reduce the noise generated by the drive unit. A reduction in the

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seeing tires and road generated noise would therefore contribute directly solve the noise problems on roads and highways, where speeds higher than 50 km / h exist and would further help to achieve a general reduction in traffic noise at lower speeds, since a reduced one Roll-on noise would increase the motivation to reduce the noise threshold generated by drive units. It There are essentially three known processes-up to the present day Days to reduce the rolling noise between the tire and the road.

Λ. Change of profile

The length of the various profile blocks is in the direction of rotation varies so that the tonal components of the noise generation are distributed around the middle frequency.

2. Change of the rubber composition , so that a higher suspension is achieved. /.

5 »Influencing the surface texture of the road in order to achieve an optimal texture depth in terms of noise development

reach. ■ ·

No further noise reduction is likely to be possible using the first method, as this is already a very advanced one . Represents technology. The tonal component of the overall noise development is less dominant with rough road surfaces, since the accidental excitation of the tire by the road surface determines the noise development in these cases.

The second method cannot be used without increasing tire wear . Although it leads to a noise reduction, it is, however, from the economic standpoint

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point lier not acceptable.

Laboratory studies have shown that the most likely cause of the widespread field of tire / road noise is higher frequencies lies in the fact that the lugs of the profile vibrate between air resonances in acoustic resonance circles the tire and the road surface. One method of preventing this from happening is to detect differences in air pressure neutralize in the tire cavities through the tire tread. This can be done by changing the size the cleat of the profile is reduced and it is ensured that the air is in open and contiguous channels can move between the studs. However, if the tread lugs are too small, the road grip of the tire decreases from an unacceptable level. The proposal according to the present invention is, in contrast, the cleats of the profile to produce in a form that is sufficient for road grip or other requirements, but here the entire Profile is provided with contiguous air channels or pores, for example by using a porous rubber composition or by having holes drilled or otherwise shaped through the tread lugs during or after manufacture will. As a result, air pressure can be neutralized by the tread stud itself, while the tread is stable is maintained. Due to the porosity, the damping properties (mechanical losses) of the rubber are increased, which has a further advantage in terms of radiation ' of tires / road noise. When a tread suddenly accelerates and brakes while touching the road the aerodynamically stored energy becomes acoustic in the form Energy released. If the tread lug itself is porous, some of the energy can get into the through frictional losses Pores are absorbed and consequently will not be released to the environment

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■ blasted.'If the profile surface is made porous, is the radiated noise to the environment is reduced because

1) the radiation efficiency is reduced,

2) the vibration level of the profile lugs is reduced and

3) the stored aerodynamic energy during speed changes are absorbed.

His important question is how does a tire work with a porous profile surface can be produced in an economical manner. There are several alternative methods.

A profile: can be made by pre-vulcanization. This means that the vulcanization process is not completed. In this pre-vulcanization process, the profile is built up from / a large 'number' of rubber balls or granules, for example balls or pebble-like parts of a suitable hardness. The rubber balls are connected to one another to a certain extent by the pre-vulcanization. During tire manufacture, this pre-vulcanized profile is treated in the normal way, which means that it is applied to the unvulcanized tire carcass and is used in the molds of conventional tire vulcanization machines . As a result , the entire tire structure is vulcanized at the same time as the tire tread is formed in the tread rubber.

As an alternative to this, an unvulcanized tire carcass can be inserted into a mold in a vulcanizing machine. Then rubber or plastic granulate (in the form of balls or other shaped pieces of rubber) is poured into the mold in loose form. The tire is then vulcanized in its final form.

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The amount of rubber granules and the size distribution of the same is chosen in each case in such a way that a sufficient Degree of open pores is achieved. . 'j

An interesting side effect from the point of view of road grip is that the drainage capacity of the tire tread surface is drastically increased. This considerably increases the road grip on wet road surfaces. In connection with this it should be noted that the purpose of most erofil patterns is to ^; to achieve a sufficient grip on wet ■ road surfaces. On dry surfaces, adequate grip or grip is achieved with slick or worn tires without any tread pattern.

In the following the invention with reference to in the drawings exemplified embodiments explained in more detail. It shows:

Figure 1 is a perspective sectional view of a first embodiment according to the invention;

2 shows a part of a section through the carcass and the tread of the tire according to FIG Λ; : · ':

FIG. 3 shows a view corresponding to FIG. 1 of a second embodiment according to the invention and

Figure 4 is a perspective sectional view along the line IV-IY in Figure 3. "

In the drawings, 1 is the tire carcass and 2 is Tire tread called. In the embodiment according to FIG and 2 the profile surface consists of a plurality of through

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Vulcanization of interconnected rubber · »or plastic balls or other shaped bodies, between which air spaces communicating with one another, "for example air-permeable channels or pores, are provided. It is of particular importance that this air-carrying connection between the leading Side 5 and the trailing side 6 of the profile lugs 4 is present. .. · ■. ' ·.

In the embodiment according to FIG. 3 and FIG. 4, the connection between the leading side 5 and. been the trailing side 6 of the tread lug 4 created by the fact that the tread lugs 4 has been pierced, or by other means at least a covered channel 7, which is open at both ends, was created (ie not open to the tread surface as shown. '· in Grooves of the profile).

Such channels can be produced, for example, when the tire is vulcanized, in that appropriately shaped cores are arranged in the carcass. After vulcanization, the cores are removed from the tire.

In summary, the invention has a vehicle tire . created reduced roll noise generation. The tire tread is provided with one or more air-permeable channels or pores 6 which serve to neutralize the air pressure differences between different parts of the tread surface in contact with the road, for example on each side of a cleat in the tread pattern. The invention also describes a method how these channels or pores ; by piecewise vulcanization of rubber or plastic balls or otherwise shaped rubber or plastic oil bodies can be Herge provides, from which the profile is built up in such a way that interconnected channels or pores between

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see these moldings remain.

All from the description, claims and drawings emerging features and advantages of the invention including structural details and spatial arrangements, can be essential to the invention both individually and in any combination be.

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Claims (9)

TRANSLATION OF THE ORIGINAL CLAIMS 1. Vehicle tires, characterized in that its Profile (2) is provided with at least one air-permeable covered channel (6). 2. Vehicle tire according to claim 1, characterized by a variety of channels. 3. Vehicle tire according to claim 2, characterized in that the channels are in communication with one another. 4. Vehicle tire according to one of the preceding claims, characterized in that the channels are designed as pores. 5- vehicle tire according to one of the preceding claims, characterized in that the channels or pores have a surface of a tread with one of its other surfaces associate. 6. Vehicle tire according to one of claims 2 to 5 _S, characterized in that the profile consists of a number of rubber or plastic balls or otherwise shaped bodies connected to one another by vulcanization, between which the channels or pores remain. 7. A method for manufacturing a vehicle tire, the The tread is provided with a plurality of air-permeable channels or pores, characterized in that the Profile made of rubber or plastic balls or otherwise Shaped moldings is built, which were connected to one another by vulcanization such that between the shaped bodies communicating spaces 0 30605/0070 remain, which together are in connection with each other standing pores or channels form. . 8. The method according to claim 7, characterized in that the profile surface is pre-vulcanized in such a way that the balls or otherwise shaped rubber or plastic body adhere to one another to a sufficient extent, whereupon the
Profile is mounted in the usual way on an unvulcanized tire carcass for final vulcanization. 9. Procedure according to. Claim 7, characterized in that an unvulcanized tire carcass is placed in a mold in a vulcanizing machine, and that loosely, not
vulcanized rubber or plastic balls or other shaped rubber or plastic bodies are poured into the vulcanizing mold, after which the tire is vulcanized into its final shape .. '' ··. '■ DBr / pr 0306 0 5/00 7 0 BROSE ^{u Ka} BROSE Engineers D-8023 Munchen-Pullach. Wiener Str 2: Tel. (069 '/ .7 93 3 (J A; 7e "ifc) C5 212 747.bföS" d; Cables «Patentibus» Munich; IFM-Akustikbyran AB, Varfvinges väg 26, S- 112 51 Stockholm, Sweden Your reference: 19591 Day: 10 March 1980 .Yourref .: Date: DBr-aU PATENT CLAIMS 1. / Vehicle tires, "beivelchem the studs of the profile are provided with k _v JUut-permeable channels which are covered in the direction of the profile surface, whereby atmospheric air can flow through the profile studs in the rolling direction between its leading and trailing side by means of the channels That the channels consist of interconnected pores between rubber or plastic granulate, which are connected to one another by vulcanization. 2. Process for the production of a vehicle tire, the profile surface of which has a large number of air-permeable channels or is provided with pores, characterized in that the profile is made of rubber or plastic balls or otherwise shaped Molded bodies is built up, which were connected to one another by vulcanization in such a way that between the Shaped bodies that are connected to one another remain, which together are connected to one another Form pores or channels. 030605/0070 - 2 - $. ' Method according to claim 2, characterized in that the Profile surface is pre-vulcanized in such a way that the balls or otherwise shaped rubber or plastic moldings in a ■ Adhere to each other to a sufficient degree, whereupon the profile in the usual Way is attached to an unvulcanized tire carcass for final vulcanization. 4. The method according to claim 2, characterized in that a unvulcanized tire carcass into a mold in a vulcanizing machine is arranged and that loose, not vulcanized rubber or plastic balls or otherwise shaped rubber or Plastic moldings are poured into the vulcanizing mold, after which the tire is vulcanized into its final shape. 030605/0070