Vehicle pneumatic tires

Abstract

Vehicle pneumatic tire (1) of radial design with a carcass (4) and with components (9, 10) adjacent to the carcass (4), wherein thread-like elements (11, 12) are arranged on at least one of the two surfaces of the carcass (4) which serve to dissipate trapped air between the carcass (4) and the adjacent components (9, 10) during tire construction, characterized in that thread-like elements (11, 12) in the form of air dissipation threads (11) made of cotton are provided on the outer surface of the carcass (4), which are arranged at a distance of 25 mm to 40 mm - measured in the circumferential direction - and in a radial orientation, have a diameter of <0.3 mm and span the full carcass ply width, wherein some of the thread-like, air-dissipation elements (11, 12) are designed to be electrically conductive or are replaced by electrically conductive, thread-like elements (12).

Description

[0001] The invention relates to a radial-type pneumatic tire for vehicles, comprising a carcass and components adjacent to the carcass, wherein thread-like elements are arranged on at least one of the two surfaces of the carcass, which serve to remove trapped air between the carcass and the adjacent components during the tire construction process.

[0002] Radial tires with thread-like elements for air drainage are well known to those skilled in the art. Such a vehicle tire is known, for example, from DE 3014 268 A1. Radial tires are characterized by the radial orientation of the carcass reinforcement members. The carcass is manufactured in a textile calender by coating the ply with a compound layer of rubber.

[0003] To prevent air from becoming trapped between the joined components during tire manufacturing, thus reducing tire quality, the carcass component is coated on the surface of the compound layer in the textile calender with thread-like, parallel air-draining elements. This coating can be applied to one side only, i.e., only one of the two carcass surfaces, or to both sides. The thread-like air-draining elements are typically spaced 25 to 40 mm apart. These air-draining elements are, for example, cotton threads with a diameter of 0.1–1 mm. Inside the tire, the thread-like air-draining elements run radially and span the full width of the carcass plies.

[0004] To dissipate the electrostatic charge that occurs during tire operation, the bead area in contact with the road surface, the bead area in contact with the tire rim, and at least one component, such as the inner layer, carcass, or sidewall, which connects the tread and the bead area, are designed to be electrically conductive. This can be achieved, for example, by using electrically conductive rubber compounds. Electrically conductive means that the tire has an electrical resistance of no more than 1 × 10⁻⁶. 8 exhibits Ω.

[0005] The term "head area" refers to the components running strip, belt, belt bandage and intermediate layers between the aforementioned components.

[0006] The current development is focused on reducing tire rolling resistance. One approach is the use of low rolling resistance compounds. These are primarily used as so-called "body compounds" in the sidewall area, for the inner layer, and the carcass. The hysteresis of these low rolling resistance compounds can be reduced mainly by using lower levels of active fillers, smaller amounts of filler, or by replacing carbon black with silica. However, the use of these low rolling resistance compounds leads to an increase in their electrical resistance, thus reducing their electrical conductivity. The required electrical resistance of the entire tire is a maximum of 1 × 10⁻⁶. 8 The required Ω for dissipating the electrostatic charge cannot be guaranteed.

[0007] Often, conductive carbon blacks are used in minute concentrations to remedy this. However, these have a very high reinforcing / stiffening effect and also negatively impact hysteresis behavior and thus rolling resistance. To avoid exceeding the required low stiffness of a compound, e.g., in the sidewall area, the filler content of other reinforcing fillers must be significantly reduced to compensate for the conductive carbon blacks. This can lead to a very low overall filler content in soft components such as the sidewall. Consequently, satisfactory dispersion of the highly conductive carbon blacks is no longer possible, resulting in disadvantages such as reduced strength or abrasion resistance. Furthermore, such a measure based on conductive carbon blacks is expensive.

[0008] The invention is based on the objective of providing a cost-effective, high-quality pneumatic vehicle tire that exhibits improved electrical conductivity through simple measures.

[0009] The problem according to the preamble and characterizing features of claim 1 is solved by the fact that at least some of the thread-like, air-discharging elements are designed to be electrically conductive or are replaced by electrically conductive elements.

[0010] The essential aspect of the invention is that the electrical conductivity of the pneumatic tire can be improved by simply making some thread-like, air-discharging elements (air vent threads) electrically conductive, or by replacing some air vent threads with thread-like, electrically conductive elements. This ensures that the dissipation of electrostatic charge from the rim, via the bead, through the electrically conductive elements, to the electrically conductive tread is improved. The pneumatic tire remains of high manufacturing quality because the air trapped between the components during tire construction can still be reliably dissipated through the remaining air vent threads. The electrical conductivity of the pneumatic tire is improved with simple and cost-effective measures. No complex design modifications to the tire are necessary.

[0011] The thread-like element for air drainage can be completely replaced by an electrically conductive element, or the thread-like element for air drainage can be designed to be electrically conductive in addition to its air-draining property.

[0012] However, so many air-draining, thread-like elements remain that both the air can be reliably drained and the electrical conductivity of the tire can be improved.

[0013] The thread-like, electrically conductive element can be arranged on the outer surface or on the inner surface, or on both the outer and inner surfaces of the carcass.

[0014] “Outer surface” refers to the surface of the carcass facing the sidewall, while “inner surface” refers to the surface facing the inner layer.

[0015] In an advantageous embodiment of the invention, to ensure or improve the electrical conductivity, electrically conductive thread-like elements are arranged on the surface(s) of the carcass between 1 and 20, preferably between 3 and 10.

[0016] In a further advantageous embodiment of the invention, the electrically conductive thread-like element in the unvulcanized tire has an elongation of 1% to 500%, preferably 2% to 100%, particularly preferably 5% to 50%, and most preferably 2.5% to 35%. The electrically conductive thread-like element thus allows sufficient elongation during tire manufacturing and is not prone to breakage.

[0017] In a further advantageous embodiment of the invention, it is provided that the diameter of the electrically conductive thread-like element is between 0.01 and 1.00 mm and thus advantageously does not differ from the dimensions of the air drainage threads commonly used.

[0018] In a further advantageous embodiment of the invention, the electrically conductive thread-like element is a simply twisted yarn or cord made of electrically conductive material, thereby ensuring sufficient elongation of the cord. The simply twisted yarn or cord can, for example, consist of metal or carbon fiber.

[0019] In a further advantageous embodiment of the invention, the cord is a hybrid cord made of conductive and non-conductive materials. In this configuration, one yarn / filament of the cord can be conductive, while the other yarn / filament is non-conductive. Alternatively, a single yarn within a cord can comprise both conductive and non-conductive filaments, forming a hybrid yarn. The non-conductive yarns / filaments can be designed to vent air.

[0020] In a further advantageous embodiment of the invention, the hybrid cord is made of copper-clad PET and has a diameter of 0.3 mm. This allows for good adhesion to the rubber.

[0021] The non-conductive materials of the thread-like elements can be, for example, PES, polyamide or cotton.

[0022] The conductive materials of the thread-like elements can be, for example, copper, iron, carbon, brass or brass-plated versions thereof, in order to enable good bonding to the rubber matrix.

[0023] In a preferred embodiment, the pneumatic tire has a tread and bead areas made of electrically conductive rubber compounds, while the rubber compound(s) of the carcass and / or sidewall area and / or inner layer is / are insufficiently electrically conductive. Despite the use of low rolling resistance, poorly electrically conductive rubber compounds in the sidewall area and / or carcass and / or inner layer, improved electrical conductivity is achieved through the electrically conductive design of at least some of the air vent threads. This ensures that the electrostatic charge is adequately dissipated from the rim, via the bead, through the electrically conductive elements, to the electrically conductive tread.The pneumatic tire is nevertheless of high manufacturing quality because the air trapped between the components during tire construction can still be reliably released via the air-draining thread-like elements. Complex design modifications to the pneumatic tire are avoided by simply replacing the air-draining threads with electrically conductive thread-like elements.

[0024] “Insufficiently electrically conductive rubber compounds” refers to compounds with which the tire has an electrical resistance of > 1 × 10 8 exhibits Ω.

[0025] The invention will now be explained in more detail using schematic embodiments, a figure, and a graphic.

[0026] The single figure shows a radial partial section through a passenger car tire. The tire is made of rubber compounds. 1 has a bulge area 2to the bulge area 3 extending radial carcass 4 , which consists of a rubber-embedded insert of reinforcing elements and is surrounded by tensile-resistant bead cores 5 from axial inside to axial outside in a carcass high-cut 8 is led around at the end. The vehicle's pneumatic tire 1 still features a running track 6 and to the carcass 4 adjacent components such as the inner layer 9 and the side wall 10 on. Between the carcass 4 and the belt is the running track 7 arranged. The inner layer 9 borders the inner surface of the carcass 4 , while the side wall 10 to the outer surface of the carcass 4 borders on at least one of the two surfaces of the carcass. 4 are thread-like elements in the form of air vent threads 11 Arranged in cotton. The air vent threads.11 They serve to remove the air trapped between the carcass during tire construction. 4 and the adjacent components inner layer and / or side wall 9 , 10 to vent. Here are the air vent threads. 11 on the outer surface of the carcass 4 arranged.

[0027] The air vent threads 11 are spaced 25 to 40 mm apart – measured in the circumferential direction – on the surface of the carcass 4 They are arranged in a radial orientation and have a diameter of < 0.3 mm, preferably 0.15 mm. The air vent threads 11 span the full width of the carcass layers.

[0028] Between 1 and ten pieces of the air vent threads 11 are designed to be electrically conductive or to contain electrically conductive, thread-like elements 12 replaced, while the remaining air vent threads 11as is known. These include – distributed around the circumference of the tire – approximately three air vent threads. 11 through three electrically conductive, thread-like elements 12 replaced. The electrically conductive, thread-like element is advantageously a hybrid cord. 12 Made of copper-clad PET with a diameter of 0.3 mm. The copper cladding ensures electrical conductivity and also allows for good adhesion to the rubber. The electrically conductive hybrid cord 12 as well as the air vent threads 11 are across the entire axial width of the carcass 4 arranged. graphic

[0029] The diagram shows the electrical resistances in ohms of a reference passenger car tire (reference) and of six passenger car tires (tires 1–6) according to the invention, which have conductive, thread-like elements, and their position relative to the carcass. The reference tire and the tires according to the invention have the same construction. The bead area and the head area have electrically conductive rubber compounds, while the sidewall and / or the carcass and / or the inner layer compound are not electrically conductive. Air vent threads are arranged on the outer and / or inner surface of the carcass rubber. The tires have the dimension 205 / 55 R16. The tires according to the invention differ from the reference tire in that some of the thread-like, air-venting elements (air vent threads) are replaced by electrically conductive, thread-like elements (threads).The electrically conductive, thread-like elements have a diameter of 0.3 mm and are made of copper-clad PET. Starting from the reference tire without conductive air vent threads (> 1 × 10 ohms), the electrical resistance of the tires decreases to values ​​of approximately 1 × 10, depending on the number and design of the conductive threads used. 5 up to 1 × 10 7 Ohm off.

[0030] Tire 1 has three electrically conductive threads on the outer surface of the carcass. Tire 2 has three electrically conductive threads on the inner surface of the carcass. Tire 3 has two electrically conductive threads on the outer surface and two electrically conductive threads on the inner surface of the carcass. Tire 4 has eight electrically conductive threads on the outer surface of the carcass. Tire 5 has four electrically conductive threads on the outer surface and four electrically conductive threads on the inner surface of the carcass. Tire 6 has sixteen electrically conductive threads on the outer surface of the carcass. Reference symbol list 1 vehicle pneumatic tire 2. Bead area 3. Bead area 4 Carcass 5 bead core 6 treads 7 belts 8 Carcass high impact 9 inner layer 10 side wall 11 Air vent thread 12 electrically conductive hybrid cords QUOTES INCLUDED IN THE DESCRIPTION

[0031] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0032] DE 3014268 A1

[0002]

Claims

[1] Vehicle pneumatic tires ( 1 ) in radial construction with a carcass ( 4 ) and attached to the carcass ( 4 ) adjacent components ( 9 , 10 ), wherein on at least one of the two surfaces of the carcass ( 4 ) thread-like elements ( 11 , 12 ) are arranged to allow air trapped between the carcass to escape during tire construction ( 4 ) and the adjacent components ( 11 , 12 ) serve, characterized by , that some of the thread-like, air-discharging elements ( 11 ) are designed to be electrically conductive or are made by electrically conductive, thread-like elements ( 12 ) are replaced. [2] Vehicle pneumatic tire according to claim 1, characterized in that between one and 20, preferably between three and 10, electrically conductive, thread-like elements ( 12 ) on the surface(s) of the carcass ( 4 are arranged. [3] Vehicle pneumatic tire according to claim 1 or 2, characterized in that the electrically conductive, thread-like element ( 11 , 12 ) in the unvulcanized tire exhibits an elongation of 1% to 500%, preferably 2% to 100%, particularly preferably 5% to 50% and most preferably 2.5% to 35%. [4] Vehicle pneumatic tire according to one or more of the preceding claims, characterized in that the diameter of the electrically conductive, thread-like element ( 11 , 12 ) between 0.01 and 1.00 mm. [5] Vehicle pneumatic tires according to one or more of the preceding claims, characterized in that the electrically conductive, thread-like elements ( 12 ) is a simply twisted yarn made of electrically conductive yarns / filaments. [6] Vehicle pneumatic tires according to one or more of the preceding claims, characterized in that the electrically conductive, thread-like element ( 11 , 12 ) a yarn / hybrid cord consisting of at least two filaments / yarns ( 12 ) made of conductive and non-conductive materials. [7] Vehicle pneumatic tire according to claim 6, characterized in that the hybrid cord ( 12 ) is made of copper-coated PET and has a diameter of 0.3 mm. [8] Vehicle pneumatic tires according to one or more of claims 1–7, characterized in that the rubber compounds of the tread ( 6 ) and the bulge areas ( 2 , 3 ) of the vehicle's pneumatic tire ( 1 ) have electrically conductive rubber compounds, while the rubber compound(s) of the carcass ( 4 ) and / or the side wall area ( 10 ) and / or the inner layer ( 9) is / are insufficiently electrically conductive.

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