3128results about "Rolling resistance optimization" patented technology

The invention relates to a high / low-temperature-resistant wear-resistant tear-resistant fluorosilicone rubber compound and a preparation method thereof, and belongs to the technical field of special rubber materials, the high / low-temperature-resistant wear-resistant tear-resistant fluorosilicone rubber compound comprises the following components: raw fluorosilicone rubber, a reactive liquid rubber compatibilizer, a reinforcing filler, a tear-resistant aid, a high-temperature-resistant aid, a vulcanizing agent, an accelerant, an anti-aging agent and an anti-attrition filler, the provided reaction type liquid rubber compatibilizer contains vinyl carboxyl liquid fluorosilicone rubber, the tear-resistant auxiliary agent contains zinc polymethacrylate, the high-temperature auxiliary agent contains vinyl fluorosilane modified carbon nanotubes, and the anti-friction filler contains molybdenum disulfide and layered nano zirconium phosphate which are treated by oxygen plasma. The high and low temperature resistance stability, oil resistance, wear resistance and tear strength of the fluorosilicone rubber are synergistically improved by regulating and controlling the multi-cross-linked network structure of the fluorosilicone rubber, strengthening the interface action of the rubber and the filler and optimizing the composite vulcanization system, meanwhile, structuralization of a rubber compound is prevented by optimizing the preparation process, and the requirement for adaptability to severe working conditions is met.

The invention discloses a tire with a continuously woven carcass ply, and relates to the technical field of tires. Comprising a steel wire ring framework, a bead filler part, a sidewall rubber layer, a continuous woven carcass ply, a belted layer, a tread upper layer, a tread lower layer, a tire shoulder pad rubber layer, an airtight layer, a steel ring wrapping cloth layer and a seam allowance rubber protection layer, the tire side rubber layer, the belted layer, the tire shoulder pad rubber layer and the steel ring wrapping cloth layer are all arranged on the outer side of the continuously woven tire body cord fabric layer and are all attached to the continuously woven tire body cord fabric layer, and the continuously woven tire body cord fabric layer is an endpoint-free tire body cord fabric cylinder formed by continuously weaving cord threads or rubber-coated cord threads in a zigzag mode. The bead ring skeleton and at least a portion of the apex member are located inside the continuously woven carcass ply structure. The tire body cord thread cutting point generated in the manufacturing process of a traditional tire body cord fabric layer can be eliminated, and the technical problems that the rigidity at the cutting point of an existing tire body cord fabric layer is discontinuous and the bonding defect of a tire body cord thread and a rubber interface exists are solved.

The present invention aims to provide tire rubber composition with significantly improved overall performance in terms of wet grip performance and fuel economy, and pneumatic tires including the rubber compositions. The tire rubber compositions of the present invention have a tan δ versus temperature curve whose peak tan δ and half width satisfy the following relationship (1):Peak tan δ / Half width≥0.025  (1).

A spoke winding type high-sensitivity humidity sensor, the humidity sensor comprising a humidity-sensitive winding material and a spoke winding skeleton disc; a plurality of "T" shaped winding skeletons are uniformly distributed in a radial manner on the circumference of the spoke winding skeleton disc, and the humidity-sensitive winding material is wound on the plurality of "T" shaped winding skeletons; the space between every two adjacent "T" shaped winding skeletons simultaneously constitutes a winding limiting groove and an air flow channel, and after the humidity-sensitive winding material is wound, there is still space, i.e. the air flow channel, for air circulation, which is used to shorten the humidity absorption response time and the humidity desorption response time of the humidity-sensitive winding material.

The invention provides an all-steel tire tread pattern, and relates to the technical field of tire production. The tire tread is sequentially divided into a first tire shoulder, a first pattern block, a central pattern block, a second pattern block and a second tire shoulder by the four longitudinally formed pattern grooves along a first direction; a plurality of transverse grooves are longitudinally distributed in the surfaces of the first pattern blocks, the central pattern blocks and the second pattern blocks, and frosted lines are further arranged on the sides, tightly attached to the transverse grooves, of the first pattern blocks and the second pattern blocks; the pattern grooves extend to the groove bottoms in a wavy shape, the groove wall angles alpha of the tops of the pattern grooves range from 10 degrees to 15 degrees, and the groove wall angles beta of the groove bottoms of the pattern grooves range from 20 degrees to 25 degrees. The problems that in the prior art, an all-steel tire pattern cannot enhance the road holding force, and foreign matter such as pebbles is often clamped into a tire tread are solved, and the technical effects that the performance of an all-steel tire under various road surface conditions is improved, and the stability and safety of a vehicle during high-speed running are improved are achieved.

The invention provides a light-weight aluminum alloy truck hub forging spinning device and belongs to the technical field of hub production.The light-weight aluminum alloy truck hub forging spinning device comprises a machine body, an upper die base and a lower die base, the upper die base is provided with a first pressing die, the lower die base is provided with a second pressing die, the first pressing die comprises a first fixing piece, and the second pressing die comprises a second fixing piece; the first pressing die comprises a first fixing piece, a positioning assembly is arranged on the outer wall of the first fixing piece in a sliding mode and used for fixing the top of the blank hub, the second pressing die comprises a second fixing piece, a plurality of jacking pieces are evenly arranged in the second fixing piece and used for limiting the inner wall of the blank hub, and a plurality of supporting pieces are arranged at the bottom of the second pressing die in a sliding mode and used for supporting the blank hub. The support is used for supporting the bottom of a blank hub; the moving distance of the connecting piece can be adjusted by adjusting the extrusion degree of the piston piece, the device can adapt to various hub models with different inner diameters, demolding is convenient, and the production efficiency is improved.

The invention discloses a low-resistance and high-wear-resistance tire rubber composition as well as a preparation method and application thereof, and belongs to the technical field of rubber materials. The tire rubber composition comprises the following raw materials in parts by weight: 50-70 parts of natural rubber NR, 30-50 parts of solution polymerized styrene-butadiene rubber SSBR, 40-60 parts of modified white carbon black, 3-5 parts of zinc oxide, 1-2 parts of stearic acid, 1-3 parts of an anti-aging agent 6PPD and 2.5-3.5 parts of a vulcanization system. The prepared tire rubber material has the advantages that the rolling resistance is obviously reduced, the wear resistance is improved, the energy consumption is effectively reduced, and the requirements of new energy automobiles on high-performance tires are met. Through three-step modification treatment, the white carbon black is uniformly dispersed in a rubber matrix, and the interface bonding is firm, so that the prepared tire can reduce the rolling resistance of the tire using the tread rubber, and the tread rubber has higher wear resistance, tensile strength and elongation at break, and accords with the development direction of new energy automobiles in the future.

The invention provides an ultrasonic impact strengthening device and method for improving the fatigue strength of an aluminum alloy hub of a new energy automobile. According to the new energy automobile aluminum alloy hub ultrasonic impact strengthening device and method, ultrasonic impact strengthening of the spoke area and the rim area of the aluminum alloy hub can be rapidly achieved, the working efficiency is high, the equipment investment is small, the manufacturing cost is low, and the process applicability is high; the method can be used for surface strengthening of aluminum alloy hubs of various complex structures in the new energy automobile industry in China, the fatigue strength of the aluminum alloy hubs is improved, the service life of the aluminum alloy hubs is prolonged, the stress corrosion resistance of the aluminum alloy hubs is improved, the surface smoothness of the aluminum alloy hubs subjected to ultrasonic impact strengthening is effectively improved, the surface attractiveness of the aluminum alloy hubs is improved, and the service life of the aluminum alloy hubs is prolonged. And the controllability, the stability and the safety of the new energy automobile are obviously improved.

The rubber composition for a tire tread according to the embodiment contains a rubber component containing a diene rubber and vegetable granules having a surface treated with a sulfonic acid-type surfactant. The rubber composition for a tire tread has excellent on-ice performance, excellent wet performance, and excellent low heat generation property.

The invention belongs to the technical field of brake pad materials, and particularly relates to a low-metal friction material for a racing car, a preparation method of the low-metal friction material, a brake pad and application. The low-metal friction material comprises the following raw materials: phenolic resin modified stainless steel, composite rubber, a lubricating material, a friction increasing material and a filler. Through the synergistic effect of the phenolic resin modified stainless steel, the composite rubber, the lubricating material, the friction increasing material and the filler, the low-metal friction material has stable friction coefficient, excellent wear resistance, low noise and excellent thermal stability.

The invention discloses a composite rubber material for track rubber coating and a preparation method thereof, and relates to the technical field of polymer materials; the composite rubber material for track rubber coating consists of a carbon black-doped modified boron nitride reinforcing filler, a porous skeleton main filler, glutaric acid, natural rubber, styrene-butadiene rubber, benzothiazole disulfide and zinc oxide; the porous skeleton main filler consists of a modified melamine skeleton material, and multi-walled carbon nanotubes double-modified with stearic acid and chitosan; the carbon black-doped modified boron nitride reinforcing filler is attached to the skeleton structure of the porous skeleton main filler to form a filler compound system, which can be evenly dispersed in the rubber matrix to form a more complete filler network, and the network structure can enable the various components of the filler to better play a synergistic reinforcing role, and under the dual effects of the structure and the components, the wear resistance, aging resistance and mechanical properties of the rubber material are effectively enhanced.

The invention discloses a preparation method of tread rubber, and belongs to the field of rubber processing. The preparation method comprises the following steps: pretreating aramid pulp, a coupling agent and a lubricant, and then adding the pretreated aramid pulp, the coupling agent and the lubricant into natural rubber to prepare aramid pulp master batch particles; the obtained aramid pulp master batch particles are added into raw materials for preparing tread rubber, and the prepared rubber material has excellent mechanical properties, wear resistance and low rolling resistance. According to the method, the dispersity and interface combination of the aramid pulp in the rubber are remarkably optimized, the comprehensive improvement of the mechanical property, the wear resistance and the rolling resistance of the tread rubber is realized, and the tread rubber has outstanding industrial application value.

The utility model discloses an axle rear axle head press-fitting device, and particularly relates to the field of axle head press-fitting, two sides of the top of a workbench base are fixedly connected with axle tube fixing seats, the tops of the axle tube fixing seats are provided with placing grooves, and the tops of the placing grooves are provided with connecting axle tubes. The shaft head press-in oil cylinder is started through an external power source, the output end of the shaft head press-in oil cylinder drives the shaft head fixing base to move, the shaft head fixing base drives the sliding base to slide along the surface of the linear guide rail, the connecting shaft head and the connecting shaft tube are press-fitted, when the press-fitting device is manufactured, the linear guide rail with high precision is selected as the movable guide rail, the error of the 100mm stroke is very small, and the press-fitting efficiency is high. And bearing positioning parts at the two ends are required to be clamped and machined on numerical control equipment at one time after being assembled. And the coaxiality error of the positioning part of the bearing position is less than 0.05. The coaxiality of shaft head press-in holes of the shaft tube assembly is 0.1, and the coaxiality of bearing positions of the shaft heads at the two ends can be smaller than 0.25 mm after the shaft heads at the two ends are pressed in. Therefore, the effect of high-precision press fitting is achieved.

The invention provides a wheel which comprises an outer spoke, an inner spoke and a rim, the outer spoke and the inner spoke are sequentially and fixedly connected with the inner wall of the rim in the axis direction of the rim, a plurality of mounting through holes are formed in the outer spoke, a plurality of connecting through holes are formed in the inner spoke, and the connecting through holes correspond to the mounting through holes in position in a one-to-one mode. And the outer spoke is fixedly connected with the inner spoke at the connecting through holes and the corresponding mounting through holes. According to the wheel, the hub spoke part is of a double-layer structure formed by combining the outer spoke and the inner spoke, and the multiple connecting sleeves are arranged at the positions needing to be connected, so that the outer spoke and the inner spoke do not need to bear too much torque, the lateral rigidity of the wheel can be remarkably improved, meanwhile, the material of the hub spoke of the wheel and the total weight of the wheel can be reduced, and the service life of the wheel is prolonged. Therefore, the material cost of the wheel is reduced, and light weight of a vehicle is achieved.

The invention relates to an indirect rear viewing system for a motor vehicle having a supporting element for fastening at least one reflective element, wherein the supporting element has a coupling region for a position variable fastening / attachment to an adjusting element, which in turn can be attached to the vehicle, wherein the coupling region contacts a counter contact regions, of the adjusting element, wherein interlocking anti rotation means are present on the supporting element and on the adjusting element, wherein the anti rotation means are forming an index geometry, which, in a first operating state, permits an adjustment of the supporting element relative to the adjusting element about two axes of rotation, which are transverse to one another, and, in at least a second operating state, permits a basic position change of the supporting element relative to the adjusting element about a third axis of rotation which is aligned transversely to the two other axes of rotation.

The invention provides a track pattern side rubber composition, track pattern side rubber and application thereof, and particularly relates to the technical field of tire manufacturing. The track pattern side rubber composition comprises the following components in parts by weight: 10-50 parts of natural rubber, 50-90 parts of chloroprene rubber, 10-30 parts of carbon black, 5-15 parts of white carbon black, 25-70 parts of a flame retardant, 5-10 parts of an activating agent, 0.5-1.5 parts of an activating auxiliary agent, 1-3 parts of an anti-aging agent, 1-4 parts of a vulcanizing agent and 2-4 parts of an accelerant, the flame retardant comprises antimony trioxide. According to the track pattern side rubber composition provided by the invention, through the synergistic effect of the raw materials, the maintenance of physical properties is ensured while the flame-retardant property is improved, and dual optimization of the flame-retardant property and the physical properties is realized. Meanwhile, the invention provides a mixing method of the track pattern side rubber, and the problem that high-part white carbon black is not easy to disperse is solved.

The invention discloses an anti-aging rubber product and a preparation method thereof, and belongs to the technical field of rubber product preparation, the anti-aging rubber product comprises the following raw materials by weight: 100-120 parts of styrene butadiene rubber, 2-4 parts of a modified anti-aging agent, 3-5 parts of zinc oxide, 2-3 parts of stearic acid, 2-3 parts of sulfur, and 4-7 parts of a functional reinforcing agent. The macromolecular modified anti-aging agent capable of being crosslinked and entangled with a butadiene styrene rubber molecular chain is introduced, so that the intermolecular acting force of the modified anti-aging agent and the butadiene styrene rubber is enhanced, and the defects that a small-molecular-weight anti-aging agent is easy to migrate and volatilize from a butadiene styrene rubber matrix in a high-temperature environment, a blooming phenomenon is generated and the like are effectively overcome; meanwhile, the introduction of the functional reinforcing agent effectively improves the mechanical strength and the anti-aging time of the rubber product, and through the synergistic effect of the functional reinforcing agent and the rubber product, the anti-aging performance of the rubber product is further enhanced, and the service life of the rubber product is prolonged.

The present invention discloses a rubber material and a preparation method thereof for improving the durability of a semi-steel tire, wherein the rubber material comprises the following components in parts by weight: 75-85 parts of natural rubber; 5-10 parts of butadiene-styrene rubber; 5-15 parts of rare earth cis-butadiene rubber; 5-10 parts of zinc oxide; 1-2 parts of stearic acid; 30-40 parts of N330 carbon black; 30-40 parts of N660 carbon black; 4.5-6 parts of phenolic reinforcing resin; 1-2 parts of tert-butyl tackifying resin; 2-4 parts of antioxidant; 2-3.5 parts of accelerator; 3-5 parts of insoluble sulfur. The rubber material proposed by the present invention has high hardness and low heat generation characteristics, and the Mooney viscosity of the rubber material is effectively controlled by a multi-step mixing method, avoiding the frosting phenomenon that may occur in the extrusion process. By introducing rare earth cis-butadiene rubber and two carbon blacks of different particle sizes, not only the fatigue resistance of the rubber material is improved, but also the rubber material is ensured to have a higher hardness while reducing heat generation. Ultimately, the application of this new rubber compound allows the tire to maintain good rigidity while greatly improving the durability of the tire.

The high-strength low-friction retainer formed through high-pressure casting comprises a retainer body, the retainer body comprises two arc-shaped sections and a plurality of window beams connected with the two arc-shaped sections, window holes for containing rolling bodies are formed between the adjacent window beams, and the sides, away from the window holes, of the window beams located at the two ends of the retainer body are provided with inward concave faces. And the inner concave surfaces of the two adjacent retainer main bodies are oppositely arranged to form an oil accommodating gap, so that the oil storage space in the bearing is obviously increased. According to the retainer, sufficient lubricating oil is guaranteed between the rolling body and the retainer main bodies and between the retainer main bodies, more effective heat dissipation is further facilitated, the design of the inner concave faces reduces the direct contact area between the adjacent retainer main bodies compared with a straight face, and therefore friction and abrasion between the retainer main bodies are reduced, and the service life of the retainer main bodies is prolonged. And the overall performance and stability of the bearing are improved.

This invention relates to the field of rear drive axle assembly technology, and more particularly to an assembly fixture for a wire retaining ring for a rear drive axle half-shaft. The fixture includes an assembly sleeve containing a cylindrical wire retaining ring placement groove and a cylindrical clearance groove, the latter communicating with the bottom surface of the placement groove. During assembly, the wire retaining ring is first placed in the placement groove. Then, the assembly fixture with the wire retaining ring is aligned with the half-shaft end face. Next, the second end of the assembly sleeve is pressed or struck, causing the wire retaining ring and the assembly sleeve to expand outwards by the half-shaft. Finally, after the wire retaining ring moves into the half-shaft groove, it retracts and returns to its original position. Using this assembly fixture, the wire retaining ring only needs to expand to the outer diameter of the half-shaft to complete the assembly, effectively reducing the possibility of the wire retaining ring failing to retract and return to its original position, thus improving the assembly quality stability of the wire retaining ring.

The invention provides star-shaped functionalized solution polymerized styrene-butadiene rubber and a preparation method thereof, and the preparation method comprises the following steps: S10, in an inert atmosphere, in an organic solvent, taking a conjugated diene monomer as a polymeric monomer, taking a substance obtained by premixing lithium alkyl and a front-end modifier as a functionalized initiator, and carrying out solution polymerization to obtain a polymer precursor; s20, adding an active coupling agent into the polymer precursor to obtain a star polymer with an active star core and a polar functional group at the tail end of each star arm; and S30, adding a functionalization reagent into the star polymer to obtain the star functionalized solution polymerized styrene-butadiene rubber with both chain end functionalization and chain middle functionalization. The front-end modifier and the active coupling agent are introduced, so that an active center is reserved in a star core, and the functionalization reagent is introduced to modify in a chain and enhance the interface bonding force between white carbon black and butadiene styrene rubber, so that the hysteresis loss of tire rubber is reduced, and the tire rubber is endowed with wear resistance, fatigue resistance and wet skid-rolling resistance balance.

The application provides a heavy truck axle housing manufacturing method, which comprises the following steps: selecting a ladder-shaped pipe blank, firstly performing axial annular material supplementing pre-expanding to obtain a pre-expanding pipe blank with an upper flat side, a lower side and front and rear convex sides, the wall thickness of the upper flat side is almost not thinned, and the wall thickness gradually decreases from the upper side to the lower side along the annular direction; and performing final expanding after annealing to obtain an axle housing pipe, the upper side of the pre-expanding pipe blank becomes a front flat surface with a bell-shaped additional front cover, the front and rear sides are shaped into a H-shaped side beam, the lower side becomes a semispherical rear oil cover, and the wall thickness of the front flat surface and the side beam is increased. The pre-expanding die is composed of left and right pressing heads, left and right sliding dies, an upper control die and a lower control die, the cavity axial width of the upper flat area of the upper control die is greater than that of the front and rear convex sides. The manufactured heavy truck axle housing is free of welds and oil leakage, the wall thickness of the front flat surface and the side beam of the axle housing is large, the bending and torsion resistance is improved, the diameter expansion rate is large during hydraulic expanding, the wall thickness thinning rate is small, the forming quality is good, and the material utilization rate is high.

The invention discloses a rubber composition for tire crown components, specifically related to the field of rubber, including the following raw materials by weight: 100 parts of diene rubber, 0.3-3 parts of hydrazide compounds, 40-160 parts of reinforcing fillers, 0-1.5 parts of low rolling resistance modifiers, 2-18 parts of silane coupling agents, vulcanization accelerators, vulcanizing agents, antioxidants, vulcanization activators, processing aids, resins and plasticizers. Hydrazide compounds can improve the compatibility between rubbers, and after complexing with zinc oxide, stabilize sulfur cross-linking bonds, thereby improving fatigue crack resistance, delaying crack initiation, reducing crack propagation rate, and improving physical property retention after aging. Low rolling resistance modifiers can react with the double bonds of synthetic diene rubbers in a trans-Diels-Alder reaction, which has the effect of reducing rolling resistance. Hydrazide compounds and low rolling resistance modifiers are used together, and the rubber composition has the performance of anti-fatigue, anti-crack growth, anti-collapse and block falling, low hysteresis loss, low heat generation, and low rolling resistance.

The utility model discloses a carbon fiber composite reinforced electric automobile hub which comprises a hub body, the hub body comprises a rim, the left side and the right side of the rim are respectively provided with a front wheel flange and a rear wheel flange, and the front wheel flange and the rear wheel flange are respectively provided with a wheel flange groove. Grid patterns are pressed in the rim groove, and a composite layer integrally formed with the hub body is arranged in the rim groove. The composite layer comprises gridding cloth and liquid glue, and the surface of the composite layer is flush with the surface of the rim; a plurality of strip-shaped grooves which are uniformly and annularly distributed are formed in the front surface of the hub body, and two polygonal grooves which are symmetrically formed are formed between any two strip-shaped grooves; the polygonal grooves are evenly and annularly distributed along the hub body and are arranged in a bilateral symmetry mode. The rim groove is formed in the rim of the hub body, and the composite layer integrally formed with the hub body is arranged in the rim groove, so that the structural strength is higher; and a plurality of grooves are formed in the hub body, so that the overall mass is lighter.

The invention discloses a preparation method of bio-based material modified coumarone resin, an obtained product and application. The preparation method comprises the following steps: mixing a mixture containing polymerizable components indene and coumarone, styrene or a derivative thereof and a catalyst; then dropwise adding a mixture containing polymerizable components indene and coumarone and an organic solvent solution of a bio-based material to carry out polymerization reaction; and adding a quenching agent after the reaction, and performing post-treatment to obtain a final product. According to the invention, a bio-based material is adopted as a raw material, and the raw material is derived from natural plants and has the characteristics of environmental friendliness, degradability and the like, so that the cyclic utilization of resources is realized, and the generation of wastes is reduced. The bio-based modified coumarone resin is high in hydroxyl content and narrow in molecular weight distribution, the compatibility of the coumarone resin and polar resin is improved, the use performance and the application range of the coumarone resin are improved, and the bio-based modified coumarone resin has good application prospects in the fields of adhesives, rubber, coatings, ink and the like, and is particularly suitable for tire tread rubber.

The invention relates to the technical field of production of cloth liners, in particular to a tire cloth liner with a high-temperature-resistant coating and a preparation method of the tire cloth liner. According to the invention, the problems of poor anti-sticking property and poor durability of the existing tire mat cloth are solved. The cloth liner comprises a base body layer, a hard layer, a high-temperature-resistant layer and an anti-sticking layer, the base body layer is coated and cured with hard layer mixed slurry, then the high-temperature-resistant layer is hot-pressed on the hard layer through a high-strength adhesive, then anti-sticking layer slurry is sprayed on the high-temperature-resistant layer, and the tire cloth liner is obtained after curing and cooling. Carbon fiber reinforced epoxy resin is added into the hard layer, and the carbon fiber reinforced epoxy resin, silicon carbide and boron nitride can synergistically improve the mechanical property of the cloth liner; the high-temperature-resistant layer and the hard layer are bonded through the high-strength adhesive, so that the bonding force between the layers is improved; modified graphene oxide and a composite coupling agent are added into the high-temperature-resistant layer, so that the high-temperature-resistant performance of the cloth liner is jointly improved; silane modified organic silicon is added into the anti-sticking layer, so that the anti-sticking performance of the cloth liner can be improved together with other components.

The invention relates to the technical field of tire rubber manufacturing, and discloses a tread rubber composition containing modified lignin and a mixing method thereof, and the rubber composition is added with the modified lignin. The modified lignin is water-soluble lignin obtained by modifying lignin by grafting citric acid groups. Citric acid is adopted to modify lignin, a citric acid group is grafted on a lignin group under the catalytic action of sodium hypophosphite to enhance the hydrophilicity of the lignin group, wet mixing is combined, the dispersity of the lignin in rubber is effectively improved, the rolling resistance of the rubber composition is reduced, meanwhile, the added lignin can enhance the strength of a rubber network, and the rolling resistance of the rubber composition is reduced. The tensile property of the rubber is improved.

It is an object of the present invention to provide a tire for heavy load with an improvement in wet grip performance thereof. A tire of the present invention is a tire for heavy load, which tire comprises a tread part, wherein the tread part comprises one or a plurality of main circumferential grooves extending continuously in the tire circumferential direction, wherein the tread part is composed of a rubber composition comprising a rubber component and silica, wherein the groove depth of the deepest part of the main circumferential groove is defined as H1, in mm, and a content of silica based on 100 parts by mass of the rubber component when the rubber composition comprises silica is D, in parts by mass, H1 is 15.0 or less, H1 × D is 250 or more, preferably 350 or more, a land ratio R on the ground surface of the tread part after the tread part is caused to wear along the tread radius such that the groove depth of the deepest part of the main circumferential groove is 75% of that when the tire is new is 0.90 or more.

The invention relates to the technical field of tire rubber manufacturing, and discloses an EV tire tread rubber composition adapting to low temperature and a mixing method thereof. According to the invention, the high-vinyl solution polymerized styrene-butadiene rubber A, the low-glass transition temperature solution polymerized styrene-butadiene rubber B and the lithium-series cis-butadiene are matched to form a rubber substrate, and the high-dispersion white carbon black, the bio-based filling oil and the high-proportion wet-skid-resistant resin are matched, so that the matching amount of various raw materials is strictly controlled; and the rolling resistance of the tire at low temperature is effectively reduced while the gripping performance of the tire is ensured.

To lighten a weight of a vehicle wheel.SOLUTION: A vehicle wheel 1 consists of a cast integrally comprising a disc 10 and a rim 20, wherein a plurality of windows 12, 13 and spokes 14, 15 are arranged alternately in a circumferential direction on the disc 10. An annular space 30 is formed between a disc-side side wall part 23 and an outer peripheral edge part of the disc 10 in the inside in a radial direction of a disc-side bead seat part 22 in the rim 20. Thickness reduction recesses 41, 42 are formed on a back face of the disc 10. The thickness reduction recesses 41, 42 have extension parts 41a, 42a extending outside in a lateral direction to face the annular space 30.SELECTED DRAWING: Figure 3