RU2248279C2 - Reinforced solid rubber tire - Google Patents

Abstract

FIELD: tire industry.

SUBSTANCE: invention relates to designing and making of solid rubber tires for wheeled road and electric vehicles. Proposed reinforced tire has at least tread and seat parts and reinforcement rings. Seat part of tire is made of solid tuber reinforced by randomly arranged lengths of cord fibers accommodating reinforcement rings whose axes coincide with axis of mounting surface of seat part formed by two meeting taper surfaces with vertices pointed to each other. Reinforcement rings are installed with interference on surface of hub to provided transmission of torque. Mathematical relationship between torque, interference force and parameters of tires are provided. Reinforcement rings can be made in from of two procured wire coils. Direction of winding of wire coils can be different.

EFFECT: reduced cost of manufacture, possibility of determination of relationship of all parameters to choose their best combination.

4 cl, 1 dwg

Description

The claimed invention relates to the field of design and manufacture of solid rubber tires intended for wheeled trackless auto-electric vehicles.

Massive tires are used to equip industrial vehicles used for transportation of goods inside enterprises on roads and driveways with wooden, concrete, metal coatings, when lifting capacity, maneuverability, stability, high resistance to cuts and punctures are required.

As a rule, bandage-free massive tires are a solid rubber ring, sometimes reinforced with a metal cord in the landing area. During installation, the ring is pressed onto the wheel with an interference fit [1].

A similar in design tire, containing at least one turn of a rigid element inside the annular element that receives tensile forces and extends inside the molded rubber ring forming the tire array at a distance from its inner, outer and side walls, is described in [2]. The metal cord can also be located near the area of the running surface of the tire [3].

The tireless tires of the type specified in GOST 5883-89 [1] contain a metal cord connected into a ring inside the ring rubber array. In their production, for reliable mounting of the tire on the wheel, it is necessary to ensure high bond strength of rubber with steel cord (at least 4.4 kN / m in accordance with Clause 1.3.3 of GOST 5883-89), which requires the use of expensive brass-plated steel cord and use for manufacturing an array of tire mixtures with a high (up to 40% or more) content of SCSM butadiene-methylstyrene synthetic rubber with insignificant (about 5%) use of rubber production waste in the form of RC regenerate [4, p.52].

The possibility of detachment of steel cord during operation, as well as the high cost of the mixture for the production of tires caused by the inability to widely use secondary raw materials, accordingly reduces their operational reliability and increases the cost of production, which reduces the competitiveness of products.

Similar shortcomings are distinguished by domestic industry bandageless tires [5], corresponding to TU 104224-75, designed for electric cars, electric forklifts, grain cleaning machines, which are a rubber reinforced array in the form of a ring worn on the rim.

The aforementioned disadvantages, expressed in reducing operational reliability and increasing manufacturing costs due to the possibility of detachment of the steel cord, and a small fraction of the secondary raw materials used in the preparation of the rubber mixture, also feature a massive tire with an outer running and inner smooth cylindrical landing part reinforced with wire rings, shown in fig.19d of the book [4].

The latter design in its technical essence can be adopted as a prototype.

The problem solved by the invention is to reduce the cost of manufacturing tires and determining the ratio of all parameters of the tire to select their best combination.

To solve this problem, in the well-known massive tire containing at least the tread and seat parts and reinforcing rings, the latter is made of a rubber array reinforced with randomly oriented cuttings of fiber cords, inside of which there are reinforcing rings whose axes coincide with the axis of the mounting surface formed two converging conical surfaces facing the vertices to each other with the possibility of installation on the corresponding surface of the hub with an interference fit and transmission of torque, associated with the main parameters of the tire corresponding ratios.

In this case, the reinforcing rings are made in the form of solid rings or vulcanized wire coils. A different direction of the winding of the wire at adjacent rings is possible for the equivalence of torque transmission in the forward and reverse motion of the vehicle.

The drawing shows a drawing of the claimed tire.

The tire contains a rubber mass formed by the tread part 1 and the landing part 2, made of rubber of different grades. At the same time, the landing part, made in the form of a rubber array, is reinforced with randomly oriented cord cuttings, inside of which there are reinforcing rings 3, the axes of which coincide with the axis of the installation landing surface, formed by two converging conical surfaces that allow the transmission of the required torque M _cr with a certain tightness T _nat , which can be calculated from the following ratios:

where [σθ] - permissible tangential stresses in the reinforcing ring, kg / mm ² ,

b is the width of the ring, mm

R _H is the outer radius of the ring, mm,

R _ct is the radius of the hub at the location of the reinforcing ring, mm,

n is the number of reinforcing rings,

To _Tr - the coefficient of friction of the landing part of the tire on the hub,

To _n is the coefficient of proportionality,

α is the angle of the cone of the landing surface, deg.

In this case, the reinforcing rings can be made continuous, composite, wound from wire. In the latter case, the coiled wire bay is pre-vulcanized and embedded inside the rubber array when forming a tire filled with randomly oriented strands of cord fibers, which increase the adhesion of the reinforcing rings to the rubber and increase the strength of the array itself.

The device operates as follows.

During the movement of the vehicle, the main task of the drive wheels is to transmit torque M _cr from the hub to the tire. And since this transmission is carried out due to friction forces, the tire – hub pair must have a sufficient coefficient of friction K _tr and normal radial forces T _rad arising at the time of pressing the tire onto the conical surface of the hub. Tire tensile forces also arise in the tire, tending to break the reinforcing rings, which take up this load. The strength of these rings depends on the material from which they are made, and are determined by the allowable tensile stresses [σθ]. Actual stresses σθ are determined by the pressing force (preload) T _nat .

Between the reinforcing rings and the seating surface there is a rubber layer which, in interaction with the hub, determines the coefficient of friction, in fact - steel-rubber pairs.

At the moment of application of a torque M _cr to the wheel, a tangential friction force T _Tr arises, loading the reinforcing rings with an additional tangential load that occurred when the wheel was pressed onto the hub.

Thus, the permissible tangential stresses [σθ] are "consumed" on the tire interference on the hub and on the torque resistance M _cr . The ratio of these loads is taken into account by the proportionality coefficient K _n .

The above formulas allow you to choose the optimal dimensions of the reinforcing rings, calculate the required strength of their material and determine the allowable force of pressing the tire onto the hub.

List of references

1. Massive rubber tires. Technical conditions GOST 5883-89.

2. US patent No. 4446903.

3. Auth. testimonial. No. 369027.

4. Savosin B.C., Bograchev M.L. Massive tires. Design, manufacture, operation. M .: Chemistry, 1981 (prototype).

Claims (4)

1. A reinforced tire containing at least a tread and a seating part, and reinforcing rings, characterized in that the landing part is made of a rubber array reinforced with randomly oriented cord cuttings, inside of which reinforcing rings are placed, the axes of which coincide with the installation axis the surface of the landing part, formed by two converging conical surfaces facing the vertices to each other, and the reinforcing rings are mounted on the corresponding surface of the hub with an interference fit, d lowering the transmission of torque. 2. The reinforced tire according to claim 1, characterized in that the torque M _cr and the interference force T _nat are related to the tire parameters by the following relationships:

where [σθ] - permissible tangential stresses in the reinforcing ring, kg / mm ² ; b is the width of the ring, mm; R _h is the outer radius of the reinforcing ring, mm; R _ct is the radius of the hub, mm; n is the number of reinforcing rings; To _Tr - the coefficient of friction of the landing part of the tire on the hub; K _p - coefficient of proportionality; α is the angle of the cone of the landing surface, degrees; R _count - radius of the wheel (tire), mm. 3. The reinforced tire according to claim 1, characterized in that the reinforcing rings are made in the form of vulcanized wire coils. 4. The reinforced tire according to claim 3, characterized in that the direction of winding the wire coils is different.