JPS5830161B2 - radial cord floating tire - Google Patents

Description

[Detailed description of the invention] The present invention relates to radial cord pneumatic tires.

Throughout the history of pneumatic tires, air has been forced out of the tire, the vehicle has to be brought to a sudden stop if the original vehicle is in motion, and, if necessary, air has to be removed from the re-inflated tire. I have been plagued by the hassle of having to re-inflate the tires after repairs to prevent them from falling out.

Continuing to run with a deflated tire can cause a variety of damage, including making the tire irreparable and sometimes causing damage to the rim and other parts.

Therefore, the main object of the present invention is that it can be used as a pneumatic tire to give the car a normal comfortable cushioning effect even on bad roads, and in case of emergency without causing any damage to the tire or the car. To provide a tire capable of driving a considerable distance without inflating the vehicle without making the vehicle inoperable.

According to the present invention, a pair of non-extensible beads seated in bead seats of a flanged rim and a radial cord or bead for reinforcing the tire to withstand the pressure of the compressed gas used to inflate the tire. A tire is provided having a plurality of cords anchored to and lying on a radial surface.

As is common with radial cord tires, the tire includes an essentially inextensible belt surrounding the circumference of the tire and a tread layer of wear-resistant rubber with a suitable non-slip pattern.

Furthermore, in the present invention, the tire is provided with an inner cushion and an outer cushion in a specific location and with specific dimensions.

The external cushion includes a tough, cut-resistant rubber covering on the outside of the reinforcing cord at positions that engage the tip 26 of each rim flange and taper on both sides.

In the normal case where the rim lounge protrusion is relatively small, the cushion thickness decreases from the location of the rim flange towards the corner occupied by the heel of the tire bead, resulting in The cushion on the underside of the foot has a small thickness for a firm engagement with the rim and a tight fit of the bead to the rim.

The cushion tapers gently in the other direction outwardly from the tip 26 of the rim flange to a thickness sufficient to protect the tire sidewall closest to the rim against light wear that may occur on that sidewall.

The other external portion of the cushion is made of tough, wear- and cut-resistant rubber that tapers gently toward the midpoint of the tire's sidewall and has a thickness close to that of the tread. It consists of a continuous lateral part that extends beyond the shoulder area.

If necessary, this part of the sidewall can be curved.
A thicker ring may be provided to engage the side wall and serve as a scuffing rib to protect the side wall and its reinforcing cord from damage.

However, if scuffing ribs are provided, they are preferably provided in specific areas of the tire sidewall.

The area in which the scuffing ribs are located is positioned based on the shape of the tire and its cross-sectional shape.

Pneumatic tires are typically designed to seat on a rim within a relatively narrow area of the rim from heel to heel of the bead seat.

If the tire is attached to a mating rim with the tire bead correctly positioned in the bead seat 27 of the tire rim 25, the inner surface of the tire near the shoulder and the inner surface of the tire near the tip 26 of the rim flange engages the inner surface of the rim flange near the tip 26. In this way, a fairly sharp crease 30 (FIG. 3) is created in the sidewall of the tire until the tire is completely flattened.

The position of such a fold must be predetermined, and if a scuffing rib is provided, it must be located radially outward of the fold.

In other words, the sidewall rubber on the outer surface of the tire must have a minimum thickness at the crease location and must not include any scuffing ribs or other thick structures at that location.

The inner cushion in the present invention preferably consists of a layer of cellular rubber with closed cells containing pressurized nitrogen gas.

This layer should be thick enough to provide adequate cushioning so that vehicle weight can escape from the tip of the rim flange, pass over one side of the folded tire, and then pass through the other side. When finally transmitted to the road surface, it has a protective effect against the tire cutting that would occur if the cellular rubber layer were not present, i.e. if the flat tire were not supported by a cushion layer of air. have

The coefficient of friction on the inner surface of the tire is low, so that when the tire is driven with air removed, the relative movement between the facing part of the tire bead area and the inner side of the tire shoulder area will affect the surface of the tire. It must not create destructive forces that can cause cracking, abrasion, or heating.

Such a low coefficient of friction is obtained by covering the exposed surfaces of the cellular nocom 20, ie, the surfaces in contact with the tire building drum, with a very thin coating of a slippery material such as polytetrafluoroethylene.

However, since it is difficult to obtain a satisfactorily low coefficient of friction and at the same time to prevent the coating from slipping, the inner surface of the tire, that is, the exposed cellular portion 20 after vulcanization is completed, Preferably, a type of lubricant is applied to the surface.

This lubricant 21 is applied to the opposing inner surfaces of a deflated, flat tire, i.e. the inner surface just above the bead and the corresponding inner surface below the tread shoulder, which has a significantly different circumference. but are made of a solid material that has a soft, grease-like appearance under normal operating conditions so that it can slide over each other by the amount necessary to accommodate this different size difference.

Under certain conditions, the tread may shift laterally, causing its contact surface to move toward the center plane or toward the side of the tire.

Therefore, it is desirable that the lubricant be applied over the entire inner surface.

Since this lubricant is solid, it remains in place without flowing due to gravity or centrifugal force.

Its lithium-like properties also allow it to withstand the bending and twisting that the tire undergoes during both normal and deflated driving without cracking or peeling from the inner surface of the tire. It is suitable for

Practical experience with tires having such a construction has shown that such tires can be used completely without inflating them even if they leak air.

In other words, it was possible to drive the car over a considerable distance at surprisingly high speeds by applying the entire weight of the car to the tires while keeping the space inside the tires at approximately atmospheric pressure.

If the load is not extremely heavy and the road is smooth, such tires for passenger cars can be used for many miles at minimum highway speeds without damage.

On moderately uneven roads, where the irregular surface of the road creates significant impact forces, it is advisable to reduce speed, but when driven at moderate speeds with light loads, the tires of the invention will not cause damage. It is possible to run any distance.

In all cases, even if one of the front tires is deflated, the operation of a car using the tire of the invention will not be affected by the slight disturbances that can be observed in cars with power steering. You will feel a small amount of resistance, but it is not strong enough to prevent you from driving the car safely in any case.

The driving and braking torques of the powered drive wheels under a reasonable degree of normality are sufficiently transmitted without the formation of destructive transverse creases.

A typical tire according to the invention shown in the drawings has an aspect ratio of approximately 60, i.e., the radial height of the tire when inflated from the heel of the bead to the outer surface of the tread is approximately 60. This is a radial cord passenger car tire having a width corresponding to about 60% of the maximum width from one side to the other side.

This particular tire is constructed from a two-ply radial cord made of a nearly inextensible fibrous material such as polyester cord.

The innermost ply 10 is wide enough to be folded back around the bead a considerable distance at the outer surface of the bead.

The second ply 11 overlaps the folded portion of the first ply and extends outside the bead.

The bead incorporates a wire grommet 12 for holding the bead on the bead seat of the rim.

Across the part of the tire that engages the road is a belt of two plies of steel cord 13.14, and the cord is at an angle of 20 to 3 degrees to the center surface of the finished tire.
It forms an angle of 0 degrees, preferably 25 degrees.

The outer layer 14 of steel cord is slightly narrower than the layer below it.

Radial cord plies 10, 11, steel cord over rad plies 13, 14 and bead chrome 1
All reinforcing materials, including No. 2, are embedded in the rubber in the usual way.

A tread 15 of a wear-resistant rubber composition extends across the outer road-engaging surface of the belt plies of steel cord and is formed in a suitable non-slip pattern.

The side walls are also covered with a suitable thickness of rubber to protect the reinforcing cord plies.

According to the invention, the tread 15 gently joins the sidewall rubber at the shoulder portion 16, and the portion of the sidewall at the shoulder portion has approximately the same thickness as the tread rubber.

A scuffing rib 17 may be provided radially inwardly from the shoulder portion 16 and towards the axis of the tire up to the widest portion of the reinforcing cord structure Q in the inflated state.

The sidewall rubber in the direction towards the axis of the tire adjacent to the scuffing rib 17 has the smallest thickness and gradually increases in thickness towards the rim-engaging surface at the tire bead, thus making it easier to install the tire. At this time, a rim cushion 18 is placed between the edge of the rim flange and the reinforcing cord.
is formed.

The tires described here are tubeless tires,
Includes an essentially air-impermeable backing made of air-impermeable butylcomb, chlorinated butyl, or a suitable elastomer that does not allow air diffusion.

On the inside of the lining 19 (FIG. 2) are cells of considerable thickness that extend from near the toe of one bead to near the toe of the other bead and cover the entire inside surface of the tire. A cushion layer made of rubber 20 is provided.

This cellular rubber layer is the most novel part of the tire of the present invention and has important properties in carrying out the present invention.

The layer of cellular rubber 20 must be a material that adheres strongly to the lining of the tire in the case of the adjacent shoulders, and must also be strong and elastic, and therefore have strong bending and bending properties.
It shall not tear or crack under pressure and friction.

It must also be capable of forming and containing nitrogen or other suitable gas bubbles to increase its cushioning effect.

Preferred materials for this purpose include butyl rubber alone or mixed with recycled butyl or chlorinated butyl, or one of the latter with natural rubber or similar synthetic rubber.

However, other elastomers with the same properties can be used, such as vulcanizable ethylene-propylene combs and polyether rubbers.

This internal cushioning of the cellular rubber 20 and its thickness are important in obtaining the correct performance of the tire in the deflated state.

Its thickness increases roughly in proportion to the tire's largest dimension, so that larger ones are considerably thicker than smaller ones, and it also increases in thickness roughly in proportion to the load, resulting in larger internal It must provide cushioning for tires of the same size and support a greater load.

For example, a BR60-13 size tire with load range B is designed for a load of approximately 890 lbs (405 kg,) at 20 psi (1,3 atm) and up to 1150 lbs (405 kg,) at 2 psi (2,1 atm). 52
0kg).

In a tire constructed as described above, the conventional lining 19 has a thickness of approximately O.OS inches (2 mm);
50 parts chlorinated butyl rubber by weight 56 parts recycled butyl rubber with a rubber content of about 50%, 22 parts other carbohydrate polymer rubbers, 50 parts carbon black, 16 parts softening oil and 2 parts tackiness Resin, 0.5 parts of fatty acid, 5 parts of zinc oxide, 0.25 parts of sulfur (free sulfur or sulfur amount of sulfur donor), and a vulcanization accelerator that causes vulcanization under the conditions described below. It is composed of an olefin polymer rubber that prevents diffusion, such as a mixture with

Cellular rubber 20 is incorporated into the tire to form the innermost layer as a sheet of unvulcanized material having the same thickness as the airtight lining.

Therefore, when used with a backing having a thickness such as that described above, the unexpanded thickness of the sheet material that expands into cellular rubber should be approximately the same as the thickness of the backing, preferably with an inflating air. 0.10 to 0.12 inches (2,5 to 377!7
71) is preferably slightly larger.

The composition of the cellular rubber is modified to have approximately the same composition as that of the backing and to be able to expand into a fully vulcanized product having a volume several times its original volume.

More specifically, 32 parts by weight of polyisoprene, 42 parts by weight
of chlorinated butyl rubber and 52 parts of recycled butyl rubber with a rubber content ranging from 50 to 80 parts of mineral filler (
17 parts general purpose furnace black, 15 parts softening oil, 2 parts fatty acid, 5 parts zinc oxide, 2 parts adhesive resin, 0.22 part sulfur (free sulfur or )'j6 and 6 parts of azobisformamide thickened with 2 parts of rubber along with a vulcanization accelerator to effect vulcanization under the conditions described below.

Azobisformamide is a commercially available foaming agent that is approximately 320° to 390° below (160° to 200°
It decomposes at temperatures in the range (°C) giving off nitrogen gas.

In a method of manufacturing a new tire, the tire is approximately 0.10 inches (2.5 mm) thick in the uninflated state and extends completely across the inner surface of the tire near the tips of the beads on each side. A sheet of cellular rubber composition 20 having a width that reaches the desired position is placed in the center of a tire building drum, and the sled ends are joined.

A backing 19 is then placed on the layer of cellular rubber 20 having a width that spans at least the heel of one bead to the heel of the other bead and covers the entire inner surface of the tire;
The radial cord plies io, ii are then placed, followed by a conventional bead subassembly including wire grommets 12 on each side, and the edges of the cord ply are wrapped around the bead in the usual manner.

From this stage onwards, the belt cord is typically completed in two ways, depending on the angle selection and the equipment used.

For example, the belt plies 13 and 14 are placed on the radial cord body in order, and then the tread 15, shoulder portion 16,
A wear-resistant rubber of suitable thickness is placed to form the outer surface, including the scuffing ribs 17, sidewall covers and rim cushions 19, and the green tire is expanded in a vulcanization press to form a trochoidal shape. One-step injection may also be used.

Alternatively, the radial cord structure may be expanded to form the bell as a separate operation before the belt plies 13, 14 are assembled separately (with or without wall and tread rubber) and placed in the vulcanization press. Expanded inside.

(Place the side walls and tread immediately after them if they are not already provided).

The foregoing composition is approximately 338° to 405'F (170° to 2
An internal bladder containing pressurized steam and/or hot water at a temperature of approximately 338° C.
It is for press vulcanization by pressing it into a mold heated to 70°C for 15 to 25 minutes.

Once vulcanization is complete, the pressure is released to remove steam or hot water from the bladder, while the cellular rubber immediately expands to several times its original volume.

Next, the completed tire is removed from the mold.

The tire consists of solid, smooth polyethylene with a melting point of about 1.70"F (77C) and an average molecular weight of about 10
It is preferred to provide an inner coating which is covered with the entire exposed surface of a cellular rubber of 0.00 to 3,000, preferably about 2,000 polyethylene.

This material does not liquefy and flow to the bottom of the tire when warmed, does not crack or peel when cooled, and has the hardness of a hard grease that allows it to bend with the tire under normal driving conditions. have.

It is brushed or applied in the melt in an amount to provide a uniform coating thickness not exceeding 0.02 inches or about 0.7 ounces (200p).

Test results of the tire of the present invention show that even if the tire is completely deflated, it is possible to safely and comfortably drive the deflated tire for many miles until reaching the destination or repair shop. It also has the ability to support automobiles.

Since the present invention is configured as described above, as shown in FIG. The cellular rubber layer with cushioning properties disposed near the tire allows the tire to travel a considerable distance safely without damaging the tire. The surface, that is, the air chamber side, has an average molecular weight of 1000 to 3000.
The lubricant is coated with a lubricant made of polyethylene with a range of It is something that can be done.

In addition, the lubricant does not cause cracks on the inner surface of the tire or peel off from the inner surface of the tire.
It is possible to adapt to the bending and twisting that the tire undergoes not only during normal driving but also during run-flat driving.

As a result, it is possible to prevent the cellular rubber layers from rubbing against each other and causing heat generation and abrasion during the driving conditions described above, and the air inside the tire is removed by mixing with the cellular rubber layers. This makes it possible to further improve the driving condition of the vehicle.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of one embodiment of the tire of the present invention, Fig. 2 is an enlarged cutaway cross-sectional view showing the relationship between the cellular rubber and the lubricant with the rest of the tire, and Fig. 3 is a cross-sectional view of a deflated tire. It shows how the weight of the car is supported by the tire in the condition and how the tire collapses when mounted on the rim. FIG. 2 is a cutaway cross-sectional view of the tire of FIG. 1; 10: First ply, 11: Second ply, 12: Wiring metallurgy, 13, 14 Ni steel cord, 15 Ni trend, 16: Shoulder part, 11: Scuffing rib,
18: rim cushion, 19: backing layer, 20: cellular rubber layer, 21: lubricant.

Claims (1)

[Claims] 1 is a radial cord pneumatic tire that is equipped with an almost inextensible belt and can be used completely without air pressure, and has a cellular rubber layer with cushioning properties in which the cells of the rubber layer are filled with pressurized gas. is arranged on the inner surface of the tire from a position near the toe of one bead to near the toe of the other bead, and the surface of the cellular rubber layer is coated with a lubricant made of polyethylene having an average molecular weight of 1000 to 3000. A radial cord pneumatic tire characterized by being coated with wood.