CN1267604A - Tyre bead wire and tyre therewith - Google Patents
Tyre bead wire and tyre therewith Download PDFInfo
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- CN1267604A CN1267604A CN99123202A CN99123202A CN1267604A CN 1267604 A CN1267604 A CN 1267604A CN 99123202 A CN99123202 A CN 99123202A CN 99123202 A CN99123202 A CN 99123202A CN 1267604 A CN1267604 A CN 1267604A
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- bead core
- bead
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D30/00—Producing pneumatic or solid tyres or parts thereof
- B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
- B29D30/48—Bead-rings or bead-cores; Treatment thereof prior to building the tyre
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Abstract
A bead wire for a bead core of a tire, having at least one portion of its annular extent formed from a material having characteristics of superelasticity, resulting in increasing deformations of the bead core when a constant stretching load is applied at constant temperature. As the load ceases, the bead core recovers from the deformation. The characteristics of the bead core allow mounting a tire incorporating the bead core to a rim at ambient temperature, with intelligent adjustment of the bead core to the dimensions of the seat of the rim. The bead core increases the magnitude of an inward contraction stress as its temperature increases, so that it increases the gripping pressure exerted by the tire beads on the rim when the tire runs in the deflated state.
Description
The present invention relates to the bead steel wire of tire beads filled core and its tire is housed, more particularly, relate to and design to such an extent that be easy to mounting of tyre on the wheel rim and design to such an extent that can stop the bead steel wire of the tire beads filled core that tire separates with wheel rim under all service conditions.
Known in this specialty, tire comprises at least one carcass enhancement Layer substantially, and it has the edge of digging around bead core; A tyre surface; And be arranged on band between carcass and the tyre surface.The gum filler bar is arranged between the edge that carcass enhancement Layer side and this enhancement Layer dig.The part that comprises bead core and gum filler of tire constitutes the bead of tire, and its effect is that tire is anchored on the corresponding mounting rim.
Wheel rim comprises a central cylindrical conduit, and the surface of dispersing is axial, protruding from these conduit both sides, and each surface ends at vertical periphery, and this vertical periphery flange is called " wheel rim platform (rim balcony) ".The surface of dispersing constitutes the tire beads seat.
Bead core upwards is not extensible substantially in week, can be made of as steel wire, steel cable and other similar component that is provided with in the form of a ring solid memder or several member.Each member is called the bead steel wire, and when fitting together, they constitute bead core.
The diameter of the basic inner surface with bead core of bead internal diameter is consistent, just the thin difference that causes between two diameters that serves as a contrast of rubber.The diameter of the interior annular surface of bead core and bead is less than the wheel rim platform diameter, it selects proper bead on the bead seat that is depressed on the wheel rim platform on wheel rim the time, and they can be pushed on the flange inside face along the bead divergence surface by the tire inner air pressure.
The operation that tire is contained on the wheel rim is carried out according to the those skilled in the art known method.When beginning operation is deformed into elliptical shape with first bead, thereby makes elliptical aperture suitably during orientation when being placed on wheel rim before, and the part of bead is slided on the wheel rim platform.Then, the bead remainder slides on the wheel rim platform fully, thereby can push bead to bead seat then.Abovementioned steps is repeated on second bead.At last, with inflation of tire, bead is pressed on the wheel rim flat-bed inside face of bead seat.
Because the rigidity of bead core, tire is contained in needs to apply big strength on the wheel rim, so that make bead core become ellipse from its circle, thereby for some bead core structure, can cause tangible difficulty, if surpassed the elastic deformability of bead steel wire, had the danger of fracture in some cases.
Because the forced air in the tire is used to make bead to keep being pressed in the rim flange inside face, thereby when bleeding a tire, this power has not existed, bead may leave its bead seat, falls into the central conduit of wheel rim.This seat that takes off makes vehicle not removable usually, because the wheel rim platform contacts with the road surface rapidly, vehicle can not be pulled and control.For example, conventional tyre is gas filed under the operation pressure of 1.8 to 2.0 crust.When inflation pressure is brought down below about 0.8 when crust, bead just breaks away from from bead seat easily.Therefore, second requirement to modern tire is also can remain on the position of wheel rim under the situation that tire is lost heart.This requirement needs bead core to act on enough power on wheel rim, even bead is held in place when on the throne on wheel rim there not being air pressure that it is pushed.Unless on wheel rim, form projection,, use traditional bead core can not obtain above-mentioned effect as preventing that bead from slipping into the obstacle of the central conduit of wheel rim.According to prior art, the bead core that provides can not the time make it apply enough power at wheel rim 5 in venting so that bead is remained on the wheel rim, can fully stretch simultaneously and with traditional instrument with mounting of tyre on wheel rim.
The known several traditional bead core that in bead, uses.For example, the bead core that the steel wire that first kind of structure is coating rubber forms, this steel wire helix is twined to form and to put the ground floor of coil form.Stacked thereafter each layer also is to twine with identical steel wire helix to form on ground floor.A kind of known structure of the bead core of this form comprises four layers, every layer of four steel wire.Another kind of bead core adopts independently steel wire, and or rather, the first steel wire spiral twines the some circles that are formed on radial arrangement on the perpendicular.Thereafter steel wire twines on perpendicular similarly, and with first plane and put.A kind ofly be called four steel wires that 4 * 4 this known configurations comprises four layers of layout of branch.
Known bead core is also arranged, and it has improved flexible nature, thereby has bigger deformability and can not rupture.The formation of this bead core is a central cable, twines several steel wires around its spiral.In this structure, 4 or 5 groups of steel wires can be arranged to a kind of structure, and this structure has the steel wire group of 4 or 5 helical layer forms.But, a plurality of reels that are respectively applied for cable and each steel wire of the structural requirement of this spiral bead core.Like this, with the bead core texture ratio of single steel wire, increased manufacturing cost.
Another problem when tire is installed is that in the structure of bead core, and in rim structure, resulting actual size generally often changes according to selected tolerance to some extent.In this case, the dovetail form variation can take place in the bead on relevant bead seat.The fracture of bead core when this may cause actual size when bead significantly less than given size, or cause when bead core during the slip of bead on bead seat in rotation process greater than given size.
German patent application DE 3829460 A1 have described and have used shape-memory material, the bead core that the most handy Ni-Ti alloy is made.Need temporarily bead core to be deformed into ellipse at the described installation method of this application, after being contained in tire on the wheel rim, under the crystallization point (65 ℃ to 91 ℃) of alloy, make bead core accept heat treatment, thereby make bead core return to its annular.Therefore, this method provides a kind of bead core, and this bead core can make bead be fixed on the wheel rim with enough power, has enough elastomeric mounting tires simultaneously.But tire is installed according to the method needs special tool and heating device.
The practice that known prevention tire takes off seat is based on the mating surfaces of revising bead and bead seat.The hole that protrusion on one of these practices are to use bottom bead and being used on wheel rim are admitted this protrusion.The Kong Shike of protrusion on the bead on the insertion wheel rim prevents that bead from separating with wheel rim.
Must consider when the deformability of bead on wheel rim the time the exploration of bead core appropriate configuration, keep bead flexibly to be clamped on the wheel rim after the installation again simultaneously mounting of tyre.This should have the performance that can stretch and largely and not damage with regard at first requiring to form the used material of bead core.In addition, do not keep former stretching action at ambient temperature, when load had been removed, material must be able to return its original shape.
After the additional requirement tire is losing heart, can travel tens of kilometers and when not making tire break away from wheel rim, can make above-mentioned requirements become more complicated and urgent.The tire that loses heart should be able to make the chaufeur of vehicle and passenger safety arrive the garage ideally, may travel under roughly up to 80 kilometers/hour speed after at least 50 to 100 kilometers, at the garage changing of tire.
Even this safety performance requires the bead of flat also can not remain in its bead seat when having air pressure to be pushed against on the bead inside face.Bead must be avoided inwardly sliding towards the central cylindrical conduit of less wheel diameter, and this can cause the seat that takes off of bead when having the transverse force of the generation of turning.
In view of above-mentioned prior art, the applicant recognizes that in order to obtain not having the acceptable solution of technology and/or shortcoming economically, tire that must will relate to and wheel rim part keep at ambient temperature in installation phase.Standardized parts also must be used in interface at wheel rim and tire, comprises that the tire that is used for exitting remains adhered to the part on the wheel rim.This has got rid of the use mechanical connection to prevent the seat that takes off of tire.
The applicant recognizes that also best solution may be to utilize the actual conditions that causes in flat tyre especially, seeks to utilize the phenomenon of generation to overcome the danger of taking off seat as much as possible.Observe, under the venting condition, the part that the side of tire can fold and make folding sidewall to form is in contact with one another, and causes friction, and this makes whole folding zone generate heat until bead core.
When determining best solution, the applicant recognizes that the temperature-rise effect that reaches bead core may cause the reaction that bead core is interior, if bead core is to be made by the material that temperature rise is responded.The preferred plan of obviously dealing with problems can comprise uses following bead core, that is, this bead core can shrink in the situation that has the temperature rise that is caused by venting gradually.Adopt this scheme just bead core can be remained in the bead seat, even also like this during no air pressure in the tire.But this scheme also requires the bead core must be easily deformable so that be installed on the wheel rim, and shrinks gradually in deflated state.Have been found that, accurately, because the requirement of the conflict of bead core deformability under condition of different temperatures, by forming a kind of super-elasticity and/or shape memory characteristic of comprising, the bead core of the material that best two specific characters have concurrently just can be dealt with problems.Whole bead core, or just its circular portion can be formed by above-mentioned material.
As known, and the material that as this specification sheets is employed, has " super-elasticity " characteristic is by applying steady temperature and keeping steady temperature just can be deformed into material significantly gradually.Then, when removing load and temperature when remaining unchanged, the distortion that material can stand recovers.In addition, employed material also has " shape memory " character, in other words, in the condition of mechanical constraint, when material bore heating between two predetermined temperatures, material stood from the transformation of first structure to the second structure, produced the stress of being revolted by above-mentioned constraint.Actual result is, when temperature build-up must surpass predetermined value, convergent force by material effects in constraint.
Therefore, the present invention is a kind of bead core that is used for tire, it designs to such an extent that tire can easily be assembled on the wheel rim, because it can bear big elastic elongation adapting to the size of wheel rim, can stop that bead separates from wheel rim when travelling behind the tire flat simultaneously again.This realizes by following manner: make at least one annular section of bead core have super-elasticity and two kinds of character of shape memory, thereby it can react to the tire working condition, and tire is installed is need not special tool.
Therefore, a first aspect of the present invention is a kind of metal bead core of bead, and bead is used for being applied on the wheel rim, and bead core is to form with the material with super-elasticity and/or shape memory characteristic.
Hyperelastic characteristic can be out of shape bead core at ambient temperature, produces the elongation that increases for constant duty.This is because the structure of elastic material changes under the load effect.This load is defined as the distortion critical loading.Therefore, bead can slide on the wheel rim platform and can not cause heavy load stress on material.Thereafter removing load at ambient temperature can restore from distortion, keeps the clamping pressure of bead on bead seat simultaneously.
In addition, the shape memory characteristic of bead core makes and bead is remained on convergent force on the bead seat producing during the tire working.This convergent force increases as the function of the heating that bead core bore, and this is because the structure of shape-memory material changes as the result of temperature traverse.When deflated state, described convergent force is to increasing the clamping of bead on wheel rim, and it is particularly useful to keep tire not take off seat.
Bead core is preferably formed by the material with following characteristic:
A) temperature A
s<T
a
B) temperature A
f<T
Max
Wherein:
-A
sBe material corresponding to from martensitic structure to the transition temperature that begins to form the austenitic structure transition;
-A
fBe to change the austenic temperature fully into corresponding to material structure;
-T
aIt is ambient temperature;
-T
MaxBe predetermined temperature, the highest temperature that it uses when working under deflated state the tire of this bead core to reach.
A second aspect of the present invention is a kind of tire with at least one environment carcass and a tyre surface, carcass has a central bizet and two sidewalls, sidewall ends at a pair of annular bead, and the metal bead core is arranged in each bead, so that bead is anchored on the corresponding mounting rim.This tire is characterised in that to have at least one bead, it has the bead core that super-elasticity and shape-memory material are made, this material at ambient temperature, when bearing the installation load of constant size, bead core can cumulatively be out of shape, and in case load is eliminated the original circular dimension of just recovering bead core.
Tire preferably includes at least one bead core part, and its material has super-elasticity and shape memory characteristic, like this, can increase the inside convergent force of bead core when reaching predetermined temperature.When tire was worked under the venting condition, this convergent force formed, and increased the gripping power of bead on wheel rim.
Another aspect of the present invention be with mounting of tyre in the method that has on the wheel rim of terrace part, this method has following steps: form a tire that has bead core, comprise the part that at least one super-elasticity and marmem are made; Each bead core that one after the other stretches, this is it to be slided realize on the terrace part of wheel rim by applying a constant load.The above-mentioned constant load of pine oil then makes the bead steel wire become length corresponding to wheel diameter again, makes inflation of tire.
Above general introduction and following detailed obviously be for example and illustrative, purpose is that claimed the present invention is made an explanation.
Accompanying drawing is convenient to further understand the present invention, constitutes the part of this specification sheets, and the expression several embodiments of the present invention are used from explanation principle of the present invention with specification sheets one.
In the partial perspective view of Fig. 1, some parts omit, and the figure shows the tire that has bead core according to of the present invention;
The cross-sectional figure of Fig. 2 represents the thin bilge construction of bead, and bead is connected in the relevant bead seat of the wheel rim that tire is housed;
Fig. 3 is the stress-strain diagram qualitatively of bead core performance when the seat that bead is installed in Fig. 2 is gone up;
Temperature rose to the increase of bead core shrink stress when stoping the maxim of taking off seat when the qualitative curve figure of Fig. 4 represented to exit;
Fig. 5 is the time dependent qualitative curve figure of temperature of the tire of temperature build-up when venting;
The stress/strain figure of Fig. 6 represents the performance of the steel wire of the bead core made according to prior art.
Preferred embodiment of the present invention is described in detail in detail now, and the example is consulted accompanying drawing hereinafter and is described.
Though the present invention can be widely used in the tire field, it is specially adapted to the radial mode tire.Radial mode tire 1 contrast accompanying drawing 1 is described, but the present invention does not get rid of the tire of other type, for example is commonly referred to bias voltage band body piles tire.
Carcass 9 is made of one or more body piless, have around the folded-out edge 9 of bead core 6 '.Band structure 10 comprises one group of band that is made of three layers of rubberized fabrics 11,12,13, in reinforcement is arranged. Inner fabric 11,12 preferably includes steel line feeder 14 in the two-layer footpath, and with the equatorial plane of tire 1 angle that tilts, each line 14 intersects mutually.Radially the rubberized fabrics 13 of outermost preferably includes nylon wire 15.Nylon wire 15 becomes 0 ° of angle with the equatorial plane of tire 1.Bead 5 is used to be installed in the wheel rim (not shown).
Fig. 2 represents the example of one embodiment of the invention.Bead 5 is applied on the wheel rim, the upper limb of the wheel rim that only draws in the drawings.Wheel rim has a cylindrical center conduit 10 and two horizontal bead seat 11 of outwards dispersing, and only draws one of them among the figure.The combination of drawing among another bead seat and bead combination and the figure is about vertical axis symmetry among the figure.
Laterally bead seat is formed by surface 12, and surface 12 is with respect to the angle α of straight line 13 inclinations with the wheel rim parallel axes.Angle α changes according to tyre type, for example 15 ° from 5 ° of motor tire to truck tyre.Laterally bead seat 11 comprises flange 14, the bottom of the outside lateral surfaces of its surface bearing bead 5, as shown in Figure 2.Flange 14 is also referred to as the wheel rim platform.
In a preferred embodiment, bead core is made by the metal alloy of superelastic shape memory material fully, and the characteristic that has obtains the alterable height shape property of bead core when helping to be installed to bead on the wheel rim at ambient temperature.
The material that has super elastic characteristics " has been done basic description among the Engineering Aspects of ShapeMemory Alloys (Butterworth-Heinemann ed.London, 1990) at publication.The material that forms bead core can comprise multiple metal, particularly following alloy: Ni-Ti, NiTiX (X=Fe, Cu, Nb), CuZnAl, CuAlNi, CuAlBe, FeMnSi base alloy and FeNiCo base alloy.
In order to understand the present invention better, Fig. 3 represent when bead core be stretched in case the wheel rim platform be on the flange by the time and be clamped in one of bead core performance when taking turns on ring support example qualitatively when it.The coordinate diagram of Fig. 3 is represented deformability load curve.Ordinate represents to act on the stress that makes its distortion on the bead core, and abscissa is represented the elongation strain of bead core, is expressed as its full-sized percentum.
In the origin of coordinates, bead core is in the state of the superelastic shape memory material with austenitic structure.At point 0 with put curved segments between 1 and represent to act on distortional stress on the bead core.From putting 1, material fades to martensitic structure from austenitic structure, becomes martensitic structure fully at point 2, and this is corresponding to percentum elongation strain ε 2.Value σ 1 corresponding to ε 1 represents the critical loading that changes, and this critical loading begins from austenite to martensitic structural change bead core.As shown in Figure 3, when the load on acting on bead core kept constant, the structure of bead core made bead core can be out of shape a big percentum elongation from austenite to martensitic transformation.
Cause the state of martensitic structure corresponding to the stress in the bead core at point 1 and the line segment of putting parallel abscissa axis between 2.
At stretch value ε 0, material has partial martensite and part austenic structure, and when the line 0-1 in the diagram of curves of ε 0 convergence Fig. 3, the martensite composition reduces.The stress value that is acted on the bead seat by bead core descends with respect to critical loading, and the value of occupying σ K.Shrink stress σ K depends on the heat treatment that material bears before forming bead core corresponding to the decline of stress σ 1, depends on that particularly material is converted to martensitic structure and the opposite temperature that changes from austenitic structure.
In the bead core made from superelastic shape memory material, the value difference between σ 1 and σ K is preferably between 50MPa and the 300MPa.
When second bead was installed on the wheel rim, identical process and Consideration also were suitable for.When two beads all were installed on the wheel rim, forced air charged into tire, two beads axially outwards was pressed on the surface of the platform 14 that is provided with on the wheel rim, as shown in Figure 2.
In addition, the characteristic that bead core had made of superelastic shape memory material helps when bleeding a tire bead to be remained in the bead seat.In order to understand these characteristics better, in the coordinate diagram of Fig. 4, when being illustrated in normal operation, abscissa reaches the heating-up temperature that bead and bead core thereof are born when deflated state.Ordinate is illustrated in the stress of its structure of transformation that bead core bore in the heat process.
The stress that 3 representatives of Fig. 4 mid point take place in bead core at temperature As is corresponding to the end of martensitic state and the beginning of austenitic structure formation.The stress that the temperature that point 4 representatives are completed in austenitic structure takes place in bead core.The increase of the stress that in transition process, takes place in the bead core in the line segment representative of 3 and 4 of points.
Symbol Δ σ representative is restored to austenic stress from martensite, corresponding to bead core and bead thereof the increase convergent force against the wheel ring support.Value Δ σ selects to such an extent that produce one bead is locked at strong coupling mechanism force in the bead seat, to stop any phenomenon of taking off when flat tire travels.
The characteristic that this bead core made from superelastic shape memory material has is convenient at ambient temperature mounting of tyre on wheel rim, also helps stoping taking off seat when tire flat occurring.The description purpose of characteristic at ambient temperature is to cover different regions, the very wide range of temperatures that in a year, in any season mounting of tyre may be existed on wheel rim the time.Described ambient temperature for example can be between-20 ℃ to+30 ℃.
In order to be easier to understand the present invention, the coordinate diagram of Fig. 5 is represented around the progress of the heat curve in the zone of the bead of flat tyre.Abscissa is represented the time, and ordinate is represented temperature.Shown in this diagram of curves, after representing the constant line segment of cruising state, venting appears, and the initial linearity of following by temperature raises.Be corresponding to temperature T subsequently
MaxSteady temperature.Surpass this point, temperature is basicly stable, rises no longer in time.
In the venting situation, after 20 seconds to 2 minute a period of times, reached temperature T
Max, generally between 60 ℃ to 120 ℃.
In the example of the embodiment that is applicable to motor tire, the bead core that superelastic shape memory material is made in order to be installed at ambient temperature and to stop the good character of taking off seat after the gas leakage, can have following preferred characteristic:
-with the atomic percentage metering, contain Ni 50.6% and the alloy NiTi that contains Ti 49.4%.
The temperature A that-austenite formation stage begins
sBetween 15 ℃ to 60 ℃.
-austenite forms the temperature A that finishes
fBetween 60 ℃ to 80 ℃.
-form the limit stress σ 1 of the transformation that begins from austenite between 0.2 to 0.7GPa to the martensite that stress causes.
-equal 0.2% corresponding to the stretch value ε 1 of σ 1.
-equal 6% corresponding to the stretch value ε 2 of σ 1.
-equal 0.2GPa corresponding to the stress σ K of distortion recovery when pine oil is loaded.
-equal 4% corresponding to the stretch value ε 0 of σ K.
-from martensite to stress value Δ σ that austenite changes again between 0.21 to 0.6GPa.
In addition, the bead core properties of materials must meet following formula:
-temperature A
s<T
a
-temperature A
f<T
Max
Wherein, Ta represents ambient temperature, T
MaxThe highest temperature that representative reaches in deflated state.
About first critical conditions, at the starting temperature of transformation A of material
sIn the situation greater than ambient temperature, the represented transformation of Fig. 3 diagram of curves is inapplicable.In fact, have martensitic structure and temperature T
a<A
sThe material of formation bead core will be in a little 2 state, removing load will still make material be in martensitic state.In this case, removing load will be by from putting 2 any process prescriptions to abscissa or Fig. 3 X-axis, material not can from before distortion restore.
About second critical relation.Maximum collapse that it should be noted that bead core is the maximum temperature value T that reaches when being lower than venting
MaxTemperature take place, this be since under higher temperature maximum collapse no longer include any positive effect, may cause problem, on the time of the highest temperature that reaches, provide constant situation.
In a concrete embodiment, the installation environment temperature is 25 ℃, and the highest temperature that reaches after the venting equals 100 ℃, and the characteristic of the superelastic shape memory material of bead core is as described below:
-austenite forms the temperature A of beginning
sIt is 20 ℃.
-austenite forms the temperature A that finishes
fIt is 80 ℃.
-equal 0.25GPa from austenite to the limit stress σ 1 of martensite transfor mation.
-equal 0.2% corresponding to the stretch value ε 1 of σ 1.
-equal 6% corresponding to the stretch value ε 2 of σ 1.
-equal 0.2GPa corresponding to the stress σ K of distortion recovery.
-equal 4% corresponding to the stretch value ε 0 of σ K.
-from martensite to stress value Δ σ that austenite changes again between 0.2 to 0.6GPa.
In another embodiment, bead core can form by silk, but is forming from holding on one's body continuously with the bonding jumper of alloy NiTi.In this embodiment, the thickness of bonding jumper is between 0.3 to 0.9mm, and its width is between 4 to 8mm.
As can be seen, above-mentioned tire can use the material that has the super-elastic shape memory characteristic on its entire cross section and its full annular size to make.In according to other embodiment more of the present invention, tire can comprise following bead core, and promptly at least one part of its full annular size is made by superelastic shape memory material, and remainder is made by ordinary steel wire.
For example, tire can comprise the bead core that some different silks constitute, and every rhizoid forms along the radially overlapping a series of circles of a vertical plane surface, and vertical plane surface separates them.A kind of structure of bead core has some different silks, for example is made of 4 rhizoids and 4 layers, and this structure abbreviates 4 * 4 as.Bead core can form by following manner: form circle with the material with characteristic of the present invention along some vertical plane surfacies, form the circle on all the other planes with ordinary steel wire, perhaps be used alternatingly the silk and the ordinary steel wire that have super elastic characteristics.
Substitute independent silk, bead core can comprise other reinforcement such as bonding jumper, line etc., and its structure is radially stacked definite by the circle of a member of the radially circle setting of contiguous another member.
In another embodiment, tire can have spiral bead core, and it is twined on it by several steel wire spirals by a center cable and forms.This spiral bead core can comprise one, and perhaps in other embodiments, above-mentioned cable can be a superelastic shape memory material fully by having the part of making according to the material of characteristic of the present invention, and above-mentioned silk can be a steel.Perhaps, cable and some can be superelastic shape memory material, and remaining is a steel.
In all scenario, have several rhizoids or several be not that each embodiment of reinforcement of silk comprises above-mentioned those embodiment, got by body plan no matter how many silk or reinforcements are arranged, they still have needs at ambient temperature mounting characteristics and in response to work in temperature rise, the particularly temperature rise in deflated state acts on the ability that the contraction load on the bead seat increases.Bead core is by like this body plan, and the size of silk or reinforcement, quantity and physical property are beneficial to install at ambient temperature through suitably selecting, and in order that obtains under the venting situation better clamping to bead seat.
In a further advantageous embodiment, bead core is to be made by several different silks, comprises the part that a superelastic shape memory material is made, and it has following structure:
The number of the silk that-superelastic shape memory material is made is 3.
The number of-ordinary steel wire is 2.
-radially the number of turn is 5.
The diameter of the silk of-superelastic shape memory material is 0.96mm.
-gauge of wire is 0.96mm.
The thickness of-rubber coating is 0.12mm, and hardness is 80IRDH.
-superelastic shape memory material the silk break the load be 1GPa.
The percentage elongation of the breaking load of the silk of-superelastic shape memory material is 16%.
-steel wire break the load be 2-3GPa.
-the percentage elongation of steel wire under breaking load is 6%.
The affined physical property with silk of super-elasticity and shape memory characteristic of at both ends is:
-austenite forms the temperature A of beginning
sIt is 20 ℃.
-austenite forms the temperature A that finishes
fIt is 70 ℃.
-induce the transformation limit stress σ 1 that martensite begins from austenite and equal 0.3GPa.
-equal 0.2% corresponding to the stretch value ε 1 of σ 1.
-equal 6% corresponding to the stretch value ε 2 of σ 1.
-equal 0.15GPa corresponding to the stress σ K of distortion recovery.
-equal 4% corresponding to the stretch value ε 0 of σ K.
-from martensite to stress value Δ σ that austenic changes again between 0.2 to 0.8GPa.
Use these preferred parameters, the present invention can realize all re-set targets.By bead core being applied constant power, on wheel rim, assemble tire at ambient temperature, tire-like is stretched to suitable size, unlikelyly so that bead is easily slided on the wheel rim platform causes big stress on material.
As consulting the description that Fig. 3 has done, in case reach corresponding to the stress value σ 1 that changes critical loading, the percentage distortion under constant duty significantly increases.
Understand advantage of the present invention for better, Fig. 6 represents for the load-deformation curve the steel wire of the 0.96mm diameter that uses in the plain metal bead core.Represent by ordinate with the load value that KN expresses, represent by abscissa from the percentage stretch value of dormant state.Fig. 6 represents first section an of linearity, is a segment of curve subsequently, surpasses the then yield situation of convergence material of this segment of curve.In the linear portion end of diagram of curves, the silk that uses in the common bead core of representing among Fig. 6 shows that distortion is lower than 1.0% under the load of 1.3KN.
According to silk of the present invention, for example make by the super-elastic NiTi alloy material of diameter 0.96mm fully, be used for making and the similar bead core of above-mentioned common bead core, this silk is under 25 ℃ ambient temperature, under transformation limit stress σ 1 effect, has 6% maximum elongation percentage ε 2 corresponding to the 400MPa of 0.3KN.By removing the load that causes distortion, above-mentioned distortion is restored.
At common bead core with according to comparison shows that the former can not reach the latter's percentage stretch value between the bead core of the present invention.Can be deformed into 1% to 6% stretch value according to bead core of the present invention, and the percentage of elasticity stretch value of common bead core is about 1% to 5%, surpasses this scope, its structure will be damaged, and use is limited.
In addition, according to bead core of the present invention tire can be used in any common tire maintenance and the equipment that can find in the shop is installed to be installed on the wheel rim at ambient temperature.Therefore, technical scheme of the present invention has the advantage above other technical scheme, because the assembling of tire on wheel rim requires to carry out at ambient temperature, does not need the desired special-purpose heating device of other method to reach the installation temperature.
In addition, the present invention makes bead core even the size beyond the bead seat of wheel rim has tolerance, thereby and also can install during the nominal dimension of do not match bead core and relevant bead.This is possible, as long as form bead core with the superelastic shape memory material of the martensitic structure with stress initiation, makes bead core at ambient temperature the elongation strain that needs be arranged under constant load effect.This effect is appreciated that by checking Fig. 3.When bead seat and flat-bed height during less than nominal dimension, the elongation strain of bead core can be prevented from before 2 reaching a little.The pine oil load makes distortion return to the new value ε in ε 0 left side then, and it is corresponding to the actual size of bead seat.
When the size of bead seat and flat-bed height during, reach the stretch value that under the constant duty effect, can further increase bead core at ambient temperature greater than nominal dimension.Then, load is made distortion return to the value of bead seat actual size decision by pine oil.
In fact, in installation process, by automatically being adjusted to the size that bead core must be installed to the object on it, bead core can provide the performance of improvement.Characteristic of the present invention also can keep the correct clamping pressure of bead on bead seat stably in a long term.
In fact, in the course of the work, the clamping pressure of bead tends to increase, and this can find out by checking Fig. 4.In Fig. 4, the bead core that σ K representative is shunk is being installed temperature T
aAct on the stress value on the wheel rim down.
At work, tire is heated to gradually to be increased and a conditional temperature, and when tyre temperature raise, heat reached bead core, and corresponding making under the stress that acts on the bead seat increases gradually.Stress in the work is expressed as temperature T qualitatively on the ordinate of Fig. 4
a, T
1, T
2And T
3Function.Therefore, determine not only that according to bead core of the present invention bead should be applied to the correct pressure on the bead seat, and tend to increase its value that the safe handling of tire is had tangible benefit.
Characteristic of the present invention also make bead core be applied to gripping power on the bead seat can be especially in response to heavy running condition such as the sort of running condition of running into the gas filed high-performance tires of air pressure of 3 crust and automatically regulating.In fact, high-performance tire often will bear unexpected braking, and bead has skid hazards on the wheel rim bead seat, thereby causes the decline of braking effect.The present invention can reduce this danger, because in braking procedure, metal rim is born strong heating, and heat reaches the bead core that the super-elastic shape memory metal alloy is made immediately.Like this, because the contraction of bead core increases the stress F that acts on the wheel rim.
In Fig. 4, the maximum stress in above-mentioned state is only represented at temperature T 3 places by qualitative mode of giving an example.In fact, in the extremity that occurs in braking procedure, bead core automatically is increased in the pressure on the bead seat, thereby prevents bead skidding on wheel rim.
Even at puncture of tire, lose fully in the situation of air pressure, the present invention also can eliminate the danger that tire comes off or takes off seat.The reason that obtains this effect is that the material of bead core designs to such an extent that have a temperature A
fThe highest temperature T that is lower than but preferably very approaches in the running that bleeds a tire, to occur
Max
The shrink stress value σ of bead core is being lower than ambient temperature T
aTemperature A
sUnder begin to increase, and when reaching temperature A
fThe time develop into maxim, this maxim in many situations near 120 ℃.Corresponding to temperature A
fThe bead core value of shrinking will be significantly greater than at ambient temperature T
aThe value that obtains, thereby stress is increased, when bleeding a tire running, bead is locked on wheel rim.Therefore, use the vehicle of the tire of making according to the present invention can be when tire loses heart tens kilometers of safety traffics, thereby arrive the garage that can change flat.
In according to a preferred embodiment of the present invention, bead core shrink stress F is corresponding to 95 ℃ to 120 ℃ temperature A
f, equaling 0.8GPa, it can be used as the function bead core geometric configuration and the bead steel wire and calculates.
The obvious not strict top description that is confined to of the present invention.Those skilled in the art is understood, and can make various modifications and variations and not exceed scope of the present invention structure of the present invention.Therefore, the present invention covers various to modifications and variations of the present invention, as long as they do not exceed the scope of claims and equivalent thereof.
Claims (19)
1. tire that comprises a ring shaped tyre and a tread strip, described carcass has a central bizet and two sidewalls that end at a pair of annular bead, each bead comprises the metal bead core that is used for anchoring on the corresponding bead seat of wheel rim, and described bead core comprises the annular section that at least one is made by the material with super-elasticity and shape memory characteristic.
2. tire as claimed in claim 1, it is characterized in that: the material with super-elasticity and shape memory characteristic at ambient temperature can be in response to a constant force deformation, and when removing above-mentioned constant force, return to original shape, be beneficial to the assembling of tire on wheel rim.
3. tire as claimed in claim 1, it is characterized in that: when in tire working, reaching predetermined temperature, have described at least one part that the material of super-elasticity and shape memory characteristic makes and give bead core vertical shrink stress, described shrink stress increases to one gradually corresponding to temperature A
fMaxim, at temperature A
fFollowing material is finished the formation of austenitic structure.
4. tire as claimed in claim 1, it is characterized in that: when tire loses heart work, bead core is heated gradually, and form cumulative convergent force, until the maxim corresponding to the temperature of the formation of finishing austenitic structure, described convergent force is clamped on the bead seat more tightly to prevent separating of tire and wheel rim bead core.
5. be applied to the metal bead core of the tire beads on the vehicle wheel rim, described metal bead core comprises the bead wire that is formed by the material with super-elasticity and shape memory characteristic.
6. bead core as claimed in claim 5 is characterized in that: the material with super-elasticity and shape memory characteristic at ambient temperature can be by a constant force elastic deformation, and returns to the original form when removing described constant force.
7. bead core as claimed in claim 5 is characterized in that: the material response with super-elasticity and shape memory characteristic acts on a cumulative stress in cumulative temperature on wheel rim, thereby prevents that bead wire from changing shape.
8. bead core as claimed in claim 5 is characterized in that: the material with super-elasticity and shape memory characteristic has following character:
A
s<T
a
A
f<T
max
Wherein:
A
sIt is the temperature that martensitic structure with material of super-elasticity and shape memory characteristic begins to be transformed into austenitic structure;
A
fIt is the temperature that changes to austenitic structure corresponding to finishing;
T
aIt is ambient temperature;
T
MaxBe in air deflating state when running the maximum temperature that reaches of tire.
9. bead core as claimed in claim 5, it is characterized in that: at least one part with material of super-elasticity and shape memory characteristic has following structure, promptly, this structure is finished from martensite substantially when reaching two predetermined temperatures in the material and is changed to austenic, stress between 0.2GPa to 0.8GPa of this part generation, thereby cause the contraction of bead wire, bead wire is clamped on the wheel rim more firmly.
10. bead core as claimed in claim 5, it is characterized in that: at least one part with material of super-elasticity and shape memory characteristic has the critical transitions load of 0.2GPa to 0.7GPa at ambient temperature, and it is corresponding to the transformation of the martensitic structure that causes to stress from austenitic structure; When the constant stress corresponding to described critical loading was applied on the bead wire, the elongation strain of bead wire increased.
11. bead core as claimed in claim 10 is characterized in that: the material with super-elasticity and shape memory characteristic has 0.2% to 6% elongation strain at ambient temperature under the critical loading effect that changes.
12. bead core as claimed in claim 10 is characterized in that: when described critical loading was eliminated, bead wire restored from distortion.
13. bead core as claimed in claim 8 is characterized in that: at least one part with material of super-elasticity and shape memory characteristic has the temperature A that beginning between 15 ℃ to 60 ℃ changes to martensitic structure from austenitic structure
s
14. bead core as claimed in claim 8 is characterized in that: at least one one with material of super-elasticity and shape memory characteristic has the temperature A that austenitic structure forms that finishes between 60 ℃ to 80 ℃
f
15. bead core as claimed in claim 5 is characterized in that: at least one part with material of super-elasticity and shape memory characteristic is that the material that comprises the Ni-Ti alloy forms.
16. bead core as claimed in claim 5 is characterized in that: the full annular scope of bead wire is to be formed by the material with super-elasticity and shape memory characteristic.
17. mounting of tyre in the method that has on the wheel rim of terrace part, be may further comprise the steps:
Selection has the tire of bead core, and bead core comprises at least one part of the material with super-elasticity and shape memory characteristic;
By applying constant load to bead core at ambient temperature, each bead core that one after the other stretches makes the diameter of its oval length greater than terrace part;
Each bead core is slided on terrace part;
Loosen above-mentioned constant load, make bead core flexibly return and be installed on the wheel rim corresponding to the length of wheel diameter;
Make inflation of tire.
18. be applied to the metal bead core of the tire beads on the vehicle wheel rim, described metal bead core comprises the bead wire of the material formation with super elastic characteristics.
19. metal bead core as claimed in claim 18 is characterized in that: described material with super elastic characteristics is a shape-memory material.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP98120358 | 1998-10-28 | ||
EP98120358.1 | 1998-10-28 |
Publications (2)
Publication Number | Publication Date |
---|---|
CN1267604A true CN1267604A (en) | 2000-09-27 |
CN1210171C CN1210171C (en) | 2005-07-13 |
Family
ID=8232873
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CNB99123202XA Expired - Fee Related CN1210171C (en) | 1998-10-28 | 1999-10-28 | Tyre bead wire and tyre therewith |
Country Status (8)
Country | Link |
---|---|
JP (1) | JP2000313211A (en) |
KR (1) | KR20000029389A (en) |
CN (1) | CN1210171C (en) |
AR (1) | AR021002A1 (en) |
AT (1) | ATE236801T1 (en) |
BR (1) | BR9904705A (en) |
DE (1) | DE69906658T2 (en) |
TR (1) | TR199902654A3 (en) |
-
1999
- 1999-10-20 DE DE69906658T patent/DE69906658T2/en not_active Expired - Fee Related
- 1999-10-20 AT AT99120747T patent/ATE236801T1/en not_active IP Right Cessation
- 1999-10-25 TR TR1999/02654A patent/TR199902654A3/en unknown
- 1999-10-27 BR BR9904705-5A patent/BR9904705A/en not_active IP Right Cessation
- 1999-10-28 CN CNB99123202XA patent/CN1210171C/en not_active Expired - Fee Related
- 1999-10-28 JP JP11307225A patent/JP2000313211A/en not_active Withdrawn
- 1999-10-28 AR ARP990105439A patent/AR021002A1/en active IP Right Grant
- 1999-10-28 KR KR1019990047208A patent/KR20000029389A/en not_active Application Discontinuation
Also Published As
Publication number | Publication date |
---|---|
CN1210171C (en) | 2005-07-13 |
ATE236801T1 (en) | 2003-04-15 |
JP2000313211A (en) | 2000-11-14 |
DE69906658T2 (en) | 2004-02-05 |
KR20000029389A (en) | 2000-05-25 |
TR199902654A2 (en) | 2000-06-21 |
TR199902654A3 (en) | 2000-06-21 |
BR9904705A (en) | 2000-08-15 |
AR021002A1 (en) | 2002-06-05 |
DE69906658D1 (en) | 2003-05-15 |
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Granted publication date: 20050713 Termination date: 20091130 |