JPH11342711A - Tire for vehicle wheel, detecting system for tire physical state parameter and manufacture of tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make at least one of ring cores comprising a material layer with high magnetic permeability so as to be usable as a ferromagnetic core by installing a secondary inductive element which is able to related to a primary inductive element for forming a generator, and making both these primary and secondary inductive elements possible to be moved with each other. SOLUTION: An assembly consisting of winding and a bead core 22 is produced in a bead 28 of a tire 20 together with a bead filler as one device wherein it is assembled together with such a circuit as using a generated electric current, and in this constitution, more than one of magnets is locked to a wheel hub, or it is united in a body with a vehicle chassis comprising a wheel 18 attached to the tire 20 guiding the electric current to the winding. If the magnet is an electric magnet 36 being fed with an alternating current, a generator operates when the wheel 18 is rotated and when the wheel stops. If the magnet is a permanent magnet or another electromagnet fed with a direct current, the generator operates only when the wheel 18 is rotating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to galvanic contacts with fixed or rotating components present in vehicles, which can supply sensors and any other circuits incorporated in the tire. ) Cars, trailers, motorcycles,
Aircraft, etc. (Hereinafter, this is generally called "vehicle")
Related to tires. In particular, the present invention relates to a tire which constitutes an assembly in which the device formed by the generator, the sensor and a part of the bead wire is integrated into the carcass during the manufacture of the tire.

[0002] The invention also relates to a method for the manufacture of said tire.

[0003]

2. Description of the Prior Art A typical tire construction comprises at least one rubber yoke reinforced fabric (carcass).
The carcass substantially comprises a ply-mounted carcass, each edge of which is at least one circumferentially non-extendable, commonly known as a bead core, which is a reinforcing member that holds the tire on its mounting rim. Fixed to a metallic annular metal core. The carcass is formed by a pair of axially opposed side walls and a tread strip engraved with a relief pattern that is located on the crown of the casing and that gives the tire in use specific behavioral characteristics. Be completed. The tire may also be provided with a belt structure made of rubber fabric incorporating metal reinforcement cords, usually interposed between the carcass and the tread band.

[0004] An encoder connected to an inductively powered transponder (receiving signals and sending responses) and / or
Or circuits including sensors are sometimes well known, which circuits are housed in tires or wheels of vehicles.

[0005] For example, International Patent Application WO 12,474.
/ 90 "Vehicle Tire Identification System (Vehicle
tire identification system
em) describes a system consisting of a transponder located inside the tire, which transponder is located in the crown of the tire or at least located far away from the bead core of the tire. Power is supplied by a winding (see page 5 of the above-mentioned patent application,
Lines 20-22).

[0006] The winding is fed by a large excitation winding by means of alternating current induction of the appropriate frequency, which excitation winding comprises:
It is located outside the tire and is supported by a scanning device such as a bar, or is located at a fixed location, such as a road surface, and the excitation winding is close to the equator of the tire in which the transponder feed winding is housed. Can be

[0007] In the absence of any information on this, the Applicant has determined that such a device remote from the bead core:
Although it is necessary to prevent the winding efficiency from being reduced by the eddy current generated in the bead core, this eddy current is generated by the inductive coupling between the bead core and the winding placed near the bead core. Occurs. The advantages of the system described above are:
The fact that the transponder-fed windings can operate even if the windings of the scanning tool are not located very close due to their dimensions,
On the other hand, if the diameter of the power supply winding is small and arranged at a strictly defined position on the crown or side wall of the tire, a scanning tool winding is required.

[0008]

However, the device proposed in International Patent Application No. WO12,474 / 90 has at least the following disadvantages.

A) To minimize the efficiency loss of the windings due to the presence of the bead core, it is placed close to the equator of the cover, in other words directly under or very close to the tread band. Requires transponder feed windings.
This significantly complicates the tire manufacturing process,
And there are potential structural problems due to the presence of windings in the part of the tire that undergo considerable stress and deformation during use.

B) It is necessary to incorporate a device that uses the power generated by the windings in the part of the cover on which the windings are subjected to high mechanical stress, or alternatively to a location that is more suitable for use. It is necessary to incorporate the power transfer electrode into the tire sidewall structure.

Another case is described in US Pat. No. 5,181,97.
No. 5 provided. According to this, there is disclosed a winding-fed transponder disposed within a bead of a cover and separated from the bead core but inductively coupled to the bead core, thereby providing a sinusoidal transponder. The current induced in the bead core by the changing external magnetic field induces a voltage sequentially in the transponder feed winding.

[0012] Such an arrangement of the secondary winding (induction antenna), such as the arrangement in the crown described above, offers the advantage of always having good inductive coupling to the primary winding (transmitter). But such a solution also
(Especially complex and partially deformable structural areas, ie having substantially inextensible windings accommodated in bead areas)
Problems arise in the mechanical properties of the tire and its manufacturing process.

US Pat. No. 4,006,449 “Information detector for tires and wheels (Information)
detector for a tire while
l) "discloses a system for feeding sensors of tire operating parameters such as internal pressure and / or temperature, whereby the system is radially inward at the edge of the rim with respect to the axis of rotation of the wheel. It consists of windings containing a specific number of turns arranged in a position.

The winding is connected to a passive transducer (sensor) located on the sealing cap of the air filling valve of the tire and communicating with the interior of the tire. The circuit receives an excitation signal fixed to a vehicle chassis and induced by a first coil connected to an AC power supply (also fixed to the vehicle). The impedance of the coil depends on the passive transducer, since it affects the strength and / or phase of the excitation signal.

[0015] A second fixed coil inductively coupled to the winding portion of the rotating winding is connected to a circuit for sensing the amplitude and / or phase and processing the sensed signal.
This processing circuit controls both the indication of the sensed value and an alarm that is activated when an abnormal value of a parameter is present, such as pressure loss in the tire due to puncture or tire damage.

The system behaves fairly satisfactorily and displays reliable vehicle information on the operation of the tire in combination with warnings of dangers due to unusual situations on the dashboard, which is located on the rim. The condition was that there was no inherent weakness in the flexible connection between the rounded winding and the transducer located inside the cap of the air-filled valve. These connections are affected both by centrifugal stresses caused by the rotation of the wheel and by stresses resulting from the inevitable impact of the wheel with accidental obstacles (running on broken ground, pavement, etc.). So the possibility of frequent punk is inevitable.

US Pat. No. 4,717,905 entitled "Alarm system including means for remotely energizing a condition sensing device (W
arning system including m
eans for remotely energyiz
ing condition sensing devi
ce) "is a system that remotely powers one or more devices by radio frequency to detect conditions such as internal conditions of a tire. According to this, a radio signal emanating from a radio frequency source is received by a circular coil antenna mounted on the rim of a vehicle wheel, and this signal further comprises a physical value such as, for example, pressure, connected to one of the antennas connected to the antenna. Supply to the above transducers. This transducer
The resonant frequency of the oscillator circuit including the antenna mounted on the rim is varied as a function of the value of the monitored physical quantity. Variations in the resonance frequency are detected by circuitry associated with the radio frequency generator and are used to control instruments and alarms on the vehicle dashboard.

The major disadvantages of the system described above are inherent in the geometric and mechanical design of the system,
The coil antenna mounted on the rim must be electrically connected to the sensor built into the tire, which reduces the reliability of connectors built into parts that are subject to large deformations, such as tire structural components This causes the usual problem.

Examination of the prior art as described above shows that a simple and reliable generator has not yet been obtained. That is, a simple and reliable generator can provide a sensor of the operating parameters of a tire or other device, in particular the electrical connection of equipment fixed outside the tire, from which all problems arise. Such an electrical connection is not used.

Applicants have found that a tire bead core, a structural component that is always present in both tires with radial carcass and tires with conventional carcass, is advantageously used as the core of the secondary inductive element. I discovered what I could do. In particular, bead wires are usually made from steel wire or billets, in other words from ferromagnetic materials, and are therefore suitable for use as cores of secondary inductive elements. Still further, their magnetic permeability can be increased by adding appropriate materials capable of increasing the linked magnetic flux as needed.

The applicant has also discovered that a magnet or electromagnet, preferably fixed to a support mounted on the hub of the wheel, and thus in a fixed position, is used as the primary inductive element.

Applicants have further discovered that it is desirable that the user's circuitry, along with the secondary inductive element, also be mounted on a structural member that is substantially free of large deformations, such as the bead's reinforced bead core.

This bead core is in fact the least deformable structural member of the tire and is therefore well suited for use as a base for mounting electronic devices for sensing and transmitting signals. Because of their stiffness, fragility and sensitivity, these devices are generally not suitable for incorporation into elastic elements that undergo large deformations.

In a first aspect, the invention relates to a tire for a vehicle wheel, axially ending with a bead for fixing said tire to a corresponding support rib, each provided with a reinforcing annular core. In a tire including an annular carcass provided with a side wall portion and a tread band disposed in a crown portion of the carcass and continuously extending in an axial direction between the side wall portions, at least one of the annular cores is a ferromagnetic core. Wherein at least one winding of a conductive wire is wound around a transverse profile of the annular core to form a secondary inductive element of the generator.

[0025]

According to the invention, the secondary inductive element has at least one element for forming the generator.
One primary guidance element can be associated with the primary guidance element and the secondary guidance element are mutually movable.

Preferably, the annular core includes a material layer having a high magnetic permeability. In an alternative embodiment, the annular core includes a plurality of material blocks having high magnetic permeability. In a different preferred embodiment, the annular core comprises a thermoplastic or thermoset elastic or plastic type matrix made of steel and comprising a soft ferromagnetic material in powder form.

Preferably, said type comprises an electronic circuit powered by said secondary inductive element. Preferably, the electronic circuit includes means for detecting certain parameters of the tire. In particular, said electronic circuit is fixed to said annular core.

Preferably, said sensing means comprises at least one temperature sensor and / or at least one pressure sensor and / or a pair of extensometers, which detect deformation of said annular core in two orthogonal directions. Placed in

In particular, the electronic circuit includes a data transmitter (transmission) means capable of transmitting the parameters of the tire. In another different aspect, the invention relates to a system for sensing and signaling parameters of the physical condition of a tire for a vehicle wheel mounted on a corresponding mounting rim, for securing the tire to the rim. An annular carcass provided with an axially facing side wall ending in the bead provided with an annular reinforcing core, and an annular carcass disposed at a crown of the carcass and continuously between the side walls. A system comprising a tire having an elongating tread band, a device for sensing said parameter of the physical condition of the tire, and a generator for powering the sensing device, wherein at least one of the annular cores is ferromagnetic. Used as a core, wherein at least one winding of conductive wire is wound around a transverse profile of the annular core to provide secondary induction of the generator. And forming a hydrogen.

Preferably, said secondary inductive element forms said generator by associating with at least one primary inductive element, wherein said primary and secondary inductive elements are mutually movable.

According to a preferred embodiment, said primary inductive element comprises at least one permanent magnet. In an alternative form, the primary inductive element includes at least one electromagnet and a secondary winding of at least one conductive wire around a transverse profile of the at least one electromagnet; Form the primary winding.

In particular, the electromagnet is supplied with DC or AC, or DC and AC. In another different aspect, the present invention comprises the steps of manufacturing, on a preparation machine, a semi-finished product required to form a tire including a pair of ferromagnetic annular cores for securing the tire to a corresponding mounting rim; By generating at least one of the pair of annular cores, called annular coil elements, at least one first winding of a conductive wire wound around a transverse profile of the annular coil core Forming a first secondary winding of the machine, and assembling the semi-finished product on a tire building machine to form the green carcass for the tire including at least one annular coil core. The present invention relates to a tire manufacturing method.

Preferably, the step of forming the first secondary winding comprises the step of fixing to the toroidal coil core means for sensing certain physical parameters of the tire powered by the generator. It is desirable.

In particular, the step of arranging a material layer having a high magnetic permeability around the at least one annular core in the absence of the one winding is performed before the step of forming the first secondary winding. Will be

In another different aspect, the invention relates to a method for generating a power supply current for at least one electronic device in a tire, wherein the at least one winding is wound around a bead core belonging to said tire. A step of inducing a variable magnetic field in a winding formed by the method.

The present invention will now be described, by way of non-limiting example only, with reference to certain preferred embodiments, as illustrated by way of example in the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a tire 20 includes an annular carcass having a central crown 21 having two axially opposed side walls 24 from its edge. Extends inward in the direction and terminates in a rigid annular region 28 commonly known as a bead. Each annular region 28 is reinforced with at least one inextensible annular reinforcing core 22, commonly known as a bead core.

The carcass support structure has at least one
And each of the opposing side flaps of the ply with respect to the corresponding bead core 22 includes:
For example, it is fixed by winding the bead core around from the inside to the outside. At the peripheral edge of each bead core, a substance commonly referred to as a "bead filler" occupying the space formed between the reinforcing ply and the correspondingly wound side flaps An annular elastic filler 26 having a triangular cross-section is attached as desired.

As mentioned above, the bead core 22
The axially opposed areas of the tire, including the tires and their bead fillers 26, form so-called beads, each of which is indicated generally by the numeral 28 and has a tire mounted on a corresponding mounting rim 16 of a vehicle wheel. 20 is fixed.

Textile or metal cord (textile)
A belt structure 25 comprising two or more strips of rubberized fabric made from or metal cords and incorporated into a sheet of compound is coaxially associated with the carcass structure.

On the crown of the carcass or on the belt structure 25 if present, a tread band 27 extending continuously in the axial direction is mounted between the side walls,
Thereby, the tire 20 comes into contact with the ground. The tread band 27 includes a plurality of recesses and grooves, which bound a corresponding plurality of strips and / or blocks to form a tread pattern as a whole.

The above-described tire structures are well known to those skilled in the art, and need not be described in further detail. This construction also provides a bead reinforcement edge according to the particular tire type in question, a filler strip below the edge of the belt, a waterproof liner on the carcass ply in a radially inward position, and many other structural components such as It is also known to include

In FIG. 2, the current generator according to the present invention includes a secondary inductive element, a bead core 22 as a ferromagnetic core, and a secondary inductive element wound around the core. And at least one winding 30 of conductive wire comprising at least one winding forming an element. This secondary inductive element (shown in FIG. 2 in a version with only one winding on the bead wire) constitutes the moving (rotating) part of the current generator according to the invention.

In operation, the secondary inductive element is linked to a magnetic field 34 generated by the primary inductive element, the primary inductive element being at least an electromagnet 36 with a core 38 covered by an excitation winding 39. Includes one magnet.
The electromagnet 36 is mounted on the support 1 mounted on the hub of the wheel.
2 and constitutes a fixed part of the current generator according to the invention.

The bead wire 22 generally consists of a winding section consisting of a single winding or a group of windings adjacent to each other, or alternatively, is spirally formed with a predetermined number of radially overlapping layers. It consists of a rolled billet 19 (see FIG. 2). The material of the winding section or billet 19 is typically at least 500MP
It has good mechanical properties which desirably have a breaking load of a (megapascal) and a breaking strain of at least 3%.

Preferably, in order to increase the magnetic properties of the material, the windings are preferably provided with radially inward and / or outward locations with a high permeability, preferably greater than 5000 Gs / Oe (Gauss / Oersted). Includes a material layer such as an amorphous metal alloy with magnetic susceptibility.

Alternatively, a layer of material having a high magnetic permeability is desirably when it has a breaking strain of, for example, less than 3%, and especially when its malleability is particularly high when mounting the cover on the rim. When it is insufficient to withstand the resulting deformation, it is desirable to divide it into a number of parts.

According to yet another alternative, the bead core 22 comprises at least a fiber having a tensile strength.
s) or windings of yarns or cords, which windings are preferably 50G
Textile cords having a modulus of stiffness equal to or greater than Pa (gigapascal) and a breaking load equal to or greater than 500 MPa, such as Kevlar (DuPont) preferably incorporated in a matrix based on elastic material (Registered Trademark) is made of textile cords. This matrix may be in the form of powder or fibrils (fi
It includes a ferromagnetic material in the form of (brils) or is combined with a material layer having a high magnetic permeability as described above.

Preferably, only one bead core 22 (hereinafter referred to as “coil bead core”) of tire 20 is prepared to form said secondary inductive element,
More preferably, the tire 20 is mounted on a mounting rim 16 having a bead 28, said bead 28 being provided with said bead core 22 mounted axially inward, in other words on the vehicle side.

Still referring to FIG. 2, the periodically occurring voltage at the end of the winding portion 30 can be used to supply tire conditions and / or operation to electronics and sensors. In accordance with the present invention, this voltage can be used to sense electronic data, including sensors for tire conditions, such as extensometers for detecting bead core deformation, or microcircuits connected to temperature and / or pressure sensors. Preferably, it is applied to the transfer device 44. As an example, FIG. 2 shows two extensometers 4
6, 48 are also known as "strain gauge transducers" mounted orthogonally to each other and mounted in two directions to form a conventional temperature compensating bridge means. This one
The twin extensometer constitutes a sensor for the longitudinal deformation of the bead core with the effects of temperature fluctuations removed. In FIG. 2, the temperature sensor is not shown, because the temperature sensor is conveniently integrated with the electronic device 44.

As far as the primary inductive element is concerned, the winding 39 of the electromagnet 36 is preferably supplied with alternating current and the wheel 1
8 allows the winding 30 to generate the supply current both during standstill and during movement. The frequency of the power supply is preferably such that the effective induction signal in winding 30 is
4 to be given to the user.

The power supply frequency is, for example, 3 kHz to 3 kHz.
It is within the range of 0 KHz, preferably about 10 KHz. The supply power is about several watts (about 3 W),
It is supplied to a circuit that consumes about 10 mW.

The winding 39 is excited by a DC / AC converter supplied from the vehicle electrical system, but is not shown in the drawing as it is not relevant for the purpose of the present invention. FIG.
Shows a first preferred embodiment of the present invention. In this case, the bead core 22 is 1700MP
It has a breaking load of at least a and a cross section of 6 × 0.7 mm, and itself consists of a steel piece 19 spirally wound so as to form five radially superposed layers.

At a position radially inward from the bead wire 22, a layer 29 is wound around the entire width of the billet 19 along the entire circumference of the bead core, and the layer 29 is 1.5 mm thick.
Fe81B14S having a thickness of 50 μm
It consists of 30 turns of an i3C2 amorphous metal alloy (metallic glass) and forms a bead wire with high permeability properties.

The two windings 30a and 30b are
It is placed around the core (FIG. 3). Each of the windings
Desirably, the adjacent winding is formed by a wire of enameled copper wire having a diameter of 0.2 mm wound around the transverse profile of the bead core 22 arranged at a linear density of 2 turns / mm. The two electromagnets 36a, 36b are mounted at 180 ° to each other on the fixed part of the wheel hub and face the windings 30a, 30b sequentially during one rotation of the wheel.

Each of the electromagnets 36a and 36b integral with the hub has a substantially C-shaped opening whose opening faces the bead core 22.
A ferromagnetic core 38, and an electromagnet 36
Each of a and b has windings 39a and 39b made of enameled copper wire (alternating current flows) having a diameter of 0.2 mm. The windings 39a, 39b serve as primary inductive elements of the generator rotating relative to the windings 30a, 30b on the bead core both during stationary and moving wheels, and the windings of the bead core Lines 30a, 30b
Provides power to an electronic device 44 that acts as a secondary inductive element of the generator to monitor the condition of the tire.

In this case, the electromagnets 36a, 36b are supplied with an alternating current, preferably at a frequency of 10 KHz, to produce a particularly efficient, continuous and uniform power in the secondary inductive element, which is used for data detection and transfer. Electronic device 4 for
4 is supplied. If the circumferential distance between the windings 30a, 30b is small, as shown in FIG. 3, the simultaneously occurring voltage is virtually constant. Also, if this distance is large enough, two small power interruptions occur for each revolution, making it possible to incorporate a high precision tachometer into the electronic device 44.

Although the impedance of each winding is about half that of a single winding, as described above, this introduces additional mechanical complexity. The choice between the two solutions preferably depends on the electrical characteristics of the circuitry of the electronic device 44.

Preferably, the number of turns of the winding 30 in the bead core 22 is in the range of 1 to 8, and the ratio of circumferential division of the bead core covered by the winding is 1/1.
It is in the range of 0 to 10/10. The total number of turns of all windings is preferably in the range of 500 to 5000.

Preferably, the number of magnets of the primary inductive element is also in the range of 1 to 8. The overall configuration of the system (number and length of windings) depends on the requirements of the user circuit, in particular on whether uninterrupted power is required or on the possibility of operating only a part of the wheel rotation period. . The simplest design is a design having one primary electromagnet 36 and preferably consisting of a single winding on all bead cores that are preferably integral with the hub of the wheel, thereby providing a primary electromagnet 3
The distance between 6 and the adjacent surface of the rim 16 is preferably 1 mm
To allow movement transmitted to the tire by the steering and suspension while being within the range of .about.10 mm and held substantially unchanged.

A single turn solution is desirable where the relatively high impedance of such a circuit does not adversely affect the operation of the system. In another alternative embodiment, a single secondary winding 30 is excited by two or more primary electromagnets 36. This solution is advantageous when it is desirable to incorporate a plurality of low power magnets instead of one strong and large magnet for reasons related to the vehicle suspension configuration.

In another preferred embodiment of the present invention, the magnet is a direct current supplied electromagnet 36 or a permanent magnet (66a-66f in FIG. 6). In this way, the electronic device 44 is powered only when the wheel is in motion, which has the advantage that it can provide an additional indication that the speed of rotation of the wheel can be measured.

FIG. 6 shows an example in which the wheel operates only when the wheel is in motion, and the permanent magnets 66a to 66c are provided.
66f, wherein the permanent magnets 66a-66f desirably comprise samarium-cobalt or a sintered iron-neodymium-boron alloy.

In the case shown, the bead core 22 carries three winding portions 30a, 30b, 30c, which are connected in series, each having a length of less than 1/6 of the circumferential length. That's it. This winding is made of one enamelled copper wire having a diameter of about 0.2 mm and a number of turns of about 3000.

The circuit constructed in this case is particularly simple. That is, the system requires three secondary windings, but only one rectifying bridge 50a including a corresponding capacitor. The primary inductive element comprises six C-shaped permanent magnets 66a, 66b, 66c, 66d, 66e,
66f, these permanent magnets are mounted in parallel so that a change in north and south pole extension occurs and are fixed to a support 12 integral with the hub of the wheel 18. The printed circuit attached to the bead core in this example is described below with respect to FIG. 5, since the assembly of three secondary windings connected in series corresponds to the circuit formed by a single winding. It corresponds to a printed circuit.

Alternatively, the permanent magnet can be replaced by an electromagnet having a winding supplied with direct current from the vehicle's electrical system. A preferred form of this alternative type of generator is that the circumferential portion of the bead core is divided into 2N equal arcs and N, for example an odd number of said arcs, each arc being formed on it. And having one winding connected in series. It should be noted here that each of the N arcs is not necessarily completely covered by the winding, and in practice it is advantageous to concentrate the winding on a part of the length of each of said arcs. It is. A desirable way to accomplish this is to form the windings from a single piece of enameled copper wire, thereby forming a series connection without the need for connection points, soldering or connectors. Alternatively, the one or more wires used to form the secondary winding are:
It can also be made of any other suitable material with a sufficient cross section.
For example, aluminum wires or conductive polymers can be used.

To increase the available power, a plurality of serially connected windings are formed on the bead core, as described above, with each winding providing its own rectification and control circuit. It is also possible to have. The 2N C-shaped permanent magnets are made of, for example, samarium-cobalt or iron-neodymium-boron alloys in sintered or powdered form incorporated in an organic or ceramic matrix; -North Pole, North Pole-South Pole, and so on, thereby forming an alternation of the South Pole and the North Pole. Further, the permanent magnet is mounted on a circular support integral with the hub. Alternatively, all these magnets could be replaced by a single ring magnet with N north pole extensions and N south pole extensions alternating with each other. Optionally, the system has a smaller number of pairs of poles than N that cover only a portion of the circumferential portion. Such a configuration, which is clearly lighter than the fully equipped configuration, can supply less power than that of the fully equipped configuration, but the number of turns of the secondary winding is less than the number of turns required to operate the entire circumferential portion Unlike the situation that would occur in the case of, there is no adverse effect on the continuity of power generation during wheel rotation.

The case shown in FIG. 6 is provided solely for guidance, as it requires a simple and easily read diagram. Indeed, given the size of the rim and space in which the magnets are located, it is desirable to use 2N permanent magnets 66 in a range of 20 to 60 in combination with N windings. This can increase the operating frequency of the system, especially at low wheel rotational speeds, increase the induced magnetic flux and reduce the capacitance, and consequently reduce the size of the capacitor used.

In a further alternative embodiment, the magnet is a permanent magnet 66, one or more of which are supplied with a combination of direct current and alternating current, whereby one is a primary (reference frequency) alternating current. , And two other harmonic components at a frequency equal to n times the reciprocal of the wheel rotation period. This makes it possible for the circuits present in the cover to distinguish between the stationary state of the wheel and the state in which the wheel is moving, and to determine the rotational speed of the wheel very accurately. This is done by inferring the rotational speed of the wheel from the ratio between the two frequencies without having to use a reference frequency as provided by a crystal oscillator. This crystal oscillator is necessary if the same result is required from a permanent magnet or an electromagnet supplied with direct current.

Referring now to FIG. 4, according to the present invention, this is an electronic device 44 for detecting and transferring data which is preferably provided by a current generator according to the present invention.
1 shows a preferred embodiment of the present invention.

The part of the figure surrounded by a broken line corresponds to the conventional highly integrated electronic device 44 shown in FIG. The device comprises electromagnets 36a, 36b,.
n are electrically connected to windings 30a, 30b on bead core 22 that are inductively coupled to windings 39a, 39b,..., 39n in n ferromagnetic cores 38a, 38b,.

These windings 30a-30b are connected to rectifier bridges 50a, 50b,... 50n (via corresponding capacitors 58a, 58b,. The capacitance is determined by the fact that the resonance frequency of the oscillation circuit is
a, 36b,... 36n are set to be tuned to the resonance frequency of the power supply. This power supply is connected to a first filter capacitor 5 (via a resistor, not shown if necessary).
2, the voltage stabilizing circuit 54, and preferably consists of a second filter capacitor 56, thereby caused a continuous supply voltage to the power supply terminal labeled 0V and V _s, the continuous supply voltage, electrons It is used to feed the remaining circuits of device 44.

The electronic device 44 includes sensors 46, 4 in addition to the rectifying bridge 50 and the voltage stabilizing circuit 54 for processing the obtained data and for controlling the transmission protocol.
8 converts the analog signal provided by the analog / digital converter 8 into digital data sent to the microprocessor 62.
A digital (A / D) converter 60 and a wireless transmitter (transmitter) that drives a transmit antenna 67 to send a message to a computer or instrument, for example, a display mounted on the dashboard of the vehicle, or to other devices. Machine) 64.

The circuit in FIG. 4 also uses the extensometers 46, 48 described above connected by a Wheatstone bridge.
including. Preferably, the electronic device 44, the sensors 46, 4
8, capacitors 52, 56, 58 and transmitting antenna 6
7 are trade names Makrolon (registered trademark), Tefl
Mounted on a printed circuit formed from a suitable insulating material, such as those known by On® or Kapton®.

The transmitting antenna 67 is desirably formed by appropriately configuring the printed circuit. Preferably, the printed circuit is glued or otherwise secured to the bead core 22, and more preferably, the filler 26
Is fixed to the radially outer surface of the bead core before it is added to the bead core.

In FIG. 5, a possible physical form of the printed circuit is shown for the case of one secondary winding around a bead core. It is important to know that within the scope of the present invention, many other solutions known per se can be used for data transmission in the field of data transmission without electrochemical contact.

For example, as an alternative to a conventional or direct sequence spread spectrum (DSSS) type wireless transmitter 64, the same magnetic coupling used for power transfer between the primary magnet and the secondary winding It is possible to use a subsystem that sends a stream of digital data over

The transmission modulates, for example, the impedance of the secondary winding so that the coded signal of the parameters of the tire 20 can be transferred to a suitable receiver connected to a display mounted on the dashboard of the vehicle. By doing
Alternatively, it is performed by transmitting an AC signal at a frequency different from the frequency of the primary electromagnet.

The layout of the data sensing and transfer device shown in FIG. 4 shows only one of the possible circuits that can be configured for this purpose,
With knowledge of the present invention, it is not difficult for those skilled in the art to make alternative circuits that can best meet the requirements.

Conventionally, the process of manufacturing a tire, or more precisely, the process of assembling a semi-finished product, involves two successive steps, already known and briefly described below. See, for example, European Patent EP 433,974.

In the first stage, the carcass is in the form of a cylindrical sleeve without belts and tread bands by wrapping the carcass ply on a suitable forming drum, preferably in a rigid and shrinkable form. Prepared. Conventionally, the reinforcing bead core 22 is made separately and desirably is pre-combined with a corresponding filler 26. A pair of such bead cores 22 is attached to the carcass by securing the edges of the ply to the bead core 22, after which the sidewalls 24 of the tire 20 are also attached to the sleeve. In the second stage, the sleeve is shaped into an annulus on a suitable inflatable shaping drum and the belt structure 25 and tread band 2 are preferably separately pre-assembled on a special auxiliary forming drum.
7 is attached to the crown portion of the drum. All the semi-finished products needed to make a green carcass are
It is supplied to the tire building machine by a transport device associated with the machine.

The two stages are performed on the same tire building machine or on two separate machines, one in the first stage and the other in the second stage. For the purposes of the present invention,
Two separate machines are treated as if they formed one tire building machine.

For the purpose of the tire 20 manufacturing process, providing a bead core 22 according to the present invention comprises:
No major modifications are required in the various stages of manufacture described briefly above. In particular, it is possible to modify only the manufacturing stages of the bead core 22 without changing the manufacturing cycle of assembling the various semi-finished products.

In the first case, to manufacture a bead core of the type described in FIGS. 3 and 5, when the bead core 22 was made in a conventional manner, a 0.2 mm diameter enameled copper was used. Two solenoids 30a, 30b of the wire are wrapped around a portion of the bead wire around its transverse profile.

Each solenoid whose adjacent winding has a linear density of 2 turns / mm covers another half of the circumferential portion of the bead core 22. The solenoids 30a, 3 thus made
0b are connected together in series. The ends of the series windings are connected to the electronic device 44 to enable power to the electronic device 44.

The printed circuit including the transmitting antenna 67, the electronic device 44, the sensors 46, 48 and the capacitors 52, 56 and 58 is fixed to the bead core 22 using, for example, an adhesive.

When the formation of the windings and the application of the printed circuit are both completed in a conventional manner, the bead filler 26 is replaced by the bead filler.
Attached to the core 22. In different manufacturing examples, beads
The wire 22 has a breaking load of 1700 MPa or more and 6 ×
It consists of five turns of a billet 19 having a cross section of 0.7 mm. Next, before the conductive wires 30a and 30b are attached, a total of 1.5 mm
Layers of Fe81B145Si3C2 alloy (metallic glass) strips resulting in a cross-section of 30 are arranged along the entire circumference of the bead core at radially outward or inward positions to provide a layer of material with high magnetic permeability 29 are formed in the bead core 22.

The latter alternative is, for example, Kevlar
(Registered trademark) and fibers (yarns) having low magnetic permeability.
It is desirable in any case where the bead core 22 is formed by dings.

Alternatively, instead of winding the amorphous alloy slab, the layer is formed around the bead core in order to avoid the risk of breaking of a continuous layer of material having a low breaking strain, usually less than 3%. It may be divided into a plurality of small blocks glued around the direction part.

For the purposes of the present invention, a conductive element or an element with good mechanical properties, or an element with high or low magnetic permeability, is intended to have physical properties as deemed appropriate by a person skilled in the art. Things.

Preferably, “conductive material” means a material having a conductivity of at least 10 S / cm (Siemens / cm), and “material having good mechanical properties” means a breaking load of at least 500 MPa. And a material having a breaking strain of at least 3%, and a "material having a high magnetic permeability" means a material having a magnetic permeability "maximum" of at least 5000 Gs / Oe.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional perspective view showing a tire mounted on a wheel rim of a motor vehicle including a current generator according to the present invention.

FIG. 2 is a partial view showing an assembly inserted into a bead of a tire.

FIG. 3 is a partial view of a case of a current generator according to the invention (version with two magnets and two windings on a bead wire) in a plane perpendicular to the axis of rotation.

4 is a circuit diagram type part and a block diagram type partial view of a supply current generator and a device for transmitting measured values obtained by detecting tire parameters. FIG.

FIG. 5 shows an example of a possible mechanical form of the entire electronic system mounted on one flexible printed circuit.

FIG. 6 is the same view as FIG. 3, showing an example of an embodiment of the generator in a version in which permanent magnets are provided and therefore can only operate when the wheel is in motion;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Support part 16 Mounting rim 18 Wheel 19 Steel bill 20 Tire 21 Central crown part 22 Bead core 24 Side wall part 25 Belt structure 26 Bead filler 27 Tread band 28 Bead 29 High permeability material layer 30 Conductive wire 34 Magnetic field 36 Electromagnet 38 Core 39 Excitation Winding 44 Electronics 46 Extensometer (Sensor) 48 Extensometer (Sensor) 50 Rectifier Bridge 52 First Filter Capacitor 54 Voltage Stabilizer 56 Second Filter Capacitor 58 Capacitor 60 Analog / Digital (A / D) Converter 64 Wireless transmitter 66 C-shaped permanent magnet 67 Transmitting antenna

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B60C 15/00 B60C 15/00 EA 23/00 23/00 Z

Claims (23)

[Claims] 1. A tire (20) for a vehicle wheel, comprising a bead (28) provided with a reinforcing annular core (22) for fixing the tire (20) to a corresponding mounting rim (16). A) an annular carcass provided with a pair of axially opposed side walls ending with a) and a tread band (27) disposed on the crown of the carcass and extending continuously in the axial direction between the side walls. A tire having at least one of said annular cores (22) comprising at least one turn (30) of conductive wire wound about a transverse profile of said annular core (22), thereby generating electricity. Tire forming a secondary guidance element of the machine. 2. The tire of claim 1 wherein said secondary inductive element is at least one to form said generator.
A tire that can be associated with one primary guide element (36, 66), wherein the primary guide element (36, 66) and the secondary guide element are mutually movable. 3. The tire according to claim 1, wherein said annular core (22) is made of at least one material having a high magnetic permeability.
Tire with two layers. 4. The tire of claim 1 wherein said annular core includes a plurality of blocks of a material having a high magnetic permeability. 5. The tire of claim 1, wherein said annular core (22) is made of steel and comprises either a thermoplastic or thermoset elastomer or an elastomer type matrix, said matrix being a powder. A tire comprising a flexible ferromagnetic material in a form. 6. The tire according to claim 1, including an electronic circuit powered by the secondary inductive element. 7. The tire according to claim 6, wherein the electronic circuit includes means (46, 48) for detecting certain parameters of the tire. 8. The tire according to claim 6, wherein the electronic circuit is fixed to the annular core (22). 9. The tire according to claim 7, wherein said detecting means includes at least one temperature sensor. 10. The tire according to claim 7, wherein said detecting means includes at least one pressure sensor. 11. The tire according to claim 7, wherein said detecting means includes a pair of extensometers (46, 48) arranged in two orthogonal directions to detect deformation of said annular core 22. 12. The tire according to claim 11, wherein the electronic circuit includes data transmission means capable of transmitting the parameter of the tire. 13. A system for detecting a parameter of a physical condition of a vehicle wheel tire mounted on a corresponding mounting rim (16) and outputting a signal to fix the tire (20) to the rim. An annular carcass provided with axially opposed side walls ending with said beads (28) each provided with a reinforcing annular core (22); and a crown portion of said carcass. A tire having a tread band (27) extending continuously in the axial direction between the side wall portions; a device for detecting the parameter of the physical state of the tire; and a power generator for supplying power to the detection device. At least one of said annular cores (22) comprises a small number of conductive wires wound around a transverse profile of said annular core (22). Kutomo by including one winding (30), system characterized in that to form a secondary inductive element of the generator. 14. The sensing system according to claim 13, wherein the secondary inductive element is associated with at least one primary inductive element (36, 66) to form the generator and the primary inductive element (36, 66). 66) and a detection system wherein the secondary guidance element is mutually movable. 15. The sensing system according to claim 14, wherein the primary inductive element includes at least one permanent magnet (66a-66f). 16. The sensing system according to claim 14, wherein the primary inductive element comprises at least one electromagnet (3).
6a, 36b) and the at least one electromagnet (36
a, 36b) a secondary winding (39a, 39b) of at least one conductive wire wound around said transverse profile.
39b), wherein at least one primary winding of the generator is formed. 17. The sensing system according to claim 15, wherein the electromagnets (36a, 36b) are supplied with a direct current. 18. The sensing system according to claim 15, wherein the electromagnets (36a, 36b) are supplied with an alternating current. 19. The detection system according to claim 15, wherein the electromagnets (36a, 36b) are supplied with DC and AC. 20. A method of manufacturing a tire, comprising: a semi-finished product required to form a tire including a pair of ferromagnetic annular elements (22) for securing the tire to a corresponding mounting rim (16). Forming on a preparation machine; said pair of annular cores (22) called annular coil elements
At least one of the at least one first turns of a conductive wire wound around a transverse profile of the toroidal coil core (22), thereby forming a first secondary of the generator. Forming a winding (30); and assembling the semi-finished product on a tire building machine to form a green carcass for the tire including at least one annular coil core (22). Method. 21. The method according to claim 20, wherein the means for sensing certain physical parameters of the tire, supplied from the generator to the toroidal coil core, are fixed. A method for manufacturing a tire, further comprising a step. 22. The tire manufacturing method according to claim 20, wherein, when the one winding is not present, the at least one
A method for manufacturing a tire, wherein the step of arranging a material layer having high magnetic permeability around the periphery of the two annular cores (22) is performed before the step of forming the first secondary winding. 23. A method for generating a current for powering at least one electronic device inside a tire, wherein a variable magnetic field is applied to a winding formed by at least one winding wound around a bead core belonging to the tire. Inducing.