Instrumented method for measuring the internal temperature of a tyre while rolling

Abstract

The present invention relates to an instrumental measuring method for measuring the temperature inside a rubber compound of a civil engineering tyre (20). The method comprises the step of positioning an application zone of sensors (10), each sensor (10) comprising a microprocessor, a radio transmission device, a temperature measuring probe and a power supply device. The sensors (10) are then inserted into cavities (205, 206, 207) in the rubber compound, the sensors remaining in a fixed position during the rolling of the tyre (20) to send the measurements to a remote receiver located in the vehicle.

Description

Instrumental measurement method for measuring the internal temperature of a tire while it is rolling Technical Field

[0001] This invention relates to an instrumental measurement method for tires, used to measure the temperature within the rubber compound of the tire while it is rolling. The tires involved are primarily mounted on civil engineering vehicles used in mining.

[0002] For example, these vehicles (dump trucks or tipper trucks) are used in open-pit mines to transport materials extracted from quarries, and can carry loads exceeding 350 tons. The tires are of appropriate size, with each tire weighing approximately 5 tons.

[0003] For example, the tire involved in this invention is designated 59 / 80R63 according to the standardized designation of ETRTO (European Tyre and Rim Technology Organization), with an inflation pressure of 650 kPa. The outer diameter of a tire mounted on a rim and inflated to 650 kPa can be measured to be over 4 meters. Other diameters ranging from 49 to 57 inches can also be found on these vehicles. Background Technology

[0004] definition

[0005] By convention, in the reference frame (O, t, y, r), the center O coincides with the center of the tire. The circumferential direction (O, t), the axial direction (O, y), and the radial direction (O, r) refer to the directions tangent to the tire tread surface, parallel to the tire's axis of rotation, and orthogonal to the tire's axis of rotation, respectively, in the direction of rotation.

[0006] The inner radial side and the outer radial side represent the closer and farther distances from the tire's axis of rotation, respectively.

[0007] The inner and outer sides of the axial axis represent the distance from the tire's equatorial plane, which is the plane that passes through the middle of the tire's tread and is perpendicular to the tire's axis of rotation.

[0008] Elastomer blends or rubber blends are understood as elastomeric materials obtained by mixing various components. Elastomer blends typically include an elastomeric matrix comprising at least one natural or synthetic rubber-type diene elastomer, at least one carbon black-type and / or silica-type reinforcing filler, a crosslinking system typically sulfur-based, and a protective agent.

[0009] Elastomer blends can be mechanically characterized by their dynamic properties, especially after curing; for example, the dynamic shear modulus G* = (G') 2 +G” 2 ) 1 / 2Where G' is the elastic shear modulus, G” is the viscous shear modulus, and the dynamic loss tanδ = G” / G'. The dynamic shear modulus G* and dynamic loss tanδ were measured on a Metravib VA4000 viscometer according to standard ASTM D5992-96. Measurements were recorded at a given temperature (e.g., 60°C) for a thickness of 4 mm and a cross-section of 400 mm. 2 The cylindrical specimens of the vulcanized elastomer compound were subjected to alternating single sinusoidal shear stress at a frequency of 10 Hz, with strain amplitude sweeps from 0.1% to 50% (forward cycle) and then from 50% to 0.1% (reverse cycle). Therefore, these dynamic properties were measured at a frequency of 10 Hz, a strain equal to 50% of the peak-to-peak strain amplitude, and a temperature that could be 60°C or 100°C.

[0010] Elastomer blends can also be characterized by static mechanical properties. Tensile testing can determine elastic stress and fracture characteristics. Unless otherwise specified, it is performed according to French standard NF T 46-002 of September 1988. The secant modulus, referred to as the “nominal” secant modulus (or apparent stress, in MPa), is measured at 10% elongation (denoted as “MA10”) and 100% elongation (“MA100”) at the second elongation (i.e., after the conditioning period). All these tensile measurements are performed according to French standard NF T 40-101 (December 1979) under standard temperature (23 ± 2 °C) and humidity (50 ± 5% relative humidity). Fracture stress (in MPa) and elongation at break (in %) are also measured at a temperature of 23 °C.

[0011] Typically, a tire includes a tread designed to contact the ground through its surface, with two axial ends of the tread connected to two beaded tires via two sidewalls, the two beaded tires providing a mechanical connection between the tire and a rim intended for mounting.

[0012] The radial tire further includes a reinforcement consisting of a crown reinforcement radially located inside the tread and a carcass reinforcement radially located inside the crown reinforcement.

[0013] Radial tires for heavy-duty civil engineering vehicles typically include at least one carcass layer, which usually comprises a metal reinforcement coated with an elastomeric compound obtained through mixing and referred to as a coating compound. The carcass layer includes the main portion connecting two beads together, and typically within each bead, a retournement is formed by winding a circumferential reinforcing element (usually metal, called a bead wire) from the inside to the outside of the tire. The metal reinforcements of the carcass layers are substantially parallel to each other and form an angle between 85° and 95° with respect to the circumferential direction.

[0014] The crown reinforcement of radial tires for heavy-duty civil engineering vehicles comprises a stack of crown layers that extend circumferentially and are located radially outside the carcass reinforcement. Each crown layer typically includes parallel metal reinforcements and is coated with a rubber compound called a coating compound.

[0015] In the tire crown layer, a distinction is usually made between the protective layer and the working layer. The protective layer constitutes a protective reinforcement and is located radially on the outermost side, while the working layer constitutes a working reinforcement and is located radially between the protective reinforcement and the carcass reinforcement.

[0016] A protective reinforcement, including at least one protective layer, essentially protects the working layer from mechanical or physicochemical attacks that could propagate radially toward the inside of the tire through the tread.

[0017] The protective reinforcement of a GC type tire (e.g., the tire described above) typically comprises two radially stacked protective layers made of elastic metal reinforcements, which are parallel to each other in each layer and cross from one layer to the next, forming an angle of at least 10° and at most 35° with respect to the circumferential direction.

[0018] The working reinforcement, comprising at least two working layers, surrounds the tire and provides it with stiffness and road retention. This working reinforcement absorbs mechanical inflation stresses generated by tire inflation pressure and transmitted by the carcass reinforcement, as well as rolling stresses generated when the tire rolls on the ground and transmitted by the tread. The working reinforcement is also designed to withstand oxidation, impact, and punctures, thanks in particular to its inherent design and the design of the protective reinforcement.

[0019] The working reinforcement typically comprises two radially stacked working layers, each consisting of inextensible metal reinforcements parallel to each other within each layer and intersecting from one layer to the next, forming an angle with the circumferential direction of at most 60°, preferably at least 15° and at most 45°. Here, inextensible metal reinforcement is understood to mean a metal reinforcement characterized by an elongation of at most 0.2% under a tensile force equal to 10% of the breaking force.

[0020] To reduce the mechanical inflation stress transmitted to the working reinforcement, a known practice is to radially install frettage reinforcements on the outer side of the carcass reinforcement. The function of the frettage reinforcement is to at least partially absorb mechanical inflation stress, thereby improving the durability of the tread reinforcement by hardening it. The frettage reinforcement can be radially positioned inside the working reinforcement, between the two working layers of the working reinforcement, or radially positioned on the outer side of the working reinforcement.

[0021] The hoop reinforcement typically comprises two radially stacked hoop layers, each composed of metal reinforcements that are parallel to each other in each layer and intersect from one layer to the next, forming an angle of up to 10° with respect to the circumferential direction.

[0022] Mining involves extracting ore from the earth's crust, that is, rocks containing useful minerals or metals in a proportion high enough to justify the extraction.

[0023] Transportation steps in mining are crucial to its economic viability. Vehicles (dump trucks or tipper trucks) are typically in constant operation to maximize productivity by moving the largest possible volume of crushed stone for mineral processing.

[0024] The fleet's tire management involves using predictive maintenance methods to monitor inflation pressure, temperature, and wear to predict tire-related failures, thereby avoiding vehicle downtime and maximizing usage time.

[0025] Therefore, one of the expectations of customers in the mining industry is the productivity of mining operations, which should not be affected by product defects; thus, tire lifespan should be as long as possible. It is necessary to avoid vehicle downtime, therefore preventative maintenance needs to be developed to control tire usage.

[0026] Real-time monitoring of tire temperature is a crucial step in fleet management. Temperature is directly related to tire durability and lifespan.

[0027] Document FR3060463 proposes a method for estimating the severity of wear conditions of tires mounted on vehicles. One step of this method involves assessing the temperature within the compound, but this assessment is based on a mathematical model that can be complex to implement in some cases.

[0028] Application WO2008046766A1 discloses a method for indicating the degree of tire aging, wherein temperature is locally measured at at least one point on the tire. This method requires the direct installation of a temperature sensor in the tire, which may incur additional costs.

[0029] To obtain temperature measurements within the rubber compound of tires, conventional methods exist, such as using thermocouples. However, these methods require significant intervention to install the thermocouples and perform the measurements. Furthermore, these conventional methods assume the vehicle has been stopped for temperature measurement, thus leading to reduced mining productivity in order to obtain accurate temperature measurements.

[0030] In the context of mining, where profitability is directly related to vehicle travel time, the above method is not suitable.

[0031] There remains a need for a simple, non-destructive, and automated method to obtain the temperature within the rubber compound of a tire while it is rolling, without requiring the vehicle measuring the tire to stop. For real-time temperature measurement, it is essential to be able to pinpoint the areas of the tire most sensitive to heat. This requires consideration of rolling conditions, such as the nature of the ground (whether it is stony, muddy, or asphalt), the tire's internal structure, or the terrain of a mine. Summary of the Invention

[0032] In order to obtain the temperature, the inventor set himself a goal: to find an instrumental method for measuring tires that includes the above conditions.

[0033] The proposed solution is an instrumental measurement method for civil engineering tires used to measure the temperature within the rubber compound in the most heat-sensitive area while the tire is rolling. The method includes the following steps:

[0034] a. Based on predefined selection criteria, at least one area is identified on the outer surface of the tire, and a temperature measurement sensor is designed to be inserted into said at least one area;

[0035] b. Drill a cavity in the at least one insertion region identified in the previous step, the cavity having a depth of Hc in a drilling direction defined by a straight line, the drilling direction forming an angle Alpha between the drilling point and the radial direction of the tire;

[0036] c. Activate the sensor, which is equipped with a microprocessor, a radio transmission device, a temperature measurement detector, and a power supply;

[0037] d. Insert the sensor into the cavity;

[0038] e. Secure the sensor to the bottom and / or sidewall of the cavity using a fixing device;

[0039] f. The cavity is sealed with an airtight seal by a filling device.

[0040] Civil engineering tires consist of a tread designed for contact with the ground. The nature of the ground varies depending on the conditions of use (sometimes muddy, stony, or asphalt). To accommodate various soil types, the tread has cuts, particularly lateral, circumferential, or angled cuts, to define blocks of rubber compound designed to provide sufficient grip to transmit the vehicle's torque regardless of the ground's properties. The rubber compound blocks of the tread also have grooves to form flexible, reinforced groove blades, thereby promoting grip, for example, on snow.

[0041] The first step of an instrumented measurement method for tires involves examining the outer surface of the tire to identify the sensor insertion area. This step, for example, relies on the visual expertise of those skilled in the art when examining the outer surface of the tire to detect the sensor insertion area.

[0042] Preferably, one of the predefined selection criteria for the drilling area used to insert the temperature measurement sensor includes positioning within the tread of the tire intended to contact the ground. Additional criteria can be defined based on factors such as the nature of the ground (whether it is stony, muddy, or asphalt), the internal structure of the tire, or the rolling conditions of the terrain in the mine.

[0043] The rubber compound blocks in the tire tread periodically come into contact with the ground and are subjected to severe stress during rolling. Therefore, the temperature in these high-strain areas is typically very high. To prevent these rubber blocks from spontaneously combusting, it is important to be able to determine their temperature under severe stress. Inserting sensors into these rubber blocks allows for real-time acquisition of their temperature levels.

[0044] This invention also specifies that tire areas located at the lower part of the tire and the rim flange can be measured by instruments. These areas are where the tire has undergone significant bending due to the compression of the load it bears, and these areas are also locations where the temperature has increased due to severe strain.

[0045] After the insertion area is identified, the drilling process is completed using a drill equipped with a directional drill bit. The drilling depth HC depends on the tire's internal structure, such as the number of tread layers and their stepped arrangement. For traceability, the drilling angle Alpha, measured between the drilling direction and the radial direction, is recorded, as it is conceivable that the sensor will be removed from the tire after the testing phase.

[0046] Advantageously, since the sensor has a cylindrical shape, the drilling step can be performed using a drill bit with a diameter at most equal to the diameter of the sensor.

[0047] This is because, in this configuration, when the sensor and the cavity have the same diameter, the sensor is placed into the cavity by natural clamping. Under these conditions, it is easier to keep the sensor in a fixed position.

[0048] Before inserting the sensor, activate it by disconnecting the activation wires connected to the sensor's electrodes. Then, connect the electronic circuit board and activate the communication device. Measure the temperature and average it over the time interval between two transmissions.

[0049] After drilling, the cavity is precisely cleaned by removing the rubber residue left by the drilling operation, and each sensor is fixed to the bottom and / or sidewall of the cavity.

[0050] Preferably, the sensor is fixed to the bottom and / or sidewall of the cavity by gluing.

[0051] More preferably, the bonding is performed using a cold vulcanizing adhesive, and the curing time of the bond is at least 24 hours.

[0052] Cold vulcanizing adhesives are understood to refer to adhesives that induce a chemical reaction, including the addition of a vulcanizing agent (usually sulfur) to an unprocessed elastomer to form bridges between molecular chains. This process typically reduces the material's plasticity but enhances its elasticity.

[0053] The inventors have observed that, in the context of this invention, the use of this adhesive enables a high-quality bond between the sensor and the rubber compound of the cavity.

[0054] A preferred example of an adhesive is the one sold by Tiptop under the adhesive name "bluecement".

[0055] A 24-hour curing time ensures a sufficient level of adhesion to the rubber compound, securing the sensor firmly in place. Therefore, the sensor, bonded to the rubber compound, will not move as the tire rolls.

[0056] Advantageously, the sensor is inserted into a cavity drilled in the tire and is coupled with a device for venting air present in the cavity.

[0057] When the sensor is placed into the cavity, a certain amount of air is created between the bottom of the cavity and the first entry surface of the sensor. This amount of air prevents the sensor from entering the cavity. An air venting device must be used simultaneously with sensor insertion.

[0058] In one embodiment of the invention, the means for discharging air from the cavity while inserting the sensor includes a hollow cylindrical tube formed in the sensor, such that while the sensor is inserted into the cavity, air is discharged through the hollow tube due to the compression of a certain amount of air between the first bottoms of the sensor facing the bottom of the cavity.

[0059] Once each sensor is properly secured in the cavity, in contact with the bottom and side walls, there is an empty three-dimensional space radially outside the sensor within the cavity. To protect the sensor, it is necessary to fill this empty space. To protect the sensor and ensure a good seal, a filling device fills this empty three-dimensional space using a filling material.

[0060] Advantageously, the device for filling the cavity drilled in the tire includes a blockage fixed to the sidewall of the cavity by adhesive bonding.

[0061] Preferably, the device for filling the cavity drilled in the tire is used in conjunction with a device for venting air present in the cavity.

[0062] A similar device for venting air from a cavity as described above for inserting a sensor into a cavity can then be used to insert the filling device.

[0063] Advantageously, the device for filling the cavity drilled in the tire includes a plug made of the same rubber compound as the rubber compound forming the sidewalls of the cavity.

[0064] The use of the same compound bonded with cold vulcanizing adhesive promoted the adhesion of the two supports and resulted in better fixation.

[0065] In order to obtain temperature measurement results in the entire three-dimensional space of the tire, it is advantageous to position the first sensor along the circumferential direction at a first distribution spacing, and / or position the second sensor along the axial direction at a second distribution spacing.

[0066] Temperature measurement operations can continue for 10 to 15 days. Another aspect of the invention is the ability to recover the sensor after the testing phase. To this end, the invention also proposes a method for recovering a sensor after a tire has rolled, the sensor having been inserted into a civil engineering tire according to the instrumentation method described above, the method for recovering the sensor comprising the following steps:

[0067] i. Identify the sensor insertion area on the outer surface of the tire;

[0068] ii. Remove the filling device;

[0069] iii. Eliminate the fixation of the sensor to the bottom and / or sidewalls of the cavity;

[0070] iv. Remove the sensor;

[0071] v. to fill a cavity.

[0072] Gradual wear of the tire tread can cause the sensor to pop out into the environment. To avoid this contamination, the sensor is recycled, and some of its unmodified components are reused.

[0073] Advantageously, the step of recovering the sensor after the tire has rolled includes the step of dissolving the fixing adhesive and the apparatus.

[0074] For example, if the device used to fill the cavity is an adhesive blockage as described above, the blockage glued to the cavity must first be removed in order to remove the sensor. A dissolving solvent can break the adhesive bond between the blockage and the cavity. The blockage can be removed using a tool in the form of a bottle opener. To remove the sensor, a dissolving solvent is also needed to break the adhesive bond between the sensor and the surface of the cavity. Then, a device comprising a hollow tube is used, which passes through the sensor along the maximum length direction of the cavity. Advantageously, the sensor recovery step includes a compressed air injection device for purging the sensor. The injection of compressed air into the hollow tube is accompanied by the purging of the sensor from the tire.

[0075] Removing the obstruction and then the sensor can damage the tire. Advantageously, the method for recovering the sensor includes a step of repairing the tire after removing the obstruction and the sensor from the cavity.

[0076] The repair steps include, for example, filling all cavities with rubber plugs in a manner similar to those used in the instrument measurement methods described above. Each cavity is pre-cleaned to remove any remaining rubber compound.

[0077] The present invention also relates to a tire having a sensor for measuring the internal temperature of a rubber compound, the sensor being installed according to the method described above for instrumental measurement of a civil engineering tire. Attached Figure Description

[0078] The invention will be better understood by reading the following description, which is given by way of non-limiting example only, and with reference to Figures 1-A, 1-B, 2, 3-A to 3-D, 4-A to 4-D, and 5, wherein:

[0079] Figures 1-A and 1-B illustrate schematic diagrams of the sensor for the temperature measurement system proposed in this invention;

[0080] Figure 2 shows the radial plane (y, r) of the tire. That is, the three-dimensional tire generation plane is generated by rotating this radial plane around the axis (O, y) of the cylindrical reference system (O, t, y, r) associated with the tire.

[0081] Figures 3-A to 3-D illustrate the different steps used to insert sensors and plugs into cavities cut out of the rubber compound in a tire.

[0082] Figures 4-A to 4-D illustrate the steps for removing the sensor and obstruction from a cavity hollowed out of the rubber compound of the tire;

[0083] Figure 5 illustrates a curve showing a comparison between temperature measurement results obtained using conventional methods with thermocouples and the instrument measurement method of the present invention. Detailed Implementation

[0084] Figure 1-A shows a sensor 10 with a cylindrical geometry, a length of LC, and a diameter of PHI, and an activation line 12 with a length of LF. A perspective view of the sensor 10 can be seen in Figure 1-B. The sensor 10 is designed to be inserted into the tire 20 of Figure 2. Reference numeral A in Figure 1-A indicates a groove, which is a series of recesses and protrusions along the longest direction of the sensor, designed to facilitate easier attachment of the sensor to the rubber compound of the tire 20.

[0085] Tire 20 is mounted on a vehicle equipped with a device for communicating with the sensor.

[0086] The reading device located in the vehicle stores data in a database accessible by a remote server. Sensor 10 includes an electronic circuit board with circuitry connecting components such as a temperature measuring detector, a microprocessor, a radio transmitter, and a battery.

[0087] When the sensor is activated before being inserted into the rubber compound, the activation line 12 is cut off at the end that contacts the sensor.

[0088] Tire 20 has a tread 201, represented by a three-dimensional portion including black dots on the outermost radial side of the tire. The crown reinforcement 210 consists of radially outwardly stacked working reinforcements 211, protective reinforcements 212, and clamp reinforcements 213. Each reinforcement comprises two layers of reinforcement coated with a rubber compound. Finally, in this example, the crown reinforcement comprises six radially stacked crown layers, each composed of reinforcement coated with a rubber compound. Radially inner of the crown reinforcement 210 is a carcass reinforcement 220, which includes at least one carcass layer composed of brin allers 217 axially surrounding the bead wire 218 from the inside to the outside of the bead and extending radially outward through brin retours 216. The reinforcements of the carcass layers form an angle of approximately 90° with the circumferential direction.

[0089] This structure optimizes tire durability to withstand the required load, but its drawback is that it is sensitive to temperature, which can catalyze tire cracking and damage, especially at the ends of the tread layer.

[0090] Still in Figure 2, cavities 205, oriented from the outer circumference of the tire to the ends of the crown layer in the rubber compound, and cavities 206 at the center of the tread are hollowed out to accommodate the respective temperature measuring sensors 10. The invention also applies to cavities 207 located further inward radially, where the angle Alpha formed by the drilling direction and the radial direction, and the cavity depth HC, can be visualized. For cavities 205 and 206, the drilling direction is parallel to the radial direction, therefore the angle Alpha is zero. In this example, each sensor 10 has a length of 45 mm and a diameter of 17 mm, thus occupying a relatively small three-dimensional space relative to the size of the tire. This is because it is essential to be able to remove each sensor without damaging the tire.

[0091] Figures 3-A to 3-D illustrate the different steps involved in inserting the sensor and the plug into a cavity hollowed out of the rubber compound in the tire:

[0092] i. In Figure 3-A, a rubber compound block 208 including a cavity 205 filled with air 16 can be seen. A sensor 10 is placed into the cavity 205. The sensor 10 includes a hollow tube 14 extending through its entire length. The outer surface of the sensor 10, intended to contact the sidewalls of the cavity, is coated with an adhesive layer 13. When the sensor 10 is placed into the cavity 205, air 16 is expelled through the hollow tube 14 in the direction of arrow 161;

[0093] ii. In Figure 3-B, the sensor is fixed to the bottom and sidewalls of cavity 205. Since the depth of the cavity is greater than the length of the sensor, the remaining three-dimensional space up to the outer surface of the tire remains empty. A filling device must be used to protect the sensor;

[0094] iii. In Figure 3-C, a blockage 15, including a hollow tube 14 and surrounded by adhesive 13, is inserted into the cavity after the sensor. The air venting device is the same as that used for inserting the sensor into the cavity, and air flows through the hollow tube 14 in the direction indicated by arrow 161;

[0095] iv. In Figure 3-D, sensor 10 and plug 15 are mounted. The sensor is hermetically sealed in the cavity and protected by the plug, which is made of the same rubber compound as the cavity.

[0096] Figures 4-A to 4-D illustrate the different steps for removing obstructions and sensors from the cavities hollowed out of the tire's rubber compound:

[0097] i. In Figure 4-A, a rubber compound block 208 comprising a cavity 205 can be seen. The cavity contains a sensor 10, which is bonded to the sidewalls and bottom of the cavity using an adhesive layer 13. The sensor 10 is protected by a plug 15. A dissolving solvent 18 can also be seen on both sides of the surface of the plug, which contacts the sidewalls of the cavity 205. The solvent disrupts the bond between the surface of the plug and the sidewalls of the cavity 205. Therefore, the plug 15 can be removed using a tool 17 in the form of a bottle opener;

[0098] ii. In Figure 4-B, the blockage is removed, but solvent continues to be poured between the sensor surface and the cavity surface to separate it. For this purpose, a hollow tube 19 is used, which runs through the entire length of the sensor to the bottom of the cavity.

[0099] iii. In Figure 4-C, compressed air, as indicated by arrow 161, is injected into the tube 19 formed in sensor 10, which has been separated from cavity 205 by the action of a solvent. Compressed air is injected in the direction of arrow 161;

[0100] iv. In Figure 4-D, compressed air causes sensor 10 to rise to the surface and is expelled from the cavity.

[0101] This invention has been implemented on a tire of size 59 / 80R63, specified by ETRTO (European Tyre and Rim Technology Organization) standards, mounted on a dump truck type vehicle. The test tire was inflated to 650 kPa.

[0102] The dump truck is equipped with tires of the aforementioned size on its front axle. The load capacity on the front axle is 63 tons.

[0103] Sensors were positioned to measure the temperature of the tread layer near the tire shoulder in cavity 205 and the temperature of the tire center in cavity 206. These areas were identified as the most temperature-sensitive regions through digital simulations that took into account tire usage (particularly in mining operations). Testing lasted for over 10 days.

[0104] The sensor comprises an electronic circuit board equipped with a temperature measuring detector and a radio transmitter, which can be interrogated by a reader located in the vehicle. The temperature detector, radio transmitter, and reader are commercially available conventional reference devices. The data transmission cycle from the sensor to the vehicle is five minutes.

[0105] Figure 5 shows a comparison between the temperature measured by the thermocouple (curve C2, represented by the dashed line) and the temperature measured by the device of the present invention (curve C1, represented by the solid line). The horizontal axis represents rolling time, and the vertical axis represents the measured temperature value. This result was obtained by adding thermocouples to the tire of the present invention for comparative testing on a suitable machine under the same stress load conditions. The results of temperature measurements using thermocouples and the device according to the present invention are sufficiently close to confirm the significance of the invention.

[0106] The advantage of this invention is that it allows for easy and automatic acquisition of the temperature level of rubber compound without negatively impacting mining productivity as with conventional methods (e.g., using thermocouples). This is because the temperature measurement method proposed in this invention does not require vehicle stopping and involves limited human intervention.

[0107] These results support the measuring device, the method of inserting the measuring device, the device for holding the sensor in a fixed position, and the device for transmitting the measured temperature value.

[0108] A first example of applying the results of this invention is adjusting tire usage conditions in real time based on average temperature levels. Warning devices can be installed to notify the driver when temperatures reach excessively high levels.

[0109] The principles of the invention can be extended to other types of tires besides those described herein, particularly heavy-duty tires, and more generally, tires with a radial thickness extending to the tread sufficient to implement the invention.

Claims

1. An instrumental method for measuring the temperature within the rubber compound of a civil engineering tire, comprising the following steps: a. Based on predefined selection criteria, at least one region is identified on the outer surface of the tire, and a temperature measurement sensor is designed to be inserted into said at least one region; b. Drill a cavity in the at least one region identified in the previous step, the cavity having a depth of Hc in a drilling direction defined by a straight line, the drilling direction forming an angle Alpha between the drilling point and the radial direction of the tire; c. Activate the temperature measurement sensor, the temperature measurement sensor being equipped with a microprocessor, a radio transmission device, a temperature measurement detector, and a power supply. d. Insert the sensor into the cavity drilled in the tire using a device for venting air from the cavity; e. Secure the sensor to the bottom and / or sidewall of the cavity using a fixing device; f. Seal the cavity with an airtight seal using a filling device.

2. The instrument measurement method for measuring the temperature within the rubber compound of a civil engineering tire according to the preceding claim, characterized in that, One of the predefined selection criteria for the drilling area used to insert the temperature measurement sensor includes positioning it in the tread of the tire, which is designed to make contact with the ground.

3. The instrument measurement method for measuring the temperature within the rubber compound of a civil engineering tire according to claim 1, wherein the sensor has a cylindrical shape, characterized in that... The drilling step is performed using a drill bit with a diameter at most equal to that of the sensor.

4. The instrument measurement method for the tire used to measure the temperature within the rubber compound of a civil engineering tire according to claim 1, characterized in that, The sensor is fixed to the bottom and / or sidewall of the cavity by gluing.

5. The instrument measurement method for the tire used to measure the temperature within the rubber compound of a civil engineering tire according to claim 4, characterized in that, The bonding is performed using cold vulcanizing adhesives.

6. The instrument measurement method for the tire used to measure the temperature within the rubber compound of a civil engineering tire according to claim 5, characterized in that, The curing time of the adhesive is at least 24 hours.

7. The instrumental measurement method for measuring the temperature within the rubber compound of a civil engineering tire according to any one of the preceding claims, characterized in that, The filling device includes a plug that is glued to the inner surface of the sidewall of the cavity.

8. The instrument measurement method for the tire used to measure the temperature within the rubber compound of a civil engineering tire according to claim 1, characterized in that, The insertion of the filling device cooperates with a device for venting air present in the cavity.

9. The instrument measurement method for the tire used to measure the temperature within the rubber compound of a civil engineering tire according to claim 1, characterized in that, The filling device includes a plug made of the same rubber compound as the rubber compound forming the sidewalls of the cavity.

10. The instrumental measurement method for the tire used to measure the temperature within the rubber compound of a civil engineering tire according to claim 1, wherein, The first sensor is positioned along the circumferential direction with a first distribution spacing, and / or the second sensor is positioned along the axial direction with a second distribution spacing.

Images