Device and method for testing tires under imposed stress in a cold and controlled environment

Abstract

The present invention relates to a testing machine (100) comprising a self-supporting frame (1), a first and second rotation hub (2, 3), an adjustment system (5) for the support force F between a first and second tire (10, 11), and at least one motor (4) for easily and quickly rotating and monitoring parameters such as the fatigue limit or the rolling resistance of said first and second tires (10, 11). The present invention also relates to a testing device for use in a cold and controlled environment (200) and a method for implementing the testing machine (100) in a thermal vacuum chamber (20). Figure 6

Description

Title of the invention: Device and method for testing tires under imposed stress in a cold and controlled environment

[0001] The present invention relates to a tire testing machine and, in particular, a tire testing machine placed in a cold environment and under a controlled atmosphere, typically in an environment with a temperature that can go down to 40 K and in an atmosphere that can go up to a vacuum.

[0002] Conventional tire testing machines, also called "testing machines" or "rollers", allow the measurement of various parameters characterizing tires such as, for example, rolling resistance, uniformity or fatigue resistance also known as "endurance limit".

[0003] As is known, these control machines mainly comprise, on the one hand, a rotating axis intended to support a tire and, on the other hand, a cylindrical flywheel including an outer or inner track, intended to be in contact with the tire. A drive system, most often an electric or hydraulic motor, allows the cylindrical flywheel to be rotated at one or more predetermined rotational speeds. A system for moving the tire's rotating axis allows the tire to be brought into contact with the outer or inner track of the cylindrical flywheel, according to an imposed force or displacement, the contact also producing, by a driving effect, the rotation of the said tire.A sensor tracks and records the number of rotations made by the tire until the end of the test, and in some cases, other sensors track and record parameters such as tire temperature, rolling resistance, or the pressure exerted by the tire on the flywheel. These machines have the drawback of not being representative of real-world tire operating conditions, particularly due to the curvature of the cylindrical flywheel, which produces greater stress on the tire and can lead to inaccurate estimation of the tested parameters.

[0004] Other types of machines exist, such as those described in US patent application 4238954A, in which the cylindrical flywheel is replaced by a flexible band set in motion along a predetermined closed circuit. Generally, the tire to be tested is brought into contact with the flexible band in a flat portion of the closed circuit. Generally, the tire to be tested is brought into contact with the flexible band in a flat portion of the closed circuit. of the flexible belt. In order to control the pressure exerted by the tire on the flexible belt and to limit the deflection of the flexible belt in the flat section, supports, such as friction plates or rotating supports, are placed beneath the flexible belt. As with flywheel-type testing machines, this type of machine is complex, often bulky, and requires a significant amount of space for installation.

[0005] Patent CN107121298B discloses an example of an endurance testing machine that does not rotate the tire under test. Such a machine performs only cyclic loading by means of a translational mechanism, pressing the tire against a plate at a predetermined frequency and with a predetermined loading force. Again, this type of testing mechanism is not representative of driving under real-world conditions and requires significant testing times to reach the final point of tire deterioration. Furthermore, as with the other types of testing machines mentioned previously, these translational loading testing machines are bulky and difficult to transport.

[0006] Testing machines can also be used to test airless tires in cold environments where the temperature can drop well below 0°C. Airless tires are unique in that they carry the load using structural elements that form a carcass and have performance comparable to that of a conventional tire subjected to the internal pressure of a gas, usually air. Airless tires can be used for specific applications such as, for example, on vehicles that must withstand conditions of intense cold, typically down to temperatures of 40 K. Such temperatures may be encountered by vehicles, typically lunar rovers, sent into outer space.

[0007] Thus, the need arose to control the proper performance of tires, in particular airless tires, subjected to mechanical stresses combined with very cold environments.

[0008] In order to reproduce the atmosphere of extreme cold and the conditions encountered in outer space, it is possible to use a thermal vacuum chamber (in English Thermal Vacuum Chamber or TVAC), which allows control of the temperature, pressure and gas content of the interior space of said thermal vacuum chamber.

[0009] Such thermal vacuum chambers typically make it possible to achieve a vacuum and temperatures on the order of 40 K. It is known that increasing the size of thermal vacuum chambers leads, on the one hand, to an increase in costs, both in terms of purchase and use, and, on the other hand, to an increase in difficulties techniques to maintain the cold atmosphere and vacuum in the interior space. Also, the installation in a thermal vacuum chamber of control machines as usually known, i.e. bulky and difficult to transport, is industrially complex.

[0010] The object of the present invention is therefore to propose a pneumatic control machine, representative of real conditions of use, of small size, easy to transport and to implement in a small thermal vacuum chamber.

[0011] The objects assigned to the invention are reached by means of a control machine, intended to simultaneously control a first and a second identical pneumatic, characterized in that it comprises: -a self-supporting chassis comprising an interface means for placing said self-supporting chassis on a flat surface, - a first rotation hub connected to the self-supporting chassis by a pivot joint with axis of rotation XX', said first rotation hub being intended to receive, in a removable manner, a first rim on which the first tire is mounted, said first rim being mounted concentrically to the axis of rotation XX', - a second rotation hub connected to the self-supporting chassis by a pivot joint with axis of rotation YY' parallel to the axis of rotation XX', said axis of rotation YY' being distant from the axis of rotation XX' by a center distance E, along a direction parallel to a segment ZZ' perpendicular to the respective axes of rotation XX', YY' and passing through said respective axes of rotation XX', YY', said second rotation hub being intended to receive in a removable manner a second rim on which a second tire is mounted, said second rim being mounted concentrically to the axis of rotation YY',said second rotation hub being positioned such that an axially medial plane to the first tire is coplanar with an axially medial plane to the second tire, -at least one motor driving the first or second rotating hub, -a system for adjusting a support force F allowing the first tread of the first tire to be pressed against a second tread of the second tire in order to obtain a flat contact surface between the first and second tires, -at least one force sensor to determine the contact force F of the first tire on the second tire, -at least one rotation sensor enabling the determination of the number of rotations performed by the first and second tires during the control of said first and second tires, -a rolling resistance sensor to determine the evolution of the rolling resistance of the first and second tires, - a center distance sensor E allowing to follow the evolution of the center distance value E, - electrical connectors intended to transmit electrical energy to at least one motor, the adjustment system, at least one force sensor, at least one rotation sensor, the rolling resistance sensor and the center distance sensor E.

[0012] Essentially, the invention provides a simple, compact, lightweight, and easy-to-install testing machine for use in a thermal vacuum chamber. In particular, the presence of at least one rotation sensor allows for monitoring the endurance of the first and second tires by recording the number of rotations completed before potential failure. Furthermore, the testing machine allows for the simultaneous testing of two tires, which is particularly advantageous when a large series of tires needs to be inspected.

[0013] The presence of a rolling resistance sensor associated with at least one force sensor, at least one rotation sensor and the center distance sensor E makes it possible to obtain a versatile control machine capable of carrying out several kinds of controls simultaneously, in a simple and economical way.

[0014] In some embodiments, a projection system positions an interface body between the first tread and the second tread, allowing the wear of the first and second tires to be accelerated during the inspection.

[0015] The presence of the projection system of an interface body allows the control machine to simultaneously test the endurance and wear resistance of the first and second tires in a simple and economical way.

[0016] In a preferred embodiment, at least one force sensor is integrated into one of the first or second rotation hubs, thus maintaining compactness while having a means of monitoring the evolution of the support force F of the first tire on the second tire.

[0017] In a preferred embodiment, the interface means includes a clamping system allowing the self-supporting chassis to be removably fixed to the flat surface.

[0018] The clamping system makes it possible to immobilize and prevent unintentional movements of the control machine during the control while allowing quick and easy placement and removal of said control machine from the flat surface.

[0019] Preferably, the self-supporting chassis is a telescopic self-supporting chassis along at least two directions XI and Y1 perpendicular to each other and perpendicular to the respective axes of rotation XX', YY', the direction XI being a direction parallel to the segment ZZ'.

[0020] The use of a telescopic self-supporting chassis allows the dimensions of the self-supporting chassis to be adapted to the dimensions of the first and second tires which can be of variable diameter and width.

[0021] Advantageously, the first and second rotation hubs are positioned and oriented so as to obtain, in any plane parallel to a plane X1Z1 passing through the respective rotation axes XX', YY', a projection of the external dimensions of the first and second tires contained within the projection, in any plane X1Z1, of the external dimensions of the self-supporting chassis. Such a positioning of the first and second hubs makes it possible to obtain a very limited overall footprint for the testing machine, even when the first and second tires are mounted on the endurance testing machine.

[0022] Advantageously, at least one motor is integrated into one of the first or second rims, making it possible to avoid having at least one motor protruding from the first or second rims, thus ensuring better compactness of the endurance control machine.

[0023] Advantageously, the support force adjustment system F is an automatic linear displacement system cooperating with the force sensor and comprising an electric actuator for displacing, along a displacement axis corresponding to segment ZZ', at least the first or second rotation hub. The use of an automatic support force adjustment system F makes it possible to maintain the support force F throughout the entire control period.

[0024] In a particular embodiment, the rotation axes XX' and YY' of the first and second rotation hubs, respectively, are horizontal, the segment ZZ' is substantially vertical, the rotation axis YY' is located above the rotation axis XX', the adjustment system includes a guiding means, along a direction parallel to the segment ZZ', of a moving assembly comprising the first rotation hub, the first rim, and the first tire, and the support force F corresponds to the weight of the moving assembly. Preferably, in this particular embodiment, additional weights or counterweights are added to the weight of the moving assembly to adjust the support force F.Using the weight of the moving assembly alone, or the weight of the moving assembly with weights or counterweights, allows the first tread of the first tire to be pressed against the second tread of the second tire with a simple pressure force adjustment system F, without additional energy.

[0025] The invention also relates to a control device for use in a cold and controlled environment, intended to simultaneously control first and second tires in a cold and controlled atmosphere environment, said control device for use in a cold and controlled environment comprising: -a thermal vacuum chamber comprising, on the one hand, a sealed enclosure including sealed panels, an access door and a flat surface, and, on the other hand, a control system allowing the temperature and atmosphere inside said sealed enclosure to be controlled, -the control machine for the various embodiments described above, intended to be placed, in a removable manner, on the flat surface of the sealed enclosure of the thermal vacuum chamber, -Additional electrical connectors designed to cooperate removably with the electrical connectors of the control machine, - a tracking and recording system cooperating with at least one rotation sensor, at least one force sensor, the rolling resistance sensor and the center distance sensor E in order to track and record the number of rotations made by the first and second tires, the support force F of the first tire on the second tire, the rolling resistance of said first and second tires and the value of the center distance E.

[0026] Essentially, the control device in a cold and controlled environment allows the previously described control machine to be implemented in a small thermal vacuum chamber, thus limiting the manufacturing and operating costs of said thermal vacuum chamber, and consequently, the costs of implementing the control machine in a cold environment. Furthermore, the possibility of installing the control machine in a removable manner within the thermal vacuum chamber facilitates the use of existing thermal vacuum chambers where the modifications required for installing the control machine are minimal, thus allowing the thermal vacuum chamber to be used for other applications.Furthermore, the additional electrical connectors designed to cooperate removably with the electrical connectors allow for quick and easy installation and removal of the control machine while ensuring the power supply to the various electrical sensors and actuators.

[0027] Advantageously, a complementary clamping system cooperates with the clamping system to removably fix the control machine, thus preventing any untimely movement of said control machine during the performance of the endurance test, while ensuring quick and easy placement and removal of said control machine in the sealed enclosure of the thermal vacuum chamber.

[0028] The invention also relates to a method for checking the first and second tires in a cold and controlled environment, implementing the cold and controlled environment control device defined above and comprising the following steps: -Installation of the first and second tires to be tested on the testing machine, -Cooperation of the support force adjustment system F with the force sensor in order to adjust the support force F to obtain and maintain a target support force value Fl, allowing the first tread of the first tire to be placed in contact with the second tread of the second tire in such a way as to obtain a flat contact surface, -installation of the control machine within the sealed enclosure of the thermal vacuum chamber, -Electrical connection of the control machine by connecting the electrical connectors with the complementary electrical connectors, -activation of the control system to change the temperature and gas content of the atmosphere inside the sealed enclosure towards a predetermined temperature T and a predetermined gas content G respectively, -during the evolution of the temperature and gas content inside the sealed enclosure, activation of at least one motor to rotate the first and second pneumatics at a speed VI, -when the temperature and gas content inside the sealed enclosure have reached temperature T and gas content G respectively, activation of at least one motor to rotate the first and second pneumatics at a speed V2, -monitoring and recording, by the tracking and recording system, of the values ​​transmitted by the rolling resistance sensor, by at least one force sensor and by the center distance sensor E, and when the measured center distance E falls below a predetermined threshold S, recording of the number of rotations performed by the first and second pneumatics and deactivation of at least one motor to stop the rotation of said first and second pneumatics, -electrical disconnection of the control machine by disconnecting the electrical connectors from the supplementary electrical connectors, -removal of the control machine from the sealed enclosure of the thermal vacuum chamber.

[0029] Essentially, the method of the invention makes it possible to perform control tests of the first and second tires in a cold and controlled environment simply and quickly, with a limited number of steps and without unnecessary time loss. The use of the support force adjustment system F makes it possible to adjust the target support force Fl value even when the temperature and gas content have reached temperature T and gas content G, respectively, thus correcting any drift in said support force F due to temperature variations inside the sealed chamber. In particular, for airless tires made mostly of materials such as thermoplastics, it is known that the rigidity of the thermoplastic, and therefore of the airless tire, varies with temperature, consequently requiring an adjustment of the support force F when the temperature of said airless tire has changed.

[0030] Preferably, the temperature T is at least equal to 40 K and at most equal to 373 K, and even more preferably at most equal to 213 K, thus allowing control to be carried out at temperatures corresponding to the temperatures encountered in outer space.

[0031] Advantageously, the speed V1 is at least equal to one revolution per minute and at most equal to five revolutions per minute. Rotating the first and second tires during the temperature and gas content evolution phase inside the sealed enclosure prevents seizing of moving parts such as bearings or bushings, such seizing being due to rapid and non-uniform contractions or expansions of the different materials constituting the various moving parts.

[0032] Preferably, the speed V2 is variable and is at least equal to 6 revolutions per minute and at most equal to 700 revolutions per minute, and, even more preferably, at least equal to 100 revolutions per minute and at most equal to 350 revolutions per minute. The variable speed V2 is preferably greater than the maximum rotational speed of the tires in use on a vehicle so as to reduce the time required for tire inspection.

[0033] Advantageously, the target support force Fl is at least equal to 100N and at most equal to 5000N, thus allowing a deformation of the first and second treads of the first and second tires until a flat contact surface is obtained, representative of the use of the first and second tires mounted on a vehicle rolling on a ground and with a target support force Fl representative of the weight exerted by said vehicle on said first and second tires.

[0034] Advantageously, the threshold S is at least equal to 70% and at most equal to 95% of the value of the average center distance E measured on at least the first revolution made by the first and second tires during the rotation of said first and second tires at a speed V2.

[0035] When the first or second tire reaches the limit of its endurance, a degradation of the first and / or second tire is often observed, resulting in a rapid decrease in the stiffness of the first and / or second tire and therefore a reduction in the center distance E. The use of a threshold S below which the cold control is stopped therefore makes it possible to match the cessation of the control with a deterioration of the first and / or second tire.

[0036] Preferably, the first and second tires tested are airless tires.

[0037] Other objects, features and advantages of the invention will become apparent in more detail from the following description and with the aid of the accompanying drawings, which are provided by way of illustration only and are not intended to be limiting, among which: -[Fig.l]: Perspective view of a control machine according to the invention placed on a flat surface with the first and second tires to be tested. -[Fig.2]: Side view of a control machine according to the invention placed on a flat surface without the first and second tires to be tested. -[Fig.3]: Perspective view and with a sealed panel removed from a control device in a cold and controlled environment according to the invention. -[Fig.4]: Perspective view of a particular embodiment of the control machine according to the invention. -[Fig.5]: Perspective view of an embodiment of the control machine according to the invention with the first and second hubs having horizontal axes of rotation XX' and YY' and with a support force adjustment system F comprising an automatic linear displacement system. -[Fig.6]: Perspective view of an embodiment of the control machine of the invention with the first and second hubs having horizontal axes of rotation XX' and YY' and with a support force adjustment system F comprising additional weights.

[0038] In what follows, for the sake of clarity, the horizontal direction and the vertical direction correspond to the natural orientation of figures 1 to 9. Similarly, the terms "top", "bottom", "lower", "upper" and their variants should be understood with reference to the vertical direction of the figures.

[0039] As can be seen in [Fig.1], the present invention relates to a control machine 100, intended to simultaneously control a first and second identical pneumatic 10, 11, characterized in that it comprises a self-supporting chassis 1 including an interface means 13 allowing said self-supporting chassis 1 to be placed on a flat surface 12.

[0040] By self-supporting chassis 1, it is necessary to understand a chassis sufficiently rigid to be able to be moved by conventional lifting means, such as forklift trucks or mobile workshop cranes, without risking harmful and irreversible deformations of said self-supporting chassis 1.

[0041] By way of example, the self-supporting chassis 1 can be made from a welded, bolted, glued, or riveted tubular aluminum structure. Other types of aluminum structures, such as rigid, solid, or honeycomb panels, can also be used.

[0042] Preferably, the structural elements, such as tubes, panels or any other type of element, do not have a material thickness exceeding 20mm, so as to reduce the weight and thermal inertia of the self-supporting chassis 1. As an example, for tires with an outside diameter of 880mm, the weight of the control machine 100, made mainly of aluminum tubes, sheets and plates, does not exceed 400kg.

[0043] The interface means 13 may include, for example, at least three feet, adjustable or not, allowing the self-supporting chassis 1 to be placed stably on a flat surface 12, which may be the upper surface of a workshop floor or the upper surface of a floor of an enclosed space.

[0044] In a preferred embodiment, the interface means 13 includes a clamping system 25 allowing the self-supporting chassis 1 to be removably fixed to the flat surface 12.

[0045] As further illustrated by [Fig. 1], the control machine 100 also comprises: -a first rotation hub 2 connected to the self-supporting chassis 1 by a pivot joint with axis of rotation XX', said first rotation hub 2 being intended to receive, in a removable manner, a first rim 14 on which the first tire 10 is mounted, said first rim 14 being mounted concentrically to the axis of rotation XX', -a second rotation hub 3 connected to the self-supporting chassis 1 by a pivot joint with axis of rotation YY' parallel to the axis of rotation XX', said axis of rotation YY' being distant from the axis of rotation XX' by a center distance E, along a direction parallel to a segment ZZ' perpendicular to the respective axes of rotation XX', YY' and passing through said respective axes of rotation XX', YY', said second rotation hub 3 being intended to receive, in a removable manner, a second rim 15 on which a second tire 11 is mounted, said second rim 15 being mounted concentrically to the axis of rotation YY', said second rotation hub 3 being positioned so that an axially median plane to the first tire 10 is coplanar with an axially median plane to the second tire 11.

[0046] Preferably, and as can be seen in [Fig.1] and [Fig.5], the rotation axes XX' and YY' are oriented horizontally or vertically in order to obtain a control machine 100 having a general parallelepiped shape that is easier to position in a workshop or enclosed space.

[0047] In a known manner, the pivot links, used to connect the first and second rotation hubs 2, 3 with the self-supporting chassis 1, are bearing housings, lubricated bearings or any other similar device.

[0048] The first and second rims 14, 15 can be positioned, in a removable manner, on respectively the first and second rotation hubs 2, 3 by bolting, or by electromagnetic locking systems, such as, for example, electromagnetic expanding mandrels.

[0049] By axially median plane to the first tire 10 or to the second tire 11, it is necessary to understand a plane perpendicular to the axis of rotation of the tire and passing through the axial middle of the tread of said tire.

[0050] As can be seen in [Fig. 1], the control machine 100 includes at least one motor 4 driving in rotation the first rotation hub 2 or the second rotation hub 3.

[0051] In some unclaimed embodiments, the control machine 100 may include two motors, a first motor serving to drive the first rotation hub 2 and a second motor driving the second rotation hub 3. The use of two motors makes it possible to limit the size of each motor and therefore the overall size of the control machine 100.

[0052] Preferably, at least one motor 4 is an electric motor, which is not very sensitive to temperature changes.

[0053] As shown in [Fig.1], the control machine 100 further includes a system for adjusting a support force F 5 to bring a first tread 16 of the first tire 10 into contact with a second tread 17 of the second tire 11 so as to obtain a flat contact surface 18 between the first and second tires 10, 11.

[0054] The flatness of the contact surface 18 makes it possible to represent, in a simple way, the actual driving conditions of the first and second tires 10, 11 when used on moving vehicles. For example, the endurance limit check of the first and second tires 10, 11, carried out by the testing machine 100, does not overestimate or underestimate the results of said endurance limit.

[0055] As can be seen in [Fig. 1] and [Fig. 2], the control machine 100 also comprises: -at least one force sensor 9 allowing the determination of the support force F of the first tire 10 on the second tire 11, -at least one rotation sensor 19 allowing the number of rotations performed by the first and second pneumatics 10, 11 to be determined during the control of said first and second pneumatics 10, 11, -a rolling resistance sensor 6 allowing the determination of the evolution of the rolling resistance of the first and second tires 10, 11, -a center distance sensor 31 allowing the evolution of the center distance value E to be followed, -electrical connectors 7 intended to transmit electrical energy to at least one motor 4, the adjustment system 5, at least one force sensor 9, at least one rotation sensor 19, the rolling resistance sensor 6 and the center distance sensor 31 E.

[0056] At least one force sensor 9 can cooperate with a display to allow an operator to visualize the support force F.

[0057] The at least one force sensor 9 can be, for example, a piezoelectric type sensor or a strain gauge sensor, which can be placed on the self-supporting chassis 1 or on the adjustment system 5 of the support force F.

[0058] In a preferred embodiment, at least one force sensor 9 is integrated into one of the first or second rotation hubs 2, 3.

[0059] In some unclaimed embodiments, two force sensors 9 are used and can be integrated into the first rotation hub 2 and into the second rotation hub 3.

[0060] The at least one rotation sensor 19 may be, for example, an incremental or absolute encoder, contactless or with contact, which can be placed on the first or second rotation hub 2, 3 or on the shaft of at least one motor 4.

[0061] In certain unclaimed embodiments, each of the first and second rotation hubs 2, 3 is equipped with a rotation sensor 19, making it possible to know precisely the number of revolutions made by each of said first and second hubs 2, 3 even in case of slippage, at the level of the flat contact surface 18, of the first tread 16 relative to the second tread 17.

[0062] The rolling resistance sensor 6 can be, for example, a torque sensor mounted on the first or second rotating hub 2, 3, or a sensor measuring the electrical current consumption of at least one motor 4 during the control operation.

[0063] The sensor 31 with center distance E can be, for example, a linear potentiometer, a linear laser measuring sensor or a vision system.

[0064] In some embodiments, and as illustrated in [Fig.5], a projection system 27 positions an interface body between the first tread 16 and the second tread 17, allowing the wear of the first and second tires 10, 11 to be accelerated during the inspection.

[0065] The interface body, also called the "third body", can be, for example, regolith, silica or any other abrasive material that can flow and accelerate the abrasion of the first and second treads 16, 17.

[0066] Preferably, and as shown in [Fig.5], when the interface body is positioned between the first tread 16 and the second tread 17, the rotation axes XX' and YY' of the first and second rotation hubs 2, 3 respectively have a horizontal direction in order to allow the interface body to be held for a longer time between said first tread 16 and said second tread 17.

[0067] Preferably, the self-supporting chassis 1 is a self-supporting telescopic chassis along at least two directions XI and Y1 perpendicular to each other and perpendicular to the respective axes of rotation XX', YY', the direction XI being a direction parallel to the segment ZZ'.

[0068] In a known manner, the telescopic function of the self-supporting telescopic chassis 1 can be achieved by systems of electric jacks animating tubes that fit together and slide into one another.

[0069] Advantageously, and as can be seen in [Fig. 4], the first and second rotation hubs 2, 3 are positioned and oriented so as to obtain, in any plane parallel to a plane X1Z1 passing through the respective rotation axes XX', YY', a projection of the external dimensions of the first and second tires 10, 11 contained in the projection, in any plane X1Z1, of the external dimensions of the self-supporting chassis 1. In such an embodiment, and as shown in [Fig. 4], the motor is preferably mounted with a right-angle gearbox so as to be arranged horizontally and thus obtain a particularly compact control machine 100.

[0070] Advantageously, at least one motor 4 is integrated into one of the first or second rim 14, 15.

[0071] Advantageously, the support force adjustment system 5 is an automatic linear displacement system cooperating with the force sensor 9 and comprising an electric actuator for moving, along a displacement axis corresponding to the segment ZZ', at least the first or second rotation hub 2, 3. The electric actuator may comprise, in a known manner, an electric motor driving a screw / nut system or an electric motor driving a toothed wheel associated with a rack, the rotation of the motor allowing the movement of at least the first or second rotation hub 2, 3 until the support force F corresponds to a predetermined support force value F. Preferably, only the first rotation hub 2 is moved by the actuation of the electric actuator.

[0072] In other unclaimed embodiments, the support force adjustment system 5 comprises an eccentric displacement system, automated by means of an electric or electromagnetic actuator.

[0073] As can be seen in [Fig. 6], in a particular embodiment, the rotation axes XX' and YY' of the first and second rotation hubs 2, 3 respectively are horizontal, the segment ZZ' is substantially vertical, the rotation axis YY' is located above the rotation axis XX', the adjustment system 5 includes a guiding means, along a direction parallel to the segment ZZ', of a movable assembly 29 comprising the first rotation hub 2, the first rim 14 and the first tire 10 and the support force F corresponds to the weight of the movable assembly 29. Preferably, in this particular embodiment, additional weights 30 or counterweights are added to the weight of the movable assembly 29 to adjust the support force F.

[0074] In a known manner, the counterweights can cooperate with a system comprising cables and pulleys, each of said cables having one end attached to said counterweights and the other end to the moving assembly 29, so that said counterweights reduce the support force F exerted by the weight of the moving assembly 29.

[0075] As can be seen in [Fig. 3], the invention also relates to a cold and controlled environment control device 200 intended to simultaneously control first and second tires 10, 11 in a cold environment and under a controlled atmosphere, said cold and controlled environment control device 200 comprising: -a thermal vacuum chamber 20 comprising, on the one hand, a sealed enclosure 21 comprising sealed panels 28, an access door 22 and a flat surface 12, and, on the other hand, a control system 23 allowing control of the temperature and atmosphere inside said sealed enclosure 21, -the control machine 100 of the different embodiments previously described, intended to be placed, in a removable manner, on the flat surface 12 of the sealed enclosure 21 of the thermal vacuum chamber 20, -additional electrical connectors 8 intended to cooperate removably with the electrical connectors 7 of the control machine 100, -a tracking and recording system 24 cooperating with at least one rotation sensor 19, at least one force sensor 9, the rolling resistance sensor 6 and the center distance sensor 31 E in order to track and record the number of rotations made by the first and second tires 10, 11, the support force F of the first tire 10 on the second tire 11, the rolling resistance of said first and second tires 10, 11 and the value of the center distance E.

[0076] As is known, the airtight panels 28 are insulating panels connected together in a sealed manner to form a closed chamber, generally cubic or parallelepiped in shape. The access door 22 generally includes a seal and a locking system to maintain the airtightness of the sealed enclosure 21 when said access door 22 is closed. As is known to those skilled in the art, the thermal vacuum chamber 20 also includes at least one airtight bulkhead passage allowing a conduit to communicate with the interior of the airtight enclosure 21, said conduit being connected to a device, such as a vacuum pump, for controlling the atmosphere inside said airtight enclosure 21. Cable glands are generally used to allow electrical cables to run from outside the airtight enclosure 21 to the additional electrical connectors 8.

[0077] Advantageously and as illustrated in [Fig.3], a supplementary clamping system 26 cooperates with the clamping system 25 to removably fix the control machine 100, said supplementary clamping system 26 being able to be added in the thermal vacuum chamber 20 and being able to be a flange, a jack, a hook, an expanding mandrel or any other equivalent device.

[0078] The invention also relates to a method for checking the first and second tires 10, 11 in a cold and controlled environment, implementing the cold and controlled environment checking device 200 defined previously and comprising the following steps: -installation of the first and second pneumatics 10, 11 to be tested on the control machine 100, -Cooperation of the support force adjustment system 5 with the force sensor 9 in order to adjust the support force F to obtain and maintain a target support force value Fl, allowing the first tread 16 of the first tire 10 to bear against the second tread 17 of the second tire 11 so as to obtain a flat contact surface 18, -Placement of the control machine 100 in the sealed enclosure 21 of the thermal vacuum chamber 20, - Electrical connection of the control machine 100 by connecting the electrical connectors 7 with the complementary electrical connectors 8, - Activation of the control system 23 to change the temperature and gas content of the atmosphere inside the sealed enclosure 21 towards respectively a predetermined temperature T and a predetermined gas content G, - During the change in temperature and gas content inside the sealed enclosure 21, activation of at least one motor 4 to rotate the first and second pneumatics 10, 11 at a speed VI, -when the temperature and gas content inside the sealed enclosure 21 have reached temperature T and gas content G respectively, activation of at least one motor 4 to rotate the first and second pneumatics 10, 11 at a speed V2, - monitoring and recording, by the tracking and recording system 24, of the values ​​transmitted by the rolling resistance sensor 6, by at least one force sensor 9 and by the center distance sensor 31 E, and when the measured center distance value E falls below a predetermined threshold S, recording of the number of rotations carried out by the first and second pneumatics 10, 11 and deactivation of at least one motor 4 to stop the rotation of said first and second pneumatics 10, 11, -electrical disconnection of the control machine 100 by disconnecting the electrical connectors 7 from the complementary electrical connectors 8, -removal of the control machine 100 from the sealed enclosure 21 of the thermal vacuum chamber 20.

[0079] The adjustment of the support force F, carried out before the installation of the control machine 100 in the sealed enclosure 21 of the thermal vacuum chamber 20, makes it possible to put the first tread 16 in contact with the second tread 17, thus reducing the external dimensions of the first and second tires 10, 11. This reduction in dimensions therefore makes it possible to use a smaller thermal vacuum chamber 20.

[0080] When the first and second pneumatics 10, 11 are controlled under extra-atmospheric conditions, the predetermined temperature T will be 40 K and the predetermined gas content G will be close to a vacuum.

[0081] Preferably, the temperature T is at least equal to 40 K and at most equal to 373 K, and even more preferably at most equal to 213 K.

[0082] Advantageously, the speed V1 is at least equal to one revolution per minute and at most equal to five revolutions per minute.

[0083] Preferably, the speed V2 is variable and is at least equal to 6 revolutions per minute and at most equal to 700 revolutions per minute, and, even more preferably, at least equal to 100 revolutions per minute and at most equal to 350 revolutions per minute.

[0084] Advantageously, the target support force Fl is at least equal to 100N and at most equal to 5000N.

[0085] Advantageously, the threshold S is at least equal to 70% and at most equal to 95% of the value of the average center distance E measured on at least the first revolution made by the first and second tires 10, 11 during the rotation of said first and second tires 10, 11 at a speed V2.

[0086] Preferably, the first and second tires 10, 11 tested are airless tires.

Claims

1. Demands Control machine (100), intended to simultaneously control a first and second identical pneumatic (10, 11), characterized in that it comprises -a self-supporting chassis (1) comprising an interface means (13) allowing said self-supporting chassis (1) to be placed on a flat surface (12), -a first rotation hub (2) connected to the self-supporting chassis (1) by a pivot joint with axis of rotation (XX'), said first rotation hub (2) being intended to receive, in a removable manner, a first rim (14) on which the first tire (10) is mounted, said first rim (14) being mounted concentrically to the axis of rotation (XX'), - a second rotation hub (3) connected to the self-supporting chassis (1) by a pivot joint with axis of rotation (YY') parallel to the axis of rotation (XX'), said axis of rotation (YY') being center-to-center distance E from the axis of rotation (XX'), along a direction parallel to a segment (ZZ') perpendicular to the respective axes of rotation (XX', YY') and passing through said respective axes of rotation (XX', YY'), said second rotation hub (3) being designed to removably receive a second rim (15) on which a second tire (11) is mounted, said second rim (15) being mounted concentrically to the axis of rotation (YY'), said second rotation hub (3) being positioned so that an axially median plane to the first tire (10) is coplanar with an axially median plane to the second tire (11), - at least one motor (4) driving the rotation of the first rotation hub (2) or the second rotation hub (3), -a system for adjusting a support force F allowing a first tread (16) of the first tire (10) to be pressed against a second tread (17) of the second tire (11) so as to obtain a flat contact surface (18) between the first and second tires (10, H), -at least one force sensor (9) allowing the determination of the support force F of the first tire (10) on the second tire (H), -at least one rotation sensor (19) allowing the number of rotations made by the first and second tires (10, 11) during the control of said first and second tires (10, 11), - a rolling resistance sensor (6) allowing the evolution of the rolling resistance of the first and second tires (10, 11), - a center distance sensor (31) allowing the monitoring of the evolution of the center distance value E, - electrical connectors (7) intended to transmit electrical energy to at least one motor (4), the adjustment system (5), at least one force sensor (9), at least one rotation sensor (19), the rolling resistance sensor (6) and the center distance sensor (31) E.

2. Inspection machine (100) according to claim 1, in which a projection system (27) positions an interface body between the first tread (16) and the second tread (17) allowing the wear of the first and second tires (10, 11) to be accelerated during inspection.

3. Control machine (100) according to any one of claims 1 or 2, wherein at least one force sensor (9) is integrated into one of the first or second rotation hubs (2, 3).

4. Control machine (100) according to any one of claims 1 to 3, wherein the interface means (13) comprises a clamping system (25) allowing the self-supporting frame (1) to be removably fixed to the flat surface (12).

5. Control machine (100) according to any one of claims 1 to 4, wherein the self-supporting frame (1) is a self-supporting telescopic frame along at least two directions XI and Y1 perpendicular to each other and perpendicular to the respective axes of rotation (XX', YY'), the direction XI being a direction parallel to the segment (ZZ').

6. A control machine (100) according to claim 5, wherein the first and second rotation hubs (2, 3) are positioned and oriented so as to obtain, in any plane parallel to a plane (X1Z1) passing through the respective rotation axes (XX', YY'), a projection of the external dimensions of the first and second pneumatics (10, 11) contained in the projection, in any plane (X1Z1), of the external dimensions of the self-supporting chassis (1).

7. Control machine (100) according to any one of claims 1 to 6, wherein at least one motor (4) is integrated into one of the first or second rim (14, 15).

8. Control machine (100) according to any one of claims 1 to 7, wherein the adjustment system (5) of the support force F is an automatic linear displacement system cooperating with the force sensor (9) and comprising an electric actuator enabling displacement, along a displacement axis corresponding to the segment (ZZ'), of at least the first or second rotation hub (2, 3).

9. Control machine (100) according to any one of claims 1 to 7, wherein the axes of rotation (XX') and (YY') of the first and second rotation hubs (2, 3) respectively are horizontal, the segment (ZZ') is substantially vertical, the axis of rotation (YY') is located above the axis of rotation (XX'), the adjustment system (5) includes a guiding means, along a direction parallel to the segment (ZZ'), of a moving assembly (29) comprising the first rotation hub (2), the first rim (14) and the first tire (10) and wherein the support force F corresponds to the weight of the moving assembly (29).

10. Control machine (100) according to claim 9, wherein additional weights (30) or counterweights are added to the weight of the moving assembly (29) to adjust the support force F.

11. A cold and controlled environment testing device (200) for simultaneously testing first and second tires (10, 11) in a cold environment and under a controlled atmosphere, said cold and controlled environment testing device (200) comprising: - a thermal vacuum chamber (20) comprising, on the one hand, a sealed enclosure (21) comprising sealed panels (28), an access door (22) and a flat surface (12), and, on the other hand, a control system (23) for controlling the temperature and atmosphere inside said sealed enclosure (21), - the testing machine (100) according to claims 1 to 8 or the testing machine (100) according to claims 1 to 7 and 9 to 10, intended to be placed, in a removable manner, on the flat surface (12) of the sealed enclosure (21) of the thermal vacuum chamber (20), -supplementary electrical connectors (8) intended to cooperate removably with the electrical connectors (7) of the control machine (100), -a tracking and recording system (24) cooperating with at least one rotation sensor (19), at least one force sensor (9), the rolling resistance sensor (6) and the center distance sensor (31) E in order to track and record the number of rotations made by the first and second tires (10, 11), the support force F of the first tire (10) on the second tire (11), the rolling resistance of said first and second tires (10, 11) and the value of the center distance E.

12. Control device in a cold and controlled environment (200) according to claim 11, wherein a complementary clamping system (26) cooperates with the clamping system (25) to removably fix the control machine (100).

13. A method for testing the first and second tires (10, 11) in a cold and controlled environment, implementing the testing device in a cold and controlled environment (200) defined according to claims 11 or 12, comprising the following steps: - placing the first and second tires (10, 11) to be tested on the testing machine (100), - cooperation of the support force adjustment system (5) with the force sensor (9) in order to adjust the support force F to obtain and maintain a target support force value Fl, allowing the first tread (16) of the first tire (10) to bear against the second tread (17) of the second tire (11) so as to obtain a flat contact surface (18), - placing the testing machine (100) in the sealed enclosure (21) of the thermal vacuum chamber (20),-electrical connection of the control machine (100) by connecting the electrical connectors (7) with the complementary electrical connectors (8), -activation of the regulation system (23) to change the temperature and gas content of the atmosphere inside the sealed enclosure (21) towards respectively a predetermined temperature T and a predetermined gas content G, - during the evolution of the temperature and gas content inside the sealed enclosure (21), activation of at least one motor (4) to rotate the first and second tires (10, 11) at a speed VI, - when the temperature and gas content inside the sealed enclosure (21) have reached temperature T and gas content G respectively, activation of at least one motor (4) to rotate the first and second tires (10, 11) at a speed V2, - monitoring and recording, by the monitoring and recording system (24), of the values ​​transmitted by the rolling resistance sensor (6), by at least one force sensor (9) and by the center distance sensor (31) E, and when the measured center distance E falls below a predetermined threshold S, recording of the number of rotations performed by the first and second tires (10,11) and deactivation of at least one motor (4) to stop the rotation of said first and second pneumatics (10, 11), -electrical disconnection of the control machine (100) by disconnecting the electrical connectors (7) from the complementary electrical connectors (8), -removal of the control machine (100) from the sealed enclosure (21) of the thermal vacuum chamber (20).

14. A method for testing the first and second tires (10, 11) in a cold and controlled environment according to claim 13, wherein the temperature T is preferably at least equal to 40 K and at most equal to 373 K, and even more preferably at most equal to 213 K.

15. A method for testing the first and second tires (10, 11) in a cold and controlled environment according to any one of claims 13 or 14, wherein the speed VI is at least equal to one revolution per minute and at most equal to five revolutions per minute.

16. A method for testing the first and second tires (10, 11) in a cold and controlled environment according to any one of claims 13 to 15, wherein the speed V2 is preferably variable and is at least equal to 6 revolutions per minute and at most equal to 700 revolutions per minute, and, even more preferably, at least equal to 100 revolutions per minute and at most equal to 350 revolutions per minute.

17. A method for testing the first and second tires (10, 11) in a cold and controlled environment according to any one of claims 13 to 16, wherein the target support force Fl is at least equal to 100N and at most equal to 5000N.

18. A method for testing the first and second tires (10, 11) in a cold and controlled environment according to any one of claims 13 to 17, wherein the threshold S is at least equal to 70% and at most equal to 95% of the value of the average center distance E measured on at least the first revolution made by the first and second tires (10, 11) during the rotation of said first and second tires (10, 11) at a speed V2.

19. A method for testing first and second tires (10, 11) in a cold and controlled environment according to any one of claims 13 to 18, wherein said first and second tires (10, 11) tested are airless tires.

Images