Vehicle wheel provided with an assembly carried by a wheel rim for adjusting the air pressure

Abstract

A vehicle wheel (1) has a rim (3), a tyre (4) defining an air chamber (5) together with the rim (3), and an assembly (20) for adjusting the air pressure in this chamber (5); the assembly (20) is provided with at least one compressor (21) pneumatically connected to the chamber (5), and at least one reservoir (22) pneumatically connected to the compressor (21) to receive compressed air; the compressor (21) and the reservoir (22) are housed in respective compartments (30) that are defined by respective spokes (13) of the rim (3).

Description

[0001] "VEHICLE WHEEL PROVIDED WITH AN ASSEMBLY CARRIED BY A WHEEL RIM FOR ADJUSTING THE AIR PRESSURE"

[0002] Cross-Reference to Related Applications

[0003] This Patent Appl ication claims priority from Italian Patent Application No . 102023000027384 filed on December 20 , 2023 , the entire disclosure of which is incorporated herein by reference .

[0004] Technical Field

[0005] This invention relates to a vehicle wheel provided with an assembly for adj usting the air pressure inside its tyre , and this assembly is carried by the wheel rim .

[0006] In particular, this assembly includes a motorised compressor, driven to trans fer air into one or more reservoirs , while adj ustment valves manage air flows from the reservoirs to the air chamber in the tyre and from such air chamber to the compressor .

[0007] Prior Art

[0008] In order to adj ust the internal pressure in tyres , solutions are known with a centralised on-vehicle architecture , which has a single reservoir and a single compressor, controlled by an appropriate control unit to be activated and feed compressed air into this reservoir . The reservoir is then connected to the wheels via respective conduits fitted with valves , which are also controlled by the above-mentioned control unit to adj ust the flow of compressed air : these valves are switched to inflate the tyre or discharge air from it towards the outside environment .

[0009] In addition, another valve pneumatically connects the compressor to the reservoir so that the two components can be isolated when required .

[0010] Compared to this type of centralised solution, it is preferable to adopt inflation and deflation systems that are arranged directly on the wheel , to reduce the number of components , reduce the space required on board the vehicle , and avoid passages of compressed air between a fixed part , i . e . the vehicle body, and a rotating part , i . e . the wheel .

[0011] In the context of these decentralised solutions , document EP0621144 discloses an example where a two-way compressor is provided on the wheel , which trans fers air between the air chamber in the tyre and an additional annular chamber, integrated in the wheel rim and defining a reservoir for storing air .

[0012] Another example disclosed by EP0621144 , namely the one in Figure 2 , involves the use of a one-way compressor and an additional pneumatic line , which connects the tyre air chamber with the rim integrated annular reservoir, in parallel with the compressor . A valve then manages the passage of air through this line to inflate the tyre .

[0013] In both these solutions , to adj ust the pressure in the tyre , air is exchanged between the air chamber and the reservoir integrated into the rim, without contamination by external air .

[0014] There is a need to refine this type of solution, especially with regard to the simpli fication of the rim structure where the air storage reservoir is located .

[0015] In particular, there is a need to find a solution that is relatively compact but does not negatively af fect the design and construction of the rim .

[0016] More speci fically, it is preferable to adopt a solution that is relatively easy to assemble and does not negatively af fect the aesthetic value of the rim .

[0017] In addition, it is preferable to adopt a solution in which the various components of the system for adj usting the pressure are arranged outside the tyre air chamber, for safety reasons .

[0018] One purpose of this invention is that of meeting the needs described above , preferably in a simple and / or ef fective and / or cost-ef fective way .

[0019] Summary of the Invention

[0020] The above-mentioned purpose is achieved with a vehicle wheel as defined in claim 1 .

[0021] The dependent claims define particular embodiments of the invention .

[0022] Brief Description of the Drawings

[0023] For a better understanding of this invention, preferred embodiments will be described below, by way of non- limiting example , with reference to the accompanying drawings , wherein :

[0024] Figure 1 illustrates , in perspective , a vehicle wheel according to a preferred embodiment of this invention;

[0025] Figure 2 is a rear perspective view of the wheel in Figure 1 ;

[0026] Figure 3 shows the wheel of Figure 1 from a di f ferent viewpoint and with parts in exploded view;

[0027] Figure 4 is a detail of Figure 2 on an enlarged scale ;

[0028] Figure 5 shows a detail of Figure 3 , on an enlarged scale and from a di f ferent viewpoint ;

[0029] Figure 6 illustrates some wheel components of the previous figures ; and

[0030] Figure 7 is a cross section obtained from a sectional plane on which the wheel axis lies . Detailed Description of Preferred Embodiments of the Invention

[0031] In Figure 1, reference number 1 indicates, as a whole, a vehicle wheel, which is partially illustrated.

[0032] The wheel 1 has an axis 2, coinciding, in use, with its rotation axis, and comprises a rim 3 and a tyre 4 (illustrated in dotted lines) , fitted on the rim 3 in such a way as to define, together with the latter, a chamber 5 that is filled with air and can be pressurized from the outside through a valve 6. The valve 6, a known type, is brought to a relative fixed position by the rim 3.

[0033] In particular, the rim 3 has an outer annular wall 7, which radially delimits the chamber 5 and is shaped to include an intermediate portion 8 and two shoulders 9 arranged at opposite axial ends of the rim 3. These shoulders 9 protrude radially outwards from the intermediate portion 8; furthermore, at the shoulders 9, the wall 7 defines two concave areas that are shaped so as to couple the tyre 4 beads, in a sealed manner, according to shapes and techniques that are known and not shown in detail.

[0034] With reference to Figure 2, the rim 3 comprises a central hub 12 and a plurality of spokes 13 joining the central hub 12 to the outer annular wall 7 and, preferably, extending radially with respect to the axis 2.

[0035] As shown in Figure 3, the wheel 1 further comprises an assembly 20 for adjusting the pressure in the chamber 5 automatically, for example to keep it within a predetermined setpoint range, and / or to keep it as close as possible to a predetermined setpoint value, during use (i.e. during vehicle travel) .

[0036] The assembly 20 is carried by the rim 3, on the wheel 1 , and therefore rotates together with the rim 3 around the axis 2 during use .

[0037] As can be seen in detail in Figure 5 , the assembly 20 comprises at least one motorised compressor 21 , at least one reservoir 22 defining, within it , a chamber with a substantially fixed volume , separated from the chamber 5 and the external environment ; and at least one battery 22a ( Figure 5 ) for supplying electricity to the electric motor of the compressor 21 . In the preferred example shown, the battery 22a is carried by the same compressor 21 .

[0038] As shown in Figure 6 , the compressor 21 has an inlet port designed to communicate with the chamber 5 via a conduit 23 that passes through the wall 7 in such a way as to still ensure the fluid tightness of the chamber 5 . The configuration of the reservoir 22 is similar : as indicated in Figure 6 , the reservoir 22 has an outlet port designed to communicate with the chamber 5 via a conduit 24 that passes through the wall 7 in such a way as to ensure the fluid tightness of the chamber 5 .

[0039] The assembly 20 also comprises a microprocessor 25 , which controls this electric motor in response to command signals emitted wirelessly by an emitter (not illustrated) placed in a fixed position on board the vehicle , and / or in response to operations performed by a control strategy stored in a memory forming part of the same microprocessor 25 . In the speci fic example , the microprocessor 25 is brought to a fixed position by the compressor 21 .

[0040] This architecture is therefore decentralised, as the assembly 20 is mounted on each of the wheels of the vehicle and has no pneumatic and / or electrical connections to the fixed parts of the vehicle . More speci fically, the microproces sor 25 is configured to drive the compressor 21 motor and then activate the latter, e . g . in response to a control signal and / or a reference signal ( setpoint ) provided by the vehicle instrument panel , to send pressurised air from the chamber 5 to the reservoir 22 , but not vice versa .

[0041] According to a preferred aspect of this invention, in fact , the compressor 21 is one-way, i . e . it is constructed and assembled in such a way that it can only convey a flow of air in one direction ( from the chamber 5 to the reservoir 22 ) .

[0042] In particular, a valve or solenoid valve 26 is interposed between the chamber 5 and the inlet port of the compressor 21 , to prevent air leakage from the chamber 5 when the compressor 21 is switched of f . Alternatively, the valve 26 is integrated into the inlet port of the compressor 21 .

[0043] The assembly 20 also includes a solenoid valve 27 , which is arranged along the conduit 24 and switches in response to an electric command, sent by the microprocessor 25 in a not illustrated way, between a closed configuration, in which the reservoir 22 is pneumatically isolated from the chamber 5 , and an open configuration, to allow a flow of air from the reservoir 22 to the chamber 5 ( i . e . a flow in the opposite direction to that imposed by the compressor 21 ) .

[0044] The microprocessor 25 is preferably configured to also check the temperature of the air inside the chamber 5 , by at least one temperature sensor (not illustrated) , connected wirelessly or wired to communicate with the same microprocessor 25, for a possible correction of the pressure of the air to be introduced / discharged and / or a possible correction of the setpoint values, depending on the temperature detected.

[0045] In addition, the microprocessor 25 is connected, wirelessly or wired, to communicate with at least one pressure sensor mounted on the wheel 1 and designed to detect the pressure in the chamber 5. The pressure sensor can be of a known type, usually referred to as a TPMS. In other words, the microprocessor 25 interacts with this sensor to receive readings of the pressure values inside the chamber 5.

[0046] The temperature and / or pressure sensors are usually installed at the valve 6.

[0047] The control logics implemented in the microprocessor 25, and / or the control signals coming from a fixed control unit, on board the vehicle, are configured in such a way as to inflate and deflate the chamber 5, i.e. to adjust the air pressure inside it, preferably with such quantities / pressures of air that optimise adherence to the ground during use, depending also on the type of ground or according to a driver's command that is indicative of this type (e.g. on mud or sand the pressure should be reduced, while on asphalt the pressure should be higher to reduce rolling resistance) .

[0048] As mentioned above, the air in the chamber 5, previously supplied from outside through the valve 6, is pumped by the compressor 21 and transferred to the reservoir 22 in order to reduce the pressure, i.e. to deflate the tyre 4.

[0049] Similarly, by controlling the solenoid valve 27 that is placed at the outlet of the tank 22 (between the latter and the chamber 5) , a flow of air is allowed from the same reservoir 22 ( at a higher pressure ) to the chamber 5 ( at a lower pressure ) , and thus the pressure in the chamber 5 increases : in other words , the tyre 4 is inflated .

[0050] The microprocessor 25 is preferably configured with appropriate control logics to carry out diagnostics of the entire assembly 20 and then transmit information relating to any mal functions and / or information relating to adj ustment and stand-by steps between two successive adj ustments to an on-board control unit ( and then to the instrument panel in the passenger compartment ) .

[0051] The assembly 20 also includes a system (not shown) for recharging electricity in the battery 22a . In particular, such a system is of the induction type and / or is arranged at an external surface of the wheel 1 to be coupled to the mains power supply, or to a vehicle power supply device ( e . g . a cigarette lighter device ) , only when the vehicle is stationary . Other charging systems can still be envisaged, for example by using the very rotation of the wheel 1 to generate power for the battery 22a .

[0052] During deflation, the pressure in the reservoir 22 increases more than the pressure in the chamber 5 decreases , with the same amount of air entering and respectively leaving, because the volumes in the reservoir 22 are smaller than in the chamber 5 , and the pressure in the reservoir 22 is much higher than that in the chamber 5 .

[0053] During inflation, by operating the solenoid valve 27 , the compressor 21 remains deactivated and the pressure in the reservoir 22 decreases .

[0054] With reference to Figure 5 , according to this invention, the compressor 21 and tank 22 are at least partially housed in respective seats or compartments 30 within respective spokes 13 of the rim 3. The compartments 30 are elongated along their respective axes 31, which are straight and coincide with the axes of the respective spokes 13 (so the axes 31 are preferably radial) . In other words, each of the seats 30 is obtained, in the circumferential direction, at the centre of the corresponding spoke 13.

[0055] In particular, the compressor 21 and reservoir 22 are configured to extend along the axes 31 and to be fully housed in their respective seats 30. In other words, the compressor 21 and reservoir 22 do not protrude axially beyond a front face 32 that axially delimits the spokes 13 towards the outside of the vehicle. For example, the seats 30 and corresponding access openings 33 extend substantially along the entire radial length of the spokes 13.

[0056] More specifically, at the front face 32 of the spokes 13 the compartments 30 have respective access openings 33, which are closed by at least one cover 34, shown in exploded view in Figure 3.

[0057] The cover 34 is attached in a fixed position to the rim 3, e.g. by a snap-on coupling or by screws, and is configured in such a way as to seal the seats 30 (against water and dust) , e.g. by gaskets (not shown) interposed between the cover 34 and the spokes 13.

[0058] In the specific example illustrated, the cover 34 has a star shape, consisting of a central portion 35, which overlaps axially with the hub 12 of the rim 3, and a plurality of arms 36, which protrude from the central portion 35 and are intended to close the access openings 33, respectively. According to non-illustrated variants, the cover 33 consists of separate elements defined by arms 36 (with no central portion joining them together) . As shown in Figures 5 and 6, the attachment of the compressor 21 and the reservoir 22 to the spokes 13 of the rim 3 is defined by a screw or bolt coupling. However, other fastening methods could be used.

[0059] In the example shown in Figure 4, the seats 30 are also open at the rear, i.e. on a rear face 36 of the spokes 13 that is opposite the front face 32. The openings or slits on the rear face 36 can also be closed by respective plugs, not illustrated, applied to the spokes 13.

[0060] With reference to Figure 6, the compressor 21 has an outlet port that communicates with the reservoir 22 via a conduit 37 that extends, at least in part, at the central hub 12. As can be seen in Figure 4, the conduit 37 is arranged behind the spokes 13 and central hub 12, i.e. on the opposite side to the front face 32 (in other words, it extends, at least in part, at the rear face 36 of the spokes 13) .

[0061] The assembly 20 preferably comprises more than one reservoir 22, each arranged within a respective spoke 13, separately from the others. In this case, the conduit 37 connects all the tanks 22 simultaneously with the outlet port of the compressor 21, so it also performs a distributor function from the outlet port towards all the reservoirs 22. In particular, the conduit 37 extends in the form of a continuous ring, e.g. in a circular shape, and is fitted around a rear portion of the hub 12.

[0062] It is clear from the above that the proposed arrangement for the compressor 21 and reservoirs 22 allows the use of spokes 13 to support the assembly 20 and, at the same time, to protect these components from external agents or shocks.

[0063] Furthermore, the fact of having to install the assembly 20 on the wheel 1 does not negatively affect the design of the wall 7 structure and / or the safety conditions during driving, since the various components (with the possible exception of the solenoid valves 26 and / or 27 ) are arranged outside the chamber 5 .

[0064] In terms of design and construction, the wall 7 only needs to be drilled for the passage of the conduits 23 and 24 . For the rest, it is the spokes 13 that are essentially af fected by modifications , compared to the known standard rim solutions , in order to fit and support the assembly 20 .

[0065] The conduits 23 , 24 and 37 , which connect the components to each other or to the internal cavity of the tyre 4 , are preferably coupled during assembly by quick coupling systems (not illustrated) , for ease of assembly and / or disassembly of the assembly 20 on the wheel 1 .

[0066] Furthermore , the proposed solution also simpli fies the assembly of the components of the assembly 20 with respect to known solutions , since it is possible to operate directly in front of the wheel 1 , i . e . by placing onesel f in front of the front face 32 , before positioning and coupling these components and then closing the compartments 30 .

[0067] According to a variant not illustrated, the compressor 21 and / or reservoir 22 can also be supported in fixed positions by the cover 34 , instead of being fixed to the rim 3 . In other words , in this variant , the components of the assembly 20 constitute , together with the cover 34 , a unit or module that can be attached to the rim 3 in a single operation ( after connecting the conduits 23 and 24 to the chamber 5 ) , with consequent advantages in assembly time and cost .

[0068] Other advantages are also clear to a person skilled in the art based on what is described above and what is illustrated in the attached figures .

[0069] Lastly it is clear that modi fications and variations may be made to the wheel 1 according to this invention without departing from the scope of protection defined by the attached claims .

[0070] In particular, the cover 34 could be shaped di f ferently than illustrated by way of example ; for example , as mentioned above , it could consist of a series of separate closing elements . Furthermore , the manner in which air is trans ferred from the reservoir 22 to the chamber 5 during inflation of the wheel 1 could take place in a di f ferent manner, for example by exploiting the passage defined by the compressor 21 itsel f ( and thus excluding the presence of the solenoid valve 27 and the conduit 24 ) .

Claims

CLAIMS1.- A vehicle wheel (1) extending along a central axis (2) and comprising:- a rim (3) comprising an outer annular wall (7) , a hub (12) , and a plurality of spokes (13) extending from said hub (12) to said outer annular wall (7) ,- a tyre (4) defining, together with said outer annular wall (7) , a chamber (5) which is filled with air and can be pressurized;- an assembly (20) for adjusting the air pressure in said chamber (5) , the assembly comprising: a) at least one compressor (21) having:(1) an inlet port capable of being pneumatically connected to said chamber (5) , and(2) an outlet port; b) at least one reservoir (22) pneumatically connected to said outlet port to receive compressed air from said compressor (21) and capable of being pneumatically connected to said chamber (5) to transfer air to said chamber (5) ; characterized in that at least a part of said reservoir (22) and at least a part of said compressor (21) are housed in respective compartments (30) defined by respective said spokes ( 13 ) .2.- The vehicle wheel according to claim 1, wherein said compartments (30) have respective access apertures (33) in respective said spokes (13) ; said access apertures (33) being closed by at least one cover (34) fixed to said rim (3) .3.- The vehicle wheel according to claim 2, wherein said reservoir (22) and said compressor (21) are supported in fixed positions by said cover (34) .4.- The vehicle wheel according to claim 1 or 2, wherein said reservoir (22) and said compressor (21) are supported in fixed positions by said spokes (13) .5.- The vehicle wheel according to any one of claims 2 to 4, wherein said access apertures (32) and said cover (34) are arranged at a front face (32) of said spokes (13) ; wherein said front face (32) is arranged towards the outside of the vehicle during use.6.- The vehicle wheel according to any one of the preceding claims, wherein said assembly (20) comprises a microprocessor (25) arranged in one of said compartments(30) .7.- The vehicle wheel according to any one of the preceding claims, wherein said reservoir (22) and said compressor (21) are completely housed in the respective said compartments (30) .8.- The vehicle wheel according to any one of the preceding claims, wherein said compartments (30) are elongated along respective axes (33) , coinciding with the axes of said spokes (13) .9.- The vehicle wheel according to any one of the preceding claims, wherein said assembly comprises a plurality of reservoirs, each one housed in a respective one of said spokes (13) and communicating with the other reservoirs and with the outlet port of said compressor (21) via a single conduit (37) .

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